JPH11229947A - Cylinder determination method and device thereof for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder determination method and its device capable of early determining cylinder for an internal combustion engine. SOLUTION: In a cam angle detection rotor 10, a large diameter part 11 and a small diameter part 12 are arranged at an interval of 180 degrees. In a crank angle detection rotor 30, a crest part 31 and a valley part 32 or a crest part 33 and a valley part 34 are arranged at predetermined angle intervals for forming crank angle information. In the outer circumferences of the cam angle detection rotor 10 and the crank angle detection rotor 30, a cam angle sensor 30 and a crank angle sensor 40 are arranged. A cylinder determining means determines a rotation angle of the crank shaft at predetermined angle intervals according to a crank angle information combination pattern contained in a crank angle signal outputted from the crank angle sensor 20 so as to perform cylinder determination on the basis of the determined crank shaft rotation angle and the cam information contained in a cam angle signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cylinder discriminating method and a cylinder discriminating apparatus for discriminating a cylinder of an internal combustion engine.

[0002]

2. Description of the Related Art Internal combustion engines used in automobiles and the like are:
By connecting the piston of each cylinder to the crankshaft, the reciprocating motion of the piston is converted into rotary motion and taken out. Here, when a four-cycle internal combustion engine in which four cycles of intake, compression, expansion, and exhaust are performed by two rotations of a crankshaft is connected to multiple cylinders, which cylinder is detected only by detecting the rotation angle of the crankshaft. Is at the ignition timing, the fuel injection timing, the exhaust position, etc., that is, the cylinder cannot be accurately determined. For this reason, the rotation angle of the camshaft and the rotation angle of the crankshaft, which are usually connected to the crankshaft via a connection means such as a timing belt and have a cam for opening and closing the intake / exhaust valve, are detected. Cylinder discrimination is performed based on the rotation angle of.

Conventionally, a cylinder discriminating device for an internal combustion engine as disclosed in Japanese Patent Application Laid-Open No. 7-4300 has been known. FIG. 16A shows a cam angle detecting rotor and a crank angle detecting rotor used in the cylinder discriminating device of the internal combustion engine.
And FIG. 16b. The cam angle detecting rotor 100 connected to the camshaft is formed of a ferromagnetic material, and has a large-diameter portion 101 extending over 180 degrees and a small-diameter portion 102 extending over 180 degrees. In addition, a concave portion 103 having the same diameter as the small diameter portion 102 is provided from 90 degrees to 100 degrees from the rotation direction start end of the large diameter portion 101, and the large diameter portion 101 is formed from 80 degrees to 90 degrees from the rotation direction start end of the small diameter portion 102. Is provided with a convex portion 104 having the same diameter. This cam angle detection row
A cam angle sensor 110 such as a magnetic sensor using a ball element or a magneto-resistive element is provided facing the outer periphery of the motor 100. The cam angle sensor 110 is disposed 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, for example. On the other hand, the crank angle detecting rotor 120 connected to the crankshaft is formed of a ferromagnetic material,
The teeth 121 are provided at intervals of 0 degrees, and a missing tooth portion 123 in which two consecutive teeth are missing is provided. A crank angle sensor 130 such as a magnetic sensor using a Hall element or a magnetoresistive element is provided to face the outer periphery of the crank angle detecting rotor 120. The crank angle sensor 130 is disposed at the rotation direction end position of the toothless portion 123 in a state where the crankshaft is located at the compression top dead center 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, for example, the cam angle detection rotor 10.
0, Hi when the distance from the outer periphery of the rotor 120 for detecting the crank angle is small, and Lo when it is wide. Further, a cylinder discriminating 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.

This conventional cylinder discriminating apparatus for an internal combustion engine performs cylinder discrimination based on a cam angle signal and a crank angle signal as shown in FIG. First, the time interval from the rise of the crank angle signal to the next rise, that is, the pulse interval T
Measure (n). And the current pulse interval T (n)
Is larger than the previous pulse interval T (n-1), and when it is larger, that is, at the position of the toothless portion 123, the crankshaft is at the position of 0 or 360 degrees in crank angle. Recognize. Next, it is determined whether the cam angle signal is Hi or Lo. If Hi, it is the compression top dead center position of the first cylinder, and if Lo, it is the compression top dead center position of the fourth cylinder. recognize. On the other hand, the current pulse interval T
When (n) is not greater than the previous pulse interval T (n-1), that is, when it is at the position of the tooth 121, the state where the crankshaft is at a position of 180 degrees or 540 degrees in crank angle is detected. For example, a point in time when the cam angle signal changes from Hi to Lo to Hi or Lo to Hi to Lo while counting two pulses of the crank angle signal is detected. If the cam angle signal is Hi at this time, it is recognized as the compression top dead center position of the third cylinder, and if 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]

