The new Weil Multiroller is a new programmable multi-roll bending that can produce short tubes with different diameters and geometry without mechanical adjustment, opening up new opportunities previously not possible with roll bending machines.

In recent times, flexibility has overtaken productivity as the most important criterion for investment and equipment. The new target is economical, flexible production for batch quantities of as few as one. The requirement is a machine that needs very little or no set-up time or tooling costs. The Multiroller achieves this in the production of tubular components in a manner previously not achievable.

The demand for increased flexibility prompted Weil Technology, the German manufacturer of tube production machinery, to develop the first parameter-controlled, multiple roll-forming machines in the Multiroller series, thereby creating a launchpad for the development of flexible product flow from flat blanks to finished product. Due to Weil’s design concept to enable automatic bending of cylindrical shapes from flat blanks, these machines can now produce anything from a simple tube shape to the most complex tubular geometry in almost any shape, without needing mechanical setting or readjustment. Variation in diameter and geometry are achieved exclusively through parametric programming.

Weil has developed various Multiroller models covering a large range of diameters and material thicknesses, achieving diameter-to-material-thickness ratios previously not possible. For example Multiroller 150/2000 is able to produce tubes with a diameter of 60mm from high-tensile material in 1.5mm thickness and a maximum length of 2000mm.

Automated production

Weil can offer solutions for the fully automatic production of tubes from material with a thickness of 0.2mm to 3mm. The range of diameters goes from 50mm to 600mm with tube lengths from 80mm up to 2150mm, at material tensiles up to 980 Newton per square millimetre. It is also possible to process material thicknesses up to 3.5mm, though it may be necessary to pre-bend the edges if perfect roundness is required.

Apart from cylindrical tubes, the Multiroller can easily produce oval or polygonal tubes. Typical applications are the manufacture of bellows, tubes for ventilation and fume extraction, or automotive exhaust systems, cylinders for hot water services and boilers, as well as tubes used for IHU forming. Rear-axle tubes for passenger cars and similar products that were previously made by pressing and appropriate tooling can now be produced with Weil’s Multiroller technology.

The upper vending roll is supported along its entire length, with the ability to pre-bend the roller in a process similar to crowning. This allows the manufacture of thick-walled tubes with diameter to length ratios that previously could only be produced by the U-O bending process without the need for special, single-purpose tooling and multiple process steps.

The key innovation of Weil’s Multiroller technology is its ability to manufacture diverse tube diameters or tube geometry using simple parametric programming with built-in process safety. By simply changing machining parameters it is possible to produce a variety of tube geometries, giving the user maximum flexibility to react to varying production requirements.

The Weil Multiroller with CNC control is able to change the diameter setting during the bending process allowing the production of polygonally shaped tubular components such as oval shapes or even shapes with a number of varying radii.

Programming is simple and should take no longer than 10-15 minutes, even with complicated shapes. Previously used programmes can be simply recalled in case of repeating product runs. High-quality roundness and repeatable shape accuracy is ensured by the machine design and control capability combination. Variations in material consistency can be easily compensated by parameter tuning.

Depending on the length of the components produced, it is possible to increase output by bending multiple parts simultaneously side by side.

The Weil Multiroller has been designed to be adaptable to a multitude of production requirements such as the addition of peripheral materials-handling equipment and linking to additional processes such as welding or folding. The Multiroller can be used as a stand-alone machine or expanded into a tube-manufacturing cell with a varying degree of automation at any stage in the future.

The Weil Multiroller comes with an optical sensor to control bend accuracy. Further sensor technology is available to meet individual quality control needs and to enable maximum process control of the bending cycle.

Flexibility and productivity

The Weil Multiroller can produce cylindrical components with different parameters without set-up time losses as it is not necessary to change tools. Depending on the required diameter, typical cycle times range between 15 and 30 seconds and a corresponding output of up to 240 tubes per hour. In case short tubes are required it is possible to bend multiple parts side by side, with corresponding higher output rates. Typical applications are cylindrical bodies for pressure vessels, tanks, hot water systems and chimney tubes. As the bending radius can be varied within a bend cycle it is also possible to produce oval shells or any other irregular shape as found in automotive muffler assemblies.