Valve mechanism, fluid flow device, and fluid discharge device

Abstract

To provide a valve mechanism, a fluid flow device, and a fluid discharge device capable of causing fluid to flow by changing a pressure or a flow rate corresponding to a control status.SOLUTION: A first downstream chamber 62 forming a first valve mechanism 21 communicates with a first upstream chamber 61 via a first communication port 69. A first air chamber 63 is configured to be able to communicate with an external space. A first flexible film 64 separates the first downstream chamber 62 and the first air chamber 63. A second flexible film 65 separates the first upstream chamber 61 and the first downstream chamber 62. A first open and close part 66 is configured to be able open and close the first communication port 69. A first energization part 67 energizes the first flexible film 64 in a direction in which a capacity of the first downstream chamber 62 decreases. The first open and close part 66 includes a first shaft part 72 and a first valve part 73. The first shaft part 72 is provided across the first upstream chamber 61 and the first downstream chamber 62. The first shaft part 72 is configured to be movable following displacement of the first flexible film 64 and the second flexible film 65. The first valve part 73 is connected to the first shaft part 72 and opens and closes the first communication port 69.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a valve mechanism, a fluid flow device, and a fluid ejection device. [Background technology]

[0002] For example, as disclosed in Patent Document 1, there is a printer, which is an example of a liquid ejection device, that prints by ejecting ink, which is an example of a liquid, from a recording head, which is an example of a liquid ejection section. The printer is equipped with a pressure control valve, which is an example of a valve mechanism. The pressure control valve includes a valve chamber, a pressure chamber, an on-off valve, and an elastic partition.

[0003] Ink supplied from an ink cartridge, which is an example of a liquid storage unit, is sent to a valve chamber. When the pressure in the pressure chamber decreases, the elastic partition deforms, opening the on-off valve. When the on-off valve opens, liquid flows from the valve chamber to the pressure chamber, and liquid is sent from the pressure chamber to the recording head. At this time, the output pressure of the pressure control valve is adjusted to a set pressure required for the recording head. When the recording head is adjusted to a set pressure, for example, a negative pressure, ink droplets can be properly ejected from the nozzles of the recording head. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-86535 Summary of the Invention [Problem to be solved by the invention]

[0005] The pressure control valve of Patent Document 1 has a problem in that, because the output pressure is adjusted to the set pressure, it is not possible to change the output pressure from the set pressure when it is desired to change the output pressure depending on the control situation. [Means for solving the problem]

[0006] A valve mechanism that solves the above problem comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and connected to the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane that separates the downstream chamber from the air chamber, a second flexible membrane that separates the upstream chamber from the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that is movable in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0007] A valve mechanism that solves the above problem comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and connected to the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane separating the upstream chamber and the air chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the upstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that is movable in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0008] A valve mechanism that solves the above problem comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and connected to the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane that separates the downstream chamber from the air chamber, a second flexible membrane that separates the upstream chamber from the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that is movable in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0009] A valve mechanism that solves the above problem comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber having a first flexible membrane and communicating with the upstream chamber through a communication port downstream of the upstream chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0010] A valve mechanism that solves the above problem comprises an upstream chamber having a first flexible membrane into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and connected to the upstream chamber through a communication port, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the upstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0011] A valve mechanism that solves the above problem comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber having a first flexible membrane and communicating with the upstream chamber through a communication port downstream of the upstream chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has a shaft unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the shaft unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0012] A fluid flow device that solves the above problem comprises the above valve mechanism, a fluid storage section that stores fluid, a fluid flow path that is connected to the fluid storage section and in which the valve mechanism is provided, a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path, and a pressure generating section that applies pressure to the air chamber.

[0013] A fluid flow device that solves the above problem comprises the above valve mechanism, a fluid storage section that stores a fluid, a fluid flow path connected to the fluid storage section and in which the valve mechanism is provided, a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path, and a magnetic force generating section that applies a magnetic force to the opening and closing section.

[0014] A fluid ejection device that solves the above problem includes the above fluid flow device and a fluid ejection portion provided in the fluid flow path. A fluid ejection device that solves the above problem comprises the above fluid flow device and a fluid ejection section capable of ejecting the fluid, wherein the fluid flow path has a first fluid flow path whose downstream end is connected to the fluid ejection section and a second fluid flow path whose upstream end is connected to the fluid ejection section, the first valve mechanism being located in the first fluid flow path, and the second valve mechanism being located in the second fluid flow path.

[0015] A fluid ejection device that solves the above problem includes a fluid ejection portion capable of ejecting a fluid, a first fluid storage portion that stores a fluid, a second fluid storage portion that stores a fluid, a first fluid flow path that connects the first fluid storage portion and the fluid ejection portion, a second fluid flow path that connects the second fluid storage portion and the fluid ejection portion, a pressure fluctuation mechanism that fluctuates the pressure of the fluid stored in the first fluid storage portion and the second fluid storage portion, a first pressure adjustment valve provided in the first fluid flow path, a second pressure adjustment valve provided in the second fluid flow path, and a switching portion that can switch the states of the first pressure adjustment valve and the second pressure adjustment valve, is switchable between a first adjustment state in which the pressure downstream of the first pressure adjustment valve in the first fluid flow path is adjusted to a first set pressure, and a first open state in which the pressure downstream of the first pressure adjustment valve is adjusted to a pressure higher than the first set pressure by maintaining the first fluid flow path in an open state, and the second pressure adjustment valve is switchable between a second adjustment state in which the pressure upstream of the second pressure adjustment valve in the second fluid flow path is adjusted to a second set pressure, and a second open state in which the pressure upstream of the second pressure adjustment valve is adjusted to a pressure lower than the second set pressure by maintaining the second fluid flow path in an open state. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram of a liquid ejection device according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a first valve mechanism that opens and closes by air pressure. [Figure 3] FIG. 3 is a schematic diagram showing a second valve mechanism that opens and closes by air pressure. [Figure 4] FIG. 4 is a schematic diagram showing the detailed configuration of the pressure fluctuation mechanism and the switching unit. [Figure 5] FIG. 5 is a schematic diagram showing the main parts of the liquid ejection device during normal circulation. [Figure 6] FIG. 6 is a schematic diagram showing the main parts of the liquid ejection device when it is on standby or stopped. [Figure 7] FIG. 7 is a schematic diagram showing the main parts of the liquid ejection device when the power is off. [Figure 8] FIG. 8 is a schematic diagram showing the main parts of the liquid ejection device during cleaning. [Figure 9] FIG. 9 is a schematic diagram showing the main parts of the liquid ejection device when liquid is being removed from the liquid ejection section. [Figure 10] FIG. 10 is a schematic diagram showing the main parts of the liquid ejection device when air bubbles are discharged by forced circulation. [Figure 11] FIG. 11 is a schematic diagram of a liquid ejection device according to the second embodiment. [Figure 12] FIG. 12 is a schematic diagram showing a first valve mechanism that opens and closes by magnetic force. [Figure 13] FIG. 13 is a schematic diagram showing a second valve mechanism that opens and closes using magnetic force. [Figure 14] FIG. 14 is a schematic diagram showing a first valve mechanism that opens and closes by electromagnetic force. [Figure 15] FIG. 15 is a schematic diagram showing a second valve mechanism that opens and closes by electromagnetic force. [Figure 16] FIG. 16 is a schematic diagram of a liquid ejection device according to the third embodiment. [Figure 17] FIG. 17 is a schematic diagram showing the detailed configuration of the pressure fluctuation mechanism and the switching unit. [Figure 18] FIG. 18 is a schematic diagram showing the main parts of the liquid ejection device during normal circulation. [Figure 19] FIG. 19 is a schematic diagram showing the main parts of the liquid ejection device when it is on standby or stopped. [Figure 20] FIG. 20 is a schematic diagram showing the main parts of the liquid ejection device when the power is off. [Figure 21] FIG. 21 is a schematic diagram showing the main parts of the liquid ejection device during cleaning. [Figure 22] FIG. 22 is a schematic diagram showing the main parts of the liquid ejection device during cleaning. [Figure 23] FIG. 23 is a schematic diagram showing the main parts of the liquid ejection device when liquid is being removed from the liquid ejection section. [Figure 24] FIG. 24 is a schematic diagram showing the main part of a liquid ejection device that removes liquid from the liquid ejection section by using a reverse flow. [Figure 25] FIG. 25 is a schematic diagram showing the main part of a liquid ejection device that removes liquid from the liquid ejection section in both forward and reverse flows. [Figure 26] FIG. 26 is a schematic diagram showing the main parts of the liquid discharger when air bubbles are discharged by forced circulation. [Figure 27] FIG. 27 is a schematic diagram showing the main parts of the liquid discharge device when air bubbles are discharged by forced circulation with a reverse flow. [Figure 28] FIG. 28 is a schematic diagram of a liquid ejection device according to the fourth embodiment. [Figure 29] FIG. 29 is a schematic diagram showing a third valve mechanism that opens and closes by air pressure. [Figure 30] FIG. 30 is a schematic diagram showing a liquid ejection device according to a first modified example. [Figure 31] FIG. 31 is a schematic diagram showing a liquid ejection device according to a second modified example. [Figure 32] FIG. 32 is a schematic diagram showing a liquid ejection device according to a third modified example. [Figure 33] FIG. 33 is a schematic diagram showing a liquid ejection device according to a fourth modified example. [Figure 34] FIG. 34 is a schematic diagram showing the liquid discharge device during filter cleaning. [Figure 35] FIG. 35 is a schematic diagram showing a detailed configuration of a switching section in the fifth modified example. [Figure 36] FIG. 36 is a schematic diagram showing a third valve mechanism that opens and closes by magnetic force in the sixth modified example. [Figure 37] FIG. 37 is a schematic diagram showing a third valve mechanism that opens and closes by electromagnetic force in the seventh modified example. [Figure 38] FIG. 38 is a schematic diagram showing a fourth valve mechanism that opens and closes by air pressure in the eighth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] A first embodiment of the valve mechanism, fluid flow device, and fluid ejection device will be described below with reference to the drawings. The fluid ejection device is an inkjet printer that prints by ejecting ink, which is an example of a fluid, onto a medium such as paper, fabric, vinyl, plastic parts, or metal parts.

[0018] In the drawings, the liquid discharger 11 is placed on a horizontal plane, with the direction of gravity indicated by the Z axis, and directions along the horizontal plane indicated by the X and Y axes. The X, Y, and Z axes are perpendicular to one another. In the following description, the direction parallel to the Z axis is also referred to as the vertical direction Z.

[0019] <Liquid discharge device 11> 1, a liquid ejection device 11, which is an example of a fluid ejection device, includes a liquid ejection unit 12, which is an example of a fluid ejection unit, and a liquid flowing device 13, which is an example of a fluid flow device. In this embodiment, the fluid ejected by the fluid ejection device and the fluid caused to flow by the fluid flowing device are examples of liquids.

[0020] The liquid ejection unit 12 is capable of ejecting liquid. The liquid ejection unit 12 is configured to eject liquid onto a medium 14. The liquid ejection unit 12 has a nozzle surface 16 in which one or more nozzles 15 open. The liquid ejection unit 12 ejects liquid from the nozzles 15. A negative pressure is usually maintained inside the liquid ejection unit 12. This is to form a meniscus in the nozzles 15. This allows the liquid ejection unit 12 to eject the liquid appropriately. Furthermore, leakage of the liquid from the nozzles 15 can be suppressed.

[0021] <Liquid flow device> The liquid flowing device 13 is a device that causes the liquid to flow in a flow path that passes through the liquid discharger 12. The liquid flowing device 13 of this embodiment may include a first liquid flowing section 13A that causes the liquid to flow to be supplied to the liquid discharger 12, and a second liquid flowing section 13B that causes the liquid to flow to be recovered from the liquid discharger 12. The liquid flowing device 13 may supply the liquid to the liquid discharger 12 and recover the liquid from the liquid discharger 12 by causing the liquid to flow.

[0022] Furthermore, the liquid flow device 13 includes a pressure fluctuation mechanism 35. The pressure fluctuation mechanism 35 fluctuates the pressure of the liquid flowing through the liquid flow path 19. Below, the first liquid flow section 13A and the second liquid flow section 13B will be described in order.

[0023] <Configuration of first liquid flowing device 13A> First, the configuration of first liquid-flow section 13A will be described. First liquid-flow section 13A includes liquid storage section 17, which is an example of a fluid storage section, liquid flow path 19, which is an example of a fluid flow path, and first valve mechanism 21, which is an example of a valve mechanism. Liquid storage section 17 stores the fluid. Pressure fluctuation mechanism 35 includes pressure pump 20 that pressurizes liquid storage section 17. Pressure pump 20 fluctuates the pressure of the liquid by pressurizing liquid storage section 17.

[0024] The liquid flow path 19 is connected to a liquid storage section 17. The liquid storage section 17 stores the liquid to be supplied to the liquid ejection section 12. In this embodiment, the liquid storage section 17 is a first liquid storage section 17. The first liquid storage section 17 is, for example, a tank that can store liquid. The tank may be configured to be refillable with liquid. The liquid storage section 17 may have an area where the liquid is stored and an area of ​​air above the liquid.

[0025] The pressure pump 20 pressurizes the first liquid storage section 17. For example, the pressure pump 20 may pressurize the first liquid storage section 17 by pumping air into the first liquid storage section 17. When the pressure pump 20 pressurizes the first liquid storage section 17, the pressurized liquid flows out of the first liquid storage section 17. In other words, the pressure pump 20 varies the pressure of the liquid flowing through the first liquid flow path 23 by applying pressure.

[0026] The pressure fluctuation mechanism 35 may include a pressure release valve 22. The pressure release valve 22 is provided in the gas flow path 18 connected to the first liquid storage portion 17. The pressure release valve 22 communicates with the air region within the first liquid storage portion 17. When the pressure in the first liquid storage portion 17 exceeds a predetermined positive pressure, the pressure release valve 22 releases the air pressure, thereby adjusting the pressure within the first liquid storage portion 17 to a predetermined positive pressure. The air and liquid within the first liquid storage portion 17 are maintained at a constant positive pressure.

[0027] The liquid discharger 12 is provided in a liquid flow path 19 through which the liquid flows. The liquid flow path 19 connects the first liquid storage portion 17 and the liquid discharger 12. The liquid in the first liquid storage portion 17 is supplied to the liquid discharger 12 through the liquid flow path 19.

[0028] In the liquid flow path 19, the direction in which the liquid flows from the liquid storage section 17 toward the liquid discharge section 12 is defined as the supply direction Ds. The upstream end of the liquid flow path 19 in the supply direction Ds is connected to the liquid storage section 17. The liquid flow path 19 has a first liquid flow path 23 whose downstream end in the supply direction Ds is connected to the liquid discharge section 12. The first liquid flow path 23 connects the first liquid storage section 17 and the liquid discharge section 12.

[0029] The first valve mechanism 21 is provided in the liquid flow path 19. The first valve mechanism 21 is located in the first liquid flow path 23. The first valve mechanism 21 is located in the liquid flow path 19 between the liquid storage section 17 and the liquid discharge section 12, and opens and closes the liquid flow path 19. In other words, the first valve mechanism 21 opens and closes the first liquid flow path 23. The first valve mechanism 21 is a pressure adjustment valve 36 that adjusts the pressure of the liquid supplied to the liquid discharge section 12. In this embodiment, the pressure adjustment valve 36 is referred to as the first pressure adjustment valve 36. The first pressure adjustment valve 36 is constituted by the first valve mechanism 21. The first pressure adjustment valve 36 provided in the first liquid flow path 23 adjusts the output pressure so that the inside of the liquid discharge section 12 becomes a set positive pressure. The first pressure adjustment valve 36 has an air chamber 63.

[0030] The pressure pump 20 pressurizes the liquid in the first liquid storage section 17. Due to this pressurization, the liquid flowing through the liquid flow path 19 from the first liquid storage section 17 toward the liquid discharge section 12 is pressurized. <Configuration of second liquid flowing device 13B> Next, the configuration of second liquid-flow section 13B will be described. Second liquid-flow section 13B includes a liquid storage section 24, which is an example of a fluid storage section, a liquid flow path 19, and a second valve mechanism 28, which is an example of a valve mechanism. Liquid storage section 24 stores liquid. Pressure fluctuation mechanism 35 includes a decompression pump 27 that decompresses liquid storage section 24. Decompression pump 27 decompresses liquid storage section 24, thereby fluctuating the pressure of the liquid.

[0031] The liquid flow path 19 is connected to a liquid storage section 24. The liquid storage section 24 stores the liquid collected from the liquid ejection section 12. In this embodiment, the liquid storage section 24 is a second liquid storage section 24. The second liquid storage section 24 is, for example, a tank that can store liquid. The tank may be configured to be refillable with liquid. The second liquid storage section 24 may have an area where liquid is stored and an area of ​​air above the liquid.

[0032] The liquid flow path 19 of this embodiment connects the liquid discharger 12 and the second liquid storage section 24. That is, the liquid flow path 19 connects the first liquid storage section 17, the liquid discharger 12, and the second liquid storage section 24. The liquid flow path 19 of this embodiment allows the liquid supplied from the first liquid storage section 17 to the liquid discharger 12 to flow, and also allows the liquid recovered from the liquid discharger 12 to the second liquid storage section 24 to flow.

[0033] The liquid flow path 19 has a second liquid flow path 26, the upstream end of which is connected to the liquid discharger 12. The liquid flow path 19 includes a first liquid flow path 23 and a second liquid flow path 26. The second liquid flow path 26 connects the second liquid storage section 24 and the liquid discharger 12. In the liquid flow path 19, the direction in which the liquid flows from the liquid discharger 12 toward the liquid storage section 24 is defined as the recovery direction Dr. The upstream end of the second liquid flow path 26 in the recovery direction Dr is connected to the liquid discharger 12. The downstream end of the second liquid flow path 26 in the recovery direction Dr is connected to the second liquid storage section 24. The second liquid flow path 26 is where the liquid flows to be recovered from the liquid discharger 12 to the second liquid storage section 24.

[0034] The second valve mechanism 28 is provided in the liquid flow path 19. The second valve mechanism 28 is located in the second liquid flow path 26. The second valve mechanism 28 is located in the liquid flow path 19 between the liquid storage section 24 and the liquid discharger 12, and opens and closes the liquid flow path 19. In other words, the second valve mechanism 28 opens and closes the second liquid flow path 26. The second valve mechanism 28 functions as a negative pressure adjustment valve that adjusts the liquid discharger 12, located upstream, to a negative pressure. The second valve mechanism 28 is a pressure adjustment valve 37 that adjusts the pressure of the liquid in the liquid discharger 12. In this embodiment, the pressure adjustment valve 37 is referred to as the second pressure adjustment valve 37. The second pressure adjustment valve 37 provided in the second liquid flow path 26 is constituted by the second valve mechanism 28. The second pressure adjustment valve 37 is provided in the second liquid flow path 26. The second pressure adjustment valve 37 provided in the second liquid flow path 26 adjusts the output pressure so that the liquid discharger 12 reaches a set negative pressure. The second pressure regulating valve 37 has an air chamber 83 .

[0035] The pressure fluctuation mechanism 35 may include a decompression pump 27. The decompression pump 27 fluctuates the pressure of the liquid stored in the second liquid storage section 24 to a negative pressure. The decompression pump 27 fluctuates the pressure of the liquid flowing through the second liquid flow path 26 to a negative pressure. The decompression pump 27 decompresses the second liquid storage section 24. For example, the decompression pump 27 may decompress the second liquid storage section 24 by discharging air from the second liquid storage section 24.

[0036] The pressure fluctuation mechanism 35 may include a negative pressure release valve 29. The negative pressure release valve 29 is provided in the gas flow path 25 connected to the second liquid storage portion 24. The negative pressure release valve 29 communicates with the air region within the second liquid storage portion 24. When the negative pressure within the second liquid storage portion 24 exceeds a predetermined negative pressure, the negative pressure release valve 29 releases the air pressure, thereby adjusting the pressure within the second liquid storage portion 24 to the predetermined negative pressure. The air and liquid within the second liquid storage portion 24 are maintained at a constant negative pressure.

[0037] The pressure fluctuation mechanism 35 shown in FIG. 1 fluctuates the pressure of the liquid stored in each of the first liquid storage section 17 and the second liquid storage section 24. The pressurizing pump 20 is also used to generate positive pressure to be supplied to air chambers 63, 83 (described later) of the first valve mechanism 21 and the second valve mechanism 28. The decompression pump 27 is also used to generate negative pressure to be supplied to air chambers 63, 83 (described later) of the first valve mechanism 21 and the second valve mechanism 28. The pressurizing pump 20 and the decompression pump 27 have a pressure fluctuation function that increases and decreases the pressure of the liquid, and a pressure generation function that generates positive and negative pressure to be supplied to the air chambers 63, 83. In this way, in this embodiment, the pressurizing pump 20 and the decompression pump 27 serve both as the pressure fluctuation mechanism 35 and a pressure generation unit.

[0038] The liquid flow device 13 may include a connection flow path 30 and a liquid delivery unit 31. The connection flow path 30 connects the second liquid storage unit 24 and the first liquid storage unit 17. The liquid delivery unit 31 is provided in the connection flow path 30. The liquid delivery unit 31 delivers the liquid through the connection flow path 30 in a supply direction Ds from the second liquid storage unit 24 to the first liquid storage unit 17.

[0039] The liquid ejection device 11 of this embodiment employs a liquid circulation system. The liquid flow device 13 is capable of circulating the liquid in the supply direction Ds through a path passing through the liquid flow path 19 and the connecting flow path 30. In other words, it is possible to circulate the liquid through a path passing through the liquid ejection unit 12. The circulation of the liquid has a stirring effect due to the flow of the liquid. Even when the ink, which is an example of the liquid, contains a type of ink containing particles such as pigments that tend to settle (e.g., pigment ink), the settling of particles in the liquid can be suppressed. Note that the liquid circulation system may be employed for purposes other than suppressing particle settling in the liquid. The purpose of the liquid circulation may be, for example, to keep the liquid warm or to remove foreign matter from the liquid.

