LEXUS MANUFACTURING ENSURES GREEN IS EVEN CLEANER
Lexus manufacturing standards ensure that even the smallest contaminant doesn’t taint its all-new RX 450h SUV.
From the hybrid component assembly to vehicle production lines, Lexus has developed a raft of new manufacturing technologies to ensure its Kokura plant minimises entry of contaminants – such as dust – from the production process.
Lexus states that a dust particle measuring just 20 microns – about the size of a grain of pollen – can have an adverse affect on the quality of body panel stamping, leaving scratches that are difficult to rectify later in the production process.
Kokura is the world’s only dedicated hybrid vehicle manufacturing facility.
It was designed to provide the perfect environment for making hybrid components.
The measures used by Lexus to combat dust in the production process begin in the panel shop, where the stamping dies are rigorously sanded and washed twice a week.
This process creates dust, so the maintenance area is screened by three metre-high net screens, with a constant flow of water across them.
The screens have been nicknamed
Lexus has invested in in-depth research to achieve high surface quality from its multi-coating paint process.
The Kokura paint shop combines conventional methods of contamination prevention at the entry and exit points, with technology similar to that used in semi-conductor factories.
Lexus has installed a number of small one-way air outlets that pressurise the area prior to the topcoat paint booth, forcing air away from it and significantly reducing the amount of airborne particles entering the booth.
Furthermore, assembly staff wear pocket-less anti-static clothing and wash their shoes prior to commencing work to ensure that outside contaminants do not enter the workplace.
Hybrid Unit Production:
Key to quality hybrid products is cleanliness and Lexus’Kokura hybrid production facility was designed for optimum cleanliness.
The assembly line has a low ceiling and a positive air pressure system.
Air is constantly forced from outside the building, to help prevent dust and other matter from entering.
Inside, air pressure is modulated between different areas to create a flow of air that moves in the opposite direction to the manufacturing sequence.
Components move downstream on shuttered conveyor routes; the further along they move, the higher the air pressure rises, with maximum pressure reached in the assembly process itself.
Temperature and humidity are rigorously monitored to maintain the stability of the factory environment all year round.
Double measures are in place at the shipping exit to prevent any foreign matter entering, with a completely enclosed loading dock from where a conveyor moves parts to the receiving door via an airlock.
Assembly:
“Clean and silent” are the watchwords for the Lexus RX 450h assembly line.
Lexus has replaced the chain-driven conveyor with one that uses urethane rollers to create a quieter working environment.
As well as being quieter, the new system also uses less energy and is easier to maintain.
Air tools are typically used for engine and underbody mounting; however the RX Kokura assembly line uses electric nut runners that automatically adjust to a preset torque for a consistently high level of precision.
The electric tools are quieter and vibrate less.