JP3358288B2 - Engine cylinder discriminator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder discriminating apparatus used for ignition control of an electronic distribution type of an engine.

[0002]

2. Description of the Related Art In a conventional cylinder discriminating apparatus for an engine, a crank angle (720 ° / 6 = 120 ° in the case of six cylinders) set according to the number of cylinders and each of them is determined with respect to a top dead center of each cylinder. A crank angle sensor for outputting a reference signal REF corresponding to the crank angle position;
A cylinder discriminating sensor that outputs a cylinder discriminating signal PHASE capable of discriminating each cylinder between F is used to discriminate a cylinder (ignition cylinder) from the cylinder discriminating signal PHASE between the reference signals REF every time the reference signal REF is generated. (Japanese Patent Laid-Open No. 5-106)
No. 500, etc.).

[0003]

However, in such a conventional cylinder discriminating apparatus for an engine, when even one cylinder discrimination signal becomes abnormal, an incorrect cylinder discrimination is performed, and ignition is performed for the wrong cylinder. There is a problem that the ignition cannot be performed. In addition, Japanese Unexamined Patent Publication
As disclosed in Japanese Patent Application Laid-Open No. 233878, a cylinder discrimination is performed by comparing a cylinder discrimination result based on a cylinder discrimination signal with a result estimated based on a series of past cylinder discrimination results. Because of the comparison, even if any abnormality can be detected, it is difficult to reliably determine whether any of them is correct, and there is a similar problem.

The present invention has been made in view of the above-described conventional problems, and enables the correct cylinder discrimination even when a single abnormality occurs in the cylinder discrimination signal, thereby improving the reliability of the cylinder discrimination. The purpose is to:

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
As shown in FIG. 1, a reference signal generating means a for generating a reference signal for each crank angle set by the number of cylinders and each corresponding to a predetermined crank angle position with respect to the top dead center of each cylinder, A cylinder discriminating signal generating means b for generating a cylinder discriminating signal capable of discriminating each cylinder, and a cylinder discriminating means c for discriminating a cylinder from a cylinder discriminating signal between the reference signals each time a reference signal is generated. In the discriminating device, at least three storage units d respectively corresponding to at least three predetermined cylinders (for example, # 1, # 3, # 5 cylinders) among all the cylinders, and the cylinder discriminating means c
When any one of the predetermined at least three cylinders is determined, a cylinder discrimination result writing means e for writing a cylinder number as a cylinder discrimination result into a storage unit corresponding to the cylinder, a reference signal Shift processing in which the cylinder number stored in each storage unit other than the storage unit in which the cylinder number has been written by the cylinder determination result writing means e at that time is rewritten to the next cylinder number in the ignition order. Means f and the cylinder discrimination result writing means e and the shift processing means f each time a reference signal is generated. Final determination means g for performing cylinder determination
Are provided.

Here, the number of the storage units d is preferably smaller than the number of cylinders, and is preferably an odd number. Further, the cylinder discrimination by the cylinder discriminating means c is prohibited until the cylinder discriminating result writing means e has completed writing to all the storage units d at least once each time. May be provided as a final cylinder discrimination result.

[0007]

The operation in the above configuration is as follows.
In a six-cylinder engine of # 2 → # 3 → # 4 → # 5 → # 6, three storage units are provided corresponding to predetermined cylinders # 1, # 3 and # 5 among all the cylinders, for example. The case will be described. When the cylinder discriminating means determines that the cylinder is # 1 when the reference signal is generated, the cylinder number 1 which is the cylinder determination result is written into the storage unit corresponding to the cylinder # 1. The cylinder number stored in the storage unit is sequentially shifted and rewritten to the next cylinder number 2, 3,... In the order of ignition.

Further, when the cylinder discriminating means determines that the cylinder is # 3 when the reference signal is generated, the cylinder number 3 which is the cylinder discrimination result is written in the storage section corresponding to the cylinder # 3, and the reference signal is subsequently transmitted. Each time a cylinder number is generated, the cylinder number stored in the storage unit is sequentially shifted and rewritten to the next cylinder number 4, 5,. Also, when the cylinder discriminating means determines that the cylinder is # 5 when the reference signal is generated, #
The cylinder number 5, which is the cylinder discrimination result, is written into the storage unit corresponding to the five cylinders, and each time a reference signal is generated, the cylinder number stored in the storage unit is stored in the storage unit corresponding to the next cylinder number 6-1 in the ignition order. ,... Are sequentially rewritten.

