Multi-energy field assisted deep drawing device and method of difficult-to-deform alloy equivalent to drawbead

Abstract

The application discloses a kind of difficult deformation alloy multi-energy field assisted deep drawing device and method of equivalent draw bead, belong to plate deep drawing process field, including drawing punch, sliding cover and draw bead ring of drawing punch peripheral side and drawing die, drawing punch can be inserted into drawing die, draw bead ring and the temperature system of the coincident part of draw bead ring is symmetrically arranged, the temperature system includes annular heating zone one with drawing punch as center, cooling zone and heating zone two, the cooling zone is located between heating zone one and heating zone two, when blank is drawn, cooling zone temperature is lower than heating zone one and heating zone two.The yield strength of material at different temperatures is different, the radial tensile stress of material in this section is increased by controlling local cooling temperature, so as to avoid hoop wrinkling, improve forming quality, different temperatures can be applied to different materials to change the radial tensile stress, with higher adaptability.

Description

Technical Field

[0001] This invention relates to sheet metal deep drawing processes, specifically to a multi-energy field assisted deep drawing device and method for difficult-to-deform alloys with equivalent draw beads. Background Technology

[0002] Sheet metal deep drawing is a cold forming process that uses a die to press a flat blank or semi-finished blank into an open hollow part. Its core principle is that the pressure of the punch causes plastic deformation in the annular portion of the sheet metal placed between the die and the blank holder. Under the combined action of radial tensile stress and tangential compressive stress, the material is continuously drawn into the die cavity, ultimately forming complex hollow parts such as cylinders, boxes, and spheres. Radial tensile stress is the main driving force propelling the material from the flange area into the die. At room temperature, alloys have low plasticity and excessive resistance to deformation, requiring large radial forces, making them prone to thinning and cracking, resulting in poor forming quality and difficulty in manufacturing parts with large deformations or complex shapes.

[0003] During the sheet metal drawing process, the metal material experiences complex stresses as it flows through areas with significant shape changes and corners within the die. This leads to bidirectional or even multidirectional flow, resulting in uneven forming and a high likelihood of wrinkles and folds. Particularly for drawn parts with large flange areas, using a blank holder to address wrinkling requires significant blank holder force, which greatly increases material friction in the blank holder area, hinders material flow throughout the flange area, and generates substantial radial tensile stress, easily causing cracking defects. Currently, to address wrinkles during the drawing process, draw beads are used. Draw beads typically consist of raised and recessed ribs. Raised ribs are generally placed on the blank holder, while recessed ribs are grooves cut into the die surface, or can be placed in the opposite direction. During deep drawing, the sheet metal undergoes bending and reverse bending deformation through the draw beads, generating flow resistance, increasing radial tensile stress, and preventing circumferential wrinkling on the flange exterior. When the radial tensile stress added by the traditional drawbead design is fixed, the different requirements of different areas of complex parts require the setting of multiple different drawbeads, which lacks flexibility and adaptability. Moreover, if the drawbead parameters are not set properly, it will affect the drawing quality. If the radial tensile stress is too small, wrinkling is easy to occur; conversely, if it is too large, tearing is easy to occur. Traditional drawbeads are difficult to modify and cannot adjust the magnitude of radial tensile stress in a timely manner. Summary of the Invention

[0004] Purpose of the invention: To address the above-mentioned shortcomings, the present invention provides a multi-energy field assisted deep drawing device and method for difficult-to-deform alloys with equivalent draw beads that improves adaptability.

[0005] Technical Solution: To solve the above problems, the present invention provides a multi-energy field assisted deep drawing device for difficult-to-deform alloys with equivalent draw beads, comprising a deep drawing punch, a blank holder slidably sleeved on the periphery of the deep drawing punch, and a deep drawing die. The deep drawing punch can be inserted into the deep drawing die. A temperature system is symmetrically arranged on the blank holder and the overlapping part of the deep drawing die and the blank holder. The temperature system includes a ring-shaped heating zone 1, a cooling zone, and a heating zone 2 centered on the deep drawing punch. The cooling zone is located between the heating zone 1 and the heating zone 2. When the billet is deep drawn, the temperature of the cooling zone is lower than that of the heating zone 1 and the heating zone 2. The cooling zone serves as an equivalent draw bead.

