Slowly-closed check valve

Abstract

The slow-closing check valve comprises a valve body, a water inlet and a water outlet are formed in the two ends of the valve body in the length direction of the valve body correspondingly, a supporting column is connected into the valve body, the two sides of the supporting column and the inner wall of the valve body are arranged at intervals, diaphragms are arranged on the two sides of the supporting column and are made of flexible materials, and the diaphragms and the inner wall of the valve body are arranged at intervals to form a first cavity; the diaphragm and the supporting column are provided with circulation channels for water to pass through at intervals, the valve body is communicated with a water injection assembly, the water injection assembly is used for injecting water into the first cavity, and when the first cavity is filled with water, the diaphragm makes contact with the supporting column and drives the circulation channels to be closed. In the closing process of the circulation channel, the diaphragm makes contact with the supporting column, the diaphragm is made of a flexible material, so that noise generated when the diaphragm collides with the supporting column is reduced, and then noise generated when the check valve works is reduced.

Description

Technical Field

[0001] The present application relates to water supply in the field of fire protection, and in particular to a slow-closing check valve. Background Art

[0002] The check valve is also called a one-way valve or a non-return valve. Its function is to prevent the medium in the pipeline from flowing back.

[0003] The Chinese patent with the authorization announcement number CN102678981B discloses a check valve that can release the internal pressure of the valve body to the outside during maintenance, etc., and can reliably prevent the hinge pin from flying out. The check valve includes: a valve body, which has an inlet and an outlet for fluid, and a valve seat on the inlet side; a pin support portion, which is formed on the inner side of the valve body and supports the hinge pin; a pin insertion hole, which is formed in the pin support portion and is inserted into the hinge pin; a valve core, which is installed on the hinge pin to swing freely with the help of a swing arm and abuts against the valve seat of the valve body; an external communication hole, which is composed of a pressure release hole connecting the inside of the valve body and the pin insertion hole part and a pin external communication hole.

[0004] Regarding the above-mentioned related technologies, the valve core is usually made of metal. When the water flow is large, the collision process between the valve core and the valve seat or valve body is likely to generate large noise. Utility Model Content

[0005] In order to reduce the noise generated during the use of the check valve, the present application provides a slow-closing check valve.

[0006] The slow-closing check valve provided in this application adopts the following technical solution:

[0007] A slow-closing check valve comprises a valve body, wherein the valve body is provided with a water inlet and a water outlet at both ends along the length direction thereof, a support column is connected to the valve body, the length direction of the support column is consistent with the width direction of the valve body, the support column is connected to the inner wall of the valve body at both ends along the length direction thereof, both sides of the support column are spaced apart from the inner wall of the valve body, a diaphragm is provided on both sides of the support column, the circumferential side of the diaphragm is connected to the inner wall of the valve body, the diaphragm is made of a flexible material, a first cavity is formed between the diaphragm and the inner wall of the valve body, a flow channel for water is provided between the diaphragm and the support column, the valve body is connected with a water injection assembly, the water injection assembly is used to inject water into the first cavity, when the first cavity is filled with water, the diaphragm contacts the support column and drives the flow channel to close.

[0008] By adopting the above technical solution, when water in the valve body flows from the water outlet to the water inlet, the water injection assembly injects water into the first cavity. When the first cavity is full of water, the diaphragm protrudes toward the support column and contacts the support column, so that the flow channel is closed, thereby minimizing the backflow of water. During the closing process of the flow channel, the diaphragm contacts the support column. The diaphragm is made of flexible material, thereby reducing the noise generated when the diaphragm collides with the support column, thereby reducing the noise generated when the check valve is working.

[0009] Optionally, the water injection assembly includes a first tube, one end of the first tube is connected to an end of the valve body close to the water outlet, and the other end of the first tube is connected to the two first cavities.

[0010] By adopting the above technical solution, when water flows from one end of the water outlet to the other end of the water inlet, the water enters the first cavity through the first tube, so that the first cavity is filled with water. When the first cavity is full of water, the diaphragm contacts the support column and closes the flow channel, so as to avoid water backflow as much as possible.

[0011] Optionally, the water injection assembly also includes a second tube, one end of the second tube is connected to an end of the valve body near the water inlet, the other end of the second tube is connected to the two first cavities, the end of the second tube near the water inlet is connected to a one-way valve for controlling the one-way flow of water from the valve body to the first cavity, the end of the second tube near the first cavity is connected to a first flow regulating valve, and the end of the first tube near the first cavity is connected to a second flow regulating valve.

