Negative pressure regulating valve and ink-jet recording device with the same

Abstract

To provide a negative pressure regulating valve, with a simple configuration, capable of selectively flowing out air and solid matter from an outflow-side pressure chamber and to provide an ink-jet recording device with the same.SOLUTION: A negative pressure regulating valve includes: an inflow-side pressure chamber that communicates with a liquid inflow passage on a liquid storage part side; an outflow-side pressure chamber having a plurality of liquid outflow holes that communicates with a liquid outflow passage on a liquid discharge part side; a communication hole that connects the inflow-side pressure chamber and the outflow-side pressure chamber; a communication hole valve member communicated with the communication hole and movable between a closed position, in which the communication hole is closed in response to pressure changes in the outflow-side pressure chamber, and an open position, in which the communication hole is opened; and an outflow hole valve member provided in each of the plurality of liquid outflow holes and movable between a closed position, in which the liquid outflow hole is closed in response to pressure changes in the outflow-side pressure chamber, and an open position, in which the liquid outflow hole is opened. Regulating pressure in the outflow-side pressure chamber enables selectively opening at least one of the liquid outflow holes.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a negative pressure adjusting valve to be mounted on an inkjet recording apparatus, and to an inkjet recording apparatus equipped with the same. [Background technology]

[0002] In inkjet recording devices, it is important to maintain constant ink ejection conditions and ejection states in order to ensure high print quality. To address this issue, a pressure adjustment unit (negative pressure adjustment valve, damper, etc.) is installed in the ink flow path connecting the ink container and the recording head to store ink and adjust the pressure.

[0003] Patent Document 1 discloses a liquid ejection device having a pressure adjustment unit (negative pressure adjustment valve) that is provided in a liquid flow path connecting a liquid storage unit and a liquid ejection head and stores liquid to adjust the pressure. The pressure adjustment unit has a liquid storage unit that has a liquid outlet hole that communicates with the liquid ejection head and a communication hole that communicates with the liquid storage unit. The liquid storage unit has a displacement wall portion on part of its outer surface that displaces in response to the pressure inside the liquid storage unit.

[0004] Patent Document 2 discloses a liquid storage mechanism (negative pressure adjustment valve) that is provided between a liquid supply unit on the device main body and an inkjet printhead, and that includes a pressure chamber that stores liquid to be supplied to the inkjet printhead, with the pressure chamber having a liquid supply port and a liquid outlet located higher than the bottom of the pressure chamber. The liquid storage mechanism connects a first flow path that flows the liquid in the pressure chamber toward the printhead to the liquid outlet, connects one side of a second flow path to the bottom of the pressure chamber, and connects the other side of the second flow path to the first flow path, with the flow path resistance of the second flow path set greater than the flow path resistance of the first flow path, and the pressure chamber forms a damper mechanism that absorbs pressure fluctuations applied to the ink in the inkjet printhead.

[0005] Patent Document 3 discloses a damper device having a head-side chamber communicating with a recording head, a tank-side chamber communicating with a tank, and multiple communication passages communicating the head-side chamber and the tank-side chamber, a valve for opening and closing the communication passage, a biasing member for biasing the valve in the direction in which the valve closes the communication passage, a pressure-receiving portion that receives atmospheric pressure and changes the volume of the head-side chamber by changing its position, and a force-transmitting portion disposed between the valve and the pressure-receiving portion and transmits the force received from either the valve or the pressure-receiving portion to the other. The valve, biasing member, and force-transmitting portion are provided for each of the multiple communication passages, and the position of the pressure-receiving portion differs for each point in time when each of the multiple force-transmitting portions is able to transmit the force received from either the valve or the pressure-receiving portion to the other, and the total cross-sectional area of ​​the communication passages opened by the valve differs depending on the valve opening / closing state. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-166194 [Patent Document 2] Japanese Patent Application Publication No. 2018-149685 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-94462 Summary of the Invention [Problem to be solved by the invention]

[0007] The outlet pressure chamber of the above-mentioned negative pressure regulating valve has a large volume due to the presence of a diaphragm (displacement wall) that is in contact with the atmosphere and determines the threshold pressure for opening and closing the valve. Therefore, when the valve is opened, the flow rate of the liquid flowing in from the inlet pressure chamber slows, creating areas where the flow stagnates. As a result, when an attempt is made to fill the negative pressure regulating valve from an empty state with liquid, air tends to remain in the outlet pressure chamber, and a large amount of liquid must be flowed to expel the air.

