The hydraulic excavator is widely used in sheet metal processing industry, the general use of intermediate relay and a time relay to build a control circuit. Due to the hydraulic bending machine commonly used in mass production, the machine's continuous work time is relatively long. Therefore, the control circuit of the intermediate relay and a time relay action frequently, after a certain time the contacts and coil failure will lead to machine failure rate increased significantly, hydraulic bending machine, work is not stable.
Intelligent controller is a programmable controller, intelligent controller using alternative composed of an intermediate relay and a time relay is composed of hydraulic bending machine control circuit, by the controller output direct drive solenoid valve, well solves the hydraulic bending captain time running after work is not reliable. After two years of electric control of the improved hydraulic bending machine, the stability and reliability of the control system have been greatly improved, and the application requirements have been achieved.
Hydraulic bending machine in the original control circuit, control loop is constructed by four intermediate relay, a time relay, driving the movement of the slider is 24V DC electromagnetic valve, control circuit of DC 24V, provided by a bridge rectifier circuit, due to the continuous operation for a long time, driving solenoid valve relay contacts and coils damaged rapidly, often leads to the bending machine is not normal. In the transformation of the control loop, using the switching power supply DC24V power supply, directly use the output drive solenoid valve with the characteristics of the controller output relay to solve the frequent operation of hydraulic bending machine is not reliable.
