JP3634137B2 - Cylinder discrimination method and apparatus for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder discriminating method and a cylinder discriminating apparatus for an internal combustion engine that discriminate cylinders of an internal combustion engine.
[0002]
[Prior art]
An internal combustion engine used in an automobile or the like converts a piston's reciprocating motion into a rotational motion and extracts it by connecting the piston of each cylinder to a crankshaft.
Here, when a four-cycle internal combustion engine in which a four-stroke cycle of intake, compression, expansion, and exhaust is performed by two rotations of the crankshaft is connected to a multi-cylinder, which cylinder only needs to be detected by detecting the rotation angle of the crankshaft. Is in the ignition timing, fuel injection timing, exhaust position, etc., that is, cylinder discrimination cannot be performed accurately.
For this reason, normally, the rotation angle of the camshaft and the rotation angle of the crankshaft, which are connected to the crankshaft via connecting means such as a timing belt and have a cam for opening and closing the intake and exhaust valves, are detected. Cylinder discrimination is performed based on the rotation angle.
[0003]
Conventionally, a cylinder discrimination device for an internal combustion engine as described in JP-A-5-133268 is known. However, this cylinder discrimination device of the internal combustion engine has a problem that the start timing of ignition control, fuel injection control, etc. at the time of engine start is delayed because the cylinder cannot be discriminated unless the crankshaft rotates 360 degrees. .
Accordingly, a cylinder discrimination device for an internal combustion engine has been developed that can perform cylinder discrimination before the crankshaft rotates 360 degrees, as described in Japanese Patent Application Laid-Open No. 7-4300. 4a and 4b show a cam angle detection rotor and a crank angle detection rotor used in the cylinder discrimination device of the internal combustion engine.
The cam angle detecting rotor 100 connected to the camshaft is made of a ferromagnetic material, and is provided with a large-diameter portion 101 extending 180 degrees and a small-diameter portion 102 extending 180 degrees. Further, a recess 103 having the same diameter as that of the small-diameter portion 102 is provided 90 to 100 degrees from the rotation direction start end of the large-diameter portion 101, and the large-diameter portion 101 is 80 to 90 degrees from the rotation direction start end of the small-diameter portion 102. The convex part 104 of the same diameter is provided. A cam angle sensor 110 such as a magnetic sensor using a hall element or a magnetoresistive element is disposed facing the outer periphery of the cam angle detection rotor 100. The cam angle sensor 110 is disposed, for example, at a position 5 degrees from the rotation direction start end of the small diameter portion 102 in a state where the crankshaft is at the compression top dead center (TDC) position of the fourth cylinder.
On the other hand, the crank angle detection rotor 120 connected to the crankshaft is made of a ferromagnetic material, provided with teeth 121 at intervals of 10 degrees, and missing teeth with two consecutive teeth missing. A portion 123 is provided. A crank angle sensor 130 such as a magnetic sensor using a Hall element or a magnetoresistive element is disposed opposite to the outer periphery of the crank angle detection rotor 120. The crank angle sensor 130 is disposed at the rotational end position of the missing tooth portion 123 in a state where, for example, the crankshaft is at the compression top dead center position of the fourth cylinder.
For example, the cam angle signal output from the cam angle sensor 110 and the crank angle signal output from the crank angle sensor 130 are narrowly spaced from the outer periphery of the cam angle detection rotor 100 and the crank angle detection rotor 120. Hi at times, Lo at wide.
In addition, cylinder discrimination means for performing cylinder discrimination based on the cam angle signal from the cam angle sensor 110 and the crank angle signal from the crank angle sensor 130 is provided.
[0004]
This conventional cylinder discrimination device for an internal combustion engine performs cylinder discrimination as shown in FIG. 5 based on the cam angle signal and the crank angle signal.
First, the time interval from the rise of the crank angle signal to the next rise, that is, the pulse interval T (n) is measured.
Then, it is determined whether or not the current pulse interval T (n) is larger than the previous pulse interval T (n−1). It is recognized that the position is 0 degree or 360 degrees. Next, it is determined whether the cam angle signal is Hi or Lo. If it is Hi, it is the compression top dead center position of the first cylinder, and if it is Lo, it is the compression top dead center position of the fourth cylinder. recognize.