[0008] Furthermore, if the printer is shipped with an initial filler liquid, and the ink is replaced during installation, if the ink is pigment ink, the ink density will be higher than that of the initial filler liquid due to the pigment dispersion. Therefore, the initial filler liquid, which has a low density, tends to remain at the top of the outlet pressure chamber and is difficult to replace with ink. As a result, a large amount of ink must be flushed to completely replace the initial filler liquid with ink. Furthermore, if ink components solidify or foreign matter is mixed in during the printer's use, the solidified matter or foreign matter tends to remain at the bottom of the outlet pressure chamber. As a result, if the solidified matter or foreign matter gets caught in the valve opening and closing section, the valve will not close.

[0009] In the configuration of Patent Document 1, the flow path leading to the outflow pressure chamber toward the recording head is arranged only on the vertically lower side, which causes a problem that air or initial filling liquid tends to remain in the upper part of the outflow pressure chamber.In the configuration of Patent Document 2, the flow path leading to the outflow pressure chamber toward the recording head is arranged only on the vertically upper side, which causes a problem that solidified matter and foreign matter tends to remain in the lower part of the outflow pressure chamber.

[0010] The configuration of Patent Document 3 involves switching the cross-sectional area of ​​the opening / closing valve mechanism between the ink storage section and the head depending on the pressure threshold, but because the outlet pressure chamber does not have two or more flow paths, there is a problem in that it is not possible to optimize the discharge performance depending on the object to be discharged.

[0011] In view of the above problems, an object of the present invention is to provide a negative pressure adjustment valve that can selectively discharge air and solid matter in an outlet pressure chamber with a simple configuration, and an inkjet recording apparatus equipped with the same. [Means for solving the problem]

[0012] In order to achieve the above object, a first aspect of the present invention is a negative pressure adjustment valve connected to a liquid flow path that communicates between a liquid storage portion that stores liquid and a liquid ejection portion that ejects liquid. The negative pressure adjustment valve has an inlet pressure chamber, an outlet pressure chamber, a communication hole, a communication hole valve member, and an outlet hole valve member. The inlet pressure chamber communicates with a liquid inlet path that is a liquid flow path on the liquid storage portion side. The outlet pressure chamber has multiple liquid outlet holes that communicate with liquid outlet paths that are liquid flow paths on the liquid ejection portion side. The communication hole communicates between the inlet pressure chamber and the outlet pressure chamber. The communication hole valve member is inserted into the communication hole and is movable between a closed position that closes the communication hole and an open position that opens the communication hole in response to pressure changes in the outlet pressure chamber. The outlet hole valve member is provided for each of the multiple liquid outlet holes and is movable between a closed position that closes the liquid outlet hole and an open position that opens the liquid outlet hole in response to pressure changes in the outlet pressure chamber. At least one of the liquid outlet holes can be selectively opened by adjusting the pressure in the outlet pressure chamber. [Effects of the Invention]

[0013] According to the first configuration of the present invention, the outflow path of the liquid from the negative pressure adjustment valve can be switched to one of the plurality of liquid outflow holes by adjusting the pressure in the outflow pressure chamber, so that the outflow path of the liquid from the negative pressure adjustment valve can be selected arbitrarily depending on the object to which the liquid is to be preferentially discharged from the outflow pressure chamber. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram showing the general configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] A plan view of the recording unit 9 included in the printer 100. [Figure 3] 1 is a schematic diagram showing the arrangement of an ink flow path 40, an ink container 30 connected to the ink flow path 40, a negative pressure adjustment valve 31, and a recording head 17. [Figure 4] FIG. 10 is a side cross-sectional view of the negative pressure adjustment valve 31, showing a state in which ink is normally supplied from the ink container 30 to the recording head 17. [Figure 5] FIG. 1 is a side cross-sectional view of the negative pressure adjustment valve 31, showing a state in which the negative pressure in the outlet pressure chamber 51 is set to a first pressure P1. [Figure 6] FIG. 10 is a side cross-sectional view of the negative pressure adjustment valve 31, showing a state in which the negative pressure in the outlet pressure chamber 51 is set to a second pressure P2. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1. Configuration of Inkjet Recording Apparatus Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing the general configuration of a printer 100 as an inkjet recording device according to an embodiment of the present invention. The printer 100 is equipped with a paper feed cassette 2, which is a paper storage unit. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Inside the paper feed cassette 2, paper P, which is an example of a recording medium, is stored.

[0016] A paper feed device 3 is disposed downstream in the paper transport direction of the paper feed cassette 2, i.e., above the right side of the paper feed cassette 2 in Fig. 1. The paper feed device 3 separates and feeds the paper P one sheet at a time toward the upper right of the paper feed cassette 2 in Fig. 1.

