JP7510138B2 - Differential pressure valve and valve device having the same - Google Patents

Description

The present invention relates to a differential pressure valve and a valve device having the differential pressure valve.

Patent Document 1 discloses a solenoid valve with a differential pressure valve, which is an example of a conventional valve device. The solenoid valve of Patent Document 1 has a solenoid valve section and a differential pressure valve section integrally provided in one valve body. The valve body has a main valve chamber, a differential pressure valve chamber, an inlet, a first outlet, and a second outlet. The inlet is connected to the main valve chamber. The main valve chamber is connected to the first outlet via a main valve seat. The main valve chamber is also connected to the differential pressure valve chamber via a branch passage. The differential pressure valve chamber is connected to the second outlet via a differential pressure valve seat. The solenoid valve section has a main valve body that opens and closes the main valve seat. The differential pressure valve section has a differential pressure valve body that opens and closes the differential pressure valve seat.

The differential pressure valve body is attached to a synthetic resin diaphragm that is arranged to separate the differential pressure valve chamber and the first outlet (back pressure chamber). The outer periphery of the diaphragm is sandwiched between the valve body and a cylindrical retaining member. The retaining member has an inner circumferential surface and an annular plane that contacts the diaphragm, and the annular plane and the inner circumferential surface are smoothly connected by a curved connecting surface. In the solenoid valve, the diaphragm deforms to follow the connecting surface, preventing the deformation of the diaphragm from concentrating in one place. When the diaphragm deforms due to the pressure difference between the differential pressure valve chamber and the first outlet, the differential pressure valve body moves to open and close the differential pressure valve seat.

JP 2014-152848 A

The above-mentioned solenoid valve is used, for example, in a heat pump system. The refrigerant in a heat pump system may contain foreign matter such as metal powder that is generated by the operation of the solenoid valve or pump. When the diaphragm deforms, the foreign matter may become trapped between the diaphragm and the retaining member. This may result in damage to the diaphragm.

The present invention aims to provide a differential pressure valve that can suppress damage to the diaphragm caused by foreign objects and a valve device having the same.

In order to achieve the above object, a differential pressure valve according to one aspect of the present invention is a differential pressure valve having a valve body having a valve chamber and a back pressure chamber, a synthetic resin diaphragm arranged to separate the valve chamber from the back pressure chamber, a ring-shaped retaining member arranged to sandwich the outer periphery of the diaphragm between the valve body and the diaphragm, and a valve body arranged in the valve chamber and moved by the diaphragm, characterized in that it has a synthetic resin ring-shaped protective sheet arranged on one side of the outer periphery of the diaphragm and sandwiched together with the diaphragm between the valve body and the retaining member.

According to the present invention, the differential pressure valve has a synthetic resin annular protective sheet that is placed over one surface of the outer periphery of the diaphragm and is sandwiched together with the diaphragm between the valve body and the retaining member. This prevents foreign matter from being caught between the valve body or the retaining member and the protective sheet and coming into direct contact with the diaphragm when the diaphragm is deformed. This makes it possible to suppress damage to the diaphragm in the differential pressure valve.

In the present invention, the central portion of the diaphragm is configured to have a truncated cone shape when there is no pressure difference between the valve chamber and the back pressure chamber, and the valve element is attached to the central portion of the diaphragm . This makes it possible to increase the amount of movement of the valve element.
In the present invention, the sealing member is preferably made of polytetrafluoroethylene .

In the present invention, it is preferable that the inner diameter of the protective sheet is smaller than the outer diameter of the central portion of the diaphragm. In this way, the deformation location of the diaphragm can be made to be different when the valve is open and when it is closed, improving the durability of the diaphragm.

In the present invention , it is preferable that the holding member has an annular plane that contacts the protective sheet, a cylindrical inner peripheral surface, and a curved connecting surface that smoothly connects the annular plane and the inner peripheral surface, and the inner diameter of the protective sheet is smaller than the diameter of the inner peripheral surface of the holding member. In this way, the protective sheet is disposed so as to face the entire connecting surface, which more reliably prevents foreign matter from being caught between the diaphragm and the connecting surface, and further suppresses damage to the diaphragm.

In the present invention, the differential pressure valve further includes an annular sealing member disposed on the other surface of the outer periphery of the diaphragm and held together with the diaphragm by the valve body and the holding member, thereby effectively sealing the valve chamber and the back pressure chamber from each other.

