TW202130933A - Check valve which can reduce the pressure loss caused by fluid flow - Google Patents

Abstract

The check valve (1) is an oblique lifting type and a straight tube joint type. The check valve (1) comprises a valve seat (12a); a movable body (2) capable of moving linearly back and forth in the closed state that it is tightly connected to the valve seat (12a) and the open state that it moves away from the valve seat (12a); a primary flow path (inflow path (12c)) located more upstream than the movable body (2); and a secondary flow path (outflow path (12d)) located more downstream than the mobile body (2) . The movable 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 to cross the center line (CL) in a cross-sectional view having a center line (CL) of a connecting flow path extending linearly and including the primary flow path (inflow path 12c) and the secondary flow path (outflow path 12d). The mobile body has a water stop abutting against the valve seat in the closed state. One part of the water stop is located further below the center line in the closed state. The water stop at any position in the open state is moved to a position higher than the center line. The valve body includes the lower part of the valve body and the upper part of the valve body. The lower part of the valve body is formed into a partial spherical shape with a hollow part. A downstream protruding portion protruding toward the center line is provided at the lower part of the inner wall surface forming the secondary flow path and located more upstream than the valve seat. Thus, the check valve of the present invention can reduce the pressure loss caused by fluid flow.

Description

Check valve

The present invention relates to the structure of a bottom valve, that is, to an ascending check valve of a descending type.

There is known a check valve that allows the fluid in the pipe to pass in one direction. There are many types of check valves classified according to the behavior of the valve body. Among them, the lift check valve is a structure in which the valve body reciprocates linearly in the direction of approaching or leaving relative to the valve seat, so it can perform a rapid closing action. In particular, the Smolensky type lift check valve is equipped with a spring body, which can better suppress the occurrence of water hammer.

Patent Document 1 discloses a straight-pipe joint type diagonal lift type, that is, a Y-shaped check valve. The check valve includes a valve body and a spring body that energizes the valve body toward the valve seat side in a direction of downward pressure. The valve body of the check valve is opened by the fluid flowing in the forward direction rising obliquely upward with respect to the linear direction connecting the inlet and the outlet. If the fluid wants to flow in the reverse direction, it will be pressed down by the spring body. The valve body moves obliquely downward and becomes a closed state. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Specification of U.S. Patent Application Publication No. 2005/0062000

[The problem to be solved by the invention]

As described above, 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 inlet and the outlet, the fluid pressure in the flow path Prone to unevenness. Therefore, a vortex may be generated in a part of the flow path, which may increase the pressure loss.

The present invention has been accomplished in view of the above-mentioned problems, and is to provide a check valve that can reduce the pressure loss generated when the fluid flows. [Technical means to solve the problem]

According to the present invention, there is provided a non-return valve characterized in that it is a straight pipe joint type diagonal lift type, and has: a valve seat; It can reciprocate linearly in the open state; the primary flow path is located more upstream than the moving body; and the secondary flow path is located more downstream than the moving body; the moving body includes: the valve body, which is in the closed state The lower part is supported by the valve seat; and the valve shaft, which extends from the valve body; and the valve seat is formed so as to cross in a section including the center line of the connecting flow path that connects the connecting objects, that is, the connecting parts connected to other pipe bodies. Centerline. [Effects of Invention]

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

Hereinafter, the embodiments of the present invention will be described using drawings. In addition, the embodiment described below is only an example for easy understanding of the present invention, and does not limit the present invention. That is, the shape, size, arrangement, etc. of the components described below can of course be changed and improved without departing from the spirit of the present invention, and their equivalents are also included in the present invention. In addition, in all the drawings, the same symbols are attached to the same constituent elements, and repeated descriptions are appropriately omitted.

