Large-diameter bar ring gauge and its calibration method

Abstract

The invention discloses a large-diameter strip ring gauge and a method for calibrating the large-diameter strip ring gauge. The calibrating method comprises the following steps that (1) temperature balancing is conducted on the strip ring gauge; (2) the ring gauge is placed on three equal-height blocks placed on a coordinate machine workbench, and a standard plane and a measurement surface of the ring gauge are then cleaned up through an absorbent cotton ball; (3) a coordinate machine is started, a working plane is found out and a coordinate system is built according to operation programs of the coordinate machine, point collecting is conducted at the two ends of a circular arc in an equidistance mode, the position of the circle center of the circular arc is measured according to a least square method, a straight line is arranged on a circular arc surface through a centre point, and the intersection point of the straight line and the circular arc is a marked point of the diameter; (4) an accurate indicating value of the diameter of the circle is measured, and the end surface of the ring gauge is labeled with the actual measured value and the measured position; (5) after the diameters of circles of the upper section, the middle section and the lower section of the ring gauge are respectively measured, conicity error evaluation is conducted. According to the large-diameter strip ring gauge and the method for calibrating the large-diameter strip ring gauge, cost is saved, the quality of products is guaranteed and the difficulties for measuring a large-diameter workpiece are successfully overcome.

Description

technical field [0001] The invention relates to a large-diameter bar-type ring gauge and a calibration method thereof, which are applied to the machining of large-diameter dimensions (above φ350mm) in mechanical processing. Background technique [0002] When measuring the diameter of large workpieces (above φ350mm) in normal processing, the inner diameter micrometer or outer diameter micrometer is generally used for size inspection. Before using the inner or outer micrometer for testing, it is generally necessary to use a standard block gauge for calibration. However, the block gauge material is often different from the processing material, because the thermal expansion coefficient of the material is different, and there is a detection error when measuring a large diameter (above φ350mm). Moreover, the general ring gauge is designed as a ring, and when it is large in diameter, it is difficult to store, difficult to manufacture, low in material utilization, and unstable in s...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the above-mentioned shortcomings in existing ring gauges and large diameter detection of processed workpieces, the present invention provides a large-diameter bar type that can successfully solve the detection and calibration problem of ring gauges and finally realize accurate detection of large diameters (above φ350mm). Ring gauge and its calibration method, the calibration method in the present invention adopts CMM equipment, and the CMM equipment needs to pass the national metrology inspection and acceptance

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