A torsion extrusion device driven in rotation by a press ram

Abstract

The present application relates to a kind of torsion extrusion device driven by pressure machine slider rotation, comprising: rotary extrusion die, including the extrusion cylinder with extrusion cavity, the pressure head that can be extended into the extrusion cavity and moves up and down along its inner wall, the rotary die with the upper opening of the extrusion cavity is connected;Upper platen, it is set in the extrusion cylinder outside, and with the pressure head fixed connection;Middle platen is located below the upper platen and is rotated by it;Lower platen is located below the middle platen and is rotated by it;The lower platen is also connected with the rotary die transmission.The device of the present application can convert the linear motion of the pressure machine slider into the rotary motion of the die while extruding.In the absence of external motor, the die can carry out linear motion and rated rotary motion simultaneously, so that the material can be extruded and twisted simultaneously, realize large plastic deformation, obtain ultra-fine grain structure.

Description

Technical Field

[0001] This invention belongs to the technical field of metal material torsional extrusion equipment, and relates to a torsional extrusion device driven by a press slide. Background Technology

[0002] Ultrafine-grained materials typically possess excellent physical and mechanical properties and are widely used in aerospace, advanced weaponry, and transportation. While traditional plastic processing techniques can refine the microstructure, the difficulty in generating significant strain during processing makes it challenging to achieve ultrafine grains. Large plastic deformation techniques, combining high hydrostatic pressure and strong shear, can directly refine the internal microstructure of materials to submicron or even nanometer scales, and are considered by the materials science community to be the most promising method for preparing bulk ultrafine-grained materials. In recent years, techniques such as equal-channel diameter angular extrusion, high-pressure torsion, and torsional extrusion have developed rapidly.

[0003] Torsional extrusion, as a high-plasticity deformation technology, not only introduces strong shear deformation but also boasts advantages such as simple processing and the ability to produce large-sized products. Currently, torsional extrusion equipment mainly consists of an extrusion die and a rotary die. During the forming process, the rotation of the rotary die relies on an external motor, which complicates die assembly and disassembly processes and reduces production efficiency. Furthermore, when relying on an external motor as the power source for rotation, the actual rotational speed during torsional extrusion is affected by the extrusion load, making accurate control difficult. When the extrusion pressure is relatively high, the rotary die, subjected to the extrusion load, struggles to reach the required rotational speed, failing to demonstrate the torsional effect.

[0004] Chinese patent application CN202310772583.9 discloses a torsional extrusion device and method to enhance the torsional shear effect. It uses a multi-stage cavity rotating mold containing a circular cross-section conical cavity, a first transition cavity, a wave-shaped cross-section straight cavity, a second transition cavity, and a circular cross-section straight cavity to solve the slippage problem in the torsional extrusion process. However, it also cannot solve the defects in the torsional extrusion process mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a torsional extrusion device driven by a press slide, which can convert the linear motion of the press slide into a fixed rotational motion of the die during extrusion. In this way, without the need for an external motor, the die can simultaneously perform linear motion and a fixed rotational motion, and there will be no slippage of the motor during torsion due to increased load. This allows the material to undergo both extrusion and torsional deformation simultaneously, achieving large plastic deformation and obtaining an ultrafine-grained structure.

[0006] The objective of this invention can be achieved through the following technical solutions: A torsional extrusion device driven to rotate by a press slide includes: A rotary extrusion die includes an extrusion cylinder having an extrusion cavity, a pressure head that can extend into the extrusion cavity and move up and down along its inner wall, and a rotary die with an upper opening that receives the extrusion cavity. The upper pressure plate is sleeved on the outside of the extrusion cylinder and is pushed down by the pressure head; The intermediate pressure plate is located below the upper pressure plate and is driven to rotate by it; The lower pressure plate is located below the intermediate pressure plate and is driven to rotate by it; The lower pressure plate is also connected to the rotating mold via a transmission, and the rotation of the lower pressure plate drives the rotating mold to rotate.

