non-return valve

Abstract

To provide a check valve capable of suppressing wear caused by the circumferential movement of the valve body. [Solution] The device comprises a housing 10 having a valve seat 14 through which a fluid flowing through the piping passes along the flow direction, a valve body 20 that contacts the valve seat 14 in a first direction X1 which is the upstream direction of the flow direction X, and opens and closes a flow path through which the fluid flows away from the valve seat 14 in a second direction X2 which is the downstream direction of the flow direction X, a coil spring 30 supported by the housing 10 that biases the valve body 20 toward the valve seat 14 in the first direction X1, and a limiting part 40 that extends between the valve body 20 and the coil spring 30 and limits the relative circumferential displacement of the valve body 20 with respect to the coil spring 30.

Description

Technical Field

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[0001] The present invention relates to a check valve disposed in the middle of a fluid pipe.

Background Art

[0002] Conventionally, in a check valve disposed in the middle of a fluid pipe, for example, a water pipe located on the secondary side of a water meter, it is known that wear occurs on the valve body and the housing due to the forward and backward movement of the valve body when the fluid passes through. The packing-integrated check valve described in Patent Document 1 is fixed in the middle of a fluid pipe and has a housing (outer shell body) having a valve seat and a valve body that reciprocates with respect to the housing to open and close a passage space through which the fluid passes by contacting and separating from the valve seat. The valve body is integrally provided with a valve shaft, and this valve shaft is slidably supported with respect to the housing. In the invention described in Patent Document 1, the inner peripheral wall of the hole that supports the valve shaft in the housing is formed of a synthetic resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the packing-integrated check valve described in Patent Document 1 merely forms the inner peripheral wall with a synthetic resin, and there is a risk that the valve body may rotate in the circumferential direction. That is, since the technique of Patent Document 1 does not consider at all the behavior of the valve body in the circumferential direction, the valve body may rotate in the circumferential direction, and as a result, wear due to the circumferential behavior may occur on the valve body and the housing. Therefore, the technique of Patent Document 1 is not sufficient for suppressing the wear of the check valve.

[0005] Therefore, an object of the present invention is to provide a check valve capable of suppressing wear. [Means for solving the problem]

[0006] The check valve of the present invention is characterized by comprising: a housing having a valve seat through which a fluid flowing through a pipe passes along the flow direction; a valve body that contacts the valve seat in a first direction which is the upstream direction of the flow direction and opens and closes a flow path through which the fluid flows while moving away from the valve seat in a second direction which is the downstream direction of the flow direction; a biasing member supported by the housing that biases the valve body toward the valve seat in the first direction; and a limiting portion that extends between the valve body and the biasing member and limits the relative circumferential displacement of the valve body with respect to the biasing member.

[0007] According to the present invention, since the valve body and the biasing member have a limiting portion that limits the relative circumferential displacement of the valve body with respect to the biasing member, the relative circumferential displacement of the valve body can be limited via the biasing member. In other words, since the relative circumferential displacement of the valve body can be limited via the biasing member, the circumferential behavior of the valve body can be suppressed, and wear of the valve body and housing can be suppressed.

[0008] Furthermore, the valve body has a connected portion to which the biasing member is connected, the biasing member has a connecting portion that connects to the connected portion, and the restricting portion is provided extending between the connected portion and the connecting portion.

[0009] According to the above configuration, the limiting portion extends from the connected portion to the connecting portion, thereby ensuring a secure connection between the valve body and the biasing member. Therefore, by ensuring a secure connection between the valve body and the biasing member, the circumferential movement of the valve body can be reliably suppressed via the biasing member.

[0010] Furthermore, one of the connecting portion and the connected portion includes a radial extension portion that extends radially outward and / or radially inward of the valve body, and the other of the connecting portion and the connected portion includes a locking portion that locks the radial extension portion in the circumferential direction.

[0011] According to the above configuration, since the locking portion locks the diameter extension portion from the circumferential side, the circumferential movement of the valve body can be suppressed with a simple configuration.

[0012] Furthermore, one of the connecting portion and the connected portion includes an axial extension portion extending in the first direction, and the other of the connecting portion and the connected portion includes a recess through which the axial extension portion is inserted in the first direction.

[0013] According to the above configuration, since the recess allows the axial extension to pass through, the circumferential movement of the valve body can be suppressed with a simple structure.

[0014] Furthermore, the restricting portion is characterized by including a resistive portion having irregularities formed on the connected portion.

[0015] According to the above configuration, the resistance part increases the frictional force with the connecting part. In other words, because the resistance part restricts the circumferential movement of the valve body, wear between the valve body and the housing can be suppressed with a simple configuration.

[0016] Furthermore, the connected portion and the connecting portion are fitted together, and the restricting portion is configured as a fitting portion in which the connecting portion and the connected portion are fitted together so that the connected portion does not rotate in the circumferential direction relative to the connecting portion.

[0017] According to the above configuration, the connecting portion and the connected portion are fitted together so that the connected portion does not rotate circumferentially relative to the connecting portion, thereby suppressing the relative circumferential displacement between the valve body and the biasing member. Therefore, since the relative circumferential displacement between the valve body and the biasing member can be suppressed, the circumferential behavior of the valve body can be suppressed by the biasing member.

[0018] Furthermore, the valve body comprises a valve body body having a portion on the first direction side that contacts the valve seat and a portion on the second direction side that is connected, and a valve stem portion extending from the connected portion in the second direction, and the housing comprises a base portion located on the first direction side on which the valve seat is provided, a support portion located on the second direction side that slidably supports the valve stem portion, and a housing body connecting the base portion and the support portion.