[0040] <Switching section> 1, the liquid ejection device 11 includes a switching unit 38. The switching unit 38 is configured to be able to switch the states of the first pressure regulation valve 36 and the second pressure regulation valve 37. The states of the first pressure regulation valve 36 and the second pressure regulation valve 37 are switched by the application of pressure by the switching unit 38.

[0041] The first pressure regulating valve 36 is switchable between a first adjustment state and a first open state by a switching unit 38. The first adjustment state adjusts the pressure downstream of the first pressure regulating valve 36 in the first liquid flow path 23 to a first set pressure. The first open state maintains the first liquid flow path 23 open, thereby adjusting the pressure downstream of the first pressure regulating valve 36 to a pressure higher than the first set pressure. Here, the first open state maintains the first liquid flow path 23 open, and therefore also adjusts the flow rate of liquid flowing through the first liquid flow path 23. The first pressure regulating valve 36 may be switchable to a first closed state, which maintains the first liquid flow path 23 closed. The first closed state maintains the first liquid flow path 23 closed, thereby adjusting the flow rate of liquid flowing through the first liquid flow path 23 to zero.

[0042] The second pressure regulating valve 37 is switchable between a second adjustment state and a second open state by the switching unit 38. The second adjustment state adjusts the pressure upstream of the second pressure regulating valve 37 in the second liquid flow path 26 to a second set pressure. The second open state maintains the second liquid flow path 26 open, thereby adjusting the pressure upstream of the second pressure regulating valve 37 to a pressure lower than the second set pressure. Here, the second open state maintains the second liquid flow path 26 open, and therefore also adjusts the flow rate of liquid flowing through the second liquid flow path 26. The second pressure regulating valve 37 may be switchable to a second closed state, which maintains the second liquid flow path 26 closed. The second closed state maintains the second liquid flow path 26 closed, thereby adjusting the flow rate of liquid flowing through the second liquid flow path 26 to zero.

[0043] The switching unit 38 has a first gas flow path 41, a second gas flow path 42, a third gas flow path 43, a fourth gas flow path 44, and a switching mechanism 46. The switching unit 38 may have a fifth gas flow path 45.

[0044] The first gas flow path 41 is connected to the first pressure regulating valve 36. The second gas flow path 42 is connected to the second pressure regulating valve 37. Pressurized gas flows through the third gas flow path 43. Gas pressurized by the pressure pump 20 may flow through the third gas flow path 43. Depressurized gas flows through the fourth gas flow path 44. Gas depressurized by the pressure reducing pump 27 may flow through the fourth gas flow path 44. The fifth gas flow path 45 is open to the atmosphere. Air at atmospheric pressure may flow through the fifth gas flow path 45.

[0045] The switching mechanism 46 switches the connection state between the gas flow paths 41 to 45. The switching mechanism 46 may be a selector valve. The detailed configuration of the switching mechanism 46 will be described later.

[0046] The first pressure regulating valve 36 is in the first adjustment state when the first gas flow path 41 and the fifth gas flow path 45 are connected. That is, the first pressure regulating valve 36 is in the first adjustment state when the air chamber 63 is switched to atmospheric pressure.

[0047] The first pressure regulation valve 36 is in the first open state when the first gas flow path 41 and the third gas flow path 43 are connected. In other words, the first pressure regulation valve 36 is in the first open state when the air chamber 63 is switched to a positive pressure.

[0048] The first pressure regulation valve 36 can be switched to a first closed state in which the first liquid flow path 23 is kept closed. The first pressure regulation valve 36 is in the first closed state when the first gas flow path 41 and the fourth gas flow path 44 are connected. In other words, the first pressure regulation valve 36 is in the first closed state when the air chamber 63 is switched to a negative pressure.

[0049] The second pressure regulation valve 37 is in the second regulation state when the second gas flow path 42 is connected to the fifth gas flow path 45. In other words, the second pressure regulation valve 37 is in the first regulation state when the air chamber 83 is switched to atmospheric pressure.

[0050] The second pressure regulation valve 37 is in the second open state when the second gas flow path 42 is connected to the fourth gas flow path 44. In other words, the second pressure regulation valve 37 is in the second open state when the air chamber 83 is switched to a negative pressure.

[0051] The second pressure regulation valve 37 can be switched to a second closed state in which the second liquid flow path 26 is kept closed. The second pressure regulation valve 37 is in the second closed state when the second gas flow path 42 and the third gas flow path 43 are connected. In other words, the second pressure regulation valve 37 is in the second closed state when the air chamber 83 is switched to a positive pressure.

[0052] Fluid and hydration The liquid flowing device 13 may be connected to a liquid supply source 49A and a moisture supply source 49B. The moisture supply source 49B contains moisture, i.e., water. The moisture supply source 49B may be a cartridge or a pack that is detachable from the liquid ejection device 11, or may be a tank that can be replenished with liquid.

[0053] The first liquid storage section 17 is capable of storing the liquid to be supplied to the liquid ejection section 12. The second liquid storage section 24 is capable of storing the liquid recovered from the liquid ejection section 12. The second liquid storage section 24 may have a moisture-permeable membrane 50. The moisture-permeable membrane 50 divides the interior of the second liquid storage section 24 into a liquid chamber 51 and a moisture chamber 52. The liquid chamber 51 is capable of containing liquid. Liquid is supplied to the liquid chamber 51 from a liquid supply source 49A. The moisture chamber 52 is capable of containing moisture. Moisture is supplied to the moisture chamber 52 from a moisture supply source 49B.

[0054] The moisture-permeable membrane 50 is a membrane that allows gas to pass through but does not allow liquid to pass through. Therefore, the moisture-permeable membrane 50 separates the liquid stored in the liquid chamber 51 and the moisturizer stored in the moisturizer chamber 52, preventing them from mixing. The moisture-permeable membrane 50 is a porous membrane with multiple pores formed therein. A meniscus is formed in these pores due to the surface tension of the liquid. This allows the moisture-permeable membrane 50 to allow gas to pass through but does not allow liquid to pass through. The moisturizer moisturizes the liquid by supplying moisture to the liquid through the moisture-permeable membrane 50.

[0055] The liquid flow device 13 may have a liquid supply channel 53 and a moisture supply channel 54. The liquid supply channel 53 is connected to the liquid supply source 49A and the liquid chamber 51. The moisture supply channel 54 is connected to the moisture supply source 49B and the moisture chamber 52.

[0056] The liquid flow device 13 may have a liquid supply valve 55 and a water supply valve 56. The liquid supply valve 55 is located in the liquid supply flow path 53. When the liquid supply valve 55 is open, liquid can be supplied from the liquid supply source 49A to the second liquid storage portion 24. The water supply valve 56 is located in the water supply flow path 54. When the water supply valve 56 is open, water can be supplied from the water supply source 49B to the second liquid storage portion 24. Normally, the liquid supply valve 55 and the water supply valve 56 are closed. The liquid supply valve 55 is opened when liquid needs to be supplied to the second liquid storage portion 24. The water supply valve 56 is opened when water needs to be supplied to the second liquid storage portion 24.

[0057] The liquid flow device 13 may have an agitator 57. The agitator 57 is attached to the second liquid storage section 24. The agitator 57 agitates the moisturizer stored in the moisturizer chamber 52. By agitating the moisturizer with the agitator 57, the concentration of the moisturizer is made uniform. This reduces the risk of the moisturizer concentration becoming too high.

[0058] The agitation unit 57 may have an agitation flow path 58 and an agitation pump 59. The agitation flow path 58 is connected to the moisturizer chamber 52 and the water supply flow path 54. The agitation pump 59 is located in the agitation flow path 58. The agitation pump 59 circulates the moisturizer in the second liquid storage unit 24 through the agitation flow path 58. This causes the moisturizer to be agitated.

[0059] The liquid discharge device 11 includes a control unit 100. The control unit 100 controls the liquid discharge unit 12, the pumps 20, 27, and 59, the liquid delivery unit 31, the switching mechanism 46, and the like. The control unit 100 is not limited to a system that performs all of its processing using software. For example, the control unit 100 may include a dedicated hardware circuit (e.g., an application-specific integrated circuit (ASIC)) that performs hardware processing for at least some of the processing it performs. That is, the control unit 100 may be configured as a circuit including one or more processors that operate according to a computer program (software), one or more dedicated hardware circuits that perform at least some of the various processes, or a combination thereof. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform processing. The memory, i.e., computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer.

[0060] <Configuration of the first valve mechanism> Next, the configuration of the first valve mechanism 21 will be described with reference to Fig. 2. The fluid handled by the first valve mechanism 21 of this embodiment is a liquid.

[0061] As shown in FIG. 2 , the first valve mechanism 21 includes a first upstream chamber 61, which is an example of an upstream chamber, a first downstream chamber 62, which is an example of a downstream chamber, and a first air chamber 63, which is an example of an air chamber. The first valve mechanism 21 includes a first flexible membrane 64, a second flexible membrane 65, a first opening / closing unit 66, which is an example of an opening / closing unit, and a first biasing unit 67, which is an example of a biasing unit. The first opening / closing unit 66 is movable between a first closed position indicated by a solid line in FIG. 2 and a first open position indicated by a two-dot chain line in FIG. 2 . In this embodiment, a state in which the first opening / closing unit 66 is located at the first closed position is also referred to as a first closed state, and a state in which the first opening / closing unit 66 is located at the first open position is also referred to as a first open state. The fluid handled by the first valve mechanism 21 in this embodiment is, for example, a liquid.

[0062] The fluid flows into the first upstream chamber 61 via a first inlet 68, which is an example of an inlet. The first downstream chamber 62 is provided downstream of the first upstream chamber 61. The first downstream chamber 62 communicates with the first upstream chamber 61 downstream of the first upstream chamber 61 via a first communication port 69, which is an example of a communication port. The first downstream chamber 62 discharges the fluid via a first outlet 70, which is an example of an outlet. The first outlet 70 of this embodiment communicates with the liquid discharger 12 via a first liquid flow path 23.

[0063] The first air chamber 63 is configured to be able to communicate with the outside space. The first air chamber 63 is able to communicate with the outside space via the first ventilation port 71. The first valve mechanism 21 has a first housing 75 having a cylindrical shape with a bottom and an open end, and a first lid 76 having a cylindrical shape with a bottom and an open end. The first housing 75 and the first lid 76 are joined at their open ends with a first flexible membrane 64 sandwiched between them. The first housing 75 has a first inlet pipe 75a, a cylindrical first chamber forming portion 75b, and a first outlet pipe 75c. The first inlet pipe 75a communicates with the first chamber forming portion 75b. One opening of the first chamber forming portion 75b is closed by the second flexible membrane 65, and the other opening forms a first communication port 69.

[0064] The first upstream chamber 61 is defined by the first housing 75, the first flexible membrane 64, etc. The first downstream chamber 62 is defined by the first chamber forming portion 75b, the second flexible membrane 65, etc. The first air chamber 63 is defined by the first cover 76 and the first flexible membrane 64. The first cover 76 has a pipe portion 76a that connects the first air chamber 63 to the outside space. The first ventilation port 71 is defined by the pipe portion 76a.

[0065] The first flexible membrane 64 separates the first downstream chamber 62 from the first air chamber 63. The first flexible membrane 64 forms part of the wall of the first downstream chamber 62. The first flexible membrane 64 is formed by a flexible member such as a diaphragm. The first flexible membrane 64 is displaced in response to the difference in pressure applied to the outer surface and the inner surface.

[0066] The second flexible membrane 65 separates the first upstream chamber 61 and the first downstream chamber 62. The second flexible membrane 65 may be located above the first communication port 69. The second flexible membrane 65 is located between the first communication port 69 and the first flexible membrane 64.

[0067] The first communication port 69, the second flexible film 65, the first flexible film 64, and the first biasing portion 67 may be arranged in this order in the first direction D1. The first direction D1 may be the direction opposite to the vertical direction Z.

[0068] The first biasing portion 67 biases the first flexible membrane 64. The first biasing portion 67 biases the first flexible membrane 64 in a first direction D1 in which the volume of the first downstream chamber 62 decreases. The first biasing portion 67 is provided outside the first downstream chamber 62. The first biasing portion 67 is, for example, a compression spring.

[0069] The first biasing portion 67 may be housed in the air chamber 63. A first end of the first biasing portion 67 abuts against the first flexible membrane 64, and a second end opposite the first end is restricted by a restricting portion (not shown) so as to be immovable. If the first biasing portion 67 is a compression spring, it is held in a compressed state. Therefore, the first biasing portion 67 presses the first flexible membrane 64 in a direction that reduces the volume of the first downstream chamber 62. The first biasing portion 67 presses the first flexible membrane 64 in the first direction D1. The first biasing portion 67 applies a force to the first opening / closing portion 66 via the first flexible membrane 64 in a direction that moves the first opening / closing portion 66 from the first closed position shown by the solid line in FIG. 2 to the first open position shown by the two-dot chain line in the same figure.

[0070] A force based on the air pressure in the air chamber 63 and a biasing force of the first biasing portion 67 act on the outer surface of the first flexible membrane 64. A force based on the pressure of the fluid in the first downstream chamber 62 acts on the inner surface of the first flexible membrane 64.

[0071] The first opening / closing unit 66 is configured to be able to open and close the first communication port 69. The first communication port 69 opens at an end of the first upstream chamber 61 opposite to the end on the second flexible membrane 65 side. The first opening / closing unit 66 may have a first shaft portion 72 which is an example of a shaft portion, and a first valve portion 73 which is an example of a valve portion.

[0072] The first shaft portion 72 is provided across the first upstream chamber 61 and the first downstream chamber 62. The first shaft portion 72 may be inserted into the second flexible membrane 65. The longitudinal direction of the first shaft portion 72 may be parallel to the first direction D1. The first shaft portion 72 may be rod-shaped. The first shaft portion 72 may be cylindrical. The diameter of the first shaft portion 72 is smaller than the inner diameter of the first communication port 69.

[0073] The first shaft portion 72 is movable in response to the displacement of the first flexible membrane 64 and the second flexible membrane 65. The first shaft portion 72 may be fixed to the first flexible membrane 64 and the second flexible membrane 65 directly or via a fixing member. One end of the first shaft portion 72 may be connected to the first flexible membrane 64. The other end of the first shaft portion 72 may be connected to the first valve portion 73.

[0074] The first valve portion 73 is connected to the first shaft portion 72. The first valve portion 73 is capable of opening and closing the first communication port 69. The first valve portion 73 moves together with the first shaft portion 72. The first shaft portion 72 moves in response to the displacement of the first flexible membrane 64, thereby displacing the second flexible membrane 65 and the first valve portion 73. In other words, the first opening / closing portion 66 moves in response to the displacement of the first flexible membrane 64, causing the first valve portion 73 to open and close the first communication port 69.

[0075] The first valve portion 73 may have a first seal portion 74. The first seal portion 74 is capable of tightly fitting to the first communication port 69. The first seal portion 74 forms the outer periphery of the first valve portion 73. The first seal portion 74 may be annular. The first seal portion 74 may be a torus-shaped O-ring.

[0076] As shown in Figure 2, within the first valve mechanism 21, the second flexible membrane 65 receives a force corresponding to the difference in pressure between the first surface 65a and the second surface 65b. The first valve portion 73 receives a force corresponding to the difference in pressure between the outer surface and the inner surface. The pressure-receiving area of ​​the second flexible membrane 65 and the pressure-receiving area of ​​the first valve portion 73 are approximately equal to each other or the difference therebetween is small. Therefore, the force received by the second flexible membrane 65 and the force received by the first valve portion 73 are approximately equal in magnitude but in opposite directions, and therefore generally cancel each other out.

[0077] Therefore, the first opening / closing portion 66 is displaced mainly in accordance with the difference in force applied to both sides of the first flexible membrane 64. The pressure-receiving area over which the first flexible membrane 64 receives the pressure of the fluid in the first downstream chamber 62 is larger than the pressure-receiving area over which the second flexible membrane 65 receives the pressure of the fluid in the first downstream chamber 62. Therefore, the first valve portion 73 is highly responsive to changes in the pressure applied to both sides of the first flexible membrane 64 in opening and closing. The first flexible membrane 64 is subjected to a force in a direction corresponding to the air pressure in the first air chamber 63, a biasing force in the first direction D1 of the first biasing portion 67, and a force in a direction corresponding to the pressure of the fluid in the first downstream chamber 62. The first opening / closing portion 66 moves in a direction corresponding to the difference in force applied to both sides of the first flexible membrane 64.

[0078] The first opening / closing unit 66 is movable between a first closed position shown by a solid line in Fig. 2 and a first open position shown by a two-dot chain line in Fig. 2. In Fig. 2, the direction in which the fluid flows is indicated by an outline arrow. When the first opening / closing unit 66 is in the first closed position shown by the solid line in Fig. 2, the first valve unit 73 disconnects the first upstream chamber 61 from the first downstream chamber 62. When the first opening / closing unit 66 is in the first open position shown by the two-dot chain line in Fig. 2, the first valve unit 73 connects the first upstream chamber 61 to the first downstream chamber 62.

[0079] The first valve mechanism 21 functions as a pressure regulation valve. The pressure regulation valve is a valve that can be switched between a first regulation state in which it functions as a pressure regulation valve, a first open state in which it maintains the first open state, and a first closed state in which it maintains the first closed state. When the first valve mechanism 21 is in the first regulation state, the fluid in the first upstream chamber 61 is at an input pressure P1, and the fluid in the first downstream chamber 62 is at an output pressure P2. The first valve mechanism 21 regulates the output pressure P2 to a first set pressure SP1. Here, the input side and output side of the valve mechanism do not refer to the direction in which the fluid flows, but rather refer to the side where the pressure is regulated as the output side and the opposite side as the input side.

[0080] <Operation of the first valve mechanism> The first valve mechanism 21 switches between a first adjustment state, a first open state, and a first closed state in response to the air pressure acting on the outside of the first flexible membrane 64. That is, the first valve mechanism 21 switches between the first adjustment state, a first open state, and a first closed state in response to the pressure of air introduced into the first air chamber 63. These three states will be described in order below.

[0081] The first valve mechanism 21 is in a first adjustment state for adjusting pressure when atmospheric pressure acts on the outside of the first flexible membrane 64. That is, the first valve mechanism 21 is in the first adjustment state for adjusting pressure when atmospheric pressure is introduced into the first air chamber 63. In the first adjustment state, the first valve portion 73 opens and closes in response to changes in the output pressure P2, thereby adjusting the output pressure P2 to a first set pressure SP1. In this embodiment, the first set pressure SP1 is set to a predetermined positive pressure.

[0082] The first valve mechanism 21 is in a first open state in which it is maintained in an open state when a positive pressure is acting on the outside of the first flexible membrane 64. That is, the first valve mechanism 21 is in the first open state when a positive pressure is introduced into the first air chamber 63. In the first open state, the first flexible membrane 64, on whose outer surface a positive pressure is acting, is displaced in a direction that reduces the volume of the first downstream chamber 62. The first opening / closing unit 66 is maintained in an open position. In the first open state, the first valve unit 73 is maintained in a first open state in which the first upstream chamber 61 and the first downstream chamber 62 communicate with each other. When in the first open state, the first valve mechanism 21 maintains an open state, thereby adjusting the downstream pressure to a pressure P2 (>SP1) that is greater than the first set pressure SP1.

[0083] The first valve mechanism 21 is in a first closed state in which it is maintained in a closed state when negative pressure is applied to the outside of the first flexible membrane 64. That is, the first valve mechanism 21 is in the first closed state when negative pressure is introduced into the first air chamber 63. In the first closed state, the first flexible membrane 64, on whose outer surface negative pressure is applied, is displaced in a direction that increases the volume of the first downstream chamber 62. The first opening / closing unit 66 is maintained in a closed position. In the first closed state, the first valve unit 73 is maintained in a first closed state in which the first upstream chamber 61 and the first downstream chamber 62 are not in communication with each other. When in the first closed state, the first valve mechanism 21 maintains a closed state, thereby adjusting the flow rate of fluid from upstream to downstream to zero.

[0084] Here, the operation of the first valve mechanism 21 when it is in the first adjustment state will be described. When the first valve mechanism 21 shown in FIG. 2 is in the first adjustment state, the first opening / closing unit 66 is displaced mainly in accordance with the difference in force applied to both sides of the first flexible membrane 64. For example, in the first adjustment state, both sides of the first flexible membrane 64 are subjected to a force in the valve opening direction due to atmospheric pressure, a biasing force (compression force) in the first direction D1 (valve opening direction) due to the first biasing unit 67, and a force in the valve closing direction based on the pressure (e.g., positive pressure) of the fluid in the first downstream chamber 62. In this way, the force in the valve opening direction due to atmospheric pressure and the biasing force in the valve opening direction due to the first biasing unit 67 act on the surface of the first flexible membrane 64 facing the first air chamber 63. The first valve mechanism 21 is configured so that the first opening / closing unit 66 moves from the open position to the closed position when the output pressure P2 becomes greater than the first set pressure SP1. That is, when the output pressure P2 becomes greater than the first set pressure SP1, the first opening / closing portion 66 is set to move from the open position to the closed position.

[0085] When the output pressure P2, which determines the pressure of the fluid in the first downstream chamber 62, falls below the first set pressure SP1, the first flexible membrane 64 is displaced in the first direction D1, causing the first opening / closing part 66 to move to the open position. This opening allows fluid to flow from the first upstream chamber 61 to the first downstream chamber 62 through the first communication port 69. As a result, the pressure of the fluid in the first downstream chamber 62 rises to the first set pressure SP1. This operation adjusts the output pressure P2 on the downstream side of the first valve mechanism 21 to the first set pressure SP1.

