Practical implementation of energy-saving electrical clamps

In the body shop, many metal sheets and parts are attached to the frame. Before the parts can be welded they must first be fixed in their exact position, which requires many individual clamps. Conventionally, these clamps are pneumatically driven but recently there has been a growing demand for electrical clamps.

Markus Oerder, managing director of Univer GmbH explains: "An electrical drive with an efficiency rating of over 80 per cent is considered to be considerably more efficient than pneumatic drivers. However, when cost factors into the equation, electrical components only make sense when pneumatics are no longer needed for assembly. This is why electrical clamps are an interesting choice when welding tongs, cutters and lifting units are already electrically driven."

Costs are merely one part of the equation though, because electrically driven units also offer technical benefits. For instance, unlike with pneumatics, processes and functions can be carried out individually. This is required for body shop applications, where different models are produced in individual lines.

But electrical clamps are still not universally accepted, according to Oerder: "The price is higher at the moment because of the quantities being used and also from the investment costs caused by switching over to electrical components.

"If you compared the prices based on the same quantities and calculated this against necessary, new installations, the prices would be similar. Moreover, engineers often assume electrical solutions can only be designed with expensive, special constructions and many accommodations for the power supply."

It became obvious that electrical clamps (operating at 24V) require a relatively high current when starting up and during the actual clamping process. Therefore, it is important to produce and distribute energy that can operate up to 5000 clamps per system. This is where Murrelektronik components come into their own.

Peter Ohr, Key Account Manager Automotive at Murrelektronik, says: "The discussions with Univer showed that Murrelektronik could drive the electrical clamp using standard components. We immediately started endurance testing that proved successful.

"To control the clamps, they can use a standard MvK Metal module that is already installed in high quantities in many automotive plants [see photo above]. This also means they can use a proven technology. They do not have to get familiar with new technology and no new spare parts are required for maintenance. With Emparro67, Murrelektronik provides the appropriate solution for an intelligent power supply."

Innovation in car body construction

Together with Univer, Murrelektronik built a prototype to demonstrate how easy this procedure really is and the company now uses this to present the concept to engineers in automotive plants. So what is the future for such an approach? Oerder says: "Our aim is playing a leading role in clamping technology. Therefore, we are studying the latest technologies and we make the corresponding investments. This is why integrating electrical clamping technology plays an important role for us. To implement them in the markets, we are looking for a partnership. Together with Murrelektronik we can present an innovation in car body construction."

For more information about energy-saving electrical clamps go to www.murrelektronik.uk.