JP6717160B2 - Check valve - Google Patents

Description

The present invention relates to a check valve.

BACKGROUND ART Conventionally, a check valve has been known which prevents a reverse flow of a fluid flowing from a primary side to a secondary side in a line such as a pipe through which a fluid flows. Such a check valve has a valve body and a valve seat capable of contacting the valve body. The valve body comes into contact with the valve seat by being urged from the secondary side toward the primary side toward the valve seat.

When the fluid flows from the primary side to the secondary side, the valve body separates from the valve seat against the biasing force due to the pressure of the fluid, and allows the fluid to flow from the primary side to the secondary side. On the other hand, when the fluid tries to flow from the secondary side to the primary side, the valve body comes into contact with the valve seat due to the pressure and biasing force of the fluid, and prevents the fluid from flowing from the secondary side to the primary side. ..

By the way, when the foreign matter mixed in the fluid enters between the valve body and the valve seat, the foreign matter impedes the contact operation of the valve body with the valve seat. Therefore, in a situation where the fluid flows backward from the secondary side to the primary side, a gap may be created between the valve body and the valve seat, and it may not be possible to completely prevent the fluid reverse flow. Therefore, a check valve that can detect such foreign matter (dust) entry has been proposed (for example, refer to Patent Document 1).
Further, by arranging the two check valves in series, even if the contact operation of one check valve is obstructed by foreign matter, there is also a technique that allows the contact operation of the other check valve to prevent backflow. It has been proposed (for example, see Patent Document 2).

Japanese Patent No. 4014353 Japanese Patent No. 4151007

In the check valve proposed in Patent Document 1, the first valve seat with which the first valve contacts, and the second valve that is formed with a smaller diameter than the first valve and that is superposed on the primary side of the first valve make contact. A pressure sensor is provided between the pressure sensor and the second valve seat. Further, in the proposed check valve, another pressure sensor is provided on the secondary side of the second valve. When the pressure difference between the two pressure sensors becomes small, it is determined that the first valve is not sealed. Therefore, the proposed check valve does not actually eliminate the obstruction of the contact operation due to foreign matter.

Further, as proposed in Patent Document 2, although it is very useful to dispose two check valves, even if foreign matter enters from the viewpoint of increasing the number of operating parts and improving maintainability, etc. It is preferable to be able to prevent backflow with one check valve.

Therefore, it is an object of the present invention to provide a check valve capable of maintaining a suitable sealing property even when foreign matter has entered.

The present invention relates to a casing in which a fluid inlet, a valve chamber, a valve seat portion and a fluid outlet are formed, a valve body arranged in the valve chamber, and a biasing portion for biasing the valve body toward the valve seat portion. And a filter disposed on the fluid inlet side of the casing, wherein the valve seat portion includes a first valve seat portion disposed on the fluid inlet side of the valve chamber. A second valve seat portion arranged on an outer peripheral side of the first valve seat portion, the valve body being a plate-shaped first seal portion that is in close contact with the first valve seat portion, and the first valve seat portion. A second seal portion disposed on an outer peripheral side of the seal portion and closely contacting the second valve seat portion, wherein the second seal portion bends due to a pressure applied from the fluid outlet side to the fluid inlet side, and The present invention relates to a check valve having flexibility that can be in close contact with the second valve seat portion.

Further, the second seal portion may be in close contact with the second valve seat portion in a state where the foreign matter that has passed through the filter is sandwiched between the first seal portion and the first valve seat portion.

Further, the valve body may further include a hinge portion arranged at a position of the second seal portion and serving as a starting point of bending of the second seal portion.

Further, the thickness of the second seal portion may be formed so as to gradually decrease toward the outer peripheral side.

In addition, the first valve seat portion is formed as a vertical surface perpendicular to the fluid inflow direction, and the second valve seat portion is inclined so that an angle formed with the fluid inflow direction is an acute angle. It may be formed as a surface.

Further, the urging portion includes a plate-shaped body that is superposed on a surface on the fluid outlet side of the valve body, and an elastic member that urges the plate-shaped body from the fluid outlet side toward the fluid inlet side. May be.

According to the present invention, it is possible to provide a check valve capable of maintaining a suitable sealing property even when a foreign matter enters.

It is the top view which looked the check valve concerning one embodiment of the present invention from the primary side. It is the sectional view on the AA line of FIG. It is the top view which looked the check valve of one embodiment from the secondary side. It is sectional drawing which shows the filter of the check valve of one Embodiment. It is a top view which shows the state before bending the outer peripheral side of the plate member of the check valve of one Embodiment. It is a top view showing the state where the peripheral side of the plate member of the check valve of one embodiment was bent. FIG. 5 is a schematic cross-sectional view showing the operation of the second valve seat portion when foreign matter has entered between the first seal portion and the first valve seat portion of the check valve according to the embodiment. FIG. 5 is a schematic cross-sectional view when foreign matter has entered between the second seal portion and the second valve seat portion of the check valve according to the embodiment. FIG. 3 is a schematic cross-sectional view when foreign matter has entered the outer peripheral side between the second seal portion and the second valve seat portion of the check valve according to the embodiment. The schematic sectional drawing of the modification of the check valve of one Embodiment is shown.

