TWI761761B - check valve - Google Patents

Abstract

The check valve (1) is an oblique lift type of straight pipe joint type. The check valve (1) is provided with: a valve seat (12a); a moving body (2), which can move linearly reciprocatingly in a closed state in close contact with the valve seat (12a) and an open state in which it is separated from the valve seat (12a); A primary flow path (inflow path (12c)), which is located more upstream than the moving body (2); and a secondary flow path (outflow path (12d)), which is located more downstream than the moving body (2) . The moving body (2) includes a valve body (6) and a valve shaft (7) extending from the valve body (6). The valve seat (12a) supporting the valve body (6) is characterized in that it is formed so as to have a centerline of a connecting flow path including a primary flow path (inflow path 12c) and a secondary flow path (outflow path 12d) and extending linearly In the cross-sectional view of (CL), it crosses the center line (CL).

Description

check valve

The present invention relates to the constructor of a bottom valve, ie, a lift-down check valve.

There are known check valves that allow fluid in piping to pass in one direction. There are many ways to classify the check valve by the action mode of the valve body. Among them, the lift check valve is a structure in which the valve body moves linearly back and forth in the direction of approaching or separating relative to the valve seat, so it can perform a fast closing action. In particular, the slow-closing (Smolensky type) lift check valve can effectively suppress the occurrence of water hammer due to its spring body.

In Patent Document 1, a straight pipe joint type oblique lift type, that is, a Y-shaped check valve is disclosed. This check valve includes a valve body and a spring body that urges the valve body toward the valve seat side in a downward pressing direction. The valve body of the check valve becomes open when the fluid flowing in the forward direction rises obliquely upward relative to the straight line connecting the inflow inlet and the outflow outlet. If the fluid wants to flow in the reverse direction, it is pressed down by the spring body. The valve body moves diagonally downward to be in a closed state. [Prior Art Literature] [Patent Literature]

[Patent Document 1] US Patent Application Publication No. 2005/0062000

[Problems to be Solved by Invention]

As described above, in the check valve disclosed in Patent Document 1, when the fluid flows in the forward direction, when the valve body is raised obliquely upward with respect to the linear direction connecting the inflow port and the outflow port, the fluid pressure in the flow path Inhomogeneity is prone to occur. Therefore, a vortex flow may be generated in a part of the flow path, and the pressure loss may increase.

The present invention has been made in view of the above-mentioned problems, and is to provide a check valve which can reduce the pressure loss during fluid flow. [Technical means to solve problems]

According to the present invention, a check valve is provided, which is characterized in that it is an oblique lift type of straight pipe joint type, and includes: a valve seat; In the open state, it can move linearly back and forth; the primary flow path, which is located on the upstream side of the moving body; and the secondary flow path, which is located on the downstream side of the moving body; the moving body includes: a valve body, which is in a closed state and a valve shaft extending from the valve body; and the valve seat is formed so as to span across the section including the centerline of the connection flow path connecting the connection objects, that is, the connection parts connected to the other pipe bodies, to each other centerline. [Effect of invention]

According to the present invention, it is possible to provide a check valve capable of reducing the pressure loss generated when a fluid flows.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the embodiment described below is merely an example for facilitating understanding of the present invention, and does not limit the present invention. That is, the shape, size, arrangement, etc. of the members described below can of course be changed and improved without departing from the gist of the present invention, and the equivalents thereof are also included in the present invention. In addition, in all drawings, the same code|symbol is attached|subjected to the same component, and the overlapping description is abbreviate|omitted suitably.

In this specification, there are cases where the vertical direction is specified and described, but this is set for the convenience of explaining the relative relationship of the constituent elements, and does not specify the direction at the time of manufacture or use of the product of the present invention. Ideally, the vertical upper direction is the upward direction, and the vertical downward direction is the downward direction, but the installation state of the check valve is not limited. The "up and down" of the check valve refers to the direction in which the moving body moves away from the valve body in the direction perpendicular to the flow path to which the check valve is connected, that is, the direction of the connection flow path is set as the upward direction, and the direction close to the valve body is set as the downward direction. direction.

<<First Embodiment>> <Outline of the check valve of this embodiment> First, the outline of the check valve 1 of the present embodiment will be mainly described with reference to FIGS. 1 and 2 . 1 is a perspective view showing the external appearance of the check valve 1 according to the first embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing the closed state of the check valve 1 according to the first embodiment. In addition, the cross section including the axial center of the valve shaft 7 is called a vertical cross section. As shown in FIGS. 1 and 2 , the check valve 1 of the present embodiment is a straight pipe joint type oblique lift type. The check valve 1 includes: a valve seat 12a; a movable body 2 that can move linearly back and forth in a closed state in close contact with the valve seat 12a and an open state in which it is separated from the valve seat 12a; a primary flow path (inflow path 12c), It is located more upstream than the moving body 2 ; and the secondary flow path (outflow path 12d ) is located more downstream than the moving body 2 . The movable body 2 includes: a valve body 6 , which is supported by the valve seat in a closed state; and a valve shaft 7 , which extends from the valve body 6 . The valve seat 12a is characterized in that it is formed so as to cross the center line CL in a cross section having a center line CL of a connecting flow path including a primary flow path (inflow path 12c) and a secondary flow path (outflow path 12d) and extending linearly .