In the conventional cylinder discriminating apparatus for an internal combustion engine, cylinder discrimination cannot be performed unless at least the cam angle detecting rotor 100 rotates 90 degrees, that is, the crankshaft rotates 180 degrees. Also, when the camshaft is connected to the crankshaft by the timing belt, the timing belt may be stretched during acceleration of the engine, etc., and the relative position between the crankshaft and the camshaft may be deviated and the cylinder determination may be erroneously determined. there's a possibility that. In particular, when a variable valve timing mechanism is employed, the deviation is further increased. Even when the cylinder discrimination is erroneously determined due to such a difference in the relative position between the crankshaft and the camshaft, the next cylinder discrimination cannot be performed unless the crankshaft rotates at least 180 degrees. As described above, the conventional cylinder discriminating apparatus for an internal combustion engine cannot perform cylinder discrimination unless the crankshaft rotates 180 degrees, and the start timing of ignition control, fuel injection control, and the like at the time of engine start is delayed. There was a point. The present invention has been made in order to solve such a problem, and can perform cylinder discrimination at an early stage, and can advance the start timing of ignition control and fuel injection control at the time of engine start. It is an object to provide a cylinder discriminating method and a cylinder discriminating device for an internal combustion engine.

[0006]

According to one aspect of the present invention, there is provided an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft. A cylinder discriminating method for an engine, wherein cylinder discrimination is performed based on crank angle information indicating each of the predetermined angles of the crankshaft and cam angle information indicating in which section the camshaft extends over 180 degrees. This is a cylinder discrimination method for an internal combustion engine. According to the cylinder discriminating method for an internal combustion engine described in claim 1, cylinder discrimination can be performed at an early stage. According to a second aspect of the present invention, in the method for determining a cylinder of an internal combustion engine according to the first aspect, the cylinder is determined based on a combination pattern of the crank angle information and the cam angle information. By using the cylinder discriminating method for an internal combustion engine according to the second aspect, the cylinder discrimination can be stably performed. According to a third aspect of the present invention, there is provided a cylinder discriminating apparatus for an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft, wherein the crankshaft has a predetermined angle. Crank angle information output means for outputting crank angle information indicating the predetermined angle each time the motor rotates, and cam angle information output means for outputting cam angle information indicating in which section of the camshaft a 180-degree section is located And a cylinder discriminating means for performing cylinder discrimination based on the crank angle information and the cam angle information. By using the cylinder discriminating device for an internal combustion engine according to the third aspect, the cylinder discrimination can be performed early.
According to a fourth aspect of the present invention, in the cylinder discriminating apparatus for an internal combustion engine according to the third aspect, the cylinder discriminating means performs cylinder discrimination based on a combination pattern of the crank angle information and cam angle information. Do. By using the cylinder discriminating device for an internal combustion engine according to the fourth aspect, cylinder discrimination can be performed stably. In the cylinder discriminating apparatus for an internal combustion engine according to claim 5, the crank angle information is data of "1" or "0". The use of the cylinder discriminating device for an internal combustion engine according to claim 5 simplifies the configuration of the crank angle information output means. According to a sixth aspect of the present invention, in the cylinder discriminating device for an internal combustion engine according to any one of the third to fifth aspects, the crank angle information output means includes a crank angle detecting rotor and a crank angle sensor. With
The cam angle information output means is composed of a cam angle detection rotor and a cam angle sensor, and the crank angle detection rotor and the cam angle detection rotor are provided with peaks and valleys in opposite phases on both sides in the thickness direction, The crank angle sensor and the cam angle sensor are configured to differentially output detection signals of peaks and valleys on both sides in the thickness direction of the crank angle detection rotor and the cam angle detection rotor, respectively. With the use of the cylinder discriminating apparatus for an internal combustion engine according to the sixth aspect, a detection error due to a sensor mounting error can be prevented, and detection accuracy can be improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B show a cam angle detection rotor and a crank angle detection rotor used in the first embodiment of the present invention. A cam angle detecting rotor 10 which rotates in conjunction with a cam shaft is made of a ferromagnetic material, and has a large diameter portion (peak portion) 11 and a small diameter portion (valley portion) which form cam angle information at intervals of approximately 180 degrees. ) 12 are provided. A cam angle sensor 20 such as a magnetic element using a hall element or a magnetoresistive element for detecting the large-diameter portion 11 and the small-diameter portion 12 is provided facing the outer periphery of the cam angle detecting rotor 10. ing. On the other hand, the crank angle detecting rotor 30, which rotates in conjunction with the crankshaft, is formed of a ferromagnetic material, and forms a crank angle information indicating the predetermined angle at predetermined angles, for example, at intervals of 15 degrees in the figure. 31 and valleys 32 or ridges 33 and valleys 34 are provided. Confronting the outer periphery of the crank angle detecting rotor 30, a peak portion 31,
A crank angle sensor 40, such as a magnetic element using a hall element or a magnetoresistive element for detecting 33 and the valleys 32 and 34, is provided. In this embodiment, data of "1" or "0" is formed by peaks and valleys and used as crank angle information. Crest 31 of a portion indicating data "1"
The shape of the valley portion 32 is, for example, as shown in FIG. 2A, between the time interval t1 from the fall to the rise of the crank angle signal output from the crank angle detection sensor 40 and the time interval t2 from the rise to the fall. The ratio, that is, the ratio (t1 / t2) of the Hi time interval t1 and the Lo time interval t2 within the reference angle (15 degrees in this case) is formed to be smaller than 1. Further, the shapes of the peaks 33 and the valleys 34 at the portions indicating the data "0" are, as shown in FIG.
It is formed such that t2 is larger than 1. The cam angle detecting rotor 10, the cam angle sensor 20, the crank angle detecting rotor 30, and the crank angle sensor 40 are arranged, for example, in a relationship shown in FIG. The cam angle detecting rotor 10 and the cam angle sensor 20 constitute the cam angle information output means of the present invention, and the crank angle detecting rotor 30 and the crank angle sensor 40 output the crank angle information of the present invention. Means are configured.