Hereinafter, an embodiment of a check valve according to the present invention will be described with reference to the drawings.
The check valve is arranged in the pipe through which the fluid flows and prevents the reverse flow of the fluid in the pipe. The check valve is connected between the primary side pipe (fluid inlet side pipe) provided on the upstream side of the fluid and the secondary side pipe (fluid outlet side pipe) provided on the downstream side of the fluid. The check valve opens the valve to allow the flow of fluid from the primary side pipe to the secondary side pipe, while allowing the flow of the fluid from the secondary side pipe to the primary side pipe. Backflow is prevented by closing the valve to prevent flow.

Foreign matter may be mixed in the fluid flowing through the pipe, and when this foreign matter enters the position of the check valve, the operation of closing the valve may be hindered. The check valve according to the present embodiment prevents the backflow of fluid by minimizing the effect of foreign matter even if it enters.

As shown in FIGS. 1 to 3, the check valve 1 according to the present embodiment includes a casing 10, a valve body 20, a biasing section 40, and a filter 60.

The casing 10 is a member in which a flow path 15 through which a fluid flows is formed, and forms the outer shape of the check valve 1. The casing 10 includes a fluid inlet 11, a valve chamber 12, a valve seat portion 13 and a fluid outlet 14.
The fluid inlet 11 is arranged at the end of the flow path 15 on the primary side. A primary side pipe is connected to the fluid inlet 11.
The fluid outlet 14 is arranged at the end of the flow path 15 on the secondary side. A secondary side pipe is connected to the fluid outlet 14.

The valve chamber 12 is arranged between the fluid inlet 11 and the fluid outlet 14 in the flow path 15, and is formed as a space having a larger diameter than the fluid inlet 11 and the fluid outlet 14.
The valve seat portion 13 is formed in a concave shape by the inner wall surface of the valve chamber 12 on the primary side. Details of the valve seat portion 13 will be described later.

In the present embodiment, the casing 10 is formed by combining the first casing 111 that constitutes the primary side and the second casing 112 that constitutes the secondary side, and fastening the bolts 50 together to integrate them. In the first casing 111, a fluid inlet 11, a valve seat portion 13, and a primary side portion of the valve chamber 12 are formed. In the second casing 112, a part on the secondary side of the valve chamber 12 and the fluid outlet 14 are formed.

The valve body 20 is arranged in the valve chamber 12 and is arranged to face the valve seat portion 13. The valve body 20 is formed in a convex shape so that it can be brought into close contact with the valve seat portion 13. Details of the valve body 20 will be described later.

The urging portion 40 is arranged on the secondary side of the valve body 20 in the valve chamber 12. The urging portion 40 urges the valve body 20 toward the valve seat portion 13 side. The urging portion 40 includes a plate-shaped body 41, an elastic member 42, and a shaft member 43.

The plate-shaped body 41 is formed of, for example, an inelastic material (for example, metal or the like), and is superposed on the fluid outlet 14 side of the valve body 20. In the present embodiment, the plate-like body 41 is formed in a substantially circular shape having substantially the same diameter as the valve body 20, and is arranged along the surface of the valve body 20 on the secondary side. A plurality of through holes (not shown) are formed in the plate body 41. This allows the fluid to flow between the plate-shaped body 41 and the valve body 20. Therefore, the pressure (back pressure) of the fluid applied from the fluid outlet 14 side to the fluid inlet 11 side acts on the valve body 20 without being obstructed by the plate-shaped body 41.

The elastic member 42 is a so-called compression spring, and biases the plate-shaped body 41 from the fluid outlet 14 side toward the fluid inlet 11 side. One end of the elastic member 42 is arranged in contact with the surface of the plate-shaped body 41 on the fluid outlet 14 side, and the other end of the elastic member 42 is arranged in contact with the inner surface of the valve chamber 12 on the fluid outlet 14 side. The elastic member 42 contracts when the valve body 20 is pushed by the pressure of the fluid flowing from the fluid inlet 11 side to the fluid outlet 14 side, whereby the valve body 20 and the plate-like body 41 move to the secondary side. Then, the valve body 20 separates from the valve seat portion 13. Further, the elastic member 42 extends in a state where no pressure is applied due to the inflow of the fluid from the fluid inlet 11 side to the fluid outlet 14 side, and presses the plate-shaped body 41 and the valve body 20 against the valve seat portion 13 side.

The shaft member 43 is arranged such that the longitudinal direction thereof is along the inflow direction F of the fluid. Further, the shaft member 43 is arranged so as to match the position of the central axis of the elastic member 42. In the present embodiment, the central axis of the shaft member 43 is arranged so as to coincide with the central position of the flow path 15 of the casing 10.
The primary side of the shaft member 43 penetrates the valve chamber 12, and the secondary side extends to the fluid outlet 14 of the casing 10. The shaft member 43 is inserted into the primary side support member 16 extending inward in the radial direction from the casing 10 at the primary side end portion, and is movable in the axial direction (along the fluid inflow direction F) with respect to the casing 10. Supported. Further, the shaft member 43 is inserted into the secondary side support member 17 extending inward in the radial direction from the casing 10 at the secondary side end portion thereof, and is axially directed to the casing 10 (along the fluid inflow direction F). ) It is movably supported.
The shaft member 43 described above guides the movement of the valve body 20 and the plate-like body 41 to the primary side or the secondary side.