[0007] Furthermore, connecting rod assemblies are provided between the upper pressure plate and the middle pressure plate, and between the middle pressure plate and the lower pressure plate. The connecting rod assembly consists of several evenly arranged connecting rods, and the two ends of the connecting rods are respectively connected to the upper pressure plate and the middle pressure plate, or the middle pressure plate and the lower pressure plate, through ball joints.

[0008] Furthermore, in the same set of connecting rods, the angle between each connecting rod and the tangent at its bottom hinge point is the same. That is, when the distance between two adjacent pressure plates is at its maximum, the connecting rod between the two pressure plates is in a vertical or nearly vertical state. Then, during the downward pressing process, the distance between the two pressure plates tends to decrease, causing the connecting rod to deflect at the same angle, which in turn causes the pressure plate located below (such as the middle pressure plate, the lower pressure plate, etc.) to rotate.

[0009] Furthermore, an upper limit mechanism is provided between the upper pressure plate and the middle pressure plate. The upper limit mechanism includes one or more upper limit rods fixed on the middle pressure plate and an upper limit groove machined on the upper pressure plate into which the upper limit rods can extend. When the upper pressure plate is pressed down with the pressure head, the middle pressure plate rotates accordingly, and the distance between the upper pressure plate and the middle pressure plate decreases, so that the upper limit rods extend into the upper limit groove and rotate with the middle pressure plate until they abut against the inner wall of the upper limit groove. At this time, the upper pressure plate and the middle pressure plate are relatively stationary. A lower limit mechanism is also provided between the intermediate pressure plate and the lower pressure plate. The lower limit mechanism includes one or more lower limit rods fixed on the lower pressure plate and a lower limit groove machined on the intermediate pressure plate into which the lower limit rods can extend. When the intermediate pressure plate moves down, the lower pressure plate rotates accordingly, and the distance between the intermediate pressure plate and the lower pressure plate decreases, so that the lower limit rods extend into the lower limit groove and rotate with the lower pressure plate until they abut against the inner wall of the lower limit groove. At this time, the intermediate pressure plate and the lower pressure plate are relatively stationary.

[0010] Furthermore, the curvature of the upper and lower limit grooves matches the rotational stroke of the upper and lower limit rods, respectively. These upper and lower limit mechanisms serve two purposes: firstly, to guide and limit the rotational movement between two adjacent pressure plates; and secondly, to protect the connecting rod assembly positioned between the two pressure plates, preventing the distance between them from being too small or too large, thus exceeding the allowable deflection range of the ball joint at the connecting rod connection point.

[0011] Furthermore, there is one or more intermediate pressure plates. When there are multiple intermediate pressure plates, the upper intermediate pressure plate drives the lower intermediate pressure plate to rotate as it moves up and down, thereby increasing the rotation angle of the lower pressure plate. At this time, a connecting rod assembly as described above can also be set between two adjacent intermediate pressure plates to achieve relative rotation. In addition, a corresponding limiting mechanism can also be set, and the specific structure can refer to the upper limit mechanism or the lower limit mechanism.

[0012] Furthermore, the lower pressure plate is connected to the rotating mold via a rotating mechanism. The rotating mechanism includes a planetary gear carrier arranged around the central axis of the lower pressure plate, planetary gears rotatably mounted on the planetary gear carrier, a sun gear fixed to the lower part of the rotating mold, and an internal gear ring mounted at the bottom of the extrusion cylinder and surrounding the sun gear. The planetary gears are located between the sun gear and the internal gear ring and mesh with the sun gear and the internal gear ring respectively.

[0013] Furthermore, the bottom of the rotary mold is connected to the sun gear in the planetary gear system. The sun gear is connected to the planet gears in the planetary gear system. The planet gears maintain their relative positions with the planet carrier, which is fixed to the lower pressure plate. This achieves the connection between the rotary mold and the lower pressure plate. The two are connected by the planetary gear system and achieve relative rotational motion between them.

[0014] Furthermore, the internal cavity of the rotating mold has a variable cross-section structure.

