JPH1030489A - Cylinder judging method of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder judging method in an internal combustion engine, sufficiently capable of securing an improvement of startability in this multicylindered internal combustion engine as using one turning angle sensor. SOLUTION: In this judging method, a turning angle sensor, rotating at one half of crankshaft revolution in an internal combustion engine, and generating a pulse signal being shown in an illustration (a), corresponding to respective cylinders ranging from first to fourth, and a judging pattern being shown in another illustration (b) or (c) are jointly used, and in this constitution, when a pattern of the pulse signal being shown in the illustration (a) is accorded with the judging pattern being shown in the illustration (b) or (c), a cylinder judgment is carried out. In this case, since a judgment in regard to other cylinders is not given after the specified cylinder is judged, and each cylinder is separately judgeable directly by a signal alone of one turning angle sensor, a delay of cylinder judgment will get off with smallness, therefore in time of engine starting, a speedy cylinder judgment is securable, and since fuel injection control and ignition timing control both can be started at once, engine's startability is thus improvable to the full.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder discriminating method for a multi-cylinder internal combustion engine, and more particularly to a cylinder discriminating method suitable for an internal combustion engine for an automobile.

[0002]

2. Description of the Related Art In an internal combustion engine for a vehicle, especially for an automobile,
In order to respond to strict exhaust gas regulations and increase output, an electronic control method that can precisely control fuel injection amount, fuel injection timing, ignition timing, etc. has been widely used as a control method. It has become

Since the control of the fuel injection timing and the ignition timing requires a crank angle, the engine is provided with a sensor for detecting the rotation angle of the crankshaft. However, it is necessary to further determine the cylinder. is there.

Therefore, it is customary to provide a crankshaft sensor and a cylinder discriminating sensor on a camshaft or the like which rotates synchronously at half the rotational speed of the crankshaft.
However, such a method of using different sensors for detecting the crank angle and for discriminating the cylinder has problems such as an increase in the number of sensors, an increase in cost, and a complicated control system.

Therefore, a method of using a sensor for outputting a cylinder determination pulse signal immediately after the end of one of the reference pulse signals of several cylinders as a crank angle sensor, A method of determining the crank angle and the cylinder based on the signal of one rotation angle sensor by using a sensor that changes the length of the pulse signal from the other cylinders and outputs the signal is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-219341. JP-A-5-089553, or Japanese Patent Publication No. 7-888.
No. 11 has proposed this.

In these prior arts, for example, every time a sensor signal is input, the pulse interval between the previous and current pulses is
The reference pulse signal and the cylinder determination pulse signal are determined by measuring (periodic time), calculating the ratio between them, and comparing the ratio with a predetermined value.

[0007]

The prior art described above does not take into account delay in cylinder determination at the time of starting the internal combustion engine, and has a problem in that the startability of the internal combustion engine is reduced. That is, in the related art, a specific one of a plurality of cylinders is determined instead of individually determining a plurality of cylinders, and the specific cylinder is determined for the remaining cylinders. It is determined as a result of having been performed.

Therefore, until a specific cylinder is determined, or when the determination of this specific cylinder is not obtained,
Cylinder discrimination cannot be obtained until the crankshaft rotates and then the reference pulse of the specific cylinder is detected again, that is, during two revolutions. During this time, fuel injection control and ignition timing are not performed. Control cannot be started.

[0009] Cylinder determination is required when the internal combustion engine is started. Therefore, in the prior art, as a result of the cylinder determination delay, the start of fuel injection control and ignition timing control is also delayed, and the startability of the internal combustion engine deteriorates. It is.

An object of the present invention is to provide a method for judging the cylinder of an internal combustion engine, which is capable of sufficiently improving the startability of a multi-cylinder internal combustion engine while using one rotation angle sensor.

[0011]

An object of the present invention is to use a rotating member which is synchronized with the rotation of a crankshaft of an internal combustion engine and rotates at a rotation speed of 1/2 of the rotation speed, and is provided at the same stroke position of each cylinder. Sensor means for generating two pulse signals and generating one pulse signal at a position different from the stroke position of a specific one cylinder, and a determination value sequentially appearing in time series by the pulse signals The pattern is compared with a determination pattern previously set for each cylinder corresponding to each of the cylinders, and the cylinder is determined based on the type of the determination pattern at the time when the matched determination value pattern appears. Is achieved.

