JP2017137848A - Compressed air drying system and check valve for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve capable of improving sealing performance when the same is closed and to provide a compressed air drying system mounted with the check valve.SOLUTION: A compressed air drying system comprises: a compressor; an air dryer which performs load operation to dry compressed air sent from the compressor and unload operation to remove oily water content from a desiccant and discharge the same; a governor device which pneumatically opens and closes a drain valve device of the air dryer and pneumatically outputs a signal notifying the compressor of execution of the unloading operation; and a check valve 20. The check valve 20 has: a body 21 provided with a first port 26, a second port 27 and a third port 28; and a piston 50 which is slidably installed in the body 21. The piston 50 has: a contact member 60 which contacts the body 21 and is made of an elastic body; and a slide contact member 51 which slides with respect to the body 21 while contacting the same.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a compressed air drying system for drying compressed air supplied from a compressor and a check valve for the compressed air drying system.

  Automobiles such as trucks, buses, and construction machinery control systems such as brakes and suspensions using compressed air sent from a compressor connected to an internal combustion engine. An air dryer may be provided downstream of the compressor to remove moisture and oil from the compressed air.

  The air dryer is filled with a desiccant such as silica gel or zeolite. The air dryer performs a load operation for removing moisture contained in the compressed air and an unload operation for regenerating the desiccant. During the road operation, the compressed air sent from the inlet of the air dryer passes through the desiccant and is discharged as dry compressed air from the outlet of the air dryer. Further, when the unload operation is performed, the drain valve device provided in the air dryer is opened, so that the dry compressed air passes through the air dryer in the opposite direction to that during the load operation. Thereby, the oil and water trapped in the desiccant of the air dryer is removed, and the oil and water are discharged from the drain valve device as drain.

  By the way, if the inlet of the air dryer is open during the unloading operation, the compressed air flowing in from the inlet will be discharged to the atmosphere from the drain valve device opened. That is, the compressed air is discharged to the atmosphere through the air dryer. Therefore, it has been proposed that the air dryer is provided with a check valve (inlet opening / closing device) that opens the inlet and outlet of the air dryer during the load operation and closes the inlet and outlet of the air dryer during the unload operation (see, for example, Patent Document 1). .

International Publication No. 2014/061582

  As described above, compressed air containing oil is introduced into the inlet of the check valve connected to the compressor at high pressure and high temperature. Therefore, the check valve is required to improve the sealing performance when the check valve is closed in such a severe situation.

Such problems are not limited to automobiles, but are generally common to apparatuses equipped with a compressed air drying system for purifying compressed air connected to a compressor.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a check valve capable of improving the sealing performance when the valve is closed, and a compressed air drying system provided with the check valve. To do.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A compressed air drying system that solves the above problems includes a compressor, a load operation for capturing at least one of moisture and oil contained in compressed air sent from the compressor, and at least one of the captured moisture and oil. A removal device that performs an unloading operation for discharging drain through a drain valve device, and provided inside the removal device or outside the removal device, opens and closes the drain valve device with air pressure, and unloads the compressor. A pressure adjusting device that outputs a signal indicating that it is a road operation by compressed air, a first port connected to the compressor, a second port connected to the removing device, and a third input of the signal A check valve having a port, the check valve having a body having the first port, the second port, and the third port. And a piston slidably provided in the body, wherein the piston abuts on the body and is made of an elastic body, and a sliding contact member that is in sliding contact with the body. The gist is to prepare.

  A check valve for a compressed air drying system that solves the above problems includes a compressor, a load operation that captures at least one of moisture and oil contained in compressed air sent from the compressor, and captured moisture and oil. A removal device that performs an unloading operation that discharges drain containing at least one through a drain valve device; and is provided inside the removal device or outside the removal device, and opens and closes the drain valve device by air pressure, A pressure regulator that outputs a signal indicating that the compressor is in an unload operation with compressed air, and a check valve used in a compressed air drying system, the first port connected to the compressor, A body having a second port connected to the removal device and a third port to which the signal is input, and sliding in the body The piston is provided with a contact member made of an elastic body, and a sliding contact member that is in sliding contact with the body. .

  In the above configuration, the contact member of the piston that contacts the body of the check valve is made of an elastic body, and this contact member is fixed to the sliding contact member of the piston by the pin. For this reason, when the abutting member made of an elastic body abuts on the body when the piston abuts on the body, the abutting member is sealed while being elastically deformed. Therefore, the sealing performance when the valve is closed can be improved.

  In the compressed air drying system, the piston includes a pin for fixing the contact member to the sliding contact member, the sliding contact member accommodates the protruding contact member, and the contact member It is preferable to provide an accommodating portion that is press-fitted and fixed by the pin.

