Anatomical measurement method for common thread root arc radius

Abstract

The invention discloses an anatomical measurement method for the common thread root circular arc radius. The method comprises the following steps that linear cutting equipment passes through a commonthread center line, longitudinal splitting is carried out perpendicular to threads, and a section is roughly ground, finely ground and polished to be manufactured into a test sample; the thread root circular arc radius of the prepared test sample is observed under a metallographic microscope by using a proper multiple, and images are acquired, wherein 50 times or 100 times is generally selected for the multiple; the acquired images are analyzed and measured by using an OLYCIA m<3> metallographic image analysis system, and the thread root circular arc radius is measured by using a 'circle' toolin 'advanced image measurement'; and the radiuses of a plurality of circular arcs at the thread root are measured correspondingly, the circular arc of the measuring circle is adjusted to coincide with the circular arcs of the measured thread root as much as possible, and the obtained radius of the measuring circle is the common thread root circular arc radius. The anatomical measurement method can be specially used for accurately measuring the circular arc radiuses of the plurality of circular arcs at the thread root and the radius of a circular arc with the radius smaller than 0.30 mm.

Description

technical field [0001] The invention belongs to the technical field of metal material detection, and in particular relates to an anatomical measurement method for the arc radius of a common thread tooth bottom. Background technique [0002] The size of the arc radius of the bottom of the ordinary thread directly affects the performance of the threaded parts to withstand fatigue and impact loads, and often becomes the main reason for the fracture and failure of the threaded parts. The arc radius of the base. GB / T 197-2018 "Ordinary Thread Tolerance" clearly stipulates the requirements for the radius of the arc at the bottom of the ordinary thread. The radius of the arc at the bottom of the tooth should not be less than 0.125P (P is the pitch). Since the arc radius of the thread bottom is generally small (≤0.30mm), it is impossible to quantitatively measure the arc radius size of less than 0.3mm by using traditional R lens, projector, universal tool microscope and radius gaug...

AI Technical Summary

Problems solved by technology

Since the arc radius of the thread bottom is generally small (≤0.30mm), it is impossible to quantitatively measure the arc radius size of less than 0.3mm by using traditional R lens, projector, universal tool microscope and radius gauge; R lens and The projector cannot quantitatively measure the arc radius; the universal tool microscope can only indirectly measure the size of some screw teeth and then calculate the size of the arc radius based on the triangular relationship, which cannot be directly obtained and the error is large; the radius gauge measurement tool The lower limit is 0.30mm and can only measure the radius of one arc at the bottom of the tooth, but cannot measure the radius less than 0.30mm and have multiple arcs at the bottom of the tooth

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