Device for controlling slow closing of check valve and check valve

Abstract

The utility model 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 present application relates to the technical field of pipeline valves, in particular to a device for controlling slow closing of a check valve and the check valve. BACKGROUND

[0002] In a water supply system, a check valve is usually installed at the outlet of a water pump to prevent the water in the pipeline from flowing back to the water pump when the water pump stops running, thereby avoiding the water pump from reversing and protecting the water pump equipment. Therefore, a heavy hammer is installed on the valve stem of the existing pipeline check valve, and when fluid passes through the check valve, the water flow needs to overcome the gravity of the heavy hammer to open the valve disc of the check valve. When the water pump suddenly stops or fails, the water flow in the pipeline will continue to flow due to inertia, and when the flow stops, the water in the closed pipeline will flow back in the opposite direction. The pipeline check valve can quickly close the valve disc under the action of the heavy hammer. However, the water flow in the closed pipeline generates a high-pressure shock wave flow, resulting in water hammer effect. The water hammer effect can cause the pipeline to bear a load far exceeding the normal working pressure, leading to pipeline rupture, leakage, and shortening of the service life of the pipeline. The connection parts of the pipeline, such as flanges, elbows, and tees, are prone to loosening, causing sealing failure.

[0003] To this end, the existing technology uses a slow closing check valve to eliminate water hammer effect. For example, patent No. CN202021173186.8, a slow closing check valve, is provided with a heavy hammer fixed to the outer valve stem end of the valve body through a connecting rod, an oil cylinder fixed to the outer side of the valve body through an L-shaped base, and an oil cylinder piston rod fixed to the outer valve stem end of the valve body. In the working process, the oil cylinder is connected and driven by the valve stem, the heavy hammer, and the connecting rod and the oil cylinder seat. When closing, the gravity of the valve disc plus the sagging force of the heavy hammer and the medium backflow force act on the oil cylinder, slowly closing the valve disc. However, in the process of closing the valve disc, the heavy hammer type slow closing check valve has a small action area between the backflow liquid and the valve disc, 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 closure, the action area between the backflow liquid and the valve disc increases, the pressure increases, and the oil return speed of the oil cylinder increases, causing the valve disc to close rapidly. Therefore, the slow closing effect is not stable, and water hammer effect still exists. SUMMARY

[0004] To solve the problem of existing slow closing check valves that the valve disc still closes quickly, resulting in poor slow closing effect and water hammer effect still existing, the present application provides a device for controlling slow closing of a check valve, which has the characteristics of stable slow closing effect and obvious water hammer effect elimination.

[0005] To achieve the above-mentioned purpose, the following technical solutions are provided:

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

[0007] The brake is driven by an internal brake piston to drive a brake assembly to generate friction braking with the brake housing;

[0008] The piston rod of the double-acting piston cylinder is connected with the brake housing through a turnover assembly; the brake housing drives the piston rod to extend or contract through the turnover assembly during rotation;

[0009] The brake liquid storage tank is connected with the liquid inlet cavity and the brake piston of the double-acting piston cylinder through a first pipeline in one-way communication, and the first pipeline allows the brake liquid to flow from the brake liquid storage tank to the liquid inlet cavity and the brake piston of the double-acting piston cylinder in one-way; the brake liquid storage tank is connected with the liquid inlet cavity and the brake piston of the double-acting piston cylinder through a second pipeline in two-way communication, and a control valve is arranged on the second pipeline; the brake liquid storage tank is connected with the liquid return cavity of the double-acting piston cylinder through a third pipeline in two-way communication.

[0010] Further, the first pipeline and the second pipeline are connected with the liquid inlet cavity and the brake piston of the double-acting piston cylinder through a three-way joint, and a one-way valve is arranged on the first pipeline between the brake liquid storage tank and the three-way joint.

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

[0012] Further, the turnover assembly includes a turnover plate fixedly connected with the brake housing, one side of the turnover plate is hinged with the cylinder body of the double-acting piston cylinder, and the other side is hinged with the piston rod of the double-acting piston cylinder through a connecting lug.

[0013] The application also provides the following technical solutions:

[0014] A check valve includes a valve body including an internal valve disc for opening and closing a pipeline and a valve rod connected with the valve disc, and the device for controlling the slow closing of the check valve described above, and the valve rod is fixedly connected with the brake housing at the outer end of the valve body.

