EP0433690A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus and method for detecting misfire in a cylinder of an internal combustion engine
Assignee: Hitachi Ltd
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Filing: 1990-11-22
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Granted: —
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Expires: 2010-11-22
Abstract
Abstract Apparatus and method for detecting misfire cylinder of internal combustion engine wherein calculation is made to obtain a misfire discriminating value for each cylinder on the basis of revolutional period of the engine. The value approximately corresponds to change amount of mean effective pressure in each cylinder. The value is compared with a slice level to discriminate a misfired cylinder. The slice level is set in response to the discriminating value, thereby reducing the number of slice level matching process. Misfire discrimination process is prohibited in transitional driving state, thereby avoiding error detection of misfired cylinder. A period measuring range peculiar to the engine is arranged so that reliable detection can be achieved irrespective of number of cylinders.
Inventors
- 👤 Shinpei C/O Japan Electronic Control Nakaniwa
- 👤 Seiichi C/O Japan Electronic Control Ohtani
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 16:21
CPC Classifications
G; G01; G01M; G01M15/00; G01M15/04; G01M15/11
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
121 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a revolutional period measuring means for measuring a revolutional period of an internal combustion engine; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said revolutional period measured by said revolutional period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said value calculated by said misfire discriminating value calculation means with a slice level; and a slice level varying and setting means for varying and setting said slice level in response to said misfire discriminating value.
Claim 2
Independent Claim
121 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a revolutional period measuring means for measuring a revolutional period of an internal combustion engine; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said revolutional period measured by said revolutional period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said value calculated by said misfire discriminating value calculation means with a slice level; and a slice level varying and setting means for varying and setting said slice level in response to said misfire discriminating value.
Claim 3
Dependent Claim
70 words
An apparatus for detecting a misfire cylinder of an internal combustion engine according to claim 1, wherein said slice level varying an setting means comprises: a change ratio calculation means for calculating a change ratio of said misfire discriminating value; and a change ratio based slice level setting means for varying and setting said slice level on the basis of said change ratio calculated by said change ratio calculation means.
Claim 4
Dependent Claim
78 words
An apparatus for detecting a misfire cylinder of an internal combustion engine according to claim 1, wherein said slice level varying and setting means comprises: a change ratio calculation means for calculating a change ratio of said misfire discriminating value; and a change ratio and revolution speed based slice level setting means for varying and setting said slice level on the basis of said change ratio calculated by said change ratio calculation means and an engine revolution speed.
Claim 5
Dependent Claim
55 words
An apparatus for detecting a misfire cylinder of an internal combustion engine according to claim 1, wherein said misfire discriminating value calculation means calculates said value LU from an equation wherein Tφ is most lately measured revolutional period, T1 is revolutional period measured 1/2 cycle before, and T2 is revolutional period measured one cycle before.
Claim 6
Independent Claim
162 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a revolutional period measuring means for measuring a revolutional period of an internal combustion engine; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said revolutional period measured by said revolutional period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said value calculated by said misfire discriminating value calculation meas with a slice level; a transitional drive detecting means for detecting a transitional driving state of an internal combustion engine; and a transition misfire discrimination prohibiting means for prohibiting said misfire cylinder discrimination means from discriminating said misfired cylinder when said transitional drive detecting means detects said transitional driving state and within a predetermined time after shifting from said transitional driving state to a normal driving state.
Claim 7
Independent Claim
162 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a revolutional period measuring means for measuring a revolutional period of an internal combustion engine; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said revolutional period measured by said revolutional period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said value calculated by said misfire discriminating value calculation meas with a slice level; a transitional drive detecting means for detecting a transitional driving state of an internal combustion engine; and a transition misfire discrimination prohibiting means for prohibiting said misfire cylinder discrimination means from discriminating said misfired cylinder when said transitional drive detecting means detects said transitional driving state and within a predetermined time after shifting from said transitional driving state to a normal driving state.
Claim 8
Independent Claim
124 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a period measuring means for measuring a period of a predetermined angle range peculiar to the engine in which range a change of crank angular velocity appears, using a predetermined crank angle position of each cylinder of the engine as a reference position for measuring said period; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said period measured by said period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said calculated value with a predetermined slice level.
Claim 9
Independent Claim
124 words
An apparatus for detecting a misfire cylinder of an internal combustion engine comprising: a period measuring means for measuring a period of a predetermined angle range peculiar to the engine in which range a change of crank angular velocity appears, using a predetermined crank angle position of each cylinder of the engine as a reference position for measuring said period; a misfire discriminating value calculation means for calculating a misfire discriminating value for each cylinder on the basis of said period measured by said period measuring means, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and a misfire cylinder discrimination means for discriminating a misfired cylinder by comparing said calculated value with a predetermined slice level.