In this specification, there are cases where the up and down direction is specified, but this is set for the convenience of explaining the relative relationship of the constituent elements, and does not specify the direction when the product of the present invention is manufactured or used. Ideally, the vertical upward direction is the upward direction and the vertical downward direction is the downward direction, but it does not limit the installation state of the check valve. The "up and down" of the check valve is to set the direction of the moving body in the direction perpendicular to the flow path connected with the check valve, that is, the direction of the connecting flow path, to the upward direction, and the direction approaching the valve body to the downward direction. direction.

＜＜The first embodiment＞＞ <Overview of the check valve of this embodiment> First, the outline of the check valve 1 of this embodiment will be described mainly with reference to FIGS. 1 and 2. Fig. 1 is a perspective view showing the appearance of the check valve 1 of the first embodiment of the present invention, and Fig. 2 is a longitudinal sectional view showing the closed state of the check valve 1 of the first embodiment. In addition, the section including the axis of the valve shaft 7 is referred to as a longitudinal section. As shown in Figs. 1 and 2, the check valve 1 of the present embodiment is a straight pipe joint type diagonal 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 tightly connected to the valve seat 12a and an open state away from the valve seat 12a; a primary flow path (inflow path 12c), It is located on the upstream side of the moving body 2; and the secondary flow path (outflow path 12d) is located on the downstream side of the moving body 2. The moving body 2 includes: a valve body 6 which is supported by a valve seat in the 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 that includes a primary flow path (inflow path 12c) and a secondary flow path (outflow path 12d) and extends straight. .

"Straight pipe joint type" refers to pipe joints that are connected to other piping, that is, those that have an outflow direction on the extension of the inflow direction. The "oblique lift type" refers to a type in which the valve body is tilted relative to the straight line connecting the inflow direction and the outflow direction, that is, the valve body is lifted by the fluid. In the present embodiment, the connecting portions to be connected to other pipes are flange portions 13, 14, that is, flanges, but it is not limited to such a structure, as long as it is connected to other pipes. For example, it can also be a part of a ferrule connection or a part of a threaded connection. Regarding "the valve seat 12a crosses the center line CL", in other words, it means that the center line CL passes through the opening defined by the valve seat 12a, and also means that a part of the valve seat 12a is located below the center line CL, and the other part is located more The center line CL is further above. In addition, the valve seat 12a may be formed so as to cross the center line in any one of the arbitrary cross sections including the center line CL.

According to the above configuration, by forming the valve seat 12a so as to cross the center line CL of the connecting flow path, it is easier for the fluid to flow straight when the valve body 6 is opened, compared with the one that does not cross the center line CL and is formed to one side. Suppress the generation of turbulence (vortex). Therefore, the pressure loss of the check valve 1 generated when the fluid flows can be reduced.

＜The composition of each department＞ Next, the structure 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. Fig. 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 side of the inflow path 12c, and Fig. 5 shows the flow of fluid to the first embodiment. 1. An explanatory diagram of the dynamic pressure distribution in the flow path of the check valve 1 of the embodiment. In addition, FIG. 5 omits the upper part 6b of the valve body, the gasket 8, the valve box 12, the spring body 20, etc., and simplifies the other structure of the check valve 1, and mainly illustrates the dynamic pressure distribution.

As described above, the check valve 1 of this embodiment is a straight pipe joint type diagonal lift type, that is, the movable body 2 including the valve body 6 reciprocates linearly in the direction of approaching or leaving with respect to the valve seat 12a. In particular, the check valve 1 includes an inflow path 12c and an outflow path 12d on the same center line CL. The moving body 2 is one that reciprocates in a direction inclined obliquely with respect to the center line CL, specifically, a direction inclined to the outflow path 12d side. The reverse flow restricted by the check valve 1 is liquid such as water or 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 12a. The check valve 1 of this embodiment is a so-called slow closing type. Therefore, with the power 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 quickly closes the flow path. . Thereby, the check valve 1 can prevent backflow and suppress the occurrence of water hammer, and improve the certainty (water stop) of the closed state. However, the check valve 1 is not limited to a 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 to the valve seat 12a only by the weight of the movable body 2, or by the weight of the movable body 2 applied from the damping mechanism, the valve shaft 7 and the load of 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 reliability of water stop, thereby preventing water falling in the pumping pipe.