[0017] The printer 100 is equipped with a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner, in the paper feed direction, of the paper feed cassette 2. Paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0018] A pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first transport unit 5 and a recording unit 9 are arranged immediately downstream in the paper transport direction of the pair of registration rollers 13. The paper P sent out from the paper feed cassette 2 passes through the first paper transport path 4a and reaches the pair of registration rollers 13. The pair of registration rollers 13 corrects skewed feed of the paper P and sends the paper P toward the first transport unit 5 (particularly the first transport belt 8, which will be described later) in time with the ink ejection operation performed by the recording unit 9.

[0019] 2 is a plan view of the recording unit 9. The recording unit 9 includes a head housing 10 and line heads 11Y, 11M, 11C, and 11K. The line heads 11Y to 11K are held in the head housing 10 at a height that forms a predetermined gap (for example, 1 mm) with respect to the conveyance surface of an endless first conveyor belt 8 that is stretched over multiple rollers including a drive roller 6a, a driven roller 6b, and a tension roller (not shown). The drive roller 6a causes the first conveyor belt 8 to travel in the conveyance direction of the paper P (the direction of arrow A).

[0020] Each of the line heads 11Y to 11K has a plurality of (three in this example) recording heads 17a to 17c. The recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (arrow BB' direction), which is perpendicular to the paper transport direction (arrow A direction). Each of the recording heads 17a to 17c has a plurality of ink ejection orifices 18 (nozzles). The ink ejection orifices 18 are arranged at equal intervals along the width direction of the recording head, i.e., the paper width direction (arrow BB' direction). From the line heads 11Y to 11K, inks of yellow (Y), magenta (M), cyan (C), and black (K) are ejected via the ink ejection orifices 18 of the recording heads 17a to 17c toward the paper P transported by the first transport belt 8.

[0021] Four colors of ink (yellow, magenta, cyan, and black) are supplied to the recording heads 17a to 17c constituting each of the line heads 11C to 11K from ink containers 30 (see FIG. 1). A negative pressure adjustment valve 31 (see FIG. 1) is connected between the ink containers 30 and the recording heads 17a to 17c. The detailed configuration of the negative pressure adjustment valve 31 will be described later.

[0022] In response to a control signal from the control device 110 (see FIG. 1), each of the recording heads 17a to 17c ejects ink from the ink ejection openings 18 toward the paper P, which is adsorbed and held on the conveying surface of the first conveyor belt 8 and conveyed, in accordance with image data received from an external computer. As a result, a color image is formed on the paper P on the first conveyor belt 8, with inks of four colors, yellow, magenta, cyan, and black, superimposed on top of each other.

[0023] Returning to FIG. 1, the paper P sent to the first transport unit 5 by the pair of registration rollers 13 is transported by the first transport belt 8 to a position facing the recording unit 9 (particularly recording heads 17a to 17c, which will be described later). Ink is ejected from the recording unit 9 onto the paper P, thereby recording an image on the paper P. The ejection of ink in the recording unit 9 is controlled by a control device 110 inside the printer 100.

[0024] In the paper transport direction, a second transport unit 12 is disposed downstream of the first transport unit 5 (on the left side in FIG. 1). The paper P on which an image has been recorded by the recording unit 9 is sent to the second transport unit 12. The ink ejected onto the surface of the paper P is dried while passing through the second transport unit 12.

[0025] In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side of the printer body 1. The paper P from which the ink has been dried by the second transport unit 12 is sent to the decurler unit 14, where any curl that has occurred in the paper P is straightened.

[0026] In the paper transport direction, a second paper transport path 4b is provided downstream (upper in FIG. 1) of the decurler unit 14. If double-sided recording is not performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged to a paper discharge tray 15 provided outside the left side of the printer 100.

[0027] In addition, a maintenance unit 19 and a cap unit 20 are disposed below the second transport unit 12. When performing purging, the maintenance unit 19 moves horizontally below the recording unit 9, wipes off ink discharged from the ink discharge ports of the recording heads, and collects the wiped ink. Purging refers to the operation of forcibly discharging ink from the ink discharge ports of the recording heads 17a to 17c in order to expel thickened ink, foreign matter, and air bubbles from the ink discharge ports. When capping the ink discharge surfaces of the recording heads, the cap unit 20 moves horizontally below the recording unit 9 and then moves upward to be attached to the undersides of the recording heads 17a to 17c.

