Internal-combustion engines – Poppet valve operating mechanism – With means for varying timing
Reexamination Certificate
1999-11-15
2001-04-10
Lo, Weilun (Department: 3748)
Internal-combustion engines
Poppet valve operating mechanism
With means for varying timing
C123S090170
Reexamination Certificate
active
06213067
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control device for an internal combustion engine which controls a fuel, ignition, valve timing of at least one of an intake valve and an exhaust valve, and so on.
2. Discussion of Background
A conventional technique is disclosed in, for example, JP-A-7-180565. It discloses a means for detecting a cam angle with respect to a crank angle to identify cylinders based on a signal of the cam angle and to detect the cam angle, i.e. valve timing.
FIG. 5
illustrates a structure of a device according to the conventional technique.
Numerical reference
1
designates an internal combustion engine. Numerical reference
2
designates an air cleaner for purifying an air taken in by the internal combustion engine
1
. Numerical reference
3
designates an air flow sensor, which measures the amount of the air taken in by the internal combustion engine
1
. Numerical reference
4
designates a throttle valve, which adjusts the amount of the air taken in and controls an output of the internal combustion engine
1
. Numerical reference
5
designates a throttle sensor, which detects an opening degree of the throttle valve. Numerical reference
6
designates an intake pipe. Numerical reference
7
designates an injector for supplying a fuel in conformity with the amount of the taken air. Numerical reference
8
designates an ignition plug for generating a spark, which burns a mixed air in a combustion chamber of the internal combustion engine
1
. Numerical reference
9
designates an exhaust pipe, which exhausts a burned exhaust gas. Numerical reference
10
designates an O
2
sensor, which detects the amount-of remaining oxygen in the exhaust gas. Numerical reference
11
designates a catalytic converter rhodium (CCRO), which can simultaneously purify THC, CO, and No
x
, being a noxious gas in the exhaust gas.
Numerical reference
12
designates a sensor plate for detecting the crank angle, which is attached to a crank shaft and is integrally rotated along with the crank shaft. Numerical reference
13
designates a crank angle sensor for detecting a position of the crank shaft, which crank angle sensor generates a signal when a protrusion (not shown) of the sensor plate
12
passes through the crank angle sensor
13
to detect the crank angle. Numerical reference
14
designates a sensor plate for detecting the cam angle; and numerical reference
15
designates a cam angle sensor, which generates a signal when a protrusion (not shown) of the sensor plate
14
passes through the cam angle sensor
15
to detect the cam angle in a similar manner to that in the crank angle sensor. Numerical reference
16
designates an oil control valve for controlling a phase of a cam shaft with respect to the crank shaft by switching an oil pressure to an actuator for varying a cam phase (not shown), which oil control valve is attached to the cam shaft. Numerical reference
17
designates an engine control unit (hereinbelow, referred to as ECU), which controls the phase of the cam shaft with respect to the crank shaft and also controls the fuel and the ignition of the internal combustion engine
1
. Numerical reference
18
designates an ignition coil.
An operation of the conventional device will be described with reference to FIG.
6
.
An output from the crank angle sensor
13
is formed such that a raise and drop occur at a predetermined position of the crank angle to enable detection of the crank angle. The cam angle sensor
15
is provided such that a signal is generated at a predetermined crank angle. However, the cam angle sensor
15
does not generate a signal to identify a particular cylinder, whereby the fuel, the ignition, and so on are subjected to a sequential control based on information of the above signal.
In
FIG. 6
, numerical reference
100
designates a difference between a raise of a signal from the crank angle sensor and a drop of a signal from the cam angle sensor. By this difference, an angle of cam shaft, i.e. valve timing, with respect to the crank shaft is detected. The ECU
17
operates a target valve timing in response to a current running condition based on various sensor outputs, and conducts a feedback control based on a deflection between the target valve timing and the detected actual valve timing in order to control the oil control valve
16
so that the actual valve timing conforms to the target valve timing.
However, the conventional device has problems that valve timing is not controlled and cylinders are not identified in case that a cam angle sensor, by an output from which the cylinders are identified and variable valve timing is controlled, is troubled, whereby a sequential control of a fuel and ignition is impossible and the fuel and the ignition are not controlled in conformity with a running condition of the engine.
Further, in the conventional device, there are problems that actual valve timing is not detected for a predetermined cylinder and a performance of controlling valve timing is not improved because an output from the cam angle sensor is not generated for the predetermined cylinder.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above-mentioned problems inherent in the conventional technique and to provide a control device for an internal combustion engine which continues to control the engine even when a cam angle sensor is troubled.
Further, another object of the present invention is to improve an accuracy of controlling valve timing by detecting actual valve timing for each cylinder.
Further, another object of the present invention is to reduce the number of components by giving a function of a means for generating a signal of identifying a cylinder to a means for detecting the crank angle and to enable to accurately detect valve timing.
Further, another object of the present invention is to improve a capability of preventing the engine from stopping by reducing an overlap of valve timing when a cam angle sensor is troubled.
Further, another object of the present invention is to improve a control of valve timing by generating a cam angle signal on a descending side of a cam.
According to a first aspect of the present invention, there is provided a control device for an internal combustion engine comprising: a means for detecting a crank angle, which detects an crank angle of the internal combustion engine; a means for detecting a cam angle, which is provided in a cam shaft variable with respect to a crank shaft; a means for generating a cylinder identifying signal of the internal combustion engine, which is provided separately from the means for detecting the cam angle; a means for changing valve timing, which changes a cam angle with respect to the crank angle; a means for controlling valve timing, which controls the means for changing the valve timing; and a means for controlling the internal combustion engine.
According to a second aspect of the present invention, the means for detecting the cam angle generates a detection signal of the cam angle for each cylinder of the combustion engine.
According to a third aspect of the present invention, the means for generating the cylinder identifying signal generates a signal for a predetermined cylinder different from those in the other cylinders and is included in the means for detecting crank angle provided for the cam shaft connected to the crank shaft.
According to a fourth aspect of the present invention, a means for detecting trouble is further equipped to detect a trouble in the means for detecting the cam angle, which means reduces an overlap of valve timing when it is troubled.
According to a fifth aspect of the present invention, the means for detecting the cam angle generates a signal on a descending side of the cam.
REFERENCES:
patent: 5462022 (1995-10-01), Ushida
patent: 6006707 (1999-12-01), Ito
patent: 6041647 (1999-03-01), Matsuoka
patent: 7-180565 (1995-07-01), None
Hashimoto Atsuko
Kawakami Takeshi
Ohuchi Hirofumi
Takahashi Tatsuhiko
Lo Weilun
Mitsubishi Denki & Kabushiki Kaisha
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Control device for 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 Control device for internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control device for internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2457553