The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 2004
Filed:
Jan. 25, 2002
Electromagnetic driving device and flow rate controlling apparatus employing the same driving device
Denso Corporation, , JP;
Abstract
Non-magnetic layers are formed on an inner circumferential wall of a housing portion and an outer circumferential wall of a plunger , respectively. Assuming that the thickness of the non-magnetic layer of the housing portion is t0, the thickness of the non-magnetic layer of the plunger is t1, a magnetic gap formed in a radial direction between respective magnetic materials of the housing portion and the plunger which excludes the non-magnetic layers is d0, and an air gap formed in a radial direction between the non-magnetic layers when the plunger does not deviate from but remains coaxial with the housing portion is d1, the thickness are set so as to satisfy 40 &mgr;m≦t0+t1≦80 &mgr;m, d0≈100 &mgr;m. In addition, it is set such that the attracting portion becomes saturated magnetically when the value of electric current that is supplied to a coil increases to reach a predetermined value which falls between 40% or larger and 60% of smaller of a maximum value of the electric current.