[0015] Furthermore, a fixed cylinder is also fitted outside the extrusion cylinder, and the side wall of the fixed cylinder is also machined with clearance space to allow the upper pressure plate, middle pressure plate and lower pressure plate to move up and down.

[0016] Furthermore, the lower pressure plate, serving as the base of the entire mold set, is placed on the turntable of the hydraulic press workbench, reducing the friction it experiences while rotating.

[0017] Compared with the prior art, the present invention has the following advantages: 1. Through the friction between the rotating die and the billet, the billet can be simultaneously subjected to extrusion and torsional deformation, which refines the grains in the material under intense plastic deformation.

[0018] 2. Through the linkage of the mechanical structure, the rotation of the rotary mold and the linear motion of the slider can form a certain functional relationship, so that the speed is insufficient or the rotation cannot be completed when the power of the external motor is insufficient.

[0019] 3. By simultaneously achieving the effects of extrusion and torsion through mechanical structure, the number of power sources is reduced, operation is simplified, the footprint of the mold is reduced, and subsequent maintenance is convenient.

[0020] 4. Unlike traditional motors that provide torsion, which reduce their speed under high loads and cannot achieve the ideal rotational speed, the rotational motion of this invention is rigidly one-to-one with the linear motion of the press slide, thus preventing slippage. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 A schematic diagram of the torsion extrusion device after the fixed cylinder has been removed; Figure 3 This is a structural diagram of the main transmission mechanism and mold section; Explanation of markings in the diagram: 1-Pressure head; 2-Extrusion cylinder; 3-Rotating mold; 4-Fixed cylinder; 5-Sun gear; 6-Planetary gear; 7-Planetary gear carrier; 8-Internal gear ring; 9-Mold part; 10-Planetary gear system; 11-Upper pressure plate; 12-Upper ball joint; 13-Upper connecting rod; 14-Upper limit mechanism; 15-First middle ball joint; 16-Middle pressure plate; 17-Second middle ball joint; 18-Lower connecting rod; 19-Lower limit mechanism; 20-Lower ball joint; 21-Lower pressure plate; 22-Rotating mechanism. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] Unless otherwise specified, the functional components or structures in the following embodiments or examples are all commonly used components or structures in the art to achieve the corresponding functions.

[0024] To enable materials to undergo simultaneous extrusion and torsional deformation, achieving large plastic deformation and obtaining ultrafine grain structures, this invention provides a torsional extrusion device driven by a press slide block. Its structure can be found in [reference needed]. Figures 1 to 3 As shown, it includes: A rotary extrusion die includes an extrusion cylinder 2 with an extrusion cavity, a pressure head 1 that can extend into the extrusion cavity and move up and down along its inner wall, and a rotary die 3 with its upper opening receiving the extrusion cavity. The upper pressure plate 11 is sleeved on the outside of the extrusion cylinder 2 and is pushed down by the pressure head 1; The intermediate pressure plate 16 is located below the upper pressure plate 11 and is driven to rotate by it; The lower pressure plate 21 is located below the intermediate pressure plate 16 and is driven to rotate by it; The lower pressure plate 21 is also connected to the rotating mold 3 via a transmission connection, and the rotation of the lower pressure plate 21 drives the rotating mold 3 to rotate. In this invention, the connection between the upper pressure plate 11 and the extrusion cylinder 2 is similar to a ring fitted onto a shaft. The upper pressure plate 11 is not fixedly connected to the pressure head 1; the pressure head 1 only serves to push the upper pressure plate 11 downwards. The pressure head 1 also acts as an extrusion head that needs to extrude the blank, so it needs to be able to rise to allow the next blank to be inserted, at which point it disengages from the upper pressure plate. The pressure head 1 should be fixedly connected to the press slide block.

[0025] In some specific embodiments, connecting rod assemblies are provided between the upper pressure plate 11 and the middle pressure plate 16, and between the middle pressure plate 16 and the lower pressure plate 21. The connecting rod assembly consists of a plurality of evenly arranged connecting rods, and the two ends of the connecting rods are respectively connected to the upper pressure plate 11 and the middle pressure plate 16, or the middle pressure plate 16 and the lower pressure plate 21 by ball joints.

