Brake rattle
Brake judder is a term used in automotive engineering . These are low-frequency (up to 100 Hz) vibrations of a motor vehicle, which are induced by its braking . They are characterized by periodic fluctuations in the braking torque .
A distinction is made between cold rub , which is characterized by a geometric deviation of the brake disc over the circumference (DTV - Disc Thickness Variation), and hot rub , in which additional effects come from local heat zones on the brake disc.
Brake judder manifests itself through the braking torque fluctuations that occur in a movement of the wheel carrier in the longitudinal direction of the vehicle. They are induced by manufacturing-related irregularities in the surface properties of the brake disc or by impact ( imbalance ) in the disc. The driver notices it by pulsing the brake pedal, steering wheel torsional vibrations and vibrations of the body ( seat rail ).
The industry is currently investigating these effects (status: 2005) with extensive tests, since fundamental theoretical design guidelines for brakes to avoid vibrations are not yet known. Therefore, as part of a joint project between universities and industry, attempts are being made to clarify the basic properties of the vibration excitation and thus create a basis for development.
literature
- Bert Breuer, Karlheinz H. Bill (Hrsg.): Brake manual - fundamentals, components, systems, driving dynamics. 2nd edition, Friedrich Vieweg '& Sohn Fachverlage GmbH, Wiesbaden 2004, ISBN 978-3-322-99536-0 .
Web links
- Brake rubbing (accessed May 12, 2016)
- The "warped" brake disc and other myths of the brakes (accessed May 12, 2016)
- Chain of effects for the emergence of hotspots and hot scratches in disc brakes (accessed on May 12, 2016)