Design And Application Of Pneumatic Crimping In Aluminum Cover Mould

1. The status quo of aluminum alloy cap stretching die at the same time

At present, the aluminum cover has a rubber ring crimping method. The rubber ring is connected to the screw and is isolated by a flat metal disc. The screw is screwed onto the lower die plate directly below the center of the die punch, and the bottom of the screw is fastened with a nut. The bead ring of the mold is connected to the rubber ring through the template through three ejector pins to form a structure for providing the blanking force. Different blanking dimensions require different blanking forces and are adjusted by the tightening nut below the screw.

Disadvantages of the rubber ring crimping method: 

1) The blanking force of the aluminum cylinder during the drawing process is small and large, which is not conducive to deformation and stretching. 

2) The rubber ring is easily broken after repeated compression. 

3) Through the lower template, the three top rods are easy to wear under the working template, and the excessively large holes cause the blanking force to be unstable. 

4) The rubber ring forms a long “tail” under the lower template, which is inconvenient to load and unload the mold and has high labor intensity.

2. Design and application of pneumatic crimping for one-time drawing die of aluminum cover

How to overcome the defects of the rubber ring crimping method, need to change the way the blanking force is provided. The following is the design of the pneumatic crimping edge. The seal between the piston and the base and between the piston and the punch die is sealed with a small wear resistance. The seal between the base and the lower die is sealed by a sealing ring. A confined space is formed between the piston, the base, the male mold shank and the lower die plate, and is connected to the external compressed air through the compressed air passage, and the compressed air pushes the piston upward to connect with the presser ring, so that the blanking force of the presser ring It can be supplied and adjusted by compressed air.

Apply grease to the piston to reduce friction and improve sealing. Compressed air is provided with a suitable size of the gas storage tank to ensure the stability of the compressed air pressure in the mold.

Advantages of pneumatic crimping:

1) The blanking force of the drawing process is always consistent, thus ensuring uniform wall thickness of the aluminum cylinder after stretching and high homogeneity of the produced product. 

2) The structure is reasonable, the sealing ring is wear-resistant, the service life is long, and the mold is stable and reliable. 

3) Remove the long “tail” formed by the rubber cover of the aluminum cover, which is easy to load and unload, low in labor intensity and high in safety.