Leveling system for movable cross beam of hydraulic machine

Abstract

The invention provides a leveling system for a movable cross beam of a hydraulic machine, and relates to the technical field of forging equipment, the leveling system for the movable cross beam of the hydraulic machine comprises at least two working cylinders and working cylinder control valve banks corresponding to the working cylinders respectively, and the at least two working cylinders are uniformly arranged above the movable cross beam; the working cylinder control valve group comprises a first electromagnetic switch valve, a proportional flow valve and a proportional servo valve, one end of the first electromagnetic switch valve is communicated with an oil tank, the other end of the first electromagnetic switch valve is communicated with the working cylinder, one end of the proportional flow valve is communicated with the oil tank, and the other end of the proportional servo valve is communicated with the working cylinder. The other end of the proportional flow valve is communicated with an oil way between the first electromagnetic switch valve and the working cylinder, the first end and the second end of the proportional servo valve are both communicated with the oil tank, and the third end of the proportional servo valve is communicated with the oil way between the first electromagnetic switch valve and the working cylinder. Only the existing working cylinder is adopted for leveling, so that the cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of forging equipment, and in particular to a movable crossbeam leveling system for a hydraulic press. Background Art

[0002] The leveling of the hydraulic press's movable crossbeam is an important step to ensure that the machine remains stable and accurate during operation. If the hydraulic press's movable crossbeam is not properly leveled, it may cause uneven pressure distribution during operation, thus affecting processing accuracy, reducing product quality, and even causing damage to the equipment itself.

[0003] In the related art, the leveling of the movable crossbeam of the hydraulic press is achieved by providing an independent leveling and deflection-correcting cylinder, but the cost of the independent leveling and deflection-correcting cylinder is relatively high. Summary of the invention

[0004] The problem solved by the invention is how to reduce the leveling cost of the movable crossbeam of the hydraulic press.

[0005] To solve the above problems, the present invention provides a hydraulic press movable beam leveling system, comprising at least two working cylinders and working cylinder control valve groups corresponding to the working cylinders respectively, at least two of the working cylinders are evenly arranged above the movable beam, the working cylinder control valve group comprises a first electromagnetic switch valve, a proportional flow valve and a proportional servo valve, one end of the first electromagnetic switch valve is connected to an oil tank, the other end of the first electromagnetic switch valve is connected to the corresponding working cylinder, one end of the proportional flow valve is connected to the oil tank, the other end of the proportional flow valve is connected to the oil circuit between the first electromagnetic switch valve and the working cylinder, the first end and the second end of the proportional servo valve are both connected to the oil tank, and the third end of the proportional servo valve is connected to the oil circuit between the first electromagnetic switch valve and the working cylinder.

[0006] Optionally, the working cylinder control valve group also includes a second solenoid switch valve, one end of the second solenoid switch valve is connected to the oil circuit between the first solenoid switch valve and the working cylinder, and the other end of the second solenoid switch valve is connected to the other end of the second solenoid switch valve in other working cylinder control valve groups.

[0007] Optionally, a displacement sensor is provided on the working cylinder, or the displacement sensor is provided at a position on the movable crossbeam corresponding to the working cylinder.

[0008] Optionally, a working pump and a working pump head control valve group are provided at one end of the oil circuit between the first solenoid switch valve and the oil tank close to the oil tank.

[0009] Optionally, the working pump head control valve group includes a pressure valve and a filter connected in sequence.

[0010] Optionally, a leveling pump and a leveling pump head control valve group are provided at one end of the oil circuit between the proportional servo valve and the oil tank close to the oil tank.

[0011] Optionally, an accumulator is provided on the oil circuit between the proportional servo valve and the oil tank.

[0012] Optionally, a one-way valve is provided on the oil circuit connecting the first electromagnetic switch valve and the working cylinder, the oil inlet of the one-way valve is communicated with the first electromagnetic switch valve, and the oil outlet of the one-way valve is communicated with the working cylinder.

[0013] Optionally, a pressure sensor is provided on the oil circuit between the first electromagnetic switch valve and the working cylinder.

[0014] Optionally, the hydraulic press movable crossbeam leveling system further includes a processor, and the processor is communicatively connected with the first electromagnetic switch valve, the proportional flow valve and the proportional servo valve respectively.

