Laser ultrasound-based online air compressor cylinder surface crack detection method and system

Abstract

The invention discloses a laser ultrasound-based online air compressor cylinder surface crack detection method and system. The detection method comprises steps: (1) a pulse laser generator generates alaser beam, and the laser beam is incident to the surface of a to-be-detected cylinder to generate a detection ultrasonic signal; (2) a laser interferometer emits a detection beam and the detection beam receives the detection ultrasonic signal; (3) the detection ultrasonic signal is amplified and is then transmitted to a high-speed data acquisition card for being processed and is then transmittedto a data analysis system; (4) the data analysis system performs imaging detection on the detection ultrasonic signal; and (5) the detection result is displayed in real time. The online detection system comprises a PLC, the laser interferometer, the high-speed data acquisition card, the data analysis system, a display screen, the laser pulse generator, an optical path adjustment system and the like. The detection method in the invention has the advantages of completely non contact, high detection efficiency, high precision, and intuitive detection result, and the detection system can realizeonline, real-time, fast and accurate detection on the surface crack of the cylinder.

Description

technical field [0001] The invention relates to the technical field of detection, in particular to an online detection method and system for cracks on the cylinder body of an air compressor based on laser ultrasound. Background technique [0002] Air compressor (referred to as air compressor) is a kind of power equipment that generates compressed air. Hammers, etc., are widely used in transportation, textiles, food, energy, chemical and pharmaceutical fields. The air compressor cylinder is generally cast and processed by gray iron, including upper and lower parts. The upper and lower parts are fixedly connected by positioning pins and bolts. When working, the cylinder of the air compressor needs to continuously withstand the action of high temperature and high pressure gas, so the requirements for the smoothness and flatness of the upper and lower cylinder surfaces and connecting surfaces are extremely strict. In fact, during the casting and processing process, sand holes...

AI Technical Summary

Problems solved by technology

Infrared detection detects cracks by scanning and recording temperature changes on the surface of the object to be inspected due to defects or different thermal properties of the material. However, this method is greatly affected by the ambient temperature and the surface temperature of the object to be inspected, and it is extremely prone to measurement errors.

In addition, camera imaging detection has high requirements on the test environment, such as light intensity, and because of the imaging pixels, it is difficult to detect small cracks in a large detection area, and its application is also limited in some occasions

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