As shown in FIG. 2, the filter 60 is arranged on the fluid inlet 11 side of the valve chamber 12 in the flow path 15 of the casing 10. The filter 60 catches foreign matter having a size larger than a predetermined size (for example, more than 1.4 mm) and prevents the foreign matter from entering the valve body 20. As shown in FIG. 4, this filter 60 is provided with a convex filter body 61 and a rib portion 62 when viewed from the primary side into which foreign matter flows, and is arranged so that the concave opening faces the fluid outlet 14 side. To be done.

As shown in FIG. 1, a plurality of openings are formed on the entire surface of the filter body 61. In the present embodiment, the filter body 61 is formed by pressing a metal net in which metal wires are knitted in a mesh shape (for example, a 14-mesh, stainless net having a wire diameter of 0.4 mm and an opening of 1.4 mm). .. Thereby, a plurality of openings are formed on the entire surface of the filter body 61. The filter body 61 includes a receiving surface portion 611, a side surface portion 612, and a flange portion 613.

The receiving surface portion 611 is a portion corresponding to the top surface of the convex filter main body 61, and is arranged substantially perpendicular to the fluid flow direction F. The receiving surface portion 611 is formed in a circular shape when viewed from the front. Further, the receiving surface portion 611 has a concave portion 614 that is recessed toward the secondary side. The recess 614 is formed by curving the central portion of the receiving surface portion 611 to the secondary side in the fluid flow direction F.

The side surface portion 612 is a portion corresponding to the side surface of the concave filter body 61, and extends from the outer periphery of the receiving surface portion 611 in the direction along the fluid flow direction F. That is, the side surface portion 612 is formed in a cylindrical shape extending from the entire circumference of the receiving surface portion 611 toward the secondary side in the fluid flow direction F. The side surface portion 612 is integrally formed with the receiving surface portion 611. In the present embodiment, the side surface portion 612 extends in a direction bent by approximately 90 degrees with respect to the receiving surface portion 611.

The flange portion 613 extends substantially perpendicular to the fluid flow direction F from the tip end side of the side surface portion 612 (the side opposite to the receiving surface portion 611 that is the base end side). In the present embodiment, the brim portion 613 is integrally formed with the filter body 61 by bending a mesh-shaped metal net at the tip portion of the side surface portion 612. The collar portion 613 constitutes a part of a rib portion 62 described later.

The rib portion 62 extends substantially perpendicular to the fluid flow direction F from the tip end side of the side surface portion 612 (the side opposite to the receiving surface portion 611 that is the base end side). The rib portion 62 is formed with a notch or a gap through which a fluid can flow. The rib portion 62 includes the above-mentioned collar portion 613 and the plate member 621.

As shown in FIG. 5, the plate member 621 is formed in an annular shape with notches d formed at predetermined intervals on the outer circumference. Further, the inner diameter of the plate member 621 is formed to be substantially the same as the inner diameter of the side surface portion 612. Then, as shown in FIG. 6, the plate member 621 is bent such that the cuts d at predetermined intervals partially remain. As shown in FIG. 2, the plate member 621 is bent so as to sandwich the collar portion 613, so that the plate member 621 is formed so that the fluid can flow in the portion of the cut d.

The above-described filter 60 is arranged in the first casing 111 with the rib portion 62 supported by the portion L of the casing 10 supporting the rib portion 62. As shown in FIGS. 1 and 2, in the filter 60, the receiving surface portion 611 is arranged on the primary side (the fluid inlet 11 side), and the rib portion 62 (the collar portion 613) is on the secondary side (the fluid outlet 14 side). Is located in. As a result, the filter 60 is arranged such that the opening side (tip side) faces the valve chamber 12. A notch or a gap through which a fluid can flow is also formed in a portion L of the casing 10 that supports the rib portion 62 (not shown).

Of the fluids flowing from the primary side to the secondary side, the receiving surface portion 611 allows passage of the fluid flowing through the central portion of the flow path 15. As a result, the receiving surface portion 611 can catch foreign matter mixed in the fluid flowing from the primary side to the secondary side. By forming the concave portion 614 in the receiving surface portion 611, it is possible to improve the strength of the receiving surface portion 611 as compared with the case where the receiving surface portion 611 is formed only by the surface perpendicular to the fluid inflow direction F.

Among the fluids flowing from the primary side to the secondary side, the side surface portion 612 and the rib portion 62 allow the fluid flowing on the outer peripheral side of the flow path 15 to pass therethrough. Here, in the present embodiment, the side surface portion 612 is configured to include a plurality of openings and is arranged along the inflow direction F of the fluid, so that the side surface portion 612 is allowed to pass a part of the fluid. It is possible to prevent foreign matter from clogging. Further, since the notch or the gap through which the fluid can flow is formed in the rib portion 62 and the portion L that supports the rib portion 62 in the casing 10, the fluid that passes through the rib portion 62 also flows into the valve chamber 12. You can

Accordingly, it is possible to form a flow along the inflow direction F on the outer peripheral side of the side surface portion 612, and a part of the fluid flowing on the outer peripheral side of the side surface portion 612 is caused to flow from the side surface portion 612, while part of the fluid is also ribbed You can lead to 62. Therefore, the pressure loss due to the arrangement of the filter 60 can be reduced. Further, since the plate member 621 protects the collar portion 613 which is the end of the filter body 61 formed by knitting the metal wire, the filter body 61 is prevented from being damaged due to the loosening of the metal wire and the shape of the filter 60. Can be maintained.

