Powertrain & Energy - January 25, 2012 - 10

tech Report
Ricardo applies a nofaults-forward philosophy at its engine build facility in southern England.

directly into a central warranty database for each engine built, to give complete finished product traceability. The individual line stations are interlocked via their HMI to ensure that all operations and checks have been successfully completed and recorded before the line can be indexed and the engine advanced to the next station. As well as the main production line, the Ricardo facility includes a cylinder-head subassembly line, dress area, and an end-of-line hot-test cell that enables the performance of every engine to be fully tested and validated. Because of the small size of the facility, “designing the conveying system proved particularly challenging, as did the 50-minute TACT [total average cycle time], which was relatively slow due to the low production volume of eight engines per shift,” explained Ricardo technical specialist Dave Thompson. The Exmac handling system allows workers to load engine blocks on the line and rotate them at any of the assembly stations. The system is also indexed manually to allow greater control over the assembly process, provide the flexibility to accommodate long cycle times, and enable Ricardo to achieve batch production of single engines or

different engines as required. Exmac designed the 10-station line to take up very little floor space. Engine blocks are fixed to lightweight trolleys using a vertically mounted slew ring and quick-release plate, which mates with a bracket located on the engine bell housing. With the engine block locked in place, it can be rotated through 360°, allowing complete access for operators. At station 1, when all assembly functions are completed, the Exmac control system allows a stop to retract, enabling the operator to push the trolley to a holding position until station 2 is clear. The system then allows the trolley to be pushed to station 2, where the same stop and lock procedure holds it in place for that station’s assembly functions. This continues to the end of the line. If there is a problem at any station, the trolley continues to the end of the line where it is removed to a holding position for the engine to be reworked as required. Trolley and engine are then returned to station 1 and moved to the appropriate station to allow the engine to continue its build program. Exmac-designed mechanical locking systems locate and secure trolleys in position at each station while ensuring that they cannot be released until the HMI system confirms that operators have comSAE Powertrain & Energy

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January 25, 2012
Powertrain & Energy - January 25, 2012

Table of Contents for the Digital Edition of Powertrain & Energy - January 25, 2012
