阅读说明：本技术 一种异形件相变复合成型装置及加工方法 (Phase-change composite forming device and processing method for special-shaped piece ) 是由 张池 刘�文 严翔 林立 叶鑫宇 庄忠柱 滕叶莹 宁敬威 于 2021-08-03 设计创作，主要内容包括：本发明公开一种异形件相变复合成型装置,包括复合冲头和模具组件,模具组件内设有模型槽,模型槽内设有直壁段和难以进行刚性冲压加工的异形段,复合冲头包括刚性体和低熔点合金,模具组件上设有板坯,低熔点合金用于对板坯进行异形段冲压成型,模具组件内还设有加热器,加热器用于将低熔点合金半液化；本发明还公开了一种异形件相变复合成型装置的加工方法,控制模具组件温度在120℃以下,复合冲头下压,使板坯在直壁段成型,控制模具组件的温度在135≤t＜175℃,对异形段进行整体成型。本发明提供一种可以对带有异形结构的壳体零件通过用对钣金进行冲压的加工方式来成型的一种异形件相变复合成型装置及加工方法。(The invention discloses a phase change composite forming device for special-shaped parts, which comprises a composite punch and a die assembly, wherein a die groove is arranged in the die assembly, a straight wall section and a special-shaped section which is difficult to perform rigid stamping processing are arranged in the die groove, the composite punch comprises a rigid body and a low-melting-point alloy, a plate blank is arranged on the die assembly, the low-melting-point alloy is used for performing special-shaped section stamping forming on the plate blank, and a heater is also arranged in the die assembly and used for semi-liquefying the low-melting-point alloy; the invention also discloses a processing method of the special-shaped piece phase change composite forming device, wherein the temperature of the mould component is controlled to be below 120 ℃, the composite punch is pressed downwards to form the plate blank in the straight wall section, the temperature of the mould component is controlled to be t which is more than or equal to 135 and less than 175 ℃, and the special-shaped section is integrally formed. The invention provides a special-shaped part phase change composite forming device and a special-shaped part phase change composite forming method, which can form a shell part with a special-shaped structure by a processing mode of stamping a metal plate.)

1. The utility model provides a dysmorphism phase transition composite forming device which characterized in that: comprises a composite punch head (1) and a die component (2), wherein the composite punch head (1) is arranged above the die component (2), a mould groove (2.4) is arranged in the mould component (2), a straight wall section (2.4.1) and a special-shaped section (2.4.2) which is difficult to be subjected to rigid stamping processing are arranged in the mould groove (2.4), the special-shaped section (2.4.2) is arranged at the bottom end of the straight wall section (2.4.1), the composite punch (1) comprises a rigid body (1.1) and a low-melting-point alloy (1.2), the low-melting-point alloy (1.2) is arranged at the front end of the composite punch (1), a plate blank (3) is arranged on the die component (2), the low-melting-point alloy (1.2) is used for punch forming of the special-shaped section (2.4.2) of the plate blank (3), the die assembly (2) is also internally provided with a heater (2.3), and the heater (2.3) is used for semi-liquefying the low-melting-point alloy (1.2).

2. The phase-change composite molding device for the special-shaped piece according to claim 1, wherein: the low-melting-point alloy (1.2) is made of 70Sn-30 In.

3. The phase-change composite molding device for the special-shaped piece according to claim 2, wherein: the special-shaped section (2.4.2) comprises a first special-shaped part (2.4.3), the first special-shaped part (2.4.3) is arranged at the bottom end of the straight wall section (2.4.1), the outer diameter of the first special-shaped part (2.4.3) is larger than the diameter of the straight wall section (2.4.1), the edge of the first special-shaped part (2.4.3) is a smooth arc surface, and when the first special-shaped part (2.4.3) is machined, the inner temperature of the die assembly (2) is 155 ℃ or less and t is smaller than 175 ℃.

4. The phase-change composite molding device for the special-shaped piece according to claim 2, wherein: the special-shaped section (2.4.2) further comprises a second special-shaped part (2.4.4), the second special-shaped part (2.4.4) is arranged at the bottom end of the straight wall section (2.4.1), the second special-shaped part (2.4.4) is an acute-angle groove, and when the second special-shaped part (2.4.4) is machined, the internal temperature of the die assembly (2) is more than or equal to 135 and t is less than 155 ℃.

