Research On Variant Part NC Programming

In order to respond to the individual needs of customers rapidly and improve product development and design processes, variant design, as one of new product design methodologies, has become one of research hot topics nowadays. At present, the researches on variant design mainly focus on the geometry variant. However, the researches about process-planning design, NC programming, manufacturing system which fit to variant design are few. Aiming at the rapid design issues of NC programming for variant part, a rapid NC programming method, which is based on the master NC programming template of master part model, was researched. Firstly, the process-planning process of master part model is analyzed to determine the machining features of machined part. Then, the geometrical data of machining features are elicited from master part model. Together with the process-planning data of machining feature, the master NC programming template corresponding to master part model can be constructed. During variant design, a new variant part is derived from master part model. Then the geometrical data of this variant part can be used to update the corresponding geometry data in the master NC programming template. With the aid of a decision-support system, the NC program of this variant part can be generated automatically. In this way, the data-driven NC programming methodology can be realized. Finally, an NC programming prototype system was developed according to the principles and methods mentioned above. At the same time, an application example was given to prove the feasibility of these methods and principles. This thesis is organized as follows:Chapter one introduces the concepts concerned with variant design and literature review about rapid NC programming. The background and the research contents of this thesis are also discussed as well as its architecture.Chapter two analyses the characteristics of dimensional variant design and structure variant design, and research the principle of Variant-Design-Oriented NC Programming. A rapid NC programming method of variant part, which is based on the master NC programming template of the master part model, was proposed. In addition, the structure, content and generation process of master NC programming template were discussed in detail.Chapter three introduces the definition and classify of machining features, and researches the modeling method of master part model supporting to the data elicitation of machining feature. At the same time, the describing way of geometry data and process data of machining features in the master NC programming template were discussed as well.