Device for controlling slow closing of check valve and check valve

Abstract

The invention relates to the technical field of pipeline valves, in particular to a device for controlling slow closing of a check valve, the check valve and a brake, a shell of the brake can axially rotate on a base of the brake, and the brake drives a brake assembly through an internal brake piston to generate friction braking with the shell of the brake; a piston rod of the double-acting piston cylinder is fixedly connected with a shell of the brake through the overturning assembly. The brake fluid storage tank is in one-way communication with a fluid inlet cavity of the double-acting piston cylinder and the brake piston through a first pipeline, the brake fluid storage tank is in two-way communication with the fluid inlet cavity of the double-acting piston cylinder and the brake piston through a second pipeline, and a control valve is arranged on the second pipeline. The brake fluid storage tank is bidirectionally communicated with the fluid return cavity through a third pipeline; friction braking is generated through the braking assembly and the brake shell, the slow closing effect of the valve clack is achieved, the slow closing effect is stable, the water hammer effect is remarkably eliminated, and when a water pump is started, the valve clack of the check valve can be easily and normally opened.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline valves, and in particular to a device for controlling the slow closing of a check valve and a check valve. Background Art

[0002] In the water supply system, a check valve is usually installed at the outlet of the water pump to prevent the water in the pipeline from flowing back to the water pump when the water pump stops running, so as to avoid causing the water pump to reverse and protect the water pump equipment. Therefore, a weight is installed on the valve stem of the existing pipeline check valve. When fluid passes through the check valve, the water flow needs to overcome the gravity of the weight to open the valve flap of the check valve. When the water pump is suddenly closed, stopped or fails, the water flow in the pipeline will continue to flow due to inertia. When the flow stops, the water in the closed pipeline will flow back in the opposite direction. The pipeline check valve can also quickly close the valve flap under the action of the weight. However, the water flow generates a high-pressure shock wave flow in the closed pipeline to produce a water hammer effect. The water hammer effect may cause the pipeline to bear a load far exceeding the normal working pressure, resulting in pipeline rupture and leakage, shortening the service life of the pipeline. Under the impact of water hammer for a long time, the connection parts of the pipeline such as flanges, elbows, tees, etc. are easy to loosen, causing sealing failure.

[0003] To this end, the prior art eliminates the water hammer effect by setting a slow-closing check valve, such as a slow-closing check valve with patent number CN202021173186.8, in which a heavy hammer is fixed to the valve stem end outside the valve body through a connecting rod, the oil cylinder is hinged and fixed to the outside of the valve body through an L-shaped base, and the extended end of the oil cylinder piston rod is hinged and fixed to the valve stem end outside the valve body. During the working process, the oil cylinder is lifted by the transmission belt connected between the valve stem, the heavy hammer, the connecting rod, and the oil cylinder seat. When closing, the self-weight of the valve disc plus the drooping force of the heavy hammer and the medium return force act on the oil cylinder to slowly close the valve disc. However, in the first stage of the valve disc closing, the action area of ​​the reflux liquid and the valve disc is small, and the slow closing effect is obvious. Since the oil return speed of the oil cylinder is determined by the pressure, as the valve disc gradually approaches closing, the action area of ​​the reflux liquid and the valve disc becomes larger, the pressure increases, resulting in an accelerated oil return speed of the oil cylinder, and the valve disc closes quickly, which still produces a water hammer effect, so the slow closing effect is not stable. Summary of the invention

[0004] In order to solve the problem in the prior art that the slow-closing check valve has the problem that the valve disc will still close quickly, resulting in poor slow-closing effect and the water hammer effect still existing, the present invention provides a device for controlling the slow closing of the check valve, which has the characteristics of stable slow-closing effect and obvious effect of eliminating water hammer effect.

[0005] In order to achieve the above objectives, the following technical solutions are provided:

[0006] A device for controlling the slow closing of a check valve, comprising:

[0007] The brake, the housing of the brake can rotate axially on the base of the brake, and the brake drives the brake assembly through the internal brake piston, so that the brake assembly can generate friction braking with the brake housing;

[0008] Double-acting piston cylinder, the piston rod of the double-acting piston cylinder is connected to the outer shell of the brake through a flip assembly; during the rotation of the outer shell of the brake, the piston rod is driven to extend or contract through the flip assembly;

[0009] A brake fluid storage tank, the brake fluid storage tank is unidirectionally connected with the fluid inlet chamber of the double-acting piston cylinder and the brake piston respectively through a first pipeline, and the first pipeline allows the brake fluid to flow from the brake fluid storage tank into the fluid inlet chamber of the double-acting piston cylinder and the brake piston in one direction; the brake fluid storage tank is bidirectionally connected with the fluid inlet chamber of the double-acting piston cylinder and the brake piston respectively through a second pipeline, and a control valve is provided on the second pipeline; the brake fluid storage tank is bidirectionally connected with the return chamber of the double-acting piston cylinder through a third pipeline.

