Vacuum hot press for aluminum-based copper-clad plate

Abstract

The invention provides a vacuum hot press for an aluminum-based copper-clad plate, which belongs to the technical field of hot presses, comprises a vacuum bin and a hot pressing mold positioned in the vacuum bin, and is characterized in that the hot pressing mold comprises a plurality of hot pressing plates which are longitudinally distributed in an array manner; first positioning mechanisms and a second positioning mechanism are arranged in the vacuum bin, the two first positioning mechanisms are located on the two sides of the hot pressing plate correspondingly, and each first positioning mechanism comprises a rotating rod vertically arranged in the vacuum bin; by arranging the first positioning mechanism and the second positioning mechanism, one side of the aluminum plate and one side of the copper foil can be aligned through the second positioning mechanism when the aluminum plate and the copper foil are fed, then the first positioning mechanism is started, and the other two sides of the aluminum plate and the other two sides of the copper foil can be aligned; therefore, the problem of material waste caused by the increase of the area of the waste material at the edge of the finished product of the laminated aluminum-based copper-clad plate is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of hot presses, and in particular relates to a vacuum hot press for an aluminum-based copper-clad plate. Background Art

[0002] As an advanced material processing equipment, the vacuum hot press has its technical origins traced back to the growing demand for composite materials and high-performance materials processing. With the advancement of science and technology and the need for industrialized production, the vacuum hot press has gradually developed into an important processing equipment, widely used in many fields.

[0003] A vacuum hot press machine is disclosed in a Chinese patent with the authorization announcement number CN110605897B, including a frame, a vacuum chamber is provided on the frame, an upper hot pressing die and a lower hot pressing die are installed in the vacuum chamber, a workpiece entrance and a workpiece exit are respectively provided on the rear side and the front side of the vacuum chamber, a first hatch is installed at the workpiece entrance, a second hatch is installed at the workpiece exit, the lower ends of the first hatch and the second hatch are hinged on the vacuum chamber, a first hatch driving device capable of driving the first hatch to flip backward and place it flat on the frame is provided on the frame, a second hatch driving device capable of driving the second hatch to flip forward and place it flat on the frame is provided on the frame, a plurality of rollers are installed at intervals on the side of the first hatch near the workpiece entrance, and a plurality of rollers are installed at intervals on the part of the second hatch near the workpiece exit. The hatch in the present invention can be opened and closed automatically, and the hatch after opening can be flipped and laid flat to serve as an input roller or an output roller, so that the placement and removal of the workpiece are relatively convenient.

[0004] In the production of aluminum-based copper-clad laminates, multiple sets of aluminum plates and copper foils are usually placed between the upper hot-pressing die and the lower hot-pressing die. Each set of aluminum plates and copper foils will be pressed into a finished aluminum-based copper-clad laminate. During the transportation and loading process of the multiple sets of aluminum plates and copper foils, the vibration of mechanical equipment will cause a certain amount of displacement between the multiple sets of aluminum plates and copper foils, resulting in the multiple sets of aluminum plates and copper foils not being aligned when placed between the upper hot-pressing die and the lower hot-pressing die, which can easily cause the area of ​​waste at the edge of the finished aluminum-based copper-clad laminate after pressing to increase. In the subsequent trimming process, a large amount of waste needs to be cut off, resulting in material waste. Summary of the invention

[0005] The object of the present invention is to provide a vacuum hot press for aluminum-based copper-clad laminates, aiming to solve the problem that the vacuum hot press in the prior art cannot align the aluminum plate and the copper foil, which easily causes the area of ​​waste material at the edge of the finished aluminum-based copper-clad laminate after pressing to increase, and in the subsequent trimming process, a large amount of waste material needs to be cut off, resulting in material waste.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a vacuum hot pressing machine for aluminum-based copper-clad laminates, comprising: a vacuum chamber and a hot pressing mold located inside the vacuum chamber, characterized in that the hot pressing mold comprises a plurality of hot pressing plates distributed in a longitudinal array, a first positioning mechanism and a second positioning mechanism are arranged inside the vacuum chamber, two of the first positioning mechanisms are arranged, which are respectively located on both sides of the hot pressing plate, the first positioning mechanism comprises a rotating rod vertically arranged inside the vacuum chamber, the rotating rod is rotatably connected in the vacuum chamber, and an eccentric top block matching the number of hot pressing plates is arranged on the rotating rod, when the hot pressing mold is in an open mold state, the lower surface of the eccentric top block remains flush with the upper surface of the hot pressing plate, when the rotating rod rotates, it can drive the eccentric top block to rotate at the same time, so that the eccentric part of the eccentric top block can be against one side of the aluminum plate and the copper foil, and the second positioning mechanism is used to align the other side of the aluminum plate and the copper foil when the aluminum plate and the copper foil are fed.