  Regarding the check valve for the compressed air drying system, the piston includes a pin that fixes the contact member to the sliding contact member, and the sliding contact member accommodates the contact member in a protruding state, It is preferable that the abutting member includes an accommodating portion that is press-fitted and fixed by the pin.

  In the above configuration, since the contact member is press-fitted and fixed to the housing portion by the pin, the generation of a gap between the sliding contact member and the contact member can be suppressed. Therefore, it can suppress that compressed air enters into the clearance gap between a sliding contact member and a contact member, and can improve the sealing performance at the time of valve closing.

About the said compressed air drying system, it is preferable that the said sliding contact member is equipped with the support part which supports the outer periphery of the said contact member.
Regarding the check valve for the compressed air drying system, it is preferable that the sliding contact member includes a support portion that supports an outer periphery of the contact member.

  In the above configuration, the support portion supports the outer periphery of the contact member. For this reason, even if the contact member contacts and deforms the body of the check valve, excessive deformation can be suppressed and the contact member can be prevented from being sag. Further, when the contact member is excessively deformed, the support portion contacts the body of the check valve, so that excessive movement of the piston when the valve is closed can be suppressed.

  In the compressed air drying system, the body forms the third port with the first port formed with a passage connecting the first port, the second port, and the third port, and the piston. A cylindrical second body having a slidable contact portion, and a female screw is provided on an inner peripheral surface of a portion of the first body to which the second body is connected, It is preferable that a male screw that engages with the female screw is provided on the outer peripheral surface.

  As for the check valve for the compressed air drying system, the body forms the third port with the first body in which a passage connecting the first port, the second port, and the third port is formed. And a cylindrical second body having a sliding contact portion with which the piston is slidably contacted, a female screw is provided on an inner peripheral surface of a portion of the first body to which the second body is connected, It is preferable that a male screw that engages with the female screw is provided on the outer peripheral surface of the second body.

  In the above configuration, the second body having a sliding contact portion with which the piston is in sliding contact is separated from the first body, and is assembled by screwing the second body into the first body. For this reason, it can be easily detached during maintenance.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of valve closing of the check valve used for a compressed air drying system can be improved.

The block diagram which shows the flow of the compressed air at the time of load operation of an air dryer about one Embodiment of a compressed air drying system. The block diagram which shows the flow of the compressed air at the time of the unload operation | movement of an air dryer about the compressed air drying system of the embodiment. It is a check valve of the embodiment, and is a sectional view in a valve open state. The cross-sectional enlarged view in the valve opening state of the check valve of the embodiment. It is a check valve of the embodiment, Comprising: Sectional drawing in a valve closing state. It is a modification of a check valve, Comprising: Sectional drawing in a valve opening state. It is a modification of a compressed air drying system, Comprising: The block diagram which shows the flow of compressed air at the time of load driving | running of an air dryer. It is a compressed air drying system of the modification, Comprising: The block diagram which shows the flow of the compressed air at the time of the unload driving | operation of an air dryer.

Hereinafter, an embodiment of a compressed air drying system will be described with reference to FIGS. The compressed air drying system is mounted on automobiles such as trucks, buses, and construction machines.
As shown in FIG. 1, the compressed air drying system 1 is connected downstream of a supercharger 15 connected to an internal combustion engine. The compressed air drying system 1 includes a compressor 10, an air dryer 11 as a removing device, and a governor device 19 as a pressure adjusting device. The compressed air drying system 1 removes oil and moisture in compressed air sent from a compressor 10 connected to a supercharger 15 by an air dryer 11, stores the dried compressed air in a tank 18, and stores the dried compressed air in a tank. Supply from 18 to systems such as brakes and suspensions. Since the compressed air compressed by the supercharger 15 is supplied to the compressor 10, the amount of compression in the compressor 10 can be small. For this reason, the compressor 10 is reduced in size compared with the compressor mounted in the motor vehicle which does not have the supercharger 15 or is not supplied from the supercharger 15.

  The compressor 10 is connected to the check valve 20 via a pipe line 17a. The check valve 20 has a first port 26, a second port 27, and a third port 28. The first port 26 is connected to the compressor 10 via a pipe line 17a. The second port 27 is connected to the air dryer 11 via the pipe line 17b. The third port 28 is connected to the governor device 19 via the conduit 17 c and a conduit 19 a that is a connecting pipe connecting the compressor 10 and the governor device 19. The pipe line 19a is a connecting pipe through which compressed air is sent as an air pressure signal that outputs to the compressor 10 that the unloading operation is being performed.

  The air dryer 11 includes a desiccant 11a inside. The air dryer 11 includes a check valve 12 provided on the outlet 11c side. The check valve 12 allows the supply of dry compressed air from the air dryer 11 to the tank 18 when the internal pressure of the tank 18 is equal to or lower than the set pressure. The check valve 12 stops the supply of dry compressed air from the air dryer 11 to the tank 18 when the internal pressure of the tank 18 exceeds the set pressure.

