Hydraulic machine

Abstract

The hydraulic machine comprises a rack, a main cylinder, a working table, a top cylinder, a side cylinder, a liquid path system and a hydraulic source, the main cylinder is arranged at the upper end of the rack, the working table is arranged below the main cylinder, the top cylinder is arranged in the working table and corresponds to the main cylinder, the side cylinder is arranged on one side of the working table and is transversely arranged, and the hydraulic source is connected with the hydraulic source. The main cylinder, the side cylinder and the top cylinder are respectively connected with the liquid path system, the main cylinder, the side cylinder and the top cylinder are connected with the hydraulic source through the liquid path system, the hydraulic machine can adapt to the combination of various machining processes, and different cylinder body parts can be selected for control through the liquid path system according to different dies so as to achieve corresponding processes in a matched mode. Therefore, the whole machine has multiple process forming functions, actions such as extrusion, shunting and pressing can be realized in different directions in different processes, and one-time or few-time forming of forgings with complex shapes can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic equipment, and in particular to a hydraulic press. Background Art

[0002] At present, the high-precision precision forging processes include multi-directional die forging and closed forging. As for the multi-directional die forging process, it is usually carried out on a special multi-directional die forging hydraulic press, which can apply pressure to the blank from different directions such as vertical and horizontal. The closed forging is a forging method that drives multiple punches or die cavities to allow the material to mainly undergo lateral extrusion deformation and flow, enter the die space set on the side, and produce forgings with radial protrusions. It is usually carried out on a closed forging hydraulic press. In this way, different processes need to be produced on the corresponding hydraulic presses, and it is difficult to achieve the effect of multiple uses of one device, which leads to increased production costs and complicated processes, and ultimately has an adverse effect on the reasonable layout and automation process of the production line. There are certain limitations in actual production applications, and optimization and improvement are urgently needed. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art.

[0004] The present application provides a hydraulic press, which includes a frame, a main cylinder, a workbench, a top cylinder, a side cylinder, a hydraulic circuit system and a hydraulic source; the main cylinder is arranged at the upper end of the frame; the workbench is arranged below the main cylinder; the top cylinder is arranged in the workbench and corresponds to the main cylinder; the side cylinder is arranged on one side of the workbench, and the side cylinder is arranged horizontally; the hydraulic circuit system, the main cylinder, the side cylinder and the top cylinder are respectively connected to the hydraulic circuit system; the hydraulic source, the main cylinder, the side cylinder and the top cylinder are connected to the hydraulic source through the hydraulic circuit system.

[0005] According to some embodiments of the present application, the fluid circuit system includes a first fluid circuit, a second fluid circuit and a third fluid circuit, the first fluid circuit is connected to the main cylinder, the second fluid circuit is connected to the side cylinder, and the third fluid circuit is connected to the top cylinder.

[0006] According to some embodiments of the present application, the first fluid circuit includes an upward control valve, a downward control valve, and a support control valve;

[0007] The upward control valve includes a first cartridge valve and a first reversing valve for controlling the opening and closing of the first cartridge valve, the first cartridge valve is respectively connected to the hydraulic source and the rod chamber of the master cylinder, and the first reversing valve is connected to the first cartridge valve;

[0008] The down control valve comprises a second cartridge valve and a second reversing valve for controlling the opening and closing of the second cartridge valve, the second cartridge valve is respectively connected to the hydraulic source and the rodless chamber of the master cylinder, and the second reversing valve is connected to the second cartridge valve;

[0009] The support control valve includes a third cartridge valve, a third reversing valve for controlling the opening and closing of the third cartridge valve, and a relief valve. The third cartridge valve is respectively connected to the rodless chamber and the rod chamber of the master cylinder. The third reversing valve and the third cartridge valve are connected through the relief valve.

[0010] According to some embodiments of the present application, the second fluid circuit includes a fourth reversing valve, and the fourth reversing valve is respectively connected to the hydraulic source and the side cylinder.

[0011] According to some embodiments of the present application, the third fluid circuit includes a fifth reversing valve and a pressure regulating valve, the fifth reversing valve is respectively connected to the hydraulic source and the top cylinder, and the pressure regulating valve is connected between the hydraulic source and the fifth reversing valve.

