First, the grinding process is more complicated than other cutting processes. The cutting process of the abrasive grains includes three states of sliding, ploughing and cutting. The grinding process of the grinding wheel consists of three stages: spark cutting, stable grinding and spark cleaning.
Second, the elastic deformation and plastic deformation during grinding are relatively large, which is less common in other cutting methods. It directly affects the dimensional accuracy, roughness, grinding heat, surface quality and grinding efficiency of the machined workpiece. In use, it is necessary to understand the critical condition that the elastic zone is transformed into a plastic zone and the plastic zone is transformed into a cutting zone.
Third, compared with general machining, the tangential force is much larger than the normal force in general machining, and the normal force is about 2 to 4 times the tangential force in the grinding. Grinding system The stiffness has a great influence on it. The grinding force consists of two parts: cutting force and friction. In the case of rough grinding, the cutting force is dominant, and in the case of fine grinding, the friction is dominant.
Fourth, grinding is an energy-consuming processing method that is 20 times larger than other processing methods. Attention must be paid to the effects of grinding heat and increasing temperature on the processing.
Fifth, the size, roundness and contour accuracy of the part are guaranteed during fine grinding.
(1) In order to improve the roundness of the part, first, the blank cannot have excessive roundness and concentricity error.
(2) In order to ensure the final dimensional accuracy and roughness of the machined workpiece, attention should be paid to the change of the grinding force. When the old and new grinding wheels are replaced, the instability will be greatly increased. For this reason, it is necessary to change the grinding wheel frequently and reduce the number of grinding the workpiece. .
(3) When the curved shape of the cam profile is ground, the change of the trajectory of the workpiece contact area of the grinding wheel at the cam notch will result in a change in the grinding force, resulting in instability of the grinding and formation of a shape error. It is difficult to control on a cam grinder, and the effect of the above factors can be greatly reduced by the method of insert grinding and controlling the forming motion of the table on the coordinate grinding machine. Thereby improving the processing precision, which is one of the advantages of forming a mold by coordinate grinding.