[0006] Furthermore, the temperature system also includes a heating system and a cooling system. The heating zone 1 and heating zone 2 are provided with several circumferential heating pipes, and the cooling zone is provided with circumferential cooling pipes. The cooling pipes are connected to the cooling system, and the heating pipes are connected to the heating system.

[0007] Furthermore, an adaptive valve system is included. The heating zone one is closest to the drawing punch, followed by the cooling zone, and the heating zone two is furthest from the drawing punch. The adaptive valve system is located between the cooling pipe and the heating pipe in the heating zone two, as well as between the cooling pipe and the refrigeration system. The adaptive valve system includes an annular groove between the cooling zone and the heating zone two, and a piston that moves along the annular groove. One end of the piston is connected to the annular groove via an elastic component, and the other end extends out of the annular groove. Both the cooling pipe and the heating pipe have channels communicating with the annular groove. When the billet is located between the adaptive valve system of the blank holder and the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The piston blocks the channels communicating between the cooling pipe and the heating pipe and the annular groove, at which point the cooling pipe is connected to the refrigeration system. When the billet moves away from the adaptive valve system of the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston, and the cooling pipe and the heating pipe are connected through the annular groove. At this point, the piston blocks the cooling pipe from the refrigeration system.

[0008] Furthermore, the heating system introduces a high-temperature gas flow or a high-temperature liquid into the heating pipe, and the refrigeration system introduces a low-temperature gas flow or a low-temperature liquid into the cooling pipe.

[0009] Furthermore, the temperature system also includes a heating system and a cooling system. The heating zone one and heating zone two are provided with independent circumferential resistance heating circuits, and the cooling zone is provided with circumferential cooling pipes. The heating system is used to supply power to the resistance heating circuits of heating zone one and heating zone two, and the cooling pipes are connected to the cooling system.

[0010] Furthermore, an adaptive valve system is included. A resistance heating circuit is installed within the cooling pipes of the cooling zone. The adaptive valve system is positioned between the heating system and the resistance heating circuit of the cooling zone, as well as between the cooling pipes and the refrigeration system. The adaptive valve system includes an annular groove and a piston that moves along the annular groove. A conductive block is installed on the piston. The piston's outer periphery, except for the conductive block, is insulated. One end of the piston is connected to the annular groove via an elastic component, and the other end extends out of the annular groove. The conductive block is electrically connected to the heating system. A metal patch is installed in the resistance heating circuit of the cooling zone, and the metal patch slides in contact with the piston and the conductive block. When the billet is located between the adaptive valve system of the blank holder and the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The metal patch contacts the outer periphery of the piston, and at this time, the cooling pipes are connected to the refrigeration system. When the billet moves away from the adaptive valve system of the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston. The metal patch contacts the outer periphery of the conductive block, and at this time, the piston blocks the cooling pipes from the refrigeration system.

[0011] The deep drawing method of the multi-energy field assisted deep drawing device for difficult-to-deform alloys using the above-mentioned equivalent draw beads, as described in this invention, includes the following steps:

[0012] Step 1: Determine the blank parameters and the parameters of the formed workpiece;

[0013] Step 2: Based on the blank parameters and the formed workpiece parameters, perform finite element simulation on the blank, and determine the cooling zone radius and cooling zone width based on stress analysis;

[0014] Step 3: Based on the blank parameters, forming workpiece parameters, and cooling zone radius and width, obtain the drawing punch, blank holder, and drawing die;

[0015] Step 4: The blank is drawn into shape using a drawing punch, a blank holder, and a drawing die.

