Forge piece design method for preventing bottom deformation dead zone of large special-shaped barrel forge piece

Abstract

The invention provides a forge piece design method for preventing a deformation dead zone at the bottom of a large barrel-shaped forge piece. The method comprises the steps that a two-step boss structure is additionally arranged on the outer side area of the flat bottom of the forge piece; performing shape matching design on a lower die or a lower ejection die structure corresponding to the bottom of the forge piece; carrying out three-dimensional modeling; performing analog simulation on the large special-shaped barrel forge piece, and adjusting the height and width of a two-step boss structure at the bottom of the forge piece and the matched shape and size of a lower die or a lower ejection die according to strain distribution of the large special-shaped barrel forge piece; streamline distribution of the large special-shaped barrel forge piece is analyzed, it is ensured that a to-be-machined part area is uniform in deformation and smooth in streamline, and the structure property requirement is met. According to the method, deformation dead zones on the two sides can be effectively moved outwards or downwards to the position below the to-be-machined part area, meanwhile, the possibility that the deformation dead zones appear in the center area is prevented due to increase of the bottom deformation amount, and it is greatly guaranteed that strain of the to-be-machined part area at the bottom of the large special-shaped barrel-shaped forge piece is evenly distributed, and the streamline is smooth and reasonable.

Description

Technical Field

[0001] The invention relates to a forging design method and a die for preventing a large barrel-shaped forging bottom deformation dead zone, and belongs to the technical field of forging design. Background Art

[0003] Large-sized special-shaped barrel components are key components in the aviation field. Their maximum dimensions are 600~1500mm, and the barrel wall thickness is 10~100mm. They are large-sized thin-walled components with extremely high and uniform requirements for organization and performance. Figure 1 As shown, when designing and manufacturing large barrel-shaped forgings by traditional forging methods, the bottom of the barrel-shaped forgings is generally designed to be flat; Figure 2 As shown in the figure, there is a large uneven strain distribution and three difficult-to-deform areas or deformation dead areas in the bottom area of ​​the forging, which leads to large differences in microstructure and grain size, large differences in mechanical properties, and uneven streamlines in different areas of the bottom of the forging. As a result, the microstructure and performance of the bottom of the part after processing are greatly different, and the bottom center and two side areas cannot meet the product microstructure and performance requirements.

[0004] Therefore, how to control the uneven strain distribution, eliminate the deformation dead zone in the area of ​​the forging parts to be processed, and obtain reasonable streamlines to ensure that the parts to be processed that meet the organizational performance requirements are technical problems that need to be solved by technical personnel in this field. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a forging design method that prevents deformation dead zones at the bottom of large special-shaped barrel forgings, thereby solving the problems of uneven strain distribution at the bottom of large special-shaped barrel forgings and deformation dead zones in the area of ​​forging parts to be processed.

[0007] The invention also provides a forging die designed according to the method for preventing the bottom deformation dead zone of a large-sized special-shaped barrel forging.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions: A forging design method for preventing the bottom deformation dead zone of a large-sized special-shaped barrel forging, characterized in that it comprises the following steps: Step 1: Based on the traditional forging design method, the bottom of the barrel forging is generally designed to be flat. In this design, a two-step boss structure is added to the outer area of ​​the flat bottom of the forging; Step 2: Based on the first step, shape matching design and three-dimensional modeling are performed on the corresponding lower die or lower ejector die structure at the bottom of the forging; Step 3: Based on steps 1 and 2, three-dimensional modeling of the designed forging and the corresponding die is performed; Step 4: simulate the large special-shaped barrel forging, and adjust the height and width dimensions of the two-step boss structure at the bottom of the forging and the matching shape and size of the lower die or lower ejector die according to the strain distribution of the large special-shaped barrel forging; Step 5: Analyze the streamline distribution of large special-shaped barrel forgings to ensure that the deformation of the parts to be processed is uniform, the streamlines are smooth, and the organizational performance requirements are met.

[0009] Further, in step 1, the present design adds a two-step boss structure to the outer area of ​​the flat bottom of the forging, wherein the width b0 of the flat bottom of the forging is 400-800 mm, the design height h1 of the first step is 20-50 mm, the single-side width b1 is 50-100 mm, the height h2 of the second step platform is 50 mm, the single-side width b2 is 50-100 mm, and the step draft angle is 15-30°.

