A forming method of annular forging and a forming die thereof

Abstract

The present invention provides a forming method and a forming die of an annular forging that can make the three-dimensional performance of the forging more uniform, and relates to the field of forging technology. A forming method of an annular forging, comprising the following steps: designing a final forging according to the shape of the annular forging, and final forging convex rings are respectively provided on both sides of the final forging; designing a preliminary forging according to the final forging, and pre-forging convex rings are respectively provided on both sides of the preliminary forging, and the position of the pre-forging convex ring deviates from the position of the final forging convex ring; blanking: blanking to obtain a cylindrical blank, the diameter of the blank is smaller than the inner diameter of the annular forging; pre-forging: using a pre-forging die to extrude the blank from the axial direction of the blank to form the preliminary forging; final forging: using a final forging die to form the final forging, wherein, during the final forging process, the final forging die causes the material at the pre-forging convex rings on both sides of the preliminary forging to produce opposite extrusion deformation to form the final forging. The forging formed by this method has better performance.

Description

Technical Field

[0001] The invention relates to the technical field of forging, and in particular to a forming method of a ring forging and a forming die thereof. Background Art

[0002] In the aerospace field, there are many annular forgings. In order to ensure the annular performance of the forgings, the three-dimensional (chordal, radial, and axial) performance of the annular forgings is required to be as uniform as possible.

[0003] At present, ring forgings are usually prepared by ring rolling or horse bar expansion. However, the deformation of ring rolling and hole expansion mainly occurs in the tangential and radial directions, and the axial deformation is relatively small, which will lead to uneven three-dimensional performance of forgings, and the performance details in the axial direction are lower than those in other directions. Especially in aluminum alloy forgings, the above phenomenon is particularly prominent. In addition, ring rolling and hole expansion will significantly elongate the diameter and tangential direction of the grain, resulting in the axial streamline not following the shape during the die forging process, and the performance difference in the three directions is too large, which does not meet the high performance requirements of forgings. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a forming method and a forming die for an annular forging which can make the three-dimensional properties of the forging more uniform.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a forming method of an annular forging, comprising the following steps:

[0006] A ring-plate-shaped final forging is designed according to the shape of the annular forging, and both sides of the final forging are respectively provided with symmetrically arranged final forging convex rings;

[0007] A disc-shaped preliminary forging is designed according to the final forging, and symmetrically arranged pre-forging convex rings are respectively provided on both sides of the preliminary forging, and the position of the pre-forging convex ring deviates from the position of the final forging convex ring;

[0008] Blank making: blanking is performed to obtain a cylindrical blank, wherein the diameter of the blank is smaller than the inner diameter of the annular forging;

[0009] Pre-forging: using a pre-forging die to extrude the blank from the axial direction of the blank to form the preliminary forging;

[0010] Final forging: forming the final forging by using a final forging die, wherein, during the final forging process, the final forging die causes the materials at the pre-forging convex rings on both sides of the initial forging to be extruded and deformed toward each other, and then squeezes the materials into the position of the final forging convex ring to form the final forging;

[0011] Machining removes excess material from the final forging.

[0012] Furthermore, in the pre-forging step, the deformation amount of each part of the blank is greater than or equal to 50%, and in the final forging step, the deformation amount of each part of the initial forging is greater than or equal to 50%.

[0013] Furthermore, the position of the pre-forging convex ring deviates toward the outside of the final forging convex ring.

[0014] Further, the pre-forging die comprises a pre-forging upper die and a pre-forging lower die, the pre-forging upper die and the pre-forging lower die are respectively provided with a circular pre-forging cavity, the bottom surface of the pre-forging cavity is provided with a pre-forging annular groove for forming a pre-forging convex ring, and the pre-forging cavity of the pre-forging upper die cooperates with the pre-forging cavity of the pre-forging lower die to form a pre-forging forming cavity for forming the pre-forging;

[0015] During pre-forging, the blank is placed in the center of the pre-forging cavity of the pre-forging lower die, and the blank is squeezed in the axial direction of the blank by the pre-forging upper die so that the material fills the preliminary forging forming cavity, thereby forming the preliminary forging.

