Asymmetric single-hole frame die forging forming method

Abstract

The invention relates to the technical field of metal non-cutting machining, in particular to an asymmetric single-hole frame type die forging forming method. Comprising the following steps that S1, the weight t1 of a bar is selected according to the weight t of the asymmetric single-hole frame type die forging; s2, the bar is heated to the forging temperature, and after the core of the bar reaches the temperature, the bar is placed on a fast forging machine to be upset to the thickness H; s3, punching is conducted on the bar subjected to upsetting in the step 2, chambering is conducted through a saddle after punching is conducted, and an original rough blank is formed after chambering; s4, the original blank is arranged on a forming tool in a sleeving mode to form a final blank; and S5, the final blank is placed on a die forging machine to form the asymmetric single-hole frame type die forging. By means of the forming method, the final annular rough blank conforming to the shape of the forge piece can be obtained, a skin connecting dressing does not need to be added when the asymmetric single-hole frame type die forging piece is designed, materials needed for forming the asymmetric single-hole frame type die forging piece are reduced by more than 30%, and loads needed for forming are reduced by more than 20% due to reduction of the projection area.

Description

Technical Field

[0001] The invention relates to the technical field of metal non-cutting processing, in particular to a forming method of an asymmetric single-hole frame-type die forging. Background Art

[0002] In order to achieve design indicators such as lightweight, long life, and high reliability, the design of the main load-bearing structural parts of the new generation of aircraft is developing towards large-scale, integrated, and complex directions, and the manufacturing difficulty is increasing. Large frame and beam forgings are widely used in key parts of transport aircraft and various fighter fuselages and engines, such as Figure 1 The asymmetric single-hole frame type die forging shown in the figure is also provided with a plurality of grooves on the upper surface of the asymmetric single-hole frame type die forging, including a first semicircular portion and a second semicircular portion with openings opposite to each other, the diameter of the first semicircular portion is larger than the diameter of the second semicircular portion, the first end of the first semicircular portion is connected to the first end of the second semicircular portion by a first straight line segment, and the second end of the first semicircular portion is connected to the second end of the second semicircular portion by a first arc segment.

[0003] This type of special-shaped die forgings is difficult to manufacture because of its asymmetric structure, which cannot be achieved by conventional ring rolling + die forging. The commonly used method is the method of slab passing bar material + die forging for overall forming. However, using the above method, the interior of the frame forging needs to be covered with a skinning dressing, and the skinning is removed after the die forging process is completed, resulting in a large amount of material waste and extremely low material utilization. In addition, the streamline of the forging is damaged, which will affect the fatigue life of the forging. At the same time, if the size of this type of forging is large, adding a skinning dressing will greatly increase the projection area of ​​the forging, the required forming load increases linearly, and the required equipment tonnage is also very large. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for forming an asymmetric single-hole frame-type die forging, so as to realize rapid and low-cost manufacturing of the forging and reduce the requirement on the tonnage of the equipment.

[0005] The technical solution adopted by the present invention to solve the technical problem is a method for forming an asymmetric single-hole frame-type die forging, comprising the following steps:

[0006] S1: Select the weight t1 of the bar according to the weight t of the asymmetric single-hole frame die forging, where t1 = α*t, α∈(1.1-1.2);

[0007] S2: Heat the bar to the forging temperature. After the core of the bar reaches the temperature, put the bar on the fast forging machine and roughen it to a thickness of H, where H = β*h, β∈(1.1-1.2), and h is the thickness of the asymmetric single-hole frame die forging;

[0008] S3: punching the bar after being roughened in step 2, and expanding the hole with a horse bar after punching, so as to form an original blank after expanding the hole, wherein the circumference of the inner hole of the original blank is the same as the circumference of the inner hole of the asymmetric single-hole frame type die forging, and the width of the original blank is consistent with the width of the asymmetric single-hole frame type die forging;

