Abstract
KEYWORDS
Hybrid vehicle, Drive belt, Integrated Starter Generator (ISG), Auto-tensioner
ABSTRACT
An idling stop system incorporating a belt-driven ISG (Integrated Starter Generator) is a system with excellent product acceptability that can quietly restart an engine without gear noise. There are several examples of massproduced automobiles fitted with this system. The system uses a single belt which is capable of not only driving the conventional accessories, but also driving the ISG and starting the engine. Specification changes from the base model, such as the change in the layout of the auto-tensioner and an increase in the belt tension, have been made. Because an increase in the belt tension causes increases of power loss to the bearings of each accessory and engine, the reduction of tension was considered an issue in relation to the application of this technology to an idling stop system intended to improve fuel economy. Examining the matter from a different perspective, research was carried out for developing a superior system, and the tension was reduced by the use of an auto-tensioner provided with a contraction suppression function, utilizing the incompressibility of a liquid and the adoption of an appropriate belt layout. In addition, a method of further reducing the tension of the belt by applying reverse torque control of the ISG was devised, and its effectiveness was verified. In summary, it was possible to create an excellent belt system that met the aims of an idling stop system.