Akira Kabasawa

Development of the IMA Motor for the V6 Hybrid Midsize Sedan

The Integrated Motor Assist (IMA) Hybrid Electric Vehicle (HEV) technology used in Civic Hybrid or Insight is developed originally by Honda, and is mounted in a V6 Accord with the aim of enhancing fuel economy of a mid-size passenger car. The development goal was to realize a mid-size passenger car that provides acceleration performance superior to a V6 Accord and the fuel economy of a compact class vehicle. Various means are employed to achieve high torque and high efficiency simultaneously, including an Interior Permanent Magnet (IPM) type rotor, low-loss electrical steel sheets as the stator material, and high maximum energy product magnets. These technologies increase the maximum power of the newly developed motor by approximately 20%, the maximum torque by 26% and motor efficiency over all ranges by approximately 1% to 3% compared to the current Civic Hybrid motor. Consequently, the maximum motor power of 14 kW and maximum motor torque of 136 Nm are achieved. In addition,direct couplers for high voltage connections and simplified structure of distribution parts are employed to increase production efficiency.