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:
Jun. 13, 1989
Filed:
Nov. 08, 1988
Satoshi Hayashi, Nagoya, JP;
Masahiro Tomita, Anjo, JP;
Hitoshi Niwa, Okazaki, JP;
Hirokatsu Mukai, Okazaki, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A pilot injection system according to the present invention, which is used in a fuel injection pump, has a casing attached to the pump. The casing connects internally with a pump chamber of the injection pump. A partition wall is fixed in the casing, whereby the pump chamber is divided from the inside of the casing. A movable wall, which is movably located in the casing, divides the inside space of the casing between a fuel-spill chamber and a holding chamber. The partition wall is formed with a valve hole, which connects the pump chamber and the spill chamber. The valve hole has a seat surface which faces the pump chamber. A valve plug, which is located in the pump chamber, can be seated on the seat surface. The valve plug is connected to the movable wall by means of a coupling rod, which extends through the valve hole. Located in the spill chamber is a return spring which urges the movable wall in a direction such that the valve plug closes the valve hole. Moreover, an actuator for moving the movable wall is disposed in the holding chamber of the casing. The actuator includes a stack of piezoelectric elements, which can extend or contract in accordance with a voltage applied thereto.