Measuring and testing – Engine detonation
Reexamination Certificate
1999-05-14
2001-09-18
McCall, Eric S. (Department: 2855)
Measuring and testing
Engine detonation
Reexamination Certificate
active
06289720
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a knocking control means for an internal combustion engine by combination of knocking detection means for detecting the knocking phenomenon generated in the internal combustion engine with knocking decision means for deciding the knocking on the basis of the detection results by use of the knocking decision means.
BACKGROUND OF THE INVENTION
Conventionally, vibrations caused by a knocking phenomenon generated in an internal combustion engine are detected as knocking detection signals by a knocking sensor,so that the knocking detection signals are allowed to pass through a filter circuit to remove noise components of low frequency and high frequency and only the knocking frequency component of specific frequency is allowed to pass, and thereafter, only the detected signal of a predetermined period is taken out to thereby compare a magnitude of wave form of the detected signal with a previously preset set value for decision, so as to decide whether the knocking exists or not, which is well-known as disclosed in, for example, the Japanese Patent Publication Gazette No. Hei 7-13507.
Conventionally, one vibration detector is used for detecting knocking vibrations from a plurality of cylinders, for example, three to four cylinders, and distances from respective cylinders to the vibration detector are different, so that even when the respective cylinders are equal in strength generated therein, the magnitudes of signal detected by the vibration detector are different from each other, whereby there has been the inconvenience that, regardless of generating the knocking, the signals detected by the vibration detector lead to decision of no knocking generation.
An extent of damage given to the engine, when the knocking is generated, changes according to the strength of knocking and frequency of knocking generation, whereby the ignition timing control, which is performed only by deciding the existence of knocking as conventional, is insufficient for the knocking avoid control, resulting in that the knocking cannot be avoided in spite of controlling.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a knocking detection method which makes equal the magnitude of detected signal of knocking vibration of the equal strength generated in a plurality of cylinders regardless of differences in distances and in loads between a knocking sensor and a cylinder corresponding thereto, thereby enabling performing an accurate knocking decision to be performed.
In a knocking control method for an internal combustion engine, which detects by at least one knocking sensor the vibrations caused by the knocking phenomenon generated in the internal combustion engine, the detected signals by each knocking sensor are allowed to pass through a plurality of sets of filter circuits of each one set of time gate which allows only vibrations generated for a specified time to pass and of filters which allow only vibrations of specified frequency to pass a knocking decision device calculates the detected signals obtained after passing through the plural sets of filter circuits so as to decide the knocking, and the control signals are outputted on the basis of the decision; the time gate of one set of the plural sets of filter circuits is used as a knocking part time gate set in a knocking generation time, the time gate of the other set is used as a combustion part time gate which has been set prior to the knocking generation time, the knocking part signal having passed through the knocking part time gate is allowed to pass through a knocking part filter which passes therethrough only the component of knocking frequency, in the other set of filter circuits, the combustion part signal having passed through the combustion part time gate passes through a combustion part filter which allows the component of excitation frequency in the cylinder, and are presentative value of knocking signals having passed through the knocking part time gate and knocking part filter is compared with that of combustion signal having passed through the combustion part time gate and combustion part filter so as to calculate a ratio of both the representative values to thereby use the calculated value for knocking decision.
A second object of the present invention is to provide a knocking decision method for an internal combustion engine, which enables the control signals outputted on the basis of knocking decision by the knocking decision device to correspond, in high precision, to the strength and frequency so as to accurately and efficiently avoid the knocking.
Hence, in the knocking control method which detects by a knocking sensor the knocking generated in the internal combustion engine and calculates the detected signals by the knocking decision device so as to decide the knocking and output the control signals on the basis of the decision, output voltage of control signal from the knocking device is changed correspondingly to the knocking strength, desirably, in proportion to n-th power of knocking strength. Also, the output voltage of control signals from the knocking decision device is changed correspondingly to the knocking strength and knocking generation frequency, for example, to a mean value of strength and generating frequency generated during the numbers of predetermined cycles, or a medium value of frequency in the frequency distribution obtained with respect to strength of knocking generated during the numbers of predetermined cycles, and desirably in proportion to m-th power of medium value of frequency in the frequency distribution, and further desirably to a value of n-th power of mean value of strength and that of m-th power of medium value of frequency in the frequency distribution.
A further object of the invention is to provide a knocking control method which applies the above-mentioned knocking detection method and knocking control method in order to simultaneously attain the first and second objects.
REFERENCES:
patent: 4528955 (1985-07-01), Sugiura
patent: 5230316 (1993-07-01), Ichihara et al.
patent: 5408863 (1995-04-01), Sawyers et al.
patent: 5522254 (1996-06-01), Kamabora et al.
patent: 5535722 (1996-07-01), Graessley et al.
patent: 5598822 (1997-02-01), Fujishita et al.
patent: 5979406 (1999-11-01), Aoki et al.
patent: 5996398 (1999-12-01), Schleupen et al.
patent: 6000276 (1999-12-01), Mogi et al.
patent: 56-66727 (1981-06-01), None
patent: 58-28646 (1983-02-01), None
patent: 60-95190 (1985-05-01), None
patent: 61-16267 (1986-01-01), None
patent: 3-202661 (1991-09-01), None
patent: 4-8628 (1992-02-01), None
patent: 6-66195 (1994-03-01), None
patent: 6-280728 (1994-10-01), None
patent: 7-27011 (1995-01-01), None
patent: 7-13507 (1995-02-01), None
Nakazono Tohru
Ohkubo Minoru
Jordan and Hamburg LLP
McCall Eric S.
Yanmar Diesel Engine Co. Ltd.
LandOfFree
Method of knocking control of internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of knocking control of internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of knocking control of internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2528908