The Virtual Devise And Simulate Of Four DOF Parallel Workbench

Parallel machine tool is the innovative application of space polycyclic institution in machine manufacturing, and the product combing parallel mechanism with modern machine tool technology, which will boast of profound complementarity with traditional CNC machine. The parallel machine tool has many advantages, such as its simple structure, light quality, high stiffness and fast response speed, etc. Nevertheless, with the development of the parallel mechanism theory technology, certain disadvantages begin to surface like its high manufacturing cost, unreasonable ratio of its size to the work space, which has made it difficult to accomplish the processing of the parts at arbitrary spatial angle (such as sphere node of grid). According to the structure and both its advantages and disadvantages of the current domestic and international parallel mechanism and based on the theory of parallel mechanism, this paper puts forward a new kind of parallel mechanism—4-dof parallel workbench, which can be used with machine sets such as the milling, boring and milling center and can meet the processing requirements of workpieces at arbitrary angle plane. In this regard, it is of great significance to promote the function and enhance its working efficiency of the machine tool. The major work in this paper includes the following aspects:Firstly, through the analysis of parallel mechanism and with the application of parallel mechanism theory, the paper conducts studies on the structure of the parallel workbench, introduces the working principle, establishes the direct and inverse kinematics models of the workbench, and also analyzes the factors that have influences on its working space size.Secondly, with combining the working space size of ZH5132 NC drill with the milling machining center, the paper identifies the workbench institutions parameters. According to the structure characteristics of the existing parallel mechanism parts and the actual requirements of the processing, the papter figures out the structure of the parallel workbench parts, and invents a new telescopic rod structure which, driven by a stepping motor, transmits power to the ball screw through the gear reducer, and then realizes the expansion through ball nuts and expansion socket.Thirdly, the paper still covers the efforts to carrying out the 3D modeling of the main parts of workbench and then conducting the virtual assemble and interference of them, by means of Pro/E 4.0, that is, a parametric 3D drawing software, and consequently getting the virtual prototype of the parallel workbench. Fourthly, the paper also relates that through the kinematics simulation analysis of the virtual prototype of workbench by means of the mechanical system dynamics simulation software—ADAMS, efforts are made to verify the rationality of the design regarding both the positions and sizes of its parts, and meanwihle the rationality and operability of the workbench structure through the entity simulation in ADAMS.