[0007] A further technical solution of the present invention is that a second sliding groove is provided on the eccentric top block, a second limiting groove is provided in the second sliding groove, a second limiting block adapted to the second limiting groove is provided on the rotating rod, the eccentric top block can slide in a horizontal direction on the rotating rod through the second sliding groove, the cross-section of the rotating rod is rectangular, and an elastic member is provided in the second sliding groove for resetting the eccentric top block.

[0008] A further technical solution of the present invention is that the top end of the eccentric portion of the eccentric top block is in an arc shape.

[0009] A further technical solution of the present invention is that a mounting platform is provided at an eccentric position of the eccentric top block, a roller is installed on the mounting platform, and a belt is jointly sleeved on the mounting platform and the roller.

[0010] A further technical solution of the present invention is that a first groove is designed on the mounting platform, a second groove is designed on the roller, and a protrusion that can be embedded in the first groove and the second groove at the same time is provided on the belt.

[0011] A further technical solution of the present invention is that the belt is made of flexible material.

[0012] A further technical solution of the present invention is that a driving device is provided on the vacuum chamber, and the driving device includes two independent driving sources, and the two driving sources correspond to and control the first positioning mechanism and the second positioning mechanism respectively. One of the driving sources is provided with a transmission structure, and the transmission structure can simultaneously drive the two rotating rods to rotate synchronously in opposite directions, and the other driving source is directly connected to the second positioning mechanism for independently controlling the opening and closing of the second positioning mechanism.

[0013] A further technical solution of the present invention is that guide rails are vertically arranged on both sides of the inner wall of the vacuum chamber, a first slide groove adapted to the guide rail is arranged on the hot pressing plate, a plurality of first limit grooves arranged in a longitudinal array are arranged on the guide rail, a first limit block capable of sliding in the first limit groove is arranged on the first slide groove, and each of the hot pressing plates corresponds to a first limit groove.

[0014] A further technical solution of the present invention is that the structure of the second positioning mechanism is consistent with that of the first positioning mechanism, and the eccentricity of the eccentric top block is located outside the hot pressing plate in an initial state.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting the first positioning mechanism and the second positioning mechanism, when the aluminum plate and the copper foil are loaded, the second positioning mechanism can be used to align one side of the aluminum plate and the copper foil, and then the first positioning mechanism is started to align the other two sides of the aluminum plate and the copper foil, thereby avoiding the increase of the area of ​​waste at the edge of the finished product of the aluminum-based copper clad laminate after pressing, resulting in the problem of material waste.

[0016] 2. A second slide groove is provided in the eccentric top block, and the rotating rod can slide inside the second slide groove. When aligning larger aluminum plates and copper foils, the eccentric top block is pushed to slide on the rotating rod by the aluminum plate and copper foil, thereby avoiding interference between the eccentric top block and the aluminum plate and copper foil, and thus being suitable for aluminum-based copper-clad laminates of different sizes.