[0026] In a more specific embodiment, in all connecting rods of the same group of connecting rod assemblies, the angle between each connecting rod and the tangent direction at its bottom hinge point is the same. That is, when the distance between two adjacent pressure plates is at its maximum, the connecting rod located between the two pressure plates is in a vertical or nearly vertical state. Then, during the downward pressing process, the distance between the two pressure plates tends to decrease, causing the connecting rod to deflect at the same angle, which in turn causes the lower pressure plate (e.g., middle pressure plate 16, lower pressure plate 21, etc.) to rotate.

[0027] In some specific embodiments, an upper limit mechanism 14 is further provided between the upper pressure plate 11 and the middle pressure plate 16. The upper limit mechanism 14 includes one or more upper limit rods fixed on the middle pressure plate 16 and an upper limit groove machined on the upper pressure plate 11 into which the upper limit rods can extend. When the upper pressure plate 11 is pressed down with the pressure head 1, the middle pressure plate 16 rotates accordingly, and the distance between the upper pressure plate 11 and the middle pressure plate 16 decreases, so that the upper limit rods extend into the upper limit groove and rotate with the middle pressure plate 16 until they abut against the inner wall of the upper limit groove. At this time, the upper pressure plate 11 and the middle pressure plate 16 are relatively stationary. A lower limit mechanism 19 is also provided between the intermediate pressure plate 16 and the lower pressure plate 21. The lower limit mechanism 19 includes one or more lower limit rods fixed on the lower pressure plate 21, and a lower limit groove processed on the intermediate pressure plate 16 into which the lower limit rods can extend. When the intermediate pressure plate 16 moves down, the lower pressure plate 21 rotates accordingly, and the distance between the intermediate pressure plate 16 and the lower pressure plate 21 decreases, so that the lower limit rods extend into the lower limit groove and rotate with the lower pressure plate 21 until they abut against the inner wall of the lower limit groove. At this time, the intermediate pressure plate 16 and the lower pressure plate 21 are relatively stationary.

[0028] In a more specific embodiment, the curvature of the upper limit groove and the lower limit groove are matched with the rotational stroke of the upper limit rod and the lower limit rod, respectively. The upper limit mechanism 14 and the lower limit mechanism 19 are designed to guide and limit the rotational movement between two adjacent pressure plates, and also to protect the connecting rod assembly located between the two pressure plates, preventing the distance between the two pressure plates from being too small or too large, thus exceeding the allowable deflection range of the ball joint at the connecting rod connection point.

[0029] In some specific embodiments, there is one or more intermediate pressure plates 16. When there are multiple intermediate pressure plates 16, the intermediate pressure plate 16 located above drives the intermediate pressure plate 16 located below it to rotate as it moves up and down. At this time, a connecting rod assembly as described above can also be provided between two adjacent intermediate pressure plates 16 to achieve relative rotation. In addition, a corresponding limiting mechanism can also be provided. The specific structure can be referred to as the upper limiting mechanism 14 or the lower limiting mechanism 19.

[0030] In some specific embodiments, the lower pressure plate 21 is connected to the rotating mold 3 via a rotating mechanism 22. The rotating mechanism 22 includes a plurality of planetary gear carriers 7 arranged around the central axis of the lower pressure plate 21, planetary gears 6 rotatably mounted on the planetary gear carriers 7, a sun gear 5 fixed to the lower part of the rotating mold 3, and an internal gear ring 8 mounted on the bottom of the extrusion cylinder 2 and surrounding the sun gear 5. The planetary gears 6 are located between the sun gear 5 and the internal gear ring 8, and mesh with the sun gear 5 and the internal gear ring 8 respectively.