"Straight pipe joint type" means a pipe joint connected to other pipes, that is, one with an outflow direction extending from the inflow direction. The "inclined lift type" refers to a valve body that tilts with respect to a straight line connecting the inflow direction and the outflow direction, that is, a type in which the valve body is raised by the fluid. In the present embodiment, the connection parts to other pipes are the flange parts 13 and 14, that is, Flange, but it is not limited to this configuration, and it is only required to be connected to other pipes. For example, it can also be a part of a ferrule connection or a part of a threaded connection. "The valve seat 12a spans the center line CL", in other words, it means that the center line CL passes through the opening delimited by the valve seat 12a, and also means that a part of the valve seat 12a is located further below the center line CL, and the other part is located lower than the center line CL. The centerline CL is further above. In addition, the valve seat 12a should just be formed so that it may straddle the center line in any of arbitrary cross sections including the center line CL.

According to the above configuration, by forming the valve seat 12a so as to straddle the center line CL of the connecting flow path, the fluid can easily flow in a straight line when the valve body 6 is opened, as compared with the case where the valve seat 12a is formed to one side without crossing the center line CL. Suppresses the generation of turbulent currents (eddy currents). Therefore, the pressure loss of the check valve 1 generated when the fluid flows can be reduced.

＜Construction of each department＞ Next, the configuration of each part constituting the check valve 1 of the first embodiment will be described with reference to FIGS. 3 to 5 in addition to FIGS. 1 and 2 . 3 is a longitudinal sectional view showing the open state of the check valve 1 of the first embodiment, FIG. 4 is a side view of the check valve 1 of the first embodiment viewed from the inflow path 12c side, and FIG. An explanatory diagram of the dynamic pressure distribution in the flow path of the check valve 1 of the first embodiment. In addition, FIG. 5 omits the valve body upper part 6b, the gasket 8, the valve box 12, the spring body 20, etc., and shows the other structure of the check valve 1 in a simplified manner, and mainly explains the dynamic pressure distribution figure.

The check valve 1 of the present embodiment is of the straight pipe joint oblique lift type as described above, that is, the movable body 2 including the valve body 6 swings linearly back and forth in the direction of approaching or separating from the valve seat 12a. In particular, the check valve 1 includes an inflow path 12c and an outflow path 12d having the same centerline CL. The movable body 2 reciprocates in a direction inclined obliquely with respect to the center line CL, specifically, in a direction inclined to the outflow path 12d side. The fluid whose reverse flow is restricted by the check valve 1 is a liquid such as water or a gas such as air.

In the closed state shown in FIG. 2 , the valve body 6 is energized by the spring body 20 and pressed against the valve seat 12 a, and the check valve 1 of this embodiment is of the so-called slow closing type. Therefore, due to the energizing force of the spring body 20, the check valve 1 makes the valve body 6 abut against the valve seat 12a at the moment when the flow of the fluid turns into a reverse flow from the secondary side to the primary side, and the flow path is quickly closed. . Thereby, the check valve 1 can prevent backflow, suppress the occurrence of water hammer, and improve the certainty (water resistance) of the tightly closed state. However, the check valve 1 is not limited to the configuration in which the spring body 20 is provided and the valve body 6 is pressed against the valve seat 12a. For example, the valve body 6 may be pressed against the valve seat 12a only by the self-weight of the movable body 2, or by the self-weight of the movable body 2 applied by the self-damping mechanism, and the load of the valve shaft 7 and the guide cylinder 4 described later. constitute.

For example, the check valve 1 of the present embodiment is used as a so-called bottom valve on the primary side of a pumping pump (not shown) to improve the certainty of water stoppage, thereby effectively preventing water from falling into the pumping pipe.

The check valve 1 is installed in a flow path for flowing liquid or gas (fluid). When the differential pressure between the primary side and the secondary side of the valve body 6 exceeds a specific minimum operating pressure (peak pressure), as shown in Figure 3, the valve body 6 is in an open state and fluid flows. When the differential pressure between the primary side and the secondary side of the valve body 6 is negative or below the minimum operating pressure, as shown in FIG. 2 , the valve body 6 is in a closed state to block the flow of fluid. In addition, with regard to the fluid, if a desired amount of flow area can be secured, the valve body 6 does not need to be in the fully open state shown in FIG. 3 . In FIG. 3 , the fully open state of the valve body 6 is shown, but according to the mass of the moving body 2 and the restoring force of the spring body 20 , the opening degree of the valve body 6 will change due to the flow rate.

The check valve 1 includes a movable body 2 , a valve box 12 that accommodates at least a part of the movable body 2 opposite to the valve body 6 , a guide cover 3 having a guide cylinder 4 and attached to the valve box 12 , and a valve body 6 . A spring body 20 between the guide cover 3 and urging the valve body 6 toward the primary flow path side. That is, the check valve 1 in this document refers to the whole pipe joint including the valve body 6 and the like inside.

(About valve box and joint part) The valve box 12 of the present embodiment is integrally formed by the dewaxing method with the joint portion 9 extending substantially in a straight line forming the inflow path 12c and the outflow path 12d, and branches from the joint portion 9 to intersect. The valve box 12 and the valve shaft 7 described later extend obliquely toward the outflow passage 12d in a direction intersecting the flow passage directions of the primary passage (inflow passage 12c ) and the secondary passage (outflow passage 12d ).

