A plate-type double-deck press and a prestress loading method thereof

Abstract

The present application relates to the field of top pressing machine, especially to a plate type two-side top pressing machine and prestress loading method thereof. The plate type two-side top pressing machine comprises a frame and a hydraulic cylinder arranged in the frame, the frame comprises a fixed stress plate arranged integrally and an adjustable stress plate arranged separately, the outer side of the extrusion base surface of the fixed stress plate and the adjustable stress plate is provided with a connecting structure, and the fixed stress plate and the adjustable stress plate are fixedly connected through the connecting structure. By arranging the two kinds of stress plates, the different parts of the frame have different performance, in the process of the fixed stress plate being extruded and deformed by the hydraulic cylinder, the adjustable stress plate can be adjusted to adapt to the distance of the extrusion base surface and not be stressed, thereby solving the problem that the frame is easily deformed in the process of the hydraulic cylinder pushing the frame, the pressure of the synthetic cavity is deviated, and the synthetic quality is affected.

Description

Technical Field

[0001] This invention relates to the field of top press machines, and more particularly to a plate-type double-sided top press machine and its prestressing loading method. Background Technology

[0002] In the artificial synthesis of superhard materials, a top press is required to create the high-pressure environment needed for synthesis. Among them, the double-sided top press is widely used as a type of top press. For example, an invention patent application with publication number CN109647288A and publication number April 19, 2019 discloses a floating top hammer multi-layer processing device for a double-sided top press of synthetic diamond. The device includes a frame, in which an active top hammer driven by a hydraulic cylinder and an upper floating top hammer and a lower floating top hammer pressed by the active top hammer are arranged. The die core to be extruded is arranged in the synthesis cavity formed between the top hammers. The frame has two oppositely arranged extrusion base surfaces that bear the force of the hydraulic cylinder along the driving direction of the hydraulic cylinder torque.

[0003] However, in the above technical solution, during the pressurization process, a large torque is generated between the hydraulic cylinder and the frame. This torque acts on the extrusion base surface on the frame, causing irregular deformation of the frame and making the two previously parallel extrusion base surfaces no longer parallel. The direction of the force generated by the hydraulic cylinder is related to the extrusion base surface of the frame. After the two extrusion base surfaces deform, the hydraulic cylinder will move, resulting in a deviation in the pressure of the upper and lower synthesis chambers, thus affecting the synthesis quality. Summary of the Invention

[0004] The purpose of this invention is to provide a plate-type double-sided top press to solve the problem in the prior art where the uncontrollable deformation of the frame during the hydraulic cylinder pushing of the frame in the double-sided top press leads to changes in the two extrusion base surfaces, resulting in pressure deviation in the synthesis chamber and affecting the synthesis quality. The purpose of this invention is also to provide a prestressing loading method for the plate-type double-sided top press to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the plate-type double-sided top press of the present invention adopts the following technical solution: A plate-type double-sided top press includes a frame and a hydraulic cylinder disposed inside the frame. The frame includes an integrally formed fixed stress plate and a separately disposed adjustable stress plate to adjust the distance between two oppositely arranged extrusion base surfaces. At least two fixed stress plates are provided and located outside the adjustable stress plates. A connecting structure is provided on the outer side of the extrusion base surfaces of both the fixed stress plates and the adjustable stress plates, and the fixed stress plates and the adjustable stress plates are fixedly connected by the connecting structure.

[0006] Furthermore, the adjustable stress plate includes an upper frame, a lower frame, and a wedge block located between the upper frame and the lower frame. The wedge block is provided with a first wedge surface, and the upper frame and / or the lower frame is provided with a second wedge surface that mates with the first wedge surface.

[0007] Furthermore, a spherical convex surface is provided on the side of the wedge block opposite to the first wedge surface, and a second wedge surface that mates with the first wedge surface is provided on one of the upper and lower frames, while a spherical concave surface that mates with the arc surface is provided on the other of the upper and lower frames, so that the wedge block can make the first wedge surface and the second wedge surface fit together through the spherical convex surface.