[0031] More specifically, the bottom of the rotating mold 3 is connected to the sun gear 5 in the planetary gear system 10. The sun gear 5 is connected to the planetary gear 6 in the planetary gear system 10. The planetary gears 6 maintain their relative positions by means of the planetary gear carrier 7. The planetary gear carrier 7 is fixed together with the lower pressure plate 21, thereby realizing the connection between the rotating mold 3 and the lower pressure plate 21. The two are connected by means of the planetary gear system 10 and realize the relative rotational motion between them.

[0032] In some specific embodiments, the internal cavity of the rotating mold 3 has a variable cross-section structure.

[0033] In some specific embodiments, a fixed cylinder 4 is also sleeved outside the extrusion cylinder 2, and the side wall of the fixed cylinder 4 is also machined with clearance space to allow the upper pressure plate 11, the middle pressure plate 16 and the lower pressure plate 21 to move up and down.

[0034] Each of the above implementation methods can be implemented individually, or in any combination of two or more.

[0035] The above implementation methods will be described in more detail below with reference to specific embodiments.

[0036] Example 1: To simultaneously perform extrusion and torsional deformation on materials, achieving large plastic deformation and obtaining ultrafine grain structures, this embodiment provides a torsional extrusion device driven by a press slide block. Its structure can be found in [reference needed]. Figures 1 to 3 As shown, it includes a mold part 9, a fixed cylinder 4, a transmission mechanism, a rotating mechanism 22, etc., wherein the fixed cylinder 4 is fixed on the hydraulic press worktable, the mold part 9 is in contact with the hydraulic press slider, the rotating mechanism 22 is connected to the mold part 9, the transmission mechanism is connected to the mold part 9 and the rotating mechanism 22, and the transmission mechanism is in contact with the hydraulic press worktable surface.

[0037] The mold part 9 includes: a pressure head 1, an extrusion cylinder 2, and a rotary mold 3.

[0038] The rotating mechanism 22 includes a sun gear 5, a planetary gear 6, a planetary gear carrier 7, and an internal gear ring 8.

[0039] The transmission mechanism includes an upper pressure plate 11, an upper ball joint 12, an upper connecting rod 13, an upper limit mechanism 14, a first middle ball joint 15, a middle pressure plate 16, a second middle ball joint 17, a lower connecting rod 18, a lower limit mechanism 19, a lower ball joint 20, and a lower pressure plate 21. Specifically: the pressure head 1 contacts the upper pressure plate 11 and mates with the groove of the fixed cylinder 4; the sun gear 5 is connected to the rotating mold 3; the internal gear ring 8 is connected to the extrusion cylinder 2; the planetary gear carrier 7 is connected to the lower pressure plate 21; and the upper pressure plate 11, the middle pressure plate 16, and the lower pressure plate 21 all mate with the extrusion cylinder 2.

[0040] The mold part 9 includes: a pressure head 1, an extrusion cylinder 2, and a rotating mold 3. The pressure head 1 can be inserted into the extrusion cylinder 2, and its bottom end is machined with a shape that matches the internal cavity of the rotating mold 3 to extrude the material placed inside the mold. Meanwhile, the fixed cylinder 4 mainly serves as a guide rail. The pressure head 1 and the upper pressure plate 11 move vertically, requiring a motion guide rail to limit their movement and prevent deviation. The pressure head 1 and the upper pressure plate 11 are confined within the slot of the fixed cylinder 4 and move vertically along the slot. The upper opening of the rotating mold 3 connects to the extrusion cavity of the extrusion cylinder 2, and the outer wall of the rotating mold 3 is in contact with the lower inner wall of the extrusion cylinder 2. As shown in the figure, the inner cavity of the rotating mold 3 has a variable cross-section structure, allowing the material to undergo both extrusion and torsion. For the specific cross-sectional shape, refer to the multi-stage cavity rotating mold disclosed in CN 2023107725839.

[0041] The rotating mechanism 22 includes a planetary gear system 10, which consists of a sun gear 5, a planetary gear 6, a planetary gear carrier 7, and an internal gear ring 8. The sun gear 5 is connected to the rotating mold 3, the planetary gear 6 is engaged with the planetary gear carrier 7, the internal gear ring 8 is connected to the extrusion cylinder 2, the planetary gear carrier 7 is connected to the lower pressure plate 21, and the planetary gear 6 is engaged between the sun gear 5 and the internal gear ring 8, and simultaneously meshes with both the sun gear 5 and the internal gear ring 8.

