JPH0256517B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition control device for a multi-cylinder internal combustion engine, and more particularly to an ignition control device equipped with a switching device for switching between individual ignition control of ignition coils and group-based ignition control during backup. Regarding equipment.

Hereinafter, the internal combustion engine will be abbreviated as engine.

As a conventional individual ignition control device, for example, in a 4-cylinder engine, the 1st cylinder, 3rd cylinder, 4th cylinder,
It is known that the second cylinder is discriminated, a cylinder discrimination signal is generated, and the ignition coils corresponding to each cylinder are sequentially activated by a microcomputer, etc., to perform ignition control.
Publication No. 143834 is known. In this case, when the microcomputer fails or when the engine starts, a backup circuit is provided and the backup circuit controls the ignition of each ignition coil.

However, with conventional ignition control devices, for example, even if an attempt is made to identify the first cylinder when starting the engine, the ignition coil cannot operate because the first cylinder cannot be identified unless the engine rotates twice at worst.
There was a problem that caused the engine to start poorly. Furthermore, in the case of a failure of the ignition control device, a backup circuit is provided to sequentially control and operate the ignition coils in the cylinders, which has the problem of complicating the circuit and increasing costs.

The present invention was made to solve the above-mentioned problems, and in order to perform ignition control of the ignition coils connected to each cylinder of a multi-cylinder engine, the ignition timing of each ignition coil is usually adjusted. Using a calculation ignition control means that performs calculation control, and using a group-based ignition control device that can control the ignition of a group of ignition coils group by group when the engine is started or when there is an abnormality in the calculation ignition control means. Even if an abnormality occurs, it can be backed up to improve engine starting performance.
Moreover, it is an object of the present invention to provide an ignition control device with a simple circuit configuration.

In order to achieve this object, the present invention provides an ignition coil connected to each cylinder of a multi-cylinder internal combustion engine, and an arithmetic ignition control means capable of controlling individual energization start points and energization end points of the ignition coil. , group-specific ignition control means for forming an ignition control signal for controlling the ignition of one group of ignition coils among the ignition coils on a group-by-group basis; and detection for detecting a failure of the arithmetic ignition control means or a starting state of the internal combustion engine. and means for switching between the computational ignition control means and the group-based ignition control device to perform ignition control of the ignition coil, and the detecting means detects when the computational ignition control means malfunctions or when the internal combustion engine is started. An ignition control device is provided, characterized in that when a state is detected, the ignition coils are controlled group by group by a group-specific ignition control means, and in other cases, the ignition coils are controlled individually by arithmetic ignition control means. be done.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, which are illustrated in the accompanying drawings.

1 and 2 are block diagrams of a first embodiment of the present invention. FIG. 1 is a block diagram showing the entire embodiment of the present invention, and the ignition control device according to the present invention includes a signal section 10 that generates various detection signals.
, an ignition coil section 50 , and a control unit 100 .

The signal section 10 includes a starter switch 1 that outputs a starter drive signal 1' when starting the engine, and a control value (ignition timing, closing angle, etc.) of the control unit 100 based on the engine condition (cooling water temperature, intake temperature, etc.). Correction signal 2' to be corrected (cooling water temperature sensor,
a correction device 2 that outputs a signal generated from an intake air temperature sensor, etc.; a load sensor 3 that outputs a load signal 3' (for example, an intake pipe pressure sensor signal, etc.) representing the engine load condition; and a battery voltage signal 4. ′
The battery voltage detection device 4 is attached to a camshaft that rotates in synchronization with the rotation of the engine crankshaft, and a reference position signal 5' (with the waveform shown in Figure 4b) of 4 pulses every 2 engine rotations is installed. G (reference position) signal sensor 5 and engine 2 that output a signal)
It is composed of an N (detection angle) signal sensor 6 which outputs an angle signal 6' (waveform signal shown in FIG. 3a) of 18 pulses upon rotation.

The control unit 100 includes a CPU 104 that receives output signals from various sensors, processes them, and outputs calculated ignition control signals, a cylinder discrimination signal and fixed ignition control formation circuit 110, and a CPU 104 that receives output signals from various sensors, processes them, and outputs calculated ignition control signals, a cylinder discrimination signal and fixed ignition control formation circuit 110, and a A start discriminator 101 and a fail discriminator 10.2 for detecting the occurrence of an abnormality,
It is composed of a watchdog timer 103, a multiplexer 106 for switching control outputs, and the like.

