Stamping process for lower longitudinal beam of front floor of automobile

Abstract

The invention discloses an automobile front floor lower longitudinal beam stamping process which comprises the steps that a primary forming die is adopted for conducting primary stamping on a raw material plate, the upper top face part, the secondary top face part, the two side face parts and the two side lower edge parts of a workpiece are primarily formed, and the side wall of a forming groove of an upper forming block of the primary forming die is provided with an inwards-sunken compensation reverse arc face; the plane forming angle of the lower edge of the workpiece downwards deviates from the horizontal plane by 3-5 degrees; then a second punching die is adopted for partially punching the edge of the workpiece, and forward punching is conducted on the end portion of the workpiece from top to bottom on the end portion of the workpiece; thirdly, a three-way shaping punching die is adopted for cutting off the workpiece excess material, excess material punching is conducted on the inclined face excess material at the end of the workpiece in the direction right opposite to the diagonal plane, and the lower edge of the workpiece is formed to be in the horizontal state; then shaping the side surface and the lower flange surface of the workpiece by adopting a shaping die; and finally, the punching die is used for punching other parts, needing to be punched, of the workpiece.

Description

Technical Field

[0001] The invention relates to the field of stamping processing of automobile parts, and in particular to a stamping process for a longitudinal beam under a front floor of an automobile. Background Art

[0002] The longitudinal beam structure under the front floor of the car is as follows Figure 1-3 As shown in the figure, the part material is SCR420D+Z, which is a high-strength plate. As a result, a large outward rebound occurs on the side of the workpiece after stamping, causing the flange surface at the bottom of the workpiece to be warped. The rebound of the flange surface edge can even reach more than 10MM. The workpiece size is out of the set accuracy range, resulting in unqualified finished products after rebound.

[0003] Moreover, during the design and production, the existing stamping die manufacturing process mainly considers springback compensation, and often the parts have excessive compensation during the stretching process, which makes it difficult for the final product size accuracy to reach the set range, and the finished product qualification rate is still low.

[0004] In order to obtain qualified stamping products, not only do we need to set up more stamping processes to control product springback, but the subsequent molds of each process need to be rectified many times and in a long period of time. During the rectification, alternative materials are used for trial mold sampling in advance. After the part size is within the tolerance range of 1MM, the formal materials are used to make molds for each process. Because the two materials are inconsistent, the finished product size data still has a large error. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a stamping process for a longitudinal beam under a front floor of an automobile with fewer forming steps, high yield and low manufacturing cost.

[0006] 2. To solve the above technical problems, the technical solution adopted by the present invention is: a stamping process for the longitudinal beam under the front floor of an automobile, the steps of which are:

[0007] Step 1: Use the primary forming mold to perform preliminary stamping on the raw material sheet. The lower mold of the primary forming mold is provided with a floating pressing ring on the outer periphery of the lower forming block group, which cooperates with the upper pressing ring on the upper mold to press the edge of the raw material, so that the sheet can be drawn to preliminarily form the upper top face portion, the secondary top face portion, the two side faces, and the two side lower edge portions of the workpiece, and the side wall of the forming groove of the upper forming block of the primary forming mold is provided with an inwardly concave compensating anti-arc surface, the upper starting position of the compensating anti-arc surface is the upper 1 / 3 of the side surface, and the corresponding distance between the vertex of the compensating anti-arc surface and the side surface of the finished product is 0.5-2mm; the plane forming angle of the lower edge of the workpiece deviates downward from the horizontal plane by α°, and the α value is 1-2 times the rebound angle of the flange surface;

[0008] Step 2: Use a two-pass punching die to partially punch the edge of the workpiece, perform positive punching from top to bottom on the end of the workpiece, and punch a pair of positioning pin holes on the workpiece;

[0009] Step 3: Use three shaping and punching dies to cut off the excess material on both sides of the workpiece, and punch out the excess material on the inclined surface at the end of the workpiece in the direction opposite to the bevel surface, so as to form the lower edge of the workpiece to a horizontal state; punch out the excess material at the other end of the workpiece;

[0010] Step 4: Use a shaping die to shape the side and lower flange surface of the workpiece;

[0011] Step 5: Use a punching die to punch the remaining parts of the workpiece that need to be punched.

[0012] As a preferred scheme, in step one, the outer side of the lower forming block is provided with a lower guide slope inclined outward, and the inner side of the upper pressure ring is provided with an upper guide slope matched with the lower guide slope. The upper pressure ring cooperates with the floating pressure ring and the lower forming block group, so that a Z-shaped step portion is formed on the outer side of the lower edge portion on both sides of the workpiece.

