EGA uses formability siimulations like this one of the Acura TL front fender to catch possible deforms early in the die design process.
Through extensive use of simulations, EGA was able to give the Acura TL’s stylists the deep-draw panels they needed for the car’s low and wide stance.
Honda usually doesn’t make the short list when it comes to radical styling. They’ve got quality and reliability nailed, but traditionally not many heads have turned as a Honda or Acura blew by. This is partly due to a general Japanese reluctance to produce any vehicle that might be polarizing enough to scare off part of the customer base. But there is also a mechanical aspect: cost effectively producing the complex body panels needed to achieve an extreme styling statement isn’t easy. Low-volume luxury makers can get away with artistically sculpted panels because they often produce only a few thousand units of a given vehicle and charge prodigious sums for each one, so they can afford to coddle their stamping dies with lots of expensive hand polishing. But when the goal is to churn out 400,000 $20,000 Accords, that approach doesn’t work. Yet in a competitive environment where every maker’s quality is on the uptick, producing uninspired but highly reliable econoboxes is not a formula for long-term success. So Honda executives have recognized that styling matters, and the latest results of this epiphany are cars whose complex surfaces bear scant resemblance to their conservative predecessors. Which, of course, means that the die makers’ jobs have become a little tougher.
Achieving those surfaces is largely the job of Honda Engineering North America (EGA), Honda’s in-house die-makers. Tucked away in a small facility behind the mammoth Marysville Auto Plant in Marysville, OH, EGA oversees the design and production of all of the key stamping dies for Honda’s North American-developed vehicles. As the go-to group for stylists looking to make a statement, EGA has to figure out not only how to reliably stamp a given radical radius to make a design work, but how to do it on a budget. Here are some of the ways they do it.
Digital Prototyping. Over the past few years Honda has stepped up its use of digital prototyping. For EGA this means engineering data expressed in 3-D solids has replaced non-surface data, making it easier for its die engineers to visualize and critique the drawings they receive from their counterparts at Honda R&D. This early back-and-forth has led to reductions in part count and die investment and helped to speed approval of new designs. EGA vice-president James Wehrman says the end goal is to, “Make all changes in the virtual world and then go straight to cutter paths.” But he reckons that despite steady progress his company is less than half way to reaching that die-making Nirvana.
Better Simulations. “We could not have built this design five years ago,” says senior staff engineer Cory Hauberg. He’s talking about the third generation Acura TL, the latest public example of EGA’s handiwork, and perhaps Honda’s most uncompromising design to date. “The TL is the best we have ever done in turning a styling concept into a final vehicle,” he says. He credits the leap in capabilities largely to increased use of sophisticated computer simulations and cheap computational power. “Five years ago we could only pick one or two of the biggest formability issues and then we only had time to run one simulation,” explains Hauberg. Now much smaller problems get ironed out while the die is still in CAD, and that encourages stylists to take more chances.
For example, though it’s based on the Accord platform, the TL is a significantly wider vehicle and its exterior panels need a much deeper draw than that of the base car, in some cases up to 40mm deeper–a veritable abyss in stamping terms. Die-makers would generally rather avoid deep-draw designs because the deeper the draw the greater the chance for forming defects. But EGA’s simulations were able to verify that the design could be produced without compromise.
Keeping Costs Low. Talk to any Honda executive and he will lament how financially poor his company is. Honda has institutionalized this sense of being the little match girl of the automotive industry to keep its folks creative and hungry. The thinking essentially goes like this: it’s easy to get lazy if you think your company’s coffers are bulging, but if you think of yourself as the scrappy little guy about to get crushed by massive competitors with unlimited resources, then you come up with cheap, creative solutions. At EGA that mindset means getting more work for less money out of each die set.
Instead of purchasing expensive hardened blocks for its dies like many automakers, and then spending hours machining them, EGA uses die blocks that are cast into shapes much closer to the final panel contour. This saves money in two ways: material costs are lower for the cast blocks and machining time is a fraction of what it otherwise would be. The downside to this approach is that the dies require more maintenance once they are in production, but EGA is willing to trade off the extra hassle for the up front savings.
Along the same lines, EGA reduces the overall number of die sets it makes by making each one do more. Where other automakers might use five or six processes to stamp a panel, Honda does it in four or less. And since the first process is always a draw, that only leaves three die sets to complete trimming, piercing and bending regardless of how involved the panel is, which forces EGA to be creative about how it mixes and matches die features. The resulting dies are complex, perhaps the most complex in the auto industry, but because there are far fewer of them Honda achieves a ripple effect of cost reductions: less die material, fewer stamping machines and smaller storage areas.