With the above construction, the crankshaft can be set at a predetermined angle (15) by determining crank angle information, in this case, data of "1" or "0".
Degree) Rotation can be detected. FIG. 3 shows an example of setting the crank angle information. Rotor 3 for detecting crank angle
When the peak 31 and the valley 32 or the peak 33 and the valley 34 indicating the crank angle information of “1” or “0” as shown in FIG. 6
By combining the two pieces of crank angle information, the rotation angle of the crankshaft can be detected every 15 degrees. That is, in FIG. 3, “0, 0, 0, 0, 0,
When the combination pattern of the crank angle information of “1” is recognized, it is understood that the crankshaft is at the position of 90 degrees. Then, according to the next data, "0, 0,
When the combination pattern of “0, 0, 1, 0” is recognized, it is understood that the crankshaft is at the position of 105 degrees. FIG. 4 shows the correspondence between the combination pattern of six pieces of continuous crank angle information and the rotation angle of the crankshaft.

Since the four-stroke 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 of the crankshaft. Therefore, the cylinder discrimination is performed based on the thus-recognized rotation angle of the crankshaft and cam angle information included in the cam angle signal output from the cam angle sensor 20, in this case, the Hi or Lo state of the cam angle signal. Perform For example, if the rotation angle of the crankshaft is 0
When the cam angle signal is Hi and the first cylinder is at the compression top dead center position, when the rotation angle of the crankshaft is 0 degree and the cam angle signal is Lo, the fourth cylinder is at the compression top dead center position. You can see that. Similarly, when the rotation angle of the crankshaft is 180 degrees and the cam angle signal is Hi, the third cylinder is at the compression top dead center position, and when the rotation angle of the crankshaft is 180 degrees and the cam angle signal is Lo, 2 It can be seen that the cylinder No. is located at the compression top dead center.

