Working principle of bending machine
A bending machine is a mechanical equipment used for processing metal sheets, mainly used to bend metal sheets into the desired shape. It is widely used in the manufacturing industry, especially in industries such as automotive, aerospace, construction, and home appliances. The working principle of a bending machine involves knowledge from multiple fields such as mechanical, hydraulic, electrical, etc. The working principle of the bending machine will be explained in detail below.
1. Basic structure of bending machine
The bending machine mainly consists of the following parts:
-Rack: The rack is the main structure of the bending machine, usually welded from steel plates, with sufficient strength and rigidity to withstand the enormous pressure generated during the bending process.
-Workbench: A workbench is a platform for placing metal sheets, usually made of wear-resistant materials to ensure long-term use without deformation.
-Sliding block: The sliding block is a moving part of the bending machine, which moves up and down through hydraulic or mechanical drive, applying pressure to the metal sheet to bend it.
-Mold: The mold includes an upper mold and a lower mold, with the upper mold installed on the slider and the lower mold fixed on the workbench. The shape of the mold determines the bending angle and shape of the metal sheet.
-Hydraulic system: The hydraulic system is the power source of the bending machine, which drives the slider to move up and down through hydraulic cylinders.
-Electrical control system: The electrical control system is used to control various operations of the bending machine, including the movement speed, pressure, and stroke of the slider.
2. Working process of bending machine
The working process of a bending machine can be divided into the following steps:
1. Preparation work: Firstly, the operator selects the appropriate mold according to the processing requirements and installs it on the bending machine. Then, place the metal sheet to be processed on the workbench and adjust its position to ensure alignment with the mold.
2. Parameter setting: Set various parameters of the bending machine through the electrical control system, such as the movement speed, pressure, and stroke of the slider. These parameters are determined based on the material, thickness, and bending angle of the metal sheet.
3. Start the bending machine: After starting the bending machine, the hydraulic system starts working, and the hydraulic cylinder drives the slider to move downward. The upper mold on the slider comes into contact with the metal sheet and applies pressure to start bending.
4. Bending process: As the slider continues to move downwards, the metal sheet gradually bends under the action of the upper and lower molds until it reaches the set bending angle. During this process, the hydraulic system will automatically adjust according to the set pressure value to ensure the stability and accuracy of the bending process.
5. Return journey: When the metal sheet reaches the desired bending angle, the slider stops moving downwards and begins to return upwards. At this point, the metal sheet is fixed in a bent state, waiting for further processing.
6. Remove the workpiece: After the slider returns to its position, the operator removes the bent metal sheet from the workbench to complete the entire bending process.
3. Hydraulic system of bending machine
The hydraulic system is the core part of the bending machine, and its working principle is as follows:
1. Hydraulic pump: The hydraulic pump extracts hydraulic oil from the oil tank, pressurizes it, and sends it to the hydraulic cylinder. Hydraulic pumps are usually driven by electric motors, and their output pressure and flow rate can be adjusted through an electrical control system.
2. Hydraulic cylinder: The hydraulic cylinder is the executing component of the hydraulic system, responsible for driving the slider to move up and down. There are pistons and piston rods inside the hydraulic cylinder. When hydraulic oil enters the cylinder, the piston moves under the action of oil pressure, driving the piston rod and slider to move.
3. Control valve: The control valve is used to regulate the flow direction and quantity of hydraulic oil, and to control the movement speed and direction of the slider. Common control valves include directional control valves, pressure control valves, and flow control valves.
4. Oil tank: The oil tank is used to store hydraulic oil and is connected to the hydraulic pump and hydraulic cylinder through oil pipes. The oil tank is also equipped with filters and coolers to ensure the cleanliness and temperature stability of the hydraulic oil.
4. Electrical control system of bending machine
The electrical control system is the "brain" of the bending machine, and its working principle is as follows:
1. PLC controller: PLC (Programmable Logic Controller) is the core of the electrical control system, responsible for receiving instructions from operators and controlling the actions of hydraulic systems and mechanical components. PLC has high reliability and flexibility, and can be programmed according to different processing requirements.
2. Sensor: Sensors are used to detect parameters such as the position, pressure, and speed of the slider, and provide feedback to the PLC controller. Common sensors include position sensors, pressure sensors, and speed sensors.
3. Human Machine Interface: The Human Machine Interface (HMI) is the window through which operators interact with the bending machine, typically a touch screen or button panel. Through the human-machine interface, operators can set bending parameters, start and stop the bending machine, and monitor the bending process.
4. Motors and Drivers: Motors and drivers are used to drive hydraulic pumps and other auxiliary equipment, such as feeding devices and mold replacement devices. Motors are usually controlled by frequency converters to achieve stepless speed regulation and energy-saving operation.
5. Precision control of bending machine
The precision control of the bending machine is the key to ensuring processing quality, mainly involving the following aspects:
1. Positioning accuracy of slider: The positioning accuracy of slider directly affects the bending angle of metal sheet. Through high-precision position sensors and PLC control, precise positioning of the slider can be achieved.
2. Pressure control: During the bending process, the magnitude and stability of the pressure have a significant impact on the bending quality. The hydraulic system achieves precise control and regulation of pressure through pressure sensors and proportional valves.
3. Mold accuracy: The manufacturing and installation accuracy of the mold directly affect the accuracy of the bending shape. High precision molds and strict installation processes are the foundation for ensuring bending accuracy.
4. Plate positioning: The positioning accuracy of metal plates has a significant impact on the bending results. By using feeding and positioning devices, the accurate position of the board during the bending process can be ensured.
6. Safety protection of bending machine
During the operation of the bending machine, high-pressure hydraulic and high-speed moving parts are involved, so safety protection is crucial. Common security measures include:
1. Emergency stop button: In case of emergency, the operator can press the emergency stop button to immediately stop all actions of the bending machine.
2. Protective cover: The protective cover is used to isolate moving parts and prevent operators from accidentally touching or getting injured.
3. Overload protection: The hydraulic system is equipped with an overload protection device. When the pressure exceeds the set value, the hydraulic pump will automatically stop to prevent equipment damage.
4. Two handed operation: Some bending machines require operators to simultaneously press two start buttons to ensure that both hands are away from the danger zone.
summary
The working principle of a bending machine involves knowledge from multiple fields such as mechanics, hydraulics, and electronics. Its core is to drive the slider up and down through a hydraulic system, and use a mold to apply pressure to the metal sheet to bend it into the desired shape. The precision control and safety protection of the bending machine are key to ensuring processing quality and operational safety. With the continuous advancement of technology, the automation level and processing accuracy of bending machines will continue to improve, providing strong support for the development of the manufacturing industry.
