Patent US2669426A successfully refreshed from Google Patents.
Patent EP0610508A1 successfully refreshed from Google Patents.
EP0610508A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of detecting misfire by utilizing variation of rotation of crankshaft
Assignee: Mitsubishi Motors Corp
•
Filing: 1993-06-08
•
Granted: —
•
Expires: 2013-06-08
Abstract
Abstract A method of detecting misfire by utilizing the variation of rotation of a crankshaft, capable of detecting the occurrence of misfire accurately with the influence of a detection error eliminated which is ascribed to a structural error of a crank angle sensor used in the detection of variation of rotation of the crankshaft. When a processor receives pulses sequentially from a crank angle sensor, it detects (S2) the length of a period of time between the entry of the detection operation into a region of angle of rotation of crankshaft concerning a cylinder corresponding to the two pulses and the departure of the same operation from the same region. An angular acceleration Dωn of the crankshaft is calculated (S3, S4) by using a correction factor which is determined on the basis of this detected length of period of time and the length of period of time which is free from an error of operation of the sensor and determined by dividing the time required for one turn of the crankshaft by the number of the cylinders. When a calculated value Dωn is smaller than a judgement value, the occurrence of misfire is detected (S5-S7).
Inventors
- 👤 Takuya Mitsubishi Jidosha Kogyo K. K. Matsumoto
- 👤 Toru Mitsubishi Jidosha Kogyo K. K. Hashimoto
- 👤 Mitsuhiro Mitsubishi Jidosha Kogyo K. K. Miyake
- 👤 Yasuhisa Mitsubishi Jidosha Kogyo K. K. Yoshida
- 👤 Mitsuhiko Mitsubishi Jidosha Kogyo Kk Yanagisawa
- 👤 Hiroyuki Mitsubishi Jidosha Kogyo K. K. Nakajima
- 👤 Koichi Mitsubishi Jidosha Kogyo K. K. Namiki
- 👤 Satoshi Mitsubishi Jidosha Kogyo K. K. Kasai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:57
CPC Classifications
F; F02; F02D; F02D45/00; F02D41/00; F02D41/22; F02D41/02; F02D41/14; F02D41/1497; F02D41/1498; F02D41/222; G; G01; G01M; G01M15/00; G01M15/04; G01M15/11; F02D2200/00; F02D2200/02; F02D2200/10; F02D2200/1015; F02D2200/70; F02D2200/702; F02D41/0097
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
138 words
In a misfire detection method in which a time interval from a time point, detected by a crank angle sensor, of entering into a crankshaft rotation angle region corresponding to a particular stroke phase of each cylinder of an internal combustion engine to a time point, detected by the crank angle sensor, of leaving from the angle region is sequentially detected, and an occurrence of misfire is detected based on the time interval, a method for detecting misfire by fluctuation in crankshaft rotation comprising the steps of: calculating a correction factor for compensating an error in construction of the crank angle sensor; correcting rotation information of the internal combustion engine based on the detected time interval by using said correction factor; and detecting the occurrence of misfire based on said corrected rotation information of the internal combustion engine.
Claim 2
Dependent Claim
31 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein said rotation information of the internal combustion engine is an average angular acceleration of the crankshaft.
Claim 3
Dependent Claim
77 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 2 wherein said correction factor is repeatedly calculated based on the time interval detected sequentially during operation of the internal combustion engine to renew said correction factor, and an average angular velocity of the crankshaft is sequentially determined based on the time interval, and said average angular acceleration is sequentially calculated based on the time interval, said average angular velocity, and said correction factor.
Claim 4
Dependent Claim
71 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein said correction factor is repeatedly calculated based on the time interval sequentially detected during operation of the internal combustion engine to renew said correction factor, whereas the renewal of said correction factor is prohibited when the internal combustion engine is operated in a particular operating condition where a load of the internal combustion engine changes suddenly.
Claim 5
Dependent Claim
67 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 4 wherein at least one of conditions where the internal combustion engine is decelerated, where gear shift is performed by a transmission connected to the internal combustion engine, and where a vehicle on which the internal combustion engine is mounted is running on a rough road, is judged to be said particular operating condition.
