A torsion extrusion device and method for enhancing the torsional shear effect

Abstract

The application relates to a torsion extrusion device and method for enhancing torsion shear effect, which comprises an extrusion cylinder for arranging a blank to be extruded; a movable extrusion punch mounted in the extrusion cylinder and used for extruding the blank; and a multi-stage cavity rotary die connected with the extrusion cylinder and comprising a circular cross-section conical cavity, a first transition cavity, a wavy cross-section straight cavity, a second transition cavity and a circular cross-section straight cavity which are connected in sequence and integrally formed. Compared with the prior art, the application can solve the problem of slip in the torsion extrusion process and make the torsion deformation zone and the extrusion deformation zone of the material coincide, so as to enhance the torsion shear effect and realize good grain refinement effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of twist extrusion, and relates to a twist extrusion device and method for enhancing twist shear effect. BACKGROUND

[0002] As a large plastic deformation technology, twist extrusion has the characteristics of high hydrostatic pressure and strong shear, and can be used to prepare large-scale products with simple process. It is recognized by the material field as one of the most promising methods for preparing bulk ultra-fine grain materials. In the twist extrusion process, twist shear deformation is mainly realized through the friction between the rotating die and the material. When the rotating die rotates at a high speed, the material and the rotating die will slip, which seriously weakens the shear effect and makes it difficult to reflect the twist effect.

[0003] Through literature retrieval of the prior art, it is found that the Chinese invention patent CN111889528B discloses a variable cross-section cavity secondary twist extrusion device and method for refining grain, which uses a variable cross-section cavity rotating die composed of a circular cross-section to elliptical cross-section transition deformation cavity, an elliptical cross-section straight cavity and an elliptical cross-section to circular cross-section transition deformation cavity to solve the problem of material slipping in the twist extrusion process to some extent. However, the irregular cross-section deformation cavity limits the relative twist of the material in the deformation cavity, and the twist deformation mainly occurs before the material enters the deformation cavity, which is essentially twist first and extrusion later. This results in the twist deformation zone and the extrusion deformation zone of the material not being effectively overlapped, which weakens the twist shear effect and thus weakens the function of improving the performance of the material. SUMMARY

[0004] The purpose of the present application is to provide a twist extrusion device and method for enhancing twist shear effect, which can solve the problem of slipping in the twist extrusion process and make the twist deformation zone and the extrusion deformation zone of the material overlap, thereby enhancing the twist shear effect and achieving good grain refinement effect.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present application provides a twist extrusion device for enhancing twist shear effect, comprising:

[0007] an extrusion cylinder for placing a billet to be extruded;

[0008] a movable extrusion punch installed in the extrusion cylinder and used for extruding the billet;

[0009] a multi-stage cavity rotating die connected with the extrusion cylinder, which comprises a circular cross-section conical cavity, a first transition cavity, a wave cross-section straight cavity, a second transition cavity and a circular cross-section straight cavity connected in sequence and integrally formed.

[0010] The core of the present application is the multi-stage cavity design of the rotary die, especially the wave cross-section straight cavity and the circular cross-section straight cavity, one of which can overcome the slip, and one of which can coincide with the torsion and extrusion deformation area. The taper and extrusion ratio can not be limited.

[0011] Further, the diameter of the circular cross-section straight cavity is smaller than that of the wave cross-section straight cavity, and the diameter of the wave cross-section straight cavity is not greater than that of the smallest end of the circular cross-section tapered cavity. In addition, the relationship between the wave cross-section straight cavity and the circular cross-section straight cavity is that the irregular cross-section billet of the circular cross-section straight cavity is reshaped into a rod-shaped billet.

[0012] Further, the height of the circular cross-section tapered cavity along the moving direction of the billet is greater than the height of the wave cross-section straight cavity along the moving direction of the billet, and the height of the wave cross-section straight cavity along the moving direction of the billet is not less than the height of the circular cross-section straight cavity along the moving direction of the billet. If the length of the wave cross-section straight cavity is too short, slip will occur, and if the length is too long, additional friction will be increased. Therefore, the length of the wave cross-section straight cavity is defined.

[0013] Further, the wave cross-section straight cavity comprises a circular straight cavity body and a plurality of wave-shaped protruding straight cavity bodies arranged around the outer edge of the circular straight cavity body and connected in sequence to form a cycle. It should be noted that the wave-shaped protruding straight cavity bodies are adjacent to each other. The wave amplitude (i.e. the protruding degree of the wave-shaped protrusion) is controlled to be 2% to 5% of the diameter of the finished rod product (the diameter of the extruded product is equivalent to the diameter of the circular cross-section straight cavity), and the maximum is not more than 5%; the number of waves is controlled to be 20% to 50% of the circumference of the finished rod product, and the maximum is not more than 50%. The limitation of the amplitude and the number of teeth in the present application is for the protection of the multi-stage cavity die. In addition, if the wave amplitude is too small and the number is too small, the effect of overcoming slip is not obvious.