A further object of the present invention is to use a rotating member which is synchronized with the rotation of the crankshaft of the internal combustion engine and rotates at a rotation speed of 1/2 of the rotation speed, and two rotation members are provided at the same stroke position of each cylinder. A pulse signal is generated, and a sensor means for generating one pulse signal at a position different from the stroke position of a specific one cylinder is provided.
The cylinders are determined based on the type of the determination pattern at the time when a matching determination value pattern appears in comparison with a determination pattern previously set for each cylinder corresponding to each of the cylinders. In the above, the pattern for determination is
A preliminary cylinder judgment is performed when a judgment value pattern that matches the preliminary judgment pattern with a small number of bits is prepared, and the judgment coincides with the main judgment pattern with a large number of bits. This is also achieved by shifting to full-scale cylinder discrimination when the value pattern appears.

More specifically, according to the present invention, as a sensor, for example, a notch for a cylinder signal corresponding to each cylinder of the internal combustion engine is provided on a disk rotating at half the speed of the crankshaft of the internal combustion engine. Hole) and a notch for a cylinder determination signal for determining a specific cylinder are used.

Each time the pulse signal falls at the notch due to the rotation of the crankshaft, the time interval from the previous pulse signal fall time is measured, and the level "1" or A determination value having a level “0” is subjected to a binary operation as a determination bit, so that the determination bits arranged in time series with the rotation of the internal combustion engine are obtained.

On the other hand, with respect to the pattern of the determination bits thus obtained in a time-series manner, a predetermined bit pattern obtained for each cylinder is stored and set in advance for each cylinder as a determination pattern. When the pattern of the determination bits appearing in chronological order with the rotation of the internal combustion engine matches a predetermined plurality of digits, for example, a five-digit determination pattern, the number of the number corresponding to the determination pattern is determined. It is determined that the cylinder is a cylinder.

Then, when the cylinder determination is obtained, the fuel injection control and the ignition timing control of the internal combustion engine are started. As a result, after the specific cylinder is determined, the determination of the other cylinders is not given, but each cylinder can be directly determined independently.Therefore, the delay of the cylinder determination can be reduced, and the engine can be quickly started. Cylinder determination is obtained, and fuel injection control and ignition timing control can be started immediately.
Startability is improved.

At this time, a number of digits smaller than the above-mentioned plural-digit determination pattern, for example, a three-digit determination pattern is separately set as a preliminary determination pattern, and the engine is first started to rotate, and is initially set. It is assumed that the cylinder determination has been obtained for the time being when the pattern matches the preliminary determination pattern. At this time, simultaneous injection control (simultaneous injection control of all cylinders of fuel) may be started.

That is, before the total number of bits of the bit pattern necessary for the cylinder determination is obtained, the preliminary determination pattern condition of a smaller number of digits is set, and the simultaneous injection control is started when the determination is satisfied. Then, the cylinder is determined based on the determination pattern conditions of all digits, and normal fuel injection control (sequential injection control for each cylinder) and ignition timing control are started to further improve the startability of the internal combustion engine. Can be.

As described above, simultaneous injection control can be performed before the end of the cylinder determination. If ignition timing control is started at the end of the cylinder determination, fuel has already been injected into the cylinder.
Since it is ignited by the ignition spark, a complete explosion is obtained immediately, resulting in improved startability.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a cylinder determining method for an internal combustion engine according to the present invention will be described in detail with reference to embodiments. FIG. 1 shows an example in which the embodiment of the present invention is applied to a four-cylinder internal combustion engine. In the drawing, E represents the entire engine and has a cylinder 1. The engine E
Has four cylinders, but only one is shown in the figure.

First, the air to be taken in by the engine E enters from the air cleaner 2, is guided through a duct to a throttle body having a throttle valve 4, is distributed by an intake pipe, and is taken into the cylinder 1. . On the other hand, fuel
The fuel is sucked and pressurized from a fuel tank by a fuel pump (not shown), injected from an injector 5 into an intake pipe, and supplied into a cylinder together with intake air.

A pressure sensor 3 for detecting the intake pressure and an intake temperature sensor 7 are attached to the throttle body, and detect the pressure and temperature of the intake air. Further, a water temperature sensor 9 for detecting a cooling water temperature is attached to a water jacket of the cylinder 1, and an oxygen sensor 10 is attached to an exhaust pipe. Then, outputs of these sensors are input to the control unit 11. On the other hand, the spark plug 6
A high voltage generated in the ignition coil 8 is supplied by an output from the control unit 11.

Reference numeral 12 denotes a rotation angle sensor, which includes a photoelectric element 13 and a disk 14. The photoelectric element 13 includes a light-emitting element and a light-receiving element as a pair, and is disposed between the light-emitting element and the light-receiving element so as to sandwich the disk 14. On the other hand, the disk 14 is provided with a plurality of notches 15 for generating cylinder signals as shown in the drawing, and the space between the light emitting element and the light receiving element of the photoelectric element 13 is positioned therebetween. It is arranged.

