Assembly In Action: Automated Feed System Heats up Production of Cold Forming Press
November 28, 2011
Automotive components are increasingly being manufactured in smaller lot sizes. Aware of this trend, German Tier 1 automotive supplier Neumayer Tekfor GmbH recently automated the feed system for a cold forming press used to form drivetrain components.
For many years, metal blanks were fed into the press with gripping tongs, which were part of a system that required extensive manual adjustments every time a different size blank needed to be formed. Setup time took about four hours, resulting in low press productivity and high per-piece cost.
The press now uses the Schunk Inc. HSB linear feed system, which is highly automated and takes about 15 minutes to set up for each different blank. The blank has a diameter of 80 millimeters and weighs up to 1 kilogram. The press produces a maximum force of 500 tons and an operational tolerance below 0.05 millimeter.
Workers manually place blanks on one to three conveyors, depending on project volume. Each conveyor can hold up to 40 blanks. At the end of the conveyor is an SRU rotary unit with LGW two-finger gripper. After the gripper grips the blank, the rotary unit swivels the blank 180 degrees and places it in a nest that sits on a 5,500-millimeter-long horizontal feed axis.
As the gripper swivels back to retrieve the next blank, the axis feeds the blank into the press, which forms the blank. The axis then moves the formed blank into the machining area where a second gripper removes the formed blank and places it onto a chute for collection and further machining. The feed axis then returns to the pick-up area for another blank. Cycle time is four seconds, and the press can process 3,000 pieces in an eight-hour shift.
Two other important components of the HSB system are linear axes that vertically adjust the height of the horizontal feed axis, depending on the size of the formed blank. The linear axes are attached to the left and right of the press. Various component dimensions are stored in the control system and synchronized via a master-slave operation to ensure correct part forming.
The linear axes are driven by a robust, play-free toothed belt drive with adjustable tension. They also feature profile rail guidance for high precision and a polyamide cover that resists dirt. Neumayer Tekfor also likes the HSB system’s modularity, which allows it to be easily, quickly and economically automated with machines of other dimensions.
Since being installed, the automated feed system has greatly improved press reliability. Plant malfunctions, which regularly occurred during the transfer with gripping tongues, are practically nonexistent.
For more information on feed system components, call 919-572-2705 or visit www.schunk.com.