In the joint part 9, a flange part 13 and a flange part 14 are integrally formed on the upstream side (primary side) and the downstream side (secondary side), respectively, and the pipes (not shown) are tightened with bolts, nuts, etc. Fixtures (not shown) to fix it. On the inflow path 12c side of the valve box 12 (joint portion 9) of the present embodiment, as shown in FIG. 1, a flat surface for mounting a suction pipe (not shown) connected to a suction pump (not shown) is formed. Mounting table 15. A decompression port 15 a that penetrates to the inside of the primary flow path side of the valve box 12 is formed in the mounting base 15 .

By actuating the suction pump, the operator draws in the fluid from the suction pipe to the decompression port 15a, thereby making the upstream side a negative pressure compared to the valve body 6 and filling the fluid with the fluid. In addition, if the pressure sensor is installed in the decompression port 15a, the operator can also check the pressure state inside the valve box 12 and check whether the inside of the valve box 12 is filled with fluid. Next, a guide cover 3 described later is detachably attached to the end of the valve box 12 extending in the direction intersecting the center line CL of the inflow path 12c and the outflow path 12d.

(About the valve seat) As shown in FIG. 2 and the above, the valve seat 12a is formed so as to span across the center line CL of the connection flow path connecting the connection parts (flange parts 13 and 14 ) connected to the connection object, that is, other pipe body. Centerline CL. Moreover, the valve seat 12a is formed so that a part of the inner wall of the valve box 12 protrudes toward the flow path side over the entire circumference (the inflow path 12c is narrowed). The seat surface of the valve seat 12 a is formed in an annular shape, and extends vertically along the reciprocating direction of the movable body 2 . That is, the valve seat 12a extends in a direction intersecting with the flow path direction of the inflow path 12c and the outflow path 12d and the extending direction of the valve shaft 7 and the valve box 12 .

An annular groove 12h is formed on the outer periphery of the valve seat 12a. The annular groove 12h is formed to be recessed toward the inflow path 12c side (the side away from the movable body 2) with respect to the seat surface of the valve seat 12a. The annular groove 12h limits the area of the valve seat 12a that the valve body 6 of the movable body 2 abuts against, and it is easy to make the valve body 6 tightly contact the valve seat 12a.

The valve seat 12a extends in a direction intersecting with the flow path direction of the primary flow path (inflow path 12c ) and the secondary flow path (outflow path 12d ) and the extending direction of the valve shaft 7 . On the lower part of the inner wall surface on the downstream side of the valve seat 12a forming the secondary flow path (outflow path 12d), there is provided a downstream side projecting part 12f projecting toward the center line CL side. Here, "protruding toward the center line CL side" means protruding toward the center line CL side than the main wall surface of the inner wall surface of the joint portion 9 (inner wall surface linearly continuous from the flange portions 13 and 14 ). That is, as shown in FIG. 9 , even if the downstream side projecting portion is formed continuously from the valve seat, it projects (from the main wall surface). In the present embodiment, the downstream side projecting portion 12f shown in FIG. 2 is formed by thickening the wall of the lower portion of the joint portion 9 that defines the outflow path 12d, so that the inner wall of the thick portion faces the center line CL side. The composition of the extension. And the protrusion amount of the downstream side protrusion part 12f gradually reduces as it goes to the downstream side.

In other words, the cross-sectional area of the flow path on the downstream side of the valve seat 12a is not locally abruptly changed. In the check valve 1 of the present embodiment, the downstream side projecting portion 12f in the portion forming the outflow path 12d does not protrude further toward the centerline CL side of the flow path than the portion closer to the centerline CL side in the valve seat 12a. on the extension of this part. Then, the downstream side projecting portion 12f protrudes toward the inside of the flow path so as to define the downstream side outer periphery of the annular groove 12h, and then gradually expands toward the downstream side surface side toward the outer periphery side.

For example, in the check valve shown in FIG. 2 and the like of US Patent Application Publication No. 2005/0062000, the cross-sectional area of the flow path on the downstream side of the valve seat is rapidly enlarged. Therefore, a vortex is generated due to the difference in the dynamic pressure of the fluid flowing into the enlarged portion on the downstream side.

In the present embodiment, the cross-sectional area of the flow path in the vicinity of the valve seat 12a of the outflow path 12d is fixed or gradually changed as it goes to the downstream side, thereby preventing the flow path cross-sectional area from rapidly increasing on the secondary side beyond the valve seat 12a. eddy to expand.

In addition, on the upper part of the inner wall surface which forms the primary flow path (inflow path 12c ) on the upstream side rather than the valve seat 12a, there is provided an upstream side projecting portion 12i projecting toward the center line side.

More specifically, the upstream side projecting portion 12i projects obliquely downward toward the downstream side.

And the protrusion amount of the upstream side protrusion part 12i gradually increases toward a downstream side.

For example, in the check valve shown in FIG. 2 of US Patent Application Publication No. 2005/0062000, etc., the upstream protrusion 12i of this embodiment is not provided on the upstream side of the valve seat, so the primary flow path Facing diagonally upwards. Therefore, the fluid flowing through the opening of the valve body to the downstream side largely meanders.

On the other hand, in the present embodiment, a part of the fluid flowing in from the inflow path 12c abuts on the upstream extension portion 12i, whereby the upstream extension portion 12i can form a fluid that faces obliquely downward. Therefore, in order to push up the valve body 6 using the opening of the valve seat 12a portion, the fluid that must be inclined upward can flow straightly through the inflow path 12c and the outflow path 12d, thereby suppressing pressure loss.

The upstream side projecting portion 12i does not project to the center line CL. For example, in the longitudinal section shown in FIG. 3, the upstream side extension part 12i of this embodiment only protrudes from the upper wall surface by 1/3 (including approximately 1/3) of the width of the flow path on the inflow side.