On the other hand, when the current pulse interval T (n) is not larger than the previous pulse interval T (n−1), that is, when the tooth 121 is in position, the crankshaft is at a crank angle of 180 ° or 540 °. Detect a condition. For example, the time point when the cam angle signal changes from Hi → Lo → Hi or Lo → Hi → Lo while counting two pulses of the crank angle signal is detected. At that time, if the cam angle signal is Hi, it is recognized as the compression top dead center position of the third cylinder, and if it is Lo, it is recognized as the compression top dead center position of the second cylinder. Further, the engine speed is detected based on the pulse interval T (n) at this time.
[0005]
[Problems to be solved by the invention]
In a conventional internal combustion engine cylinder discriminating device, the fact that the crankshaft is at a 0 or 360 degree crank angle is recognized by the detection of the missing tooth portion 123 of the crank angle detecting rotor and the level of the cam angle signal. can do. However, if the crankshaft is at a position of 180 degrees or 540 degrees in crank angle, the cam angle signal changes from Hi → Lo → Hi or Lo → Hi → Lo while counting two pulses of the crank angle signal. Need to be detected. For this reason, complicated processing is required, and the burden of the cylinder discrimination device is large.
The present invention was devised to solve such problems, and provides a cylinder discrimination method and a cylinder discrimination device for an internal combustion engine that can perform cylinder discrimination at an early stage with simple processing. Let it be an issue.
[0006]
[Means for Solving the Problems]
The above-described problems are solved by the inventions of the claims.
The invention according to claim 1 is a cylinder discrimination method for an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft, wherein the reference angle extends over the entire circumference of the peripheral portion. The crankshaft is mounted on the crankshaft with a crank angle detecting rotor provided with a large number of teeth provided every time and a portion where the teeth are missing, and a missing tooth portion provided every predetermined angle. by detecting the toothless portion of the crank angle detecting rotor by angular sensor, a step of determining a crank angle information indicating whether the crankshaft is positioned at any of a plurality of predetermined angular positions, provided over substantially 180 ° With the cam angle detection rotor having a large diameter portion and a small diameter portion mounted on the cam shaft, the cam angle detection rotor is By detecting part or the small diameter portion, a step of determining a cam angle information indicating whether the camshaft is positioned at any of the section over 180 °, the cylinder discrimination based on said crank angle information and the cam angle information And performing the process .
If this cylinder discrimination method for an internal combustion engine is used, cylinder discrimination can be performed early with simple processing.
According to the second aspect of the present invention, in the step of obtaining the crank angle information, the crank angle sensor that detects the teeth of the crank angle detecting rotor is from the timing at which an arbitrary tooth is detected to the timing at which the next tooth is detected. The time interval is memorized, and if the time interval measured this time is twice or more than the time interval measured last time, it is determined as a missing tooth portion.
The invention of claim 3 is a cylinder discrimination device for an internal combustion engine having a crankshaft connected to the piston of each cylinder and a camshaft connected to the crankshaft, and is mounted on the crankshaft, A crank angle detecting rotor comprising a large number of teeth provided for every reference angle over the entire circumference of the part, and a missing tooth part that is a part where the teeth are missing and is provided for each predetermined angle; by detecting the toothless portion of the crank angle detecting rotor, a crank angle information output means for outputting a crank angle information indicating whether the crankshaft is positioned at any of a plurality of predetermined angular positions, said cam shaft It is attached, and the cam angle detecting rotor and a large diameter portion and a small diameter portion provided over approximately 180 °, the large diameter portion or the small diameter portion of the cam angle detecting rotor By leaving a cam angle information output means for outputting the cam angle information indicating whether the camshaft is positioned at any of the section over 180 °, the cylinder discrimination based on said crank angle information and the cam angle information And a cylinder discriminating means for performing .
If the cylinder discrimination device for an internal combustion engine according to claim 3 is used, the configuration is simple.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1a shows a cam angle detecting rotor used in an embodiment of the present invention, and FIG. 1b shows a crank angle detecting rotor. The present embodiment is applied to an 8-cylinder engine.
The cam angle detection rotor 10 is made of a ferromagnetic material, and has a large diameter portion 11 that forms cam angle information indicating in which of the 180 degree sections the cam angle detection rotor 10 is located. The small diameter portion 12 is provided over almost 180 degrees. A cam angle sensor 20 such as a magnetic sensor using a hall element or a magnetoresistive element that detects the large diameter portion 11 and the small diameter portion 12 is disposed opposite to the outer periphery of the cam angle detection rotor 10. ing.
