Jul. 16, 2004
Daihatsu Motor Co., Ltd. has succeeded in industrializing a "catalyst early activation system" that purifies exhaust emissions right after the engine starts up.
The new system - the world's first to use ions detected in flames to control combustion and achieve early catalyst activation - will help mass production vehicles achieve emissions that are 75% lower than Japan's year 2005 motor vehicle exhaust emission standards.
Daihatsu is actively working to launch new low-emission vehicles. In 2001, the Move and Mira (domestic model) became the first petrol-powered mini cars certified for meeting Japan's ultra-low emission standard in effect at the time. In 2002, the company industrialized an "intelligent catalyst" that significantly reduces the amount of precious metals needed. The intelligent catalyst is now installed in almost all of the company's domestic models.
In addition to exhaust gas purification technologies, Daihatsu continues to develop advanced engine control technologies that help cars achieve higher levels of both environmental performance and running performance.
The new catalyst early activation technology will help cars meet increasingly strict emission standards. In conventional systems, the precious metals used as the catalyst worked best when heated – that is, after they came into contact with hot exhaust gas produced when the engine had been running for a while. They did not work well right after the engine started up.
The new system utilizes the fact that the combustion condition can be judged by the condition of ion generation in flames. It detects ions generated during combustion, determines the combustion conditions in detail, and controls the ignition timing with 1/10,000-second accuracy while maintaining optimum combustion conditions. This same ion-detection principle has been used in gas equipment to develop safety devices that shut off the gas supply when a pilot light goes out.
The new system sends hot gas to the catalyst immediately after engine startup to activate it, eliminating the shortcoming of conventional systems. Emission reduction is improved and optimum engine performance maintained.
The ion detection circuitry and other system components are compact and can be incorporated into existing ignition devices without changing the coil size, so the new technology is compatible with current mini cars.