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Flexible drive for rollforming systems

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July 2017

 

The Italian company Gasparini S.p.A. has produced an exceptionally flexible and complex rollforming system for a German customer. The IndraMotion MLC system solution from Rexroth made it possible.

Every rollforming system that leaves the Gasparini S.p.A. plant in Mirano near Venice is a one-off. The Italian company’s technical director, Carlo Betetto, is very familiar with meeting very specific customer requirements. Nevertheless, the rollforming system for a German contract manufacturer of profiles in the logistics sector posed a significant challenge for him and his team. “The customer required an extremely flexible system with which they can handle a wide variety of different profiling contracts without having to completely reconfigure the system each time,” Betetto explains.

Gasparini have been experts in sheet metal forming since 1952. Today, 110 employees work there, designing and producing rollforming systems for customers from all over the world. The systems are used in logistics, construction, the energy sector and also in the automotive industry. More than 1,500 tailored systems are currently in use around the globe, systems that are utilized by small, medium and big size companies. Betetto has been tracking the trend towards increasingly flexible systems for a long time. “Our customers are facing increasingly tough requirements. They have to create a large number of different profiles quickly and cost-effectively.”

Punching, rollforming, cutting

The system that Betetto and his team developed for their German customer is 65 meters long and six meters wide. Depending on the task and material, it can shape between 2 and 40 meters of sheet metal per minute. As well as rollforming the sheet metal, the production line also performs punching and cutting tasks. The process on the production line looks like this: First of all, the coils are on a decoiling system, equipped with precision tilting mechanism, enabling much easier processing of different sizes of coils in different materials, after which a feed unit transfers them into the punching system. This consists of three electrically powered hydraulic presses with a force of 80 tons. Once the punching tasks have been completed, the prepared sheet metal moves into the heart of the plant – the rollforming system. “We have designed the system to enable the user to switch between different shapes fully automatically,” says Betetto. When the sheets have the required shape, they are transferred to the next production step – cutting. Here too, the cutting tools can be flexibly changed to cut the profiles to the required lengths. At the end of the plant is an automatic unloading system, which is capable of handling profiles with a length of up to twelve meters.

Flexible drive

The required flexibility resulted in very demanding requirements for the drive and control system in the plant. As a result, Betetto searched far and wide for an appropriate technical solution. “We had already worked with Bosch Rexroth on previous projects and the technology was the perfect fit for our plant design. As a result, we opted to work with the company on this project.” Because the plant is designed to perform a variety of different profiling tasks, it was important to be able to individually control each individual axis in the rollforming system. In the past, Gasparini has used a single drive to mechanically move the individual axes in his plants.

Gasparini plant Magnifier

After unrolling by the loading station (1), the coils are fed into the punching system (2) in the Gasparini plant, which is a total of 65 meters in length. 48 motors power the axes of the profiling machine, into which the sheet metal is fed after punching (3). The individual drives make the plant extremely flexible. This enables a huge number of different profiling tasks to be performed (4).

 
Profiling is followed by cutting. Thanks to on-the-fly shears, the cutting system is also flexible and fast. Magnifier

Profiling is followed by cutting. Thanks to on-the-fly shears, the cutting system is also flexible and fast.

Bosch Rexroth’s Italian team therefore suggested the IndraMotion MLC system solution, which was specially developed for metal forming. Thanks to the Sercos automation bus, the control system can manage electric shafts, electronic cams, and independent positioners for up to 64 axes. In this case, there are a total of 48 motors, which can be individually controlled to regulate the speed of the rolls. This precision control enables all the of profile geometries to be achieved without any reconfiguration times. The speed can simply be adapted for each forming tool in use. “The plant operator can change the program at the press of a button. They simply have to change the parameters in the software and each different profile will be managed in the best way automatically calculated,” Betetto said.

On-the-fly shears

The operator can also choose between different tools in the downstream cutting system. Depending on the material and profile, the cut is carried out using a circular saw or a cutting chamber. To increase throughput, Gasparini put his faith in what is known as an on-the-fly shears system. This means that the sheet metal is not stopped while the machine is cutting. For lengthwise cuts, the cutting processes must therefore be synchronized with the feed speed of the material, while for lateral cuts the tool is carried along in a frame. This movement is managed by a special function integrated into the Rexroth IndraDrive electrical drive, part of the IndraMotion system solution. “The advantage is that the drive solution is ready to use. This hugely sped up the development of the entire plant,” says Betetto. It took a total of seven months, from contract award to delivery of the production line.

Even though every plant that Gasparini develops is a one-off customized product, Betetto and his team of developers can use the know-how gained from this production line for future projects. “We are always looking for innovative solutions that will help us to produce exceptionally flexible plants. The drive solution from Bosch Rexroth has given us important impetus for future developments,” Betetto emphasizes.