[0086] <Configuration of the second valve mechanism> Next, the configuration of the second valve mechanism 28 will be described with reference to FIG. 3. As shown in FIG. 3, the second valve mechanism 28 includes a second upstream chamber 81, which is an example of an upstream chamber, a second downstream chamber 82, which is an example of a downstream chamber, and a second air chamber 83, which is an example of an air chamber. The second valve mechanism 28 includes a third flexible membrane 84, which is an example of a first flexible membrane, a fourth flexible membrane 85, which is an example of a second flexible membrane, a second opening / closing unit 86, which is an example of an opening / closing unit, and a second biasing unit 87, which is an example of a biasing unit. The second opening / closing unit 86 is movable between a second closed position indicated by a solid line in FIG. 3 and a second open position indicated by a two-dot chain line in FIG. 3. In this embodiment, a state in which the second opening / closing unit 86 is located at the second closed position is also referred to as a second closed state, and a state in which the second opening / closing unit 86 is located at the second open position is also referred to as a second open state. Note that the fluid handled by the second valve mechanism 28 in this embodiment is, for example, a liquid.

[0087] The second upstream chamber 81 receives the fluid via a second inlet 89, which is an example of an inlet. The second inlet 89 of this embodiment is connected to the liquid discharger 12 via a liquid flow path 19. The second downstream chamber 82 is provided downstream of the second upstream chamber 81. The second downstream chamber 82 communicates with the second upstream chamber 81 downstream of the second upstream chamber 81 via a second communication port 90, which is an example of a communication port. The second downstream chamber 82 discharges the fluid via a second outlet 91. In this embodiment, the second outlet 91 communicates with the second liquid storage section 24 via the second liquid flow path 26.

[0088] The second air chamber 83 is configured to be able to communicate with the outside space. The second air chamber 83 is able to communicate with the outside space via the second ventilation port 88. The second valve mechanism 28 has a second housing 95 having a cylindrical shape with a bottom and an open end, and a second lid 96 having a cylindrical shape with a bottom and an open end. The second housing 95 and the second lid 96 are joined at the open ends of each other with a third flexible membrane 84 sandwiched therebetween. The second housing 95 has a second inlet pipe 95a, a cylindrical second chamber forming portion 95b, and a second outlet pipe 95c. The second inlet pipe 95a communicates with the second chamber forming portion 95b. One opening of the second chamber forming portion 95b is closed by the fourth flexible membrane 85, and the other opening forms the second communication port 90.

[0089] The second upstream chamber 81 is defined by the second housing 95, the third flexible membrane 84, etc. The second downstream chamber 82 is defined by the second chamber forming portion 95b, the fourth flexible membrane 85, etc. The second air chamber 83 is defined by the second cover 96 and the third flexible membrane 84. The second cover 96 has a pipe portion 96a that communicates with the second air chamber 83. The second air vent 88 is defined by the pipe portion 96a.

[0090] The third flexible membrane 84 separates the second upstream chamber 81 from the second air chamber 83. The third flexible membrane 84 forms part of the wall of the second upstream chamber 81. The third flexible membrane 84 is formed by a flexible member such as a diaphragm. The third flexible membrane 84 is displaced in response to the difference in pressure applied to the outer surface and the inner surface.

[0091] The fourth flexible membrane 85 separates the second upstream chamber 81 from the second downstream chamber 82. The fourth flexible membrane 85 may be located above the second communication port 90. The fourth flexible membrane 85 is located between the second communication port 90 and the third flexible membrane 84.

[0092] The second communication port 90, the fourth flexible film 85, the third flexible film 84, and the second biasing portion 87 may be arranged in this order in the second direction D2. The second direction D2 may be the direction opposite to the vertical direction Z.

[0093] The second biasing portion 87 biases the third flexible membrane 84. The second biasing portion 87 biases the third flexible membrane 84 in the second direction D2 in which the volume of the second upstream chamber 81 increases. The second biasing portion 87 is provided outside the second upstream chamber 81. The second biasing portion 87 presses the second opening / closing portion 86 via the third flexible membrane 84. The second biasing portion 87 is, for example, a tension spring.

[0094] The second biasing portion 87 may be housed in the air chamber 83. The second biasing portion 87 has a first end fixed to the first flexible membrane 64 and a second end opposite the first end supported immovably by a hook (not shown). Therefore, the second biasing portion 87 is in a state of pulling the first flexible membrane 64 in a direction that increases the volume of the second upstream chamber 81. The second biasing portion 87 pulls the third flexible membrane 84 in the second direction D2. The second biasing portion 87 applies a force to the second opening / closing portion 86 via the third flexible membrane 84 in a direction that moves the second opening / closing portion 86 from the second closed position shown by the solid line in FIG. 3 to the second open position shown by the two-dot chain line in the same figure.

[0095] The second opening / closing unit 86 is configured to be able to open and close the second communication port 90. The second communication port 90 opens at an end of the second chamber forming portion 95b opposite to the end on the fourth flexible membrane 85 side. The second opening / closing unit 86 may have a second shaft portion 92, which is an example of a shaft portion, and a second valve portion 93, which is an example of a valve portion.

[0096] The second shaft portion 92 is provided across the second upstream chamber 81 and the second downstream chamber 82. The second shaft portion 92 is inserted into the fourth flexible membrane 85. The longitudinal direction of the second shaft portion 92 may be parallel to the second direction D2. The second shaft portion 92 may be rod-shaped. The second shaft portion 92 may be cylindrical. The diameter of the second shaft portion 92 is smaller than the inner diameter of the second communication port 90.

[0097] The second shaft portion 92 is movable in response to the displacement of the third flexible film 84 and the fourth flexible film 85. The second shaft portion 92 is fixed to the third flexible film 84 and the fourth flexible film 85 directly or via a fixing member. One end of the second shaft portion 92 may be connected to the third flexible film 84. The other end of the second shaft portion 92 may be connected to the second valve portion 93.

[0098] The second valve portion 93 is connected to the second shaft portion 92. The second valve portion 93 is capable of opening and closing the second communication port 90. The second valve portion 93 moves together with the second shaft portion 92. The second shaft portion 92 moves in response to the displacement of the third flexible membrane 84, thereby displacing the fourth flexible membrane 85 and the second valve portion 93. In other words, the second opening / closing portion 86 moves in response to the displacement of the third flexible membrane 84, causing the second valve portion 93 to open and close the second communication port 90.

[0099] The second valve portion 93 may have a second seal portion 94. The second seal portion 94 is capable of tightly fitting to the second communication port 90. The second seal portion 94 forms the outer periphery of the second valve portion 93. The second seal portion 94 may be annular. The second seal portion 94 may be a torus-shaped O-ring.

[0100] 3, within the second valve mechanism 28, the fourth flexible membrane 85 receives a force corresponding to the difference in pressure between the third surface 85a and the fourth surface 85b. The second valve portion 93 receives a force corresponding to the difference in pressure between the outer surface and the inner surface. The pressure-receiving area of ​​the fourth flexible membrane 85 and the pressure-receiving area of ​​the second valve portion 93 are substantially equal to each other or the difference therebetween is small. Therefore, the forces received by the fourth flexible membrane 85 and the second valve portion 93 are substantially equal in magnitude but act in opposite directions, and therefore generally cancel each other out.

[0101] Therefore, the second opening / closing portion 86 is displaced mainly in accordance with the difference in force applied to both sides of the third flexible membrane 84. The pressure-receiving area of ​​the third flexible membrane 84 is larger than the pressure-receiving area of ​​the fourth flexible membrane 85. Therefore, the second valve portion 93 is highly responsive to the change in pressure applied to both sides of the third flexible membrane 84 in opening and closing. The third flexible membrane 84 is subjected to a force in a direction corresponding to the air pressure in the second air chamber 83, a biasing force in the second direction D2 of the second biasing portion 87, and a force in a direction corresponding to the pressure of the fluid in the second upstream chamber 81. The second opening / closing portion 86 moves in a direction corresponding to the difference in force applied to both sides of the third flexible membrane 84.

[0102] The second opening / closing unit 86 is movable between a second closed position shown by a solid line in Fig. 3 and a second open position shown by a two-dot chain line in Fig. 3. In Fig. 3, the direction of fluid flow is indicated by an outline arrow. When the second opening / closing unit 86 is in the closed position shown by a solid line in Fig. 3, the second valve unit 93 disconnects the second upstream chamber 81 from the second downstream chamber 82. When the second opening / closing unit 86 is in the open position shown by a two-dot chain line in Fig. 3, the second valve unit 93 connects the second upstream chamber 81 to the second downstream chamber 82.

[0103] The second valve mechanism 28 functions as a negative pressure adjustment valve. The negative pressure adjustment valve is a valve that can be switched between a second adjustment state in which it functions as a negative pressure adjustment valve, a second open state in which the second open state is maintained, and a second closed state in which the second closed state is maintained. When the second valve mechanism 28 is in the second adjustment state, the fluid in the second upstream chamber 81 is at output pressure P3, and the fluid in the second downstream chamber 82 is at input pressure P4. The second valve mechanism 28 adjusts the output pressure P3 to a second set pressure SP2.

[0104] <Operation of the second valve mechanism> Second valve mechanism 28 switches between a second adjustment state, a second open state, and a second closed state depending on the air pressure acting on the outside of third flexible membrane 84. That is, second valve mechanism 28 switches between the second adjustment state, the second open state, and the second closed state depending on the air pressure introduced into second air chamber 83. These three states will be described in order below.

[0105] The second valve mechanism 28 is in the second adjustment state to adjust the pressure when atmospheric pressure acts on the outside of the third flexible membrane 84. That is, the second valve mechanism 28 is in the second adjustment state to adjust the pressure when atmospheric pressure is introduced into the second air chamber 83. In the second adjustment state, the second valve unit 93 opens and closes in response to changes in the output pressure P3, thereby adjusting the output pressure P3 to a second set pressure SP2. In this embodiment, the second set pressure SP2 is set to a predetermined negative pressure.

[0106] The second valve mechanism 28 assumes a second open state in which it is maintained in an open state when a negative pressure acts on the outside of the third flexible membrane 84. That is, the second valve mechanism 28 assumes the second open state when a negative pressure is introduced into the second air chamber 83. In the second open state, the third flexible membrane 84, on the outer surface of which the negative pressure acts, is in a displaced state in a direction to increase the volume of the second upstream chamber 81. The second opening / closing portion 86 is maintained in the open position. In the second open state, the second valve portion 93 is maintained in a second open state in which the second upstream chamber 81 and the second downstream chamber 82 are put into communication with each other. When the second valve mechanism 28 is in the second open state, it maintains the open state, thereby adjusting the upstream pressure to a pressure P3 (<SP) lower than the second set pressure SP2.

[0107] The second valve mechanism 28 assumes a second closed state in which it is maintained in a closed state when a positive pressure acts on the outside of the third flexible membrane 84. That is, the second valve mechanism 28 assumes the second closed state when a positive pressure is introduced into the second air chamber 83. In the second closed state, the third flexible membrane 84, on the outer surface of which the positive pressure acts, is in a displaced state in a direction to decrease the volume of the second upstream chamber 81. The second opening / closing portion 86 is maintained in the closed position. In the second closed state, the second valve portion 93 is maintained in a second state in which the second upstream chamber 81 and the second downstream chamber 82 are put out of communication with each other. When the second valve mechanism 28 is in the second closed state, it maintains the closed state, thereby adjusting the flow rate of the fluid from the upstream to the downstream to zero.

[0108] Here, the operation of the second valve mechanism 28 when it is in the second adjustment state will be described. When the second valve mechanism 28 shown in FIG. 3 is in the second adjustment state, the second opening / closing portion 86 is displaced mainly in accordance with the difference in force applied to both sides of the third flexible membrane 84. For example, when it is in the second adjustment state, both sides of the third flexible membrane 84 are subjected to a force in the valve closing direction due to atmospheric pressure, a biasing force (tensile force) in the second direction D2 (valve opening direction) due to the second biasing portion 87, and a force in the valve closing direction based on the negative pressure of the fluid in the second upstream chamber 81. In this way, a tensile force in the valve opening direction that resists the force in the valve closing direction due to atmospheric pressure acts on the surface of the third flexible membrane 84 facing the second air chamber 83. When the second opening / closing unit 86 is in the closed position and the output pressure P3 becomes greater than the second set pressure SP2, i.e., the negative pressure of the fluid in the second upstream chamber 81 becomes smaller, the third flexible membrane 84 is displaced in the second direction D2, moving the second opening / closing unit 86 to the open position. This valve opening allows fluid to flow from the second upstream chamber 81 to the second downstream chamber 82 through the second communication port 90. As a result, the pressure of the fluid in the second upstream chamber 81 is adjusted to the second set pressure SP2. When the output pressure P3 becomes smaller than the second set pressure SP2, i.e., the negative pressure of the fluid in the second upstream chamber 81 becomes larger, the second opening / closing unit 86 moves from the open position to the closed position. As a result, the pressure of the fluid in the second upstream chamber 81 is adjusted to the second set pressure SP2. In this way, the output pressure P3 on the upstream side of the second valve mechanism 28 is adjusted to the second set pressure SP2.

[0109] <Configuration of Switching Unit 38> Next, the configuration of the switching unit 38 will be described with reference to FIG. 4. The switching unit 38 includes two valve groups, each of which includes a first valve 101, a second valve 102, and a third valve 103. The first valve 101, the second valve 102, and the third valve 103 may be configured, for example, as electromagnetic on-off valves, or may be configured to open and close via a cam mechanism (not shown) that rotates by the power of a motor. In this case, the electromagnetic on-off valves or the motor may be driven and controlled by the control unit 100. The downstream ends of the first valve 101, the second valve 102, and the third valve 103 that belong to one group are connected to the first gas flow path 41. The downstream ends of the first valve 101, the second valve 102, and the third valve 103 that belong to the other group are connected to the second gas flow path 42. The upstream ends of the two first valves 101 are connected to the third gas flow path 43. The upstream ends of the two second valves 102 are connected to a fifth gas flow path 45 that communicates with the atmosphere. The upstream ends of the two third valves 103 are connected to a fourth gas flow path 44.

[0110] The pressure of the gas in the first gas flow path 41 is selected depending on which of the first valve 101, the second valve 102, and the third valve 103 is opened. When the first valve 101 is opened, the pressure of the gas in the first gas flow path 41 becomes positive pressure. When the second valve 102 is opened, the pressure of the gas in the first gas flow path 41 becomes atmospheric pressure. When the third valve 103 is opened, the pressure of the gas in the first gas flow path 41 becomes negative pressure.

[0111] The pressure of the gas in the first gas flow path 41 is selected depending on which of the first valve 101, the second valve 102, and the third valve 103 is opened. When the first valve 101 is opened, the pressure of the gas in the first gas flow path 41 becomes positive pressure. When the second valve 102 is opened, the pressure of the gas in the first gas flow path 41 becomes atmospheric pressure. When the third valve 103 is opened, the pressure of the gas in the first gas flow path 41 becomes negative pressure.

[0112] <Operation of the First Embodiment> The operation of this embodiment will be described. The inside of the first liquid storage section 17 is pressurized to a positive pressure higher than the atmospheric pressure. The pressurized liquid in the first liquid storage section 17 flows out to the liquid flow path 19. The pressure of the liquid supplied from the first liquid storage section 17 to the liquid discharge section 12 is adjusted to the first set pressure SP1 by the first pressure regulating valve 36. Therefore, the inside of the liquid discharge section 12 is adjusted to the first set pressure SP1, which is a predetermined positive pressure smaller than the pressure in the pressurized first liquid storage section 17.

[0113] The inside of the second liquid storage section 24 is depressurized to a negative pressure lower than the atmospheric pressure. The liquid is recovered from the liquid discharge section 12 to the second liquid storage section 24 through the second liquid flow path 26. The pressure in the liquid discharge section 12 located upstream thereof is adjusted to the second set pressure SP2 by the second pressure regulating valve 37 provided in the second liquid flow path 26. Therefore, the inside of the liquid discharge section 12 is adjusted to the second set pressure SP2, which is a predetermined negative pressure larger than the pressure in the depressurized second liquid storage section 24.

[0114] For example, the second set pressure SP2 (<SP1) is set to a value smaller than the first set pressure SP1. Therefore, even when both the first pressure regulating valve 36 and the second pressure regulating valve 37 are in the adjustment state, it is possible to circulate the liquid while maintaining a predetermined negative pressure inside the liquid discharge section 12.

[0115] <Operation of the liquid discharge device 11> Next, referring to FIGS. 5 to 10, the operation of the liquid discharge device 11 will be described. In FIGS. 5 to 10, the three states of the first pressure regulating valve 36 and the second pressure regulating valve 37 are distinguished by the combination of white and black of the valve symbols. That is, the adjustment state is shown by black and white (for example, FIG. 5), the closed state is shown by black (for example, FIG. 6), and the open state is shown by white (for example, FIG. 8).

[0116] The switching mechanism 46 is controlled by the control unit 100 (see FIG. 1). The switching mechanism 46 adjusts the pressure in the first air chamber 63 of the first pressure regulating valve 36 through the first gas flow path 41. The switching mechanism 46 adjusts the pressure in the second air chamber 83 of the second pressure regulating valve 37 through the second gas flow path 42. The control unit 100 controls the flow of liquid in the liquid flow path 19 by switching the states of the first pressure regulating valve 36 and the second pressure regulating valve 37.

[0117] FIG. 5 shows normal circulation. The first air chamber 63 of the first pressure regulating valve 36 is open to the atmosphere through the first gas flow path 41. The second air chamber 83 of the second pressure regulating valve 37 is open to the atmosphere through the second gas flow path 42. As a result, both the first pressure regulating valve 36 and the second pressure regulating valve 37 are in an adjustment state. Therefore, the output pressure P2 of the first pressure regulating valve 36 is adjusted to the first set pressure SP1. The output pressure P3 of the second pressure regulating valve 37 is adjusted to the second set pressure SP2. Here, the first set pressure SP1 is a positive pressure, and the second set pressure SP2 is a negative pressure. The pressure inside the liquid ejection unit 12 is adjusted to a negative pressure. Furthermore, the relationship SP1 > SP2 holds. Therefore, liquid circulates through a path passing through the liquid ejection unit 12. A recording operation in which liquid is ejected onto the medium 14 is performed while the liquid is circulating.

[0118] FIG. 6 shows the standby state and the stopped state. The standby state is a state in which the device waits for an instruction to eject liquid. The stopped state is the state before the device enters the standby state when the power is on. Negative pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in a closed state. Therefore, the circulation of liquid to the liquid ejection unit 12 is stopped.

[0119] FIG. 7 shows the power-off state. In the power-off state, both the pressure pump 20 and the pressure-reducing pump 27 are stopped. When the pressure release valve 22 is switched to the open state, the first liquid storage section 17 is opened to the atmosphere. When the pressure release valve 22 is switched to the open state, the second liquid storage section 24 is opened to the atmosphere. The third gas flow path 43 and the fourth gas flow path 44 are opened to the atmosphere. Before the power is turned off, the two first valves 101 in the switching mechanism 46 are closed. Negative pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, while the power is off, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are maintained in a closed state. Note that buffer chambers 41B and 42B, shown by two-dot chain lines in FIG. 7, may also be provided. The presence of the buffer chambers 41B and 42B allows both the first pressure regulating valve 36 and the second pressure regulating valve 37 to be maintained in a closed state for a long period of time.

[0120] FIG. 8 shows the cleaning state. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, the first pressure adjustment valve 36 is in an open state, and the second pressure adjustment valve 37 is in a closed state. The liquid supplied into the liquid ejection unit 12 is discharged from the nozzle 15. In other words, cleaning is performed to forcibly discharge the liquid from the nozzle 15 of the liquid ejection unit 12. By cleaning, thickened ink, air bubbles, and the like in the nozzle 15 are discharged together with the liquid. The liquid discharged from the nozzle 15 is received, for example, in a cap of a maintenance device (both not shown).

[0121] 9 shows the state in which the liquid is drained from the liquid discharger 12. Negative pressure is introduced into the first air chamber 63 of the first pressure regulating valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure regulating valve 37 through the second gas flow path 42. As a result, the first pressure regulating valve 36 is closed, and the second pressure regulating valve 37 is open. With the first pressure regulating valve 36 closed, the liquid in the liquid discharger 12 is collected in the second liquid storage section 24. In other words, the liquid in the liquid discharger 12 is forcibly drained. After the liquid is drained from the liquid discharger 12, for example, the liquid discharger 12 is replaced.

[0122] FIG. 10 shows forced circulation. Positive pressure is introduced into the first air chamber 63 of the first pressure regulating valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure regulating valve 37 through the second gas flow path 42. As a result, both the first pressure regulating valve 36 and the second pressure regulating valve 37 are in an open state. The liquid delivery unit 31 is driven. The liquid is forcibly circulated through a path passing through the liquid discharge unit 12. For example, air bubbles accumulated in the filter 141 (see FIG. 33) in the liquid discharge unit 12 are forcibly discharged. That is, in forced circulation, the amount of circulating liquid per unit time increases, and the high flow rate of the liquid forcibly discharges air bubbles accumulated in the filter 141.

[0123] <Effects of the first embodiment> The effects of the first embodiment will be described. (1-1) The first valve mechanism 21 has a first air chamber 63, and therefore pressure can be applied via the first air chamber 63. Therefore, the state of the first opening / closing unit 66 can be configured to be switchable between a first adjustment state and a first open state. The first adjustment state is a state in which the output pressure P2 is adjusted to a first set pressure SP1 (constant). The first open state is a state in which the pressure is adjusted to a pressure higher than the first set pressure SP1 by maintaining the liquid flow path 19 in an open state. Therefore, the pressure and flow rate can be changed according to the control situation, allowing the fluid to flow.

