An Axiom Too coordinate measuring machine (CMM) from Aberlink has helped an automotive-parts manufacturer tighten geometric tolerances between its EUIs. Delphi's Stonehouse, Gloucestershire facility makes electronic unit injectors (EUIs) for heavy-duty applications.
These help vehicle and engine manufacturers around the world to meet demanding emissions legislation. Delphi's advanced EUI comprises an individual camshaft-plunger pump for each cylinder, capable of delivering fuel at very high pressures (up to 2,500 bar).
These high injection pressures are absolutely essential to enable engines to meet current and future emissions legislation, but require incredible manufacturing tolerances - often in the sub-micron region. Delphi's EUI systems incorporate full electronic control, with pilot injection reducing noise. Ensuring optimum operation efficiency, sensors located around the engine feed a continuous stream of data to the engine control unit (ECU), which calculates the exact amount of fuel to be injected and the timing of its delivery.
An international truck manufacturer recently challenged Delphi Stonehouse to tighten the geometric tolerances on the interface between the EUIs from 100 to 30um. Exceeding drawing requirements and beyond the inherent capability of the processes involved, the new increased tolerance demanded a revaluation of the manufacturing and inspection methods. A manufacturing and inspection strategy was embarked upon for the high-volume injectors. An inspection bottle-neck was quickly identified as a major potential difficulty. In consultation with Chris Gay, one of the Delphi Stonehouse's preferred inspection-equipment suppliers, several potential gauging solutions were explored. Having deemed dedicated fixtures as being too inflexible, an ideal solution was found, in the Axiom Too Coordinate Measuring Machine from Aberlink.
Will Johnson, quality manager at Delphi Stonehouse, said: 'Within a two-week period, working closely with Delphi personnel, Aberlink ran injector measurement trials, made minor modifications to its software, successfully completed arduous RandR trials and installed two Axiom Too CNC CMMs within the Stonehouse facility.
'Mindful of the urgency of our requirements and to further expedite the procurement process, we took advantage of Aberlink's Lease Hire Scheme. 'As the Aberlink operator interface is relatively simple, we have enjoyed the benefits of a reduced training time, while the high speed of our new Aberlink CMMs will enable us to keep up with the current unit-inspection volume of 2000 units per week and our projected throughput of 3000 units,' he added.
Always at the forefront of CMM innovation, Aberlink has recently completed installation of several specialist machining centres at its worldwide headquarters in Gloucester. Every Aberlink CMM features a high-grade aluminium bridge incorporating premium-quality air bearings, ensuring optimum performance across a range of environments, including less than perfect shop-floor conditions.
Integration of the machine electronics into the CMM frame, rather than a separate desk unit, has resulted in Aberlink machines boasting the smallest footprint of any equivalent-sized machine. Aberlink's 3D measurement-software provides the user with a powerful yet easy to use interface, substantially increasing new users' component throughput.
Aberlink's flexible 3D metrology software package has been developed as a multi-platform solution. In addition to supporting both manual and CNC CMMs, it can also be used on portable arms, vision systems, video machines and profile projectors.
