Pump and valve device

Abstract

To provide a pump and a valve device that can improve convenience of a user.SOLUTION: A pump comprises: a pressure generating part for alternately generating positive pressure and negative pressure in a flow passage; a suction valve for closing a suction port, and opening the suction port when the negative pressure is generated in the flow passage; a discharge valve for closing a discharge port, and opening the discharge port when the positive pressure is generated in the flow passage; a first communication passage capable of making the suction port and the flow passage communicate with each other when the suction valve is closed; a second communication passage capable of making the discharge port and the flow passage communicate with each other when the discharge valve is closed; a first opening / closing valve for opening the first communication passage, and closing the first communication passage when the positive pressure is generated in the flow passage; and a second opening / closing valve for opening the second communication passage, and closing the second communication passage when the negative pressure is generated in the flow passage. When the suction valve is opened, the suction port and the flow passage communicate with each other. When the discharge valve is opened, the discharge port and the flow passage communicate with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to pumps and valve arrangements. [Background technology]

[0002] Conventionally, pumps have been used that include a pressure generating unit, a suction valve, and a discharge valve. The pressure generating unit alternately generates positive pressure and negative pressure inside the pump, for example, by reciprocating movement of a plunger. The pump is provided with a suction port and a discharge port. When negative pressure is generated inside the pump, fluid is sucked into the pump through the suction port. While the fluid is being sucked in, the discharge valve closes the discharge port. When positive pressure is generated inside the pump, fluid is discharged from the pump through the discharge port. While the fluid is being discharged, the suction valve closes the suction port. This type of pump is disclosed, for example, in US Pat. No. 5,399,633. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-184184 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, if the fluid is water and a large amount of water remains in the pump after use, there is a concern that the water will freeze inside the pump and deteriorate the pump. Therefore, in winter or in cold regions, when the user has finished using the pump, he or she may have to manually drain the water from the pump. In other words, this reduces the user's convenience.

[0005] An object of the present disclosure is to provide a pump and a valve device that can improve convenience for users. [Means for solving the problem]

[0006] The pump according to the present disclosure is a pump in which a fluid sucked into a flow path through an intake port is discharged from the flow path through an exhaust port, and the pump comprises a pressure generating unit which alternately generates positive pressure and negative pressure in the flow path, an intake valve which closes the intake port and opens the intake port when negative pressure is generated in the flow path, a exhaust valve which closes the exhaust port and opens the exhaust port when positive pressure is generated in the flow path, a first communication passage which can communicate between the intake port and the flow path when the intake valve is closed, a second communication passage which can communicate between the exhaust port and the flow path when the exhaust valve is closed, a first opening / closing valve which opens the first communication passage and closes the first communication passage when positive pressure is generated in the flow path, and a second opening / closing valve which opens the second communication passage and closes the second communication passage when negative pressure is generated in the flow path, and is characterized in that when the intake valve is open, the intake port and the flow path are connected to each other, and when the exhaust valve is open, the exhaust port and the flow path are connected to each other.

[0007] In the present disclosure, the pressure generating unit alternately generates positive pressure and negative pressure in the flow path. Typically, the inlet is connected, directly or indirectly, to something external to the pump (e.g., a liquid source), while the outlet is connected, directly or indirectly, to something external to the pump (e.g., a nozzle). The suction valve closes the suction port, so communication between the suction port and the flow path through the suction valve is cut off. However, if negative pressure occurs in the flow path, the suction valve opens the suction port, so that the suction port and the flow path communicate with each other through the suction valve. The discharge valve closes the discharge port, so communication between the discharge port and the flow path through the discharge valve is cut off. However, when a positive pressure is generated in the flow path, the discharge valve opens the discharge port, so that the discharge port and the flow path communicate with each other through the discharge valve.

[0008] The first on-off valve opens the first communication passage, so that the suction port and the flow passage communicate with each other through the first communication passage and the first on-off valve. However, when positive pressure is generated in the flow passage, the first on-off valve closes the first communication passage, so that communication between the suction port and the flow passage through the first communication passage and the first on-off valve is interrupted. The second on-off valve opens the second communication passage, so that the discharge port and the flow passage communicate with each other through the second communication passage and the second on-off valve. However, if negative pressure occurs in the flow passage, the second on-off valve closes the second communication passage, so that communication between the discharge port and the flow passage through the second communication passage and the second on-off valve is interrupted.

[0009] When negative pressure occurs in the flow path, the suction valve opens the suction port, and fluid is sucked into the flow path through the suction port from the upstream side of the suction port (e.g., the liquid source side). At this time, the discharge valve closes the discharge port, and the second on-off valve closes the second communication passage, so there is no risk of fluid flowing unnecessarily through the discharge port or the second communication passage. Therefore, there is no risk of the existence of the second communication passage deteriorating the pump performance.

[0010] When positive pressure is generated in the flow path, the discharge valve opens the discharge port, and the fluid is discharged from the flow path through the discharge port to the downstream side of the discharge port. At this time, the suction valve closes the suction port, and the first on-off valve closes the first communication passage, so there is no risk of the fluid flowing unnecessarily through the suction port or the first communication passage. Therefore, there is no risk of the existence of the first communication passage deteriorating the pump performance. As a result of the above, the fluid that has been drawn into the flow passage from the upstream side of the suction port through the suction port is discharged from the flow passage through the discharge port to the downstream side of the discharge port.

[0011] After the pump is no longer in use, the pressure generating unit does not operate, so no positive or negative pressure is generated in the flow path. Therefore, the suction valve closes the suction port, and the discharge valve closes the discharge port. Meanwhile, the first on-off valve opens the first communication passage, so the suction port and the flow path communicate with each other through the first communication passage. Also, the second on-off valve opens the second communication passage, so the discharge port and the flow path communicate with each other through the second communication passage. Then, the flow path communicates with the outside of the pump through the first communication passage and the suction port, and through the second communication passage and the discharge port. Therefore, the fluid remaining in the flow path can be discharged to the outside of the pump. As a result of the above, the user does not need to manually drain the fluid from the pump when finished using it, thereby improving user convenience.

[0012] In the pump disclosed herein, the suction valve comprises a suction side valve seat, a suction side valve body that opens and closes the suction port by seating on and off the suction side valve seat, and a suction side biasing member that biases the suction side valve body in a direction toward seating on the suction side valve seat, and the suction side valve body is lifted from the suction side valve seat by negative pressure generated in the flow path, and the first opening / closing valve comprises a first valve seat provided on the suction side valve body, a first valve body that opens and closes the first communicating passage by seating on and off the first valve seat, and a first biasing member that biases the first valve body in a direction toward seating off the first valve seat, and the first valve body is seated on the first valve seat by positive pressure generated in the flow path.

