Large-flow unloading valve

Abstract

The utility model provides a large-flow unloading valve which comprises a valve body, a cylinder cover installed on the rear side of the valve body, a main valve installed between the valve body and the cylinder cover, a main valve sleeve installed in the valve body, the front end of the main valve embedded in the main valve sleeve, the rear end of the main valve located in a cavity formed in the cylinder cover, and a pre-pressing valve seat installed at the front end of the main valve. A pre-pressing valve is installed on the pre-pressing valve seat, a spring seat is installed in a groove formed in the rear side of the main valve, a spring is connected to the spring seat in a sleeved mode, center holes of the main valve, the main valve sleeve, the pre-pressing valve seat, the pre-pressing valve and the pre-pressing valve deck are concentrically arranged and sequentially communicated, an oil outlet pipe is arranged at the top of the valve body, and an oil return opening and a plate type oil supply opening are formed in the bottom of the valve body. A travel switch and a microswitch are installed on the outer side of the valve body and connected with the main valve through a sinker bar. The large-flow unloading valve is reasonable in design, simple in structure, high in unloading reaction sensitivity, high in control precision and long in service life.

Description

Technical Field

[0001] The utility model relates to the technical field of unloading valves, in particular to a large-flow unloading valve. Background Art

[0002] An unloading valve is a valve that can unload a hydraulic pump under certain conditions. It's typically a relief valve with a two-position, two-way valve (often a solenoid valve). Its function is to set the system (oil pump) main pressure when not unloading. When unloading (via the two-position, two-way valve), pressurized oil returns directly to the tank, reducing pump pressure to near zero. This allows for certain circuit controls, improves pump life, and reduces power consumption. In a circuit, a pressure reducing valve is integrated. It adjusts the pressure required by actuators and is connected in series within the circuit. Generally, these valves cannot be used interchangeably.

[0003] Traditional pressure relief valves are easily damaged when unloading high-pressure, large-flow equipment, which leads to a short service life of the pressure relief valve. In addition, the unloading response sensitivity and control accuracy of the existing unloading valves are poor, and the unloading response sensitivity cannot be adjusted, so improvement is needed. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model proposes a large-flow unloading valve with high unloading response sensitivity, high control accuracy and long service life.

[0005] The utility model provides a large flow unloading valve, comprising: a valve body, a cylinder cover is installed on the rear side of the valve body, a main valve is installed between the valve body and the cylinder cover, a main valve sleeve is installed in the valve body, the front end of the main valve is embedded in the main valve sleeve, and the rear end of the main valve is located in a cavity provided in the cylinder cover, a pre-pressure valve seat is installed at the front end of the main valve, a pre-pressure valve is installed on the pre-pressure valve seat, and the pre-pressure valve is closed in the main valve sleeve by the pre-pressure valve cover, a spring seat is installed in a groove provided on the rear side of the main valve, a spring is sleeved on the spring seat, one end of the spring is against the groove provided on the rear side of the main valve, and the other end of the spring is against the groove provided on the rear side of the main valve. The outer end is against the inner side surface of the cylinder head, and the main valve, main valve sleeve, pre-pressure valve seat, pre-pressure valve and pre-pressure valve cover center holes are concentrically arranged and connected in sequence. The top of the valve body is provided with an oil outlet pipe, and the oil outlet pipe is connected with the center hole of the pre-pressure valve cover. The bottom of the valve body is provided with an oil return port and a plate-type oil supply port, wherein the plate-type oil supply port is connected with the pre-pressure valve, and the oil return port is connected with the main valve. The cylinder head is provided with an air supply port, and the air supply port is connected with a cavity provided on the cylinder head. A travel switch and a microswitch are installed on the outside of the valve body, and the travel switch and the microswitch are respectively connected to the main valve through a striker rod.

[0006] In the above technical solution, during actual operation, the large flow unloading valve is connected to the hydraulic pump of the punch press. (1) Normal operation state: hydraulic oil enters the right side of the main valve from the plate oil supply port, enters the punch cylinder through the oil outlet pipe, and the air pressure enters the left side of the main valve from the air supply port. The pressure is added to the spring force and reaches a pressure balance with the hydraulic oil on the right side. The striker triggers the travel switch to send a signal, reaching the set pre-pressure, and the machine tool can operate normally. (2) Overload state: the press is overloaded, the pressure of the slider hydraulic cylinder rises to above the set unloading valve pressure, the main valve overcomes the air pressure and spring force and moves to the left, the main valve opens to unload, and the oil pressure flows from the cylinder back to the oil tank through the return oil port. At this time, the striker is away from the travel switch, the travel switch sends a signal, and the main valve cannot be operated. (3) Insufficient pre-pressure: the pressure of the press slider hydraulic cylinder is lower than the set pre-pressure and cannot push the pre-pressure valve. The main valve is pushed to the right by the spring, the main valve is closed, the travel switch sends a signal, and the press cannot operate. The present invention provides effective protection for the main valve by providing a pre-compression valve, which can improve the protection of the main valve under ultra-high pressure or low pressure conditions. By providing a travel switch and a micro switch, which can be connected to the main valve via a striker, the sensitivity of the unloading reaction and the control accuracy can be improved.

