Forming method of special-shaped press-riveting sleeve, special-shaped press-riveting sleeve and device for forming special-shaped press-riveting sleeve

Abstract

The forming method comprises the following steps that a stamping die abuts against the end face of a wire rod, and cold heading is conducted on the wire rod from top to bottom so that a flange part and a rod part can be formed; a through hole is punched from the end, away from the flange part, of the rod part from bottom to top, a chamfering part is arranged at the bottom of the through hole, and the inner diameter of the chamfering part is gradually increased towards the bottom end of the rod part; stamping is conducted from the end face of the flange part, and the chamfering part flows in the radial direction under the action of the stamping die, so that the diameter of the bottom end of the rod part gradually becomes larger towards the side away from the flange part, and a horn mouth part is formed; and electroplating the wire rod on which the flange part, the rod part and the horn mouth part are formed so as to form the pressing rivet sleeve. A one-time cold heading forming process is adopted, so that the rod part of the front station is formed into the structure of the chamfering part, and then the chamfering part flows in the radial direction and gradually deforms to form the horn mouth part at the bottom of the rod part under the action of the punching die of the rear station, so that the production efficiency is greatly improved, the production cost is reduced, and the production period is shortened.

Description

technical field [0001] The invention relates to the technical field of fastener manufacturing, in particular to a forming method of a special-shaped riveting sleeve, a special-shaped riveting sleeve and a device for forming a special-shaped riveting sleeve. Background technique [0002] The pressure riveting sleeve is fastened to the connected parts through pressure riveting, and is widely used in automobile bumpers. The pressure riveting nut has the characteristics of a small diameter in the middle stem and a flared shape at one end of the stem, which is often processed by a cold heading forming process. According to the traditional cold heading forming process, the shape of the bell mouth of the riveting sleeve cannot be formed, and subsequent machining is required to obtain the shape of the mouth bell mouth. The processing and forming process is more complicated, which makes the production efficiency lower and the production cycle longer. It is not suitable for Large-sca...

Images