阅读说明：本技术 一种超大高径比圆棒的镦粗模具及成形方法 (Upsetting die and forming method for round bar with ultra-large height-diameter ratio ) 是由 刘惠 唐鹏钧 马志锋 王建国 李伟 陆政 戴圣龙 于 2021-09-26 设计创作，主要内容包括：本发明提供了一种超大高径比圆棒的镦粗模具及成形方法,所述镦粗模具将多次镦粗成形集中在一套上下模内完成,通过叠加垫板,实现了超大高径比、镦粗易失稳折叠的圆棒的无折叠均匀镦粗成形,为后续的拔长、镦粗等自由锻造工序提供了适宜的坯料。所述镦粗模具的制备成本低,不用频繁更换模具,生产效率高,生产成本低。此外,该模具适用于铝、钢、钛、高温合金等多种金属材料,通用性强。(The invention provides an upsetting die and a forming method for a round bar with an ultra-large height-diameter ratio. The upsetting die is low in preparation cost, high in production efficiency and low in production cost, and the die does not need to be replaced frequently. In addition, the die is suitable for various metal materials such as aluminum, steel, titanium, high-temperature alloy and the like, and has strong universality.)

1. The upsetting die for the round bar is characterized by comprising an upper die and a lower die; the upper die comprises an upper anvil block, an upper padding plate and an upper female die, and the upper padding plate and the upper female die are connected with the upper anvil block; the lower die comprises a lower female die, a lower backing plate and a lower anvil block, and the lower female die and the lower backing plate are connected with the lower anvil block;

the upper female die is provided with a structure with two open ends and a first inner concave cavity, and the structure of the first inner concave cavity comprises a first non-deformation constraint area and a first deformation area; the lower female die is provided with a structure with two open ends and a second inner concave cavity, and the structure of the second inner concave cavity comprises a second non-deformation constraint area and a second deformation area; the first deformation area is close to the second deformation area, and the first deformation area and the second deformation area are assembled into a bar upsetting forming area with the height-diameter ratio being less than or equal to 3.

2. The upsetting die for the round bar as recited in claim 1, wherein the upper die has a structure with a first inner cavity opened at both ends, the structure of the first inner cavity comprising a first non-deforming restraining region and a first deforming region connected; the structure of the first non-deforming constraint area is a first truncated cone-shaped structure, the structure of the first deforming area is a second truncated cone-shaped structure, and the taper of the wall surface of the first truncated cone-shaped structure is smaller than that of the wall surface of the second truncated cone-shaped structure;

and/or the diameter of the bottom surface of the first truncated cone-shaped structure is equal to the diameter of the top surface of the second truncated cone-shaped structure.

3. The upsetting die for a round bar as recited in claim 1, wherein the taper α of the wall surface of the second truncated cone structure is 60 to 80 °; the taper of the wall surface of the second truncated cone-shaped structure is the taper of the forming wall surface of the upper concave die.

4. The upsetting die for a round bar as recited in claim 1, wherein the height h of the first truncated cone structure satisfies the following relation: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of a round rod; the height h of the first truncated cone-shaped structure is the forming height of the upper concave die.

5. The upsetting die for the round bar as recited in claim 1, wherein the lower die has a structure with a second inner cavity opened at both ends, the structure of the second inner cavity comprising a second non-deforming restraining region and a second deforming region connected; the structure of the second non-deforming constraint area is a third truncated cone-shaped structure, the structure of the second deforming area is a fourth truncated cone-shaped structure, a cylindrical structure and a fifth truncated cone-shaped structure which are sequentially connected, the taper of the wall surface of the third truncated cone-shaped structure is smaller than that of the wall surface of the fourth truncated cone-shaped structure, and the taper of the wall surface of the fourth truncated cone-shaped structure is smaller than that of the wall surface of the fifth truncated cone-shaped structure;

and/or the diameter of the cylindrical structure is equal to the diameter of the bottom surface of the fourth truncated cone-shaped structure, and the diameter of the cylindrical structure is equal to the diameter of the top surface of the fifth truncated cone-shaped structure; the diameter of the bottom surface of the third truncated cone-shaped structure is equal to the diameter of the top surface of the fourth truncated cone-shaped structure.

