Rolling mill pressing-up hydraulic servo high-low pressure control loop

Abstract

A rolling mill pressure hydraulic servo high-low pressure control loop comprises a pump station, a high-low pressure valve set and a servo valve working valve set. The high-low pressure valve group comprises a plug-in pressure reducing valve, a first plug-in one-way valve, a second plug-in one-way valve, an electromagnetic directional valve and a third plug-in one-way valve; the servo valve working valve group comprises a filter and a servo valve; according to the hydraulic control loop, the logic cartridge valve and the electromagnetic directional valve are combined, high-low pressure switching can be rapidly achieved, and a proper pressure oil source is provided for work of the servo valve; when the servo valve works normally, high-pressure oil supply is switched; when the servo valve is tested, low-pressure oil supply is switched, so that the manual debugging time is shortened, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of hydraulic servo control for rolling mills, in particular to a hydraulic servo high and low pressure control circuit for rolling mills. Background Art

[0002] The roll gap adjustment and control of the non-ferrous metal plate, strip and foil rolling mill is achieved by controlling the AGC hydraulic cylinder (pressing cylinder) with a hydraulic servo valve. The servo valve has high control accuracy and fast response speed, but its structure is precise and requires a high level of cleanliness for the hydraulic oil. During initial debugging, the servo valve is often out of control due to over-sensitivity. During use, the machine often shuts down due to valve jamming and other faults.

[0003] Due to the high pressure of the hydraulic system, the system pressure needs to be reduced for testing during the initial debugging for safety reasons, and the normal operating pressure of the system is restored after the test is normal. When a valve jam occurs, the machine needs to be shut down and replaced with a new valve. After the new valve is replaced, it also needs to be tested with a small pressure. In this way, the staff needs to manually reduce the pressure during each test, and then restore the pressure to normal after the test. Because the pump station is located far away, the pressure adjustment process takes up production time. If the pressure is not adjusted for testing, there will be safety risks. Utility Model Content

[0004] In order to overcome the above-mentioned shortcomings, the utility model provides a rolling mill press hydraulic servo high and low pressure control circuit.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A rolling mill hydraulic servo high and low pressure control circuit, comprising

[0007] Pump station, high and low pressure valve group and servo valve working valve group;

[0008] The high and low pressure valve group includes: a cartridge pressure reducing valve, a first cartridge check valve, a second cartridge check valve, an electromagnetic reversing valve and a third cartridge check valve;

[0009] The pump station is connected to the a port of the second cartridge check valve and the oil inlet of the electromagnetic reversing valve through the oil circuit series ball valve, the oil outlet c of the electromagnetic reversing valve is connected to the oil circuit of the valve core upper cavity of the second cartridge check valve, the oil outlet d of the electromagnetic reversing valve is connected to the oil circuit of the valve core upper cavity of the third cartridge check valve, and the oil return port of the electromagnetic reversing valve is connected to the oil circuit of the pump station;

[0010] The c port of the second cartridge-type one-way valve is connected to the oil inlet oil circuit of the cartridge-type pressure reducing valve, and the oil outlet of the cartridge-type pressure reducing valve is connected to the b port oil circuit of the first cartridge-type one-way valve;

[0011] The port b of the second cartridge check valve is connected to the port a of the third cartridge check valve through an oil circuit, and the port a of the first cartridge check valve is connected to the port b of the third cartridge check valve through an oil circuit and then connected to the inlet of the servo valve working valve group;

[0012] The servo valve working valve group includes a filter and a servo valve;

[0013] One end of the filter is connected to the oil circuits of port a of the first cartridge-type one-way valve and port b of the third cartridge-type one-way valve, and the other end is connected to the oil inlet oil circuit of the servo valve, the oil return port of the servo valve is connected to the oil circuit of the pump station, the port a of the servo valve is connected to the oil circuit of the pressure cylinder and the pressure sensor, and the piston rod chamber of the pressure cylinder is connected to the oil circuit of the pump station.

[0014] The servo valve working valve group also includes an electromagnetic overflow valve, one end of which is connected to the pressure measuring joint oil circuit, and the other end is connected to the oil return port of the servo valve and the pump station oil circuit.

[0015] The oil inlet, oil return and A ports of the servo valve are provided with an oil inlet check valve, an oil return check valve and an outlet ball valve respectively on the oil circuits where the oil inlet, oil return and A ports are located.

[0016] A pressure measuring joint is provided on the oil circuit between the filter and the first cartridge one-way valve and the third cartridge one-way valve; a pressure measuring joint is provided on the oil circuit between the cartridge pressure reducing valve and the first cartridge one-way valve.

[0017] The piston rod chamber of the pressure cylinder is provided with a back pressure Pb of 2 MPa by the pump station.

