Slow-closing oil cylinder for check valve

Abstract

The utility model relates to the technical field of check valves, in particular to a slow-closing oil cylinder for a check valve, which comprises a cylinder barrel, a first oil port is arranged on the cylinder barrel, an oil cylinder cover is arranged at the top of the cylinder barrel, a second oil port is arranged on the oil cylinder cover, a first piston is arranged in the cylinder barrel in a sliding manner, a piston rod is fixed on the first piston, and a second oil port is arranged on the second piston. A joint is fixed at the top of the piston rod; and a slow closing device is arranged at the bottom of the cylinder barrel and is fixed on the mounting seat. According to the slowly-closed oil cylinder for the check valve, the problems existing in an original slowly-closed oil cylinder are solved, and therefore the defect that an existing check valve can not be closed in place or can not be completely opened is overcome.

Description

Technical Field

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

[0002] The slow closing check valve is a check valve with a slow closing system, which can slow down the closing speed of the check valve at the end of the closing stage, reduce the impact of water hammer on the pipeline system, and protect the entire pipeline. Its basic structure is shown in Figure 5 When the water pump is working, the valve plate of the check valve rotates counterclockwise under the impact of the water flow, and the valve opens. The piston rod of the slow-closing cylinder system extends out driven by the valve plate shaft, and at the same time, the weight system rotates counterclockwise around the valve plate shaft and lifts up; when the pump is stopped, the valve plate is closed under the gravity of the weight, and the piston rod retracts.

[0003] The existing slow-closing oil cylinder structure has obvious shortcomings. Due to the different areas of cavity A and cavity B, the volume of cavity A is significantly larger than that of cavity B. When injecting hydraulic oil into the oil cylinder, if cavity A is filled with hydraulic oil when the piston rod is fully extended, when the piston rod is retracted, since the volume of cavity A is larger than that of cavity B, cavity B cannot completely accommodate the hydraulic oil in cavity A. Therefore, a part of the hydraulic oil will remain in cavity A and cannot be discharged (the volume of this part of the hydraulic oil is equal to the volume difference between A and cavity B), and the piston rod cannot be fully retracted, resulting in the check valve not being able to be completely closed and the valve leaking. Similarly, if cavity B is filled with hydraulic oil when the piston rod is fully retracted, when the valve is opened and the piston rod is extended, since the injected hydraulic oil is not enough to fill cavity A, negative pressure will be formed in cavity A, which will generate a certain suction force on the piston rod, preventing the piston rod from being fully extended, thereby causing the valve to be unable to be fully opened, increasing the pipeline flow resistance, and affecting the flow of the pipeline. Utility Model Content

[0004] Purpose of the utility model: The utility model provides a slow-closing oil cylinder for a check valve, which overcomes the problems existing in the original slow-closing oil cylinder, thereby solving the disadvantages of the current check valve that the valve may not be fully closed or cannot be fully opened.

[0005] In order to achieve the above object, the technical solution of the utility model is as follows:

[0006] A slow-closing oil cylinder for a check valve comprises a cylinder barrel, a first oil port is arranged on the cylinder barrel, a cylinder cover is arranged on the top of the cylinder barrel, a second oil port is arranged on the cylinder cover, a first piston is slidably arranged inside the cylinder barrel, a piston rod is fixed on the first piston, and a joint is fixed on the top of the piston rod;

[0007] A slow closing device is arranged at the bottom of the cylinder and is fixed on a mounting seat.

[0008] As an improvement: the slow closing device includes a slow closing cylinder, one end of which is mounted on a mounting seat, and the other end is mounted on a base, a third oil port and a fourth oil port are provided on the base, the input end of the third oil port extends to the inside of the cylinder, and the output end of the fourth oil port extends to the inside of the slow closing cylinder;

[0009] A second piston is slidably arranged inside the slow-closing cylinder.

[0010] As an improvement, the area below the second piston may be filled with gas under a certain pressure.

