Search Results

A new hybrid concept is applied to a small carburetted lean burn 2-stroke engine where, according to the underlying patent, the asynchronous motor is mounted on the ICE crankshaft, to provide increased torque during acceleration, lower and stabilise idle speed, replace the electric starter, act as a speed limiter, recover energy during deceleration and to provide the power for the electrically heated catalyst. The paper describes the mechanical development, the redesign of the thermodynamic parts of the donor engine, the light-off optimisation of the electrically heated catalyst, the electric and electronic development including ECU, power electronics, sensors, battery management, mapped ignition system and control strategies. The results show acceleration performance at par of a 50% bigger engine, ULEV level emissions including cold start, and no visible smoke or smell and very low particulate emissions very short after the cold start.

A complete vehicle including engine has been developed with the main aims of fulfilling future noise and pollutant emission limits but also to satisfy customers demands in terms of comfort and low NVH level and good fuel economy. The engine layout and design features are discussed with the thermodynamic calculation and the optimisation of ports and the variable intake system. The modal analysis of the engine parts and the simulation of the surface vibrations shows the effect of acoustic measures and the obtained results. Ancillaries like CVT drive, double link lever engine mount, water cooling system, lubrication system, exhaust system with catalyst and secondary air are discussed. Characteristic diagrams and driving cycle emission show the achieved performance, low emissions and fuel economy.