CNC hydraulic automatic pipe bending machine is widely used in various industries, with complete functions, simple and convenient structure, simple operation and other characteristics. CNC hydraulic system is an important part of the pipe bending machine and plays a primary role in the pipe bending machine. Effect, therefore need to fully understand the CNC hydraulic system, the following editor introduces you to what are the three major circuits of the CNC hydraulic bending machine hydraulic system? Let's understand it together.

(1) Unloading circuit

This circuit consists of an overflow valve and two-position four-way solenoid valve. After the hydraulic pump is started, the two-position four-way solenoid valve is in the unloading state under normal conditions. At this time, the output of the hydraulic pump is all returned to the oil tank through the solenoid valve.

When the electromagnet is energized, the solenoid valve commutation is in working condition, and the relief valve is adjusted to the working pressure. To facilitate valve selection, this circuit uses a two-position four-way solenoid valve instead of a two-position two-way valve.

(2) Speed ​​control loop

The speed control circuit uses oil inlet to save speed and simply select a pressure relay to end the pressure control; this speed control method has the characteristics of convenient scheduling and energy saving. The flow into the hydraulic cylinder is limited by the saving valve, which can reduce starting shock and bend. When the pipe is required, the lower speed of the hydraulic cylinder is required, and the oil-saving speed regulation can easily reach the requirement.

(3) Pressure holding circuit

Separately set double hydraulic control check valves in the circuit. When the solenoid valve in the circuit is in the neutral position, the hydraulic cylinder can maintain its pressure. Other considerations for the leakage of the hydraulic cylinder, add an accumulator in the circuit to compensate For the leakage volume, it is necessary to pay attention to the fact that when selecting the electromagnetic directional valve, considering that the oil port of the control chamber of the double hydraulic control check valve must not have back pressure, the central function of the solenoid valve must be selected, and the one-way saving valve should be Install on the side near the cylinder.