The check valve 1 is set in the flow path of liquid or gas (fluid), when the differential pressure between the primary side and the secondary side of the valve body 6 exceeds a certain minimum operating pressure (peak pressure), as shown in Figure 3, the valve body 6 is in the 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 lower than 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, as for the fluid, if a desired amount of flow area can be ensured, the valve body 6 does not need to be in the fully opened 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 on the side opposite to the valve body 6, a guide cap 3 that has a guide tube 4 and is attached to the valve box 12, and is installed on the valve body 6. Between the guide cover 3 and the spring body 20 energizing the valve body 6 toward the primary flow path. That is, the check valve 1 in this book refers to the entire pipe joint including the valve body 6 and the like inside.

(Regarding valve box and joint part) The valve box 12 of the present embodiment is formed integrally with the substantially linearly extending joint portion 9 forming the inflow path 12c and the outflow path 12d by a dewaxing method, and branches and crosses from the joint portion 9. The valve box 12 and the valve shaft 7 described later extend obliquely toward the outflow path 12d in a direction that intersects the flow path direction of the primary flow path (inflow path 12c) and the secondary flow path (outflow path 12d).

In the joint portion 9, a flange portion 13 and a flange portion 14 are integrally formed on the upstream side (primary side) and the downstream side (secondary side), respectively, and the piping (not shown) is tightened with bolts, nuts, etc. Fix it with a fixture (not shown). On the side of the inflow path 12c of the valve box 12 (joint portion 9) of this embodiment, as shown in FIG. Installation table 15. A pressure reducing port 15a penetrating to the inside of the primary flow path side of the valve box 12 is formed in the mounting base 15.

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

(About valve seat) As shown in FIG. 2 and the above, the valve seat 12a is formed in a cross-sectional view including the center line CL of the connection flow path connecting the connection parts (flange portions 13, 14) connected to the connection object, that is, other pipe bodies, and spans Centerline CL. In addition, the valve seat 12a is formed such that a part of the inner wall of the valve box 12 protrudes toward the flow path over the entire circumference (the inflow path 12c is narrowed). The seat surface of the valve seat 12a is formed in a ring shape and extends vertically along the reciprocating direction of the moving body 2. That is, the valve seat 12a extends in a direction intersecting the direction of the flow path with respect to 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 by being recessed toward the side of the inflow path 12c (the side away from the movable body 2) with respect to the seating surface of the valve seat 12a. With the annular groove 12h, the area of the valve seat 12a to which the valve body 6 of the movable body 2 abuts is restricted, and the valve body 6 is easily brought into close contact with the valve seat 12a.

The valve seat 12a extends in a direction intersecting 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. At the lower part of the inner wall surface that forms the secondary flow path (outflow path 12d) on the downstream side of the valve seat 12a, a downstream side protrusion 12f is provided that protrudes toward the center line CL side. Here, "extending toward the centerline CL side" means that the main wall surface of the inner wall surface of the joint portion 9 (the inner wall surface linearly continuous from the flange portions 13, 14) extends toward the centerline CL side. That is, as shown in FIG. 9, even if the downstream side extension part is formed continuously from the valve seat, it will extend (autonomous wall surface). In this embodiment, the downstream side extension portion 12f shown in FIG. 2 thickens the inner wall of the thick portion toward the center line CL side by thickening the wall below the joint portion 9 that defines the outflow path 12d The extension of the composition. In addition, the amount of extension of the downstream-side extension portion 12f gradually decreases toward the downstream side.