[0012] According to some embodiments of the present application, the top cylinder includes a material withdrawal cylinder and a mold closing cylinder, the material withdrawal cylinder is arranged at the center of the workbench, and the mold closing cylinder is arranged on one side of the material withdrawal cylinder.

[0013] According to some embodiments of the present application, the side cylinder includes a left cylinder and a right cylinder, and the left cylinder and the right cylinder are arranged on opposite sides of the workbench.

[0014] According to some embodiments of the present application, a mold changing cylinder is further provided on the frame, and the mold changing cylinder is arranged on one side of the side cylinder, and the mold changing cylinder is connected to the hydraulic system.

[0015] According to some embodiments of the present application, the liquid circuit system further includes a plurality of pressure gauges, and the plurality of pressure gauges are respectively arranged on the pipelines of the first liquid circuit, the second liquid circuit, and the third liquid circuit.

[0016] According to some embodiments of the present application, displacement sensors are provided on the side cylinder, the material return cylinder, the mold closing cylinder and the main cylinder, and the piston rods of the side cylinder, the material return cylinder, the mold closing cylinder and the main cylinder are electrically connected to the corresponding displacement sensors.

[0017] A hydraulic press provided in the present application has at least the following beneficial effects: the whole machine is equipped with a main cylinder, a side cylinder and a top cylinder, which can realize multiple sets of action combination control, and different components can be selected according to different molds through the hydraulic system to realize the corresponding process, so that the whole machine has multiple process molding functions to improve production efficiency and economic benefits.

[0018] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 This is a structural diagram of a hydraulic press according to an embodiment of the present application;

[0021] Figure 2 A schematic diagram of a hydraulic circuit of a hydraulic machine according to an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the fluid circuit of the master cylinder of an embodiment of the present application. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0024] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In relation to the orientation description, the orientation or position relationship indicated by, for example, up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0025] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0026] Combine the following Figures 1 to 3 The embodiments of the present application are described.

[0027] The embodiment of the present application provides a hydraulic press, including a hydraulic press, which includes a frame 100, a main cylinder 200, a workbench 300, a top cylinder 500, a side cylinder 400, a hydraulic system 600 and a hydraulic source 700;

[0028] The main cylinder 200 is arranged at the upper end of the frame 100. The piston rod of the main cylinder 200 extends downward under the push of hydraulic oil, thereby generating strong pressure to press the material into the desired shape. The workbench 300 is arranged below the main cylinder 200 as a supporting structure to provide a flat and stable mold placement surface; the top cylinder 500 is arranged in the workbench 300 and corresponds to the main cylinder 200, and is used to eject the molded product from the mold; the side cylinder 400 is arranged on one side of the workbench 300, and the side cylinder 400 is arranged horizontally. The side cylinder 400 can cooperate with the main cylinder 200 to achieve some complex action combinations.

[0029] The hydraulic system 600, the main cylinder 200, the side cylinder 400 and the top cylinder 500 are respectively connected to the hydraulic system 600, which is used to change the flow direction of the hydraulic oil in the pipeline, thereby controlling the extension and retraction direction of the hydraulic cylinder, and also to safely control the pipeline. For example, by setting a reversing valve in the hydraulic system 600, the hydraulic oil flows to different hydraulic cylinder chambers, thereby achieving actions in different directions such as lifting, lowering, extending and retracting. For example, the hydraulic system 600 controls the flow of the hydraulic oil by adjusting the control valve, and then controls the movement speed of the hydraulic actuator to meet different processing technology and efficiency requirements.

