Pressure self-adjusting press machine and pressure self-adjusting method

Abstract

The invention discloses a pressure self-adjusting press machine and a pressure self-adjusting method. The problem that in the prior art, all areas of a workpiece are stressed unevenly in the pressing process is solved. The pressure self-adjusting press machine comprises a rack, a static pressure structure is arranged on the rack, the static pressure structure comprises a pressure self-adjusting oil cylinder arranged on the upper portion of the rack, and an upper static pressure head is arranged on the lower portion of the pressure self-adjusting oil cylinder; a main oil cylinder is arranged on the lower portion of the rack, a lower static pressure head is arranged on the upper portion of the main oil cylinder, and the lower static pressure head and the upper static pressure head are correspondingly arranged up and down. Through the design of the pressure self-adjusting oil cylinder, the upper static pressure head and the lower static pressure head, multi-aspect pressure adjustment is carried out in the workpiece pressing process, so that all parts of a pressed workpiece are stressed consistently in the pressing process of a press machine, the problem that all areas of the workpiece are stressed unevenly in the pressing process in the prior art is solved, and the quality of the pressed workpiece is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of presses, in particular to a static pressure press. Background Art

[0002] A press is a widely used pressure device for applying pressure to workpieces. It usually adopts a four-column or frame structure, and uses a power unit such as an oil cylinder to push the sliding worktable up and down. The workpiece to be pressed is placed between the sliding worktable and the fixed worktable. For example, a safety frame hydraulic press and its use method and component manufacturing method with application publication number CN104527114A can be used for safe pressing. However, there are the following problems: 1. Usually, multiple layers of plates such as heat insulation boards need to be stacked between the sliding worktable and the sliding beam, and multiple layers of plates such as heat insulation boards are also stacked between the fixed worktable and the fixed beam. Due to the cumulative error between the plates and the problem of inconsistent compression of the plates after being pressurized, and the problem of inconsistent compression of the same plate under different pressures, it is difficult to ensure absolute parallelism between the upper and lower worktables. 2. When the oil cylinder or electric cylinder unit pushes the sliding worktable forward, the upper and lower worktables are not parallel due to inconsistent resistance on all sides. 3. At the same time, the upper and lower surfaces of the pressurized workpiece also have certain errors and are not absolutely parallel. 4. When the workpiece is powdered or flaky, due to the uneven density inside the workpiece, the rigid indenter cannot deform when in contact with the workpiece. Instead, it acts on the area with lower density, resulting in inconsistent density after the product is pressed. Due to the existence of these factors, it is impossible to ensure that the force is evenly distributed across the workpiece during the pressing process, which ultimately leads to uneven density of the workpiece, thus affecting the quality of the workpiece. Summary of the Invention

[0003] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a self-regulating pressure press and a self-regulating pressure method, which solve the problem in the prior art that different regions of a workpiece are subjected to uneven force during the pressing process.

[0004] The technical solution of the present invention is achieved as follows: a pressure self-regulating press comprises a frame, the frame is provided with a static pressure structure, the static pressure structure comprises a pressure self-regulating oil cylinder arranged on the upper part of the frame, and an upper static pressure head is arranged at the lower part of the pressure self-regulating oil cylinder; a main oil cylinder is provided at the lower part of the frame, and a lower static pressure head is provided at the upper part of the main oil cylinder, and the lower static pressure head and the upper static pressure head are arranged correspondingly up and down; the lower static pressure head moves upward under the action of the main oil cylinder, and cooperates with the pressure self-regulating oil cylinder and the upper static pressure head to perform isostatic pressing on the workpiece; the workpiece is subjected to uniform force, the density of the pressed workpiece is ensured to be uniform, and the pressing quality of the workpiece is further improved.