[0015] The beneficial effects of the movable crossbeam leveling system of a hydraulic press of the present invention are:

[0016] The first electromagnetic switch valve is connected to the oil tank and the working cylinder respectively, so the oil circuit can be quickly switched open and closed, and is connected to the oil tank through one end of the proportional flow valve, and the other end of the proportional flow valve is connected to the oil circuit between the first electromagnetic switch valve and the working cylinder. It can be used to discharge oil from the working cylinder to reduce impact and vibration when the working cylinder is proportionally unloaded and the movable crossbeam is lifted after the movable crossbeam reaches the forging end point, and then the first and second ends of the proportional servo valve are connected to the oil tank, and the third end of the proportional servo valve is connected to the oil circuit between the first electromagnetic switch valve and the working cylinder. The first and second ends of the proportional servo valve can be used to replenish or drain oil from the working cylinder connected to the third end, respectively, so as to adjust the position of the corresponding working cylinder to achieve leveling. For example, the working cylinder with a lagging position can be replenished with oil through the first end of the proportional servo valve, or the working cylinder with an advanced position can be drained through the second end of the proportional servo valve, so as to complete the leveling task. The present invention controls the setting of the working cylinder control valve group and only uses the existing working cylinder to complete the leveling task. There is no need to install an additional independent synchronous leveling and correcting hydraulic cylinder, thereby reducing material costs and equipment complexity, which not only reduces the initial investment but also simplifies subsequent maintenance work. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a hydraulic press movable crossbeam leveling system provided by an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of the structure of a working cylinder control valve group provided in an embodiment of the present invention;

[0019] Figure 3One of the structural schematic diagrams of the working cylinder and the movable crossbeam provided in the embodiment of the present invention;

[0020] Figure 4 The second structural schematic diagram of the working cylinder and the movable crossbeam provided in the embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1. Working cylinder; 2. Working cylinder control valve group; 21. First solenoid switch valve; 22. Proportional flow valve; 23. Proportional servo valve; 24. Second solenoid switch valve; 25. Check valve; 26. Pressure sensor; 3. Working pump; 4. Working pump head control valve group; 5. Leveling pump; 6. Leveling pump head control valve group; 7. Movable crossbeam; 8. Displacement sensor; 9. Accumulator. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0024] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0025] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0026] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a hydraulic press movable beam leveling system.

[0027] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a hydraulic press movable beam leveling system, comprising at least two working cylinders 1 and working cylinder control valve groups 2 corresponding to the working cylinders 1 respectively, at least two of the working cylinders are evenly arranged above the movable beam 7, the working cylinder control valve group 2 comprises a first electromagnetic switch valve 21, a proportional flow valve 22 and a proportional servo valve 23, one end of the first electromagnetic switch valve 21 is connected to the oil tank, the other end of the first electromagnetic switch valve 21 is connected to the corresponding working cylinder 1, one end of the proportional flow valve 22 is connected to the oil tank, the other end of the proportional flow valve 22 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1, the first end and the second end of the proportional servo valve 23 are both connected to the oil tank, and the third end of the proportional servo valve 23 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1.

