Case Study 002 - Finite Cleaning of Cylinder Heads - Ford

FORD MOTOR CO. required the development of a single station automated system for the removal of aluminum chips and extraneous debris being found in the internal oil passageways of the ZETA 2-Litre cylinder head.

ABSTRACT

FORD MOTOR CO. working with I.C.A. as the prime systems integrator contracted TECH-TRANS for the development of a single station automated system for the removal of aluminum chips and extraneous debris being found in the internal oil passageways of the ZETA 2-Litre cylinder head. This product was being released for manufacturing on an existing I.C.A. line in Chihuahua, Mexico. Areas which required cleaning required a unique approach as some oil galleys were “dead-ends” where extraction could only occur in one direction. Part to part cycle time was 23 seconds which left an actual vacuum contact process time of 18 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 remote mounting the main vacuum generator and mounting the actual mechanical work station over the existing line. The system provided for the mechanical motions required for part lift, vacuum port tooling orientation as well as returning the part to the transfer pallet after vacuuming the internal areas..

THE PROBLEM

Problems with engine failures in the field were being attributed to the V.C.T. ( variable cam timing ) valve becoming contaminated and remaining open, causing an engine sensor fault indicating a motor failure. From a warranty and customer satisfaction standpoint, the high incident of the problem was not acceptable and exceeded warranty cost expectations. It was quickly determined that small aluminum chips, generated during the final machining process, were entering the deep tapped oil galley holes. Existing washer systems were not capable of extracting these chips and debris from these deep galleys and in some cases may have deposited them from other areas being washed. Other debris entered these dead end holes during subsequent assembly stages, such as when the V.C.T. valve was pressed into place. The blind hole designs of the intersecting galleys also minimized the opportunity for a direct access. Main oil galley holes, as well as the cam tower oiling holes were however, accessible to serve as a conduit for the removal of the debris. However, pulling chips in their direction caused the chips to jam or find a dead-air location where they could not be forced from the interior holes. As this engine was a new launch the situation required resolution. Not only was a new process required, is was needed on an as soon as possible basis.

SOLUTION

FORD MOTOR turned to TECH-TRANS based upon the proven experience and results being achieved at the FORD Livonia plant extracting oil, debris, and chips from transmission valve bodies. The initial TECH-TRANS process, as employed at Livonia was further refined and applied in a test cell to verify the anticipated results. Within the newly developed process, pressurized air would flow in the direction of a contained vacuum source and then be reversed. The reversing rate, or “pulse” rate, and, critical air flow volumes were tested and confirmed. In order to control the process, special contact tooling similar to that supplied for other controlled vacuum recovery processes was molded to mate with the available open ports of the head. Where ports had to be sealed while in station, moving seals were also developed within the TECH TRANS supplied tooling. Additionally controls and mechanical drive components were developed to create the alternating “PULSED-AIRE” action required to dislodge and remove the debris. Due to floor space constraints, the main vacuum generator and debris drop-out would be remote mounted at 50 feet from the work station. The work station was built to surround the existing line without excessive installation. Within the lower portion, a mechanical lift carried the pallet / head upward, into the molded vacuum tooling. When located within the tooling, the forward cam tower and rear oil galley ports were mechanically sealed. The main oil feed port at the bottom of the head was sealed by means of an extension located within the lift. The constant reversing air flow actions dislodge debris as well as extract it from the internal areas. The debris was directed into a collection chamber where filters could collect the materials for inspection. A final H.E.P.A. filter is employed to scrub any particulates from the main air stream prior to discharge into the plant. Additional labor costs were saved by building a higher quality part that required less re-work, thus increasing the overall line efficiencies and part quality. Warranty issues were reduced with improved customer satisfaction. TECH-TRANS supplied the vacuum equipment, tooling vacuum head and related automation well within the promised delivery date. 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 – WARRANTY COST REDUCTION

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