5. The phase-change composite molding device for the special-shaped piece according to claim 1, wherein: the die assembly (2) comprises a shell (2.1) and a forming die core (2.2), a placing groove (2.5) used for placing the forming die core (2.2) is formed in the shell (2.1), the die groove (2.4) is formed in the forming die core (2.2), the forming die core (2.2) is detachably connected in the placing groove (2.5), a heater (2.3) is placed along the circumferential direction of the placing groove (2.5), the shell (2.1) is formed by overlapping a plurality of modules (2.1.1), and the heater (2.3) is arranged between two adjacent modules (2.1.1).

6. The phase-change composite molding device for the special-shaped piece according to claim 5, wherein: the side of standing groove (2.5) is the slope setting, the bottom of standing groove (2.5) is equipped with ejector rod (4) that are used for ejecting standing groove (2.5) with forming die core (2.2), ejector rod (4) are connected with the driver, forming die core (2.2) are formed along circumference concatenation through polylith mold core (2.2.1).

7. The phase-change composite molding device for the special-shaped piece according to claim 1, wherein: a T-shaped block (1.1.1) is arranged at the joint of the rigid body (1.1) and the low-melting-point alloy (1.2), and a T-shaped groove (1.2.1) matched with the T-shaped block (1.1.1) is arranged at the joint of the low-melting-point alloy (1.2) and the rigid body (1.1).

8. The phase-change composite molding device for the special-shaped piece according to claim 1, wherein: be equipped with blank silo (2.6) that are used for placing slab (3) on mould subassembly (2), the top movably connected with clamp plate (5) of blank silo (2.6), clamp plate (5) are used for preventing when punching press slab (3), the perk of slab (3) both sides, be equipped with punching press hole (5.1) that supply compound drift (1) to pass on clamp plate (5).

9. A processing method of a special-shaped piece phase change composite forming device is characterized in that: comprising the apparatus of any one of claims 1-8, comprising the steps of,

s1: placing the plate blank (3) on the blank groove (2.6), moving the pressing plate (5) downwards, and covering the plate blank (3);

s2: controlling the temperature of the die assembly (2) to be below 120 ℃, and pressing down the composite punch (1) to form the plate blank (3) on the straight wall section (2.4.1);

s3: when the low-melting-point alloy (1.2) is abutted against the bottom of the die groove (2.4), controlling the temperature of the die component (2) to be more than or equal to 155 and less than 175 ℃, and integrally forming the first special-shaped part (2.4.3);

s4: and after the first special-shaped part (2.4.3) is integrally formed, controlling the temperature of the mold component (2) to be more than or equal to 135 and t less than 155 ℃, and integrally forming the second special-shaped part (2.4.4).

10. The processing method of the phase-change composite molding device for the special-shaped piece according to claim 10, wherein the processing method comprises the following steps: the method also comprises the step of carrying out the following steps,

s5: after the plate blank (3) is shaped, the composite punch (1) is withdrawn, the pressing plate (5) moves upwards, and the ejector rod (4) is ejected out of the forming mold core (2.2);

s6: the forming mold core (2.2) is disassembled into a plurality of mold cores (2.2.1), and the formed plate is taken out;

s7: the plate is placed in an environment above 175 ℃ and is reversed, and the low melting point alloy (1.2) in the plate is separated and collected for manufacturing the composite punch (1) again.

Technical Field

The invention belongs to the field of stamping equipment, and particularly relates to a special-shaped piece phase change composite forming device and a processing method.

Background

Some shell parts can be designed in a special-shaped structure in the design process due to the structural or attractive requirements, and in the traditional machining process, the special-shaped structures are difficult to form through stamping and forming, and can be formed through machining for many times by equipment such as lathes, cutting machines, bending machines, welding machines and the like, or through die casting and then surface polishing. In the two processing modes, the former has complex process and multiple steps in processing and forming, and can cause waste of a large amount of raw materials, and the latter needs to manufacture a die, so that for some special-shaped structures with more bends, more pouring gates are arranged, the production cost is higher, the production period is long, and parts are easily damaged in the polishing process.