[0028] Specifically, the number of working cylinders 1 can be set according to actual conditions, such as Figure 1 and Figure 3 As shown, five working cylinders 1 and their corresponding working cylinder control valve groups 2 may be provided, or as shown in FIG. Figure 4 As shown, three working cylinders 1 are provided. Figure 3 and Figure 4 As shown, at least two working cylinders 1 are evenly and symmetrically arranged above the movable crossbeam 7, and the movable crossbeam 7 is connected to the movable ends of the working cylinders 1, so that the movable crossbeam 7 is evenly stressed and the balance of different areas of the movable crossbeam 7 is adjusted easily. Figure 2 As shown, the working cylinder control valve group 2 includes a first electromagnetic switch valve 21, a proportional flow valve 22 and a proportional servo valve 23. One end of the first electromagnetic switch valve 21 is connected to the oil tank, and the other end of the first electromagnetic switch valve 21 is connected to the corresponding working cylinder 1. The first electromagnetic switch valve 21 is used to open when the movable crossbeam 7 is forged and pressurized, so as to supply oil to the working cylinder 1. One end of the proportional flow valve 22 is connected to the oil tank, and the other end of the proportional flow valve 22 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1. The proportional flow valve 22 is used to discharge oil from the working cylinder 1 when the working cylinder 1 is unloaded and the movable crossbeam 7 is lifted after the movable crossbeam 7 reaches the forging end point, so as to achieve unloading and oil discharge. The first end and the second end of the proportional servo valve 23 are both connected to the oil tank, and the third end of the proportional servo valve 23 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1, so that when the movable crossbeam 7 deflects, the corresponding working cylinder 1 is replenished with oil and discharged according to the deflection condition, so as to level the movable crossbeam 7. The first end of the proportional servo valve 23 may be an oil inlet port, and the second end may be an oil outlet port, or the first end may be an oil outlet port, and the second end may be an oil inlet port. It should be understood that the layout of the working cylinder 1 is only for illustration, and the number, cylinder diameter, and layout position of the working cylinder 1 are all set according to actual conditions.

[0029] In this embodiment, the first electromagnetic switch valve 21 is connected to the oil tank and the working cylinder 1 respectively, so that the oil circuit can be quickly switched open and closed, and is connected to the oil tank through one end of the proportional flow valve 22, and the other end of the proportional flow valve 22 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1, which can be used to discharge oil from the working cylinder 1 when the working cylinder 1 is proportionally unloaded and the movable crossbeam 7 is lifted after the movable crossbeam 7 reaches the forging end point, so as to reduce impact and vibration, and then the first and second ends of the proportional servo valve 23 are both connected to the oil tank, and the third end of the proportional servo valve 23 is connected to the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1, and the first and second ends of the proportional servo valve 23 can be used to replenish or drain oil from the working cylinder 1 connected to the third end, respectively, so as to adjust the position of the corresponding working cylinder 1 to achieve leveling, for example, the working cylinder 1 with a lagging position can be replenished with oil through the first end of the proportional servo valve 23, or the working cylinder 1 with an advanced position can be drained through the second end of the proportional servo valve 23, so as to complete the leveling task. The present invention uses the existing working cylinder 1 to complete the leveling task through the setting of the working cylinder control valve group 2, without the need to install an additional independent synchronous leveling and correcting hydraulic cylinder, thereby reducing material costs and equipment complexity, which not only reduces the initial investment, but also simplifies subsequent maintenance work.

[0030] Optionally, the working cylinder control valve group 2 also includes a second solenoid switch valve 24, one end of the second solenoid switch valve 24 is connected to the oil circuit between the first solenoid switch valve 21 and the working cylinder 1, and the other end of the second solenoid switch valve 24 is respectively connected to the other end of the second solenoid switch valve 24 in other working cylinder control valve groups 2.

[0031] Specifically, the working cylinder control valve group 2 also includes a second solenoid switch valve 24, one end of the second solenoid switch valve 24 is connected to the oil circuit between the first solenoid switch valve 21 and the working cylinder 1, and the other end of the second solenoid switch valve 24 is respectively connected to the other end of other second solenoid switch valves 24, thereby connecting each working cylinder 1. In this way, when leveling and correction are not required, such as when the movable crossbeam 7 is lowered and returned in the idle stroke, the hydraulic oil can flow between the working cylinders 1, thereby reducing the pressure difference between the working cylinders 1.

