non-return valve

Abstract

This prevents or suppresses the generation of a collision sound from the check valve 11 (valve assembly 13) when the valve is opened. [Solution] The check valve 11 comprises a cylindrical guide member 17, a valve body 20 slidably housed inside the guide member, and a valve seat 16 positioned at one end of the guide member, wherein the guide member has a stopper portion 18 at the other end that defines the limit of movement of the valve body in the opening direction, and includes a stopper member 25 that is movable relative to the valve body and moves in the opening direction together with the valve body in the early stages of opening, while stopping its movement by contacting the stopper portion in the later stages of opening, and a coil spring 31 that supports the stopper member in the axial direction and moves the stopper member in the opening direction together with the valve body in the early stages of opening, while being compressed by the valve body moving in the opening direction in the later stages of opening, allowing the valve body to move in the opening direction.

Description

Technical Field

[0001] The present invention relates to a check valve, and more particularly to a structure of a check valve that prevents the generation of a collision sound of a valve body during valve opening.

Background Art

[0002] Refrigeration and refrigeration devices and air-conditioning equipment using a refrigeration cycle are widely used today. For example, a heat pump type air-conditioning system capable of heating and cooling is used as an air conditioner for transportation machines such as car air conditioners, a room air conditioner for houses and stores, and a central air-conditioning facility for large buildings.

[0003] In such an air-conditioning system, a check valve is used in a refrigerant pipe (for example, a branch portion, etc.) to switch the flow path of the refrigerant.

[0004] FIGS. 13 to 14 show an example of a conventional check valve (FIG. 13 shows a closed valve state and FIG. 14 shows an open valve state). As shown in these figures, this check valve 61 has an outer pipe 12 having an inlet port (not shown / formed below FIGS. 13 and 14) for allowing fluid to flow in and an outlet port (not shown / formed above FIGS. 13 and 14) for allowing fluid to flow out, and a valve assembly 13 housed inside the outer pipe 12 between the inlet port and the outlet port.

[0005] The valve assembly 13 includes a cylindrical guide member 17, a valve body 20 slidably housed inside the guide member 17, a valve seat member 14 having a valve seat 16 with which the valve body 20 comes into contact and separates, and a seal member 32 that seals between the outer peripheral surface of the valve seat member 14 and the inner peripheral surface of the outer pipe 12. The valve seat member 14 is attached to one end portion of the guide member 17. A bent portion 18 obtained by bending the other end portion inward is formed at the other end portion of the guide member 17.

[0006] The valve body 20 has a valve portion 21 that moves toward and away from the valve seat 16, and four wing-shaped portions 22 that extend axially on the back side of the valve portion 21. The valve body 20 moves axially while being guided by the guide member 17 without radial displacement, as these four wing-shaped portions 22 slidably contact the inner circumferential surface of the guide member 17.

[0007] Furthermore, the bent portion 18 defines the limit of movement of the valve body 20 in the opening direction. When the valve body 20 moves in the opening direction (away from the valve seat 16), it stops when the wing-shaped portion 22 abuts against the bent portion 18 (see Figure 14), and the check valve 61 becomes fully open.

[0008] Furthermore, the following patent document discloses a check valve used in such an air conditioning system. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2013-44418 [Overview of the project] [Problems that the invention aims to solve]

[0010] By the way, the conventional check valve 61 may generate noise (collision sound) when the valve body 20 (wing-shaped part 22) collides with the bent part 18 during opening.

[0011] On the other hand, coupled with the increasing popularity of electric and hybrid vehicles, the quietness inside automobiles has been steadily improving in recent years. Therefore, if collision noises like those described above occur in car air conditioners, it will reduce the quietness inside the vehicle and impair comfort. Furthermore, this problem of collision noise is not limited to car air conditioners; it can also occur in other refrigeration cycle devices such as room air conditioners and building air conditioning systems.

[0012] Furthermore, the aforementioned problems are not pointed out in Patent Document 1, nor does Patent Document 1 provide a solution to them.