[0016] Furthermore, a positioning groove is processed at the center of one end of the blank, and a protrusion adapted to the positioning groove is provided at the center of the pre-forging cavity of the pre-forging lower die. During pre-forging, the blank is placed in the pre-forging cavity of the pre-forging lower die so that the positioning groove cooperates with the protrusion, thereby realizing the pre-forging positioning of the blank.

[0017] Further, the final forging die comprises a final forging upper die and a final forging lower die, the final forging upper die and the final forging lower die are respectively provided with an annular final forging cavity, the bottom surface of the final forging cavity is provided with a final forging annular groove for forming a final forging convex ring, and the final forging cavity of the final forging upper die cooperates with the final forging cavity of the final forging lower die to form a final forging forming cavity for forming the final forging;

[0018] During final forging, the initial forging is placed in the final forging cavity of the final forging lower die, so that the pre-forging convex ring is located on the outside or inside of the final forging annular groove, and the final forging upper die is used to extrude the initial forging from the axial direction of the initial forging, so that the materials at the pre-forging convex rings on both sides of the initial forging are extruded and deformed towards each other, and then the material is squeezed into the final forging annular groove and fills the final forging forming cavity to form the final forging.

[0019] A forming die for the above-mentioned ring forging forming method, comprising a pre-forging die and a final forging die;

[0020] The pre-forging die comprises a pre-forging upper die and a pre-forging lower die, each of which is provided with a circular pre-forging cavity, the bottom surface of which is provided with a pre-forging annular groove for forming a pre-forging convex ring, and the pre-forging cavity of the pre-forging upper die cooperates with the pre-forging cavity of the pre-forging lower die to form a pre-forging forming cavity for forming the pre-forging;

[0021] The final forging die comprises a final forging upper die and a final forging lower die, wherein the final forging upper die and the final forging lower die are respectively provided with an annular final forging cavity, and the bottom surface of the final forging cavity is provided with a final forging annular groove for forming a final forging convex ring, and the final forging cavity of the final forging upper die cooperates with the final forging cavity of the final forging lower die to form a final forging forming cavity for forming the final forging;

[0022] The position of the pre-forging annular groove deviates from the position of the final forging annular groove.

[0023] Furthermore, a protrusion is provided at the center of the pre-forging cavity of the pre-forging lower die.

[0024] Furthermore, the position of the pre-forging annular groove deviates toward the outside of the final forging annular groove.

[0025] The beneficial effects of the present invention are as follows: in the forming method of the ring forging of the present invention and its forming die, during pre-forging, the material mainly flows radially outward along the blank, which can ensure that the formed initial forging is uniformly deformed in the radial and rotational directions. During final forging, since the positions of the pre-forging convex rings on both sides of the initial forging deviate from the positions of the final forging convex rings of the final forging, the material of the pre-forging convex ring part can be squeezed and deformed downward during the die forging process, so that the material of the pre-forging convex ring part with smaller extrusion deformation during the pre-forging deformation is squeezed again, thereby obtaining a final forging with more uniform three-dimensional deformation, and the three-dimensional performance of the forging is more uniform. In addition, when the present invention forms the ring forging, the forging is mainly subjected to extrusion deformation in all directions, and the grains of the forging formed by this method will not be extended or elongated, the grains are finer and more uniform, and the performance of the forging is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic cross-sectional view of a final forging of the present invention;

[0027] Figure 2 is a schematic cross-sectional view of a preliminary forging of the present invention;

[0028] Figure 3 is a schematic diagram of the forming process of the ring forging of the present invention;

[0029] Figure 4 It is the final forging schematic diagram;

[0030] Figure 5 It is a schematic diagram of the structure of the rough block;

[0031] Figure 6 It is a structural schematic diagram of the pre-forging lower die;

[0032] Figure 7 It is a structural schematic diagram of the final forging lower die;