The disk 14 is mounted on the engine E
The crankshaft is driven to rotate at one half of its rotation speed, and therefore, is generally directly connected to an intake / exhaust valve opening / closing camshaft.

When the disk 14 rotates and the opening of the cylinder signal notch 15 coincides with the position of the photoelectric element 13, the light of the light emitting element reaches the light receiving element, which corresponds to the rotation angle of the crankshaft of the engine. A signal, that is, a signal indicating a specific crank angle position of each cylinder is output, and a reference signal for injection timing and ignition timing and a reference signal for detecting a rotational speed can be obtained.

As shown in FIG. 2, the control unit 11
It is composed of an arithmetic unit including a PU, a ROM, an A / D converter and an input circuit, and performs a predetermined arithmetic processing based on an input signal from each of the sensors and an input signal from the rotation angle sensor 12. Is operated to inject a required amount of fuel into each intake pipe, and an ignition spark is generated in the ignition plug 6 at an appropriate ignition timing according to the crankshaft rotation angle.

This embodiment is directed to a four-stroke, four-cylinder internal combustion engine. For this reason, in FIG. 2, four injectors 5 from No. 1 to No. 4 are shown in FIG. Is an example. In a three-cylinder internal combustion engine, for example, the number of injectors may be three or less, and the number of ignition coils 8 is also the same. The invention is not limited to a cylinder internal combustion engine.

Next, the operation of this embodiment will be described. FIG. 3 shows an output signal of the rotation angle sensor 12. In this embodiment, as shown in FIG. 3, two pulse signals are generated for each cylinder, and one pulse signal is additionally generated. A cylinder discrimination pulse signal is generated.

For this reason, the rotation angle sensor 1 described with reference to FIG.
The second disk 14 is provided with a number of cylinder signal notches corresponding to the number of cylinders and a number of cylinder signal notches for determining the reference cylinder. The intermediate portion between the light emitting element portion and the light receiving element portion of the photoelectric element 14 is provided. When these signal notches 15 pass, these pulse signals are generated from the rotation angle sensor 12 and input to the control unit 11.

At this time, the pulse signal waveform rises due to the open end of the notch 15, and the pulse signal waveform falls at the end of the signal notch 15. Accordingly, the pulse length of the sensor signal waveform is proportional to the circumferential length of the signal notch 15 of the disk 14.

As shown in FIG. 3, in this embodiment, the signals corresponding to each of the first to fourth cylinders are all composed of two pairs of pulse signals having the same shape. The fall is a position at a predetermined angle before the top dead center TDC, which is the end of the compression process of the corresponding cylinder, that is, BTDC
It is set to be.

In this embodiment, the advance angle value AG1 shown in FIG. 3 is set in the range of 65 to 75 degrees BTDC, and similarly, the advance value AG2 is set to 15 to 15 degrees BTDC.
Therefore, the interval between the pulse signal pairs corresponding to the respective cylinders is larger than the interval between the respective pulse signals of the pulse signal pair. Note that these two pulse signal pairs are used for fuel injection control and ignition timing control.

In FIG. 3, each top dead center TDC
Are described in order from the first cylinder to the second cylinder, the third cylinder, and the fourth cylinder, but this is for the sake of simplicity. In an actual four-cylinder internal combustion engine, usually, 1-3-4- 2 or 1
The explosion order of -2-4-3 is adopted. Needless to say, this order is changed according to the cylinder number of the internal combustion engine to be applied.

In this embodiment, as the signal obtained from the rotation angle sensor 12, in addition to the pulse signals obtained two by two for each of the cylinders, the signal before the first cylinder pulse signal, that is, The notch of the disk 14 built in the rotation angle sensor 12 so that one reference cylinder determination pulse signal is generated between the four-cylinder pulse signal and the first cylinder pulse signal as shown in the figure. 15 are formed.

Next, FIG. 4 shows that with the rotation of the internal combustion engine,
In this embodiment, the waveform of a pulse signal generated from the rotation angle sensor 12 changes. In this embodiment, the CPU of the control unit 11 starts changing the waveform of the next pulse signal from the falling edge of the pulse signal. Time T to fall
Is calculated every time a pulse signal is input.

Here, as shown in FIG. 4, assuming that the latest operation value is Tnew and the immediately preceding operation value is Told, as described above, these operation values Tnew and Told are equal to the input pulse signal. Are sequentially updated every time the waveform changes. Next, the latest operation value Tnew is compared with the immediately preceding operation value Told by the following equation (1) to make a determination. Told × K ≧ Tnew (1) Here, K is a constant of a predetermined value, which is set in order to allow a margin for the comparison calculation with respect to the fluctuation of the crankshaft rotation speed.