Next, FIG. 5 shows a block diagram of an embodiment of a cylinder discriminating apparatus for an internal combustion engine according to the present invention. The cylinder discriminating device includes a cam angle detecting rotor (not shown), a crank angle detecting rotor (not shown), a cam angle sensor 20, a crank angle sensor 40, a cylinder discriminating means 50, and the like. I have. The cylinder discriminating means 50 converts a crank angle signal output from the crank angle sensor 40 into a pulse signal into a central processing circuit (microprocessor MPU) 51, a clock generator 52 for supplying a master clock to the central processing circuit 51, and the like. A pulse discriminating circuit 53 for shaping the waveform, an input port 54 for inputting a crank angle signal via the cam angle sensor 20 and the pulse discriminating circuit 53, a read only memory (ROM) 55 storing a cylinder discriminating program, etc., a work area, etc. Random access memory (RAM) 5 used as
6, a bus line 57 for connecting these components, and the like.
Note that the pulse determination circuit may be built in the sensor in some cases.

The cylinder discriminating process by the cylinder discriminating means 50 will be described with reference to flowcharts of FIGS. This cylinder discriminating process is started when the engine is started, for example, when an ignition key is operated. First, the time interval of the trough (time interval from fall to rise) t1 of the pulse of the crank angle signal whose waveform is shaped by the pulse discriminating circuit 53, and the time interval of the peak (time interval from rise to fall) t2 Is measured (step S1). Next, the ratio (t1 / t2) between the time interval t1 of the valley and the time interval t2 of the peak is determined, and if the ratio is 1 or less, for example, t1 / t2 <1, it is recognized as “1”. Is 1 or more, for example, if t1 / t2 ≧ 1, “0”
Is recognized (step S2). Also, the time interval t of the valley
The time interval (t1 + t2) with respect to the reference angle (15 degrees in crank angle) is obtained by adding 1 to the time interval t2 between the peaks (step S3). Then, the engine speed is obtained based on the time interval with respect to the reference angle (step S).
4). The engine speed is, for example, 60 / [24 × (t
1 + t2)].

Next, it is determined whether or not a predetermined number or more of continuous crank angle information, in this case, six or more pulses have been counted (step S5). If six or more pulses have not been counted, the process returns to step S1. If six or more pulses are counted, a sequence of six consecutive pulses in the past,
That is, six consecutive combination patterns of "1" or "0" are recognized (step S6). Then, based on the combination pattern of the six “1” or “0” recognized in step S6, the rotation angle (absolute angle θ) of the crankshaft is recognized using, for example, the map shown in FIG. 4 (step S7). Next, the absolute angle θ of the crankshaft recognized in step S7 is 0 degree (360 degrees).
, 180 degrees, 0 degrees or 180 degrees (step S8).

If the absolute angle θ of the crankshaft is 0 degrees, it is determined whether the cam angle signal is Hi or Lo (step S9). If the cam angle signal is Hi, it is recognized that the first cylinder is at the position of the compression top dead center (step S10). On the other hand, when the cam angle signal is Lo, it is recognized that the fourth cylinder is located at the compression top dead center (step S11).

If the absolute angle θ of the crankshaft is 180 degrees in step S8, it is determined whether the cam angle signal is Hi or Lo (step S12). If the cam angle signal is Hi, it is recognized that the third cylinder is at the position of the compression top dead center (step S13). On the other hand, when the cam angle signal is Lo, it is recognized that the second cylinder is located at the compression top dead center (step S14).

If the absolute angle θ of the crankshaft is neither 0 ° nor 180 ° in step S8, it is determined whether the cam angle signal is Hi or Lo (step S15). When the cam angle signal is Hi, it is recognized that the crankshaft is at an arbitrary position between -10 degrees and 350 degrees of the crank angle (step S16). On the other hand, when the cam angle signal is Lo, it is recognized that the crankshaft is at an arbitrary position between 350 degrees and 710 degrees in crank angle (step S17).

Steps S10, S11, S13, S1
4. After recognizing the position of the crankshaft in S16 and S17, it is determined whether or not an engine stop command has been input (step S18). If the engine stop command has not been input, the process returns to step S1, and if the engine stop command has been input, the cylinder determination process ends.

FIG. 8 shows a timing chart between the cam angle signal and the crank angle signal and the cylinder discrimination position when the present invention is used. As shown in FIG. 8, when the cylinder discriminating method or the cylinder discriminating apparatus of the present embodiment is used, the crankshaft can be detected continuously by detecting six pulses of the crank angle signal regardless of the position of the crankshaft. 15 degrees × 6 pulses =
90 degrees (crank angle) is the shortest cylinder discrimination section. Considering the start of detection immediately after the falling of the pulse, 90 ° + 15 ° = 105 ° (crank angle) is the longest cylinder discrimination section. That is, even if the crankshaft of the engine is started from any position, cylinder discrimination can be performed at less than 105 degrees, and ignition timing control, fuel injection timing control, and the like can be started early, so that the engine startability is improved. .

