Compared to pure electric drive, hydraulic bending machines offer strong and durable power. Their compact design eliminates the need for external piping, and the system is directly mounted on the hydraulic cylinder, resulting in a cleaner and leak-free operation.
The system converts electrical signals from the CNC controller into mechanical linear motion. To achieve this motion, signals are transmitted between the machine's CNC controller and the motor drive controller. Synchronized hydraulic cylinders control the tracking of the working process and enable rapid operation based on pre-set work curves. A variable-speed servo pump unit is used to drive the position of the bending tool and the bending force during the bending process.
I. Principles of dual-servo bending machines
The working process involves generating pressure through the hydraulic system, transmitting it through the upper and lower dies, and ultimately obtaining the desired shape of the material.
II. Correct usage of servo-controlled CNC bending machines
1. First, power on the machine and turn on the key switch on the control panel, then start the hydraulic pump.
2. Stroke adjustment is crucial in using CNC bending machines. It is necessary to adjust the stroke and conduct a trial run before bending. The upper die of the CNC bending machine must have a gap of one sheet thickness when it reaches the bottom to avoid damage to the dies and the machine.
3. Select the appropriate bending slot, which is usually eight times the width of the material thickness.
4. The backgauge adjustment usually has both electric rapid adjustment and manual fine adjustment, similar to a shearing machine.
5. Press the foot pedal switch to start the bending process. Unlike a shearing machine, the foot pedal can be released at any time to stop the CNC bending machine. Pressing it again will resume the downward movement.
III. Functions of various components in the hydraulic system of dual-servo bending machines
1. Function of the hydraulic pump:
The hydraulic pump is the power device in the hydraulic system. It supplies a certain flow rate and pressure of oil to the hydraulic system. Driven by an electric motor, it continuously draws oil from or pressurizes oil into the reservoir, converting mechanical energy into fluid pressure energy. The hydraulic pump is an essential core component in every hydraulic system.
2. Function of the filter:
The filter reduces the contamination of hydraulic oil by removing impurities mixed in the oil, ensuring the normal operation of the system.
3. Function of the solenoid directional valve:
The solenoid directional valve serves as an intermediate conversion component between the hydraulic control system and the electrical control system of hydraulic equipment. Various relays, such as button switches, stroke switches, time relays, current relays, and pressure relays, generate electrical signals according to predetermined conditions. These signals energize or de-energize the solenoid valve. Under the combined action of the electromagnetic force and the valve's internal spring, the spool is displaced, thereby controlling the on/off, switching, or unloading of the hydraulic circuit. This controls the actions and functions of the hydraulic system and the entire hydraulic equipment.
4. Function of the relief valve:
The relief valve is primarily responsible for maintaining a constant pressure in the hydraulic system. It is often used in conjunction with flow control valves in throttle speed control systems to regulate the flow entering the system and maintain the system pressure at a basic constant level.
5. Function of the one-way throttle valve:
Similar to the relief valve, the one-way throttle valve controls and regulates the flow entering the hydraulic system, maintaining a basic constant pressure in the hydraulic system.
6. Function of the flow control valve:
The flow control valve controls and regulates the flow rate of the hydraulic fluid in the hydraulic system, maintaining a constant pressure and ensuring the normal operation of the hydraulic system.
7. Function of the hydraulic cylinder:
Hydraulic cylinders can be classified into piston cylinders, plunger cylinders, and swing cylinders based on their structural forms. Piston and plunger cylinders achieve reciprocating motion, outputting thrust and velocity, while swing cylinders can achieve less than 360° reciprocating motion, outputting torque and angular velocity. In addition to individual use, hydraulic cylinders can be combined with other mechanisms to fulfill specific functions.