[0010] Furthermore, the first pipeline and the second pipeline are connected to the liquid inlet chamber of the double-acting piston cylinder and the brake piston through a three-way joint, and a one-way valve is provided on the first pipeline between the brake fluid storage tank and the three-way joint.

[0011] Furthermore, the control valve is a flow regulating valve, and the flow regulating valve is a manual flow regulating valve or an automatic flow regulating valve.

[0012] Furthermore, the flip assembly includes a flip plate fixedly connected to the housing of the brake, one side of the flip plate is hinged to the cylinder body of the double-acting piston cylinder, and the other side is hinged to the piston rod of the double-acting piston cylinder through a connecting ear.

[0013] The present invention also provides the following technical solutions:

[0014] A check valve comprises a valve body, wherein the valve body comprises a valve disc inside for opening and closing a pipeline and a valve stem connected to the valve disc, and also comprises the above-mentioned device for controlling the slow closing of the check valve, wherein the valve stem is fixedly connected to the outer shell of the brake at the outer end of the valve body.

[0015] Furthermore, a mounting plate is included, and the base and the double-acting piston cylinder of the brake are fixed on the mounting plate.

[0016] The beneficial effects of the present invention are:

[0017] The brake housing is driven to rotate through the valve stem to control the extension or contraction of the piston rod of the double-acting piston cylinder, thereby controlling the extension or contraction of the brake piston inside the brake, thereby generating friction braking through the brake assembly and the brake housing to achieve the effect of slow closing of the valve disc. The slow closing effect is stable and the effect of eliminating the water hammer effect is obvious. When the water pump is turned on, the valve disc of the check valve can be easily and normally opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the device for controlling the slow closing of the check valve and the check valve in the present invention;

[0019] Figure 2 for Figure 1 A schematic diagram of the structure from another perspective;

[0020] Figure 3 It is a structural state diagram of a double-acting piston cylinder;

[0021] Figure 4 for Figure 3 Another structural state diagram of ;

[0022] Figure 5 A schematic diagram of a check valve structure;

[0023] Figure 6 A schematic diagram of the structure of a brake;

[0024] In the figure: 1. brake; 2. housing; 3. base; 4. brake piston; 5. brake assembly; 6. double-acting piston cylinder; 7. brake fluid storage tank; 8. first pipeline; 9. liquid inlet interface; 10. second pipeline; 11. liquid return interface; 12. third pipeline; 13. three-way connector; 14. one-way valve; 15. flow regulating valve; 16. flip plate; 17. connecting ear; 18. cylinder body; 19. piston rod; 20. valve body; 21. valve disc; 22. valve stem; 23. mounting plate; 24. friction plate; 25. brake shoe; 26. support pin. DETAILED DESCRIPTION

[0025] The following is a detailed description of a device for controlling the slow closing of a check valve and a check valve according to the present invention in conjunction with specific embodiments.

[0026] like Figure 1 , Figure 2 , Figure 6 As shown, a device for controlling the slow closing of a check valve comprises:

[0027] The brake 1, the housing 2 of the brake 1 can rotate axially on the base 3 of the brake 1, and the brake 1 drives the brake assembly 5 through the internal brake piston 4 to generate friction braking with the housing 2 of the brake 1;

[0028] like Figure 3 , Figure 4 As shown, a double-acting piston cylinder 6, a piston rod 19 of the double-acting piston cylinder 6 is connected to the housing 2 of the brake through a flip assembly; during the rotation process, the housing 2 of the brake 1 drives the piston rod 19 to extend or contract through the flip assembly;

[0029] The brake fluid storage tank 7 is connected to the liquid inlet chamber of the double-acting piston cylinder 6 and the brake piston 4 in one way through the first pipeline 8, and is connected to the liquid inlet chamber of the double-acting piston cylinder 6 and the brake piston 4 in two ways through the second pipeline 10. A control valve is provided on the second pipeline 10; the brake fluid storage tank 7 is connected to the return liquid chamber in two ways through the third pipeline 12.