[0013] Therefore, the object of the present invention is to prevent or suppress the generation of collision noise from the check valve when it is opened. [Means for solving the problem]

[0014] To solve the aforementioned problems and achieve the objective, the check valve according to the present invention comprises a cylindrical guide member, a valve body slidably housed inside the guide member, and a valve seat disposed at one end of the guide member. The guide member also has a stopper portion that defines the limit of movement of the valve body in the opening direction (i.e., stops the valve body so that it does not move any further in the opening direction). The valve seat may be formed as part of the guide member, or it may be formed as a separate member from the guide member (for example, a valve seat member as described later in one aspect or embodiment of the present invention).

[0015] Furthermore, if we define the state in which the valve body is in contact with the valve seat as the "closed state," the state in which the valve body has moved to its maximum extent in the opening direction as the "fully open state," the state in which the valve body is neither in the closed state nor the fully open state but is a predetermined distance (i.e., a predetermined distance) away from the valve seat as the "intermediate state," the period from the closed state to the intermediate state during the valve opening operation period from the closed state to the fully open state as the "early opening phase," and the period from the intermediate state to the fully open state as the "late opening phase," then the above check valve has the following stopper member and coil spring.

[0016] The stopper member is provided so as to be movable relative to the valve body. In the early stages of valve opening, it moves in the opening direction together with the valve body, while in the later stages of valve opening, it abuts against the abutment and its movement is stopped. The coil spring supports the stopper member in the axial direction, thereby moving the stopper member in the opening direction together with the valve body in the early stages of valve opening, while in the later stages of valve opening, it is compressed by the valve body moving in the opening direction, thereby allowing the valve body to move in the opening direction.

[0017] Furthermore, the term "intermediate state" as used in this invention does not mean (or is limited to) a state in which the valve body has moved to half the position of the movement stroke of the valve body from the closed state to the fully open state (half the distance the valve body moves). In other words, the "intermediate state" is a state in which, during the opening operation (when the valve body leaves the valve seat and moves toward the abutment), the stopper member has come into contact with the abutment, but the coil spring still maintains its initial length (when the valve is closed). In other words, the stopper member has come into contact with the abutment, and the distance (gap) between the valve body and the stopper member has not yet changed compared to when the valve is closed.

[0018] Furthermore, in this invention, "axial direction" refers to the direction in which the central axes of the guide member, valve body, and valve seat member extend, and the direction in which the valve body moves. In other words, "axial direction" refers to the longitudinal direction of the outer tube (described later) and the guide member. Also, "opening direction" refers to the direction from the valve seat toward the abutment. "Closing direction" refers to the direction from the abutment toward the valve seat.

[0019] Furthermore, the above-described check valve of the present invention (and the check valves according to each embodiment described later) typically has an outer tube having an inlet port for introducing fluid and an outlet port for introducing fluid, and the guide member is housed inside the outer tube and positioned between the inlet port and the outlet port.

[0020] The check valve of the present invention, like the conventional check valve 61 (Figures 13 and 14), is equipped with a stopper portion (which performs the same function as the bent portion 18 and includes, but is not limited to, the bent portion 18) to stop the valve body from moving in the opening direction when the valve is opened, thereby achieving a fully open state. However, unlike the conventional check valve 61, the check valve of the present invention prevents or suppresses the generation of a collision sound by absorbing the impact when the valve body stops (becomes fully open) with a coil spring. More specifically, it is as follows.

[0021] In the check valve of the present invention, when the pressure on the outlet port side is higher than the pressure on the inlet port side, the valve element moves in the valve closing direction due to the differential pressure (the difference between the pressure on the outlet port side and the pressure on the inlet port side), abuts against the valve seat, and enters the valve closed state. On the other hand, when the pressure on the inlet port side becomes higher than the pressure on the outlet port side, the valve element separates from the valve seat due to the differential pressure (the difference between the pressure on the inlet port side and the pressure on the outlet port side) and moves toward the abutting portion. In the initial stage of this valve opening operation (the initial valve opening stage), the valve element, the stopper member, and the coil spring provided between the valve element and the stopper member move integrally in the valve opening direction.

