JPH09170481A - Cylinder identifying device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To identify a cylinder with high accuracy in a short time by identifying cylinders based on signals from revolution detection means over a specified identification period just after an engine start signal is input, and changing the identification period according to temp. relating to operation of engine. SOLUTION: A reference signal showing a reference crank angle position corresponding to each cylinder according to each protrusion 13a-13d is obtained from 24 sensor 17 sensing a reference marker 14 of a crank shaft rotation plate 11, and first cylinder identification pattern signals composed of reverse signal group are obtained for every cylinder from a sensor 18 sensing cylinder identification marker 16. Second cylinder identification signals are obtained from a sensor 21 sensing a cylinder identification marker 20 of a cam shaft rotation plate 12. The identification of cylinders are performed according to the combination of first and second cylinder identification pattern signals. In this case, a cylinder identification period is changed according to intake air temp. and water temp. so that cylinder identification results improving reliability entirely is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder engine capable of reliably performing cylinder identification corresponding to engine rotation necessary for determining fuel injection timing, ignition timing and the like in a multi-cylinder engine even during cold start. The present invention relates to an engine cylinder identification device.

[0002]

2. Related Background Art In an electronically controlled multi-cylinder engine, it is important to identify a cylinder corresponding to engine rotation in determining fuel injection timing, ignition timing, etc. for each cylinder. Therefore, conventionally, a reference marker (crankshaft sensor) that generates a reference signal indicating a predetermined reference crank angular position is provided on the crankshaft of the engine corresponding to each cylinder, while a cam that rotates in synchronization with the crankshaft is provided. The shaft is provided with a cylinder identification marker (cam shaft sensor) that generates a cylinder identification pattern signal having a different value corresponding to each cylinder at each of the reference crank angle positions. Then, the cylinder corresponding to each of the reference crank angle positions is identified based on the value of the cylinder identification pattern signal at the time when the reference signal is detected (reference crank angle position).

Specifically, in the case of a four-cylinder engine, the reference marker corresponds to each cylinder and, for example, the first reference is obtained at a crank angle of 5 ° before the piston reaches the top dead center. Crank angle signal (BTDC5 °)
And a second reference crank angle signal (BTDC 75 °) before the crank angle of 75 ° are generated as a reference signal with a leading edge (rising edge) and a trailing edge (falling edge) thereof. There is. Each of these reference crank angle signals is also used as a signal that defines fuel injection timing and ignition timing.

On the other hand, the cylinder identification pattern signal is generated from the cylinder identification marker so that an inversion signal forming a set of different values for each cylinder is obtained at the two reference crank angle positions corresponding to each cylinder. . Specifically, at each of the reference crank angle positions, an inversion signal forming a set of values [H, H], [H, L], [L, H], [L, L] corresponding to each cylinder is generated. It is generated as a cylinder identification pattern signal. Then, according to the set of values of the cylinder identification pattern signal at the time when the reference signal is detected, the cylinder that is going to the intake stroke (or the combustion stroke) at that time is identified.

[0005]

By the way, in a multi-cylinder engine, for example, as shown in FIG. 1, a pulley 2 attached to a crank shaft 1 thereof and the pulley 2 attached to two cam shafts 3 and 4 respectively. A timing belt 7 is stretched between the pulleys 5 and 6 having a double circumference. When the crankshaft 1 makes two revolutions and operates for one combustion cycle, the camshafts 3, 4 are each made to make one revolution in synchronization with this. In the figure, 8 and 9 are guide pulleys, and 10 is a tensioner pulley. In addition, in the case of an in-line type multi-cylinder engine, only one cam shaft may be provided.