[0030] In this embodiment, the brake 1 is a drum brake mechanism, such as Figure 6 As shown, the brake 1 includes a housing 2, a base 3, and brake shoes 25 and friction plates 24 symmetrically installed in the base 3, a compression spring is connected between the brake shoes 25, and the friction plate 24 is installed on the outside of the brake shoes 25. One end of the brake shoe 25 is limited by a support pin 26, and the other end is connected by a brake piston 4 cylinder.

[0031] When the brake fluid enters the brake piston 4 cylinder, the brake piston 4 cylinder overcomes the stress of the compression spring and stretches to both sides, thereby driving the brake shoe 25 to move toward the inner wall of the outer shell 2, so that the friction plate 24 comes into contact with the inner wall of the outer shell 2. The greater the pressure generated by the brake fluid, the greater the friction between the friction plate 24 and the inner wall of the outer shell 2.

[0032] The double-acting piston cylinder 6 includes a cylinder body 18, a piston rod 19 and a piston. One end of the piston rod 19 is fixedly connected to the piston, and the other end extends out of the outer end of the cylinder body 18. There are oil chambers on both sides of the piston, one side is a liquid inlet chamber, and the other side is a liquid return chamber. The piston rod 19 is fixedly connected to the housing 2 of the brake 1 through a flip assembly. When used on a check valve, the valve stem 22 of the check valve is fixedly connected to the housing 2 of the brake 1. When the valve disc 21 connected to the valve stem 22 rotates forward or reverse, the valve stem 22 drives the housing 2 to rotate accordingly, thereby driving the piston rod 19 of the double-acting piston cylinder 6 to extend or contract accordingly. For example, in this embodiment, when the valve disc 21 is opened, the valve stem 22 rotates counterclockwise, driving the housing 2 of the brake 1 to rotate counterclockwise, the piston rod 19 of the double-acting piston cylinder 6 extends, the space of the liquid inlet chamber increases, the liquid medium entering the liquid inlet chamber increases, the space of the liquid return chamber decreases, and the liquid medium in the liquid return chamber returns to the inside of the brake fluid storage tank 7 through the third pipeline 12. In this embodiment, the brake fluid is hydraulic oil, and the double-acting piston cylinder 6 is a hydraulic oil cylinder. The following is a detailed description of a check valve claimed in this solution.

[0033] like Figure 5As shown, the check valve in this scheme includes a valve body 20, and the valve body 20 includes a valve disc 21 that plays the role of opening and closing the pipeline and a valve stem 22 connected to the valve disc 21, and also includes the above-mentioned device for controlling the slow closing of the check valve, and the valve stem 22 is fixedly connected to the outer shell 2 of the brake 1 at the outer end of the valve body 20. In this embodiment, the base 3 and the double-acting piston cylinder 6 of the brake 1 are fixed on the mounting plate 23. The outer shell 2 is key-connected with the valve stem 22, and the valve stem 22 is fixedly connected to the upper end of the valve disc 21. When the valve disc 21 rotates forward and reverse, it drives the valve stem 22 and the outer shell 2 to rotate accordingly, and the outer shell 2 drives the piston rod 19 of the double-acting piston cylinder 6 to play a hydraulic role.

[0034] The working principle of the present invention is:

[0035] The hydraulic oil in the brake fluid storage tank 7 is connected to the liquid inlet interface 9 of the double-acting piston cylinder 6 through the first pipeline 8, and the hydraulic oil in the brake fluid storage tank 7 enters the liquid inlet cavity through the liquid inlet interface 9. The third pipeline 12 is connected to the liquid return interface 11 of the double-acting piston cylinder 6. The hydraulic oil in the brake fluid storage tank 7 enters the liquid return cavity through the liquid return interface 11, so that the liquid inlet cavity and the liquid return cavity are both filled with hydraulic oil. The hydraulic oil in the brake fluid storage tank 7 can be filled into the internal cavity of the brake piston 4 of the brake 1 through the second pipeline 10.

[0036] When the water pump starts to work, the valve disc 21 in the check valve gradually opens. At this time, the valve stem 22 connected to the valve disc 21 drives the outer shell 2 of the brake 1 to rotate. The outer shell 2 drives the piston rod 19 of the double-acting piston cylinder 6 to extend through the flip assembly. The piston rod 19 compresses the liquid cavity space and returns the hydraulic oil in the return liquid cavity to the brake fluid storage tank 7. At the same time, the space of the liquid inlet cavity becomes larger and oil begins to flow in. At this time, because the compression spring inside the brake 1 shrinks the brake shoe 25, the internal cavity space of the brake piston 4 is small, and the hydraulic oil in the brake fluid storage tank 7 does not enter the internal cavity of the brake piston 4 to generate enough pressure to drive the brake piston 4 to extend. The brake shoe 25 in the brake 1 does not contact and rub against the inner wall of the outer shell 2. The valve disc 21 is not hindered by the brake 1 during the opening process and can be opened easily.

