Method for thermally upsetting and forming flange plate bolt head

Abstract

The invention discloses a method for thermally upsetting and forming a flange plate bolt head. The method comprises the following steps: turning raw materials into shapes of steps; reducing the diameters of material for forming a hexagonal head to phi=S-sigma-alpha by turning, wherein S is the dimensions of opposite sides of a hexagon, sigma is thermal expansion and shrinkage amount of the material, alpha is a dislocation value of upper and lower die holders used in a thermal upsetting process, and hexagonal small-diameter parts, connected transition inclined surfaces and un-reduced large-diameter parts on raw materials are formed by reducing through turning; and finally, regulating a heating temperature of hexagonal small-diameter parts in the thermal upsetting process to be a heating temperature required for thermally upsetting to form a flange plate part on the raw materials, thereby thermally upsetting and forming the flange plate bolt head. The method has the characteristics of being high in milling speed, good in surface quality, short in period, high in benefit and low in cost, and has the characteristic that folding is not generated at junctions of a hexagonal part and a flange plate, and a product can be upset fully.

Description

technical field [0001] The invention belongs to the technical field of machinery, and in particular relates to a method for hot heading forming of a flange bolt head. Background technique [0002] At present, for the head forming of flange bolts whose hexagonal head is smaller than the diameter of the shank, because the hexagonal size is smaller than the shank diameter, and the process material selection is larger than the shank diameter, the hexagonal mold will be larger than the hexagonal part during the upsetting process. The part of the material with large sides is scraped down to produce creases. As the material at the flange expands, it will eventually fold at the junction of the hexagon and the flange, and the head hexagon may be twisted off during assembly. For this reason, the commonly used solution is to select a round bar with a diameter similar to that of the flange to turn the outer circle and mill the hexagon, or use a material with a small diameter to make ...

AI Technical Summary

Problems solved by technology

For this reason, the commonly used solution is to select a round bar with a diameter similar to that of the flange to turn the outer circle and mill the hexagon, or use a material with a small diameter to make the head larger, then turn the outer circle and mill the hexagon, but there are still problems. The milling speed is slow, the surface quality is not good, the cycle is long, the benefit is low, the cost is high, and it is difficult to meet the problems of mass production

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