Claim 10
Dependent Claim
43 words
An apparatus for detecting a misfire cylinder of an internal combustion engine according to claim 6, wherein said predetermined angle range for measuring period thereof by said period measuring means is narrower than that between the compression top dead center of respective cylinders.
Claim 11
Dependent Claim
47 words
An apparatus for detecting a misfire cylinder of an internal combustion engine according to claim 6, wherein said predetermined angle range for measuring period thereof by said period measuring means is arranged predetermined times as large as the angle between predetermined crank angle positions of each cylinder.
Claim 12
Independent Claim
78 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a revolutional period of an internal combustion engine; calculating a misfire discriminating value for each cylinder on the basis of said revolutional period, said value approximately corresponding to a change amount of an mean effective pressure; and comparing said misfire discriminating value with a slice level which is adjustably set in response to said value so as to detecting a misfired cylinder.
Claim 13
Independent Claim
78 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a revolutional period of an internal combustion engine; calculating a misfire discriminating value for each cylinder on the basis of said revolutional period, said value approximately corresponding to a change amount of an mean effective pressure; and comparing said misfire discriminating value with a slice level which is adjustably set in response to said value so as to detecting a misfired cylinder.
Claim 14
Dependent Claim
48 words
A method for detecting a misfire cylinder of an internal combustion engine according to claim 9, wherein said slice level is variably set by calculating a change ratio of said misfire discriminating value to define magnitude thereof and adjusting said slice level in response to said change ratio.
Claim 15
Dependent Claim
52 words
A method for detecting a misfire cylinder of an internal combustion engine according to claim 9, wherein said slice level is variably set by calculating a change ratio of said misfire discriminating value to define magnitude thereof and adjusting said slice level in response to said change ratio and engine revolutional speed.
Claim 16
Dependent Claim
52 words
A method for detecting a misfire cylinder of an internal combustion engine according to claim 9, wherein said misfire discriminating value LU is calculated from an equation wherein Tφ is most lately measured revolutional period, T1 is revolutional period measured 1/2 cycle before, and T2 is revolutional period measured one cycle before.
Claim 17
Independent Claim
111 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a revolutional period of an internal combustion engine; calculating a misfire discriminating value for each cylinder on the basis of said revolutional period, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and comparing said value with a slice level to discriminate a misfired cylinder, wherein the process for discriminating said misfired cylinder on the basis of said value is prohibited when a transitional driving state of the engine is detected and within a predetermined time after shifting from said transitional driving state to a normal driving state.
Claim 18
Independent Claim
111 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a revolutional period of an internal combustion engine; calculating a misfire discriminating value for each cylinder on the basis of said revolutional period, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and comparing said value with a slice level to discriminate a misfired cylinder, wherein the process for discriminating said misfired cylinder on the basis of said value is prohibited when a transitional driving state of the engine is detected and within a predetermined time after shifting from said transitional driving state to a normal driving state.
Claim 19
Independent Claim
102 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a period of a predetermined angle range peculiar to the engine in which range a change of crank angular velocity appears, using a predetermined crank angle position of each cylinder of the engine as a reference position for measuring said period; calculating a misfire discriminating value for each cylinder on the basis of said period, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and discriminating a misfired cylinder by comparing said calculated value with a predetermined slice level.
Claim 20
Independent Claim
102 words
A method for detecting a misfire cylinder of an internal combustion engine comprising steps of: measuring a period of a predetermined angle range peculiar to the engine in which range a change of crank angular velocity appears, using a predetermined crank angle position of each cylinder of the engine as a reference position for measuring said period; calculating a misfire discriminating value for each cylinder on the basis of said period, said value approximately corresponding to a change amount of an mean effective pressure in each cylinder; and discriminating a misfired cylinder by comparing said calculated value with a predetermined slice level.
Claim 21
Dependent Claim
34 words
A method for detecting a misfire cylinder of an internal combustion engine according to claim 14, wherein said predetermined angle range is narrower than that between the compression top dead center of respective cylinders.
Claim 22
Dependent Claim
38 words
A method for detecting a misfire cylinder of an internal combustion engine according to claim 14, wherein said predetermined angle range is arranged predetermined times as large as the angle between predetermined crank angle positions of each cylinder.
References Cited (Backward Citations)
No citation records indexed.
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