[0124] Furthermore, by using the first valve mechanism 21, only one liquid flow path 19 (first liquid flow path 23) is required, which simplifies the flow path design. For example, it is possible to address this by using a flow path in which a pressure release valve and an on-off valve are arranged in parallel, but this would complicate the flow path design. Furthermore, by using the second valve mechanism 28, only one liquid flow path 19 (second liquid flow path 26) is required, which simplifies the flow path design. For example, it is possible to address this by using a flow path in which a negative pressure release valve and an on-off valve are arranged in parallel, but this would complicate the flow path design.

[0125] Furthermore, by using the valve mechanisms 21, 28, switching between the adjusted state and the open state can be performed smoothly. For example, a mechanical valve mechanism that moves a valve element by rotating a screw portion requires time to switch states. However, the valve mechanisms 21, 28 of this embodiment are configured to switch states by changing the pressure in the air chambers 63, 83, so they can switch states instantly.

[0126] (1-2) The second valve mechanism 28 has a second air chamber 83, and therefore pressure can be applied via the second air chamber 83. Therefore, the state of the second opening / closing unit 86 can be configured to be switchable between a second adjustment state and a second open state. The second adjustment state is a state in which the output pressure P3 is adjusted to a second set pressure SP2 (constant). The second open state is a state in which the pressure is adjusted to a pressure lower than the second set pressure SP2 by maintaining the liquid flow path 19 open. Therefore, the pressure and flow rate can be changed according to the control situation, allowing the fluid to flow.

[0127] (1-3) A conventional self-sealing pressure regulating valve may also be configured with an air chamber. That is, an air chamber may be added to the exterior of the flexible membrane of a conventional self-sealing pressure regulating valve, and the pressure in the air chamber may be changed to forcibly switch the pressure regulating valve between an open state and a closed state. However, when a self-sealing pressure regulating valve is used, the valve portion is subjected to the pressure of the fluid in the upstream chamber after being forcibly switched to a closed state. Therefore, the valve portion cannot be opened unless a pressure greater than the set pressure is applied. In contrast, the first valve mechanism 21 applies a valve-opening force due to atmospheric pressure, a biasing force (compression force) in the first direction D1 (valve-opening direction) due to the first biasing member 67, and a closing force based on the pressure of the fluid in the first downstream chamber 62 to both sides of the first flexible membrane 64. Therefore, even after being forcibly switched to a closed state, the first opening / closing member can be opened by returning the pressure in the air chamber to atmospheric pressure. Therefore, it is possible to provide an air chamber to forcibly close and open the valve, while adjusting the output pressure P2 to the first set pressure SP1. Similarly, in the second valve mechanism 28, a force in the valve closing direction due to atmospheric pressure, a biasing force (tensile force) in the second direction D2 (valve opening direction) due to the second biasing portion 87, and a force in the valve closing direction due to the negative pressure of the fluid in the second upstream chamber 81 are applied to both surfaces of the third flexible membrane 84. Even after the valve is forcibly closed, the second opening / closing portion can be opened by returning the pressure in the air chamber to atmospheric pressure. Therefore, it is possible to provide an air chamber to forcibly close and open the valve, while adjusting the output pressure P2 to the first set pressure SP1.

[0128] (1-4) In the first valve mechanism 21, the first shaft 72 is inserted into the second flexible membrane 65. One end of the first shaft 72 is connected to the first flexible membrane 64, and the other end of the first shaft 72 is connected to the first valve unit 73. With this configuration, the first shaft 72 can move in accordance with the first flexible membrane 64 and the second flexible membrane 65. This improves the responsiveness of the first valve unit 73, which opens and closes in response to changes in the pressure difference between the first upstream chamber 61 and the first downstream chamber 62. Furthermore, in the second valve mechanism 28, the second shaft 92 is inserted into the fourth flexible membrane 85. One end of the second shaft 92 is connected to the third flexible membrane 84, and the other end of the second shaft 92 is connected to the second valve unit 93. With this configuration, the second shaft 92 can move in accordance with the third flexible membrane 84 and the fourth flexible membrane 85. The response of the second valve portion 93, which opens and closes in response to changes in the pressure difference between the second upstream chamber 81 and the second downstream chamber 82, is improved.

[0129] (1-5) The first valve mechanism 21 is in an adjustment state for adjusting pressure when atmospheric pressure is acting on the outside of the first flexible membrane 64. The first valve mechanism 21 can be put into a state for adjusting pressure simply by opening the outside of the first flexible membrane 64 (first air chamber 63) to the atmosphere. This makes it easy to control the pressure of the liquid by the first valve mechanism 21. Furthermore, the second valve mechanism 28 is in an adjustment state for adjusting pressure when atmospheric pressure is acting on the outside of the third flexible membrane 84. The second valve mechanism 28 can be put into a state for adjusting pressure simply by opening the outside of the third flexible membrane 84 (second air chamber 83) to the atmosphere. This makes it easy to control the pressure of the liquid by the second valve mechanism 28.

[0130] (1-6) The liquid flow device 13 (first liquid flow section 13A) includes a first valve mechanism 21, a first liquid storage section 17, a first liquid flow path 23, a pressure fluctuation mechanism 35, and a pressure pump 20, which is an example of a pressure generating section. The pressure fluctuation mechanism 35 fluctuates the pressure of the fluid flowing through the first liquid flow path 23. The pressure pump 20 applies pressure to the inside of the first air chamber 63. With this configuration, the pressure and flow rate in the first liquid flow path 23 can be changed according to the control situation, causing the liquid to flow.

[0131] (1-7) The liquid flow device 13 (second liquid flow section 13B) includes a second valve mechanism 28, a second liquid storage section 24, a second liquid flow path 26, a pressure fluctuation mechanism 35, and a decompression pump 27, which is an example of a pressure generating section. The pressure fluctuation mechanism 35 fluctuates the pressure of the fluid flowing through the second liquid flow path 26. The decompression pump 27 applies pressure to the second air chamber 83. With this configuration, the pressure and flow rate in the second liquid flow path 26 can be changed according to the control situation, causing the liquid to flow.

[0132] (1-8) The liquid flow device 13 includes a first valve mechanism 21 and a second valve mechanism 28. The first valve mechanism 21 includes a first inlet 68, a first upstream chamber 61, a first communication port 69, a first downstream chamber 62, a first air chamber 63, a first opening / closing unit 66, a first biasing unit 67, a first shaft 72, and a first valve unit 73. The second valve mechanism 28 includes a second inlet 89, a second upstream chamber 81, a second communication port 90, a second downstream chamber 82, a second air chamber 83, a second opening / closing unit 86, a second biasing unit 87, a second shaft 92, and a second valve unit 93. Thus, the multiple valve mechanisms 21 and 28 can change the pressure and flow rate at multiple points in the liquid flow path 19 according to the control status. For example, normal circulation, a standby state, a stopped state, a power-off state, forced circulation, and the like can be performed.

[0133] (1-9) The liquid ejection device 11 includes a liquid flow device 13 and a liquid ejection unit 12 provided in a liquid flow path 19. This allows the liquid to flow by changing the pressure and flow rate according to the control situation. For example, the liquid ejection device 11 can perform normal circulation, standby state, stopped state, power-off state, cleaning, liquid removal from the liquid ejection unit 12, and forced circulation.

[0134] (1-10) The liquid ejection device 11 includes a liquid flow device 13 and a liquid ejection unit 12. The liquid flow path 19 has a first liquid flow path 23 and a second liquid flow path 26. The first valve mechanism 21 is located in the first liquid flow path 23, and the second valve mechanism 28 is located in the second liquid flow path 26. Therefore, by switching the valve mechanisms 21, 28 through control of air pressure, the pressure of the liquid flowing into the liquid ejection unit 12 and the pressure of the liquid flowing out of the liquid ejection unit 12 can be changed to a pressure and flow rate that corresponds to the control situation.

[0135] (1-11) The liquid ejection device 11 includes a first liquid storage section 17, a second liquid storage section 24, a first liquid flow path 23, a second liquid flow path 26, a pressure fluctuation mechanism 35, a first pressure adjustment valve 36, a second pressure adjustment valve 37, and a switching section 38. The first pressure adjustment valve 36 is switchable between a first adjustment state and a first open state. In the first adjustment state, the pressure downstream of the first pressure adjustment valve 36 in the first liquid flow path 23 is adjusted to a first set pressure SP1. In the first open state, the first liquid flow path 23 is maintained open, thereby adjusting the pressure downstream of the first pressure adjustment valve 36 to a pressure higher than the first set pressure SP1. The second pressure adjustment valve 37 is switchable between a second adjustment state and a second open state. In the second adjustment state, the pressure upstream of the second pressure adjustment valve 37 in the second liquid flow path 26 is adjusted to a second set pressure SP2. In the second open state, the second liquid flow path 26 is kept open, and the pressure upstream of the second pressure regulating valve 37 is adjusted to a pressure lower than the second set pressure SP2. Therefore, by providing pressure regulating valves 36, 37 that can be switched between an adjusted state and an open state and using this configuration for circulation, it is possible to circulate the fluid at a pressure and flow rate that suits the control situation.

[0136] (1-12) The first pressure regulating valve 36 and the second pressure regulating valve 37 switch their states when pressure is applied by the switching unit 38. With this configuration, the states can be easily switched when pressure is applied.

[0137] (1-13) The first pressure regulating valve 36 can be switched to a first closed state in which the first liquid flow path 23 is kept closed. The second pressure regulating valve 37 can be switched to a second closed state in which the second liquid flow path 26 is kept closed. With this configuration, the liquid flow path 19 can be closed in a control situation in which supply to / recovery from the liquid ejection unit 12 is not performed.

[0138] (1-14) The switching unit 38 includes a first gas flow path 41 connected to the first pressure adjustment valve 36 and a second gas flow path 42 connected to the second pressure adjustment valve 37. The switching unit 38 includes a third gas flow path 43 through which pressurized gas flows and a fourth gas flow path 44 through which decompressed gas flows. Furthermore, the switching unit 38 includes a switching mechanism 46 that switches the connection states of the gas flow paths 41 to 44. With this configuration, the switching unit 38 can be shared by the first pressure adjustment valve 36 and the second pressure adjustment valve 37, allowing the liquid discharger 11 to be made smaller.

[0139] (1-15) The pressure fluctuation mechanism 35 has a pressure pump 20 that pressurizes the first liquid storage section 17 and a pressure reduction pump 27 that depressurizes the second liquid storage section 24. Gas pressurized by the pressure pump 20 flows through the third gas flow path 43, and gas depressurized by the pressure reduction pump 27 flows through the fourth gas flow path 44. With this configuration, the pressure applied by the pressure pump 20 for circulation and the pressure reduction by the pressure reduction pump 27 for circulation are used as the pressures used to switch the states of the pressure adjustment valves 36, 37, thereby simplifying the configuration. This allows the liquid discharge device 11 and the liquid flow device 13 to be made smaller.

[0140] (1-16) The first pressure regulating valve 36 is in a first open state when the first gas flow path 41 and the third gas flow path 43 are connected. The second pressure regulating valve 37 is in a second open state when the second gas flow path 42 and the fourth gas flow path 44 are connected. With this configuration, the pressure regulating valves 36 and 37 can be opened by connecting the first gas flow path 41 and the third gas flow path 43 and connecting the second gas flow path 42 and the fourth gas flow path 44 depending on the control situation. This allows the liquid flow paths 23 and 26 connected to the liquid discharge unit 12 to be opened. Therefore, it is possible to circulate the fluid at a pressure other than the set pressures SP1 and SP2.

[0141] (1-17) The first pressure regulating valve 36 is switchable to a first closed state, which maintains the first liquid flow path 23 closed. The first pressure regulating valve 36 is in the first closed state when the first gas flow path 41 and the fourth gas flow path 44 are connected. The second pressure regulating valve 37 is switchable to a second closed state, which maintains the second liquid flow path 26 closed. The second pressure regulating valve 37 is in the second closed state when the second gas flow path 42 and the third gas flow path 43 are connected. With this configuration, at least one of the first liquid flow path 23 and the second liquid flow path 26 can be closed by connecting the first gas flow path 41 and the fourth gas flow path 44 and connecting the second gas flow path 42 and the third gas flow path 43 depending on the control situation. The liquid ejection device 11 can be set to a state suitable for, for example, a standby state, a stopped state, or a power-off state, or can be used for operations such as cleaning or draining liquid from the liquid ejection unit 12.

[0142] (1-18) The switching unit 38 has a fifth gas flow path 45 that is open to the atmosphere. The first pressure adjustment valve 36 is in the first adjustment state when the first gas flow path 41 and the fifth gas flow path 45 are connected. The second pressure adjustment valve 37 is in the second adjustment state when the second gas flow path 42 and the fifth gas flow path 45 are connected. With this configuration, the adjustment state can be achieved simply by opening to the atmosphere. Therefore, switching from the open state to the adjustment state can be easily performed.

[0143] [Second embodiment] Next, the liquid ejection device 11, liquid flowing device 13, and valve mechanism in the second embodiment will be described with reference to Figures 11 to 15. In the first embodiment, the valve mechanisms 21, 28 were configured to be switched by the action of pressure on the air chambers 63, 83, but the valve mechanisms 21, 28 in this embodiment are configured to be switched by the action of magnetic force. Note that the same components as in the first embodiment will be given the same reference numerals and their description will be omitted, and only the different components will be described.

[0144] 11, the configuration of the liquid ejection device 11 is basically the same as that of the first embodiment. Only the configuration for switching the states of the valve mechanisms 21 and 28 differs from that of the first embodiment. That is, the liquid ejection device 11 includes a liquid flowing device 13 and a liquid ejection unit 12. The liquid flow path 19 has a first liquid flow path 23 whose downstream end is connected to the liquid ejection unit 12, and a second liquid flow path 26 whose upstream end is connected to the liquid ejection unit 12. The liquid flowing device 13 includes a first valve mechanism 21, which is an example of a valve mechanism, and a second valve mechanism 28, which is also an example of a valve mechanism. The first valve mechanism 21 is a first pressure adjustment valve 36 that functions as a pressurization adjustment valve. The second valve mechanism 28 is a second pressure adjustment valve 37 that functions as a negative pressure adjustment valve.

[0145] The liquid flow device 13 includes a first liquid flow section 13A and a second liquid flow section 13B. Similar to the first embodiment, the first liquid flow section 13A includes a first valve mechanism 21, a first liquid storage section 17, a liquid flow path 19 (first liquid flow path 23), and a pressure fluctuation mechanism 35.

[0146] The first liquid flow unit 13A of the present embodiment includes a first magnetic force generating unit 110, which is an example of a magnetic force generating unit. The liquid ejection device 11 includes a switching unit 38 that switches the state of the first pressure adjustment valve 36. The switching unit 38 of the present embodiment includes the first magnetic force generating unit 110. The state of the first pressure adjustment valve 36 is switched by the application of magnetic force by the switching unit 38.

[0147] The first magnetic force generator 110 applies the generated magnetic force to the first opening / closing unit 66 (see FIG. 12) of the first valve mechanism 21. In this embodiment, the first opening / closing unit 66 of the first valve mechanism 21 has magnetic force. The state of the first pressure regulating valve 36 is switched by the action of the magnetic force from the first magnetic force generator 110. The first pressure regulating valve 36 can be switched among a first regulating state, a first open state, and a first closed state by the action of the magnetic force.

[0148] Similar to the first embodiment, the second liquid flow section 13B includes a second valve mechanism 28, a second liquid storage section 24, a liquid flow path 19 (second liquid flow path 26), and a pressure fluctuation mechanism 35. The second liquid flow section 13B of this embodiment includes a second magnetic force generation section 120, which is an example of a magnetic force generation section. The liquid ejection device 11 includes a switching section 38 that switches the state of the second pressure adjustment valve 37. The switching section 38 of this embodiment includes the second magnetic force generation section 120. The state of the second pressure adjustment valve 37 is switched by the application of magnetic force by the switching section 38.

[0149] The second magnetic force generator 120 applies the generated magnetic force to the second opening / closing unit 86 (see FIG. 13) of the second valve mechanism 28. In this embodiment, the second opening / closing unit 86 of the second valve mechanism 28 has magnetic force. The state of the second pressure regulating valve 37 is switched by the action of the magnetic force from the second magnetic force generator 120. The second pressure regulating valve 37 can be switched among a second regulating state, a second open state, and a second closed state by the magnetic force.

[0150] As shown in FIG. 11, the liquid ejection device 11 and the liquid flow device 13 are equipped with a magnetic force type switching unit 38, and therefore do not have the switching mechanism 46 that applies pressure to the air chambers 63, 83 or the gas flow paths 41, 42, etc., as in the first embodiment.

[0151] Next, the configuration of the valve mechanisms 21, 28 of this embodiment will be described with reference to Figures 12 to 15. The basic configuration of the first valve mechanism 21 and the second valve mechanism 28 is the same as that of the first embodiment. The difference is that the force used to switch the states of the first valve mechanism 21 and the second valve mechanism 28 is magnetic force instead of air pressure.

[0152] 12, the first valve mechanism 21 has the same configuration as the first embodiment, including a first upstream chamber 61, a first downstream chamber 62, a first flexible membrane 64, a second flexible membrane 65, a first opening / closing unit 66, and a first biasing unit 67. The first opening / closing unit 66 has a first shaft 72 and a first valve unit 73. The first shaft 72 is inserted into the second flexible membrane 65. One end of the first shaft 72 is connected to the first flexible membrane 64. The other end of the first shaft 72 is connected to the first valve unit 73.

[0153] The first opening / closing unit 66 in this embodiment has a magnetic force. The first valve mechanism 21 may have a magnet 105 in the first opening / closing unit 66. When no external magnetic force is acting on the first opening / closing unit 66, the first valve mechanism 21 is in an adjustment state in which the pressure is adjusted. The first valve mechanism 21 is switched to any one of a first adjustment state, a first open state, and a first closed state by the first opening / closing unit 66 being displaced by the external magnetic force.

[0154] A first magnetic force generating unit 110 that applies a magnetic force to the magnet 105 of the first opening / closing unit 66 is disposed on the outside of the housing of the first valve mechanism 21. The first magnetic force generating unit 110 is disposed at an outer position facing the magnet 105 provided in the first opening / closing unit 66 with respect to the first valve mechanism 21.

[0155] 13, the second valve mechanism 28 has the same configuration as in the first embodiment, including a second upstream chamber 81, a second downstream chamber 82, a third flexible membrane 84, a fourth flexible membrane 85, a second opening / closing portion 86, and a second biasing portion 87. The second opening / closing portion 86 has a second shaft portion 92 and a second valve portion 93. The second shaft portion 92 is inserted into the fourth flexible membrane 85. One end of the second shaft portion 92 is connected to the third flexible membrane 84. The other end of the second shaft portion 92 is connected to the second valve portion 93.

[0156] The second opening / closing unit 86 has a magnetic force. The second valve mechanism 28 may have a magnet 106 in the second opening / closing unit 86. When no external magnetic force is acting on the second opening / closing unit 86, the second valve mechanism 28 is in a second adjustment state in which the pressure is adjusted. The second valve mechanism 28 is switched between a second open state and a second closed state by the second opening / closing unit 86 being displaced by the action of an external magnetic force.

[0157] A second magnetic force generating unit 120 that applies a magnetic force to the magnet 106 of the second opening / closing unit 86 is disposed on the outside of the housing of the second valve mechanism 28. The second magnetic force generating unit 120 is disposed at an outer position facing the magnet 106 provided in the second opening / closing unit 86 with respect to the second valve mechanism 28.

[0158] Here, the magnetic force generation units 110, 120 may have the same configuration. The magnetic force generation units 110, 120 may employ either of two different types of configurations for applying magnetic force. One type of the magnetic force generation units 110, 120 is a magnet movement type in which the magnetic force acting on the magnets 105, 106 is switched by moving the magnets closer to or further away from each other. The other type is an electromagnet type in which the magnetic force acting on the magnets 105, 106 is generated by an electromagnet.

[0159] <Magnetic force generating unit using the moving magnet method> First, the moving magnet type magnetic force generators 110 and 120 will be described with reference to Fig. 12 and Fig. 13. Note that the configurations of the magnetic force generators 110 and 120 in Fig. 12 and Fig. 13 are generally the same, so the description will be made with reference to Fig. 12.

[0160] As shown in Fig. 12, the first valve mechanism 21 includes a first opening / closing part 66 having magnetic force. The first valve mechanism 21 shown in Fig. 2 includes the air chamber 63, but the first valve mechanism 21 includes an opening / closing part 66 having magnetic force instead of the air chamber 63.

[0161] 2, the first valve mechanism 21 includes a first upstream chamber 61, a first downstream chamber 62, a first flexible membrane 64, a second flexible membrane 65, a first opening / closing unit 66, and a first biasing unit 67. The first opening / closing unit 66 has a first shaft portion 72 and a first valve portion 73. The first opening / closing unit 66 has magnetic force.

[0162] More specifically, a magnet 105 is fixed to the first valve portion 73 that constitutes the first opening / closing portion 66. A first magnetic force generating portion 110 that applies a magnetic force to the magnet 105 is disposed in a position facing the outside of the surface portion opposite the first flexible membrane 64 in the housing that forms the first downstream chamber 62 of the first valve mechanism 21.

[0163] The first magnetic force generation unit 110 includes a moving body 110S, two magnets 112 and 113 fixed to the moving body 110S, a drive source 114, and a power transmission mechanism 115. The moving body 110S is configured to be movable along a predetermined direction. The predetermined direction may be a direction intersecting the movement direction of the first opening / closing unit 66. In the example shown in FIG. 12, when the movement direction of the first opening / closing unit 66 is the Z direction, the predetermined direction is, for example, a direction along the XY plane. When the moving body 110S moves in the predetermined direction, the two magnets 112 and 113 can move closer to or away from the magnet 105.

