copper-free brake padMR Fluid Brake PrincipleMR uid brake (prototype) and ultra-compact mobility vehicle tted with itMagnetic eld = 0Magnetic eld > 0Strongly magnetic particles (iron powder) are suspended in a fluid such as oil.MR uidMR uidApplied magnetic eldNorth poleSouth poleRotating discRotating discFixed discFixed discWhen acted upon by a magnetic field, the magnetic particles join up to form chain-shaped clusters (chain structures)Shear stress applied when the disc on one side moves in parallel at a constant speedThis resistance force acts as the braking force3PARTE Development and Promotion of Copper-Free Friction MaterialsIn the U.S. states of Washington and California, state laws have been enforced regarding restrictions on chemicals contained in automotive brake friction materials to prevent the impact of emissions of such substances on river and marine ecosystems. In the state of California, restrictions on copper will be enforced from 2021, and from 2025 onward, it will be illegal to t new vehicles with friction materials containing 0.5% or more of copper. Conventional friction materials have used copper to ensure safe and effective performance at high temperature. Akebono developed copper-free friction materials and started to market them for aftermarket products in 2007 and supply them as OEM parts to automakers since 2014. By combining multiple component materials, Akebono achieved the same performance as copper contained pads while keeping the cost at the same level. Around 80%* of Akebono brand aftermarket brake pads have a copper content that is lower than the 2025 standard for the state of California. Furthermore, we are also working to quickly develop antimony-free materials, as these could potentially be targeted under future regulations. Akebono will continue to comply steadily with laws, including Washington state laws going forward. *Shipment volume basisMR Fluid Brakes that Emit No Brake DustAt Akebono Research & Development Centre, we are conducting research and development into magneto rheological (MR) uid brakes that will eliminate brake dust. The brakes are being developed in response to the electrication of vehicles and out of consideration for the global environment. A functional material that has been researched since the 1960s, MR uid has the characteristic that it changes from a liquid to a semi-solid state in reaction to magnetism. When a magnetic eld is applied, the strongly magnetic particles (iron powder) several microns in diameter suspended in the uid align with the direction of the magnetic eld, forming chain-shaped particle clusters that change the uid to a semi solid state. MR uid brakes are constructed with a space lled with MR uid between a disc xed to the vehicle and a disc that rotates together with the wheel hub bearing. When electricity is passed through a magnetic coil mounted inside the brake, a magnetic eld is generated in an orthogonal direction to the discs, causing chain-shaped particle clusters to form between the xed disc and the rotating disc. As the rotating disc continues to rotate, the chain-shaped particle clusters are broken by shear stress, and then form connections to the neighboring cluster, before being broken again in a repeated cycle that generates a resistance force on the rotating disk. This resistance force is the braking force. Using MR uid for brakes can reduce the emission of environmentally damaging substances by eliminating abrasion powder because the brakes do not wear. Moreover, MR uid responds to a magnetic eld in less than a micro second, enabling sensitive and stable braking. Since the voltage (excited magnetic force) is electronically controlled, users can select their preferred brake feel from among several preset patterns. Akebono started research and development on ultra-compact mobility three years ago, completing its prototype product in March 2015. We will continue experimental work and improving MR uid brakes as a smart brake suitable for smart cities and smart mobility, aiming for implementation in 2020. Environment|Reducing Environmental ImpactInitiatives in Development• MSDS evaluations of materials• Response to ELV directive• Reduction of environmentally hazardous substances• Reduction of VOCs• Response to REACH regulations• Response to the North American chemical substance regulations• Response to laws and regulations in every countrySustainable Management31 AKEBONO REPORT 2017

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