[0012] By adopting the above technical solution, under normal circumstances, the flow rate of the first tube is greater than the flow rate of the second tube through the setting of the first flow regulating valve and the second flow regulating valve. When water flows from the water inlet to the water outlet, the water in the valve body near the water inlet enters the first cavity through the second tube, and the water in the first cavity flows to the valve body near the water outlet through the first tube, so as to avoid as much as possible the situation in normal use where the water near the water outlet end flows to the first cavity through the first tube and closes the flow channel because the pressure in the first cavity is lower than the pressure at the water outlet end.

[0013] Optionally, one end of the first tube close to the water inlet and one end of the second tube close to the water outlet are both connected to a filter element, and the filter element is used to filter impurities in the water.

[0014] By adopting the above technical solution and adding a filter, the impurities entering the first tube and the second tube can be reduced, and the blockage of the first tube and the second tube can be avoided as much as possible.

[0015] Optionally, arc-shaped grooves are provided on both sides of the support column, and the concave arc surface of the arc-shaped groove is arranged toward the diaphragm. When the first cavity is filled with water, the diaphragm fits against the inner wall of the arc-shaped groove.

[0016] By adopting the above technical solution and adding an arc groove, when the first cavity is filled with water, the diaphragm fits against the inner wall of the arc groove, thereby improving the sealing performance of the connection between the diaphragm and the inner wall of the arc groove and further avoiding water backflow as much as possible.

[0017] Optionally, the diaphragm is provided with reinforcing ribs on both sides along the length direction of the valve body, one end of the reinforcing rib is connected to the inner wall of the valve body, and the other end of the reinforcing rib is connected to the support column, and the two reinforcing ribs are respectively arranged on both sides of the support column along the length direction of the valve body, and the reinforcing ribs are arranged in an arc shape, and the concave arc surface of the reinforcing rib is arranged toward the diaphragm. When the first cavity is filled with water, the diaphragm fits with the concave arc surface of the reinforcing rib.

[0018] By adopting the above technical solution and adding reinforcing ribs, when the flow channel is closed, the connection between the diaphragm, the reinforcing ribs and the support column is more stable, thereby improving the sealing performance of the connection between the diaphragm and the inner wall of the arc groove.

[0019] Optionally, a through hole is opened on one side of the valve body along the length direction of the support column, the length direction of the through hole is consistent with the length direction of the support column, and the through hole passes through the support column and the valve body.

[0020] By adopting the above technical solution and adding through holes, the volume of the support column is reduced, thereby reducing the manufacturing cost.

[0021] Optionally, valve covers are connected on both sides of the valve body, the first cavity is formed by the valve cover and the diaphragm, the periphery of the diaphragm is pressed against the valve body by the valve cover, a storage cavity for accommodating the diaphragm is provided in the valve cover, and the first tube and the second tube are connected to the valve cover.

[0022] By adopting the above technical solution, under normal use, the circulation channel is opened, and the diaphragm is away from the support column and enters the storage cavity, so as to avoid as much as possible the situation where the diaphragm blocks the water flow and thus affects the flow rate when the water flows through the circulation channel, and try to avoid as much as possible the situation where the pressure in the circulation channel is greater than the pressure in the first cavity when the circulation channel is opened, causing the diaphragm to be squeezed and wrinkled, thereby causing damage to the diaphragm.

[0023] Optionally, a first annular protrusion is connected to a side of the diaphragm close to the valve cover, the first annular protrusion is made of a flexible material, the circumference of the first annular protrusion is consistent with the circumference of the diaphragm, and the first annular protrusion is in contact with the valve cover.

[0024] By adopting the above technical solution, the first annular bulge is added, the gap between the first annular bulge and the valve cover is reduced, the sealing performance of the connection between the first annular bulge and the valve cover is improved, and the water in the first cavity is prevented from leaking through the gap between the valve cover and the diaphragm.

[0025] Optionally, a second annular protrusion is connected to a side of the diaphragm close to the valve body, the circumference of the second annular protrusion is consistent with the circumference of the diaphragm, and the second annular protrusion is in contact with the valve body.