[0008] Furthermore, fastening bolt holes are provided on both sides of the spherical convex surface of the wedge block, and a first bolt mounting hole that mates with the fastening bolt holes is provided on one of the upper and lower frames with a spherical concave surface.

[0009] Furthermore, one end of the first wedge-shaped surface is provided with a stepped structure, and the second wedge-shaped surface is provided with a stop surface for cooperating with the stop of the stepped structure.

[0010] Furthermore, one of the upper and lower frames having a second wedge-shaped surface is provided with an adjusting bolt hole, and the wedge block is provided with a second bolt mounting hole that mates with the adjusting bolt hole, so that the wedge block is fixedly connected to the frame under the action of the adjusting bolt.

[0011] Furthermore, the hydraulic cylinder includes a cylinder body and a piston. The cylinder body is provided with a receiving cavity, and the piston has a sliding part that slides in conjunction with the receiving cavity. The sliding part is provided with a U-shaped groove, and the cylinder body is provided with an oil inlet arranged in the groove facing the U-shaped groove.

[0012] Furthermore, the cylinder block is also provided with a guide post that cooperates with the U-shaped groove, and the oil inlet is located on the guide post.

[0013] The beneficial effects of the plate-type double-sided top press in this invention are as follows: This invention improves upon existing plate-type double-sided top presses by setting two types of stress plates: a fixed stress plate and an adjustable stress plate. This allows different parts of the frame to exhibit different performance characteristics. The fixed stress plate is an integral structure with a fixed distance between its two extrusion base surfaces. When the distance between the two extrusion base surfaces changes, it means that the fixed stress plate is subjected to a larger torque and is stretched. The distance between the two extrusion base surfaces of the adjustable stress plate can be adjusted. Furthermore, both the fixed stress plate and the adjustable stress plate have connecting structures on the outer sides of their extrusion base surfaces. Therefore, during the process of the fixed stress plate being deformed by the hydraulic cylinder, the adjustable stress plate can be adjusted to adapt to the distance between the extrusion base surfaces. When the hydraulic cylinder does not act on the fixed stress plate, the adjustable stress plate, having already adjusted its spacing, will not be compressed and will thus support the fixed stress plate, preventing it from retracting. In other words, the fixed stress plate can be prestressed by adjusting the adjustable stress plate, causing the two extrusion surfaces on the frame to deform. During use, a portion of the torque exerted by the hydraulic cylinder on the frame will be offset by this prestress, making the frame less prone to further deformation and thus ensuring controllable deformation. This solves the problem in existing double-sided presses where uncontrollable frame deformation during hydraulic cylinder pushing causes changes in the two extrusion surfaces, leading to pressure deviations in the synthesis chamber and affecting synthesis quality.

[0014] To achieve the above objectives, the prestressing loading method of the plate-type double-sided top press in this invention adopts the following technical solution: A prestressing loading method for a plate-type double-sided top press involves placing a hydraulic cylinder and a leveling block between fixed stress plates. The leveling block has two relatively parallel reference surfaces. The hydraulic cylinder and the leveling block compress the two extrusion base surfaces of the fixed stress plate, so that the two extrusion base surfaces remain parallel after deformation under the action of the leveling block. Then, an adjustable stress plate is fixed so that the adjustable stress plate supports the fixed stress plate to maintain the deformation state of the fixed stress plate.

[0015] Furthermore, during the process of the hydraulic cylinder and the leveling block pressing the two extrusion bases, the thrust of the hydraulic cylinder is not less than the rated thrust when extruding the workpiece.