  The air dryer 11 includes a drain discharge port 11d that discharges drain that is oil and water generated by the regeneration of the desiccant 11a. A drain valve device 13 is provided on the drain discharge port 11d side. A drain discharge pipe 17g is connected to the drain discharge port 11d. The drain discharge pipe 17g is connected to an oil separator (not shown) that separates drain and air and stores oil and moisture. This oil separator is open to the atmosphere.

  In addition, a governor device 19 is connected to the drain valve device 13 via a pipe line 17f. The governor device 19 is connected to the tank 18 via a pipe line 17e. A conduit 17 e that connects the governor device 19 and the tank 18 branches off from a conduit 17 d that connects the air dryer 11 and the tank 18. The tank 18 is connected to an automobile air system such as a brake system or a suspension system.

  The governor device 19 supplies the dry compressed air in the tank 18 to the compressor 10 via the conduit 19a when the air system is not operated, in other words, when the compressor 10 does not supply the tank 18 with the air system. Thereby, the compressor 10 will be in the state which does not supply compressed air to the air dryer 11 side. When the governor device 19 stops supplying the dry compressed air to the compressor 10, the compressor 10 enters a state of supplying the compressed air to the air dryer 11 side. When the compressor 10 supplies compressed air to the air dryer 11 and the internal pressure of the tank 18 exceeds the set pressure, the dry compressed air in the tank 18 is sent from the governor device 19 as an air pressure signal to the compressor 10. , The drain valve device 13 and the check valve 20.

  The air dryer 11 has a dehumidifying action (load operation) for removing oil and moisture from the compressed air, and a regenerating action (unloading operation) for regenerating the desiccant 11a by removing the oil and moisture adsorbed on the desiccant 11a and releasing it to the outside. And do. During the load operation, the check valve 20 is in a state where the first port 26 and the second port 27 are in communication. Further, the drain valve device 13 is closed and the check valve 12 is opened. At this time, the compressed air sent from the compressor 10 is dehumidified by flowing from the inlet 11b of the air dryer 11 and passing through the desiccant 11a. Dry compressed air that is dehumidified compressed air is discharged from the outlet 11 c of the air dryer 11 and stored in the tank 18.

  As shown in FIG. 2, when the internal pressure of the tank 18 exceeds the set pressure, dry compressed air is sent from the tank 18 to the governor device 19 via the conduit 17e. At this time, when the check valve 12 of the air dryer 11 is closed, dry compressed air does not flow back from the tank 18 into the air dryer 11. The governor device 19 supplies dry compressed air to the check valve 20 via the pipe line 19a and the pipe line 17c, and closes the check valve 20 with air pressure. As a result, the check valve 20 brings the first port 26 and the second port 27 into a non-communication state. At the same time, the governor device 19 supplies dry compressed air to the drain valve device 13 via the pipe line 17e, and opens the drain valve device 13 by air pressure. The timing at which the check valve 20 is closed is preferably the same as or slightly earlier than the timing at which the drain valve device 13 is opened. By closing the check valve 20 in this way, the supply of compressed air from the compressor 10 to the air dryer 11 is prevented, so the compressed air sent from the compressor 10 is discharged to the atmosphere via the drain valve device 13. Can be prevented. Therefore, it can prevent that the supercharging pressure by the supercharger 15 falls.

  The dry compressed air in the air dryer 11 flows in the desiccant 11a in the direction opposite to that during the load operation. As a result, the oil and moisture adsorbed on the desiccant 11a are removed and flow to the drain discharge port 11d together with the dry compressed air. The air dryer 11 may be provided with a filter having pores through which air passes, such as a sponge, a metal compression material, and a fibrous material. During the unloading operation, the oil and moisture adsorbed by the filter of the air dryer 11 is also removed and discharged from the air dryer 11 as a drain.

Next, the check valve 20 will be described in detail with reference to FIGS.
As shown in FIGS. 3 and 5, the check valve 20 includes a body 21. The body 21 includes a first body 22 and a second body 23.

  The first body 22 and the second body 23 are made of a material having heat resistance and oil resistance. The 1st body 22 and the 2nd body 23 may be formed from the same material, and may be formed from a different material. For example, the first body 22 or the second body 23 is made of a metal such as aluminum, iron, or titanium, or an alloy containing a plurality of metal elements, such as stainless steel or zinc cast iron. When the first body 22 or the second body 23 is made of metal, it is formed by casting. Alternatively, the first body 22 or the second body 23 is made of, for example, thermosetting resin such as PBT (polybutylene terephthalate resin), PPS (polyphenylene sulfide resin), POM (polyacetal resin), or nylon resin. When the first body 22 or the second body 23 is made of a synthetic resin, it is formed by injection molding or the like.