[0030] The hydraulic source 700, the main cylinder 200, the side cylinder 400 and the top cylinder 500 are connected to the hydraulic source 700 through the hydraulic circuit system 600. It is used to promote the flow of hydraulic oil in the pipeline of the entire hydraulic system. For example, by setting up an oil tank 703, a hydraulic pump 701 and a motor 702, the motor 702 is connected to the input shaft of the hydraulic pump 701 through a coupling or a belt or other connection methods. When the motor 702 is started, the rotation of the motor 702 is transmitted to the input shaft of the hydraulic pump 701, driving the hydraulic pump 701 to work, so that the hydraulic pump 701 continuously extracts hydraulic oil from the oil tank 703. The hydraulic pump 701 will pressurize the hydraulic oil during the working process, thereby building up pressure in the liquid circuit, and then send it to the hydraulic cylinders such as the main cylinder 200, the side cylinder 400 and the top cylinder 500 through various valves and pipelines, thereby driving the piston rod of the hydraulic cylinder to move. After completing the work, the hydraulic oil is sent back to the oil tank 703 to maintain the circulation of the entire liquid circuit.

[0031] Therefore, the whole machine is equipped with a main cylinder 200, a side cylinder 400 and a top cylinder 500, which can realize multiple sets of combined action control. When a multi-directional die forging process is required, the main cylinder 200 is used to press down to close the mold, and then the side cylinder 400 is used for extrusion; when a closed forging process is used, the main cylinder 200 is pressed down to close the mold, and at the same time, the top cylinder 500 is passively pressed down to close the mold, so that the hydraulic press can adapt to a combination of various processing processes. Through the hydraulic system 600, different cylinder components can be selected according to different molds for control to cooperate with the corresponding process, so that the whole machine has a variety of process forming functions, so that in different processes, extrusion, diversion, pressing and other actions can be realized in different directions, and complex forgings can be formed once or in a few times to improve production efficiency and economic benefits.

[0032] In some embodiments, the fluid circuit system 600 includes a first fluid circuit 610 , a second fluid circuit 620 , and a third fluid circuit 630 . The first fluid circuit 610 is connected to the main cylinder 200 , the second fluid circuit 620 is connected to the side cylinder 400 , and the third fluid circuit 630 is connected to the top cylinder 500 .

[0033] In this way, through the three fluid circuits, the work coordination of different cylinders can be better achieved, and the working order of the top cylinder 500, the side cylinder 400 and the main cylinder 200 can be arranged more conveniently. For example, in a hydraulic processing process, the side cylinder 400 can be controlled by the second fluid circuit 620 to perform the side positioning, clamping or forming of the workpiece, and then the main cylinder 200 can be controlled by the first fluid circuit 610 to perform the main processing operation, and finally the top cylinder 500 can be controlled by the third fluid circuit 630 to eject the processed workpiece. Since different processes require different speeds and pressures, different fluid circuits can be adjusted according to specific conditions to ensure that different cylinders can complete the corresponding actions at appropriate pressures and speeds without being interfered by the actions of other cylinders, thereby improving the work efficiency and automation of the entire hydraulic system. In addition, the main cylinder 200 can also be controlled by a fluid circuit alone, and the cylinder on the left side of the workbench 300 can be controlled by one fluid circuit, and the cylinder on the right side of the workbench 300 can be controlled by another fluid circuit, so as to facilitate the adjustment and control in the left and right directions respectively.

[0034] In some embodiments, the first fluid circuit 610 includes an upward control valve, a downward control valve, and a support control valve.

[0035] The upward control valve is used to control the piston rod of the master cylinder to be quickly retracted upward, and includes a first cartridge valve and a first reversing valve for controlling the opening and closing of the first cartridge valve. The first cartridge valve is connected to the hydraulic source 700 and the rod chamber of the master cylinder 200 respectively, and the first reversing valve is connected to the first cartridge valve;

[0036] The downward control valve is used to control the piston rod of the master cylinder to extend downward quickly. It includes a second cartridge valve and a second reversing valve for controlling the opening and closing of the second cartridge valve. The second cartridge valve is respectively connected to the hydraulic source 700 and the rodless chamber of the master cylinder 200. The second reversing valve is connected to the second cartridge valve. Since the other valves in the first fluid circuit are placed in the middle position, the liquid output by the pump flows to the rodless chamber of the master cylinder 200. At this time, the pressure of the system is low and the output flow of the pump is large, so that the piston rod of the master cylinder 200 extends downward quickly; further, a slow downward control valve 614 can be set in the first fluid circuit 610. The two-position four-way valve of the slow downward control valve 614 moves from the middle position to the right position, so that a part of the liquid output by the pump flows back to the oil tank 703 along the branch, the liquid in the rodless chamber is reduced, the working pressure is increased, the piston rod extension speed is reduced, and the output force is increased, which is convenient for workpiece processing;