[0017] 3. By arranging a belt at the top of the eccentric top block, friction between the eccentric top block and the aluminum plate and copper foil can be avoided, thereby avoiding wear on the side walls of the aluminum plate and copper foil. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a structural schematic diagram of a specific embodiment of the present invention; Figure 2 It is a schematic diagram of the internal structure of a specific embodiment of the present invention; Figure 3 It is a schematic diagram of the installation structure of the first positioning mechanism in a specific embodiment of the present invention; Figure 4 It is a schematic diagram of the installation position structure of the first positioning mechanism and the second positioning mechanism in a specific embodiment of the present invention; Figure 5 It is a schematic diagram of the installation structure of the eccentric top block in a specific embodiment of the present invention; Figure 6It is a structural schematic diagram of an eccentric top block in a specific embodiment of the present invention; Figure 7 for Figure 3 A schematic diagram of the structure enlargement at the center A; Figure 8 for Figure 2 A magnified schematic diagram of the structure at point B in the middle.

[0019] In the figure: 1. vacuum chamber; 11. feed door opening; 12. sealing door; 2. hot pressing mold; 21. hot pressing plate; 22. guide rail; 23. first limit groove; 24. first slide groove; 25. first limit block; 3. first positioning mechanism; 31. rotating rod; 32. eccentric top block; 33. second slide groove; 34. second limit block; 35. second limit groove; 36. elastic member; 4. second positioning mechanism; 5. driving device; 51. driving source; 52. transmission structure; 6. mounting table; 61. first groove; 7. roller; 71. second groove; 8. belt; 81. protrusion. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1-Figure 8 , the present invention provides the following technical solutions: a vacuum hot press machine for aluminum-based copper-clad laminates, comprising a vacuum chamber 1, a hot pressing mold 2, two first positioning mechanisms 3, a second positioning mechanism 4, and a driving device 5 located above the vacuum chamber 1; The hot pressing mold 2, the first positioning mechanism 3 and the two second positioning mechanisms 4 are all arranged inside the vacuum chamber 1. The hot pressing mold 2 is responsible for pressing the aluminum plate and the copper foil. During the feeding process, when the aluminum plate and the copper foil are loaded into the hot pressing mold 2, the feeding mechanism (not shown in the figure) pushes the edge of one side to push them into the hot pressing mold 2. When the feeding mechanism feeds the aluminum plate and the copper foil, the second positioning mechanism 4 is brought into contact with the other side of the aluminum plate and the copper foil through the driving device 5 to ensure that one side of the aluminum plate and the copper foil are aligned. The two first positioning mechanisms 3 are mirror-imaged on both sides of the vacuum chamber 1. Subsequently, the driving device 5 can also move the two first positioning mechanisms 3 at the same time to align the other two sides of the aluminum plate and the copper foil, thereby effectively avoiding the misalignment or offset between the aluminum plate and the copper foil.

[0022] It should be noted that the feeding mechanism is a common supporting equipment of the vacuum hot press, and the specific structure will not be described in detail.

[0023] The vacuum bin 1 is a rectangular structure, standing vertically on the ground. A feeding door opening 11 is opened on one side of the vacuum bin 1, and the feeding door opening 11 is located on the side wall of the vacuum bin 1. A sealing door 12 is installed at the position of the feeding door opening 11. The sealing door 12 is opened by a lateral sliding method. When the sealing door 12 slides to the feeding door opening 11, it can completely cover the feeding door opening 11 and tightly close it.

[0024] See also Figure 2 and Figure 3 The hot pressing mold 2 includes a plurality of hot pressing plates 21 arranged in a longitudinal array. Vertical guide rails 22 are arranged on both sides of the inner wall of the vacuum chamber 1. The hot pressing plate 21 is provided with a first slide groove 24 (such as Figure 4 As shown in FIG. 1 ), through these first slide grooves 24, the hot pressing plate 21 can slide smoothly on the guide rail 22. The guide rail 22 guides the hot pressing plate 21 to ensure that the hot pressing plate 21 does not deviate during the movement. In addition, a plurality of first limiting grooves 23 arranged in a longitudinal array are provided on the guide rail 22 (as shown in FIG. Figure 8 As shown in the figure, the spacings between these first limiting grooves 23 are equal. The first sliding groove 24 is provided with a first limiting block 25 that can slide in the first limiting groove 23. Each hot pressing plate 21 corresponds to a first limiting groove 23. Through the design of the first limiting groove 23, a uniform distribution of multiple hot pressing plates 21 can be achieved. When each hot pressing plate 21 slides to the bottom of the first limiting groove 23, the distance between the hot pressing plates 21 remains consistent.