  The first body 22 has a rectangular parallelepiped shape, and a first port 26 connected to the compressor 10 and a second port 27 connected to the air dryer 11 are provided on two orthogonal surfaces of the first body 22. Yes.

  A second body 23 is attached to the first body 22 on the side opposite to the first port 26. The second body 23 includes a third port 28 connected to the governor device 19. The second body 23 includes a cylindrical portion 36 and a fastening portion 37 formed in a hexagonal cylindrical shape, and is attached in a state where the cylindrical portion 36 and the fastening portion 37 protrude from the first body 22. Since the fastening portion 37 has a hexagonal shape, it can be easily gripped with a tool such as a wrench.

  The first port 26 provided in the first body 22 and the third port 28 provided in the second body 23 extend on the same straight line, and the second port 27 provided in the first body 22 is connected to the first port 26. And extends in a direction perpendicular to the third port 28. The first port 26 has a diameter that decreases from the port inlet 26a toward the second port 27 side. In the first port 26, an end portion of a pipe line 17a connected to the compressor 10 is fitted.

  The first port 26 is connected to the passage 32 via the communication passage 31. A female screw 33 for screwing the second body 23 is formed on the inner peripheral surface of the passage 32. Further, a valve seat 39 is provided on the side of the passage 32 in the communication passage 31.

  The passage 32 is connected to the second port 27 via the communication passage 35. The diameter of the second port 27 is reduced from the port inlet 27a toward the communication path 35. A pipe line 17 b connected to the air dryer 11 is fitted into the second port 27.

  The third port 28 provided in the second body 23 has a diameter reduced from the port inlet 28a toward the first port 26 side. In the third port 28, a pipe line 17c connected to the governor device 19 is fitted. The second body 23 includes a screwing portion 42 in which a male screw 41 is formed. A cylindrical fitting hole 45 is formed inside the screwing portion 42. A columnar piston 50 is slidably provided in the fitting hole 45. Further, a communication hole 46 connected to the third port 28 is formed through the cylindrical portion 36. The second body 23 and the piston 50 are in sliding contact, and the second body 23 has a sliding contact portion.

  As shown in FIG. 4, the piston 50 includes an abutment member 60 that abuts on the valve seat 39 of the first body 22, a slidable contact member 51 that slidably contacts the second body 23, and an abutment member 60 that contacts the slidable contact member 51. And a pin 70 for fixing the. The contact member 60 is cylindrical, and a through hole 61 that penetrates the pin 70 is formed at the center of the contact member 60. The sliding contact member 51 is cylindrical, and the outer peripheral surface of the sliding contact member 51 is in sliding contact with the sliding contact portion of the second body 23. An accommodating portion 54 having a cylindrical space for accommodating the contact member 60 is provided at the end of the sliding contact member 51 on the valve seat 39 side. The outer diameter of the contact member 60 is set slightly longer than the inner diameter of the housing portion 54 of the sliding contact member 51. For this reason, the contact member 60 is press-fitted and fixed to the housing portion 54 by being pushed into the housing portion 54. The pin 70 includes a flat plate portion 71 and a columnar column portion 72. A fixing hole 54 a for fixing the pin 70 is provided in the center of the bottom of the housing portion 54. The outer diameter of the cylindrical portion 72 of the pin 70 is set slightly longer than the inner diameter of the fixing hole 54a. For this reason, the pin 70 is press-fitted and fixed to the fixing hole 54a by being pushed into the fixing hole 54a.

  The tip of the contact member 60 on the valve seat 39 side protrudes from the tip of the sliding contact member 51 on the valve seat 39 side, and when the piston 50 is seated on the valve seat 39, the contact member 60 contacts the valve seat 39. It comes to contact. Note that a support portion 51 a that supports the outer periphery of the contact member 60 is provided at the tip of the sliding contact member 51. The protrusion amount H of the contact member 60 from the tip of the sliding contact member 51 is set so that the contact member 60 is not excessively deformed, and the excessive deformation of the contact member 60 is suppressed. When the contact member 60 is deformed more than the protrusion amount H, the contact member 51 is brought into contact with the valve seat 39 to prevent the contact member 60 from being deformed excessively. Further, the tip of the pin 70 on the valve seat 39 side protrudes from the tip of the contact member 60, but the outer diameter of the flat plate portion 71 of the pin 70 is shorter than the inner diameter of the communication path 31. It protrudes to 31 and does not contact the valve seat 39.

  The contact member 60 is formed of a material having heat resistance and oil resistance such as nitrile rubber (NBR) which is a copolymer of acrylonitrile and 1,3 butadiene, or fluorine rubber (FKM) obtained by polymerizing a fluorine-containing monomer. Has been. The contact member 60 may further have ozone resistance.