Therefore, if the cylinder discrimination by the cylinder discriminating means is normal, every time the reference signal is generated, after the cylinder discrimination result is written and the shift processing is performed, all the cylinder numbers stored in all the storage units are changed. Will be the same. Further, even if an abnormality occurs in the cylinder discrimination by the cylinder discriminating means, if it is a single event, only one of the three storage units will have an abnormality, and the other two will have the same normal cylinder number. Is stored.

Therefore, if the final cylinder discrimination is performed by majority decision based on the cylinder numbers stored in all the storage units after writing the cylinder discrimination result and shifting processing each time the reference signal is generated, the majority decision is made. Thereby, correct cylinder discrimination becomes possible. The number of storage units may be provided by the number of cylinders, but by setting the number to be smaller than that of all cylinders, the arithmetic processing can be simplified.

The number of storage units may be even,
By using an odd number, it is possible to simplify the judgment by majority vote. Further, since it is difficult to make a final determination until the writing of the cylinder determination results to all the storage units has been completed at least once each time, the cylinder determination result of the cylinder determination means is directly used as the final cylinder determination result until then. By doing
The control is prevented from becoming uncontrollable until the final judgment becomes possible.

[0012]

An embodiment of the present invention will be described below. Here, a V-type six-cylinder engine is taken as an example. The ignition order of the V6 engine is # 1 → # 2 → # 3 → # 4 → # 5 → # 6
It is. As shown in FIG. 2, a timing plate 13 is mounted on a drive plate 12 provided on a crankshaft 11 of the engine 10, a reference crank angle sensor 14 is provided on an inner peripheral side of the timing plate 13, and a unit crank angle sensor 15 is provided on an outer peripheral side. Is arranged.

As the reference crank angle sensor 14 and the unit crank angle sensor 15, an electromagnetic pickup is used here. A predetermined crank angle position (for example, BTDC) before the compression top dead center of each cylinder is provided on the side of the timing plate 13 corresponding to the reference crank angle sensor 14 at intervals of 120 ° in the case of six cylinders.
15 °), the reference signal REF is output from the reference crank angle sensor 14 each time the projection 16 passes (see FIG. 3).

Accordingly, the reference crank angle sensor 14 detects the crank angle (720 ° in the case of six cylinders) set by the number of cylinders.
/ 6 = 120 °) and a reference signal generating means for generating a reference signal REF corresponding to a predetermined crank angle position (BTDC 15 °) with respect to the top dead center of each cylinder. On the outer peripheral side of the timing plate 13, for example,
The teeth 17 are cut every 2 °, and 1 to 2 ° according to the rotation.
Each time, the unit signal POS is output from the unit crank angle sensor 15.

On the other hand, in synchronization with the crankshaft 11, 1 /
A timing plate 19 is attached to a camshaft 18 that rotates at a speed of 2, and a cylinder discrimination sensor 20 is disposed on the side of the timing plate 19. As the cylinder discrimination sensor 20, an electromagnetic pickup is used here. On the side of the timing plate 19 corresponding to the cylinder discrimination sensor 20,
Reference signal REF output from reference crank angle sensor 14
The number of cylinders that can be distinguished in between (for example, 6
(Projection 21) is provided, and when the projection 21 passes, a cylinder discrimination signal (a signal having a different number of pulses for each cylinder between the reference signals REF) PHASE is output from the cylinder discrimination sensor 20. .

That is, as shown in FIG. 3, in the case of a six-cylinder engine, corresponding to each of the # 1 to # 6 cylinders,
Between the reference signal REF, 4 pulses, 5 pulses, 2 pulses,
3 pulse, 6 pulse, 1 pulse cylinder discrimination signal PHAS
E is output. Here, the reference signal REF from the reference crank angle sensor 14, the unit signal POS from the unit crank angle sensor 15, and the cylinder discrimination signal PHASE from the cylinder discrimination sensor 20 are input to a control unit 22 for engine control. You.