[0032] Exemplarily, in order to better understand the leveling principle of the working cylinder control valve group 2 of the present invention, this embodiment provides the action process of the working cylinder control valve group 2: when the movable crossbeam 7 is working and stops at the highest position, the first solenoid switch valve 21, the proportional flow valve 22 and the proportional servo valve 23 can be controlled to be closed, and the second solenoid switch valve 24 can be opened; when the movable crossbeam 7 is in the idle stroke, the first solenoid switch valve 21 and the proportional servo valve 23 can be controlled to be closed, and the proportional flow valve 22 and the second solenoid switch valve 24 can be opened, wherein, if the hydraulic press has a separate filling valve and filling pipeline, the proportional flow valve 22 can also be closed; after the idle stroke descent of the movable crossbeam 7 ends and the working cylinder 1 starts to pressurize, the movable crossbeam 7 needs to enter the synchronous leveling and deviation correction state. At this time, the first solenoid switch valve 21 is opened, and the hydraulic oil enters the corresponding working cylinder 1. In cylinder 1, pressurized forging begins, the proportional flow valve 22 and the second electromagnetic switch valve 24 are closed, so that each working cylinder 1 is independently controlled and not affected by other working cylinders 1, the proportional servo valve 23 is opened, and according to the deflection of the movable crossbeam 7, the corresponding working cylinder 1 is supplemented with oil or discharged through the proportional servo valve 23, so as to achieve leveling; when the movable crossbeam 7 reaches the forging end point and stops, the first electromagnetic switch valve 21 is closed, the proportional flow valve 22 is opened, and the corresponding working cylinder 1 is unloaded, the second electromagnetic switch valve 24 is opened, so that each working cylinder 1 is connected, and the proportional servo valve 23 is closed; when the movable crossbeam 7 rises, the first electromagnetic switch valve 21 remains closed, the proportional flow valve 22 remains open, the second electromagnetic switch valve 24 remains open, and the proportional servo valve 23 remains closed.

[0033] Optionally, a displacement sensor 8 is provided on the working cylinder 1 , or the displacement sensor 8 is provided at a position on the movable crossbeam 7 corresponding to the working cylinder 1 .

[0034] Specifically, a displacement sensor 8 is provided on the working cylinder 1, for example, inside or outside the working cylinder 1, or a displacement sensor 8 is provided at a corresponding position between the movable cross beam 7 and the working cylinder 1. Figure 3 As shown, the movable crossbeam 7 is rectangular, and the working cylinders 1 are evenly distributed on the movable crossbeam 7, and displacement sensors 8 can be set at the four corners of the movable crossbeam 7. The displacement sensor 8 can detect the yaw displacement of different areas of the movable crossbeam 7, and leveling is performed in combination with the proportional servo valve 23 according to the yaw displacement. For example, due to actual setting reasons, the displacement sensor 8 will detect that the extended distances of each working cylinder 1 are inconsistent, some are higher and some are lower. According to the data of these sensors, a target position deviation value is set for each working cylinder 1 for zeroing. When the movable crossbeam deflects, if the actual displacement of a working cylinder exceeds its target position deviation value, for example, more than 0.3 mm, it is adjusted through the corresponding proportional servo valve:

[0035] For higher corners, a proportional servo valve controls the flow of hydraulic oil into the cylinder, causing this portion of the movable crossbar to drop.

[0036] For the lower corner, the proportional servo valve controls the hydraulic oil to be discharged from the working cylinder, so that this part of the movable beam can be raised.

[0037] Optionally, a working pump 3 and a working pump head control valve group 4 are provided at one end of the oil circuit between the first electromagnetic switch valve 21 and the oil tank close to the oil tank.

[0038] Specifically, if Figure 1 As shown, a working pump 3 and a working pump head control valve group 4 are provided at one end of the oil circuit between the first solenoid switch valve 21 and the oil tank close to the oil tank. The working pump 3 is connected to the oil tank. One end of the working pump head control valve group 4 is connected to the working pump 3, and the other end is connected to the oil circuit of the first solenoid switch valve 21. The working pump 3 is used to supply oil to the working cylinder 1, and the working pump head control valve group 4 is used to control the output of the working pump 3.

[0039] Optionally, the working pump head control valve group 4 includes a pressure valve and a filter connected in sequence.

[0040] Specifically, the working pump head control valve group 4 includes a pressure valve and a filter connected in sequence. The pressure valve is used to limit pressure and other safety protection, pressure and circulation functions, and the filter is used to filter impurities. The pressure valve is connected to the working pump 3, and the filter is connected to the oil circuit of the first electromagnetic switch valve 21.

[0041] Optionally, a leveling pump 5 and a leveling pump head control valve group 6 are provided at one end of the oil circuit between the proportional servo valve 23 and the oil tank close to the oil tank.

