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:
Dec. 26, 1995
Filed:
Jan. 19, 1994
Motonobu Akaki, Anjo, JP;
Yasutoshi Yamada, Chita, JP;
Nobuyuki Oota, Kariya, JP;
Masaki Mitsuyasu, Susono, JP;
Daisaku Sawada, Gotenba, JP;
Aisin Seiki Kabushiki Kaisha, Aichi, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
An excess voltage applied to a piezoelectric element is detected and controlled to improve durability and reliability of the piezoelectric element. A fuel injection control device for an internal combustion engine in which a power source voltage is boosted by a dc-dc converter and the so-boosted output voltage is supplied via a first choke coil and a first thyristor to a piezoelectric element for charging the piezoelectric element, the electric charge of which is subsequently discharged via a second thyristor and a second choke coil. The fuel injection control device includes a positive voltage detection unit for detecting an excess voltage arranged between the first choke coil and the first thyristor and a positive voltage control unit controlled by an output signal of the positive voltage detection unit and adapted for shorting both ends of the first choke coil. The current through the first thyristor is cutoff to prevent the excess voltage from being applied to the piezoelectric element.