Slowly-closed swing check valve

Abstract

The utility model discloses a slowly-closed swing check valve, relates to the technical field of check valves, and overcomes the defects of the check valve in the aspects of economy, safety and the like. The pressure damping mechanism comprises a fixing piece and a rotating sleeve, and the fixing piece protrudes outwards in the radial direction of the fixing piece to form a protruding shoulder. A pressure inner cavity is formed between the interior of the rotating sleeve and the outer wall of the fixing piece, the protruding shoulder makes sliding contact with the inner wall of the pressure inner cavity and divides the pressure inner cavity into a first cavity and a second cavity, and the aperture of the first pressure relief hole is smaller than that of the second pressure relief hole. When the rocker rotates in the forward direction, the first cavity is gradually enlarged, the second cavity is gradually reduced, and when the rocker rotates in the reverse direction, the first cavity is gradually reduced, and the second cavity is gradually enlarged. The smooth operation process when the valve clack is closed is achieved; the problems of leakage risk and complexity caused by a traditional external buffering oil cylinder or spring structure are solved, the structure is compact, the whole structure of the valve cannot become huge and complex, the manufacturing cost is reduced, and the safety and economical efficiency of the valve are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of check valves, in particular to a slow-closing swing check valve. Background Art

[0002] As one of the common types of check valves, swing check valves are mainly used to prevent the reverse flow of media and are widely used in many fields such as petroleum, chemical industry, electric power, water supply and drainage, etc. However, in the prior art, in order to slow down the impact of the valve flap on the valve seat when closing, an external buffer oil cylinder or a damping structure such as a spring is usually used for buffering. Although the external buffer oil cylinder can play a buffering role to a certain extent, the external buffer oil cylinder is prone to form artificial leakage points, which may lead to the leakage of the medium. At the same time, the presence of the external buffer oil cylinder makes the structure of the entire valve relatively large and complex, increasing the manufacturing cost.

[0003] Using a spring as a damping structure also has some defects. For example, the swing check valve mentioned in the Chinese invention patent CN110397769B adopts a spring structure. Although this structure can reduce the impact between the valve flap and the valve seat when closing to a certain extent, the complexity of the spring structure is relatively high. During long-term use, the spring is prone to elastic fatigue, resulting in a decrease in its buffering performance, thereby affecting the overall performance of the valve. Moreover, the complex structure also increases the difficulty of maintenance and repair of the valve. Content of the Utility Model

[0004] The purpose of the utility model: In order to overcome the defects of the prior art, the utility model provides a slow-closing swing check valve to make up for the deficiencies in terms of economy, safety and structural complexity of the check valve.

[0005] Technical solution of the utility model: It includes a valve flap, a valve body, a rocker and a fork member. The fork member is fixed inside the valve body. The rocker is fixedly connected to the valve flap. The fork member is rotatably connected to the rocker. A pressure damping mechanism is provided at the connection between the fork member and the rocker. The pressure damping mechanism includes a fixed member and a rotating sleeve located at the rotating position of the rocker. The fixed member is fixedly connected to the fork member and movably penetrates through the rotating sleeve. The fixed member protrudes radially outwards with a shoulder. A pressure inner cavity is formed between the inner wall of the rotating sleeve and the outer wall of the fixed member. The shoulder slidably contacts the inner wall of the pressure inner cavity and divides the pressure inner cavity into a first chamber and a second chamber. First pressure relief holes penetrating inside and outside the first chamber are respectively opened at the inner wall of the first chamber. Second pressure relief holes penetrating inside and outside the second chamber are respectively opened at the inner wall of the second chamber. The aperture of the first pressure relief hole is smaller than that of the second pressure relief hole. The opening process of the valve flap is regarded as the positive direction according to the rotation direction of the rocker movement. The closing process of the valve flap is regarded as the reverse direction according to the rotation direction of the rocker movement. The first chamber and the second chamber are respectively located in the positive direction and the reverse direction of the shoulder, so that when the rocker rotates in the positive direction, the first chamber gradually expands and the second chamber gradually shrinks, and when the rocker rotates in the reverse direction, the first chamber gradually shrinks and the second chamber gradually expands.

