Turbocharger Production is Speeded up with Automated Jigs (February 2003)

Turbocharger manufacturer, Garrett Engine Boosting Systems, has increased production at its factory in Cheadle Hulme by automating the turntable jigs used to set the required inlet and outlet port angles of each turbocharger. The company manufactures and refurbishes over 300 different types of turbocharger, destined for manufacturers such as, BMW, Jaguar and Ford.

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As part of the final assembly process the port angles must be set to an accuracy of within 0.2 degrees so that they align correctly with the matching ports on the engine. Previously this was accomplished manually on a rotating turntable jig, with the correct port angles being read from a mechanical scale marked around the edge.

Whilst the system worked satisfactorily, it was time consuming and vulnerable to human error as operators had to read from a long list of 10-digit part numbers to establish the correct port-angle settings for each product. Misreading from the list would obviously result in the port angles being set incorrectly. A simpler system was required that would automate the operation and remove the possibility of human error from the selection of the correct settings.

The solution was developed by Motor Technology, of Stockport, after working in close consultation with Garrett’s own engineers. The company designed and installed an automated system that enables the jig operators to select the relevant 10-digit part number on an easy-to-use control panel. Software, written by Motor Technology, drives the system and powers a database containing the part numbers and specifications of all Garrett’s turbochargers.

After selecting the relevant part number on the controller, the two port angles, named Epsilon and Alpha, are shown clearly on two digital displays. Each one shows the actual and required port-angle settings so that the operator can position the turntable until both of them match.

As soon as the required and actual angles correspond, the operator then brings a metal slide, housing two proximity sensors, onto the face of the outlet port. When the face of the slide is flush with the turbocharger’s port, outputs from the controller switch on the air supply to the power-tool required to tighten the turbocharger’s bolts, securing the ports in the correct position. If the turntable angle is altered, the air supply is immediately shut off and the operator is alerted to the error.

After the operator has set the correct angles he can then mount another turbocharger with the same part number, bring the slide into position and tighten the fixing bolts. When a new turbocharger is mounted with a different part number, he simply goes back to part-entry mode and is immediately provided with the new angles on the digital displays.

The time saved by automating the process has resulted in a significant increase in production, and Garrett’s jig operators have stated that they feel more confident in working with the new system. The removal of human error from setting port-angles has improved the company’s overall quality assurance, and, so successful has it been, that it is now in the process of upgrading all its turntable jigs to incorporate the new technology.