[0009] S4, putting the original blank on a forming tool, the forming tool includes a cylindrical table, a forming table and a plurality of punches, the forming table includes a first arc surface matching the inner surface of the first semicircular portion, a second arc surface matching the inner surface of the second semicircular portion, a third arc surface matching the inner surface of the first arc segment, and a first plane matching the inner surface of the first straight segment, the first arc surface, the second arc surface, the third arc surface and the first plane all smoothly transition to the outer surface of the cylindrical table through a transition surface; putting the original blank on the cylindrical table, a plurality of punches contacting the upper surface of the original blank, using a press to drive the punches to move downward, pushing the original blank to move downward along the transition surface, until the inner surface of the original blank is sequentially fitted with the first arc surface, the second arc surface, the third arc surface and the first plane to form a final blank;

[0010] S5: The final blank is placed on a die forging machine to form an asymmetric single-hole frame-type die forging.

[0011] Furthermore, the circumference of the outer surface of the cylindrical platform is consistent with the circumference of the outer surface of the forming platform.

[0012] Furthermore, in step S4, when the multiple punches push the original blank downward, the punches need to continuously adjust the contact points with the upper surface of the original blank.

[0013] Furthermore, the high-speed forging machine is a 45MN high-speed forging machine.

[0014] The beneficial effect of the present invention is that through the forming method of the present invention, a final annular blank that follows the shape of an asymmetric single-hole frame type die forging can be obtained. When designing the asymmetric single-hole frame type die forging, there is no need to add skin dressings, so that the material required for the forming of the asymmetric single-hole frame type die forging is reduced by more than 30%. The reduction in the projected area also reduces the load required for forming by more than 20%, and large-sized forgings can be manufactured on small equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of an asymmetric single-hole frame-type die forging of the present invention;

[0016] Figure 2 It is a schematic diagram of the formation from the initial rough block to the final rough block;

[0017] Figure 3 This is a bottom view of the molding tool.

[0018] Figure markings: 1-first semicircular portion; 2-second semicircular portion; 3-first straight portion; 4-first arc portion; 5-original blank; 6-cylindrical table; 7-forming table; 701-first arc surface; 702-second arc surface; 703-third arc surface; 704-first plane; 8-punch; 9-transition surface; 10-final blank. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] like Figure 2 and Figure 3 As shown, the present invention provides an asymmetric single-hole frame type die forging forming method, comprising the following steps:

[0021] S1: Select the weight t1 of the bar according to the weight t of the asymmetric single-hole frame type die forging, where t1 = α*t, α∈(1.1~1.2); since a small amount of flash will always appear during the die forging process, when selecting the bar weight t1, the bar weight must be greater than the weight t of the asymmetric single-hole frame type die forging.

[0022] S2: Heat the bar to the forging temperature, and after the core of the bar reaches the temperature, put the bar on the fast forging machine and roughen it to a thickness of H, wherein H=β*h, β∈(1.1~1.2), and h is the thickness of the asymmetric single-hole frame type die forging; when performing die forging, the upper die is provided with a boss matching the groove on the asymmetric single-hole frame type die forging, and the lower die is provided with a groove matching the shape of the asymmetric single-hole frame type die forging, so when the bar is roughened, the width of the subsequent original blank is consistent with the width of the asymmetric single-hole frame type die forging, so the thickness can only be made greater than the thickness of the asymmetric single-hole frame type die forging, so that the final formed blank can be placed in the groove of the lower die.

[0023] S3: Punch the bar after being roughened in step 2, and then use a horse bar to expand the hole after punching to form an original blank. The circumference of the inner hole of the original blank is the same as the circumference of the inner hole of the asymmetric single-hole frame type die forging, and the width of the original blank is consistent with the width of the asymmetric single-hole frame type die forging; the inner hole of the original blank is a standard circle, and when the original blank is subsequently formed into the final blank, only the contour shape of the blank will be changed. Therefore, it is necessary to ensure that the circumference of the inner hole of the original blank is the same as the circumference of the inner hole of the asymmetric single-hole frame type die forging, and the width of the original blank is consistent with the width of the asymmetric single-hole frame type die forging.