In order to achieve the above object, a valve device according to another aspect of the present invention includes a valve body having an inlet, a main valve chamber connected to the inlet, a first outlet connected to the main valve chamber via a main valve seat, a differential pressure valve chamber connected to the main valve chamber via a branch passage, and a second outlet connected to the differential pressure valve chamber via the differential pressure valve seat, a main valve element disposed in the main valve chamber and opening and closing the main valve seat, a diaphragm made of synthetic resin disposed to separate the differential pressure valve chamber from the first outlet serving as a back pressure chamber, a ring-shaped retaining member disposed between the valve body and the diaphragm, and a valve body having a ring-shaped retaining member disposed in the differential pressure valve chamber and connected to the diaphragm. and a differential pressure valve body that is moved by a pressure adjusting mechanism, wherein a central portion of the diaphragm is configured to be frustum-shaped when there is no pressure difference between the differential pressure valve chamber and the first outlet, the valve body is attached to the central portion of the diaphragm, the valve device has a circular ring-shaped sealing member arranged to overlap the surface of the outer periphery of the diaphragm facing the differential pressure valve chamber, and a circular ring- shaped protective sheet made of synthetic resin arranged to overlap the surface of the outer periphery of the diaphragm facing the first outlet , and the sealing member, the outer periphery of the diaphragm and the protective sheet are held by being sandwiched between the valve body and the holding member .

According to the present invention, the valve device has a synthetic resin annular protective sheet that is placed over one surface of the outer periphery of the diaphragm and is sandwiched together with the diaphragm between the valve body and the retaining member. This prevents foreign matter from being caught between the valve body or the retaining member and the protective sheet and coming into direct contact with the diaphragm when the diaphragm is deformed. This makes it possible to suppress damage to the diaphragm in the valve device.

The present invention can prevent damage to the diaphragm caused by foreign objects.

1 is a cross-sectional view of a differential pressure valve-equipped solenoid valve according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a differential pressure valve portion of the differential pressure valve-equipped solenoid valve of FIG. 1 (valve closed state). 3 is an enlarged cross-sectional view of a portion surrounded by a dashed dotted circle in FIG. 2 . FIG. 2 is an enlarged cross-sectional view of a differential pressure valve portion of the differential pressure valve-equipped solenoid valve of FIG. 1 (valve open state). 5 is an enlarged cross-sectional view of a portion surrounded by a dashed line circle in FIG. 4 .

Below, a differential pressure valve-equipped solenoid valve according to one embodiment of the valve device of the present invention will be described with reference to Figures 1 to 5.

Figure 1 is a cross-sectional view of a solenoid valve with a differential pressure valve according to one embodiment of the present invention. Figure 2 is an enlarged cross-sectional view of a differential pressure valve section of the solenoid valve with a differential pressure valve of Figure 1. Figure 2 shows the differential pressure valve section in a closed state. Figure 3 is an enlarged cross-sectional view of a portion circled with a dashed line in Figure 2. Figure 4 is an enlarged cross-sectional view of a differential pressure valve section of the solenoid valve with a differential pressure valve of Figure 1. Figure 4 shows the differential pressure valve section in an open state. Figure 5 is an enlarged cross-sectional view of a portion circled with a dashed line in Figure 4. In the following description, the terms "up, down, left, right" and "down" refer to the relative positional relationship of the components shown in each figure.

As shown in Figures 1 to 5, the differential pressure valve-equipped solenoid valve 1 (hereinafter simply referred to as "solenoid valve 1") of this embodiment has a valve body 10. The valve body 10 is provided with a solenoid valve section 30 and a differential pressure valve section 50.

The valve body 10 has a generally rectangular parallelepiped shape. The valve body 10 has an inlet 11, a main valve chamber 12, a differential pressure valve chamber 13, a first outlet 14, and a second outlet 15.