Next, details of the valve seat portion 13 and the valve body 20 of the present embodiment will be described.

As shown in FIG. 2, the valve seat portion 13 includes a first valve seat portion 131 and a second valve seat portion 132.
The first valve seat portion 131 is formed as a vertical surface (a surface along the radial direction of the flow path 15) perpendicular to the fluid inflow direction F. The first valve seat portion 131 is arranged on the fluid inlet 11 side of the valve chamber 12. Specifically, the first valve seat portion 131 is arranged so as to surround the outer periphery of the inlet of the valve chamber 12 on the inner wall surface of the valve chamber 12 on the fluid inlet 11 side. In the present embodiment, the first valve seat portion 131 is annularly arranged along the outer circumference of the inlet of the valve chamber 12.

The second valve seat portion 132 is arranged on the outer peripheral side of the first valve seat portion 131. The second valve seat portion 132 includes a vertical surface 133 and an inclined surface 134.

The vertical surface 133 is formed as a surface vertical to the inflow direction F of the fluid. The vertical surface 133 is formed as an inner peripheral surface of the surfaces forming the second valve seat portion 132. The vertical surface 133 is arranged along the outer circumference of the first valve seat portion 131. In the present embodiment, the vertical surface 133 is disposed so as to form a step between the vertical surface 133 and the first valve seat portion 131, and is disposed closer to the fluid outlet 14 side than the first valve seat portion 131.

The inclined surface 134 is formed as a surface inclined so that the angle formed with the fluid inflow direction F is an acute angle. In other words, the inclined surface 134 is formed as an inclined surface that gradually increases in diameter along the fluid inflow direction F (from the fluid inlet 11 toward the fluid outlet 14). The inclined surface 134 is formed as an outer peripheral surface of the surfaces forming the second valve seat portion 132. The inclined surface 134 is arranged along the outer circumference of the vertical surface 133. In the present embodiment, the inclined surface 134 is arranged so as to form a step between it and the vertical surface 133, and is arranged closer to the fluid outlet 14 side than the vertical surface 133.

The valve body 20 includes a first valve body 21, a second valve body 22, and a hinge portion 30.
The first valve body 21 is inelastic in order to maintain the mechanical strength of the valve body 20 against contact with the valve seat portion 13 due to the back pressure of the fluid (pressure from the fluid outlet 14 side to the fluid inlet 11 side). It is formed of a material (for example, metal such as stainless steel) with a predetermined hardness. Further, the first valve body 21 has substantially the same thickness as the step between the first valve seat portion 131 and the vertical surface 133 of the second valve seat portion 132. The first valve body 21 is larger than the inner diameter of the first valve seat portion 131 (diameter of the inlet of the valve chamber 12) so that the first valve seat portion 131 can be in close contact with the first valve seat portion 131, and the outer diameter of the first valve seat portion 131. It is formed in a disc shape having a diameter of the following size. Then, the center position of the first valve body 21 is inserted into the shaft member 43 and is fixed to the shaft member 43.

Accordingly, the first valve body 21 is arranged so as to be movable along with the shaft member 43 along the fluid inflow direction F. Further, the first valve body 21 is arranged in the valve chamber 12 so that the radial direction is perpendicular to the fluid inflow direction F. That is, the surface of the first valve body 21 on the side of the fluid inlet 11 is arranged substantially parallel to the first valve seat portion 131, and is also arranged so as to face it. The first valve body 21 constitutes a first seal portion 210 that is in close contact with the first valve seat portion 131.

The second valve body 22 is formed of an elastic material (for example, synthetic rubber such as fluororubber or silicon rubber) into a truncated cone shape with a lower bottom surface recessed. The second valve body 22 is arranged such that the upper bottom formed with a shorter diameter than the lower bottom is superposed on the surface of the first valve body 21 on the fluid outlet 14 side. The diameter of the upper bottom of the second valve body 22 is larger than the diameter of the first valve body 21 and the inner diameter of the vertical surface 133 of the second valve seat portion 132, and is larger than the outer diameter of the vertical surface 133 of the second valve seat portion 132. Is also formed small. Then, the side surface of the second valve body 22 is formed according to the inclination angle of the inclined surface 134 of the second valve seat portion 132. Further, the second valve body 22 is fixed to the shaft member 43 while the central position is inserted into the shaft member 43. Accordingly, the second valve body 22 is arranged so as to be movable along with the shaft member 43 along the inflow direction F of the fluid. The second valve body 22 constitutes a second seal portion 220 that is in close contact with the second valve seat portion 132.