According to the above-described configuration, as shown in FIGS. 3 to 5 , a part of the fluid can be easily made to flow linearly along the center line CL from the inflow path 12c, and the pressure loss can be reduced.

(about moving body) The moving body 2 moves back and forth inside the valve box 12, and between the primary flow path and the secondary flow path, makes the valve body 6 approach and separate from the valve seat 12a, thereby adjusting the opening amount of the valve body 6 according to the flow rate and preventing countercurrent. The movable body 2 is mainly composed of a valve shaft 7 extending in the reciprocating direction, a valve body 6 provided on the lower end of the valve shaft 7, and a valve body 6 attached to the valve seat 12a in a closed state the water stop (liner 8).

As shown in FIG. 3 , the valve shaft 7 is housed in a guide cylinder 4 to be described later, so that the movable body 2 is not swung in a direction perpendicular to the axial direction of the valve shaft 7 , and is used to reciprocate the movable body 2 mover. The valve shaft 7 is formed in a rod shape and extends continuously from the central portion of the upper surface of the valve body 6 .

The valve body 6 and the valve shaft 7 are formed of stainless steel, but may also be formed of a corrosion-resistant synthetic resin material such as polyvinyl chloride. In the closed state shown in FIG. 2 and the open state shown in FIG. 3 , the spring body 20 installed around the valve shaft 7 elastically biases the upper surface of the valve body 6 (valve body upper part 6 b ).

The valve body 6 includes a valve body lower part 6a and a valve body upper part 6b and is configured. The upper portion 6b of the valve body extends in a direction intersecting with the flow path direction of the inflow path 12c and the outflow path 12d and the extending direction of the valve shaft 7 and the valve box 12 . The upper part 6b of the valve body has a flange 6c which is more radially expanded with the valve shaft 7 as the center than the lower part 6a of the valve body. In the present embodiment, the end portion of the valve body upper portion 6b itself is the flange 6c.

The lower end of the flange 6c is located further below the center line CL in the closed state shown in FIG. 2 , and is moved to a position above the center line CL at any position in the open state shown in FIG. 3 .

According to the above configuration, when the self-closing state becomes the open state at any position, the flange 6c moves to a position higher than the center line CL, thereby increasing the amount of fluid flowing in a straight line.

In the present embodiment, the lower end portion of the gasket 8 to be described later is positioned further below than the lower end portion of the flange 6c.

However, the lower end of the flange 6c may be located further below the lower end of the gasket 8 by increasing the diameter of the flange 6c relative to the gasket 8 or making the valve box 12 more inclined. .

In this case, if the lower end of the flange 6c is moved to a position higher than the center line CL at any position in the open state, the lower end of the gasket 8 is also moved to a position higher than the center line CL. position, and the amount of fluid flowing in a straight line in the check valve 1 can be increased.

In addition, the upper part 6b of the valve body has the following function: when the movable body 2 reciprocates, the lower end side of the movable body 2 does not shake in the direction perpendicular to the axial direction of the valve shaft 7, and the inner part of the valve box 12 The wall 12b is slidably connected to guide the movement of the movable body 2 .

That is, when the valve body 6 is opened, the end portion on the inflow path 12c side of the valve body upper portion 6b is disposed so as to be slidable with the inner wall 12b of the valve box 12 .

The inner wall 12b of the valve box 12 to which the upper part 6b of the valve body is slid is not limited to be flat, and a rib-shaped one with a guide rib 12g protruding from the periphery is also included in a part of the inner wall 12b.

In this embodiment, the upper part 6b of the valve body is arranged so as to be slidable with the four guide ribs 12g which protrude toward the inside of the valve box 12 and extend in the longitudinal direction of the valve box 12 .

According to the above configuration, by arranging the end of the valve body upper part 6b on the inflow path 12c side to be slidable with the inner wall 12b of the valve box 12, the valve box 12 can suppress vibration of the valve body upper part 6b.

In addition, the valve body upper part 6b has a function as a gasket, which supports the gasket 8 evenly in the surface direction between the valve body lower part 6a and the valve body lower part 6a by being pressed into the upper surface from the nut 11 . In the center of the upper part 6b of the valve body, an insertion hole 6g through which the valve shaft 7 is inserted is formed in the thickness direction.

The valve body lower part 6a is provided with the planar upper surface which continuously forms the valve shaft 7 in the center part, and the other surface which is formed in the partial spherical shape.

More specifically, the valve body lower portion 6a has a partial spherical surface on the outer surface on the side facing the flow path. In particular, as shown in FIG. 4, the partial spherical surface of the lower part 6a of the valve body is arranged at a position where the fluid flowing straight in the flow path direction from the inflow path 12c abuts.

The fluid flowing in from the inflow path 12c abuts on the valve body 6 (the lower part 6a of the valve body), and pushes the movable body 2 (the valve body 6) upward so as to move away from the valve seat 12a, and the fluid surface is in contact with the lower part 6a of the valve body. The partial spherical side contact surface flows in the check valve 1 . Therefore, the valve body 6 is less likely to hinder the flow of the fluid, and the decrease in the velocity of the fluid can be suppressed. Therefore, the fluid can be circulated with low head loss (frictional resistance).

The lower part of the valve shaft 7, the lower part 6a of the valve body, and the upper part 6b of the valve body are constituted by assembling independent members.

