Mitsubishi Heavy Industries Ltd. has sold three of its 3,300-ton EM-series hybrid presses - giant new electric and hydraulic presses twice the size as the next-largest EM - to three automotive molders in Japan, company officials said.
Mitsubishi still is looking to sell its first 3,300-ton EM press in North America, said Tom Geddes, general manager of the engineering department at MHI Injection Molding Machinery Inc., which sells the Japanese presses. Contacted Aug. 18, he said MHI was submitting a quote to a U.S. automotive company for one of the 3,300-tonners.
Geddes declined to identify any customers.
``Obviously, automotive would be our biggest target for this technology,'' Geddes said in an interview at MHI headquarters in Bensenville.
Mitsubishi had offered the hybrid EM presses in clamping forces of 720, 950, 1,200 and 1,600 tons.
Geddes said the company was looking at a 2,000-ton EM, but decided to jump up to 3,300 tons to meet customer requests.
The two-platen press, which boasts low-pressure, high-speed molding, moves a lot of material in a hurry. MHI said the press can mold a car bumper in a 30-second cycle. A special screw has high mixing capacity, so the big press can plasticize 1,890 pounds of resin an hour.
Twelve electric servomotors drive various movements on the 3,300-ton EM.
The only hydraulic power is used to build up final clamp-tonnage pressure, nozzle force and core pull - and the hydraulic power also is run by alternating-current servomotors.
To power the clamp opening and closing, two AC servomotors drive two ball screws in a conventional, belt-driven arrangement.
Injection of the big shot sizes is done by direct drive, with four servomotors directly coupled to four ball screws.
The four motors are electronically synchronized to run together at low speed, but with high torque. Geddes said direct drive provides high injection rates at high pressure, with very accurate and repeatable movements.
The 3,300-ton press is the only one of Mitsubishi's EM models to use direct drive for injection, Geddes said.
One AC servomotor runs the screw drive. Another motor runs the ejectors. Two servomotors drive the split nuts, which mechanically lock the platens in place. Then the hydraulics kick in to build up clamp tonnage.
In other news, Nagoya, Japan-based Mitsubishi Heavy Industries Ltd. in April spun off its Injection Molding Machine Division into a separate operation called Mitsubishi Heavy Industries Plastic Technology Co. Ltd.
MHI President and Chief Executive Officer Nobuo Maki said the focus on plastics machines will streamline decision making.