[0033] As shown in the figure: blank 1, pre-forging die 2, initial forging 3, final forging die 4, annular final forging 5, extrusion pressure 6, positioning groove 11, pre-forging cavity 21, pre-forging annular groove 22, protrusion 23, pre-forging upper die 24, pre-forging lower die 25, pre-forging convex ring 31, final forging cavity 41, final forging annular groove 42, flash bin 43, final forging upper die 44, final forging lower die 45, final forging convex ring 51. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0035] See also Figures 1 to 3 A forming method of a ring forging of the present invention comprises the following steps:

[0036] Step 1: designing a ring-plate-shaped final forging 5 according to the shape of the annular forging, wherein two sides of the final forging 5 are respectively provided with symmetrically arranged final forging convex rings 51;

[0037] Step 2: designing a disc-shaped preliminary forging 3 according to the final forging 5, wherein two sides of the preliminary forging 3 are respectively provided with symmetrically arranged pre-forging convex rings 31, and the position of the pre-forging convex ring 31 deviates from the position of the final forging convex ring 51;

[0038] Step 3, blank making: blanking is performed to obtain a cylindrical blank 1, wherein the diameter of the blank 1 is smaller than the inner diameter of the annular forging;

[0039] Step 4: pre-forging: using the pre-forging die 2 to extrude the blank 1 in the axial direction of the blank 1 to form the preliminary forging 3;

[0040] Step 5, final forging: forming the final forging 5 by using the final forging die 4, wherein, during the final forging process, the final forging die 4 causes the materials at the pre-forging convex rings 31 on both sides of the initial forging 3 to be extruded and deformed toward each other, and then squeezes the materials into the position of the final forging convex ring 51, thereby forming the final forging 5;

[0041] Step 6: Process and remove excess material from the final forging.

[0042] It should be noted that in the present invention, the blank 1 is made into a cylindrical blank, which can be a solid or hollow cylinder. When the inner diameter of the annular forging is large, the blank 1 can be a hollow cylinder; the disc-shaped preliminary forging 3 also includes a circular ring plate structure, that is, a hole is provided in the center of the disc-shaped preliminary forging 3. When the inner diameter of the annular forging is large, the disc-shaped preliminary forging 3 can be designed as an annular plate structure.

[0043] Step six is ​​mainly to remove the excess material on both sides of the final forging convex ring 51 of the final forging.

[0044] During final forging, in order to facilitate the placement of the preliminary forging 3, part of the material of the preliminary forging 3 can be removed to make it ring-shaped.

[0045] In the pre-forging, the blank 1 is in a flattening process, and the chordal and radial extrusion of the initial forging 3 is relatively sufficient during the forming process, while in the axial direction, the material is difficult to enter, so the axial (height) deformation is small. Figure 4 As shown, since the position of the pre-forging convex rings 31 on both sides of the initial forging 3 deviates from the position of the final forging convex rings 51 of the final forging 5, during the final forging, the final forging die 4 provides an opposite extrusion force 6 to the pre-forging convex rings 31 on both sides of the initial forging 3, and the materials at the pre-forging convex rings 31 on both sides of the initial forging 3 are subjected to opposite extrusion deformation, and then the materials are squeezed into the position of the final forging convex rings 51 to form the final forging 5. In this way, the material with smaller extrusion deformation in the pre-forging convex ring part during the pre-forging deformation can be squeezed again, thereby compensating for the lack of axial extrusion deformation of the forging during the pre-forging process, and then a final forging with three-dimensional deformation and more uniform performance can be obtained. When the method of the present invention forms annular forgings, the forgings are mainly subjected to extrusion deformation in all directions. Compared with conventional ring rolling and hole expansion forming methods, the grains of the forgings formed by this method will not be extended or elongated, the grains are finer and more uniform, and the performance of the forgings is also better.

[0046] The position of the pre-forging convex ring 31 can deviate toward the outside or inside of the final forging convex ring 51. Preferably, the position of the pre-forging convex ring 31 deviates toward the outside of the final forging convex ring 51. In this way, during final forging, the first convex ring 31 is located outside the final forging annular groove 43. During final forging, the flow direction of the material is first radially inward and then enters the final forging annular groove 42. There is a reverse extrusion process opposite to the extrusion during pre-forging. In this way, the annular deformation of the forging can be more uniform and the annular performance of the forging can be better.

