JPH0552172A - Control device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a control device for an internal combustion engine that can perform electronic power distribution even if a cylinder discrimination sensor fails. [Structure] When the cylinder discrimination sensor fails, ignition is performed to one of the coils of the cylinder group obtained from the reference position signal. As a result of ignition, if the increase in engine speed is recognized, the control is continued as it is, and if the increase in engine speed is not recognized, the control is continued by switching to the other and performing control for the cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine, which enables good control even when an angle detector which generates a cylinder discrimination signal fails.

[0002]

2. Description of the Related Art In electronic power distribution control, instead of a conventional distributor provided on a crankshaft determining an ignition cylinder, the cylinder discrimination signal information is used to determine the cylinder in question and the ignition coils are sequentially provided with ignition signals. The method of distribution is adopted.

Therefore, when the angle detector that generates the cylinder discrimination signal fails, the cylinder discrimination becomes impossible. Therefore, conventionally, it has been proposed that the engine can be started by performing simultaneous ignition from a reference position detection signal provided on the crankshaft as a substitute signal, which is disclosed in Japanese Patent Laid-Open No. 60-98171. Has been done.

[0004]

However, when performing simultaneous ignition, ignition sparks are originally generated in cylinders that do not need to be ignited. Therefore, when the fuel remaining in the cylinders is vaporized, etc. Due to this ignition spark, combustion occurs in a cylinder that should not be ignited, torque is generated in a direction opposite to that in normal ignition, and in the worst case, an accident such as engine damage may occur. In order to eliminate this problem, it is necessary to set the valve timing and the ignition timing to a position where such a problem does not occur, which is a great limitation on engine performance.

[0005]

In order to solve this problem, when an angle detector that generates a cylinder discrimination signal fails, one of a pair of coil groups detected from a reference position signal is detected. This is achieved by obtaining the means for selecting one coil from the engine information.

[0006]

When the cylinder discrimination signal fails, one of the pair of coil groups obtained from the reference position signal is determined as the cylinder to be originally ignited, and the ignition control is started. If the selected cylinder is the cylinder to be originally ignited, this ignition raises the engine speed. If the rotation increase does not occur even if the ignition is started, the other cylinder is reselected, the ignition control is started in the same manner as described above, and the rotation increase is determined. By performing these series of operations, it becomes possible to ignite only the cylinder to be ignited even when the cylinder discrimination signal fails.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A system configuration of an embodiment of the present invention will be described with reference to FIG. This embodiment is a 4-cylinder engine. The engine 1 is provided with an injection valve 3 and an ignition coil 4 for each cylinder. The cylinder discrimination sensor 2 is directly connected to the cam shaft.
A pin 7 is set at a reference position on a ring gear 8 connected to the crankshaft, and the magnetic angle sensor 5 and the magnetic reference position sensor 6 have a gap of about 1 mm with the gear 8 and the pin 7, respectively. Installed. When the engine 1 starts rotating, the cylinder discrimination sensor 2, the magnetic angle sensor 5, and the magnetic reference position sensor 6 generate the signals shown in FIG.
In FIG. 2, 201 is a cylinder discrimination signal generated by the cylinder discrimination sensor 2, 202 is a reference position signal generated by the magnetic reference position sensor 6, and 203 is an angle signal generated by the magnetic angle sensor 5. These signals are input to the unit 10 of FIG. 1, which sends a signal to the power transistor 9 for the ignition timing and cylinder position determined from this signal and other signals. In response to this signal, the power transistor 9 cuts off the current of the corresponding ignition coil 4 and ignites for each cylinder. Here, first, the processing method when the cylinder discrimination sensor 2 is normal will be described, and then the processing when the cylinder discrimination sensor 2 that is the object of the present invention fails will be described.