6. The upsetting die for a round bar as recited in claim 1, wherein the taper α of the wall surface of the fourth truncated cone structure is 60 to 80 °; the taper of the wall surface of the fourth truncated cone-shaped structure is the taper of the forming wall surface of the lower concave die.

7. The upsetting die for a round bar as recited in claim 1, wherein the height h of the third truncated cone structure satisfies the following relation: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of a round rod; and the height h of the third truncated cone-shaped structure is the forming height of the lower concave die.

8. Upsetting die for round bars as in claim 1, characterized in that said cylindrical structure has a diameter d_{Wall surface}Satisfies the following relation: d_{Wall surface}=（1.4~1.8）d_{Round bar}(ii) a Diameter d of the cylindrical structure_{Wall surface}The diameter of the forming wall surface of the lower concave die;

and/or the height h of the cylindrical structure_{Wall surface}Satisfies the following relation: h is_{Wall surface}=（1.0~1.2）d_{Round bar} ²×h_{Round bar}/d_{Wall surface} ²，d_{Round bar}Is the diameter of the round bar, h_{Round bar}Is the height of the round bar; height h of the cylindrical structure_{Wall surface}The height of the formed wall surface of the lower concave die.

9. A method for forming a round bar with an ultra-large height-to-diameter ratio, characterized in that the method is based on an upsetting die for a round bar as recited in any one of claims 1 to 8, the method comprising the steps of:

1) according to the diameter and the height of the round bar, determining the conicity of the forming wall surfaces of the upper female die and the lower female die, the diameter and the height of the forming wall surface of the lower female die and the forming height of the upper female die and the lower female die, and further determining the upsetting reduction and the upsetting times of each time;

2) placing a round bar into the upper female die and the lower female die, heating, carrying out primary upsetting forming, and respectively adding base plates with the same thickness into the upper female die and the lower female die according to the upsetting reduction of each time;

3) and repeating the upsetting forming treatment for many times until the height-diameter ratio of the round bar is less than 3.

10. The method for forming the round bar with the ultra-large aspect ratio as claimed in claim 9, wherein the calculation formula of the reduction per upset in the step 1) is h_{Reduction of}=(0.4~0.6）[3d_{Round bar}-（3d_{Round bar} ³/d_{Wall surface} ²）]，d_{Round bar}Is the diameter of the round bar, d_{Wall surface}The diameter of the cylindrical structure;

and/or, in the step 1), the upsetting times n is more than or equal to (h)_{Round bar}-3d_{Wall surface}）/h_{Reduction of}，h_{Round bar}Is the height of the round bar, d_{Wall surface}Diameter of cylindrical structure, h_{Reduction of}The reduction is the upsetting reduction per time;

and/or, in the step 2), the thickness of the backing plate is 1/2 of the reduction per upsetting.

Technical Field

The invention belongs to the technical field of metal material forming, and relates to an upsetting die of a round bar with an ultra-large height-diameter ratio and a forming method of the round bar with the ultra-large height-diameter ratio.

Background

In the fields of aviation, aerospace, ships and the like, metal forgings gradually develop towards large size and high performance, and the requirements on the forgings are higher and higher. The height-diameter ratio of a round rod subjected to normal flat anvil upsetting of the forge piece is generally not more than 2-3, and when the height-diameter ratio exceeds 3, instability and folding phenomena are easy to occur in the upsetting process. The forming and manufacturing difficulty of large forgings and alloy forgings difficult to deform is very high, so that the height-diameter ratio of the original bar materials for the forgings is far more than 3, and even the height-diameter ratio is as high as more than 6. For the original bars with the ultra-large height-diameter ratio, instability and folding phenomena are easy to occur in the upsetting process, so that the upsetting formation of the round bar with the ultra-large height-diameter ratio is an important process in plastic forming, the problems that the round bar with the ultra-large height-diameter ratio is uniformly deformed in the upsetting process, and instability and folding are not generated are solved, and the problems are urgently needed to be solved in the plastic forming.