[0024] S4, see Figure 2 and Figure 3, the original blank is mounted on the forming tool, the forming tool includes a cylindrical table, a forming table and a plurality of punches, the forming table includes a first arc surface matching the inner surface of the first semicircular portion, a second arc surface matching the inner surface of the second semicircular portion, a third arc surface matching the inner surface of the first arc segment, and a first plane matching the inner surface of the first straight segment, the first arc surface, the second arc surface, the third arc surface, and the first plane are all smoothly transitioned to the outer surface of the cylindrical table through a transition surface; the original blank is mounted on the cylindrical table, a plurality of punches are in contact with the upper surface of the original blank, and the punches are driven downward by a press to push the original blank downward along the transition surface until the inner surface of the original blank is sequentially aligned with the first arc surface. The first arc surface, the second arc surface, the third arc surface and the first plane are fitted together to form a final blank; the circumference of the outer surface of the cylindrical table is consistent with the circumference of the outer surface of the forming table, and the cylindrical table plays a positioning role to ensure that the inner surface of the original blank is fitted with the outer side surface of the cylindrical table. In the process of using the punch to push the original blank downward, the inner surface of the original blank will gradually deform under the action of the transition surface until the inner surface of the original blank is fitted with the first arc surface, the second arc surface, the third arc surface and the first plane in turn, so that the shape of the inner surface of the original blank can be changed. During the forming process, the thickness of the original blank remains unchanged, and the final blank formed is the same as the overall shape of the asymmetric single-hole frame-type die forging.

[0025] S5: The final blank is placed on a die forging machine for forming, and after the flash and burrs are removed, an asymmetric single-hole frame-type die forging is formed.

[0026] Since the shape of the original blank will be constantly changed during the downward movement of the punch, interference between the cylindrical table or transition surface and the punch may occur. Furthermore, in step S4, when multiple punches push the original blank downward, the punch needs to continuously adjust the contact point with the upper surface of the original blank.

[0027] Furthermore, the high-speed forging machine is a 45MN high-speed forging machine.

[0028] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for forming an asymmetric single-hole frame die forging, characterized in that: The following steps are included: S1: Select the weight t1 of the bar according to the weight t of the asymmetric single-hole frame die forging, where t1 = α*t, α∈ (1.1～1.2)； S2: Heat the bar to the forging temperature. After the core of the bar reaches the temperature, put the bar on the fast forging machine and roughen it to a thickness of H, where H = β*h, β∈(1.1-1.2), and h is the thickness of the asymmetric single-hole frame die forging; S3: punching the bar after being roughened in step 2, and expanding the hole with a horse bar after punching, so as to form an original blank after expanding the hole, wherein the circumference of the inner hole of the original blank is the same as the circumference of the inner hole of the asymmetric single-hole frame type die forging, and the width of the original blank is consistent with the width of the asymmetric single-hole frame type die forging; S4, putting the original blank on a forming tool, the forming tool includes a cylindrical table, a forming table and a plurality of punches, the forming table includes a first arc surface matching the inner surface of the first semicircular portion, a second arc surface matching the inner surface of the second semicircular portion, a third arc surface matching the inner surface of the first arc segment, and a first plane matching the inner surface of the first straight segment, the first arc surface, the second arc surface, the third arc surface and the first plane all smoothly transition to the outer surface of the cylindrical table through a transition surface; putting the original blank on the cylindrical table, a plurality of punches contacting the upper surface of the original blank, using a press to drive the punches to move downward, pushing the original blank to move downward along the transition surface, until the inner surface of the original blank is sequentially fitted with the first arc surface, the second arc surface, the third arc surface and the first plane to form a final blank; S5: The final blank is placed on a die forging machine to form an asymmetric single-hole frame-type die forging.

2. A method for forming an asymmetric single-hole frame-type die forging according to claim 1, characterized in that: The circumference of the outer surface of the cylindrical platform is consistent with the circumference of the outer surface of the forming platform.

3. The method for forming an asymmetric single-hole frame-type die forging according to claim 1, characterized in that: In step S4, when the multiple punches push the original blank downward, the punches need to continuously adjust the contact points with the upper surface of the original blank.

4. The method for forming an asymmetric single-hole frame-type die forging according to claim 1, characterized in that: The high-speed forging machine is a 45MN high-speed forging machine.

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