Blank holder force is an important factor affecting the stamping quality of the head. Because the stamping and forming process of the head is relatively complicated, it is difficult to control the wall thickness reduction of the head at the same time by relying on the traditional constant blank holder force to avoid bulging, wrinkling and pulling. The occurrence of cracks, and in actual production, these are the forming quality problems that must be controlled for the head.

　　It is precisely because of this problem that variable blank holder force occurs. The variable blank holder force is to set the blank holder force according to each deformation stage of the head. The use of variable blank holder force can make full use of the forming performance of the material and maximize the forming quality of the head. The disadvantage is that it increases the difficulty of the process design of the head. This is difficult to achieve in the traditional head production enterprises relying solely on experience and testing. Borrowing finite element simulation software can make up for the lack of experience, visualize the stamping forming process, and greatly improve the quality of the head. The YH24-2400/4000A double-acting hydraulic machine used in the test can provide up to 10 levels of blank holder force. With the help of finite element methods, the blank holder force distribution can be set according to different punching depths, thereby optimizing the blank holder force process plan.