[0016] The beneficial effects of the prestressing loading method for a plate-type double-sided top press in this invention are as follows: This invention innovatively proposes a prestressing loading method for a plate-type double-sided top press. By controlling the piston extension of the hydraulic cylinder before use, the hydraulic cylinder applies a torque to the frame. Since the fixed stress plate is an integral structure, under the action of the hydraulic cylinder, the fixed stress plate is stretched, increasing the distance between the two extrusion base surfaces. At this time, the fixed stress plate generates a reaction force opposite to the loading torque of the hydraulic cylinder. The deformation of the fixed stress plate is guided by the setting of the leveling block, allowing the fixed stress plate to undergo controllable deformation. By adjusting the adjustable stress plate, the adjustable stress plate adapts to the extrusion base surface. The adjustable stress plate, having already adjusted its spacing, will not be compressed even after the hydraulic cylinder load is removed, as the distance between the surfaces is not affected by force. This allows it to support the fixed stress plate and prevent it from retracting. In other words, the fixed stress plate can be prestressed by adjusting the adjustable stress plate. During use, a portion of the torque exerted by the hydraulic cylinder on the frame will be offset by this prestress, making the frame less prone to deformation. This solves the problem in existing double-sided presses where uncontrollable frame deformation during hydraulic cylinder pushing causes changes in the two extrusion surfaces, leading to pressure deviations in the synthesis chamber and affecting synthesis quality. Attached Figure Description

[0017] Figure 1 This is a front view of an embodiment of the plate-type double-sided top press in this invention; Figure 2 This is a side view of an embodiment of the plate-type double-sided top press in this invention; Figure 3 This is a front view of the fixed stress plate in an embodiment of the plate-type double-sided top press of the present invention; Figure 4 This is a front view of the adjustable stress plate in an embodiment of the plate-type double-sided top press of the present invention; Figure 5 This is a side view of the adjustable stress plate in an embodiment of the plate-type double-sided top press of the present invention; Figure 6 This is a schematic diagram of the processing in an embodiment of the plate-type double-sided top press of the present invention; Figure 7 This is a schematic diagram of the hydraulic cylinder in an embodiment of the plate-type double-sided top press of the present invention; Figure 8 This is a schematic diagram of the piston structure in an embodiment of the plate-type double-sided top press of the present invention.

[0018] In the diagram: 11. Frame; 12. Cylinder limit block; 13. Lower pressure head; 14. Leveling pressure column; 15. Upper pressure head; 16. Pad plate; 17. Pin shaft; 18. Spacer sleeve; 2. Hydraulic cylinder; 21. Cylinder body; 22. Piston; 221. Guide belt; 222. Sealing ring; 23. U-groove; 24. Guide column; 25. Oil inlet passage; 26. Guide sleeve; 3. Fixed stress plate; 4. Adjustable stress plate; 41. Upper frame; 42. Lower frame; 43. Wedge block; 44. Fastening bolt; 45. Adjusting bolt; 5. Pin shaft hole. Detailed Implementation

[0019] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0020] In this invention, the plate-type double-sided top press is equipped with an adjustable stress plate. When the hydraulic cylinder presses against the frame, the adjustable stress plate is adjusted so that the fixed stress plate is deformed by the pressure while the adjustable stress plate is not stressed. When the hydraulic cylinder loses its load, the adjustable stress plate will support the fixed stress plate, causing prestress to be generated inside the frame. During use, the hydraulic cylinder needs to overcome this prestress before the frame will deform, which means that the deformation of the frame is avoided during use.

[0021] In Embodiment 1 of the platen double-sided top press of the present invention: like Figure 1 and Figure 2 As shown, in this embodiment, the plate-type double-sided pressing machine includes a frame 11 and a hydraulic cylinder 2 disposed inside the frame 11. The hydraulic cylinder 2 is vertically arranged, and the piston 22 in the hydraulic cylinder 2 is vertically upward. The frame 11 has a receiving space for accommodating the hydraulic cylinder 2. Two extrusion bases that generate extrusion during use are provided in the vertical direction of the receiving space. The cylinder body 21 of the hydraulic cylinder 2 is disposed on the lower extrusion base. A limiting block is provided on the extrusion base to limit the movement of the hydraulic cylinder 2. A lower pressing head 13 is provided on the end face of the piston 22. An upper pressing head 15 is provided above the lower pressing head 13. A pad 16 that fits against the other extrusion base of the frame 11 is also provided on the top of the upper pressing head 15. The upper pressure head 15 and the lower pressure head 13 are used to place the workpiece to be placed. That is, when the piston 22 of the hydraulic cylinder 2 extends outward, it will generate a torque on the upper pressure head 15 and the pad 16, causing the frame 11 to be stressed, and correspondingly generating a reaction force on the piston 22 on the frame 11.