[0028] 2. Configuration of ink flow path including negative pressure adjustment valve 3 is a schematic diagram showing the arrangement of an ink flow path 40, an ink container 30 connected to the ink flow path 40, a negative pressure adjustment valve 31, and a recording head 17. In the following description, the recording heads 17a to 17c will be simply referred to as recording head 17. The up and down directions in FIGS. 3 and 4 to 6 correspond to the vertical direction (the direction of gravity).

[0029] The ink flow path 40 has an ink inlet path 41, a first outlet path 42, and a second outlet path 43. A negative pressure adjustment valve 31 is connected between the ink inlet path 41 and the first and second outlet paths 42 and 43.

[0030] Ink introduced from the ink container 30 into the ink flow path 40 is supplied to the recording head 17 via the ink inflow path 41, the negative pressure adjustment valve 31, the first outflow path 42, and the second outflow path 43. A pressure pump 33 is connected to the ink inflow path 41. The pressure pump 33 maintains the internal pressure of the inflow side pressure chamber 50 (see FIG. 4) of the negative pressure adjustment valve 31 at a constant pressure higher than the internal pressure of the outflow side pressure chamber 51 (see FIG. 4).

[0031] It is also possible to adopt a configuration in which the pressure inside the inlet pressure chamber 50 is maintained at a constant pressure by using the ink head pressure, by locating the ink container 30 at a position higher than the negative pressure adjustment valve 31, without providing the pressure pump 33. Furthermore, if a sub-tank (not shown) is located between the ink container 30 and the negative pressure adjustment valve 31, the sub-tank may be located at a position higher than the negative pressure adjustment valve 31.

[0032] A cap 201 is attached to the recording head 17. The cap 201 is supported by a cap unit 20 (see FIG. 1) and is attached to the ink ejection surface (nozzle surface) 171 of the recording head 17 when printing processing is not performed for a certain period of time or more. By attaching the cap 201, the ink ejection surface 171 of the recording head 17 is kept sealed. The cap 201 is provided with a flow path (not shown) that communicates with the atmosphere, and prevents excessive pressure changes from occurring in the nozzles of the recording head due to temperature changes in the space between the ink ejection surface 171 and the cap 201. A suction pump 45 and a waste ink discharge flow path 47 are connected to the cap 201.

[0033] In the printer 100, in order to remove dried or thickened ink and foreign matter from inside the ink ejection ports 18 (see FIG. 2) of the recording head 17, when starting printing after a long period of inactivity or between printing operations, a cap 201 is attached to the ink ejection surface 171, and with the flow path communicating with the atmosphere closed, a suction purge process is performed in which the air is sucked from the space (sealed space) between the ink ejection surface 171 and the cap 201 using the suction pump 45 to forcibly suck ink from all of the ink ejection ports 18 of the recording head 17, in preparation for the next printing operation. The ink sucked into the cap 201 from the recording head 17 (purged ink) is discharged outside the cap 201 by the suction pump 45 and then collected in a waste ink tank (not shown) via a waste ink discharge flow path 47.

[0034] The suction purge process is also performed when initially filling the ink flow path 40 with initial filling liquid or ink, when replacing the ink flow path 40 filled with initial filling liquid with ink, and when discharging air or foreign matter from the ink flow path 40.

[0035] [3. Configuration of the negative pressure adjustment valve] 4 is a side cross-sectional view of the negative pressure adjustment valve 31 according to one embodiment of the present invention. The negative pressure adjustment valve 31 stores ink flowing through the ink flow path 40 and functions as a pressure adjustment valve that opens and closes the ink flow path 40 in accordance with the pressure on the recording head 17 side. The negative pressure adjustment valve 31 has an inlet pressure chamber 50, an outlet pressure chamber 51, a first valve member 52a, a second valve member 52b, a third valve member 52c, a first opening / closing pressure adjustment spring 53a, a second opening / closing pressure adjustment spring 53b, and a link member 57.

[0036] The inlet pressure chamber 50 is connected to the ink inlet channel 41. The inlet pressure chamber 50 has a predetermined volume for storing ink that has flowed in from the ink inlet channel 41. The inlet pressure chamber 50 is connected to the outlet pressure chamber 51 by a communication hole 54. The inlet pressure chamber 50 accommodates one end (large diameter portion) of a first valve member 52a that can close the communication hole 54, and a first opening / closing pressure adjustment spring 53a.

[0037] The outflow pressure chamber 51 has a first outflow hole 51a to which the first outflow path 42 is connected, a second outflow hole 51b to which the second outflow path 43 is connected, and a diaphragm portion 55. The outflow pressure chamber 51 stores ink that has flowed in from the communication hole 54. The volume of the outflow pressure chamber 51 changes depending on the displacement of the diaphragm portion 55.

