Bolt forming method and cold heading device

Abstract

The invention discloses a bolt forming method. The method comprises the steps: subjecting a wire rod to cold heading to form a first mold material, wherein in the process, the wire rod forms a head part and a rod part, and a chamfer is formed at the tail part of the rod part; subjecting the first mold material to cold heading to form a second mold material, in the process, preforming the head part, and preforming the part between the head part and the rod part to form two step parts; subjecting the second die material to cold heading to form a third die material, in the process, subjecting the head of the second die material to upsetting forming, and subjecting the two step parts to upsetting forming; subjecting the third mold material to cold heading to form a fourth mold material, in the process, only shrinking the rod part, and subjecting the rod part to cold heading forming; and subjecting the fourth die material to cold heading to form a fifth die material, and in the process, trimming the head into a hexagon. The method also comprises a cold heading device. The cold heading device comprises first to fifth dies used for cold heading forming of the first to fifth die materials. The concentricity of the head part and the rod part can be ensured through cold heading forming.

Description

technical field [0001] The invention relates to a bolt forming method and a cold heading device. Background technique [0002] The bolt has a head of a nut and a threaded stem, and as a fastener, the bolt needs to cooperate with a nut for fastening and connecting two parts with through holes. In order to connect securely, the requirement for the bolt requires that the concentricity of the head and the shank is better, however, the diameter of the head of the bolt is larger than the diameter of the shank. In the traditional machining method, the concentricity of the head and the shank is poor, resulting in unstable bolt quality and high product scrap rate. In addition, the machining time is long and the production efficiency is low. [0003] Bolts used in automobile braking systems, a brake caliper guide bolt is a fixed bolt installed on the brake cylinder frame, used to connect the cylinder cylinder piston assembly and the cylinder cylinder mounting frame, its structure is...

AI Technical Summary

Problems solved by technology

In the traditional machining method, the concentricity of the head and the shank is poor, resulting in unstable bolt quality and high product scrap rate

In addition, the processing time of machining is long and the production efficiency is low

[0003] Bolts used in automobile braking systems, a brake caliper guide bolt is a fixed bolt installed on the brake cylinder frame, used to connect the cylinder cylinder piston assembly and the cylinder cylinder mounting frame, its structure is more complicated, With multiple steps, its concentricity is more difficult to ensure

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