Then, based on the determination by the equation (1), a determination value (bit for determination) is set as follows. When the expression (1) is satisfied, the judgment value → 1. When the expression (1) is not satisfied, the judgment value → 0. Thus, when this judgment result is obtained for the pulse signal of FIG. Thus, a judgment value 0 is given to a pulse signal whose interval from the immediately preceding pulse signal is large, and a decision value 1 is given to a pulse signal whose interval from the immediately preceding pulse signal is small. Will be done.

To obtain such a determination result, the interval between the notches 15 provided on the disk 14 of the rotation angle sensor 12 may be set to a predetermined value. That is, if the interval of the notch 15 is made equal to the interval of the notch for the pulse signal pair, the judgment value becomes 1, and if the interval is made larger than that by a predetermined value, the judgment value becomes 0.

FIG. 5 (a) shows an arrangement state when the judgment values are arranged in chronological order in the order of generation of the pulse signal.
As shown in FIG.
The shape of the notch 15 formed in the disk 14 of the rotation angle sensor 12 is set so that Note that FIG.
Represents the case of a four-cylinder engine as described above, and 3
FIG. 6 shows the case of a cylinder engine.

That is, in the case of four cylinders, the top dead center interval of each cylinder is 180 degrees of crank angle, but in the case of three cylinders, the crank angle is 240 degrees. Therefore, as shown in FIG. Since the interval between the reference cylinder determination signal and the first cylinder signal increases, the determination value of the AG1 portion of the first cylinder is 0. In the case of four cylinders, as shown in FIG.
It is one.

Therefore, in the case of three cylinders, the notches 15 of the disk 14 are formed so that the arrangement of the judgment values becomes 1010101...

Next, the CPU of the control unit 11 sequentially interprets the judgment values given in time series as a pattern comprising an array of a predetermined number of judgment values each time a new judgment value is obtained. The cylinder is compared with several different patterns that have been set, and the cylinder is determined based on any of the patterns.

At this time, as a feature of this embodiment, the cylinder determination is performed by two types of patterns having different numbers of determination values as follows. That is, (1) determination of cylinder and angle using a five-digit determination pattern (5
Digit determination). (2) Cylinder or angle determination using a three-digit determination pattern (3
Digit determination).

Here, a three-digit determination pattern having a small number of determination values is referred to as a preliminary determination pattern, and the determination at the time when a pattern that coincides with this pattern appears appears as a preliminary determination.
A five-digit determination pattern having a large number of determination values is referred to as a main determination pattern, and a determination obtained at the time when a matching pattern appears appears as a full-scale determination. In the following, the judgment value pattern will be referred to as a bit pattern in order to easily distinguish it from the judgment pattern.

Therefore, the CPU of the control unit 11 stores the five-digit determination pattern shown in FIG. 5B and the three-digit determination pattern shown in FIG. 5C in a predetermined memory in advance. In addition, every time a pulse signal appears when the engine rotates and a new judgment value is obtained, a 5-digit bit pattern formed by the four judgment values obtained before that, and 2
The three-digit bit pattern formed by the three determination values is compared with the five-digit determination pattern and the three-digit determination pattern, and each time a matched determination pattern appears, the matched determination pattern Fig. 5
As shown in FIG. 5B and FIG. 5C, the determination cylinder and the determination angle are obtained.

For example, when the obtained 5-digit bit pattern is, for example, "10111", it is determined that the angle is AG1 before the top dead center at the falling edge of the signal waveform for the first cylinder, If it is “11110”, it is determined that the angle is AG1 before the top dead center at the falling edge of the signal waveform for the second cylinder. Hereinafter, a signal falling at the angle of AG1 before the top dead center is simply described as AG1, and the same applies to the description of AG2.

Similarly, when the three-digit bit pattern is, for example, "111", it indicates that the signal is for the first cylinder, but it cannot be specified which of AG1 and AG2. ], It is not possible to specify the cylinder, but A of either the third cylinder or the fourth cylinder
G1 can be determined.

The above is the case of a four-cylinder engine,
Similarly, in the case of a three-cylinder engine, the five-cylinder engine shown in FIG.
The determination can be made in the same manner using a digit and a three-digit determination pattern.

Next, the fuel injection control and the ignition control based on the two types of cylinder discrimination of the above-mentioned five-digit determination and three-digit determination will be described with reference to FIG.
This will be described below. In this embodiment, the simultaneous injection control is performed immediately when the cylinder and / or both the angles AG1 and AG2 are determined by the three-digit determination.

FIG. 7 shows a case of four cylinders. For example, when the three-digit bit pattern becomes "111", either AG1 or AG2 cannot be specified yet, but the first cylinder since it has been found in, as shown, the fuel injection by the signal waveform falling time t _F at which anyway is "111".