[0005] Further preferably, the self-regulating pressure cylinder includes a curved piston and a cylinder body. The curved piston is restrained within the cylinder body by a piston end cap, and an automatic reset mechanism is provided between the piston end cap and the curved piston. The curved piston contacts and cooperates with the curved surface of the cylinder inner wall. A first seal is provided between the curved piston and the inner wall of the cylinder, and hydraulic oil is provided within the sealed chamber formed by the bottom of the curved piston and the cylinder body. The self-regulating pressure cylinder drives the upper static pressure head to automatically adjust its tilt angle. If the upper and lower heating plates of the entire device are not parallel, or the upper and lower surfaces of the workpiece are not parallel, the self-regulating pressure cylinder adaptively adjusts the tilt to ensure uniform force across the entire plane of the workpiece.

[0006] It is further preferred that the arc-shaped piston includes an integrally formed arc-shaped head and a rod. The arc-shaped head is located in the cylinder body, the rod is connected to the frame through a transition connecting plate, and the upper static pressure head is fixed to the lower part of the cylinder body. The outer arc surface of the arc-shaped head contacts the vertical wall surface of the cylinder body to form a hinged structure. The upper static pressure head can swing relative to the arc-shaped piston under the action of the cylinder body; so as to realize automatic adjustment of the tilt angle, ensure that the upper static pressure head applies parallel static pressure to the workpiece, and make the workpiece evenly stressed.

[0007] Further preferably, the automatic reset mechanism includes a plurality of vertically arranged springs. The piston end cap is fixed to the upper portion of the cylinder body by bolts, with a gap between the piston end cap and the rod. The springs are circumferentially and equiangularly arranged between the piston end cap and the arc-shaped head. When compression is completed, the self-regulating pressure cylinder automatically resets due to the deadweight of the springs, the cylinder body, and the upper static pressure head.

[0008] Further preferably, the upper hydrostatic pressure head includes an upper heating plate connected to the lower portion of the self-regulating pressure cylinder, an upper heat insulation plate is provided between the upper heating plate and the self-regulating pressure cylinder, an upper elastic hydrostatic frame is provided at the bottom of the upper heating plate, and an upper elastic hydrostatic body is provided at the bottom of the upper elastic hydrostatic frame. During the pressing process, when the upper elastic hydrostatic body contacts the workpiece, areas of higher density in the workpiece exert a greater reaction force on the hydrostatic body than areas of lower density, resulting in a greater contraction deformation of the hydrostatic body. Conversely, areas of lower density in the workpiece exert a smaller reaction force on the hydrostatic body, resulting in a smaller contraction deformation of the hydrostatic body, thereby ensuring that the internal forces of the workpieces are consistent across different densities.

[0009] Further preferably, the upper elastic static pressure frame is provided with a positioning groove, the upper elastic static pressure body being located within the positioning groove, and the upper elastic static pressure body being formed from a polyurethane elastomer. Polyurethane elastomers have extremely high mechanical strength, wear resistance, tear resistance, good oil resistance, high load-bearing capacity, and excellent elasticity. They are commonly used in static pressure support or cushioning components requiring high load-bearing capacity and wear resistance.

[0010] Further preferably, the master cylinder includes a lower cylinder beam and a master cylinder piston disposed within the lower cylinder beam. The lower cylinder beam is positioned within a retaining groove defined in the lower portion of the frame and secured thereto by fasteners. The lower static pressure head is secured to the upper portion of the master cylinder piston. The retaining groove and fasteners positionally secure the master cylinder, ensuring its stability and, consequently, the stability of the lower static pressure head during upward movement.

[0011] Further preferably, the lower hydrostatic pressure head includes a lower heating plate fixed to the upper portion of the master cylinder piston, a lower heat insulation plate disposed between the lower heating plate and the master cylinder piston, and a lower elastic hydrostatic frame disposed above the lower heating plate; a lower elastic hydrostatic body disposed within the lower elastic hydrostatic frame. The lower elastic hydrostatic body cooperates with the upper hydrostatic body, with the workpiece positioned between the two elastic hydrostatic bodies, ensuring uniform density throughout the final workpiece after molding.