[0025] See also Figure 3-Figure 5 The first positioning mechanism 3 is composed of a rotating rod 31 and an eccentric top block 32 whose number matches the number of the hot pressing plates 21. The rotating rod 31 has a rectangular cross section. It is vertically installed inside the vacuum chamber 1, and its two ends are rotatably connected to the upper and lower ends of the vacuum chamber 1 respectively. In order to enhance the smoothness of the rotation of the rotating rod 31, its two ends are designed to be cylindrical, thereby improving the stability of the rotation. A second slide groove 33 is provided in the middle of the eccentric top block 32, and a second limiting groove 35 is also provided inside the second slide groove 33. The rotating rod 31 is provided with a second limiting block 34 adapted to the second limiting groove 35. The number of these second limiting blocks 34 is consistent with the number of eccentric top blocks 32, and they are evenly arranged along the length direction of the rotating rod 31. Through the cooperation of the second limiting block 34 and the second limiting groove 35, the up and down sliding of the eccentric top block 32 on the rotating rod 31 can be effectively limited to ensure that the eccentric top block 32 will not move at will. When the hot pressing mold 2 is in the mold opening state, the lower surface of the eccentric top block 32 is kept flush with the upper surface of the hot pressing plate 21; When the two rotating rods 31 rotate at the same time, they will drive the eccentric top blocks 32 on each of them to perform mirror motion, that is, the two rotating rods 31 drive the eccentric top blocks 32 to rotate in opposite directions. Since the eccentric top blocks 32 are eccentrically designed, during the rotation process, they can make the eccentric parts of the eccentric top blocks 32 on the two rotating rods 31 swing towards the direction of the aluminum plate and the copper foil at the same time. In this way, the eccentric parts of the two eccentric top blocks 32 can be against the two side walls of the aluminum plate and the copper foil, thereby achieving precise alignment of the side edges of the aluminum plate and the copper foil, and at the same time, the aluminum plate and the copper foil can be positioned in the middle of the hot press plate 21. In addition, since the lower surface of the eccentric top blocks 32 is flush with the upper surface of the hot press plate 21, they will not interfere with the hot press plate 21 during the movement of the eccentric top blocks 32.

[0026] See also Figure 7 The driving device 5 includes two independent driving sources 51, which correspond to and control the first positioning mechanism 3 and the second positioning mechanism 4 respectively. One of the driving sources 51 is connected to a transmission structure 52, and the transmission structure 52 adopts a chain transmission method. Specifically, the transmission structure 52 includes a driving sprocket and two driven sprockets, and the two driven sprockets are connected to the driving sprocket through a chain. A rotating rod 31 is connected to each driven sprocket. Therefore, when the driving source 51 drives the driving sprocket to rotate, it can simultaneously drive the two driven sprockets to rotate in opposite directions, thereby causing the two rotating rods 31 to rotate synchronously in opposite directions. The other driving source 51 is directly connected to the second positioning mechanism 4, and is used to independently control the opening and closing of the second positioning mechanism 4.

