图1所示的工件若在高精度内外圆磨床上加工,精度是完全可以达到的。但对于一般不具备上述条件的单位,加工就比较困难。为此,我们设计了三弦线拨动的磨胎(图2)。并在普通磨床上配备两个闭式中心架6,中心架的三个支承点应采用胶木支承,要保证三支点与内孔磨胎7之间有良好 If the workpiece shown in Figure 1 is machined on a high-precision cylindrical grinding machine, the accuracy can be achieved. But generally do not have the above conditions for the unit, the processing is more difficult. To this end, we have designed a tri-string toggle grinding wheel (Figure 2). And in the ordinary grinder equipped with two closed center frame 6, the center frame of the three support points should be bakelite support, to ensure that the three fulcrum 7 with the hole between the good