为克服螺钉自动装配作业中存在的认扣成功率低、机构复杂、专用设备成本较高等缺点 ,在分析典型轴孔间隙配合插入问题的基础上 ,采用自然参数向量对螺钉在螺孔中装配时的允许倾斜角度进行了计算 ,阐述了螺钉认扣过程中的几种状态 ,设计出利用立式加工中心对 M8内 6角螺钉自动抓拿认扣的装置。经实验验证 ,该装置结构简单、性能可靠 ,在保证螺钉装配成功率的同时 ,扩充了原加工中心的功能 In order to overcome the shortcoming of low success rate, complicated mechanism and high cost of special equipment in the automatic assembly operation of screw, based on the analysis of the problem of the fitting and insertion of the typical shaft hole clearance, when using the natural parameter vector to assemble the screw in the screw hole, The allowable tilt angle was calculated. Several states in the process of screw thread identification were elaborated, and a device that used the vertical machining center to automatically catch the hexagonal screw in M8 was designed. The experimental verification, the device structure is simple, reliable performance, while ensuring the success rate of screw assembly, while expanding the functionality of the original machining center