A non-contact measurement method for measuring the diameter of deep and small holes by combining images

Abstract

The present invention discloses a non-contact measurement method for measuring the diameter of a deep small hole by means of image combination. The invention aims to provide a high-measurement efficiency non-contact measurement method. According to the technical schemes of the invention, a CCD telecentric lens generates two intersection points of a seed basic circle and the arc edge image of a measured workpiece through an image sensor, the intersection lengths of the two intersection points of the seed basic circle and the arc edge image of the measured workpiece being inconsistent, and the extreme positions of the diameter of the measured workpiece are found out; a computer is adopted to control three-dimensional servo motors on a fine-tuning worktable to gradually adjust a reflected image and a non-reflective edge image to make the reflected image and the non-reflective edge image approach an optical axis until distances between the images and the optical axis are equal to 0; the edge image and the reflected image are tangent to each other at the optical axis so as to be combined into an edge image combined point; computer control software adopts the edge image combined point as a length reference point which is aimed currently; and the precise position dimension of a grating scale is obtained according to the position of the reference point, and the dimension of one edge point of the diameter of the messed workpiece and the dimension of the other edge point of the diameter of the messed workpiece are calculated, the dimensions of the two points are calculated, and the dimension of the diameter of the measured workpiece is obtained.

Description

technical field [0001] The invention relates to a detection method for the inner diameter of a small hole with a high aspect ratio, in particular to a non-contact measurement rapid measurement method for measuring the inner hole of φ0.1mm to φ25mm in machining. Background technique [0002] Length measurement is an important content in geometric quantity measurement, and aperture measurement is one of the key technologies and difficulties in length measurement. With the development of science and technology and the increasing precision, integration and miniaturization of cutting-edge products, micro-holes are more and more widely used in the fields of automobiles, electronics, optical fiber communications, and fluid control. higher requirements. For example, shaft holes and measuring needles on precision instruments require not only accurate hole diameters, but also smooth hole walls. The high-precision measurement of inner and outer diameters is a key technical issue, and...

AI Technical Summary

Problems solved by technology

For tiny holes with a hole depth of 4mm, due to the small diameter of the measured tiny hole, the controllable light source cannot accurately penetrate into the hole, so it cannot be measured by the method of light interference principle

If the direct contact measurement method is used, although the diameter of the probe is smaller than the inner diameter of the micro-hole, the subsequent part connected to it is too large, so that the probe cannot go deep into the micro-hole for direct measurement

Images