The inlet 11 opens to the left side surface 10a of the valve body 10. The inlet 11 is connected to the main valve chamber 12. The main valve chamber 12 is provided with a circular main valve seat 17 surrounding the main valve port 16. The main valve chamber 12 is connected to the first outlet 14 via the main valve seat 17 and the main valve port 16. The first outlet 14 opens to the left side surface 10a of the valve body 10. The main valve chamber 12 is also connected to the differential pressure valve chamber 13 via a branch passage 18. The differential pressure valve chamber 13 is provided with a circular differential pressure valve seat 20 surrounding the differential pressure valve port 19. The differential pressure valve chamber 13 is connected to the second outlet 15 via the differential pressure valve seat 20 and the differential pressure valve port 19. The second outlet 15 opens to the back surface of the valve body 10.

The solenoid valve section 30 has an attractor 31, a can 32, a plunger 33, an electromagnetic coil 34, a valve shaft 35, a pilot valve body 36, and a main valve body 40.

The suction element 31 has a large diameter cylindrical portion 31a and a small diameter cylindrical portion 31b that is connected to the upper end of the large diameter cylindrical portion 31a. The large diameter cylindrical portion 31a is fixed to the valve body 10 by a screw structure. The small diameter cylindrical portion 31b is arranged to extend upward from the valve body 10.

The can 32 has a cylindrical shape with the upper end closed. The small diameter cylindrical portion 31b of the suction element 31 is inserted into the lower end of the can 32. The can 32 is joined to the suction element 31.

The plunger 33 has a cylindrical shape with an outer diameter slightly smaller than the inner diameter of the can 32. The plunger 33 is arranged inside the can 32 so that it can move up and down. A valve-opening spring 38 is arranged between the plunger 33 and the small-diameter cylindrical portion 31b of the suction element 31. The valve-opening spring 38 is a compression coil spring, and pushes the plunger 33 upward.

The electromagnetic coil 34 has a cylindrical shape with an inner diameter slightly larger than the outer diameter of the can 32. The can 32 is inserted inside the electromagnetic coil 34. The electromagnetic coil 34 is disposed outside the can 32 so that the attractor 31 and the plunger 33 are magnetized by its electromagnetic force.

The valve shaft 35 has an elongated cylindrical shape. The upper end of the valve shaft 35 is fixed to the plunger 33. The valve shaft 35 is inserted into the small diameter cylindrical portion 31b of the suction element 31. The valve shaft 35 is supported by the small diameter cylindrical portion 31b so that it can move in the vertical direction. The valve shaft 35 has a fluid passage 35a that extends from the upper end to near the lower end.

The pilot valve body 36 is integrally provided at the lower end of the valve shaft 35. A disk-shaped gasket 36a is attached to the underside of the pilot valve body 36.

The main valve body 40 has a cylindrical body 41, an upper flange 42 disposed at the top of the body 41, and a lower flange 43 disposed at the bottom of the body 41, which are integral with the body 41. The body 41 is provided with a pilot valve port 44 that penetrates from the top to the bottom. The upper end of the body 41 is provided with a pilot valve seat 45 that surrounds the pilot valve port 44. The upper flange 42 is arranged inside the large diameter cylindrical portion 31a of the suction element 31 so as to be able to slide in the vertical direction. The upper flange 42 divides the main valve chamber 12 and the pilot valve chamber 37 inside the suction element 31. The upper flange 42 is provided with a pressure equalizing passage 42a that connects the main valve chamber 12 and the pilot valve chamber 37. A packing 43a in the shape of an annular disk is attached to the bottom surface of the lower flange 43. The outer diameter of the lower flange 43 is smaller than the outer diameter of the upper flange 42. A valve-opening spring 39 is disposed between the upper flange portion 42 of the main valve body 40 and the valve body 10. The valve-opening spring 39 is a compression coil spring that pushes the main valve body 40 upward.

The solenoid valve unit 30 is a normally open solenoid valve that is in an open state when no current is applied to the solenoid coil 34, but it may also be a normally closed solenoid valve that is in a closed state when no current is applied to the solenoid coil 34.

The differential pressure valve section 50 has a diaphragm 51, a protective sheet 52, a sealing member 53, a retaining member 54, a differential pressure valve frame 55, a differential pressure valve body 56, and a stopper 57.