[0013] As a preferred solution, the upper and lower edges on the inner side of the upper pressing ring are provided with transition arc surfaces, and the upper edge on the outer side of the lower forming block is provided with a transition arc surface.

[0014] As a preferred solution, in step 2, two punching dies are used to punch the end holes close to the end of the workpiece.

[0015] As a preferred solution, in step 2, two punching dies are used to punch a portion of the end hole of the workpiece close to the end; in step 3, three shaping punching dies are used to punch the remaining portion of the end hole of the workpiece close to the end.

[0016] The beneficial effects of the present invention are:

[0017] This method reduces the number of processing steps in the entire processing procedure by rationally designing the processing content of each step, ensuring the product processing quality while greatly reducing the mold cost and processing cost. In addition, this method provides an inwardly concave compensating anti-arc surface on the side wall of the forming groove of the upper forming block of the initial forming mold. The upper starting position of the compensating anti-arc surface is the upper 1 / 3 of the side surface, and the corresponding distance between the vertex of the compensating anti-arc surface and the side surface of the finished product is 0.5-2mm; the plane forming angle of the lower edge of the workpiece deviates downward from the horizontal plane by 3-5°; so that the side of the stamped workpiece will not require subsequent multiple shaping stampings to correct the workpiece due to the occurrence of anti-arcs, or even part of the workpiece will be scrapped due to inadequate correction, which greatly improves the yield rate and reduces processing costs; and the lower edge of the workpiece is set to be slightly deflected downward so that the workpiece is closer to a horizontal state after the first stamping rebound, thereby The amount of rebound in subsequent back correction is reduced, so that the workpiece can be shaped in place with fewer processes, and the processing cost of the workpiece is reduced while the yield of the workpiece is improved. In addition, a two-pass punching die is used to partially punch the edge of the workpiece and the end of the workpiece is punched from top to bottom. A three-pass shaping punching die is used to cut off the excess material on both sides of the workpiece. The separate cutting of the excess material on the edge reduces the cutting stress, thereby making the deformation smaller and further ensuring the processing quality of the workpiece. A three-pass shaping punching die is used to punch the excess material on the bevel of the end of the workpiece in the direction of the bevel, thereby completing the precise punching process while avoiding deformation of the end of the workpiece.

[0018] Because in the step one, the outer side of the lower forming block is provided with a lower guiding slope inclined outward, and the inner side of the upper pressing ring is provided with an upper guiding slope matched with the lower guiding slope, the upper pressing ring cooperates with the floating pressing ring and the lower forming block group, so that a Z-shaped step portion is formed on the outer side of the lower edge portion on both sides of the workpiece; the material flow and shaping of the workpiece during drawing are made more reliable, and the accuracy of the forming size of the lower edge portion of the workpiece is guaranteed, so as to ensure that the size of the subsequent workpiece after rebound is within the set range. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the workpiece structure.

[0020] Figure 2 This is a schematic diagram of the workpiece structure from another angle.

[0021] Figure 3 This is a schematic diagram of the workpiece structure from another angle.

[0022] Figure 4 Comparison between the cross-sectional view of the workpiece after processing in step 1 (gray part) and the cross-sectional view of the finished workpiece (black part).

[0023] Figure 5 This is a comparison between a cross-section of the workpiece after processing in step 2 (the gray part) and a cross-section of the finished workpiece (the black part).

[0024] Figure 6 This is a comparison between a cross-section of the workpiece after processing in step three (the gray part) and a cross-section of the finished workpiece (the black part).

[0025] Figure 7 Comparison between the cross-sectional view of the workpiece after processing in step 4 (gray part) and the cross-sectional view of the finished workpiece (black part).

[0026] Figure 8 Comparison between the cross-sectional view of the workpiece after processing in step five (gray part) and the cross-sectional view of the finished workpiece (black part).

