Developing the car engine of the future with generative design

In the global fight to reduce greenhouse-gas emissions, automotive manufacturers have set major goals around improving fuel economy and reducing the CO2 emissions of automobiles. Design can play a crucial role in driving vehicle fuel efficiency—and an extremely effective means for achieving this is weight reduction. To achieve a reductive design, the structure and materials used in every part of a car, from body frames and engines down to the bolts, must be scrutinized. The latest target for Honda R&D, the automaker’s research and development division, is one of the most fundamental parts of the combustion engine: the crankshaft.

A record of design innovation

Honda’s R&D arm in Japan has closely studied advanced manufacturing technologies, such as additive manufacturing, since its inception. While researching design technology such as topology optimization, it found generative design (where multiple designs are generated and iterated upon) and realized that it could greatly change conventional design norms. Generative design had already helped the industry to redesign components such as seatbelt brackets, engine control units, and motorcycle frames. In each case, significant weight reduction resulted.

The crankshaft offers a unique set of design challenges for lightweighting. It’s one of the most important functional parts of an engine. It converts the oscillation of pistons into rotational force. To do so, it must be extremely strong and durable.

Building a better crankshaft

Autodesk prepared a first-lot model that fulfilled Honda’s requirements for the part using Netfabb and Fusion 360. “We shared Honda’s expertise to provide data on weight and various operating constraints, then went over each point with the Autodesk team as the model took shape,” Todaka says. In his work on engine parts for two- and four-wheel vehicles, Todaka had relied on his past experience to come up with designs to then analyze and refine. When he first saw the result, he was blown away. “The part had an organic shape, like a human bone,” he says. “It was something beyond my wildest imagination.”

Honda R&D project team members traveled to London, where they received training in generative design; toured the Autodesk Technology Center in Birmingham, England; and discussed topics beyond design, such as additive manufacturing. At the facility, Todaka says: “Prototypes could be made from designs quickly. I felt it was an ideal environment where feedback could be quickly applied to your work.”