[0027] In the production process of aluminum-based copper-clad laminates, in order to meet the diverse needs of different manufacturers, aluminum-based copper-clad laminates of various sizes need to be processed and handled. However, in the above scheme, only aluminum-based copper-clad laminates of fixed sizes can be aligned. When trying to align aluminum-based copper-clad laminates of larger sizes, since the drive device 5 adopts a rigid driving method, it is easy to cause damage to the side wall of the aluminum-based copper-clad laminate, and it may also accelerate the damage of the drive device 5 and shorten its service life. Therefore, we need to further optimize the scheme to ensure that the alignment operations of aluminum-based copper-clad laminates of different sizes can be performed flexibly and effectively; See also Figure 5 In order to make this solution adaptable to aluminum-based copper-clad laminates of different sizes, the eccentric top block 32 is designed to slide horizontally on the rotating rod 31 through the second slide groove 33. Inside the second slide groove 33, there is an elastic member 36, which is a compression spring. One end of the compression spring is fixed to the rotating rod 31, and the other end is connected to the inside of the second slide groove 33 to ensure that the eccentric top block 32 has appropriate elasticity and return ability during the sliding process; When aligning a larger aluminum-based copper-clad laminate, one side of the eccentric portion of the eccentric top block 32 will first contact the side walls of the aluminum plate and the copper foil. Subsequently, the driving device 5 drives the two rotating rods 31 to continue rotating, thereby driving the respective eccentric top blocks 32 to rotate accordingly. Since the top of the eccentric portion is designed to be an arc, the side walls of the aluminum plate and the copper foil can push the eccentric top block 32 to slide horizontally on the rotating rod 31 through the rotation of the eccentric portion. The rotating rod 31 stops after rotating 180 degrees. Under the action of the elastic member 36, the eccentric portion of the eccentric top block 32 can always maintain close contact with the side walls of the aluminum plate and the copper foil when the eccentric top block 32 rotates. At the same time, the elastic member 36 can also be used to reset the eccentric top block 32, thereby ensuring that this solution can flexibly adapt to and accurately align aluminum-based copper-clad laminates of different sizes.

[0028] When the eccentric top block 32 rotates, since its eccentric portion always keeps in contact with the side walls of the aluminum plate and the copper foil, friction will be generated between the two, and this friction will easily cause the side walls of the aluminum plate and the copper foil to wear; See also Figure 5 Therefore, a mounting platform 6 is provided at the eccentric position of the eccentric top block 32, a roller 7 is installed on the mounting platform 6, and a rubber belt 8 is sleeved on the mounting platform 6 and the roller 7. When the eccentric top block 32 contacts the aluminum plate and the copper foil, the belt 8 contacts the side wall of the aluminum plate and the copper foil first. The belt 8 can rotate on the mounting platform 6 and the roller 7 through the friction between the belt 8 and the side wall of the aluminum plate and the copper foil, thereby effectively avoiding the wear of the side wall of the aluminum-based copper clad laminate.

[0029] In addition, in order to prevent the belt 8 from falling off the mounting platform 6, a first groove 61 is designed on the mounting platform 6, and a second groove 71 is designed on the roller 7. The belt 8 is provided with a protrusion 81 that can be embedded in the first groove 61 and the second groove 71 at the same time. Through the cooperation between the first groove 61, the second groove 71 and the protrusion 81, the belt 8 can be effectively limited to ensure that it does not fall off the mounting platform 6.

[0030] It should be noted that the structure of the second positioning mechanism 4 is consistent with that of the first positioning mechanism 3, and the eccentricity of the eccentric top block 32 is located outside the hot pressing plate 21 in the initial state, that is, the eccentric top block 32 and the hot pressing plate 21 do not overlap in vertical projection.

[0031] When in use, the aluminum plate and copper foil are first pushed smoothly onto the hot pressing plate 21 by the feeding mechanism. During the feeding process, the driving device 5 is started in advance, and the second positioning mechanism 4 is adjusted so that the eccentric part of the eccentric top block 32 thereon is aligned with the position of the aluminum plate and the copper foil. Subsequently, the feeding mechanism pushes one side edge of the aluminum plate and the copper foil to move until they contact the eccentric top block 32 on the second positioning mechanism 4, thereby achieving preliminary alignment of the aluminum plate and the copper foil. During this process, the eccentric top block 32 will slide on the rotating rod 31 and compress the elastic member 36 at the same time. After the feeding mechanism completes the pushing, it withdraws, and at this time the elastic force of the elastic member 36 will push the aluminum plate and the copper foil to move further, ensuring that their positions are accurately positioned. Next, the first positioning mechanism 3 is started so that the eccentric top block 32 thereon contacts the other two side walls of the aluminum plate and the copper foil, completing the comprehensive alignment of the aluminum plate and the copper foil. The belt 8 provided on the eccentric top block 32 effectively reduces the friction between the aluminum plate and the copper foil and avoids the wear of the side walls. After the alignment is completed, that is, after the first positioning mechanism 3 rotates 180 degrees, the second positioning mechanism 4 then rotates in the opposite direction, so that the eccentric part of the eccentric top block 32 is away from the aluminum plate and the copper foil, making room for the hot pressing operation. Then the aluminum plate and the copper foil are hot pressed. After the hot pressing is completed, the first positioning mechanism 3 rotates 180 degrees in the opposite direction to reset, ready for the next operation.

