Fixture for detecting symmetry degree of key slot of automobile engine crankshaft

Abstract

The invention discloses a fixture for detecting the symmetry degree of a key slot of an automobile engine crankshaft. The fixture is characterized by comprising a gauge stand, positioning gauge blocks, and a dial indicator; each positioning gauge block is a square block which is in zero clearance fit with the key slot of a crankshaft to be detected; the lower end face of the gauge stand is matched with the square block; the dial indicator is connected with one side of the gauge stand; a measurement rod of the dial indicator is vertical to the lower end face of the gauge stand; multiple groups of the positioning gauge blocks are arranged at intervals of 0.005 mm and the thickness of the positioning gauge blocks is set according to the tolerance dimension of the key slot of the crankshaft to be detected; and the dial meter is connected with the gauge stand through a connection rod which is provided with at least one through hole. The invention has the advantages that: the fixture has a simple structure, is convenient to operate, can quickly detect three parameters of the symmetry degree of the central plane of the key slot of the crankshaft to a shaft neck where the central plane of the key slot is, the symmetry degree of the central plane of the key slot to a reference plane and the angle error of the central plane of the key slot to the reference plane, solve the problem that the detection result differs from man to man, and realize the on-line detection of the processing of the key slot of the crankshaft, and the result is accurate.

Description

Technical field: [0001] The invention relates to a tool for measuring accessories in the manufacture of auto parts, in particular to a checking tool for detecting the symmetry of the crankshaft keyway of an automobile engine. Background technique [0002] The detection of the keyway of the crankshaft of the automobile engine and other shaft parts involves three parameters: the symmetry of the center plane of the keyway to the journal where it is located; The symmetry of the common plane; the angular deviation of the center plane of the keyway to the common plane formed by the center line of the I and V main journals and the center line of the first connecting pin journal. [0003] In GB1958 "Regulations on Shape and Position Tolerance Detection", the detection of symmetry error stipulates the detection method and calculation formula of the symmetry error of the keyway center plane to the journal where it is located, and the calculation formula of the angle error between the ...

AI Technical Summary

Problems solved by technology

[0031] 3. Although the values ​​of e, d, r, and h are calculated according to the basic size, the error rate is extremely low. This detection method is very simple and practical. Its core content is to measure two pairs of data a and t on the platform, and then calculate the keyway The error of the three position accuracy of the center plane

[0032] Therefore, how to measure the a and t values ​​of the keyway more quickly and accurately has become the key to the keyway inspection. At present, ordinary measuring tools can only be used to remove the crankshaft from the processing station and hang it on the platform. The operation is very cumbersome , It takes 15 minutes for skilled quality inspectors to complete the detection of a and t values. The detection time is long and the error is large and the accuracy is low. Generally, operators cannot realize self-inspection at the processing station.

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