Double-piston type axial-flow check valve

Abstract

The utility model relates to the technical field of valves, and particularly discloses a double-piston type axial-flow check valve which comprises a valve body, a valve seat, a valve clack, pistons, an elastic piece and a flow guide cover. A water inlet and a water outlet are formed in the two sides of the valve body respectively, the valve seat is installed at the water inlet of the valve body, the valve clack is located on the side, close to the water inlet, in the valve body, the flow guide cover is located on the side, away from the water inlet, in the valve body, a piston sleeve is fixedly connected to the inner side of the flow guide cover, and the piston is slidably installed in the piston sleeve. A guide rod is fixedly connected between the piston and the valve clack, the piston sleeve comprises a first piston cavity and a second piston cavity which are adjacently arranged, the diameter of the first piston cavity is larger than that of the second piston cavity, the first piston cavity is located on the side, away from the valve clack, of the piston sleeve, and the second piston cavity is located on the side, close to the valve clack, of the piston sleeve. According to the check valve, the impact of the valve clack on the valve seat when the valve is closed is reduced, the damage of the water hammer effect of the valve to equipment is reduced, the service life of the valve is prolonged, and the noise of the valve is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of valves, and more specifically to a double-piston axial flow check valve. Background Technology

[0002] A check valve, also known as a non-return valve or one-way valve, is used to prevent fluid backflow. It is typically installed in piping systems to allow the medium to flow freely in one direction while preventing flow in the opposite direction. The design principle of a check valve relies on its internal valve disc, which automatically opens or closes under fluid pressure.

[0003] When the valve is open, the inlet pressure is high. Under the action of the medium, the valve disc moves away from the inlet and comes into contact with the flow guide. At this time, the medium flows into the valve outlet along the flow channel between the flow guide and the valve body. When the valve inlet pressure is low, the valve disc moves towards the valve inlet under the combined action of the medium force and elastic force until it comes into contact with the valve inlet, preventing the medium from flowing backward.

[0004] During valve closure, a piston structure is typically installed inside the flow guide to slow the valve disc's movement towards the inlet. Most piston structures are single-piston designs, where a piston sleeve is placed inside the flow guide, and the piston slides within the sleeve. Simultaneously, the piston is connected to the valve disc via a guide rod. In this type of structure, during valve closure, the force exerted by the medium and the elastic force on the valve disc are always greater than the frictional force between the guide rod and the guide seat, the viscous damping force generated by the shear deformation of the medium within the piston sleeve, and the heat energy generated by the medium under piston pressure. Therefore, the valve disc's movement speed gradually accelerates until the valve is completely closed.

[0005] Regarding the aforementioned technologies, since the valve disc is constantly accelerating as it approaches the closed position at the instant the valve closes, the valve seat and valve disc will be subjected to a large impact. As a result, the water hammer effect generated by the valve will damage pipelines, equipment and instruments, thereby reducing the service life of the valve and generating a lot of valve noise. Utility Model Content

[0006] In order to reduce the impact of the valve disc on the valve seat when the valve is closed and reduce the damage of water hammer effect to pipelines, equipment and instruments, this application provides a double piston axial flow check valve.

[0007] This application provides a dual-piston axial flow check valve, which adopts the following technical solution:

[0008] A double-piston axial flow check valve includes a valve body, a valve seat, a valve disc, a piston, and a flow guide. The valve body has an inlet and an outlet on both sides. The valve seat is installed at the inlet of the valve body. The valve disc and flow guide are both located within the valve body. The valve disc is located within the valve body near the inlet and abuts against the valve seat. The flow guide is located within the valve body away from the inlet. A piston sleeve is fixedly connected to the inner side of the flow guide, and the piston is slidably installed within the piston sleeve. A guide rod is fixedly connected between the piston and the valve disc, and an elastic element is sleeved on the guide rod. One end of the elastic element abuts against the valve disc, and the other end acts on the piston sleeve. The piston sleeve includes a first piston chamber and a second piston chamber arranged adjacent to each other. The diameter of the first piston chamber is larger than the diameter of the second piston chamber. The first piston chamber is located on the piston sleeve away from the valve disc, and the second piston chamber is located on the piston sleeve near the valve disc.