[0012] Further preferably, the lower elastic static pressure frame is provided with a positioning groove, the lower elastic static pressure body being located within the positioning groove, and the lower elastic static pressure body being formed from a polyurethane elastomer. Polyurethane elastomers have extremely high mechanical strength, wear resistance, tear resistance, good oil resistance, high load-bearing capacity, and excellent elasticity. They are commonly used in static pressure support or cushioning components requiring high load-bearing capacity and wear resistance.

[0013] A method for self-regulating pressure of a press, adopting the self-regulating pressure press; the steps of the self-regulating pressure method are: placing the workpiece on the upper surface of the lower heating plate of the lower static pressure head, the lower static pressure head drives the workpiece upward under the action of the main oil cylinder, and the workpiece begins to be pressurized when it contacts the upper static pressure head; during the pressurization process, the pressure self-regulating oil cylinder swings at a certain angle around the arc piston according to the force condition of the upper static pressure head, realizing automatic adjustment, so that the entire plane of the workpiece is subjected to uniform force; at the same time, the pressurized workpiece is located between the upper elastic static pressure body and the lower elastic static pressure body, when the density distribution of the pressurized workpiece is uneven, and the press is pressed, the upper elastic static pressure body and the lower elastic static pressure body produce larger shrinkage deformation corresponding to the area with high density of the pressurized workpiece, and produce smaller shrinkage deformation corresponding to the area with low density of the pressurized workpiece, so that the internal force of the workpiece with uneven density distribution is consistent, and finally the density of the entire workpiece after static pressure forming is consistent.

[0014] The beneficial effects of the present invention are as follows: the present invention performs multi-faceted pressure adjustment during the workpiece pressing process through the design of a pressure self-regulating cylinder + upper and lower static pressure heads, so that the pressed workpiece is subjected to consistent force at all locations during the pressing process of the press, thereby solving the problem of uneven force in various areas of the workpiece during the pressing process in the prior art and greatly improving the quality of the pressed workpiece.

[0015] The self-regulating pressure cylinder of this invention utilizes an articulated swinging cylinder formed by a curved piston and a cylinder body. Combined with high-viscosity hydraulic oil, the swinging cylinder body can adaptively fine-tune its angle according to the load direction, ensuring load-bearing capacity. This ensures that the piston is always under axial force, preventing eccentric wear. Furthermore, the cylinder body can flexibly respond to mold eccentricity even at low speeds, ensuring compact and uniform compaction of the pressed workpiece. Furthermore, an automatic reset mechanism addresses the return delay caused by the combination of high-viscosity hydraulic oil and swinging cylinder body, maintaining the swinging cylinder body's "centering" and reducing the impact of the next start-up.