First, when the cylinder discrimination sensor 2 is normal, the signal input to the unit 10 is processed according to the block diagram of FIG. As the input signals, the cylinder discrimination signal 201, the reference signal 202, and the angle signal 203 shown in FIG. 2 are input, and the signal 201 is converted into cylinder information by the cylinder discrimination circuit and input to the microcomputer 305. The microcomputer 305 has an ignition output line 30.
6 to 309, the output for the first cylinder is from 306 to the second
The cylinder output is from 307, and there is an output corresponding to each cylinder. The signal 202 is input to both the cylinder discrimination circuit 304 and the microcomputer 305, and the signal 203 is input to the microcomputer 305. Here, the cylinder discrimination signal circuit 304 counts the number of cylinder discrimination signal pulses 201 input between the pulses generated by the reference position signal 202, and the cylinder information is transmitted to the signal line 310, when the reference position signal 202 is input. 311 is output as binary number information. As specific information, when four pulses of the cylinder discrimination signal 201 are input during the reference position signal pulse 202, 0 is output to the signal line 310 and 0 is output to the signal line 311.
When three pulses of the cylinder discrimination signal 201 are input, both the signal lines 310 and 311 are "1, 0" when two pulses of the cylinder discrimination signal 201 are input, and when one pulse of the 201 is " When the 0, 1 ″, 201 pulses are 0, the previously input information is held.
The microcomputer 305 confirms the information of the signal lines 310 and 311 every time the reference position signal 202 is input, and determines which position of the ignition output information 306 to 309, that is, which cylinder the ignition signal is generated based on this information. And output a signal. The series of steps 204 to 2 in FIG.
The cylinder-specific ignition signal of 07 is output from the unit 10 to the power transistor 9, and accordingly, the ignition signal is supplied to the ignition coil 4.

However, in the case where the cylinder discrimination signal 201 is not input due to a malfunction of the cylinder discrimination sensor 2, FIG.
The cylinder discriminating circuit 304 does not operate, and the ignition cylinder cannot be determined. Here, the only cylinder information is the pulse interval difference of the reference position signal 202 in FIG. 2, and it can be seen that when the interval is narrow, it is one of the 1 and 3 cylinders. Therefore, the microcomputer 305 is provided with the processing shown in FIG. FIG. 4 is executed every time the pulse of the reference position signal 202 is input. In step 401, it is determined whether or not the cylinder discrimination sensor 2 is out of order, and when it is determined to be normal, the process proceeds to step 419 and the cylinder information signals 310, 311
The ignition cylinder is determined according to. If a sensor abnormality is detected, the routine proceeds to step 402, where it is judged if the cylinder discrimination end flag is set. This flag is set to step 41.
This flag is set after the determination of the ignition cylinder is completed in 3. If it is determined in step 402 that the cylinder determination has not ended, it is determined in step 403 whether the cylinder selection start flag is set. When the flag is not set, the routine proceeds to step 404 to start the cylinder selection, and the time interval at which the pulse of the reference cylinder signal 202 is input is determined. Here, the previous pulse interval and the current pulse interval are compared. If the current time interval is ⅛ or less compared to the previous time, this position indicates one cylinder or three cylinders from FIG. Expected to be one. Therefore, first in step 405, the cylinder selection start flag is set to store that the cylinder selection has started. Then, the ignition signal for one cylinder is permitted in step 406, the cylinder counter is set to 1 in step 407, and the flowchart is ended. When the cylinder selection start flag is set in step 403, the process proceeds to step 408 and step 4
It is determined whether or not the cylinder selected after 04 is correct.
In step 408, it is determined whether the engine speed has risen compared to when this step was executed last time, and if it has risen, the routine proceeds to step 409 and the rise counter is counted up. When the rotation increase is not detected in step 408, the down counter is counted up in step 420 and the process proceeds to step 410. In step 410, the value of the descending counter is checked. If the counter value is 8 or more, it is determined that the wrong cylinder is ignited, and the value of the cylinder counter is incremented by 2 in step 412. Since the ignition cylinder is selected according to the value of this cylinder counter, increasing the counter value by 2 means reselecting the other cylinder of the cylinder group selected in step 406. Then, in step 413, the cylinder discrimination end flag is set, and the fact that the cylinder discrimination is completed is stored. On the other hand, when the down counter is less than 8 in step 410, the process proceeds to step 411 and it is determined whether the up counter is 16 or more. If it is equal to or greater than the counter 16, it is determined in step 406 that the cylinder selected is correct, and therefore the rotation increase occurs, and in step 413, the cylinder determination end flag is set,
Go to step 414. In step 414, the pulse interval of the reference signal is determined similarly to step 404, and if the interval is ⅛ or less of the previous interval, step 4
If it is determined that the value is larger than 1/8, the process proceeds to step 415. In step 415, the cylinder counter is incremented by 1, and in step 416 it is determined whether the cylinder counter is 5 or more. If it is 5 or more, the cylinder counter value is decremented by 4 in step 417, and then the process proceeds to step 418. If it is less than 5, the process directly proceeds to step 418. In step 418, ignition is permitted for the cylinder corresponding to the cylinder counter value, and the flow chart of FIG. 4 ends. The reason why the cylinder counter value is repeatedly incremented from 1 to 4 in steps 414 to 417 is 4
This is because the cylinder counter is changed from 1 to 4 and the corresponding cylinder is ignited by taking the cylinder engine as an example, and the cylinder counter is changed from 1 to 6 in the 6-cylinder engine. It is also effective to use the engine state function as the determination data used for determining the counter in steps 410 and 411. Further, in step 408, instead of determining whether the engine speed has increased, it is determined whether the intake air amount has increased, or if an in-cylinder pressure sensor that detects the in-cylinder pressure is installed in each cylinder, the cylinder that has ignited It is also effective to detect the increase in pressure and determine the cylinder to be ignited by determining whether or not the result is a predetermined value or more.

