Impacts of non-tailpipe particle emissions on atmospheric environment have increased due to the great reduction of engine exhausted particles from tailpipe. According to studies, it is considered that non-tailpipe particle emissions are almost similar level to those from tailpipe. In the future, non-tailpipe particles will dominate emissions from automobile because of spreading of electrical vehicles which don’t have tailpipe. Emissions from brake system is one of the highest emission sources of non-tailpipe particle emissions. And European commission have interest to regulate these emissions. In the United Nation, PMP informal group of GRPE is discussing to settle a world standard measurement procedure for particle emissions from automobile brake systems. The procedure focuses on how to reproduce actual braking events in real world. To reduce the particle emissions from brake system, fundamental understandings that how brake particles are produced and emitted are required. Thus, in this study, we observe fundamental properties of particle emissions from brake system with newly developed brake particle evaluation system. Developed system is driven by AC motor instead of dynamometer to reduce weight, size, and cost was achieved. The brake system is packed in a sealed chamber to collect the particle emission. The chamber is designed that emitted particles are blown to a sampling tunnel by HEPA filtered dilution air. Using this system, particle emissions form a brake with non-asbestos organics were evaluated. Particle number size distributions and particle mass were observed as functions of brake temperature and brake pressure. Sharp increase of particle number emissions over 190 degree C of brake rotor temperature was observed. A peak diameter of particle emission sifted from 34 to 80 nm with an increasing rotor temperature from 193 to 219 degree C.

Toyko Denki University: Mr. Kosuke Harihara, Prof. Hiroyuki Yamada, Mr. Kohei Iida