High cost pressure and the compulsion to continuously increase productivity are part of everyday life in the automotive supplier industry. Safety and ergonomics in the workplace can quickly get into the background. Not so at Hörmann Automotive Components GmbH: By using the automated rapid-clamping system for dies, they succeed in reducing set-up times by up to ten minutes, simplifying work and eliminating the risks of manual clamping. Thanks to the excellent order situation, the attachment will even pay for itself faster than initially calculated.
With around 900 employees, Hörmann Automotive Components GmbH in Ginsheim-Gustavsburg near Mainz produces body, chassis and frame components for car and commercial vehicle manufacturers. Customers include industry giants such as VW, MAN, Mercedes, BMW and Porsche. Steel sheets up to 12 mm thick are processed on eight press lines - some of them fully automated - and two large presses.
After a Siempelkamp punch press with a press force of 12,500 kN, built in 1994, was equipped with a coil system in the commercial vehicle parts production in 2008, the equipment with rapid-clamping systems was a further step towards increasing productivity. Hubertus Friedmann, who is responsible for plant planning, wanted to improve work safety at the same time: “During the manual clamping process, the operator stands on an oily surface - this cannot be prevented in a press shop”, admits Friedmann, “by using the automatic rapid-clamping system, we make a decisive contribution to occupational safety."
Furthermore, technology brings significantly reduced set-up times. Automatic clamping of the die takes up to ten minutes less than manual fixing. At least one die change per shift must be carried out – an enormous amount of time and economic loss per year. Also, the manual tightening of eight clamping screws was always accompanied by the risk of damage due to overtightening.
In 2009, hydraulic Hilma rapid-clamping systems with push chain and sliding clamps were retrofitted on the Siempelkamp punch press. The systems automatically clamp the die to the clamping edge of the press ram with an electrically driven push chain and apply a clamping force of 78 kN per element. Travelling paths from 200 to 1,000 millimetres are offered as standard; Hörmann uses a solution with 600 millimetres. The T-slots of the machine serve as a guide for the push chain and the sliding clamp. Clamping and unclamping the clamping cylinder is done centrally.
Eight rapid-clamping systems – four each on the infeed and outfeed side – have been in use since then, and even ten are possible if required. At the push of a button, all elements simultaneously fix the die, which can be up to 2m x 2m in size at Hörmann and weighs between eight and twelve tons. This enables uniform clamping, which is not possible manually, eliminates clamping errors and also prevents possible die wear.
Friedmann, a trained machine fitter and graduate mechanical engineer, has been responsible for plant planning at Hörmann Automotive for five years. “Solid steel forming has always been my topic”, he smiles as he stands in front of the punch press, which is continuously producing 8 millimetres thick gusset plates that serve as frame reinforcements for trucks.
The plant planner prefers simple solutions that work: “A press must open and close”, with a clear emphasis on the “must”. Because stopping a machine due to clamping errors, repairs or operating accidents is extremely expensive. The decision for products of the Hilma-Römheld GmbH was not difficult. The company is the leading expert for clamping dies, workpieces and the effective die change in the craft, mechanical engineering, forming technology and the plastics & rubber industry. It develops, produces and sells worldwide individual clamping systems and standard fixtures for machining and non-cutting production.
“Hilma is not the cheapest supplier, but we have received premium-class products in return”, says the plant planner with satisfaction. Quality was the decisive factor in the decision, as the value of the dies is often more than a quarter of a million euros. After the profitability calculation had shown that the costs would be amortized within three years, Hilma was able to hold its own against the competition, also thanks to its excellent customer service. The company is already pleased with other products from Hilchenbach – after all, mechanical and hydraulic sliding clamps have been doing their job in operation for 25 years, without any failures. Competitive products bent after a short time. The fact that installation by Hilma and integration into the machine control system were realised just as easily and quickly increases Hörmann's satisfaction even further.
Friedmann confirms this: “As a supplier, Hilma convinces with quality and customer service. Also, thanks to this latest cooperation between the two companies, the company is the first contact of Hörmann for future orders.
After all, the sales figures of the company are rising steeply again after the crisis year. Due to the improved order situation, the demand for new machines and the necessity to modernise existing presses is increasing. Especially the upgrading of existing plants is an important option to expand production due to the current long waiting time for new orders.