[0019] According to the above configuration, in the valve body having a valve shaft, wear of the valve shaft can be suppressed.

[0020] Further, the valve body includes a valve body main body having a portion on the first direction side contacting the valve seat and the connected portion on the second direction side, and a valve shaft portion extending from the connected portion in the second direction. The housing includes a base portion provided with the valve seat and located on the first direction side, a support portion located on the second direction side and slidably supporting the valve shaft portion, and a housing main body connecting the base portion and the support portion. The restricting portion includes an outer diameter extension portion extending from the connecting portion to the outside in the radial direction of the valve body, a locking portion provided on the connected portion and locking the outer diameter extension portion in the circumferential direction, and a guiding portion provided on the housing main body and allowing the outer diameter end portion of the outer diameter extension portion to move in the flow direction and restricting movement in the circumferential direction.

[0021] According to the above configuration, displacement of the valve body in the circumferential direction can be restricted from both the inner and outer sides in the radial direction, so that wear of the valve shaft can be further suppressed.

Advantages of the Invention

[0022] According to the present invention, it is possible to provide a check valve capable of suppressing wear caused by the behavior of the valve body in the circumferential direction.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view of a check valve according to an embodiment of the present invention. [Figure 2] It is a radial cross-sectional view of the check valve. [Figure 3] It is a perspective view of the valve body viewed from the back side. [Figure 4] It is a perspective view of a coil spring. [Figure 5] It is a radial cross-sectional view of a check valve according to a modified example. [Figure 6] It is a rear view of the valve body. [Figure 7] It is a perspective view of a coil spring. [Figure 8]This is a radial cross-sectional view of a check valve according to another modified example. [Figure 9] This is a rear view of the valve body. [Figure 10] This is a perspective view of a coil spring. [Figure 11] This is a radial cross-sectional view of a check valve relating to yet another modified example. [Figure 12] This is a magnified view of a portion of the rear section. [Figure 13] This is a radial cross-sectional view of a check valve relating to yet another modified example. [Figure 14] This is a radial cross-sectional view of a check valve relating to yet another modified example. [Figure 15] This is a rear view of the valve body. [Figure 16] This is an exploded perspective view of the valve body and coil spring in yet another modified example. [Figure 17] This is an exploded perspective view of the valve body and coil spring in yet another modified example. [Figure 18] This is an exploded perspective view of the valve body and coil spring in yet another modified example. [Modes for carrying out the invention]

[0024] Hereinafter, embodiments of the check valve according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and will not be repeated in the description.

[0025] A check valve 100 according to one embodiment of the present invention will be described with reference to Figures 1 to 4. Figure 1 is a perspective view of the check valve 100 according to one embodiment of the present invention. Figure 2 is a radial cross-sectional view of the check valve 100. Figure 3 is a perspective view of the valve body 20 viewed from the rear side. Figure 4 is a perspective view of the coil spring 30. The check valve 100 is arranged, for example, in a joint portion of a water pipe located downstream of a water meter inside a meter box. As shown in Figures 1 to 4, the check valve 100 has a housing 10, a valve body 20, a coil spring 30, and a limiting portion 40. The coil spring 30 corresponds to, for example, a "biasing member".

[0026] The housing 10 holds the valve body 20 and the coil spring 30. This housing 10 allows tap water (hereinafter sometimes referred to as fluid) to pass through. The housing 10 is made of a metal material such as bronze casting. This housing 10 is not limited to a metal material, but may also be made of a synthetic resin material. The housing 10 has a base portion 11, a support portion 12, and a housing body 13.

[0027] The base portion 11 is located on the upstream side in the direction of fluid flow. The base portion 11 is formed in a cylindrical shape with a flange-like portion on the base end side. Hereinafter, the direction of fluid flow will be referred to as the flow direction X, the upstream direction of the flow direction X will be referred to as the first direction X1, and the direction opposite to the first direction X1 will be referred to as the second direction X2. As shown in Figures 1 and 2, the base portion 11 is provided with a valve seat 14, a packing 15, and a valve seat packing 16.

[0028] The valve seat 14 is through which the fluid flowing through the piping passes along the flow direction X. The valve seat 14 is formed in a cylindrical shape with a flange-like portion at the end on the first direction X1 side. The valve seat 14 is attached to the end on the first direction X1 side of the base 11 from the first direction X1 side. A valve seat packing 16 is placed between the inner circumferential surface of the base 11 and the outer circumferential surface of the valve seat 14. The valve seat 14 can be attached by various joining methods such as screwing, fitting, welding, and bonding.

[0029] The packing 15 is configured to cover the entire circumference of the radially outer portion of the valve seat 14. This packing 15 is made of an elastic material such as rubber and is roughly annular in shape. The packing 15 is sandwiched between the pipe end on the first direction X1 side and the pipe end on the second direction X2 side. This allows the check valve 100 to be fixed without fluid leakage between the two pipe ends. In this state, the housing 10 and the valve body 20 are located inside the downstream pipe.

[0030] The valve seat packing 16 is a sealing member. The valve seat packing 16 is formed in a substantially annular shape. The portion of the valve seat packing 16 on the first direction X1 side abuts against the valve seat 14, and the portion on the second direction X2 side abuts against the valve body 20.

[0031] The support portion 12 supports the valve body 20 which reciprocates along the flow direction X. The support portion 12 supports the end of the coil spring 30 on the second direction X2 side. The support portion 12 is located on the second direction X2 side. The support portion 12 has a sliding cylinder portion 121 and a connecting portion 122.

[0032] The sliding cylinder portion 121 slidably supports the valve shaft portion 22 of the valve body 20, which will be described later. The sliding cylinder portion 121 has a through hole having an axis along the flow direction X. The sliding cylinder portion 121 is fitted onto the outside in a state that allows it to expand and contract by a coil spring 30.