[0009] By adopting the above technical solution, when the valve is opened, the inlet pressure is greater than the sum of the outlet pressure and the elastic force. Under the action of the medium, the valve disc drives the guide rod and piston to move away from the inlet, and the elastic element is compressed until the valve disc abuts against the flow guide. At this time, the medium flows into the valve outlet along the flow channel between the flow guide and the valve body. When the sum of the medium force and the elastic force on the valve disc is greater than the inlet pressure of the valve disc, the valve disc, under the combined action of the medium force and the elastic force, drives the guide rod and piston to move towards the valve inlet. The elastic element gradually elongates until the valve disc abuts against the valve seat and forms a sealing fit with the valve seat, preventing the medium from flowing backward. This process realizes the automatic closure of the valve. The double-piston axial flow check valve of this application not only significantly reduces the impact of the valve disc on the valve seat when the valve is closed, reduces the damage of water hammer effect to pipelines, equipment and instruments, and extends the service life of the valve, but also reduces valve noise, ensures the safe operation of the check valve, and provides a stable flow control function for the safe operation of the check valve.

[0010] Preferably, it also includes a guide seat, which is fixedly connected to the side of the piston sleeve near the valve disc. The guide seat is sleeved on the guide rod and slides with the guide rod. The end of the elastic element away from the valve disc abuts against the guide seat.

[0011] By adopting the above technical solution, the elastic element abuts against the guide seat and acts on the piston sleeve through the guide seat. The guide seat accurately positions and guides the guide rod, ensuring that the guide rod can move in a straight line along a predetermined trajectory during the movement. The guide seat plays a key supporting role in the movement of the guide rod.

[0012] Preferably, the guide seat is stepped, and the stepped surface of the guide seat near the valve disc abuts against the elastic element.

[0013] By adopting the above technical solution, the stepped structure can effectively distribute and bear the pressure from the mating components, avoid excessive load on a single point or local area, thereby extending the service life of the guide seat. The stepped structure can also facilitate the installation and disassembly of the guide seat.

[0014] Preferably, the end of the guide rod away from the valve disc is formed with a connecting rod, which is inserted into the piston and fixedly connected to the piston coaxially.

[0015] By adopting the above technical solution, it is ensured that the piston can move accurately in a straight line along the axis of the connecting rod during operation, thereby improving the stability and accuracy of the check valve.

[0016] Preferably, the piston is radially perforated with a second connecting pin, which also passes through the connecting rod and is fixedly connected to the connecting rod.

[0017] By adopting the above technical solution, the second connecting pin is used to ensure the correct positioning of the piston in the check valve and prevent it from rotating or deviating. At the same time, this connection method is used to ensure the synchronous movement of the piston and the guide rod.

[0018] Preferably, the valve disc consists of a valve disc body and a connecting sleeve. The connecting sleeve is fixed on the side of the valve disc body away from the water inlet and is used to connect with the guide rod. The valve disc body is adapted to the valve seat and is used to abut against the valve seat.

[0019] By adopting the above technical solution, the valve disc body is mainly responsible for the cut-off and regulation of the medium, while the connecting sleeve is responsible for ensuring the stability and reliability of the valve disc. Together, they constitute the core components of the check valve, ensuring that the check valve can work normally.

[0020] Preferably, a first connecting pin is provided on the connecting sleeve, and the first connecting pin is also inserted into the guide rod near the valve disc.

[0021] By adopting the above technical solution, the first connecting pin is used to maintain the stability of the valve disc and prevent the valve disc from moving or rotating during use. This design helps to improve the reliability of the check valve.

[0022] Preferably, the elastic element is a spring, with one end of the spring abutting against the valve disc and the other end acting on the piston sleeve.

[0023] By adopting the above technical solution, the elastic element can control and adjust the movement state of the check valve, thereby improving the stability and reliability of the check valve.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. A double-piston axial flow check valve can significantly reduce the impact of the valve disc on the valve seat when the valve is closed; reduce the damage of water hammer effect on pipelines, equipment and instruments; extend the service life of the valve; and reduce valve noise.

