Laser welding system using twin-station operation allows for cycle time-concurrent loading and unloading of the two work spindles, so increasing output and makes maximum use of laser availability.

EMAG UK said that laser welding as a means to permanently joining components has gained considerably in importance over the last few years In many cases laser welded joints are the solution to a more compact design with the benefit of reduced cost and weight of components and, in particular in the automotive industry, a lowering of fuel consumption

For many years EMAG has followed its objective to offer its customers - from a single source - all the machining technologies and processes that can be applied to round and 'not so round' workpieces, including 'ready-to-install' component assemblies.

Many workpieces first undergo a number of metal cutting processes and are then assembled and laser welded.

Since the foundation of EMAG Laser Tec in 2003, EMAG has been able to offer complete manufacturing systems from 'first cut' to laser welded, ready-to-install component assemblies.

* ELC 250 DUO compact laser welding machine - the ELC 250 DUO is a very compact laser welding machine.

Machining stations, laser, laser cooling unit, electrical cabinet and peripherals are all mounted on a single, self-supporting base frame.

The outstanding advantages of this design are the high degree of precision and long-term accuracy, much shorter commissioning periods and the possibility to move the whole system with a minimum of effort, allowing the end user to adjust quickly to changing production requirements.

The DUO variant of the ELC has two spindles.

This twin-station operation allows for cycle time-concurrent loading and unloading of the work spindles.

An integrated beam diverter allows for the laser to be switched between focusing optics, thus optimising laser utilisation and increasing productivity.

The ELC is equipped with a Rofin Sinar diffusion-cooled CO2 slab laser (DC - diffusion-cooled series), which has excellent beam-focusing capability, compact design and low operating costs, especially where energy and laser gas consumption - and maintenance work - are concerned.

Its excellent beam-focusing capability (K-number >0.9, i e, close to the physical maximum of K=1) ensures that the welding seam geometry can be fine-tuned to suit individual workpiece requirements.

The beam can produce narrow, deep welding seams using little heat, as well as welding wider seams.

Diffusion-cooled lasers are known to attract low operating costs, including extremely low laser gas consumption.

The laser uses Premix gas from a laser gas bottle.

The laser system equipment is located above generously dimensioned maintenance doors that provide easy access for the setter.

Set-up and maintenance times are thus drastically reduced.

To achieve the ambitious twin objectives of increased productivity and reduced set-up times, there have been developments in integrated work-handling.

The EMAG ELC 250 DUO features 12 NC axes, offering great flexibility in work-handling and realising short set-up times demanded, particularly for smaller batch sizes.

The machine is equipped with Siemens Sinumerik 840D CNC and a large number of application orientated software aids from EMAG Laser Tec.

The advantages of laser welding include the following.

* High welding power density.

* High processing speeds.

* A low heat load minimises component distortion.

* Exceptional process integrity.

EMAG's twin-spindle design offers a high degree of productivity.

In reality, laser welding machines are often used to clear production 'bottlenecks' and as such face high demands on productivity levels, availability and component quality.

These considerations provide the reason why the ELC 250 DUO's welding station has two spindles.

Whilst one spindle supports the component assembly during the welding process, the second one is used to unload the previously welded assembly and to load and clamp the mating parts for the next assembly.

The laser beam switches between the two stations.

EMAG said that this system guarantees optimum use of the system and a high productivity rating.

* ELC 250 DUO for transmission components - an increasingly important area of application for laser welding is the manufacture of automotive transmission systems.

Many components, such as differential housings, drive rings and output shafts for passenger car transmissions, are frequently machined individually, then assembled and welded together.

It makes transmission systems more compact and ensures they also meet the highest demands for noise level reduction and power density.

Laser welding has, to a large extent, achieved ascendancy over other methods of permanently joining components, such as the screw fitting of differential housing and ring gear. 

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