[0164] The driving source 114 moves the moving body 110S in a predetermined direction. The driving source 114 is, for example, a motor or a cylinder. The power transmission mechanism 115 is configured to be able to transmit the power of the drive source 114 to the moving body 110S. Examples of the power transmission mechanism 115 include a link mechanism, a belt power transmission mechanism, a rack and pinion mechanism, etc. When the drive source is configured to move directly, such as a cylinder, the power transmission mechanism 115 may be eliminated, and the tip of a direct-acting movable body, such as a piston rod of the cylinder, may be directly fixed to the moving body 110S.

[0165] The two magnets 112, 113 may be arranged at positions spaced apart from each other in the direction of movement of the movable body 110S. The movable body 110S is movable between an adjustment position, an open position, and a closed position. Here, the position facing the magnet 105 is referred to as the action position PT. The position of the movable body 110S shown in FIG. 12 is the adjustment position. The adjustment position is a position where a position corresponding to the gap 111 between the two magnets 112, 113 is arranged at the action position PT. The open position is a position where the magnet 112 is arranged at the action position PT. The closed position is a position where the magnet 113 is arranged at the action position PT.

[0166] When the movable body 110S is in the adjustment position where the gap 111 between the first magnet 112 and the second magnet 113 is located at the operating position PT shown in FIG. 12 , the gap 111 faces the magnet 105. The magnetic force of the magnetic force generating unit 110 does not act on the magnet 105 of the first valve unit 73. Therefore, the first valve mechanism 21 is in the adjustment state because no magnetic force acts on the first opening / closing unit 66. A large positive input pressure P1 acts on the first inlet 68. The first opening / closing unit 66 opens and closes the first communication port 69 so that the output pressure P2 acting on the first outlet 70 is adjusted to the first set pressure SP1.

[0167] When the movable body 110S moves to the open position where the first magnet 112 is located at the operative position PT, an attractive force is generated between the magnet 105 and the first magnet 112. This attractive force moves the first valve portion 73 to the open position where it opens the first communication port 69. In this way, the first valve mechanism 21 is forcibly opened.

[0168] On the other hand, when the movable body 110S moves to the closed position where the second magnet 113 is located at the operative position PT, a magnetic repulsive force is generated between the second magnet 113 and the magnet 105. This repulsive force moves the first valve portion 73 to the closed position where it closes the first communication port 69. In this way, the first valve mechanism 21 is forcibly closed.

[0169] The second valve mechanism 28 shown in FIG. 13 is similar to the second valve mechanism 28 shown in FIG. 3, except that the second opening / closing portion 86 has a magnet 105 instead of the second air chamber 83. 3, the second valve mechanism 28 includes a second upstream chamber 81, a second downstream chamber 82, a third flexible membrane 84, a fourth flexible membrane 85, a second opening / closing portion 86, and a second biasing portion 87. The second opening / closing portion 86 includes a second shaft portion 92 and a second valve portion 93. The second opening / closing portion 86 has magnetic force.

[0170] 13, a magnet 106 is fixed to the second valve portion 93. A magnetic force generating unit 110 is provided on the outer surface of the housing of the second valve mechanism 28 on the side opposite to the third flexible membrane 84. The magnetic force generating unit 110 has the same configuration as the magnetic force generating unit 110 shown in FIG. 12, and includes a moving body 110S, a driving source 114, and a power transmission mechanism 115.

[0171] When the movable body 110S is in the adjustment position where the gap 111 between the first magnet 112 and the second magnet 113 is at the operating position PT shown in Figure 13, the magnetic force of the magnetic force generating unit 110 does not act on the magnet 106 of the second valve unit 93. Therefore, the second valve mechanism 28 is in the adjustment state. The second opening / closing unit 86 opens and closes the second communication port 90 so that the output pressure P3 is adjusted to the second set pressure SP2.

[0172] When the movable body 110S moves to the closed position where the first magnet 112 is located at the operating position PT, the magnetic attraction force acting between the magnet 106 and the first magnet 112 moves the second valve portion 93 to the closed position where it closes the first communication port 69. In other words, the second valve mechanism 28 is forcibly closed.

[0173] On the other hand, when the movable body 110S moves to the open position where the second magnet 113 is located at the operative position PT, the second valve portion 93 moves to the open position where it opens the second communication port 90 due to the magnetic repulsive force acting between the second magnet 113 and the magnet 106. In this way, the second valve mechanism 28 is forcibly opened.

[0174] <Electromagnetic valve mechanism> The configuration of the valve mechanisms 21, 28 equipped with electromagnetic magnetic force generators 110, 120 will be described with reference to Figures 14 and 15. Note that the electromagnetic magnetic force generators 110, 120 differ from the configurations shown in Figures 12 and 13, but the configuration of the valve mechanisms 21, 22 themselves is the same as that of the magnet moving type. Therefore, the following description will focus on the configuration of the electromagnetic magnetic force generators 110, 120.

[0175] As shown in FIG. 14, the configuration of the first valve mechanism 21 is basically the same as that shown in FIG. 12. The first opening / closing unit 66 has magnetic force. In the example shown in FIG. 14, a magnet 105 is fixed to the first valve unit 73. The first valve mechanism 21 includes a first magnetic force generating unit 110 on the outer surface of the housing that forms the first downstream chamber 62, on the side opposite the first flexible membrane 64. The first magnetic force generating unit 110 includes a coil 121 that forms an electromagnet, a battery 122 that generates current in the coil 121, and a switching circuit 123 that switches the direction of the current flowing through the coil 121. The magnet 105 is located on an extension of the axis of the coil 121.

[0176] When no current flows through the coil 121, the coil 121 does not generate a magnetic force. As a result, the first valve mechanism 21 is in the first adjustment state. The first opening / closing unit 66 opens and closes the first communication port 69 so that the output pressure P2 acting on the first outlet 70 is adjusted to the first set pressure SP1.

[0177] When a current flows through the coil 121 in the first direction, a magnetic force is generated at the end of the coil 121 on the magnet 105 side, causing a repulsive force between the magnet 105 and the coil 121. This repulsive force causes the first valve portion 73 to move to a closed position that closes the first communication port 69. In this way, the first valve mechanism 21 enters a first closed state in which the closed state is maintained.

[0178] On the other hand, when a current flows through the coil 121 in a second direction opposite to the first direction, a magnetic force is generated at the end of the coil 121 on the magnet 105 side, causing an attractive force (attractive force) between the magnet 105 and the coil 121. This attractive force moves the first valve portion 73 to an open position that opens the first communication port 69. In this way, the first valve mechanism 21 enters a first open state in which it remains open.

[0179] The second valve mechanism 28 shown in Fig. 15 has the same configuration as the second valve mechanism 28 shown in Fig. 13, and the second opening / closing unit 86 has magnetic force. A magnet 106 is fixed to the second valve unit 93. The second valve mechanism 28 includes a second magnetic force generating unit 120, which has the same configuration as the first magnetic force generating unit 110 shown in Fig. 14, on the outer side of the surface of the housing opposite the third flexible membrane 84. The second magnetic force generating unit 120 includes a coil 121, a battery 122, and a switching circuit 123.

[0180] When no current flows through the coil 121, the coil 121 does not generate a magnetic force. As a result, the second valve mechanism 28 is in an adjustment state. In the adjustment state, the second opening / closing part 86 opens and closes the second communication port 90 so that the output pressure P3 is adjusted to the second set pressure SP2.

[0181] When a current flows through the coil 121 in the first direction, a repulsive force is generated between the magnet 105 and the coil 121. This repulsive force moves the second valve portion 93 to an open position that opens the second communication port 90. In this way, the second valve mechanism 28 is set to the second open state.

[0182] On the other hand, when a current flows through the coil 121 in a second direction, which is opposite to the first direction, an attractive force is generated between the magnet 105 and the coil 121. This attractive force moves the second valve portion 93 to a closed position that closes the second communication port 90. In this way, the second valve mechanism 28 is set to the second closed state.

[0183] <Operation of the Second Embodiment> Next, the operation of the second embodiment will be described. The control unit 100 controls the first magnetic force generation unit 110 and the second magnetic force generation unit 120. The state of the first pressure regulation valve 36 is switched by the action of the magnetic force generated by the first magnetic force generation unit 110. The first pressure regulation valve 36 is switched to any one of a first regulation state, a first open state, and a first closed state. The state of the second pressure regulation valve 37 is switched by the action of the magnetic force generated by the second magnetic force generation unit 120. The second pressure regulation valve 37 is switched to any one of a second regulation state, a second open state, and a second closed state.

[0184] The liquid ejection device 11 performs various operations depending on the combination of the states of the first pressure adjustment valve 36 and the second pressure adjustment valve 37. The control unit 100 switches the first pressure adjustment valve 36 and the second pressure adjustment valve 37 to the same states as those of the first embodiment shown in Figures 5 to 10. As a result, the liquid ejection device 11 performs the operations of normal circulation (Figure 5), standby state and stopped state (Figure 6), power-off state (Figure 7), cleaning (Figure 8), draining liquid from the liquid ejection unit 12 (Figure 9), and forced circulation (Figure 10), just like the first embodiment.

[0185] <Effects of the second embodiment> The effects of this embodiment will be described. (2-1) The first opening / closing unit 66 of the first valve mechanism 21 has magnetic force, so that magnetic force can be applied. Therefore, the state of the first opening / closing unit 66 can be switched between a first adjustment state in which the output pressure P2 is adjusted to the first set pressure SP1, and a first open state in which the liquid flow path 19 is kept open to adjust the pressure to a pressure higher than the first set pressure SP1. Therefore, the pressure and flow rate can be changed according to the control situation, allowing the liquid to flow.

[0186] (2-2) The second opening / closing unit 86 of the second valve mechanism 28 has magnetic force, and thus can exert magnetic force. Therefore, the state of the second opening / closing unit 86 can be switched between a second adjustment state in which the output pressure P3 is adjusted to the second set pressure SP2, and an open state in which the liquid flow path 19 is kept open to adjust the pressure to a pressure higher than the second set pressure SP2. Therefore, the pressure and flow rate can be changed according to the control situation, allowing the liquid to flow.

[0187] (2-3) The valve mechanisms 21, 28 can be brought into an adjusting state for adjusting the pressure simply by eliminating the magnetic force acting from the outside on the opening / closing portions 66, 86. This makes it easier to control the pressure of the liquid by the valve mechanisms 21, 28.

[0188] (2-4) The liquid flowing device 13 (first liquid flowing section 13A) includes a first magnetic force generating section 110 that applies a magnetic force to the first opening / closing section 66 of the first valve mechanism 21. Therefore, by applying a magnetic force to the first opening / closing section 66, the pressure and flow rate can be changed according to the control situation, and the liquid can be caused to flow.

[0189] (2-5) The liquid flow device 13 (second liquid flow section 13B) includes a second magnetic force generating section 120 that applies a magnetic force to the second opening / closing section 86 of the second valve mechanism 28. Therefore, by applying a magnetic force to the second opening / closing section 86, the pressure and flow rate can be changed according to the control situation, and the liquid can be caused to flow.

[0190] (2-6) The liquid flow device 13 includes a first valve mechanism 21 having a first opening / closing part 66 having a magnetic force, and a second valve mechanism 28 having a second opening / closing part 86 having a magnetic force. By applying magnetic force to the opening / closing parts 66, 86, the pressure and flow rate can be changed according to the control situation, allowing the liquid to flow.

[0191] (2-7) The liquid discharger 11 includes a liquid flow device 13 having magnetic force generating units 110 and 120. Therefore, the pressure of the liquid flowing into the liquid discharger 12 and the pressure of the liquid flowing out of the liquid discharger 12 can be changed to a pressure and flow rate according to the control situation.

[0192] (2-8) The states of the first pressure regulating valve 36 and the second pressure regulating valve 37 are switched by the application of magnetic force by the switching unit 38. Therefore, the application of magnetic force makes it possible to easily switch the states of the first pressure regulating valve 36 and the second pressure regulating valve 37.

[0193] [Third embodiment] Next, a third embodiment of the valve mechanism, liquid flowing device, and liquid ejection device will be described with reference to the drawings. Note that the third embodiment differs from the first embodiment in the liquid flowing device. Since the third embodiment is otherwise substantially the same as the first embodiment, the same components are designated by the same reference numerals and redundant description will be omitted.

[0194] 16, the liquid ejection device 11 includes a liquid flowing device 13, similar to the first embodiment. The liquid flowing device 13 includes a pressure fluctuation mechanism 35 and a switching unit 38. In the first embodiment, the pressure fluctuation mechanism 35 was connected to the liquid storage units 17, 24. The pressure fluctuated by the pressure fluctuation mechanism 35 was introduced into a switching mechanism 46 that constitutes the switching unit 38 via the liquid storage units 17, 24.

[0195] In this embodiment, the pressure fluctuation mechanism 35 is connected to a switching mechanism 46 that constitutes the switching unit 38. The pressure fluctuation mechanism 35 has a pressure pump 20 and a pressure release valve 22. The pressure fluctuation mechanism 35 has a pressure reduction pump 27 and a negative pressure release valve 29.

[0196] The switching unit 38 has a first gas flow path 41, a second gas flow path 42, a third gas flow path 43, a fourth gas flow path 44, a fifth gas flow path 45, a sixth gas flow path 47, and a seventh gas flow path 48. These gas flow paths 41 to 45, 47, and 48 are connected to a switching mechanism 46. The pressure pump 20 is connected to the switching mechanism 46 via the sixth gas flow path 47. The pressure release valve 22 is connected to the switching mechanism 46 via gas flow paths 47a and the like. The pressure reduction pump 27 is connected to the switching mechanism 46 via the seventh gas flow path 48. The negative pressure release valve 29 is connected to the switching mechanism 46 via gas flow paths 48a and the like.

[0197] The pressure pump 20 is configured to be able to pressurize the switching mechanism 46. The pressure reducing pump 27 is configured to be able to depressurize the switching mechanism 46. The switching mechanism 46 is capable of introducing a positive pressure pressurized by the pressure pump 20, a negative pressure reduced by the pressure reducing pump 27, and atmospheric pressure through the fifth gas flow path 45. The switching mechanism 46 is configured to be able to individually switch the pressures output to the first gas flow path 41, the second gas flow path 42, the third gas flow path 43, and the fourth gas flow path 44. The switching mechanism 46 is, for example, a selector valve.

[0198] As described above, in this embodiment, the pressure fluctuation mechanism 35 is connected to the switching mechanism 46, and the pressure fluctuation mechanism 35 switches between the pressure applied to the liquid storage portions 17, 24 and the pressure introduced into the air chambers 63, 83 of the two pressure adjustment valves 36, 37 via the switching mechanism 46. The other configurations are the same as those of the first embodiment.

[0199] As in the first embodiment, the control unit 100 controls the liquid discharge unit 12, the pumps 20, 27, and 59, the liquid delivery unit 31, the switching mechanism 46, and the like. <Configuration of Switching Unit 38> Next, the configuration of the switching mechanism 46 will be described with reference to FIG. 17. As shown in FIG. 17, the switching mechanism 46 constituting the switching unit 38 includes four valve groups, each of which includes a first valve 101, a second valve 102, and a third valve 103. The three valves 101 to 103 constituting the valve groups have the same configuration as the switching mechanism 46 of the first embodiment. The three valves 101 to 103 constituting the four valve groups are controlled by a control unit 100. The four valve groups are connected to the first gas flow path 41, the second gas flow path 42, the third gas flow path 43, and the fourth gas flow path 44, respectively. In other words, the three valves 101 to 103 constituting the four valve groups are connected to the common gas flow paths 41 to 44, respectively. Furthermore, the upstream end of each first valve 101 is connected to the pressure pump 20 via the sixth gas flow path 47. The upstream end of each second valve 102 is connected to the fifth gas flow path 45. The upstream end of each third valve 103 is connected to the decompression pump 27 through a seventh gas flow path 48 .

[0200] The pressure of the gas in each gas flow path 41-44 is selected depending on which of the first valve 101, second valve 102, and third valve 103 for that gas flow path 41-44 is opened. For example, the pressure of the gas in the first gas flow path 41 becomes positive when the first valve 101 is opened. The pressure of the gas in the first gas flow path 41 becomes atmospheric pressure when the second valve 102 is opened. The pressure of the gas in the first gas flow path 41 becomes negative pressure when the third valve 103 is opened. The pressure of the gas in the other three gas flow paths 42-44 is selected depending on which of the three valves 101-103 is opened.

[0201] In this way, the switching mechanism 46 switches the pressure of the gas supplied to the first pressure adjustment valve 36 through the first gas flow path 41 to any one of positive pressure, atmospheric pressure, and negative pressure. The switching mechanism 46 switches the pressure of the gas supplied to the second pressure adjustment valve 37 through the second gas flow path 42 to any one of positive pressure, atmospheric pressure, and negative pressure. In addition, the switching mechanism 46 switches the pressure of the gas supplied to the first liquid storage portion 17 through the third gas flow path 43 to any one of positive pressure, atmospheric pressure, and negative pressure. The switching mechanism 46 switches the pressure of the gas supplied to the second liquid storage portion 24 through the fourth gas flow path 44 to any one of positive pressure, atmospheric pressure, and negative pressure.

[0202] <Operation of the liquid ejection device 11> Next, the operation of the liquid ejection device 11 will be described with reference to Figures 18 to 27. Note that in Figures 18 to 27, similar to Figure 5 of the first embodiment, the three states of the first pressure regulating valve 36 and the second pressure regulating valve 37 are distinguished by a combination of white and black in the valve symbols inside them. The three states include an adjusting state, a closed state, and an open state.

[0203] The switching mechanism 46 is controlled by the control unit 100 (see FIG. 16). The switching mechanism 46 is supplied with positive pressure (pressurized air) from the pressure pump 20, negative pressure (decompressed air) from the decompression pump 27, and atmospheric pressure through the fifth gas flow path 45. The switching mechanism 46 adjusts the pressures output to the gas flow paths 41-44 by switching the internal valves 101-103.

[0204] The switching mechanism 46 adjusts the pressure in the air chamber 63 of the first pressure regulating valve 36 through the first gas flow path 41. The switching mechanism 46 adjusts the pressure in the air chamber 83 of the second pressure regulating valve 37 through the second gas flow path 42. The switching mechanism 46 adjusts the pressure in the first liquid storage section 17 through the third gas flow path 43. The switching mechanism 46 adjusts the pressure in the second liquid storage section 24 through the fourth gas flow path 44.

[0205] FIG. 18 shows normal circulation. The first air chamber 63 of the first pressure adjustment valve 36 is open to the atmosphere through the first gas flow path 41. The second air chamber 83 of the second pressure adjustment valve 37 is open to the atmosphere through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in an adjustment state. The first pressure adjustment valve 36 adjusts the output pressure P2 to a first set pressure SP1. The second pressure adjustment valve 37 adjusts the output pressure P3 to a second set pressure SP2. Here, the first set pressure SP1 is a positive pressure, and the second set pressure SP2 is a negative pressure. The pressure inside the liquid ejection unit 12 is adjusted to a negative pressure. Alternatively, the relationship P2 > P3 may be satisfied. Therefore, the liquid flows in the supply direction Ds inside the liquid ejection unit 12, thereby circulating the liquid. A recording operation in which the liquid is ejected onto the medium 14 is performed while the liquid is circulating.

[0206] 19 shows the standby state and the stopped state. Negative pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in a closed state. Therefore, in the standby state and the stopped state, circulation of liquid to the liquid discharger 12 is stopped.

[0207] FIG. 20 shows the power-off state. In the power-off state, both the pressure pump 20 and the pressure-reducing pump 27 are stopped. The third gas flow path 43 and the fourth gas flow path 44 are open to the atmosphere. The first liquid storage section 17 and the second liquid storage section 24 are both open to the atmosphere. Before the power is turned off, the two first valves 101 in the switching mechanism 46 are closed. Negative pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, while the power is off, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are held in a closed state. Buffer chambers 41B and 42B, shown by two-dot chain lines in FIG. 20, may also be provided. The presence of the buffer chambers 41B and 42B allows both the first pressure regulating valve 36 and the second pressure regulating valve 37 to be maintained in a closed state for a long period of time.

[0208] 21 shows the cleaning state. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, the first pressure adjustment valve 36 is in an open state, and the second pressure adjustment valve 37 is in a closed state. The liquid supplied into the liquid discharger 12 is discharged from the nozzle 15. In other words, cleaning is performed to forcibly discharge the liquid from the nozzle 15 of the liquid discharger 12.

[0209] FIG. 22 shows a cleaning state using a method different from that shown in FIG. 21. By switching the switching mechanism 46, positive pressure is supplied to both the first liquid storage section 17 and the second liquid storage section 24. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in an open state. Liquid under positive pressure from the first liquid storage section 17 and liquid under positive pressure from the second liquid storage section 24 are supplied to the liquid discharge section 12. The liquid supplied into the liquid discharge section 12 is discharged from the nozzle 15. At this time, liquid from the first liquid storage section 17 and liquid from the second liquid storage section 24 are supplied to the liquid discharge section 12 from both sides. This increases the flow rate of liquid discharged from the nozzle 15. That is, stronger cleaning than that shown in FIG. 21 is performed.

[0210] 23 shows a state in which liquid is drained from the liquid discharger 12. By switching control of the switching mechanism 46, positive pressure is supplied to the first liquid storage section 17, and negative pressure is supplied to the second liquid storage section 24. Negative pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, the first pressure adjustment valve 36 is in a closed state, and the second pressure adjustment valve 37 is in an open state. With the first pressure adjustment valve 36 in a closed state, the liquid in the liquid discharger 12 is recovered into the second liquid storage section 24. In other words, the liquid in the liquid discharger 12 is forcibly drained into the second liquid storage section 24 through the second liquid flow path 26.