The second seal portion 220 is formed in the second valve seat portion 132 at a position that does not overlap the first valve body 21 (first seal portion 210) in the fluid inflow direction F. That is, the second seal portion 220 is formed by a portion of the second valve body 22 arranged on the outer peripheral side of the first valve body 21. The thickness of the second seal portion 220 is formed so as to gradually decrease toward the outer peripheral side (see FIGS. 7 to 9). The second seal portion 220 has flexibility so that it can be bent by the pressure (back pressure) applied from the fluid outlet 14 side to the fluid inlet 11 side to be in close contact with the second valve seat portion 132. The second seal part 220 includes a vertical seal part 221 and an inclined seal part 222.

The vertical seal portion 221 is arranged along the outer circumference of the first valve body 21. Specifically, the vertical seal portion 221 is formed in an annular shape with the upper surface exposed from the first valve body 21 of the second valve body 22 as a vertical plane H. The vertical surface H of the vertical seal portion 221 is arranged to face the vertical surface 133 of the second valve seat portion 132. Further, the vertical seal portion 221 is formed to be the thickest of the second seal portions 220.

The inclined seal part 222 is formed along the outer periphery of the vertical seal part 221. That is, the inclined seal portion 222 is formed in an annular shape having the side surface of the second valve body 22 as the inclined surface S. The inclined surface S of the inclined seal portion 222 is arranged to face the inclined surface 134 of the second valve seat portion 132. In the present embodiment, the inclined seal portion 222 is formed so as to extend radially outward from the side surface of the vertical seal portion 221, and is formed so as to gradually become thinner along the extending direction. That is, the thickness of the inclined seal portion 222 is formed so as to gradually decrease toward the outer peripheral side.

The hinge portion 30 is arranged at the position of the second seal portion 220, and serves as a starting point of the bending of the second seal portion 220. Specifically, the hinge portion 30 is formed as a groove cut out from the surface of the second seal portion 220 along the fluid flow direction (inflow direction F or the opposite direction). The hinge part 30 includes a first hinge part 310 and a second hinge part 320.

The first hinge portion 310 is formed as a groove cut out from the upper bottom of the second valve body 22. The first hinge portion 310 is formed in an annular shape along the outer circumference of the first valve body 21 (first seal portion 210). That is, the first hinge part 310 is formed in a ring shape along the outer periphery of the first valve body 21 (first seal part 210) as a groove cut out from the vertical surface H of the vertical seal part 221.

The second hinge portion 320 is formed as a groove cut out from the lower bottom of the second valve body 22. The second hinge part 320 is formed in an annular shape along the outer circumference of the vertical seal part 221. That is, the second hinge portion 320 is formed as an annular groove along the outer circumference of the vertical seal portion 221 as a groove cut out from the surface of the inclined seal portion 222 on the fluid outlet 14 side.

According to the valve element 20, the valve seat portion 13, and the hinge portion 30 as described above, the first seal portion 210 is in close contact with the first valve seat portion 131, so that the inlet of the valve chamber 12 can be sealed. it can. Further, the second seal portion 220 is in close contact with the second valve seat portion 132, so that the inlet of the valve chamber 12 can be further sealed.

Here, since the first hinge portion 310 is provided, the vertical seal portion 221 and the inclined seal portion 222 can be easily bent from the first hinge portion 310 as a starting point. Further, since the second hinge portion 320 is provided, the tilted seal portion 222 can be more easily bent. Further, since the inclined seal portion 222 and the inclined surface 134 of the second valve seat portion 132 are formed to be inclined at an acute angle with respect to the fluid inflow direction F, they are formed vertically from the viewpoint of pressure loss. The fluid flow can be made smoother than in the case.

The check valve 1 as described above is used as follows.
First, the fluid inlet 11 of the casing 10 (first casing 111) is connected to the primary side pipe (not shown). Then, the fluid outlet 14 of the casing 10 (second casing 112) is connected to the secondary side pipe (not shown).

When the fluid does not flow between the primary side pipe (not shown) and the secondary side pipe (not shown), the fluid inside the check valve 1 does not move either. At this time, the valve body 20 is brought into close contact with the valve seat portion 13 by being biased by the biasing portion 40. Specifically, the elastic member 42 urges the valve body 20 from the fluid outlet 14 side to the fluid inlet 11 side, so that the first seal portion 210 comes into close contact with the first valve seat portion 131. Further, the vertical seal portion 221 (vertical surface H) of the second seal portion 220 comes into close contact with the vertical surface 133 of the second valve seat portion 132. Then, the inclined seal portion 222 (inclined surface S) of the second seal portion 220 comes into close contact with the inclined surface 134 of the second valve seat portion 132. As a result, the inlet of the valve chamber 12 is sealed, so that fluid does not move between the fluid inlet 11 side and the fluid outlet 14 side.

