400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 2002-01-1086 Engine Starting System Development by Belt Drive Mechanism Masae O-hori, Katsutoshi Tane i, Yu-ichi Yano, Kenji Hayama, Shinji Sako and Tomohiro Ezoe Toyota Motor Corp. Reprinted From: Adv anced Hybrid Vehicle Powertrain Technology (SP–1697) SAE 2002 World Congress Detroit, Michigan March 4-7, 2002Downloaded from SAE International by Univ of California Berkeley, Saturday, July 28, 2018The appearance of this I SSN code at the bottom of this page indicates SAE’s co nsent that copies of the paper may be made for personal or internal use of spec ific clients. This consent is given on the condition, however, that the copier pay a per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sections 107 or108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying forgeneral distribution, for advertising or promotional purposes, for creating new collective works, or forresale. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department.To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright 2002 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by whic h discussions will be printed with the paper if it is p ublished in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be c onsidered for presentation or publication thr ough SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in theGlobal Mobility DatabaseDownloaded from SAE International by Univ of California Berkeley, Saturday, July 28, 20182002-01-1086 Engine Starting System Development by Belt Drive Mechanism Masae O-hori, Katsutoshi Tanei, Yu-ichi Yano, Kenji Hayama, Shinji Sako, Tomohiro Ezoe Toyota Motor Corporation Copyright © 2002 Society of Automotive Engineers, Inc ABSTRACT The basic concept of the Toyota mild hybrid system is to provide a smooth and reliable engine restarting method from an idling stop, while at the same time being able to drive all of the accessories during theidling stop. This concept has been realized and marketed for the first time in the world, by utilizing a newly developed simulation of belt behavior to optimize thespecification of the belt and its peripheral parts. INTRODUCTION Along with the growing interest in environment, automobiles are increasingly required to reduce fuelconsumption and exhaust emissions. In such abackground, Toyota has recently developed the "Toyota Mild Hybrid System THS-M", laying stress on flexibility in terms of development, cost, and scale of changes infuture hybrid vehicles that are based on the Prius. In this Toyota Mild Hybrid System, engine starting is done through a belt, using a small motor/generator (M/G)as the power source. This is adopted in order to reducethe vibration and noise of engine restarting, which was aproblem with conventional idling stop systems. The newly developed simulation of belt behavior is utilized in order to reduce the load to the belt as much as possible,while ensuring engine restartability by the M/G. That isto say, in order to optimize the system. A magnetic