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:
Apr. 14, 1998
Filed:
Apr. 09, 1992
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
An improved piezoelectric sensor for detecting pressure, vibration, acceleration or the like physical quantity is disclosed. The pressure sensor to be attached to a cylinder block of an internal combustion engine includes a main body adapted to be attached to the cylinder and defining an axially extending hole therewithin, a diaphragm attached to one end of the main body for closing the hole; and a piezoelectric element disposed within the hole so that the pressure within the cylinder is transmitted to the piezoelectric element through the diaphragm. The piezoelectric element is a circular or polygonal disc with a thickness of 0.3-1.5 mm and is formed of a single crystal piezoelectric ceramic having a Curie temperature greater than 500.degree. C., such as LiNbO.sub.3.