Automotive Engineering - September 2021 - 28

Acura TLX is
HONDA'S NEW
BODY-BUILD
BENCHMARK
Honda R&D increased the TLX's advanced high-strength steel (AHSS) content from 4.2% on the
outgoing model, to 17% on the 2021 car. AHSS (shown in pink) is used in the front side frames, side
sills, crossmembers and B-pillars. Press-hardened steel content rises from 8.3% to 9.5%. Aluminum
(AL) front fenders are new for '21; the AL hood is carryover.
H
onda body-engineering presentations have become a muchanticipated
highlight of the annual Great Designs in Steel
(GDIS) conference in Michigan. Honda's " ACE " vehicle structures
are considered by competitors to be benchmarks in
overall integrity, occupant protection and mass efficiency. The newest
iteration - that of the all-new 2021 Acura TLX - adds dynamic behavior
to the other ACE attributes.
The TLX's body development leader, Jeremy Lucas, deems the new
sport sedan to be " the most exciting project I've been involved with in my
23 years at Honda. " In a recent interview with SAE Media, he also praised
the GDIS event, as " an environment in which we in the body-engineering
and materials communities can learn from each other. "
For the first time in its history, the TLX is on an exclusive platform that
uses both higher percentages of high-strength steel alloys (980 and 1500
MPa in the underbody structure) and aluminum including the front fenders.
The unique architecture gave Honda's body stylists and Lucas' body
team more freedom to achieve their goals, including meeting the new
angle-oblique and narrow-offset impact modes. And it gave the powertrain
engineers space and structure to accommodate two turbocharged
engines (including a new V6) with both front-drive and " super handling "
AWD drivelines. Overall body width increased 50 mm (1.9 in.) versus the
previous-generation car, and the new model is dramatically styled with
deeper rear-quarter " hips. " Rear fender angle is 30.3° from horizontal.
Executing the new car's more aggressive, sophisticated styling required
Honda to develop a new stamping sequence. A second draw
process was added to the traditional Honda " draw, trim, bend " cadence
to achieve the sharp character lines on the aluminum hood.
" Often you're hamstrung by whatever commonality you're trying
28 September 2021
All-new for 2021, Acura's
midsize sport sedan gets
an exclusive platform
to go with its structural,
materials and dynamic
advancements. Body
development leader
Jeremy Lucas explains.
by Lindsay Brooke
to share, " Lucas noted. " Having the all-new V6 turbo
engine meant we didn't have an existing package that
we had to clear. " Keeping the TLX's hoodline as low as
possible was a key program goal, enabled by changes
that could be made to the new V6, which was in parallel
development. " We usually don't get that opportunity
because we're working with engines that already
exist, " he added.
The cabin-to-trunk bulkhead, previously bolted on
gussets in the 2020 vehicle, is now a new all-welded
ring structure on the '21 car that improves rear torsional
rigidity by 90% and saves 8 kg (17.6 lb) versus
previous methods for that level of rigitity. Carryover
technologies include one-piece hot-stamped door
rings, aluminum hood and magnesium cross-car beam.
Ditching the ditch for brazing
Laser brazing, a first for Acura, was employed to join
the roof panel to the bodysides along a 2.9-meter
(9.5-ft) run. The robotic construction technique helps
increase body stiffness, Lucas said, while giving the
TLX a premium look by eliminating the ditch joint and
its typically fussy plastic trim strips.
" We feel that having a laser-brazed roof was simply a
requirement for TLX - and it's not the easiest thing for
Manufacturing to execute, " Lucas observed. " Ditch joints
are simpler and easier to do from a manufacturing
AUTOMOTIVE ENGINEERING
ACURA

Automotive Engineering - September 2021

Table of Contents for the Digital Edition of Automotive Engineering - September 2021