Research On Real-time Controlled Injection System Of Die-Casting Machine

Die-casting machine is the important equipment used to process alloy castings with complex shapes. Real-time velocity control and pressure control during injection process of die-casting machine is crucial to obtain good quantity and high accuracy. For this purpose, common valve and logical control based injection system is reformed to be a preferable electro-hydraulic proportional control system in which velocity and pressure can be well controlled.Firstly, the blue print of injection system of die-casting, which includes hydraulic circle design, control scheme design, hardware choose, software structure design, is presented. The fact that the injection process is a process with high speed and high pressure requires the control valves and sensors to have rapid response and fine precision, sampling plate to has high Sampling frequency, control software to has better real-time property.In this paper, the principle of injection system of die-casting machine based on electro-hydraulic proportional control is introduced in detail. In order to get a in-depth and visual understanding of the performance of real-time controlled injection system, MTALB and its SIMULINK toolbox is used to build model, simulate and analyze for velocity control system and pressure control system of injection process. As result, response curves and dynamic characteristic parameters, which roundly represent the system performance, are obtained under various control signals during common PID control. To optimize the performance of velocity control system, a common fuzzy controller and an adaptive fuzzy PID controller are designed by MATLAB fuzzy logic toolbox. And response curves under such two controllers, which are used to analyze the dynamic characteristic of the system, are obtained. Compared to the response curve under the well-designed common PID controller, that under the common fuzzy controller is similar to it but more robust, and that under the adaptive fuzzy PID controller has better shape which denotes much more better performance of system.Since the die-casting machine based on electro-hydraulic proportional control is still under development, the study of this thesis has practical meaning to the upgrade of domestic die-casting machine.