When the fluid starts to flow from the fluid inlet 11 side (primary side) to the fluid outlet 14 side (secondary side), the valve body 20 will move from the fluid inlet 11 side to the fluid outlet 14 side due to the fluid pressure. Receive the power to That is, the valve body 20 receives a force that tends to move in a direction against the pressure of the biasing portion 40 due to the pressure of the fluid. The elastic member 42 contracts due to the force of movement of the valve body 20, and the valve body 20 and the plate-like body 41 move in the direction away from the valve seat portion 13 along the fluid inflow direction F together with the shaft member 43. To do. As a result, the first seal portion 210 is separated from the first valve seat portion 131. Further, the vertical seal portion 221 and the inclined seal portion 222 of the second seal portion 220 are separated from the vertical surface 133 and the inclined surface 134 of the second valve seat portion 132. Therefore, the seal between the valve seat portion 13 and the valve body 20 is released, and the fluid can flow from the fluid inlet 11 side to the fluid outlet 14 side.

On the other hand, when the fluid tries to flow backward from the fluid outlet 14 side to the fluid inlet 11 side, the valve body 20 and the plate-shaped body 41 try to move from the fluid outlet 14 side to the fluid inlet 11 side due to the fluid pressure (back pressure). Receive the power to do. Further, the valve body 20 and the plate-like body 41 receive the force of moving from the fluid outlet 14 side to the fluid inlet 11 side by the urging force of the urging portion 40. As a result, the valve body 20 and the plate-like body 41 start moving together with the shaft member 43 toward the valve seat portion 13 along the fluid inflow direction F.

At this time, the plate-shaped body 41 transmits the biasing force of the elastic member 42 to the entire surface of the second seal portion 220 on the fluid outlet 14 side. This prevents the second seal portion 220 from bending from the fluid inlet 11 side to the fluid outlet 14 side when the second seal portion 220 moves toward the second valve seat portion 132.

When the fluid in the valve chamber 12 enters between the second seal portion 220 and the plate-like body 41, the second seal portion 220 is pressed from the fluid outlet 14 side to the fluid inlet 11 side by the pressure applied from the fluid outlet 14 side. Bends toward the fluid inlet 11 side. That is, the vertical seal portion 221 bends toward the vertical surface 133 of the second valve seat portion 132, and the inclined seal portion 222 bends toward the inclined surface 134 of the second valve seat portion 132. At this time, the first hinge portion 310 serves as a starting point of bending of the vertical seal portion 221 and the inclined seal portion 222, and the second hinge portion 320 serves as a starting point of bending of the inclined seal portion 222.

Therefore, when the valve body 20 moves toward the valve seat portion 13, the sealing by the second sealing portion 220 is started before the sealing by the first sealing portion 210. The sealing by the second seal portion 220 is in close contact with the inclined surface 134 from the tip (outer peripheral side) of the inclined seal portion 222 in the extending direction. Then, after the root portion of the inclined seal portion 222 comes into close contact with the inclined surface 134, the vertical seal portion 221 comes into close contact with the vertical surface 133. That is, the sealing by the valve body 20 is sequentially performed from the fluid outlet 14 side to the fluid inlet 11 side.

As a result, it is possible to prevent a fluid having a high pressure (a fluid having a pressure on the fluid outlet 14 side) from remaining between the valve body 20 and the wall surface of the valve chamber 12 on the fluid inlet 11 side. Therefore, it is possible to prevent the valve body 20 from being unintentionally separated from the valve seat portion 13 due to the pressure of the valve body 20 from the remaining fluid. Furthermore, since the second seal portion 220 starts the seal before the first seal portion 210, it is possible to prevent the first seal portion 210 from vigorously contacting the first valve seat portion 131.

Finally, the first seal portion 210 comes into close contact with the first valve seat portion 131 by the biasing force of the elastic member 42 and the pressure of the fluid from the fluid outlet 14 side to the fluid inlet 11 side. In addition, the second seal portion 220 is in close contact with the second valve seat portion 132 due to the biasing force of the elastic member 42 and the bending due to the fluid pressure from the fluid outlet 14 side to the fluid inlet 11 side. In this way, the valve body 20 is brought into close contact with the valve seat portion 13, whereby the inlet of the valve chamber 12 is sealed, so that the reverse flow of the fluid from the fluid outlet 14 side to the fluid inlet 11 side is prevented.

By the way, the filter 60 prevents foreign matter of a predetermined size or more from entering the positions of the valve body 20 and the valve seat portion 13 by catching foreign matter mixed in the fluid flowing from the primary side to the secondary side. On the other hand, when a foreign object having a size smaller than the predetermined size that has passed through the filter 60 enters between the valve body 20 and the valve seat portion 13, the valve body 20 is configured as follows to prevent the reverse flow of the fluid. Operate.

First, as shown in FIG. 7, when the foreign material D enters between the first seal portion 210 and the first valve seat portion 131, the first seal portion 210 formed of an inelastic material is Since the foreign matter D is caught in the portion 131, the foreign matter D cannot be brought into close contact with the first valve seat portion 131. Therefore, the first seal portion 210 cannot seal the fluid inlet 11 of the valve chamber 12. The second seal portion 220 cannot move to the second valve seat portion 132 because the first seal portion 210 cannot be in close contact with the first valve seat portion 131. At this time, since the pressure in the valve chamber 12 is higher than the pressure on the fluid inlet 11 side of the casing 10, the fluid tries to flow backward from the valve chamber 12 to the fluid inlet 11 side of the casing 10.