[0033] The connecting portion 122 is to which the coil spring 30 is connected. In other words, the connecting portion 122 is the connection between the coil spring 30 and the housing 10. The connecting portion 122 contacts the end of the coil spring 30 on the second direction X2 side. The connecting portion 122 has a locking portion 122a.

[0034] The locking portion 122a locks the end of the coil spring 30 on the second direction X2 side. Specifically, the locking portion 122a is a groove that recesses in the second direction X2 from the end face of the support portion 12 on the first direction X1 side on the radially outer side of the coil spring 30. The locking portion 122a has a pair of faces that face each other in the circumferential direction and intersect with respect to the circumferential direction. The locking portion 122a restricts the circumferential movement of the coil spring 30.

[0035] The housing body 13 connects the base 11 and the support 12. The housing body 13 is integrally formed. If the housing body 13 is made of metal, it is formed by machining or casting; if it is made of synthetic resin, it is formed by mold molding. The housing body 13 has four elongated members extending circumferentially along the flow direction X. The fluid that passes between the valve seat 14 and the valve body 20 flows through the four elongated members in the second direction X2.

[0036] The valve body 20 opens and closes the passage space through which the fluid passes. The valve body 20 reciprocates relative to the housing 10 along the flow direction X. Specifically, the valve body 20 contacts the valve seat 14 in a first direction X1 and moves away from the valve seat 14 in a second direction X2 to open and close the fluid passage. The valve body 20 is integrally formed. If the valve body 20 is made of metal, it is formed by machining or casting, and if it is made of synthetic resin, it is formed by mold molding. In the case of synthetic resin, POM resin (polyoxymethylene), which has friction resistance, fatigue resistance, and self-lubricating properties, is preferred. As shown in Figures 2 and 3, the valve body 20 has a valve body 21 and a valve stem 22.

[0037] The valve body 21 opens and closes the valve seat 14. The valve body 21 has a front portion 211, a rear portion 212, and a connected portion 213.

[0038] The front portion 211 contacts the valve seat 14 and the valve seat packing 16. The front portion 211 has the end face of the valve body 21 on the first direction X1 side. The radially inner portion of the front portion 211 is located in the first direction X1, and the radially outer portion is located in the second direction X2. The radially middle portion of the front portion 211 contacts the valve seat 14 and the valve seat packing 16 to restrict the passage of fluid.

[0039] The rear portion 212 supports the end of the coil spring 30 in the first direction X1. The rear portion 212 is substantially perpendicular to the flow direction X. The rear portion 212 has a connected portion 213.

[0040] The coil spring 30 is connected to the connected portion 213. In other words, the connected portion 213 is the connection point between the coil spring 30 and the valve body 20. The connected portion 213 contacts the end of the coil spring 30 in the first direction X1. The connected portion 213 has a locking portion 213a.

[0041] The locking portion 213a locks the end of the coil spring 30 on the first direction X1 side. Specifically, the locking portion 213a is a groove that recesses from the back surface 212 in the first direction X1 on the radially outer side of the coil spring 30. The locking portion 213a has a pair of surfaces that face each other in the circumferential direction and intersect with respect to the circumferential direction.

[0042] The valve stem portion 22 slides back and forth relative to the housing 10. The valve stem portion 22 is a round bar-shaped portion that protrudes from the rear portion 212 in a second direction X2. In other words, the valve stem portion 22 extends from the first connected portion 213 in a second direction X2. The valve stem portion 22 slides through the through hole of the sliding cylinder portion 121.

[0043] The coil spring 30 biases the valve body 20 toward the valve seat 14 in a first direction X1. The coil spring 30 constantly biases the valve body 20 toward the first direction X1. In the check valve 100, when fluid passes through, the fluid pressure exceeding the biasing force of the coil spring 30 is applied to the front portion 211, causing the valve body 21 to move toward the second direction X2. Furthermore, for fluid flow attempting to move from the second direction X2 toward the first direction X1, the biasing force of the coil spring 30 is constantly applied to the valve body 20, maintaining the closed state of the check valve 100 and preventing backflow. This backflow applies pressure to the back portion 212 of the valve body 20. The biasing force of the coil spring 30 is set according to the target fluid pressure. As shown in Figures 2 and 4, the coil spring 30 has a spring body 31, a first connecting portion 32, and a second connected portion 33.

[0044] The spring body 31 exerts a biasing force. A portion of the spring body 31 on the second direction X2 side is positioned on the outer circumference of the sliding cylinder portion 121. Since the spring body 31 is externally fitted onto the sliding cylinder portion 121 in an expandable and contractible manner, the circumferential movement of the coil spring 30 relative to the sliding cylinder portion 121 is suppressed.

[0045] The first connecting portion 32 is connected to the first connected portion 213. In this embodiment, the first connecting portion 32 is located at the end of the coil spring 30 on the first direction X1 side that does not contribute to the biasing force. However, the first connecting portion 32 is not limited to the end of the coil spring 30 on the first direction X1 side. The first connecting portion 32 may be located at least on the first direction X1 side of the coil spring 30, and may be provided on a part of the spring body 31. The first connecting portion 32 includes the first outer diameter extension portion 321.

[0046] The first outer diameter extension 321 extends radially outward from the valve body 20. The radial length of the first outer diameter extension 321 is, for example, less than or equal to the radial length of the back surface 212. The first outer diameter extension 321 is locked to the locking portion 213a. Since the first outer diameter extension 321 enters the locking portion 213a, which is a groove, it contacts at least one of the pair of surfaces of the locking portion 213a. In other words, since the locking portion 213a locks the first outer diameter extension 321 in the circumferential direction, the first outer diameter extension 321 restricts the circumferential movement of the valve body 20.

