400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 2002-01-0565 Optimization Technology of Magnetic Circuit for Linear Solenoid Takashi Arakawa and Shigeki Niimi Aisin Seiki Co., Ltd. Reprinted From: Computer Simu lation for Automo tive Applications (SP–1663) SAE 2002 World Congress Detroit, Michigan March 4-7, 2002Downloaded from SAE International by Univ of California Berkeley, Saturday, August 04, 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, August 04, 20181.ABSTRACT A linear solenoid is an important element part which hydraulically controls a VVT(Variable Valve Timing) system, etc. The demanded feature of the solenoid is that it performs an electromagnetic force output being constant regardless of the stroke and being proportional to coil current. In order to minimize the si ze, the electromagnetic force per volume has to be improved but the linearity is contradictory to the electromagnetic force and the consistency therebetween is very difficult to be achieved. Currently, the magnetic field analysis is repeatedlyperformed with trial and error to eventually obtain optimal designing of a magnetic circuit. We will introduce herein the results of our development in optimization technology for a magnetic circuit which can be used to effectively design a compact linear solenoid upon development of a new VVT system for a vehicle. 2.INTRODUCTION Figure 1.VVT system VVT system is a system component optimally controlling intake and exhaust valve opening/closing timing byshifting relative rotational phase between cam shaft and crank shaft in response to the vehicle running condition(the engine rpm, torque) and is very effective to improve fuel economy and to reduce exhaust gas. Recently, as one of a countermeasure to cope with such environmental trend, the installation of the VVT system has been increasing drastically. VVT system comprises VVT actuator, linear solenoid valve(OCV, Oil Control Valve), ECU(Electric Control Unit), and oil pump (Figure 1).Such VVT system has to be small in size and light in weight du