为了提高对大孔划线工作的速度,我设计了一个简易、高效孔划线自定心装置(如图所示),且适合一般条件下的精加工孔的划线。结构及原理该装置设有三根等一长定心杆2,靠弹簧4的张力将它们支撑在待划线的孔中,则 In order to speed up the work of large-hole scribing, I designed a simple and efficient self-centering device for hole scribing (as shown in the figure), which is suitable for the scribing of the finished hole under normal conditions. Structure and principle The device is equipped with three such as a long centering rod 2, by the tension of the spring 4 to support them in the hole to be scribed, then