Measuring instrument for space curve type long distance fine pipe internal surface shape and its detecting method

Abstract

The present invention discloses a space curve type long-distance microfine pipe internal surface form measurement instrument and its detection method. Said pipe internal surface form measurement instrument is formed from the components of 2-D position sensor, semiconductor laser, transparent window, micromotor, scanning lens, reflector, convergent lens and receiving lens group, etc. Said measurement instrument is applicable to defect detection and 3-D measurement of curve type microfine pipe internal wall whose inner diameter is 9-11 mm and curvature radius is greater than 100 mm, and its measuring accuracy can be up to plus or minus 0.1 mm.

Description

technical field [0001] The invention relates to a space curve type long-distance micro-pipe inner surface topography measuring instrument and a detection method. Background technique [0002] A large number of pipeline parts are used in many industries such as machinery, energy, chemical industry, etc. After long-term use, defects such as cracks may appear, which may cause gas or liquid leakage, damage the entire system, and cause unnecessary economic losses, and even endanger the lives of staff. Therefore, the detection of such parts has become a very important subject. Many literatures at home and abroad have done in-depth research on this issue, but most of them are for pipes with an inner diameter greater than 20mm, and there are few research reports for small pipes, especially those with an inner diameter of less than 10mm. [0003] The detection technology of the inner wall of large pipes is relatively mature. The most common method is to use a CCD camera to image th...

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Problems solved by technology

Because the processing circuit of the CCD chip is complex and miniaturization is difficult, it is difficult for ordinary CCD cameras to enter the interior of small pipes.

Although the special industrial electronic endoscope can detect the inner wall of small pipes, it is difficult to determine the size of the defect, the specific spatial location and the three-dimensional shape of the inside of the pipe.

Although the micro pipeline robot developed by Tsuruta k. et al. can also enter the 10mm pipeline for detection, it can only observe the inner wall of the pipeline by the pictures taken by the CCD, and cannot make up for the above-mentioned shortcomings of the endoscope.

Mizunuma M and others used the position sensor PSD (Position Sensitive Detector) to realize the detection and three-dimensional reconstruction of the inner wall of the pipeline, but the rotation mechanism of the system developed by them is complicated, and it is only suitable for straight pipes with an inner diameter of 66-83mm, and cannot detect curved pipes or tiny pipe

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