[0026] 2. The valve disc body is mainly responsible for cutting off and regulating the medium, while the connecting sleeve is responsible for ensuring the stability and reliability of the valve disc. Together, they constitute the core components of the check valve, ensuring that the check valve can work normally.

[0027] 3. The first connecting pin is used to maintain the stability of the valve disc and prevent it from moving or rotating during use. This design helps improve the reliability of the check valve and ensures that it can work normally under various operating conditions. The second connecting pin is used to ensure the correct positioning of the piston within the check valve and prevent it from rotating or deviating. At the same time, this connection method is used to ensure that the piston and connecting rod move synchronously, so that the reciprocating linear motion of the piston transmits force to the connecting rod. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the check valve in the closed state in the embodiments of this application;

[0029] Figure 2 This is a schematic diagram of the check valve in the open state in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram illustrating the piston chamber structure in an embodiment of this application.

[0031] Reference numerals in the attached drawings: 1. Valve body; 2. Valve seat; 3. Valve disc; 31. Valve disc body; 32. Connecting sleeve; 4. Flow guide; 5. Piston sleeve; 51. First piston chamber; 52. Second piston chamber; 6. Piston; 7. Guide rod; 8. First connecting pin; 9. Second connecting pin; 10. Elastic element; 11. Inlet; 12. Outlet; 13. Guide seat; 14. Connecting rod. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail.

[0033] This application discloses a double-piston axial flow check valve.

[0034] Reference Figure 1A double-piston axial flow check valve includes a valve body 1, a valve seat 2, a valve disc 3, and a flow guide 4. The valve body 1 has a hollow structure, with an inlet 11 and an outlet 12 on both sides. The valve seat 2 is installed at the inlet 11 of the valve body 1. The valve disc 3 and the flow guide 4 are both located inside the valve body 1. The valve disc 3 is located inside the valve body 1 near the inlet 11 and is used to abut against the valve seat 2. The flow guide 4 is located inside the valve body 1 away from the inlet 11 and is integrally connected to the valve body 1. A piston sleeve 5 is fixedly connected to the inside of the flow guide 4, and a piston 6 is provided inside the piston sleeve 5. The piston sleeve 5 and the piston 6 are slidably connected. A guide rod 7 is fixedly connected between the piston 6 and the valve disc 3. At the same time, an elastic element 10 is sleeved on the guide rod 7. One end of the elastic element 10 abuts against the valve disc 3, and the other end acts on the piston sleeve 5.

[0035] When the valve is opened, the pressure at the inlet 11 is greater than the sum of the pressure at the outlet 12 and the elastic force. Under the action of the medium, the valve disc 3 drives the guide rod 7 and the piston 6 to move away from the inlet 11. The elastic element 10 is compressed until the valve disc 3 comes into contact with the flow guide 4. At this time, the medium flows into the valve outlet 12 along the flow channel between the flow guide 4 and the valve body 1.

[0036] When the sum of the medium force and the elastic force on valve disc 3 exceeds the pressure at valve disc 3 inlet 11, valve disc 3, under the combined action of the medium force and the elastic force, drives guide rod 7 and piston 6 to move towards valve inlet 11. The elastic element 10 gradually extends until valve disc 3 abuts against valve seat 2 and forms a sealing fit with valve seat 2, preventing reverse flow of the medium. This process achieves automatic valve closure.

[0037] Specifically, valve seat 2, valve disc 3, and flow guide shroud 4 are located on the same axis. Valve disc 3 consists of valve disc body 31 and connecting sleeve 32. Valve disc body is adapted to valve seat. Connecting sleeve 32 is fixed on the side of valve disc body 31 away from water inlet 11. Connecting sleeve 32 is used to connect with guide rod 7. Valve disc body 31 abuts against valve seat 2 to block water inlet 11. When the pressure of water inlet 11 increases, valve disc body 31 disengages from valve seat 2, and valve is opened.