[0047] The second connected portion 33 is connected to the second connected portion 122. In this embodiment, the second connected portion 33 is located at the end of the coil spring 30 on the second direction X2 side that does not contribute to the biasing force. However, the second connected portion 33 is not limited to the end of the coil spring 30 on the second direction X2 side. The second connected portion 33 may be located at least on the second direction X2 side of the coil spring 30, and may be provided on a part of the spring body 31. The second connected portion 33 includes the second outer diameter extension portion 331.

[0048] The second outer diameter extension 331 extends radially outward from the valve body 20. The radial length of the second outer diameter extension 331 is, for example, less than or equal to the radial length of the support portion 12. The second outer diameter extension 331 is locked to the locking portion 122a. As the second outer diameter extension 331 enters the locking portion 122a, which is a groove, it contacts at least one of the pair of surfaces of the locking portion 122a. In other words, because the locking portion 122a locks the second outer diameter extension 331 in the circumferential direction, the movement of the second outer diameter extension 331 is restricted.

[0049] As shown in Figures 1 and 2, the limiting portion 40 extends between the valve body 20 and the coil spring 30, limiting the circumferential relative displacement of the valve body 20 with respect to the coil spring 30. More specifically, the limiting portion 40 extends between the first connecting portion 32 and the first connected portion 213. In other words, the limiting portion 40 includes the first outer diameter extension portion 321 and the locking portion 213a. In this embodiment, "extending between the valve body 20 and the coil spring 30" means not only the first outer diameter extension portion 321 and the locking portion 213a, but also the vicinity of the first outer diameter extension portion 321 and the locking portion 213a.

[0050] The biasing member, the coil spring 30, has elasticity that allows it to return to its original position when deformed in the circumferential direction. Therefore, even if the valve body 20 is displaced in the circumferential direction and the coil spring 30 is deformed in the circumferential direction, the circumferential displacement of the valve body 20 is returned to its original position as the coil spring 30 returns to its original position. As a result, the valve body 20 is biased back to a reference position in the circumferential direction, a position where no wear occurs, thus suppressing wear. With the above configuration, since there is a limiting portion 40 that extends to both the valve body 20 and the coil spring 30 and limits the relative circumferential displacement of the valve body 20 with respect to the coil spring 30, the relative circumferential displacement of the valve body 20 can be limited via the coil spring 30. In other words, since the locking portion 213a locks the first outer diameter extension portion 321 in the circumferential direction, the coil spring 30 limits the circumferential behavior of the valve body 20. Therefore, since the relative circumferential displacement of the valve body 20 can be limited via the coil spring 30, the circumferential behavior of the valve body 20 can be suppressed, and wear of the valve body 20 and the housing 10 can be suppressed.

[0051] Next, a modified example of the check valve 100 will be described with reference to Figures 5 to 7. Figure 5 is a radial cross-sectional view of the modified check valve 100A. Figure 6 is a rear view of the valve body 20A. Figure 7 is a perspective view of the coil spring 30A. Note that the various modified examples described below are basically the same as the embodiments described above, so the same parts are denoted by the same reference numerals and detailed descriptions are omitted. As shown in Figures 5 to 7, the check valve 100A includes a housing 10A, a valve body 20A, a coil spring 30A, and a limiting portion 40A.

[0052] The housing 10A has a base portion 11, a support portion 12, and a housing body 13. The support portion 12 has a sliding cylinder portion 121 and a connecting portion 122. The coil spring 30A is connected to the connecting portion 122. The connecting portion 122 has a locking portion 122b.

[0053] The locking portion 122b locks the end of the coil spring 30A on the second direction X2 side. Specifically, the locking portion 122b is a groove recessed in the radially inward side of the coil spring 30A from the end face of the support portion 12 on the first direction X1 side in the second direction X2. The locking portion 122b has a surface that intersects with respect to the circumferential direction. The locking portion 122a restricts the circumferential movement of the coil spring 30A.

[0054] The valve body 20A has a valve body main body 21 and a valve stem portion 22. The valve body main body 21 has a front portion 211, a rear portion 212, and a connected portion 213. A coil spring 30A is connected to the connected portion 213. The connected portion 213 has a locking portion 213b.

[0055] The locking portion 213b locks the end of the coil spring 30A on the first direction X1 side. Specifically, the locking portion 213b is a recess on the radially inward side of the coil spring 30A that recesses from the back surface 212 in the first direction X1. The locking portion 213b has a surface that intersects with respect to the circumferential direction. This surface that intersects with respect to the circumferential direction is, for example, integrally formed with the valve stem portion 22.

[0056] The coil spring 30A has a spring body 31, a first connecting portion 32, and a second connected portion 33.

[0057] The first connecting portion 32 is connected to the first connected portion 213. The first connecting portion 32 includes the first inner diameter extension portion 322.

[0058] The first inner diameter extension 322 extends radially inward from the valve body 20. The first inner diameter extension 322 is locked to the locking portion 213b. As the first inner diameter extension 322 enters the recessed locking portion 213b, it contacts the surface of the locking portion 213b that intersects with respect to the circumferential direction. In other words, because the locking portion 213b locks the first inner diameter extension 322 in the circumferential direction, the first inner diameter extension 322 restricts the circumferential movement of the valve body 20.

[0059] The second connected portion 33 is connected to the second connecting portion 122. The second connected portion 33 includes the second inner diameter extension portion 332.