[0026] By adopting the above technical solution, the first annular protrusion is added to reduce the gap between the second annular protrusion and the valve body, improve the sealing performance of the connection between the second annular protrusion and the valve cover, and minimize the leakage of water in the valve body through the gap between the valve body and the diaphragm.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. When the water in the valve body flows from the water outlet to the water inlet, the water injection assembly injects water into the first cavity. When the first cavity is filled with water, the diaphragm protrudes toward the support column and contacts the support column, so that the flow channel is closed to avoid water backflow as much as possible. During the closing process of the flow channel, the diaphragm contacts the support column. The diaphragm is made of flexible material to reduce the noise generated when the diaphragm collides with the support column, thereby reducing the noise generated when the check valve is working;

[0029] 2. When water flows from the water outlet to the water inlet, the water enters the first cavity through the first tube, so that the first cavity is filled with water. When the first cavity is filled with water, the diaphragm contacts the support column and closes the flow channel, so as to avoid water backflow as much as possible;

[0030] 3. Under normal circumstances, the first flow regulating valve and the second flow regulating valve are arranged so that the flow of the first pipe is greater than the flow of the second pipe. When water flows from the water inlet to the water outlet, the water in the valve body near the water inlet enters the first cavity through the second pipe, and the water in the first cavity flows to the valve body near the water outlet through the first pipe, so as to avoid as much as possible the situation in normal use where the water near the water outlet flows to the first cavity through the first pipe and closes the flow channel because the pressure in the first cavity is lower than the pressure at the water outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a three-dimensional structural diagram of this embodiment.

[0032] Figure 2 It is a top view of this embodiment.

[0033] Figure 3 This embodiment Figure 2 Sectional view along AA direction.

[0034] Figure 4 This embodiment Figure 2 Cross-sectional view along the BB axis.

[0035] Figure 5 This embodiment Figure 3 Enlarged view of part D.

[0036] Figure 6 This embodiment Figure 2 Sectional view along CC direction.

[0037] Description of reference numerals: 100, valve body; 110, water inlet; 120, water outlet; 130, first cavity; 140, circulation channel; 150, connection port; 160, valve cover; 161, storage cavity; 162, sliding hole; 163, connecting cylinder; 170, three-way filter; 180, through hole; 190, support frame; 191, roller travel switch; 200, support column; 210, arc groove; 300, diaphragm; 310, reinforcing rib; 320, first annular protrusion; 330, second annular protrusion; 340, buffer column; 400, water injection assembly; 410, first pipe; 411, first shunt pipe; 412, first flow regulating valve; 420, second pipe; 421, second shunt pipe; 422, second flow regulating valve; 423, one-way valve; 500, valve stem; 510, mounting seat; 511, buffer pad; 520, spring; 530, sleeve. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1-4 This application is described in further detail.

[0039] The present application embodiment discloses a slow closing check valve. Figure 1 and Figure 2 A slow closing check valve includes a valve body 100, wherein a water inlet 110 is provided at one end of the valve body 100 along its length direction and a water outlet 120 is provided at the other end of the valve body 100.

[0040] Reference Figure 3 Figure 4 , a support column 200 is connected to the valve body 100, the length direction of the support column 200 is consistent with the width direction of the valve body 100, and the two ends of the support column 200 along its length direction are respectively connected to the inner wall of the corresponding side of the valve body 100. The support column 200 is spaced from the inner wall of the valve body 100 on both sides along its width direction. The valve body 100 is provided with a connection port 150 on both sides along the width direction of the support column 200. The connection port 150 is a circular port. A diaphragm 300 is arranged in the connection port 150. The diaphragm 300 is made of a flexible material. The circumference of the diaphragm 300 is pressed against the valve body 100 through a valve cover 160. The valve cover 160 is arranged on the side of the connection port 150 away from the support column 200, and the valve cover 160 is flange-connected to the valve body 100. The diaphragm 300 and the inner wall of the valve cover 160 are spaced to form a first cavity 130, and a flow channel 140 for water to pass through is spaced between the diaphragm 300 and the support column 200. The first cavity 130 is connected to a water injection assembly 400 for injecting water into the first cavity 130 . When the first cavity 130 is filled with water, the diaphragm 300 contacts the support column 200 and drives the flow channel 140 to close.

[0041] When water in the valve body 100 flows from the water outlet 120 to the water inlet 110, the diaphragm 300 contacts the support column 200 and closes the flow channel 140. The noise generated by the collision between the diaphragm 300 and the support column 200 is small, thereby reducing the noise generated during the operation of the check valve.

