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. 10, 2013
Filed:
Oct. 29, 2009
Eiichiro Ohata, Kasama, JP;
Eiichiro Ohata, Kasama, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Abstract
A method for correcting an output characteristic of an in-cylinder pressure sensor has a problem of insufficient correction precision because the measurement range required for the detection of a peak in-cylinder pressure and an ignition timing resides in a high-pressure region of an in-cylinder combustion cycle, whereas a reference pressure used for correction is measured while leaving an intake valve and an exhaust valve open, so that the reference pressure is out of the required measurement range. An apparatus for measuring an in-cylinder pressure includes: exhaust pressure detection means disposed in an exhaust port of an internal combustion engine to measure an exhaust pressure in the exhaust port; exhaust pressure recording means that records time history of the measured exhaust pressure; and peak exhaust pressure detection means that detects a peak value for each pulsation cycle of the exhaust pressure on the basis of the recorded time history of the exhaust pressure. A peak value of the in-cylinder pressure for each combustion cycle is calculated using the detected peak value of the exhaust pressure, and the calculated peak value of the in-cylinder pressure is used as a reference pressure.