If the bit pattern of "111" is determined in this way, as shown in FIG. 7, the fuel simultaneously injected into all the cylinders in the cylinder of the internal combustion engine during the intake stroke of the second cylinder The fuel injection control and the ignition control are started based on the determination value input next and the result of the five-digit pattern cylinder determination based on the determination value, so that the internal combustion engine can explode, Will be able to move to

At the start, when the judgment value starts to appear,
Since the pattern with the smaller number of digits matches first, 3
In the digit determination and the five-digit determination, the three-digit determination can obtain the determination earlier. This situation will be described in more detail with reference to FIG. 7. In FIG. 7, if the pattern for determination is three digits, a determination can be obtained at the end of the compression stroke of the first cylinder.
This is the end of the compression stroke of the cylinder.

Therefore, when only the five-digit determination is made, the cylinder determination is made only at the end of the compression stroke of the second cylinder in FIG. 7, and as a result fuel is injected. In this case, the fuel is injected into the second cylinder. Since it is not sucked into the cylinder, the explosion is obtained from the third cylinder.

That is, the difference of two digits in the number of bits of the pattern results in a delay of 180 degrees in the crank rotation angle in the case of the four cylinders in FIG. 7, and similarly, in the case of three cylinders, a delay of 240 degrees in the crank rotation angle Therefore, according to this embodiment, a great effect of improving the startability can be obtained.

Next, the flow of control in this embodiment will be described. First, FIG. 8 and FIG. 9 show the entire flow.
In step, it is determined whether the three-digit bit pattern determination is completed. If the determination is completed, the process proceeds to step 1002, and after performing the simultaneous injection control, the process proceeds to step 1003. The three-digit pattern determination in step 1001 will be described later.

In step 1003, it is determined whether or not the five-digit bit pattern determination is completed. If the determination is completed, the process proceeds to step 1004. In step 1004, fuel injection control and ignition timing control for each cylinder are started.

Next, at step 1005, it is determined whether or not a permuted cylinder has been detected. That is, as shown in FIG. 5, the change of the determination value appearing in time series with the rotation of the crankshaft is 1110101101 over time.
.. Since the following is set so as to be repeated, the pattern of the judgment value inputted every five digits is 111
01, 11010, 10101, 01010, 1010
1,01011,10111,01111,11110
... The following is the order of repetition, and no other bit patterns should appear. Therefore, when a pattern other than the above order is input, it is determined that a signal is erroneously input or a control malfunction is caused.

For example, if the previously determined cylinder is the first cylinder, the 5-digit bit pattern obtained by adding the two-digit determination value obtained by the latest calculation accompanying the crank rotation and the immediately preceding three-digit determination value is the second cylinder. If it matches the cylinder determination pattern, it is determined that normal operation is being performed.

If the result of step 1005 is YES
If so, the fuel injection control and the ignition timing control are continued in step 1006, and the process returns to step 1005 again.
This repetition is performed when the determination result in step 1005 is NO.
As long as the condition does not hold, the operation is performed until a command to stop the internal combustion engine due to the key switch OFF or other causes is given to the control unit 11.

On the other hand, step 1001 or step 10
In 03, when the determination result is NO, the cylinder determination control ends. If the determination result in step 1005 is NO
In the case of, it is determined that there is an erroneous input of a signal or a malfunction of the control, and the routine proceeds to step 1007, where the fuel injection control and the ignition timing control are stopped.

Next, in step 1008, the number of erroneous determinations in the past, that is, the NG number memo is referred to
If O, that is, if it has exceeded once, the cylinder determination control is stopped. When the NG count memory is 1 or less, that is, when the result is YES, the process proceeds to step 1009, and the erroneous determination count is recorded once, that is, the NG count memory is counted up.

Subsequently, in step 1010, the five-digit pattern determination is performed again. If the result is YES, the process proceeds to step 1006, where the fuel injection control and the ignition timing control are restarted. To end.
The 5-digit pattern determination in step 1010 will be described later.

Next, the details of the three-digit bit pattern determination process in step 1001 (FIG. 8) will be described with reference to FIGS.
It will be explained by. First, in step 2001, the interval between input signals from the rotation angle sensor 12 is calculated. This calculation and calculation method are the same as those already described with reference to FIG.

Next, in step 2002, a binary operation is performed based on the relationship between the latest operation value Tnew, the immediately preceding operation value Told, and the constant K, and the results are referred to as step 2203 and step 2004. Here, step 2003 is 2
The result of the value calculation determination, that is, the determination value is 1,
In the case of 004, it is assumed that the determination value, which is the binary operation determination result, is 0.

Next, in step 2005, it is determined whether or not the bit patterns are arranged in the order of 111. Here, as described above, the bit pattern array has three digits, and the latest binary operation value is treated as the lower-order bit of the three-digit bit pattern.