[0038] The first outlet hole 51a is connected to the recording head 17 via the first outlet path 42. The first outlet hole 51a is formed at a position lower than the communication hole 54. In this embodiment, the first outlet hole 51a is formed at the lower end of the outlet-side pressure chamber 51.

[0039] The second outlet hole 51b is connected to the recording head 17 via the second outlet path 43. The second outlet hole 51b is formed at a higher position than the communication hole 54. In this embodiment, the second outlet hole 51b is formed at the upper end of the outlet-side pressure chamber 51.

[0040] The outlet side pressure chamber 51 accommodates the other end (small diameter portion) of the first valve member 52a, the second valve member 52b, the third valve member 52c, the second opening / closing pressure adjustment spring 53b, a pressure plate 56, a link member 57, and a pressing member 58.

[0041] The first valve member 52a is movable between a closed position where it closes the communication hole 54 and an open position where it opens the communication hole 54 against the bias of the opening / closing pressure adjustment spring 53, in response to pressure changes in the outlet pressure chamber 51. The second valve member 52b and the third valve member 52c are each movable between a closed position where it closes the first outlet hole 51a and the second outlet hole 51b, and an open position where it opens the first outlet hole 51a and the second outlet hole 51b, in response to pressure changes in the outlet pressure chamber 51.

[0042] The diaphragm portion 55 is formed from a laminated flexible resin film. The diaphragm portion 55 is fixed to the outer surface of the outlet pressure chamber 51 with a predetermined amount of slack. The diaphragm portion 55 displaces in response to pressure changes within the outlet pressure chamber 51, changing the volume of the outlet pressure chamber 51.

[0043] The pressure plate 56 is fixed to the inner surface of the diaphragm portion 55 (the resin layer facing the outlet-side pressure chamber 51) and is movable integrally with the diaphragm portion 55. The other end (small diameter portion) of the first valve member 52a inserted into the communication hole 54 abuts against the pressure plate 56. A force acts on the pressure plate 56 by the biasing force of the first opening / closing pressure adjusting spring 53a via the first valve member 52a in a direction that displaces (expands) the diaphragm portion 55 outward.

[0044] The link member 57 is connected to the second valve member 52b and the third valve member 52c, and transmits the displacement of the diaphragm portion 55 to the second valve member 52b and the third valve member 52c. A second opening / closing pressure adjusting spring 53b and a pressing member 58 are fitted onto the first valve member 52a. The link member 57 is biased by the second opening / closing pressure adjusting spring 53b in a direction approaching the diaphragm portion 55 (to the right in FIG. 4). The pressing member 58 transmits the displacement of the diaphragm portion 55 to the link member 57 via the pressure receiving plate 56.

[0045] 4 shows the negative pressure adjustment valve 31 in a state where ink is normally supplied from the ink container 30 to the recording head 17. When the recording head 17 is filled with ink, the pressure inside the outlet pressure chamber 51 is maintained constant, and the communication hole 54 is closed by the first valve member 52a. The second valve member 52b opens the first outlet hole 51a, and the third valve member 52c opens the second outlet hole 51b. In the state shown in FIG. 4, the communication hole 54 is closed, so no ink is supplied from the inlet pressure chamber 50 to the outlet pressure chamber 51.

[0046] As ink is consumed in the recording head 17 and the pressure in the outlet pressure chamber 51 decreases, the diaphragm 55 is displaced inward (contracts). This causes the pressure-receiving plate 56 to press the first valve member 52a into the inlet pressure chamber 50 (open position) against the biasing force of the first opening / closing pressure adjustment spring 53a, opening the communication hole 54. As a result, ink is supplied from the inlet pressure chamber 50 to the outlet pressure chamber 51. When the pressure in the outlet pressure chamber 51 reaches a predetermined negative pressure, the biasing force of the first opening / closing pressure adjustment spring 53a pushes the first valve member 52a back into the outlet pressure chamber 51 (closed position), closing the communication hole 54 and stopping the supply of ink from the inlet pressure chamber 50 to the outlet pressure chamber 51. In this way, the pressure of ink supplied to the recording head 17 is adjusted.

[0047] When performing the suction purge process, the ink ejection surface 171 of the recording head 17 is covered with the cap 201, and the space (sealed space) between the ink ejection surface 171 and the cap 201 is sucked by the suction pump 45 to generate negative pressure. This causes the liquid (ink or initial filling liquid) inside the recording head 17 to be discharged from the ink ejection ports 18.

