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:
Aug. 22, 1995
Filed:
Apr. 08, 1994
Hiroshi Ishiwata, Higashimatsuyama, JP;
Takashi Ohishi, Higashimatsuyama, JP;
Atsushi Ueda, Higashimatsuyama, JP;
Naotake Ohi, Higashimatsuyama, JP;
Zexel Corporation, Tokyo, JP;
Abstract
A solenoid valve unit is provided in the middle of fuel supply path that leads to a compression space in an injection pump main body, and the fuel injection quantity is adjusted through the open and close control of the solenoid valve unit. In this fuel injection system, the plug valve is moved until it is seated on the valve seat during the preliminary injection that is performed prior to the main injection. An arrangement for leaking the fuel from within the compression space is provided in the injection pump main body and the time period during which the fuel in the compression space is leaked via the arrangement for leaking and the time period during which the fuel supply path is restricted with the plug valve being seated on the valve seat are combined to stabilize the movement of the plug valve. Consequently, an optimal small quantity is achieved for the preliminary injection that is nearly constant regardless of the rate of rotation of the engine. Also, if a drive pulse that closes the fuel supply path over the period during which the fuel is leaked is supplied to the solenoid valve unit, the solenoid valve unit needs to be operated only once and stable injection characteristics are achieved from the pilot injection through the main injection.