Injection molding machine controller design using LPC2138 single-chip computer - Power Circuit - Circuit Diagram

The development of modern injection molding machines focuses on improving the control level and automation of the whole machine, as well as the optimization of the whole machine design and processing technology to meet the requirements for the quality and energy saving of injection molding products. With the development of microelectronics technology, embedded system chips are widely used due to their high integration, low price and strong performance. The 32-bit ARM processor is used to realize the automatic control of the injection molding process, real-time display and online modification of the process parameters of each stage, which not only improves the automation degree of the injection molding machine, but also greatly improves the production efficiency and product quality of the plastic products.

1 The composition of the injection molding machine and its working process

1.1 The composition of the injection molding machine

The controller is controlled by a combined electric-hydraulic combined injection molding machine, which is a typical system integrating machine-electric-liquid. It is mainly composed of auxiliary systems such as hydraulic oil circuit system, clamping system, injection system, heating and cooling system, lubrication system, electrical control system, safety protection device, monitoring system and feeding. The various parts of the injection molding machine are mutually restrained and coordinated with each other to complete the cycle action of the injection molding machine. The electric control system is the "central nerve" of the injection molding machine. It controls various procedures and actions of the injection molding machine, and effectively controls and adjusts time, position, pressure, speed and speed. The controller realizes the control function of the electrical control system of the injection molding machine.

1.2 The working process of the injection molding machine

The controller of modern injection molding machine is mainly composed of injection molding machine process control, barrel temperature control, man-machine interface, etc. It can control the whole process flow of injection molding machine; flow, pressure, position and barrel in injection molding process Temperature control; display of parameters of the injection molding process and modification of online parameters. The working process of the injection molding machine is actually a process control. When a certain action is to be performed, the controller must output a corresponding control signal to energize the relevant solenoid valve, otherwise it will not work normally, and when the corresponding input switch or proximity switch input signal is detected, the control signal can be removed. The solenoid valve is de-energized to end the action and then proceed to the next action or stop working according to the process requirements. The workflow is shown in Figure 1.

2 system hardware circuit design

The controller is composed of two control modules, and adopts a master-slave structure to control the injection molding process, temperature, man-machine interface, communication and the like of the injection molding machine. The two control modules are each managed by a processor. The processors are all ARM processor LPC2138, one of which is responsible for keyboard and LCD display management, realizing parameter online setting and display to provide a friendly human-machine interface; A processor is responsible for detecting the various inputs of the injection molding machine and achieving process control and barrel temperature control of the injection molding. The RS 232C serial interface is used for real-time communication between the two to exchange information and data. The overall block diagram of the system hardware is shown in Figure 2.