Claims

1. A vacuum hot press for aluminum-based copper-clad laminates, comprising: A vacuum chamber (1) and a hot pressing mold (2) located inside the vacuum chamber (1), characterized in that the hot pressing mold (2) comprises a plurality of hot pressing plates (21) arranged in a longitudinal array, a first positioning mechanism (3) and a second positioning mechanism (4) are arranged inside the vacuum chamber (1), two first positioning mechanisms (3) are provided, which are respectively located on both sides of the hot pressing plates (21), and the first positioning mechanism (3) comprises a rotating rod (31) vertically arranged inside the vacuum chamber (1), and the rotating rod (31) is rotatably connected to the vacuum chamber (1). The rotating rod (31) is provided with eccentric top blocks (32) whose number matches the number of the hot pressing plates (21); when the hot pressing mold (2) is in the mold opening state, the lower surface of the eccentric top block (32) remains flush with the upper surface of the hot pressing plate (21); when the rotating rod (31) rotates, it can drive the eccentric top block (32) to rotate simultaneously, so that the eccentric part of the eccentric top block (32) can abut against one side of the aluminum plate and the copper foil; the second positioning mechanism (4) is used to align the other side of the aluminum plate and the copper foil when the aluminum plate and the copper foil are loaded.

2. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 1, characterized in that: The eccentric top block (32) is provided with a second slide groove (33), a second limit groove (35) is provided in the second slide groove (33), a second limit block (34) matched with the second limit groove (35) is provided on the rotating rod (31), the eccentric top block (32) can slide on the rotating rod (31) in a horizontal direction through the second slide groove (33), the cross-section of the rotating rod (31) is rectangular, and an elastic member (36) is provided in the second slide groove (33) for resetting the eccentric top block (32).

3. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 2, characterized in that: The top end of the eccentric portion of the eccentric top block (32) is in an arc shape.

4. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 3, characterized in that: A mounting platform (6) is provided at the eccentric portion of the eccentric top block (32), a roller (7) is mounted on the mounting platform (6), and a belt (8) is sleeved on the mounting platform (6) and the roller (7).

5. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 4, characterized in that: A first groove (61) is designed on the mounting platform (6), a second groove (71) is designed on the roller (7), and a protrusion (81) capable of being embedded in both the first groove (61) and the second groove (71) is provided on the belt (8).

6. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 4, characterized in that: The belt (8) is made of a flexible material.

7. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 1, characterized in that: The vacuum chamber (1) is provided with a driving device (5), the driving device (5) comprising two independent driving sources (51), the two driving sources (51) corresponding to and controlling the first positioning mechanism (3) and the second positioning mechanism (4) respectively, one of the driving sources (51) being provided with a transmission structure (52), the transmission structure (52) being capable of simultaneously driving the two rotating rods (31) to rotate synchronously in opposite directions, and the other driving source (51) being directly connected to the second positioning mechanism (4) for independently controlling the opening and closing of the second positioning mechanism (4).

8. The vacuum hot press machine for aluminum-based copper-clad laminate according to claim 1, characterized in that: Guide rails (22) are vertically arranged on both sides of the inner wall of the vacuum chamber (1); a first slide groove (24) adapted to the guide rail (22) is arranged on the hot pressing plate (21); a plurality of first limiting grooves (23) arranged in a longitudinal array are arranged on the guide rail (22); a first limiting block (25) capable of sliding in the first limiting groove (23) is arranged on the first slide groove (24); and each of the hot pressing plates (21) corresponds to a first limiting groove (23).

9. A vacuum hot press machine for aluminum-based copper-clad laminates according to any one of claims 1 to 8, characterized in that: The second positioning mechanism (4) has a structure consistent with that of the first positioning mechanism (3), and the eccentricity of the eccentric top block (32) is located outside the hot pressing plate (21) in the initial state.

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