Research Of A Precise In-situ Inspection Device For The Non-circular Piston Pin Hole's Geometric Accuracy

Engine is the heart of the locomotive,and the piston is the key components of engine,its property is directly related to the dynamic performance of the whole car and the engine.With the development of the society,the requirement to piston is higher and higher,and the working condition of piston is getting worse.The pin hole is designed to taper ellipse,Fall elliptical conical etc.Non-circular pin hole,homogenization stress distribution,ameliorating the stress distribution of the piston,prolonging the service life of the piston.As a result,people go into the non-circular pin hole,and gradually becoming popular,and the non-circular pin hole is increasingly widely applied.Precise mechanical manufacturing technology and inspection technology are inseparable.it is unbelievable that we can manufacture high top products without sophisticated inspection equipment and technology.With high geometry accuracy requirement,small geometry size change and limited detecting space,it is still the key problem and difficulty for the inspection of piston pin hole,especially for the geometric contour of non-circle piston pin hole's inspection and evaluation in current production.In order to solve these problems,this dissertation has carried out the research of an precise in-situ inspection device for the non-circle piston pin hole's geometric accuracy.Based on literature search,this dissertation summarized precision inspection technology for complex shaped surface and non-circular piston pin hole both domestic and abroad,based on these,design the structure of an precise in-situ inspection device for the non-circular piston pin hole's geometric accuracy and preset an shaft sleeve pre-measurements.After that,the details about the hardware design of the inspection device and software design and development are presented.The hardware include the choice and finalize the design of the transducer,processing and manufacturing the shaft device,the choice of acquisition card,processing some isolation interference circuit and so on.Software design and development include data acquisition,data storage and data processing.Then establish the mathematical model for cylindrical hole,taper hole,elliptical hole and pour elliptic taper hole of piston,at the same time,elaborate the elements of the measurement and evaluation method.At last,some inspection experiment of cylindrical hole generatrix straightness and cross section roundness error,taper hole Angle and generatrix straightness and elliptical hole of ovality and contour error is operated,and the error of inspection device is analyse,verifying the validity,reliability and precision of the scheme.Finally,the main contents of the dissertation are summarized,and the further research work that is worthy to be done is listed.