Design of Roundness and Cylindricity Detector for Axle Housing Based on Multi-Step Error Separation Technique

The error measurement of roundness and cylindricity of heavy truck axle housings is an important dimension of their machining accuracy test. The conventional testing method currently adopted in the production is inefficient and of low accuracy. The proposed design of an automated detector is dedicated for the accuracy testing of roundness and cylindricity of heavy truck axle housings, and also includes a control system for the device. The control platform consists of PLC and servo drive system. The shape and dimensional properties of heavy truck axle housings have been taken into account. The design is based on the multi-step method and the roundness error separation techniques, and also adopts the least square method as an error evaluation standard. It improves testing accuracy by separating roundness and cylindricity errors from compound testing errors. During the test, the sensors of the detector measure its multiple facets when the device revolves around it. This design eliminates motionbalance induced eccentricity that tends to occur when a large irregular work piece rotates. The detector is highly automated. If an upper monitor in place can process the test results, then it may enable the detector to mark the substantially deviated points on the surface of the axle house being tested, which eases the subsequent machining and correction and also achieves a low defect rate.