[0015] Further, a mounting plate is further included, and the base of the brake and the double-acting piston cylinder are fixedly connected with the mounting plate.

[0016] The application has the following beneficial effects:

[0017] The valve rod drives the brake housing to rotate, controls the extension or contraction of the piston rod of the double-acting piston cylinder, controls the extension or contraction of the brake piston inside the brake, generates friction braking with the brake assembly and the brake housing, achieves the slow closing effect of the valve disc, and the slow closing effect is stable, the water hammer effect is obvious, and when the water pump is opened, the valve disc of the check valve can be easily and normally opened. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0019] Figure 2 Structure diagram of the device for controlling slow closing of check valve and check valve in the application; Figure 1 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0020] Figure 3 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0021] Figure 4 Structure diagram of the device for controlling slow closing of check valve and check valve in the application; Figure 3 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0022] Figure 5 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0023] Figure 6 Structure diagram of the device for controlling slow closing of check valve and check valve in the application;

[0024] In the figure: 1, brake; 2, shell; 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 joint; 14, check valve; 15, flow regulating valve; 16, reversing plate; 17, connecting lug; 18, cylinder body; 19, piston rod; 20, valve body; 21, valve flap; 22, valve rod; 23, mounting plate; 24, friction plate; 25, brake shoe; 26, support pin. DETAILED DESCRIPTION

[0025] The device for controlling slow closing of check valve and check valve in the application will be described in detail below in combination with specific embodiments.

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

[0027] Brake 1, the shell 2 of the brake 1 can rotate axially on the base 3 of the brake 1, and the brake 1 can generate friction braking with the shell 2 of the brake 1 by driving the brake assembly 5 through the internal brake piston 4;

[0028] As shown in Figure 3 , Figure 4 , double-acting piston cylinder 6, the piston rod 19 of the double-acting piston cylinder 6 is connected with the shell 2 of the brake through the reversing assembly; the shell 2 of the brake 1 drives the piston rod 19 to extend or contract through the reversing assembly during rotation;

[0029] The brake fluid storage tank 7 is connected unidirectionally to the inlet chamber of the double-acting piston cylinder 6 and the brake piston 4 via a first pipeline 8. The brake fluid storage tank 7 is connected bidirectionally to the inlet chamber of the double-acting piston cylinder 6 and the brake piston 4 via a second pipeline 10. A control valve is provided on the second pipeline 10. The brake fluid storage tank 7 is bidirectionally connected to the return chamber via a third pipeline 12.

[0030] In this embodiment, 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 pads 24 symmetrically installed inside the base 3. A compression spring is connected between the brake shoes 25. The friction pads 24 are installed on the outside of the brake shoes 25. One end of the brake shoes 25 is limited by a support pin 26, and the other end is connected by a brake piston cylinder 4.

[0031] When the brake fluid enters the brake piston cylinder 4, the brake piston cylinder 4 extends to both sides against the stress of the compression spring, thereby driving the brake shoe 25 to move towards the inner wall of the outer casing 2, so that the friction pad 24 comes into contact with the inner wall of the outer casing 2. The greater the pressure generated by the brake fluid, the greater the friction between the friction pad 24 and the inner wall of the outer casing 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 cylinder body 18. Both sides of the piston have oil chambers: one is the inlet chamber, and the other is the return chamber. The piston rod 19 is fixedly connected to the outer casing 2 of the brake 1 via a flipping assembly. When used with a check valve, the valve stem 22 of the check valve is fixedly connected to the outer casing 2 of the brake 1. When the valve disc 21 connected to the valve stem 22 rotates in the forward or reverse direction, the valve stem 22 drives the outer casing 2 to rotate accordingly, thereby causing the piston rod 19 of the double-acting piston cylinder 6 to extend or retract accordingly. For example, in this embodiment, when the valve disc 21 is open, the valve stem 22 rotates counterclockwise, causing the outer casing 2 of the brake 1 to rotate counterclockwise. The piston rod 19 of the double-acting piston cylinder 6 extends, increasing the space of the inlet chamber and increasing the amount of liquid medium entering the inlet chamber. The space of the return chamber decreases, and the liquid medium in the return chamber returns to 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 cylinder. The following description details a check valve as claimed in this solution.