[0016] The upper and lower static pressure heads of the present invention adopt elastic static pressure bodies. When the elastic static pressure bodies are pressurized, they produce uniform volume contraction, converting the uniaxial load applied by the pressure heads into a quasi-isostatic pressure field. The workpiece blank is pressurized uniformly in all directions, reducing the density gradient, so that the pressed workpiece obtains uniform high density in all directions; it retains the high efficiency of the press while also achieving the uniform density and complex forming capabilities of isostatic pressing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the pressure self-regulating oil cylinder of the present invention; Figure 3 for Figure 2 A partial enlarged view of the middle part; Figure 4 Schematic diagram of the upper static pressure head and the lower static pressure head; Figure 5 This is a schematic diagram of the state of a workpiece with medium density being pressed by a static pressure elastic body; Figure 6 Schematic diagram of the state of a small workpiece with intermediate density being pressed by a static pressure elastomer. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0020] Example 1, as Figure 1As shown, a pressure self-regulating press comprises a frame 1. In this embodiment, the frame is preferably, but not limited to, a frame-type mainframe, which itself consists of an upper beam, a lower beam, a frame upright, and a column pin, and is the main frame of the equipment. A static pressure structure is provided on the frame 1, which is the core component of the present invention. Specifically, the static pressure structure comprises a pressure self-regulating oil cylinder 2 arranged on the upper part of the frame 1, and an upper static pressure head 30 is provided at the lower part of the pressure self-regulating oil cylinder 2; the pressure self-regulating oil cylinder adjusts the inclination angle of the upper static pressure head according to the condition of the workpiece, so that the upper static pressure head is parallel to the workpiece, ensuring that the workpiece is uniformly stressed. In this embodiment, a main oil cylinder 40 is provided at the lower part of the frame 1, and a lower static pressure head 50 is provided at the upper part of the main oil cylinder 40. The workpiece is placed on the lower static pressure head and moves toward the upper static pressure head under the action of the main oil cylinder to perform static pressure pressing of the workpiece. The lower static pressure head 50 is arranged correspondingly to the upper static pressure head 30 above and below, so that the workpiece can be pressed evenly. The lower hydrostatic ram 50, driven upward by the main cylinder 40, cooperates with the self-regulating pressure cylinder 2 and the upper hydrostatic ram 30 to isostatically press the workpiece. If the upper and lower heating plates of the entire system are not parallel, or if the top and bottom surfaces of the workpiece are not parallel, the self-regulating pressure cylinder adaptively adjusts its tilt to ensure uniform force across the entire surface of the workpiece. The elastic hydrostatic ram contacts the workpiece. Due to its high compressive strength and internal uniformity under pressure, it achieves an isostatic pressing effect, resulting in a uniform density of the workpiece.

[0021] like Figure 2 As shown, the pressure self-regulating cylinder 2 in this embodiment includes an arc-shaped piston 22 and a cylinder body 27. The arc-shaped piston 22 is limited in the cylinder body 27 by the piston end cover 23, and an automatic reset mechanism is provided between the piston end cover 23 and the arc-shaped piston 22; after the pressing is completed, the automatic reset mechanism assists the cylinder body 27 to reset so that the next pressing can proceed smoothly. The arcuate piston 22 contacts and cooperates with the arcuate surface of the inner wall of the cylinder body 27, allowing the two to swing relative to each other to balance the non-parallelism between the upper and lower static pressure heads and the non-parallelism of the workpiece surface, ensuring that the workpiece is evenly stressed during the pressing process. A first seal 25 is provided between the arcuate piston 22 and the inner wall of the cylinder body 27, and hydraulic oil 26 is provided in the sealed chamber formed by the bottom of the arcuate piston 22 and the cylinder body 27. This hydraulic oil can be high-viscosity hydraulic oil, whose core characteristics are high viscosity, strong bearing capacity, and good thermal stability. High-viscosity oil has low fluidity, which solves the problem of traditional fixed cylinder bodies easily producing uneven oil film due to piston rod eccentric loading, leading to creep, vibration, and unilateral wear of the seal. The hydraulic oil 26 inside the cylinder is fluid. When there is a left-right or front-to-back force inconsistency between the upper and lower static pressure heads of the press, the cylinder will swing accordingly with the force inconsistency, thereby ensuring that the workpiece is evenly stressed.

