A method for cup-shaped part upsetting forming

Abstract

The application discloses a method applied to cup-shaped part upsetting forming, which comprises five steps of blanking, stamping, sheet forming, trimming and shaping, side wall upsetting forming, etc., and the uneven customized plate is introduced in the stamping forming process which is easy to realize, so as to change the traditional drawing upsetting forming process chain. In addition, due to the local thickening of the uneven customized plate, the large round corner punch in the traditional sheet drawing forming is replaced by a small round corner punch, the drawing process is simplified into one step, and the round corner shaping process can also be omitted, so that the drawing forming limit and forming efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sheet stamping process, in particular to a method applied to cup-shaped part upsetting forming. BACKGROUND

[0002] Sheet stamping process mainly deforms under tensile stress, which can accurately shape the external shape of the part, but cannot control the wall thickness distribution of the part, and the wall thickness thinning at the round corner of the stamping part is easy to cause the overall strength of the part to decrease. Some structural parts, such as automobile transmission devices and hub parts, usually have high strength requirements at the round corner, if the original sheet thickness is increased to improve the strength of the round corner area of the part, it will inevitably lead to a decrease in material utilization and an increase in the total mass of the part, which does not meet the development trend of green manufacturing, energy saving and emission reduction. In addition, excessive wall thickness thinning may even cause the sheet to break, which restricts the forming limit of stamping forming processes such as drawing and bending. Therefore, the drawing-side wall upsetting sheet volume forming process has become a manufacturing method for complex shell parts to control the wall thickness distribution and realize lightweight structure manufacturing. However, the cup-shaped part preform obtained by drawing has a serious thinning at the round corner, which will cause folding defects in the subsequent upsetting process, such as Figure 2 , thereby affecting the performance of the part.

[0003] When the traditional sheet drawing cup-shaped part is used at present, although the multi-step bottom round corner shaping is performed, there is still an outer round corner, and due to the action of tensile stress, the bottom round corner is severely thinned. How to solve the round corner upsetting folding problem has become the core problem affecting the quality of cup-shaped part side wall upsetting forming. SUMMARY

[0004] (I) Technical problem to be solved

[0005] In order to overcome the shortcomings of the prior art, the present application proposes a method applied to cup-shaped part upsetting forming, which introduces a non-uniform customized sheet in the easy-to-implement coining forming process to change the traditional drawing-upsetting forming process chain. In addition, due to the local thickening of the non-uniform customized sheet, a small round corner punch is used to replace the large round corner punch in the traditional sheet drawing forming, the drawing process is simplified to one step, and the round corner shaping process can also be omitted, thereby improving the drawing forming limit and forming efficiency.

[0006] (II) Technical scheme

[0007] The present application is realized by the following technical scheme: the present application proposes a method applied to cup-shaped part upsetting forming, comprising the following steps:

[0008] 1) Step 1: blanking, obtaining a circular blank with the size of the cup-shaped part contour by stamping and shearing;

[0009] 2) Step 2: embossing, embossing a circular pointed protrusion with the same diameter as the bottom diameter of the required cup-shaped part on the bottom of the circular blank in step 1 by extrusion machinery, so as to obtain a non-uniform customized plate with local thickening;

[0010] 3) Step 3: plate forming, deep drawing the non-uniform customized plate in step 2, specifically taking the opposite side of the circular pointed protrusion as the deep drawing bottom surface and taking the center of the circular pointed protrusion as the deep drawing corner, to deep draw a cup-shaped blank;

[0011] 4) Step 4: trimming and shaping, rounding and shaping the wall profile of the cup-shaped blank obtained in step 3, wall thickness shaping and cup-shaped height trimming shaping are performed to obtain a fine blank with a roundness that meets the standard, a uniform cup wall thickness and a cup-shaped height that meets the preset value;

[0012] Step 5: side wall upset forming, the fine blank in step 4 is subjected to side wall upset forming to obtain a cup-shaped part product with a preset thickness and a preset height.

[0013] Further, the longitudinal section of the circular pointed protrusion in step 2 is an isosceles right triangle.