In particular, when the present invention is applied to electronic distribution type ignition control, as shown in FIG. 4, a control unit 22 includes a microcomputer 23 for controlling the ignition timing, and an electronic control system for determining the cylinder of the ignition cylinder. Gate array to control power distribution
24. The microcomputer 23 receives a reference signal REF and a unit signal POS for controlling the ignition timing.

The microcomputer 23 sets an ignition timing in accordance with the operating state of the engine, and counts unit signals starting from the reference signal REF to output an ignition signal IG to the gate array 24 at the ignition timing. The reference signal REF and the cylinder identification signal PHASE are input to the gate array 24 for cylinder identification and electronic power distribution.

The processing contents of the cylinder discrimination and the electronic distribution based on the reference signal REF and the cylinder discrimination signal PHASE performed in the gate array 24 are shown in the flowcharts of FIGS. In the gate array 24, three storage units (shift registers) SR # 1 and SR # 3 corresponding to predetermined # 1, # 3 and # 5 cylinders among all the cylinders, respectively.
# 3 and SR # 5 are provided.

The flowcharts of FIGS. 5 to 7 will be described. In step 1 (indicated as S1 in the figure; the same applies hereinafter), it is determined whether or not the power is turned on (the power is turned off → on). Only when the power is turned on, the process proceeds to step 2 for initialization. Predetermined # 1, # 3, # 5 out of all cylinders
Storage unit (shift register) S corresponding to each cylinder
The stored contents of R # 1, SR # 3, and SR # 5 are cleared to 0. Further, the cylinder identification counter C and the first REF input flag F are cleared to zero.

After the power is turned on, the process proceeds to step 3. In step 3, the cylinder discrimination pulse (each pulse of the cylinder discrimination signal)
It is determined whether or not has been input. When a cylinder discrimination pulse is input, the cylinder discrimination counter C is counted up. After these, go to step 5.

In step 5, it is determined whether or not the reference signal REF has been input. When the reference signal REF is input, the process proceeds to step 6 to determine the value of the initial REF input flag F. If F = 0 (the first REF input after the power is turned on), the process proceeds to step 7 and the first REF is input. Input flag F = 1
And the cylinder discriminating counter C is cleared to 0, followed by terminating the present routine.

F = 1 (REF after the second power-on
In the case of (input), the process proceeds to step 8. In step 8,
Cylinder discrimination is performed based on the value of the cylinder discrimination counter C, and the cylinder discrimination result is set to X. This part corresponds to a cylinder determination unit. In the case of FIG. 3, when C = 4, X = # 1 cylinder, when C = 5, X = # 2 cylinder, and when C = 2, X = # 1 cylinder.
Cylinder # 3, X = # 4 when C = 3, X = # 5 when C = 6, X = # 6 when C = 1.

After the cylinder discrimination, the counter C for cylinder discrimination is cleared to 0 in step 9 and the routine proceeds to step 10 (FIG. 6).
In step 10, it is determined whether or not the cylinder discrimination result X = # 1 cylinder. If the cylinder is # 1 cylinder, the process proceeds to step 11, where #
The cylinder number 1 is written in the storage section SR # 1 corresponding to one cylinder.

If the cylinder is not the # 1 cylinder, the process proceeds to step 12, where it is determined whether or not the storage unit SR # 1 corresponding to the # 1 cylinder is in the clear state (= 0). Only when writing has been performed, the process proceeds to step S13. In step 13, the cylinder number stored in the storage unit SR # 1 corresponding to the cylinder # 1 is shifted to the next cylinder number in the ignition order and rewritten. That is, if SR # 1 = 1,
Rewrite to SR # 1 = 2, if SR # 1 = 2, SR #
Shift processing is performed such as rewriting to 1 = 3.