[0022] Example 2, as Figure 3As shown, a self-regulating pressure press is described. This embodiment is a further optimization of Example 1. In this embodiment, the arcuate piston 22 comprises an integrally formed arcuate head 2201 and a rod 2202. The arcuate head 2201 is located within the cylinder body 27, and the rod 2202 is connected to the frame 1 via a transition plate 21. The transition plate is fixed to the upper beam of the frame via bolts. The rod and transition plate are connected via screws to secure the arcuate piston. The cylinder body is connected to the arcuate piston via a hinged structure, allowing the cylinder body to swing relative to the piston. An upper static pressure head 30 is fixed to the lower portion of the cylinder body 27. The cylinder body drives the upper static pressure head to swing at a certain angle, ensuring uniform force on the workpiece during pressing. In this embodiment, the outer curved surface of the arcuate head 2201 contacts the vertical wall of the cylinder body 27 to form a hinged structure. Under the action of the cylinder body 27, the upper static pressure head 30 can swing relative to the arcuate piston 22. The swing-type cylinder body can adaptively fine-tune its angle (±2° to 5°) according to the load direction, ensuring that the piston is always under axial force and avoiding eccentric wear. Even with thick oil, it can maintain smooth movement and extend the life of the seal. High-viscosity hydraulic oil (such as ISO150) is used in conjunction with the swing-type cylinder body. The oil film thickness of high-viscosity oil (such as ISO150) is 2 to 3 times that of ordinary oil, maintaining lubrication of the sealing gap under high pressures of 30 to 50 MPa. The swing-type cylinder body can fine-tune the angle to evenly distribute the high-pressure oil film around the piston, avoiding leakage caused by local pressure peaks. In addition, the articulated design of the arc-shaped piston and cylinder body allows the swing-type cylinder body to flexibly respond to mold eccentricity at low speeds, ensuring dense and uniform results.

[0023] The automatic reset mechanism described in this embodiment includes several vertically arranged springs 24. The piston end cover 23 is fixed to the upper part of the cylinder body 27 by bolts 28, and a gap is left between the piston end cover 23 and the rod portion 2202; that is, the piston end cover 3 does not contact the arc-shaped piston 2, providing a certain amount of swing space for the piston to avoid interference. The springs 24 are arranged circumferentially and at equal angles between the piston end cover 23 and the arc-shaped head 2201, ensuring that the restoring force is evenly applied to the arc-shaped piston. When the pressing is completed, the pressure self-regulating cylinder will automatically reset due to the weight of the spring 4, the cylinder body and the heating plate. An automatic reset mechanism is added inside the pressure self-regulating cylinder to solve the return delay caused by "high viscosity hydraulic oil + cylinder body swing". The reset mechanism accurately pushes it back to the center position, so that the oil film is redistributed evenly, reducing the starting impact and unilateral wear of the seal; maintaining the "centering" of the cylinder body and reducing the impact of the next start. In other words, the automatic reset mechanism turns the "stickiness" of high-viscosity hydraulic oil and the "flexibility" of the swing cylinder into complementary advantages: viscosity brings high-pressure bearing, and mechanical reset ensures that it starts at zero position every time, which is fast, stable and energy-saving.

[0024] Example 3, as Figure 4As shown, a self-regulating pressure press is described. This embodiment is further optimized based on Embodiments 1 or 2. The upper static pressure head 30 in this embodiment includes an upper heating plate 4 connected to the lower portion of the self-regulating pressure cylinder 2. The upper heating plate is fixed to the bottom surface of the cylinder body by bolts to ensure a stable connection. An upper heat insulation plate 3 is provided between the upper heating plate 4 and the self-regulating pressure cylinder 2 to reduce heat transfer to the cylinder. An upper elastic static pressure frame 5 is provided at the bottom of the upper heating plate 4, and an upper elastic static pressure body 6 is provided at the bottom of the upper elastic static pressure frame 5. Specifically, the upper elastic static pressure frame 5 has a positioning groove, and the upper elastic static pressure body 6 is positioned within the positioning groove to ensure the secure installation of the upper elastic static pressure body. The upper elastic static pressure body 6 is made of polyurethane elastomer. Polyurethane elastomer has extremely high mechanical strength, wear resistance, tear resistance, good oil resistance, strong load-bearing capacity, and good elasticity; it is suitable for this press for stacking sheet workpieces and static pressing of powder workpieces. When the elastomer is compressed, it undergoes uniform volume contraction, transforming the uniaxial load applied by the indenter into a quasi-isostatic pressure field. The workpiece is subjected to uniform pressure in all directions, reducing density gradients. This maintains the high efficiency of the press while also achieving the uniform density and complex forming capabilities of isostatic pressing.