However, in the engine having the above-mentioned structure, the tensioner pulley 10 compensates for the rotation synchronization timing between the pulleys 2, 5 and 6, and even when the engine is started, the tension of the timing belt 7 and Due to the bending, the friction of the cam shafts 3, 4 and the reduction of the rotational driving force of the crank shaft 1 due to the starter, for example, as shown in FIG. In many cases, there is a rotational phase difference in No. 4.
Specifically, at low temperature start, the friction of the cam shaft is large, and further, the rotation speed of the crank shaft is slowed down due to the deterioration of the capacity of the starter, and the rotation fluctuation is also large and unstable. Such fluctuations in the rotation of the crankshaft at the time of starting greatly depend on the temperatures involved in the operation of the engine, such as the intake air temperature and the water temperature of the engine. Because of this,
Cylinder identification is likely to be erroneous at the time of cold start, etc., and cylinder identification accuracy becomes a problem.

That is, in the case of cylinder identification in an 8-cylinder type engine proposed by the applicant (the present inventor) in Japanese Patent Application No. 7-206102, the reference marker attached to the crankshaft is used as shown in FIG. The reference signal corresponding to each cylinder as shown in FIG. 2 is obtained, while the first cylinder identification pattern signal as shown in FIG. 2B is obtained from the cylinder identification marker attached to the camshaft at a predetermined crank angle position. . Further, at another crank angle position apart from the crank angle position for obtaining the first cylinder identification pattern by a predetermined crank angle (for example, 90 °), the cylinder identification marker outputs a predetermined timing with respect to the first cylinder identification pattern signal. The delayed second cylinder identification pattern signal as shown in FIG. 2 (c) is obtained. Then, the values of the first and second cylinder identification pattern signals at the time of detecting the reference signal are respectively detected, and cylinder identification is performed based on the combination of these signal values.

However, during the specific period indicated by a star in the figure, the inversion timing of the reference signal and the inversion timing of the cylinder identification pattern signal are close to each other, so that the crankshaft 1 does not rotate as described above. When the camshafts 3 and 4 are stable and have a rotational phase difference with respect to the crankshaft 1, a timing difference between the reference signal and the cylinder identification pattern signal is likely to occur, which may cause erroneous detection.

By the way, Japanese Patent Laid-Open No. 6-101616 discloses that erroneous identification is prevented by prohibiting cylinder identification immediately after engine start, in which crankshaft rotation is unstable. Then, it takes a long time to obtain the cylinder identification result. The present invention has been made in consideration of such circumstances, and an object thereof is to easily and accurately identify cylinders in a short time at the time of starting without being influenced by the operating environment of the engine. (EN) Provided is a cylinder identification device for a multi-cylinder engine that can perform.

[0010]

In order to achieve the above-mentioned object, an engine cylinder identification apparatus according to the present invention, based on a signal from a rotation detecting means for detecting the rotation of the engine,
When a cylinder is identified for a predetermined identification period immediately after the engine start signal is input, the temperature detection means for detecting the temperature involved in the operation of the engine is provided, and the temperature detected by the temperature detection means. And an identification period changing means for changing the identification period according to the above.

That is, the reliability of cylinder identification is improved by detecting the intake air temperature, the water temperature, etc. involved in the operation of the engine and changing the period for which the cylinder identification is executed according to these detected temperatures. It is characterized by. According to a second aspect of the present invention, the engine cylinder identification device according to the first aspect further comprises means for correcting the execution period of the cylinder identification according to the engine speed or the degree of change thereof. It is a feature.

That is, not only the cylinder identification period is changed according to the temperature involved in the operation of the engine, but also the cylinder identification period is adaptively corrected according to the engine speed or the degree of change thereof. It is a thing.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An engine cylinder identification device according to an embodiment of the present invention will be described below with reference to the drawings. In the apparatus of this embodiment, basically, a crankshaft rotating plate 11 having a structure as shown in FIG. 3A is attached to a crankshaft 1 of an engine, and a camshaft 3 rotating in synchronization with the crankshaft 1 is mounted on a crankshaft 1 shown in FIG. The camshaft rotary plate 12 having the structure shown in FIG. 4B) is attached, and the rotary plates 11 and 12 are configured to obtain a reference signal and a cylinder discrimination pattern signal synchronized with the engine rotation as shown in FIG.