[0018] Due to the adoption of the above-mentioned technical solution, the utility model has the following advantages:

[0019] The utility model provides a rolling mill hydraulic servo high and low pressure control circuit. The hydraulic control circuit adopts a combination of a logic cartridge valve and an electromagnetic reversing valve to quickly realize high and low pressure switching, and provide a suitable pressure oil source for the servo valve to work; when the servo valve works normally, it switches to high-pressure oil supply; when the servo valve is tested, it switches to low-pressure oil supply, thereby shortening the manual debugging time and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a hydraulic control circuit diagram of the utility model.

[0021] 1. Pump station; 2. Ball valve; 3. Cartridge pressure reducing valve; 4. First cartridge check valve; 5. Second cartridge check valve; 6. Solenoid reversing valve; 7. Third cartridge check valve; 8. Filter; 9. Oil inlet check valve; 10. Servo valve; 11. Oil return check valve; 12. Solenoid overflow valve; 13. Pressure measuring joint; 14. Pressure sensor; 15. Pressure cylinder. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Combined with Figure 1 The rolling mill press hydraulic servo high and low pressure control circuit comprises: a pump station, a high and low pressure valve group and a servo valve working valve group;

[0024] The high and low pressure valve group includes: a cartridge pressure reducing valve 3, a first cartridge check valve 4, a second cartridge check valve 5, an electromagnetic reversing valve 6 and a third cartridge check valve 7;

[0025] The pump station 1 is connected to the ball valve 2 in series through the oil circuit, and is connected to the port a of the second cartridge check valve 5 and the oil inlet of the electromagnetic reversing valve 6. The oil outlet c of the electromagnetic reversing valve 6 is connected to the oil circuit of the upper cavity of the valve core of the second cartridge check valve 5. The oil outlet d of the electromagnetic reversing valve 6 is connected to the oil circuit of the upper cavity of the valve core of the third cartridge check valve 7. The oil return port of the electromagnetic reversing valve 6 is connected to the oil circuit of the pump station.

[0026] It should be noted that the oil circuit connection mentioned above and below refers to connecting the relevant ports of two components through a hydraulic oil pipe.

[0027] The c port of the second cartridge check valve 5 is connected to the oil inlet circuit of the cartridge pressure reducing valve 3, and the oil outlet of the cartridge pressure reducing valve 3 is connected to the oil circuit of the b port of the first cartridge check valve 4;

[0028] The port b of the second cartridge check valve 5 is connected to the port a of the third cartridge check valve 7 through an oil circuit, and the port a of the first cartridge check valve 4 is connected to the port b of the third cartridge check valve 7 through an oil circuit and then connected to the inlet of the servo valve working valve group;

[0029] The servo valve working valve group includes a filter 8 and a servo valve 10;

[0030] One end of the filter 8 is connected to the oil circuit of port a of the first cartridge check valve 4 and port b of the third cartridge check valve 7, and the other end is connected to the oil inlet oil circuit of the servo valve, the oil return port of the servo valve is connected to the oil circuit of the pump station, the port a of the servo valve is connected to the oil circuit of the pressure cylinder 15 and the pressure sensor 14, and the piston rod chamber of the pressure cylinder 15 is connected to the oil circuit of the pump station.

[0031] The servo valve working valve group also includes an electromagnetic overflow valve 12, one end of which is connected to the pressure measuring joint oil circuit, and the other end is connected to the return oil port of the servo valve and the pump station oil circuit. Under normal conditions, the electromagnetic overflow valve 12 is in the power-on position, there is no overflow, and it only plays a safety protection role; only when the control is abnormal or the pressure exceeds the maximum pressure, the electromagnetic overflow valve 12 is powered off and unloaded.

[0032] The oil inlet, oil return and a port of the servo valve are provided with an oil inlet check valve 9, an oil return check valve 11 and an outlet ball valve respectively on the oil circuit. Since the servo valve 10 is easy to be blocked, in order to prevent oil leakage when the servo valve 10 is replaced, the three oil ports of the servo valve 10 used are equipped with an oil inlet check valve 9, an oil return check valve 11 and an outlet ball valve; when the servo valve is replaced, the outlet ball valve is closed; after the servo valve 10 is replaced, the outlet ball valve is opened.

[0033] A pressure measuring joint is provided on the oil circuit between the filter 8 and the first cartridge check valve 4 and the third cartridge check valve; a pressure measuring joint is provided on the oil circuit between the cartridge pressure reducing valve 3 and the first cartridge check valve 4.

[0034] The piston rod chamber of the pressing cylinder 15 is provided with a back pressure Pb of 2 MPa by the pump station 1, which is used for the return of the pressing cylinder 15, so that the control accuracy and response speed of the servo valve 10 are higher.

[0035] Figure 1 The servo valve working valve group of the pressing cylinder 15 on one side of the rolling mill is shown. The servo valve working valve group of the pressing cylinder 15 on the other side of the rolling mill also adopts the same control circuit. The two sides are connected by a three-way connection to share the high and low pressure valve group. The two sides are controlled synchronously, which can well realize the roll gap control of the rolling mill.

