A method for predicting the exit damage width of rotary ultrasonic hole machining of hard and brittle materials for vehicles

Abstract

The invention discloses a method for predicting the damage width at the exit of rotary ultrasonic hole machining of hard and brittle materials for vehicles. Theoretical relationship model between the maximum cutting depth of abrasive grains; (3) determine the number of abrasive grains N on the end face of the tool all and the average cutting force F of the tool average ; (4) Determine the maximum cutting force F of the tool max And the maximum additional bending moment M acting on the edge of the processed surface max ; (5) Establish the stress intensity factor K I with the maximum subsurface crack depth and the maximum additional bending moment M max The relationship model between; (6) Establish the theoretical thickness h of the outlet damage theo Relationship with the maximum subsurface crack depth; (7) Establishing the width of the exit damage b chipping and the average cutting force F of the tool average theoretical relationship. The invention comprehensively considers multiple factors, realizes the prediction of the exit damage width in the process of machining the rotary ultrasonic hole of the hard and brittle material for vehicles, and improves the prediction accuracy.

Description

technical field [0001] The invention relates to the technical field of rotary ultrasonic hole machining, in particular to a method for predicting the damage width of the exit of rotary ultrasonic hole machining of hard and brittle materials for vehicles. Background technique [0002] The inherent high strength, good wear resistance, low thermal conductivity, low density and low expansion coefficient of structural ceramics make them widely used in the manufacture of engines and heat exchange parts. In addition, ceramics have strong corrosion resistance and good thermal stability at high temperatures, and are widely used in the manufacture of spark plug substrates for gasoline engine ignition systems. However, as a typical hard and brittle material, during the hole machining of structural ceramics, the large extrusion force of the tool-workpiece inevitably causes edge damage at the hole exit position, which seriously reduces the assembly accuracy and structural integrity, and ...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims at the failure of the existing method for predicting the exit damage width during the rotary ultrasonic hole machining of hard and brittle materials for vehicles in the field to consider the influence of the maximum additional bending moment and the maximum depth crack on the exit damage width of the hole, resulting in poor prediction accuracy and reliability. Low problem, the present invention provides a method for predicting the exit damage width of the rotary ultrasonic hole machining of hard and brittle materials for vehicles, so as to realize accurate prediction of the exit damage width during the process of rotary ultrasonic hole machining of hard and brittle materials for vehicles

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