  As shown in FIGS. 3 and 5, a first annular groove 52 and a second annular groove 53 are formed on the outer peripheral surface of the piston 50 on the third port 28 side. A first sealing material 55 and a second sealing material 56 are fitted in the first annular groove 52 and the second annular groove 53.

  The check valve 20 is attached to the compressed air drying system 1 so that the piston 50 is disposed vertically above the first port 26 (see FIGS. 1 and 2). In other words, the third port 28 is disposed above the first port 26 in the vertical direction. Thereby, it can suppress that water and oil accumulate on the sealing materials 55 and 56 side. These water and oil are liquefied ones contained in the compressed air supplied from the compressor 10. Therefore, swelling of the sealing materials 55 and 56 due to water or oil can be suppressed.

  The first seal material 55 provided on the side of the pipe line 17a connected to the compressor 10 is formed of a material having heat resistance and oil resistance such as NBR and FKM. The first sealing material 55 may further have ozone resistance. The second sealing material 56 is formed from a material different from that of the first sealing material 55. High-temperature compressed air containing oil and moisture is supplied from the compressor 10 through the pipe line 17a, but the first sealing material 55 is made of a material having heat resistance and oil resistance, and thus has improved durability. Hard to deteriorate. On the other hand, since the second sealing material 56 is not required to have a high level of heat resistance and oil resistance as compared with the first sealing material 55, the material restrictions can be reduced.

  A seal groove 48 is formed in the circumferential direction on the outer peripheral surface of the threaded portion 42 of the second body 23. An annular seal member 47 is fitted in the seal groove 48. The second body 23 is inserted into the first body 22 by inserting the screwing portion 42 into the first body 22 and screwing the male screw 41 of the second body 23 to the female screw 33 of the first body 22. It is attached to. In a state where the second body 23 is attached to the first body 22, the bottom surface of the cylindrical portion 36 of the second body 23 contacts the attachment port 49 of the first body 22.

  The sliding contact member 51 of the piston 50 is formed of a material having a hardness different from that of the material of the second body 23. For example, the combination of the material of the second body 23 and the material of the sliding contact member 51 of the piston 50 may be a combination of metals having different hardness such as aluminum (hardness: small) and iron (hardness: large), or a resin (hardness) such as POM. : Small) and a combination of different materials such as metal (hardness: large), a combination of synthetic resins having different hardness such as PPS (hardness: small) and PBT containing glass fiber (hardness: large).

  The sliding contact member 51 of the piston 50 may be formed of a material having a hardness higher than that of the second body 23 or may be formed of a material having a hardness lower than that of the second body 23. For example, when the hardness of the material of the second body 23 is smaller than the material of the sliding contact member 51 of the piston 50, the second body 23 is worn so as to match the shape of the sliding contact member 51 of the piston 50. Further, when the hardness of the material of the sliding contact member 51 of the piston 50 is smaller than the material of the second body 23, the fitting in which the stress due to the second body 23 tends to concentrate in the sliding contact member 51 of the piston 50. The sliding part with the corner 45a of the hole 45 is worn. For this reason, since the wear proceeds so that the sliding contact member 51 of the piston 50 and the second body 23 are engaged with each other via the lubricating oil even if worn, the sliding contact member 51 of the piston 50 and the second body It is difficult to form a large gap with 23. Therefore, the period during which the sealing performance between the sliding contact member 51 of the piston 50 and the second body 23 is maintained is longer than when the sliding contact member 51 of the piston 50 and the second body 23 are made of the same material. .

  3 to 5, the area of the pressure receiving surface on the end face 45 b side of the piston 50 is the same as the area of the pressure receiving surface on the valve seat 39 side of the piston 50, and the governor is driven by the sliding resistance of the sealing materials 55 and 56. After the device 19 is opened, the check valve 20 is closed after the pressure on the valve seat 39 side of the piston 50 is slightly reduced. Even in such a configuration, since the supply of compressed air from the compressor 10 to the air dryer 11 is prevented by closing the check valve 20, the compressed air sent from the compressor 10 passes through the drain valve device 13. Can be prevented from being discharged into the atmosphere. If the area of the pressure receiving surface on the end face 45b side of the piston 50 is made larger than the area of the pressure receiving surface on the valve seat 39 side of the piston 50, the check valve 20 is closed immediately after the governor device 19 is opened. .