[0211] 24 shows a state in which liquid is drained from the liquid discharger 12 using a method different from that shown in FIG. 23 . By switching control of the switching mechanism 46, negative pressure is supplied to the first liquid storage portion 17, and positive pressure is supplied to the second liquid storage portion 24. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Positive pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, the first pressure adjustment valve 36 is in an open state, and the second pressure adjustment valve 37 is in a closed state. With the second pressure adjustment valve 37 in a closed state, the liquid in the liquid discharger 12 is recovered into the first liquid storage portion 17. In other words, the liquid in the liquid discharger 12 is forcibly drained into the first liquid storage portion 17 through the first liquid flow path 23.

[0212] FIG. 25 shows a state in which liquid is drained from the liquid discharger 12 using a method different from that shown in FIG. 24 . Negative pressure is supplied to both the first liquid storage section 17 and the second liquid storage section 24 through switching control of the switching mechanism 46. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in an open state. Liquid in the liquid discharger 12 is recovered into the first liquid storage section 17 through the first liquid flow path 23, and is also recovered into the second liquid storage section 24 through the second liquid flow path 26. In other words, liquid in the liquid discharger 12 is forcibly drained into the first liquid storage section 17 and the second liquid storage section 24 through the first liquid flow path 23 and the second liquid flow path 26 on both sides. Therefore, compared to the liquid extraction method shown in FIGS. 23 and 24, the liquid can be extracted from the liquid discharge portion 12 in a shorter time.

[0213] FIG. 26 illustrates forced circulation. Through switching control of the switching mechanism 46, positive pressure is supplied to the first liquid storage section 17, and negative pressure is supplied to the second liquid storage section 24. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in an open state. The liquid delivery section 31 is driven. Liquid is forcibly circulated through a path passing through the liquid ejection section 12. For example, air bubbles accumulated in the filter 141 (see FIG. 33) in the liquid ejection section 12 are forcibly expelled. In other words, in forced circulation, the amount of circulating liquid per unit time is increased compared to liquid circulation during printing, and the high flow rate of the liquid forcibly expels air bubbles accumulated in the filter 141. For example, forced circulation may be performed when a nozzle inspection device (not shown) detects clogging of the nozzle 15. Furthermore, forced circulation may be performed periodically or irregularly when not recording (for example, during standby).

[0214] FIG. 27 shows forced circulation using a method different from that shown in FIG. 26. In this example, the direction of liquid circulation is opposite to that shown in FIG. 26. By controlling the switching of the switching mechanism 46, negative pressure is supplied to the first liquid storage section 17 and positive pressure is supplied to the second liquid storage section 24. Positive pressure is introduced into the first air chamber 63 of the first pressure adjustment valve 36 through the first gas flow path 41. Negative pressure is introduced into the second air chamber 83 of the second pressure adjustment valve 37 through the second gas flow path 42. As a result, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in an open state. The liquid delivery section 31 is driven. Liquid is forced to circulate through a path passing through the liquid discharge section 12. Liquid supplied from the second liquid storage section 24 through the second liquid flow path 26 passes through the liquid discharge section 12 and is collected into the first liquid storage section 17 via the first liquid flow path 23. For example, by performing forced circulation in the direction opposite to the normal circulation direction, air bubbles accumulated in the filter 141 in the liquid discharger 12 are efficiently discharged. That is, in the method shown in Fig. 26, air bubbles accumulated in the filter 141 are removed by forcibly passing them through. In contrast, in the method shown in Fig. 27, air bubbles accumulated in the filter 141 are relatively easily removed by flowing them backward.

[0215] <Effects of the third embodiment> The effects of the third embodiment will be described below. In addition to the effects (1-1) to (1-18) of the first embodiment, the following effects can also be obtained.

[0216] (3-1) The pressurizing pump 20 is connected to the switching mechanism 46, and the switching mechanism 46 is connected to the first liquid storage section 17 through the third gas flow path 43. The decompression pump 27 is connected to the switching mechanism 46, and the switching mechanism 46 is connected to the second liquid storage section 24 through the fourth gas flow path 44. Thus, the switching mechanism 46 can pressurize and depressurize the first liquid storage section 17 through the third gas flow path 43. The switching mechanism 46 can pressurize and depressurize the second liquid storage section 24 through the fourth gas flow path 44. Therefore, it becomes possible to cause the liquid discharge device 11 and the liquid flow device 13 to perform more operations than in the first embodiment, or to select an operation to be adopted from a larger number of candidate operations. For example, it is possible to perform a backflow cleaning state (Figure 22), a backflow liquid drain state from the liquid discharge section 12 (Figure 24), a liquid drain from the liquid discharge section 12 in both forward and reverse flows (Figure 25), and a forced backflow circulation state (Figure 27), or these can be selected as the operation to be adopted.

[0217] [Fourth embodiment] Next, a fourth embodiment of the valve mechanism, liquid flow device, and liquid ejection device will be described with reference to the drawings. Note that the same components as those in the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0218] 28, a liquid ejection device 11 may include a liquid ejection unit 12 and a liquid flowing device 13 in which the liquid is not circulated. The liquid flowing device 13 may be of a type other than a liquid circulation type. The liquid flowing device 13 does not include components necessary for recovering the liquid, such as a second liquid storage unit 24, a second liquid flow path 26, and a second pressure adjustment valve 37.

[0219] That is, liquid discharger 11 includes liquid flowing device 13 and liquid discharger 12 provided in liquid flow path 19. Liquid flowing device 13 includes third valve mechanism 125 which is an example of a valve mechanism, liquid storage section 17, liquid flow path 19 which is an example of a fluid flow path, pressure fluctuation mechanism 35, and pressure pump 20 which is an example of a pressure generating section. Liquid flowing device 13 also includes switching section 38.

[0220] The liquid flow path 19 is composed of only the first liquid flow path 23 and does not have the second liquid flow path 26. The liquid reservoir 17 stores a fluid. The liquid flow path 19 is connected to the liquid reservoir 17. The third valve mechanism 125 is provided in the liquid flow path 19.

[0221] The pressure fluctuation mechanism 35 fluctuates the pressure of the liquid flowing through the liquid flow path 19. The pressure fluctuation mechanism 35 includes a pressure pump 20 and a pressure release valve 22. The pressure pump 20 pressurizes the liquid storage portion 17. When the pressure inside the liquid storage portion 17 exceeds a set pressurized pressure, the pressure release valve 22 releases air inside the first liquid storage portion 17 to the outside, thereby maintaining the pressure inside the liquid storage portion 17 at the set pressurized pressure.

[0222] The pressurizing pump 20, which is an example of a pressure generating unit, applies pressure to the air chamber 63. The switching unit 38 switches the pressure in the air chamber 63 of the negative pressure release valve 80, thereby switching the state of the negative pressure release valve 80. The switching unit 38 has a switching mechanism 46. The pressure applied to the liquid storage unit 17 by the pressurizing pump 20 is introduced into the switching mechanism 46. In this respect, the pressurizing pump 20 serves both as the pressure fluctuation mechanism 35 and the pressure generating unit.

[0223] The switching mechanism 46 is, for example, a selector valve. The switching unit 38 has a first gas flow path 41, a third gas flow path 43, a fourth gas flow path 44, and a fifth gas flow path 45 connected to the switching mechanism 46. The switching mechanism 46 and the air chamber 63 of the negative pressure release valve 80 are connected through the first gas flow path 41. Pressurized air is introduced into the switching mechanism 46 through the third gas flow path 43, and negative pressure is introduced through the fourth gas flow path 44. The switching mechanism 46 can be communicated with the atmosphere through the fifth gas flow path 45. The switching mechanism 46 switches the pressure in the air chamber 63 of the negative pressure release valve 80 through the first gas flow path 41.

[0224] The negative pressure release valve 80 is configured by the third valve mechanism 125. The state of the negative pressure release valve 80 is switched by switching the pressure of the air introduced into the air chamber 63. The negative pressure release valve 80 is switched between a third adjustment state, a third open state, and a third closed state. In the third adjustment state, the negative pressure release valve 80 adjusts the downstream output pressure to a set pressure. In the third adjustment state, the negative pressure release valve 80 functions similarly to a conventional self-sealing valve. In addition to the third adjustment state, which functions similarly to a self-sealing valve, the negative pressure release valve 80 can be switched between a third open state and a third closed state.

[0225] The negative pressure release valve 80 is provided in the liquid flow path 19. The negative pressure release valve 80 receives liquid under positive pressure supplied from the liquid storage section 17 and outputs liquid that has been reduced to a predetermined negative pressure. The liquid under negative pressure output from the negative pressure release valve 80 is supplied to the liquid ejection section 12. A negative pressure is maintained inside the liquid ejection section 12. During standby or during recording, a negative pressure is maintained inside the liquid ejection section 12, causing a meniscus of liquid to be formed inside the nozzle 15. This allows appropriate liquid to be ejected from the nozzle 15 and also prevents liquid leakage from the nozzle 15.

[0226] <Configuration of the third valve mechanism> Next, with reference to Fig. 29, a third valve mechanism 125, which is an example of a valve mechanism used in the negative pressure release valve 80, will be described. The third valve mechanism 125 has a configuration in which the first biasing portion 67 in the first valve mechanism 21 is replaced with a second biasing portion 87, which is an example of a biasing portion.

[0227] Similar to the first valve mechanism 21 in the first embodiment, the third valve mechanism 125 includes a first upstream chamber 61, a first downstream chamber 62, a first air chamber 63, a first flexible membrane 64, a second flexible membrane 65, a first opening / closing unit 66, and a first biasing unit 67. The first opening / closing unit 66 has a first shaft portion 72 and a first valve portion 73. The second biasing unit 87 biases the first flexible membrane 64 in the air chamber 63. The second biasing unit 87 biases the first flexible membrane 64 in a direction that increases the volume of the first downstream chamber 62. The second biasing unit 87 may be a tension spring.

[0228] The first shaft 72 is inserted into the second flexible membrane 65. One end of the first shaft 72 is connected to the first flexible membrane 64. The other end of the first shaft 72 is connected to the first valve unit 73. The first opening / closing unit 66 is movable between a closed position indicated by a solid line in FIG. 29 and an open position indicated by a two-dot chain line in FIG. 29. In FIG. 29, the direction in which the liquid flows is indicated by an outline arrow.

[0229] The third valve mechanism 125 is in a third adjustment state for adjusting pressure when atmospheric pressure acts on the outside of the first flexible membrane 64. The third valve mechanism 125 is in a third open state when positive pressure acts on the outside of the first flexible membrane 64. The third valve mechanism 125 is in a third closed state when negative pressure acts on the outside of the first flexible membrane 64.

[0230] During recording or standby, the third valve mechanism 125 is switched to a third adjustment state. In the third adjustment state, the output pressure P2 of the third valve mechanism 125 is adjusted to a set pressure that is a negative pressure smaller than the input pressure P1. During cleaning, the third valve mechanism 125 is switched to a third open state. For example, the third valve mechanism 125 may be switched to a third closed state when the power is turned off.

[0231] <Effects of the Fourth Embodiment> The effects of this embodiment will be described. (4-1) The third valve mechanism 125 includes the first air chamber 63, and therefore pressure can be applied via the first air chamber 63. Therefore, the state of the first opening / closing unit 66 can be configured to be switchable between an adjustment state in which the output pressure is adjusted to a set pressure (constant), and an open state in which the pressure is adjusted to a pressure higher than the set pressure by maintaining the liquid flow path 19 in an open state. Therefore, the pressure and flow rate can be changed according to the control situation, allowing the liquid to flow.

[0232] (4-2) The pressure can be adjusted simply by opening the outside of the third flexible film 84 (second air chamber 83) to the atmosphere, so pressure control is easy. (4-3) The liquid flowing device 13 has the third valve mechanism 125, and therefore can change the pressure and flow rate according to the control situation and cause the fluid to flow.

[0233] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0234] <First change example> As shown in FIG. 30 , a liquid pump 130 may be provided in the liquid flow path 19. The liquid pump 130 constitutes a pressure fluctuation mechanism 35 that fluctuates the pressure of the liquid flowing through the liquid flow path 19. The liquid pump 130 is provided in the liquid flow path 19 at a position between the liquid storage section 17 and the third valve mechanism 125. The liquid pump 130 causes the liquid in the liquid flow path 19 to flow in the supply direction Ds. A negative pressure release valve 80, which is an example of a valve mechanism, is provided in the liquid flow path 19 at a position downstream of the liquid pump 130. An air chamber 63 of the negative pressure release valve 80 is connected to a switching mechanism 46 that constitutes the switching unit 38 through a first gas flow path 41. The switching mechanism 46 may be connected to a third gas flow path 43 through which pressurized gas flows, a fourth gas flow path 44 through which depressurized gas flows, and a fifth gas flow path 45 that is open to the atmosphere. The switching mechanism 46 switches the pressure of the air introduced into the air chamber 63 of the negative pressure release valve 80 through the first gas flow path 41 to either atmospheric pressure, positive pressure, or negative pressure. When the air chamber 63 is at atmospheric pressure, the negative pressure release valve 80 functions as a self-sealing valve that adjusts the output pressure to a set pressure (negative pressure set value). For example, when positive pressure is introduced into the air chamber 63 during cleaning, the negative pressure release valve 80 opens. In this state, the liquid pump 130 sends liquid to the liquid discharge unit 12 at a pressure higher than the set pressure, thereby forcibly discharging the liquid from the nozzle 15, thereby performing cleaning. In this way, the liquid pump 130 constituting the pressure fluctuation mechanism 35 does not have to also function as a pressure generator that applies pressure to the air chamber 63.

[0235] <Second modification example> As shown in FIG. 31 , the liquid flowing device 13 of the fourth embodiment may be configured such that a switching mechanism 46 supplies gas pressurized by a pressure pump 20 constituting a pressure fluctuation mechanism 35 to the liquid storage section 17 through a third gas flow path 43. The pressure pump 20 is connected to the switching mechanism 46 constituting a switching unit 38 through a gas flow path 47. The pressure release valve 22 is provided in a gas flow path 47a connected to the gas flow path 47. The switching mechanism 46 and the liquid storage section 17 are connected through the third gas flow path 43. The pressure of the air region above the liquid level in the liquid storage section 17 can be switched between positive pressure and atmospheric pressure through the third gas flow path 43. For example, during recording or standby, the liquid storage section 17 is pressurized. Positively pressurized liquid flows from the liquid storage section 17 to the liquid flow path 19. At this time, the air chamber 63 is set to atmospheric pressure, causing the negative pressure release valve 80 to enter an adjustment state. Furthermore, during cleaning, the liquid storage section 17 is pressurized. Positive pressure in the air chamber 63 opens the negative pressure release valve 80. Positive pressure liquid is supplied to the liquid ejection section 12, forcing the liquid to be discharged from the nozzle 15. For example, when the power is turned off, atmospheric pressure is set inside the liquid storage section 17. Negative pressure in the air chamber 63 may close the negative pressure release valve 80.

[0236] <Third modification example> 32, the liquid flowing device 13 in the fourth embodiment may be configured to supply liquid from the liquid storage section 17 to the liquid discharge section 12 by using the head difference between the liquid storage section 17 and the liquid discharge section 12. The pressure pump 20 may only have the function of a pressure generator that generates pressure to be applied to the air chamber 63 of the negative pressure release valve 80. Cleaning may be performed by introducing positive pressure into the air chamber 63 to open the negative pressure release valve 80, thereby sending the liquid pressurized by the head difference to the liquid discharge section 12, or by suction cleaning, in which the liquid is sucked from the nozzle 15 of the liquid discharge section 12.

[0237] <Fourth modified example> As shown in FIGS. 33 and 34 , a mechanism for removing air bubbles accumulated in a filter 141 in the liquid ejection unit 12 may be provided. The liquid ejection unit 12 includes a filter 141 that filters the liquid supplied through the liquid flow path 19. The filter 141 is provided in the liquid flow path 19 within the liquid ejection unit 12. The filter 141 removes air bubbles, foreign matter, and the like from the liquid. The liquid filtered by the filter 141 is supplied to each nozzle 15 through a flow path 140. The flow path 140 is part of the liquid flow path 19. The nozzle 15 ejects the liquid from which air bubbles have been removed. If air bubbles accumulate in the filter 141, the supply of liquid to the nozzle 15 and the circulation of the liquid will not be smooth. As shown in FIG. 33 , the downstream end of the first liquid flow path 23 and the upstream end of the bypass flow path 142 face each other at different positions on the upstream surface of the filter 141. An on-off valve 143 is provided in the bypass flow path 142. The on-off valve 143 and the switching mechanism 46 are connected through an eighth gas flow path 144. The switching mechanism 46 switches the open / close state of the on-off valve 143 by switching the pressure of the air supplied to the on-off valve 143 through the eighth gas flow path 144. As shown in FIG. 33 , during normal circulation, such as during recording or standby, both the first pressure adjustment valve 36 and the second pressure adjustment valve 37 are in the adjustment state. The on-off valve 143 is closed. Therefore, the liquid circulating through the liquid ejection unit 12 is filtered by the filter 141. On the other hand, if air bubbles or the like accumulate in the filter 141, the flow resistance of the filter 141 increases, making it difficult for the liquid to flow smoothly. When a regular or irregular cleaning is required, the control unit 100 controls the switching mechanism 46 to switch the on-off valve 143 from the closed state to the open state, as shown in FIG. 34 . As a result, the liquid flows from the downstream end of the first liquid flow path 23 toward the upstream end of the bypass flow path 142 along the upstream surface of the filter 141. This flow of liquid removes air bubbles and the like that have accumulated on the upstream surface of the filter 141 from the filter 141. Note that the timing of cleaning may be determined by the control unit 100 based on the detection result of a detection unit such as a sensor that detects the accumulation of air bubbles and the like in the filter 141.

[0238] <Fifth modification example> 35 , the third gas flow path 43 and the fourth gas flow path 44, one end of which is connected to a switching mechanism 46, may be connected at the other end to a pressurizing pump 20 and a decompression pump 27, which are dedicated to switching the pressure adjustment valves 36 and 37. The switching mechanism 46 is connected to the first gas flow path 41, which is connected to the air chambers 63 and 83 of the first pressure adjustment valve 36, and the second gas flow path 42, which is connected to the air chamber 83 of the second pressure adjustment valve 37. In this way, the pressurizing pump 20 and the decompression pump 27 constitute a pressure generating unit that generates pressure to be applied to the air chambers 63 and 83, but they may not also serve as the pressure fluctuation mechanism 35 that fluctuates the pressure of the liquid flowing through the liquid flow path 19. Note that the pumps that constitute the pressure fluctuation mechanism 35 that pressurizes the first liquid storage portion 17 and decompresses the second liquid storage portion 24 may be provided separately.

[0239] <Sixth Change Example> In the liquid ejection device 11 and liquid flowing device 13 of the fourth embodiment (FIG. 28), the state of the third valve mechanism 125 may be switched by a magnetic force method in which a magnetic force is applied to an opening / closing unit 66, instead of a pressure method in which pressure is applied to an air chamber 63. The switching unit 38 includes a magnetic force generating unit 150, as shown in FIG. 36, in place of the first air chamber 63. A liquid flowing device 13 including this third valve mechanism 125 as a negative pressure release valve 80 includes the third valve mechanism 125, a liquid storage unit 17, a liquid flow path 19, and a pressure fluctuation mechanism 35, similar to the fourth embodiment shown in FIG. 28. The pressure fluctuation mechanism 35, which fluctuates the pressure of the liquid flowing through the liquid flow path 19, includes a magnetic force generating unit 150 that applies a magnetic force to the opening / closing unit 66. The magnetic force generating unit 150 fluctuates the pressure of the liquid flowing through the liquid flow path 19 by applying a magnetic force to the opening / closing unit 66, which has a magnetic force.

[0240] As shown in Figure 36, the third valve mechanism 125 has basically the same configuration as the fourth embodiment except for the air chamber 63. That is, the third valve mechanism 125 includes an upstream chamber 61, a downstream chamber 62, a second flexible membrane 65, an opening / closing unit 66, and a biasing unit 87. In the third valve mechanism 125 shown in Figure 36, the opening / closing unit 66 has magnetic force.

[0241] 36, a magnet 105 is fixed to the valve portion 73. The third valve mechanism 125 includes a magnetic force generating unit 150 located on the outer side of the surface of the housing that forms the downstream chamber 62, opposite the first flexible membrane 64. The magnetic force generating unit 150 has the same configuration as that of the second embodiment.

[0242] When the movable body 110S is in the adjustment position where the gap 111 between the first magnet 112 and the second magnet 113 is at the operating position PT shown in Figure 36, the magnetic force of the magnetic force generating unit 150 does not act on the magnet 105 of the valve unit 73. Therefore, the third valve mechanism 125 is in the adjustment state. In the adjustment state, the opening / closing unit 66 opens and closes the communication port 69 so that the output pressure P2 is adjusted to the first set pressure SP1.

[0243] When the movable body 110S moves to the open position where the first magnet 112 is located in the operative position PT, the magnetic attraction force acting between the first magnet 112 and the magnet 105 moves the valve unit 73 to the open position where the communication port 69 is opened. In this way, the third valve mechanism 125 is in the open state. For example, during cleaning, the third valve mechanism 125 is in the open state. When the movable body 110S moves to the open position where the first magnet 112 is located in the operative position PT, the magnetic repulsion force acting between the second magnet 113 and the magnet 105 moves the valve unit 73 to the closed position where the communication port 69 is closed. In this way, the third valve mechanism 125 is in the closed state. For example, when the power is turned off, the third valve mechanism 125 is in the closed state.