[0048] At this time, the outlet pressure chamber 51 in the negative pressure adjustment valve 31 becomes negative pressure, and the first valve member 52a is pressed by the diaphragm portion 55. As a result, the first valve member 52a moves into the inlet pressure chamber 50 against the biasing force of the first opening / closing pressure adjustment spring 53a, opening the communication hole 54 and connecting the inlet pressure chamber 50 to the outlet pressure chamber 51. This causes liquid to flow from the ink container 30 through the ink inlet channel 41, the negative pressure adjustment valve 31, and the first outlet channel 42 (or the second outlet channel 43) to the recording head 17.

[0049] 5 is a side cross-sectional view of the negative pressure adjustment valve 31, showing a state in which the negative pressure in the outlet pressure chamber 51 is set to a first pressure P1. When the negative pressure in the outlet pressure chamber 51 is set to the first pressure P1 by the suction purge process, as shown in FIG. 5, the diaphragm portion 55 presses the first valve member 52a, opening the communication hole 54 and connecting the inlet pressure chamber 50 and the outlet pressure chamber 51.

[0050] Further, the second valve member 52b is spaced apart from the first outflow hole 51a, and the first outflow hole 51a is in an open state. On the other hand, the third valve member 52c is in contact with the second outflow hole 51b, and the second outflow hole 51b is in a closed state. As a result, ink flows from the outflow-side pressure chamber 51 through the first outflow hole 51a and the first outflow path 42 to the recording head 17.

[0051] FIG. 6 is a side cross-sectional view of the negative pressure regulating valve 31, showing a state in which the negative pressure in the outflow-side pressure chamber 51 is the second pressure P2 (P1 < P2). When the negative pressure in the outflow-side pressure chamber 51 is set to the second pressure P2 by the suction purge process, as shown in FIG. 6, the first valve member 52a is pressed by the diaphragm portion 55 and the communication hole 54 is opened, and the inflow-side pressure chamber 50 and the outflow-side pressure chamber 51 are communicated with each other.

[0052] Further, due to the displacement of the diaphragm portion 55, the link member 57 is pressed inward from the state shown in FIG. 5 via the pressure receiving plate 56 and the pressing member 58, and the second valve member 52b moves in a direction approaching the first outflow hole 51a to close the first outflow hole 51a. Further, the third valve member 52c moves in a direction away from the second outflow hole 51b to open the second outflow hole 51b. As a result, ink flows from the outflow-side pressure chamber 51 through the second outflow hole 51b and the second outflow path 43 to the recording head 17.

[0053] [[ID=......]] According to the configuration of the present embodiment, by changing the negative pressure in the outflow-side pressure chamber 51 between the first pressure P1 and the second pressure P2, the outflow path from the negative pressure regulating valve 31 to the recording head 17 can be switched between the path passing through the first outflow hole 51a and the first outflow path 42 and the path passing through the second outflow hole 51b and the second outflow path 43.

[0054] Thereby, the outflow path from the negative pressure regulating valve 31 can be arbitrarily selected according to the object to be preferentially discharged from the outflow-side pressure chamber 51. The negative pressure in the outflow-side pressure chamber 51 can be adjusted by adjusting the negative pressure in the cap 201 by the suction pump 45 when performing the suction purge process.

[0055] For example, solid matter such as solidified ink components and foreign matter contained in the liquid flowing into the outflow pressure chamber 51 accumulates in the lower part of the outflow pressure chamber 51. Therefore, if it is desired to preferentially flush out the solid matter contained in the ink by performing a suction purge process while the printer 100 is in use, the negative pressure inside the outflow pressure chamber 51 is set to a first pressure P1, as shown in FIG. 5, and the first outflow hole 51a formed in the lower part of the outflow pressure chamber 51 is opened.

[0056] As a result, solid matter in the outlet pressure chamber 51 flows out smoothly and efficiently from the first outlet hole 51a through the first outlet path 42 and does not remain in the outlet pressure chamber 51. This prevents solid matter from getting caught in the gap between the first valve member 52a and the communication hole 54 or the gap between the second valve member 52b and the first communication hole 51a, preventing the first valve member 52a and the second valve member 52b from moving.

[0057] Furthermore, air contained in the liquid flowing into the outflow pressure chamber 51 accumulates above the outflow pressure chamber 51. Therefore, when the ink flow path 40 is filled with initial filling liquid by performing a suction purge process before shipping the printer 100, the negative pressure inside the outflow pressure chamber 51 is set to a second pressure P2, and the second outflow hole 51b formed above the outflow pressure chamber 51 is opened, as shown in FIG.