The fluid that is about to flow back enters between the plate-shaped body 41 and the second seal portion 220. Then, the second seal portion 220 formed of an elastic material is bent by the pressure applied from the fluid outlet 14 side to the fluid inlet 11 side and the elastic force of the elastic member 42 and is brought into close contact with the second valve seat portion 132. That is, the vertical seal portion 221 bends toward the fluid inlet 11 side with the first hinge portion 310 as a starting point, so that the vertical surface H closely contacts the vertical surface 133 of the second valve seat portion 132. Further, the inclined seal portion 222 bends toward the fluid inlet 11 side with the second hinge portion 320 as a starting point, so that the inclined surface S closely contacts the inclined surface 134 of the second valve seat portion 132.

At this time, since the hinge portion 30 serves as a starting point of bending, the second seal portion 220 can be easily bent. Further, the second seal portion 220 can be easily bent because the thickness of the second seal portion 220 is gradually reduced toward the outer peripheral side. As a result, the valve body 20 can seal the fluid inlet 11 of the valve chamber 12 in the second seal portion 220 even when the fluid inlet 11 of the valve chamber 12 cannot be sealed in the first seal portion 210. Backflow of fluid can be prevented.

As shown in FIG. 8, when the foreign matter D enters between the vertical surface H of the vertical seal portion 221 and the vertical surface 133 of the second valve seat portion 132, the vertical seal portion 221 receives the urging force of the elastic member 42. The foreign matter D is deformed so as to wrap it by the pressure applied from the fluid outlet 14 side to the fluid inlet 11 side. As a result, the vertical seal portion 221 can move up to the vertical surface 133 of the second valve seat portion 132 and be in close contact therewith. Further, the first seal portion 210 can be in close contact with the first valve seat portion 131. Further, the inclined seal portion 222 can be in close contact with the inclined surface 134 of the second valve seat portion 132. Accordingly, the inlet of the valve chamber 12 can be sealed by the first seal portion 210 and the second seal portion 220.

If the first seal portion 210 cannot be brought into close contact with the first valve seat portion 131 even by the deformation of the vertical seal portion 221, the vertical seal portion 221 bends with the foreign matter D as a fulcrum, and thus the second valve seat portion 132. It adheres to the vertical surface 133 of. Further, the tilted seal part 222 comes into close contact with the tilted surface 134 of the second valve seat part by being bent by the pressure of the fluid that tries to flow backward. As a result, the inlet of the valve chamber 12 can be sealed at the second seal portion 220, and backflow of fluid can be prevented.

Next, as shown in FIG. 9, when the foreign matter D enters between the inclined seal portion 222 and the inclined surface 134 of the second valve seat portion 132, the inclined seal portion 222 moves from the fluid outlet 14 side to the fluid inlet 11 side. The foreign matter D is deformed so as to wrap it by the pressure applied to. As a result, the inclined seal portion 222 can move to the inclined surface 134 of the second valve seat portion 132 and can be brought into close contact therewith. That is, the first seal portion 210 can be in close contact with the first valve seat portion 131. Further, the inclined seal portion 222 can be in close contact with the inclined surface 134 of the second valve seat portion 132. Accordingly, the inlet of the valve chamber 12 can be sealed by the first seal portion 210 and the second seal portion 220.

When the first seal portion 210 cannot be brought into close contact with the first valve seat portion 131 due to the deformation of the inclined seal portion 222, the inclined seal portion 222 is subjected to pressure (back pressure) applied from the fluid outlet 14 side to the fluid inlet 11 side. Thus, the second hinge portion 320 bends from the second hinge portion 320 to be in close contact with the inclined surface 134 of the second valve seat portion 132. Further, the tip end side of the inclined seal portion 222 adheres to the inclined surface 134 with the foreign matter D as a fulcrum. The vertical seal portion 221 bends from the first hinge portion 310 as a starting point by the pressure (back pressure) applied from the fluid outlet 14 side to the fluid inlet 11 side. The vertical seal portion 221 is in close contact with the vertical surface 133 of the second valve seat portion 132. As a result, the inlet of the valve chamber 12 can be sealed at the second seal portion 220, and backflow of fluid can be prevented.

The check valve 1 according to the embodiment described above has the following effects.
(1) The check valve 1 includes a casing 10 in which a fluid inlet 11, a valve chamber 12, a valve seat portion 13 and a fluid outlet 14 are formed, a valve body 20 disposed in the valve chamber 12, and a valve body 20. A biasing portion 40 that biases the seat portion 13 side is included. The check valve 1 further includes a filter 60 arranged on the fluid inlet 11 side of the casing 10. Here, the valve seat portion 13 includes a first valve seat portion 131 arranged on the fluid inlet 11 side of the valve chamber 12, and a second valve seat portion 132 arranged on the outer peripheral side of the first valve seat portion 131. And a plate-shaped first seal portion 210 that is in close contact with the first valve seat portion 131 and a second seal portion that is disposed on the outer peripheral side of the first seal portion 210 and that is in close contact with the second valve seat portion 132. 2 seal part 220, and it comprised. Then, the second seal portion 220 is configured to be flexible so as to bend due to the pressure applied from the fluid outlet 14 side to the fluid inlet 11 side so as to be able to come into close contact with the second valve seat portion 132. As a result, a large foreign matter can be prevented from entering by the filter 60, and even if there is a foreign matter D that has passed through the filter 60, the second seal portion 220 bends and can adhere to the second valve seat portion 132. .. Therefore, even if the foreign matter D enters, it is possible to maintain a suitable sealing property.

