A Brief Discussion on Quality Control Strategies for Automotive Stamping Parts

Stamping is a forming process that uses a press and mold to apply external force to sheets, strips, pipes, and profiles to obtain the desired shape and size. Due to the presence of local shape features within the overall contour of many coverings, forming control technology is helpful in analyzing process and quality issues that arise during the stretching process.

Control of stamping production process

1.1 Determine the process plan

Determine stamping parts; When designing the process plan, it is necessary to consider the arrangement of auxiliary processes, and the nature of the stamping process can be determined through the part drawing. The process sequence is the order in which each process is carried out, and a reasonable arrangement can improve production efficiency and the timeliness of product molding.

1.2 Mold installation process

The correct mold can extend the service life of the mold. If the mold design is not sufficient, the subsequent processing of stamping parts cannot be achieved, which affects the service life of the mold and leads to quality problems of stamping parts. For thick sheet metal and composite die stamping processing, it is necessary to prepare process cards and carry out installation and debugging work.

1.3 Clarify the stamping direction

When determining the stamping direction, one is to ensure that the convex mold can enter the concave mold, and the other is to consider whether the feeding resistance of each part of the pressing surface is uniform. Stamping processing is easy to operate and achieve mechanization and automation in both technical and economic aspects. Generally, stamping does not damage the surface quality of stamping parts, and stamping has good interchangeability, with "identical characteristics". Stamping generally consumes less materials, and has a wide range of applications in the national economy.

Control of Stamping Processing Technology for Part 2

2.1 Stretching process

The molds used in stamping processing require several sets of molds to process and form, and the mold technology requirements are high. Therefore, the process of stamping is the stretching process, and the quality of the stretching process is the comprehensive coordination of various variables. On the basis of meeting the stretching requirements, a good foundation should be laid for edge cutting and flanging. Due to the fact that the pressing surface is a supplementary part of the stretching process, the stretching should be controlled reasonably. The pressing surface needs to be processed into a tilted angle with an angle, in order to allow the blank to fit well with the pressing surface to a large extent, while avoiding the influence of the punch on the drawing of the blank. The stretching effect generated by the pressing surface on the drawn blank, but if the number of wrinkles generated in the stretching process is small, they may be affected by the stretching effect, making it difficult to make a comparative judgment on the wrinkles formed.

2.2 Wrinkle control

The main reasons for stretching parts during the stretching process are as follows: the sheet metal flows too quickly during the feeding process of stamped parts, resulting in wrinkling; If the R angle of the stamping die is too large, it is likely to cause the sheet metal to flow too quickly and form wrinkles; Unreasonable mold positioning design leads to the inability to press the material during the stretching process of the stamped part or the pressing edge is too small, resulting in wrinkling; Excessive clearance between convex and concave molds causes wrinkling.

2.3 Process Management

Sometimes stamping products may be scrapped due to surface defects on the blank board, so only qualified blank boards can be stamped and formed. Surface inspection is also required for the inspection of stamped products. During the stretching process, the sheet metal should flow at a reasonable speed. If the flow rate of the sheet metal is too slow, it may cause the parts to crack. When using a pressing device, the pressing device exerts a pressing force on it, which can effectively regulate the flow of the material. For complex curved stretching parts, it is necessary to increase the radial tensile stress during stretching to control wrinkling; For drawn parts with significant differences in stretching, they should be placed in areas with less feed to prevent wrinkling. Wrinkles are the result of insufficient pressing force, and the method is to adjust the magnitude of the edge pressing force. When stretching begins, in addition to increasing the edge pressing force, the method of adding picking and stretching tendons should also be used to wrinkle.

3. Quality control of stamping forming

The quality control of stamping forming is achieved through the prediction and monitoring process of statistical control methods to make real-time adjustments, thereby improving production efficiency and benefits.

3.1 Pareto diagram method

The purpose of drawing a layout diagram is to visually represent it in a graphical way, so that manufacturers can clarify where to start improving product quality. In the factors that cause quality problems in stamped parts, the phenomena and causes of quality are usually classified, and the frequently occurring quality problems and influencing factors are found from them.

3.2 Control Chart Method

Control chart is the application of statistical techniques to achieve process control, mainly to timely trace the control chart of each process according to the rules in the dynamic production process, and take measures to reduce costs.

4. Increase detection technology

To accumulate errors in the mold manufacturing process, it is necessary to do a good job in assembly and debugging.