[0013] In the present disclosure, the suction valve includes a suction side valve seat, a suction side valve body, and a suction side biasing member. When the suction side biasing member biases the suction side valve body so that it seats on the suction side valve seat, the suction port is closed. When negative pressure generated in the flow path causes the suction side valve body to leave the suction side valve seat, the suction port is opened. The first on-off valve includes a first valve seat, a first valve body, and a first biasing member. When the first valve body is seated on the first valve seat due to a positive pressure generated in the flow path, the first communication passage is closed. When the first biasing member biases the first valve body so that the first valve body is separated from the first valve seat, the first communication passage is opened.

[0014] The first valve seat is provided on the suction side valve body. That is, the first valve seat is integral with the suction valve, and the first valve body seated on the first valve seat is integral with the suction valve. As a result, the pump can be constructed compactly.

[0015] The pump according to the present disclosure is characterized in that the discharge valve comprises a discharge side valve seat, a discharge side valve body that opens and closes the discharge port by seating on and off the discharge side valve seat, and a discharge side biasing member that biases the discharge side valve body in a direction in which the discharge side valve body seats on the discharge side valve seat, and the discharge side valve body is lifted off the discharge side valve seat by positive pressure generated in the flow path, and the second opening / closing valve comprises a second valve seat provided on the discharge side valve body, a second valve body that opens and closes the second communication passage by seating on and off the second valve seat, and a second biasing member that biases the second valve body in a direction in which the second valve body leaves the second valve seat, and the second valve body is seated on the second valve seat by negative pressure generated in the flow path.

[0016] In the present disclosure, the discharge valve includes a discharge-side valve seat, a discharge-side valve body, and a discharge-side biasing member. When the discharge-side biasing member biases the discharge-side valve body so that the discharge-side valve body seats on the discharge-side valve seat, the discharge port is closed. When the discharge-side valve body is separated from the discharge-side valve seat by a positive pressure generated in the flow path, the discharge port is opened. The second on-off valve includes a second valve seat, a second valve body, and a second biasing member. When the second valve body is seated on the second valve seat due to negative pressure generated in the flow path, the second communication passage is closed. When the second biasing member biases the second valve body so that the second valve body is separated from the second valve seat, the second communication passage is opened.

[0017] The second valve seat is provided on the discharge side valve body. That is, the second valve seat is integral with the discharge valve, and the second valve body seated on the second valve seat is integral with the discharge valve. As a result, the pump can be constructed compactly.

[0018] The pump of the present disclosure is characterized in that at least a portion of the flow path extends vertically, and when the first on-off valve is open, the suction port is connected to a lower end of the portion via the first communication passage, and when the second on-off valve is open, the discharge port is connected to an upper end of the portion via the second communication passage.

[0019] In the present disclosure, at least a portion of the flow path extends vertically. When the first on-off valve opens the first communication passage, the intake port communicates with the lower end of the vertically extending portion of the flow path via the first communication passage, while when the second on-off valve opens the second communication passage, the discharge port communicates with the upper end of the vertically extending portion of the flow path via the second communication passage. In particular, when the fluid is a liquid, the fluid remaining in the flow path is naturally discharged from the flow path through the first communication passage and the suction port to the outside of the pump due to its own weight, and the outside air naturally flows into the flow path through the discharge port and the second communication passage, accelerating the discharge of the fluid from the pump.

[0020] A valve device according to the present disclosure includes a valve that opens and closes a flow port through which a fluid flows, a communication passage that can communicate a flow path through which the fluid communicates and the flow port when the first valve is closed, and another valve that opens and closes the communication passage, and when the first valve opens the flow port, the flow port and the flow path communicate with each other, and the first valve includes a valve seat, a valve body that opens and closes the flow port by seating on and off the first valve seat, and a biasing member that biases the first valve body in a direction in which the first valve body seats on the first valve seat, The one valve element is separated from the one valve seat by the internal pressure of the flow path when the internal pressure of the flow path is one of positive pressure and negative pressure, and the other valve includes another valve seat provided on the one valve element, another valve element which opens and closes the communicating passage by seating on and off the other valve seat, and another biasing member which biases the other valve element in a direction in which the other valve element separates from the other valve seat, and the other valve element is seated on the other valve seat by the internal pressure of the flow path when the internal pressure of the flow path is the other of positive pressure and negative pressure.

[0021] In the present disclosure, one valve opens and closes a flow port. The one valve includes one valve seat, one valve body, and one biasing member. When the one biasing member biases the one valve body so that the one valve body seats on the one valve seat, the flow port is closed. When the one valve body is disengaged from the one valve seat due to negative pressure (or positive pressure) in the flow path, the flow port is opened. When the one valve opens the flow port, the flow port and the flow path are connected to each other. The other valve opens and closes the communication passage. The other valve includes another valve seat, another valve body, and another biasing member. When the other valve body is seated on the other valve seat due to positive pressure (or negative pressure) in the flow passage, the communication passage is closed. When the other biasing member biases the other valve body so that the other valve body is separated from the other valve seat, the communication passage is opened.

[0022] When one valve closes the flow port and the other valve opens the communication passage, the flow port and the flow path communicate with each other through the communication passage. The case where one valve that opens due to negative pressure (or positive pressure) in the flow path closes the flow port and the other valve that closes due to positive pressure (or negative pressure) in the flow path opens the communication passage occurs when the internal pressure of the flow path is neither positive nor negative. When the internal pressure of the flow path is positive (or negative), one valve closes the flow port and the other valve closes the communication passage.

[0023] The valve seat is provided on the valve element. That is, the valve seat is integral with the valve element, and the valve element seated on the valve seat is integral with the valve element. As a result, the valve device can be configured compactly. The first valve, the second valve, and the communicating passage provided in the valve device of the present disclosure can constitute, for example, the suction valve, the first on-off valve, and the first communicating passage (or the discharge valve, the second on-off valve, and the second communicating passage) provided in the pump of the present disclosure.

[0024] The valve device according to the present disclosure is characterized in that the one valve body is provided with a through hole extending in a seating / seating direction of the one valve body, the other biasing member is accommodated in the through hole, the other valve body advances and retreats in the seating / seating direction relative to the through hole, and when the other valve body advances from the through hole, it unseats the other valve seat, and when the other valve body retracts into the through hole, it seats on the other valve seat to close the through hole.

