Flow path switching valve

Abstract

Provided is a flow path switching valve capable of switching a flow path with a small force. When a valve stem (30) of a flow path switching valve (1) moves to a first back pressure chamber (21) side, a first valve chamber (22) and the first back pressure chamber (21) are closed by a first valve core (41), and a second valve chamber (24) and an intermediate chamber (23) are closed by a second valve core (42). When the valve stem (30) moves to a second back pressure chamber side, the first valve chamber (22) and the intermediate chamber (23) are closed by the first valve core (41), and the second valve chamber (24) and the second back pressure chamber (25) are closed by the second valve core (42). Furthermore, the valve stem (30) is provided with a pressure equalizing passage (31) that communicates the first back pressure chamber (21) and the second back pressure chamber (25).

Description

[0001] This application is a divisional application of the following patent application:

[0002] Application Number: 202080051580.0

[0003] Application date: June 25, 2020

[0004] Invention Title: Flow Path Switching Valve Technical Field

[0005] This invention relates to a flow path switching valve. Background Technology

[0006] Patent Document 1 discloses a conventional flow path switching valve. This flow path switching valve has a generally cylindrical main body that serves as the valve body. The main body has a first inlet, a second inlet, and an outlet. A first flow path is provided within the main body for fluid to flow between the first inlet and the outlet. A first valve seat is provided within the first flow path. A second flow path is provided within the main body for fluid to flow between the second inlet and the outlet. A second valve seat is provided within the second flow path. A push rod is axially arranged within the main body. A first valve core and a second valve core are mounted on the push rod. When the push rod moves in one direction, the second valve core contacts the second valve seat, thereby closing the second flow path, and the first valve core separates from the first valve seat, thereby opening the first flow path. When the push rod moves in the other direction, the first valve core contacts the first valve seat, thereby closing the first flow path, and the second valve core separates from the second valve seat, thereby opening the second flow path.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2016-89931

[0010] The technical problem that the invention aims to solve

[0011] In the aforementioned conventional flow path switching valve, when the first flow path is open and the second flow path is closed, the second valve core is subjected to a force that presses the fluid from the second inlet against the second valve seat. Therefore, to open the second flow path and separate the second valve core from the second valve seat, a large force is required to move the push rod. Similarly, when the second flow path is open and the first flow path is closed, to open the first flow path and separate the first valve core from the first valve seat, a large force is also required to move the push rod. Therefore, a powerful drive device for moving the push rod is needed. Summary of the Invention

[0012] Therefore, the object of the present invention is to provide a flow path switching valve that can switch the flow path with a small amount of force.

[0013] Technical means for solving technical problems

[0014] To achieve the above objectives, the flow path switching valve of the present invention comprises: a cylindrical valve body, a valve stem housed in the valve body along an axial direction, and a first valve core and a second valve core mounted on the valve stem. The valve body comprises: a first back pressure chamber, a first valve chamber, an intermediate chamber, a second valve chamber, and a second back pressure chamber arranged sequentially along an axial direction; a first flow path connected to the first valve chamber; a second flow path connected to the second valve chamber; and a third flow path connected to the intermediate chamber. The first valve core is disposed in the first valve chamber, and the second valve core is disposed in the second valve chamber. When the valve stem moves toward the first back pressure chamber, the first valve chamber and the intermediate chamber are separated. When the valve stem moves toward the second back pressure chamber, the first valve chamber and the first back pressure chamber are closed together by the first valve core, the second valve chamber and the second back pressure chamber are opened together, and the second valve chamber and the second back pressure chamber are closed together by the second valve core. When the valve stem moves toward the second back pressure chamber, the first valve chamber and the first back pressure chamber are opened together, the first valve chamber and the intermediate chamber are closed together by the first valve core, the second valve chamber and the intermediate chamber are opened together, and the second valve chamber and the second back pressure chamber are closed together by the second valve core. A pressure equalization passage connecting the first back pressure chamber and the second back pressure chamber is provided in the valve body or the valve stem.

