| All electric injection molding machine are more and more widely used in aerospace, automobile, ship, electronic, medical and other high-end processing of plastic products because of its high precision, high speed stability, high responsiveness, energy saving, green environmental protection and Cleanness. Too much pressure can't be got by all electric clamping mechanism owning to its servo motor driving not like hydraulic clamping mechanism obtaining pressure owing to Hydraulic oil pressure energy, therefore toggle mechanism is generally used to meet the requirements of clamping force. double-toggle clamping mechanism is more and more popular in the design of all electric clamping mechanism because of its good performance, but its amplification and motion performance will be greatly affected if the design is not ideal because of complex structure and multiple parameter. In this paper,1300kN all electric injection molding machine clamping mechanism is optimization designed according to the domestic and foreign same specification mechanism. The overall scheme of clamping mechanism is determined using genetic algorithm toolbox. Simulation of movement performance and mechanical performance of clamping mechanism is carried out. Key components are checked to meet the requirement. The main content of this paper is shown as follow:(1)By comparing some of the parameters of the domestic and foreign 1300kN all electric injection molding machine clamping mechanism, main technical parameters is determined. The mechanical characteristics and movement characteristics of toggle mechanism are analyzed. The mathematical models of displacement, stroke ratio, velocity ratio, amplification ratio of clamping force, deformation force, systematic stiffness and deflection angle are built.(2)The toggle mechanism is optimization designed using MATLAB genetic algorithm toolbox (GAOT).12 parameters including elbow size, the size of big connecting rod and small connecting rod, rotation diameter of pin, template hinge point positioning size, etc are Optimized together to remove the limitation of clamping unit's performance caused by unreasonable pin rotation diameter and template hinge point positioning size. The curve of mold stroke, force amplification ratio and speed ratio are all satisfied with the performance requirements of the clamping mechanism.(3) SOLID WORKS model is built according to the optimized dimensions to analyse the minimum distance which may lead to interfere. Rotation diameter of pin and template hinge point positioning size can be adjusted ensuring the performance of the toggle mechanism does not change, which makes the non-intervention model of toggle mechanism be obtained easier. The total stiffness, deflection angle and the relationship between elbow angle and deformation force are calculated. The scheme of clamping and lift-out attachment is determined. The reducer, ball screw and motor is calculated, and the selection and check of tiebar, axle pin, screw and bolt are carried out to meet the design requirements.(4) Kinematics analysis was carried out by ADAMS using the simplified simulation model of toggle mechanism taking motor starting and stopping process into account. The displacement curve and velocity curve of the cross head and moving plate are obtained. Open and close of mold meet the slow Fast-slow process, and the velocity and the velocity ratio of the moving plate get closer to the actual situation. the relationship curve between elbow angle and deformation force simulated by ADAMS is consistent to MATLAB simulation, which verifies the feasibility and rationality of toggle mechanism.(5)The material of key components of clamping mechanism is selected. The value and position of stress and deformation of fixed mode plate, tail plate, moving plate, elbow, big connecting rod, small connecting rod and tiebar are simulated to meet the design requirements. |
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