[0014] Further, the extrusion punch is also connected to the moving end of the external extrusion device and is driven to move along the central axis of the extrusion cylinder by the moving end.

[0015] Further, the moving end of the extrusion device is the sliding block of the hydraulic machine.

[0016] Further, the multi-stage cavity rotary die is also connected to a rotary driving mechanism for driving it to rotate.

[0017] Further, the rotary driving mechanism comprises a power unit, a transmission unit and a bevel gear set, the power unit is connected to the transmission unit, and the bevel gear set comprises two bevel gears which are meshed with each other and are respectively installed on the multi-stage cavity rotary die and the transmission unit.

[0018] More preferably, the transmission unit is a transmission shaft.

[0019] The technical scheme of the application provides a torsion extrusion method for enhancing torsion shear effect, which is realized based on the torsion extrusion device.

[0020] The blank is placed in the extrusion cylinder, and under the pressure of the extrusion punch, the blank flows into the multi-stage cavity rotating die to bear extrusion deformation, at the same time, the multi-stage cavity rotating die rotates to drive the blank to bear torsion shear deformation in the circumferential flow in the extrusion process, and the torsion extrusion process is completed by extruding from the circular cross-section straight cavity to obtain a rod product.

[0021] Compared with the prior art, the application has the following advantages:

[0022] (1) By adopting the multi-stage cavity rotating die of the circular cross-section conical cavity, the circular cross-section to wave cross-section transition cavity, the wave cross-section straight cavity, the wave cross-section to circular cross-section transition cavity and the circular cross-section straight cavity, especially the wave cross-section straight cavity can drive the material to rotate at the same speed, which overcomes the slippage phenomenon of the material in the torsion extrusion process, and further can increase the rotating speed of the rotating die and improve the forming efficiency.

[0023] (2) The multi-stage cavity rotating die circular cross-section conical cavity can make the material produce a large circumferential velocity gradient in the extrusion direction while deforming, and further make the torsion deformation zone and the extrusion deformation zone in the torsion extrusion process of the material coincide, so as to enhance the torsion shear effect, realize large plastic deformation and achieve good grain refinement effect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 It is a structural schematic diagram of the application;

[0025] Fig. 2 It is a structural schematic diagram of the multi-stage cavity rotating die;

[0026] Fig. 3 It is a sectional view of the wave cross-section straight cavity;

[0027] MARK DESCRIPTION IN THE DRAWINGS:

[0028] 1-extrusion punch, 2-extrusion cylinder, 3-blank, 4-multi-stage cavity rotating die, 41-circular cross-section conical cavity, 42-first transition cavity, 43-wave cross-section straight cavity, 44-second transition cavity, 45-circular cross-section straight cavity, 5-conical gear set, 6-transmission unit, 7-power unit. DETAILED DESCRIPTION

[0029] The application will be described in detail below with reference to the drawings and specific embodiments. The embodiments are implemented on the premise of the technical solutions of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0030] In the following embodiments or examples, if no specific description is given for the function, structure or component, it means that the corresponding function is achieved by using the conventional component or structure in the art.

[0031] In order to better realize the simultaneous process of material torsion and extrusion, and effectively overlap the torsion deformation zone and the extrusion deformation zone of the material, the application provides a torsion extrusion device for enhancing torsion shear effect, the structure of which can be seen from Figs. 1 to 3 and includes:

[0032] an extrusion cylinder 2 for arranging a blank 3 to be extruded;

[0033] a movable extrusion punch 1 installed in the extrusion cylinder 2 and used for extruding the blank 3;

[0034] a multi-stage cavity rotating die 4 connected with the extrusion cylinder 2, which includes a circular cross-section conical cavity 41, a first transition cavity 42, a wave cross-section straight cavity 43, a second transition cavity 44 and a circular cross-section straight cavity 45 connected in sequence and integrally formed.

[0035] In some specific embodiments, the diameter of the circular cross-section straight cavity 45 is smaller than the diameter of the wave cross-section straight cavity 43, and the diameter of the wave cross-section straight cavity 43 is not greater than the diameter of the smallest end of the circular cross-section conical cavity 41.

[0036] In some specific embodiments, the height of the circular cross-section conical cavity 41 along the moving direction of the blank 3 is greater than the height of the wave cross-section straight cavity 43 along the moving direction of the blank 3, and the height of the wave cross-section straight cavity 43 along the moving direction of the blank 3 is not less than the height of the circular cross-section straight cavity 45 along the moving direction of the blank 3.