[0058] As a result, the air inside the outflow-side pressure chamber 51 flows out smoothly and efficiently from the second outflow hole 51b formed in the upper part of the outflow-side pressure chamber 51 through the second outflow path 43, and does not remain in the outflow-side pressure chamber 51. Therefore, the flow rate of the initial fill liquid when filling the ink flow path 40 with the initial fill liquid can be reduced.

[0059] Furthermore, when the initial filling liquid in the ink flow path 40 is replaced with ink, the initial filling liquid with a low density moves to the upper part of the outflow pressure chamber 51, and the ink with a high density moves to the lower part of the outflow pressure chamber 51. Therefore, when the initial filling liquid in the ink flow path 40 is replaced with ink by performing a suction purge process when installing the printer 100, the negative pressure in the outflow pressure chamber 51 is set to a second pressure P2, and the second outflow hole 51b formed in the upper part of the outflow pressure chamber 51 is opened, as shown in FIG.

[0060] As a result, the initial filling liquid in the outflow-side pressure chamber 51 flows out smoothly and efficiently from the second outflow hole 51b formed in the upper part of the outflow-side pressure chamber 51 via the second outflow path 43, so that no initial filling liquid remains in the outflow-side pressure chamber 51. Therefore, it is possible to reduce the flow rate of ink when the initial filling liquid in the ink flow path 40 is replaced with ink.

[0061] Furthermore, because the outflow path can be switched by the negative pressure applied to the outflow-side pressure chamber 51, there is no need for on-off valves for opening and closing the first outflow path 42 and the second outflow path 43, or drive units such as cams, motors, and solenoids for switching the on-off valves. This simplifies the configuration and control of the device, which is also advantageous in terms of cost.

[0062] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the above-described embodiment, the negative pressure in the outlet-side pressure chamber 51 is set to the first pressure P1, the first outlet hole 51a is open, and the negative pressure in the outlet-side pressure chamber 51 is set to the second pressure P2, the second outlet hole 51b is open. Instead of this configuration, the configurations of the second valve member 52b and the third valve member 52c may be reversed, so that the negative pressure in the outlet-side pressure chamber 51 is set to the first pressure P1, the second outlet hole 51b is open, and the negative pressure in the outlet-side pressure chamber 51 is set to the second pressure P2, the first outlet hole 51a is open.

[0063] In addition, in the above embodiment, two liquid outflow holes, the first outflow hole 51a and the second outflow hole 51b, are formed in the outflow side pressure chamber 51, and the second valve member 52b and the third valve member 52c are provided to open and close the first outflow hole 51a and the second outflow hole 51b, respectively, but it is also possible to provide three or more liquid outflow holes and three or more outflow hole valve members to open and close them.

[0064] In addition, in the above embodiment, the recording head 17, the negative pressure adjustment valve 31, the pressure pump 33, and the suction pump 45 are exemplified as components connected to the ink flow path 40, but the present invention is also applicable to configurations in which other components are connected to the ink flow path 40.

[0065] In addition, in the above embodiment, an example was described in which a color printer that records color images using four colors of ink was used as the inkjet recording device, but the ink supply unit of this embodiment can also be used when a monochrome printer that records monochrome images using black ink is used. [Industrial Applicability]

[0066] The present invention is applicable to a negative pressure adjustment valve connected between a liquid storage unit such as an ink container and a liquid ejection unit such as a recording head, and to an inkjet recording device such as an inkjet printer equipped with a negative pressure adjustment valve. [Explanation of symbols]

[0067] 17, 17a to 17c recording head (liquid ejection unit) 18 Ink outlet (nozzle) 30 Ink container (liquid storage section) 31 Negative pressure adjustment valve 33 Pressure pump 40 Ink flow path (liquid flow path) 41 Ink inlet channel (liquid inlet channel) 42 1st outflow path (liquid outflow path) 43 2nd outflow path (liquid outflow path) 45 Suction Pump 47 Waste ink discharge flow path 50 inlet pressure chamber 51 Outlet pressure chamber 51a 1st outflow hole (liquid outflow hole) 51b 2nd outflow hole (liquid outflow hole) 52a First valve member (communication hole valve member) 52b Second valve member (first outlet port valve member) 52c third valve member (second outlet port valve member) 53a First opening / closing pressure adjusting spring (biasing member) 53b Second opening / closing pressure adjusting spring (biasing member) 54 Communication hole 55 Diaphragm part 56 Pressure plate 57 Link member 100 Printers (inkjet recording devices) A. Air S solids