Although the upsetting die and the forming method reported at present can realize no bending and no folding upsetting, the upsetting die and the forming method can only realize bar upsetting forming with the height-diameter ratio not more than 4.2, and cannot realize bar upsetting forming with a larger height-diameter ratio, and when the bar upsetting forming with a higher height-diameter ratio is carried out, multiple sets of upsetting dies are often needed, so that the manufacturing cost of the die is high, and the production efficiency is extremely low due to frequent replacement of the die.

Disclosure of Invention

Aiming at the defects in the existing large-height-diameter-ratio bar upsetting technology, the invention provides an upsetting die suitable for a round bar with an ultra-large height-diameter ratio and a forming method of the round bar, wherein the upsetting die can be used for realizing the upsetting forming of the bar with the height-diameter ratio of 3-6 and the folding-free uniform upsetting forming of the bar with the height-diameter ratio of more than 6, the die is low in preparation cost, and is not required to be frequently replaced in the using process, and the production efficiency is high.

The purpose of the invention is realized by the following technical scheme:

an upsetting die for a round bar, which comprises an upper die and a lower die; the upper die comprises an upper anvil block, an upper padding plate and an upper female die, and the upper padding plate and the upper female die are connected with the upper anvil block; the lower die comprises a lower female die, a lower backing plate and a lower anvil block, and the lower female die and the lower backing plate are connected with the lower anvil block;

the upper female die is provided with a structure with two open ends and a first inner concave cavity, and the structure of the first inner concave cavity comprises a first non-deformation constraint area and a first deformation area; the lower female die is provided with a structure with two open ends and a second inner concave cavity, and the structure of the second inner concave cavity comprises a second non-deformation constraint area and a second deformation area; the first deformation area is close to the second deformation area, and the first deformation area and the second deformation area are assembled into a bar upsetting forming area with the height-diameter ratio being less than or equal to 3.

According to the embodiment of the invention, the bar upsetting forming area formed by assembling the first deformation area and the second deformation area is used for realizing the folding-free uniform upsetting forming of the bar with the height-diameter ratio of more than 3.

According to the embodiment of the invention, the first and second non-deforming restraining areas are internally provided with cushion blocks for controlling the blanks in the first and second non-deforming restraining areas to enter the first and second deforming areas so as to finish the folding-free uniform upsetting formation.

According to an embodiment of the invention, the upper die may be embedded in the lower die, i.e. the upper die fits into the lower die. Preferably, the upper concave die in the upper die can be embedded into the lower concave die in the lower die, that is, the upper concave die is matched with the inner concave cavity of the lower concave die in the lower die.

According to the embodiment of the invention, the upper concave die is provided with a structure with a first inner concave cavity with two open ends, and the structure of the first inner concave cavity comprises a first non-deformation restraining area and a first deformation area which are connected; the structure of the first non-deforming constraint area is a first truncated cone-shaped structure, the structure of the first deforming area is a second truncated cone-shaped structure, and the taper of the wall surface of the first truncated cone-shaped structure is smaller than that of the wall surface of the second truncated cone-shaped structure.

According to an embodiment of the invention, the diameter of the bottom surface of the first truncated cone-shaped structure is equal to the diameter of the top surface of the second truncated cone-shaped structure.

According to an embodiment of the invention, said first undeformed restraining zone is adjacent to the side of the upper anvil and said first deforming zone is remote from the side of the upper anvil, i.e. the first frustoconical configuration of said first undeformed restraining zone is adjacent to the side of the upper anvil and the second frustoconical configuration of said first deforming zone is remote from the side of the upper anvil.

According to an embodiment of the invention, the taper of the wall surface of the first truncated cone-shaped structure is smaller than the taper of the wall surface of the second truncated cone-shaped structure, i.e. smaller than 60-80 °.

According to an embodiment of the present invention, a taper α of the wall surface of the second truncated cone structure is 60 to 80 °. The taper of the wall surface of the second truncated cone-shaped structure is the taper of the forming wall surface of the upper concave die.

