HEMEL HEMPSTEAD -- To meet the main requirements of ruggedness and torsion resistance for the housing of Continental Automotive Systems Division's recently-introduced ESC (Electronic Stability Control) system, the part's developers chose high-impact DuPont™ Zytel® SST (Stiff-Super-Tough) nylon.
"In the past we used aluminium for such housings," says Kai Allissat, manager, Program Planning & Control ESC Sensors at Continental's Automotive Systems Division, "but to save costs we looked for alternatives. Our new design is made of two halves injection-moulded from heat-stabilised Zytel® SST nylon reinforced with 25 percent glass fibre. With this material we were able to cut the housing's manufacturing costs by 40 percent compared to metal."
Mounted centrally in a vehicle, the new plastics housing holds the yaw rate sensor, the lateral acceleration sensors and a CPU for internal pre-processing, and a CAN (Controller Area Network) interface which transmits the collected data to the electronic braking and safety system.
The cluster design and the housing material isolate the sensor module from mechanical shock and vibration and shield it from electromagnetic influences. DuPont's Engineering Polymers Technical Centre at Bad Homburg carried out computer simulations on CAE models, to determine how the parts behave when they are subjected to vibrations at frequencies up to 500 Hz at temperatures between - 40 °C und 85 °C. "The housing of Zytel® withstood these virtual tests brilliantly," Allissat comments.
The precise detection of a vehicle's movements through measurement of the inertia values of yaw rate and lateral acceleration is the basis of modern electronic vehicle stabilisation systems and for roll-over protection, active steering and airbag systems. That is why Continental chose a modular design for the cluster, which allows for incorporation of other sensor functions which may be needed in future. "Based on the successful use of Zytel® SST for the current sensor cluster, there is every reason to believe that the next generation will have a housing of the same high-impact DuPont nylon," says Allissat.
Continental AG's Automotive Systems Division is a leading technology partner in the global automotive industry, delivering outstanding systems, components and engineering services for vehicle safety, comfort and powertrain performance. With more than 22,500 employees, it had a worldwide turnover of about ˆ 5 billion in 2004. Automotive Systems includes two major operations: Continental Teves, one of the world's leading manufacturers of electronic and hydraulic brake, stability and chassis control systems, electronic air suspension systems and sensors; and Continental Temic, which specialises in vehicle electronics, motor management and gear systems, electric drives and comfort electronics.
The DuPont Engineering Polymers business manufactures and sells Crastin® PBT and Rynite® PET thermoplastic polyester resins, Delrin® acetal resins, Hytrel® thermoplastic polyester elastomers, DuPont™ ETPV engineering thermoplastic vulcanizates, Minlon® mineral-reinforced nylon resins, Thermx® PCT polycyclohexylene dimethylterephthalates, Tynex® nylon filaments, Vespel® parts and shapes, Zenite® liquid crystal polymers and Zytel® nylon resins and Zytel® HTN high-performance polyamides. These products serve global markets in the aerospace, appliance, automotive, consumer, electrical, electronic, industrial, sporting goods and many other diversified industries.
DuPont is a science company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture, nutrition, electronics, communications, safety and protection, home and construction, transportation and apparel.