For example, in the case of an eight-cylinder engine, the crankshaft rotary plate 11 has four protrusions 13a, 13b, 13c, 13d formed on the peripheral edge thereof at an angular width of 70 ° at equal angular intervals. And these protrusions 13a,
13b, 13c and 13d correspond to each cylinder (BTDC5
, BTDC 75 °) is used as a reference marker 14 for generating a reference signal indicating two reference crank angle positions. Further, on the main surface of the crankshaft rotary plate 11, three through holes 15a, 15b, 15c are formed along the peripheral edge thereof. These through holes 15a, 15b, 15c are used as a first cylinder identification marker 16 for generating a first cylinder identification pattern signal for identifying the cylinder at the reference crank angle position corresponding to each cylinder.

Incidentally, the through hole 15a is the BTDC of the protrusion 13b.
It is formed by hanging from the front position of 75 ° to a position past BTDC 75 ° of the protrusion 13b. The second through hole 15b
Is from the position before BTDC 5 ° of the protrusion 13c to the position of the next protrusion 13c.
It is formed by hanging it past BTDC 75 °. The third through hole 15c is formed so as to extend from the position before the BTDC 5 ° of the protrusion 13d to the position past the BTDC 5 ° of the protrusion 13d.

The generation of the reference signal and the first cylinder identification pattern signal from the reference marker 14 and the first cylinder identification marker 16 accompanying the rotation of the crankshaft 1 is fixedly arranged around the crankshaft rotating plate 11. Each of the projections 13a, 1
Presence of 3b, 13c, 13d, and each through hole 15a, 1
This is performed by detecting the presence of 5b and 15c, respectively. still,
Hall elements are generally used as the first and second sensors 17 and 18, but it is of course possible to use optical sensors.

Then, from the first sensor 17 which senses the reference marker 14 of the crankshaft rotary plate 11 which rotates with the rotation of the crankshaft 1, the respective protrusions 13a, 13 are introduced.
b, 13c, 13d, the above-mentioned two reference crank angle positions (BTDC5 °, BTDC75 °) corresponding to each cylinder.
The reference signal SGT1 as shown in FIG. 4 (a), which is composed of pulse signal sequences respectively indicating Further, from the second sensor 18 which senses the first cylinder identification marker 16, as shown in FIG. 4B, in synchronization with the reference signal, the two reference crank angle positions (BTDC5 °,
BTDC75 °), a first cylinder identification pattern signal SGT2 is obtained which is composed of a series of inversion signals having different sets of values. The points to be noted here are the reference marker 14 and the first marker.
Since the cylinder identification markers 16 of No. 1 are both formed on the crankshaft rotating plate 11, there is no rotational phase difference between the reference signal SGT1 and the first cylinder identification pattern signal SGT2.

On the other hand, the camshaft rotary plate 12 is formed with a notch 19 extending over a half circumference of the camshaft rotary plate 12. The notch 1
An outer peripheral edge portion of the camshaft rotary plate 12 including 9 is used as a second cylinder identification marker 20 for generating a second cylinder identification pattern signal SGC different from the first cylinder identification pattern signal SGT2. A third sensor 21 is fixedly arranged around the camshaft rotary plate 12 and senses the second cylinder identification marker 20 associated with the rotation of the camshaft rotary plate 12.
The second cylinder identification pattern signal SGC as shown in FIG. 4 (c) is obtained from the presence or absence of the notch 19 in synchronization with the rotation thereof.
Seeking.

However, the cam shaft rotating plate 12 makes one rotation in synchronization with the rotation of the cylinder shaft 1 when the cylinder shaft 1 makes two rotations. Therefore, the second cylinder identification pattern signal
When the reference signal SGT1 and the first cylinder identification pattern signal SGT2 are obtained for two cycles, the SGC is set to 1 in synchronization with this.
The cycle will be turned. Therefore, whether the second cylinder identification pattern signal SGC has a value of [L] in the first half of the rotation,
On the contrary, whether the crankshaft 1 is the first rotation or the second rotation can be determined by taking the value [H] in the latter half of the rotation. That is, the plurality of cylinders are divided into two groups, that is, a cylinder group that faces the cycle on the intake stroke side and a cylinder group that faces the cycle on the combustion stroke side according to the rotation of the crankshaft 1, and the second cylinder identification pattern signal SGC is ,
It is possible to distinguish which of the two cylinder groups is the identification target.