The diaphragm 51 is a thin film made of a synthetic resin such as polyimide. The diaphragm 51 is arranged in the valve body 10 so as to separate the differential pressure valve chamber 13 and the first outlet 14 as a back pressure chamber. The diaphragm 51 has a central portion 51a and an outer peripheral portion 51b. The central portion 51a is configured to have a truncated cone shape that protrudes toward the differential pressure valve chamber 13 when there is no pressure difference between the differential pressure valve chamber 13 and the first outlet 14. The outer peripheral portion 51b has a ring shape. The inner peripheral edge of the outer peripheral portion 51b is connected to the outer peripheral edge of the central portion 51a. In FIG. 3, the boundary between the central portion 51a and the outer peripheral portion 51b is indicated by an arrow A. In this specification, the truncated cone shape includes a shape in which the outer peripheral edge and the ceiling portion are connected by a smoothly curved surface, such as a dome shape with a gently raised central portion, and a shape in which the outer peripheral edge and the ceiling portion are composed of a smoothly curved surface.

The protective sheet 52 is a thin film made of synthetic resin such as polyimide. The protective sheet 52 has a circular ring shape. The outer diameter of the protective sheet 52 is the same as the outer diameter of the diaphragm 51. The inner diameter of the protective sheet 52 is slightly smaller than the outer diameter of the central portion 51a of the diaphragm 51. By making the inner diameter of the protective sheet 52 such a dimension, the deformation location of the diaphragm can be different when the valve is open and when the valve is closed. Therefore, the durability of the diaphragm 51 is improved. It is desirable that the inner diameter of the protective sheet 52 is larger than the abutment range (abutment surface) of the diaphragm 51 and the stopper 57 in the closed state shown in FIG. 3 so that the protective sheet 52 is not sandwiched between the stopper 57 and the diaphragm 51. In this way, the inner peripheral portion of the protective sheet 52 is prevented from overlapping the central portion 51a of the diaphragm 51, and the deformation characteristics of the diaphragm 51 with respect to the differential pressure can be suppressed from changing. The protective sheet 52 is arranged so as to closely overlap the surface (one surface) of the outer circumferential portion 51b of the diaphragm 51 on the first outlet 14 side. In this embodiment, the protective sheet 52 is made of the same material as the diaphragm 51 and has the same thickness as the diaphragm 51. The material of the diaphragm 51 may be a synthetic resin that can be used in a refrigerant, for example, HFC134a or HFO1234yf, and the plate thickness may be within a range that does not impair the deformation characteristics of the diaphragm 51. The protective sheet 52 may be arranged so as to closely overlap the surface of the outer circumferential portion 51b of the diaphragm 51 on the differential pressure valve chamber 13 side. In this embodiment, the inner diameter of the protective sheet 52 is slightly smaller than the outer diameter of the central portion 51a of the diaphragm 51, but the inner diameter of the protective sheet 52 and the outer diameter of the central portion 51a may be the same. Even if the inner diameter of the protective sheet 52 is made larger than the outer diameter of the central portion 51a, it still has the effect of suppressing damage to the diaphragm 51 caused by foreign objects.

The sealing member 53 is made of a synthetic resin such as polytetrafluoroethylene (PTFE). The sealing member 53 has a circular plate shape with the same outer diameter as the diaphragm 51. The sealing member 53 is arranged so as to closely overlap the surface (the other surface) of the outer periphery 51b of the diaphragm 51 that faces the differential pressure valve chamber 13.

The retaining member 54 has an overall annular shape. The retaining member 54 has an integral cylindrical portion 54a and a flange portion 54b. The flange portion 54b is connected to one end of the cylindrical portion 54a (the right end in each figure). The flange portion 54b has an annular flat surface 54c that contacts the protective sheet 52. The annular flat surface 54c and the cylindrical inner surface 54d of the cylindrical portion 54a are smoothly connected by a curved connecting surface 54e. The diameter of the inner surface 54d is larger than the inner diameter of the protective sheet 52.

The retaining member 54 is arranged to sandwich the protective sheet 52, the outer periphery 51b of the diaphragm 51, and the sealing member 53 between the retaining surface 10b in the valve body 10 and the retaining member 54. The gap between the protective sheet 52 and the connection surface 54e of the retaining member 54 is formed so as to gradually narrow as it moves radially outward.