[0047] like Figure 3 , Figure 6 , Figure 7As shown, the present invention also provides a forming die for the above-mentioned forming method, including a pre-forging die 3 and a final forging die 4; the pre-forging die 2 includes a pre-forging upper die 24 and a pre-forging lower die 25, the pre-forging upper die 24 and the pre-forging lower die 25 are respectively provided with a circular pre-forging cavity 21, the bottom surface of the pre-forging cavity 21 (the side opposite to the opening of the pre-forging cavity 21) is provided with a pre-forging annular groove 22 for forming a pre-forging convex ring 31, when the pre-forging upper die 24 and the pre-forging lower die 25 are closed, the pre-forging cavity 21 of the pre-forging upper die 24 cooperates with the pre-forging cavity 21 of the pre-forging lower die 25 to form a forming The initial forging forming cavity of the initial forging 3; the final forging die 4 includes a final forging upper die 44 and a final forging lower die 45, the final forging upper die 44 and the final forging lower die 45 are respectively provided with an annular final forging cavity 41, the bottom surface of the final forging cavity 41 is provided with a final forging annular groove 42 for forming a final forging convex ring 51, when the final forging upper die 44 and the final forging lower die 45 are closed, the final forging cavity 41 of the final forging upper die 44 cooperates with the final forging cavity 41 of the final forging lower die 45 to form a final forging forming cavity for forming the final forging 5; the position of the pre-forging annular groove 22 deviates from the position of the final forging annular groove 42.

[0048] Specific pre-forging process: During pre-forging, the blank 1 is placed in the center of the pre-forging cavity 21 of the pre-forging lower die 25, and the blank 1 is squeezed from the axial direction of the blank 1 by the pre-forging upper die 24 so that the material fills the preliminary forging forming cavity, thereby forming the preliminary forging 3.

[0049] Specific final forging process: During final forging, the initial forging 3 is placed in the final forging cavity 41 of the final forging lower die 45, so that the pre-forging convex ring 31 is located on the outside or inside of the final forging annular groove 43, and the final forging upper die 44 is used to extrude the initial forging 3 from the axial direction of the initial forging 3, so that the materials at the pre-forging convex rings 31 on both sides of the initial forging 3 are extruded and deformed in opposite directions, and then the materials are squeezed into the final forging annular groove 43 and fill the final forging forming cavity to form the final forging 5.

[0050] It can be understood that whether the pre-forging convex ring 31 is located outside or inside the final forging annular groove 43 during final forging is determined according to the position deviation of the pre-forging convex ring 31. When the position of the pre-forging convex ring 31 deviates toward the outside of the final forging convex ring 51, the pre-forging convex ring 31 is located outside the final forging annular groove 43 during final forging; when the position of the pre-forging convex ring 31 deviates toward the inside of the final forging convex ring 51, the pre-forging convex ring 31 is located inside the final forging annular groove 43 during final forging.

[0051] Since the position of the pre-forging annular groove 22 of the pre-forging die 3 deviates from the position of the final forging annular groove 42, during final forging, the final forging die 4 can provide an opposite extrusion force 6 to the pre-forging convex rings 31 on both sides of the initial forging 3, and the materials at the pre-forging convex rings 31 on both sides of the initial forging 3 are extruded and deformed in opposite directions, and then the materials are squeezed into the position of the final forging convex ring 51 to form the final forging 5. In addition, when the forming die forms the annular forging, the forging is mainly subjected to extrusion deformation in all directions. Compared with the conventional ring rolling and hole expansion forming method, the grains of the forging formed by this method will not be extended or elongated, the grains are finer and more uniform, and the performance of the forging is also better.

[0052] When the pre-forging die 3 and the final forging die 4 simultaneously adopt the above-mentioned structure, the anisotropic properties and the quality of the forged parts are optimal.