[0025] In the present disclosure, a through hole is provided in one of the valve bodies, and the through hole extends in a seating / seating direction of the one of the valve bodies. The other biasing member is housed in the through hole. That is, the other biasing member is built into the one valve. The other valve body advances and retreats in the seating and unseating direction of the one valve body relative to the through hole. When the other valve body advances from the through hole, it unseats the other valve seat, and when it retracts into the through hole, it seats on the other valve seat. That is, the other valve body seated on the other valve seat is built into the one valve. Moreover, the seating and unseating direction of the other valve body is aligned with the seating and unseating direction of the one valve body. As a result of the above, the valve device can be configured compactly.

[0026] If the internal pressure of the flow path is positive (or negative), one valve element is seated on one valve seat by the biasing force of one biasing member, and the other valve element is seated on the other valve seat by the internal pressure of the flow path. At this time, the other valve element closes the through hole. Therefore, there is no risk of fluid unnecessarily flowing through the through hole of the one valve element. In other words, the other valve element seated on the other valve seat functions as part of the one valve element.

[0027] The valve device according to the present disclosure further comprises a valve seat member having an opening communicating with the flow port, the first valve seat being provided on a peripheral portion of the opening, and an axially-shaped guided portion extending from the other valve body in the seating / seating direction, the first valve body being columnar in shape with its axial length direction facing the seating / seating direction and one end face facing the valve seat member, and having a guide portion for guiding the advancement and retreat of the other valve body, the through hole having a one-end opening located on the one end face and an other-end opening located on the other end face of the first valve body, at one and the other ends in the seating / seating direction, the other valve body advances and retreats through the other-end opening relative to the through hole, the guided portion penetrates the one-end opening and is supported by the guide portion so as to be slidable in the seating / seating direction, and at least a portion of the communicating passage is provided from the guided portion to the other valve body.

[0028] In the present disclosure, the valve seat member has an opening. The opening of the valve seat member is in communication with the flow port. One valve seat is provided on the periphery of the opening of the valve seat member. When one valve body is seated on or off the one valve seat, the opening of the valve seat member is opened or closed, and thus the flow port is opened or closed. The first valve element is columnar. The axial length direction of the first valve element faces the seating / unseating direction of the first valve element. One end face of the first valve element faces the valve seat member. The through hole of the first valve element has one end opening and the other end opening at one end and the other end of the first valve element in the seating / unseating direction. The one end opening of the through hole of the first valve element is located at one end face of the first valve element, and the other end opening of the through hole is located at the other end face of the first valve element.

[0029] One valve body has a guide portion. The guided portion is axially shaped, extends from the other valve body in the seating / seating direction of the one valve body, and passes through one end opening (the opening closer to the valve seat member) of the through hole. The guided portion is supported by the guide portion so as to be slidable in the seating / seating direction of the one valve body. The guided portion slides relative to the guide portion in the seating / seating direction of the one valve body, thereby guiding the advancement and retreat of the other valve body. The other valve element advances and retreats through the other end opening (the opening farther from the valve seat member) of the through hole of the one valve element.

[0030] Since at least a part of the communication passage is provided from the guided portion to the other valve body, no other member is required to configure at least a part of the communication passage. Moreover, when the other valve opens the communication passage, the communication passage passes through the one valve body to communicate between the flow port and the flow path. In other words, there is no need to provide a communication passage that bypasses the one valve. As a result, the valve device can be constructed compactly. Effect of the Invention

[0031] The pump and valve device of the present disclosure can improve convenience for the user. [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 is a cross-sectional view showing a configuration of a pump according to the embodiment. [Diagram 2] FIG. 2 is an enlarged view of the suction side valve device shown in FIG. [Diagram 3] 4 is a cross-sectional view showing the valve device in a state where the suction valve is open and the on-off valve is closed. FIG. [Figure 4] 2 is a cross-sectional view showing the valve device in a state in which the suction valve and the on-off valve are both closed. FIG. [Diagram 5] FIG. 2 is an enlarged view of the discharge side valve device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, embodiments of the present disclosure will be described.

[0034] FIG. 1 is a cross-sectional view showing the configuration of a pump according to an embodiment. In the figure, reference numeral 1 denotes a pump, which is configured such that a fluid is drawn into a flow path 12 through an intake port 11 and is discharged from the flow path 12 through an exhaust port 13. In the following, a liquid will be exemplified as the fluid. For ease of explanation, the following description will be given of a case where the pump 1 has one set of the suction port 11, the flow path 12, and the discharge port 13. Fig. 1 shows the vicinity of the suction port 11, the flow path 12, and the discharge port 13.

[0035] The suction port 11 is provided at the bottom of the pump 1 and is connected to a liquid source 21 that is external to the pump 1. The liquid source 21 is, for example, a liquid storage tank that stores tap water, a chemical liquid, or the like. The flow passage 12 extends vertically. The discharge port 13 is provided on the top of the pump 1 and is connected to a nozzle 22 located outside the pump 1. The nozzle 22 opens and closes in response to, for example, manual operation by a user.

[0036] The pump 1 comprises a liquid chamber 14 and a plunger 15 . The liquid chamber 14 is cylindrical in shape. The liquid chamber 14 extends in a direction intersecting the longitudinal direction of the flow passage 12. One end of the liquid chamber 14 in the axial direction communicates with the middle of the flow passage 12 in the longitudinal direction. The plunger 15 is cylindrical and is fitted coaxially and liquid-tightly into the liquid chamber 14. The plunger 15 is slidable in the axial direction relative to the inner circumferential surface of the liquid chamber 14. The plunger 15 is connected to a drive source (not shown) and is driven by the drive source to reciprocate in the axial direction.

[0037] 1, the plunger 15 shown sliding in a direction away from the flow path 12 is shown above the dashed line, and the plunger 15 sliding in a direction toward the flow path 12 is shown below the dashed line. When the plunger 15 slides in a direction away from the flow path 12, negative pressure is generated in the flow path 12. When the plunger 15 slides in a direction toward the flow path 12, positive pressure is generated in the flow path 12. That is, the plunger 15 functions as a pressure generating unit that alternately generates positive pressure and negative pressure in the flow path 12. The pump 1 includes two valve devices 16, 17. The suction port 11 and the lower end of the flow passage 12 communicate with each other through the valve device 16, and the upper end of the flow passage 12 and the discharge port 13 communicate with each other through the valve device 17.