[0042] Reference Figure 4 and Figure 5 A first annular protrusion 320 is connected to the side of the diaphragm 300 close to the valve cover 160 . The circumference of the first annular protrusion 320 is consistent with the circumference of the diaphragm 300 , and the central axis of the first annular protrusion 320 is colinear with the central axis of the valve cover 160 . The first annular protrusion 320 contacts the valve cover 160 .

[0043] Reference Figure 4 and Figure 5 The diaphragm 300 is connected to a second annular protrusion 330 on the side close to the valve body 100. Two second annular protrusions 330 are provided. The central axis of the second annular protrusion 330 is colinear with the central axis of the valve cover 160. The circumference of the second annular protrusion 330 is consistent with the circumference of the valve cover 160. The second annular protrusion 330 contacts the valve body 100. The first annular protrusion 320 and the second annular protrusion 330 are both made of flexible materials. The first annular protrusion 320, the second annular protrusion 330 and the diaphragm 300 are all made of rubber materials. The middle part of the valve cover 160 is concave inward to form a spherical surface, and a receiving cavity 161 is provided in the valve cover 160.

[0044] Reference Figure 1 and Figure 4 The water injection assembly 400 includes a first tube 410 and a second tube 420. One end of the first tube 410 and the second tube 420 are both connected to a valve cover 160 and are both connected to a first cavity 130. The end of the second tube 420 away from the first cavity 130 is connected to the end of the valve body 100 close to the water inlet 110, and the end of the second tube 420 close to the first cavity 130 is connected to a second diverter tube 421, the second diverter tube 421 is connected to the valve cover 160 provided on the side of the valve body 100 away from the second tube 420, and the second diverter tube 421 is connected to another first cavity 130. The end of the second tube 420 close to the water inlet 110 is connected to a one-way valve 423, and the one-way valve 423 is used to control the one-way flow of water from the valve body 100 to the first cavity 130. The second pipe 420 is connected to a second flow regulating valve 422 at one end close to the first cavity 130 . The second flow regulating valve 422 and the second diversion pipe 421 are sequentially distributed along the water flow direction.

[0045] Reference Figure 1 and Figure 4, the end of the first tube 410 away from the first cavity is connected to the end of the valve body 100 near the water outlet 120, the first tube 410 is connected to the first diverter tube 411, one end of the first diverter tube 411 is connected to the end of the first tube 410 away from the water outlet 120, the other end of the first diverter tube 411 is connected to the valve cover 160 arranged on the side of the valve body 100 away from the first tube 410, and the first diverter tube 411 is connected to the first cavity 130. The end of the first tube 410 close to the first cavity 130 is connected to the first flow regulating valve 412, and the first diverter tube 411 is arranged between the first flow regulating valve 412 and the first cavity 130. The first flow regulating valve 412 and the second flow regulating valve 422 are both needle valve settings. The end of the first tube 410 close to the water inlet 110 is connected to a filter element, and the end of the second tube 420 close to the water outlet 120 is also connected to a filter element, and the filter element is a three-way filter 170.

[0046] When water in the valve body 100 flows from the water outlet 120 to the water inlet 110, the water enters the first cavity 130 through the first tube 410, so that the first cavity 130 is filled with water, and the diaphragm 300 contacts the support column 200, so that the flow channel 140 is closed, thereby minimizing water backflow.

[0047] Reference Figure 4 and Figure 6 The valve cover 160 is provided with a sliding hole 162, the depth direction of the sliding hole 162 is consistent with the width direction of the valve body 100, a connecting tube 163 is provided in the sliding hole 162, the length direction of the connecting tube 163 is consistent with the width direction of the valve body 100, the connecting tube 163 passes through the valve cover 160 along its length direction, and the circumference of the connecting tube 163 contacts the inner wall of the sliding hole 162. The connecting tube 163 is slidingly connected with the valve stem 500, the connecting tube 163 is slidingly sleeved on the valve stem 500, the central axis of the valve stem 500 is colinear with the central axis of the connecting tube 163, and the valve stem 500 is slidingly connected in the connecting tube 163 along its length direction. The bottom end of the valve stem 500 is connected to a mounting seat 510, which is sleeved on the bottom end of the valve stem 500. The bottom of the mounting seat 510 is connected to a buffer pad 511, which is arranged in a truncated cone shape. The central axis of the buffer pad 511 is colinear with the central axis of the valve stem 500, and the buffer pad 511 is arranged with chamfered corners at both ends along the length direction of the valve stem 500.