[0015] According to the present invention, when the valve stem moves towards the first back pressure chamber side, the first valve chamber and the intermediate chamber are opened, and the first valve chamber and the first back pressure chamber are closed through the first valve core; the second valve chamber and the second back pressure chamber are opened, and the second valve chamber and the intermediate chamber are closed through the second valve core. A pressure equalization passage connecting the first back pressure chamber and the second back pressure chamber is provided in the valve body or valve stem. Thus, the pressure of the fluid in the second flow path is applied to the surface of the first valve core on the first back pressure chamber side and the surface of the second valve core on the second back pressure chamber side, thereby eliminating this pressure. Furthermore, when the valve stem moves towards the second back pressure chamber side, the first valve chamber and the first back pressure chamber are opened, and the first valve chamber and the intermediate chamber are closed through the first valve core; the second valve chamber and the intermediate chamber are opened, and the second valve chamber and the second back pressure chamber are closed through the second valve core. A pressure equalization passage connecting the first back pressure chamber and the second back pressure chamber is provided in the valve body or valve stem. Therefore, the pressure of the fluid in the first flow path is applied to the surface of the first back pressure chamber in the first valve core and the surface of the second back pressure chamber in the second valve core, thereby eliminating the pressure. Thus, the force required to move the valve stem can be reduced.

[0016] The effects of the invention

[0017] According to the present invention, the flow path can be switched with a smaller force. Attached Figure Description

[0018] Figure 1 This is a perspective view of a flow path switching valve according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 A longitudinal sectional view of the flow path switching valve.

[0020] Figure 3 yes Figure 1 An enlarged cross-sectional view of the valve core and its vicinity of the flow path switching valve.

[0021] Figure 4 yes Figure 1 Enlarged cross-sectional view of the valve core and its vicinity in other states of the flow path switching valve. Detailed Implementation

[0022] The following is for reference Figures 1-4 This invention describes a flow path switching valve according to one embodiment of the present invention.

[0023] Figure 1 , Figure 2 This is a perspective view and a cross-sectional view (longitudinal view) along the axial direction of a flow path switching valve according to an embodiment of the present invention. Figure 3 , Figure 4 yes Figure 1 An enlarged cross-sectional view of the valve core and its vicinity of the flow path switching valve. Figure 3 This indicates the state where the first flow path and the third flow path are connected. Figure 4 This indicates the state where the second flow path and the third flow path are connected.

[0024] like Figures 1-4 As shown, the flow path switching valve 1 in this embodiment is a three-way switching valve. The flow path switching valve 1 has a valve body 5, a valve stem 30, a first valve core 41, a second valve core 42, and a drive device 50.

[0025] The valve body 5 has a valve housing 10 and cover components 14 and 15.

[0026] The valve housing 10 is generally cylindrical. The valve housing 10 has a first tubular portion 11, a second tubular portion 12, and a third tubular portion 13 extending in a direction orthogonal to the axis L. The first tubular portion 11 and the second tubular portion 12 are arranged at intervals along the axis L. The first tubular portion 11 and the second tubular portion 12 are oriented in the same direction (…). Figure 1 , Figure 2 The third tubular portion 13 extends to the left of the first tubular portion 11 and the second tubular portion 12 in the direction of axis L. The third tubular portion 13 extends in the opposite direction to the first tubular portion 11 and the second tubular portion 12. Figure 1 , Figure 2(Extending to the right of). A first flow path 11a is provided inside the first tubular portion 11. A second flow path 12a is provided inside the second tubular portion 12. A third flow path 13a is provided inside the third tubular portion 13.

[0027] In this embodiment, the flow path switching valve 1 is used to allow fluid to flow into the first flow path 11a and the second flow path 12a, and to allow fluid to flow out from the third flow path 13a. Alternatively, the flow path switching valve 1 can also be used to allow fluid to flow into the third flow path 13a and to allow fluid to flow out from either the first flow path 11a or the second flow path 12a.

[0028] The cover component 14 is installed on the valve housing 10 in such a way that it blocks the upper opening of the valve housing 10. The cover component 15 is installed on the valve housing 10 in such a way that it blocks the lower opening of the valve housing 10.

[0029] The valve body 5 has a first back pressure chamber 21, a first valve chamber 22, an intermediate chamber 23, a second valve chamber 24 and a second back pressure chamber 25 arranged sequentially from top to bottom along the axis L.

[0030] The first flow path 11a is connected to the first valve chamber 22. The third flow path 13a is connected to the intermediate chamber 23. The second flow path 12a is connected to the second valve chamber 24.

[0031] The first back pressure chamber 21 opens into the first valve chamber 22. The second back pressure chamber 25 opens into the second valve chamber 24. The intermediate chamber 23 opens into the first valve chamber 22 and the second valve chamber 24.