[0011] As an improvement, an elastic air bag may be placed below the second piston.

[0012] As an improvement: a spring may be provided below the second piston, one end of the spring being limited on the base, and the other end of the spring being limited on the second piston.

[0013] As an improvement: the first oil port is connected to the second oil port through a first oil pipeline, the first oil port is connected to the fourth oil port through a second oil pipeline, and a control valve is provided on the second oil pipeline;

[0014] The second oil port is connected to a first node through a third oil pipeline, the first node is located on the second oil pipeline, and the first node is located between the first oil port and the control valve;

[0015] The second oil port is connected to the third oil port through a fourth oil pipeline, a one-way throttle valve is provided on the fourth oil pipeline, and a second node is provided on the fourth oil pipeline, and the second node is located between the one-way throttle valve and the second oil port;

[0016] The first oil port is connected to the second node through a fifth oil pipeline.

[0017] In summary, the utility model has the following beneficial effects:

[0018] By arranging a slow closing device at the bottom of the cylinder, the problem existing in the original slow closing oil cylinder is overcome, thereby solving the disadvantage of the current check valve that the valve may not be fully closed or cannot be fully opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution in the present practical embodiment, the drawings required for use in the embodiment or the description of the prior art will be briefly introduced below.

[0020] Figure 1 The overall structure of a slow-closing cylinder for a check valve is shown in Figure 1. Figure 1 ;

[0021] Figure 2The overall structure of a slow-closing cylinder for a check valve is shown in Figure 1. Figure 2 ;

[0022] Figure 3 The overall structure of a slow-closing cylinder for a check valve is shown in Figure 1. Figure 3 ;

[0023] Figure 4 This is a schematic diagram of the connection relationship of each oil port;

[0024] Figure 5 It is a structural schematic diagram of an existing slow-closing check valve;

[0025] Among them: 1. Cylinder barrel; 2. First oil port; 3. Cylinder head; 4. Second oil port; 5. First piston; 6. Piston rod; 7. Joint; 8. Mounting seat; 9. Slow-closing cylinder; 10. Base; 11. Third oil port; 12. Fourth oil port; 13. Second piston; 14. First oil pipeline; 15. Second oil pipeline; 16. Third oil pipeline; 17. Fourth oil pipeline; 18. First node; 19. Second node; 20. One-way throttle valve; 21. Control valve; 22. Fifth oil pipeline; 23. Gas; 24. Elastic airbag; 25. Spring; 26. Air inlet; 27. One-way valve. DETAILED DESCRIPTION

[0026] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0027] Please refer to Figure 1 A slow-closing oil cylinder for a check valve comprises a cylinder barrel 1, a first oil port 2 is arranged on the cylinder barrel 1, a cylinder cover 3 is arranged on the top of the cylinder barrel 1, a second oil port 4 is arranged on the cylinder cover 3, a first piston 5 is slidably arranged inside the cylinder barrel 1, a piston rod 6 is fixed on the first piston 5, and a joint 7 is fixed on the top of the piston rod 6;

[0028] A slow closing device is provided at the bottom of the cylinder 1, and the slow closing device is fixed on the mounting seat 8. In this embodiment, by providing a slow closing device at the bottom of the cylinder 1, the problem existing in the original slow closing oil cylinder is overcome, thereby solving the disadvantage of the current check valve that the valve may not be fully closed or fully opened.

[0029] The slow-closing device includes a slow-closing cylinder 9, one end of which is mounted on a mounting seat 8, and the other end is mounted on a base 10. A third oil port 11 and a fourth oil port 12 are provided on the base 10. The input end of the third oil port 11 extends to the inside of the cylinder 1, and the output end of the fourth oil port 12 extends to the inside of the slow-closing cylinder 9; a second piston 13 is slidably provided inside the slow-closing cylinder 9.