[0022] like Figure 3 and Figure 4The frame 11 includes an integrally formed fixed stress plate 3 and a separately formed adjustable stress plate 4. Both the fixed stress plate 3 and the adjustable stress plate 4 have a set of extrusion base surfaces, and the distance between the two extrusion base surfaces of the adjustable stress plate 4 is adjustable. Connecting structures are provided on the outer sides of the fixed stress plate 3 and the adjustable stress plate 4 located on the extrusion base surfaces, and adjacent stress plates are fixedly connected together through these connecting structures. In this embodiment, a total of five stress plates are provided, including three fixed stress plates 3 and two adjustable stress plates 4, arranged alternately. That is, the two outermost stress plates are fixed stress plates 3. Of course, in other embodiments, other numbers of fixed stress plates 3 and adjustable stress plates 4 can be provided, such as only two fixed stress plates 3 on the outermost side and three or one adjustable stress plate 4 in the middle. In this embodiment, the connecting structure is a pin 17 passing through a pin hole 5, which fixes the different fixed stress plates 3 and adjustable stress plates 4 together. To ensure spacing between different stress plates, a spacer sleeve 18 is also fitted onto the pin 17. Of course, in other embodiments, the connection structure can also be configured as mutually mating protrusions and grooves.

[0023] like Figure 4 and Figure 5As shown, the adjustable stress plate 4 is configured as separate parts. Specifically, the adjustable stress plate 4 includes an upper frame 41, a lower frame 42, and a wedge block 43 located between the upper frame 41 and the lower frame 42. The fixed stress plate 3 is a one-piece structure. Therefore, when the shape of the fixed stress plate 3 changes, that is, when the distance between the two extrusion base surfaces increases, the pin 17 will cause the upper frame 41 and the lower frame 42 of the adjustable stress plate 4 to move, resulting in a change in the distance between the upper frame 41 and the lower frame 42. In order to maintain the connection between the upper frame 41 and the lower frame 42, a wedge block 43 is used to compensate for the change in distance. Specifically, the wedge block 43 is provided with a first wedge surface, the lower frame 42 is provided with a second wedge surface that mates with the first wedge surface, the side of the wedge block 43 away from the first wedge surface is provided with a spherical convex surface, and the upper frame 41 is provided with a spherical concave surface that mates with the spherical convex surface. In use, simply adjusting the horizontal position of the wedge block 43 changes the mating position between the first and second wedge surfaces, thus maintaining the connection between the upper frame 41 and the lower frame 42 through the wedge block 43. Alternatively, in other embodiments, the positions of the first wedge surface and the spherical concave surface can be reversed; that is, the second wedge surface can be on the upper frame 41 and the spherical concave surface on the lower frame 42. Or, in other embodiments, the spherical concave surface may be omitted, and the second wedge surface may be provided on both the upper frame 41 and the lower frame 42. Alternatively, in other embodiments, the wedge block 43 and the wedge surface may be omitted, and the surfaces of the upper frame 41 and the lower frame 42 may be horizontal. When adjusting the distance between the upper frame 41 and the lower frame 42, the distance can be adjusted by increasing the number of shims.

[0024] like Figure 4 and Figure 5 As shown, in order to achieve relative fixation between the wedge block 43 and the lower frame 42, a stepped structure is provided at one end of the first wedge surface of the wedge block 43, and a stop surface that mates with the stepped structure is provided on the second wedge surface of the lower frame 42. A second bolt mounting hole is provided through the stepped structure, and an adjusting bolt 45 hole that mates with the second bolt mounting hole is provided on the stop surface of the lower frame 42. The adjusting bolt 45 is installed in the adjusting bolt 45 hole, thereby fixing the wedge block 43 to the lower frame 42. The bolt head of the adjusting bolt 45 is fixed on the wedge block 43 by adjusting the screwing length of the adjusting bolt 45, which facilitates the adjustment of the position of the wedge block 43 relative to the lower frame 42.

