Ultrasonic non-destructive testing method for measuring circumference residual stress at gear root

Abstract

The invention provides an ultrasonic non-destructive testing method for measuring circumference residual stress at root, the method is suitable for the non-destructive measurement of residual stress at the gear root. An LCR (critically refracted longitudinal) wave which is most sensitive to the stress is motivated through the combination of an ultrasonic stress measurement system, an ultrasonic transducer and a wedge block, and the residue stress at the region is precisely computed by using acoustic time difference of the LCR wave for detecting whether the stress is near to the root. The method is capable of accurately, fast and non-destructively detecting the residue stress value.

Description

1. Technical field [0001] The invention provides an ultrasonic non-destructive testing method for measuring the residual stress of the tooth root of the gear, and the method is suitable for the non-destructive measurement of the residual stress of the tooth root of the gear. 2. Background technology [0002] Gears are important parts in machines such as automobiles, tractors, and machine tools. They are responsible for the important tasks of transmitting motion, changing the speed and direction of motion. Therefore, whether it is the stress situation during the manufacturing process of the gear or the stress situation during work, it is an important subject for people to study. [0003] Literature search found that the paper: (Zhao Xiyong. Determination of tooth root stress of worn traction gear) mentioned the method of sticking strain gauges to measure the stress of the tooth root, but this method is limited to measuring the tooth root stress during the motion process. In ...

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Problems solved by technology

Patent: (Jiang Chuanhai, et al. Detection method for residual stress of shot peening layer at the root of small curved gears [P]. Patent No.: CN102628815A, 2012) discloses a rectangular diffraction baffle with different sizes prepared according to the curvature radius of the gear. Under the condition of different sizes of baffles, the residual stress value of the root of the curved gear is obtained, and the relationship between the width of the rectangular baffle and the residual stress value is obtained. This is an X-ray-based stress detection method, which requires that the gear root surface is basically flat and must be Appropriate chemical treatment exposes the lattice, and repeatedly adjusts the incident angle of X-rays to obtain a certain intensity at a suitable diffraction angle. The operation is complicated, there are many influencing factors, and the accuracy is not high. Practical applications are greatly affected. big limit

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