Claims

1. a liquid storage section that stores liquid; a liquid ejection unit that ejects the liquid; A negative pressure regulating valve connected to a liquid flow path communicating between an inflow pressure chamber communicating with a liquid inflow channel, which is the liquid flow channel on the liquid storage portion side; an outflow pressure chamber having a plurality of liquid outflow holes communicating with a liquid outflow path, which is the liquid flow path on the liquid ejection unit side; a communication hole that communicates the inlet pressure chamber with the outlet pressure chamber; a communication hole valve member that is inserted into the communication hole and that is movable between a closing position where the communication hole is closed and an opening position where the communication hole is opened in response to a pressure change in the outlet pressure chamber; an outflow hole valve member provided in each of the plurality of liquid outflow holes, the outflow hole valve member being movable between a closing position where the liquid outflow hole is closed and an opening position where the liquid outflow hole is opened in response to a pressure change in the outflow pressure chamber; and A negative pressure regulating valve, characterized in that at least one of the liquid outflow holes can be selectively opened by adjusting the pressure in the outflow pressure chamber.

2. The outlet pressure chamber has the liquid outlet hole, a first outlet hole formed below the communication hole; a second outlet hole formed above the communication hole; and The communication hole valve member includes: a first outlet port valve member that opens and closes the first outlet port; a second outlet port valve member that opens and closes the second outlet port; 2. The negative pressure regulating valve according to claim 1, further comprising:

3. 3. The negative pressure regulating valve according to claim 2, wherein the first outlet hole is formed at a lower end of the outlet pressure chamber, and the second outlet hole is formed at an upper end of the outlet pressure chamber.

4. when the pressure in the outlet pressure chamber reaches a first pressure, the communication hole valve member and the first outlet hole valve member move to the open position and the second outlet hole valve member moves to the closed position, thereby causing the liquid to flow out of the outlet pressure chamber through the first outlet hole, 3. The negative pressure regulating valve according to claim 2, wherein when the pressure in the outlet-side pressure chamber reaches a second pressure different from the first pressure, the communication hole valve member and the second outlet-hole valve member move to the open position and the first outlet-hole valve member moves to the closed position, thereby allowing the liquid to flow out of the outlet-side pressure chamber through the second outlet hole.

5. a diaphragm portion that constitutes a part of the outlet pressure chamber and that changes the volume of the outlet pressure chamber by being displaced in response to a pressure change in the outlet pressure chamber; a biasing member that biases the valve member toward the closed position; and 2. The negative pressure regulating valve according to claim 1, wherein the communication hole valve member and the outflow hole valve member are moved between the closed position and the open position by displacement of the diaphragm portion and the biasing force of the biasing member.

6. an ink container for storing liquid ink; one or more recording heads each having a plurality of nozzles for ejecting the ink; an ink flow path that connects the ink container and the recording head; a negative pressure adjusting valve according to any one of claims 1 to 5, connected to the ink flow path; An inkjet recording apparatus comprising:

7. an ink container for storing liquid ink; one or more recording heads each having a plurality of nozzles for ejecting the ink; an ink flow path that connects the ink container and the recording head; a negative pressure adjusting valve according to claim 4 connected to the ink flow path; a cap that is attached to the ink ejection surface of the recording head and that can form a sealed space between the cap and the ink ejection surface; a suction pump that sucks air from inside the cap; a waste ink discharge flow path that discharges the liquid sucked into the inside of the cap by the suction pump; Equipped with an inkjet recording apparatus capable of performing a suction purge process in which, with the cap attached to the ink ejection surface, the air in the sealed space is sucked by the suction pump, thereby forcibly discharging the ink from all the nozzles of the recording head; an ink jet recording apparatus, characterized in that the pressure in the outlet-side pressure chamber is set to the first pressure or the second pressure and the suction purge process is performed, thereby switching the liquid outlet hole of the outlet-side pressure chamber to the first outlet hole or the second outlet hole.

8. When the suction purge process is performed to discharge solid matter remaining in the ink flow path, 8. The ink jet recording apparatus according to claim 7, wherein the suction purge process is performed with the pressure in the outlet pressure chamber set to the first pressure.

9. When the suction purge process is performed in a state where the ink flow path is empty to fill the ink flow path with initial filling liquid or the ink, or when the suction purge process is performed in a state where the ink flow path is filled with the initial filling liquid to replace the initial filling liquid in the ink flow path with the ink, 8. The ink jet recording apparatus according to claim 7, wherein the suction purge process is performed with the pressure in the outlet pressure chamber set to the second pressure.

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