In other words, the cross-sectional area of the flow path on the downstream side of the valve seat 12a does not change rapidly locally. 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 center line CL side of the flow path than the portion on the valve seat 12a near the center line CL side. And located on the extension of that part. In addition, the downstream side extension portion 12f protrudes toward the inside of the flow path so as to define the downstream outer periphery of the annular groove 12h, and then gently expands toward the downstream side surface toward the outer peripheral surface side.

For example, in the check valve shown in FIG. 2 of the specification of U.S. Patent Application Publication No. 2005/0062000, the cross-sectional area of the flow path on the downstream side of the valve seat is drastically 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 this 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 changes toward the downstream side, thereby suppressing the flow path cross-sectional area on the secondary side that crosses the valve seat 12a. It expands and produces a vortex.

In addition, on the upper portion of the inner wall surface on the upstream side of the valve seat 12a that forms the primary flow path (inflow path 12c), an upstream side extension portion 12i extending toward the centerline side is provided. More specifically, the upstream-side projecting portion 12i projects obliquely downward as it goes to the downstream side. In addition, the amount of extension of the upstream-side extension portion 12i gradually increases toward the downstream side.

For example, in the check valve shown in Fig. 2 of the specification of U.S. Patent Application Publication No. 2005/0062000, the upstream side extension 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 that passes through the opening of the valve body to the downstream side greatly 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 obliquely downward. Therefore, the fluid that must go diagonally upward to push up the valve body 6 by using the opening of the valve seat 12a portion can flow straight through the inflow path 12c and the outflow path 12d, and pressure loss can be suppressed.

The upstream side projecting portion 12i does not project to the center line CL. For example, in the vertical section shown in FIG. 3, the upstream extension 12i of the present embodiment extends from the upper wall surface by only 1/3 (including approximately 1/3) of the width of the flow path on the inflow side. According to the above configuration, as shown in FIG. 4, a part of the fluid can be easily caused to flow in a straight line along the center line CL from the inflow path 12c, and the pressure loss can be reduced.

(About moving objects) The moving body 2 reciprocates inside the valve box 12, and between the primary flow path and the secondary flow path, the valve body 6 is approached and separated from the valve seat 12a, thereby adjusting the opening amount of the valve body 6 according to the flow rate and preventing countercurrent. The moving body 2 is mainly composed of the following: a valve shaft 7 extending in the reciprocating direction, a valve body 6 provided at the lower end of the valve shaft 7, and a valve body 6 attached to the valve seat 12a in the closed state The water stop (liner 8).

As shown in FIG. 3, the valve shaft 7 is stored in the guide cylinder 4 described later, and the movable body 2 is used to reciprocate the movable body 2 in a direction perpendicular to the axial direction of the valve shaft 7 Mover. The valve shaft 7 is formed in a rod shape and continuously extends 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 they 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 urges the upper surface of the valve body 6 (the upper part of the valve body 6b).

The valve body 6 includes a valve body lower portion 6a and a valve body upper portion 6b. The upper portion 6b of the valve body extends in a direction intersecting the direction of the flow path with respect to 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 that expands in the radial direction with the valve shaft 7 as the center rather than the lower part 6a of the valve body. In this embodiment, the end of the upper part 6b of the valve body itself is a flange 6c. When the lower end of the flange 6c is in the closed state shown in FIG. 3, it is located below the center line CL, and at any position in the open state shown in FIG. 2, it moves to a position higher than the center line CL.

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

In this embodiment, the lower end of the gasket 8 described later is located below the lower end of the flange 6c. However, it can also be configured that by increasing the diameter of the flange 6c relative to the gasket 8 or making the valve box 12 more inclined, the lower end of the flange 6c is located below the lower end of the gasket 8. . 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 higher position than the center line CL. Position, and can increase the amount of straight-flowing fluid in the check valve 1.