[0007] Preferably, a pressure adjusting screw is installed in the cylinder head, and the inner end of the pressure adjusting screw is against the spring seat. During actual operation, the position of the spring seat can be adjusted by the pressure adjusting screw, and then the elastic force of the spring can be adjusted, and then the reaction sensitivity of the main valve unloading can be adjusted.

[0008] Preferably, the outer side of the pressure regulating screw is locked in the cylinder cover by a locking cover.

[0009] Preferably, an exhaust block is further installed on the valve body, and a pressure oil outlet and an exhaust valve are provided on the exhaust block. Both the pressure oil outlet and the exhaust valve are connected to the main valve to further protect the main valve.

[0010] Preferably, the valve body is provided with a flange for external connection to facilitate external installation of the large flow unloading valve.

[0011] The beneficial effects of a large flow unloading valve provided by the present invention are as follows: the large flow unloading valve is rationally designed and simple in structure. By setting a pre-pressure valve, it can effectively protect the main valve, and can improve the protection of the main valve under ultra-high pressure or low pressure conditions. By setting a travel switch and a micro switch, it can be connected to the main valve through a striker rod, which can improve the sensitivity and control accuracy of the unloading reaction. In actual operation, the large flow unloading valve is connected to the hydraulic pump of the punch press, (1) Normal operation state: hydraulic oil enters the right side of the main valve from the plate oil supply port, enters the punch press cylinder through the oil outlet pipe, and the air pressure enters the left side of the main valve from the air supply port, and is added with the spring force to achieve pressure balance with the hydraulic oil on the right side. The striker rod triggers the travel switch to send information, reaching the set pre-pressure, and the machine tool can operate normally. (2) Overload state: The press is overloaded, and the pressure of the slider hydraulic cylinder rises to above the set unloading valve pressure. The main valve overcomes the air pressure and spring force and moves to the left. The main valve opens to unload, and the oil pressure flows from the cylinder back to the oil tank through the return port. At this time, the striker is away from the travel switch, and the travel switch sends a signal, and the main valve cannot be operated. (3) Insufficient pre-pressure: The pressure of the slider hydraulic cylinder of the press is lower than the set pre-pressure, and the pre-pressure valve cannot be pushed. The main valve is pushed to the right by the spring, and the main valve closes. The travel switch sends a signal, and the press cannot operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional view of the present utility model.

[0013] Figure 2 It is a top view of the present utility model.

[0014] In the figure: 1. Valve body; 2. Oil outlet pipe; 3. Cylinder head; 4. Air supply port; 5. Pressure adjusting screw; 6. Locking cover; 7. Spring seat; 8. Spring; 9. Oil return port; 10. Preload valve cover; 11. Plate oil supply port; 12. Preload valve; 13. Preload valve seat; 14. Main valve; 15. Main valve sleeve; 16. Exhaust block; 17. Pressure oil outlet; 18. Exhaust valve; 19. Flange; 20. Plug; 21. Travel switch; 22. Micro switch; 23. Impact rod. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary persons in this field without creative work are within the scope of protection of the present invention.

[0016] Embodiment: A large flow unloading valve.

[0017] Reference Figures 1 to 2As shown, a large flow unloading valve comprises: a valve body 1, a flange 19 for external connection is provided on the valve body 1 to facilitate external installation of the large flow unloading valve, a cylinder head 3 is installed on the rear side of the valve body 1, a main valve 14 is installed between the valve body 1 and the cylinder head 3, a main valve sleeve 15 is installed in the valve body 1, the front end of the main valve 14 is embedded in the main valve sleeve 15, the rear end of the main valve 14 is located in the cavity provided by the cylinder head 2, and the main valve 14 can move left and right in the cavity provided by the cylinder head 2, a pre-pressure valve seat 13 is installed at the front end of the main valve 14, a pre-pressure valve 12 is installed on the pre-pressure valve seat 13, and the pre-pressure valve 12 is enclosed in the main valve sleeve 15 by the pre-pressure valve cover 10. The purpose of providing the pre-pressure valve 12 is to effectively protect the main valve 14 in ultra-high pressure Or the protection of the main valve 14 can be improved under low pressure conditions. A spring seat 7 is installed in the groove provided on the rear side of the main valve 14, and a spring 8 is sleeved on the spring seat 7. One end of the spring 8 is against the groove provided on the rear side of the main valve 14, and the other end of the spring 8 is against the inner side of the cylinder cover 3. The function of the spring 8 is mainly to push the main valve 14 to move in the cavity provided in the cylinder cover 2. A pressure adjusting screw 5 is installed in the cylinder cover 3, and the inner end of the pressure adjusting screw 5 is against the spring seat 7. The outer side of the pressure adjusting screw 5 is locked in the cylinder cover 3 by the locking cover 6. During actual work, the position of the spring seat 7 can be adjusted by the pressure adjusting screw 5, and then the elastic force of the spring 8 can be adjusted, and then the reaction sensitivity of the main valve 14 to unload can be adjusted.