[0042] The transmission mechanism includes an upper pressure plate 11, an upper ball joint 12, an upper connecting rod 13, an upper limit mechanism 14, a first middle ball joint 15, a middle pressure plate 16, a second middle ball joint 17, a lower connecting rod 18, a lower limit mechanism 19, a lower ball joint 20, and a lower pressure plate 21. The upper end of the upper connecting rod 13 is connected to the upper pressure plate 11 via the upper ball joint 12, and the lower end is connected to the upper surface of the middle pressure plate 16 via the first middle ball joint 15. The upper end of the lower connecting rod 18 is connected to the lower surface of the middle pressure plate 16 via the second middle ball joint 17, and the lower end is connected to the lower pressure plate 21 via the lower ball joint 20. The upper limit mechanism 14 includes an upper limit rod fixed to the intermediate pressure plate 16 and an arc-shaped upper limit groove machined on the upper pressure plate 11. During the rotation of the intermediate pressure plate 16 as the upper pressure plate 11 presses down, the upper limit rod extends into the upper limit groove. When the intermediate pressure plate 16 rotates to a certain extent, the upper limit rod abuts against the end of the upper limit groove, making the intermediate pressure plate 16 and the upper pressure plate 11 relatively stationary. The lower limit mechanism 19 includes a lower limit rod fixed to the lower pressure plate 21 and an arc-shaped lower limit groove machined on the intermediate pressure plate 16. Similarly, when the lower pressure plate 21 rotates to a certain extent, the lower limit rod extends into the lower limit groove and abuts against its end, making the intermediate pressure plate 16 and the lower pressure plate 21 relatively stationary.

[0043] The upper pressure plate 11 is in contact with the pressure head 1 and mates with the groove of the fixed cylinder 4. The lower pressure plate 21 is connected to the planetary gear carrier 7 and mates with the turntable on the hydraulic press worktable. The upper pressure plate 11, the middle pressure plate 16 and the lower pressure plate 21 are all mates with the extrusion cylinder 2.

[0044] In this embodiment, when the device is in operation, the hydraulic press slider contacts the press head 1, causing the press head 1 to move downwards. Simultaneously, the press head 11 moves downwards, causing the upper pressure plate 11 to deflect, which in turn causes the upper connecting rod 13 to rotate. This rotation continues until the middle pressure plate 16 reaches its limit position. At this point, the upper pressure plate 11 and the lower pressure plate 21 remain relatively stationary via the upper limit mechanism 14. During this process, the lower pressure plate 21 also rotates simultaneously. Similarly, the lower limit mechanism 19 can adjust the rotation limit position of the lower pressure plate 21. When the lower pressure plate 21 rotates, it drives the planetary gear carrier 7 to rotate. The planetary gears 6 mesh with the sun gear 5 and the internal gear ring 8, respectively. The internal gear ring 8 remains stationary due to its connection with the extrusion cylinder 2. This creates a state where the planetary gear carrier 7 is the driving member and the sun gear 5 is the driven member, thus giving the sun gear 5 an acceleration effect, thereby increasing the speed and angle of rotation of the rotary mold 3. Since the rotating mold 3 has an irregular cross-section, it will subject the rod-shaped billet to torsion, resulting in circumferential shear deformation. This allows the billet to be subjected to the combined effects of torsion and extrusion, thereby achieving the effect of refining the grains.

[0045] During the above-mentioned operation, the rotation speed and rotation angle of the lower pressure plate 21 can be changed by adjusting the number of intermediate pressure plates 16, or by changing the gear transmission ratio in the rotating mechanism 22, so that the rotating mold 3 can obtain different rotation speeds and rotation angles to obtain extrusion torsion parameters that meet the process requirements.