[0006] By adopting the above technical solution, by providing a pressure damping mechanism at the connection between the fork member and the rocker, a smooth operation process when the valve flap closes is realized; when the valve flap closes and the rocker rotates in the reverse direction, the volume of the first chamber decreases, and the internal medium slowly discharges through the smaller first pressure relief hole, resulting in a gradual increase in the pressure inside the first chamber, thereby forming a resistance to the closing speed of the valve flap and playing a buffering role; when the valve flap opens and the rocker rotates in the positive direction, the volume of the second chamber decreases. Due to its larger second pressure relief hole, it allows rapid liquid discharge and does not affect the opening speed of the valve flap. In this way, the leakage risk and complexity problems brought by the traditional external buffer oil cylinder or spring structure are avoided, the safety of the valve is improved. At the same time, its structure is compact, the overall structure of the valve will not become large and complex, the manufacturing cost is reduced, and the economy is improved.

[0007] In a possible design, a square pin is fixedly inserted inside the fixed member, and both ends of the square pin are fixedly inserted on the fork member.

[0008] By adopting the above design, this structure enhances the stability of the connection between the fixed member and the fork member. During the frequent opening and closing process of the valve flap, it can ensure that the fixed member of the pressure damping mechanism will not be displaced or loosened, guarantee the stable operation of the pressure damping mechanism, and make the buffering effect continuous and reliable.

[0009] In a possible design, covers are respectively covered and fixed on both axial sides of the rotating sleeve. The covers are also fixedly connected to the fixed member and the joint between the two is sealed by a sealing member.

[0010] With the above design, the cover not only protects the pressure inner cavity inside the rotating sleeve from the external environment except the pressure relief hole, ensures the fluidity of the medium inside the pressure inner cavity and the stability of the pressure change, and guarantees the normal function of the buffering function, but also ensures the sealing performance of the whole system through the seal, preventing possible medium leakage.

[0011] In a possible design, the aperture diameter of the second pressure relief hole is 3 to 5 times that of the first pressure relief hole.

[0012] With the above design, this aperture ratio can better adapt to the different speed requirements when the valve flap opens and closes. This optimization of the aperture ratio enables the check valve to take into account the requirements of rapid opening while meeting the slow closing function, comprehensively improving the working performance of the valve. Description of the Drawings

[0013] Figure 1 is a cross-sectional view of the whole of the present utility model;

[0014] Figure 2 is of the present utility model Figure 1 is a partial structural cross-sectional view of the A-A plane in;

[0015] Figure 3 is in the closed state of the present utility model Figure 2 is a cross-sectional view of the B-B plane in;

[0016] Figure 4 is in the open state of the present utility model Figure 2 is a cross-sectional view of the B-B plane in;

[0017] Wherein, 1. valve flap; 2. valve body; 3. rocker; 4. fork member; 5. pressure damping mechanism; 51. fixing member; 511. shoulder; 52. rotating sleeve; 53. pressure inner cavity; 531. first chamber; 532. second chamber; 541. first pressure relief hole; 542. second pressure relief hole; 55. square pin; 56. cover; 57. seal. Detailed Embodiment

[0018] Such as Figures 1 to 4A kind of slow-closing swing check valve shown in the figure includes a valve flap 1, a valve body 2, a rocker 3 and a fork member 4. The fork member 4 is fixed to the inner wall of the valve body 2. The rocker 3 is fixedly connected to the valve flap 1 through a bolt, and the fork member 4 is rotatably connected to the rocker 3. A pressure damping mechanism 5 is arranged at the connection between the fork member 4 and the rocker 3. The pressure damping mechanism 5 includes a fixed member 51 and a rotating sleeve 52 located at the rotating position of the rocker 3. The fixed member 51 is fixedly connected to the fork member 4 and is movably inserted into the rotating sleeve 52. The fixed member 51 has a shoulder 511 protruding radially outward; a pressure inner cavity 53 is formed between the inner wall of the rotating sleeve 52 and the outer wall of the fixed member 51. The shoulder 511 slidably contacts the inner wall of the pressure inner cavity 53. The shoulder 511 and the pressure inner cavity 53 are in clearance fit, and the pressure inner cavity 53 is divided into a first chamber 531 and a second chamber 532 by the shoulder 511. First pressure relief holes 541 communicating with the inside and outside of the first chamber 531 are respectively formed at the inner wall of the first chamber 531, and second pressure relief holes 542 communicating with the inside and outside of the second chamber 532 are respectively formed at the inner wall of the second chamber 532. The first pressure relief holes 541 and the second pressure relief holes 542 are both formed on the rotating sleeve 52. The aperture of the first pressure relief holes 541 is smaller than that of the second pressure relief holes 542; when the valve flap 1 opens, the rotation direction of the rocker 3 is regarded as the positive direction, and when the valve flap 1 closes, the rotation direction of the rocker 3 is regarded as the negative direction. The first chamber 531 and the second chamber 532 are respectively located in the positive direction and the negative direction of the shoulder 511, so that when the rocker 3 rotates in the positive direction, the first chamber 531 gradually expands and the second chamber 532 gradually shrinks, and when the rocker 3 rotates in the negative direction, the first chamber 531 gradually shrinks and the second chamber 532 gradually expands.

