The hydroforming operation, the rubber diaphragm is pressurized by fluid and which act as both the flexible tool and blank holder for forming process. the fluid backed augmented increase the draw depth and reduction of local stress concentration induced. These set up to reduce the defects in formed parts and increase the formability. The hydro forming setup process as shown in figure below. The container is having high pressure of fluid until maximum pressure of 150 Mpa used. These fluid container is fixed on bed press.
The rubber diaphragm is placed in between pressurized fluid and the blank. The draw ring is mounted on blank. The punch move upward and create high pressure of fluid in the blank and then the punch travel into container, the cup is formed together and again hydro static pressure is developed in the fluid. The rigid tool is act as punch in the forming. After form of cup, the punch released along with the draw ring.
The hydraulic pressure of fluid exerted in the blank, when the stress is controlled uniformly and accurately. And also that allow dimensional control and product is free from tearing and wrinkling.
Reduce the sheet metal thinning and consider suppression of cracks, higher ratio of draw (up to R=3) are done because the fluid pressure around the blank in uniformly and less stress induced on the plate corners.
Advantages of hydroforming:
- The cost of tool is low
- Flexible and ease operation
- Die wear is low
- Wrinkling and tear on the plate avoided
- The complex shape can be manufactured.
- The laminate sheets are formed also.
Application of hydro forming:
The hydro forming is a cost effective method of malleable metals such as structurally stiff and strong piece, aluminum and light weight.
That is popularly as particular high end sports car industries and also most effective method of shaping of aluminum tube used as bicycle frames.
It is suitable for both jet engine equipment and car components including roof and side panels.
The popular company product can be formed as follow.