[0022] When the stopper member abuts against the abutting portion, the stopper member stops (the intermediate state). On the other hand, the valve element continues to move toward the abutting portion. For this reason, the coil spring is compressed by the valve element, and the valve element is decelerated by the compression of this coil spring (the elastic force (rebound force) of the compressed coil spring).

[0023] When the valve element further moves in the valve closing direction from the above intermediate state and abuts against the abutting portion (or against the abutting portion via the stopper member), the valve element also stops (fully open state). At this time, the speed of the valve element is sufficiently decelerated by compressing the coil spring, preventing or suppressing the generation of a collision sound.

[0024] Also, according to the present invention as described above, in the initial valve opening stage, since the stopper member moves together with the valve element and the coil spring is not compressed, the valve opening operation is not hindered and the valve opening responsiveness is not impaired.

[0025] Furthermore, in a conventional check valve, the valve element in the fully open state vibrates in the axial direction due to fluid pulsation or pressure fluctuation, causing chattering (repeating fine collisions against the bent portion), which may generate abnormal noise. However, according to the check valve of the present invention, since a coil spring is provided between the valve element and the stopper member, it is possible to suppress such vibration of the valve element and prevent (or suppress) the generation of abnormal noise.

[0026] Also, the check valve according to one aspect of the present invention includes a support shaft and a retaining portion. The support shaft is fixed to the valve body so as to extend from the valve body along the central axis of the valve body to the side opposite to the valve seat, and supports the stopper member so as to be movable in the axial direction. Further, the retaining portion is provided at the end of the support shaft on the side opposite to the valve body, and prevents the stopper member from coming out of the support shaft.

[0027] The above-mentioned retaining portion can be provided as a separate member from the support shaft (for example, a member such as a retaining ring or a split pin). On the other hand, it is also possible to form the retaining portion integrally with the support shaft (for example, increasing the outer diameter of the end of the support shaft, or forming a flange portion at the end of the support shaft, etc.). According to such an aspect, the number of parts of the check valve can be reduced.

[0028] Also, the check valve according to another aspect of the present invention includes a support shaft and a retaining portion similar to the above aspect, and has a damper space. This damper space is a recess formed in the valve body, into which the end of the support shaft on the valve body side is fitted so as to be relatively movable in the axial direction. As the valve body moves in the opening direction during the late stage of valve opening, the support shaft is inserted, thereby reducing the internal volume and performing a function of braking the valve body moving in the opening direction. By providing such a damper space, it is possible to further decelerate the valve body before it reaches the fully open state and reduce the collision sound at the time of full opening.

[0029] Also, in still another aspect of the present invention, a valve seat member having a valve seat is fixed to one end of a guide member, whereby the valve seat is provided.

Effects of the Invention

[0030] According to the present invention, it is possible to prevent or suppress the generation of a collision sound from the check valve during valve opening.

[0031] Other objects, features, and advantages of the present invention will be made clearer by the following description of embodiments of the invention based on the drawings. It should be noted that the present invention is not limited to the embodiments described below, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims. Furthermore, in each figure, the same reference numerals indicate the same or corresponding parts. [Brief explanation of the drawing]