[0037] In some specific embodiments, the wave cross-section straight cavity 43 includes a circular straight cavity body and a plurality of wave-shaped convex straight cavity bodies arranged around the outer edge of the circular straight cavity body and connected in sequence to form a cycle. The wave amplitude is controlled to be 2% to 5% of the diameter of the finished bar product, and the maximum is not more than 5%; the number of waves is controlled to be 20% to 50% of the circumference of the finished bar product, and the maximum is not more than 50%. In some specific embodiments, the extrusion punch 1 is also connected to the moving end of the external extrusion equipment and is driven to move along the central axis direction of the extrusion cylinder 2 by the external extrusion equipment.

[0038] In a more specific embodiment, the moving end of the extrusion equipment is a slider of a hydraulic machine.

[0039] In some specific embodiments, the multi-stage cavity rotary die 4 is further connected with a rotary driving mechanism for driving the rotation thereof.

[0040] In more specific embodiments, the rotary driving mechanism comprises a power unit 7, a transmission unit 6 and a bevel gear set 5, the power unit 7 is connected with the transmission unit 6, and the bevel gear set 5 comprises two bevel gears which are meshed with each other and are respectively installed on the multi-stage cavity rotary die 4 and the transmission unit 6.

[0041] More preferably, the transmission unit 6 is a transmission shaft, and the power unit 7 is a power device which can drive the transmission shaft to rotate, and is conventional in the art, and comprises a coupling, a speed reducer, a frequency converter, a speed-reducing motor and a control cabinet.

[0042] In addition, in some embodiments, the application further provides a torsion extrusion method for enhancing torsion shear effect, which is realized based on the torsion extrusion device as described in any of the above embodiments, and the torsion extrusion method is specifically as follows:

[0043] The blank 3 is placed in the extrusion cylinder 2, and under the pressure of the extrusion punch 1, the blank 3 flows into the multi-stage cavity rotary die 4 to bear extrusion deformation, at the same time, the multi-stage cavity rotary die 4 rotates to drive the blank 3 to simultaneously bear torsion shear deformation in the circumferential flow during the extrusion process, and the blank 3 is extruded out of the straight cavity 45 with a circular cross section to complete the torsion extrusion process, and a rod product is obtained.

[0044] The above embodiments can be implemented individually, or can be implemented in any two or more combinations.

[0045] The above embodiments will be described in more detail below in combination with specific examples.

[0046] Example 1:

[0047] In order to better realize the simultaneous performance of the material torsion and extrusion process, and effectively overlap the torsion deformation zone and the extrusion deformation zone of the material, etc., the present embodiment provides a torsion extrusion device for enhancing torsion shear effect, the structure of which can be seen from Figs. 1 to 3 as shown, which comprises:

[0048] an extrusion cylinder 2 for placing the blank 3 to be extruded;

[0049] a movable extrusion punch 1 installed in the extrusion cylinder 2 and used for extruding the blank 3;

[0050] The multi-stage cavity rotating die 4 connected with the extrusion cylinder 2 is of multi-stage cavity structure, and is composed of five parts from top to bottom, i.e. a circular cross-section conical cavity 41, a first transition cavity 42, a wave cross-section straight cavity 43, a second transition cavity 44 and a circular cross-section straight cavity 45 which are connected in sequence and integrally formed.

[0051] Please refer to Fig. 1 As shown in the drawings, the diameter of the circular cross-section straight cavity 45 is smaller than the diameter of the wave cross-section straight cavity 43, and the diameter of the wave cross-section straight cavity 43 is not greater than the diameter of the smallest end of the circular cross-section conical cavity 41.

[0052] Please refer to Fig. 1 As shown in the drawings, the height of the circular cross-section conical cavity 41 along the moving direction of the blank 3 is greater than the height of the wave cross-section straight cavity 43 along the moving direction of the blank 3, and the height of the wave cross-section straight cavity 43 along the moving direction of the blank 3 is not less than the height of the circular cross-section straight cavity 45 along the moving direction of the blank 3.

[0053] Please refer to Fig. 1 As shown in the drawings, the wave cross-section straight cavity 43 comprises a circular straight cavity body and a plurality of wave-shaped convex straight cavity bodies arranged around the outer edge of the circular straight cavity body and connected in sequence to form a cycle. The wave amplitude is controlled to be 2% to 5% of the diameter of the finished bar product, and the maximum is not more than 5%; the number of waves is controlled to be 20% to 50% of the circumference of the finished bar product, and the maximum is not more than 50%.