The crank angle detection rotor 30 is made of a ferromagnetic material, and is provided with teeth 31 every 10 degrees in the reference angle, FIG. 1b. Further, the crank angle detecting rotor 30 is provided with a member for forming crank angle information indicating which of the plurality of predetermined rotation angle positions the crank angle detecting rotor 30 is located. In the figure, a 20-degree missing tooth portion 33 in which one tooth is missing to show a rotation angle position of 0 degree, and two teeth are missing to show a rotation angle position of 90 degrees in the figure. The tooth part 34 of the degree, three teeth are shown to show the rotational angle position of 180 degrees, and the tooth part 35 of 40 degrees is scraped off and four teeth are shown to show the rotational angle position of 270 degrees. A missing tooth portion 36 of 50 degrees is provided. A crank angle sensor 40 such as a magnetic sensor using a hall element or a magnetoresistive element that detects the teeth 31 and the missing tooth portions 33 to 36 is disposed opposite to the outer periphery of the crank angle detection rotor 30. Has been.
The output signals of the cam angle sensor 20 and the crank angle sensor 40 are Hi when the distance from the cam angle detecting rotor 10 and the crank angle detecting rotor 30 is small, and Lo when the distance is large.
The cam angle detection rotor 10 and the cam angle sensor 20 constitute the cam angle information output means of the present invention. The crank angle detection rotor 30 and the crank angle sensor 40 constitute the crank angle information of the present invention. Output means is configured.
[0008]
Next, FIG. 2 shows the configuration of an embodiment of the cylinder discrimination device for an internal combustion engine of the present invention. The cylinder discrimination device includes a cam angle detection rotor (not shown), a cam angle sensor 20, a crank angle detection rotor (not shown), a crank angle sensor 40, a cylinder discrimination means 50, and the like. ing.
The cylinder discriminating means 50 has a central arithmetic processing circuit (MPU) 51, a clock generator 52 for supplying a master clock to the central arithmetic processing circuit 51 and the like, and a crank angle signal output from the crank angle sensor 40 as a pulse signal. A pulse discriminating circuit 53, a cam angle signal from the cam angle sensor 20, an input port 54 for inputting a crank angle signal from the crank angle sensor 40 whose waveform is shaped by the pulse discriminating circuit 53, a processing program and the like stored therein. -A memory (ROM) 55, a random access memory (RAM) 55 used as a work area, and a bus line 57 for connecting them. The pulse discrimination circuit may be built in the sensor.
[0009]
The cylinder discrimination process by the cylinder discrimination means 50 will be described with reference to the time chart shown in FIG. The crank angle signal in FIG. 3 is Lo when the crank angle sensor 40 detects the teeth 31 and Hi when the missing tooth portions 33 to 36 are detected. First, the cylinder discriminating means 50 measures the time interval T (n) of each cycle of the crank angle signal output from the crank angle sensor 40. The time interval T (n) of each cycle includes, for example, a time interval (Hi time interval) TH (n) from the rise to the fall of the crank angle signal and a time interval (Lo time interval) TL ( n) is measured and measured by T (n) = TH (n) + TL (n). In the present embodiment, when the time interval corresponding to the reference angle portion where the teeth 31 are provided is t0, the time intervals t1 to t4 corresponding to the missing tooth portions 33, 34, 35, and 36 are t1 = 2t0. T2 = 3t0, t3 = 4t0, and t4 = 5t0.
[0010]
Next, the rotational angle position of the crank angle detection rotor 30 is recognized based on the measured time interval T (n) and the previous time interval T (n−1). For example, a time interval ratio [T (n) / T (n-1)] is obtained, and when the obtained ratio is approximately 1, it is recognized that the rotation angle position is other than 0 degrees, 90 degrees, 180 degrees, and 270 degrees. When the ratio is approximately 2, the tooth missing part 33 is recognized as being at a rotation angle position of 0 degrees, and when the ratio is approximately 3, the tooth missing part 34 is recognized as being at a rotation angle position of 90 degrees, When the ratio is approximately 4, it is recognized that the tooth missing portion 35 is located at a rotation angle position of 180 degrees, and when the ratio is approximately 5, it is recognized that the tooth missing portion 36 is located at a rotation angle position of 270 degrees.