[0032] The valve housing 10 is provided with a first back pressure chamber side valve seat 26, a second back pressure chamber side valve seat 27, a first valve seat 28, and a second valve seat 29. Each valve seat is formed in an annular shape. The first back pressure chamber side valve seat 26 surrounds the opening of the first back pressure chamber 21. The second back pressure chamber side valve seat 27 surrounds the opening of the second back pressure chamber 25. The first valve seat 28 surrounds the opening on the side of the first valve chamber 22 in the intermediate chamber 23. The second valve seat 29 surrounds the opening on the side of the second valve chamber 24 in the intermediate chamber 23.

[0033] The valve stem 30 is housed within the valve body 5 along the axis L. The axes of the valve housing 10 and the valve stem 30 are aligned with the axis L. The valve stem 30 is supported by cover members 14 and 15 and is movable along the axis L. The upper end 30a of the valve stem 30 protrudes upward through the cover member 14. A plunger 53 of the drive device 50 is mounted at the upper end 30a of the valve stem 30.

[0034] The valve stem 30 is provided with a pressure equalization passage 31. The pressure equalization passage 31 has a longitudinal passage 32 and a transverse passage 33. The longitudinal passage 32 extends along the axis L inside the valve stem 30. The transverse passage 33 is continuous with the upper end of the longitudinal passage 32 and extends in a direction orthogonal to the axis L. One end 31a of the pressure equalization passage 31 opens into the first back pressure chamber 21. The other end 31b of the pressure equalization passage 31 opens into the second back pressure chamber 25. The pressure equalization passage 31 connects the first back pressure chamber 21 and the second back pressure chamber 25. By providing the pressure equalization passage 31 in the valve stem 30, the flow path switching valve 1 can be made smaller. Alternatively, the pressure equalization passage 31 of the valve stem 30 can be replaced by providing the pressure equalization passage connecting the first back pressure chamber 21 and the second back pressure chamber 25 in the valve body 5.

[0035] The first valve core 41 and the second valve core 42 are cylindrical. Both the first valve core 41 and the second valve core 42 have outwardly protruding flanges at both ends. The first valve core 41 and the second valve core 42 are fixed to the valve stem 30 with their inner sides inserted through it. The first valve core 41 is disposed in the first valve chamber 22. The second valve core 42 is disposed in the second valve chamber. The first valve core 41 and the second valve core 42 are made of, for example, synthetic resin or rubber material. This reduces the noise level when the first valve core 41 and the second valve core 42 contact their respective valve seats.

[0036] The first valve core 41 contacts and separates from the first valve seat 28, thereby opening and closing the space between the first valve chamber 22 and the intermediate chamber 23. That is, the first valve core 41 opens and closes the opening on the first valve chamber 22 side of the intermediate chamber 23. The first valve core 41 contacts and separates from the first back pressure chamber side valve seat 26, thereby opening and closing the space between the first back pressure chamber 21 and the first valve chamber 22. That is, the first valve core 41 opens and closes the opening of the first back pressure chamber 21. The second valve core 42 contacts and separates from the second valve seat 29, thereby opening and closing the space between the second valve chamber 24 and the intermediate chamber 23. That is, the second valve core 42 opens and closes the opening on the second valve chamber 24 side of the intermediate chamber 23. The second valve core 42 contacts and separates from the second back pressure chamber side valve seat 27, thereby opening and closing the space between the second back pressure chamber 25 and the second valve chamber 24. That is, the second valve core 42 opens and closes the opening of the second back pressure chamber 25.

[0037] In this embodiment, the area of ​​the opening of the first back pressure chamber 21 is the same as the area of ​​the opening on the side of the second valve chamber 24 in the intermediate chamber 23. Furthermore, the area of ​​the opening of the second back pressure chamber 25 is the same as the area of ​​the opening on the side of the first valve chamber 22 in the intermediate chamber 23. This allows for further appropriate elimination of fluid pressure and reduces the force required to move the valve stem 30.

[0038] The drive unit 50 is an electromagnetic actuator. The drive unit 50 is positioned above the valve body 5. The drive unit 50 includes a housing 51, a suction element 52, a plunger 53, a coil body 54, and a compression coil spring 55. Alternatively, the drive unit 50 may use an electric motor to move the valve stem 30 along the axis L.