[0038] The valve device 16 is a suction-side valve device, and includes a communication passage 160 (first communication passage), a suction valve 3, and an on-off valve 4 (first on-off valve). The suction valve 3 is configured to close the suction port 11 from the side of the flow path 12 and open the suction port 11 by negative pressure generated in the flow path 12. When the suction valve 3 is opened, the suction port 11 and the flow path 12 communicate with each other. The communication passage 160 is capable of communicating the suction port 11 and the flow passage 12 with each other when the suction valve 3 is closed.

[0039] The on-off valve 4 is configured to open the communication passage 160 and close the communication passage 160 by a positive pressure generated in the flow passage 12. When the suction valve 3 is closed and the on-off valve 4 is open, the suction port 11 and the flow passage 12 communicate with each other through the communication passage 160. The detailed configuration of the valve device 16 will be described later.

[0040] The valve device 17 is a valve device on the discharge side, and includes a communication passage 170 (a second communication passage), a discharge valve 5, and an on-off valve 6 (a second on-off valve). The discharge valve 5 is configured to close the discharge port 13 from the side of the flow path 12, and to open the discharge port 13 by a positive pressure generated in the flow path 12. When the discharge valve 5 is opened, the flow path 12 and the discharge port 13 communicate with each other. The communication passage 170 is capable of communicating the flow path 12 and the discharge port 13 with each other when the discharge valve 5 is closed.

[0041] The on-off valve 6 is configured to open the communication passage 170 and close the communication passage 170 by the negative pressure generated in the flow path 12. When the discharge valve 5 is closed and the on-off valve 6 is open, the discharge port 13 and the flow path 12 communicate with each other through the communication passage 170. The detailed configuration of the valve device 17 will be described later.

[0042] When negative pressure occurs in flow path 12, the negative pressure generated in flow path 12 causes suction valve 3 to open suction port 11, and liquid is sucked from liquid source 21 into flow path 12 through suction port 11. At this time, discharge valve 5 closes discharge port 13, and the negative pressure generated in flow path 12 causes on-off valve 6 to close communication passage 170, so there is no risk of liquid unnecessarily flowing through discharge port 13 or communication passage 170. Therefore, there is no risk of the presence of communication passage 170 deteriorating the performance of pump 1.

[0043] When positive pressure is generated in the flow path 12, the discharge valve 5 opens the discharge port 13 due to the positive pressure generated in the flow path 12, and the liquid is discharged (pressurized) from the flow path 12 through the discharge port 13 to the nozzle 22 side. At this time, the suction valve 3 closes the suction port 11, and the positive pressure generated in the flow path 12 causes the on-off valve 4 to close the communication passage 160, so there is no risk of the liquid flowing unnecessarily through the suction port 11 or the communication passage 160. Therefore, there is no risk that the presence of the communication passage 160 will deteriorate the performance of the pump 1.

[0044] As a result of the above, liquid sucked from liquid source 21 through suction port 11 into flow path 12 is discharged from flow path 12 to nozzle 22 through discharge port 13. If nozzle 22 is open when liquid is discharged from flow path 12 through discharge port 13 to nozzle 22, the liquid will spurt out from nozzle 22.

[0045] After the pump 1 has finished being used, the plunger 15 does not operate, so that neither positive nor negative pressure is generated in the flow path 12. Therefore, the suction valve 3 closes the suction port 11, and the discharge valve 5 closes the discharge port 13. Meanwhile, the on-off valve 4 opens the communication passage 160, so that the suction port 11 and the flow path 12 communicate with each other through the communication passage 160. In addition, the on-off valve 6 opens the communication passage 170, so that the discharge port 13 and the flow path 12 communicate with each other through the communication passage 170.

[0046] Flow path 12 extends vertically, and communication passage 160 and suction port 11 are located at the bottom of pump 1. Therefore, liquid remaining in flow path 12 is naturally discharged by its own weight from flow path 12 through communication passage 160 and suction port 11 to liquid source 21. As a result, outside air naturally flows into flow path 12 through discharge port 13 and communication passage 170 located at the top of pump 1, accelerating the discharge of liquid from pump 1. The discharged liquid is collected in liquid source 21, so there is no waste. As a result of the above, the user does not need to manually drain the liquid from the pump 1 when he or she has finished using the pump 1, thereby improving user convenience.

[0047] Next, an example of a detailed configuration of the valve device 16 will be described. FIG. 2 is an enlarged view of the suction side valve device 16 shown in FIG. As shown in FIGS. 1 and 2, the valve device 16 includes a valve seat member 161 and a cover 162 . The valve seat member 161 is cylindrical. As shown in Fig. 1, the valve seat member 161 is disposed between the suction port 11 (flow port) and the lower end of the flow path 12 with its axial direction aligned with the axial direction of the plunger 15. Both end openings of the valve seat member 161 communicate with the suction port 11. 1 and 2. When viewed from the valve seat member 161, the left side is the suction port 11 side, and the right side is the lower end side of the flow path 12. Hereinafter, the suction port 11 side will be referred to as the left side, and the lower end side of the flow path 12 will be referred to as the right side.

[0048] The cover 162 has a cylindrical shape with a bottom. As shown in Fig. 2, the cover 162 is attached coaxially to the valve seat member 161 such that the peripheral edge of the opening of the cover 162 covers the outer peripheral surface of the right end of the valve seat member 161 from the outside of the valve seat member 161. The inner bottom surface of the cover 162 faces the right end of the valve seat member 161. A plurality of flow holes 163 are arranged in parallel in the circumferential direction in the peripheral wall of the cover 162. Each of the flow holes 163 penetrates the peripheral wall of the cover 162. A flow hole 164 is provided in the bottom wall of the cover 162. The flow hole 164 penetrates the bottom wall of the cover 162.

[0049] The suction valve 3 (one valve) of the valve device 16 includes a valve seat 31 (suction side valve seat; one valve seat), a valve body 32 (suction side valve body; one valve body), and a biasing member 33 (suction side biasing member; one biasing member). The valve seat 31 is annular and coaxial with the valve seat member 161. The valve seat 31 is provided on the periphery of a right end opening of the valve seat member 161 (opening communicating with the flow port) by chamfering the inner periphery of the right end opening of the valve seat member 161 (see FIG. 3 described later).