In addition, the upper part 6b of the valve body has the following function: when the movable body 2 reciprocates, the lower end of the movable body 2 does not shake in the direction perpendicular to the axial direction of the valve shaft 7, and the valve box 12 The wall 12b is slidably contacted to guide the movement of the mobile body 2. That is, when the valve body 6 is opened, the end of the upper portion 6b of the valve body on the side of the inflow path 12c is arranged so as to be slidable in contact 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 slidably connected is not limited to flat ones, and ribs with guide ribs 12g protruding from the periphery are 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 slidably connected to the four guide ribs 12g that protrude toward the inside of the valve box 12 and extend along the longitudinal direction of the valve box 12. According to the above configuration, the end portion of the inflow path 12c side of the upper valve body 6b can be slidably contacted with the inner wall 12b of the valve box 12, and the vibration of the upper valve body 6b can be suppressed by the valve box 12.

In addition, the upper part 6b of the valve body has a function as a gasket, which evenly supports the packing 8 in the surface direction between the lower part 6a of the valve body by being pressed into the upper surface from the nut 11. At 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 through in the thickness direction.

The valve body lower part 6a is provided with a planar upper surface in which the valve shaft 7 is continuously formed in the center part, and another surface formed in a partial spherical shape. More specifically, the lower part 6a of the valve body has a partial spherical surface on the outer surface of the side facing the flow path. In particular, the partial spherical surface of the lower part 6a of the valve body, as shown in FIG. The fluid flowing in from the inflow path 12c abuts on the valve body 6 (the lower part of the valve body 6a), and after pushing the moving body 2 (the valve body 6) upwardly away from the valve seat 12a, the fluid side and the lower part of the valve body 6a The part of the spherical side contacts the side to flow in the check valve 1. Therefore, the valve body 36 is unlikely to obstruct the flow of the fluid, and the reduction in the fluid velocity can be suppressed. Therefore, the fluid can be circulated with a lower head loss (frictional resistance).

The lower part of the valve shaft 7, the lower part of the valve body 6a, and the upper part of the valve body 6b are constituted by assembling independent components. However, it is not limited to this structure. As long as the gasket 8 can be made flexible, and the gasket 8 is deformed and mounted on the valve body 6, it is not necessary to form the valve body lower part 6a and the valve body 6 with separate members. The upper part of the valve body 6b.

The water stop (pad 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 water from the valve seat 12a in the closed state of the check valve 1, and is arranged on the lower part of the valve body 6a Between the upper part of the valve body 6b (flange 6c). The spacer 8 has a center hole penetrating in the thickness direction and is formed in a ring shape. Specifically, the gasket 8 is located in the center 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 liner 8 is in the closed state shown in FIG. 3, it is located further below the center line CL. When at any position in the open state shown in FIG. 2, the entire liner 8 moves to a distance from the center line CL. A higher position. According to the above configuration, it is possible to prevent the spacer 8 from obstructing the flow through the center line CL when the self-closing state changes to the open state at any position, and the pressure loss can be reduced.

The above-mentioned "arbitrary position in 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 where 70% of the check valve 1 (valve body 6) is opened (70% of the maximum opening of the check valve 1) relative to the fully open state. According to this structure, it is possible to suppress the flow of the fluid in the vicinity of the center line CL where the flow rate is the fastest when the gasket 8 is at the standard flow rate, and it is possible to suppress an increase in pressure loss.

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

(About guide cover) As shown in FIG. 2, the guide cover 3 is used to detachably install the valve box 12, seal the upper side of the valve body 6 and guide the reciprocating movement of the movable body 2. The guide cover 3 is composed of a guide tube 4 and a disk-shaped top plate 5 integrally formed on the upper end of the guide tube 4. The top plate part 5 has the 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 at the upper end of the valve box 12. It is detachably fastened by a ferrule joint (not shown).