[0032] [Figure 1] Figure 1 is a longitudinal cross-sectional view (DD section in Figure 2) showing a check valve (closed state) according to the first embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view (BB section in Figure 1) showing the check valve according to the first embodiment. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing an enlarged portion of the check valve according to the first embodiment (part C in Figure 1). [Figure 4] Figure 4 is a longitudinal cross-sectional view showing the check valve (intermediate state) according to the first embodiment, similar to Figure 1. [Figure 5] Figure 5 is a longitudinal cross-sectional view showing the check valve (fully open state) according to the first embodiment, similar to Figure 1. [Figure 6] Figure 6 is a longitudinal cross-sectional view showing a check valve (closed state) according to a second embodiment of the present invention, similar to Figure 1. [Figure 7] Figure 7 is a longitudinal cross-sectional view showing an enlarged portion of the check valve according to the second embodiment (portion C1 in Figure 6). [Figure 8] Figure 8 is a longitudinal cross-sectional view showing the check valve (intermediate state) according to the second embodiment, similar to Figure 6. [Figure 9] Figure 9 is a longitudinal cross-sectional view showing the check valve (fully open) according to the second embodiment, similar to Figure 6. [Figure 10] Figure 10 is a longitudinal cross-sectional view showing a check valve (closed state) according to a third embodiment of the present invention, similar to Figure 1. [Figure 11] Figure 11 is a longitudinal cross-sectional view showing the check valve (intermediate state) according to the third embodiment, similar to Figure 10. [Figure 12]Figure 12 is a longitudinal cross-sectional view showing the check valve (fully open) according to the third embodiment, similar to Figure 10. [Figure 13] Figure 13 is a diagram showing the internal structure (closed state) of a conventional check valve, with the outer tube, guide member, valve seat member, and sealing member cut out. [Figure 14] Figure 14 is a diagram showing the internal structure of a conventional check valve (fully open state) with the outer tube, guide member, valve seat member, and sealing member cut out. [Modes for carrying out the invention]

[0033] [First Embodiment] A check valve according to the first embodiment of the present invention will be described with reference to Figures 1 to 5.

[0034] As shown in Figures 1 to 5, the check valve 11 according to the first embodiment of the present invention has an outer tube 12 having an inlet port 1 (not shown in Figures 4 and 5) for introducing a fluid (refrigerant, etc.) and an outlet port 2 (not shown in Figures 4 and 5) for releasing a fluid, and a valve assembly 13 housed inside the outer tube 12 between the inlet port 1 and the outlet port 2.

[0035] In this embodiment, one side in the axial direction where the inlet port 1 is located (the lower side in Figures 1, 4, and 5) is referred to as the "front," and the other side in the axial direction where the outlet port 2 is located (the upper side in Figures 1, 4, and 5) is referred to as the "rear." Based on these concepts of "front" and "rear," terms related to front and rear, such as "front," "rear," "front end," "rear end," "front side," and "rear side," are used. Furthermore, the outer tube 12, as well as the guide member 17, valve body 20, and valve seat member 14 described later, are arranged coaxially, and their central axes A coincide with each other. The direction in which this central axis A extends is the "axial direction."

[0036] The valve assembly 13 includes a cylindrical guide member 17, a valve body 20 slidably housed inside the guide member 17, a valve seat member 14 having a valve seat 16 that the valve body 20 moves toward and away from, and a sealing member 32 that seals the space between the outer circumferential surface of the valve seat member 14 and the inner circumferential surface of the outer tube 12.

[0037] The outer tube 12 is fixed to the connection point to which the check valve 11 is connected. The connection point is, for example, a pipe. The fixing means is, for example, welding using heat. In this embodiment, the outer tube 12 has a main body portion 12a on which the valve assembly 13 is arranged, and pipe portions 12b formed at each end of the main body portion 12a.

[0038] In this embodiment, the main body portion 12a is cylindrical. The inner diameter of the main body portion 12a is approximately the same as the outer diameter of the valve assembly 13.

[0039] One pipe section 12b constitutes the inlet port 1, and the other pipe section 12b constitutes the outlet port 2. Both pipe sections 12b have shapes corresponding to the connection destinations of the check valve 11. In this embodiment, both pipe sections 12b have a smaller inner diameter than the main body 12a to prevent the valve assembly 13 from coming out of the main body 12a. Furthermore, both pipe sections 12b have similar shapes. Hereafter, the pipe section 12b will be described as the throttling section 12b.

[0040] To illustrate with a representative example of the constricted portion 12b that constitutes the inlet port 1, the constricted portion 12b has a portion that is reduced in diameter relative to the main body portion 12a, and a portion that continues from this reduced diameter portion and has a constant inner diameter. The tip of the constricted portion 12b becomes the inlet port 1 (in the case of the constricted portion 12b on the outlet port side, the tip becomes the outlet port 2). The length of the constricted portion 12b is such that, when the outer pipe 12 of the check valve 11 is fixed to the connection point of other piping etc. by welding which applies heat, the effect of the heat on the sealing member 32 is minimized. The length that minimizes the effect is such that the function of the sealing member 32 is not impaired by the heat.

