A surface-enhanced inner step shaft inner hole precision forming process

Abstract

A surface-strengthened inner step shaft precision forming process, first design the blank, and then pump lubricant into the inner area formed by the lubricant-filled main flow channel and the lubricant branch channel of the mandrel; then assemble the mandrel and the blank, Install the rotary forging machine through the installation hole at the back of the mandrel, the mandrel and the blank are subjected to the high-frequency forging of the forging die, and the rotary forging forms a large inner hole; then adjust the position of the mandrel and the blank, from the raised part of the blank Start rotary forging, rotary forging to form a small inner hole; replace the mold for strengthening, assemble the rotary forging machine, reduce the motor speed of the rotary forging machine to reduce the impact energy of the mold, and forge the entire surface of the billet after the inner hole rotary forging, Add uniform compressive stress on the surface of the blank to achieve a secondary surface strengthening effect similar to shot peening impact; finally remove the workpiece; the invention can not only ensure the formation of the inner hole, but also effectively strengthen the surface of the shaft and improve the fatigue strength.

Description

technical field [0001] The invention relates to the technical field of mechanical processing, in particular to a surface-strengthened inner step shaft inner hole precision forming process. Background technique [0002] Thin-walled and slender shaft parts, especially those with stepped inner holes, occupy an important position in small and medium-sized aero-engines, and are subjected to alternating bending and torsional stresses. The processing quality of parts affects the safety and reliability of the engine. [0003] The shape of the inner hole of the stepped shaft in the thin-walled slender shaft is complex, the precision is high, and there are blind holes that are difficult to process. The current processing technology is: blank-drilling small holes-deep hole drilling large holes-finishing of the outer surface, or blank-drilling small holes-drilling large holes from one side-drilling large holes from the other side-finishing of the outer surface. [0004] Rotary forging ...

AI Technical Summary

Problems solved by technology

[0005] The traditional deep hole drilling is used for manufacturing, the cycle is long, the efficiency is low, and the scrap rate is high, and the large holes are processed from both sides separately, which is prone to problems such as poor coaxiality and straightness.

Using the usual rotary forging process that uses pipes as blanks, for shafts with a large change in the inner hole step or a shaft with a requirement for the outer circle size, the rotary forging may damage the mandrel or fail to form.

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