In the next step 14, the cylinder discrimination result X = #
It is determined whether or not the cylinder is a three-cylinder cylinder. If the cylinder is a three-cylinder cylinder, the process proceeds to step 15, and the cylinder number 3 is written into the storage unit SR # 3 corresponding to the third cylinder. If it is not # 3 cylinder, step 16
Then, it is determined whether or not the storage unit SR # 3 corresponding to the # 3 cylinder is in the clear state (= 0), and the process proceeds to step 17 only when SR # 3 ≠ 0 and writing has already been performed. .
In step 17, the cylinder number stored in the storage section SR # 3 corresponding to the cylinder # 3 is rewritten by shifting to the next cylinder number in the ignition order. That is, if SR # 3 = 3, rewrite to SR # 3 = 4, and if SR # 3 = 4, rewrite to S
A shift process is performed so as to rewrite R # 3 = 5.

In the next step 18, the cylinder discrimination result X = #
It is determined whether or not the cylinder is a 5-cylinder. If the cylinder is a 5-cylinder, the process proceeds to step 19, and the cylinder number 5 is written into the storage unit SR # 5 corresponding to the # 5 cylinder. If it is not # 5 cylinder, step 20
Then, it is determined whether or not the storage unit SR # 5 corresponding to the # 5 cylinder is in the clear state (= 0). Only when SR # 5 ≠ 0 and the writing has already been performed, the processing proceeds to step 21. .
In step 21, the cylinder number stored in the storage unit SR # 5 corresponding to the cylinder # 5 is shifted to the next cylinder number in the ignition order and rewritten. That is, if SR # 5 = 5, rewrite to SR # 5 = 6, and if SR # 5 = 6, rewrite to S
A shift process is performed so that R # 5 = 1 is rewritten.

Here, steps 11, 15, and 19 correspond to cylinder discrimination result writing means, and steps 13, 17, and 21 correspond to shift processing means. After these, the process proceeds to step 22 (FIG. 7) for a final decision. In step 22, it is determined whether at least one of the three storage units SR # 1, SR # 3, SR # 5 is 0.

If the determination in step 22 is NO, that is, if SR # 1 ≠ 0, SR # 3 ≠ 0, and SR # 5 ≠ 0, the three storage units SR # 1, SR # 3, SR # 5 is a case where the cylinder discrimination result is written at least once each time. In this case, the process proceeds to step 23. In step 23, 3
Based on the cylinder numbers stored in the two storage units SR # 1, SR # 3, and SR # 5, the final cylinder discrimination is performed by majority decision, and the result is set to Y. This part corresponds to the final determination means.

After step 23, the process proceeds to step 24,
It is determined whether the majority cannot be decided. That is, when the cylinder numbers stored in the three storage units SR # 1, SR # 3, and SR # 5 are the same for two or more cylinders, the final cylinder discrimination can be performed by majority decision, but all cylinders are different. Shall be undecidable. If the final cylinder discrimination is performed by majority vote, the process proceeds to step 25, and power distribution is performed on the Y cylinder finally discriminated.

If the majority cannot be determined, the process proceeds to step 26 to stop the power distribution. On the other hand, YE
In the case of S, that is, SR # 1 = 0 or SR # 3 =
0 or SR # 5 = 0, three storage units SR #
1, SR # 3, and SR # 5, in which the writing of the cylinder discrimination results has not been completed. In this case, the process proceeds to step 27.

In step 27, power distribution is performed to the X cylinder determined in step 8 by the cylinder determination signal.
Therefore, steps 22 and 27 correspond to switching means.
Next, FIG. 8 will be described. FIG. 8 shows three storage units SR # 1, SR # 3, SR # when cylinder determination results X are obtained in the order of 4, 5, 6, 1, 2, 3,.
5 shows the cylinder number stored in No. 5 and the cylinder number to be finally determined (distributed).

In the drawing, the circled cylinder number indicates that the cylinder discrimination result has been written, and the other indicates that the cylinder has been shifted.
In this example, SR # 1, SR # 3, S #
Since at least one of R # 5 is in the clear state (= 0), the cylinder discrimination result X becomes the cylinder for final determination (power distribution) as it is, and after time A, the cylinder for final determination (power distribution) is determined by majority decision. Can be

Further, even if an erroneous determination occurs in the cylinder determination result X as shown in the figure, the cylinder to be finally determined (distributed) is determined by majority decision, so that it can be understood that correct cylinder determination is possible. In the present embodiment, three cylinders corresponding to three predetermined cylinders among the six cylinders are used.
Although three storage units are provided, if the number is three, the number is smaller than that of all cylinders, and the arithmetic processing can be simplified. Further, since the number is odd, it is possible to simplify the judgment by majority decision. Wear. This can be said to be sufficient for four cylinders and eight cylinders.

