Research And Realization Of Pivotal Module In CAPP System On Involute Spline Axis Cold Rolling Rack

Precision cold rolling forming is a kind of non-cutting technology combined metalicity forming with rolling forming. It has the advantages such as high production efficiency, strong bearing ability and high machining precision and so on. Since 1990s, Yanshan University has researched on precision cold rolling forming technology deeply in domestic and has obtained creative scientific research achievements. Precision cold rolling forming technology has been paid wide attention currently. With the extension of this technology, some domestic tool and mould factories also undertake the design and machining of some cold rolling dies. Because these factories couldn't perform digital design and manufacture independently and can only imitating and manufacturing by surveying and mapping imported rack tooth profile, the rack precision is low and the manufacture scale is small. So, it has seriously restricted the application and development of Chinese precision cold rolling technology. Therefore, in order to promote the quick development of cold rolling technology in mechanical manufacturing industry, the author takes practice and research according to every system function module implementation of involute spline axis cold rolling rack in CAPP, which is under the direction of involute spline axis cold rolling CAPP system architecture and takes overall integration as the goal. The research purpose is to realize parametric design of spline cold rolling rack, numerical simulation and digital manufacturing of spline axis cold rolling forming and intelligent model establishment of equipment strength parameters based on back-stepping design thought. The method researched in the paper can shorten the developing cycle of involute spline axis cold rolling rack, decrease the rack test times and improve the product design quality. This research has important practical significance on extending the application of precision cold rolling forming technology.In parametric design module, the author has realized the standardization and serialization CAD design through parametric design and development of spline axis cold rolling rack with software Pro/E,AGW in VB environment based on back-stepping thought. Meanwhile, the way and criterions to determine key parameters of involute spline axis cold rolling rack accurately and quickly are put forward. In order to verify the feasibility of involute spline axis cold rolling rack designed by back-stepping design method, The author performs the forming simulation and emulation of involute spline axis using the digital model of cold rolling rack on the large-scale software MSC.Marc platform in numerical simulation module and analyzes the relationship between the design parameters of involute spline axis cold rolling rack and the forming precision of spline axis, giving the method of revising rack design parameters.In order to apply artificial intelligence technology to rack CAPP system and to make CAPP system to be with deduction, judgement, analysis and memory, the author establishes the strength parameter intelligent analysis model of involute spline axis cold rolling forming through error back propagation BP neural network, providing technology support for the overall design of cold rolling rack and the design of cold rolling machine.In digital manufacturing module, in order to verify the actual effect of involute spline axis cold rolling rack obtained through back-stepping design method, the involute spline axis rack whose value of Ra is smaller than 0.4μm is obtained according to the technical process of"forging blank-annealing-rough machining overall dimensions-heat treatment-grinding", the method of grinding after numerical control wire cutting. The spline axis work piece obtained by cold rolling is placed on three coordinates measuring machine to be dotted partially for external profile and the machined spline tooth profile can be obtained by curve fitting in Matlab. By comparing this spline tooth profile with that in theory, the tolerance of the tooth profile is 0.03mm, meeting the precision requirement. Meanwhile, the related factors effecting cold rolling spline axis forming precision is analyzed further more in this paper, therefore the feasibility of back-stepping design method being verified.While this system overall integration which is based on shared data base and has artificial intelligence characteristics is the important development direction of rack CAPP system. The implementation of above function modules lays a good foundation for the overall integration of rack CAPP system.