[0037] When the water pump suddenly stops working or fails, the liquid medium in the pipeline flows back to the valve disc 21, and the pressure acts on the valve disc 21, pushing the valve disc 21 to start closing. The valve disc 21 drives the housing 2 of the brake 1 to rotate through the valve stem 22. The housing 2 drives the piston rod 19 of the double-acting piston cylinder 6 to contract through the flip assembly, and the piston compresses the liquid chamber space. Since the first pipeline 8 is unidirectionally connected, the hydraulic oil cannot flow back to the brake fluid storage tank 7 through the first pipeline 8. Therefore, the piston can only fill most of the hydraulic oil from the liquid inlet interface 9 into the brake piston 4 of the brake 1. The high pressure makes the brake piston 4 extend, driving the two brake shoes 25 and the friction plate 24 to open outward, that is, move toward the inner wall of the housing 2. The friction plate 24 contacts the inner wall of the housing 2 to generate friction, thereby braking the housing 2, thereby slowing down the closing speed of the valve disc 21, playing a role of slow closing. At the same time, in order to prevent the brake shoe 25 from causing excessive friction on the inner wall of the brake housing 2, resulting in the brake locking and the valve disc being unable to close normally, the control valve on the second pipeline 10 opens a small part of the flow passage, and the second pipeline 10 is used as a pressure relief pipeline at this time, so that the internal pressure of the brake piston 4 decreases. When the pressure is less than the compression spring stress between the brake shoe 25, the brake shoe 25 retracts under the tension of the compression spring, so that the friction force becomes smaller. At this time, the housing 2 can continue to rotate, and the piston rod 19 of the double-acting piston cylinder 6 continues to compress into the liquid cavity space, so that the brake piston is extended again, and the friction between the friction plate and the housing increases. In this way, the repeated linkage and mutual restriction form the effect of slow closing of the valve disc. When the valve disc 21 is completely closed, the valve stem 22 stops rotating, and the piston rod 19 of the double-acting piston cylinder 6 stops pressurizing. Under the pressure relief action of the control valve opened on the second pipeline 10, the brake piston 4 returns to the normal pressure state, the brake shoe 25 is reset, and the friction plate is separated from the housing. When the water pump is turned on next time, the valve disc 21 can also be easily opened.

[0038] In addition, in the present embodiment, when the valve flap 21 of the check valve is opened, the piston rod 19 of the double-acting piston cylinder 6 is extended and moved, and the space of the liquid inlet chamber becomes larger. At this time, a vacuum may be formed in the liquid inlet chamber. When the valve flap 21 is closed next time and the piston rod 19 of the double-acting piston cylinder 6 is squeezed and contracted, it will not be able to drive the brake piston to work normally. Since the control valve on the second pipeline 10 only opens a small part of the flow passage for use as a pressure relief pipeline, the first pipeline is passed and a one-way valve is arranged on the first pipeline. When the piston rod 19 of the double-acting piston cylinder 6 is extended and moved and a negative pressure is formed in the liquid inlet chamber, the one-way valve automatically opens, and the brake fluid flows out of the brake fluid storage tank into the liquid inlet chamber to prepare for the slow closing action.

[0039] The rotation of the valve disc 21 will compress the piston rod 19 of the double-acting piston cylinder 6, filling the hydraulic oil into the brake piston 4 of the brake 1, thereby driving the friction plate 24 on the brake shoe 25 to generate contact friction with the housing 2 of the brake 1, and the magnitude of the friction force is related to the pressure borne by the valve disc 21. Therefore, the valve disc 21 will not be unable to close during the closing process or will not suddenly close after the contact area with the water flow increases and the pressure increases. The slow closing effect of the valve disc 21 is obvious and stable. According to the flow rate of different pipelines, the opening and closing degree of the control valve can be adjusted to adapt to pipelines with different flow rates.

[0040] In this embodiment, the first pipeline 8 and the second pipeline 10 are connected to the liquid inlet chamber of the double-acting piston cylinder 6 and the brake piston 4 through the three-way joint 13, and a one-way valve 14 is provided on the first pipeline 8 between the brake fluid storage tank 7 and the three-way joint 13. Specifically, the first pipeline 8 and the second pipeline 10 are divided into a first section close to the brake fluid storage tank 7 and a second section close to the double-acting piston cylinder 6 by the three-way joint 13. Specifically, the first joint of the three-way joint 13 is connected to the first section of the first pipeline 8, the second joint is connected to the first section of the second pipeline 10, and the second section of the first pipeline 8 and the second section of the second pipeline 10 are connected to each other and then connected to the third joint.