Disclosure of Invention

The technical scheme adopted by the invention for solving the problems is as follows: the utility model provides a dysmorphism piece phase transition composite forming device, includes composite punch and mould subassembly, the top of mould subassembly is located to composite punch, be equipped with the model groove in the mould subassembly, the model inslot is equipped with straight wall section and is difficult to carry out the dysmorphism section of rigidity punching press processing, the bottom of straight wall section is located to dysmorphism section, composite punch includes rigid body and low-melting alloy, the front end of composite punch is located to the low-melting alloy, be equipped with the slab on the mould subassembly, the low-melting alloy is used for carrying out dysmorphism section stamping forming to the slab, still be equipped with the heater in the mould subassembly, the heater is used for low-melting alloy semi-liquefaction.

Compared with the prior art, the invention has the advantages that: in the traditional punching process, the punch is made of high-hardness and high-strength materials, so that the punching structure of the punch is greatly limited, when the width of the bottom of the die groove is larger than the width of the insertion end of the die groove, the punch is difficult to form the bottom of the die, and when a sharp-corner structure to be processed is arranged in the die groove, the punch cannot perform corresponding sharp-corner structure design, otherwise the punch is damaged in the punching process of the punch, so that the sharp-corner structure is difficult to process in a punching processing mode, through the design of the invention, the composite punch firstly passes through the straight wall section to form the straight wall section of the slab in the punching processing process, when the composite punch pushes the slab to move against the bottom of the die groove, the rigid body on the composite punch is matched with the straight wall section at the moment to seal the space between the rigid body and the slab, the space of the low-melting-point alloy is closed, then the low-melting-point alloy is heated by a heater to be semi-liquefied, the semi-liquefied low-melting-point alloy is in a solid-liquid mixed state, the plate blank has certain expansion forming capacity, the composite punch can continue to punch at the moment, the semi-liquefied low-melting-point alloy is expanded at high pressure, the special-shaped section of the plate blank is complemented, and the purpose of forming the shell part with the special-shaped structure by a sheet metal punching processing mode is achieved.

As a modification, the low melting point alloy is made of 70Sn-30In, and through the modification, the 70Sn-30In material is composed of 70% of tin and 30% of indium, and has a solidus line of 120 ℃ and a liquidus line of 175 ℃. The alloy has a solidification interval of 55 ℃, is convenient for controlling solid-liquid phase transformation, and has low cost.

As an improvement, the special-shaped section comprises a first special-shaped part, the first special-shaped part is arranged at the bottom end of the straight wall section, the outer diameter of the first special-shaped part is larger than the diameter of the straight wall section, the edge of the first special-shaped part is a smooth cambered surface, when the first special-shaped part is processed, the temperature in the die assembly is more than or equal to 155 and less than 175 ℃, through the improvement, when the temperature in the die assembly is more than or equal to 155 and less than 175 ℃, the low-melting-point alloy is in a high liquid phase state, so that the low-melting-point alloy has better fluidity, meanwhile, compared with a pure liquid fluid, the attraction among molecules is stronger, the low-melting-point alloy is more easily sealed and is not easily flowed out from between the rigid body and the plate blank, under the high pressure action of the composite punch, the low-melting-point alloy can expand outwards to drive the plate blank to expand, the stamping processing and forming of the first special-shaped part of the plate blank is completed, and the process is suitable for the first special-shaped part with gentle change of the special-shaped structure, namely, the edge of the first special-shaped part is a smooth cambered surface.

As an improvement, the special-shaped section further comprises a second special-shaped part, the second special-shaped part is arranged at the bottom end of the straight wall section, the second special-shaped part is an acute angle groove, when the second special-shaped part is machined, the temperature in the die assembly is more than or equal to 135 and less than 155 ℃, through the improvement, when the temperature in the die assembly is more than or equal to 135 and less than 155 ℃, the low-melting-point alloy is in a high solid phase state, the low-melting-point alloy in the state not only has certain fluidity, but also has intermolecular attraction which is second to a pure solid state and can bear larger pressure, the semi-liquefied low-melting-point alloy still cannot easily flow out, and the plate blank can be subjected to better expansion deformation, so that the acute angle grooves can be well formed, and the situation that the punch head can be damaged by the traditional punching process for the acute angle grooves is avoided.

As an improvement, the mold assembly comprises a shell and a molding mold core, a placing groove for placing the molding mold core is formed in the shell, the mold groove is formed in the molding mold core, the molding mold core is detachably connected in the placing groove, the heater is placed along the circumferential direction of the placing groove, the shell is formed by stacking a plurality of modules, the heater is arranged between two adjacent modules, through the improvement, the installation of the molding mold core and the heater is realized, the heating effect of the heater on the molding mold core is ensured, and meanwhile, the heater is easy to detach and replace.