If the decision result in the step 2005 is YES, the process proceeds to a step 2006, where it is determined that the cylinder is the first cylinder. In this case, as shown in FIG.
1 or AG2 (see FIG. 3) cannot be specified. If the result in step 2005 is NO, the process proceeds to the next step 2007, and if the determination result in this step is YES, the process proceeds to step 2008, where the second cylinder and the angle A
It is determined to be G1.

If the result in step 2007 is NO, the process proceeds to step 2009, but this step 2009
If the determination result in step is YES, the process proceeds to step 2010, and although the cylinder number cannot be specified, it is determined that the angle is AG1 in any one of the third cylinder and the fourth cylinder.

In any case, the three-digit pattern determination is OK in step 2015 thereafter. Therefore, the result of step 2009 is NO, that is, step 2005, step 2007 and step 2009
If all the determination results are NO, step 2011
Then, it is determined whether or not the bit pattern is in an impossible array.

As shown in FIG. 5A, 11101010
When a bit pattern arrangement of 1... Is adopted, if an arbitrary continuous three-digit bit is considered, 1
There are no three types of bit pattern arrangements of 00, 001 and 000. Therefore, when such an arrangement appears, it is processed as an input signal error.

Therefore, if YES is determined in this step 2011, NG is determined in step 2012.
Count up the memory. This NG number memory is the same as step 1009 in FIG.
The number of times is stored for each erroneous signal input. The contents of the memory are retained until the battery terminal is opened, for example.

Returning to step 2011, the possible pattern of the three-digit bit pattern in this embodiment is 11 bits.
Since there are five types, 1, 110, 101, 011 and 010, the determination target in step 2011 is 10 excluding the bit patterns already determined in step 2205 and step 2007 and step 2009.
There are only two types of bit patterns, 1 and 011.

Therefore, when examined in step 2011,
When the bit pattern is 101 or 011, since these are possible bit patterns, step 201
The determination of 1 is NO. At this time, the process returns to step 2001 again, and after waiting for a new input signal, the three-digit determination is repeated.

In step 2013 of FIG. 11, it is determined whether or not the stored NG count is equal to or greater than the limit value 10. If the result is YES, a signal-related operation failure is displayed and an alarm is issued. In order to call attention,
Finally, in step 2014, a series of processes is terminated as three-digit pattern determination NG.

Next, the details of the 5-digit bit pattern determination processing in step 1003 (FIG. 8) will be described with reference to FIGS.
This will be described with reference to the drawings up to 6. First, the processing from step 3001 to step 3004 in FIG. 12 is the same as the processing from step 2001 to step 2004 in FIG. 10 described above, and a description thereof will be omitted.

In the following step 3005, the previous three-digit bit pattern is examined.
It moves to step 3008 of 3. Then, the latest input two digits following the previous three-digit bit pattern 111 are added, and when the result is a bit pattern array of 11110,
In step 3009, the angle is determined to be the angle AG1 of the second cylinder, and then, in step 3020 of FIG.

On the other hand, if the decision result in step 3008 is N
In the case of O, that is, when the bit pattern array does not become 11110, as can be seen from FIG. 5, since only the pattern can be 11101, NO is determined in step 3010 in cases other than 11101.

If the determination in step 3010 is NO, this is due to an erroneous signal input or a control processing error. Therefore, the NG count memory is counted up in step 3022 in FIG.
Then, the process ends with the five-digit pattern NG.

On the other hand, if the decision is YES in step 3010, the operation waits for the result of the calculation of a new one-digit bit pattern.
At step 3011 a decision is made. At this time, following the previous bit pattern array 11101, there is only 11010 possible bit patterns from the relationship in FIG. 5 as described repeatedly.

Then, when this bit pattern 11010 is input and the determination in step 3011 is YES, in the next step 3012, the third cylinder and the angle A
It is determined as G1. On the other hand, if the bit pattern is other than 11010, it is an error.
Proceed to.

Similarly, in step 3006 and step 3007 in FIG. 16, it is first determined whether or not the input bit pattern is possible in the arrangement by a three-digit pattern, and it is checked whether or not an erroneous signal is input. If any step is correct, the result is YES.

Therefore, the result in step 3006 is YES
After that, a 5-digit pattern determination is made in step 3013 of FIG. 14. First, when the result is NO, step 3022 is executed.
Increments the NG number of times memory in step 3
At 023, the five-digit pattern determination is NG. On the other hand, if the result is Y
In the case of ES, in step 3014, the third cylinder and AG1
Is determined, and the 5-digit pattern determination is OK in step 3020.