[0053] In some embodiments, the pre-forging upper die 24 may not be provided with a pre-forging cavity 21, while the pre-forging lower die 25 is provided with a deeper pre-forging cavity 21, a pre-forging annular groove 22 is provided at the bottom of the pre-forging cavity 21, and the pre-forging upper die 24 uses a flat anvil adapted to the pre-forging cavity 21, and the flat anvil is provided with a pre-forging annular groove 22. In some embodiments, the final forging upper die 44 may not be provided with a final forging cavity, while the final forging lower die 45 is provided with a deeper final forging cavity, a final forging annular groove 42 is provided at the bottom of the final forging cavity, and the pre-forging upper die 24 uses a flat anvil adapted to the final forging cavity, and the anvil is provided with a final forging annular groove 42.

[0054] In order to further ensure the isotropic properties of the forgings, the deformation of each part of each forging is greater than or equal to 50% in the pre-forging step and the final forging step. That is, during the pre-forging, the deformation of each part of the rough forging is greater than or equal to 50% in the process of forging the rough forging into the initial forging, and during the final forging, the deformation of each part of the initial forging is greater than or equal to 50% in the process of changing the initial forging into the final forging.

[0055] In order to facilitate pre-forging positioning, Figure 5 As shown, a positioning groove 11 is processed at the center of one end of the blank 1, and a protrusion 23 matching the positioning groove 11 is provided at the center of the pre-forging cavity 21 of the pre-forging lower die 25. During pre-forging, the blank 1 is placed in the pre-forging cavity 21 of the pre-forging die 2, so that the positioning groove 11 matches the protrusion 23, thereby achieving pre-forging positioning of the blank. In order to further ensure positioning, a positioning groove 11 can also be processed at the center of the other end of the blank 1, and a corresponding protrusion 23 is also provided at the pre-forging upper die 24.

[0056] In the present invention, both sides of the cavities of the upper and lower dies of the pre-forging die 2 and the final forging die are provided with flash storage parts 43 .

[0057] Preferably, the position of the pre-forging annular groove 22 deviates from the outer side of the final forging annular groove 42. In this way, during final forging, the first convex ring 31 is located outside the final forging annular groove 43, and the flow direction of the material during final forging is to flow radially inward first and then enter the final forging annular groove 42. There is a reverse extrusion process opposite to the extrusion during pre-forging, so that the annular deformation of the forging can be more uniform and the annular performance of the forging can be better.

Claims

1. A method for forming a ring forging, characterized in that: The following steps are involved: A ring-plate-shaped final forging (5) is designed according to the shape of the annular forging, and both sides of the final forging (5) are respectively provided with symmetrically arranged final forging convex rings (51); A disc-shaped preliminary forging (3) is designed according to the final forging (5), wherein two sides of the preliminary forging (3) are respectively provided with symmetrically arranged pre-forging convex rings (31), and the position of the pre-forging convex ring (31) deviates from the position of the final forging convex ring (51); Blank making: blanking is performed to obtain a cylindrical blank (1), wherein the diameter of the blank (1) is smaller than the inner diameter of the annular forging; Pre-forging: using a pre-forging die (2) to extrude the blank (1) in the axial direction of the blank (1) to form the preliminary forging (3); Final forging: forming the final forging (5) by using a final forging die (4), wherein during the final forging process, the final forging die (4) causes the materials at the pre-forging convex rings (31) on both sides of the initial forging (3) to be extruded and deformed toward each other, and then the materials are squeezed into the position of the final forging convex ring (51), thereby forming the final forging (5); Machining removes excess material from the final forging.

2. A method for forming a ring forging according to claim 1, characterized in that: In the pre-forging step, the deformation amount of each part of the blank (1) is greater than or equal to 50%, and in the final forging step, the deformation amount of each part of the initial forging (3) is greater than or equal to 50%.

3. A method for forming a ring forging according to claim 1, characterized in that: The position of the pre-forging convex ring (31) deviates toward the outside of the final forging convex ring (51).