As the improvement, the side of standing groove is the slope setting, the bottom of standing groove is equipped with the knock-out pin that is used for the ejecting standing groove of forming die core, the knock-out pin is connected with the driver, forming die core forms along circumference concatenation through the polylith mold core, through the improvement, the side of standing groove is the slope setting, not only can treat slab processing completion back, and the ejecting forming die core of knock-out pin is more convenient, can also make the polylith mold core put into the standing groove when, along the automatic concatenation in inclined plane, and the compound die is more accurate, is difficult for producing the overlap.

As an improvement, a T-shaped block is arranged at the joint of the rigid body and the low-melting-point alloy, a T-shaped groove matched with the T-shaped block is arranged at the joint of the low-melting-point alloy and the rigid body, and through the improvement, the rigid body and the low-melting-point alloy can be fixedly connected, so that the low-melting-point alloy is prevented from falling off from the rigid body, and meanwhile, the situation that the rigid body and the low-melting-point alloy deviate in the stamping process can be avoided.

As the improvement, be equipped with the blank groove that is used for placing the slab on the mould subassembly, the top movably connected with clamp plate of blank groove, the clamp plate is used for preventing when the punching press slab, the perk of slab both sides, be equipped with the punching press hole that supplies compound drift to pass on the clamp plate, through the improvement, can avoid slab both sides perk when the punching press, can also increase the frictional force of slab both sides, make the slab by the punching press in-process, the fastness of slab both sides is higher, and the stamping forming is only accomplished through tensile deformation's mode to the slab by the punching press, makes the part thickness after the shaping more unified, even.

A processing method of a special-shaped piece phase-change composite forming device comprises the following steps,

s1: placing the plate blank on a blank trough, moving a pressing plate downwards, and covering the plate blank;

s2: controlling the temperature of the die assembly below 120 ℃, and pressing down the composite punch to form the plate blank in the straight wall section;

s3: when the low-melting-point alloy is abutted against the bottom of the model groove, controlling the temperature of the mould component to be more than or equal to 155 and less than 175 ℃, and integrally forming the first special-shaped part;

s4: and after the first special-shaped part is integrally formed, controlling the temperature of the mold assembly to be t less than 155 ℃ at 135-155 ℃, and integrally forming the second special-shaped part.

Compared with the prior art, the invention has the advantages that: in the traditional punching process, the punch is made of high-hardness and high-strength materials, so that the punching structure of the punch is greatly limited, when the width of the bottom of the die groove is larger than the width of the insertion end of the die groove, the punch is difficult to form the bottom of the die, and when a sharp-corner structure to be processed is arranged in the die groove, the punch cannot be designed with a corresponding sharp-corner structure, otherwise the punch is damaged in the punching process of the punch, so that the sharp-corner structure is difficult to process in a punching processing mode, through the design of the invention, the temperature of a die assembly is controlled below 120 ℃ in the punching processing process of the composite punch, so that the liquefaction of low-melting-point alloy is avoided, the activity of a plate blank can be improved, the plate blank is easier to be punched and stretched, the composite punch forms a straight-wall section on the plate blank through the straight-wall section first, when the composite punch pushes the plate blank to move to be abutted against the bottom of the model groove, the rigid body on the composite punch is matched with the straight wall section at the moment, the space between the rigid body and the plate blank is sealed, namely the space where the low-melting-point alloy is located is sealed, then the temperature is heated by a heater, the low-melting-point alloy is semi-liquefied, the semi-liquefied low-melting-point alloy is in a solid-liquid mixed state, the plate blank has certain expansion forming capacity, the composite punch can continue to punch at the moment, the semi-liquefied low-melting-point alloy is expanded at high pressure to complement the plate blank punch forming of the special-shaped section, the temperature of a mould component is controlled to be not more than 155 ℃ at first, the expansion filling of the low-melting-point alloy is carried out on the special-shaped section at low pressure, then the temperature of a mould set is controlled to be not more than 135 ℃ and not more than 155 ℃, the secondary expansion filling of the low-melting-point alloy is carried out on the special-shaped section at high pressure, and the expansion filling process of the low-melting-point alloy is carried out in a process from low pressure to high-pressure process, make the inflation filling process of low melting point alloy more stable, it is more even, avoid appearing the inhomogeneous condition of inflation thickness of slab, and by high liquid phase to high solid phase transition in-process, the low melting point alloy of high liquid phase enters into the acute angle recess more easily, then the low melting point alloy of high liquid phase changes into high solid phase and carries out the punching press to the acute angle recess, can greatly reduced the punching press degree of difficulty to the acute angle recess, the output of compound drift has also been reduced simultaneously, the time of high-pressure punching press has been reduced, make equipment have longer life, the final completion has the shell part of special-shaped structure to carry out the fashioned purpose of processing mode of punching press through the panel beating.