If the result in step 3006 is NO, the flow advances to step 3007 in FIG. 16, and if the result is YES, the flow advances to step 3018 to make a 5-digit pattern determination. Time step 3
In step 019, the cylinder is determined to be the fourth cylinder and AG1, and step 302
If it is 0, the 5-digit pattern determination is OK.

On the other hand, if the result in step 3018 is NO, the flow advances to step 3015 in FIG. 15 to check whether or not the pattern is 01011, and if the result is YES, then in step 3016 the next one digit Is 101
When it reaches 11, in step 3017 the first cylinder and AG1
It is determined that the five-digit pattern determination is OK in step 3020.

If the determination in step 3015 or step 3016 is NO, any of step 3015 and step 3016
At 22 the NG count memory is counted up, and at step 3023 the five digit pattern determination is NG.

On the other hand, if the bit pattern becomes other than 010 in step 3007, this can only occur in the case of a control error, so a control system failure display is performed in step 3021.

Since the process has proceeded to the 5-digit determination step 1003 only when the determination in step 1001 is YES, as apparent from FIG. 8, the bit patterns other than the three types of 111, 110 and 010 This is because when it becomes, it does not come to this step 3007.

Next, the details of the 5-digit bit pattern determination processing in step 1010 (FIG. 9) will be described with reference to the drawing of FIG. In this process, when the number of erroneous signal inputs is one or less, the crank angle rotation sensor determination process is not reset, that is, the process is not returned to the first three-digit determination stage, but is performed after the three-digit determination is completed. The purpose is to return to the cylinder determination control at an early stage from the time of input of an erroneous signal.

In FIG. 17, first, at step 400
In step 1, all the bit patterns for which the binary operation has been performed are reset, and a cylinder determination is performed in step 4002 after inputting a new 5-digit bit pattern.

In this step 4002, if the five-digit bit pattern matches the determination pattern of any one of the cylinders, the determination of the five-digit pattern is OK in step 4003, and the process ends. After that, step 100 in FIG.
Returning to FIG. 6, the process proceeds to the fuel injection control and the ignition timing control as described above.

On the other hand, in step 4002,
If it is O, steps 4004 and 4005
Thus, the 5-digit determination is repeated every time a bit pattern is input up to nine times. As shown in FIG. 5, in the arrangement of this embodiment, the five-digit bit pattern should return to the same bit pattern arrangement at the ninth time even if the bit patterns are replaced one by one.

Therefore, if it does not match each of the five-digit cylinder determination patterns even after repeating nine times, it is determined that an erroneous signal has been input, and the process proceeds to step 4006 via steps 4004 and 4005. Thereafter, in step 4006,
NG count memory count-up is performed, then step 4
In 007, the five-digit pattern determination is NG.

Incidentally, in the above embodiment, the case where a photoelectric element is used as the rotation angle sensor 12 has been described. However, it is needless to say that another detecting element may be used instead of the LED photoelectric element. The function required at this time is only required to generate a signal corresponding to the rotation of the crankshaft, and therefore, for example, an electromagnetic pickup detection type sensor or the like can be used.

The same applies to the time measurement between the signal waveforms. Instead of associating the signal waveform with the falling point as shown in FIG. 4 of the above embodiment, as shown in FIG. The signal input processing at the time may be changed, and, as a matter of course, as shown in FIG. 19, arithmetic processing may be performed for each rise and fall of the signal waveform.

In FIG. 19, Told1 and Tn
ew1 and Told2 and Tnew2 are written first.
This means that the binary operation of the relationship between old1 and Tnew1 is performed, and then, when a new signal is input, the binary operation of the relationship between Told2 and Tnew2 is performed.

Further, in the above-described embodiment, the determination pattern shown in FIG. 5 is used as an example of the five-digit and three-digit determination patterns.
The present invention may be implemented using a digit determination pattern.

In the three-digit determination in the embodiment of FIG. 5, for example, even if the first cylinder is determined, it cannot be determined whether the angle AG1 or the angle AG2 is present, whereas the four-digit determination in FIG. If any cylinder is used, the determination of the angle AG1 can be obtained at the same time as the cylinder determination. Therefore, the advantage of unifying the timing of simultaneous fuel injection can be obtained. , The start of fuel injection is temporally delayed by the time required, so that it can be said that the startability is somewhat inferior.

[0097]

According to the present invention, after the specific cylinder is determined, the determination of the other cylinder is not given, but each cylinder is directly independent by the signal of one rotation angle sensor. Therefore, it is possible to reduce the delay of the cylinder determination, to obtain a quick cylinder determination at the time of engine start, and to immediately start the fuel injection control and the ignition timing control, thereby sufficiently improving the startability. Can be.