[0046] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A torsional extrusion device driven to rotate by a press slide, characterized in that, include: A rotary extrusion die includes an extrusion cylinder having an extrusion cavity, a pressure head that can extend into the extrusion cavity and move up and down along its inner wall, and a rotary die with an upper opening that receives the extrusion cavity. The upper pressure plate is sleeved on the outside of the extrusion cylinder and is pushed down by the pressure head; The intermediate pressure plate is located below the upper pressure plate and is driven to rotate by it; The lower pressure plate is located below the intermediate pressure plate and is driven to rotate by it; The lower pressure plate is also connected to the rotary mold via a transmission, and the rotation of the lower pressure plate drives the rotary mold to rotate. A connecting rod assembly is provided between the upper pressure plate and the middle pressure plate, and between the middle pressure plate and the lower pressure plate. The connecting rod assembly consists of several evenly arranged connecting rods. The two ends of the connecting rods are respectively connected to the upper pressure plate and the middle pressure plate, or the middle pressure plate and the lower pressure plate through ball joints. In the same set of connecting rods, the angle between each connecting rod and the tangent direction of its bottom hinge point is the same.

2. The torsional extrusion device driven to rotate by a press slide according to claim 1, characterized in that, An upper limit mechanism is also provided between the upper pressure plate and the middle pressure plate. The upper limit mechanism includes one or more upper limit rods fixed on the middle pressure plate and an upper limit groove machined on the upper pressure plate into which the upper limit rods can extend. When the upper pressure plate is pressed down with the pressure head, the middle pressure plate rotates accordingly, and the distance between the upper pressure plate and the middle pressure plate decreases, so that the upper limit rods extend into the upper limit groove and rotate with the middle pressure plate until they abut against the inner wall of the upper limit groove. At this time, the upper pressure plate and the middle pressure plate are relatively stationary. A lower limit mechanism is also provided between the intermediate pressure plate and the lower pressure plate. The lower limit mechanism includes one or more lower limit rods fixed on the lower pressure plate and a lower limit groove machined on the intermediate pressure plate into which the lower limit rods can extend. When the intermediate pressure plate moves down, the lower pressure plate rotates accordingly, and the distance between the intermediate pressure plate and the lower pressure plate decreases, so that the lower limit rods extend into the lower limit groove and rotate with the lower pressure plate until they abut against the inner wall of the lower limit groove. At this time, the intermediate pressure plate and the lower pressure plate are relatively stationary.

3. The torsional extrusion device driven to rotate by a press slide according to claim 2, characterized in that, The curvature of the upper limit groove and the lower limit groove are respectively matched with the rotational stroke of the upper limit rod and the lower limit rod.

4. The torsional extrusion device driven to rotate by a press slide according to claim 1, characterized in that, There is one or more intermediate pressure plates. When there are several intermediate pressure plates, the intermediate pressure plate located above drives the intermediate pressure plate located below it to rotate as it moves up and down.

5. A torsional extrusion device driven to rotate by a press slide according to claim 1, characterized in that, The lower pressure plate is connected to the rotating mold via a rotating mechanism. The rotating mechanism includes a planetary gear carrier arranged around the central axis of the lower pressure plate, planetary gears rotatably mounted on the planetary gear carrier, a sun gear fixed to the lower part of the rotating mold, and an internal gear ring mounted at the bottom of the extrusion cylinder and surrounding the sun gear. The planetary gears are located between the sun gear and the internal gear ring and mesh with the sun gear and the internal gear ring respectively.

6. A torsional extrusion device driven to rotate by a press slide according to claim 5, characterized in that, The planetary gear carrier is fixed to the lower pressure plate.

7. A torsional extrusion device driven to rotate by a press slide according to claim 1, characterized in that, The internal cavity of the rotating mold has a variable cross-section structure.

8. A torsional extrusion device driven to rotate by a press slide according to claim 1, characterized in that, A fixed cylinder is also fitted outside the extrusion cylinder, and the side wall of the fixed cylinder is also machined with clearance space to allow the upper pressure plate, middle pressure plate and lower pressure plate to move up and down.

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