[0016] Furthermore, when the formed workpiece is a shallow-drawn part, the radius of the cooling zone is:

[0017] ;

[0018] in, Where is the radius of the cooling zone. The reference radius for the drawbeam is... The initial radius of the blank;

[0019] The radial width of the cooling zone is , The thickness of the blank.

[0020] Furthermore, the reference radius of the drawbead The confirmation method is as follows:

[0021] Finite element analysis is performed on the billet to obtain its basic elements. Based on the principal stress method for plastic deformation of metals, the radial equilibrium equations of the basic elements are obtained. Combined with the Tresca yield criterion, the radial tensile stress and tangential compressive stress of the basic elements are obtained. The radius of the basic element containing the element with equal absolute values ​​of radial tensile stress and tangential compressive stress is determined as the reference radius for the drawbead. In the region larger than the radius of the intersection point, compressive strain occurs, which is prone to circumferential wrinkling. Therefore, in the region larger than the reference radius... A low-temperature cooling zone is set up to increase radial tensile stress. According to the plastic yield criterion, when the same yield stress is achieved, the tangential compressive stress is reduced, thereby avoiding circumferential wrinkling.

[0022] Furthermore, the billet is a material that is difficult to deform at room temperature, including titanium alloys, aluminum alloys, and high-strength steel.

[0023] Beneficial effects: Compared with the prior art, the significant advantages of this invention are: by using multi-energy field assisted alloy deep drawing, the thermal softening effect significantly reduces the flow stress of the alloy during the deformation process, making the material flow more easily and greatly reducing the required forming force.

[0024] The yield strength of a material varies at different temperatures. By controlling the local cooling temperature, the radial tensile stress of the material in that section can be increased, thereby avoiding circumferential wrinkling and improving forming quality. Different temperatures can be applied to different materials to change the radial tensile stress, resulting in greater adaptability.

[0025] When the billet diameter is reduced to a level where wrinkling will not occur, the cooling system is shut off, the heating system heats the cooling zone, and a high-temperature airflow is introduced. The flow stress is reduced, the radial tensile stress during billet deep drawing is reduced, and the forming limit of the material is further improved. This solves the technical problem of adaptively eliminating draw beads when the flange of the deep-drawn billet is large and wrinkling is easy to occur, and when the flange size of the deep-drawn billet is reduced and wrinkling is not easy to occur. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the deep drawing device of the present invention.

[0027] Figure 2 This is a schematic cross-sectional view of the press structure in this invention.

[0028] Figure 3 This is a schematic diagram showing the billet flowing through different regions in this invention.

[0029] Figure 4 This is a schematic diagram of different temperature zones in the deep drawing device of the present invention.

[0030] Figure 5This is a schematic diagram of the adaptive valve system closing when a heating pipe is installed in this invention.

[0031] Figure 6 This is a schematic diagram of the adaptive valve system opening when a heating pipe is installed in this invention.

[0032] Figure 7 This is a schematic diagram of the adaptive valve system closing when a heating resistance wire is installed in this invention.

[0033] Figure 8 This is a schematic diagram of the adaptive valve system opening when a heating resistance wire is installed in this invention.

[0034] Figure 9 This is a stress state analysis diagram of the blank basic element in this invention.

[0035] Figure 10 This is a schematic diagram of the final molded part in an embodiment of the present invention. Detailed Implementation

