Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – With indicator or control of power plant
Reexamination Certificate
2002-11-06
2004-06-01
Vo, Hieu T. (Department: 3747)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
With indicator or control of power plant
C073S116070, C123S406620
Reexamination Certificate
active
06745121
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cylinder identification apparatus for an internal combustion engine installed on a vehicle such as a motor vehicle, and more particularly to such a cylinder identification apparatus as can be applied to an internal combustion engine that is controlled at variable valve timing.
2. Description of the Related Art
FIG. 16
is a block diagram that shows the configuration of this kind of conventional cylinder identification apparatus for an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 8-277744 for instance.
FIG. 17
is a view that shows the configuration of each signal detector in FIG.
16
.
FIG. 18
is a waveform diagram that shows one example of each of a first signal sequence and a second signal sequence in FIG.
16
.
In these figures, a camshaft
1
with a speed reduction ratio of ½ with respect to a crankshaft
11
of the internal combustion engine is driven to rotate by and in synchronization with the crankshaft
11
through a belt drive mechanism or the like. A first signal detector
81
for generating a first signal sequence POSR related to the rotation of the crankshaft
11
includes a rotating disk
12
integrally mounted on the crankshaft
11
, a multitude of projections or teeth
81
a
formed at a first prescribed angular interval (e.g., crank angle of 1°-10°) along the outer periphery of the rotating disk
12
, and a sensor
81
b
of the magnetic pickup type, the Hall effect type, the magneto-resistance type, etc., arranged in the vicinity of the outer periphery of the rotating disk
12
for sensing each projection
81
a
when its sensing portion comes to face therewith.
The first signal sequence POSR includes a crank angle signal generated at each first prescribed angle or angular interval in synchronization with the rotation of the crankshaft
11
, and a reference position signal generated at each second prescribed angle or angular interval (e.g., crank angle of 360°) and corresponding to a reference position of a specific group of cylinders (in this case, cylinder #1 and cylinder #4 to be concurrently controlled) of the internal combustion engine.
The projections
81
a
corresponding to the respective pulses of the crank angle signal in the first signal sequence POSR includes an untoothed or lost teeth portion
80
(see
FIG. 17
) in the form of an angular range (i.e., a range where there exists no projection
81
a
) in which no crank angle signal is continuously generated over a crank angle of ten degrees to several tens degrees. An end position of the untoothed portion
80
(i.e., the position at which the next angle signal begins to be generated) corresponds to the reference positions &thgr;R of the specific cylinder group. The untoothed portion
80
is arranged at one location (i.e., every crank angle of 360°) on the rotating disk
12
formed integral with the crankshaft
11
.
A second signal detector
82
for generating a second signal sequence SGC related to the rotation of the camshaft
1
includes a rotating disk
2
integrally mounted on the camshaft
1
, projections
82
a
formed on and along the outer periphery of the rotating disk
2
at locations corresponding to the respective cylinders (in this case, four cylinders), and a sensor
82
b
in the form of an electromagnetic pickup arranged in the vicinity of the outer periphery of the rotating disk
2
for sensing each projection
82
a
when its sensing portion comes to face therewith.
In this case, the second signal sequence SGC consists of a train of pulses of a cylinder identification signal corresponding to the respective cylinders. The pulse width PW1 of a pulse of the cylinder identification signal corresponding to a specific cylinder (cylinder #1) differs from and is longer than the pulse widths PW2-PW4 of pulses corresponding to other cylinders. The first and second signal sequences POSR and SGC are input to a microcomputer
100
through an interface circuit
90
.
The microcomputer
100
constitutes a control means for controlling parameters of the internal combustion engine. The microcomputer
100
includes a reference position signal detection means
101
for detecting a reference position signal related to the specific cylinder group from the first signal sequence POSR, a reference position detection means
101
A for detecting the reference position of each cylinder based on the angle signal in the first signal sequence POSR and the reference position signal, a cylinder group identification means
102
for identifying cylinder groups based on the reference position signal, a cylinder identification means
103
for identifying each cylinder based on the ratio of generation times or durations of successive signal pulses in the second signal sequence SGC (cylinder identification signal), a control timing calculation means
104
for counting the number of angle signal pulses included in the first signal sequence POSR and calculating the control timing of control parameters P (ignition timing, etc.), and an abnormality determination means
105
for determining whether there is abnormality (or failure) in one of signal sequences POSR and SGC and outputting an abnormality determination signal E to the cylinder identification means
103
and the timing calculation means
104
when it is determined that one of the signal sequences POSR and SGC is abnormal.
Here, note that the cylinder identification means
103
identifies each cylinder based at least on the second signal sequence SGC, and the control timing calculation means
104
calculates the control timing of the control parameters P based at least on the cylinder identification result of the cylinder identification means
103
and the second signal sequence SGC.
For instance, when the first and second sequences POSR and SGC are normal, the cylinder identification means
103
measures the generation duration or range of each cylinder identification signal included in the second signal sequence SGC by counting pulses of the angle signal included in the first signal sequence POSR, so that it identifies each cylinder based on the measurement result, as will be described later. On the other hand, upon occurrence of abnormality (e.g., when there is obtained no first signal sequence POSR), the cylinder identification means
103
identifies each cylinder based on the calculation of the ratio of generation times or durations of successive pulses of the cylinder identification signal (e.g., duty ratio of adjacent or successive high (H) level and low (L) level ranges) by using only the second signal sequence SGC in response to an abnormality determination signal E, thus making it possible to perform backup control.
Similarly, when the first and second sequences POSR and SGC are normal, the control timing calculation means
104
calculates the control timing of the parameters P by using the reference position signal included in the first signal sequence POSR and the cylinder identification signal included in the second signal sequence SGC, and by counting the crank angle signal. In addition, upon occurrence of abnormality (e.g., when there is obtained no first signal sequence POSR), the control timing calculation means
104
performs the backup control by using only the second signal sequence SGC in response to an abnormality determination signal E. Moreover, when the second signal sequence SGC is not obtained, the control timing calculation means
104
performs the backup control through simultaneous ignition of each cylinder group or the like by using only the cylinder identification result of the cylinder group identification means
102
based on the first signal sequence POSR.
Incidentally, note that at normal time, the control timing calculation means
104
determines the control parameters P such as the ignition timing, the amount of fuel to be injected, etc., through calculations using a map for example, based on engine operating condition signals D from various sensors (not shown), and supplies them to the r
Kanazawa Eiji
Makino Tomokazu
Watanuki Takuo
Yonezawa Shiro
Mitsubishi Denki & Kabushiki Kaisha
Vo Hieu T.
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