Since the 4-cycle internal combustion engine executes each stroke by two rotations of the crankshaft, it is not possible to accurately determine the cylinder only by recognizing the rotation angle position of the crankshaft.
Therefore, based on the recognized rotational angle position of the crankshaft and the cam angle information included in the cam angle signal output from the cam angle sensor 20, in this case, the cylinder based on the Hi or Lo state of the cam angle signal. Make a decision.
[0011]
When the time interval ratio is approximately 1, the crank angle detection rotor 30 is in a rotational angle position other than 0 degrees, 90 degrees, 180 degrees, and 270 degrees, so that cylinder discrimination cannot be performed. However, at this time, the crank angle detection rotor 30 has rotated at a reference angle, which is 10 degrees in the figure, and therefore the engine speed is determined based on the determined time interval T (n). The engine speed can be determined by, for example, 60 / [36 × T (n)].
On the other hand, when the time interval ratio is not approximately 1, the crank angle detection rotor 30 is at any rotation angle position of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, so the cam angle signal is Hi. Cylinder discrimination is performed by determining whether it is Lo.
When the time interval ratio is approximately 2 and the cam angle signal is Lo, the crank angle detection rotor 30 is located at a crank angle of 0 degrees, that is, the compression top dead center of the first cylinder and the exhaust of the sixth cylinder. Recognize at the top dead center position.
When the time interval ratio is approximately 2 and the cam angle signal is Hi, the crankshaft is at a 360 ° crank angle, that is, the compression top dead center of the sixth cylinder and the exhaust top dead center of the first cylinder. Recognize that there is.
When the time interval ratio is approximately 3 and the cam angle signal is Lo, the crankshaft is at the 90 ° crank angle, that is, the compression top dead center of the eighth cylinder and the exhaust top dead center of the fifth cylinder. Recognize that there is.
When the time interval ratio is approximately 3 and the cam angle signal is Hi, the crankshaft is at a 450 degree crank angle, that is, the compression top dead center of the fifth cylinder and the exhaust top dead center of the eighth cylinder. Recognize that there is.
When the time interval ratio is approximately 4 and the cam angle signal is Lo, the crankshaft is at a 180 degree crank angle, that is, the compression top dead center of the fourth cylinder and the exhaust top dead center of the seventh cylinder. Recognize that there is.
When the time interval ratio is approximately 4 and the cam angle signal is Hi, the crankshaft is at a position where the crank angle is 540 degrees, that is, the compression top dead center of the seventh cylinder and the exhaust top dead center of the fourth cylinder. Recognize that there is.
When the time interval ratio is approximately 5 and the cam angle signal is Hi, the crankshaft is at the 270 degree crank angle, that is, the compression top dead center of the third cylinder and the exhaust top dead center of the second cylinder. Recognize that there is.
When the time interval ratio is approximately 5 and the cam angle signal is Lo, the crankshaft is at a crank angle of 630 degrees, that is, the compression top dead center of the second cylinder and the exhaust top dead center of the third cylinder. Recognize that there is.
As described above, in the present embodiment, the missing tooth portions 33 to 36 provided in the crank angle detection rotor and the large diameter portion and the small diameter portion provided in the cam angle detection rotor may be detected. Cylinder discrimination can be performed early by simple processing.
[0012]
Although the case where the present invention is applied to an 8-cylinder engine has been described in the above embodiment, the present invention can be applied to engines having various numbers of cylinders such as a 4-cylinder engine and a 6-cylinder engine.
Further, although the reference angle is 10 degrees, the reference angle is not limited to 10 degrees and can be variously changed.
Further, the angle of the missing tooth portion is set to an integral multiple of the reference angle, but the angle of the missing tooth portion is not limited to this, and can be distinguished from the portion where the teeth are provided, and the crankshaft is predetermined. What is necessary is just to be able to detect that it exists in a rotation angle position.
Further, the number and arrangement positions of the missing teeth can be appropriately changed according to the number of cylinders and the like.
In addition, although the member that forms the crank angle information is configured by the missing tooth portion, the configuration of the member that forms the crank angle information is not limited to the missing tooth portion, and the crankshaft is at a plurality of predetermined rotation angle positions. It only has to be detected.