[0244] <Seventh Change Example> In the sixth modified example, the third valve mechanism 125 may be modified to include an electromagnet-type magnetic force generator 150 shown in FIG. 37 instead of the magnet-moving-type magnetic force generator 150 shown in FIG. 36 . The magnetic force generator 150 of this third valve mechanism 125 has the same configuration as that shown in FIG. 14 in the second embodiment. The magnetic force generator 150 includes a switching circuit 123 that switches the direction of current flowing through a coil 121 constituting an electromagnet, and a battery 122 that serves as a power source and is connected to the switching circuit 123. When no current flows through the coil 121, the magnetic force of the magnetic force generator 150 does not act on the magnet 105 of the valve unit 73. Therefore, the opening / closing unit 66 opens and closes the communication port 69 so that the output pressure P2 is adjusted to the first set pressure SP1. When a current flows through the coil 121 in a first direction, the magnetic attraction force moves the valve unit 73 to an open position that opens the communication port 69. In this way, the third valve mechanism 125 is in an open state. For example, during cleaning, the third valve mechanism 125 is in an open state. When a current flows through the coil 121 in a second direction opposite to the first direction, the magnetic repulsive force moves the valve portion 73 to a closed position where it closes the communication port 69. In this way, the third valve mechanism 125 is in a closed state. For example, when the power is turned off, the third valve mechanism 125 is in a closed state.

[0245] <Example of change No. 8> The state may be switched using a fourth valve mechanism 160, which is an example of a valve mechanism shown in FIG. 38. In the adjustment state, the fourth valve mechanism 160 functions as a pressurization release valve. The fourth valve mechanism 160 has a configuration in which the second biasing portion 87 in the second valve mechanism 28 is replaced with a first biasing portion 67. The fourth valve mechanism 160 has the same configuration as the second valve mechanism 28, except that the first biasing portion 67 is an example of a biasing portion. That is, the fourth valve mechanism 160 includes a second upstream chamber 81, a second downstream chamber 82, a second air chamber 83, a third flexible membrane 84, a fourth flexible membrane 85, a second opening / closing portion 86, and a first biasing portion 67. Therefore, the same components as those in the second valve mechanism 28 are denoted by the same reference numerals and detailed description thereof will be omitted. The first biasing portion 67 biases the third flexible membrane 84 in a direction that reduces the volume of the upstream chamber 81. The first biasing portion 67 may be, for example, a compression spring. The direction in which the third flexible membrane 84 is displaced to decrease the volume of the upstream chamber 81 is the direction in which the valve portion 93 is closed. The fourth valve mechanism 160 is in the adjustment state when atmospheric pressure is present in the air chamber 83. When the fourth valve mechanism 160 is in the adjustment state, the surface of the third flexible membrane 84 facing the air chamber 83 is subjected to atmospheric pressure and the biasing force of the first biasing member 67 in the first direction D1. Therefore, to open the valve portion 73, which is in the closed state, a positive pressure sufficient to overcome the atmospheric pressure and the biasing force of the first biasing member 67 must act on the liquid in the upstream chamber 81. The position indicated by the solid line in FIG. 38 is the closed valve state. When the pressure P3 in the upstream chamber 81 becomes higher than the set positive pressure, the valve portion 73 opens. The position indicated by the two-dot chain line in FIG. 38 is the open valve state. When the valve portion 73 is open, liquid flows from the upstream chamber 81 to the downstream chamber 82 through the communication port 90. As a result, the pressure in the upstream chamber 81 drops, and the valve portion 73 closes. In this way, the opening and closing of the fourth valve mechanism 160 is adjusted so that the upstream output pressure P3 is maintained at a set positive pressure. Furthermore, when the air chamber 83 is depressurized, the fourth valve mechanism 160 is in an open state. When the air chamber 83 is pressurized, the fourth valve mechanism 160 is in a closed state. By providing the air chamber 83 in such a pressure release valve, the fourth valve mechanism 160 may be used by switching between three states.

[0246] <9th change example> The configuration for switching the state of the fourth valve mechanism 160 shown in FIG. 38 may be replaced by an open-close unit 86 having a magnetic force that can be switched by magnetic force, instead of the air chamber 83 that can be switched by pressure. In this case, the magnetic force generator 110 shown in FIG. 36 or the magnetic force generator 120 shown in FIG. 37 may be provided as the switching mechanism. The magnetic force generators 110 and 120 may switch the state of the fourth valve mechanism 160 by switching whether or not a magnetic force is applied to the magnet 105 and the type of magnetic pole. The magnet 105 may be provided not only in the valve unit 93 but also in other parts constituting the open-close unit 86. For example, the magnet 105 may be provided at or near the second end of the shaft 92 opposite the first end on the valve unit 93 side. In this case, the magnetic force generators 110 and 120 may be located on the outside (atmosphere side) facing the third flexible membrane 84.

[0247] <Other change examples> In the liquid discharge device 11 and the liquid flowing device 13 shown in FIGS. 1, 16, etc., the first pressure adjustment valve 36 may be replaced with a third valve mechanism 125 shown in FIG. 29 instead of the first valve mechanism 21.

[0248] In the liquid ejection device 11 and the liquid flowing device 13 shown in FIG. 11 etc., the first pressure adjustment valve 36 may be a magnetic type third valve mechanism 125 shown in FIGS. 36 and 37 instead of the magnetic type first valve mechanism 21.

[0249] In the liquid ejection device 11 and the liquid flow device 13 shown in Figures 1, 11, 16, etc., the first valve mechanism 21 and the second valve mechanism 28 may be a mixture of a pressure type having an air chamber and a magnetic type having a magnetic opening and closing part.

[0250] In the liquid discharge device 11 and the liquid flowing device 13 shown in Figures 1, 11, 16, 28, etc., a fourth valve mechanism 160 shown in Figure 38 may be used as the pressure release valve 22. In this way, the fluid that the fourth valve mechanism 160 targets may be a gas. With this configuration, the pressure release valve 22 can be switched between an adjustment state, an open state, and a closed state. Therefore, the pressure and flow rate of the pressure release valve 22 can be changed according to the control situation, and the fluid can be caused to flow.

[0251] In the liquid ejection device 11 and the liquid flowing device 13 shown in Figures 1, 11, 16, 28, etc., a third valve mechanism 125 may be used as the negative pressure release valve 29. In this way, the fluid targeted by the second valve mechanism 28 may be a gas. With this configuration, the negative pressure release valve 29 can be switched between an adjustment state, an open state, and a closed state. Therefore, the negative pressure release valve 29 can change the pressure and flow rate according to the control situation to allow the fluid to flow.

[0252] In each of the above embodiments, the states that can be switched in the valve mechanisms 21, 28, 125, and 160 may be only between the adjusting state and the open state, or only between the adjusting state and the closed state.Furthermore, only the open state and the closed state may be used.

[0253] In the liquid ejection device 11 and the liquid flow device 13 in the first to third embodiments, the first pressure adjustment valve 36 may be replaced with a first valve mechanism 21 that functions as a pressure adjustment valve, and a third valve mechanism 125 that functions as a self-sealing valve.

[0254] In the valve mechanisms 21, 28, 125, and 160, one end of the shaft portion 72 and 92 may be directly connected to the flexible membrane 64 and 84, or may be indirectly connected thereto. The pressure may be adjusted to a value lower than the set pressure.

[0255] The switching mechanism 46 is not limited to a configuration in which one switching mechanism switches between the two pressure regulation valves 36, 37, like a selector valve. For example, the first switching unit and the second switching unit corresponding to the pressure regulation valves 36, 37 may be collectively referred to as a switching unit. In this case, the first switching unit and the second switching unit may include a common pressure generating unit, or may each include a first pressure generating unit and a second pressure generating unit. Furthermore, the first switching unit and the second switching unit may include a common magnetic force generating unit, or may each include a first magnetic force generating unit and a second magnetic force generating unit.

[0256] In the second embodiment, the magnet 105 is not limited to being provided on the valve portion 73, but may be provided on the opening / closing portion 66. The magnet 105 may also be provided on the shaft portion 72. For example, the magnet 105 may be provided on the end of the shaft portion 72 on the first flexible film 64 side. In this case, the magnetic force generating units 110, 120 may be arranged on the outside facing the first flexible film 64. Furthermore, the configuration is not limited to providing the magnet 105 on the opening / closing portions 66, 86, and the opening / closing portion 66 itself may have magnetic force.

[0257] In the third embodiment, one of the pressure pump 20 and the pressure reduction pump 27 may be connected to one of the liquid storage portions 17 and 24 , and the other may be connected to the switching mechanism 46 . The liquid discharger 11 may be configured to include either the first valve mechanism 21 or the second valve mechanism 28. The liquid discharger 11 may supply the liquid by controlling the pressure pump 20, the pressure reduction pump 27, the pressure release valve 22, the negative pressure release valve 29, etc.

[0258] In the first upstream chamber 61, the pressure-receiving area of ​​the second flexible membrane 65 may be different from the pressure-receiving area of ​​the first valve portion 73. In the second downstream chamber 82, the pressure-receiving area of ​​the fourth flexible membrane 85 may be different from the pressure-receiving area of ​​the second valve portion 93. The pressure-receiving areas of the first valve mechanism 21 and the second valve mechanism 28 may be adjusted depending on the attitude, the type of fluid being handled, the ease of deformation of the second flexible membrane 65 or the fourth flexible membrane 85, etc.

[0259] The first shaft portion 72 and the second flexible film 65 may be integrally formed. The second shaft portion 92 and the fourth flexible film 85 may be integrally formed. · A configuration with only a pressure adjustment valve without circulation is also possible.

[0260] A configuration without circulation and only a negative pressure adjustment valve as a valve mechanism may be used. A configuration with circulation and a negative pressure release valve (self-sealing valve) and a negative pressure adjustment valve may also be used. In this case, similar controls can be used to perform printing, standby stop, power OFF, cleaning, ink removal from the head, forced circulation, and air bubble removal.

[0261] The pressure release valve has an air chamber, and like the pressure control valve and other valves, it can be switched between three states. The switching mechanism does not have to be a selector valve. The pressure regulating valves 36, 37 may be switched by opening and closing individual dedicated switching valves provided for the pressure regulating valves 36, 37.

[0262] All of the pressure adjustment targets are controlled by a selector valve, which is an example of the switching mechanism 46, but some of the pressure adjustment targets may be controlled by something other than a selector valve. The circulation pressure booster pump 20 may be shared between the objects to be pressurized. The circulation pressure reducer pump 27 may be shared between the objects to be depressurized. For example, the objects to be pressurized are the first liquid storage unit 17 and the second liquid storage unit 24, and the objects to be depressurized are the first liquid storage unit 17 and the second liquid storage unit 24. The destination to which the pressurized air (positive pressure) from the pressure booster pump 20 is supplied may be selected by opening or closing a valve provided in a gas flow path connecting the pressure booster pump 20 to the first liquid storage unit 17 and the second liquid storage unit 24, respectively. The destination to which the depressurized air (negative pressure) from the depressurization pump 27 is supplied may be selected by opening or closing a valve provided in a gas flow path connecting the depressurization pump 27 to the first liquid storage unit 17 and the second liquid storage unit 24, respectively.

[0263] In the above embodiments and modified examples, the fluid is a liquid, but the fluid may be a gas. The fluid ejection device may be a gas ejection device that ejects a gas. In this case, the gas ejection device has a gas storage section, which is an example of a fluid storage section, a gas ejection section, which is an example of a fluid ejection section, and a gas flow path connecting the gas storage section and the gas ejection section. The gas ejection device includes a valve mechanism provided in the gas flow path. The valve mechanism may have an air chamber and be configured to be switchable between an adjusted state and an open state by switching the pressure supplied to the air chamber. The valve mechanism may also include an opening / closing section having magnetic force and be configured to be switchable between an adjusted state and an open state depending on whether or not an external magnetic force acts on the opening / closing section.

[0264] The first valve mechanism 21 may be used as the negative pressure release valve 29. The second valve mechanism 28 may be used as the pressurization release valve 22. The third valve mechanism 125 may be used as the negative pressure release valve 29. The fourth valve mechanism 160 may be used as the pressurization release valve 22. In this way, each of the valve mechanisms 21, 28, 125, and 160 may handle gas as the fluid.

[0265] An atmosphere release valve may be used instead of the pressurization release valve 22. In this case, a detection unit such as a pressure sensor that detects the pressure inside the first liquid storage unit 17 may be provided, and the atmosphere release valve may be opened when the pressure detected by the detection unit exceeds the set pressure. After the atmosphere release valve opens, the atmosphere release valve is closed when the pressure detected by the detection unit drops to the set pressurization pressure or the pressurization lower limit pressure. Similarly, an atmosphere release valve may be used instead of the negative pressure release valve 29. In this case, a detection unit such as a pressure sensor that detects the pressure inside the second liquid storage unit 24 may be provided, and the atmosphere release valve is opened when the pressure detected by the detection unit exceeds the set negative pressure on the negative side. After the atmosphere release valve opens, the atmosphere release valve is closed when the pressure detected by the detection unit rises to the set negative pressure or the negative pressure upper limit pressure.

[0266] The liquid ejection device 11 may be a liquid ejection device that ejects or discharges liquids other than ink. The liquid ejected as minute droplets from the liquid ejection device may be in the form of granules, tears, or strings. The liquid referred to here may be any material that can be ejected from the liquid ejection device. For example, the liquid may be in any liquid phase, including fluids such as high or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and metal melts. The liquid may refer not only to a single state of matter, but also to solid functional material particles, such as pigments and metal particles, dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals, as described in the above embodiments. Here, ink encompasses various liquid compositions, such as general water-based inks and oil-based inks, as well as gel inks and hot-melt inks. Specific examples of liquid ejection devices include devices that eject liquids containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters. The liquid ejection device may be a device that ejects bioorganic materials used in biochip manufacture, a device used as a precision pipette to eject sample liquids, a textile printing device, a microdispenser, or the like. The liquid ejection device may be a device that ejects lubricating oil with pinpoint accuracy onto precision machinery such as watches and cameras, or a device that ejects transparent resin liquids such as ultraviolet-curing resins onto substrates to form micro-hemispherical lenses, optical lenses, and the like used in optical communication elements. The liquid ejection device may also be a device that ejects etching liquids such as acids or alkalis to etch substrates, etc.

[0267] [Definition] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" when the number of options is two. As another example, the phrase "at least one" as used herein means "only one option," "any combination of two options," or "any combination of three or more options" when the number of options is three or more.

[0268] [Note] The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below.

[0269] (A) The valve mechanism comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and communicating with the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane separating the downstream chamber and the air chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, and the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0270] According to this configuration, since an air chamber is provided, pressure can be applied via the air chamber. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant) and an open state in which the fluid flow path is kept open to adjust the pressure to a pressure higher than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0271] (B) The valve mechanism comprises an upstream chamber into which fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and connected to the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane separating the upstream chamber and the air chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the upstream chamber, and the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0272] According to this configuration, since an air chamber is provided, pressure can be applied via the air chamber. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant) and an open state in which the fluid flow path is kept open to adjust the pressure to a pressure lower than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0273] (C) The valve mechanism comprises an upstream chamber into which fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and communicating with the upstream chamber through a communication port, an air chamber that can communicate with an external space, a first flexible membrane separating the downstream chamber and the air chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit that can open and close the communication port, and a biasing unit that biases the first flexible membrane in a direction that increases the volume of the downstream chamber, and the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port.

[0274] According to this configuration, since an air chamber is provided, pressure can be applied via the air chamber. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant) and an open state in which the fluid flow path is kept open to adjust the pressure to a pressure higher than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0275] (D) The valve mechanism comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber having a first flexible membrane and communicating with the upstream chamber through a communication port downstream of the upstream chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit capable of opening and closing the communication port, and a biasing unit that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0276] According to this configuration, the opening / closing unit has magnetic force, so that magnetic force can be applied. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant), and an open state in which the flow path is kept open to adjust the pressure to a pressure higher than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0277] (E) The valve mechanism has an upstream chamber having a first flexible membrane into which a fluid flows through an inlet, a downstream chamber downstream of the upstream chamber and communicating with the upstream chamber through a communication port, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit capable of opening and closing the communication port, and a biasing unit that biases the first flexible membrane in a direction increasing the volume of the upstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0278] According to this configuration, the opening / closing unit has magnetic force, so that magnetic force can be applied. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant), and an open state in which the flow path is kept open to adjust the pressure to a pressure higher than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0279] (F) The valve mechanism comprises an upstream chamber into which a fluid flows through an inlet, a downstream chamber having a first flexible membrane and communicating with the upstream chamber through a communication port downstream of the upstream chamber, a second flexible membrane separating the upstream chamber and the downstream chamber, an opening / closing unit capable of opening and closing the communication port, and a biasing unit that biases the first flexible membrane in a direction increasing the volume of the downstream chamber, wherein the opening / closing unit is provided across the upstream chamber and the downstream chamber and has an axis unit that can move in response to displacement of the first flexible membrane and the second flexible membrane, and a valve unit connected to the axis unit that opens and closes the communication port, and the opening / closing unit has magnetic force.

[0280] According to this configuration, the opening / closing unit has magnetic force, so that magnetic force can be applied. Therefore, the state of the opening / closing unit can be switched between an adjustment state in which the output pressure is adjusted to a set pressure (constant), and an open state in which the flow path is kept open to adjust the pressure to a pressure higher than the set pressure. Therefore, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0281] (G) In the valve mechanism described in any one of (A) to (F) above, the stem may be inserted into the second flexible membrane, one end of the stem connected to the first flexible membrane, and the other end of the stem connected to the valve. This configuration allows the stem to move in accordance with the first and second flexible membranes. This improves the responsiveness of the valve, which opens and closes in response to changes in the pressure difference between the upstream chamber and the downstream chamber.

[0282] (H) In the valve mechanism described in any one of (A) to (C) above, when atmospheric pressure is acting on the outside of the first flexible membrane, the valve mechanism may be in an adjusting state for adjusting the pressure. With this configuration, the pressure can be adjusted simply by opening the outside of the first flexible membrane (air chamber) to the atmosphere. This makes it easier to control the pressure of the fluid by the valve mechanism.

[0283] (I) In the valve mechanism described in any one of (D) to (F) above, the valve mechanism may be in a pressure adjusting state when no external magnetic force is acting on the opening / closing portion. With this configuration, the pressure adjusting state can be achieved simply by removing the external magnetic force acting on the opening / closing portion. This makes it easy to control the pressure of the fluid by the valve mechanism.

[0284] (J) A fluid flow device includes the valve mechanism described in (A) above, a fluid reservoir for storing a fluid, a fluid flow path connected to the fluid reservoir and provided with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a pressure generating unit for applying pressure to the air chamber. With this configuration, the pressure and flow rate in the fluid flow path can be changed according to the control situation, allowing the fluid to flow.

[0285] (K) A fluid flow device includes the valve mechanism described in (B) above, a fluid reservoir for storing a fluid, a fluid flow path connected to the fluid reservoir and provided with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a pressure generating unit for applying pressure to the air chamber. With this configuration, the pressure and flow rate in the fluid flow path can be changed according to the control situation, allowing the fluid to flow.

[0286] (L) A fluid flow device includes the valve mechanism described in (C) above, a fluid reservoir for storing a fluid, a fluid flow path connected to the fluid reservoir and equipped with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a pressure generating unit for applying pressure to the air chamber. With this configuration, the pressure and flow rate can be changed according to the control situation, allowing the fluid to flow.

[0287] (M) A fluid flow device includes the valve mechanism described in (D) above, a fluid storage unit for storing a fluid, a fluid flow path connected to the fluid storage unit and equipped with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a magnetic force generator for applying a magnetic force to the opening / closing unit. With this configuration, by applying a magnetic force to the opening / closing unit, the pressure and flow rate can be changed according to the control situation, allowing the fluid to flow.

[0288] (N) A fluid flow device includes the valve mechanism described in (E) above, a fluid storage section for storing a fluid, a fluid flow path connected to the fluid storage section and provided with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a magnetic force generating section for applying a magnetic force to the opening / closing section. With this configuration, by applying a magnetic force to the opening / closing section, the pressure and flow rate can be changed according to the control situation, and the fluid can flow.

[0289] (O) A fluid flow device includes the valve mechanism described in (F) above, a fluid storage unit for storing a fluid, a fluid flow path connected to the fluid storage unit and equipped with the valve mechanism, a pressure fluctuation mechanism for fluctuating the pressure of the fluid flowing through the fluid flow path, and a magnetic force generator for applying a magnetic force to the opening / closing unit. With this configuration, by applying a magnetic force to the opening / closing unit, the pressure and flow rate can be changed according to the control situation, allowing the fluid to flow.

[0290] (P) In the fluid flow device described in (J) or (L) above, when the valve mechanism is a first valve mechanism, the inlet is a first inlet, the upstream chamber is a first upstream chamber, the communication port is a first communication port, the downstream chamber is a first downstream chamber, the air chamber is a first air chamber, the opening / closing unit is a first opening / closing unit, the biasing unit is a first biasing unit, the shaft unit is a first shaft unit, and the valve unit is a first valve unit, the fluid flow device further comprises a second valve mechanism, the second valve mechanism comprising a second upstream chamber into which fluid flows via a second inlet, and a second upstream chamber downstream of the second upstream chamber that is in communication with the second upstream chamber via a second communication port. The valve may include a downstream chamber, a second air chamber that can communicate with an external space, a third flexible membrane that separates the second upstream chamber from the second air chamber, a fourth flexible membrane that separates the second upstream chamber from the second downstream chamber, a second opening / closing unit that can open and close the second communication port, and a biasing unit that biases the third flexible membrane in a direction that increases the volume of the second upstream chamber, wherein the second opening / closing unit may include a second shaft that is provided across the second upstream chamber and the second downstream chamber and that can move following displacement of the third flexible membrane and the fourth flexible membrane, and a second valve that is connected to the second shaft and opens and closes the second communication port. With this configuration, the pressure and flow rate can be changed according to the control situation by applying pressure to the air chamber.