[0036] like Figure 1 As shown, this embodiment of a multi-energy field assisted deep drawing device for difficult-to-deform alloys with equivalent draw beads includes a press 1, a temperature system, and an adaptive valve system, such as... Figure 2 As shown, the press 1 includes a drawing punch 11, a blank holder 12 slidably sleeved around the drawing punch, and a drawing die 13. The drawing punch 11 can be inserted into the drawing die 13. A temperature system is symmetrically arranged around the blank holder and the overlapping portion of the drawing die and blank holder. The temperature system includes a ring-shaped heating zone 31, a cooling zone 41, and a heating zone 32 centered on the drawing punch. The cooling zone is located between the heating zone 1 and the heating zone 2. When the billet is drawn, the temperature of the cooling zone is lower than that of the heating zone 1 and the heating zone 2. The cooling zone serves as an equivalent draw bead. The temperature system also includes a heating system 3, a cooling system 4, and a temperature monitoring system 5. The heating system 3 heats the heating zone 1 and the heating zone 2, and the cooling system 4 cools the cooling zone. The heating system and the cooling system 4 can adjust the forming temperature in a timely manner, and the temperature monitoring system 5 monitors it in real time to ensure that the alloy is at the optimal forming temperature. In this embodiment, the heating zone 1 is closest to the drawing punch, followed by the cooling zone, and the heating zone 2 is farthest from the drawing punch.

[0037] like Figure 3 and Figure 4As shown, when the flange radius of billet 2 is larger than the edge of the cooling zone during deep drawing, the billet drawing is a compressive strain. The adaptive valve system is closed, the refrigeration system cools the cooling zone 41 to form a low-temperature zone B, and the heating system heats heating zone 31 and heating zone 32 to form a high-temperature zone A. Due to the existence of the low-temperature zone B, the billet material in contact with it is in a low-temperature state with a larger yield strength. Therefore, the radial tensile stress is increased, which allows the material to be drawn into the die cavity, thus making it less likely for circumferential wrinkling to occur in the outer flange area of ​​the material. When the flange radius of billet 2 is smaller than the cooling zone, the billet drawing is an elongation strain and wrinkling is less likely. The adaptive valve system is opened, the refrigeration system is cut off, and the heating system is connected, causing the temperature of the low-temperature zone B to rise, further improving the forming limit of the material.

[0038] The cooling zone is equipped with a circumferential cooling pipe 8. The refrigeration system introduces low-temperature airflow or low-temperature liquid into the cooling pipe for cooling. The heating zone 1 and heating zone 2 are equipped with circumferential heating pipes or heating resistance wires. The heating zone 1 is equipped with a zone 1 heating pipe 9, and the heating zone 2 is equipped with a zone 2 heating pipe 6. When heating pipes are installed, the heating system introduces high-temperature airflow or high-temperature liquid into the heating pipes. When heating resistance wires are installed, heating resistance wires are also installed in the cooling pipe 8.

[0039] like Figure 5 and Figure 6 As shown, when heating zone 1 and heating zone 2 are equipped with circumferential heating pipes, cooling pipe 8 is connected to refrigeration system 4, and heating pipes in heating zone 1 and heating zone 2 are connected to heating system 3. An adaptive valve system 7 is installed between the cooling pipes and the heating pipes in heating zone 2, and between the cooling pipes and the refrigeration system. The adaptive valve system includes an annular groove 71 installed between the cooling zone and heating zone 2, and a piston that moves along the annular groove. One end of the piston is connected to the annular groove via an elastic member 74, and the other end extends out of the annular groove. The piston includes a piston part 72 and a piston part 73. The piston part 72 is used to block the cooling pipes and the heating pipes in heating zone 2, and the piston part 73 is used to block the cooling pipes and the refrigeration system. The cooling pipes, heating pipes, and refrigeration system are all equipped with... The annular groove connects the channel; when the billet is between the blank holder and the adaptive valve system of the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The piston blocks the cooling pipe and heating pipe from the channel connecting to the annular groove. At this time, the cooling pipe is connected to the refrigeration system through the channel between the annular groove and the refrigeration system. When the billet moves away from the adaptive valve system between the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston. The cooling pipe and heating pipe are connected through the annular groove, and the piston blocks the channel connecting the cooling pipe and the refrigeration system.