In addition, the member that forms the cam angle information is configured by the large diameter portion and the small diameter portion provided in the cam angle detection rotor, but the member that forms the cam angle information is not limited to the large diameter portion and the small diameter portion. It suffices if the camshaft can be detected in any of the sections over 180 degrees.
Further, although the magnetic sensor is used as the cam angle sensor and the crank angle sensor, various sensors such as a reflection type or a transmission type optical sensor or a mechanical sensor can be used.
Further, the arrangement relationship of the cam angle detection rotor, the crank angle detection rotor, and the like is not limited to the arrangement relationship shown in FIG.
Further, the configuration of the cylinder discrimination device is not limited to the configuration shown in FIG.
[0013]
【The invention's effect】
As described above, by using the cylinder discrimination method for an internal combustion engine according to claim 1 and claim 2, cylinder discrimination can be performed early with simple processing.
If the cylinder discrimination device for an internal combustion engine according to claim 3 is used, the configuration is simple.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a cam angle detecting rotor and a crank angle detecting rotor used in an embodiment of the present invention.
FIG. 2 is a block diagram of an embodiment of a cylinder discrimination device for an internal combustion engine according to the present invention.
FIG. 3 is a timing chart showing a relationship between a cam angle signal and a crank angle signal and a cylinder discrimination position.
FIG. 4 is a configuration diagram of a conventional cam angle detection rotor and crank angle detection rotor.
FIG. 5 is a timing chart showing a relationship between a cam angle signal and a crank angle signal and a cylinder discrimination position in a conventional example.
[Explanation of symbols]
10, 100 Cam angle detection rotor 11, 101 Large diameter portion 12, 102 Small diameter portion 20, 110 Cam angle detection sensor 30, 120 Crank angle detection rotor 31, 121 Teeth 33, 34, 35, 36, 123 Missing portion 40, 130 Crank angle sensor 50 Cylinder discrimination means

Claims (3)

A cylinder discrimination method for an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft,
A crank angle detecting rotor comprising a large number of teeth provided at every reference angle over the entire circumference of the peripheral edge portion and a missing tooth portion provided at every predetermined angle, which is a portion lacking the teeth. while wearing the crankshaft, by detecting the toothless portion of the crank angle detecting rotor by the crank angle sensor, a crank angle information indicating whether the crankshaft is positioned at any of a plurality of predetermined angular positions The desired process;
With the cam angle detection rotor having a large diameter portion and a small diameter portion provided over approximately 180 ° mounted on the cam shaft, the cam angle sensor uses a large or small diameter portion of the cam angle detection rotor. by detecting the, a step of determining a cam angle information indicating whether the camshaft is positioned at any of the section over 180 °,
Performing cylinder discrimination based on the crank angle information and the cam angle information ;
A cylinder discrimination method for an internal combustion engine, comprising: A cylinder discrimination method for an internal combustion engine according to claim 1,
  In the process of obtaining the crank angle information, the crank angle sensor that detects the teeth of the rotor for detecting the crank angle stores the time interval between the timing of detecting an arbitrary tooth and the timing of detecting the next tooth. A cylinder discrimination method for an internal combustion engine, characterized in that if the time interval measured this time is twice or more than the measured time interval, it is determined as a missing tooth portion. A cylinder discrimination device for an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft,
A large number of teeth that are attached to the crankshaft and are provided at every reference angle over the entire circumference of the peripheral portion, and a missing tooth portion that is a portion where the teeth are missing and is provided at every predetermined angle A crank angle detection rotor comprising:
Crank angle information output means for outputting crank angle information indicating which of the plurality of predetermined angular positions the crankshaft is located by detecting a missing tooth portion of the crank angle detecting rotor ;
A cam angle detection rotor that is mounted on the camshaft and includes a large diameter portion and a small diameter portion that are provided over approximately 180 °;
Cam angle information output means for outputting cam angle information indicating in which section the camshaft is located over 180 ° by detecting a large diameter portion or a small diameter portion of the cam angle detection rotor ;
Cylinder discrimination means for performing cylinder discrimination based on the crank angle information and the cam angle information;
A cylinder discrimination device for an internal combustion engine characterized by comprising:

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