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

[0034] The working principle of the present application is as follows:

[0035] The hydraulic oil in the brake fluid storage tank 7 is connected with the liquid inlet interface 9 of the double-acting piston cylinder 6 through the first pipeline 8, 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 with 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 filled with hydraulic oil, and the hydraulic oil in the brake fluid storage tank 7 can be filled into the inner 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 21 of the check valve gradually opens, at this time the valve rod 22 connected with the valve 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 move by extension through the turnover assembly, the piston rod 19 compresses the liquid return cavity space, and the hydraulic oil in the liquid return cavity flows back into the brake fluid storage tank 7, at the same time the space of the liquid inlet cavity becomes larger, and the oil starts to enter. At this time, the compression spring in the brake 1 contracts the brake shoe 25, the inner cavity space of the brake piston 4 is small, the hydraulic oil in the brake fluid storage tank 7 has not entered the inner cavity of the brake piston 4 to generate enough pressure to drive the brake piston 4 to expand, the brake shoe 25 in the brake 1 does not contact and rub with the inner wall of the outer shell 2, and the valve 21 is not hindered by the brake 1 during the opening process, and can be easily opened.

[0037] When the water pump suddenly stops working or fails, the liquid medium in the pipeline flows back to the valve disc 21, the pressure acts on the valve disc 21, and the valve disc 21 is pushed to start closing, the valve disc 21 drives the outer shell 2 of the brake 1 to rotate through the valve rod 22, the outer shell 2 drives the piston rod 19 of the double-acting piston cylinder 6 to make a contraction movement through the turnover assembly, and the piston is compressed into the liquid cavity space. Since the first pipeline 8 is one-way communication, hydraulic oil cannot flow back to the brake fluid storage tank 7 through the first pipeline 8, so the piston only fills most of the hydraulic oil from the liquid inlet interface 9 into the inside of the brake piston 4 of the brake 1. High pressure makes the brake piston 4 stretch, drives the two brake shoes 25 and the friction plate 24 to open outward, that is, moves to the inner wall of the outer shell 2, the friction plate 24 contacts the inner wall of the outer shell 2 to generate friction, thereby braking the outer shell 2, and further slowing down the closing speed of the valve disc 21, thereby achieving the effect of slow closing. At the same time, in order to avoid the situation that the brake shoe 25 causes the brake 1 outer shell 2 to be braked to death due to excessive friction force, the control valve on the second pipeline 10 opens a small part of the flow path, the second pipeline 10 is used as a pressure relief pipeline at this time, so that the pressure inside the brake piston 4 decreases, and when the pressure is less than the compression spring stress between the brake shoes 25, the brake shoes 25 retract under the action of the compression spring tension, so that the friction force decreases, at this time the outer shell 2 can continue to rotate, the piston rod 19 of the double-acting piston cylinder 6 continues to compress into the liquid cavity space, the brake piston expands again, the friction between the friction plate and the shell increases, and the valve disc slowly closes. When the valve disc 21 is completely closed, the valve rod 22 stops rotating, and the piston rod 19 of the double-acting piston cylinder 6 stops pressing, under the pressure relief effect of the control valve opened on the second pipeline 10, the brake piston 4 returns to the normal pressure state, the brake shoe 25 resets, the friction plate separates from the shell, and the valve disc 21 can be easily opened when the water pump is started next time.

[0038] In addition, in the present embodiment, when the valve disc 21 of the check valve is opened, the piston rod 19 of the double-acting piston cylinder 6 moves to elongate, and the space of the liquid inlet cavity becomes larger. At this time, the liquid inlet cavity may form a vacuum. When the valve disc 21 is closed next time, the piston rod 19 of the double-acting piston cylinder 6 cannot drive the brake piston to work normally when it is extruded and contracted. Since the control valve on the second pipeline 10 only opens a small part of the flow path as a pressure relief pipeline, the single-way valve is arranged on the first pipeline, and when the piston rod 19 of the double-acting piston cylinder 6 moves to elongate and the liquid inlet cavity forms negative pressure, the single-way valve automatically opens, the brake fluid flows out from the brake fluid storage tank into the inside of the liquid inlet cavity, and prepares for the slow closing action.