However, it is not limited to this configuration, as long as the gasket 8 can be made flexible, and by making If the gasket 8 is deformed and attached to the valve body 6, the valve body lower part 6a and the valve body upper part 6b need not be constituted by separate members.

The water stopper (gasket 8) is a member that is pressed by the valve body 6 (the upper part of the valve body 6b) and the valve seat 12a to stop the water on the valve seat 12a in the closed state of the check valve 1, and is arranged on the lower part 6a of the valve body Between the valve body upper part 6b (flange 6c). The spacer 8 has a central hole penetrating in the thickness direction and is formed in a ring shape. Specifically, the gasket 8 is connected to the central hole of the gasket 8 for the valve shaft 7 to pass through, and is arranged between the lower part 6a of the valve body and the upper part 6b of the valve body.

When a part of the pad 8 is in the closed state shown in FIG. 2, it is located further below the center line CL, and at any position in the open state shown in FIG. 3, the entire pad 8 is moved to the center line CL. more above.

According to the above configuration, when the self-closing state is changed to an open state at any position, the gasket 8 can be prevented from hindering the flow through the center line CL, and the pressure loss can be reduced.

The above-mentioned "arbitrary position of the open state" is preferably the position when the valve body 6 is in the open state at the standard flow rate.

For example, this position is a position in a state in which 70% of the check valve 1 (valve body 6 ) (70% of the maximum opening of the check valve 1 ) is opened relative to the fully open state.

According to such a configuration, it can be suppressed that the gasket 8 blocks the fluid in the vicinity of the center line CL where the flow is the fastest at a standard flow rate, and the pressure loss can be suppressed from increasing.

The check valve 1 further includes a nut 11 that presses the valve body upper part 6b from the other side (upper side) toward the valve body lower part 6a side. The nut 11 has an elastically deformable friction ring and has a tightening function. In addition, the nut 11 is not limited to a friction ring as long as it has a tightening function. For example, a structure including a double nut (not shown) may be used. Specifically, it is only required that one of the double nuts has a wedge-shaped protrusion, and the other nut has a corresponding shape to form a groove to receive the protrusion.

(About the guide cover) As shown in FIG. 2 , the guide cover 3 is detachably attached to the valve box 12 , and seals the upper side of the valve body 6 and guides the reciprocating movement of the movable body 2 . The guide cover 3 is composed of a guide cylinder 4 and a disk-shaped top plate portion 5 integrally formed on the upper end of the guide cylinder 4 . The top plate portion 5 has a ferrule flange 5e shown in FIG. 2 at the end edge, and a gasket 16 is sandwiched between the ferrule flange 5e and the ferrule flange 12e formed on the upper end of the valve box 12, Removably fastened by a ferrule joint (not shown).

At the approximate center of the top plate portion 5, the guide cylinder 4 is erected obliquely downward (on the primary flow path side). The guide cylinder 4 guides the sliding of the valve shaft 7 of the valve body 6 on its inner surface, extends from the top plate portion 5 to the valve seat 12a side, that is, obliquely downward, and guides the valve body 6 to be connected to the valve body in a reciprocating manner. 6 of the valve shaft 7.

<Dynamic pressure distribution> Next, the dynamic pressure distribution assuming fluid analysis of the fluid (water) flowing in the check valve 1 will be described with reference to FIG. 5 . 5 is an explanatory diagram showing the dynamic pressure distribution in the flow path when fluid flows through the check valve 1 of the first embodiment, that is, it shows that the flow velocity on the inflow side is about 4 m/s and the flow rate is about 4800 L/min (valve A diagram of the fluid flow and dynamic pressure distribution when the opening is 50%). In addition, in FIG. 5 , the darker the color (the higher the dot density), the higher the dynamic pressure.

As shown in FIG. 5 , before and after the fluid passes between the valve seat 12 a and the valve body 6 , the main flow with higher dynamic pressure (dynamic pressure DP1 ) does not face the bottom side of the flow path, but extends generally parallel to the flow path direction. In addition, it is understood that the eddy current W caused by the main flow does not penetrate to the center side of the flow path, and its range is small. Therefore, the diffusion and separation of the fluid are less, the loss head is about 2.8m, and the pressure loss can be kept small.

<<Second Embodiment>>

Next, the check valve 1X of the second embodiment will be described mainly with reference to FIG. 6 . The check valve 1X is installed in a pipe having a larger diameter than the check valve 1 . FIG. 6 is a longitudinal cross-sectional view showing an open state of the check valve 1X of the second embodiment.

In addition, in the check valve 1X, the description of the structure common to the check valve 1 of 1st Embodiment is abbreviate|omitted.

The check valve 1X of the present embodiment includes a movable body 32 . The movable body 32 includes a valve shaft 37 and a valve body 36 integrally formed with the lower end of the valve shaft 37 . The valve body 36 includes a valve body lower portion 36a and a valve body upper portion 36b and is configured.

The valve body lower portion 36a is formed in a partial spherical shape having a hollow portion 36d.

More specifically, the valve body lower portion 36a has a partial spherical surface on the outer surface on the side facing the flow path, and has a shape that is symmetrical along the axial direction of the valve shaft 37, and is disposed in the check valve 1X.

According to the above configuration, the valve body lower portion 36a has the hollow portion 36d, so that the valve body lower portion 36a has a good response to changes in the flow rate and is formed into a partial spherical shape, thereby suppressing the flow resistance and reducing the pressure loss.

The valve body lower part 36a is provided with an annular small-diameter part 36h at a portion in contact with the valve body upper part 36b.