[0025] During adjustment or use, the upper frame 41 and lower frame 42 are not always aligned. Therefore, the first and second wedge surfaces may have an angle that prevents them from fitting tightly together. To address this, a spherical concave surface is provided on the upper frame 41, and a spherical convex surface is provided on the wedge block 43. These two surfaces cooperate to form a ball-joint structure. During the compression process of the hydraulic cylinder 2, the two surfaces cannot move relative to each other; therefore, a fastening bolt 44 is provided to prevent them from rotating relative to each other. Simultaneously, they need to be temporarily released during adjustment. Specifically, in this embodiment, fastening bolt holes are provided on both sides of the spherical convex surface of the wedge block 43, and a first bolt mounting hole is provided on the upper frame 41 to mate with the fastening bolt holes. When the fastening bolt 44 is screwed into the fastening bolt hole to different depths, relative rotation occurs between the wedge block 43 and the upper frame 41, allowing the first and second wedge surfaces to fit together according to the adjustment of the fastening bolt 44.

[0026] It is worth noting that since the frame 11 has multiple components, each component has inherent machining errors during processing. If all components are machined before assembly, the accumulated errors in the overall frame 11 will increase the overall error. Therefore, during the machining process, critical parts need to undergo secondary machining after assembly. Specifically, semi-finishing is first performed on each part of the frame 11, retaining features such as… Figure 6 Surfaces C, E, G, F, and H are shown. The remaining surfaces are machined to ensure that each of the five planes retains at least a 2mm machining allowance. After all stress plates are assembled, the machining allowance is removed. Since the frame 11 is removed as a whole, the error between the two extrusion base surfaces on the finished frame 11 is minimized. It is worth noting that surfaces C, E, and G are the three planes that are crucial for use, while surfaces F and H, being located on the inner side, are machined simultaneously with surfaces E and G to avoid repeated machining of the inner surface of the frame 11. A gantry machining center is used for machining; however, other machining methods can be employed in other embodiments.

[0027] In Embodiment 2 of the platen double-sided top press of the present invention: This embodiment is an improvement on embodiment 1. Since the quality of the hydraulic cylinder 2 directly affects the overall performance of the platen double-sided press during use, the sealing of the hydraulic cylinder 2 will be put to a great test during the pressing process. In this embodiment, the hydraulic cylinder 2 is improved to enhance the sealing performance.

[0028] Specifically, such as Figure 7 and Figure 8As shown, the hydraulic cylinder 2 includes a cylinder body 21 and a piston 22. The cylinder body 21 has a receiving cavity, and the piston 22 has a sliding part that slides into the receiving cavity. During use, the cylinder body 21 expands outward under the action of high-pressure hydraulic oil. In order to maintain reliable contact between the piston 22 and the cylinder body 21, in this embodiment, the sliding part of the piston 22 is provided with a U-shaped groove 23, and the cylinder body 21 is provided with an oil inlet arranged towards the groove of the U-shaped groove 23. That is to say, when oil enters the cylinder body 21, it will simultaneously compress the side wall of the cylinder body 21 and the side wall of the U-shaped groove 23 of the piston 22, causing the side wall of the cylinder body 21 and the side wall of the U-shaped groove 23 of the piston 22 to expand outward at the same time. Naturally, the two will also maintain a good sealing contact.