As described above, in the conventional cylinder discriminating apparatus for an internal combustion engine, cylinder discrimination cannot be performed unless the crankshaft rotates at least 180 degrees, but in the present invention, before the crankshaft rotates 180 degrees, Cylinder discrimination can be performed. Further, in the conventional cylinder discriminating apparatus for an internal combustion engine, when the cylinder discrimination is erroneously determined, the next cylinder discrimination cannot be performed unless the crankshaft rotates at least 180 degrees. On the other hand, in the present invention, even if the cylinder discrimination is erroneously determined, the rotation angle of the crankshaft can be detected if the crankshaft rotates by a predetermined angle, in this embodiment, by 15 degrees. And the engine startability is improved.

Next, a second embodiment in which the reference angle of the crank angle detecting rotor is set to 30 degrees is shown in FIG.
9A shows a cam angle detecting rotor 60, and FIG.
Indicates a rotor 80 for detecting a crank angle. The cam angle detecting rotor 60 is provided with a large-diameter portion (peak portion) 61 and a small-diameter portion (valley portion) 62 for forming cam angle information at intervals of approximately 180 degrees. Further, a cam angle sensor 70 is provided to face the outer periphery of the cam angle detecting rotor 60. On the other hand, the crank angle detection rotor 80 is provided with peaks 81 and valleys 82 or peaks 83 and valleys 84 that form crank angle information at predetermined angles, for example, at every 30 degrees in the figure. The crank angle information of "1" or "0" is output from the crank angle sensor 90 every time the crank angle detecting rotor 80 rotates 30 degrees by the peak 81 and the valley 82 or the peak 83 and the valley 84. Is done. Therefore, by detecting the crank angle information “1” or “0” included in the crank angle signal output from the crank angle sensor 90, it is possible to detect that the crankshaft has rotated 30 degrees. This is shown in FIG. Further, by combining four pieces of continuous crank angle information, the rotation angle of the crankshaft can be detected every 30 degrees. FIG. 11 shows the correspondence between the combination pattern of four pieces of continuous crank angle information and the rotation angle of the crankshaft.
Cylinder discrimination can be performed based on the thus-recognized rotation angle of the crankshaft and the cam angle information included in the cam angle signal output from the cam angle sensor 70.

In this embodiment, regardless of the position of the crankshaft, the rotation angle of the crankshaft can be recognized by detecting four consecutive pulses, so that 30 degrees × 4 pulses = 120 Cylinder discrimination can be performed within a range of 120 degrees + 30 degrees = 150 degrees (crank angle) from degrees (crank angle). In addition, even if the cylinder discrimination is erroneously determined, the crankshaft is kept at a predetermined angle,
In this embodiment, the rotation angle of the crankshaft can be detected by rotating the crankshaft by 30 degrees, so that the cylinder discrimination can be stably performed.

In the above embodiment, peaks and valleys are provided on the outer periphery of each rotor, and one magnetic sensor is provided opposite to the outer periphery of the rotor. In this case, when the rotor rotates and the peaks and valleys pass through the position where the magnetic sensor is provided, the magnetic sensor outputs a signal as shown in FIG. 12A. Then, the level of the output signal from the magnetic sensor is compared with a threshold level. For example, when the level of the output signal is smaller than the threshold level, L
o, output a Hi pulse when large. As a result, peaks and valleys of the rotor are detected. The rising characteristic and the falling characteristic of the output signal of the magnetic sensor change due to a mounting error of the magnetic sensor, that is, a variation in an air gap between the magnetic sensor and the rotor. FIG. 12B shows the rising characteristics of the output signal of the magnetic sensor.
In FIG. 12b, the solid line shows the rising characteristics when the air gap is small, and the broken line shows the rising characteristics when the air gap is large. If the rise and fall characteristics of the output signal of the magnetic sensor vary, the point that the output signal of the magnetic sensor matches the threshold level differs, and the detection error of the peak and the valley of the rotor, that is, the rotation angle of the rotor, Error occurs.