As an improvement, the method also comprises the step of,

s5: after the plate blank is shaped, the composite punch is withdrawn, the pressing plate moves upwards, and the ejector rod ejects out of the forming mold core;

s6: disassembling the forming mold core into a plurality of mold cores, and taking out the formed plate;

s7: placing the plate in an environment with the temperature of above 175 ℃, and reversing, separating and collecting the low-melting-point alloy in the plate for manufacturing the composite punch again; through the improvement, after the punch forming of the plate blank, the formed plate blank can be taken out of the die assembly, the low-melting-point alloy can be separated from the plate blank and collected, the secondary production of the composite punch is carried out, a large amount of waste can not be caused to the low-melting-point alloy, and the cost of the special-shaped piece in the production process is greatly improved.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic sectional structure view of the overall structure of the present invention.

FIG. 3 is a schematic sectional view of the molding core of the present invention.

Shown in the figure: 1. the composite punch comprises a 1.1 part, a rigid body, a 1.1.1 part, a T-shaped block, a 1.2 part, a low-melting-point alloy, a 1.2.1 part, a T-shaped groove, a 2 part, a die assembly, a 2.1 part, a 2.1.1 part, a module, a 2.2 part, a forming die core, a 2.2.1 part, a die core, a 2.3 part, a heater, a 2.4 part, a die groove, a 2.4.1 part, a straight wall part, a 2.4.2 part, an abnormal section, a 2.4.3 part, a first abnormal section, a 2.4.4 part, a second abnormal section, a 2.5 part, a placing groove, a 2.6 part, a blank groove, a 3 part, a blank, a 4 part, an ejector rod, a 5 part, a pressing plate, a 5.1 part and a punching hole.

Detailed Description

Embodiments of the present invention are further described below with reference to the accompanying drawings.

As shown in fig. 1-2, a phase change composite forming device for a shaped part includes a composite punch 1 and a die assembly 2, the composite punch 1 is disposed above the die assembly 2, a die groove 2.4 is disposed in the die assembly 2, a straight wall section 2.4.1 and a shaped section 2.4.2 difficult to be rigidly pressed are disposed in the die groove 2.4, the shaped section 2.4.2 is disposed at a bottom end of the straight wall section 2.4.1, the shaped section 2.4.2 includes a first shaped portion 2.4.3, the first shaped portion 2.4.3 is disposed at a bottom end of the straight wall section 2.4.1, an outer diameter of the first shaped portion 2.4.3 is greater than a diameter of the straight wall section 2.4.1, an edge of the first shaped portion 2.4.3 is a smooth arc surface, when the first shaped portion 2.4.3 is processed, an inner temperature of the die assembly 2 is 155 ℃ or less, t < 175 ℃ and the shaped section 2.4.2 further includes a second shaped portion 2.4.4.2, a second shaped portion 2.4.4.4.2 is disposed at an acute angle, when a second special-shaped part 2.4.4 is machined, the temperature In the die assembly 2 is 135-T < 155 ℃, the composite punch 1 comprises a rigid body 1.1 and a low-melting-point alloy 1.2, the low-melting-point alloy 1.2 is arranged at the front end of the composite punch 1, a T-shaped block 1.1.1 is arranged at the joint of the rigid body 1.1 and the low-melting-point alloy 1.2, a T-shaped groove 1.2.1 matched with the T-shaped block 1.1 is arranged at the joint of the low-melting-point alloy 1.2 and the rigid body 1.1, the low-melting-point alloy 1.2 is manufactured by 70Sn-30In, the composite punch 1 is fixedly connected to a hydraulic cylinder, the stamping machining of the composite punch 1 is realized by the driving of the hydraulic cylinder, a plate blank 3 is arranged on the die assembly 2, the low-melting-point alloy 1.2 is used for carrying out the section 2.4.2 on the plate blank 3, a heater 2.3 is further arranged In the die assembly 2, and the heater 2 is used for semi-liquefying the low-point alloy 1.2, be equipped with the blank groove 2.6 that is used for placing slab 3 on the mould subassembly 2, blank groove 2.6's top movably connected has clamp plate 5, clamp plate 5 is used for preventing when punching press slab 3, the perk of 3 both sides of slab, be equipped with the punching press hole 5.1 that supplies compound drift 1 to pass on clamp plate 5, four angles of clamp plate 5 are fixed respectively on the cylinder, through cylinder drive, realize clamp plate 5's upper and lower removal, guarantee simultaneously that clamp plate 5 pushes down the homogeneity of exerting oneself when slab 3.

