Aluminum CNC Bending Machine

As a mature bending machine manufacturer with over 10 years of technical expertise, we are now ready to reveal the principles behind pressure calculation and distribution in bending machines:

As a key piece of equipment in sheet metal processing, the precise calculation and reasonable distribution of pressure in a bending machine directly affect processing quality and equipment lifespan. Understanding the basic principles of pressure calculation and distribution helps operators set parameters correctly and avoid equipment overload or workpiece deformation.

1, Basic elements of pressure calculation  

The calculation of bending pressure primarily depends on three key factors: material properties, die parameters, and processing dimensions. Material properties include tensile strength and yield strength, with different types of metal requiring different bending forces. Die parameters primarily refer to the V-shaped opening angle of the upper die and the radius of the lower die's rounded corner. A smaller opening angle requires greater pressure. Processing dimensions include sheet thickness and bending length; doubling the thickness increases the required pressure to four times the original value.

In actual calculations, an empirical formula is typically used: P = K × T² × L/V. Here, P represents the required pressure, T is the material thickness, L is the bending length, V is the lower die opening width, and K is the material coefficient. For example, when bending a 1-meter-long, 3-millimeter-thick low-carbon steel plate using a lower die with a 32-millimeter opening, the required pressure is approximately 30 tons.

2, Basic principles of pressure distribution

Pressure distribution in multi-cylinder bending machines must follow the principle of balance. Modern bending machines typically use hydraulic synchronization systems or electro-hydraulic proportional valves to control pressure distribution among the cylinders. When bending long workpieces, it is essential to ensure that pressure is evenly distributed between the left and right cylinders to prevent inconsistencies in the bending angles at both ends.

Pressure distribution must also take into account compensation for elastic deformation of the mold. When processing high-strength materials, slight deformation may occur in the middle of the mold, requiring appropriate increase in pressure compensation in the middle section. Some high-end bending machines are equipped with deflection compensation systems that automatically adjust pressure distribution through hydraulic pads or mechanical wedges.

3.Important considerations for practical applications  

Operators should adjust pressure parameters based on material thickness. When bending hard materials such as stainless steel, an additional 20–30% pressure margin should be added to the calculated results. For soft metals like aluminum, pressure can be appropriately reduced to prevent surface damage to the material.

Mold selection directly affects pressure distribution effectiveness. Narrow-opening molds require higher pressure but achieve more precise bending angles. When processing special-shaped workpieces, it may be necessary to set different pressure parameters in segments. For example, when bending workpieces with flanges, the flange areas require greater pressure.

4, Determination of safe pressure range

Each bending machine has a rated maximum working pressure. The actual operating pressure should be controlled within 80% of the maximum pressure of the equipment, leaving sufficient safety margin. When the calculated pressure approaches the equipment limit, consider using multiple bends or replacing the equipment with a larger tonnage.

The pressure system should be equipped with overload protection devices. When the actual pressure exceeds the set value by 15%, the hydraulic system should automatically relieve pressure. Regularly check the pressure gauges and sensors to ensure accurate readings. If abnormal pressure fluctuations are detected, immediately shut down the machine and inspect the hydraulic system.

5, Pressure control technology in modern bending machines  

CNC bending machines utilize a closed-loop pressure control system. Pressure sensors continuously monitor actual pressure levels, compare them to setpoint values, and automatically adjust the oil pump output. This system effectively compensates for pressure fluctuations caused by changes in hydraulic oil temperature.

Some advanced models are equipped with adaptive pressure control functionality. The system automatically fine-tunes pressure parameters based on material springback conditions to ensure consistency in batch processing. Operators can intuitively adjust the pressure distribution curve via a touchscreen for more precise control.

The precise calculation and reasonable distribution of bending machine pressure are the foundation for ensuring processing quality. Operators must not only master basic calculation methods but also understand the working principles of the equipment. In actual operation, factors such as material, die, and equipment condition should be comprehensively considered to select the optimal pressure parameters. With the development of control technology, pressure regulation in modern bending machines has become increasingly intelligent, but the basic principles remain applicable. Proper pressure settings not only improve product quality but also extend equipment lifespan and reduce energy consumption.

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