Research On 3D Parametric Design System Of The End Mill

As the complex rotary shaped cutting tools, end mill coordinate with numerical control machine or machining center can achieve high efficiency and high quality processing. It's widely applied in the fields of aeronautics and astronautics, automobile, shipbuilding and other manufacturing. Researching the design theory of end mill, synthesizing various advanced design methods and techniques and then establishing an end mill computer aided design system will not only reduce design cost and shorten design cycle, but also drive the tool design of our country to the digital flexible automation direction.Using VB to carry on the second-development to CATIA, this paper research and develop a 3D parametric design system that applies to 5 types of end mill. The main works as follows:1.Some general mathematical models for 5 types of end mill were proposed:The general mathematical model of blank surface contains cylinder, cone, tours, sphere and their combination was constructed; Mathematic model of the Equal helix angle edge curve on the surface of revolution was built and then the parameter equation of the equal helix edge on the cylinder and ball was derived; Two kinds of spiral groove cross section were designed and calculated and the spiral groove normal section to cross section transformation equation was derived.2.Manipulate the bodies and hybrid-bodies of CATIA by VB to conduct parametric modeling: Based on analysis 5 types of end mill different structural characteristic, attributed them to flat-end mill and ball-end mill and then two parametric modeling processes were designed respectively; Describing the general mathematical models by VB programs to generate the blank body and cylinder-tooth automatically in CATIA, and then the parametric modeling methods about sphere-tooth, the end-tooth, transition-tooth and other details were researched and programmed to achieve the parametric modeling of the 5 types of end mill.3.3D parametric design system of end mill was built:Design process was developed based on the system function. A knowledge base was built to obtain the structural parameters of the end mill by inference. Only reasonable design parameters need to input for Users,3D solid model fitting all parameters can be generated automatically. As the CNC end mill with four toothes an example, the accuracy of the 3D solid model and the reliability of the system were proved. At the same time,3D solid model generated by design system and the model generated by machining simulation were compared.The system developed in this paper realizes the unification of the design and visualization of end mill. The accurate 3D model generated automatically can provide some advices to determine parameters for CNC grinding and supports to machining simulat. It is the first time to analyze various types of end mill, and then to establish general mathematical models and to research methods for 3D parametric modeling, after these, to build 3D parametric design system, which have good inspiration and direction significance for the design of related tools.