4. A method for forming a ring forging according to claim 1, characterized in that: The pre-forging die (2) comprises a pre-forging upper die (24) and a pre-forging lower die (25), each of the pre-forging upper die (24) and the pre-forging lower die (25) being provided with a circular pre-forging cavity (21), the bottom surface of the pre-forging cavity (21) being provided with a pre-forging annular groove (22) for forming a pre-forging convex ring (31), the pre-forging cavity (21) of the pre-forging upper die (24) and the pre-forging cavity (21) of the pre-forging lower die (25) cooperating to form a pre-forging forming cavity for forming the pre-forging (3); During pre-forging, the blank (1) is placed at the center of the pre-forging cavity (21) of the pre-forging lower die (25), and the blank (1) is squeezed in the axial direction of the blank (1) by the pre-forging upper die (24) so ​​that the material fills the pre-forging forming cavity, thereby forming the pre-forging (3).

5. A method for forming a ring forging according to claim 4, characterized in that: A positioning groove (11) is processed at the center of one end of the blank (1), and a protrusion (23) matching the positioning groove (11) is provided at the center of the pre-forging cavity (21) of the pre-forging lower die (25). During pre-forging, the blank (1) is placed in the pre-forging cavity (21) of the pre-forging lower die (25), so that the positioning groove (11) and the protrusion (23) match, thereby realizing the pre-forging positioning of the blank.

6. A method for forming a ring forging according to claim 4 or 5, characterized in that: The final forging die (4) comprises a final forging upper die (44) and a final forging lower die (45), wherein the final forging upper die (44) and the final forging lower die (45) are respectively provided with an annular final forging cavity (41), and the bottom surface of the final forging cavity (41) is provided with a final forging annular groove (42) for forming a final forging convex ring (51), and the final forging cavity (41) of the final forging upper die (44) cooperates with the final forging cavity (41) of the final forging lower die (45) to form a final forging forming cavity for forming the final forging (5); During final forging, the initial forging (3) is placed in the final forging cavity (41) of the final forging lower die (45), so that the pre-forging convex ring (31) is located on the outside or inside of the final forging annular groove (42), and the initial forging (3) is extruded from the axial direction of the initial forging (3) by the final forging upper die (44), so that the materials at the pre-forging convex rings (31) on both sides of the initial forging (3) are extruded and deformed in opposite directions, and then the materials are squeezed into the final forging annular groove (42) and fill the final forging forming cavity, thereby forming the final forging (5).

7. A forming die for a forming method of a ring forging as claimed in any one of claims 1 to 6, characterized in that: It comprises a pre-forging die (2) and a final forging die (4); The pre-forging die (2) comprises a pre-forging upper die (24) and a pre-forging lower die (25), each of the pre-forging upper die (24) and the pre-forging lower die (25) being provided with a circular pre-forging cavity (21), the bottom surface of the pre-forging cavity (21) being provided with a pre-forging annular groove (22) for forming a pre-forging convex ring (31), the pre-forging cavity (21) of the pre-forging upper die (24) and the pre-forging cavity (21) of the pre-forging lower die (25) cooperating to form a pre-forging forming cavity for forming the pre-forging (3); The final forging die (4) comprises a final forging upper die (44) and a final forging lower die (45), wherein the final forging upper die (44) and the final forging lower die (45) are respectively provided with an annular final forging cavity (41), and the bottom surface of the final forging cavity (41) is provided with a final forging annular groove (42) for forming a final forging convex ring (51), and the final forging cavity (41) of the final forging upper die (44) cooperates with the final forging cavity (41) of the final forging lower die (45) to form a final forging forming cavity for forming the final forging (5); The position of the pre-forging annular groove (22) deviates from the position of the final forging annular groove (42).

8. A forming die as claimed in claim 7, characterized in that: A protrusion (23) is provided at the center of the pre-forging cavity (21) of the pre-forging lower die (25).

9. A forming die as claimed in claim 7, characterized in that: The position of the pre-forging annular groove (22) deviates toward the outside of the final forging annular groove (42).

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