The second cylinder identification pattern signal SGC
The inversion timing of is positioned at a substantially intermediate timing in the pulse signal corresponding to the specific cylinder of the reference signal SGT1. In other words, it was decided corresponding to the cylinder (BTDC 5 °,
The second cylinder identification pattern signal SGC is set to be inverted at a substantially intermediate point (near BTDC 40 °) of the pulse signal indicating the two reference crank angle positions of BTDC 75 °). With such a timing setting, the second cylinder identification pattern signal SGC will not be inverted in the interval between the pulse signals corresponding to the respective cylinders of the reference signal SGT1, for example, in a section where there is a margin of only 20 ° in the crank angle, and the camshaft is temporarily assumed. Even if 3 produces a rotational phase difference with respect to the crankshaft 1, the influence thereof does not affect the second cylinder identification pattern signal SGC.

Now, the cylinder identifying apparatus according to the present invention obtains a reference signal SGT1 consisting of a pulse signal sequence corresponding to each cylinder from the reference marker 14 as shown in FIG. Indicated by timing (BTDC5
°, BTDC75 °) at two reference crank angle positions, the respective values of the first and second cylinder identification pattern signals SGT1 and SGC shown in FIGS. 4 (b) and (c) are detected, and the combination of those signal values is detected. Is used to identify the cylinder corresponding to the reference signal.

Specifically, in an 8-cylinder engine, the order in which eight cylinders move toward the intake stroke (combustion stroke) is, for example, #
1, # 2, # 7, # 8, # 4, # 5, # 3, # 6, and the first and second cylinder identification pattern signals are set as shown in FIG. Basically, with reference to the rising time (leading edge) of the reference signal SGT1, the values [A, B] of the first cylinder identification pattern signal at the reference crank angle positions of BTDC 75 ° and BTDC 5 °, and the above Value of the second cylinder identification pattern signal [C] at the reference crank angle position of BTDC 75 °
Therefore, cylinder identification (first cylinder identification) is performed as follows.

[H, H, L] ... cylinder # 1, [L, L, L] ... cylinder # 2 [H, L, L] ... cylinder # 7, [L, H, L] ... Cylinder # 8 [H, H, H] ... Cylinder # 4, [L, L, H] ... Cylinder # 5 [H, L, H] ... Cylinder # 3, [L, H, H] ... Cylinder # 6 Alternatively, when the cylinder identification is performed again subsequent to the above-described cylinder identification, the BTDC 5 ° is set with the trailing edge of the reference signal SGT1 as a reference.
And the value of the first cylinder identification pattern signal [A ', at the reference crank angle position of BTDC 75 ° corresponding to the next cylinder
B ′] and the value [C ′] of the second cylinder identification pattern signal at the reference crank angle position of 75 ° BTDC, the cylinder identification (second cylinder identification) is performed again as follows.

[H, L, L] ... cylinder # 1, [L, H, L] ... cylinder # 2 [L, L, L] ... cylinder # 7, [H, H, H] ... Cylinder # 8 [H, L, H] ... Cylinder # 4, [L, H, H] ... Cylinder # 5 [L, L, H] ... Cylinder # 3, [H, H, H] ... Cylinder # 6 Such leading edge and trailing
Cylinder identification with each edge as a reference, when the cylinder identification is continuously performed for a predetermined period as described later,
It is executed alternately.

The cylinder identification control in the embodiment based on the cylinder identification method described above is executed according to the control procedure shown in FIGS. 5 and 6 according to the temperature involved in the operation of the engine, for example, the intake air temperature and the water temperature. . This processing procedure is started when the start of the engine is detected, and is started by first detecting the temperature (water temperature) W of the engine cooling water and the intake temperature T of the engine (step S1). When the water temperature W and the intake air temperature T are respectively detected, the number of repetitions (the number of times of identification) n of the cylinder identification processing necessary for surely performing the cylinder identification according to the table shown in FIG. It is set as a cylinder identification period (step S2).