[0040] like Figure 7 and Figure 8As shown, when heating zones one and two are equipped with circumferential heating resistance wires 10, the cooling pipe 8 is connected to the refrigeration system 4. The heating system is connected to the resistance heating circuit of the cooling zone through an adaptive valve system. The heating system supplies power to the resistance heating circuits of heating zones one, two, and the cooling zone. The adaptive valve system includes an annular groove and a piston that moves along the annular groove. The piston includes a piston part and a piston part two. The piston part one is used to connect or disconnect the heating resistance wire in the cooling pipe, and the piston part two is used to block the cooling pipe and the refrigeration system. A conductive block 75 is provided on the piston part one. Except for the conductive block, the other parts of the piston's outer periphery are insulated. One end of the piston is connected to the annular groove through an elastic component, and the other end extends out of the annular groove. The device consists of a concealed groove; a conductive block is electrically connected to the heating system, and a metal patch is connected to the heating resistance wire in the cooling zone. The metal patch slides in contact with the piston and the conductive block. When the billet is located between the blank holder and the adaptive valve system of the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The metal patch contacts the outer periphery of the piston. At this time, the cooling pipe is connected to the refrigeration system through the annular groove. When the billet moves away from the adaptive valve system of the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston. The metal patch contacts the outer periphery of the conductive block, and the heating system heats the resistance wire in the cooling pipe. At this time, the piston blocks the cooling pipe from the refrigeration system.

[0041] Example 2

[0042] This embodiment presents a multi-energy field-assisted deep drawing method for difficult-to-deform alloys with equivalent draw beads, comprising the following steps:

[0043] Step 1: Determine the blank parameters and the forming workpiece parameters; the blank material can be a room-temperature difficult-to-deform alloy sheet, such as titanium alloy, high-strength steel, aluminum alloy, magnesium alloy, etc., with a sheet thickness of 0.5mm to 4mm. Alloy sheets have low plasticity at room temperature, excessive deformation resistance, require large radial forces, are prone to thinning and cracking, have poor forming quality, and are difficult to manufacture parts with large deformations or complex shapes by cold stamping. In this embodiment, aluminum alloy is used as an example of the blank, with a thickness of 2mm.

[0044] Step 2: Based on the blank parameters and the formed workpiece parameters, perform finite element simulation on the blank to analyze and determine the stress component distribution, and determine the cooling zone radius and cooling zone width based on the stress analysis.

[0045] like Figure 9 As shown, the billet is divided into finite element parts to obtain the billet's basic elements. Based on the principal stress solution method for plastic deformation of metals, the equilibrium equations of the basic elements along the radial direction are obtained:

[0046] ;

[0047] in, The thickness of the basic unit. It is the central angle of the primitive.

[0048] By combining the Tresca yield criterion, the radial tensile stress of the element is obtained. and tangential compressive stress :

[0049] ;

[0050] ;

[0051] Throughout the deformation process, a specific stress ratio exists for each tiny element 101. :

[0052] ;

[0053] When the absolute values ​​of the two stresses are equal The radius of the primitive is:

[0054] ;

[0055] The intersection point is determined as the reference radius for the drawbeam. .

[0056] When the formed workpiece is a shallow-drawn part, the optimal radius of the cooling zone is determined based on the reference radius of the draw bead. :

[0057] ;

[0058] in, Where is the radius of the cooling zone. The reference radius for the drawbeam is... The initial radius of the blank;

[0059] The radial width of the cooling zone is , The thickness of the blank is 10 mm. In this embodiment, the radial width of the cooling zone is 10 mm.

[0060] Step 3: Based on the blank parameters, forming workpiece parameters, and cooling zone radius and width, obtain the drawing punch, blank holder, and drawing die;

[0061] Step 4: The blank is drawn into shape using a drawing punch, blank holder, and drawing die to obtain the following: Figure 10 The shaped workpiece shown.