According to an embodiment of the present invention, the height h of the first truncated cone shaped structure satisfies the following relation: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of the round rod. The height h of the first truncated cone-shaped structure is the forming height of the upper concave die.

According to an embodiment of the present invention, the upper die is placed on the upper mat, and the upper die and the upper mat are fixed to the upper anvil by fastening bolts.

According to an embodiment of the invention, the diameter of the top surface of the first truncated cone shaped structure matches the diameter of the upper backing plate.

According to the embodiment of the invention, the lower concave die is provided with a structure with a second inner concave cavity with two open ends, and the structure of the second inner concave cavity comprises a second non-deformation restraining area and a second deformation area which are connected; the structure of the second non-deforming constraint area is a third truncated cone-shaped structure, the structure of the second deforming area is a fourth truncated cone-shaped structure, a cylindrical structure and a fifth truncated cone-shaped structure which are sequentially connected, the taper of the wall surface of the third truncated cone-shaped structure is smaller than that of the wall surface of the fourth truncated cone-shaped structure, and the taper of the wall surface of the fourth truncated cone-shaped structure is smaller than that of the wall surface of the fifth truncated cone-shaped structure.

According to an embodiment of the invention, the diameter of the cylindrical structure is equal to the diameter of the bottom surface of the fourth truncated cone-shaped structure, and the diameter of the cylindrical structure is equal to the diameter of the top surface of the fifth truncated cone-shaped structure; the diameter of the bottom surface of the third truncated cone-shaped structure is equal to the diameter of the top surface of the fourth truncated cone-shaped structure.

According to an embodiment of the invention said second non-deforming restraining region is adjacent to the lower anvil side and said second deforming region is remote from the lower anvil side, i.e. said third cone-shaped formation of said second non-deforming restraining region is adjacent to the lower anvil side and said fifth cone-shaped formation of said second deforming region is remote from the lower anvil side.

According to an embodiment of the invention, the taper of the wall surface of the third truncated cone structure is smaller than the taper of the wall surface of the fourth truncated cone structure, i.e. smaller than 60-80 °.

According to an embodiment of the present invention, a taper α of the wall surface of the fourth truncated cone structure is 60 to 80 °. The taper of the wall surface of the fourth truncated cone-shaped structure is the taper of the forming wall surface of the lower concave die.

According to an embodiment of the invention, the taper of the wall surface of the fifth truncated cone-shaped structure is greater than the taper of the wall surface of the fourth truncated cone-shaped structure, i.e. greater than 60-80 °.

According to an embodiment of the invention, the height h of the third truncated cone shaped structure satisfies the following relation: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of the round rod. And the height h of the third truncated cone-shaped structure is the forming height of the lower concave die.

According to an embodiment of the invention, the diameter d of the cylindrical structure_{Wall surface}Satisfies the following relation: d_{Wall surface}=（1.4~1.8）d_{Round bar}. Diameter d of the cylindrical structure_{Wall surface}The diameter of the forming wall surface of the lower concave die.

According to an embodiment of the invention, the cylinderHeight h of the profile_{Wall surface}Satisfies the following relation: h is_{Wall surface}=（1.0~1.2）d_{Round bar} ²×h_{Round bar}/d_{Wall surface} ²，d_{Round bar}Is the diameter of the round bar, h_{Round bar}Is the height of the round bar. Height h of the cylindrical structure_{Wall surface}The height of the formed wall surface of the lower concave die.

According to an embodiment of the present invention, the lower cavity die is placed on the lower pad plate, and the lower cavity die and the lower pad plate are fixed to the lower anvil by fastening bolts.

According to an embodiment of the invention, the diameter of the top surface of the third truncated cone shaped structure matches the diameter of the lower shim plate.

According to an embodiment of the invention, the second and fourth truncated cone shaped structures are symmetrical structures. Specifically, the taper of the wall surface of the second truncated cone-shaped structure is the same as the taper of the wall surface of the fourth truncated cone-shaped structure. The height of the second truncated cone-shaped structure is equal to the height of the fourth truncated cone-shaped structure.

