Analysis of the reason and control method of wrinkling of automobile stamping parts?

2019-10-31 09:18:14

The production of automobile stamping parts is a very important part in automobile manufacturing. For example, the body, frame, carriage and body body of car are made of steel stamping parts. According to statistics, an average car needs about 1500 stamping parts. With China's increasing automobile output year by year, foreign capital has entered China to set up factories, and to meet the hot domestic and export demand at the same time, the demand for automotive stamping parts is bound to be a good opportunity for China's stamping industry to enter the upgrading.

Wrinkling in stamping production will lead to scrap of parts, which not only increases the manufacturing cost, but also causes waste of raw materials. It needs to be analyzed and controlled.

The causes are as follows:

1. The blank holder force is not enough, and the gap between the blank holder surfaces is not suitable, which leads to the problem of "internal looseness and external tightness".

2. Too much lubricating oil or too frequent brushing times, or improper brushing position.

3. The test punching blank is too soft, the material strength is low, the blank size is too small, and the material cannot be pressed.

4. The rough positioning is not stable, resulting in partial unstoppable pressing, improper shape of pressing surface, resulting in uneven feeding.

5. The stamping direction is improper.

Measures for wrinkle control:

1. Check the wrinkle state. When wrinkles are evenly generated around the parts, it should be judged that the pressing force is insufficient, and gradually increasing the pressing force can eliminate them. When drawing tapered and hemispherical parts, increasing the drawbead should be used to increase the tensile stress in the inner diameter of the plate to eliminate wrinkles. The principle of "internal tightness and external tightness" is adopted to eliminate the problem of "internal tightness and external tightness".

2. For lubricating oil, oil brushing shall be carried out in accordance with the requirements of operating procedures and systems to ensure the correct amount and position of oil brushing and avoid wrinkling.

3. Under the condition that the requirements of the whole vehicle are not affected, the parts with too soft blank shall be replaced to ensure the quality of the parts and avoid wrinkling.

4. Improve the positioning, add pre bending process if necessary, to ensure that the sheet metal will not deviate during stamping. Modify the shape of the pressing surface, ensure the quality of the parts, and avoid the unevenness of the feeding caused by the immobility of the shape of the pressing surface.

5. In view of the improper stamping direction, the simulation software shall be used to analyze the process of the parts in the early stage of design to ensure the stamping direction of the parts. When the quality requirements of the parts are high, the mold shall be redeveloped and the stamping direction shall be adjusted.