[0025] The master cylinder 40 described in this embodiment includes a lower cylinder beam 11 and a master cylinder piston 10 disposed within the lower cylinder beam 11. The lower cylinder beam 11 is positioned within a retaining groove 12 defined in the lower portion of the frame 1 and secured by fasteners 13, which may be flanges and bolts. The retaining groove 12 cooperates with the fasteners 13 to ensure a stable vertical position of the lower cylinder beam. A lower static pressure head 50 is secured to the upper portion of the master cylinder piston 10 by welding or bolting. The master cylinder piston 10 extends, pushing the lower static pressure head upward. Upon contact with the upper heating plate, the workpiece is subjected to pressure. In other words, when pressure is required on the workpiece, the hydraulic power system (not shown in the schematic diagram) supplies oil to the bottom of the master cylinder, pushing the master cylinder piston upward. Pressure on the workpiece begins when the workpiece contacts the upper heating plate.

[0026] The lower static pressure head 50 described in this embodiment includes a lower heating plate 8 fixed to the upper portion of the main cylinder piston 10. A lower heat insulation plate 9 is provided between the lower heating plate 8 and the main cylinder piston 10 to reduce heat transfer to the cylinder. A lower elastic static pressure frame 7 is provided on the upper portion of the lower heating plate 8; a lower elastic static pressure body 61 is provided within the lower elastic static pressure frame 7. The lower elastic static pressure frame 7 is provided with a positioning groove, and the lower elastic static pressure body 61 is located within the positioning groove to ensure the secure installation of the lower elastic static pressure body. The lower elastic static pressure body 61 is a polyurethane elastomer. Polyurethane elastomer has extremely high mechanical strength, wear resistance, tear resistance, good oil resistance, strong load-bearing capacity, and good elasticity. It is suitable for the press's stacking molding of sheet workpieces and the static pressing of powder workpieces. When pressurized, the elastomer undergoes uniform volume contraction, converting the uniaxial load applied by the pressure head into a quasi-isostatic pressure field. The workpiece is subjected to uniform pressure in all directions, reducing density gradients. At the same time, the lower elastic static pressure body 61 is set corresponding to the upper elastic static pressure body, and the pressurized workpiece is placed between the upper and lower static pressure bodies. When the density distribution of the pressurized workpiece is uneven, and the press is pressed, the area with higher density will produce a greater reaction force on the static pressure body than the area with lower density, and then the static pressure body will produce a greater contraction deformation. On the contrary, the area with lower density of the workpiece will produce a smaller reaction force on the static pressure body, and the contraction deformation of the static pressure body will be smaller, thereby ensuring that the final internal force of the workpiece is consistent under different densities, and ensuring that the density of the entire workpiece after final molding is consistent. When the pressed workpiece is a powder or sheet material, due to the uneven density inside the workpiece, when it contacts and is pressurized by the rigid pressure head, the rigid pressure head cannot produce deformation, and acts on the area with lower density, resulting in inconsistent density of the product after being pressed. The upper and lower elastic static pressure heads of the present invention, after contacting the product, contact the pressed workpiece due to elastic deformation, so that the pressure on the pressed product is equal everywhere and the density tends to be consistent. It is particularly suitable for the stacking molding of sheet workpieces.

[0027] Example 4: A method for self-regulating the pressure of a press, using the self-regulating press described in Example 3. The steps of the self-regulating pressure method are as follows: a workpiece 5 is placed on the upper surface of the lower heating plate 8 of the lower static pressure head 50; the lower static pressure head 50 drives the workpiece 5 upward under the action of the main cylinder piston 10 of the main cylinder 40; when the workpiece 5 contacts the upper static pressure head 30, the workpiece 5 begins to be pressurized; during the pressurization process, the self-regulating pressure cylinder 2 swings the cylinder body 27 around the arc-shaped piston 22 at a certain angle according to the force applied to the upper static pressure head 30, achieving automatic adjustment so that the entire plane of the workpiece 5 is subjected to uniform force. Specifically, when the upper and lower end faces of the workpiece are not parallel, or when the upper and lower beams and various plates stacked in the middle are not parallel, the self-regulating pressure cylinder 2 will automatically adjust due to the uneven force. For example, when the force on the left side is large and the force on the right side is small, the presence of hydraulic oil in the cylinder body will cause the cylinder body to tilt to the left, thereby reducing the force on the left side and increasing the force on the right side, thereby ensuring that the force on the left and right sides of the workpiece is uniform.