[0050] The valve element 32 is cylindrical in shape and is accommodated in the cover 162 so as to be coaxial with the valve seat member 161 and so as to be reciprocatable in the axial direction. The left end face (one end face) of the valve disc 32 faces the right end of the valve seat member 161. The outer peripheral edge of the left end face of the valve disc 32 is chamfered. When the valve disc 32 seats on the valve seat 31, the chamfered portion of the valve disc 32 comes into close contact with the valve seat 31. When the valve disc 32 seats on the valve seat 31, the right end opening of the valve seat member 161 is closed, and ultimately the suction port 11 is closed from the flow path 12 side. The direction in which the valve disc 32 seats and leaves the seat is the axial length direction of the valve disc 32. The right end surface (the other end surface) of the valve body 32 faces the inner bottom surface of the cover 162. The right end surface of the valve body 32 is provided with a groove 321 that continues in the circumferential direction of the valve body 32.

[0051] The biasing member 33 is a coil spring. The biasing member 33 is housed in the cover 162 so as to be coaxial with the valve seat member 161 and so as to be extendable and contractible in the axial direction. The biasing member 33 is disposed between the groove 321 of the valve body 32 and the inner bottom surface of the cover 162. The biasing member 33 biases the valve body 32 in the axial direction and in a direction approaching the valve seat 31. That is, the biasing member 33 biases the valve body 32 in a direction in which the valve body 32 seats on the valve seat 31.

[0052] FIG. 3 is a cross-sectional view showing the valve device 16 in a state where the suction valve 3 is open and the on-off valve 4 is closed. When the negative pressure generated in the flow passage 12 overcomes the biasing force of the biasing member 33, the valve disc 32 moves in the axial direction and in a direction away from the valve seat 31. That is, the valve disc 32 is lifted off the valve seat 31 by the negative pressure generated in the flow passage 12. When the valve disc 32 is lifted off the valve seat 31, the right end opening of the valve seat member 161 is opened, and eventually the suction port 11 is opened. When the negative pressure generated in the flow path 12 causes the valve body 32 to lift off the valve seat 31 and open the right end opening of the valve seat member 161, the liquid sucked in through the intake port 11 flows into the lower end of the flow path 12 through the right end opening of the valve seat member 161 and the flow hole 163 of the cover 162.

[0053] FIG. 4 is a cross-sectional view showing the valve device 16 in a state in which the suction valve 3 and the on-off valve 4 are both closed. When a positive pressure is generated in the flow passage 12 , the biasing force of the biasing member 33 and the positive pressure in the flow passage 12 cause the valve body 32 to move in the axial direction and in a direction approaching the valve seat 31 and seat on the valve seat 31 . When neither positive nor negative pressure is generated in the flow path 12 (i.e., when the internal pressure of the flow path 12 is equal to atmospheric pressure), the biasing force of the biasing member 33 causes the valve body 32 to move in the axial direction toward the valve seat 31, as shown in FIG. 2, and to seat on the valve seat 31. 2 and 4, when the valve body 32 is seated on the valve seat 31, the right end opening of the valve seat member 161 is closed, and the suction port 11 is also closed. At this time, no liquid flows between the suction port 11 and the lower end of the flow path 12 through the right end opening of the valve seat member 161.

[0054] 2 to 4, a through hole 30 is coaxially formed in the valve body 32. The through hole 30 has an accommodating portion 301 and a guide portion 302 formed integrally therewith. The accommodation portion 301 constitutes the central portion and the right end portion in the axial direction of the through-hole 30, and has a large-diameter cylindrical internal space. The right end of the accommodation portion 301 is the right end opening (the other end opening) of the through-hole 30, and is located in a portion of the right end face of the valve body 32 that is surrounded by the groove 321. The guide portion 302 has a right end that is continuous with the left end of the accommodation portion 301, and constitutes the left end portion of the through hole 30. The guide portion 302 has a small-diameter cylindrical internal space. The left end of the guide portion 302 is the left end opening (one end opening) of the through hole 30, and is located on the left end face of the valve body 32.

[0055] The on-off valve 4 (another valve) of the valve device 16 includes a valve seat 41 (first valve seat; other valve seat), a valve body 42 (first valve body; other valve body), and a biasing member 43 (first biasing member; other biasing member). The valve seat 41 is annular and coaxial with the valve seat member 161. The valve seat 41 is provided on the peripheral edge of the right end opening of the valve seat member 161 by chamfering the inner peripheral edge of the right end opening of the through hole 30.

[0056] The valve body 42 integrally comprises a disk portion 421 and a columnar portion 422 . Both surfaces of the disk portion 421 face left and right. The left surface of the disk portion 421 faces the right end opening of the through hole 30. The outer peripheral edge of the left surface of the disk portion 421 is chamfered. When the valve body 42 seats on the valve seat 41, the chamfered portion of the disk portion 421 comes into close contact with the valve seat 41. When the valve body 42 seats on the valve seat 41, the right end opening of the through hole 30 is closed. The direction in which the valve body 42 seats and leaves the seat is the axial length direction of the valve body 42.

[0057] Cylinder portion 422 has a smaller diameter than disk portion 421, and coaxially protrudes leftward from the left surface of disk portion 421. Cylinder portion 422 is accommodated in accommodating portion 301. Cylinder portion 422 has a flange at its left end. The valve body 42 is accommodated in the accommodation portion 301 so as to be movable in the axial direction relative to the through hole 30. When the valve body 42 is seated, the valve body 42 is recessed in the accommodation portion 301 except for the right end portion of the disk portion 421 (see FIGS. 3 and 4). When the valve body 42 is unseated, the disk portion 421 protrudes rightward from the right end opening of the through hole 30 (see FIG. 2).

[0058] The biasing member 43 is a coil spring. The biasing member 43 is accommodated in the accommodation portion 301 so as to be coaxial with the cylindrical portion 422 and so as to be extendable and contractible in the axial direction. The biasing member 43 is disposed between a flange at the left end of the cylindrical portion 422 and the right-facing inner surface of the accommodation portion 301. The biasing member 43 biases the valve body 42 in the axial direction and in a direction away from the valve seat 41. That is, the biasing member 43 biases the valve body 42 in a direction in which the valve body 42 leaves the valve seat 41.

[0059] The on-off valve 4 (another valve) further includes a guided portion 44 and a stopper 45 . The guided portion 44 is provided integrally with the valve body 42. The guided portion 44 is axially shaped with a smaller diameter than the cylindrical portion 422, and protrudes coaxially leftward from the tip end surface (left end surface) of the cylindrical portion 422. The guided portion 44 is inserted into the biasing member 43 and passes through the guiding portion 302. The guided portion 44 is supported by the guiding portion 302 so as to be slidable in the axial direction along the inner circumferential surface of the guiding portion 302. The guided portion 44 slides against the inner circumferential surface of the guiding portion 302, thereby guiding the advancement and retreat of the valve body 42 in the axial direction.