[0062] When the flange radius of the blank is 2 > At that time, tangential compressive stress If the radius is too large, circumferential wrinkling is likely to occur. The adaptive valve system is set to close adaptively. Cooling channel 8 is connected to refrigeration system 4 to form low-temperature cooling zone B. Under the action of heating system 3, heating pipe 6 in zone 2 and heating pipe 9 in zone 1 form high-temperature zone A. At this time, the radius The temperature in low-temperature zone B is T2, and the temperature in high-temperature zone A is T1, causing radial tensile stress. This is because, according to the plastic yield criterion, when the same yield stress is achieved, the tangential compressive stress is reduced, thus preventing circumferential wrinkling. The alloy's melting point is... ℃, select a suitable high temperature for deformation. ℃ represents the temperature of heating system 3, and the temperature of cooling system 4 is ℃. ℃. As the alloy sheet flows through high-temperature zone A, its temperature rises, plasticity increases, springback decreases, and flow stress decreases, promoting the material's drawing into the die cavity. As the alloy sheet flows through low-temperature cooling zone B, its plasticity decreases, springback increases, and radial tensile stress increases, according to the plastic yield criterion. Qualitative analysis, The yield strength and radial tensile stress of the material are given. Increase, therefore tangential compressive stress This reduction in size decreases wrinkling during deep drawing, thus preventing wrinkling and improving material stability and finished product quality. In this embodiment, the melting point of the aluminum alloy... The temperature is 650℃, the high temperature is about 280℃, and the low temperature is about 182℃.

[0063] As the drawing process proceeds, the material is drawn into the die cavity, and the outer diameter of the flange decreases, preventing the material from becoming unstable and wrinkling. The blank flange shrinks to its radius. < Wrinkling is less likely to occur during this process. To improve the forming limit, the adaptive valve system opens adaptively, cutting off the cooling system of the cooling channel and connecting the heating system, raising the temperature of the cooling zone to a higher level. This reduces flow stress and decreases the radial tensile stress during deep drawing of the billet. This further improves the forming limit of the material.

Claims

1. A multi-energy field assisted deep drawing device of a difficult-to-deform alloy equivalent to a drawbead, characterized by, The device includes a drawing punch, a blank holder slidably fitted around the periphery of the drawing punch, and a drawing die. The drawing punch can be inserted into the drawing die. A temperature system is symmetrically arranged on the blank holder and the overlapping part of the drawing die and the blank holder. The temperature system includes a ring-shaped heating zone 1, a cooling zone, and a heating zone 2 centered on the drawing punch. The cooling zone is located between the heating zone 1 and the heating zone 2. When the blank is drawn, the temperature of the cooling zone is lower than that of the heating zone 1 and the heating zone 2. The cooling zone serves as an equivalent draw bead. The temperature system also includes a heating system (3) and a cooling system (4). The heating zone 1 and heating zone 2 are provided with several circumferential heating pipes (6), and the cooling zone is provided with circumferential cooling pipes (8). The cooling pipes (8) are connected to the cooling system, and the heating pipes (6) are connected to the heating system (3). Alternatively, the temperature system may also include a heating system (3) and a cooling system (4). The heating zone 1 and the heating zone 2 are provided with independent circumferential resistance heating circuits, and the cooling zone is provided with circumferential cooling pipes. The heating system is used to supply power to the resistance heating circuits of the heating zone 1 and the heating zone 2, and the cooling pipes (8) are connected to the cooling system. It also includes an adaptive valve system. The first heating zone is closest to the drawing punch, followed by the cooling zone, and the second heating zone is furthest from the drawing punch. The adaptive valve system is located between the cooling pipe and the heating pipe in the second heating zone, as well as between the cooling pipe and the refrigeration system. The adaptive valve system includes an annular groove between the cooling zone and the second heating zone, and a piston that moves along the annular groove. One end of the piston is connected to the annular groove via an elastic component, and the other end extends out of the annular groove. Both the cooling pipe and the heating pipe have channels communicating with the annular groove. When the billet is between the blank holder and the adaptive valve system of the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The piston blocks the channels communicating between the cooling pipe and the heating pipe and the annular groove. At this time, the cooling pipe is connected to the refrigeration system. When the billet moves away from the adaptive valve system between the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston. The cooling pipe and the heating pipe are connected through the annular groove. At this time, the piston blocks the cooling pipe from the refrigeration system.