[0060] The second inner diameter extension 332 extends radially inward from the valve body 20. The second inner diameter extension 332 is locked to the locking portion 122b. As the second inner diameter extension 332 enters the locking portion 122b, which is a groove, it contacts the surface of the locking portion 122b that intersects with respect to the circumferential direction. In other words, because the locking portion 122b locks the second inner diameter extension 332 in the circumferential direction, the movement of the second inner diameter extension 332 is restricted.

[0061] As shown in Figure 5, the limiting portion 40A extends between the valve body 20A and the coil spring 30A, limiting the circumferential relative displacement of the valve body 20A with respect to the coil spring 30A. More specifically, the limiting portion 40A extends between the first connecting portion 32 and the first connected portion 213. In other words, the limiting portion 40 includes a first inner diameter extension portion 322 and a locking portion 213b. With this configuration, the circumferential behavior of the valve body 20A can be suppressed without increasing the radially outward size of the coil spring 30A, and wear of the valve body 20A and the housing 10 can be suppressed.

[0062] Next, another modification of the check valve 100 will be described with reference to Figures 8 to 10. Figure 8 is a radial cross-sectional view of the check valve 100B according to another modification. Figure 9 is a rear view of the valve body 20B. Figure 10 is a perspective view of the coil spring 30B. As shown in Figures 8 to 10, the check valve 100B includes a housing 10B, a valve body 20B, a coil spring 30B, and a limiting portion 40B.

[0063] The housing 10B has a base portion 11, a support portion 12, and a housing body 13. The support portion 12 has a sliding cylinder portion 121 and a connecting portion 122. The coil spring 30B is connected to the connecting portion 122. The connecting portion 122 has a through hole 122c.

[0064] The through-hole 122c locks the end of the coil spring 30B on the second direction X2 side. Specifically, the through-hole 122c is a hole extending from the end face of the support portion 12 on the first direction X1 side in the second direction X2. If the wires of the coil spring 30B are circular, the through-hole 122c has a diameter approximately the same as the wire diameter. If the wires of the coil spring 30B are not circular, the through-hole 122c is formed in a shape that allows the wires of the coil spring 30B to be inserted. The through-hole 122c restricts the circumferential movement of the coil spring 30B.

[0065] The valve body 20B has a valve body main 21 and a valve stem portion 22. The valve body main 21 has a front portion 211, a rear portion 212, and a connecting portion 213. A coil spring 30B is connected to the connecting portion 213. The connecting portion 213 has a through hole 213c.

[0066] The through-hole 213c locks the end of the coil spring 30B on the first direction X1 side. Specifically, the through-hole 213c is a hole that extends recessed from the back portion 212 in the first direction X1. If the strands of the coil spring 30B are circular, the through-hole 213c has a diameter approximately the same as the diameter of the strands. If the strands of the coil spring 30B are not circular, the through-hole 213c is formed in a shape that allows the strands of the coil spring 30B to be inserted. The through-hole 213c corresponds to, for example, a "recess".

[0067] The coil spring 30B has a spring body 31, a first connecting portion 32, and a second connected portion 33.

[0068] The first connecting portion 32 is connected to the first connected portion 213. The first connecting portion 32 includes a first axial extension portion 323.

[0069] The first axial extension 323 extends in the first direction X1 from the end of the spring body 31 on the first direction X1 side. The first axial extension 323 is locked into the insertion hole 213c. Since the axial extension 323 is inserted into the recessed insertion hole 213c, it contacts the inner circumferential surface of the insertion hole 213c. In other words, because the insertion hole 213c locks the first axial extension 323 in the circumferential direction, the first axial extension 323 restricts the circumferential movement of the valve body 20.

[0070] The second connected portion 33 is connected to the second connecting portion 122. The second connected portion 33 includes a second axial extension portion 333.

[0071] The second axial extension 333 extends in the second direction X2 from the end of the spring body 31 on the second direction X2 side. The second axial extension 333 is locked into the insertion hole 122c. Since the second axial extension 333 is inserted into the recessed insertion hole 122c, it contacts the inner circumferential surface of the insertion hole 122c. In other words, because the insertion hole 122c locks the second axial extension 333 in the circumferential direction, the movement of the second axial extension 333 in the circumferential direction is restricted.

[0072] As shown in Figure 8, the limiting portion 40B extends between the valve body 20B and the coil spring 30B, limiting the circumferential relative displacement of the valve body 20B with respect to the coil spring 30B. More specifically, the limiting portion 40B extends between the first connecting portion 32 and the first connected portion 213. In other words, the limiting portion 40B includes a first axial extension portion 323 and an insertion hole 213c. With this configuration, the contact area between the valve body 20B and the coil spring 30B can be increased without increasing the radially outward size of the coil spring 30B, and the circumferential behavior of the valve body 20B can be further suppressed.

[0073] Next, another modification of the check valve 100 will be described with reference to Figures 11 and 12. Figure 11 is a radial cross-sectional view of the check valve 100C according to yet another modification. Figure 12 is a partially enlarged view of the rear portion 212. As shown in Figure 11, the check valve 100C has a housing 10C, a valve body 20C, a coil spring 30C, and a limiting portion 40C.

[0074] The housing 10C has a base portion 11, a support portion 12, and a housing body 13. The support portion 12 has a sliding cylindrical portion 121 and a connecting portion 122. The connecting portion 122 is connected to a coil spring 30C. The connecting portion 122 has a resistance portion 122d.

[0075] The resistance portion 122d locks the end of the coil spring 30C on the second direction X2 side. The resistance portion 122d is set to have a rougher surface roughness than the areas other than the resistance portion 122d. This increases the frictional force between the connecting portion 122 and the coil spring 30C compared to when the resistance portion 122d is not formed. The resistance portion 122d restricts the circumferential movement of the coil spring 30C.

