Honda Develops New Hybrid System
TOKYO, JAPAN — Honda Motor Co., Ltd. has developed a New Honda Hybrid System that features a 3-stage i-VTEC engine employing Honda’s intelligent VTEC (Variable Valve Timing and Lift Electronic Control) system to provide three stages of valve timing (low-rpm, high-rpm, and cylinder idle mode). This is combined with Honda’s IMA (Integrated Motor Assist) system that has been made significantly more compact and efficient.
The New Honda Hybrid System utilizes the new technology, along with the performance of a 1.8L engine, to achieve an approximate 20 percent increase in system output over the current powertrain. The enhanced performance is achieved while improving fuel economy by 5 percent, reducing the system size by 5 percent and attainting lower emissions.
The 3-stage i-VTEC engine employs three hydraulic pathways to couple and uncouple five rocker arm assemblies, providing three stages of valve control depending on the driving conditions to achieve a combination of responsive driving and fuel economy. Unlike the Prius, the engine starts from a dead stop, and launches the vehicle with electric motor assist. During deceleration when the cylinders are idle, combustion in all four cylinders is halted and the cylinders sealed shut, reducing pumping losses caused by engine aspiration for a 10 percent improvement in recovery of braking energy compared to the current model. In low-speed cruising, deceleration, and stationary modes, the engine is turned off.
Additional design refinement — including the use of aluminum die-cast pistons, which feature low thermal expansion for less friction under high-temperature conditions, ion-plated piston rings, and plateau honing of the cylinder walls for a smoother surface — reduces friction as well. The New Honda Hybrid System will be introduced in the all-new Civic Hybrid, which will be launched this fall.