FIGS. 13 and 14 show a third embodiment of the cam angle information output means and the crank angle information output means for preventing the detection error of the rotation angle of the rotor due to the mounting error of the magnetic sensor. 13A is a front view of the cam angle detection rotor 150, FIG. 13B is a right side view thereof, FIG. 14A is a front view of the crank angle detection rotor 170, and FIG. 14B is a right side view thereof. The cam angle detecting rotor 150 is provided with a large-diameter portion 151 and a small-diameter portion 152 for forming cam angle information at 180-degree intervals on one side in the plate thickness direction, and a small-diameter portion in opposite phase to one side on the other side. 153 and a large diameter portion 154 are provided. A magnetic sensor 161 for detecting the large diameter portion 151 and the small system portion 152 faces the outer periphery on one side of the cam angle detecting rotor, and the small system portion 1 faces the outer periphery on the other side.
A magnetic sensor 162 for detecting the 53 and the large diameter portion 154 is provided, and a differential output of the output signals of the two magnetic sensors 161 and 162 is used as a cam angle signal. The rotor 170 for detecting the crank angle has a peak 171 and a valley 172 or a peak 173 and a valley 17 at a predetermined angle on one side in the thickness direction.
4 are provided, and a valley 175 and a peak 176 or a valley 177 and a peak 178 are provided on the other side in the opposite phase to the one side. The peaks 171 and 173 and the valley 17 are opposed to the outer circumference on one side of the crank angle detection rotor 170.
Magnetic sensors 181 for detecting the valleys 175 and 177 and the peaks 176 and 17 oppose the outer periphery on the other side.
8 is provided, and the differential output of the output signals of the two magnetic sensors 181 and 182 is used as a crank angle signal. Magnetic sensors 161 and 162, 1
It is preferable that 81 and 182 are integrally formed for ease of installation work.

When the differential output of the output signal of the magnetic sensor provided on both sides in the plate pressure direction of the rotor is obtained by a comparator,
An output signal as shown in FIG. 15a is obtained. FIG. 15B shows the rising characteristic of the differential output when the threshold level is set to the GND (ground) level. In FIG. 15b, the solid line shows the rising characteristics when the air gap between both magnetic sensors and the rotor is small, and the broken line shows the rising characteristics when the air gap is large. As shown in FIG. 15B, even if there is an attachment error of the magnetic sensor, there is almost no detection error of the rotation angle of the rotor. in this way,
The cam angle detection rotor and the crank angle detection rotor are provided with peaks and valleys in opposite phases on both sides in the plate thickness direction, and the differential output of the output signals of the magnetic sensors provided on both sides in the plate pressure direction of each rotor is output by the cam. When the angle signal and the crank angle signal are used, it is possible to prevent a detection error of the rotation angle of the rotor due to a mounting error of the magnetic sensor.

In the above embodiment, the member for forming the crank angle information is constituted by the peaks and valleys provided on the crank angle detecting rotor, but the member for forming the crank angle information is constituted by the peaks. The present invention is not limited to the part and the valley, and it is only necessary to detect that the crankshaft has rotated a predetermined angle. The members forming the crank angle information can be provided at various angular intervals other than the intervals of 15 degrees and 30 degrees. Further, the number of combinations of the crank angle information can be variously changed. Although the data of "1" or "0" is used as the crank angle information, the crank angle information may use different data for each predetermined angle. In this case,
The rotation angle of the crankshaft can be recognized from the crank angle information. The member for forming the cam angle information is constituted by the large-diameter portion (peak portion) and the small-diameter portion (valley portion) provided on the cam angle detection rotor. The configuration of the member for forming the cam angle information is as follows. The present invention is not limited to the large-diameter portion and the small-diameter portion, and it suffices if the camshaft can be detected in any of the 180-degree sections. Further, magnetic sensors using a ball element or a magneto-resistive element are used as the cam angle sensor and the crank angle sensor. These sensors include various sensors such as a reflection type or transmission type optical sensor and a mechanical sensor. Can be used. The arrangement of the cam angle detection rotor and the crank angle detection rotor is not limited to the arrangement shown in FIG. The configuration of the cylinder discriminating device is as follows:
The configuration is not limited to the configuration shown in FIG.

[0025]

As described above, the cylinder discrimination method according to the first aspect enables the cylinder discrimination to be performed early. Further, the cylinder discrimination method according to the second aspect enables stable cylinder discrimination. Further, if the cylinder discriminating device for an internal combustion engine is used, the cylinder discrimination can be performed at an early stage.
Further, by using the cylinder discriminating apparatus for an internal combustion engine according to the fourth aspect, cylinder discrimination can be performed stably. Further, the use of the cylinder discriminating apparatus for an internal combustion engine according to claim 5 simplifies the configuration of the crank angle information output means. Further, the use of the cylinder discriminating device for an internal combustion engine according to claim 6 can prevent a detection error due to a sensor mounting error.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cam angle detection rotor and a crank angle detection rotor used in a first embodiment of the present invention.

