Cold precise forming technology and equipment of spur gear

Abstract

The invention relates to a kind of techniques for straight spur gear precision cold-forming and correspondent device. Within the pressure the cold-working can afford, the invention adopts the cold-forming forming method with floating die to crush from two directions, producing straight spur gear of complete teeth with only one step. The mould used for the device consists of two sections: the upper section includes upper oil cylinder, jaw, upper flatten, and upper drift, and the under section includes die, under flatten, under oil cylinder and under drift. When press machine moves downward, jaw, upper flatten, and upper drift are pressed to move down also while the under drift does not move. The die, and the under flatten are propped up by the under oil cylinder. The die floats down at a certain speed, crushing the bar stock in it from two sides and finish forming. At the end faces of the upper drift and the under drift are raised bars. When crushing from two sides, the bar stock in the die is squeezed out of the bore, then the two drifts crush it from two sides and finish the process. The invention finishes forming with only one step. The technique is simple and effective, meeting the demand of saving the forming time, energy and material.

Description

(1) Technical field [0001] The invention belongs to the medium-cooling precision process and its device in the machinery manufacturing industry, in particular to a cold-precision forming device for spur gears. (2) Background technology [0002] Spur gears (height H and diameter D) At present, spur gears with large H / D can be solved by positive extrusion method, which is not difficult in engineering, but most of spur gears are flat, generally H / D<1 / 2 to 1 / 10, and the flat gear can only use a toothed punch to upset the blank in the toothed die, so that the blank flows radially and is formed, such as figure 1 As shown, since the tooth shape of the die 2 is gradually narrowed, it is quite difficult to fill the tooth shape with radial flow, or a relatively high extrusion stress (up to 3000-4000Mpa) is required, so that the mold cannot bear it. The maximum allowable stress of the cold forging die is generally ≤2500Mpa, so the biggest difficulty in forming spur gears is to fin...

AI Technical Summary

Problems solved by technology

Researches both at home and abroad use two-step meso-hole shunt forming to cold form spur gears, but the process is complex, requiring pre-forming, punching, final forming, and some require intermediate annealing and secondary lubrication, and the process is long. Losing the high efficiency and energy saving features of precision forming, it is difficult to popularize and apply in industry

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