At approximately the center of the top plate portion 5, the guide tube 4 is erected obliquely downward (on the side of the primary flow path). 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 below, and is guided and connected to the valve body in such a way that the valve body 6 can reciprocate. 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. Figure 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, the flow velocity on the inflow side is about 4 m/s and the flow rate is about 4800 L/min (valve Diagram of fluid flow and dynamic pressure distribution at 50% opening. In addition, in Figure 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 12a 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 in parallel along the flow path direction. Moreover, the vortex W caused by the main flow does not intrude to the center side of the flow path, and it can be seen that its range is small. Therefore, the diffusion and separation of the fluid is less, and the loss head is about 2.8 m, which can suppress the pressure loss to a small amount.

＜＜The 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 with a larger diameter than the check valve 1. Fig. 6 is a longitudinal sectional view showing the open state of the check valve 1X of the second embodiment. In addition, in the check valve 1X, the description of the configuration common to the check valve 1 of the first embodiment is omitted.

The check valve 1X of this embodiment includes a moving body 32. The moving 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. The valve body lower portion 36a is formed in a partial spherical shape with a hollow portion 36d. More specifically, the lower part 36a of the valve body has a partial spherical surface on the outer surface of the side facing the flow path, and has a shape symmetrical along the center line CL, and is arranged in the check valve 1.

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

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

In the direction perpendicular to the axial direction of the valve shaft 37, the maximum diameter of the hollow portion 36d is formed to be larger than that of the opening 36i. Since the lower part 36a of the valve body is formed with the hollow part 36d, 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 a virtual surface 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 restrained from shaking due to the force applied to the valve body 36 from the fluid, and the flow of the fluid can be stabilized.

＜＜The 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 longitudinal sectional view showing the open state of the check valve 1Y of the third embodiment, and Fig. 8 is a perspective view showing the movable body 52 of 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 common to the first embodiment and the second embodiment except for the size, the description thereof is omitted.

The check valve 1Y mainly includes a moving body 52 and a valve box 62 that houses the moving body 52. The moving body 52 is mainly composed of a rod-shaped valve shaft 57 extending in the reciprocating direction, a valve body 56 provided at the lower end of the valve shaft 57, and a gasket 8 attached to the valve body 56. The valve body 56 is composed of a valve body lower portion 56a integrally formed at the end of 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 lower valve body 56a has an outer surface formed in a partially spherical shape, and at a position offset by 180 degrees with respect to the axial center direction, there are two plane portions 56f standing parallel to the walls in the reciprocating direction of the moving body 52 and extending parallel to each other. By providing these two flat parts 56f, the area of the edge part 56k mentioned later can be enlarged compared with the case where there is no flat part 56f. Therefore, the load of the fluid pushing up the valve body 56 can be greater than that of pressing the fluid into the spherical portion, and the fluid can start flowing smoothly.

In addition, an internal thread is formed in the center of the lower portion 56 a of the valve body, and is screwed with an external thread formed at the lower end of the valve shaft 57. In the initial state, as shown in FIG. 7, even if the flat portion 56f is inclined with respect to the flow path direction, when the fluid flows into the check valve 1Y and pushes the moving body 52 upward and intends to flow to the downstream side, the valve body 56 is also 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 moving body 52 in a direction parallel to the direction of the flow path. In this way, the pressure loss of the valve body 56 is reduced.

The lower valve body 56a has: an opposing portion 56j formed at a position partially opposed to the small-diameter portion 56h of the upper valve body 56b; and an edge portion 56k formed on the radially outer side of the opposing portion 56j, And in the lower part 56a of the valve body, a gasket 8 is sandwiched between the upper part 56b of the valve body.

In addition, a hollow portion 56d and an opening 56i connected to the hollow portion 56d and located opposite to the upper portion 56b of the valve body are formed in the lower portion 56a of the valve body. The opposing portion 56j is the one that defines the radially outer upper portion of the hollow portion 56d in the valve body lower portion 56a. The above-mentioned opening 56i is formed in the central portion of the opposing portion 56j in the radial direction. The edge portion 56k has a function of sandwiching the gasket 8 with the upper portion 56b of the valve body, and is formed to be thicker than the opposing portion 56j. In this way, by forming the edge portion 56k thicker than the opposing portion 56j, not only the volume of the hollow portion 56d is enlarged, but the repeated opening and closing of the valve body 56 can be stably maintained to be repeatedly applied from the valve box 62. The cushion 8 of the impact load of the valve seat 62a.