[0039] The outer casing 51 is formed as a cylinder with its upper end blocked. The lower end of the outer casing 51 is mounted on the cover member 14 of the valve body 5. The suction member 52 is formed as a cylinder. The suction member 52 is fixed inside the outer casing 51. The upper end 30a of the valve stem 30 is inserted through the suction member 52. The plunger 53 is formed as a cylinder. The plunger 53 is disposed above the suction member 52 inside the outer casing 51. The plunger 53 is fixed to the upper end 30a of the valve stem 30. A compression coil spring 55 is disposed between the suction member 52 and the plunger 53. The compression coil spring 55 applies a force to the suction member 52 and the plunger 53 in a direction that separates them from each other. The coil body 54 is formed as a generally cylindrical shape. The coil body 54 has a winding frame 54a and a coil 54b consisting of wire wound on the winding frame 54a. The coil body 54 is fixed to the outer casing 51 with its inner side inserted through it.

[0040] Next, refer to Figure 3 , Figure 4 This illustrates an example of the operation of the flow path switching valve 1 described above. Figure 3 , Figure 4 In the diagram, dots are used to schematically represent the fluid flowing in the flow path. Areas of low density dot represent fluid flowing into the first flow path 11a. Areas of high density dot represent fluid flowing into the second flow path 12a. Additionally, in... Figure 3 , Figure 4 In the image, the thick arrows schematically represent the flow of fluid.

[0041] like Figure 3 As shown, when the coil body 54 of the drive device 50 is not energized, the plunger 53 moves upward by compressing the helical spring 55, and the valve stem 30 moves along the axis L towards the first back pressure chamber 21. In this state, the first valve core 41 separates from the first valve seat 28 and contacts the first back pressure chamber side valve seat 26. As a result, the first valve chamber 22 and the intermediate chamber 23 are opened, and the first valve chamber 22 and the first back pressure chamber 21 are closed by the first valve core 41. In addition, the second valve core 42 separates from the second back pressure chamber side valve seat 27 and contacts the second valve seat 29. As a result, the second valve chamber 24 and the second back pressure chamber 25 are opened, and the second valve chamber 24 and the intermediate chamber 23 are closed by the second valve core 42.

[0042] exist Figure 3In the illustrated state, the first flow path 11a and the third flow path 13a are connected via the first valve chamber 22 and the intermediate chamber 23. Fluid flowing into the first flow path 11a flows out of the third flow path 13a. Then, fluid flowing into the second flow path 12a is introduced into the first back pressure chamber 21 via the second valve chamber 24, the second back pressure chamber 25, and the pressure equalization passage 31. As a result, the pressure of the fluid flowing into the second flow path 12a is applied to the surface 41a of the first valve core 41 on the side of the first back pressure chamber 21 and the surface 42a of the second back pressure chamber 25 in the second valve core 42. The pressure applied to surface 41a and the pressure applied to surface 42a are in opposite directions. Therefore, the pressure along the axis L applied by the fluid flowing into the second flow path 12a is eliminated.

[0043] like Figure 4 As shown, when the coil body 54 of the drive device 50 is energized, the plunger 53 is attracted downward by the magnetized attractant 52, and the valve stem 30 moves towards the second back pressure chamber 25 along the axis L. In this state, the first valve core 41 separates from the first back pressure chamber side valve seat 26 and contacts the first valve seat 28. Thus, the first valve chamber 22 and the first back pressure chamber 21 are opened, and the first valve chamber 22 and the intermediate chamber 23 are closed via the first valve core 41. Furthermore, the second valve core 42 separates from the second valve seat 29 and contacts the second back pressure chamber side valve seat 27. Thus, the second valve chamber 24 and the intermediate chamber 23 are opened, and the second valve chamber 24 and the second back pressure chamber 25 are closed via the second valve core 42.

[0044] exist Figure 4 In the illustrated state, the second flow path 12a and the third flow path 13a are connected via the second valve chamber 24 and the intermediate chamber 23. Fluid flowing into the second flow path 12a exits through the third flow path 13a. Furthermore, fluid flowing into the first flow path 11a is introduced into the second back pressure chamber 25 via the first valve chamber 22, the first back pressure chamber 21, and the pressure equalization passage 31. Consequently, the pressure of the fluid flowing into the first flow path 11a is applied to the surface 41a of the first valve core 41 on the side of the first back pressure chamber 21 and the surface 42a of the second back pressure chamber 25 in the second valve core 42. The pressure applied to surface 41a and the pressure applied to surface 42a are in opposite directions. Therefore, the pressure along the axis L applied by the fluid flowing into the first flow path 11a is eliminated.