[0018] The center holes of the main valve 14, main valve sleeve 15, pre-pressure valve seat 13, pre-pressure valve 12 and pre-pressure valve cover 10 are concentrically arranged and connected in sequence. The top of the valve body 1 is provided with an oil outlet pipe 2, and the oil outlet pipe 2 is connected to the center hole of the pre-pressure valve cover 10. The bottom of the valve body 1 is provided with an oil return port 9 and a plate oil supply port 11, wherein the plate oil supply port 11 is connected to the pre-pressure valve 12, and the oil return port 9 is connected to the main valve 14. The cylinder head 3 is provided with an air supply port 4, and the air supply port 4 is connected to the cavity provided on the cylinder head 3. A travel switch 21 and a micro switch 22 are installed on the outside of the valve body 1, and the travel switch 21 and the micro switch 22 are respectively connected to the main valve 14 through a striker rod 23. An exhaust block 16 is also installed on the valve body 1 , and a pressure oil outlet 17 and an exhaust valve 18 are provided on the exhaust block 16 . Both the pressure oil outlet 17 and the exhaust valve 18 are connected to the main valve 14 to further protect the main valve 14 .

[0019] In this embodiment, during actual operation, the high-flow unloading valve is connected to the hydraulic pump of the punch press, and its working state is as follows:

[0020] (1) Normal operation: Hydraulic oil enters the right side of the main valve 14 from the plate oil supply port 11, and enters the punch cylinder through the oil outlet pipe 2. Air pressure enters the left side of the main valve 14 from the air supply port 4, and is added to the elastic force of the spring 8 to achieve pressure balance with the hydraulic oil on the right side. The stroke switch 21 is triggered by the striker 23 to send a message, and the set pre-pressure is reached, and the machine tool can operate normally.

[0021] (2) Overload state: The press is overloaded, and the pressure of the slider hydraulic cylinder rises to above the set unloading valve pressure. The main valve 14 overcomes the air pressure and the elastic force of the spring 8 and moves to the left. The main valve 14 opens to unload, and the oil pressure flows from the cylinder back to the oil tank through the return oil port 9. At this time, the striker 23 is away from the travel switch 21, and the travel switch 21 sends a signal, and the main valve 14 cannot be moved.

[0022] (3) Insufficient pre-pressure: The pressure of the hydraulic cylinder of the press slide is lower than the set pre-pressure, and the pre-pressure valve 12 cannot be pushed. The main valve 14 is pushed to the right by the spring 8, the main valve 14 is closed, the travel switch 21 sends a signal, and the press cannot operate.

[0023] This high-flow unloading valve features a rational design and simple structure. The preload valve 12 effectively protects the main valve 14, enhancing protection under both ultra-high and low pressure conditions and extending valve life. The travel switch 21 and microswitch 22 connect the valve to the main valve 14 via the striker 23, improving the sensitivity and control accuracy of the unloading response. Furthermore, the pressure adjustment screw 5 adjusts the position of the spring seat 7, thereby adjusting the elastic force of the spring 8 and, consequently, the sensitivity of the main valve 14 in unloading.

[0024] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the contents disclosed in the embodiment and the drawings. Therefore, any equivalent or modification completed without departing from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A large flow unloading valve, characterized in that include: The cam is secured to the cam face and is located adjacent to the cylinder head, with the cam being secured to the cam face and is detachable from the cylinder head. Offsetting each other, the center holes of the main valve, main valve sleeve, pre-pressure valve seat, pre-pressure valve and pre-pressure valve cover are concentrically arranged and connected in sequence. An oil outlet pipe is provided on the top of the valve body, and the oil outlet pipe is connected to the center hole of the pre-pressure valve cover. An oil return port and a plate-type oil supply port are provided at the bottom of the valve body, wherein the plate-type oil supply port is connected to the pre-pressure valve, and the oil return port is connected to the main valve. An air supply port is provided on the cylinder head, and the air supply port is connected to the cavity provided on the cylinder head. A travel switch and a microswitch are installed on the outside of the valve body, and the travel switch and the microswitch are respectively connected to the main valve through a striker rod.

2. The large flow unloading valve according to claim 1, characterized in that: A pressure regulating screw is installed in the cylinder cover, and the inner end of the pressure regulating screw abuts against the spring seat.

3. The large flow unloading valve according to claim 2, characterized in that: The outer side of the pressure regulating screw is locked in the cylinder cover through a locking cover.

4. The large flow unloading valve according to claim 1, characterized in that: An exhaust block is also installed on the valve body. A pressure oil outlet and an exhaust valve are provided on the exhaust block. Both the pressure oil outlet and the exhaust valve are communicated with the main valve.

5. The large flow unloading valve according to claim 1, characterized in that: The valve body is provided with a flange for external connection.

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