（三）夹紧原理
在生产实践中，尽管定位方式是合理的，但由于夹紧状态不良(即夹紧力的大小、方向、作用点和支承的位置选择不当)可能出现如下问题：①加工件飞出夹具，打坏刀具，造成安全事故；②加工出来的位置尺寸不准确；③ 加工表面产生形位公差(如不平度、不垂直度)；① 加工表面粗糙度高等。因此，当加工件正确定位后．还需要获得良好的夹紧状态。使加工件获得良好的夹紧状态的措施，叫做正确的夹紧。
关键词：工艺工装设计 夹具设计 组合量具设计
Abstract：The half stalk is in automotive stalk the acceptance twist the biggest spare parts of sqire , it is bad soon machine and drive the round of delivers to twist the of solid stalk, it inside carry generally pass to spend the key and half stalk wheel gears to connect, carry outside with a conjunction, that spare parts is in the machine equipments have to spread to move sex, at carry on the half stalk of craft and work equip to account, the half axial craft carried on the detailed analysis first, designing processed craft process, according to process to request to design the appropriation tongs design, a pay is to use to come to car to pare the outside circle of the half stalk, on pay is use to drill to pare a dish of the half stalk up even distribute of eyelet, in the design the economy of the advertent tongs and usage, as far as possible lower to process of cost, reduce the worker of labor strength, in addition to this still carried on the design that the combination quantity have, use to check 6 even distribute of a business trip of position of the eyelet.