[0076] As shown in Figures 11 and 12, the valve body 20C has a valve body main 21 and a valve stem portion 22. The valve body main 21 has a front portion 211, a rear portion 212, and a connected portion 213. A coil spring 30C is connected to the connected portion 213. The connected portion 213 has a resistance portion 213d.

[0077] The resistance portion 213d locks the end of the coil spring 30C on the first direction X1 side. The resistance portion 213d is set to have a rougher surface than, for example, the area other than the resistance portion 213d. This increases the frictional force between the connecting portion 122 and the coil spring 30C compared to when the resistance portion 122d is not formed. Furthermore, the resistance portion 213d has a plurality of protrusions 214 projecting in the second direction X2 and a plurality of recesses 215 recessed in the first direction X1. The height d from the bottom recess 215 to the top of the protrusion 214 is set to a value that can suppress the circumferential movement of the valve body 20C. As a result, the resistance portion 122d increases the frictional force with the coil spring 30C and limits the circumferential movement of the valve body 20C.

[0078] The coil spring 30C has a spring body 31, a first connecting portion 32, and a second connected portion 33.

[0079] The first connecting portion 32 is located at the end of the spring body 31 on the first direction X1 side. The first connecting portion 32 is formed in a ring shape. The first connecting portion 32 is pressed toward the resistance portion 213d by the coil spring 30C.

[0080] The second connected portion 33 is located at the end of the spring body 31 on the second direction X2 side. The second connected portion 33 is formed in a ring shape. The second connected portion 33 is pressed toward the resistance portion 122d by the reaction force from the valve body 20C.

[0081] The limiting portion 40C extends between the valve body 20C and the coil spring 30C, limiting the circumferential relative displacement of the valve body 20C with respect to the coil spring 30C. More specifically, the limiting portion 40C extends between the first connecting portion 32 and the first connected portion 213. In other words, the limiting portion 40C includes the first connecting portion 32 and the resistance portion 213d. With this configuration, the resistance portion 213d increases the frictional force with the first connecting portion 32. That is, because the resistance portion 213d limits the circumferential movement of the valve body 20C, wear between the valve body 20C and the housing 10C can be suppressed with a simple configuration.

[0082] Next, with reference to Figure 13, yet another modification of the check valve 100 will be described. Figure 13 is a radial cross-sectional view of a check valve 100D according to yet another modification. As shown in Figure 13, the check valve 100D includes a housing 10D, a valve body 20D, a coil spring 30D, and a limiting portion 40D.

[0083] The housing 10D has a base portion 11, a support portion 12, and a housing body 13. The support portion 12 has a sliding cylindrical portion 121 and a connecting portion 122. The connecting portion 122 is connected to a coil spring 30D.

[0084] The connecting portion 122 locks the end of the coil spring 30D on the second direction X2 side. In this embodiment, the connecting portion 122 is a substantially annular hole in cross-section extending from the end face of the support portion 12 on the first direction X1 side in the second direction X2. Before fitting the coil spring 30D, if the strands of the coil spring 30D are circular, the connecting portion 122 has an opening width (radial width) smaller than the diameter of the strands. If the strands of the coil spring 30D are not circular, the connecting portion 122 is formed with an opening shape that prevents the strands of the coil spring 30D from being inserted before fitting.

[0085] The valve body 20D has a valve body main body 21 and a valve stem portion 22. The valve body main body 21 has a front portion 211, a rear portion 212, and a connected portion 213. A coil spring 30D is connected to the connected portion 213.

[0086] The connected portion 213 locks the end of the coil spring 30D on the first direction X1 side. In this embodiment, the connected portion 213 is a hole with a substantially annular cross-section extending from the back portion 212 in the first direction X1. Before fitting the coil spring 30D, if the strands of the coil spring 30D are circular, the connected portion 213 has an opening width (radial width) smaller than the diameter of the strands. If the strands of the coil spring 30D are not circular, the connected portion 213 is formed with an opening shape that prevents the strands of the coil spring 30D from being inserted before fitting.

[0087] The coil spring 30D has a spring body 31, a first connecting portion 32, and a second connected portion 33.

[0088] The first connecting portion 32 fits together with the connected portion 213. Because the opening width of the connected portion 213 is smaller than the wire diameter of the coil spring 30D, the first connecting portion 32 is pressed in the first direction X1 and enters the connected portion 213. The first connecting portion 32 enters the connected portion 213, forming a fitting portion 213e. As a result, the fitting portion 213e locks the first connecting portion 32 in the circumferential direction, and the coil spring 30D restricts the circumferential movement of the valve body 20D.

[0089] The second connected portion 33 fits into the connecting portion 122. Because the opening width of the connecting portion 122 is smaller than the wire diameter of the coil spring 30D, the second connected portion 33 is pressed in the second direction X2 and enters the connecting portion 122. The second connecting portion 33 enters the connecting portion 122, forming a fitting portion 122e. As a result, the fitting portion 122e locks the second connected portion 33 in the circumferential direction, and the movement of the coil spring 30D in the circumferential direction is restricted.

[0090] The limiting portion 40D is configured as a fitting portion 213e in which the first connecting portion 32 and the connected portion 213 are fitted together so that the connected portion 213 does not rotate circumferentially relative to the first connecting portion 32. With this configuration, the first connecting portion 32 and the connected portion 213 are fitted together so that the connected portion 213 does not rotate circumferentially relative to the first connecting portion 32, and thus the relative circumferential displacement between the valve body 20D and the coil spring 30D can be suppressed. Therefore, since the relative circumferential displacement between the valve body 20D and the coil spring 30D is suppressed, the circumferential behavior of the valve body 20D can be suppressed by the coil spring 30D.

