Patent ID: 6170308
Filing Date: 2001-01-09
Classification: B24B,Y10S,Y10T

Abstract:
A method for peening the internal surface of a hollow part with at least one peening element therein, the peening element having a diameter (d) and the hollow part having a cavity height (h), comprising the step(s) of: vibrating the hollow part at a vibration frequency (.function.) equal to about ##EQU8##and at an acceleration equal to or greater than about ##EQU9##wherein V.sub.pe is the desired velocity of the peening element and wherein .gamma. is a peening element speed limit ratio and wherein the peening element speed limit ratio (.gamma.) is determined by the method comprising the steps:(a) vibrating the hollow part at a first constant sinusoidal acceleration and a first vibration frequency such that the impact rate is about equal to the first vibration frequency, wherein the impact rate is a rate of impact between the peening element and an internal surface of the hollow part;(b) altering the vibration frequency of the hollow part to a first altered vibration frequency until the impact rate is less than the first altered vibration frequency, the vibration frequency immediately prior to the first altered vibration frequency being referred to as a first cut-off frequency;(c) determining the velocity of the hollow part (V.sub.p1) commensurate with the first cut-off frequency;(d) determining the velocity of the peening element (V.sub.pe1) commensurate with the first cut-off frequency;(e) vibrating the hollow part at a second constant sinusoidal acceleration and a second vibration frequency such that the impact rate is equal to about the second vibration frequency;(f) altering the vibration frequency of the hollow part to a second altered vibration frequency until the impact rate is less than the second altered vibration frequency, the vibration frequency immediately prior to the second altered vibration frequency being referred to as a second cut-off frequency;(g) determining the velocity of the hollow part (V.sub.p2) commensurate with the second cut-off frequency; and(h) determining the velocity of the peening element (V.sub.pe2) commensurate with the second cut-off vibration frequency, the peening element speed limit ratio (.gamma.) being equal to ##EQU10##