[0042] Specifically, if Figure 1 As shown, a leveling pump 5 and a leveling pump head control valve group 6 are provided at one end of the oil circuit between the proportional servo valve 23 and the oil tank near the oil tank. The leveling pump 5 is connected to the oil tank. One end of the leveling pump head control valve group 6 is connected to the leveling pump 5, and the other end is connected to the oil circuit of the proportional servo valve 23. The leveling pump 5 is used to supply oil to the proportional servo valve 23 in the working cylinder control valve group 2, and the leveling pump head control valve group 6 is used to control the output of the leveling pump 5.

[0043] Exemplarily, the leveling pump head control valve group 6 includes a pressure valve and a filter connected in sequence, the pressure valve is used for safety protection such as limiting pressure, pressurization and circulation functions, and the filter is used for filtering impurities.

[0044] Exemplarily, the leveling pump head control valve group 6 includes a filter pre-pressure mechanism, an integrated intelligent proportional servo valve, a bypass protection mechanism and a hydraulic accumulator connected in sequence. The filter pre-pressure mechanism may include a high-efficiency filter and a pre-pressure buffer. The hydraulic oil first passes through the high-efficiency filter to remove impurities to ensure the cleanliness of the subsequent system. Then, the filtered hydraulic oil enters the pre-pressure buffer, where the hydraulic oil will be initially pressure-stabilized to reduce pressure fluctuations and protect downstream equipment; the hydraulic oil from the pre-pressure buffer enters the integrated intelligent proportional servo valve. This valve is responsible for accurately controlling the direction, pressure and flow of the hydraulic oil according to the received signal. The bypass protection mechanism includes an automatic overflow valve and a one-way valve. The automatic overflow valve and the one-way valve are arranged after the intelligent proportional servo valve. The overflow valve is used to prevent the system from over-pressure. When it detects that the pressure exceeds the safety limit, it automatically opens to release excess pressure. The one-way valve ensures that even when the overflow valve is working, the hydraulic oil will not flow back to the upstream components, thereby ensuring the correct oil flow direction; finally, the hydraulic oil will pass through the hydraulic accumulator, which can store excess hydraulic energy and release it quickly when needed, helping to smooth pressure fluctuations, which not only improves the response speed, but also effectively extends the service life of other components.

[0045] Optionally, an accumulator 9 is provided on the oil circuit between the proportional servo valve 23 and the oil tank.

[0046] Specifically, Figure 1 As shown, an accumulator 9 is provided on the oil circuit between the proportional servo valve 23 and the oil tank. The accumulator 9 can store excess hydraulic energy and release it quickly when needed, thereby helping to smooth pressure fluctuations.

[0047] Optionally, a one-way valve 25 is provided on the oil circuit connecting the first electromagnetic switch valve 21 and the working cylinder 1 , the oil inlet of the one-way valve 25 is communicated with the first electromagnetic switch valve 21 , and the oil outlet of the one-way valve 25 is communicated with the working cylinder 1 .

[0048] Specifically, Figure 2 As shown, a one-way valve 25 is provided on the oil circuit connecting the first solenoid switch valve 21 and the working cylinder 1. The oil inlet of the one-way valve 25 is connected to the first solenoid switch valve 21, and the oil outlet of the one-way valve 25 is connected to the working cylinder 1. The one-way valve 25 is used to prevent the hydraulic oil of the working cylinder 1 from flowing back to the first solenoid switch valve 21 and the corresponding oil supply pipeline.

[0049] Optionally, a pressure sensor 26 is provided on the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1 .

[0050] Specifically, Figure 2As shown, a pressure sensor 26 is provided on the oil circuit between the first electromagnetic switch valve 21 and the working cylinder 1. Since the working cylinder 1 cannot relieve pressure immediately after the movable crossbeam 7 of the hydraulic press reaches the end position of forging, it is necessary to maintain a certain working pressure for a period of time, that is, to maintain pressure, in order to complete the forging. The pressure maintaining method in the related art is to maintain the pressure by continuously supplying oil to the working pump, but this method has low pressure control accuracy and high energy consumption. However, the present application sets a working cylinder control valve group 2, which can maintain pressure through the working cylinder control valve group 2, that is, supply oil through the leveling pump 5, and maintain pressure through a pressure closed loop through the proportional servo valve 23 and the pressure sensor 26, so as to improve the pressure control accuracy and reduce energy consumption.

