Error Analysis And Accuracy Control In Honing Process Of Automotive Engine Cylinder

As one of the core components of car, engine quality directly determinesthe dynamic performance of the car. The improvement of engine’smanufacturing accuracy has a direct effect on improving the engine’s fuelefficiency and decreasing engine’s friction loss. As an important process ofengine cylinder hole’s precision machining, honing not only can removelarger allowance but also is more effective than other processes in improvingsize precision, geometrical accuracy and surface roughness, therefore honingis often used as the final machining process of engine cylinder block.This thesis takes the SGMW automobile B12-type engine cylinder as theresearch object. In allusion to the consistency control problem of enginecylinder hole’s honing size and shape error, through the simulation analysis ofabrasive particle’s cutting path and function area on cylinder hole surface, theformation mechanism of cylinder hole different cross section’s size errordifference has been revealed; Through the analysis of honing cutting force,clamping force and cylinder structure stiffness’s influence on cylinder hole surface deformation, the shape error’s change rule of the four cylinder holehas been revealed; combining with the process system state of production siteand error distribution law, the processing technology optimization schemeof B12-type engine cylinder hole has been proposed. This research workmainly includes the following three aspects:Firstly, the abrasive particle’s movement locus distribution of Cylinderhole honing processing is reconstructed. Through the reconstruction andtransformation of abrasive particle’s geometrical locus, the motionparameters’ influence on the abrasive particle’s trajectory distribution hasbeen analyzed, the expression of abrasive particle’s trajectory distributioncurve along the circumference and height direction of cylinder hole has beendeduced, the abrasive particle’s trajectory distribution defect has beendiscovered in the existing honing processing, and its effect on honing sizeaccuracy has been discussed. The result shows that: the distributionuniformity of abrasive particle’s trajectory point number along circumferencedirection of cylinder hole has been well controlled; the distributionunevenness existed in the height direction of cylinder hole, and this is thebasic reason of different cross section’s size error difference in honing.Secondly, the deformation simulation of cylinder hole’s honing processhave been finished. Through the cylinder body modeling, force computation, finite element simulation and production processing measurement dataanalysis, the stiffness difference distribution regularities has been revealed,the relationship between cylinder hole surface deformation and each forcechanges has been studied, the stress deformation difference of each hole hasbeen discovered in the existing honing processing, and its effect on honingroundness and cylindricity error has been discussed. The result shows that: thecylinder structural asymmetry led to the stiffness differences between eachpart of cylinder block, caused the difference of stress deformation, and maderoundness and cylindricity error of the four cylinder hole not consistent.Finally, based on the analysis of abrasive particle’s geometrical locusdistribution and cylinder hole’s stress deformation, combined with thecylinder hole’s manufacturing process and data processing of productionprocess quality control, the consistency control scheme of engine cylinderhole’s honing size and shape error has been proposed. By the dimensionmatching design between before and after cylinder hole processing as well asthe abrasive particle’s trajectory distribution control to decrease the differenceof cylinder hole U-M-D sectional dimension. By the control of cylinder holehoning processing deformation and before-honing (fine boring) processroundness and cylindricity to decrease the difference of cylinder holes’roundness and cylindricity error. Through the data statistical analysis of production processing measurement, this paper has verified the feasibility andvalidity of the control scheme, and this will guide the optimization andimprovement of cylinder holes’ processing technic.In conclusion, the distribution of abrasive particle’s geometrical locus inhoning head movement is reconstructed, and the abrasive trajectory’sdistribution law as well as its influence on honing processing precision hasbeen studied; The numerical simulation model of cylinder holes’ machiningdeformation has been established, and the relation curve between cylinderhole deformation and honing forces has been obtained as well as the influencerule of honing accuracy caused by machining distortion has been studied; Inthe end, the control scheme of cylinder holes’ machining accuracy has beendesigned for the optimization of guiding cylinder holes’ machining process,and the above research contents provide the theoretical basis and technicalreference for automobile engine cylinder hole processing.