[0091] Next, another modification of the check valve 100 will be described with reference to Figures 14 and 15. Figure 14 is a radial cross-sectional view of the check valve 100E according to yet another modification. Figure 15 is a rear view of the valve body 20E. As shown in Figures 14 and 15, the check valve 100E includes a housing 10E, a valve body 20E, a coil spring 30E, and a limiting portion 40E.

[0092] The housing 10E has a base portion 11, a support portion 12, and a housing body 13. The support portion 12 has a sliding cylindrical portion 121 and a connecting portion 122. The connecting portion 122 is connected to a coil spring 30E. The housing body 13 also has a guide portion 131.

[0093] The valve body 20E has a valve body main 21 and a valve stem portion 22. The valve body main 21 has a front portion 211, a rear portion 212, and a connecting portion 213. A coil spring 30E is connected to the connecting portion 213. The connecting portion 213 has a locking portion 213f.

[0094] The locking portion 213f locks the end of the coil spring 30E on the first direction X1 side. Specifically, the locking portion 213f is a groove recessed in the first direction X1 from the back surface 212 on the radially outer side of the coil spring 30E. The locking portion 213f has a pair of surfaces that face each other in the circumferential direction and intersect with respect to the circumferential direction.

[0095] The coil spring 30E has a spring body 31, a first connecting portion 32, and a second connected portion 33. The first connecting portion 32 is connected to the first connected portion 213. The first connecting portion 32 includes an outer diameter extension portion 324.

[0096] The outer diameter extension 324 extends radially outward from the valve body 20E. The radial length of the first outer diameter extension 321 is made longer, for example, than the radial length of the back portion 212. The outer diameter extension 324 is locked to the locking portion 213f. As the outer diameter extension 324 enters the locking portion 213f, which is a groove, it contacts at least one of a pair of surfaces of the locking portion 213f. In other words, the locking portion 213f locks the outer diameter extension 324 in the circumferential direction, so the outer diameter extension 324 restricts the circumferential movement of the valve body 20E. The outer diameter extension 324 is guided by the guide portion 131 of the housing body 13.

[0097] The guide portion 131 is provided on the elongated member of the housing body 13 that faces the outer diameter extension portion 324. The guide portion 131 is formed by an opening in the elongated member that extends in the flow direction X. The guide portion 131 guides the radially outer end of the outer diameter extension portion 324 so that it can move in the flow direction X. The guide portion 131 also restricts the circumferential movement of the radially outer end of the outer diameter extension portion 324. The guide portion 131 is not limited to being an opening that penetrates the elongated member radially. The guide portion 131 only needs to be able to guide the outer diameter extension portion 324 in the flow direction X, and may be formed by a recess in the elongated member.

[0098] The limiting portion 40E extends between the valve body 20E and the coil spring 30E, limiting the relative circumferential displacement of the valve body 20E with respect to the coil spring 30E. Furthermore, the limiting portion 40E extends between the valve body 20E and the housing 10E, limiting the relative circumferential displacement of the valve body 20E with respect to the housing 10E. In other words, the limiting portion 40E includes an outer diameter extension portion 324, a locking portion 213f, and a guide portion 131. With this configuration, the behavior of the valve body 20E is limited by the coil spring 30E and the housing 10E, so that the circumferential displacement of the valve body 20E can be limited from both the radially inner and outer sides. Therefore, wear of the valve body 20E and the housing 10E can be further suppressed.

[0099] Embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. The drawings sometimes schematically show the components in order to facilitate understanding. The number of each component shown in the drawings may differ from the actual number due to the convenience of drawing creation. Furthermore, the components shown in the above embodiments are examples and are not particularly limiting, and various modifications are possible without substantially departing from the effects of the present invention.

[0100] (1) In this embodiment, the valve body 20 had a valve body main body 21 and a valve stem portion 22, but the disclosure is not limited thereto. The valve body 20 only needs to be able to open and close a passage space through which fluid passes, and the valve stem portion 22 may be omitted, leaving only the valve body main body 21.

[0101] (2) In this embodiment, a limiting portion 40 is provided between the valve body 20 and the coil spring 30 to restrict the circumferential movement of the valve body 20, and a limiting portion is provided between the housing 10 and the coil spring 30 to restrict the circumferential movement of the coil spring 30. However, the disclosure is not limited thereto. The coil spring 30 is pressed against the second connecting portion, and the spring body 31 is externally fitted onto the sliding cylinder portion 121 in an expandable and contractible manner, so the circumferential movement of the coil spring 30 relative to the sliding cylinder portion 121 is minimal. Therefore, depending on the operating environment and conditions, it is possible to omit the limiting portion that restricts the circumferential movement of the coil spring 30 by the housing 10.

[0102] (3) In this embodiment, a first outer diameter extension 321 is formed on the first connecting portion 32 of the coil spring 30 and a locking portion 213a is formed on the first connected portion 213 of the valve body 20, but the disclosure is not limited thereto. As shown in Figure 16, a radially extending diameter extension 213g may be provided on the first connected portion 213 of the valve body 20F and a locking portion 325 may be provided on the first connecting portion 32 of the coil spring 30F. For example, the diameter extension 213g of the first connected portion 213 is composed of a substantially rectangular parallelepiped projection that protrudes from the rear surface of the valve body 20F in a second direction X2 and extends radially. This diameter extension 213g has a surface that intersects radially, a surface that is perpendicular to the flow direction X, and a surface that is perpendicular to the circumferential direction. The locking portion 325 of the first connecting portion 32 is locked to the diameter extension 213g. Specifically, the locking portion 325 is bent in the flow direction X and formed to follow a surface perpendicular to the circumferential direction and a surface perpendicular to the flow direction X. Furthermore, as shown in Figure 17, the locking portion 326 can also be bent radially and formed to follow a surface perpendicular to the circumferential direction and a surface intersecting the radial direction.

