The Innovative Design Of Impact Tapping System Based On Computer Aided Design

Triangle thread is mainly used for screw connection,and is the most widely used detachable connections for its virtues such as simple structure, convenient assembly and disassembly, reliable work, strength interchangeability and low cost. It is significance for further explore and develop efficient new process for internal thread while several existing methods insufficient to meet the need of modern manufacturing. After collected and searched literature, the principles and techniques of several existing methods of internal thread processing have been grasped and the flaws can be summarized to:(1) low cutting speed; (2) low accuracy and reliability of spiral movement;(3) difficult chip breaking;(4) steady state power can not effectively overcome the dynamic load;(5) high machining temperature and poor heat dissipation.The virtues of each can be used to inspire the thinking of this design. The parameters features of several common internal threads have been grasped through access to technical manual.The design task of ripple impact tapping system have been brought forward according to external thread and internal thread meshing characteristics and draw external thread processing transmission chain on a lathe.In the specific design stage,this design can be definitely divided into five main stages as the proposed design task, conceptual design, detailed design, analysis and verification, generation of design documents based on computer aided design. It is facilitate to overall plan designing ideas and step on one hand while there are laws to go easy at all stages of specific measures to dealin main contradictions on the other hand.In the conceptual design stage, the four pairs of technical conflict have been determined, while use conflict resolution principles can be obtained:(1)ripple impact tapping method;(2)comply one-way pulse input to a linear reciprocating screw tap movement. The vague configuration of the tapping system has been designed finally in accordance with the principle of functions implementation under guiding ideology of TRIZ:resolve technical conflicts best of least.In the detailed design stage, the mix and match modeling and the detailed design of the parts of the tapping device have been accomplished by used WAVE module of UG.The two parameters of assembly and parts of this model created favorable conditions for the simulation and variant design.In the Analysis and verification stage, dynamic simulation of the solid model of the tapping devices has been maded by UG motion analysis module,solving and outputing response curves of various kinematic. Discussion of the curve provides the feasibility of the concept of pulse impact tapping.At last, experience and understanding in the design process has been summarized to identify shortcomings and provide ideas for further study.The study of the impact of tapping pulse method can be concluded to:(1)tapping time course is short and improve the processing efficiency;(2)tap back and forth and dynamic tapping overcome the dynamic load, easy to chip and the cooling off, improve the processing quality;(3)a set of institutions is simpler in structure than two sets of institutions to achieve tap back and forth movement, significantly improve the reliability of motion accuracy. Pulse impact tapping is a internal thread processing method as high efficiency, high processing quality and relatively simple device in structure. It will have a broad prospect of development and application.