Accurate part finish blanking method and blanking mold thereof

Abstract

The present invention discloses a fine punching method and a punching die for precise parts, which are applicable for punching cavity of the precise parts. The present invention adopts double punching method, which pre-punches to make the cavity whose size is smaller than required size of the part. And then the second fine punching is performed to finish the process of cavity punching. The punching die is used in conjunction with the punching method. Lower precision is required for a pre-punching die, while strict design of small gap and fillet is required for a fine punching die. The design has less impact for the second fine punching, so the obtained cavity has no taper and bright belt rate is close to 100 per cent. Moreover, the design can protect the die and reduce replacement frequency, thereby greatly decreasing costs.

Description

technical field [0001] The invention belongs to a metal material punching processing method and a punching die thereof, in particular to a method for punching out precision parts from a metal plate and a punching die. Background technique [0002] Smooth punching, also known as small gap, small rounded punch (die) punching, compared with ordinary punching, is characterized by the use of a small rounded edge and a small die gap. Due to the rounded corners of the cutting edge during punching, the hydrostatic pressure in the deformation zone is strengthened, the plasticity of the metal is improved, and the side of the cutting edge where cracks are prone to occur becomes a compressive stress area, and the rounded corners of the cutting edge are conducive to the material from the die end Flowing towards the side of the mold, the tensile stress of the material in contact with the side of the mold is eased, thereby preventing or delaying the occurrence of cross-section cracks, maki...

AI Technical Summary

Problems solved by technology

However, due to the small gap design between the punch and the die for smooth punching, the punch must go deep into a part of the die, and the requirements for the material, finish, and installation accuracy of the die are very high, so the cost of the die is very high. The huge impact force will easily change the installation accuracy of the mold and cause damage to the mold. Frequent replacement of expensive molds will increase the production cost of the enterprise and become the biggest defect of smooth blanking technology.

In addition, for the punching of the part cavity, since the punching is completed in an instant, the cavity obtained by one-time smooth punching has a certain taper, which reduces the accuracy of the part

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