(2) Regarding the second seal portion 220, the foreign matter D that has passed through the filter 60 is configured to come into close contact with the second valve seat portion 132 in a state of being sandwiched between the first seal portion 210 and the first valve seat portion 131. did. As a result, even when the first seal portion 210 cannot be brought into close contact with the first valve seat portion 131 due to the influence of the foreign matter D, the second seal portion 220 is bent and comes into close contact with the second valve seat portion 132. That is, even when the first seal portion 210 has moved to the fluid outlet 14 side by a predetermined distance with respect to the first valve seat portion 131, the second seal portion 220 may be in close contact with the second valve seat portion 132. it can. Therefore, a suitable sealing property can be maintained.

(3) The valve body 20 is further configured to include the hinge portion 30 which is arranged at the position of the second seal portion 220 and serves as a starting point of the bending of the second seal portion 220. Accordingly, the flexibility of the second seal portion 220 can be increased, and the flexure of the second seal portion 220 starting from the hinge portion 30 can be further increased.

(4) The thickness of the second seal portion 220 is formed so as to gradually decrease toward the outer peripheral side. This makes it easier for the second seal portion 220 to bend toward the outer peripheral side. By making the outer circumferential side of the second seal portion 220 more flexible, even if the foreign matter D enters between the second seal portion 220 and the second valve seat portion 132, the second foreign matter D on the outer circumferential side with the foreign matter D as a fulcrum. The seal part 220 can be bent.

(5) The first valve seat portion 131 is formed as a vertical surface that is perpendicular to the fluid inflow direction F, and the second valve seat portion 132 is formed so as to form an acute angle with the fluid inflow direction F. It was formed as an inclined inclined surface. As a result, the first valve seat portion 131 and the second valve seat portion 132 can have a double seal structure by the first seal portion 210 and the second seal portion 220 being in close contact with each other.

(6) A plate-like body 41 that overlaps the urging portion 40 with the surface of the valve body 20 on the fluid outlet 14 side, and elasticity that urges the plate-like body 41 from the fluid outlet 14 side toward the fluid inlet 11 side. And a member 42. By stacking the plate-like body 41 on the surface of the valve body 20 on the fluid outlet 14 side, the biasing force of the elastic member 42 can be transmitted to the entire valve body 20.

Although the preferred embodiments of the check valve according to the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate.

For example, as shown in FIG. 10, a plurality of hinge portions 30 may be provided on the surface of the second seal portion 220 on the fluid inlet 11 side. This makes it possible to make the second seal portion 220 more easily bendable.

Further, in the above-described embodiment, the filter main body 61 is formed as a mesh-shaped metal net formed by braiding metal wires, but the present invention is not limited to this. For example, the filter body 61 may be a punching metal or a resin molded product.

1 check valve 10 casing 11 fluid inlet 12 valve chamber 13 valve seat part 14 fluid outlet 20 valve body 30 hinge part 40 biasing part 41 plate-like body 42 elastic member 60 filter 131 first valve seat part 132 second valve seat part 210 first seal part 220 second seal part F inflow direction

Claims (6)

A casing in which a fluid inlet, a valve chamber, a valve seat portion and a fluid outlet are formed,
A valve body arranged in the valve chamber,
A check valve comprising: a biasing portion that biases the valve element toward the valve seat portion,
Further comprising a filter arranged on the fluid inlet side of the casing,
The valve seat is
A first valve seat portion arranged on the fluid inlet side of the valve chamber;
A second valve seat portion arranged on the outer peripheral side of the first valve seat portion,
The valve body is
A plate-shaped first seal portion that is in close contact with the first valve seat portion,
A second seal portion arranged on the outer peripheral side of the first seal portion and in close contact with the second valve seat portion,
The second seal portion is a check valve having flexibility that is capable of being bent by pressure applied from the fluid outlet side to the fluid inlet side and being in close contact with the second valve seat portion. The reverse according to claim 1, wherein the second seal portion adheres to the second valve seat portion in a state where foreign matter that has passed through the filter is sandwiched between the first seal portion and the first valve seat portion. Stop valve. The check valve according to claim 1 or 2, wherein the valve body is further provided with a hinge portion arranged at a position of the second seal portion and serving as a starting point of bending of the second seal portion. The check valve according to any one of claims 1 to 3, wherein the second seal portion is formed so that the thickness thereof gradually decreases toward the outer peripheral side. The first valve seat portion is formed as a vertical surface perpendicular to the inflow direction of fluid,
The check valve according to any one of claims 1 to 4, wherein the second valve seat portion is formed as an inclined surface that is inclined such that an angle formed with a fluid inflow direction is an acute angle. The biasing section is
A plate-shaped body that is superposed on the surface of the valve body on the fluid outlet side;
The check valve according to claim 1, further comprising an elastic member that urges the plate-shaped body from a fluid outlet side toward a fluid inlet side.

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