[0028] At the same time, if Figure 5、 6 As shown, the pressurized workpiece is located between the upper elastic hydrostatic body 6 and the lower elastic hydrostatic body 61. When the density distribution of the pressurized workpiece is uneven and the press is pressed, the upper elastic hydrostatic body 6 and the lower elastic hydrostatic body 61 produce larger shrinkage deformation in the areas corresponding to the high density of the pressurized workpiece, and produce smaller shrinkage deformation in the areas corresponding to the low density of the pressurized workpiece, thereby making the internal force of the workpiece with uneven density distribution consistent, and ultimately achieving a uniform density of the entire workpiece after hydrostatic forming. In other words, the pressurized workpiece is placed between the upper and lower elastic hydrostatic bodies. When the density distribution of the pressurized workpiece is uneven and the press is pressed, the areas with higher density of the workpiece will produce a larger reaction force on the hydrostatic body than the areas with lower density, and thus the elastic hydrostatic body will produce a larger shrinkage deformation. Conversely, the areas with lower density of the workpiece will produce a smaller reaction force on the elastic hydrostatic body, and the shrinkage deformation of the elastic hydrostatic body will be smaller, thereby ensuring that the internal force of the workpiece is consistent under different workpiece densities and ensuring that the density of the entire workpiece after final forming is consistent.

[0029] The present invention uses the design of the above-mentioned pressure self-regulating cylinder + upper and lower static pressure heads to perform multi-faceted pressure adjustment during the workpiece pressing process, thereby solving the problem of uneven force in different areas of the workpiece during the pressing process in the prior art and greatly improving the quality of the pressed workpiece.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A self-regulating pressure press, comprising a frame (1), characterized in that: The frame (1) is provided with a static pressure structure, which includes a pressure self-regulating oil cylinder (2) arranged on the upper part of the frame (1), and an upper static pressure head (30) arranged on the lower part of the pressure self-regulating oil cylinder (2); a main oil cylinder (40) is provided on the lower part of the frame (1), and a lower static pressure head (50) is provided on the upper part of the main oil cylinder (40), and the lower static pressure head (50) and the upper static pressure head (30) are arranged in correspondence with each other; the lower static pressure head (50) moves upward under the action of the main oil cylinder (40), and cooperates with the pressure self-regulating oil cylinder (2) and the upper static pressure head (30) to perform isostatic pressing on the workpiece.

2. The self-regulating pressure press according to claim 1, characterized in that: The pressure self-regulating oil cylinder (2) comprises an arcuate piston (22) and an oil cylinder body (27); the arcuate piston (22) is limited in the oil cylinder body (27) by a piston end cover (23), and an automatic reset mechanism is provided between the piston end cover (23) and the arcuate piston (22); the arcuate piston (22) contacts and cooperates with the arcuate surface of the inner wall of the oil cylinder body (27); a first sealing member (25) is provided between the arcuate piston (22) and the inner wall of the oil cylinder body (27); and hydraulic oil (26) is provided in a sealed cavity formed by the bottom of the arcuate piston (22) and the oil cylinder body (27).

3. The self-regulating pressure press according to claim 2, characterized in that: The arc-shaped piston (22) comprises an integrally formed arc-shaped head (2201) and a rod (2202). The arc-shaped head (2201) is located in the oil cylinder body (27). The rod (2202) is connected to the frame (1) via a transition connecting plate (21). The upper static pressure head (30) is fixed to the lower part of the oil cylinder body (27). The outer arc surface of the arc-shaped head (2201) contacts the vertical wall surface of the oil cylinder body (27) to form a hinged structure. The upper static pressure head (30) can swing relative to the arc-shaped piston (22) under the action of the oil cylinder body (27).