The number of discriminations n is set, for example, by determining whether the water temperature W is within the range of 20 to 95 ° C., and when it is out of the range, it is 105 ° C. or higher, or -15 ° C. or lower. It is performed by judging. At the same time, it is performed by determining whether the intake air temperature T is in the range of 20 to 60 ° C., and when it is out of the range, it is 80 ° C. or higher or −15 ° C. or lower. Then, based on these determination results, when one of the water temperature W and the intake air temperature T is lower or higher than the determination threshold value, it is assumed that there is a high possibility that the cylinder identification is erroneously determined, and the cylinder identification is performed more than in the normal state. The number of times n is set large. Specifically, in FIG. 7, the number of identifications n is set to [1] during the normal operation when the temperature condition is in the region α, and the number of identifications n is set to [3] when the temperature condition is in the region β out of the normal condition. Area γ that has been set and the above temperature conditions deviate significantly from normal times
In a severe cold or restarting in an overheated state, the number of identifications n is set to [5].

After that, the counters A and B for processing control
The values [a] and [b] of are respectively initialized to [0] (step S3). The counter A controls the number of repetitions of the cylinder identification processing, and the counter B controls the alternate execution of the cylinder identification based on BTDC75 ° and the cylinder identification based on BTDC5 ° described above. is there.
After the above initial setting is completed, first, the above-mentioned reference signal SG
The first rise of T1 (BTDC 75 °) is detected, and the respective values of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC at that time are detected (step S4). Further, following this signal detection, the next falling edge (BTDC5 °) of the reference signal SGT1 is detected, and the respective values of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC at that time are detected. Yes (step S5). Then, based on the combination of these detection signal values, the cylinder at the time point of 5 ° BTDC is identified according to the above-described first cylinder identification algorithm (step S6). Then, the identification result is set in the register C (step S7). The identification result set in the register C is given as data of [BTDC5 °-# 1] when the cylinder identified at the time point BTDC5 ° is the first cylinder, for example.

Thereafter, the values of the counters A and B [a],
Increment [b] respectively (step S8),
It is determined whether or not the value [a] of the counter A is equal to the number of times of discrimination n initialized as described above (step S).
9). When the value [a] of the counter A is equal to the identification number n, that is, when the temperature involved in the operation of the engine is in the normal range α and the identification number n is set to [1],
The operating environment of the engine is good, and it is shown that it is sufficient to identify the cylinder only once at the time of starting the engine.
The process ends only by the first cylinder identification in 3 to S7.

On the other hand, when the number of discriminations n is not [1], it is assumed that the engine operating environment is bad and the engine rotation is not stable, and the discrimination result is reliable only by one cylinder discrimination. Considering that there is a problem, the cylinder identification is set to be repeatedly executed a plurality of times, and therefore the processing procedure shown in FIG. 6 is entered. When the cylinder identification processing is repeatedly executed, it is started by first updating the identification result stored in the register C to the cylinder information expected to be identified at the next identification timing (step S10). That is, the cylinder identification is alternately repeated as shown in FIG. 4, with reference to the rising and falling timings of the reference signal. Therefore, for example, when the identification result of [BTDC5 °-# 1] is obtained in the first cylinder identification, the cylinder at the next timing is identified in the second cylinder identification. In order to show the order of the cylinders which sequentially go toward the intake (compression) stroke in the combustion cycle, the expected identification result [BTDC75 °-# 2] obtained at the next timing is updated.

Thereafter, the value [b] of the counter B is checked to determine whether the value is an odd number (step S).
11). This determination is made by checking whether or not the minimum bit (LSB) of the value [b] of the counter B is [1]. By this determination, the cylinder identification executed immediately before that is based on the rising timing of the reference signal. It is determined whether it has been executed with reference to the falling timing of the reference signal. As the counter B, a 1-bit type that stores only the minimum bit (LSB) may be used.