Next, operations of the compressed air drying system 1 and the check valve 20 will be described with reference to FIGS.
As shown in FIG. 3, when the compressed air is supplied from the compressor 10 to the air dryer 11, when the internal pressure of the tank 18 is equal to or lower than the set pressure, the drain valve device 13 of the air dryer 11 is closed. In addition, no pneumatic signal is output from the governor device 19. In this state, in the check valve 20, compressed air flows from the first port 26, and compressed air does not flow into the third port 28. For this reason, the pressure of compressed air is applied to the side surface of the piston 50 on the valve seat 39 side, and the pressure of compressed air is not applied to the end of the piston 50 on the third port 28 side. As a result, the end of the piston 50 on the valve seat 39 side is separated from the valve seat 39, and the end of the piston 50 on the third port 28 side is in contact with the end surface 45 b of the fitting hole 45, so that the first port 26 The second port 27 is open. In this way, by connecting the first port 26 to the compressor 10, it is possible to prevent pressure from the outer peripheral surface of the piston 50 from being caused by compressed air. A shift of the axis can be suppressed. And by suppressing those center axes from shifting, it is possible to suppress damage to at least one of the valve seat 39 and the piston 50 when the piston 50 contacts the valve seat 39. Air leakage due to sticking can be suppressed.

  The air dryer 11 is supplied with compressed air from the compressor 10 via the check valve 20. The dry compressed air dehumidified by the air dryer 11 is stored in the tank 18. The dry compressed air stored in the tank 18 is used for the operation of the air system.

  As shown in FIG. 5, when the internal pressure of the tank 18 exceeds the set pressure, an air pressure signal is supplied from the governor device 19 to the third port 28. At the same time, dry compressed air is supplied from the governor device 19 to the drain valve device 13 of the air dryer 11, and the drain valve device 13 is opened.

  The piston 50 of the check valve 20 slides in the fitting hole 45 toward the first port 26 due to the pressure of the dry compressed air supplied to the third port 28. As a result, the end of the piston 50 contacts the valve seat 39, and the first port 26 and the second port 27 are closed. At this time, since the contact member 60 of the piston 50 is made of an elastic body, when the contact member 60 comes into contact with the valve seat 39, the contact member 60 is elastically deformed and is in close contact with the valve seat 39. Further, since the support portion 51a of the sliding contact member 51 of the piston 50 supports the contact member 60 when the contact member 60 is elastically deformed, excessive deformation of the contact member 60 is suppressed and the contact member 60 is suppressed. And the valve seat 39 can be promoted, and the deformed part of the contact member 60 can be prevented from being pinched between the sliding contact member 51 and the valve seat 39.

  Since the first sealing material 55 provided on the piston 50 is provided on the first port 26 side as compared with the second sealing material 56, the first sealing material 55 is exposed to high temperature and oil contained in the compressed air. However, since the 1st sealing material 55 consists of material which has heat resistance and oil resistance, it can suppress deterioration.

  Further, by providing both the first sealing material 55 and the second sealing material 56 on the piston 50, even if one sealing material is deteriorated, if the other sealing material is not deteriorated, the first sealing material is used. The sealing performance between the body 22 and the second body 23 can be ensured.

As described above, according to this embodiment, the following effects can be obtained.
(1) The contact member 60 of the piston 50 that contacts the first body 22 of the check valve 20 is made of an elastic body, and this contact member 60 is fixed to the sliding contact member 51 of the piston 50 by a pin 70. For this reason, when the abutment member 60 made of an elastic body abuts on the first body 22 when the piston 50 abuts on the first body 22, the abutment member 60 is hermetically sealed while being elastically deformed. Therefore, the sealing performance when the valve is closed can be improved.

  (2) Since the contact member 60 is press-fitted and fixed to the housing portion by the pin 70, the generation of a gap between the sliding contact member 51 and the contact member 60 can be suppressed. Therefore, it can suppress that compressed air enters into the clearance gap between the sliding contact member 51 and the contact member 60, and can improve the sealing performance at the time of valve closing.

  (3) The support portion 51 a supports the outer periphery of the contact member 60. For this reason, even if the contact member 60 contacts and deforms against the first body 22 of the check valve 20, excessive deformation can be suppressed and the contact member 60 can be prevented from sagging. Further, when the contact member 60 is excessively deformed, the support portion 51a contacts the first body 22 of the check valve 20, so that excessive movement of the piston 50 when the valve is closed can be suppressed.

  (4) The second body 23 having a sliding contact portion with which the piston 50 is slidably contacted is separated from the first body 22 and is assembled by screwing the second body 23 to the first body 22. For this reason, it can be easily detached during maintenance.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, the body 21 of the check valve 20 includes the first body 22 having a rectangular parallelepiped shape and the second body 23 having a substantially cylindrical shape. However, the first body 22 may have a shape other than the above embodiment, such as a shape in which a cylindrical member having the first port 26 and a cylindrical member having the second port 27 are combined.