However, the present invention is not limited to this, and it is possible to provide the same number as the number of cylinders or an even number. For even numbers, for example 4,
In some cases, the majority cannot be decided at 2: 2, but in this case, the power distribution should be stopped. Further, in the present embodiment, the cylinder discriminating apparatus for electronic distribution type ignition control has been described.
The cylinder discriminating apparatus according to the present invention is applicable not only to ignition control but also to a case where a fuel injection valve is provided for each cylinder to control the fuel injection timing for each cylinder (sequential control).

In the present embodiment, the electromagnetic pickup type is used as the crank angle sensor and the cylinder discrimination sensor, but a photoelectric type may be used.

[0037]

As described above, according to the present invention, even if a single abnormality occurs in the cylinder discrimination signal and the cylinder discrimination by the cylinder discrimination signal is erroneous, at least three cylinders among all the cylinders are handled. According to the data in the storage unit
By making the final decision by majority decision, correct cylinder discrimination can be performed, and the effect that the control based on the cylinder discrimination becomes good can be obtained.

Further, by making the number of storage units smaller than the number of all cylinders, the arithmetic processing can be simplified.
Further, by making the number of storage units odd, it is possible to simplify the judgment by majority decision. Further, until the cylinder discrimination result is completely written into all the storage units, the cylinder discrimination result based on the cylinder discrimination signal is used as the final cylinder discrimination result, so that control becomes impossible until the final discrimination becomes possible. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram of an embodiment of the present invention.

FIG. 3 is a diagram showing a reference signal and a cylinder discrimination signal.

FIG. 4 is a circuit configuration diagram in a control unit.

FIG. 5 is a flowchart of cylinder discrimination and electronic power distribution (part 1).

FIG. 6 is a flowchart of a cylinder determination and electronic power distribution routine (part 2).

FIG. 7 is a flowchart of a cylinder determination and electronic power distribution routine (part 3).

FIG. 8 is a diagram illustrating a state of a change in storage content of a storage unit;

[Explanation of symbols]

 10 Engine 11 Crankshaft 14 Reference crank angle sensor 15 Unit crank angle sensor 20 Cylinder discrimination sensor 22 Control unit 23 Microcomputer 24 Gate array

Claims (4)

(57) [Claims] 1. A reference signal generating means for generating a reference signal for each crank angle set by the number of cylinders and each corresponding to a predetermined crank angle position with respect to the top dead center of each cylinder, and each cylinder between the reference signals. A cylinder discriminating signal generating means for generating a cylinder discriminating signal capable of discriminating a cylinder, and a cylinder discriminating means for discriminating a cylinder from a cylinder discriminating signal between reference signals each time a reference signal is generated. At least three storage units respectively corresponding to at least three predetermined cylinders among the cylinders, and when one of the predetermined at least three cylinders is determined by the cylinder determining unit, Cylinder discrimination result writing means for writing a cylinder number, which is a cylinder discrimination result, in a storage unit corresponding to the cylinder; each time a reference signal is generated, Shift processing means for rewriting the cylinder number stored in each storage unit other than the storage unit in which the cylinder number has been written by the result writing means to the next cylinder number in the ignition order, and said cylinder each time a reference signal is generated. Final operation means for performing a final cylinder judgment by majority decision based on the cylinder numbers stored in all the storage units after the operation by the judgment result writing means and the shift processing means. Engine cylinder discriminating device. 2. The engine cylinder discriminating apparatus according to claim 1, wherein the number of said storage units is smaller than the number of cylinders. 3. An engine cylinder discriminating apparatus according to claim 1, wherein the number of said storage units is an odd number. 4. The method according to claim 1, wherein the writing to all the storage units is completed at least once by the cylinder discrimination result writing means.
A switching means for prohibiting cylinder discrimination by said final discriminating means and providing the cylinder discriminating result of said cylinder discriminating means as a final cylinder discriminating result is provided.
An engine cylinder discriminating apparatus according to claim 3.