If the value [b] of the counter B is an odd number, it means that the cylinder identification immediately before that is executed with reference to the rising timing of the reference signal.
In this case, the first falling edge (BTDC 5 °) of the reference signal SGT1 described above is detected, and the respective values of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC at that time are detected. (Step S12). Further, following this signal detection, the next rising edge (BTDC75 °) of the reference signal SGT1 is detected, and the respective values of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC at that time are detected. (Step S13). Then, based on the combination of these detection signal values, the BTDC75
The cylinder at the time point is identified (step S14).

On the other hand, when the value [b] of the counter B is not an odd number, that is, an even number, it is indicated that the cylinder identification immediately before that is executed with reference to the falling timing of the reference signal. Therefore, in this case, the next rising timing of the reference signal SGT1 (BTDC 75 °)
Each value of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC is detected at (step S
15). Further, following this signal detection, the reference signal SG
Each value of the first cylinder identification pattern signal SGT2 and the second cylinder identification pattern signal SGC is detected at the next falling timing (BTDC5 °) of T1 (step S16). Then, based on the combination of these detection signal values, the BTDC 5 ° is calculated according to the first cylinder identification algorithm described above.
Identify the cylinder at the timing (step S1)
7).

When the identification result is obtained in this way,
Next, the result prediction value predicted based on the discrimination result one timing before and stored in the register C is compared with the discrimination result obtained this time, and it is determined whether or not they match (step S18). ). When a match is detected, the value [a] of the counter A is incremented on the assumption that the same result as the previous timing is obtained (step S1).
9) On the contrary, if they do not match, it is judged that there is an error in either the discrimination result at the previous timing or the discrimination result this time, and the value [a] of the counter A is set to [1]. Yes (step S20).

Thereafter, the identification result obtained this time is newly stored in the register C (step S21), and it is determined whether or not the value [a] of the counter A has reached the identification number n (step S21). S22). And the above value [a]
If has not reached the identification number n, the processing from step S10 described above is repeatedly executed. Due to such repeated control of cylinder identification, the value [a] of the counter A reaches [n] only when the cylinder identification is correctly performed n consecutive times. The value stored in the register C at that time is output as the final cylinder identification result. Fuel injection and ignition for each cylinder are sequentially controlled according to the identification result.

Thus, according to the present apparatus for identifying a cylinder as described above when the engine is started, the cylinder identification period is variably set according to the temperature information related to the operation of the engine. When the temperature is within the normal range α, there is almost no fluctuation factor of the engine rotation and it is stable, and the accuracy of cylinder identification is high. Therefore, the cylinder identification processing is executed only once at the time of starting, and the identification is performed. Fuel injection and ignition for each cylinder are controlled based on the result. However, when the temperature is out of the normal range α, for example, in the range β described above, when the same identification result is obtained three times in succession, and the temperature is in the range γ. In some cases, when the same identification result is obtained five times in a row, the identification result is obtained as the final highly reliable identification result. Therefore, even if the engine rotation is unstable immediately after starting and the reliability of the identification result at each timing is low, the identification reliability is sufficiently improved from the continuity of the identification results before the final cylinder identification. The result can be obtained correctly. Therefore, it is possible to reliably control the fuel injection and the ignition based on the cylinder identification result within a short time after the engine is started.

Further, according to the above-described embodiment apparatus, the first cylinder identification processing and the second cylinder identification processing, which are based on the respective rising and falling timings of the reference signal, are sequentially and alternately executed. However, since the cylinder discrimination results are sequentially compared and the continuity thereof is judged to obtain the final discrimination result, the time required for the processing can be shortened. That is, when the signal is detected with reference to the rising timing of the reference signal and the signal is detected at the next falling timing to perform the cylinder identification, the next cylinder identification process is immediately started with the falling timing as a reference. There is also an advantage that the cylinder loss can be minimized and the cylinder identification can be efficiently executed in a short time.