An opening 36i connected to the hollow portion 36d is formed in the small diameter portion 36h. The packing 8 is fitted in the recess 36e formed between the outer peripheral side of the small diameter part 36h and the valve body upper part 36b and the valve body lower part 36a. More specifically, the recess 36e is formed by overlapping the lower surface of the valve body upper part 36b and the part of the upper surface of the valve body lower part 36a which is continuous from the peripheral surface of the small diameter part 36h and formed into an L-shaped cross section. .

In the direction perpendicular to the axial center direction of the valve shaft 37, the maximum diameter of the hollow portion 36d is formed to be larger than the opening 36i. By forming the hollow part 36d in the valve body lower part 36a, the weight of the movable body 32 can be reduced. The valve body 36 including the hollow portion 36d is formed mirror-symmetrically with respect to an imaginary plane including the flow path direction and the axial center direction of the valve shaft 37 in the plane. By forming in this way, when the fluid flows in the direction of the flow path, the valve body 36 can be suppressed from shaking due to the force applied to the valve body 36 from the fluid, and the flow of the fluid can be stabilized.

<<Third Embodiment>> Next, the check valve 1Y of the third embodiment will be described mainly with reference to FIGS. 7 and 8 . FIG. 7 is a vertical cross-sectional view showing the open state of the check valve 1Y according to the third embodiment, and FIG. 8 is a perspective view showing the moving body 52 according to the third embodiment. In addition, in the check valve 1Y, the description of the configuration common to the check valve 1 of the first embodiment or the check valve 1X of the second embodiment is omitted. For example, since the guide cover of the check valve 1Y is the same as that of the first embodiment and the second embodiment except for the size, the description thereof is omitted.

The check valve 1Y mainly includes a movable body 52 and a valve box 62 that accommodates the movable body 52 . The movable body 52 is mainly composed of a round rod-shaped valve shaft 57 extending in the reciprocating direction, a valve body 56 provided on the lower end of the valve shaft 57 , and a gasket 8 mounted on the valve body 56 . The valve body 56 is composed of a valve body lower portion 56a integrally formed at an end portion on the lower side (primary flow path side) of the valve shaft 57, and a valve body upper portion 56b attached to the valve body lower portion 56a.

The valve body lower portion 56a has a partially spherical outer surface, and has two flat portions 56f standing parallel to and extending parallel to each other along the reciprocating direction of the movable body 52 at a position offset by 180 degrees with the axis direction as the center. By providing these two plane parts 56f, the area of the edge part 56k mentioned later can be enlarged compared with the thing without the plane part 56f. Therefore, the load of the fluid that pushes up the valve body 56 can be made larger than that of pushing the fluid into the spherical portion, so that the fluid can start to flow smoothly.

In addition, a female screw portion is formed in the center portion of the valve body lower portion 56a, and the male screw portion formed on the lower end portion of the valve shaft 57 is screwed. In the initial state, as shown in FIG. 7 , even if the flat surface portion 56f is inclined with respect to the direction of the flow path, when the fluid flows into the check valve 1Y and pushes the movable body 52 upward to flow to the downstream side, the valve body 56 also flows. Rotate together with the valve shaft. In other words, the plane portion 56f receives the dynamic pressure of the fluid, and automatically adjusts the posture of the movable body 52 in the direction parallel to the flow path direction. In this way, the pressure loss of the valve body 56 is reduced.

The lower part 56a of the valve body has: an opposing part 56j formed at a position partially facing the small diameter part 56h of the upper part 56b of the valve body; In addition, the gasket 8 is sandwiched between the valve body lower part 56a and the valve body upper part 56b.

Moreover, the hollow part 56d and the opening 56i connected to the hollow part 56d and located in the position which opposes the valve-body upper part 56b are formed in the valve body lower part 56a. The opposing portion 56j is the one that defines the upper portion on the radially outer side of the hollow portion 56d in the valve body lower portion 56a. The above-mentioned opening 56i is formed in the center part of the radial direction of the opposing part 56j. The edge portion 56k has a function of sandwiching the gasket 8 with the valve body upper portion 56b, and is formed thicker than the opposing portion 56j. In this way, by forming the edge portion 56k to be thicker than the opposing portion 56j, the volume of the hollow portion 56d is enlarged, and the repeated opening and closing of the valve body 56 can be stably maintained from the valve provided in the valve box 62. The gasket 8 for the shock load of the valve seat 62a.

As shown in FIG. 8 , a spring seat surface 56e recessed downward (primary flow path side) is formed on the radially inner side of the other side surface (upper surface) of the upper portion 56b of the valve body than the radially outer portion.

<<The fourth embodiment>> Next, the check valve 1Z of the fourth embodiment will be described mainly with reference to FIG. 9 . FIG. 9 is a schematic longitudinal sectional view showing the closed state of the check valve 1Z of the fourth embodiment. In addition, in FIG. 9, the spring body 20 is abbreviate|omitted and shown.

The valve shaft 77 included in the check valve 1Z of the present embodiment has a hollow space 77a and is formed in a cylindrical shape. The valve shaft 77 is guided reciprocally by the guide rod 74 inserted into the hollow space 77 a in the valve shaft 77 . That is, the inner surface of the valve shaft 77 facing the hollow space 77a slides against the outer surface of the guide rod 74, and is guided by the guide rod 74 in the reciprocating direction. According to the above configuration, the valve shaft 77 is guided by the guide rod 74, whereby the valve body 76 connected to the valve shaft 77 is guided in the reciprocating direction.