The differential pressure valve frame 55 has a cylindrical shape with one end (the left end in FIG. 1) closed. One end of the differential pressure valve frame 55 is provided with a flow hole 55a. The inner space of the differential pressure valve frame 55 is connected to the first outlet 14 via the flow hole 55a. The other end of the differential pressure valve frame 55 is fitted with the cylindrical portion 54a of the holding member 54. The other end of the differential pressure valve frame 55 is fixed to the valve body 10 by a screw structure. The differential pressure valve frame 55 presses the holding member 54 against the holding surface 10b of the valve body 10. As a result, the protective sheet 52, the outer peripheral portion 51b of the diaphragm 51, and the sealing member 53 are held between the holding member 54 and the holding surface 10b of the valve body in a mutually overlapping state.

The differential pressure valve body 56 has a substantially disk shape. The differential pressure valve body 56 is arranged in the differential pressure valve chamber 13 so as to be slidable in the left-right direction. A disk-shaped packing 56a is attached to one end face (the right end face in FIG. 1) of the differential pressure valve body 56. The differential pressure valve body 56 is attached to the center part 51a of the diaphragm 51. Specifically, the differential pressure valve body 56 and the stopper 57 are connected to each other with the center part 51a in between. The stopper 57 is arranged inside the differential pressure valve frame 55. When the differential pressure valve body 56 reaches the maximum valve opening position, the stopper 57 abuts against the stopper surface 55b of the differential pressure valve frame 55 to restrict the movement of the differential pressure valve body 56 in the valve opening direction. A valve closing spring 58 is arranged between the stopper 57 and the differential pressure valve frame 55. The valve-closing spring 58 is a compression coil spring, and presses the differential pressure valve body 56 to the right (valve-closing direction) via a stopper 57 .

Next, an example of the operation of solenoid valve 1 will be described.

Figure 1 shows the solenoid valve 1 in a state where the solenoid coil 34 is not energized. In Figure 1, the pilot valve body 36 (specifically, the packing 36a) is separated from the pilot valve seat 45, and the pilot valve seat 45 is open. In addition, the main valve body 40 (specifically, the packing 43a) is separated from the main valve seat 17, and the main valve seat 17 is open. At this time, the refrigerant that flows into the main valve chamber 12 from the inlet 11 flows through the main valve seat 17 and the main valve port 16 to the first outlet 14, and also flows through the branch passage 18 to the differential pressure valve chamber 13. Therefore, the pressure difference between the differential pressure valve chamber 13 and the first outlet 14 is relatively small, and as shown in Figures 2 and 3, the center portion 51a of the diaphragm 51 has a truncated cone shape that protrudes toward the differential pressure valve chamber 13. As a result, the differential pressure valve body 56 (specifically, the packing 56a) comes into contact with the differential pressure valve seat 20 to close the differential pressure valve seat 20. When the differential pressure valve seat 20 is closed, the refrigerant in the differential pressure valve chamber 13 remains in the differential pressure valve chamber 13 and does not flow to the second outlet 15.

When the electromagnetic coil 34 is energized, the plunger 33 is attracted to the attractor 31, and the pilot valve body 36 moves downward. The pilot valve body 36 then contacts the pilot valve seat 45 and pushes the main valve body 40 downward, and the main valve body 40 contacts the main valve seat 17. As a result, the pilot valve body 36 closes the pilot valve seat 45, and the main valve body 40 closes the main valve seat 17, blocking the flow of refrigerant from the main valve chamber 12 to the first outlet 14.

A little while after the main valve element 40 closes the main valve seat 17, the pressure at the first outlet 14 drops relative to the pressure at the differential pressure valve chamber 13. This causes a comparatively large pressure difference between the differential pressure valve chamber 13 and the first outlet 14, and as shown in Figures 4 and 5, the central portion 51a of the diaphragm 51 deforms so as to protrude toward the first outlet 14. This causes the differential pressure valve element 56 to move away from the differential pressure valve seat 20, opening the differential pressure valve seat 20. When the differential pressure valve seat 20 opens, the refrigerant in the differential pressure valve chamber 13 flows to the second outlet 15 via the differential pressure valve seat 20 and the differential pressure valve port 19.

The deformation of the diaphragm 51 reduces the gap between the protective sheet 52 and the connection surface 54e of the holding member 54. This can cause foreign matter that enters the gap to become trapped between the protective sheet 52 and the holding member 54. However, the protective sheet 52 is placed over the outer periphery 51b of the diaphragm 51, preventing foreign matter from coming into direct contact with the diaphragm 51.