Claim 6
Dependent Claim
67 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein said correction factor is repeatedly calculated based on the time interval sequentially detected during operation of the internal combustion engine to renew said correction factor, whereas the renewal of the correction factor is prohibited when a predetermined time does not elapse from a time point when the internal combustion engine is started.
Claim 7
Dependent Claim
80 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein a separate and independent correction factor is calculated for each of a plurality of operating regions classified by a predetermined operation parameter of the internal combustion engine, and the correction factor for a present operating region is renewed each time the present operating region is determined, whereas the renewal of the correction factor for an operating region other than said present operating region is prohibited.
Claim 8
Dependent Claim
28 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 7 wherein said predetermined operation parameter is a rotation speed of the internal combustion engine.
Claim 9
Dependent Claim
28 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 7 wherein said predetermined operation parameter is a volumetric efficiency of the internal combustion engine.
Claim 10
Dependent Claim
39 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 7 wherein said operating regions are classified by a rotation speed and a volumetric efficiency of the internal combustion engine which are said predetermined operation parameters.
Claim 11
Dependent Claim
75 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein said correction factor is repeatedly calculated based on the time interval sequentially detected during operation of the internal combustion engine to renew said correction factor, whereas a maximum or minimum value corresponding to a predetermined allowable range is used as said correction factor in place of said calculated correction factor when said calculated correction factor deviates from said allowable range.
Claim 12
Dependent Claim
38 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 11 wherein upper and lower limit values of said allowable range correspond to a maximum allowable error in the construction of the crank angle sensor.
Claim 13
Dependent Claim
51 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1 wherein said calculated correction factor is stored in a nonvolatile memory, and said correction factor read from said nonvolatile memory is used as an initial value of said correction factor when the internal combustion engine is started.
Claim 14
Dependent Claim
197 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 1, further including the steps of: using the crank angle sensor comprising a rotating body which rotates together with the crankshaft, a plurality of discriminating means which are installed at intervals in a circumferential direction on said rotating body to discriminate between the entering time point and the leaving time point, and a detecting portion which is disposed on a fixed member of the internal combustion engine and which is operable to generate a detection signal each time each of said discriminating means approaches said detecting portion, said discriminating means including first and second discriminating means for each cylinder; detecting the time interval by counting a interval between a first detection signal generated by the approach of the first discriminating means to said detecting portion and a second detection signal generated by the approach of the second discriminating means to said detecting portion; and determining said correction factor based on the time interval and a rotation period of the crankshaft including at least one of time points of occurrences of said first and second detection signals used for the detection of the time interval.
Claim 15
Dependent Claim
81 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 14 wherein said method is applied to a multi-cylinder internal combustion engine in which a plurality of cylinders are subjected to explosion strokes sequentially at equal intervals during the rotation of the crankshaft, and uses the crank angle sensor which is designed so that the second discriminating means for each cylinder functions as said first discriminating means for the next cylinder which is succeedingly subjected to explosion stroke.
Claim 16
Dependent Claim
60 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 14 wherein a momentary correction factor information determined sequentially based on the detected time interval and the rotation period of the crankshaft during operation of the internal combustion engine is smoothed, and the rotation information of the internal combustion engine is corrected by using the smoothed value.
Claim 17
Dependent Claim
117 words
A method for detecting misfire by fluctuation in crankshaft rotation according to claim 14 wherein said correction factor is repeatedly calculated based on the time interval detected sequentially during operation of the internal combustion engine to renew said correction factor, and a latest correction factor KLm(n) is calculated by using equations KLm(n) = a · KLm(n-1) + (1-a) · KLm and KLm = {A · Tm(n)} / T(n) where Tm(n) is said latest detected time interval, A is an installed number of the discriminating means installed on said rotating body, T(n) is a latest rotation period of the crankshaft, KLm(n-1) is a previously calculated correction factor, and a (0 ≦ a ≦ 1) is a weighting factor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.