[0029] Specifically, to guide the piston 22 during its movement, a guide post 24 is provided on the cylinder body 21 to guide and cooperate with the U-shaped groove 23. The guide post 24 is bolted to the cylinder body 21, and to avoid interference between the guide post 24 and the piston 22, a countersunk hole is provided on the guide post 24 to accommodate the head of the bolt. An oil inlet channel is provided on the cylinder body 21, with one end located on the outer surface of the cylinder body 21 and the other end located on the inner surface of the cylinder body 21, forming the oil inlet of the hydraulic cylinder 2. This means the oil inlet directly faces the groove of the U-shaped groove 23 of the piston 22, facilitating the deformation of the sliding part of the piston 22. Of course, grooves for accommodating the guide band 221 and the sealing ring 222 are also provided on the outer circumferential surface of the sliding part of the piston 22. During assembly, the guide band 221 and the sealing ring 222 are inserted into these grooves for guidance and sealing. It is worth noting that during the movement of the piston 22, the movement of the piston 22 needs to be guided. Therefore, a guide sleeve 26 is also provided on the cylinder body 21 and sleeved on the end of the piston 22. The piston 22 is guided by the guiding action of the guide sleeve 26.

[0030] In an embodiment of the prestressing loading method (hereinafter referred to as the prestressing loading method) of the plate-type double-sided top press in this invention: In this embodiment, by adjusting the adjustable stress plate 4, the frame 11 is deformed and prestressed in advance. During use, the prestress will offset part of the torque of the hydraulic cylinder, thus making it less likely for the frame 11 to deform again during use.

[0031] Specifically, the plate-type double-sided press used in this embodiment has the same structure as the plate-type double-sided press in any of the above embodiments, and will not be repeated here. After assembling the plate-type double-sided press, a leveling block is placed between the upper press head 15 and the lower press head 13. Specifically, the leveling block is a leveling pressure column 14, which is a metal cylinder with two parallel end faces. Because the leveling pressure column 14 is a solid metal column, it will not deform during the hydraulic cylinder pressing process.

[0032] Next, prestressing is applied. Specifically, the piston 22 of the hydraulic cylinder 2 is extended. At this time, the fixed stress plate 3 is directly subjected to the torque of the piston 22. When the torque provided by the hydraulic cylinder 2 reaches a certain level, the fixed stress plate 3 deforms, and the two extrusion base surfaces of the fixed stress plate 3 move away from each other. Due to the presence of the leveling pressure column 14, the movement between the two extrusion base surfaces is guided, so that the deformed extrusion base surfaces are also parallel to each other. At this time, the adjusting bolt 45 is adjusted so that the first wedge surface of the wedge block 43 and the second wedge surface on the lower frame 42 are in contact with each other. During the adjustment process, the fastening bolt 44 is adjusted simultaneously to ensure that the two wedge surfaces are always in contact. At this time, the adjustable stress plate 4 is not subjected to the tension provided by the hydraulic cylinder 2. After the load of the hydraulic cylinder 2 is removed, the fixed stress plate 3 will tend to retract because it is no longer subjected to the force of the hydraulic cylinder 2. However, the change in the length of the adjustable stress plate 4 at this time makes the fixed stress plate 3 unable to retract. That is to say, at this time, the fixed stress plate 3 will generate a torque that makes the two extrusion base surfaces in contact with each other. During the top-pressing process, when hydraulic cylinder 2 acts on this plate-type double-sided top press, it generates a torque opposite to that of the fixed stress plate 3. Under these conditions, the fixed stress plate 3 will not deform. As long as the torque applied by hydraulic cylinder 2 during use is less than the initial applied torque, the fixed stress plate 3 will not deform, thus ensuring that it does not deform during use. It is worth noting that the adjustment of the adjustable stress plate 4 depends on its specific form. When wedge blocks 43 are no longer used on the adjustable stress plate 4 and shims are used instead, the adjustment of the adjustable stress plate 4 requires increasing the number of shims. It is also worth noting that during prestressing, the pressure applied by the hydraulic cylinder is typically no less than 1.1 times the rated pressure of the double-sided top press during operation to ensure that the prestress is not exceeded during operation, thereby preventing deformation.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A plate-type double-sided top press, comprising a frame and a hydraulic cylinder disposed inside the frame, characterized in that: The frame includes an integrally formed fixed stress plate and a separately formed adjustable stress plate to adjust the distance between two oppositely arranged extrusion base surfaces. At least two fixed stress plates are provided and located outside the adjustable stress plate. A connecting structure is provided on the outer side of the extrusion base surfaces of both the fixed and adjustable stress plates, and the fixed and adjustable stress plates are fixedly connected by the connecting structure. The adjustable stress plate includes an upper frame, a lower frame, and a wedge block located between the upper and lower frames. A first wedge surface is provided on the wedge block, and a second wedge surface that mates with the first wedge surface is provided on the upper and / or lower frame. A spherical convex surface is provided on the side of the wedge block facing away from the first wedge surface. One of the upper and lower frames has a second wedge surface that mates with the first wedge surface, and the other of the upper and lower frames has a spherical concave surface that mates with an arcuate surface, so that the wedge block, through the spherical convex surface, allows the first and second wedge surfaces to fit together.