[0019] The working principle of the swing check valve of the present application is as follows:

[0020] Opening process: When the swing check valve is in the closed state and needs to be opened, the valve flap 1 starts to drive the rocker 3 to move in the opening direction under the action of the medium pressure. The rocker 3 rotates in the positive direction (the positive direction is counterclockwise in the figure). As the rocker 3 rotates, the change in the relative position between the fork 4 and the rocker 3 causes the volume of the first chamber 531 on the positive side of the shoulder 511 in the pressure inner cavity 53 to gradually expand, while the volume of the second chamber 532 on the opposite side of the shoulder 511 gradually decreases. As the volume of the first chamber 531 expands, the internal pressure decreases. Under the action of the pressure difference, the external medium will try to enter the first chamber 531 through the first pressure relief hole 541 for filling. However, due to the small aperture of the first pressure relief hole 541, the inflow speed of the medium is slow, and the pressure in the first chamber 531 cannot reach the equilibrium state with the outside quickly in a short time. As a result, the pressure in the first chamber 531 remains at a relatively low level for a period of time and rises slowly. The volume of the second chamber 532 decreases, and the internal pressure increases, and the medium will flow out through the second pressure relief hole 542. Since the aperture of the second pressure relief hole 542 is relatively large, the medium in the second chamber 532 can be discharged quickly to ensure that its volume can shrink smoothly as the rocker 3 rotates. The aperture of the second pressure relief hole 542 at the inner wall of the second chamber 532 is large. When the volume of the second chamber 532 becomes smaller, the liquid in it can quickly flow out through the second pressure relief hole 542, without forming an obvious obstacle to the counterclockwise rotation of the rocker 3, so that the valve flap 1 can be quickly opened to meet the requirement of rapid fluid passage. At the same time, the volume of the first chamber 531 becomes larger, and the medium is inhaled through the first pressure relief hole 541 to ensure the pressure stability in the pressure inner cavity 53 and also prepare for the subsequent possible closing action, making the whole valve efficient and smooth during the opening process and basically not affecting the fluid transportation efficiency.

[0021] Closing process: When the valve is initially in the open position, the valve flap 1 drives the rocker 3 to perform a closing movement, and the rocker 3 rotates in the opposite direction (clockwise in the illustrated figure). At this time, as the rocker 3 rotates, the relative position of the fixed part 51 and the rotating sleeve 52 in the pressure damping mechanism 5 changes. The clockwise rotation of the rocker 3 makes the volume of the first chamber 531 smaller and the volume of the second chamber 532 larger. When the volume of the first chamber 531 becomes smaller, the speed of the medium discharged through the first pressure relief hole 541 is limited and cannot be emptied instantly, thus forming a certain pressure in the chamber. This pressure will prevent the rocker 3 from rotating further quickly, and then make the valve flap 1 slowly move towards the valve seat. At the same time, the volume of the second chamber 532 becomes larger, and it inhales liquid through the second pressure relief hole 542 with a larger aperture. Because the aperture of the second pressure relief hole 542 is large, the speed of inhaling liquid is fast, which basically does not affect the buffering rhythm of the closing action of the valve flap 1. Since the aperture of the first pressure relief hole 541 is smaller than the volume change requirement of the second chamber 532 in the same time, the discharge capacity of the first pressure relief hole 541 is less than the volume reduction of the first chamber 531, that is, the discharge speed of the first pressure relief hole 541 cannot keep up with the speed of the volume reduction of the first chamber 531, so it takes a certain amount of time for the medium in the first chamber 531 to be emptied. It maintains the pressure balance of the overall pressure inner cavity 53, ensures the smooth progress of the buffering process, and finally realizes the slow closing of the valve flap 1 to avoid violent impact with the valve seat.

