THE CONTRIBUTION OF FRICTION BRAKES TO ENERGY SAVINGS AND EMISSION CONTROL

摘要

Since the triumphal march of the automobile in the middle of the 20th century the function ofrnlocomotion has long become overlapped with the requirements for individualisation, autonomyrnand automotive driving enjoyment. The continuing demand for higher performance impressivelyrnillustrates this progression. Nonetheless the automotive industry also reacted to today’srnecological and climate discussions with environmentally friendly vehicle concepts.rnThe need for a reduction in fuel consumption and CO_2 emissions as well as the energy utilisationrnin everyday driving situations have strongly influenced current trends for development.rnConsequently this leads to weight-optimised designs and the use of lightweight materials.rnEven though any weight optimizations of the brake system have to be evaluated carefully regardingrndriver security, possibilities for weight reduction still exist. Besides conventionalrnfoundation brake systems, hybrid vehicles and especially energy recovery systems will alsornhave their impact on brake systems.rnStarting from current brake power needs, this paper sheds some light on the different drivingrnscenarios. With the weight proportion of mayor brake components illustrated, a weight comparisonrnand specification of nominated brake systems is shown and possibilities for optimizationrnare discussed. Based on an in depth analysis and simulation of different driving conditionsrnusing energy recovery supported friction brakes the future demands for the developmentrnof low emission brake systems are shown.rnIn order to lower total vehicle emissions, the automobile industry has undertaken substantialrnmeasures in the last decades. Regarding the brake system, the mayor emission is brake dust.rnEven though the generation of brake dust is unavoidable with the friction brake, the most effectivernmethod to reduce dust emission is to avoid wear. Based on mojacar endurance simulations,rna regenerative friction principle is proposed, which allows a clearly improved energyrnusage over the entire service life. It is shown that by means of a self generated protectivernlayer, excessive wear can be avoided at the same time significantly improving service life ofrnbrake pad and disc. This brake pad technology is paving the way for further improvementsrnthrough adapted designs allowing further weight savings.