[0039] When the valve disc 21 rotates, hydraulic oil is filled into the brake piston 4 of the brake 1 through the compression of the piston rod 19 of the double-acting piston cylinder 6, so that the friction plate 24 on the brake shoe 25 is brought into contact with the brake 1 shell 2, and the friction force is related to the pressure intensity borne by the valve disc 21. Therefore, the valve disc 21 will not suddenly close after the pressure increases due to the increase of the contact area with the water flow during the closing process, and the slow closing effect of the valve disc 21 is obvious and stable. According to the size of the pipeline flow, the opening and closing degree of the control valve can be adjusted to adapt to the pipeline with different flow.

[0040] In the embodiment, the first pipeline 8 and the second pipeline 10 are communicated with the liquid inlet cavity of the double-acting piston cylinder 6 and the brake piston 4 through the three-way joint 13, and the one-way valve 14 is arranged 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 each 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 communicated with the first section of the first pipeline 8, the second joint is communicated with 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 communicated with each other and then communicated with the third joint.

[0041] The control valve is a flow regulating valve 15, which can be a needle valve to control the pressure relief flow and flow rate of the brake fluid. The flow regulating valve 15 can be 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 the different flow of the pipeline. By installing an electric control element and cooperating with the automatic flow regulating valve, the pressure relief pressure can also be adjusted according to the flow of the pipeline.

[0042] The turnover assembly includes a turnover plate 16 fixedly connected with the shell 2 of the brake 1. In the embodiment, the turnover plate 16 is an L-shaped plate, one side of which 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 the connecting lug 17. When the shell 2 of the brake 1 rotates, the turnover plate 16 can be driven to rotate around the hinge point of 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 stretch or contract through the connecting lug 17 on the other side.

Claims

1. A device for controlling the slow closing of a check valve, characterized in that, The application relates to a brake device, which comprises the following components: a brake (1), the shell (2) of which can rotate axially on the base (3) of the brake (1), the brake (1) drives a brake assembly (5) through an internal brake piston (4), and the brake assembly (5) can produce friction braking with the shell (2) of the brake (1); a double-acting piston cylinder (6), the piston rod (19) of which is connected with the shell (2) of the brake (1) through a turnover assembly; the shell (2) of the brake (1) drives the piston rod (19) to extend or contract through the turnover assembly during rotation; a brake fluid storage tank (7), which is connected with the liquid inlet cavity of the double-acting piston cylinder (6) and the brake piston (4) in one-way communication through a first pipeline (8), is connected with the liquid inlet cavity of the double-acting piston cylinder (6) and the brake piston (4) in two-way communication through a second pipeline (10), and the second pipeline (10) is provided with a control valve; and the brake fluid storage tank (7) is connected with the liquid return cavity of the double-acting piston cylinder (6) in two-way communication through a third pipeline (12). The first pipeline (8) and the second pipeline (10) are connected with the liquid inlet cavity 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 arranged on the first pipeline (8) between the brake fluid storage tank (7) and the three-way joint (13). The control valve is a flow regulating valve (15), which is a manual flow regulating valve or an automatic flow regulating valve. The turnover assembly comprises a turnover plate (16) fixedly connected with the shell (2) of the brake (1), one side of the turnover plate (16) is hinged with the cylinder body (18) of the double-acting piston cylinder (6), and the other side is hinged with the piston rod (19) of the double-acting piston cylinder (6) through a connecting lug (17).

2. The device for controlling the slow closing of a check valve according to claim 1, characterized in that, The turnover assembly comprises a turnover plate (16), one side of the turnover plate (16) is hinged with the cylinder body (18) of the double-acting piston cylinder (6), and the other side is hinged with the piston rod (19) of the double-acting piston cylinder (6) through a connecting lug (17).

3. A device for controlling the slow closing of a check valve according to claim 1 or 2, characterized in that The device for controlling the slow closing of the check valve in any one of claims 1 to 5 is further provided with a valve rod (22) fixedly connected with the shell (2) of the brake (1) at the outer end of the valve body (20).

4. A device for controlling the slow closing of a check valve as claimed in claim 1 or 2, characterized in that The brake (1) and the double-acting piston cylinder (6) are further fixed on a mounting plate (23).

5. The device for controlling the slow closing of a check valve of claim 3, wherein, ​ 6. A check valve comprising a valve body (20) comprising an inner valve disc (21) for closing a duct and a valve stem (22) connected to the valve disc (21), characterized in that, ​ 7. The check valve of claim 6, wherein ​

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