Research On Automatic Design Of Trimming And Punching Insert Based On NX Platform

Trimming and punching are the key processes to ensure the shape and size of the parts in the stamping process of automotive panels,which directly determine the forming quality of automotive panels.Therefore,the trimming and punching inserts in the die design occupy a very important position.Due to the variety and quantity of inserts,the traditional manual design method has the problems of high repetition rate,low standardization degree and low design efficiency,which is unable to meet the requirement of rapid die design.Therefore,it is necessary to develop a set of automatic design system for trimming and punching inserts.Under the support of the project of "Computer-aided Die Design System" of the Sichuan Chengfei Integration Technology Company,and based on the design standards and requirements of the enterprise,the key technology in the design of trimming and punching inserts is further studied on the basis of previous design methods.The NX secondary development technology is used to develop the automatic design system of trimming and punching inserts,which realizes the one-button generation of trimming and punching inserts.In order to simplify the structure of the automated design system,various trimming and punching inserts are classified in different ways.The structural characteristics of various types of inserts are summarized.The template design method is introduced.Based on the common structure of the inserts,the various designs of inserts are simplified into four basic modeling methods to serve as templates.And different inserts are redesigned on the basis of the template,thus avoiding designing all the inserts from the very beginning.In order to improve the efficiency and quality of the automatic design of the inserts,the difficulties in the process of automatic design are studied.In order to improve the quality of the cutting surface of the non-shape-conforming insert,the method of spatial curve offset is optimized,and the segmented surface method is proposed to effectively reduce the local distortions of the cutting surface.In order to solve the problem of long time consuming process in splitting body for shape-conforming insert,the local surface cutting method is proposed to splitting the insert body only by the local surface at the position of the inserts,which effectively shortens the design time.In order to meet the design requirements of inserts with different directions,the transformation problem of point coordinates and vector coordinates between different coordinate systems is analyzed and solved.The design of trimming and punching inserts with any working direction is realized.Finally,the system is used to design the trimming and punching inserts of the typical automobile cover,such as the front inner cover.The efficiency and practicability of the system are verified by comparing with the traditional manual design method.