[0022] Since the impact of the valve flap 1 on the valve seat is reduced, the problems of poor buffering caused by the easy leakage of the traditional external buffer oil cylinder and the easy fatigue of the spring are avoided. To a certain extent, the slow closing effect is improved, and the protection of the key components of the valve is stronger. Due to the improvement of the buffering performance, the wear and stress generated by the impact at the moment of closing between the valve flap 1 and the valve seat are reduced. This not only reduces the failure rate of the valve during daily operation, but also slows down the wear speed of each component of the valve, effectively extending the overall service life of the valve.

[0023] A square pin 55 is fixedly inserted into the fixed part 51. The cross-section of the square pin 55 is hexagonal, and both ends of the square pin 55 are fixedly inserted into the fork part 4. During the long-term operation of the valve, especially when it bears frequent pressure changes and dynamic impacts, this method can effectively prevent the fixed part 51 from displacing, shaking, etc.

[0024] Axial two sides of the rotating sleeve 52 are respectively covered and fixed with end covers 56. The end covers 56 are also fixedly connected with the fixing member 51, and the joint between the two is sealed by a sealing member 57. The sealing member 57 can be an O-ring. In this way, the end cover 56 can ensure that there is no other leakage position in the pressure inner cavity 53 except for the first pressure relief hole 541 and the second pressure relief hole 542, preventing the medium between the pressure inner cavity 53 and the external environment from leaking out, enabling the application of the buffering force to be carried out continuously and effectively in a predetermined manner, and ensuring the consistency and reliability of the slow-closing effect of the pressure damping mechanism 5 on the valve flap 1.

[0025] The aperture of the second pressure relief hole 542 is 3 to 5 times that of the first pressure relief hole 541. By adjusting the aperture difference between the two, the opening and closing speeds of the valve flap 1 will be different, which can be adapted to different medium pressures, provide the most suitable buffering force when the valve flap 1 is about to contact the valve seat, so as to select the scenario that meets the slow-closing requirements. Even by designing the aperture of the second pressure relief hole 542 to be smaller than that of the first pressure relief hole 541, some check valve scenarios requiring slow opening can be realized.

Claims

1. A slow-closing swing check valve, comprising a valve disc (1), a valve body (2), a rocker (3) and a fork (4), wherein the fork (4) is fixed in the valve body (2), the rocker (3) is fixedly connected to the valve disc (1), and the fork (4) is connected to the rocker (3) for relative rotation, characterized in that: A pressure damping mechanism (5) is provided at the connection between the fork member (4) and the rocker (3), the pressure damping mechanism (5) comprising a fixing member (51) and a rotating sleeve (52) located at the rotation position of the rocker (3), the fixing member (51) being fixedly connected to the fork member (4) and movably inserted into the rotating sleeve (52), the fixing member (51) being provided with a convex shoulder (511) protruding outwardly along its radial direction; a pressure inner chamber (53) is formed between the inner wall of the rotating sleeve (52) and the outer wall of the fixing member (51), the convex shoulder (511) slidingly contacts the inner wall of the pressure inner chamber (53) and the convex shoulder (511) divides the pressure inner chamber (53) into a first chamber (531) and a second chamber (532), the inner wall of the first chamber (531) being provided with a first pressure relief opening penetrating the inside and outside of the first chamber (531) The second chamber (532) has a second pressure relief hole (542) extending through the inside and outside of the second chamber (532), and the diameter of the first pressure relief hole (541) is smaller than the diameter of the second pressure relief hole (542). The valve flap (1) is opened in the rotation direction of the rocker (3) as the positive direction, and the valve flap (1) is closed in the rotation direction of the rocker (3) as the negative direction. The first chamber (531) and the second chamber (532) are respectively located in the positive direction and the negative direction of the boss (511), so that when the rocker (3) rotates in the positive direction, the first chamber (531) gradually expands and the second chamber (532) gradually shrinks, and when the rocker (3) rotates in the negative direction, the first chamber (531) gradually shrinks and the second chamber (532) gradually expands.

2. The slow-closing swing check valve according to claim 1, characterized in that: A square pin (55) is fixedly inserted into the fixing member (51), and both ends of the square pin (55) are fixedly inserted into the fork member (4).

3. The slow-closing swing check valve according to claim 1 or 2, characterized in that: The rotating sleeve (52) is covered and fixedly provided with sealing covers (56) on both axial sides respectively. The sealing covers (56) are also fixedly connected to the fixing member (51), and the joint between the two is sealed by a sealing member (57).

4. The slow-closing swing check valve according to claim 1 or 2, characterized in that: The diameter of the second pressure relief hole (542) is 3 to 5 times the diameter of the first pressure relief hole (541).

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