[0041] The control valve is a flow regulating valve 15, which can specifically use a needle valve to control the pressure relief flow and flow rate of the brake fluid. The flow regulating valve 15 is a manual flow regulating valve or an automatic flow regulating valve. The pressure relief pressure is controlled by the flow regulating valve 15 to adjust the friction force and the closing speed of the valve disc 21 according to different pipeline flows. By installing an electronic control element in conjunction with the automatic flow regulating valve, the pressure relief pressure can also be adjusted according to the pipeline flow.

[0042] The flip assembly includes a flip plate 16 fixedly connected to the housing 2 of the brake 1. In the present embodiment, the flip plate 16 is an L-shaped plate, one side of the L-shaped plate is hinged to the cylinder body 18 of the double-acting piston cylinder 6, and the other side is hinged to the piston rod 19 of the double-acting piston cylinder 6 through a connecting ear 17. When the housing 2 of the brake 1 rotates, the flip plate 16 can be driven to rotate around the hinge point with the cylinder body 18 of the double-acting piston cylinder 6, and the piston rod 19 of the double-acting piston cylinder 6 can be driven to extend or contract through the connecting ear 17 on the other side.

Claims

1. A device for controlling the slow closing of a check valve, characterized in that: include: A brake (1), wherein a housing (2) of the brake (1) is axially rotatable on a base (3) of the brake (1), and the brake (1) drives a brake assembly (5) through an internal brake piston (4), so that the brake assembly (5) can generate friction braking with the housing (2) of the brake (1); A double-acting piston cylinder (6), wherein a piston rod (19) of the double-acting piston cylinder (6) is connected to a housing (2) of a brake (1) via a flip assembly; during the rotation process, the housing (2) of the brake (1) drives the piston rod (19) to extend or contract via the flip assembly; A brake fluid storage tank (7) is unidirectionally connected to a liquid inlet chamber of a double-acting piston cylinder (6) and a brake piston (4) through a first pipeline (8); the brake fluid storage tank (7) is bidirectionally connected to the liquid inlet chamber of the double-acting piston cylinder (6) and the brake piston (4) through a second pipeline (10); a control valve is provided on the second pipeline (10); and the brake fluid storage tank (7) is bidirectionally connected to a liquid return chamber of the double-acting piston cylinder (6) through a third pipeline (12).

2. The device for controlling the slow closing of a check valve according to claim 1, characterized in that: The first pipeline (8) and the second pipeline (10) are connected to the liquid inlet chamber of the double-acting piston cylinder (6) and the brake piston (4) through a three-way joint (13), and a one-way valve (14) is provided on the first pipeline (8) between the brake fluid storage tank (7) and the three-way joint (13).

3. The device for controlling the slow closing of a check valve according to claim 1 or 2, characterized in that: The control valve is a flow regulating valve (15), and the flow regulating valve (15) is a manual flow regulating valve or an automatic flow regulating valve.

4. The device for controlling the slow closing of a check valve according to claim 1 or 2, characterized in that: The flip assembly comprises a flip plate (16) fixedly connected to a housing (2) of a brake (1), one side of the flip plate (16) being hinged to a cylinder body (18) of a double-acting piston cylinder (6), and the other side of the flip plate (16) being hinged to a piston rod (19) of the double-acting piston cylinder (6) via a connecting ear (17).

5. The device for controlling the slow closing of a check valve according to claim 3, characterized in that: The flip assembly comprises a flip plate (16), one side of which is hinged to a cylinder body (18) of a double-acting piston cylinder (6), and the other side of which is hinged to a piston rod (19) of the double-acting piston cylinder (6) through a connecting ear (17).

6. A check valve, comprising a valve body (20), wherein the valve body (20) comprises a valve flap (21) for opening and closing a pipeline and a valve stem (22) connected to the valve flap (21), characterized in that: It also comprises a device for controlling the slow closing of a check valve as claimed in any one of claims 1 to 5, wherein the valve stem (22) is fixedly connected to the housing (2) of the brake (1) at the outer end of the valve body (20).

7. The check valve according to claim 6, characterized in that It also includes a mounting plate (23), on which the base (3) and the double-acting piston cylinder (6) of the brake (1) are fixed.

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