Error Analysis And Process System Optimization Of Engine Double Cylinder Boring

The double cylinder is a key part of automobile air compressor,which is thin-walled part.The boring precision of the cylinder hole is higher.In order to solve the production problem that the cylinder hole diameter is out of tolerance in the boring process of a certain type of double cylinder,this paper comprehensively studies the influencing factors including fixture deformation,deformation of double cylinder caused by clamping and cutting force,radial runout of spindle,backlash,error of rough boring process,and proposes a series of process optimization.The cylinder hole boring process is analyzed and the parts out of tolerance are measured to find the distribution law of boring error.Then various factors that may cause the cylinder hole size to be out of tolerance are analyzed theoretically.The finite element analysis method is used to study the deformation of the fixture and the double cylinder.It is found that two supports are deformed greatly to affect cylinder hole boring error.The radial deformation of the cylinder hole caused by clamping is bigger and strong correlation to the dimensional error of the cylinder hole.The standard model of boring simulation is established to obtain the cutting force fitting curve.The finite element analysis shows that the double cylinder deformation cuases by cutting force is very little.The radial runout of spindle,backlash and rough process error are measured and the correlation analysis to the dimensional error of the cylinder hole are conducted.The results show that the dimensional error of the cylinder hole is strongly correlated with the spindle radial runout,moderately correlated to the backlash,not correlated to the rough boring error.Considering both the amount of each factor and the correlation to the dimensional error,the main factors causing the oversize of the cylinder hole are the radial runout of spindle,clamping deformation of double cylinder,the fixture deformation and the backlash.Combined with the actual processing situation,this paper improves the structure of the two supports of the ficture,and reduces the clamping force on double cylinder,replaces the electric spindle and adjusts the backlash.The machining practice shows that the boring precision of the cylinder are improved greatly and meet the processing requirements.