Misfire detecting apparatus for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9857273-B2
Application number	US-201013510968-A
Country	US
Kind code	B2
Filing date	Nov 19, 2010
Priority date	Jan 13, 2010
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A misfire detecting apparatus is provided wherein a misfire is detected based on a rotational speed parameter indicative of a rotational speed of an internal combustion engine. An average change amount of the rotational speed parameter in a first predetermined period and an inertia speed changing component which is generated with rotation of the engine are calculated, and a first corrected rotational speed parameter is calculated by correcting the rotational speed parameter according to the average change amount and the inertia speed changing component. A first relative speed parameter is calculated according to a difference between a first reference value and the first corrected rotational speed parameter, the first reference value being the first corrected rotational speed parameter corresponding to the rotational speed parameter which is detected at a reference timing at which a piston of a cylinder, which is subjected to the misfire determination, is positioned in the vicinity of the compression top dead center. A first determination parameter is calculated by integrating the first relative speed parameter for an integration period corresponding to 720/N degrees of a crank angle (“N” is a number of cylinders of the engine), and a misfire determination is performed based on the first determination parameter. The reference timing and a start timing of the integration period are set according to the ignition timing of the engine.

First claim

The invention claimed is:

1. A misfire detecting apparatus for an internal combustion engine, having rotational speed parameter detecting means for detecting a rotational speed parameter indicative of a rotational speed of said engine, and detecting a misfire of said engine based on the detected rotational speed parameter, the misfire detecting apparatus comprising:
first correcting means for calculating a first average change amount of the rotational speed parameter in a first predetermined period, calculating an inertia speed changing component which is generated with rotation of said engine, and calculating a first corrected rotational speed parameter by correcting the rotational speed parameter according to the first average change amount and the inertia speed changing component;
first relative speed parameter calculating means for calculating a first relative speed parameter according to a difference between a first reference value and the first corrected rotational speed parameter, the first reference value being the first corrected rotational speed parameter corresponding to the rotational speed parameter which is detected at a reference timing at which a piston of a cylinder, which is subjected to the misfire determination, is positioned in the vicinity of the compression top dead center;
first determination parameter calculating means for calculating a first determination parameter by integrating the first relative speed parameter for an integration period corresponding to 720/N degrees of a crank angle (“N” is a number of cylinders of said engine); and
determining means for performing a misfire determination based on the first determination parameter,
wherein the reference timing and a start timing of the integration period are set according to the ignition timing of said engine so that a retardation amount of the reference timing and the start timing of the integration period is increased as a retard amount of the ignition timing increases.

2. A misfire detecting apparatus according to claim 1 , further comprising:
second correcting means for calculating a second average change amount of the rotational speed parameter in a second predetermined period which is longer than the first predetermined period, calculating the inertia speed changing component, and calculating a second corrected rotational speed parameter by correcting the rotational speed parameter according to the second average change amount and the inertia speed changing component;
second relative speed parameter calculating means for calculating a second relative speed parameter according to a difference between a second reference value and the second corrected rotational speed parameter, the second reference value being the second corrected rotational speed parameter corresponding to the rotational speed parameter which is detected at the reference timing; and
second determination parameter calculating means for calculating a second determination parameter by integrating the second relative speed parameter for the integration period,
wherein said determining means performs the misfire determination based on the second determination parameter when the engine is in a predetermined operating condition, and said determining means performs the misfire determination based on the first determination parameter when the engine is in an operating condition other than the predetermined operating condition.

3. A misfire detecting apparatus according to claim 2 , wherein the predetermined operating condition is a warming-up idling operating condition immediately after a cold start of said engine.

4. A misfire detecting method for an internal combustion engine, for detecting a rotational speed parameter indicative of a rotational speed of said engine, and detecting a misfire of said engine based on the detected rotational speed parameter, said misfire detecting method comprising the steps of:
a) calculating a first average change amount of the rotational speed parameter in a first predetermined period;
b) calculating an inertia speed changing component which is generated with rotation of said engine;
c) calculating a first corrected rotational speed parameter by correcting the rotational speed parameter according to the first average change amount and the inertia speed changing component;
d) calculating a first relative speed parameter according to a difference between a first reference value and the first corrected rotational speed parameter, the first reference value being the first corrected rotational speed parameter corresponding to the rotational speed parameter which is detected at a reference timing at which a piston of a cylinder, which is subjected to the misfire determination, is positioned in the vicinity of the compression top dead center;
e) calculating a first determination parameter by integrating the first relative speed parameter for an integration period corresponding to 720/N degrees of a crank angle (“N” is a number of cylinders of said engine); and
f) performing a misfire determination based on the first determination parameter,
wherein the reference timing and a start timing of the integration period are set according to the ignition timing of said engine so that a retardation amount of the reference timing and the start timing of the integration period is increased as a retard amount of the ignition timing increases.

5. A misfire detecting method according to claim 4 , further comprising the steps of:
g) calculating a second average change amount of the rotational speed parameter in a second predetermined period which is longer than the first predetermined period;
h) calculating a second corrected rotational speed parameter by correcting the rotational speed parameter according to the second average change amount and the inertia speed changing component;
i) calculating a second relative speed parameter according to a difference between a second reference value and the second corrected rotational speed parameter, the second reference value being the second corrected rotational speed parameter corresponding to the rotational speed parameter which is detected at the reference timing; and
j) calculating a second determination parameter by integrating the second relative speed parameter for the integration period,
wherein the misfire determination is performed based on the second determination parameter when the engine is in a predetermined operating condition, and the misfire determination is performed based on the first determination parameter when the engine is in an operating condition other than the predetermined operating condition.

6. A misfire detecting method according to claim 5 , wherein the predetermined operating condition is a warming-up idling operating condition immediately after a cold start of said engine.

7. A computer program embodied on a non-transitory computer-readable storage medium for causing a computer to implement a misfire detecting method for an internal combustion engine, for detecting a rotational speed parameter indicative of a rotational speed of said engine, and detecting a misfire of said engine based on the detected rotational speed parameter, said misfire detecting method comprising the steps of:
a) calculating an average change amount of the rotational speed parameter in a first predetermined period and an inertia speed changing component which is generated with rotation of said engine;
b) calculating a first corrected rotational speed parameter by correcting the rotational speed parameter according to the average change amount and the inertia speed changing component;
c) calculating a first relative speed parameter according to a difference between a first reference value and the first corrected rotational speed parameter, the first reference va

Assignees

• Hozumi Tomoharu
• Nagashima Masaaki
• Matsuda Kiyonari
• Honda Motor Co Ltd

Inventors

• Hozumi Tomoharu
• Nagashima Masaaki
• Matsuda Kiyonari

Classifications

• F02D2200/1015

  Engines misfires · CPC title

• F02D2250/14

  Timing of measurement, e.g. synchronisation of measurements to the engine cycle · CPC title

• G01M15/11 Primary

  by detecting misfire · CPC title

• F02D41/1497

  With detection of the mechanical response of the engine · CPC title