Device and method for measuring roundness of inner hole of large-sized part

Abstract

The invention belongs to the field of precision testing and relates to a device and method for measuring the roundness of the inner hole of a large-sized part. According to the method, an instrument main shaft provided with non-contact displacement sensors is controlled to move along a Z axis to a set position in the inner hole of a to-be-measured workpiece, and then to rotate at least one circlealong a C axis; the readings of the sensors of the to-be-measured workpiece which are distributed at M sampling points on the inner hole of the to-be-measured workpiece, and the corresponding angulardisplacement data of the C axis are recorded in the rotating process of the instrument main shaft; least square circle fitting is performed according to the readings of the sensors of the to-be-measured workpiece at the M sampling points and the corresponding angular displacement data of the C axis, so that the center of a first least square circle can be obtained; distances between the M samplingpoints to the center are calculated, the difference value of the maximum value and minimum value of the distances is adopted as the roundness error of the inner hole of the to-be-measured workpiece;and therefore, the measurement of the roundness of the inner hole of the to-be-measured workpiece is realized, and the problem that the roundness of the inner hole of a large-sized key part is difficult to measure is solved.

Description

technical field [0001] The invention relates to the field of precision testing, in particular to an in-situ measuring device and method for the roundness of the inner hole of a large part. Background technique [0002] Roundness measurement is an important detection method to ensure the product quality and performance of mechanical parts. The basic principle of roundness measurement is to first obtain the coordinates of a series of points on the measured circle, and then calculate the center coordinates of the least square circle, the smallest area circle, the largest inscribed circle or the smallest circumscribed circle and the corresponding Outline maximum, minimum radius and other information, and finally the roundness error value can be calculated according to the method of evaluating the roundness error according to the product geometric quantity technical specification. [0003] The traditional roundness error measurement methods all use the method of placing the work...

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Problems solved by technology

[0004] The purpose of the present invention is to provide an on-site measurement device and method for the roundness of the inner hole of a large part to solve the problem that it is difficult to realize the on-site measurement of the roundness of the inner hole of a large key part

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