Further, according to the present invention, a judgment pattern having a smaller number of digits than the above-mentioned plural-digit judgment pattern is separately set as a preliminary judgment pattern. At the time when a match with the preliminary determination pattern is obtained, the cylinder determination can be made for the time being, and then the cylinder can be determined based on the satisfaction of the determination pattern condition for all digits.

In this case, since simultaneous injection control can be performed before the end of the cylinder determination, if the ignition timing control is started at the end of the cylinder determination, the fuel has already been injected into the cylinder. Is ignited by the ignition spark,
A complete explosion is obtained immediately, so that in this case even greater improvements in startability can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an internal combustion engine to which an embodiment of a cylinder determination method for an internal combustion engine according to the present invention is applied.

FIG. 2 is a configuration diagram illustrating input and output of a control device in an internal combustion engine to which the present invention is applied.

FIG. 3 is a waveform chart showing an example of a signal waveform of a rotation angle sensor used in an embodiment of the present invention.

FIG. 4 is an explanatory diagram of signal processing of a rotation angle sensor according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a determination pattern used in an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a determination pattern used in an embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between fuel injection control and ignition timing control start timing according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a flow of cylinder determination, fuel injection, and ignition control according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a flow of cylinder determination, fuel injection, and ignition control according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram of a flow of a three-digit pattern determination method for cylinder determination according to one embodiment of the present invention.

FIG. 11 is an explanatory diagram of a flow of a three-digit pattern determination method for cylinder determination according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram of a flow of a 5-digit pattern determination method for cylinder determination according to an embodiment of the present invention.

FIG. 13 is an explanatory diagram of a flow of a 5-digit pattern determination method for cylinder determination according to an embodiment of the present invention.

FIG. 14 is an explanatory diagram of a flow of a 5-digit pattern determination method for cylinder determination according to an embodiment of the present invention.

FIG. 15 is a diagram illustrating a fifth example for determining a cylinder according to the embodiment of the present invention;
It is explanatory drawing of the flow of a digit pattern determination method.

FIG. 16 is a diagram illustrating a fifth embodiment for determining a cylinder according to the embodiment of the present invention;
It is explanatory drawing of the flow of a digit pattern determination method.

FIG. 17 is a diagram illustrating a fifth embodiment for determining a cylinder according to the embodiment of the present invention;
It is explanatory drawing of the flow of a digit pattern determination method.

FIG. 18 is an explanatory diagram of signal processing of a rotation angle sensor according to another embodiment of the present invention.

FIG. 19 is an explanatory diagram of signal processing of a rotation angle sensor according to another embodiment of the present invention.

FIG. 20 is an explanatory diagram of a four-digit determination pattern relating to a four-cylinder internal combustion engine according to another embodiment of the present invention.

[Explanation of symbols]

 E Internal combustion engine body 1 Cylinder 2 Air cleaner 3 Pressure sensor 4 Throttle valve 5 Injector 6 Spark plug 7 Intake temperature sensor 8 Ignition coil 9 Water temperature sensor 10 Oxygen (air-fuel ratio) sensor 11 Control unit 12 Rotation angle sensor unit 13 Photoelectric element 14 Disk 15 Notch for cylinder signal

Claims (4)

[Claims] 1. Synchronous with rotation of a crankshaft of an internal combustion engine,
Using a rotating member that rotates at half the rotation speed of the cylinder, two pulse signals are generated at the same stroke position of each cylinder, and a position different from the stroke position of a specific one cylinder. In a cylinder determination method for an internal combustion engine, wherein a cylinder determination is performed by a sensor unit that generates one pulse signal, a determination value pattern that appears in a time-sequential manner by the pulse signal corresponds to each of the cylinders in advance. Cylinder determination of an internal combustion engine, wherein the cylinder is determined based on the type of the determination pattern at the time when a matching pattern appears, by comparing with a determination pattern set for each cylinder. Method. 2. The method according to claim 1, wherein two types of determination patterns having different numbers of bits are prepared, and when a determination value pattern that matches the preliminary determination pattern having a small number of bits appears. A cylinder determination for an internal combustion engine, wherein a preliminary cylinder determination is performed, and when a determination value pattern that matches the main determination pattern having a large number of bits appears, a transition is made to full-scale cylinder determination. Method. 3. The invention according to claim 2, wherein, when the cylinder determination cannot be obtained after the shift to the full-scale cylinder determination, the process returns to the preliminary cylinder determination processing. Cylinder determination method for an internal combustion engine to perform. 4. The method according to claim 1, wherein when the pattern is not matched within a predetermined period,
A cylinder determining method for an internal combustion engine, comprising: counting means for adding 1 to a counting value, wherein an alarm is issued when the counting value of the counting means reaches a predetermined value.