[0045] As described above, in the flow path switching valve 1 of this embodiment, when the valve stem 30 moves towards the first back pressure chamber 21, the first valve chamber 22 and the intermediate chamber 23 are opened, and the first valve chamber 22 and the first back pressure chamber 21 are closed through the first valve core 41. The second valve chamber 24 and the second back pressure chamber 25 are opened, and the second valve chamber 24 and the intermediate chamber 23 are closed through the second valve core 42. A pressure equalization passage 31 connecting the first back pressure chamber 21 and the second back pressure chamber 25 is provided on the valve stem 30. As a result, the pressure of the fluid in the second flow path 12a is applied to the surface 41a of the first valve core 41 on the side of the first back pressure chamber 21 and the surface 42a of the second valve core 42 on the side of the second back pressure chamber 25, thereby eliminating the pressure. Furthermore, when the valve stem 30 moves towards the second back pressure chamber 25, the first valve chamber 22 is opened to the first back pressure chamber 21, the first valve chamber 22 is closed to the intermediate chamber 23 via the first valve core 41, the second valve chamber 24 is opened to the intermediate chamber 23, and the second valve chamber 24 is closed to the second back pressure chamber 25 via the second valve core 42. A pressure equalization passage 31 connecting the first back pressure chamber 21 and the second back pressure chamber 25 is provided on the valve stem 30. Thus, the pressure of the fluid in the first flow path 11a is applied to the surface 41a of the first valve core 41 on the side of the first back pressure chamber 21 and the surface 42a of the second valve core 42 on the side of the second back pressure chamber 25, thereby eliminating this pressure. Therefore, the force required to move the valve stem 30 can be reduced, and the connection between the first flow path 11a, the second flow path 12a, and the third flow path 13a can be switched with a smaller force.

[0046] The embodiments of the present invention have been described above, but the present invention is not limited to these examples. Those skilled in the art may appropriately add or delete structural elements, make design changes, or appropriately combine features of the embodiments as described above, provided that such additions or deletions do not violate the spirit of the present invention, and such additions or deletions are included within the scope of the present invention.

[0047] Symbol Explanation

[0048] 1… Flow path switching valve, 5… Valve body, 10… Valve housing, 11… First tubular section, 11a… First flow path, 12… Second tubular section, 12a… Second flow path, 13… Third tubular section, 13a… Third flow path, 14, 15… Cover component, 21… First back pressure chamber, 22… First valve chamber, 23… Intermediate chamber, 24… Second valve chamber, 25… Second back pressure chamber, 26… First back pressure chamber side valve seat, 27… Second back pressure chamber side valve seat, 28… First valve seat, 29… Second valve seat, 30…valve stem, 30a…upper end, 31…evening pressure passage, 31a…one end, 31b…the other end, 32…longitudinal passage, 33…transverse passage, 41…first valve core, 41a…face on the side of the first back pressure chamber, 42…second valve core, 42a…face on the side of the second back pressure chamber, 50…drive device, 51…housing, 52…suction element, 53…plunger, 54…coil body, 54a…winding frame, 54b…coil, 55…compression helical spring, L…axis

Claims

1. A flow path switching valve, comprising: a cylindrical valve body, a valve stem housed in the valve body along an axial direction, and a first valve core and a second valve core fixed to the valve stem, characterized in that, The valve body comprises: a first back pressure chamber, a first valve chamber, an intermediate chamber, a second valve chamber, and a second back pressure chamber arranged sequentially along an axial direction; a first flow path connected to the first valve chamber; a second flow path connected to the second valve chamber; and a third flow path connected to the intermediate chamber. The first back pressure chamber opens into the first valve chamber. The second back pressure chamber opens into the second valve chamber. The intermediate chamber opens into the first valve chamber and the second valve chamber. The first valve core is disposed in the first valve chamber. The second valve core is disposed in the second valve chamber. The valve body has: a first back pressure chamber side valve seat surrounding an opening of the first back pressure chamber; a second back pressure chamber side valve seat surrounding an opening of the second back pressure chamber; a first valve seat surrounding an opening on the first valve chamber side of the intermediate chamber; and a second valve seat surrounding an opening on the second valve chamber side of the intermediate chamber. When the valve stem moves toward the first back pressure chamber side, the first valve core separates from the first valve seat and contacts the valve seat on the first back pressure chamber side, and the second valve core separates from the valve seat on the second back pressure chamber side and contacts the second valve seat. When the valve stem moves towards the second back pressure chamber side, the first valve core separates from the valve seat on the first back pressure chamber side and contacts the first valve seat, and the second valve core separates from the second valve seat and contacts the valve seat on the second back pressure chamber side. A pressure equalization passage connecting the first back pressure chamber and the second back pressure chamber is provided in the valve body or the valve stem.

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