According to an embodiment of the invention, the first and third truncated cone shaped structures are symmetrical structures. Specifically, the taper of the wall surface of the first truncated cone-shaped structure is the same as the taper of the wall surface of the third truncated cone-shaped structure. The height of the first truncated cone-shaped structure is equal to the height of the third truncated cone-shaped structure.

In the present invention, the bottom surface of the truncated cone-shaped structure refers to a surface with a larger diameter in the truncated cone-shaped structure, and the top surface of the truncated cone-shaped structure refers to a surface with a smaller diameter in the truncated cone-shaped structure.

In the invention, the taper of the wall surface of the circular truncated cone-shaped structure refers to the ratio of the diameter difference of the upper bottom circle and the lower bottom circle of the circular truncated cone to the height of the circular truncated cone.

The invention also provides a method for forming the round bar with the ultra-large height-diameter ratio, which is based on the upsetting die of the round bar and comprises the following steps:

1) according to the diameter and the height of the round bar, determining the conicity of the forming wall surfaces of the upper female die and the lower female die, the diameter and the height of the forming wall surface of the lower female die and the forming height of the upper female die and the lower female die, and further determining the upsetting reduction and the upsetting times of each time;

2) placing a round bar into the upper female die and the lower female die, heating, carrying out primary upsetting forming, and respectively adding base plates with the same thickness into the upper female die and the lower female die according to the upsetting reduction of each time;

3) and repeating the upsetting forming treatment for many times until the height-diameter ratio of the round bar is less than 3.

According to an embodiment of the present invention, in step 1), the calculation formula of the reduction per upset is h_{Reduction of}=(0.4~0.6）[3d_{Round bar}-（3d_{Round bar} ³/d_{Wall surface} ²）]，d_{Round bar}Is the diameter of the round bar, d_{Wall surface}The diameter of the cylindrical structure.

According to an embodiment of the present invention, in step 1), the number of upsetting times n is ≧ (h)_{Round bar}-3d_{Wall surface}）/h_{Reduction of}，h_{Round bar}Is the height of the round bar, d_{Wall surface}Diameter of cylindrical structure, h_{Reduction of}The reduction per upset.

According to an embodiment of the present invention, in step 2), the thickness of the pad plate was 1/2 per upset reduction.

The bar upsetting forming area assembled by the first deformation area and the second deformation area in the upsetting die of the round bar with the ultra-large height-diameter ratio is used for realizing folding-free uniform upsetting forming of the bar with the height-diameter ratio of more than 3, and specifically, the upsetting is restrained by controlling the diameter of the forming wall surface of the lower female die; according to the upsetting die for the round bar with the ultra-large height-diameter ratio, the cushion blocks are continuously added into the first non-deformation restraining area and the second non-deformation restraining area, so that the non-deformation restraining area is reduced, the amount of blanks in the first non-deformation restraining area and the second non-deformation restraining area entering the first deformation area and the second deformation area is further controlled, uniform deformation of the whole blank is realized, and non-folding uniform upsetting forming is completed.

The upsetting die for the round bar with the ultra-large height-diameter ratio is convenient to operate and high in production efficiency, and after primary upsetting, the blank is automatically ejected out, and a cushion block is continuously added for secondary upsetting; the upsetting die of the round bar with the ultra-large height-diameter ratio only utilizes one set of die, and the cushion block is very small, simple in structure and low in cost.

The invention has the beneficial effects that:

the invention provides an upsetting die and a forming method for a round bar with an ultra-large height-diameter ratio. The upsetting die is low in preparation cost, high in production efficiency and low in production cost, and the die does not need to be replaced frequently. In addition, the die is suitable for various metal materials such as aluminum, steel, titanium, high-temperature alloy and the like, and has strong universality.

Drawings

FIG. 1 is an assembly view of an upsetting die according to a preferred embodiment of the present invention;

wherein, 1-upper anvil block, 2-upper backing plate, 3-upper concave die, 4-round bar, 5-lower concave die, 6-lower backing plate, 7-lower anvil block;

FIG. 2 is a schematic critical dimension view of the upsetting die of FIG. 1;

FIG. 3 is a schematic view of upset forming according to a preferred embodiment of the present invention; wherein, from left to right are the first upsetting, the second upsetting and the third upsetting respectively.