[0014] (Three) beneficial effects

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The method for cup-shaped part upset forming mentioned in the present application proposes a non-uniform customized plate combined with controllable deformation zone upset forming process path in view of the influence of pre-forming on side wall upset forming, including embossing, deep drawing, shaping, trimming and upset forming processes. Taking the cup-shaped part with thickened side wall as an example, in order to prevent the round corner upset folding defect caused by the gap between the workpiece and the mold, a non-uniform customized plate is designed. The lubrication condition is optimized to balance the radial flow and normal flow in the embossing forming process, so as to realize the pre-concentration of the material at the round corner, so as to obtain a cup-shaped blank with full round corner filling. Taking it as a blank for controllable deformation zone upset forming, the gap between the workpiece and the mold is eliminated, so as to overcome the common round corner folding defect in side wall upset forming, and realize the efficient integrated forming of non-uniform wall thickness or functional feature integrated complex structure. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of a non-uniform customized plate and a local enlarged view of a circular pointed protrusion.

[0018] Figure 2 is a schematic diagram of bending caused by upset. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the concept and scope of the present application.

[0020] A method applied to cup-shaped part upsetting forming, comprising the following steps:

[0021] 5) Step 1: blanking, obtaining a circular blank with the size of the cup-shaped part profile by punching and shearing;

[0022] 6) Step 2: coining, coining a circular pointed protrusion with the same diameter as the bottom diameter of the required cup-shaped part on the bottom of the circular blank in step 1 by extrusion machinery, so as to obtain a locally thickened non-uniform customized plate, as shown in Figure 1 ;

[0023] 7) Step 3: sheet forming, deep drawing the non-uniform customized plate in step 2, specifically taking the opposite side of the circular pointed protrusion as the deep drawing bottom surface and taking the center of the circular pointed protrusion as the deep drawing corner, to deep draw a cup-shaped blank;

[0024] 8) Step 4: trimming and shaping, rounding and shaping the outer wall profile of the cup-shaped blank obtained in step 3, wall thickness shaping and cup-shaped height trimming shaping, so as to obtain a fine blank with a roundness that meets the standard, a uniform cup wall thickness and a cup-shaped height that reaches the preset value;

[0025] Step 5: side wall upsetting forming, upsetting the fine blank in step 4 to obtain a cup-shaped part product with a preset thickness and a preset height.

[0026] In the step 2, the longitudinal section of the circular pointed protrusion is an isosceles right triangle.

[0027] The method for cup-shaped part upsetting forming mentioned in the present application forms a circular pointed protrusion on the bottom of the circular blank by coining process, and after deep drawing forming, the corner of the bottom of the cup-shaped part is in a right angle shape, eliminating the circular arc, so that when upsetting forming is performed, the bending defect shown in Figure 2 can be avoided.

[0028] The above-described examples only describe the preferred embodiments of the present application and do not limit the concept and scope of the present application. Various modifications and improvements to the technical scheme of the present application made by those skilled in the art without departing from the design concept of the present application shall fall within the protection scope of the present application, and the technical content claimed by the present application has been fully recorded in the claims.

Claims

1. A method for upsetting a cup-shaped part, characterized in that: The steps include: 1) Step 1: Punching: Obtain a circular blank of the cup-shaped part size by punching and cutting; 2) Step 2: Imprinting: Using an extruder, a circular pointed ridge having the same diameter as the bottom of the desired cup-shaped part is imprinted on the bottom of the circular blank in step 1, thereby obtaining a locally thickened non-uniform customized plate; 3) Step 3: Sheet forming: The non-uniform customized sheet in step 2 is deep-drawn, specifically with the opposite side of the circular pointed convex corrugation as the drawing bottom surface and the center of the circular pointed convex corrugation as the drawing corner, to draw out a cup-shaped blank; 4) Step 4: trimming and shaping, performing rounding, wall thickness shaping, and cup height trimming on the outer wall contour of the cup-shaped blank obtained in step 3, so as to obtain a refined blank with a roundness that meets the standard, a uniform cup wall thickness, and a cup height that reaches a preset value; 5) Step 5: Side wall upsetting, the refined blank described in step 4 is subjected to side wall upsetting to obtain a finished cup-shaped part with a preset thickness and preset height.

2. The method for upsetting a cup-shaped part according to claim 1, characterized in that: The longitudinal section of the circular pointed ridge in step 2 is an isosceles right triangle.

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