[0048] Reference Figure 4 and Figure 6 The diaphragm 300 is connected to a buffer column 340 on one side close to the first cavity 130. The central axis of the buffer column 340 is colinear with the central axis of the valve stem 500. The buffer column 340 and the buffer pad 511 are both made of rubber. When the water in the first cavity 130 decreases, the buffer column 340 contacts the buffer pad 511.

[0049] Reference Figure 4 and Figure 6The valve stem 500 is sleeved with a spring 520, the length direction of the spring 520 is consistent with the length direction of the valve stem 500, one end of the spring 520 along its length direction is connected to the mounting seat 510 close to the end of the valve stem 500, and the other end of the spring 520 is connected to the end of the connecting tube 163 close to the diaphragm 300.

[0050] Reference Figure 4 and Figure 6 The valve stem 500 is sleeved with a sleeve 530, the central axis of the sleeve 530 is colinear with the central axis of the valve stem 500, and the sleeve 530 is arranged outside the valve body 100. The valve cover 160 is connected to a support frame 190, and the support frame 190 is connected to two roller-type travel switches 191. The two roller-type travel switches 191 are sequentially spaced and distributed on the support frame 190 along the length direction of the valve stem 500. The rollers of the two roller-type travel switches 191 are respectively arranged at both ends of the sleeve 530 along the length direction of the sleeve 530. The rollers of the roller-type travel switches 191 are in contact with the peripheral side of the valve stem 500. When the valve stem 500 rises and falls, the sleeve 530 pushes the rollers of the roller-type travel switch 191, and the rollers of the roller-type travel switch 191 are connected to the valve stem 500 in a rolling manner. When one roller-type travel switch 191 triggers the switch, the other roller-type travel switch 191 is disconnected.

[0051] Reference Figure 3 and Figure 4 The valve body 100 is provided with a through hole 180 along one side of the length direction of the support column 200. The depth direction of the through hole 180 is consistent with the length direction of the support column 200. The through hole 180 passes through the support column 200 and the valve body 100. The support column 200 is provided with arc grooves 210 along its width direction and on both sides close to the flow channel 140. The concave arc surface of the arc groove 210 is arranged toward the diaphragm 300. The diaphragm 300 is provided with reinforcing ribs 310 on both sides along the length direction of the valve body 100. One end of the reinforcing rib 310 is connected to the inner wall of the valve body 100, and the other end of the reinforcing rib 310 is connected to the support column 200, and the two support columns 200 are closed and arranged on the side walls of the support column 200 along the length direction of the valve body 100. The reinforcing rib 310 is arranged in an arc shape, and the concave arc surface of the reinforcing rib 310 is arranged toward the diaphragm 300 . When the first cavity 130 is filled with water, the diaphragm 300 fits with the concave arc surface of the reinforcing rib 310 , and the diaphragm 300 fits with the inner wall of the arc groove 210 .

[0052] The implementation principle of a slow-closing check valve in an embodiment of the present application is as follows: under normal use, water flows from the water inlet 110 to the water outlet 120, the water on one side of the water inlet 110 enters the second tube 420, and enters the two first cavities 130 through the second diversion tube 421, and the water in the first cavity 130 is discharged to the side of the water outlet 120 through the first diversion tube 411 and the first tube 410. When water flows from the water outlet 120 to the water inlet 110, the water on one side of the water outlet 120 enters the first tube 410, and enters the first diversion tube 411 along the first tube 410, and the water enters the two first cavities 130 through the second diversion tube 421. Since the second tube 420 is provided with a one-way valve 423, the first cavity 130 is filled with water, so that the diaphragm 300 protrudes toward the support column 200, and the diaphragm 300 contacts the arc groove 210 and the reinforcing rib 310, so that the circulation channel 140 is closed, so as to avoid water backflow as much as possible. When the circulation channel 140 is closed, the noise generated during the collision between the diaphragm 300, the support column 200 and the reinforcing rib 310 is small, thereby reducing the noise generated during the operation of the check valve.