  -In the said structure, as shown in FIG. 6, you may provide the urging | biasing spring 80 which urges | biases piston 50 to the valve seat 39 side. The urging spring 80 is accommodated in a spring accommodating portion 23 a provided in the second body 23 and urges the piston 50 toward the valve seat 39. When the biasing spring 80 is provided in this way, the piston 50 is moved to the valve seat 39 side when a slight air pressure signal (compressed air) flows into the third port 28 from the governor device 19, and the check valve 20. Can be closed.

In the above embodiment, the support member 51a that supports the outer periphery of the contact member 60 is provided on the sliding contact member 51. However, if the contact member 60 need not be supported, the support member 51a may be omitted.
In the above embodiment, the abutting member 60 is accommodated in a protruding state, and the accommodating portion 54 in which the abutting member 60 is press-fitted and fixed by the pin 70 is provided in the sliding contact member 51. However, the abutting member 60 is accommodated. The configuration of the accommodating portion 54 may be omitted, and the contact member 60 may be directly fixed to the sliding contact member 51.

  As shown in FIGS. 7 and 8, the air dryer 11 may incorporate a governor device 119 in addition to the check valve (not shown) and the drain valve device 13. As shown in FIG. 8, when the internal pressure of the tank 18 exceeds the set pressure, the governor device 119 uses dry compressed air (empty air) for closing the check valve 20 with respect to the check valve 20 via the pipe line 17h. Pressure signal).

In the above embodiment, the first sealing material 55 and the second sealing material 56 are formed from different materials, but may be formed from the same material having heat resistance and oil resistance.
In the above embodiment, the check valve 20 is attached to the compressed air drying system 1 so that the piston 50 is disposed vertically above the second port 27. However, if there is no problem that water or oil accumulates on the sealing materials 55 and 56 side, the check valve 20 is not attached to the compressed air drying system 1 so that the piston 50 is disposed vertically above the second port 27. May be.

  In the above embodiment, the pipeline 17c connecting the governor device 19 and the check valve 20 is branched from the pipeline 19a connecting the governor device 19 and the compressor 10, but these pipelines 17c, 19a may be a pipeline that is independently connected to the governor device 19. In this case, when the governor device 19 is a device (for example, a solenoid valve) capable of separately transmitting a pneumatic pressure signal to each of the pipes 17c and 19a, the opening / closing valve timing of the check valve 20 and the drain valve device 13 are used. It is possible to control the opening / closing timing of each independently.

  In the above embodiment, the second body 23 is a sliding contact portion, but only the sliding contact portion, which is a portion that is in sliding contact with the piston 50, of the second body 23 is made of a material different from the piston 50, and the rest is the piston 50 The same material may be used. For example, the sliding contact portion of the second body 23 may be a cylindrical member provided inside the second body 23 or a layered portion.

  In the above embodiment, the second body 23 is a slidable contact portion, but only the slidable contact portion, which is a portion that is in slidable contact with the second body 23, of the piston 50 is made of a material different from the second body 23. The same material as the second body 23 may be used. For example, the sliding contact portion of the piston 50 may be a cylindrical member provided outside the piston 50 or a layered portion such as a Teflon (registered trademark) plating.

  In the above embodiment, when priority is given to the durability of the sealing material between the second body 23 and the piston 50, at least the first sealing material 55 and the second sealing material 56 may be provided only on the piston 50. The hardness of the material of the second body 23 and the material of the piston 50 may be the same.

  In the above-described embodiment, when priority is given to suppressing the deterioration of the sealing performance due to wear between the second body 23 and the piston 50, it is sufficient that at least the material of the second body 23 and the material of the piston 50 are different in hardness. 50 may be provided with only the first sealing material 55.

  In the above embodiment, the second port 27 of the check valve 20 is connected to the air dryer 11 as a removing device (refining device), but may be connected to an oil mist separator. The oil mist separator includes a filter that performs gas-liquid separation by collision with compressed air instead of the desiccant, and captures oil contained in the compressed air sent from the compressor 10. The filter may be a compression-molded metal material or a porous material such as a sponge. The exhaust port of the oil mist separator is connected to the air dryer 11.

  In the above embodiment, the first port 26 of the check valve 20 is connected to the compressor 10. However, when the rigidity of the piston 50 is high and there is no concern that the central axis of the valve seat 39 shifts. The second port 27 may be connected to the compressor 10 and the first port 26 may be connected to the dryer.

  In the above embodiment, the compressed air drying system 1 that cleans the compressed air sent from the compressor 10 connected to the supercharger 15 is used. However, the compressed air sent from the compressor not connected to the supercharger is cleaned. It may be a compressed air drying system.

  -In the said embodiment, although the compressed air drying system 1 was applied to the compressed air drying system mounted in the motor vehicle, if it is a system which cleans the compressed air sent from the compressor connected to the supercharger, It may be applied to other systems. For example, you may apply the compressed air drying system 1 to moving bodies other than motor vehicles, such as a train, a ship, and an aircraft. Moreover, you may apply the compressed air drying system 1 to the system which is provided in addition to a moving body and operate | moves using an air pressure.