[0051] Optionally, the hydraulic press movable crossbeam leveling system further includes a processor, and the processor is communicatively connected with the first electromagnetic switch valve 21, the proportional flow valve 22 and the proportional servo valve 23 respectively.

[0052] Specifically, the hydraulic press movable crossbeam leveling system also includes a processor, which is respectively communicated with the first electromagnetic switch valve 21, the proportional flow valve 22 and the proportional servo valve 23, and is used to control the opening and closing of the first electromagnetic switch valve 21, the proportional flow valve 22 and the proportional servo valve 23.

[0053] Exemplarily, the processor is also communicatively connected to the working pump head control valve group 4, the leveling pump head control valve group 6, the displacement sensor 8, the accumulator 9, the second solenoid switch valve 24 and the pressure sensor 26, respectively, for processing sensor data and controlling the working pump head control valve group 4, the leveling pump head control valve group 6, the accumulator 9 and the second solenoid switch valve 24.

[0054] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A hydraulic press movable beam leveling system, characterized in that: The invention comprises at least two working cylinders (1) and working cylinder control valve groups (2) respectively corresponding to the working cylinders (1), wherein at least two of the working cylinders are evenly arranged above a movable crossbeam (7), wherein the working cylinder control valve group (2) comprises a first electromagnetic switch valve (21), a proportional flow valve (22) and a proportional servo valve (23), wherein one end of the first electromagnetic switch valve (21) is connected to an oil tank, and the other end of the first electromagnetic switch valve (21) is connected to the corresponding working cylinder (1), one end of the proportional flow valve (22) is connected to the oil tank, and the other end of the proportional flow valve (22) is connected to an oil path between the first electromagnetic switch valve (21) and the working cylinder (1), the first end and the second end of the proportional servo valve (23) are both connected to the oil tank, and the third end of the proportional servo valve (23) is connected to an oil path between the first electromagnetic switch valve (21) and the working cylinder (1).

2. The hydraulic press movable crossbeam leveling system according to claim 1, characterized in that: The working cylinder control valve group (2) also includes a second electromagnetic switch valve (24), one end of which is connected to the oil circuit between the first electromagnetic switch valve (21) and the working cylinder (1), and the other end of which is connected to the other end of the second electromagnetic switch valve (24) in other working cylinder control valve groups (2).

3. The hydraulic press movable beam leveling system according to claim 1, characterized in that: The working cylinder (1) is provided with a displacement sensor (8), or the movable crossbeam (7) is provided with a displacement sensor (8) at a position corresponding to the working cylinder (1).

4. The hydraulic press movable beam leveling system according to claim 1, characterized in that: A working pump (3) and a working pump head control valve group (4) are provided at one end of the oil circuit between the first electromagnetic switch valve (21) and the oil tank, close to the oil tank.

5. The hydraulic press movable crossbeam leveling system according to claim 4, characterized in that: The working pump head control valve group (4) comprises a pressure valve and a filter which are connected in sequence.

6. The hydraulic press movable crossbeam leveling system according to claim 1, characterized in that: An oil circuit between the proportional servo valve (23) and the oil tank is provided with a leveling pump (5) and a leveling pump head control valve group (6) at one end close to the oil tank.

7. The hydraulic press movable crossbeam leveling system according to claim 1, characterized in that: An accumulator (9) is provided on the oil circuit between the proportional servo valve (23) and the oil tank.

8. The hydraulic press movable crossbeam leveling system according to claim 1, characterized in that: A one-way valve (25) is provided on the oil circuit connecting the first electromagnetic switch valve (21) and the working cylinder (1); the oil inlet of the one-way valve (25) is in communication with the first electromagnetic switch valve (21), and the oil outlet of the one-way valve (25) is in communication with the working cylinder (1).

9. The hydraulic press movable crossbeam leveling system according to claim 1, characterized in that: A pressure sensor (26) is provided on the oil circuit between the first electromagnetic switch valve (21) and the working cylinder (1).

10. The hydraulic press movable crossbeam leveling system according to any one of claims 1 to 9, characterized in that: It also includes a processor, which is respectively communicatively connected to the first electromagnetic switch valve (21), the proportional flow valve (22) and the proportional servo valve (23).

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