A method of processing a roof of a motor vehicle

Abstract

The application relates to a processing method of an automobile roof, which comprises the following steps: S1, drawing, a raw plate is made into a semi-finished automobile roof through a drawing die; S2, trimming and punching, when trimming, a part of the plate is reserved at the outer side of the two ends of the tail of the semi-finished automobile roof, and a hole is punched at a predetermined position of the plate; S3, shaping, the semi-finished automobile roof with the plate is shaped through a shaping die; S4, side trimming, the semi-finished automobile roof is trimmed according to a set part contour, and the manufacturing of the finished automobile roof is completed; the processing method increases a shaping area through the reservation of the plate, avoids directly taking the part boundary with a complex shape as a shaping boundary, reduces the risk of wrinkle generation, and improves the appearance quality and dimension precision of the part.

Description

Technical Field

[0001] This invention relates to the field of automotive parts processing technology, specifically to a method for processing an automotive roof. Background Technology

[0002] With increasing emphasis placed on automotive exterior quality, while painting can improve visual perception to some extent, the vast majority of exterior quality still requires strict control over the appearance and dimensional quality of individual components. The inherent forming characteristics of stamped parts, in particular, make some defects difficult to eliminate. Some defects may even be magnified and made more noticeable after painting, leading to concerns among customers about the overall quality of the vehicle.

[0003] Automotive roof panels typically have a small curvature and a relatively flat shape. However, to better fit the tailgate, the rear of the roof is often designed with a negative angle, requiring a side-forming process for successful assembly. Under current conditions, the side-formed rear of the roof exhibits wrinkling defects. These wrinkling defects are still present when analyzed using AutoFROM software simulation. While mold structure optimization and on-site adjustments have reduced the wrinkling, it remains and cannot be completely eliminated.

[0004] Analyzing the current manufacturing process, it is generally adopted as a stamping process using OP10 (drawing), OP20 (trimming), and OP30 (side forming). To improve the wrinkling problem, pressure surfaces are set on both sides of the car roof during the side forming process, so that the sheet metal is formed in a clamped state. This has a certain effect on improving the wrinkling of the side wall at the rear. However, there is still a surface quality problem of wrinkling at both ends of the rear of the roof. Current process methods can usually improve the wrinkling defect at the rear of the roof to a certain extent through mold fitting and adjustment. However, since both ends are formed by opening, coupled with the influence of the shape of the roof itself, the wrinkling defect at the rear of the roof still exists. Moreover, the requirements for mold fitting and adjustment are relatively high. Summary of the Invention

[0005] Based on the above description, the present invention provides a method for processing an automobile roof to solve the technical problem of wrinkling defects at both ends of the rear of the automobile roof in the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A method for processing a car roof includes the following steps:

[0008] S1. Drawing: Using a drawing die, raw material sheets are made into semi-finished car roofs.

[0009] S2. Trim and punch holes. When trimming, leave some sheet material allowance on the outer sides of both ends of the semi-finished car roof, and punch holes at the predetermined positions of the sheet material allowance.

[0010] S3. Shaping: Using a shaping mold, the semi-finished car roof with excess sheet material is shaped.

[0011] S4. Side trimming: Trim the semi-finished car roof according to the set part outline to complete the production of the finished car roof.

[0012] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0013] The processing method provided in this application reserves a portion of the sheet material allowance during trimming and punches holes in the sheet material allowance. The semi-finished car roof with sheet material allowance is shaped, and finally the trimming is completed to finish the finished product. This processing method optimizes the process layout. By reserving the sheet material allowance, the shaping area is increased, avoiding the direct use of the boundary of the complex-shaped part as the shaping boundary, reducing the risk of wrinkling, and improving the appearance quality and dimensional accuracy of the part.

[0014] Based on the above technical solution, the present invention can be further improved as follows.

[0015] Furthermore, in step S2, punching forms irregular holes, and the boundary of the irregular holes near the inner side coincides with a portion of the outline of the finished car roof.