[0010] The present invention also provides a die for preventing the bottom deformation dead zone of a large barrel-shaped forging obtained by the above method, and an ejector die with a lower ejection structure is added to the lower die; the lower die and the ejector die arranged in the middle of the lower die are designed by adjusting the depth dimension of the pit at the bottom of the forging, the thickness dimension of the pit edge, and the matching shape dimension of the lower die or the lower ejector die according to the strain distribution of the large barrel forging; the streamline distribution of the large special-shaped barrel forging is analyzed to ensure that the deformation of the area of ​​the part to be processed is uniform, the streamline is smooth, and the organizational performance requirements are met.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention combines the numerical simulation analysis of forgings, and optimizes the uneven strain distribution of large special-shaped barrel forgings by changing the height and width dimensions of the boss structure at the bottom of the forgings and the matching shape and size of the lower ejection die, so that the deformation amount of the deformation dead zone in the bottom center is significantly increased, and the possibility of the deformation dead zone in the bottom center area is effectively prevented. At the same time, the two deformation dead zones on both sides can be moved outward and downward to below the area of ​​the parts to be processed. Among them, the strain amount of the forging is increased by 40%, which is very significant for achieving uniform strain distribution, uniform organizational performance, and smooth and reasonable streamlines in the area of ​​the parts to be processed at the bottom of the large special-shaped barrel forgings.

[0012] 2. The present invention can effectively move the deformation dead zones on both sides outward or downward to below the area of ​​the parts to be processed by designing a two-step boss structure forging and a mold of matching shape; at the same time, the increase in the bottom deformation prevents the possibility of a deformation dead zone in the central area, greatly ensuring that the strain of the parts to be processed at the bottom of the large special-shaped barrel forging is evenly distributed and the streamline is smooth and reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A typical (bottom area) view of the cross section of a large barrel forging formed by conventional forming methods; Figure 2 This is the strain distribution diagram of the forging by the traditional forming method; Figure 3 A typical cross-sectional view of a large-sized special-shaped barrel forging according to the present invention after a two-step boss structure is added; Figure 4 For the corresponding Figure 3 The structure diagram of the lower mold or lower ejector mold cavity; Figure 5 The strain distribution diagram of the forging obtained by the forging forming method of the present invention; Figure 6 This is the streamline distribution diagram obtained by the forging forming method of the present invention.

[0015] Specific implementation measures In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in combination with the embodiments and drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of protection claimed. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in the subsequent figures. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the figures, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0017] The present invention provides a forging forming method for preventing a large barrel-shaped forging bottom deformation dead zone, comprising the following steps: Step 1: Based on the traditional forging design method, the bottom of the barrel forging is generally designed to be flat. This design adds a two-step boss structure to the outer area of ​​the flat bottom of the forging; Step 2: Based on the first step, shape matching design is performed on the corresponding lower die or lower ejector die structure at the bottom of the forging; Step 3: Based on the first and second steps, three-dimensional modeling of the designed forgings and corresponding molds; Step 4: simulate the large special-shaped barrel forging, and adjust the height and width of the two-step boss structure at the bottom of the forging and the matching shape and size of the lower die or lower ejector die according to the strain distribution of the large special-shaped barrel forging; Step 5: Based on the above steps, analyze the streamline distribution of large special-shaped barrel forgings to ensure that the deformation of the parts to be processed is uniform, the streamlines are smooth, and the organizational performance requirements are met.

[0018] Furthermore, in the step one, the present design adds a two-step boss structure to the outer area of ​​the flat bottom of the forging, and the boss can be an arc-shaped boss or a tapered boss, wherein the width b0 of the flat bottom of the forging is 400~800mm, the design height h1 of the first step is 20~50mm, the single-side width b1 is 50~100mm, the height h2 of the second step platform is 50mm, the single-side width b2 is 50~100mm, and the step draft angle is 15~30°.

