在车削多头螺纹时,螺纹精度的提高常常受到分头的影响。一般分头的方法很多:有利用主轴主动齿轮、小拖板、卡盘、特殊分度盘等。但往往是先加工好一头后再分度加工下一头,因此各头的均匀度不易掌握,尤其当主动齿轮的齿数无法计算成头数的倍数,而小拖板的刻度又不够准确时,车出的螺纹精度就更低了。现介绍另一种分头方法,如附图所示。根据螺纹的导程、头数及车床传动丝杠的螺距计算并用粉笔在床身导轨上确定 A、B 线的位置。然后使拖板右边对 When turning multiple threads, the improvement in thread accuracy is often influenced differently. Generally divided into many ways: the use of spindle drive gear, a small carriage, chuck, a special indexing plate. But often the first one after the first indexing and processing the next one, so the uniformity of each head is not easy to grasp, especially when the number of drive gear can not be counted as a multiple of the first few, while the small carriage of the scale is not accurate enough, the car The accuracy of the thread is even lower. Now introduce another kind of division method, as shown in the figure. According to the thread lead, the number of head and lathe drive screw pitch calculation and determination of chalk on the bed rail A, B line position. Then make the right of the carriage right