FIG. 2 is a diagram showing crank angle information formed by peaks and valleys provided on a crank angle detecting rotor.

FIG. 3 is a diagram illustrating a relationship between crank angle information and a crank angle;

FIG. 4 is a diagram showing a correspondence relationship between a combination pattern of crank angle information and a rotation angle of a crankshaft;

FIG. 5 is a block diagram of a cylinder discriminating apparatus for an internal combustion engine according to an embodiment of the present invention;

FIG. 6 is a flowchart for explaining a cylinder discrimination process.

FIG. 7 is a flowchart illustrating a cylinder discrimination process.

FIG. 8 is a timing chart showing a relationship between a cam angle signal and a crank angle signal and a cylinder discrimination position.

FIG. 9 is a configuration diagram of a cam angle detection rotor and a crank angle detection rotor used in a second embodiment of the present invention.

FIG. 10 is a diagram showing a relationship between crank angle information and a crank angle.

FIG. 11 is a diagram showing a correspondence relationship between a combination pattern of crank angle information and a rotation angle of a crankshaft.

FIG. 12 is a diagram showing characteristics of an output signal of a sensor.

FIG. 13 is a configuration diagram of a cam angle detection rotor used in a third embodiment of the present invention.

FIG. 14 is a configuration diagram of a crank angle detection rotor used in a third embodiment of the present invention.

FIG. 15 is a diagram showing characteristics of an output signal of a sensor.

FIG. 16 is a configuration diagram of a conventional cam angle detecting rotor and crank angle detecting rotor.

FIG. 17 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, 60, 100, 150 Rotor for cam angle detection 11, 61, 151, 154 Large diameter part 12, 62, 152, 153 Small diameter part 20, 70, 110, 161, 162 Cam angle sensor 30, 80, 120 , 170 Crank angle detection rotors 31, 33, 81, 83, 171, 173, 176, 1
78 Mountains 32, 34, 82, 84, 172, 174, 175, 1
77 Valley part 40, 90, 130, 181, 182 Crank angle sensor 50 Cylinder discriminating means

Claims (6)

[Claims] 1. A cylinder discriminating method for an internal combustion engine having a crankshaft connected to a piston of each cylinder and a camshaft connected to the crankshaft, wherein a crank angle indicating a predetermined angle of the crankshaft. A cylinder discriminating method for an internal combustion engine that performs cylinder discrimination based on information and a cam angle information indicating in which section the camshaft extends over 180 degrees. 2. A combination pattern of the crank angle information.
2. The cylinder discriminating method for an internal combustion engine according to claim 1, wherein cylinder discrimination is performed based on the cam angle information and the cam angle information. 3. A cylinder discriminating device for an internal combustion engine having a crankshaft connected to a piston of each cylinder, and a camshaft connected to the crankshaft, wherein the cylinder discriminating means is configured to rotate the crankshaft by a predetermined angle each time the crankshaft rotates by a predetermined angle. Crank angle information output means for outputting crank angle information indicating an angle; cam angle information output means for outputting cam angle information indicating in which section the camshaft extends over 180 degrees; And a cylinder discriminating means for performing cylinder discrimination based on the cam angle information. 4. A cylinder discriminating apparatus for an internal combustion engine according to claim 3, wherein said cylinder discriminating means performs cylinder discrimination based on a combination pattern of said crank angle information and said cam angle information. 5. The cylinder discriminating apparatus for an internal combustion engine according to claim 3, wherein the crank angle information is data of “1” or “0”. 6. The crank angle information output means comprises a crank angle detection rotor and a crank angle sensor, and the cam angle information output means comprises a cam angle detection rotor and a cam angle sensor. Crests and valleys are provided on both sides in the thickness direction of the rotor for detecting the angle and the rotor for detecting the cam angle in opposite phases, and the crank angle sensor and the cam angle sensor are respectively provided for the crank angle detecting rotor and the cam angle detecting rotor. The cylinder discriminating apparatus for an internal combustion engine according to any one of claims 3 to 5, wherein detection signals of peaks and valleys on both sides in the thickness direction are differentially output.