[0041] The valve seat member 14 is a ring-shaped member equipped with an inlet 15 for allowing fluid to flow into the guide member 17, and is attached to the front end of the guide member 17. The rear end of the guide member 17 has a bent portion 18 (referred to as a stopper portion in this invention) formed by bending the rear end inward. This bent portion 18 defines the limit of movement of the valve body 20 in the opening direction. When the valve body 20 moves in the opening direction (rearward), the wing-shaped portion 22 abuts against the bent portion 18 via a stopper member 25 (described later), stopping it (see Figure 5), and the check valve 11 becomes fully open. The opening 19 formed by the bent portion 18 becomes an outlet from which fluid flows out from the inside of the guide member 17 toward the outlet port.

[0042] The valve body 20 has a valve portion 21 that moves toward and away from the valve seat 16, and four wing-shaped portions 22 that extend rearward from the rear side of the valve portion 21 (opposite the front side facing the valve seat 16). The valve body 20 moves in the front-rear direction (axial direction) while being guided by the guide member 17 without radial displacement, as these four wing-shaped portions 22 slidably contact the inner circumferential surface of the guide member 17.

[0043] Furthermore, the valve assembly 13 includes a support shaft 24 fixed to the central part (central hole 23) of the valve body 20 (valve portion 21 and four vane-shaped portions 22) and extending rearward along the central axis A; a stopper member 25 positioned behind the vane-shaped portions 22 and supported by the support shaft 24 so as to be movable (slidable) in the axial direction; a retaining ring 30 (retaining portion as referred to in this invention) fixed to the rear end of the support shaft 24 to prevent the stopper member 25 from coming out of the support shaft 24; and a coil spring 31 provided between a stepped portion formed in the middle part (intermediate position in the front-rear direction) of the support shaft 24 and the stopper member 25. In this embodiment (the same applies to the second embodiment), unlike the third embodiment which will be described later, the support shaft 24 inserted into the central hole 23 of the valve body 20 is fixed to the valve body 20 and does not move relative to the valve body 20.

[0044] The stopper member 25 has a ring-shaped stopper body 26 having an outer diameter larger than the outlet 19, a hub 27 for supporting the stopper member 25 so as to be axially slidable with respect to the support shaft 24, and a plurality of beams 28 (three in this embodiment) connecting the stopper body 26 and the hub 27. The inside of the stopper body 26, or more precisely, the area enclosed by the stopper body 26, the beams 28 and the hub 27 (there are three in this embodiment), is a fan-shaped through hole 29. As will be explained later regarding the operation of the check valve 11, from the intermediate state to the fully open state (late stage of valve opening), the stopper member 25 comes into contact with the bent portion 18, causing the outlet 19 to be covered by the stopper member 25. However, the fluid flowing inside the guide member 17 toward the outlet 19 can flow out to the outside of the guide member 17 (outlet port 2 side) through the through hole 29 of the stopper member 25.

[0045] The operation of the check valve 11 according to this embodiment is described as follows.

[0046] When the pressure at outlet port 2 (outlet 19) is higher than the pressure at inlet port 1 (inlet 15), as shown in Figure 1, the valve portion 21 of the valve body 20 comes into contact with the valve seat 16 of the valve seat member 14, closing the inlet 15 (valve closed state) and interrupting the flow of fluid.

[0047] On the other hand, when the pressure on the inlet port 1 (inlet 15) side becomes higher than the pressure on the outlet port 2 (outlet 19) side, the valve body 20 moves backward along the inner surface of the guide member 17, together with the support shaft 24, coil spring 31, stopper member 25, and retaining ring 30, that is, toward the outlet port 2 (outlet 19) side (bent portion 18 side), causing the valve portion 21 to separate from the valve seat 16 and the inlet 15 to open. As a result, the fluid flowing in from the inlet port 1 flows into the guide member 17 from the inlet 15, and flows out of the guide member 17 from the outlet 19 through the gaps between the four fin-shaped parts 22 and the through hole 29 of the stopper member 25 (until the valve opens and reaches an intermediate state, it also flows through the gaps between the fin-shaped parts 22 and the periphery of the stopper member 25 (between the stopper member 25 and the inner surface of the guide member 17)) and flows towards the outlet port 2 (see arrow F in Figures 4 and 5).

