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:
Feb. 15, 2000
Filed:
May. 20, 1998
Mikio Hamada, Handa, JP;
Aisan Kogyo Kabushiki Kaisha, , JP;
Abstract
In a fuel pump control apparatus provided by the present invention, if a target fuel pressure is changed, processing is carried out to determine whether the target fuel pressure has been increased or decreased so that proper transient state control can be executed. If the target fuel pressure has been increased, a fuel pump is driven by a maximum driving signal till the pressure of fuel reaches 90% of a new higher target fuel pressure. If the target fuel pressure has been decreased, on the other hand, the fuel pump is driven by a minimum driving signal till the pressure of fuel reaches 110% of a new lower target fuel pressure. In either case, transition state control is executed thereafter to drive the fuel pump at a duty ratio determined on the basis of an injection flow rate and the target fuel pressure till a predetermined delay time lapses. After the transition state control is finished, a steady state control is restored. In the steady state control, the duty ratio is determined on the basis of the pressure of the supplied fuel and the target fuel pressure. As a result, the fuel pump control apparatus provided by the present invention is capable of well keeping up with a change in supplied fuel pressure required by the internal combustion engine while allowing the cost and the size thereof to be reduced.