Having extensive experience using hydraulic presses for draw work, the staff at Larson Tool selected a hydraulic press builder and began to work with them to design a custom built press line suitable for fully automated transfer and operation.
Many innovative features were incorporated into the press line including:
- Double moving platens for blanking, hold-down, and drawing.
- Ram-mounted punches guided through hold-down sleeve platens.
- Multiple presses mounted on a common lower platen to facilitate automated transfer.
- Servo-hydraulic draw height controls on the final draw operation.
- A conveyorized aqueous spray wash in line with the presses.
- Transfer automation integrated into the entire press and cleaning line.
Design of tooling, transfer, presses, and wash line was done concurrently with CAD files shared between vendors and Larson on an on-going basis.
The existing assembly line for the 2-piece cylinder consisted of six separate operations, all done manually. The 1-piece shell design would require only 4 operations. However, manually handling the additional weight of the shell was a concern from an ergonomic standpoint. Automating the assembly process addressed this concern, as well as reducing direct labor. Proposals for this equipment were solicited, and the contractor was selected who offered a simple and efficient design for a custom-built assembly machine.
Site work was completed and presses were installed in March of 1999. Tooling, transfer automation, and washing equipment were installed, fine-tuned, and integrated using programmable controls. Start-up of production for the new cylinder was critical, since supply lines of raw material for the old design were replaced by the new material at the mill three months prior. There was no allowance for overlap of old and new production.
Production on the old design shells ceased, and the new design was started in June of ’99 – just eleven weeks from arrival of presses. Assembly of cylinders was done manually at first, with automated equipment delivered and installed three weeks later. Deliveries to the customer were uninterrupted through the transition. More de-bugging by the Larson staff was required after the equipment went into production, but by July ’99 the labor reduction goals were realized.