4. The self-regulating pressure press according to claim 3, characterized in that: The automatic reset mechanism includes a plurality of vertically arranged springs (24). The piston end cover (23) is fixed to the upper part of the cylinder body (27) by means of bolts (28). A gap is left between the piston end cover (23) and the rod portion (2202). The springs (24) are arranged circumferentially and at equal angles between the piston end cover (23) and the arc-shaped head portion (2201).

5. The self-regulating pressure press according to any one of claims 1 to 4, characterized in that: The upper static pressure head (30) comprises an upper heating plate (4) connected to the lower part of the pressure self-regulating oil cylinder (2), an upper heat insulation plate (3) is provided between the upper heating plate (4) and the pressure self-regulating oil cylinder (2), an upper elastic static pressure frame (5) is provided at the bottom of the upper heating plate (4), and an upper elastic static pressure body (6) is provided at the bottom of the upper elastic static pressure frame (5).

6. The self-regulating pressure press according to claim 5, characterized in that: A positioning groove is provided on the upper elastic static pressure frame (5), and the upper elastic static pressure body (6) is located in the positioning groove. The upper elastic static pressure body (6) is a polyurethane elastomer.

7. The self-regulating pressure press according to any one of claims 1 to 4 and 6, characterized in that: The master oil cylinder (40) includes a lower cylinder beam (11) and a master oil cylinder piston (10) arranged in the lower cylinder beam (11); the lower cylinder beam (11) is located in a limit groove (12) opened in the lower part of the frame (1) and is fixed by a fastener (13); and the lower static pressure head (50) is fixed to the upper part of the master oil cylinder piston (10).

8. The self-regulating pressure press according to claim 7, characterized in that: The lower static pressure head (50) includes a lower heating plate (8) fixed on the upper part of the main oil cylinder piston (10), a lower heat insulation plate (9) is provided between the lower heating plate (8) and the main oil cylinder piston (10), and a lower elastic static pressure frame (7) is provided on the upper part of the lower heating plate (8); and a lower elastic static pressure body (61) is provided in the lower elastic static pressure frame (7).

9. The self-regulating pressure press according to claim 8, characterized in that: A positioning groove is provided on the lower elastic static pressure frame (7), and the lower elastic static pressure body (61) is located in the positioning groove. The lower elastic static pressure body (61) is a polyurethane elastomer.

10. A method for self-regulating pressure of a press, characterized in that: A pressure self-regulating press machine according to any one of claims 1 to 8 is used; the pressure self-regulating method comprises the following steps: placing a workpiece (5) on the upper surface of the lower heating plate (8) of the lower static pressure head (50); the lower static pressure head (50) drives the workpiece (5) upward under the action of the main oil cylinder (40); when the workpiece (5) contacts the upper static pressure head (30), the workpiece (5) begins to be pressurized; during the pressurization process, the pressure self-regulating oil cylinder (2) swings the oil cylinder body (27) around the arc piston (22) at a certain angle according to the force applied to the upper static pressure head (30). Automatic adjustment is achieved so that the entire plane of the workpiece (5) is subjected to uniform force. At the same time, the pressurized workpiece is located between the upper elastic static pressure body (6) and the lower elastic static pressure body (61). When the density distribution of the pressurized workpiece is uneven and the press is pressed, the upper elastic static pressure body (6) and the lower elastic static pressure body (61) produce larger shrinkage deformation in the area with high density of the pressurized workpiece and smaller shrinkage deformation in the area with low density of the pressurized workpiece, thereby making the internal force of the workpiece with uneven density distribution uniform, and finally achieving uniform density of the entire workpiece after static pressure forming.

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