Synchronous Optimization Design of Fixture Layout and Clamping Force Based on UG

Abstract

In order to improve the accuracy and design efficiency of fixture, UG and ADMAS software has been introduced into the fixture design process, and the co-simulation function of software has been applied, and the fixture reasonable layout and the clamping force calculation and synchronous optimization has been realized. The fixture is carried out in the UG software, by using the machining process of the workpiece, and the fixture is fully opened by the addition of the motion constraint. The dynamics simulation is carried out by introducing UG fixture model into ADMAS software, and the sensitivity of the key points of the spring clamping force is obtained by calculating, the points that having greater impact on the spring clamping force is optimized, and the spring displacement of the variable point when the spring produces the maximum clamping force is obtained, so as to realize the fixture optimization design. Introduction In mechanical parts processing, the formation of parts size, surface relative position and the 3D geometry, mainly depends on the cutting tool and workpiece in machining process relative position relationship between the fixture is the tool constraints, workpiece and machine tool is the key link. Rational distribution and optimization of the fixture can guarantee the processing quality of the workpiece, improve productivity and expand the scope of the processing machine and clamp comprises clamping element, positioning component, a connecting component and other components, this study using CO simulation function of UG and ADAMS software, the fixture layout optimization, the clamping force of calculation and synchronous optimization, improve the precision and efficiency of fixture design. Workpiece machining process Fixture design and optimization mainly consists of the clamping force design and the overall design layout. Before the optimization design, you first need to determine the workpiece machining process, determine the process can make a reasonable layout of the fixture, clamping force of accounting, the workpiece as shown in Figure 1. Figure 1 shows the schematic diagram of the processing of the workpiece, the process is mainly milling diameter of 32mm hole end. The material of the workpiece is HT200, the material of the milling cutter is high speed steel, the diameter is 80mm, the number of teeth is 10, we choose high speed steel cylindrical milling cutter diameter d=60mm, tooth number z =10. Milling cutter shape, rn=10,a0=12, β=45, in the workpiece machining, the actual milling width ae=2.5mm, milling depth ap=50mm, we choose XA6132 horizontal milling machine. 3rd International Conference on Materials Engineering, Manufacturing Technology and Control (ICMEMTC 2016) © 2016. The authors Published by Atlantis Press 50 Fig. 1 Schematic diagram of machining workpiece (1) Determine the feed per tooth fz According to the machine power 7.5kW, the rigidity of the process system is medium, therefore, the feed rate of each tooth is fz=0.16-0.24mm/z, in this paper fz=0.18 mm/z (2) Selection of milling cutters standard The criteria for selecting a milling cutter include wear and durability, according to the parameters of the process system, the data available, the maximum wear of the milling cutter is 1.5mm, the diameter of the milling cutter d=60mm, and the durability of the milling cutter T=180min. (3) Determine the cutting speed According to the above choice of milling parameters, we can get the actual speed of milling, and then according to the characteristics of XA6132 milling machine, check speed, nc=300r/min, Vfc=475mm/s. Actual cutting speed 1000 c c n d V π = (1) min / 52 . 56 1000 300 60 14 . 3 m Vc = × × = (2)