Research On Precision Error Factors Of Crankshaft Complex Turning Test Equipment

Crankshaft complex turning test device is researched and designed in the need of high flexibility,precision and economy requirements of new crankshaft processing, through the application of parallelogram cutting tool system and inline transmission chain, the cutting tool's tip point achieves to circulate around the associated connecting neck rod, and completes rough semi-finishing processing efficiently with "one position, complete processing"; As a whole set of crankshaft machining equipment, its geometric accuracy and static,dynamic performance of relevant components are the most important error factors. This paper analyzes the main factors which affects crankshaft machining accuracy in combination with the test device's functional principle and structural features, and proposes ways to improve and enhance.Turret system is the core function part of test equipment, and its manufacturing, assembly and movement precision are also key factors to the test equipment, and the paper analyzes and discusses the error cases separately:1. Based on the kinematics analysis of tool carrier system and the loop incremental approach to cutting system error theory, comprehensive effect of length-clearance error is analyzed, under the circumstance of comparative theory point points trajectory did get different location, size and gap length error size on the motion precision cutting system; the influence of the meanwhile cutting system manufacturing and assembly of the errors in parallelogram structure error (rotary center contour, phase) was analyzed;2. Test equipment tool system formed by the planar four-bar linkage, working on high speed conditions, the factors of hinge rod gap between the cutting tool system which affects the dynamic motion accuracy and dynamic performance of the test equipment is of great importance. Firstly, the paper discussed the kinematics and dynamics research methods and current situation of mechanism with joint clearance; and then it further discussed the dynamic modeling and solving methods of four-bar linkage with clearance based on the classical state dynamic modeling;3. Based on Adams software of mechanical system of virtual simulation analysis tool, cutter system with kinds of clearance conditions was simulated, and to which the respective motion accuracy and dynamic accuracy influence with different location and gap size between different agencies was obtained. In order to guide the establishment of cutter connecting rod's manufacturing and assembly precision, the paper simulated different gap sizes of joint in driven crank rotary center.