Ted Brown, vice president and general manager, Powertrain Systems, Comau North America (comauinc.com), while taking us through the company’s operations in Southfield, MI, points to the machining centers that the company is building for systems that will be used to produce powertrain components for a number of automotive customers. Historically—and even today—blocks and heads were (are) machined on transfer lines. Transfer lines automated the process of producing these components, but they are “fixed” automation, meaning that when a feature on a component changes, then there are non-trivial, time-consuming changes required to “unfix” the fixed setup. The beauty of machining centers is that they have multiple axes of freedom controlled via a program, as well as multiple types of tools, any of which can be readily accessed. This means that when a feature on a component changes, then it may require nothing more than a change of program and an automatic tool change and voila! It isn’t a matter of getting “back in business,” because with the machining center-based system, one is never really out of business, as is the case when a transfer line goes down.
Brown points to the machining centers to make the point about the SmartCell that they’ve developed at Comau, which is readily analogous to the transfer line, or a serial processing approach, and the machining center system, or a parallel processing approach.
Traditionally, blocks and heads are assembled in a way quite like the way they’re machined: with comparatively fixed systems. Assembly lines are like transfer lines. Again, these are systems that are large (according to Brown, a line to assemble 325,000 heads per year would take up 8,100-ft2 on the factory floor) and not readily changed to accommodate differences in the assembly. Not only is the SmartCell approach significantly more compact, but it provides flexibility in assembly.
The SmartCell makes use of a programmable three-axis arm that can be fitted with interchangeable tooling as required to perform the assembly tasks. Whereas a traditional assembly line is designed and engineered for a specific product the SmartCell, Brown says, can be readily tooled up to make any number of things, from engines to transmissions. Certainly, there is a work envelope involved and appropriate fixturing, but that’s about it. They’ve calculated that initial capital expenditures can be up to 30% lower than traditional and asset reutilization can be up to 70%.