[0037] The support control valve is used to control the piston rod to maintain a corresponding position, and includes a third cartridge valve, a third reversing valve for controlling the opening and closing of the third cartridge valve, and a relief valve. The third cartridge valve is respectively connected to the rodless chamber and the rod chamber of the master cylinder 200, and the third reversing valve and the third cartridge valve are connected through the relief valve.

[0038] Therefore, by providing a reversing valve, there are multiple channels and valve cores inside the reversing valve. When the valve core is in different positions, the hydraulic oil will flow to different chambers of the cylinder body, and the movement direction of the pistons of different cylinder bodies can be achieved by changing the flow direction of the hydraulic oil, thereby achieving control. The cartridge valve is used to adjust the opening and closing of the hydraulic circuit, thereby controlling the flow rate of the hydraulic oil, controlling the movement speed of the hydraulic cylinder, or changing the flow direction of the hydraulic oil, thereby controlling the extension and retraction of the hydraulic cylinder.

[0039] In some embodiments, the second fluid circuit 620 includes a fourth reversing valve, which is connected to the hydraulic source 700 and the side cylinder 400, respectively. The fourth reversing valve is a three-position four-way reversing valve. When the reversing valve core moves to one position, the pressure oil provided by the hydraulic source 700 enters the rodless chamber of the side cylinder 400 through the fluid circuit system 600, pushing the piston rod outward. When the valve core moves to another position, the hydraulic oil enters the rod chamber of the side cylinder 400, causing the piston rod to retract. In particular, when the fourth reversing valve is in the middle position, it is in a disconnected state, the oil inlet P, the working oil port A, the working oil port B and the return oil port T are not connected to each other, the hydraulic cylinder is locked, and the piston rod is stationary, so that the mold change cylinder 900 has high adjustment accuracy and ensures higher control accuracy of the whole machine. Therefore, by controlling the fourth reversing valve, the connection, disconnection and reversal of the hydraulic oil are realized.

[0040] Similarly, the third fluid circuit 630 includes a fifth reversing valve and a pressure regulating valve. The fifth reversing valve is connected to the hydraulic source 700 and the top cylinder 500 respectively. The pressure regulating valve is connected between the hydraulic source 700 and the fifth reversing valve. By adjusting the pressure regulating valve, the pressure of this section of the fluid circuit can be set to the pressure value required for the cylinder body processing, so that the pressure of this section of the fluid circuit remains relatively stable. Preferably, a load valve 640 can also be set in each fluid circuit, one end of the load valve 640 is connected to the fluid circuit, and the other end of the load valve 640 is connected to the oil tank 703. When the hydraulic system is over-pressured due to some reason, such as the actuator encountering too much resistance, the output pressure of the hydraulic pump abnormally increases, etc., the load valve 640 will open the overflow circuit. For example, if the hydraulic pump suddenly fails and the output pressure rises sharply, the load valve 640 will discharge the excess hydraulic oil back to the oil tank when the system pressure reaches the set safety upper limit, thereby protecting the hydraulic pump, hydraulic cylinder, hydraulic valve and other components in the system from damage due to excessive pressure.

[0041] In some embodiments, the top cylinder 500 includes a material withdrawal cylinder and a mold closing cylinder, wherein the material withdrawal cylinder is arranged at the center of the workbench 300, and the mold closing cylinder is arranged at one side of the material withdrawal cylinder. The material withdrawal cylinder is connected to a three-position four-way reversing valve, wherein when the three-position four-way valve is in the middle position, the oil inlet P is closed, and the working oil ports A and B are connected to the oil return port T. At this time, the A and B ports are interconnected, so that the hydraulic cylinder floats, and the piston rod can move freely, which is convenient for adjusting the working position of the piston rod of the material withdrawal cylinder, and the switching stability is higher.

