Mazda to Adopt Common Architecture for Full Lineup

VANCOUVER, BC, Canada – Mazda plans to base all future vehicles on a common “scalable” architecture beginning with the ’12 CX-5 cross/utility vehicle launching later this year, two top executives say.

The new platform will encompass two new lightweight components: Mazda’s new Skyactiv-Chassis and Skyactiv-Body. Skyactiv is the brand name for a host of new Mazda technologies, including engines and transmissions.

Robert Davis, senior vice president-U.S. operations, says the architecture’s parts will be “different, but the same” across models.

“While the basic design would be the same, the parts would be differentiated by scale,” he tells Ward’s at a media event here. “We want to have a common design structure between cars.”

In developing the Skyactiv-Body, Mazda says engineers turned to the Miata MX-5 sports car for inspiration. The goal was to emulate the vehicle’s “fun-to-drive” characteristics, which come from its lightweight and front/rear weight distribution, says lead body engineer Hidenori Matsuuka.

Other concerns included increased safety and rigidity, two things that “typically add weight,” Matsuuka says.

Rather than turn to strong and light, yet expensive, materials such as carbon fiber and aluminum, Matsuuka and his team decided to take a “holistic” approach.

By optimizing the body structure and design, adopting new production processes and making more components out of high-tensile steel, engineers were able to make the Skyactiv-Body 8% lighter than its predecessor.

Next-generation Mazda Skyactiv chassis 14% lighter than outgoing architecture.

Matsuuka says his team cut weight while increasing body rigidity by incorporating as many straight sections as possible, which are more efficient at dispersing forces incurred during a collision.

Weld-bonding is used in the manufacturing process to attach all parts. A fully completed body is sent to the assembly line, where previously, some body components were added as the vehicle was being built.

Increased use of spot welds contributes to a 30% increase in rigidity, compared with previous Mazda platforms.

The chassis group shared many of the same objectives. Kazuhiro Okuyama says his team’s primary task was to create “Jinba Ittai,” a Japanese term meaning a “feeling of oneness with the vehicle.”

While it was important for chassis developers to deliver the “fun-to-drive” feel, they also had to ensure high-speed stability and ride comfort, while reducing weight.

To optimize ride comfort, the angle of the rear suspension was shifted upwards to more easily absorb “longitudinal” impact shocks from the road, Okuyama says. The setup also prevents the vehicle’s rear from rising due to imperfections in the road. This improvement leads to increased stability when braking.

Suspension links were optimized and the rear-wheel grip enhanced to increase ease of turning. A higher steering-gear ratio for a direct-steering feel also is employed.

Weight was reduced some 14%, compared with previous Mazda chassis, by optimizing cross members. The center front cross member was extended and the angle of the attachment position reduced.

Welding flanges were removed from the front and rear to enhance coupling rigidity of the welded sections, which Mazda says results in enhanced overall stiffness while minimizing weight.

Kiyoshi Fujiwara, Mazda executive officer-product planning and powertrain development, says the new body and chassis are needed to accommodate elements of the new Skyactiv powertrains, including a unique system meant to reduce emissions.

Making room for the new powertrains ultimately will result in minor styling changes to future Mazda vehicles, he says. “The tires are moving forward (to the corners) because of the engine and transmission location. We needed the space, and that will help the styling.”

Adds Fujiwara: “That’s why Skyactiv is a whole suite of technologies. In the end, everyone had to work together.”

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