When the electromagnetic coil 34 is de-energized again, the plunger 33 is pushed upward by the valve-opening spring 38, the pilot valve body 36 is separated from the pilot valve seat 45, and the pilot valve seat 45 opens. The refrigerant in the pilot valve chamber 37 flows to the first outlet 14 through the pilot valve seat 45 and the pilot valve port 44, and the force of the refrigerant pressing the main valve body 40 against the main valve seat 17 is weakened. The main valve body 40 is pushed upward by the valve-opening spring 39, and the main valve body 40 is separated from the main valve seat 17, opening the main valve seat 17. As a result, the refrigerant in the main valve chamber 12 flows to the first outlet 14 through the main valve seat 17 and the main valve port 16. Therefore, the pressure difference between the differential pressure valve chamber 13 and the first outlet 14 becomes relatively small, and the center portion 51a of the diaphragm 51 returns to a truncated cone shape protruding toward the differential pressure valve chamber 13 side, as shown in Figures 2 and 3. This causes the differential pressure valve body 56 to come into contact with the differential pressure valve seat 20, closing the differential pressure valve seat 20.

As described above, the solenoid valve 1 has a valve body 10 having an inlet 11, a main valve chamber 12 connected to the inlet 11, a first outlet 14 connected to the main valve chamber 12 via a main valve seat 17, a differential pressure valve chamber 13 connected to the main valve chamber 12 via a branch passage 18, and a second outlet 15 connected to the differential pressure valve chamber 13 via a differential pressure valve seat 20. The solenoid valve 1 has a main valve body 40 arranged in the main valve chamber 12 and opening and closing the main valve seat 17, a synthetic resin diaphragm 51 arranged to separate the differential pressure valve chamber 13 and the first outlet 14, a ring-shaped retaining member 54 arranged to sandwich the outer periphery 51b of the diaphragm 51 between the valve body 10, and a differential pressure valve body 56 arranged in the differential pressure valve chamber 13 and moved by the diaphragm 51. It also has a synthetic resin annular protective sheet 52 that is placed over the surface of the outer periphery 51b of the diaphragm 51 on the first outlet 14 side (i.e., the holding member 54 side) and is sandwiched together with the diaphragm 51 between the valve body 10 and the holding member 54.

By doing this, when the diaphragm 51 is deformed, it is possible to prevent foreign matter from being caught between the retaining member 54 and the protective sheet 52 and coming into direct contact with the diaphragm 51. Therefore, damage to the diaphragm 51 in the solenoid valve 1 can be suppressed.

The central portion 51a of the diaphragm 51 is configured to have a truncated cone shape when there is no pressure difference between the differential pressure valve chamber 13 and the first outlet 14. The differential pressure valve body 56 is attached to the central portion 51a of the diaphragm 51. This allows the amount of movement of the differential pressure valve body 56 to be increased.

The retaining member 54 has an annular plane 54c that contacts the protective sheet 52, a cylindrical inner peripheral surface 54d, and a curved connecting surface 54e that smoothly connects the annular plane 54c and the inner peripheral surface 54d. The inner diameter of the protective sheet 52 is smaller than the diameter of the inner peripheral surface 54d of the retaining member 54. In this way, the protective sheet 52 is positioned to face the entire connecting surface 54e, which more reliably prevents foreign matter from being caught between the diaphragm 51 and the connecting surface 54e, and further suppresses damage to the diaphragm 51.

The solenoid valve 1 also has a ring-shaped sealing member 53 that is placed over the surface of the diaphragm 51 on the differential pressure valve chamber 13 side (i.e., the valve body 10 side) at the outer periphery 51b, and is held together with the diaphragm 51 by the valve body 10 and the retaining member 54. In this way, the gap between the diaphragm 51 and the valve body 10 can be effectively sealed, and the differential pressure valve chamber 13 and the first outlet 14 can be effectively sealed from each other.

In addition, the solenoid valve 1 in this embodiment is a composite valve having a solenoid valve section 30 and a differential pressure valve section 50, but the present invention may also be applied to a single differential pressure valve.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. Those in the art who appropriately add, delete, or modify components of the above-mentioned embodiments, or those who appropriately combine features of the embodiments, are also included in the scope of the present invention as long as they do not go against the spirit of the present invention.