[0010]

According to the present invention, since the ignition output can be supplied only to the cylinder to be ignited even when the cylinder discrimination sensor is out of order, the ignition timing is limited to avoid unnecessary ignition to the cylinder. It is possible to maintain the same performance as in normal times.

[Brief description of drawings]

FIG. 1 is a system configuration of the present invention.

FIG. 2 is a signal diagram.

FIG. 3 is a signal processing block diagram.

FIG. 4 is a flowchart showing the operation of the present invention.

[Explanation of symbols]

1 ... Engine, 2 ... Cylinder discrimination sensor, 3 ... Injection valve, 4 ...
Ignition coil, 5 ... Angle sensor, 6 ... Reference position sensor, 7
... reference position detection pin, 8 ... ring gear, 9 ... power transistor, 10 ... unit, 11 ... water temperature sensor.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F02P 5/15 B 9150-3G

Claims (5)

[Claims] 1. An ignition coil provided for each cylinder of an internal combustion engine, a cylinder discrimination sensor for discriminating a cylinder of the engine, and a reference position detection sensor for discriminating a reference position of each cylinder,
Ignition control means which has at least the above-mentioned two sensors and executes ignition for each cylinder using the signals of the above-mentioned two sensors, and a group of ignition coils including the cylinder to be ignited from the reference position signal. In the control device of the internal combustion engine having the determining means, the determining means, when the cylinder determining sensor is out of order, selects one of the coils of one group based on the cylinder information obtained from the reference position signal to perform ignition. A control device for an internal combustion engine, which detects a change in physical information of the internal combustion engine after starting ignition and switches the selection. 2. The control device for an internal combustion engine according to claim 1, wherein the selection condition of the coil is performed by increasing or decreasing an intake air flow rate of the internal combustion engine. 3. The control device for an internal combustion engine according to claim 1, wherein the selection condition of the coil is performed by increasing or decreasing the rotation speed of the internal combustion engine. 4. The control device for an internal combustion engine according to claim 1, wherein the selection condition of the coil is performed based on in-cylinder pressure sensor output information provided in each cylinder. 5. The physical information of the internal combustion engine according to claim 1, wherein when the cylinder discrimination sensor is out of order, one of the cylinder groups to be injected is selected according to the cylinder information obtained from the reference position signal, and the injection is started. The control device for an internal combustion engine is characterized in that the change is detected and the selection is switched.