[0038] In this embodiment, when the valve disc 3 abuts against the valve seat 2, the valve disc body 31 and the valve seat 2 are sealed together. A connecting sleeve 32 is fitted onto the end of the guide rod 7, and a first connecting pin 8 passes through the connecting sleeve 32. The first connecting pin 8 also inserts into the guide rod 7 to fix the valve disc 3 and the guide rod 7 in the axial direction of the guide rod 7. The connecting sleeve 32 is stepped, and the stepped surface of the connecting sleeve 32 abuts against the elastic element 10.

[0039] A connecting rod 14 is formed at the end of the guide rod 7 away from the valve disc 3. The connecting rod 14 is inserted into the piston 6 and is coaxially and fixedly connected to the piston 6. A second connecting pin 9 is radially inserted through the piston 6 and simultaneously inserted into the connecting rod 14.

[0040] The piston sleeve 5 and the flow guide shroud 4 are integrally formed. A guide seat 13 is fixedly connected to the side of the piston sleeve 5 near the valve disc 3. A circular mounting groove is formed on the inner wall of the piston sleeve 5 near the valve disc 3. The guide seat 13 is fixedly installed in the circular mounting groove. The piston sleeve 5 and the guide seat 13 are connected by screws.

[0041] The guide seat 13 is stepped, with its stepped surface near the valve disc 3 abutting against the elastic element 10. The guide rod 7 passes through the guide seat 13 and slides within it. As the valve disc 3 moves within the valve body 1, it drives the guide rod 7 to slide within the guide seat 13. The guide seat 13 guides and limits the guide rod 7, improving the accuracy of the valve disc 3 during axial movement, preventing offset or jamming, and helping to improve the control accuracy and stability of the valve, ensuring smooth and reliable opening and closing of the valve.

[0042] In this embodiment, the elastic element 10 is selected as a spring.

[0043] Furthermore, the piston sleeve 5 includes a first piston chamber 51 and a second piston chamber 52. The diameter of the first piston chamber 51 is larger than the diameter of the second piston chamber 52. The first piston chamber 51 is located on the side of the piston sleeve 5 away from the valve disc 3, and the second piston chamber 52 is located on the side of the piston sleeve 5 closer to the valve disc 3. The first piston chamber 51 and the second piston chamber 52 are arranged adjacent to each other. In this embodiment, the piston 6 is cylindrical, and the first piston chamber 51 and the second piston chamber 52 are cylindrical cavities adapted to the piston 6.

[0044] When the valve tends to close, the valve disc 3 moves towards the valve seat 2 under the combined action of the medium force and the spring force, driving the piston 6 to move towards the inlet 11. When the piston 6 enters the first piston chamber 51, there is a large gap between the first piston chamber 51 and the piston 6. The medium flows into the gap between the first piston chamber 51 and the piston 6. The piston 6 squeezes the medium in the first piston chamber 51. The medium between the first piston chamber 51 and the piston 6 undergoes shear deformation, generating a viscous damping force. This viscous damping force can reduce the movement speed of the piston 6 and the piston sleeve 5 when they slide relative to each other, thereby reducing the closing speed of the valve disc 3.

[0045] The gap between the second piston chamber 52 and the piston 6 is smaller than the gap between the first piston chamber 51 and the piston 6. When the piston 6 enters the second piston chamber 52 from the first piston chamber 51, since the diameter of the second piston chamber 52 is smaller than the diameter of the first piston chamber 51, the medium in the second piston chamber 52 is excited by the pressure of the piston 6 and moves along the annular surface between the piston 6 and the second piston chamber 52. Among them, a part of the medium undergoes shear deformation to form viscous damping force, which greatly reduces the valve stroke speed; a part of the medium generates heat energy under the action of the piston 6 pressure, which consumes the energy generated by the guide rod 7 driving the piston 6 to move, thereby reducing the closing speed of the valve disc 3 and achieving the function of "slow closing" when the valve is closed.

[0046] The implementation principle of this application embodiment is as follows:

[0047] When the pressure at the inlet 11 is greater than the sum of the pressure at the outlet 12 and the spring force, the valve disc 3, under the action of the medium, drives the guide rod 7 and the piston 6 to move away from the inlet 11. The elastic element 10 is compressed until the valve disc 3 comes into contact with the flow guide shroud 4. At this time, the medium flows into the valve outlet 12 along the flow channel between the flow guide shroud 4 and the valve body 1, and the check valve opens.