[0042] In some embodiments, the side cylinder 400 includes a left cylinder 400 and a right cylinder 400, and the left cylinder 400 and the right cylinder 400 are arranged on opposite sides of the workbench 300. In this way, the left cylinder 400 and the right cylinder 400 can act on both sides of the workpiece at the same time to realize the two-way operation of the forging process. By controlling the left cylinder 400 and the right cylinder 400 differently, their extension speed, stroke, etc. can be controlled respectively, so that the left cylinder 400 and the right cylinder 400 can work together to realize some complex actions of the hydraulic press to complete the processing of products of different forms.

[0043] In some embodiments, a die-changing cylinder 900 is further provided on the frame 100. The die-changing cylinder 900 is provided on one side of the side cylinder 400, and the die-changing cylinder 900 is connected to the hydraulic system 600. When a die-changing cylinder 900 is added to the horizontal side cylinder 400, the piston movement of the die-changing cylinder 900 can drive the die to move in the horizontal direction. For example, in the multi-directional die forging process, the side cylinder 400 applies pressure to the blank from the horizontal direction during the forging process, and the die-changing cylinder 900 can be operated independently to move the die by the extension and contraction of its piston. By controlling the stroke of the die-changing cylinder 900, the die can be moved to different stations or preset positions. Each station can be set with different mold shapes or functions for forming the blank at different stages or different shapes. Through multi-station forming, multiple processes can be completed on the same device, reducing the transfer time of the blank between different devices. In actual settings, two die-changing cylinders 900 can be set, respectively on the left cylinder 400 and the right cylinder 400.

[0044] In order to detect the pressure of the hydraulic circuit system 600 in real time, the hydraulic circuit system 600 also includes a plurality of pressure gauges, which are respectively arranged on the pipelines of the first hydraulic circuit 610, the second hydraulic circuit 620 and the third hydraulic circuit 630. Specifically, pressure gauges can be arranged before and after various reversing valves and control valves in the three hydraulic circuits, which can be used to detect the working status of these valves. Taking the reversing valve as an example, by comparing the pressure before and after it, it can be judged whether the reversing valve is normally reversing. Further, pressure gauges can also be arranged at the inlet and outlet of the main cylinder 200, the side cylinder 400 and the top cylinder 500, which can directly monitor the working pressure of the hydraulic cylinder and ensure that the hydraulic cylinder works under appropriate pressure, thereby preventing excessive pressure from causing damage to the mold or excessive deformation of the workpiece. Furthermore, a pressure gauge is arranged near the hydraulic source 700, such as the hydraulic pump 701, so that the output pressure of the hydraulic pump 701 can be monitored in real time, and the output pressure of the hydraulic pump 701 can be controlled within an appropriate range, providing stable power for subsequent hydraulic circuits and actuators.

[0045] In order to accurately control the main process actions, in some embodiments, the side cylinder 400, the material withdrawal cylinder, the mold closing cylinder and the main cylinder 200 are all provided with a displacement sensor 800, and the piston rods of the side cylinder 400, the material withdrawal cylinder, the mold closing cylinder and the main cylinder 200 are electrically connected to the corresponding displacement sensor 800. By setting the displacement sensor, the displacement of the piston rod of each cylinder can be accurately measured. For example, by setting the displacement sensor in the material withdrawal cylinder, the ejection distance of the material withdrawal cylinder can be accurately controlled according to the size, shape and demoulding requirements of the workpiece, so as to avoid the workpiece being unable to be demoulded due to insufficient ejection distance, or the workpiece being damaged due to excessive ejection distance. Further, when a control system is provided, the side cylinder, the main cylinder or the ejection cylinder needs to cooperate to complete the processing work. The displacement sensor feeds back the piston rod position information of multiple cylinders to the control system, and the control system can determine when to start other cylinders for the next operation based on this information, thereby ensuring the efficiency, accuracy and automation of the entire processing process. In addition, the displacement sensor can also cooperate with other monitoring equipment such as pressure sensors to provide overload protection. Prevent the cylinder from being overloaded. For example, when the piston displacement of the master cylinder changes abnormally, such as when the displacement is too slow or cannot be normally displaced under high pressure, timely measures can be taken to protect the safety of the entire fluid circuit.