[0048] Then, as the valve body 20 moves backward and the stopper member 25 comes into contact with the bent portion 18 (intermediate state shown in Figure 4), the stopper member 25 is blocked by the bent portion 18 and can no longer move backward. On the other hand, the valve body 20 can move further backward and will continue to move backward until the valve body 20 (wing-shaped portion 22) comes into contact with the stopper member 25 (and the bent portion 18 via the stopper member 25) and is stopped (fully open state shown in Figure 5).

[0049] In the check valve 11 of this embodiment, the valve body 20 is stopped by contacting the bent portion 18 (via the stopper member 25), similar to the conventional check valve 61. However, before this (from the intermediate state shown in Figure 4 to the fully open state shown in Figure 5), the valve body 20 compresses the coil spring 31 as it moves, and only after being sufficiently decelerated does it collide with the bent portion 18 (stopper member 25). Therefore, the collision noise when the valve opens (when it becomes fully open) can be reduced. When it reaches the intermediate state (Figure 4), the stopper member 25 comes into contact with the bent portion 18, but the collision noise generated at this time is smaller compared to when the entire valve body collides, as in the conventional check valve 61.

[0050] Furthermore, as mentioned above, in conventional check valves 61, the valve body 20 in the fully open state vibrates axially due to fluid pulsation and pressure fluctuations, causing chattering (repeated small collisions with the bent portion 18), which can generate abnormal noise. However, with the check valve 11 of this embodiment, a coil spring 31 is provided between the valve body 20 and the stopper member 25, which can suppress such vibration of the valve body 20 and prevent (or suppress) the generation of abnormal noise.

[0051] [Second Embodiment] A check valve according to a second embodiment of the present invention will be described with reference to Figures 6 to 9. In this description, components identical or equivalent to those in the first embodiment are denoted by the same reference numerals, and redundant explanations are omitted, with the focus being on the differences (the same applies to the third embodiment described later).

[0052] The difference between the check valve 41 according to this embodiment and the check valve 11 according to the first embodiment lies in the structure of the retaining portion 33 that prevents the stopper member 25 from coming out of the support shaft 24.

[0053] Specifically, in the check valve 41 according to the second embodiment of the present invention, a flange portion 33 is formed at the rear end of the support shaft 24 instead of the retaining ring 30 (first embodiment). This flange portion 33 has a larger outer diameter than the central hole of the hub 27 of the stopper member 25 (i.e., it protrudes outward), thereby preventing the stopper member 25 from falling rearward from the support shaft 24. In this embodiment, the support shaft 24 does not have a stepped portion, and a coil spring 31 is provided interposed between the wing-shaped portion 22 and the stopper member 25.

[0054] According to this embodiment, the retaining ring 30 is unnecessary, making it possible to reduce the number of parts. Other parts and operation are the same as the check valve 11 of the first embodiment.

[0055] [Third Embodiment] A check valve according to a third embodiment of the present invention will be described with reference to Figures 10 to 12.

[0056] The check valve 51 according to the third embodiment of the present invention is equipped with a damper space 34 in addition to a deceleration mechanism using a stopper member 25 and a coil spring 31 as a mechanism for decelerating the valve body 20 during valve closing operation (late stage of valve opening / Figures 11-12).

[0057] Specifically, in this embodiment, the support shaft 24 is installed so as to be axially movable relative to the valve body 20, and a recessed area 34 is formed at the bottom (front end) of the central hole 23 of the valve body 20 (valve portion 21 and vane portion 22) into which the support shaft 24 is inserted, into which the tip (front end) of the support shaft 24 is inserted or removed. This recessed area 34 is formed by creating a groove 35 on the inner circumferential surface of the central hole 23 of the valve body 20 that extends axially to connect the recessed area 34 with the inside of the guide member 17. Therefore, when the support shaft 24 is not inserted into the recessed area 34, the inside of the recessed area 34 is filled with fluid, while when the support shaft 24 is inserted into the recessed area 34, the fluid is pushed out into the inside of the guide member 17 through the groove 35.

