New jounce bumper in thermoplastics for lighter suspension, lower cost, improved performance

摘要

Automotive suspension is critical to driving comfort, road handling, safety and performance - and a key suspension component is the jounce bumper, part of a vehicle's shock-absorber system, designed to absorb impact and dampen noise, vibration and harshness (NVH). It does this by preventing the metal shock-absorber spring from fully compacting when impacted by potholes, curbs and objects on the road. It also offers an additional spring function to improve vehicle behavior when negotiating smaller holes in the road surface, cobblestones, sudden braking or quick changes of direction. The jounce bumper must operate efficiently in all weathers, be highly durable and exhibit very good dynamic behavior (fatigue and impact resistance) in the most demanding conditions - making its reliability key to vehicle road handling. Traditionally, jounce bumpers have been made of combinations of PUR-NDI (polyurethane naphthalene diisocyanate), PUR-MDI (polyurethane methylene diisocyanate), or NR (natural rubber). However, little has changed in the design and material content of these components for many years. Consequently, the automotive industry is more open than ever to step changes in jounce bumper design to achieve the lightweighting objectives needed to improve fuel efficiency and reduce CO_22 emissions - but without compromising vehicle comfort and safety.