Research On Key Technologies In The Development Of The Measuring Instrument For Cylinder’s Global Sizes

For cylindrical parts,in addition to the two-point size,the new generation of Geometric Product Specifications(GPS)stipulates direct global sizes(including least squares sizes,minimum circumscribed diameter,maximum inscribed diameter and maximum minimum diameter)and calculated sizes(including circumference diameter,area diameter and volume diameter).The measurement of the radial dimension of The radial size measurement of cyclinder by using the vernier caliper,the spiral micrometer and the inner diameter hundred thousand dial gauge or the precision measuring instrument such as the cylindriaty measuring instrument cannot meet the measurement requirements of the global sizes and the calculated sizes of the cylinder.This thesis mainly studies the key technologies in the development of the global size measuring instrument of cylinder horizontal(hereinafter referred to as the measuring instrument).Based on the key components such as column,transverse arm,turntable,automatic centering and leveling worktable,the measuring instrument host was designed.The movement of the horizontal arm along the column guide rail(granite material)adopts the aerostatic structure driven by the synchronous belt.The radial movement of the horizontal arm adopts the synchronous belt drive module.The turntable adopts the aerostatic structure of the built-in motor.The turntable is equipped with a circular grating,and the automatic centering and leveling worktable is equipped with a collector ring.The structural design of the parts of the measuring instrument and the finite element analysis of the key parts are carried out.The working principle of the different leveling schemes were studied.The leveling scheme with one fixed point and two adjustable points was selected,and the structural design of the automatic centering and leveling table is carried out.The automatic leveling table device has a standard to eliminate the systematic error of radial size measurement.The parts of the measuring instrument were manufactured,purchased and assembled.Firstly,the column-wishbone parts,turntable and centering and leveling worktable are assembled.After the accuracy index of each part meets the requirements,the measuring instrument host is assembled and debugged.The main performance indexes of the measuring instrument are as follows :The straightness error of the upper and lower motion of the horizonfal arm less than1.03μm,the motion range≤380mm,the repeated positioning accuracy is 0.75μm.The straightness error of the horizontal radial motion of the horizontal arm is 1.5μm,the motion range≤330mm,the repetitive positioning accuracy is 0.76μm,the radial runout of the turntable is 0.4μm,the axial runout is 0.5μm,the load≤50kg,the positioning accuracy is 0.05°.The range of the centering leveling worktable±3mm;the leveling angle range± 1°.The influencing factors of the measurement uncertainty of the measuring instrument were analyzed,and the evaluation model of the measurement uncertainty of the measuring instrument was established.After configuring the measurement and control system program,the measuring instrument host developed in this thesis can meet the needs of high-precision profilce extraction of cylinder based on the profile extraction strategier such as roundness profile,generafix profile and bird cage,and promote the implementation of GPS related standards in the mechanical manufacturing industry.