Design Of A Special Fixture For Pre-stressed Surface Grinding And The Application Research

With the constant development of the high-tech products and the innovation of the processing technology, also, in order to meet the product demand, the essential requirements for the surface integrity of the processed component, the consistency of manufacture and the machining accuracy are increasingly important..As the last step of manufacturing cycle, grinding is the most widely used machining all the time.On the basis of the mechanism of pre-stressed grinding hardening, this paper focuses on these studies:designing a device to apply pre-stress; utilizing the finite element method analyse the force and the stress condition; putting the fixture into the practical application; performing other experiments to measure the hardness, residual stress of the specimen, and the observation of the metallography.First, this paper elaborates on the basic concepts of the residual stress, including the definition and the classification of the residual stress; describes the cause of residual stress emerging; combining with the processing properties of hardening grinding, discusses the formation of residual stress during the hardening grinding process, and makes an analysis of the mechanism of pre-stressed grinding.Next, having understand the mechanism of pre-stressed hardening grinding, consulting the existing design method of fixture for machine tool, according to the different load object and transmission way, this paper puts forward two plans to load pre-stress, calculates the theoretical value of pretension stress, and builds the fixture 3D models by Proe.And then, it depicts the content finite element analysis, such as the working step and the solution of contact pairs, which lay the foundation of the fixture finite element analysis. Taking advantage of ANS YS and Workbench, it makes the simulation of fixture, checks the accuracy and strength of key component and the distribution of prestress on the surface. In consideration of theoretical calculation and structural features, making a comparison of two plans, finally, it chooses the fixture transmitting more efficiently.At last, it puts fixture into the practical application, doing an experiment on the M7120A surface grinder, also, performing other experiments to measure the hardness, residual stress value of the specimen, in this way it proves the grinding process having positive influence on the surface quality. Meanwhile, it indicates that the fixture is suitable for using in the pre-stressed hardening grinding.