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

＜＜The fourth embodiment＞＞ Next, the check valve 1Z of the fourth embodiment will be explained 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 omitted.

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 reciprocally guided by a guide rod 74 inserted into the hollow space 77 a in the valve shaft 77. That is, the valve shaft 77 slides on the outer surface of the guide rod 74 with its inner surface facing the hollow space 77a, 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, thereby guiding the valve body 76 connected to the valve shaft 77 in the reciprocating direction.

In particular, in the valve body 76 of this 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 weight of the movable body 72 including the valve shaft 77 and the valve body 76 can be reduced, and the response to changes in flow rate 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 the above may also be adopted. The various constituent elements of the check valve and the reciprocating member constituting the check valve of the present invention do not need to exist independently. It is permissible to form a plurality of constituent elements into one component, one constituent element to be formed by multiple members, a certain constituent element as a part of other constituent elements, and a part of a constituent element overlaps with a part of other constituent elements.

This embodiment includes the following technical ideas. (1) A check valve, characterized in that it is a straight-pipe joint type diagonal lift check valve, and has: Valve seat The movable body can move linearly back and forth in the closed state tightly connected to the valve seat and the open state away from the valve seat; The primary flow path is located more upstream than the moving body; and The secondary flow path, which is located more downstream than the above-mentioned moving body; and The above-mentioned moving bodies include: The valve body, which is supported by the valve seat in the above closed state; and The valve shaft, which extends from the valve body; and The valve seat is formed to cross the center line in a cross section having a center line of a connecting flow path extending linearly including the primary flow path and the secondary flow path. (2) The check valve according to (1), wherein the moving body further has: a water stop part that abuts against the valve seat in the closed state; and When a part of the water stop is in the closed state, it is located below the center line, and when the whole of the water stop is at any position in the open state, it moves to a position higher than the center line. (3) The check valve described in (1) or (2), wherein 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 centered on the valve shaft that expands radially more than the lower part of the valve body, The lower end of the flange is located below the center line when in the closed state, and moves to a position above the center line when in any position in the open state. (4) The check valve as described in (2) or (3), wherein the arbitrary position in the open state means a position relative to 70% of the fully open state. (5) The check valve according to (3), wherein the lower part of the valve body is formed in a partial spherical shape with a hollow portion. (6) The check valve according to any one of (1) to (5), wherein the lower part of the inner wall surface forming the secondary flow path on the downstream side of the valve seat is provided with a surface facing the center line The downstream side extension of the lateral extension, and The extension amount of the downstream extension portion gradually decreases toward the downstream side. (7) The check valve according to any one of (1) to (6), wherein the upper part of the inner wall surface that forms the primary flow path on the upstream side of the valve seat is provided with a side toward the center line The upstream side of the extension, and The amount of extension of the upstream-side extension portion gradually increases toward the downstream side. (8) The check valve according to (7), wherein the upstream side extension does not extend 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 composed of 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 that intersects the flow path direction 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 the direction of the flow path with respect to the primary flow path and the secondary flow path and the extending direction of the valve shaft and the valve box, When the valve body is opened, the end on the primary flow path side in the upper part of the valve body is arranged so as 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 reciprocally guided by a guide rod inserted into the hollow space in the valve shaft. (11) The check valve according to (10), wherein a hollow portion of the hollow space continuous with the valve shaft is formed in the valve body.