[0016] Furthermore, the overlapping portion of the irregular hole and the outline of the car roof is determined by CAE fitting.

[0017] Furthermore, the excess sheet material at both ends of the semi-finished car roof is connected by scrap material; the scrap material and the excess sheet material are trimmed and flanged in step S4.

[0018] Furthermore, the forming mold has a supplementary forming area corresponding to the portion of the sheet material surplus, and the connection portion between the waste material and the sheet material surplus has a supplementary pressing area.

[0019] Furthermore, when trimming the waste material near the punching position, a transfer cutter is used.

[0020] Furthermore, the portion of the punched area of ​​the sheet metal near the car roof is rounded, and the radius of the rounded area is not less than 5mm.

[0021] Furthermore, the outer side of the sheet metal allowance and the connection part with the car roof are treated with a joint cutter.

[0022] Furthermore, the punching location is in the middle of the sheet material allowance.

[0023] Furthermore, the materials of the drawing die and the forming die are die steel. Attached Figure Description

[0024] Figure 1 A schematic diagram illustrating the steps of a method for processing an automobile roof according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a semi-finished car roof in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure around the sheet metal allowance in an embodiment of the present invention. Detailed Implementation

[0027] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0029] It is understood that spatial relation terms such as "below," "under," "below," "below," "above," "above," etc., can be used here to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as "below" or "below" of the other element or feature will be oriented "above" the other element or feature. Therefore, the exemplary terms "below" and "below" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90° or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0030] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. In the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have the transmission of electrical signals or data between them.

[0031] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0032] like Figure 1 As shown, this application provides a method for processing an automobile roof, which includes the following steps:

[0033] S1. Drawing: Using a drawing die, raw material sheets are made into semi-finished car roofs.

[0034] This step is consistent with the drawing process in the prior art, which is to form the raw material sheet into a semi-finished structure with the shape of a car roof through the drawing process.

[0035] S2. Trim and punch holes. When trimming, leave some sheet material allowance on the outer sides of both ends of the semi-finished car roof, and punch holes at the predetermined positions of the sheet material allowance.

[0036] This step is one of the changes in the technical solution of this application compared with the traditional processing technology. In the trimming process, the traditional solution trims the sheet material at both ends of the tail of the top cover according to the contour position. The resulting part contour is inclined into a trapezoid. During the shaping process, the sheet material is pressed less as you go outward, which leads to local wrinkling inside and on the inclined edge.

[0037] To address the wrinkling issue, this application reserves a portion of sheet material on the outer sides of both ends of the semi-finished car roof, and then punches holes at predetermined positions on the sheet material.

[0038] The key point of this step is to change the traditional trimming process. Instead of cutting out the boundary of the finished part all at once, a portion of the sheet material is reserved, and holes are punched at predetermined positions on the sheet material. Preferably, the holes are formed into irregularly shaped holes, and the boundary of the irregularly shaped holes near the inner side coincides with part of the outline of the finished car roof. That is, the edge of the punched part is the outline edge of the finished part. Because a portion of the sheet material is reserved, the sheet material at both ends is not completely trimmed off during subsequent shaping and is used in subsequent pressing, which will not cause insufficient sheet material to cause internal and local wrinkling.

[0039] The key to this solution is reserving sheet material to facilitate pressing during the forming process. Theoretically, the more sheet material reserved, the better the forming effect and the less prone to wrinkling. Secondly, using the edge of the punched portion as the outline of the finished part facilitates subsequent trimming and improves part processing efficiency.

[0040] The overlapping portion of the irregular hole and the outline of the car roof is determined by CAE fitting.

[0041] S3. Shaping: Using a shaping mold, the semi-finished car roof with excess sheet material is shaped.