[0060] The stopper 45 is provided on the guided portion 44. The stopper 45 is, for example, a double nut, and is screwed into a male thread provided on the outer circumferential surface of the guided portion 44. The stopper 45 is disposed on a portion of the guided portion 44 that protrudes leftward from the left end surface of the valve body 32. The stopper 45 abuts against the left end surface of the valve body 32, thereby preventing the valve body 42 and the guided portion 44 from slipping out of the through hole 30 through the right opening of the through hole 30. The stopper 45 is not limited to a double nut, and may be, for example, a single nut, or a protrusion integrally provided on the guided portion 44.

[0061] The communication passage 160 in this embodiment is provided from the guided portion 44 to the cylindrical portion 422 of the valve body 42. The communication passage 160 integrally includes a plurality of first openings provided on the outer circumferential surface of the cylindrical portion 422, a second opening provided on the tip surface (left end surface) of the guided portion 44, and a liquid flow path that connects the first openings and the second openings to each other.

[0062] When the positive pressure generated in the flow passage 12 overcomes the biasing force of the biasing member 33, the valve body 42 moves in the axial direction toward the valve seat 41, as shown in Fig. 4. That is, the valve body 42 is seated on the valve seat 41 by the positive pressure generated in the flow passage 12. When the valve body 42 is seated on the valve seat 41, the right end opening on the flow passage 12 side of the through hole 30 is closed, and the first opening of the communication passage 160 is closed.

[0063] A positive pressure is generated in the flow path 12 when the valve element 32 is seated on the valve seat 31. At this time, the valve element 42 closes both the communication passage 160 and the through hole 30. Therefore, even though the suction valve 3 closes the suction port 11, there is no risk of liquid leaking from the flow path 12 to the suction port 11 side through the communication passage 160 or the through hole 30 of the valve element 32, or entering the flow path 12 from the suction port 11 side. In other words, the valve element 42 seated on the valve seat 41 functions as a part of the valve element 32.

[0064] When neither positive pressure nor negative pressure is generated in the flow path 12, the biasing force of the biasing member 43 moves the valve element 42 in the axial direction and in a direction away from the valve seat 41, as shown in Fig. 2, and the valve element 42 leaves the valve seat 41. When the valve element 42 leaves the valve seat 41, the right end opening of the through hole 30 is opened, and further the first opening of the communication passage 160 is opened. At this time, the valve element 32 is seated on the valve seat 31, but the suction port 11 and the flow path 12 communicate with each other through the internal space of the valve seat member 161, the communication passage 160, and the flow holes 163 and 164 of the cover 162. The liquid remaining in the flow passage 12 is discharged from the flow passage 12 through the flow hole 163 or the flow hole 164 of the cover 162 , the communication passage 160 , the left end opening of the valve seat member 161 , and the suction port 11 to the liquid source 21 .

[0065] When the valve element 32 is lifted off the valve seat 31 due to the negative pressure generated in the flow passage 12, the valve element 42 continues to be seated on the valve seat 41 due to inertial force, as shown in FIG. Furthermore, when the valve body 32 leaves the valve seat 31, the suction port 11 and the flow path 12 communicate with each other through the right end opening of the valve seat member 161, so there is no particular problem even if the valve body 42 leaves the valve seat 41 and the communicating passage 160 and the through hole 30 are opened.

[0066] The valve seat 41 is provided on the valve body 32. That is, the valve seat 41 is integral with the suction valve 3, and the valve body 42 seated on the valve seat 41 is built in the suction valve 3. Furthermore, the seating and unseating direction of the valve body 42 is the same as the seating and unseating direction of the valve body 32. The biasing member 43 is built in the suction valve 3. Since the communication passage 160 is provided from the guided portion 44 to the valve body 42, no other member is required to configure the communication passage 160. Moreover, when the on-off valve 4 opens the communication passage 160, the communication passage 160 passes through the valve body 32 to communicate the suction port 11 and the flow path 12 with each other. That is, it is not necessary to provide the communication passage 160 so as to bypass the suction valve 3. As a result of the above, the valve device 16 (and therefore the pump 1) can be configured compactly.

[0067] It should be noted that the valve device 16 is not limited to a configuration including the communication passage 160, the suction valve 3, and the on-off valve 4. For example, the communication passage 160 may be provided so as to bypass the suction valve 3, and the on-off valve 4 may be provided completely separately from the suction valve 3. The guide portion 302 may be a separate member from the valve body 32. For example, the valve seat member 161 may hold a member having the guide portion 302. The suction valve 3 and the on-off valve 4 are not limited to being configured to open and close naturally in response to the internal pressure of the flow path 12. For example, the suction valve 3 and the on-off valve 4 may each be configured as a solenoid valve, the internal pressure of the flow path 12 may be detected, and the opening and closing of the suction valve 3 and the on-off valve 4 may each be controlled in response to the detection result.

[0068] The valve body 42 may not have the cylindrical portion 422. In this case, the guided portion 44 may coaxially protrude leftward from the left surface of the disk portion 421, and the first opening of the communication passage 160 may be provided on the outer circumferential surface of the base end portion of the guided portion 44. The valve body 42 may not have the disk portion 421. In this case, the inner circumferential surface of the accommodation portion 301 functions as the valve seat 41, and the outer circumferential surface of the cylindrical portion 422 comes into close contact with the inner circumferential surface of the accommodation portion 301, whereby the valve body 42 is seated on the valve seat 41. In addition to the communication passage 160 or in place of the communication passage 160, the through hole 30 may be used as a first communication passage.

[0069] Next, an example of a detailed configuration of the valve device 17 will be described. FIG. 5 is an enlarged view of the discharge side valve device 17 shown in FIG. In the case of valve device 16, the left side is the suction port 11 side, and the right side is the lower end side of flow path 12. On the other hand, in the case of valve device 17, the left side is the discharge port 13 side, and the right side is the upper end side of flow path 12. In this embodiment, a valve device having the same structure as the valve device 16 is used as the valve device 17 in a state where the left and right are inverted. The differences from the valve device 16 will be described below.

