Research On Vibration Error Analysis Of Multi-link Ultra-precision Servo Press

The press is a forging equipment that is widely used in today's engineering applications.It can be used for bending,punching,stretching,cutting,etc.It has been used in many fields such as home appliances,agricultural machinery,aerospace,automobile manufacturing,industrial robots,etc.It is an important equipment for industrial production.Compared with the traditional crank press,the multi-link press can meet the requirements of low-speed stamping,fast return,etc.,greatly improving stability and work efficiency.A large number of research data show that the manufacturing error of press machining is largely caused by self-vibration deformation,accounting for 40%?50%.Therefore,studying the vibration characteristics of multi-link presses,including mechanism transmission error,spindle rotor-bearing system vibration error,fuselage spring-vibration error is an important way to improve the dynamic accuracy of the press.The main research contents of the paper are as follows:1.Mechanism transmission error:The traditional ideal mechanism dynamics model does not consider the influence of the motion pair clearance and the flexibility of the member on the transmission performance of the mechanism.In this paper,the ideal mechanism dynamics model is improved,and the double gap model is established in turn,and the gap model considering the flexibility of the member is established.The influence of the improved model on the dynamic response of the mechanism under no-load and variable-speed deep drawing conditions is analyzed,and the tracking error of the mechanism is realized.On this basis,several excellent contact force models are provided and the friction force model embedded system dynamics model is compared and the optimal contact force model and friction force model are selected to optimize the dynamic model of the system,and the model is further improved.Dynamic tracking accuracy2.Spindle rotor-bearing system vibration error:Modeling the spindle rotor-bearing system,including rigid disk unit modeling;modeling of elastic shaft segment elements based on Timoshenko beam theory;modeling angular contact bearings based on Jones bearing model The Lagrangian method,the Hamilton principle and the Jones bearing model are used to construct the nonlinear dynamic equation of the spindle rotor-bearing system.Finally,the Newton-raphson iterative method and the Newmark numerical integration method are used to study the system in the no-load and variable speed drawing.The vibration characteristics under the condition and track the dynamic accuracy of the bearing.3.The fuselage error of the fuselage:establish the vibration model of the flexible rod unit,construct the vibration model of the press body,deduct the kinematic differential equation,and use the solution of the model to achieve accurate tracking of the dynamic response of the fuselage.4.Experimental verification and analysis of the new model:Based on the above research on the vibration error of multi-link press,a complete dynamic error dimension chain of the press is constructed.In view of the incompleteness of the existing research on the vibration error of the press,a new model considering the mechanical transmission,the vibration of the spindle system and the comprehensive vibration of the fuselage is established,and the corresponding experimental platform is built.The comparison and analysis of the simulation and experiment verify the new model.Effectiveness,accurate tracking of the vibration error of the press under no-load and variable speed drawing conditions.Finally,on the basis of the proposed new model,the dynamic response of the multi-link mechanism under different clearances,different rotational speeds,different contact angles and different blanking forces is discussed.