[0030] Please refer to Figure 4The first oil port 2 is connected to the second oil port 4 through the first oil pipeline 14, the first oil port 2 is connected to the fourth oil port 12 through the second oil pipeline 15, and a control valve 21 is provided on the second oil pipeline 15; the second oil port 4 is connected to the first node 18 through the third oil pipeline 16, the first node 18 is located on the second oil pipeline 15, and the first node 18 is located between the first oil port 2 and the control valve 21; the second oil port 4 is connected to the third oil port 11 through the fourth oil pipeline 17, a one-way throttle valve 20 is provided on the fourth oil pipeline 17, and a second node 19 is provided on the fourth oil pipeline 17, and the second node 19 is located between the one-way throttle valve 20 and the second oil port 4; the first oil port 2 is connected to the second node 19 through the fifth oil pipeline 22.

[0031] In this embodiment, the cavity formed between the first piston 5 and the base 10 is assumed to be cavity A, the cavity formed between the first piston 5 and the cylinder head 3 is assumed to be cavity B, the cavity formed between the second piston 13 and the base 10 is assumed to be cavity C, and the cavity formed between the second piston 13 and the mounting seat 8 is assumed to be cavity D for specific description.

[0032] Specific implementation method 1: Please refer to Figure 1 A gas 23 with a certain pressure may be filled under the second piston 13 . In this embodiment, the gas 23 may be an inert gas 23 . In this embodiment, an air inlet 26 is provided on the mounting seat 8 , and a one-way valve 27 is provided on the air inlet 26 .

[0033] Air (or inert gas 23) of a certain pressure is filled into cavity D through the one-way valve 27 to overcome the friction between the second piston 13 and the slow-closing cylinder 9, so as to push the second piston 13 to move freely in the slow-closing cylinder 9. When the piston rod 6 is fully extended, cavity A is filled with hydraulic oil. At this time, the second piston 13 is close to the bottom plate, the volume of cavity D is the largest, and the volume of cavity C is the smallest. When the pump is stopped, the action process of the piston rod 6 is the same as that of the original slow-closing cylinder. The piston rod 6 first retracts quickly. After the piston of the piston rod 6 passes the first oil port 2, the piston rod 6 slowly retracts at the speed set by the one-way throttle valve 20. After the hydraulic oil in cavity A fills cavity B, the excess hydraulic oil flows into cavity C through the fourth oil port 12. Since the gas 23 is compressible and the liquid is incompressible, after the hydraulic oil enters the cavity C, it pushes the second piston 13 to move toward the cavity D, the cavity D is reduced, and the pressure of the gas 23 increases slightly until the piston rod 6 is fully retracted and the valve is completely closed. When the valve is opened, the second piston 13 moves toward the cavity C under the pressure of the gas 23, discharges the hydraulic oil in the cavity C, and enters the cavity A through the first oil port 2 and the second oil port 4, replenishing the insufficient amount of reflux oil in the cavity B, so that the valve can be smoothly and fully opened.

[0034] Specific implementation method 2: Please refer to Figure 2, an elastic airbag 24 can be placed under the second piston 13, and the elastic airbag 24 is located in the cavity D. When the piston rod 6 is fully extended, the cavity A is filled with hydraulic oil. At this time, the second piston 13 is close to the bottom plate, the volume of cavity D is the largest, and the volume of cavity C is the smallest. When the pump is stopped, the action process of the piston rod 6 is the same as the action of the original slow-closing oil cylinder. The piston rod 6 first retracts quickly. When the piston of the piston rod 6 passes the first oil port 2, the piston rod 6 slowly retracts at the speed set by the one-way throttle valve 20. After the hydraulic oil in cavity A fills cavity B, the excess hydraulic oil flows into cavity C through the fourth oil port 12. Since the elastic airbag 24 is compressible and the liquid is incompressible, after the hydraulic oil enters cavity C, it pushes the second piston 13 to move toward cavity D, and cavity D is reduced, compressing the elastic airbag 24, so that the pressure inside the elastic airbag 24 increases slightly until the piston rod 6 is fully retracted and the valve is completely closed. When the valve is opened, the second piston 13 moves toward the cavity C under the pressure of the elastic airbag 24, discharges the hydraulic oil in the cavity C, and enters the cavity A through the first oil port 2 and the second oil port 4 to supplement the insufficient reflux oil in the cavity B, so that the valve can be smoothly and completely opened.

