Applications
A roller tube bending machine bends cylindrical profiles along circular arcs, using a specific bending angle or radius. In the double-angle version, the lower rollers are adjustable and define the inlet and outlet bending radius, while the central roller remains fixed.
The side supports, which are also adjustable, ensure greater stability and precision during bending, minimising deformation and ensuring a uniform, high-quality final piece.
This system optimises process control, improving the reliability, repeatability and overall performance of the machine.
Requirements:
Hydraulic circuit pressure measurement
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Control of pipe bending radius
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Hydraulic circuit oil temperature monitoring
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Requirement:
Hydraulic circuit pressure measurement
Measuring the pressure in the hydraulic circuit of a metal tube bending machine is essential for safe and accurate operation. Accurate control ensures the correct force is applied to the sheet metal, preventing overloads that could damage the machine and the finished product. Continuous monitoring allows leaks or malfunctions to be detected quickly, avoiding breakdowns and machine downtime. Hydraulic metal tube bending machines often operate at pressures exceeding 350 bar, which can vary rapidly; sensors must therefore be robust, accurate and responsive. Correct positioning on pumps, cylinders or valves and resistance to oil, vibrations and high temperatures ensure reliability and accuracy over time.
Solution:
- SIL2 certification
- Fast pressure reading (< 1 ms)
- Measuring range from 1 bar to 1000 bar
- IO-Link communication
Requirement:
Control of pipe bending radius
In the case of a double-angle tube bender, the machine must monitor the bending radius generated by the two lower rollers, driven by hydraulic cylinders, in real time and with high resolution. Since even a small variation in the positioning of the rollers can significantly alter the bending angle, a linear positioning repeatability of between 0.2 and 0.3 mm, combined with high precision, is essential to ensure the production of high-quality batches. In addition to these technical requirements, the position sensors required must be absolute and not incremental, in order to immediately provide the position of the roller when the machine is switched on. Finally, the transducers to be coupled to the cylinders must be easy to install, small in size but also economically affordable, so that they can also be used in entry-level machines.
Solution:
- Non-contact magnetostrictive technology
- Linear positioning repeatability of 0.09 mm
- Strokes from 50 to 2000 mm
Requirement:
Hydraulic circuit oil temperature monitoring
Monitoring the temperature of the hydraulic oil is essential to prevent overheating, which can compromise performance and damage components. At high temperatures, the oil loses its lubricating properties, incrementing wear and failure. Maintaining the temperature within the optimum range, generally between 45°C and 50°C, ensures proper operation and long system life, while preserving operational efficiency and avoiding unnecessary maintenance.
Solution:
- Thermoresistance technology (Pt100 / Pt1000)
- High precision and stability over time
- Robust stainless steel housing
- Easy integration into hydraulic circuits
Operating principle
The metal tube bending process is carried out thanks to the combined action of a fixed central roller and two lower rollers, which move to adjust the bending radius.
In the double-angle configuration , the lower rollers are inclined to allow both inlet and outlet bending. The central roller supports the tube while the lower rollers act on the bending of the material. In some machines, there are also adjustable side supports that stabilise the tube during bending, improving precision and reducing deformation.
The precise adjustment of these elements ensures a uniform bending process and the final quality of the product.
Requirements and technology
Metal tube bending machines must meet various requirements to ensure precision, quality and versatility in the process.
A key aspect is the precise adjustment of the position of the rollers, which must adapt to various tube diameters and thicknesses. The ability to adjust the angle and distance between the lower rollers and the central roller is essential to achieve uniform bends that comply with the required specifications.
In addition, to ensure optimal bending without deformation, it is necessary to constantly monitor the pressure of the hydraulic circuit, which manages the force applied to the rollers. The pressure must be precisely controlled to avoid damage to the material and ensure uniform bending.
Modern machines incorporate advanced position sensors to monitor the position of the rollers in real time, and hydraulic systems equipped with sensors to maintain constant and optimal pressure throughout the bending process. This combination of technologies ensures a high-quality finished product.
