With a global Headquarters in Troy, Michigan, Delphi is one of the world's largest automotive parts manufacturers. Reflecting the global nature of its business, the company operates 138 wholly owned manufacturing sites, 36 joint ventures, and 28 technical centres located in 34 countries.

Delphi has extensive experience in high pressure fuel injection technology and has developed several innovative design and control strategies to meet customer’s requirements for cost competitive, low noise systems that provide accurate injection over the life of an engine.

The company is the world’s second largest supplier of diesel technologies, providing products for a variety of applications from low cost light vehicles for developing markets, up to high technology common rail and Electronic Unit Injector (EUI) systems for sophisticated passenger cars, trucks and off highway vehicles. One of several company manufacturing plants situated in the UK, Delphi’s Stonehouse, Gloucestershire, facility specialises in the manufacture of EUIs for heavy-duty applications, helping vehicle and engine manufacturers around the world to meet increasingly demanding emissions legislation.

Delphi’s EUI comprises an individual camshaft plunger pump for each cylinder capable of delivering fuel at 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 precise manufacturing tolerances – often in the sub-micron region.

Delphi’s EUI systems incorporate full electronic control with pilot injection being employed to reduce 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 fuel to be injected and the timing of its delivery.

Recently, an international truck manufacturer challenged Delphi Stonehouse to tighten the geometric tolerances on the interface between the EUIs from 100µm to 30µm.

Exceeding drawing requirements and beyond the inherent capability of the processes involved, the new increased tolerance demanded a re-evaluation of the manufacturing and inspection methods involved. The urgency of the request called for a rapid reaction from the Stonehouse team and, mindful of the required quick response, a manufacturing and inspection strategy was embarked upon for the high volume injectors.

As an inspection bottleneck 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 CMM from Aberlink.

Will Johnson, Delphi Stonehouse quality manager, takes up the story. “Having rejected several other measurement strategies, the in-depth understanding of our complex and tight tolerance measuring problem, shown by Aberlink, on our initial approach to them, gave us the confidence to explore their suggested solution. Within a two week period, working closely with Delphi personnel, Aberlink ran injector measurement trials, made minor modifications to their software, successfully completed arduous R&R 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,” he continues. “As the Aberlink operator interface is relatively simple, we have enjoyed the benefits of reduced training time, whilst the high speed of the new Aberlink CMMs will enable us to keep up with the current, unit inspection volume of 2,000 units per week, and also our projected throughput of 3,000 units.

Despite the prevailing economic conditions, Aberlink has continued to enjoy buoyant global sales within the small and medium CMM market. Dave Robinson, business development manager at Aberlink, points out: “Our strategy of providing affordable, high quality products has enabled Aberlink to grow organically to become the largest UK owned CMM manufacturer. New initiatives, such as our Machine Leasing Scheme, have enabled customers to continue to obtain our CMMs at a time of restricted liquidity.”

Aberlink has recently completed the installation of several specialist machining centres at its worldwide headquarters in Gloucester. In-house manufacturing is an investment Aberlink has always believed in, not only to control cost but more importantly to ensure the most appropriative equipment and process are used to manufacture the key components it uses to build machines. Every Aberlink CMM features a high grade aluminium bridge incorporating air bearings ensuring optimum performance across a range of environments, including less than perfect shop floor conditions. Whilst integration of the machine electronics into the CMM frame, rather than a separate desk unit, ensures a small footprint.

Aberlink
www.aberlink.com