1: Check valve 1X: Check valve 1Y: Check valve 1Z: Check valve 2: Moving body 3: Guide cover (cover) 4: guide tube 5: Top plate 5e: Ferrule flange 6: Valve body 6a: Lower part of the valve body 6b: The upper part of the valve body 6c: flange 6g: through hole 7: Valve shaft 8: Liner (water stop) 9: Joint part 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 extension 12g: guide rib 12h: ring groove 12i: Upstream side extension 13: Flange 14: Flange 15: Installation table 15a: pressure relief port 16: gasket 20: spring body 32: moving body 36: valve body 36a: Lower part of the valve body 36b: The upper part of the valve body 36d: hollow part 36e: recessed 36h: Small diameter part 36i: opening 37: Valve shaft 52: moving body 56: Valve body 56a: Lower part of the valve body 56b: The upper part of the valve body 56d: Hollow part 56e: Spring seat surface 56f: Plane 56h: Small diameter part 56i: opening 56j: Opposite part 56k: margin 57: Valve shaft 62: valve box 62a: Valve seat 72: moving body 73: Guide cover 74: guide rod 76: Valve body 76a: Lower part of the valve body 76b: The upper part of the 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 appearance of the check valve of 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 the 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 side of the inflow path. Fig. 5 is an explanatory diagram showing the dynamic pressure distribution in the flow path when fluid flows into the check valve of the first embodiment. Fig. 6 is a longitudinal sectional view showing the open state of the check valve of the second embodiment. Fig. 7 is a longitudinal sectional view showing the open state of the check valve of the third embodiment. Fig. 8 is a perspective view showing the moving body of 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 tube

5: Top plate

5e: Ferrule flange

6: Valve body

6a: Lower part of the valve body

6b: The upper part of the valve body

6c: flange

6g: through hole

7: Valve shaft

8: Liner (water stop)

9: Joint part

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 extension

12g: guide rib

12h: ring groove

12i: Upstream side extension

13: Flange

14: Flange

15a: pressure relief port

16: gasket

20: spring body

CL: Centerline

Claims (9)

A non-return valve, characterized in that it is a straight pipe joint type of diagonal lifting type, and has: Valve seat The movable body can move linearly back and forth in the closed state tightly connected to the valve seat and the open state away from the valve seat; The primary flow path is located more upstream than the moving body; and The secondary flow path, which is located more downstream than the above-mentioned moving body; and The above-mentioned moving bodies include: The valve body, which is supported by the valve seat in the above closed state; and The valve shaft, which extends from the valve body; and The valve seat is formed to cross the center line in a cross section having a center line of a connecting flow path extending linearly including the primary flow path and the secondary flow path. According to the check valve of claim 1, wherein the movable body further has: a water stop part that abuts against the valve seat in the closed state; and When a part of the water stop is in the closed state, it is located below the center line, and the whole of the water stop is moved to a position higher than the center line in any position in the open state. Such as the check valve of claim 1 or 2, wherein 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 centered on the valve shaft and expands radially more 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. Such as the check valve of claim 2, wherein the arbitrary position in the open state mentioned above means a position relative to 70% of the fully open state. The check valve of claim 3, wherein the lower part of the valve body is formed in a partial spherical shape with a hollow part. The check valve of any one of 2 or 4, wherein a downstream side projecting portion protruding toward the center line side is provided at the lower portion of the inner wall surface forming the secondary flow path on the downstream side of the valve seat ,and The extension amount of the downstream extension portion gradually decreases toward the downstream side. The check valve of any one of 2 or 4, wherein the upper part of the inner wall surface forming the primary flow path on the upstream side of the valve seat is provided with an upstream projecting portion projecting toward the center line side, and The amount of extension of the upstream-side extension portion gradually increases toward the downstream side. Such as the check valve of claim 7, wherein the upstream side extension does not extend to the center line. The check valve of any one of 2 or 4, 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 composed of 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 that intersects the flow path direction 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 the direction of the flow path with respect to the primary flow path and the secondary flow path and the extending direction of the valve shaft and the valve box, When the valve body is opened, the end on the primary flow path side in the upper part of the valve body is arranged so as to be slidably connected to the inner wall of the valve box.

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