In particular, in the valve body 76 of the present embodiment, a hollow portion 76d continuous with the hollow space 77a of the valve shaft 77 is formed. According to the above configuration, by continuously forming the hollow space 77a of the valve shaft 77 and the hollow portion 76d of the valve body 76, the movable body 72 including the valve shaft 77 and the valve body 76 can be reduced in weight, and the responsiveness to flow changes can be improved.

The embodiments have been described above with reference to the drawings, but these are examples of the present invention, and various configurations other than those described above may be employed. The various constituent elements of the check valve and the reciprocating member constituting the check valve of the present invention do not necessarily exist independently. It is permissible to form a plurality of constituent elements into one member, one constituent element to be formed of a plurality of members, a certain constituent element to be a part of other constituent elements, and a part of a certain constituent element to overlap a part of other constituent elements, etc.

The present embodiment includes the following technical ideas. (1) A check valve, which is characterized in that it is a straight pipe joint type oblique lift type check valve, and has: valve seat; A moving body, which can move linearly reciprocatingly in the closed state in close contact with the valve seat and in the open state in which it is separated from the valve seat; a primary flow path, which is located on the upstream side of the moving body; and a secondary flow path located on the downstream side of the moving body; and The above-mentioned moving body includes: a valve body supported by said valve seat in said closed state; and a valve shaft extending from the valve body; and The said valve seat is formed so that it may cross the said center line in the cross section which has the center line of the connecting flow path which includes the said primary flow path and the said secondary flow path and extends linearly. (2) The check valve according to (1), wherein the movable body further includes: a water stop part that abuts on the valve seat in the closed state; and A part of the water stopper is positioned below the center line in the closed state, and the entire water stopper is moved to a position above the center line when the entire water stopper is at any position in the open state. (3) The check valve according to (1) or (2), wherein the valve body includes a lower portion of the valve body and an upper portion of the valve body, and The upper part of the valve body has a flange that is more radially expanded with the valve shaft as the center than the lower part of the valve body, The lower end portion of the flange is positioned below the centerline in the closed state, and is moved to a position above the centerline in any position in the open state. (4) The check valve according to (2) or (3), wherein the arbitrary position of the above-mentioned open state means a position relative to 70% of the fully open state. (5) The check valve according to (3), wherein the lower portion of the valve body is formed in a partial spherical shape having a hollow portion. (6) The check valve according to any one of (1) to (5), wherein a lower portion of the inner wall surface on the downstream side of the valve seat forming the secondary flow path is provided with a valve toward the center line. the downstream side extension of the side extension, and The protruding amount of the downstream-side protruding portion gradually decreases toward the downstream side. (7) The check valve according to any one of (1) to (6), wherein on the upper part of the inner wall surface on the upstream side of the valve seat forming the primary flow path, there is provided a valve toward the center line side. the protruding upstream side protruding portion, and The protruding amount of the upstream protruding portion gradually increases toward the downstream side. (8) The check valve according to (7), wherein the upstream side projecting portion does not project to the center line. (9) The check valve according to any one of (1) to (8), further comprising: a valve box that accommodates at least a part of the movable body on the opposite side to the valve body; and The valve body is constituted by including a lower part of the valve body and an upper part of the valve body, The valve shaft and the valve box extend obliquely toward the secondary flow path in a direction intersecting with the flow path directions of the primary flow path and the secondary flow path, The valve seat and the upper part of the valve body extend in a direction intersecting with the flow path direction of the primary flow path and the secondary flow path and the extension direction of the valve shaft and the valve box, When the valve body is opened, the end portion of the upper portion of the valve body on the side of the primary flow path is arranged to be slidably connected to the inner wall of the valve box. (10) The check valve according to any one of (1) to (9), wherein the valve shaft has a hollow space and is formed in a cylindrical shape, and It is guided reciprocally by a guide rod inserted into the hollow space in the valve shaft. (11) The check valve according to (10), wherein a hollow portion is formed in the valve body to be continuous with the hollow space of the valve shaft.

1: Check valve 1X: Check valve 1Y: Check valve 1Z: Check valve 2: moving body 3: Guide cover (cover) 4: Guide cylinder 5: Top plate 5e: Ferrule flange 6: valve body 6a: The lower part of the valve body 6b: Upper part of valve body 6c: Flange 6g: Insertion hole 7: Valve shaft 8: Pad (water stop) 9: Connector 11: Nut 12: Valve box 12a: valve seat 12b: inner wall 12c: Inflow path (primary flow path) 12d: Outflow path (secondary flow path) 12e: Ferrule flange 12f: Downstream side protrusion 12g: guide rib 12h: annular groove 12i: Upstream side protrusion 13: Flange 14: Flange part 15: Mounting table 15a: Decompression port 16: Gasket 20: spring body 32: Moving body 36: valve body 36a: The lower part of the valve body 36b: Upper part of valve body 36d: hollow part 36e: Sag 36h: Small diameter section 36i: Opening 37: valve shaft 52: Moving body 56: valve body 56a: The lower part of the valve body 56b: Upper part of valve body 56d: hollow part 56e: Spring seat surface 56f: Flat part 56h: Small diameter section 56i: Opening 56j: Opposite department 56k: Edge 57: valve shaft 62: valve box 62a: valve seat 72: Moving body 73: Guide cover 74: Guide rod 76: valve body 76a: The lower part of the valve body 76b: Upper part of valve body 76d: hollow part 77: Valve shaft 77a: Hollow space CL: Centerline DP1: Dynamic pressure W: Eddy current