[0042] In the embodiments of this application, such as Figure 2 As shown, the excess sheet material 11 at both ends of the semi-finished car roof 10 is connected by scrap material 12; wherein, the forming mold has a supplementary forming area corresponding to the portion of the excess sheet material 11, and the forming mold has a supplementary pressing area corresponding to the connection portion of the scrap material 12 and the excess sheet material 11, that is, in addition to the forming of the original semi-finished car roof 10 parts, combined with Figure 3 As shown, the forming die also has a supplementary forming area a and a supplementary pressing area b, which are used to form the sheet material surplus 11 and part of the waste material area, thereby increasing the inclined forming and inclined pressing areas and effectively controlling the part quality of the forming surface. The product (i.e. the original semi-finished car roof 10 part) is formed inside the supplementary forming area and the supplementary pressing area, which can effectively improve the wrinkling state and improve the appearance quality of the part.

[0043] S4. Side trimming: Trim the semi-finished car roof according to the set part outline to complete the production of the finished car roof. That is, the waste material and the excess sheet material are trimmed and turned over in the trimming process.

[0044] In the embodiments of this application, such as Figure 3 As shown, position 1 is defined as the location of the waste material near the punching hole, position 2 is defined as the part of the punching area of ​​the sheet metal allowance near the car roof, and position 3 is defined as the connection part between the outer side of the sheet metal allowance and the car roof.

[0045] These three locations are the areas that need attention during trimming. Location 1 should be treated with a joint cut with the tail trimming of the traditional solution to ensure a smooth flip-up of the rear edge of the car roof.

[0046] To ensure the strength of the cutting edge, position 2 requires rounding the small corners of the product, with a minimum radius of 5mm. All of this is to ensure the strength of the punch.

[0047] The beveled edge of position 3 is joined with the beveled edge of the car roof sidewall using a cutting tool.

[0048] To improve the strength of the punching pressure plate, the distance between position 2 and position 3 should be made as large as possible while meeting the basic size specifications of the parts.

[0049] The materials of the drawing die and the forming die are die steel.

[0050] The processing method provided in this application reserves a portion of the sheet material allowance during trimming and punches holes in the sheet material allowance. The semi-finished car roof with sheet material allowance is shaped, and finally the trimming is completed to finish the finished product. This processing method optimizes the process layout. By reserving the sheet material allowance, the shaping area is increased, avoiding the direct use of the boundary of the complex-shaped part as the shaping boundary, reducing the risk of wrinkling, and improving the appearance quality and dimensional accuracy of the part.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for processing an automobile roof, comprising the following steps: S1. Drawing: Using a drawing die, raw material sheets are made into semi-finished car roofs. S2. Trim and punch holes. During trimming, leave some sheet material allowance on the outer sides of both ends of the semi-finished car roof. Punch holes at the predetermined positions of the sheet material allowance. The punching forms irregular holes, and the boundary of the irregular holes near the inner side coincides with part of the outline of the finished car roof. S3. Shaping: Using a shaping die, the semi-finished car roof with sheet material surplus is shaped; the part of the punching area of ​​the sheet material surplus near the car roof is rounded, and the radius of the rounded arc is not less than 5mm. S4. Side trimming: Trim the semi-finished car roof according to the set part outline to complete the production of the finished car roof. The excess sheet material at both ends of the semi-finished car roof is connected by scrap material. The forming mold has a supplementary forming area corresponding to the excess sheet material, and the connection between the scrap material and the excess sheet material has a supplementary pressing area. The scrap material and the excess sheet material are trimmed and flanged in step S4.

2. The method for processing an automobile roof according to claim 1, characterized in that, The overlapping portion of the irregular hole and the outline of the car roof was determined by CAE fitting.

3. The method for processing an automobile roof according to claim 1, characterized in that, When trimming the waste material near the punching position, a transfer cutter is used.

4. The method for processing an automobile roof according to claim 1, characterized in that, The outer part of the sheet metal allowance and the connection part with the car roof are treated with a joint cutter.

5. The method for processing an automobile roof according to claim 1, characterized in that, The materials of the drawing die and the forming die are die steel.

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