[0035] Specific implementation method three: please refer to Figure 3 , a spring 25 may be provided below the second piston 13, one end of the spring 25 is limited on the base 10, and the other end of the spring 25 is limited on the second piston 13. When the piston rod 6 is fully extended, the cavity A is filled with hydraulic oil. At this time, the second piston 13 is close to the bottom plate, the volume of cavity D is the largest, and the volume of cavity C is the smallest. When the pump is stopped, the action process of the piston rod 6 is the same as the action of the original slow-closing oil cylinder. The piston rod 6 first retracts quickly. When the piston of the piston rod 6 passes the first oil port 2, the piston rod 6 slowly retracts at the speed set by the one-way throttle valve 20. After the hydraulic oil in cavity A fills cavity B, the excess hydraulic oil flows into cavity C through the fourth oil port 12. Since the spring 25 is compressible and the liquid is incompressible, after the hydraulic oil enters cavity C, it pushes the second piston 13 to move toward cavity D, and cavity D is reduced, compressing the spring 25, so that the spring 25 is compressed until the piston rod 6 is fully retracted and the valve is completely closed. When the valve is opened, the second piston 13 moves toward the cavity C under the pressure of the spring 25, discharges the hydraulic oil in the cavity C, and enters the cavity A through the first oil port 2 and the second oil port 4 to supplement the insufficient reflux oil in the cavity B, so that the valve can be smoothly and completely opened.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the utility model can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the utility model, which should be included in the scope of the technical solution for protection of the utility model.

Claims

1. A slow closing oil cylinder for a check valve, characterized in that: It comprises a cylinder barrel, a first oil port is arranged on the cylinder barrel, a cylinder cover is arranged on the top of the cylinder barrel, a second oil port is arranged on the cylinder cover, a first piston is slidably arranged inside the cylinder barrel, a piston rod is fixed on the first piston, and a joint is fixed on the top of the piston rod; A slow closing device is arranged at the bottom of the cylinder and is fixed on a mounting seat.

2. The slow closing cylinder for a check valve according to claim 1, characterized in that: The slow closing device comprises a slow closing cylinder, one end of which is mounted on a mounting seat, and the other end of which is mounted on a base, a third oil port and a fourth oil port are provided on the base, the input end of the third oil port extends to the inside of the cylinder, and the output end of the fourth oil port extends to the inside of the slow closing cylinder; A second piston is slidably arranged inside the slow-closing cylinder.

3. The slow closing oil cylinder for a check valve according to claim 2, characterized in that: The area below the second piston may be filled with gas under a certain pressure.

4. The slow closing oil cylinder for a check valve according to claim 2, characterized in that: An elastic airbag may be placed below the second piston.

5. The slow closing oil cylinder for a check valve according to claim 2, characterized in that: A spring may be provided below the second piston, one end of the spring being limited on the base, and the other end of the spring being limited on the second piston.

6. The slow closing oil cylinder for a check valve according to claim 2, characterized in that: The first oil port is connected to the second oil port through a first oil pipeline, the first oil port is connected to the fourth oil port through a second oil pipeline, and a control valve is provided on the second oil pipeline; The second oil port is connected to a first node through a third oil pipeline, the first node is located on the second oil pipeline, and the first node is located between the first oil port and the control valve; The second oil port is connected to the third oil port through a fourth oil pipeline, a one-way throttle valve is provided on the fourth oil pipeline, and a second node is provided on the fourth oil pipeline, and the second node is located between the one-way throttle valve and the second oil port; The first oil port is connected to the second node through a fifth oil pipeline.

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