2. The plate-type double-sided top press according to claim 1, characterized in that: The wedge-shaped block has fastening bolt holes on both sides of its spherical convex surface, and one of the upper and lower frames with a spherical concave surface has a first bolt mounting hole that mates with the fastening bolt holes.

3. The plate-type double-sided top press according to claim 1 or 2, characterized in that: One end of the first wedge-shaped surface is provided with a stepped structure, and the second wedge-shaped surface is provided with a stop surface for cooperating with the stop of the stepped structure.

4. The plate-type double-sided top press according to claim 1 or 2, characterized in that: One of the upper and lower frames with a second wedge-shaped surface is provided with an adjusting bolt hole, and the wedge block is provided with a second bolt mounting hole that mates with the adjusting bolt hole, so that the wedge block is fixedly connected to the frame under the action of the adjusting bolt.

5. The plate-type double-sided top press according to claim 1 or 2, characterized in that: The hydraulic cylinder includes a cylinder body and a piston. The cylinder body is provided with a receiving cavity, and the piston has a sliding part that slides in conjunction with the receiving cavity. The sliding part is provided with a U-shaped groove, and the cylinder body is provided with an oil inlet arranged in the groove facing the U-shaped groove.

6. The plate-type double-sided top press according to claim 5, characterized in that: The cylinder block is also provided with a guide post that cooperates with the U-shaped groove, and the oil inlet is located on the guide post.

7. A plate-type double-sided pressing machine, comprising a frame and a hydraulic cylinder disposed inside the frame, characterized in that: The frame includes an integrally formed fixed stress plate and a separately formed adjustable stress plate to adjust the distance between two oppositely arranged extrusion base surfaces. At least two fixed stress plates are provided and located outside the adjustable stress plate. A connecting structure is provided on the outer side of the extrusion base surfaces of both the fixed and adjustable stress plates, and the fixed and adjustable stress plates are fixedly connected by the connecting structure. The hydraulic cylinder includes a cylinder body and a piston. The cylinder body has a receiving cavity, and the piston has a sliding part that slides into the receiving cavity. A U-shaped groove is provided on the sliding part, and an oil inlet is provided on the cylinder body facing the U-shaped groove.

8. The plate-type double-sided top press according to claim 7, characterized in that: The cylinder block is also provided with a guide post that cooperates with the U-shaped groove, and the oil inlet is located on the guide post.

9. A prestressing loading method using the plate-type double-sided jacking press according to any one of claims 1-8, characterized in that: A hydraulic cylinder and a leveling block are placed between the fixed stress plates. The leveling block has two relatively parallel reference surfaces. The hydraulic cylinder and the leveling block compress the two extrusion base surfaces of the fixed stress plate, so that the two extrusion base surfaces remain parallel after deformation under the action of the leveling block. Then, the adjustable stress plate is fixed so that the adjustable stress plate supports the fixed stress plate to maintain the deformation state of the fixed stress plate.

10. The prestressing loading method for a plate-type double-sided top press according to claim 9, characterized in that: During the process of the hydraulic cylinder and leveling block pressing the two extrusion bases, the thrust of the hydraulic cylinder shall not be less than the rated thrust when extruding the workpiece.

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