[0019] Further, the die for preventing the bottom deformation dead zone of large-sized special-shaped barrel forgings obtained by the above design method is as follows: Figure 3 As shown in FIG. 1 , a typical cross section of a large special-shaped barrel forging of the invention is provided with a two-step boss structure, and the corresponding lower die or lower ejector die cavity structure is as follows: Figure 4 The present invention adopts a design method of a special forging structure with a two-step boss at the bottom of the forging, and the strain distribution obtained after forming is as follows Figure 5 As shown in the figure, by using the optimized design method, the deformation of the central deformation dead zone at the bottom of the forging is significantly increased, and at the same time, the two deformation dead zones on both sides of the forging move outward and downward to below the area of ​​the parts to be processed, which greatly ensures the uniform strain distribution in the area of ​​the parts to be processed at the bottom of the large special-shaped barrel forging. Figure 6 The figure shows the streamline distribution obtained after forming. It can be seen that the streamline of the forging is smooth and reasonable by using the optimized design method.

[0020] In summary, the present invention can effectively increase the deformation of the bottom center deformation dead zone by designing a special forging structure with a two-step boss at the bottom of the forging and a matching mold, and prevent the possibility of a deformation dead zone in the bottom center area. At the same time, the two deformation dead zones on both sides can be moved outward and downward to below the area of ​​the parts to be processed, thereby ensuring that the strain of the parts to be processed at the bottom of the large special-shaped barrel forging is evenly distributed and the streamline is smooth and reasonable. The problem that the forging is prone to a difficult deformation area or a deformation dead zone when the flat bottom design method is adopted at the bottom of the forging is completely overcome.

[0021] It can be seen that the present invention can effectively increase the deformation amount of the bottom center deformation dead zone by designing a special forging structure with a pit at the bottom of the forging and further thickened edges on both sides and a matching mold shape, thereby preventing the possibility of a deformation dead zone in the bottom center area, and at the same time, the two deformation dead zones on both sides can be moved outward and downward to below the area of ​​the parts to be processed, thereby ensuring that the strain in the area of ​​the parts to be processed at the bottom of the large barrel forging is evenly distributed and the streamline is smooth and reasonable.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A forging design method to prevent the bottom deformation dead zone of a large special-shaped barrel forging, characterized in that: The steps include: Step 1: Based on the traditional forging design method, the bottom of the barrel forging is generally designed to be flat. In this design, a two-step boss structure is added to the outer area of ​​the flat bottom of the forging; Step 2: Based on step 1, shape matching design is performed on the corresponding lower die or lower ejector die structure at the bottom of the forging; Step 3: Based on steps 1 and 2, three-dimensional modeling of the designed forging and the corresponding die is performed; Step 4: simulate the large special-shaped barrel forging, and adjust the height and width dimensions of the two-step boss structure at the bottom of the forging and the matching shape and size of the lower die or lower ejector die according to the strain distribution of the large special-shaped barrel forging; Step 5: Analyze the streamline distribution of large special-shaped barrel forgings to ensure that the deformation of the parts to be processed is uniform, the streamlines are smooth, and the organizational performance requirements are met.

2. The forging design method for preventing the bottom deformation dead zone of a large-sized special-shaped barrel forging according to claim 1 is characterized in that: In the step 1, a two-step boss structure is added to the outer area of ​​the flat bottom of the forging, wherein the width b0 of the flat bottom of the forging is 400-800 mm, the first step height h1 is designed to be 20-50 mm, the single-side width b1 is 50-100 mm, the second step platform height h2 is 50 mm, the single-side width b2 is 50-100 mm, and the step draft angle is 15-30°.

3. A die to prevent the bottom deformation dead zone of a large barrel forging, characterized in that: The forging design method for preventing the bottom deformation dead zone of large-sized special-shaped barrel forgings is obtained according to claim 1 or 2.

4. The die for preventing the bottom deformation dead zone of a large barrel forging according to claim 3 is characterized in that: An ejector die with a lower ejection structure is added to the lower die; the lower die and the ejector die arranged in the middle of the lower die are designed to adjust the depth dimension of the pit at the bottom of the forging, the thickness dimension of the pit edge, and the matching shape dimension of the lower die or the lower ejector die according to the strain distribution of the large special-shaped barrel forging; the streamline distribution of the large barrel forging is analyzed to ensure that the deformation of the part area to be processed is uniform, the streamline is smooth, and the organizational performance requirements are met.

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