Detailed Description

The preparation method of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.

In the description of the present invention, it should be noted that the terms "first", "second", etc. are used for descriptive purposes only and do not indicate or imply relative importance.

Example 1

The embodiment provides an upsetting die for a round bar, which specifically includes, as shown in fig. 1 to 3, an upper die and a lower die; the upper die comprises an upper anvil block 1, an upper backing plate 2 and an upper female die 3, wherein the upper backing plate 2 and the upper female die 3 are connected with the upper anvil block 1; the lower die comprises a lower female die 5, a lower backing plate 6 and a lower anvil block 7, and the lower female die 5 and the lower backing plate 6 are connected with the lower anvil block 7; the upper female die 3 is provided with a structure with two open ends and a first inner concave cavity, and the structure of the first inner concave cavity comprises a first non-deformation constraint area and a first deformation area; the lower female die 5 is provided with a structure with two open ends and a second inner concave cavity, and the structure of the second inner concave cavity comprises a second non-deformation constraint area and a second deformation area; the first deformation area is close to the second deformation area, and the first deformation area and the second deformation area are assembled into a bar upsetting forming area with the height-diameter ratio being less than or equal to 3.

The upper female die 3 is provided with a structure with two open ends and a first inner concave cavity, and the structure of the first inner concave cavity comprises a first non-deformation constraint area and a first deformation area which are connected; the structure of the first non-deforming constraint area is a first truncated cone-shaped structure, the structure of the first deforming area is a second truncated cone-shaped structure, the diameter of the bottom surface of the first truncated cone-shaped structure is equal to the diameter of the top surface of the second truncated cone-shaped structure, and the taper of the wall surface of the first truncated cone-shaped structure is smaller than that of the wall surface of the second truncated cone-shaped structure;

the lower female die 5 is provided with a structure with two open ends and a second inner concave cavity, and the structure of the second inner concave cavity comprises a second non-deforming constraint area and a second deforming area which are connected; the structure of the second non-deforming constraint area is a third truncated cone-shaped structure, the structure of the second deforming area is a fourth truncated cone-shaped structure, a cylindrical structure and a fifth truncated cone-shaped structure which are sequentially connected, the diameter of the cylindrical structure is equal to the diameter of the bottom surface of the fourth truncated cone-shaped structure, and the diameter of the cylindrical structure is equal to the diameter of the top surface of the fifth truncated cone-shaped structure; the diameter of the bottom surface of the third truncated cone-shaped structure is equal to the diameter of the top surface of the fourth truncated cone-shaped structure, the taper of the wall surface of the third truncated cone-shaped structure is smaller than that of the wall surface of the fourth truncated cone-shaped structure, and the taper of the wall surface of the fourth truncated cone-shaped structure is smaller than that of the wall surface of the fifth truncated cone-shaped structure.

The taper alpha of the wall surface of the second truncated cone-shaped structure is 60-80 degrees. The taper alpha of the wall surface of the fourth truncated cone-shaped structure is 60-80 degrees.

The height h of the first truncated cone-shaped structure satisfies the following relational expression: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of the round rod. The height h of the third truncated cone-shaped structure satisfies the following relation: h =1/2 (h)_{Round bar}-3d_{Round bar})，h_{Round bar}Is the height of the round bar, d_{Round bar}Is the diameter of the round rod.

Diameter d of the cylindrical structure_{Wall surface}Satisfies the following relation: d_{Wall surface}=（1.4~1.8）d_{Round bar}. Height h of the cylindrical structure_{Wall surface}Satisfies the following relation: h is_{Wall surface}=（1.0~1.2）d_{Round bar} ²×h_{Round bar}/d_{Wall surface} ²，d_{Round bar}Is the diameter of the round bar, h_{Round bar}Is the height of the round bar.

