Fixture design for thin-walled parts.

摘要

In manufacturing, jigs and fixtures as special tools are used to hold and locate parts, and guide the tools if required for machining, assembly, inspection, and other manufacturing operations. As an important part of manufacturing, jig and fixture design play a key role between product design and product manufacturing.; In this thesis, first, a survey of fixture design automation is presented, including the-state-of-the-art in fixture design automation, and the theory of automatic fixture design. Then, to fill in the gapes in the fields of fixture design for thin-walled parts, principles of fixture design for thin-walled parts have been proposed. The principles include how to define a thin wall, how to calculate deformation of different types of thin walls of a part, how to reduce the deformation of the thin wall with various support configurations, how to select various support configurations for thin-walled parts, and how to design a fixture for parts with thin walls.; A definition of a thin-walled part is given based on whether or not a part is deflected sufficiently to affect machining accuracy in manufacturing. Five models for calculating the elastic deformation of the walls have been established using the calculation-experiment or modeling approach. Principles related to support configurations for thin-walled parts have been proposed based on the relationship that the percentage of reduced displacement, in the same ratio, is only determined by the support configuration. A principle of fixture configuration for general parts has been proposed based on the 3-2-1 locating principle and thin wall theory. The general force model of the fixture configuration has been expanded from a prismatic part to a thin-walled part so that the theory of fixture configuration is close to real production.