Multi-body Dynamics Simulation Research On Dual-Cam Linkage Drive Automatic Tool Changer

For the purpose of improving the speed and reliability of ATC and studying the transmission characteristics of tool-changing processes, this paper designs the structure of dual-cam linkage drive ATC by analyzing MDH horizontal machining center and develops the simulation research on multi-body dynamics and finite element co-simulation of the dual-cam linkage drive ATC in many ways based on the virtual prototype technology utilizing Pro/E, ADAMS and ANSYS. Specially, the modeling, assembling, FEA, multi-rigid-body dynamics simulation and flexible multi-body dynamics simulation of the virtual prototype is focused on, which theoretical methods and simulation results will have great significance in practice, system design and product performance.In the second and third parts of the article, in the first place, to solve the problem, long tool-changing time and low reliability, of the traditional cam-type ATC, considering the structure and dimension of the horizontal machining center MDH80, it designs a dual-cam linkage drive ATC with a composite cam, which is composed of a globoidal indexing cam and a slot cam, controlling manipulator movement and a plate cam controlling tool bar movement, analyzes its working principle, matches the motion cycle chart and optimizes the motion law for various types of cam mechanisms. In the second place, using Pro/E, the virtual prototype of dual-cam linkage drive ATC is created, and the interference and simulation analysis of the whole structure are carried out. Then, using ADAMS, both the multi-body dynamics simulation of the two main parts, composite cam drive tool changer and plate cam drive tool push-pull mechanism, of the device, and the contact forces in cam-drive pair together with the dynamic response characteristics such as displacement, angular velocity and angular acceleration of mechanism, and the effect of different load conditions to the manipulator tool-changing are obtained. At last, we utilize ANSYS to calculate the stress and deformation of plate cam. Thus, the reasons for vibration and wear of mechanism are received.In the fourth and fifth parts of the article, to begin with, by multi-body dynamics theory and contact mechanics, aimed at the globoidal indexing cam mechanism and in consideration of the flexible deformation of cam axis, it uses the finite element and the virtual prototype technology to set up a contact dynamics model based on the nonlinear equivalent spring-damp model and a contact-impact dynamics model and an analysis method on rigid-flexible coupling of a globoidal indexing cam with clearance based on the Coulomb friction model which friction effect is considered. Next, the characteristics of rigid-flexible coupling and the influence law of clearance affecting to the transmission characteristics by numerical simulation are investigated. It reveals that the dynamics model can effectively deal with the transmission characteristics of complex globoidal cam with the effect of flexibility and contact-impact and the simulation results can provide basic data and valuable theoretical basis for further research on dynamics characteristics of globoidal indexing cam transmission systems. Finally, the transmission contact model of a globoidal indexing cam mechanism is established by using the finite element method, the contact response characteristics are discussed in exterior loads, the finite element analysis results are analyzed, and the general law on force and deformation characteristics of this transmission is obtained, which will offer theory gist for the intensity designed in this transmission.