Schuler has developed a drive system for hydraulic presses that is designed to reduce energy consumption by up to 60% compared to conventional lines. "The technology, called Efficient Hydraulic Forming (EHF), offers energy savings and optimizations in all operating phases, fully automatically, without the need for any action by the machine operator," said a company spokesperson. The system has a modular design and can also be retrofitted to existing lines.
The technology's stand-by function ensures that the main drives are automatically switched off when not required, i.e., as soon as no energy is needed for the forming process. "We also developed a patented start-up system that can bypass the usual start-up characteristics of drives and thus utilize even the shortest breaks without any time loss," explained Managing Director Dr. Martin Habert. This not only reduces energy consumption but also noise emissions.
These two benefits are also provided by the speed control for the power take-offs. Depending on the machine's current status, the auxiliary functions are powered acyclically; normally, however, the units operate at a constant speed. The result: frequent idling and unnecessary energy consumption. Schuler's EHF now uses an intelligent, speed-controlled drive that only supplies the auxiliary functions with energy when actually needed. This effectively minimizes idling losses.
Due to the efficiency-optimized, modular hydraulic system and energy recovery, EHF technology also has lower cooling needs. The control valves in the main circuit have been eliminated and their function has been taken over by servo pumps. Taking into account the applicable safety regulations, Schuler has reduced the number of components in the main circuits to a minimum.
The energy stored in the system does not remain unused but is fed back into the production process: the potential energy of the slide during rapid downstroke and the energy stored in the oil compression is fed back by using the discharged oil to drive units which generate power with the aid of electric motors.
The largest forging press in Switzerland, which is in operation at Imbach & Cie. in Nebikon, features EHF technology. The efficient Schuler line with a press force of 3,000 metric tons can form workpieces weighing up to four metric tons, heights of up to 2.50 meters and diameters of 1.40 meters into shafts, ring blanks, disks and other components – and all at speeds of up to 40 strokes per minute. "Whereas the press force, and thus also the output performance, has grown by several factors compared to the previous line, energy consumption has stayed virtually unchanged due to EHF," said the spokesperson.
For more information contact:
Schuler Inc.
7145 Commerce Blvd.
Canton, MI 48187
734-207-7200
info@schulerinc.com
www.schulerinc.com