The taper of the wall surface of the second truncated cone-shaped structure is the same as that of the wall surface of the fourth truncated cone-shaped structure. The height of the first truncated cone-shaped structure is equal to the height of the third truncated cone-shaped structure. The height of the second truncated cone-shaped structure is equal to the height of the fourth truncated cone-shaped structure.

The first non-deforming restraining area is close to one side of the upper anvil 1, and the first deforming area is far from one side of the upper anvil 1, that is, the first truncated cone-shaped structure of the first non-deforming restraining area is close to one side of the upper anvil 1, and the second truncated cone-shaped structure of the first deforming area is far from one side of the upper anvil 1. The upper female die 3 is placed on the upper backing plate 2, and the upper female die 3 and the upper backing plate 2 are fixed on the upper anvil block 1 through fastening bolts.

The second non-deforming restraining region is close to the lower anvil 7 side, and the second deforming region is far from the lower anvil 7 side, i.e. the third circular truncated cone shaped structure of the second non-deforming restraining region is close to the lower anvil 7 side, and the fifth circular truncated cone shaped structure of the second deforming region is far from the lower anvil 7 side. The lower die 5 is placed on the lower bolster 6, and the lower die 5 and the lower bolster 6 are fixed to the lower anvil block 7 by fastening bolts.

The bar upsetting forming area assembled by the first deformation area and the second deformation area is used for realizing folding-free uniform upsetting forming of the bar with the height-diameter ratio of more than 3; and adding cushion blocks in the first non-deformation restraining area and the second non-deformation restraining area to control the blanks in the first non-deformation restraining area and the second non-deformation restraining area to enter the first deformation area and the second deformation area so as to finish folding-free uniform upsetting forming.

Example 2

This embodiment provides a method for forming a round bar with an ultra-large height-to-diameter ratio, where the method is based on the upsetting die of the round bar described in embodiment 1, and the metal material in this embodiment is an aluminum-based composite material, and the diameter d of the original bar material is the diameter of the aluminum-based composite material_{Round bar}=100mm, height h_{Round bar}=700mm, and the height-diameter ratio of the round bar is 7.0. The forming method comprises the following steps:

step (1): according to the diameter and the height of the round bar, the conicity of the forming wall surface of the upper concave die 3 and the lower concave die 5, the diameter and the height of the forming wall surface of the lower concave die 5 and the forming height of the upper concave die 3 and the lower concave die 5 are determined, and the specific steps are as follows:

height h =1/2 (h) of molding of upper die 3_{Round bar}-3d_{Round bar}) =200mm, taper α =70 ° of the molding wall surface of the upper die 3, and height h =1/2 (h) of the molding of the lower die 5 (h)_{Round bar}-3d_{Round bar}) =200mm, taper α =70 ° of the forming wall surface of the lower die 5, and diameter d of the forming wall surface of the lower die 5_{Wall surface}=1.6d_{Round bar}=160mm, height h of the forming wall surface of the lower cavity die 5_{Wall surface}=（1.0~1.2）d_{Round bar} ²×h_{Round bar}/d_{Wall surface} ²=300mm。

Determining the reduction h of each upsetting_{Reduction of}=（0.4~0.6）[3d_{Round bar}-（3d_{Round bar} ³/d_{Wall surface} ²）]=90 mm. The upsetting frequency n is more than or equal to 2.44, namely the upsetting frequency is 3.

Step (2): heating the round rod 4, the upper female die 3 and the lower female die 5, and then performing primary upsetting forming, wherein the upsetting reduction is set to be 90mm, and the height of an upset part is 610 mm;

and (3): respectively adding base plates with the thickness of 45mm in the upper die and the lower die, and carrying out secondary upsetting forming, wherein the upsetting reduction is set to be 90mm, and the height of an upset piece is 520 mm;

and (4): and carrying out third upsetting forming according to the same method, wherein the upsetting reduction is set to be 90mm, the height of the upsetting piece is 430mm, the diameter of the upsetting piece is 160mm, and the height-diameter ratio of the upsetting piece is less than 3, so that free forging such as upsetting and drawing and plastic forming such as extrusion and rolling can be carried out, and the requirements of products in various shapes are met.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.