[0070] The valve device 17 includes a valve seat member 171 and a cover 172 corresponding to the valve seat member 161 and the cover 162 of the valve device 16. The valve seat member 171 is disposed between the discharge port 13 (flow port) and the lower end of the flow path 12 with its axial direction aligned with the axial direction of the plunger 15. The cover 172 is attached coaxially to the valve seat member 171 such that the peripheral edge of the opening of the cover 172 covers the outer peripheral surface of the left end portion of the valve seat member 171 from the outside of the valve seat member 171. The cover 172 is provided with flow holes 173, 174 corresponding to the flow holes 163, 164.

[0071] The discharge valve 5 (one valve) of the valve device 17 includes a valve seat 51 (discharge side valve seat, one valve seat), a valve body 52 (discharge side valve body, one valve body), and a biasing member 53 (discharge side biasing member, one biasing member) corresponding to the valve seat 31, the valve body 32, and the biasing member 33 of the valve device 16. A groove 521 corresponding to the groove 321 of the valve device 16 is provided on the left end surface of the valve body 52.

[0072] When the positive pressure generated in the flow passage 12 overcomes the biasing force of the biasing member 53, the valve disc 52 moves in the axial direction and in a direction away from the valve seat 51. That is, the valve disc 52 is separated from the valve seat 51 by the positive pressure generated in the flow passage 12. When the valve disc 52 is separated from the valve seat 51, the left end opening of the valve seat member 171 is opened, and eventually the discharge port 13 is opened. When the positive pressure generated in the flow path 12 causes the valve body 52 to lift off the valve seat 51 and open the left end opening of the valve seat member 171, the liquid in the flow path 12 is discharged (pressurized) toward the nozzle 22 through the left end opening of the valve seat member 171, the flow hole 173 of the cover 172, and the discharge port 13.

[0073] When negative pressure occurs in the flow passage 12 , the biasing force of the biasing member 53 and the negative pressure in the flow passage 12 cause the valve body 52 to move in the axial direction and in a direction approaching the valve seat 51 and seat on the valve seat 51 . When neither negative nor positive pressure is generated in the flow passage 12 , the biasing force of the biasing member 53 causes the valve body 52 to move in the axial direction toward the valve seat 51 and to seat on the valve seat 51 . When the valve body 52 is seated on the valve seat 51, the left end opening of the valve seat member 171 is closed, and the discharge port 13 is closed from the side of the flow path 12. At this time, no liquid flows between the discharge port 13 and the lower end of the flow path 12 through the left end opening of the valve seat member 171.

[0074] The valve body 52 is provided with a through hole 50 corresponding to the through hole 30 of the valve device 16. The through hole 50 integrally includes an accommodating portion 501 and a guide portion 502 corresponding to the accommodating portion 301 and the guide portion 302 of the valve device 16.

[0075] The on-off valve 6 (another valve) of the valve device 17 includes a valve seat 61 (second valve seat, other valve seat), a valve body 62 (second valve body, other valve body), and a biasing member 63 (second biasing member, other biasing member) corresponding to the valve seat 41, the valve body 42, and the biasing member 43 of the valve device 16. The valve body 62 integrally includes a disk portion 621 and a cylindrical portion 622 corresponding to the disk portion 421 and the cylindrical portion 422 of the valve device 16. The on-off valve 6 further includes a guided portion 64 and a stopper 65 corresponding to the guided portion 44 and the stopper 45 of the valve device 16. The communication passage 170 in this embodiment is provided from the guided portion 64 to the cylindrical portion 622 of the valve body 62 .

[0076] When the negative pressure generated in the flow passage 12 overcomes the biasing force of the biasing member 63, the valve body 62 moves in the axial direction toward the valve seat 61. That is, the valve body 62 is seated on the valve seat 61 by the negative pressure generated in the flow passage 12. When the valve body 62 is seated on the valve seat 61, the left end opening of the through hole 50 is closed, and the communication passage 170 is closed. A case where negative pressure is generated in the flow path 12 is a case where the valve element 52 is seated on the valve seat 51. At this time, the valve element 62 closes both the communication passage 170 and the through hole 50. Therefore, even though the discharge valve 5 closes the discharge port 13, there is no risk of liquid leaking from the flow path 12 to the discharge valve 5 side through the communication passage 170 or the through hole 50 of the valve element 52, or infiltrating from the discharge valve 5 side into the flow path 12. In other words, the valve element 62 seated on the valve seat 61 functions as a part of the valve element 52.

[0077] When neither positive pressure nor negative pressure is generated in the flow path 12, the biasing force of the biasing member 63 moves the valve element 62 in the axial direction and in a direction away from the valve seat 61, and the valve element 62 leaves the valve seat 61. When the valve element 62 leaves the valve seat 61, the left end opening of the through hole 50 is opened, and further the communication passage 170 is opened. At this time, the valve element 52 is seated on the valve seat 51, but the discharge port 13 and the flow path 12 communicate with each other through the right end opening of the valve seat member 171, the communication passage 170, and the flow holes 173 and 174 of the cover 172. When the valve element 52 is lifted off the valve seat 51 due to the positive pressure generated in the flow passage 12, the valve element 62 continues to be seated on the valve seat 61 due to inertial force.

[0078] Note that the configuration is not limited to one in which discharge port 13 communicates with the lower end of flow path 12 at the bottom of pump 1, and discharge port 13 communicates with the upper end of flow path 12 at the top of pump 1. Furthermore, flow path 12 is not limited to one that extends vertically. The fluid handled by the pump 1 is not limited to liquid, but may be gas.

[0079] When the pump 1 has a plurality of sets of intake ports 11, flow paths 12, and discharge ports 13, the liquid chamber 14 and the plunger 15 are provided for each of the flow paths 12. For example, when the pump 1 has two sets of intake ports 11, flow paths 12, and discharge ports 13, the intake ports 11 of one set and the intake ports 11 of the other set are connected to each other and are connected to a liquid source 21. Also, the discharge ports 13 of one set and the discharge ports 13 of the other set are connected to each other and are connected to a nozzle 22. When the plunger 15 corresponding to the flow paths 12 of one set moves away from the flow path 12 (approaches the flow path 12), the plunger 15 corresponding to the flow paths 12 of the other set moves toward the flow path 12 (moves away from the flow path 12). Therefore, when a negative pressure (positive pressure) is generated in the flow paths 12 of one set, a positive pressure (negative pressure) is generated in the flow paths 12 of the other set. Therefore, the discharge ports 13 of one set are always kept at a positive pressure. As a result, when negative pressure occurs in one set of flow paths 12, in the valve device 17 corresponding to one set of outlet ports 13, the valve body 62 is seated on the valve seat 61 by both the negative pressure generated in the flow paths 12 and the positive pressure of the outlet ports 13.