As shown in fig. 2-3, the mold assembly 2 includes a housing 2.1 and a mold core 2.2, a placement groove 2.5 for placing the mold core 2.2 is provided in the housing 2.1, the mold groove 2.4 is provided on the mold core 2.2, the mold core 2.2 is detachably connected in the placement groove 2.5, the heater 2.3 is placed along the circumferential direction of the placement groove 2.5, the housing 2.1 is formed by stacking a plurality of modules 2.1.1, the heater 2.3 is provided between two adjacent modules 2.1.1, the side surface of the placement groove 2.5 is inclined, an ejection rod 4 for ejecting the mold core 2.2 out of the placement groove 2.5 is provided at the bottom of the placement groove 2.5, the ejection rod 4 is connected with a driver, and the mold core 2.2 is formed by splicing two mold cores 2.2.2.1 along the circumferential direction.

A processing method of a phase change composite forming device for special-shaped parts comprises the following steps:

s1: placing the plate blank 3 on the blank groove 2.6, moving the pressing plate 5 downwards, and covering the plate blank 3;

s2: controlling the temperature of the die assembly 2 to be below 120 ℃, and pressing the composite punch 1 downwards to form the plate blank 3 in the straight wall section 2.4.1;

s3: when the low-melting-point alloy 1.2 is abutted against the bottom of the model groove 2.4, controlling the temperature of the model component 2 to be more than or equal to 155 and less than or equal to 175 ℃, and integrally forming the first special-shaped part 2.4.3;

s4: after the first special-shaped part 2.4.3 is integrally formed, controlling the temperature of the mold component 2 to be more than or equal to 135 and less than 155 ℃, and integrally forming the second special-shaped part 2.4.4;

s5: after the plate blank 3 is shaped, the composite punch 1 is withdrawn, the pressing plate 5 moves upwards, and the ejection rod 4 ejects out of the forming mold core 2.2;

s6: the forming mold core 2.2 is disassembled into two mold cores 2.2.1, and the formed plate is taken out;

s7: the sheet is placed in an environment above 175 ℃ and turned upside down, and the low melting point alloy 1.2 in the sheet is separated and collected for the composite punch 1 to be manufactured again.

In the forming process, the temperature rise of the die assembly 2 can be controlled, and the temperature of the die assembly 2 is below 120 ℃, so that the sheet blank 3 has stronger plasticity and is not easy to be damaged and broken under the condition of avoiding the liquefaction of the low-melting-point alloy 1.2; when the first special-shaped part 2.4.3 is integrally formed, the temperature of the control die assembly 2 is controlled to be more than or equal to 155 and less than or equal to 175 ℃, at the moment, along with the pressing of the composite punch 1, the high-liquid-phase low-melting-point alloy 1.2 expands, so that the plate blank 3 is formed along the structure of the first special-shaped part 2.4.3, meanwhile, the low-melting-point alloy also flows to the second special-shaped part 2.4.4, and although the second special-shaped part 2.4.4 cannot be integrally formed, most of the area of the second special-shaped part 2.4.4 is filled with the low-melting-point alloy 1.2; and then, controlling the temperature t of the die component 2 to be more than or equal to 135 and less than 155 ℃, wherein the low-melting-point alloy 1.2 is in a high solid phase state and has higher hardness, the hardness of the low-melting-point alloy 1.2 at the second special-shaped part 2.4.4 is higher, and the whole stamping process of the plate blank 3 is completed under the continuous pressurization of the composite punch 1.

The foregoing is merely illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof is allowed to vary. All changes which come within the scope of the invention as defined by the independent claims are intended to be embraced therein.