[0046] In addition, certain terms in this specification have been used to describe embodiments of this specification. For example, "one embodiment", "embodiment" and / or "some embodiments" mean that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of this specification. Therefore, it can be emphasized and should be understood that two or more references to "embodiment" or "one embodiment" or "alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment, and particular features, structures or characteristics may be appropriately combined in one or more embodiments of this specification.

[0047] The preferred implementation methods of the present application are described in detail above, but the invention of the present application is not limited to the described embodiments. Technical personnel familiar with the field may make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the invention of the present application.

Claims

1. A hydraulic press, characterized in that: include: frame; A master cylinder, which is arranged at the upper end of the frame; A workbench, which is arranged below the master cylinder; A top cylinder, which is arranged in the workbench and corresponds to the main cylinder; A side cylinder is arranged on one side of the workbench, and the side cylinder is arranged transversely; A hydraulic system, wherein the master cylinder, the side cylinder and the top cylinder are respectively connected to the hydraulic system; and a hydraulic source, wherein the master cylinder, the side cylinder and the top cylinder are connected to the hydraulic source via the hydraulic system.

2. A hydraulic press according to claim 1, characterized in that: The fluid circuit system includes a first fluid circuit, a second fluid circuit and a third fluid circuit, the first fluid circuit is connected to the main cylinder, the second fluid circuit is connected to the side cylinder, and the third fluid circuit is connected to the top cylinder.

3. A hydraulic press according to claim 2, characterized in that: The first fluid circuit includes an upward control valve, a downward control valve and a support control valve; The upward control valve includes a first cartridge valve and a first reversing valve for controlling the opening and closing of the first cartridge valve, the first cartridge valve is connected to the hydraulic source and the rod chamber of the master cylinder respectively, and the first reversing valve is connected to the first cartridge valve; The down control valve comprises a second cartridge valve and a second reversing valve for controlling the opening and closing of the second cartridge valve, the second cartridge valve is respectively connected to the hydraulic source and the rodless chamber of the master cylinder, and the second reversing valve is connected to the second cartridge valve; The support control valve includes a third cartridge valve, a third reversing valve for controlling the opening and closing of the third cartridge valve, and a relief valve. The third cartridge valve is respectively connected to the rodless chamber and the rod chamber of the master cylinder. The third reversing valve and the third cartridge valve are connected through the relief valve.

4. A hydraulic press according to claim 2, characterized in that: The second fluid circuit includes a fourth reversing valve, and the fourth reversing valve is connected to the hydraulic source and the side cylinder respectively.

5. A hydraulic press according to claim 2, characterized in that: The third fluid circuit includes a fifth reversing valve and a pressure regulating valve. The fifth reversing valve is connected to the hydraulic source and the top cylinder respectively, and the pressure regulating valve is connected between the hydraulic source and the fifth reversing valve.

6. A hydraulic press according to claim 1, characterized in that: The lifting cylinder comprises a material-returning cylinder and a mold-closing cylinder. The material-returning cylinder is arranged at the center of the workbench, and the mold-closing cylinder is arranged at one side of the material-returning cylinder.

7. A hydraulic press according to claim 1, characterized in that: The side cylinders include a left cylinder and a right cylinder, and the left cylinder and the right cylinder are arranged on opposite sides of the workbench.

8. A hydraulic press according to claim 1, characterized in that: The frame is also provided with a mold changing cylinder, which is arranged on one side of the side cylinder and is connected to the fluid circuit system.

9. A hydraulic press according to claim 2, characterized in that: The fluid circuit system further includes a plurality of pressure gauges, which are respectively arranged on pipelines of the first fluid circuit, the second fluid circuit, and the third fluid circuit.

10. A hydraulic press according to claim 6, characterized in that: The side cylinder, the material-returning cylinder, the mold-closing cylinder and the main cylinder are all provided with displacement sensors, and the piston rods of the side cylinder, the material-returning cylinder, the mold-closing cylinder and the main cylinder are electrically connected to the corresponding displacement sensors.

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