[0054] Specifically, the extrusion punch 1 is also connected with the moving end of an external extrusion device, and is driven to move along the central axis direction of the extrusion cylinder 2 by the moving end of the extrusion device. The moving end of the extrusion device is a sliding block of a hydraulic machine.

[0055] Please refer to Fig. 1 As shown in the drawings, the multi-stage cavity rotating die 4 is also connected with a rotating driving mechanism for driving it to rotate. The rotating driving mechanism comprises a power unit 7, a transmission unit 6 and a bevel gear set 5. The power unit 7 is connected with the transmission unit 6. The bevel gear set 5 comprises two bevel gears which are meshed with each other and are respectively installed on the multi-stage cavity rotating die 4 and the transmission unit 6. The transmission unit 6 is a transmission shaft. The power unit 7 is a power device which can drive the transmission shaft to rotate in the art, and comprises a shaft coupling, a speed reducer, a frequency converter, a speed reduction motor and a control cabinet.

[0056] In addition, the embodiment also relates to a torsion extrusion method for enhancing torsion shear effect based on the above-mentioned extrusion device, and specifically comprises the following steps:

[0057] The blank 3 is placed in the extrusion cylinder 2, under the pressure of the extrusion punch 1, the blank 3 flows into the multi-stage cavity rotary die 4 to bear extrusion deformation, at the same time, the multi-stage cavity rotary die 4 rotates under the action of the bevel gear set 5, the transmission unit 6 and the power mechanism 7, drives the blank 3 to bear torsional shear deformation in the extrusion process, and extrudes from the straight cavity 45 with a circular cross section to complete the torsional extrusion process, and obtains the rod product.

[0058] The above description of the embodiments is to facilitate the ordinary skilled person in the art to understand and use the application. Those skilled in the art can obviously make various modifications to these embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art according to the disclosure of the present application without departing from the scope of the present application should be within the scope of protection of the present application.

Claims

1. A torsion extrusion device for enhancing the effect of torsional shear, characterized in that, The utility model relates to a kind of torsion extrusion method, including: extrusion cylinder for placing blank to be extruded; Movable extrusion punch mounted in the extrusion cylinder and used for extruding the blank; Multi-stage cavity rotating die connected with the extrusion cylinder, comprising circular cross-section conical cavity, first transition cavity, wave cross-section straight cavity, second transition cavity and circular cross-section straight cavity connected in sequence and integrally formed; The diameter of the circular cross-section straight cavity is smaller than the diameter of the wave cross-section straight cavity, and the diameter of the wave cross-section straight cavity is not greater than the diameter of the smallest end of the circular cross-section conical cavity; The height of the circular cross-section conical cavity along the direction of blank movement is greater than the height of the wave cross-section straight cavity along the direction of blank movement, and the height of the wave cross-section straight cavity along the direction of blank movement is not less than the height of the circular cross-section straight cavity along the direction of blank movement; The wave cross-section straight cavity comprises a circular straight cavity body and a plurality of wave-shaped convex straight cavity bodies arranged around the outer edge of the circular straight cavity body and connected in sequence to form a cycle.

2. A torsion extrusion apparatus for enhancing the effect of torsional shear according to claim 1, wherein The extrusion punch is also connected to the moving end of the external extrusion device and is driven to move along the central axis of the extrusion cylinder by the moving end.

3. A torsion extrusion apparatus for enhancing the effect of torsional shear according to claim 2, wherein The moving end of the extrusion device is a hydraulic machine slider.

4. A torsion extrusion apparatus for enhancing the effect of torsional shear according to claim 1, wherein The multi-stage cavity rotating die is also connected to a rotating drive mechanism for driving it to rotate.

5. A torsion extrusion apparatus for enhancing the effect of torsional shear according to claim 4, wherein The rotating drive mechanism comprises a power unit, a transmission unit and a bevel gear set, the power unit is connected to the transmission unit, and the bevel gear set comprises two bevel gears that mesh with each other and are respectively mounted on the multi-stage cavity rotating die and the transmission unit.

6. A torsion extrusion apparatus for enhancing the effect of torsional shear according to claim 5, wherein The transmission unit is a transmission shaft.

7. A method of torsion extrusion with enhanced torsional shear effect, realized on the basis of a torsion extrusion device according to any one of claims 1-6, characterized in that, The torsion extrusion method specifically comprises: Placing the blank in the extrusion cylinder, under the pressure of the extrusion punch, the blank flows into the multi-stage cavity rotating die to bear extrusion deformation, at the same time, the multi-stage cavity rotating die rotates to drive the blank to simultaneously undergo circumferential flow and torsional shear deformation in the extrusion process, and the blank is extruded from the circular cross-section straight cavity to complete the torsion extrusion process, and a rod product is obtained.

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