A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward.By analyzing the kinematic characteristics of a center-located slider-crank me...A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward.By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity,the kinematic parameters of the slide,connecting rod and crank were formulated approximately.On the basis of the results above,three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis.A verification experiment was performed on a slider-crank mechanism at a high-speed press machine.The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution.It was experimentally found that the proposed formulas have an improved performance over related earlier techniques.By use of these results,a 1000 kN 1250 rpm four-point high-speed press machine was designed and manufactured.The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces.Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated.The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.展开更多
In order to improve the stability of the hydraulic balancing circuit,taking a certain type of vehicular radar flip device as the research object,the influence of different wind load,counterbalance valve parameters and...In order to improve the stability of the hydraulic balancing circuit,taking a certain type of vehicular radar flip device as the research object,the influence of different wind load,counterbalance valve parameters and hydraulic pump flow pulsation on the system flip process are simulated and analyzed.Through the force analysis of the flipping device,the total load curve of the flip cylinder is obtained by using MATLAB simulation.The simulation model of balancing circuit and plane flip device are built by AMESim software,and the reasonable parameter matching relationship is obtained by specific simulation analysis.The simulation results show that when the wind load is to the left and decreases,the system runs more stably.When wind load works in the right direction,the load on the piston rod of the hydraulic cylinder decreases but the jitter amplitude increases.At the same time,the stability of the balancing circuit can be effectively improved by properly reducing the damping diameter of the counterbalance valve,setting the pilot ratio to 4∶1 and using the hydraulic pump with small pulsation.The optimized parameter matching relationship can not only meet the requirements of typical system conditions and responses,but also improve the performance of the circuit.展开更多
基金supported by the National Natural Science Foundation of China(No.50575175)
文摘A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward.By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity,the kinematic parameters of the slide,connecting rod and crank were formulated approximately.On the basis of the results above,three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis.A verification experiment was performed on a slider-crank mechanism at a high-speed press machine.The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution.It was experimentally found that the proposed formulas have an improved performance over related earlier techniques.By use of these results,a 1000 kN 1250 rpm four-point high-speed press machine was designed and manufactured.The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces.Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated.The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.
基金Key Project of Industrial Science and Technology of Shaanxi Province(No.2015GY068)。
文摘In order to improve the stability of the hydraulic balancing circuit,taking a certain type of vehicular radar flip device as the research object,the influence of different wind load,counterbalance valve parameters and hydraulic pump flow pulsation on the system flip process are simulated and analyzed.Through the force analysis of the flipping device,the total load curve of the flip cylinder is obtained by using MATLAB simulation.The simulation model of balancing circuit and plane flip device are built by AMESim software,and the reasonable parameter matching relationship is obtained by specific simulation analysis.The simulation results show that when the wind load is to the left and decreases,the system runs more stably.When wind load works in the right direction,the load on the piston rod of the hydraulic cylinder decreases but the jitter amplitude increases.At the same time,the stability of the balancing circuit can be effectively improved by properly reducing the damping diameter of the counterbalance valve,setting the pilot ratio to 4∶1 and using the hydraulic pump with small pulsation.The optimized parameter matching relationship can not only meet the requirements of typical system conditions and responses,but also improve the performance of the circuit.