[0291] (Q) In the fluid flow device described in (M) or (N) above, if the valve mechanism is defined as a first valve mechanism, the inlet is defined as a first inlet, the upstream chamber is defined as a first upstream chamber, the communication port is defined as a first communication port, the downstream chamber is defined as a first downstream chamber, the opening / closing unit is defined as a first opening / closing unit, the biasing unit is defined as a first biasing unit, the shaft unit is defined as a first shaft unit, and the valve unit is defined as a first valve unit, the fluid flow device further comprises a second valve mechanism, the second valve mechanism having a third flexible membrane and including a second upstream chamber into which a fluid flows via a second inlet, and a second upstream chamber downstream of the second upstream chamber via a second communication port. The pressure control valve may include a second downstream chamber communicating with the second upstream chamber, a fourth flexible membrane separating the second upstream chamber and the second downstream chamber, a second opening / closing unit capable of opening and closing the second communication port, and a biasing unit biasing the third flexible membrane in a direction increasing the volume of the second downstream chamber, wherein the second opening / closing unit includes a second shaft unit provided across the second upstream chamber and the second downstream chamber and movable in response to displacement of the third flexible membrane and the fourth flexible membrane, and a second valve unit connected to the second shaft unit and opening and closing the second communication port, and the second opening / closing unit may have magnetic force. With this configuration, the pressure and flow rate can be changed according to the control situation by applying magnetic force to the opening / closing unit.

[0292] (R) A fluid discharge device includes the fluid flow device according to any one of (J) to (O) above and a fluid discharge part provided in the fluid flow path. With this configuration, the pressure and flow rate of the fluid can be changed according to the control situation.

[0293] (S) A fluid ejection device comprises the fluid flow device described in (P) above and a fluid ejection section capable of ejecting the fluid, wherein the fluid flow path has a first fluid flow path whose downstream end is connected to the fluid ejection section and a second fluid flow path whose upstream end is connected to the fluid ejection section, the first valve mechanism is located in the first fluid flow path, and the second valve mechanism is located in the second fluid flow path.

[0294] According to this configuration, by switching each valve mechanism through control of air pressure, the pressure of the fluid flowing into the fluid discharge portion and the pressure of the fluid flowing out of the fluid discharge portion can be changed to a pressure and flow rate that corresponds to the control situation.

[0295] (T) A fluid ejection device comprises the fluid flow device described in (R) above and a fluid ejection section capable of ejecting the fluid, wherein the fluid flow path has a first fluid flow path whose downstream end is connected to the fluid ejection section and a second fluid flow path whose upstream end is connected to the fluid ejection section, the first valve mechanism being located in the first fluid flow path, and the second valve mechanism being located in the second fluid flow path.

[0296] According to this configuration, by switching each valve mechanism through the action of magnetic force, the pressure of the fluid flowing into the fluid discharge portion and the pressure of the fluid flowing out of the fluid discharge portion can be changed to a pressure and flow rate that corresponds to the control situation.

[0297] (U) A fluid discharge device includes a fluid discharge portion capable of discharging a fluid, a first fluid storage portion for storing a fluid, a second fluid storage portion for storing a fluid, a first fluid flow path connecting the first fluid storage portion and the fluid discharge portion, a second fluid flow path connecting the second fluid storage portion and the fluid discharge portion, a pressure fluctuation mechanism for fluctuating the pressure of the fluid stored in the first fluid storage portion and the second fluid storage portion, a first pressure adjustment valve provided in the first fluid flow path, a second pressure adjustment valve provided in the second fluid flow path, and a switching portion capable of switching the states of the first pressure adjustment valve and the second pressure adjustment valve, The first fluid flow path is switchable between a first adjustment state in which the pressure downstream of the first pressure adjustment valve is adjusted to a first set pressure, and a first open state in which the pressure downstream of the first pressure adjustment valve is adjusted to a pressure higher than the first set pressure by maintaining the first fluid flow path in an open state, and the second pressure adjustment valve is switchable between a second adjustment state in which the pressure upstream of the second pressure adjustment valve is adjusted to a second set pressure in the second fluid flow path, and a second open state in which the pressure upstream of the second pressure adjustment valve is adjusted to a pressure lower than the second set pressure by maintaining the second fluid flow path in an open state. According to this configuration, by providing a pressure adjustment valve that can be switched between an adjustment state and an open state and circulating the fluid, it is possible to circulate the fluid at a pressure and flow rate according to the control situation.

[0298] (V) In the fluid ejection device described in (U) above, the first pressure adjustment valve and the second pressure adjustment valve may be switched between states by the application of magnetic force by the switching unit. With this configuration, the states can be easily switched by the application of magnetic force.

[0299] (W) In the fluid ejection device described in (U) above, the first pressure adjustment valve and the second pressure adjustment valve may be configured to switch states by applying pressure from the switching unit. With this configuration, the states can be easily switched by applying pressure.

[0300] (X) In the fluid ejection device described in any one of (U) to (W) above, the first pressure adjustment valve may be switchable to a first closed state that maintains the first fluid flow path closed, and the second pressure adjustment valve may be switchable to a second closed state that maintains the second fluid flow path closed. With this configuration, the flow paths can be closed when a control situation is such that supply to / recovery from the fluid ejection unit is not performed.

[0301] (Y) In the fluid ejection device described in (W) above, the switching unit may have a first gas flow path connected to the first pressure adjustment valve, a second gas flow path connected to the second pressure adjustment valve, a third gas flow path through which the pressurized gas flows, a fourth gas flow path through which the depressurized gas flows, and a switching mechanism for switching the connection states of the gas flow paths. With this configuration, the switching unit can be shared by the first pressure adjustment valve and the second pressure adjustment valve, thereby making it possible to reduce the size of the fluid ejection device.

[0302] (Z) In the fluid ejection device described in (Y) above, the pressure fluctuation mechanism may have a pressure pump that pressurizes the first fluid storage section and a pressure reduction pump that depressurizes the second fluid storage section, and the gas pressurized by the pressure pump flows through the third gas flow path, and the gas depressurized by the pressure reduction pump flows through the fourth gas flow path. This configuration simplifies the configuration by using the pressure and pressure reduction forces of the circulating pressure / depressurization pump, and allows the device to be made smaller.

[0303] (ZA) In the fluid ejection device described in (Z) above, the first pressure regulating valve may be in the first open state when the first gas flow path and the third gas flow path are connected, and the second pressure regulating valve may be in the second open state when the second gas flow path and the fourth gas flow path are connected.

[0304] According to this configuration, the first gas flow path and the third gas flow path are connected and the second gas flow path and the fourth gas flow path are connected depending on the control situation, so that the flow paths can be opened, and therefore the fluid can be circulated at a pressure other than the set pressure.

[0305] (ZB) In the fluid ejection device described in (ZA) above, the first pressure adjustment valve may be switchable to a first closed state that maintains the first fluid flow path closed, and be in the first closed state when the first gas flow path and the fourth gas flow path are connected, and the second pressure adjustment valve may be switchable to a second closed state that maintains the second fluid flow path closed, and be in the second closed state when the second gas flow path and the third gas flow path are connected. With this configuration, the flow paths can be closed by connecting the first gas flow path and the fourth gas flow path and connecting the second gas flow path and the third gas flow path depending on the control status.

[0306] (ZC) The fluid ejection device is the fluid ejection device described in any one of (Y), (Z), (ZA), and (ZB) above, wherein the switching unit has a fifth gas flow path that is open to the atmosphere, and the first pressure adjustment valve is in the first adjustment state when the first gas flow path and the fifth gas flow path are connected, and the second pressure adjustment valve is in the second adjustment state when the second gas flow path and the fifth gas flow path are connected. With this configuration, the adjustment state can be achieved simply by opening the pressure adjustment valve to the atmosphere. This makes it easy to switch from the open state to the adjustment state. [Explanation of symbols]

[0307] 11...liquid ejection device which is an example of a fluid ejection device, 12...liquid ejection section which is an example of a fluid ejection section, 13...liquid flow device which is an example of a fluid flow device, 13A...first liquid flow section, 13B...second liquid flow section, 14...medium, 15...nozzle, 16...nozzle surface, 17...first liquid storage section which is an example of a liquid storage section, 18...gas flow path, 19...liquid flow path which is an example of a fluid flow path, 20...pressurization pump, 21...first valve mechanism which is an example of a valve mechanism, 22...pressurization release valve, 23...first liquid flow path, 24...second liquid storage section which is an example of a liquid storage section, 25...gas flow path, 26...second liquid flow path, 27...pressurization Pump, 28...second valve mechanism which is an example of a valve mechanism, 29...negative pressure release valve, 30...connecting flow path, 31...liquid delivery section, 35...pressure fluctuation mechanism, 36...first pressure adjustment valve, 37...second pressure adjustment valve, 38...switching section, 41...first gas flow path, 41B...buffer chamber, 42...second gas flow path, 42B...buffer chamber, 43...third gas flow path, 44...fourth gas flow path, 45...fifth gas flow path, 46...switching mechanism, 47...sixth gas flow path, 47a...gas flow path, 48...seventh gas flow path, 48a...gas flow path, 49A...liquid supply source, 49B...moisture supply source, 50...moisture permeable membrane, 51...liquid chamber, 52...moisturizing liquid chamber, 53 ...liquid supply flow path, 54...moisture supply flow path, 55...liquid supply valve, 56...moisture supply valve, 57...agitation section, 58...agitation flow path, 59...agitation pump, 61...first upstream chamber, 62...first downstream chamber, 63...first air chamber which is an example of an air chamber, 64...first flexible membrane, 65...second flexible membrane, 65a...first surface, 65b...second surface, 66...first opening / closing section, 67...first biasing section, 68...first inlet, 69...first communication port, 70...first outlet, 71...first vent, 72...first shaft section, 73...first valve section, 74...first seal section, 75...first housing, 75a...first inlet pipe section, 75b...first chamber forming section, 75c...first outlet Pipe portion, 76...first lid body, 76a...pipe portion, 80...negative pressure release valve, 81...second upstream chamber, 82...second downstream chamber, 83...second air chamber which is an example of an air chamber, 84...third flexible membrane which is an example of a first flexible membrane, 85...fourth flexible membrane which is an example of a second flexible membrane, 85a...third surface, 85b...fourth surface, 86...second opening / closing portion, 87...second biasing portion, 88...second vent port, 89...second inlet, 90...second communication port, 91...second outlet, 92...second shaft portion, 93...second valve portion, 94...second seal portion, 95...second housing, 95a...second inlet pipe portion, 95b...second chamber forming portion, 95b...chamber forming portion, 95c...second outlet pipe portion,96...second cover, 96a...pipe section, 100...control section, 101...first valve, 102...second valve, 103...third valve, 105...magnet, 106...magnet, 110...first magnetic force generating section, 110S...moving body, 111...gap, 112...first magnet, 113...second magnet, 114...driving source, 115...power transmission mechanism, 120...second magnetic force generating section, 121...coil, 122...battery, 123...switching circuit, 125...third valve mechanism which is an example of a valve mechanism mechanism, 130... liquid pump, 140... flow path, 141... filter, 142... bypass flow path, 143... on-off valve, 144... eighth gas flow path, 150... third magnetic force generating unit, 160... fourth valve mechanism, Ds... supply direction, Dr... recovery direction, D1... first direction, D2... second direction, P1... input pressure, P2... output pressure, P3... output pressure, P4... input pressure, PT... target position, SP1... first set pressure, SP2... second set pressure, Z... vertical direction.

Claims

1. an upstream chamber into which a fluid flows via an inlet; a downstream chamber that is downstream of the upstream chamber and communicates with the upstream chamber via a communication port; an air chamber that can communicate with an external space; a first flexible membrane separating the downstream chamber and the air chamber; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port.

2. an upstream chamber into which a fluid flows via an inlet; a downstream chamber that is downstream of the upstream chamber and communicates with the upstream chamber via a communication port; an air chamber that can communicate with an external space; a first flexible membrane separating the upstream chamber and the air chamber; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that increases the volume of the upstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port.

3. an upstream chamber into which a fluid flows via an inlet; a downstream chamber that is downstream of the upstream chamber and communicates with the upstream chamber via a communication port; an air chamber that can communicate with an external space; a first flexible membrane separating the downstream chamber and the air chamber; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that increases the volume of the downstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port.

4. an upstream chamber into which a fluid flows via an inlet; a downstream chamber having a first flexible membrane and communicating with the upstream chamber via a communication port downstream of the upstream chamber; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that reduces the volume of the downstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port, The valve mechanism is characterized in that the opening and closing portion has a magnetic force.

5. an upstream chamber having a first flexible membrane and receiving fluid through an inlet; a downstream chamber that is downstream of the upstream chamber and communicates with the upstream chamber via a communication port; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that increases the volume of the upstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port, The valve mechanism is characterized in that the opening and closing portion has a magnetic force.

6. an upstream chamber into which a fluid flows via an inlet; a downstream chamber having a first flexible membrane and communicating with the upstream chamber via a communication port downstream of the upstream chamber; a second flexible membrane separating the upstream chamber and the downstream chamber; an opening / closing unit that can open and close the communication port; a biasing portion that biases the first flexible membrane in a direction that increases the volume of the downstream chamber, The opening and closing section is a shaft portion provided across the upstream chamber and the downstream chamber and movable in response to displacement of the first flexible film and the second flexible film; a valve portion connected to the shaft portion and configured to open and close the communication port, The valve mechanism is characterized in that the opening and closing portion has a magnetic force.

7. 7. The valve mechanism according to claim 1, The shaft portion is inserted into the second flexible membrane, one end of the shaft portion is connected to the first flexible film; The other end of the shaft portion is connected to the valve portion.

8. 4. The valve mechanism according to claim 1, wherein: The valve mechanism is characterized in that, when atmospheric pressure acts on the outside of the first flexible membrane, the valve mechanism is in an adjusting state for adjusting pressure.

9. 7. The valve mechanism according to claim 4, wherein: A valve mechanism characterized in that when no external magnetic force is acting on the opening / closing portion, the valve mechanism is in an adjusting state for adjusting pressure.

10. The valve mechanism according to claim 1; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a pressure generating unit that applies pressure to the air chamber.

11. The valve mechanism according to claim 2; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a pressure generating unit that applies pressure to the air chamber.

12. The valve mechanism according to claim 3; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a pressure generating unit that applies pressure to the air chamber.

13. The valve mechanism according to claim 4; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a magnetic force generating unit that applies a magnetic force to the opening and closing unit.

14. The valve mechanism according to claim 5; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a magnetic force generating unit that applies a magnetic force to the opening and closing unit.

15. The valve mechanism according to claim 6; a fluid storage portion that stores a fluid; a fluid flow path connected to the fluid reservoir and provided with the valve mechanism; a pressure fluctuation mechanism that fluctuates the pressure of the fluid flowing through the fluid flow path; a magnetic force generating unit that applies a magnetic force to the opening and closing unit.

16. The fluid flow device of claim 10 or claim 12, the valve mechanism is a first valve mechanism, The inlet is a first inlet, The upstream chamber is a first upstream chamber, The communication port is a first communication port, The downstream chamber is a first downstream chamber, The air chamber is a first air chamber, The opening / closing unit is a first opening / closing unit, The biasing portion is a first biasing portion, The shaft portion is a first shaft portion, When the valve portion is a first valve portion, a second valve mechanism; The second valve mechanism is a second upstream chamber into which the fluid flows via a second inlet; a second downstream chamber downstream of the second upstream chamber and communicating with the second upstream chamber via a second communication port; a second air chamber that can communicate with an external space; a third flexible membrane separating the second upstream chamber and the second air chamber; a fourth flexible membrane separating the second upstream chamber and the second downstream chamber; a second opening / closing unit that can open and close the second communication port; a biasing portion that biases the third flexible membrane in a direction that increases the volume of the second upstream chamber, The second opening / closing unit is a second shaft portion provided across the second upstream chamber and the second downstream chamber and movable in response to displacement of the third flexible membrane and the fourth flexible membrane; a second valve portion connected to the second shaft portion and configured to open and close the second communication port.

17. 15. The fluid flow device of claim 13 or claim 14, The valve mechanism is a first valve mechanism, The inlet is a first inlet, The upstream chamber is a first upstream chamber, The communication port is a first communication port, the downstream chamber is a first downstream chamber; The opening / closing unit is a first opening / closing unit, The biasing portion is a first biasing portion, The shaft portion is a first shaft portion, If the valve portion is a first valve portion, a second valve mechanism; The second valve mechanism is a second upstream chamber having a third flexible membrane and receiving fluid through a second inlet; a second downstream chamber downstream of the second upstream chamber and communicating with the second upstream chamber via a second communication port; a fourth flexible membrane separating the second upstream chamber and the second downstream chamber; a second opening / closing unit that can open and close the second communication port; a biasing portion that biases the third flexible membrane in a direction that increases the volume of the second downstream chamber, The second opening / closing unit is a second shaft portion provided across the second upstream chamber and the second downstream chamber and movable in response to displacement of the third flexible membrane and the fourth flexible membrane; a second valve portion connected to the second shaft portion and configured to open and close the second communication port, The fluid flow device, wherein the second opening and closing part has a magnetic force.

18. A fluid flow device according to any one of claims 10 to 15; a fluid ejection portion provided in the fluid flow path.

19. A fluid flow device according to claim 16; a fluid discharge unit capable of discharging the fluid, The fluid flow path is a first fluid flow path having a downstream end connected to the fluid discharge portion; a second fluid flow path having an upstream end connected to the fluid discharge portion, the first valve mechanism is located in the first fluid flow path; The fluid ejection device, wherein the second valve mechanism is located in the second fluid flow path.

20. A fluid flow device according to claim 17; a fluid discharge unit capable of discharging the fluid, The fluid flow path is a first fluid flow path having a downstream end connected to the fluid discharge portion; a second fluid flow path having an upstream end connected to the fluid discharge portion, the first valve mechanism is located in the first fluid flow path; The fluid ejection device, wherein the second valve mechanism is located in the second fluid flow path.

21. a fluid discharge unit capable of discharging a fluid; a first fluid storage section that stores a fluid; a second fluid storage section that stores a fluid; a first fluid flow path connecting the first fluid storage portion and the fluid discharge portion; a second fluid flow path connecting the second fluid storage portion and the fluid discharge portion; a pressure fluctuation mechanism that fluctuates the pressure of the fluid stored in the first fluid storage section and the second fluid storage section; a first pressure regulating valve provided in the first fluid flow path; a second pressure regulating valve provided in the second fluid flow path; a switching unit capable of switching the states of the first pressure regulating valve and the second pressure regulating valve, The first pressure regulating valve is a first adjustment state in which the pressure downstream of the first pressure adjustment valve in the first fluid flow path is adjusted to a first set pressure; a first open state in which the pressure downstream of the first pressure regulating valve is adjusted to a pressure higher than the first set pressure by maintaining the first fluid flow path open, The second pressure regulating valve is a second adjustment state in which the pressure upstream of the second pressure adjustment valve in the second fluid flow path is adjusted to a second set pressure; a first open state in which the second fluid flow path is maintained open, thereby adjusting the pressure upstream of the second pressure regulating valve to a pressure lower than the second set pressure; and a second open state in which the second fluid flow path is maintained open, thereby adjusting the pressure upstream of the second pressure regulating valve to a pressure lower than the second set pressure.

22. 22. The fluid ejection device of claim 21, The fluid ejection device, wherein the first pressure adjustment valve and the second pressure adjustment valve are switched between states by the application of magnetic force by the switching unit.

23. 22. The fluid ejection device of claim 21, The fluid ejection device, wherein the first pressure adjustment valve and the second pressure adjustment valve are switched between states when pressure is applied by the switching unit.

24. 24. The fluid ejection device according to claim 21, the first pressure regulating valve is switchable to a first closed state in which the first fluid flow path is kept closed; The fluid ejection device, wherein the second pressure adjustment valve is switchable to a second closed state in which the second fluid flow path is kept closed.

25. 24. The fluid ejection device of claim 23, The switching unit is a first gas flow path connected to the first pressure regulating valve; a second gas flow path connected to the second pressure regulating valve; a third gas flow path through which the pressurized gas flows; a fourth gas flow path through which the decompressed gas flows; and a switching mechanism for switching the connection state of each gas flow path.

26. 26. The fluid ejection device of claim 25, The pressure fluctuation mechanism includes: a pressure pump that pressurizes the first fluid storage portion; a decompression pump that decompresses the second fluid storage section, the third gas flow path allows gas pressurized by the pressure pump to flow; The fluid ejection device, wherein the fourth gas flow path allows gas decompressed by the decompression pump to flow through the fourth gas flow path.

27. 27. The fluid ejection device of claim 26, the first pressure regulating valve is in the first open state when the first gas flow path and the third gas flow path are connected to each other; The fluid ejection device, wherein the second pressure adjustment valve is in the second open state when the second gas flow path and the fourth gas flow path are connected to each other.

28. 28. The fluid ejection device of claim 27, The first pressure regulating valve is a first closed state that maintains a state in which the first fluid flow path is closed; When the first gas flow path and the fourth gas flow path are connected to each other, the first closed state is established; The second pressure regulating valve is a second closed state that maintains the second fluid flow path closed; The fluid ejection device is in the second closed state when the second gas flow path and the third gas flow path are connected to each other.

29. 29. The fluid ejection device according to any one of claims 25 to 28, the switching unit has a fifth gas flow path that is open to the atmosphere, the first pressure regulating valve is in the first regulating state when the first gas flow path and the fifth gas flow path are connected to each other; The fluid ejection device, wherein the second pressure adjustment valve is in the second adjustment state when the second gas flow path and the fifth gas flow path are connected to each other.

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