[0048] When the sum of the pressure at the outlet 12 and the elastic force of the spring 10 is greater than the pressure at the inlet, the valve disc 3, under the combined action of the medium force and the spring force, drives the guide rod 7 and the piston 6 to move toward the valve inlet 11. The elastic element 10 gradually extends until the valve disc 3 abuts against the valve seat 2 and forms a sealing fit with the valve seat 2, and the valve disc 3 closes.

[0049] The dual-piston axial flow check valve of this application embodiment not only significantly reduces the impact of valve disc 3 on valve seat 2 when the valve is closed, reducing the damage of valve water hammer effect to pipelines, equipment and instruments, and extending the service life of the valve, but also reduces valve noise, ensuring the safe operation of the check valve, and providing a stable flow control function for the safe operation of the check valve.

[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A double-piston axial flow check valve, characterized in that, The valve body (1) includes a valve seat (2), a valve disc (3), a piston (6), and a flow guide (4). The valve body (1) has an inlet (11) and an outlet (12) on each side. The valve seat (2) is installed at the inlet (11) of the valve body (1). The valve disc (3) and the flow guide (4) are both located inside the valve body (1). The valve disc (3) is located inside the valve body (1) near the inlet (11) and is used to abut against the valve seat (2). The flow guide (4) is located inside the valve body (1) away from the inlet (11). A piston sleeve (5) is fixedly connected to the inner side of the flow guide (4). The piston (6) is slidably installed on the piston sleeve. Inside the tube (5); a guide rod (7) is fixedly connected between the piston (6) and the valve disc (3), and an elastic element (10) is sleeved on the guide rod (7); one end of the elastic element (10) abuts against the valve disc (3), and the other end acts on the piston sleeve (5); the piston sleeve (5) includes a first piston chamber (51) and a second piston chamber (52) arranged adjacent to each other, the diameter of the first piston chamber (51) is larger than the diameter of the second piston chamber (52), the first piston chamber (51) is located on the side of the piston sleeve (5) away from the valve disc (3), and the second piston chamber (52) is located on the side of the piston sleeve (5) close to the valve disc (3).

2. The double-piston axial flow check valve according to claim 1, characterized in that, It also includes a guide seat (13), which is fixedly connected to the piston sleeve (5) on the side near the valve disc (3). The guide seat (13) is sleeved on the guide rod (7) and slides with the guide rod (7). The end of the elastic element (10) away from the valve disc (3) abuts against the guide seat (13).

3. A double-piston axial flow check valve according to claim 2, characterized in that, The guide seat (13) is stepped, and the stepped surface of the guide seat (13) near the valve disc (3) abuts against the elastic member (10).

4. The double-piston axial flow check valve according to claim 1, characterized in that, The guide rod (7) has a connecting rod (14) formed at the end away from the valve disc (3). The connecting rod (14) is inserted into the piston (6) and is coaxially and fixedly connected to the piston (6).

5. A double-piston axial flow check valve according to claim 4, characterized in that, The piston (6) is radially provided with a second connecting pin (9), which simultaneously passes through the connecting rod (14).

6. A double-piston axial flow check valve according to claim 1, characterized in that, The valve disc (3) is divided into a valve disc body (31) and a connecting sleeve (32). The connecting sleeve (32) is fixed on the side of the valve disc body (31) away from the water inlet (11). The connecting sleeve (32) is used to connect with the guide rod (7). The valve disc body is adapted to the valve seat. The valve disc body (31) is used to abut against the valve seat (2).

7. A double-piston axial flow check valve according to claim 6, characterized in that, The connecting sleeve (32) is provided with a first connecting pin (8), which is inserted into the guide rod (7) near the valve disc (3).

8. A double-piston axial flow check valve according to claim 1, characterized in that, The elastic element (10) is a spring, one end of which abuts against the valve disc (3) and the other end acts on the piston sleeve (5).

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