Case Study 003 - Ford Livonia

FORD MOTOR CO. contracted directly with TECH-TRANS for the development of a single station fully automated process cell for the removal of aluminum chips and extraneous debris being found in transmission valve bodies received from machining.

ABSTRACT

This system was fully constructed and run-off for acceptance at the TECH-TRANS facilities and included all controls and pneumatics for the functional cleaning of the upper as well as the lower areas of the valve body. Part to part cycle time was 13 seconds which left an actual vacuum contact process time of 7 seconds. As part of the proposed process, there was only one area where the system could be located as space was an issue. The design accommodated the floor space requirements by mounting over as well as under the existing I.C.A. pallet / part transfer line. The system provided for the mechanical motion required to for part removal, orientation as well as returning the part to the transfer pallet after vacuuming both the upper as well as lower areas.

THE PROBLEM

The cost associated with rejects and re-work of the transmission valve bodies on the assembly line was traced back to the main aluminum casting and it’s complex areas referred to as worm trails. Within these areas as well as the close tolerance ports where precision components are installed, there were locations which accumulated aluminum chips and debris from the machining process which were not being removed by the conventional washing systems. Additionally, these parts required being placed into dunnage racks for shipment and as they were being handled manually and presented sharp edges, mandated the use of rubber and or gloves to protect workers. All of which contributed additional contamination of the part. From the point of delivery to the line, subsequent manual operations, such as the loading of the spools and clips, were provided. Under the theory of improved productivity, many operations were being performed on the assembly of a part which would not meet final inspection criteria. Subsequent testing costs as well as additional labor for tear-down and re-build were being expended. Additional machine utilization and increased labor for overtime were also being spent in order to maintain the proper production schedules for this critical part. A cost savings could be generated by cleaning these parts to a higher level than when received however, there was virtually no area where an additional system could be placed. Further, in order to correctly clean the part, required a process which could address both upper as well as lower area of the valve body and both within the short cycle time of 13 seconds – part to part.

SOLUTION

TECH-TRANS was contracted to provide a fully automated system to address the problems as noted above. The concept design incorporated a “split” system such that the main vacuum generator and debris drop-out chamber filter would be placed under the existing transfer line. The system was divided into a “pinned” upper and lower half to facilitate installation on site and the upper section carried the mechanical automation and vacuum contact system to clean the areas required. A unique pulsing effect was created by the use of a full contact roller which engaged the lower portion of the valve body after it was removed from it’s pallet / carrier. The valve body was then replaced onto the pallet where a second roller contacted and cleaned the valve body top side as it exited the station. Within the vacuum roller heads, specific ports achieve alignment with the surface roller ports so as to create a constantly alternating directional vacuum flow. This agitation increased the ability to dislodge debris as well as be sure to not reintroduce the debris into the critical areas of the part. Filtration of the debris was directed into a collection chamber where filters could collect the materials for inspection. Subsequent to the primary filter a secondary H.E.P.A. grade filter is employed to final scrub and particulates from the main air stream prior to discharge into the plant area. The entire package was designed around an envelope of 36” X 53”. The break-down of the system allowed ease of installation and start-up on the factory floor in one weekend. Contamination recovered lead to tighter controls for the supplier source and identified the type of rubber gloves which least contaminated the product due to handling. More important, additional labor cost were saved by building a higher quality part that required less re-work, thus increasing the overall line efficiencies and part quality.

TECH-TRANS supplied this project on a full “turn-key” basis including the onsite installation – and system commissioning. Preliminary engineering included full 3-D CAD design as well as simulation of the proposed motions to verify the proposed automation design.

BENEFITS

FULLY AUTOMATED , IN--STATION CHIP REMOVAL / CLEANING IMPROVED LINE EFFICIENCIES – REDUCED RE-WORK & SCRAP IMPROVED PART QUALITY – HIGHER LINE OUTPUT

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