[0103] (4) In this embodiment, a first axial extension 323 is formed on the first connecting portion 32 of the coil spring 30B and a locking portion 213c is formed on the first connected portion 213 of the valve body 20B, but the disclosure is not limited thereto. As shown in Figure 18, an axial extension 213h may be provided on the first connected portion 213 of the valve body 20G and a locking portion 327 may be provided on the first connecting portion 32 of the coil spring 30H. For example, the axial extension 213h of the first connected portion 213 is composed of a rod-shaped portion extending from the back portion 212 along the flow direction X. The locking portion 327 of the first connecting portion 32 is locked to the axial extension 213h. Specifically, the axial extension 213h is at least partially surrounded by the locking portion 327 on its outer circumferential surface and engages with the locking portion 327. The locking portion 327 corresponds to, for example, a "recess".

[0104] (5) In this embodiment, the housing body 13 was configured to have four elongated members extending circumferentially along the flow direction X, but the disclosure is not limited thereto. The housing body 13 only needs to be able to connect the base 11 and the support 12 and allow the introduced fluid to flow in the second direction X2, and may have one, three, or five or more members.

[0105] (6) In this embodiment, the valve body 20 and the coil spring 30 are connected by engagement, crimping, and fitting, but the disclosure is not limited thereto. The valve body 20 and the coil spring 30 only need to be able to connect to each other, and this may be done by insert molding (metal insert). Alternatively, the valve body 20 and the coil spring 30 may be fixed together using an adhesive. [Explanation of Symbols]

[0106] 10, 10A, 10B, 10C, 10D, 10E…Housing, 11…Base, 12…Support, 13…Housing body, 14…Valve seat, 15…Packing, 16…Valve seat packing, 20, 20A, 20B, 20C, 20D, 20E, 20F, 20G…Valve body, 21…Valve body body, 22…Valve stem, 30, 30A, 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H…Coil spring, 31…Spring body, 32…First connecting part, 33…Second connected part, 40, 40A, 40B, 40C, 40D, 40E…Restricting part, 100, 100A, 100B, 100C, 100D, 100E...Check valve, 121...Sliding cylinder part, 122...Second connecting part, 122a...Locking part, 122b...Locking part, 122c...Through hole, 122d...Resistance part, 122e...Fitting part, 131...Guide part, 211...Front part, 212...Back part, 213...First connected part, 213a,213b...Locking part, 213c...Through hole, 213d...Resistance part, 213e...Fitting part, 213f...Locking part, 213g...Diameter extension part, 213h...Axial extension part, 214...Convex part, 215...Concave part, 321...First outer diameter extension part, 322...First inner diameter extension part, 323...First axial extension part, 324...Outer diameter extension part, 325,326,327...Locking part

Claims

1. A housing having a valve seat through which the fluid flowing through the pipe passes along the direction of flow, A valve body that contacts the valve seat in a first direction which is the upstream direction of the flow direction, and opens and closes a fluid passage that moves away from the valve seat in a second direction which is the downstream direction of the flow direction, A biasing member supported by the housing biases the valve body toward the valve seat in the first direction, A limiting portion extending from the valve body to the biasing member to limit the relative circumferential displacement of the valve body with respect to the biasing member, A check valve equipped with a check valve.

2. The valve body has a connected portion to which the biasing member is connected, The biasing member has a connecting portion that connects to the connected portion, The check valve according to claim 1, wherein the limiting portion is provided extending between the connected portion and the connecting portion.

3. One of the connecting portion and the connected portion includes a radial extension portion that extends radially outward and / or radially inward of the valve body, The check valve according to claim 2, wherein the other of the connecting portion and the connected portion includes a locking portion that locks the diameter extension portion in the circumferential direction.

4. One of the connecting portion and the connected portion includes an axial extension portion extending in the first direction, The check valve according to claim 2, wherein the other of the connecting portion and the connected portion includes a recess through which the axial extension portion is inserted in the first direction.

5. The check valve according to claim 2, wherein the restricting portion includes a resistive portion having irregularities formed on the connected portion.

6. The connected portion and the connecting portion are fitted together. The check valve according to claim 2, wherein the limiting portion is configured as a fitting portion in which the connecting portion and the connected portion are fitted together so that the connected portion does not rotate circumferentially with respect to the connecting portion.

7. The valve body is, A valve body having the portion on the first direction side in contact with the valve seat and the portion on the second direction side having the connected portion, A valve shaft portion extending in the second direction from the connected portion, It has, The aforementioned housing is The base portion on which the valve seat is provided and located on the first direction side, A support portion located on the second direction side and slidably supporting the valve shaft portion, A housing body connecting the base and the support, A check valve according to any one of claims 2 to 6, having the following features.

8. The valve body is, A valve body having the portion on the first direction side in contact with the valve seat and the portion on the second direction side having the connected portion, A valve shaft portion extending in the second direction from the connected portion, It has, The aforementioned housing is The base portion on which the valve seat is provided and located on the first direction side, A support portion located on the second direction side and slidably supporting the valve shaft portion, A housing body connecting the base and the support, It has, The aforementioned limiting section is The outer diameter extension portion extending radially outward from the valve body, A locking portion that locks the outer diameter extension portion in the circumferential direction, A guide portion provided on the housing body, which allows the radially outer end of the outer diameter extension to move in the flow direction and restricts its movement in the circumferential direction, A check valve according to claim 2, including the following:

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