Therefore, according to the present apparatus, the cylinder identification processing is suppressed to once at normal temperature to minimize the time required for the start-up, and the start-up time is slightly extended in the low temperature or extremely high temperature state, but the cylinder identification processing is performed. Cylinders can be reliably identified by repetition. Therefore, it is possible to perform cylinder identification efficiently and reliably in a short time according to the engine start environment, and to control fuel injection and ignition to the engine according to the identification result.

The present invention is not limited to the above embodiment. In the embodiment, the cylinder identification processing period (the number of repetitions) is set by focusing on the intake air temperature and the water temperature of the engine.
Since the viscosity of the engine oil also makes the engine speed uncertain, the above-mentioned temperature range classification is changed according to the battery voltage and the oil temperature that influences the viscosity of the engine oil. The number of repetitions) may be set.

Further, the engine speed immediately after starting and its fluctuation are monitored, for example, from the pulse interval of the reference signal,
If the engine speed is too low, or if the rotation fluctuation is large, a means for correcting the cylinder identification period (the number of repetitions) may be provided. Also, depending on external conditions, for example, when the battery voltage is low, the cylinder identification period is extended if the voltage drops to a certain extent, but conversely, if the voltage drop is significant, the cylinder identification period is shortened. It is also useful to take measures to prevent the battery from weakening further. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0040]

As described above, according to the present invention, based on the signal from the rotation detecting means for detecting the rotation of the engine, a predetermined discrimination period is started immediately after the engine start signal is input. When identifying a cylinder, the temperature involved in the operation of the engine is detected, and the identification period is changed according to the detected temperature to perform cylinder identification.
It is possible to obtain a highly efficient and highly reliable cylinder identification result in a short time according to the engine start environment.

According to the second aspect of the invention, the execution period of the cylinder identification is further corrected according to the engine speed or the degree of change thereof, so that the cylinder identification can be performed more accurately. And so on.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a connecting structure of a crank shaft and a cam shaft in an engine.

FIG. 2 is a diagram showing an operation of cylinder identification based on a reference signal detected by rotation of a crankshaft and a cylinder identification pattern signal detected by rotation of a camshaft synchronized with rotation of the crankshaft, and problems in the conventional device. FIG. 6 is a signal timing diagram for explaining.

FIG. 3 is a diagram showing a configuration example of a crankshaft rotary plate and a camshaft rotary plate used in the engine cylinder identification device according to the embodiment of the present invention.

FIG. 4 shows a reference signal and first and second signals in the embodiment apparatus.
5 is a signal timing chart showing the cylinder identification action and cylinder identification period based on the cylinder identification pattern signal of FIG.

FIG. 5 is a diagram showing a first half of an execution procedure of a cylinder identification process in the embodiment apparatus.

FIG. 6 is a diagram showing the latter half of the execution procedure of the cylinder identification processing in the embodiment apparatus.

FIG. 7 is a diagram showing an example of division setting of a temperature region for determining the number of times of cylinder identification repetition according to a temperature condition.

FIG. 8 is a diagram showing an example of content update (result prediction) of a register C in cylinder identification processing.

[Explanation of symbols]

 1 Crankshaft 3,4 Camshaft 11 Crankshaft Rotating Plate 12 Camshaft Rotating Plate 13a, 13b, 13c, 13d Protrusion 14 Reference Markers 15a, 15b, 15c Through Hole 16 First Cylinder Identification Marker 17, 18 Sensor 19 Notch 20 Second cylinder identification marker 21 Sensor

Claims (2)

[Claims] 1. Cylinder identification for identifying a cylinder based on a signal from the rotation detecting means for detecting a rotation of an engine, and for a predetermined identification period immediately after the engine start signal is input. Means, temperature detecting means for detecting a temperature involved in the operation of the engine, and identification period changing means for changing the identification period in the cylinder identifying means according to the temperature detected by the temperature detecting means. An engine cylinder identification device characterized by the above. 2. The cylinder identification device for an engine according to claim 1, further comprising means for correcting the predetermined identification period according to an engine speed or a degree of change thereof. apparatus.