CAM Angle Detection Process And Gauge Analysis Of Variable Valve Lift System

AVS is short for variable valve lift system, smartly designed, complicated technology, difficulty in parameter inspection, especially 700,000 of its annual output which bring challenging for measuring accuracy, measuring cycle time, fixture measuring stability. The aim of this thesis is to research the repeatability problem of CAM Angle by using special ADCOLE CAM measuring instrument. The aspects of measuring principle, benchmarks conversion process of measuring the CAM angle tooling, the clamping fixture skills, as well as tip wear and benchmark position of wear are analyzed one by one and experimental verification has been carried out. Inspection techniques have been investigated and fixtures have been analyzed regarding on inspection problem of CAM lift angle.ADCOLE CAM measuring device is unique designed with high efficiency and high precision characteristics. Due to the datum for machining and measuring is on the spline, special designed measuring gauge cleverly realized the datum conversion which saves a lot of measuring time. But behind efficient measurement, there must be a loss of precision. This thesis summarized and described the actual situation of instability of cam lift angle through repetition measurement( same device brings 0.1 degrees error). The root cause is investigated through comparison of the two CAM measuring instruments(ADCOLE). Fixture positioning and tip wear are mainly analyzed. After analyzing of inspection process and inspection tooling, operation standard of measurement and monitoring method of measuring date are standardized to ensure the accuracy of angle measurement, constructive suggestions are then given regarding on measuring fixtures.The accuracy of geometric parameter measurement on Audi variable valve lift system is investigated and listed below:(1) Combined with Audi variable valve lift system processing technology, measurement items and measurement datum are described, the difficulty measuring is pointed out, thus the significance of this research is elaborated;(2) Analyze the cause of cam angle instability and collect the Kk inspection tooling angle results for 3 month. Comparison testing regarding on repeatability and stability is carried out to obtain the root cause for CAM Angle problem.(3) Verify the measuring consistency of the two devices, analyze the tip wear results before and after assemble Master Cylinder on the core shaft and test the angel error brought by the core shaft angel wear.(4) Focus on the problem of cam positioning datum, mainly from eccentric compensate error caused by the Master Cylinder fixture assembled frequently, and using the mean control charts and poor control chart as well as plenty of experimental measurement results to support analysis hypothesis.(5) Refer to the problem during testing process, adjust the cam operation standard, comparison of loading and unloading fitting process of Kk fixture with Master Cylinder is carried out to analyze the influence on the measuring stability of cam angle.