[0080] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is intended to include not only the above-mentioned meaning, but also the meaning equivalent to the claims and all modifications within the scope of the claims. Independent claims and dependent claims described in the claims may be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims may be written in a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this format. A multiple claim that references at least one other multiple claim (multiple multiple claim format) may also be written. [Explanation of symbols]

[0081] 1 Pump 11 Suction port (ventilation port) 12 Flow Path 13 Discharge port (flow port) 15 Plunger (pressure generating part) 16 Valve gear 160 Passageway (1st Passageway) 161 Valve seat material 17 Valve gear 170 Passageway (Second Passageway) 171 Valve seat material 21 Liquid source 22 Nozzle 3. Suction valve (first valve) 30 Through hole 302 Information Department 31 Valve seat (suction side valve seat, first valve seat) 32 Valve body (suction side valve body, one valve body) 33 Urging member (suction side urging member, one urging member) 4 On-off valve (first on-off valve, other valves) 41 Valve seat (first valve seat, other valve seats) 42 Valve body (first valve body, other valve bodies) 43 Urging member (first urging member, other urging members) 44 Guided part 5. Discharge valve (first valve) 50 Through hole 502 Information Department 51 Valve seat (discharge side valve seat, first valve seat) 52 Valve body (discharge side valve body, one valve body) 53 Urging member (discharge side urging member, one urging member) 6 On-off valve (second on-off valve, other valves) 61 Valve seat (second valve seat, other valve seats) 62 Valve body (second valve body, other valve body) 63 Urging member (second urging member, other urging member) 64 Guided part

Claims

1. A pump in which a fluid is drawn into a flow path through a suction port and discharged from the flow path through a discharge port, a pressure generating unit that alternately generates positive pressure and negative pressure in the flow path; an intake valve that closes the intake port and opens the intake port when negative pressure is generated in the flow path; a discharge valve that closes the discharge port and opens the discharge port when a positive pressure is generated in the flow path; a first communication passage that allows communication between the suction port and the flow passage when the suction valve is closed; a second communication passage that allows communication between the discharge port and the flow path when the discharge valve is closed; a first on-off valve that opens the first communication passage and closes the first communication passage when a positive pressure is generated in the flow passage; a second on-off valve that opens the second communication passage and closes the second communication passage when negative pressure occurs in the flow passage; Equipped with When the intake valve is opened, the intake port and the flow path communicate with each other, A pump, characterized in that, when the discharge valve is opened, the discharge port and the flow path communicate with each other.

2. The suction valve is A suction side valve seat; a suction side valve body that opens and closes the suction port by being seated on and removed from the suction side valve seat; a suction side biasing member that biases the suction side valve body in a direction in which the suction side valve body is seated on the suction side valve seat; Equipped with the suction side valve body is lifted off the suction side valve seat by a negative pressure generated in the flow passage, The first opening / closing valve is A first valve seat provided on the suction side valve body; a first valve body that opens and closes the first communication passage by being seated on and removed from the first valve seat; a first biasing member that biases the first valve body in a direction in which the first valve body separates from the first valve seat; Equipped with 2. The pump according to claim 1, wherein the first valve body is seated on the first valve seat by a positive pressure generated in the flow passage.

3. The discharge valve is A discharge side valve seat; a discharge side valve body that opens and closes the discharge port by being seated on and removed from the discharge side valve seat; a discharge side biasing member that biases the discharge side valve body in a direction in which the discharge side valve body is seated on the discharge side valve seat; Equipped with the discharge-side valve body is lifted off the discharge-side valve seat by a positive pressure generated in the flow path, The second opening / closing valve is A second valve seat provided on the discharge side valve body; a second valve body that opens and closes the second communication passage by being seated on and removed from the second valve seat; a second biasing member that biases the second valve body in a direction in which the second valve body separates from the second valve seat; Equipped with 2. The pump according to claim 1, wherein the second valve body is seated on the second valve seat by a negative pressure generated in the flow passage.

4. At least a portion of the flow path extends vertically; When the first on-off valve is opened, the suction port communicates with a lower end of the portion through the first communication passage, 4. The pump according to claim 1, wherein when the second on-off valve is opened, the discharge port communicates with an upper end of the portion through the second communication passage.

5. A valve for opening and closing a flow port through which a fluid flows; a communication passage that can communicate the flow passage through which the fluid communicates and the flow port with each other when the one valve is closed; Another valve for opening and closing the communication passage; Equipped with When the one valve opens the flow port, the flow port and the flow path communicate with each other, The one valve is One valve seat; a valve body that opens and closes the flow port by being seated on and removed from the valve seat; a biasing member that biases the valve body in a direction in which the valve body is seated on the valve seat; Equipped with the first valve body is separated from the first valve seat by the internal pressure of the flow passage when the internal pressure of the flow passage is one of a positive pressure and a negative pressure, The other valve is Another valve seat provided on the one valve body; another valve body that opens and closes the communication passage by being seated on and removed from the other valve seat; another biasing member that biases the other valve body in a direction in which the other valve body separates from the other valve seat; Equipped with The valve device, wherein the other valve body is seated on the other valve seat by the internal pressure of the flow path when the internal pressure of the flow path is the other of positive pressure and negative pressure.

6. The one valve body is provided with a through hole extending in a seating / seating direction of the one valve body, The other biasing member is accommodated in the through hole, 6. The valve device according to claim 5, wherein the other valve body advances and retreats in the seating / unseating direction relative to the through hole, and when it advances from the through hole, it unseats the other valve seat, and when it retracts into the through hole, it seats on the other valve seat to close the through hole.

7. a valve seat member having an opening communicating with the flow port, the valve seat being provided on a peripheral edge of the opening; a shaft-shaped guided portion extending in the seating / seating direction from the other valve body; Further comprising: The one valve body is a columnar shape having an axial length direction facing the seating / seating direction and one end surface facing the valve seat member; A guide portion for guiding the advancement and retreat of the other valve body is provided, the through hole has a one end opening located in the one end surface and a other end opening located in the other end surface of the one valve body at one end and the other end in the seating / seating direction, The other valve body advances and retreats through the other end opening relative to the through hole, The guided portion is The one end opening is passed through, The seat is supported by the guide portion so as to be slidable in the seating / seating direction, 7. The valve device according to claim 6, wherein at least a portion of the communication passage is provided from the guided portion to the other valve body.

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