Research on back pressure control system of injection molding machine based on predictive self-learning Optimization PID algorithm

Abstract

Most of the hydraulic injection molding machines are controlled by proportional relief valves or proportional servo valves to control the pre-plastic back pressure, but due to the limitations of the relief valve and the servo valve itself, low back pressure or even zero back pressure control cannot be achieved in practical applications. This paper proposes to use a proportional direction valve instead of a relief valve and a servo valve to control the back pressure, and to control the back pressure by controlling the opening of the proportional direction valve, and a large number of simulation results show that under different back pressure conditions, the back pressure can be established quickly and smoothly. And the use of dual channel mode to connect the proportional directional valve, can achieve high flow and low pressure of the flow capacity. The system uses a pre-judgment self-learning algorithm to optimize the PID control algorithm, which can achieve rapid and subtle pressure adjustment of back pressure Simulation and system testing show that the system has good steady-state performance and dynamic quality.