FIG. 1 is a perspective view showing the external appearance of the check valve according to the first embodiment of the present invention. Fig. 2 is a longitudinal sectional view showing the closed state of the check valve of the first embodiment. Fig. 3 is a longitudinal sectional view showing an open state of the check valve of the first embodiment. Fig. 4 is a side view of the check valve of the first embodiment viewed from the inflow path side. FIG. 5 is an explanatory diagram showing the dynamic pressure distribution in the flow path when the fluid flows into the check valve of the first embodiment. Fig. 6 is a longitudinal sectional view showing an open state of the check valve of the second embodiment. Fig. 7 is a longitudinal sectional view showing an open state of the check valve of the third embodiment. Fig. 8 is a perspective view showing a moving body according to the third embodiment. Fig. 9 is a schematic longitudinal sectional view showing the closed state of the check valve of the fourth embodiment.

1: Check valve

2: moving body

3: Guide cover (cover)

4: Guide cylinder

5: Top plate

5e: Ferrule flange

6: valve body

6a: The lower part of the valve body

6b: Upper part of valve body

6c: Flange

6g: Insertion hole

7: Valve shaft

8: Pad (water stop)

9: Connector

11: Nut

12: Valve box

12a: valve seat

12b: inner wall

12c: Inflow path (primary flow path)

12d: Outflow path (secondary flow path)

12e: Ferrule flange

12f: Downstream side protrusion

12g: guide rib

12h: annular groove

12i: Upstream side protrusion

13: Flange

14: Flange part

15a: Decompression port

16: Gasket

20: spring body

CL: Centerline

Claims (9)

A check valve is characterized in that it is a straight pipe joint type oblique lift type, and is provided with: a valve seat; The primary flow path, which is located on the upstream side of the movable body; and the secondary flow path, which is located on the downstream side of the movable body; and the movable body includes: a valve body, which is located in the The valve seat is supported by the valve seat in the closed state; and a valve shaft extends from the valve body; and the valve seat is formed so as to have a center of a connecting flow path including the primary flow path and the secondary flow path extending linearly In the cross section of the line, it crosses the center line; the valve body includes a lower part of the valve body and an upper part of the valve body, and the upper part of the valve body has a flange that is more radially expanded with the valve shaft as the center than the lower part of the valve body; When the lower end of the flange is in the closed state, it is located below the center line, and at any position in the open state, it moves to a position above the center line; and the lower part of the valve body is formed to have a hollow Partially spherical. A check valve, characterized in that it is a straight pipe joint type oblique lift type, and has: A valve seat; a moving body, which can reciprocate linearly in a closed state in close contact with the valve seat and an open state in which it is separated from the valve seat; a primary flow path, which is located on the upstream side of the movable body; and a secondary flow path a flow path located on the downstream side of the movable body; and the movable body includes: a valve body supported by the valve seat in the closed state; and a valve shaft extending from the valve body; and the valve seat It is formed so as to cross the center line in a cross section including the center line of the connecting flow path extending linearly including the primary flow path and the secondary flow path; and the valve body is screwed with the valve shaft at the center portion; and A hollow portion is provided on the radially outer side of the portion screwed with the valve shaft. The check valve according to claim 1 or 2, wherein the moving body further has: a water stop part abutting on the valve seat in the closed state; and a part of the water stop part is located at a relatively high position when the water stop part is in the closed state. The said center line is further downward, and the whole said water stop part moves to the position more upward than the said center line in any position of the said open state. The check valve of claim 2, wherein the valve body comprises a lower part of the valve body and an upper part of the valve body, and the upper part of the valve body has a flange that is more radially expanded with the valve shaft as the center than the lower part of the valve body; The lower end portion of the flange is positioned below the center line in the closed state, and is moved to a position above the center line at any position in the open state. The check valve as claimed in claim 3, wherein any position of the above-mentioned open state means a position of 70% relative to the fully open state. The check valve of claim 3, wherein the lower portion of the valve body is formed in a partial spherical shape with a hollow portion. The check valve according to any one of Claims 1, 2, 3, or 5, wherein a lower portion of the inner wall surface on the downstream side of the valve seat forming the secondary flow path is provided with a valve extending toward the centerline side. The downstream side protruding portion comes out, and the protruding amount of the downstream side protruding portion gradually decreases toward the downstream side. The check valve according to any one of claims 1, 2, 3, or 5, wherein on the upper portion of the inner wall surface that forms the primary flow path on the upstream side of the valve seat, there is provided a valve protruding toward the centerline side. The upstream side protruding portion, and the protruding amount of the upstream side protruding portion gradually increases toward the downstream side. The check valve according to any one of claims 1, 2, 3, or 5, further comprising: a valve box that accommodates at least a part of the movable body on the opposite side to the valve body; and the valve body includes a valve The lower part of the body and the upper part of the valve body are constituted, and the valve shaft and the valve box are in the flow path relative to the primary flow path and the secondary flow path. The direction intersecting the direction extends obliquely toward the secondary flow path side, and the valve seat and the upper part of the valve body extend along the flow path direction relative to the primary flow path and the secondary flow path, as well as the valve shaft and the valve box. The direction extends in a direction intersecting, and when the valve body is open, the end portion of the upper portion of the valve body on the side of the primary flow path is arranged to be slidably connected to the inner wall of the valve box.

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