[0058] The operation of the check valve 51 in this embodiment is the same as in the first and second embodiments during the initial opening phase (from the closed state shown in Figure 10 to the intermediate state shown in Figure 11). However, in the later opening phase (from the intermediate state shown in Figure 11 to the fully open state shown in Figure 12), the valve body 20 not only compresses the coil spring 31 but also pushes fluid out from the recessed area 34. As a result, it is decelerated even more than the check valves 11 and 41 of the aforementioned embodiments, making it possible to further reduce the collision noise when fully open. [Explanation of symbols]

[0059] A Center line (axis line) F Fluid flow 1 Entrance Port 2 Exit Ports 11, 41, 51, 61 Check valve 12 Outer tube 12a Main body 12b Pipe section 13 Valve Assembly 14 Valve seat member 15 Inlet 16 valve seats 17 Guide Member 18 Bend section 19 Outlet 20 valve body 21 Valve 22. Feather-shaped part 23 Central hole of the valve body (valve portion and vane-shaped portion) 24 Support shaft 25 Stopper member 26 Stopper body 27 Hubs 28 beams 29 Through hole 30 retaining rings 31 Coil spring 32 sealing member 33 Flange section 34. Damper space (recess) 35 Groove

Claims

1. A cylindrical guide member, A valve body slidably housed inside the guide member, A valve seat is positioned at one end of the guide member, It has, The guide member has a stopper at its other end that defines the limit of movement of the valve body in the opening direction. It is a check valve, When the state in which the valve body is in contact with the valve seat is defined as the "closed state," the state in which the valve body has moved to its maximum extent in the opening direction is defined as the "fully open state," the state in which the valve body is at a predetermined distance from the valve seat, neither in the closed state nor the fully open state, is defined as the "intermediate state," and the period from the closed state to the intermediate state within the valve opening operation period from the closed state to the fully open state is defined as the "early opening period," and the period from the intermediate state to the fully open state is defined as the "late opening period," A stopper member is provided so as to be movable relative to the valve body, and moves in the opening direction together with the valve body in the early stage of valve opening, while in the later stage of valve opening, it abuts against the abutment and stops moving; A coil spring supports the stopper member in the axial direction, thereby moving the stopper member together with the valve body in the opening direction during the early stage of valve opening, while in the later stage of valve opening, it is compressed by the valve body moving in the opening direction, thereby allowing the valve body to move in the opening direction. A check valve characterized by having the following features.

2. A support shaft is fixed to the valve body so as to extend from the valve body to the opposite side of the valve seat along the central axis of the valve body, and supports the stopper member so as to be movable in the axial direction, A retaining portion is provided at the end of the support shaft opposite to the valve body, which prevents the stopper member from coming out of the support shaft. The check valve according to claim 1, further comprising:

3. The retaining portion is formed integrally with the support shaft. The check valve according to claim 2.

4. A support shaft is connected to the valve body so as to extend from the valve body to the side opposite to the valve seat along the central axis of the valve body and so as to be axially movable relative to the valve body, and supports the stopper member so as to be axially movable, A retaining portion is provided at the end of the support shaft opposite to the valve body, which prevents the stopper member from coming out of the support shaft. A recess formed in the valve body into which the valve body-side end of the support shaft is fitted so as to be axially movable, and a damper space which, in the later stages of valve opening, reduces in internal volume as the support shaft is inserted as the valve body moves in the opening direction, thereby providing braking to the valve body moving in the opening direction, The check valve according to claim 1, further comprising:

5. The valve seat member having the valve seat is fixed to one end of the guide member, thereby providing the valve seat. The check valve according to claim 1.

6. An outer tube having an inlet port for introducing fluid and an outlet port for releasing the fluid. It has, The guide member is housed inside the outer tube, between the inlet port and the outlet port. A check valve according to any one of claims 1 to 5.

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