Manual grinding on a lathe is performed on a horizontal lathe with an adjustable grinding ring. Pay attention to the grinding pressure and the concentration of the abrasive. The speed of the workpiece depends on its diameter, the diameter is less than 80mm. The speed is about 100r/rain; the diameter is greater than 100mm, and the speed is about 50r/mil.
When the double-disc grinder is grinding, the workpiece is placed in the hard wooden holder (according to the size of the piece) between the upper and lower grinding discs. When the lower grinding disc and the holder rotate, the workpiece is Rotate and reciprocate in the groove. The double-disc grinder can be divided into single eccentric type, double eccentric type and planetary type. In addition to rotating, the workpiece can perform compound motion according to the cycloid, inner cycloid and outer cycloid respectively. The grinding parameters of cylindrical workpieces can be selected as shown in Table 8-9.
The size difference of each batch of parts before researching is 3^-51cm, and the three workpieces 1}em larger than the maximum size of the batch of workpieces should be used before the polishing. Put them in the grooves separated by 1200 in the cage, appropriately reduce the speed of the lower grinding disc to ensure the requirements of conicity. For workpieces with high roundness requirements (<=0.8um), the roundness should be less than 2-3um before grinding. The polishing parameters should be selected and expressed in accordance with Table 8-8, and the workpiece should be transposed many times.
The grinding principle of centerless grinding machine is shown in Figure 8-24. The centerless grinding machine is composed of rollers, guide wheels and pressure plates (cast iron grinding bars). The pressure plate is in elastic contact with the workpiece star, the guide angle of the guide wheel is 20-50, and the taper is 0.50. The diameter ratio of the two wheels of emery is generally 1.3-1.5, and the angle a between the center of the two wheels and the center of the workpiece is generally 1300-1400. The grinding pressure is (0.4-1) X 10MPa; the grinding speed is 1-2m/s for the guide wheel and 1.5-3m/s for the inclined tube packing roller. The grinding roundness is not more than 0.3um, the cylindricity is not more than 1um, and the surface roughness Ra value is 0.1um.