[0036] A method for controlling high and low pressure of a hydraulic servo on a rolling mill, comprising a hydraulic servo high and low pressure control circuit on a rolling mill, and the specific steps are as follows:

[0037] The high-pressure oil of the pump station 1 enters the inlet of the high- and low-pressure valve group through the ball valve 2. When the end a of the electromagnet of the electromagnetic reversing valve 6 is energized, the electromagnetic reversing valve 6 is switched to the left functional position, and the pressure oil acts on the valve core upper cavity of the third cartridge check valve 7 through the electromagnetic reversing valve 6. The third cartridge check valve 7 is in a closed state. At this time, the control oil in the valve core upper cavity of the second cartridge check valve 5 returns to the oil tank through the electromagnetic reversing valve 6 and the oil drain pipe L. The high-pressure oil of the system opens the second cartridge check valve 5 and enters the cartridge pressure reducing valve 3. After pressure reduction, it enters the servo valve working valve group through the first cartridge check valve 4. The high- and low-pressure valve group is in a low-pressure state, and the servo valve can be tested.

[0038] When the electromagnet b end of the electromagnetic reversing valve 6 is energized, the pressure oil acts on the upper chamber of the valve core of the second cartridge check valve 5 through the electromagnetic reversing valve 6, and the second cartridge check valve 5 is in a closed state. At this time, the control oil in the upper chamber of the valve core of the third cartridge check valve 7 returns to the oil tank through the electromagnetic reversing valve 6 and the oil drain pipe L. The high-pressure oil of the system opens the third cartridge check valve 7 and enters the servo valve working valve group. The high and low pressure valve groups are in a high pressure state, and the servo valve can operate normally.

[0039] The high or low pressure oil enters the pressure cylinder 15 through the filter 8 and the servo valve 10. The pressure sensor 14 detects the pressure entering the pressure cylinder 15 and realizes precise control in a closed loop with the servo valve 10.

[0040] The parts not described in detail in the above content are prior art, so they are not described in detail.

Claims

1. A rolling mill hydraulic servo high and low pressure control circuit, characterized in that: include Pump station, high and low pressure valve group and servo valve working valve group; The high and low pressure valve group includes: a cartridge pressure reducing valve, a first cartridge check valve, a second cartridge check valve, an electromagnetic reversing valve and a third cartridge check valve; The pump station is connected to the a port of the second cartridge check valve and the oil inlet of the electromagnetic reversing valve through the oil circuit series ball valve, the oil outlet c of the electromagnetic reversing valve is connected to the oil circuit of the valve core upper cavity of the second cartridge check valve, the oil outlet d of the electromagnetic reversing valve is connected to the oil circuit of the valve core upper cavity of the third cartridge check valve, and the oil return port of the electromagnetic reversing valve is connected to the oil circuit of the pump station; The c port of the second cartridge-type one-way valve is connected to the oil inlet oil circuit of the cartridge-type pressure reducing valve, and the oil outlet of the cartridge-type pressure reducing valve is connected to the b port oil circuit of the first cartridge-type one-way valve; The port b of the second cartridge check valve is connected to the port a of the third cartridge check valve through an oil circuit, and the port a of the first cartridge check valve is connected to the port b of the third cartridge check valve through an oil circuit and then connected to the inlet of the servo valve working valve group; The servo valve working valve group includes a filter and a servo valve; One end of the filter is connected to the oil circuits of port a of the first cartridge-type one-way valve and port b of the third cartridge-type one-way valve, and the other end is connected to the oil inlet oil circuit of the servo valve, the oil return port of the servo valve is connected to the oil circuit of the pump station, the port a of the servo valve is connected to the oil circuit of the pressure cylinder and the pressure sensor, and the piston rod chamber of the pressure cylinder is connected to the oil circuit of the pump station.

2. The rolling mill hydraulic servo high and low pressure control circuit according to claim 1 is characterized in that: The servo valve working valve group also includes an electromagnetic overflow valve, one end of which is connected to the pressure measuring joint oil circuit, and the other end is connected to the oil return port of the servo valve and the pump station oil circuit.

3. The rolling mill hydraulic servo high and low pressure control circuit according to claim 2 is characterized in that: The oil inlet, oil return and A ports of the servo valve are provided with an oil inlet check valve, an oil return check valve and an outlet ball valve respectively on the oil circuits where the oil inlet, oil return and A ports are located.

4. The rolling mill hydraulic servo high and low pressure control circuit according to claim 1, characterized in that: A pressure measuring joint is provided on the oil circuit between the filter and the first cartridge one-way valve and the third cartridge one-way valve; a pressure measuring joint is provided on the oil circuit between the cartridge pressure reducing valve and the first cartridge one-way valve.

5. The rolling mill hydraulic servo high and low pressure control circuit according to claim 1, characterized in that: The piston rod chamber of the pressure cylinder is provided with a back pressure Pb of 2 MPa by the pump station.

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