2. The multi-energy field assisted deep drawing apparatus of a difficult-to- deform alloy equivalent drawbead according to claim 1, characterized in that, The heating system introduces high-temperature gas or liquid into the heating pipe, and the refrigeration system introduces low-temperature gas or liquid into the cooling pipe.

3. The multi-energy field assisted deep drawing apparatus of a difficult-to- deform alloy equivalent drawbead according to claim 1, characterized in that, The system includes an adaptive valve system. A resistance heating circuit is installed within the cooling pipes of the cooling zone. The adaptive valve system is positioned between the heating system and the resistance heating circuit of the cooling zone, as well as between the cooling pipes and the refrigeration system. The adaptive valve system includes an annular groove and a piston that moves along the annular groove. A conductive block is installed on the piston. The piston's outer periphery, except for the conductive block, is insulated. One end of the piston is connected to the annular groove via an elastic component, and the other end extends out of the annular groove. The conductive block is electrically connected to the heating system. A metal patch is installed in the resistance heating circuit of the cooling zone, and the metal patch slides in contact with the piston and the conductive block. When the billet is located between the adaptive valve system of the blank holder and the drawing die, the billet compresses the piston, thereby compressing and storing elastic potential energy in the elastic component. The metal patch contacts the outer periphery of the piston, and at this time, the cooling pipes are connected to the refrigeration system. When the billet moves away from the adaptive valve system of the blank holder and the drawing die, the elastic component of the adaptive valve system elastically recovers and pushes the piston. The metal patch contacts the outer periphery of the conductive block, and at this time, the piston blocks the cooling pipes from the refrigeration system, restoring the heating effect on the cooling zone.

4. A deep drawing method using a multi-energy field assisted deep drawing apparatus for a difficult-to-deform alloy with the equivalent drawbead of any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Determine the blank parameters and the parameters of the formed workpiece; Step 2: Based on the blank parameters and the formed workpiece parameters, perform finite element simulation on the blank, and determine the cooling zone radius and cooling zone width based on stress analysis; Step 3: Based on the blank parameters, forming workpiece parameters, and cooling zone radius and width, obtain the drawing punch, blank holder, and drawing die; Step 4: The blank is drawn into shape using a drawing punch, a blank holder, and a drawing die.

5. The multi-physical field assisted deep drawing method of a difficult-to- deform alloy of equivalent drawbead as claimed in claim 4, wherein, When the formed workpiece is a shallow-drawn part, the radius of the cooling zone is: ； wherein, Rc is the radius of the cooling zone, Rr is the reference radius of the drawbead, Ri is the initial radius of the blank; The radial width of the cooling zone is , is the thickness of the blank.

6. The multi-physical field assisted deep drawing method of a difficult-to- deform alloy of equivalent drawbead as claimed in claim 5, wherein, The reference radius of the drawbead The method for confirming the radius of the drawbead is: Finite element analysis is performed on the billet to obtain its basic elements. Based on the principal stress method for plastic deformation of metals, the radial equilibrium equations of the basic elements are obtained. Combined with the Tresca yield criterion, the radial tensile stress and tangential compressive stress of the basic elements are obtained. The radius of the basic element containing the element with equal absolute values ​​of radial tensile stress and tangential compressive stress is determined as the reference radius for the drawbead. .

7. The multi-physical field assisted deep drawing method of a difficult-to- deform alloy of an equivalent draw bead according to claim 6, characterized in that, The billet is a material that is difficult to deform at room temperature, including titanium alloy, aluminum alloy, high-strength steel, and magnesium alloy.

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