[0053] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A slow-closing check valve, comprising a valve body (100), wherein the valve body (100) is provided with a water inlet (110) and a water outlet (120) at both ends along the length direction thereof, and characterized in that: A support column (200) is connected to the valve body (100), the length direction of the support column (200) is consistent with the width direction of the valve body (100), the two ends of the support column (200) along the length direction are respectively connected to the inner wall of the valve body (100), both sides of the support column (200) are spaced from the inner wall of the valve body (100), both sides of the support column (200) are provided with a diaphragm (300), the periphery of the diaphragm (300) is connected to the inner wall of the valve body (100), and the diaphragm (300) is made of a flexible material. The diaphragm (300) and the inner wall of the valve body (100) are spaced apart to form a first cavity (130); a circulation channel (140) for water to pass through is provided between the diaphragm (300) and the support column (200); the valve body (100) is connected to a water injection assembly (400); the water injection assembly (400) is used to inject water into the first cavity (130); when the first cavity (130) is filled with water, the diaphragm (300) contacts the support column (200) and drives the circulation channel (140) to close.

2. A slow closing check valve according to claim 1, characterized in that: The water injection assembly (400) comprises a first tube (410), one end of the first tube (410) being connected to an end of the valve body (100) close to the water outlet (120), and the other end of the first tube (410) being connected to two first cavities (130).

3. A slow closing check valve according to claim 2, characterized in that: The water injection assembly (400) further comprises a second tube (420), one end of the second tube (420) being connected to an end of the valve body (100) close to the water inlet (110), and the other end of the second tube (420) being connected to the two first cavities (130); the end of the second tube (420) close to the water inlet (110) being connected to a one-way valve (423) for controlling the one-way conduction of water from the valve body (100) to the first cavity (130); the end of the second tube (420) close to the first cavity (130) being connected to a first flow regulating valve (412); and the end of the first tube (410) close to the first cavity (130) being connected to a second flow regulating valve (422).

4. A slow closing check valve according to claim 3, characterized in that: An end of the first tube (410) close to the water inlet (110) and an end of the second tube (420) close to the water outlet (120) are both connected to a filter element, and the filter element is used to filter impurities in water.

5. A slow closing check valve according to claim 1, characterized in that: Arc-shaped grooves (210) are provided on both sides of the support column (200), and the concave arc surface of the arc-shaped groove (210) is arranged toward the diaphragm (300). When the first cavity (130) is filled with water, the diaphragm (300) fits against the inner wall of the arc-shaped groove (210).

6. A slow closing check valve according to claim 5, characterized in that: The diaphragm (300) is provided with reinforcing ribs (310) on both sides along the length direction of the valve body (100); one end of the reinforcing rib (310) is connected to the inner wall of the valve body (100), and the other end of the reinforcing rib (310) is connected to the support column (200); the two reinforcing ribs (310) are respectively provided on both sides of the support column (200) along the length direction of the valve body (100); the reinforcing rib (310) is arranged in an arc shape, and the concave arc surface of the reinforcing rib (310) is arranged toward the diaphragm (300); when the first cavity (130) is filled with water, the diaphragm (300) fits with the concave arc surface of the reinforcing rib (310).

7. A slow closing check valve according to claim 1, characterized in that: The valve body (100) is provided with a through hole (180) on one side along the length direction of the support column (200); the length direction of the through hole (180) is consistent with the length direction of the support column (200); and the through hole (180) passes through the support column (200) and the valve body (100).

8. The slow closing check valve according to claim 3, characterized in that: Both sides of the valve body (100) are connected to valve covers (160), and the valve covers (160) correspond to the diaphragm (300) one by one. The first cavity (130) is formed by the valve cover (160) and the diaphragm (300) spaced apart. The periphery of the diaphragm (300) is pressed against the valve body (100) by the valve cover (160). A storage cavity (161) for storing and returning the diaphragm (300) is provided in the valve cover (160), and the first tube (410) and the second tube (420) are connected to the valve cover (160).

9. A slow closing check valve according to claim 8, characterized in that: A first annular protrusion (320) is connected to a side of the diaphragm (300) close to the valve cover (160); the first annular protrusion (320) is made of a flexible material; the circumference of the first annular protrusion (320) is consistent with the circumference of the diaphragm (300); and the first annular protrusion (320) is in contact with the valve cover (160).

10. A slow closing check valve according to claim 8, characterized in that: A second annular protrusion (330) is connected to a side of the diaphragm (300) close to the valve body (100); the circumference of the second annular protrusion (330) is consistent with the circumference of the diaphragm (300); and the second annular protrusion (330) is in contact with the valve body (100).

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