Automotive Design
Fig. 4. The Fiat Punto’s new jounce bumper uses DuPont’s Hytrel TPE rather than PUR or rubber.
temperature range. It eliminates the need for metal or reinforced polyamide saturation cups and acetal or rubber rings normally used to increase energy absorption. The modified
Hytrel improves several characteristics, including mechanical performance (particularly under high strain conditions),
(TPE), it integrates several components into one to boost performance and reduce system cost. The jounce bumper is designed to absorb impact
and dampen noise, vibration and harshness (NVH) by preventing the metal shock absorber spring from fully compacting under load. The redesigned part uses a TPE in place of foam
polyurethane (PUR) or rubber, for high elastic recovery, durability and low stiffness variation over a wide
shape recovery, a balance between stiffness and low- temperature properties, and thermal stability. Several OEMs have tested the new design on
a variety of vehicles. The tests indicate a similar performance to PUR, but with lower part damage. After traversing 3,000km of cobblestoned roads, the Hytrel jounce bumper showed less than 3 per cent permanent deformation - some way below the industry target of 10 per cent, said DuPont. ●
Te Latest Titles on Design Engineering from CRC Press
SAVE 20% when you order online and enter Promo Code KKM09 FREE standard shipping when you order online (Expires 30/04/2014)
www.cr cpr
ess.com For more information ✔ at
www.engineerlive.com/ede
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60