Reference Signs List 1...solenoid valve with differential pressure valve, 10...valve body, 10a...left side surface, 10b...retaining surface, 11...inlet, 12...main valve chamber, 13...differential pressure valve chamber, 14...first outlet, 15...second outlet, 16...main valve port, 17...main valve seat, 18...branch passage, 19...differential pressure valve port, 20...differential pressure valve seat, 30...solenoid valve portion, 31...suction element, 31a...large diameter cylindrical portion, 31b...small diameter cylindrical portion, 32...can, 33...plunger, 34...electromagnetic coil, 35...valve stem, 35a...fluid passage, 36...pilot valve body, 36a...packing, 37...pilot valve chamber, 38, 39...valve opening spring, 40 ...Main valve body, 41...Body portion, 42...Upper flange portion, 42a...Pressure equalizing passage, 43...Lower flange portion, 43a...Packing, 44...Pilot valve port, 45...Pilot valve seat, 50...Differential pressure valve portion, 51...Diaphragm, 51a...Central portion, 51b...Outer periphery, 52...Protective sheet, 53...Sealing member, 54...Retaining member, 54a...Cylindrical portion, 54b...Flange portion, 54c...Annular flat surface, 54d...Inner circumferential surface, 54e...Connection surface, 55...Differential pressure valve frame, 55a...Flow hole, 55b...Stopper surface, 56...Differential pressure valve body, 56a...Packing, 57...Stopper, 58...Valve closing spring

Claims (5)

A differential pressure valve comprising: a valve body having a valve chamber and a back pressure chamber; a diaphragm made of synthetic resin arranged to separate the valve chamber from the back pressure chamber; a ring-shaped retaining member arranged between the valve body and the diaphragm to sandwich an outer periphery of the diaphragm; and a valve element arranged in the valve chamber and moved by the diaphragm,
The central portion of the diaphragm is configured to have a truncated cone shape when there is no pressure difference between the valve chamber and the back pressure chamber,
The valve body is attached to a central portion of the diaphragm,
the differential pressure valve includes an annular sealing member disposed over a surface of the outer periphery of the diaphragm facing the valve chamber, and an annular protective sheet made of synthetic resin disposed over a surface of the outer periphery of the diaphragm facing the back pressure chamber ,
a sealing member, an outer periphery of the diaphragm, and the protective sheet are sandwiched and held between the valve body and the holding member, said differential pressure valve comprising: The differential pressure valve of claim 1 , wherein the sealing member is made of polytetrafluoroethylene . 3. The differential pressure valve according to claim 1 , wherein an inner diameter of the protective sheet is smaller than an outer diameter of a central portion of the diaphragm. the holding member has an annular plane in contact with the protective sheet, a cylindrical inner circumferential surface, and a curved connecting surface that smoothly connects the annular plane and the inner circumferential surface,
The differential pressure valve according to any one of claims 1 to 3, wherein an inner diameter of the protective sheet is smaller than a diameter of the inner circumferential surface of the holding member. a valve body having an inlet, a main valve chamber connected to the inlet, a first outlet connected to the main valve chamber via a main valve seat, a differential pressure valve chamber connected to the main valve chamber via a branch passage, and a second outlet connected to the differential pressure valve chamber via the differential pressure valve seat;
a main valve body disposed in the main valve chamber and configured to open and close the main valve seat;
a diaphragm made of a synthetic resin arranged to separate the differential pressure valve chamber from the first outlet port serving as a back pressure chamber;
a holding member having an annular shape arranged to sandwich an outer periphery of the diaphragm between the holding member and the valve body;
a differential pressure valve body disposed in the differential pressure valve chamber and moved by the diaphragm,
a central portion of the diaphragm is configured to have a truncated cone shape when there is no pressure difference between the differential pressure valve chamber and the first outlet,
the differential pressure valve body is attached to a center portion of the diaphragm,
the valve device includes: a ring-shaped sealing member disposed over a surface of the outer periphery of the diaphragm facing the differential pressure valve chamber; and a ring- shaped protective sheet made of a synthetic resin disposed over a surface of the outer periphery of the diaphragm facing the first outlet port ,
a valve device, characterized in that the sealing member, the outer periphery of the diaphragm, and the protective sheet are sandwiched and held between the valve body and the holding member .

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