2022 Honda Civic Hatchback Enjoys Premium Assembly, Weight-Cutting Measures
Honda’s Indiana-based manufacturing project leader shares insights on meeting all-new product challenges with the launch clock ticking during COVID.
As a veteran manufacturing engineer, Jill Fuel was an ideal choice for the project leader for the production launch of Honda’s 2022 Civic Hatchback at Honda's Indiana auto plant. In eleven generations of Civic, it’s the first hatchback variant to be built in the U.S., sharing 85% of its underbody and 99% of its chassis with the sedan. And being an all-new model with many significant design changes, Fuel expected the usual challenges when the program kicked off in 2018.
“This was my first full-model project,” she told SAE Media during the 2022 Great Designs in Steel conference. “It was a big step up for me and for our 100-person team – and then came COVID.” The subsequent suspension of production at the Greensburg facility for several weeks hit the Civic project hard, as it did vehicle programs across the industry.
“We faced a lot of curveballs during that time,” Fuel said. “Our skeleton crew of associates was all working from home. Then when Indiana started opening up, some suppliers who weren’t located in our state weren’t ready to go. Our equipment-install timing was severely affected. ‘Plan B’ became Plans C, D, or whatever happened to work. And once we got going again, we had to compress and re-compress our schedules to launch on time.”
She said the experience taught the team plenty about flexibility. Over the first three years of the project, Fuel made seven trips to Japan to attend in-person drawing reviews with the vehicle’s designers, in addition to many videoconferences and virtual meetings.
The result, delivered on schedule, earned 2022 North American Car of the Year honors, a Top Safety Pick+ rating from the Insurance Institute for Highway Safety (IIHS) and praise as the best Civic yet, thanks to design, engineering, materials and process changes.
Honda’s ’22 Civic program investment included $50.2 million in upgrades and tooling for the Greensburg plant. Most of that went to a building expansion to accommodate a four-step laser brazing line for attaching the vehicle’s steel roof panel – the first application of a laser-brazed (actually a copper weld bead) roof on a lower-priced Honda model. Typically reserved for premium vehicles, Honda first used laser welding on the 2018 Clarity, later migrating it to Accord and Acura TLX models.
“The move to a laser-welded roof is a short-term cost but a long-term gain,” Fuel noted, “because it eliminates the ditch joint, the ‘mohican’ molding, the fastener equipment for the molding, and the install cost.” New Yaskawa laser-weld robots lay down 1.5 meters (about 5 feet) of copper bead per body side in 44.5 seconds. The robots are precisely guided by a high-speed, compact 3D laser-vision seam-tracking system supplied by Montreal-based Servo Robot.
The Civic design team prioritized crash safety, driving dynamics, mass reduction and cost reduction/ease of manufacture as the car’s target attributes. The foundation of these is a new generation of Honda’s longstanding ‘ACE’ (Advanced Compatibility Engineering) body structure that is 19% stiffer in torsion and 13% stiffer in bending than the previous generation, with rear-suspension mounting points that are 17% stiffer.
“Ease of manufacture and weight reduction really complement one another, and were a big piece of our early conversation,” Fuel said. In keeping with Honda’s overall materials strategy, the ’22 Civic maintains a steel-intensive materials mix in the body-in-white, with aluminum hood inner and outer panels (stamped by Honda and the first AL hood on a Civic) to reduce mass and meet pedestrian protection (ped-pro) targets. High-strength steel (HSS) content is up versus the previous-gen vehicle, comprising 38% of the body structure. “Our focus was to improve our IIHS crash rating, which meant high-strength steel in the engine compartment, side sills and door-ring stampings,” she noted.
In her presentation at GDIS22, Fuel revealed the following high-strength steel alloys content: Hot-rolled tensile strength dual-phase, 19%; cold-rolled advanced HSS, 16%; hot-rolled high strength with excellent formability, 9%; hot-rolled ultra-high-strength, 7%, and cold-rolled very high strength, 6%. The remainder of the steel in the Civic hatchback’s body structure is 29% galvannealed commercial grade and 14% high-carbon alloy.
A sticky situation
Stiffer structures typically are more difficult to manufacture, Fuel explained. “We increased our use of structural adhesives and sealants on this project, but those materials came with a list of criteria that were a struggle. How to weld through it? How do you apply it to the same spot each time, at line rate? We had to make the technology work in our existing facilities. The learning curve with the adhesives took some time to master, but we did it.”
Honda’s use of Dow sealers throughout the Civic Hatback's BIW now includes high-performance structural adhesives in the underbody. The ’22 Civic body uses 10 times as much adhesive as was used on the outgoing model. It is applied in both continuous and stitch patterns, depending on location and adjacent welds. In conjunction with spot welds and new lateral steel reinforcements in the floor structure, the adhesives significantly improve overall rigidity.
Fuel noted the challenges in adopting weld-through sealers in the body shop. In some areas the sealant has to be applied before the weld; this creates expulsion issues with the weld robot’s electrode. And the new super-high-performance adhesives have different flow and set-up characteristics compared to the products Honda Indiana was familiar with, she said. “We had to develop new checkpoints for the robots in this process, including new vision systems on the line to ensure precise and repeatable location of the sealer with the welds,” she explained.
The new Civic hatchback features an all-new rear liftgate construction that reduces mass by 20% compared with the previous model’s all-steel liftgate. It uses a steel inner stamping surrounded by durable impact-resistant, resin-based inner and outer skins. The new “hatch” also is perhaps the 2022 car’s most recognizable visual change. The liftgate is shipped as a complete assembly to the Greensburg line from a supplier.