2022 Toyota Tundra Has World’s First “Islands of Strength” Frame
Dejima was a fan-shaped artificial island built in the bay of Nagasaki that served as the exclusive point of contact for foreign trade and exchange with that region of Japan during its historical Edo period. Dejima served to segregate Dutch and Portuguese traders from Japanese society. What the devil does an ancient Japanese island have to do with the completely American 2022 Toyota Tundra pickup truck? Toyota adopted the word to describe the “islands of strength” it incorporates into the third-generation Tundra’s new ladder frame. The islands of strength help realize a 20 percent improvement in rigidity while the frame weighs 10 percent less than equivalent ones from the second-gen truck. We’re telling you about it because Toyota touts the process as a world-first innovation and a key to the 2022 Tundra’s “Born from Invincible” ethos.
Tailored Blank Technology
The basic concept of stamping metal blanks that feature differing metal thicknesses isn’t new. Steel manufacturers can roll steel out in such a way as to vary its thickness to put extra material where it is needed. Others have welded steel sheets of varying thickness together prior to the blanking and/or stamping operations. What Toyota claims is new here is its use of lasers to perform these welds along complex curves. Straight-line laser welding is an order of magnitude easier but reduces the degree to which the thicker material can be taken advantage of. A 10-axis laser executes these welds, and it operates at comparatively high power levels of 15 to 30 kW.
Where the “Islands of Strength” Are Located
Toyota had a finished frame on display with little chalk lines to show the areas where all the thickened metal is, and we needed that aid to draw our eyes to them. That’s because the laser welds are so smooth and clean that after the chassis is painted or powder-coated in black, the welds become all but invisible, unlike the conventional welding that joins the inner and outer sections of the fully boxed frame. Most of the frame measures just shy of 3 millimeters thick, and the thicker metal (4 to 5 mm thick) is positioned primarily at stress-concentration points. Basically, it’s located wherever a crossmember intersects with the side rails or where the rails have a bend or curve.
100 Percent Inspection
The welds are executed from one side of the work piece and must penetrate 90 percent of the metal thickness. Different optical lasers and machine vision tools developed by Toyota inspect every millimeter of every weld to ensure the strengthening sections will do their job. Every tailored blank gets its own serial number that links it to the steel mills and processes that occurred upstream of the laser welding operation. When a defect is detected, it often indicates degradation in a laser lens, which gets replaced immediately to correct the problem. The system today operates at 90 welding cycles per day, with each cycle completing eight pieces.
Toyota isn’t talking much about its frame’s carbon footprint, but it travels miles before it ever gets an engine. The steel arrives at the San Antonio Tundra plant from various suppliers, primarily in the U.S. The stamping and laser welding happens inside a 140,997-square-foot addition to the plant. The welded blanks are then shipped to Monterrey, Mexico-based parts maker Metalsa, where the frames are constructed before making the return trip to San Antonio for final assembly.
What Else Is New at TMMTX?
In addition to the new stamping area at Toyota Motor Manufacturing, Texas, in San Antonio, revisions to the assembly order (like the point at which the doors and seats are installed) was revised significantly enough to require 1,263 feet of new assembly line conveyor and 5,039 feet of new overhead conveyor. Most of these major revisions were executed during normal production breaks (summer and Christmas), as the final second-gen Tundra was scheduled to roll off the line on the day of our visit (October 8, 2021). Normal production capacity typically runs between 208,000 and 234,000 vehicles per year, with the potential to boost the number with overtime work. The Tacoma pickup is also built at TMMTX.
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