APT Group
Assembly Line
Automotive Stamping Line Is Fast and Flexible
Toyota Motor Manufacturing France (TMMF) integrates many of the processes needed to manufacture a vehicle, from stamping to final assembly. Bumpers, dashboards and plastic trim parts are produced on site. Key components such as seats and roof linings are assembled less than 18 miles from the site. The wheels and windshields are produced at the same business park, and many other parts come from suppliers located in the region. In fact, the Yaris Cross has earned Origine France Garantie certification, meaning at least 50 percent of the unit cost price of the vehicle has been acquired in France.
The press shop produces 87 different parts and is one of the most impressive parts of the plant. It’s made up of four stamping presses and two cutting lines, which transform steel coils into body parts. The largest press weighs 1,567 tons and is 46 meters long. It can exert a maximum force of 4,600 tons on cold steel, 80 percent of which is produced in France.
Despite their size, the presses are fast and precise, stamping out 17 million parts annually with an accuracy of ±0.1 millimeter. A hair or a grain of dust in the die is enough to cause a defect on a part. The stamping operation consumes 300 tons of steel per day. One of the stamping lines was designed and built by AP&T Group of Ulricehamn, Sweden, in 2019.
The equipment consists of a shuttle system that receives parts from an existing transfer line and a SpeedFeeder with a servo-driven gripper for fully automatic changeover between different products. The SpeedFeeder takes parts from the shuttle system and stacks them in a fully automated pallet system. The equipment was delivered complete with a line and safety integration. The press runs at 25 strokes per minute; dual parts are produced at 23 strokes per minute. The cycle time puts high demands on the equipment. The short cycle time was not the only challenge posed by the project. More than 30 different parts are manufactured in the line, and changeover from one product to another must be fast. A gripper change may not take more than 180 seconds.
The body shop is the most automated part of the assembly plant. Some 98 percent of the body-in-white line is automated with 600 robots. At certain stations, up to 12 robots work simultaneously around the same body. Painting is the longest step. In fact, half the production time for each vehicle is for painting. Each vehicle receives three coats of paint: a primer, the base color (a water-based paint), and a clear varnish. The workshop has 12 solid colors and 19 two-tone colors. To limit the environmental impact and waste, the robots are equipped with cartridges containing just the right amount of paint, a system patented by Toyota.
When it arrives at final assembly, the Yaris is just an empty shell, but it will leave as a finished vehicle, complete with wire harnesses, hoses, brakes, engine, windows, bumpers, wheels, seats, steering wheel, and other components. There are around 3,000 components to assemble on each vehicle. The assembly line is equipped with 1,450 screwdrivers that install 1.4 million screws daily.