[0027] Fig. 9 Schematic diagram of the workpiece structure after processing in each process. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0029] like Figure 1-9 As shown, a stamping process for the longitudinal beam under the front floor of an automobile comprises the following steps:

[0030] Step 1: Use the primary forming mold to perform preliminary stamping on the raw material sheet. The lower mold of the primary forming mold is provided with a floating pressing ring on the outer periphery of the lower forming block group, which cooperates with the upper pressing ring on the upper mold to press the edge of the raw material, so that the sheet can be drawn to preliminarily form the upper top face portion, the secondary top face portion, the two side faces, and the lower edge portions on both sides of the workpiece, and the side wall of the forming groove of the upper forming block of the primary forming mold is provided with an inwardly concave compensating anti-arc surface, the upper starting position of the compensating anti-arc surface is the upper 1 / 3 of the side surface, and the corresponding distance between the vertex of the compensating anti-arc surface and the side surface of the finished product is 1.2mm; the plane forming angle of the lower edge of the workpiece deviates downward from the horizontal plane by α°, and the α value is 1-2 times the rebound angle of the flange surface (the angle in the mold of this embodiment is 3.3°);

[0031] Step 2: Use a two-pass punching die to partially punch the edge of the workpiece, punch the end of the workpiece from top to bottom, punch a part of the end hole close to the end, and punch a pair of positioning pin holes on the workpiece;

[0032] Step 3: Use three shaping punching dies to cut off the excess material on both sides of the workpiece, and punch the excess material on the inclined surface of the end of the workpiece in the direction opposite to the bevel surface, so as to complete the precise punching process while avoiding deformation of the end of the workpiece, forming the lower edge of the workpiece to a horizontal state; punching the remaining part of the end hole close to the end; punching the excess material at the other end of the workpiece;

[0033] Step 4: Use a shaping die to shape the side and lower flange surface of the workpiece;

[0034] Step 5: Use a punching die to punch the remaining parts of the workpiece that need to be punched.

[0035] The above-mentioned embodiments are only illustrative of the principles and effects of the invention, as well as some embodiments of its application, and are not intended to limit the invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the invention, and all of these belong to the protection scope of the invention.

Claims

1. A stamping process for a longitudinal beam under a front floor of an automobile, comprising the following steps: Step 1: Use the primary forming mold to perform preliminary stamping on the raw material sheet. The lower mold of the primary forming mold is provided with a floating pressing ring on the outer periphery of the lower forming block group, which cooperates with the upper pressing ring on the upper mold to press the edge of the raw material, so that the sheet can be drawn to preliminarily form the upper top face portion, the secondary top face portion, the two side faces, and the two side lower edge portions of the workpiece, and the side wall of the forming groove of the upper forming block of the primary forming mold is provided with an inwardly concave compensating anti-arc surface, the upper starting position of the compensating anti-arc surface is the upper 1 / 3 of the side surface, and the corresponding distance between the vertex of the compensating anti-arc surface and the side surface of the finished product is 0.5-2mm; the plane forming angle of the lower edge of the workpiece deviates downward from the horizontal plane by α°, and the α value is 1-2 times the rebound angle of the flange surface; Step 2: Use a two-pass punching die to partially punch the edge of the workpiece, perform positive punching from top to bottom on the end of the workpiece, and punch a pair of positioning pin holes on the workpiece; Step 3: Use three shaping and punching dies to cut off the excess material on both sides of the workpiece, and punch out the excess material on the inclined surface at the end of the workpiece in the direction opposite to the bevel surface, so as to form the lower edge of the workpiece to a horizontal state; punch out the excess material at the other end of the workpiece; Step 4: Use a shaping die to shape the side and lower flange surface of the workpiece; Step 5: Use a punching die to punch the remaining parts of the workpiece that need to be punched.

2. A stamping process for a front lower longitudinal beam of an automobile floor as claimed in claim 1, characterized in that: In step one, a lower guiding slope inclined outward is provided on the outer side of the lower forming block, and an upper guiding slope matching the lower guiding slope is provided on the inner side of the upper pressing ring. The upper pressing ring cooperates with the floating pressing ring and the lower forming block group, so that a Z-shaped step portion is formed on the outer side of the lower edge portion on both sides of the workpiece.

3. A stamping process for a front lower longitudinal beam of an automobile floor as claimed in claim 2, characterized in that: The upper and lower edges of the inner side of the upper pressing ring are both provided with transition arc surfaces, and the upper edge of the outer side of the lower forming block is provided with a transition arc surface.

4. The stamping process of the front lower longitudinal beam of an automobile floor as claimed in claim 1, characterized in that: In the step 2, two punching dies are used to punch the end holes close to the end of the workpiece.

5. The stamping process of the front lower longitudinal beam of an automobile floor as claimed in claim 1, characterized in that: In the step 2, two punching dies are used to punch a part of the end hole of the workpiece close to the end; in the step 3, three shaping punching dies are used to punch the remaining part of the end hole of the workpiece close to the end.

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