  DESCRIPTION OF SYMBOLS 1 ... Compressed air drying system, 10 ... Compressor, 11 ... Air dryer, 11a ... Desiccant, 11b ... Inlet, 11c ... Outlet, 11d ... Drain discharge port, 12 ... Check valve, 13 ... Drain valve device, 15 ... Excess 17a-17f, 17h ... pipe, 17g ... drain discharge pipe, 18 ... tank, 19 ... governor device, 20 ... check valve, 21 ... body, 22 ... first body, 23 ... second body, 23a ... Spring accommodating portion, 26 ... first port, 27 ... second port, 28 ... third port, 31 ... communication passage, 32 ... passage, 33 ... female screw, 35 ... communication passage, 36 ... cylindrical portion, 37 ... fastening portion , 39 ... Valve seat, 41 ... Male screw, 42 ... Threaded portion, 45 ... Fitting hole, 45a ... Corner, 45b ... End face, 46 ... Communication hole, 47 ... Seal member, 48 ... Seal groove, 49 ... Installation Mouth, 50 ... piston, 51 ... sliding member, DESCRIPTION OF SYMBOLS 1a ... Support part, 52 ... 1st annular groove, 53 ... 2nd annular groove, 54 ... Accommodating part, 54a ... Fixing hole, 55 ... 1st sealing material, 56 ... 2nd sealing material, 60 ... Contact member, 61 ... through-hole, 70 ... pin, 71 ... flat plate part, 72 ... cylindrical part, 80 ... biasing spring, 119 ... governor device.

Claims (8)

A compressor,
A load operation for capturing at least one of moisture and oil contained in the compressed air sent from the compressor, and an unload operation for discharging a drain containing at least one of the captured moisture and oil through a drain valve device are performed. A removal device;
A pressure regulator that is provided inside the removal device or outside the removal device, opens and closes the drain valve device with air pressure, and outputs a signal that indicates unload operation to the compressor by compressed air; and
A check valve having a first port connected to the compressor, a second port connected to the removal device, and a third port to which the signal is input,
The check valve includes a body having the first port, the second port, and the third port, and a piston slidably provided in the body,
The said piston is provided with the contact member which contacts the said body and consists of an elastic body, and the slidable contact member which slidably contacts with respect to the said body. Compressed air drying system. The piston includes a pin for fixing the contact member to the sliding contact member,
The compressed air drying system according to claim 1, wherein the sliding contact member includes a storage portion that stores the contact member in a protruding state, and the contact member is press-fitted and fixed by the pin. The compressed air drying system according to claim 1, wherein the sliding contact member includes a support portion that supports an outer periphery of the contact member. The body has a first body in which a passage connecting the first port, the second port, and the third port is formed, and a sliding contact portion that forms the third port and is in sliding contact with the piston. A cylindrical second body having,
A female screw is provided on the inner peripheral surface of the portion of the first body to which the second body is connected,
The compressed air drying system as described in any one of Claims 1-3 with which the external thread which engages with the said internal thread is provided in the outer peripheral surface of the said 2nd body. A compressor,
A load operation for capturing at least one of moisture and oil contained in the compressed air sent from the compressor, and an unload operation for discharging a drain containing at least one of the captured moisture and oil through a drain valve device are performed. A removal device;
A pressure regulator that is provided inside the removal device or outside the removal device, opens and closes the drain valve device with air pressure, and outputs a signal that indicates unload operation to the compressor by compressed air; and A check valve used in a compressed air drying system comprising:
A body having a first port connected to the compressor, a second port connected to the removing device, and a third port to which the signal is input; and a piston slidably provided in the body; With
The check valve for a compressed air drying system, wherein the piston is provided with an abutting member that abuts on the body and is made of an elastic body, and a sliding contact member that is in sliding contact with the body. The piston includes a pin for fixing the contact member to the sliding contact member,
The check valve for the compressed air drying system according to claim 5, wherein the sliding contact member includes a storage portion that stores the contact member in a protruding state, and the contact member is press-fitted and fixed by the pin. The check valve for the compressed air drying system according to claim 5 or 6, wherein the sliding contact member includes a support portion that supports an outer periphery of the contact member. The body has a first body in which a passage connecting the first port, the second port, and the third port is formed, and a sliding contact portion that forms the third port and is in sliding contact with the piston. A cylindrical second body having,
A female screw is provided on the inner peripheral surface of the portion of the first body to which the second body is connected,
The check valve for the compressed air drying system according to any one of claims 5 to 7, wherein a male screw that is screwed into the female screw is provided on an outer peripheral surface of the second body.