Measuring method for form and position tolerance

Abstract

The invention relates to a measuring method for the form and the position tolerance of ferromagnetism parts by utilizing a Hall sensor, wherein a Hall linear output sensor is arranged between a part to be measured and a magnet, has a reasonable gap with the part to be measured and is perpendicular to the surface of the part to be measured; and all factors capable of causing the change of output voltage signals of the Hall sensor, except the appearance change of the surface of the part, need to be eliminated; when the Hall sensor and the surface of the part to be measured have relative motion or rotation, the gap between the magnet and the part to be measured changes because of the appearance change of the surface of the part to be measured; the gap change is reflected into the change of the output voltage of the Hall sensor; a signal processing and display unit collects output voltage signals of the Hall sensor; and the form and the position tolerance of the measured part can be obtained on the basis of the obtained voltage signal change, as well as calibration data and a tolerance formula. The measuring method has the advantages of non-contact measurement realization, high measurement accuracy, high speed, low cost, and automation and on-line detection.

Description

technical field [0001] The invention proposes a tolerance measurement method, in particular relates to a measurement method of form and position tolerance. Background technique [0002] Geometric tolerances include straightness, flatness, perpendicularity, circular runout, etc. The shape and position tolerance is of great significance to ensure the quality of the parts. If the radial runout tolerance is too large, it will easily lead to the occurrence of dynamic imbalance, and wear and even damage the parts and supporting bearings. At present, the commonly used form and position tolerance measurement method is mainly mechanical dial indicator. The dial gauge is a measuring instrument that converts the linear displacement of the measuring rod into the angular displacement of the pointer by using rack gear or lever gear transmission. It is mainly used to measure the size, shape and position error of the workpiece. The graduation value is 0.01 mm, and the measuring range is ...

AI Technical Summary

Problems solved by technology

[0005] The dial indicator belongs to mechanical measurement, which needs to use probes to directly contact the surface of the measured part. This is the main reason for its low efficiency. It cannot be fully tested in the entire area. Generally, only a few points can be selected for detection and then the maximum difference can be taken. , the accuracy is not high

Direct contact may also damage the surface of the part

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