Since the ignition coil section 50 is based on a four-cylinder engine, four power transistors 60 are used in the ignition coil section 50.
~63, ignition coils 70~73, and spark plug 8
It consists of magnitudes 0 to 83.

The operation of the above device of the present invention will be explained next. 1st
In the figure, a starter signal 1' is input to a start determination circuit 101 and a CPU 104, and a correction signal 2', a load signal 3', and a battery voltage signal 4' are
Each is input to the CPU 104. The G signal 5' and the N signal 6' are input to the cylinder discrimination signal and fixed ignition control signal forming circuit 110.
A cylinder discrimination signal formed by 0 and an angle signal (N signal) are input to the CPU 104.

Further, the fixed ignition control signal formed by the cylinder discrimination signal and fixed ignition control signal forming circuit 110 is the first
Two types of fixed ignition control signals are sent to the multiplexer 106: a group-specific signal A for the cylinders and the fourth cylinder group [FIG. 4c] and a group-specific signal B for the second and third cylinder groups [FIG. 4d]. is input. The other input signal to multiplexer 106 is
Calculated by CPU 104. Calculated ignition control signals for each cylinder are input. The logic output of the OR circuit 107 is input to the control input terminal of the multiplexer 106, which switches the above-mentioned calculated ignition control signal to either the fixed ignition control signal or the fixed ignition control signal.
By applying the output signal of the circuit 107 to the bases of the power transistors 70 to 73 that drive the ignition coils 70 to 73 arranged for each cylinder, the calculated ignition control signal is fixed ignition control. The configuration is such that the signal can be switched to either signal. Note that 80 to 83 are spark plugs attached to each cylinder, and a terminal 90 is supplied with battery power. The input signal of the OR circuit 107 is the output signal of the start determination circuit 101 which receives the starter drive signal 1' and determines whether or not it is in the start state, or
There are three input signals: an output signal from a fail determination circuit 102 for determining whether or not the CPU 104 is in a fail state, and an output signal from a watchdog timer 103.

Next, the internal structure of the cylinder discrimination signal and fixed ignition timing signal forming circuit 110 will be explained with reference to FIG. The N signal 6' and the G signal 5' are input to waveform shapers 111 and 112, and their output signals D and E are both input to an AND circuit 113. The waveform shaped output D of the N signal is input to the reference position detection circuit 115. The waveform-shaped output E of the G signal is input to one end of an XOR (exclusive OR) circuit 114. the other
The output signal of the AND circuit 113 is input to the input of the XOR circuit 114.

The output signal of the AND circuit 113 is input to a variable pulse width circuit 116, which changes the pulse width to become the signal A shown in FIGS. 1 and 2. Similarly, XOR circuit 114
The output is input to the variable pulse width circuit 117 and becomes the signal B shown in FIGS. 1 and 2. The output of the waveform shaping circuit 111 is transmitted to the reference position detection circuit 11.
1 and 2 sent to the CPU 104 via
The reference position signal C shown in the figure and the CPU 1 as it is.
04 and the angle signal D shown in FIG. 1 and FIG.

Next, the configuration of the G signal and N signal detection section will be explained with reference to FIGS. 3a and 3b. FIG. 3a is a front view of the slit disk 8 having slits for detecting G and N signals, and FIG. 3b is a sectional view taken along line 3b-3b' of FIG. 3a. On the outer periphery of the slit disk 8, there are slits with unequal pitch on the outer periphery for cylinder discrimination, and slits with equal pitch on the outer periphery 6 for obtaining the N signal.
-1 to 6-17 are provided. Further, on the inner periphery of the slit disk 8, inner periphery slits 5-1 to 5-4 are provided for obtaining G signals. These slits detect the presence or absence of light reception by light emitting diodes 7-1, 7-2 and phototransistors 7-3, 7-4 supported by the stay 7, and output them as digital signals of G signal and N signal. be done. The light emitting diodes 7-3, 7-4 are arranged linearly in the direction of the center of the slit disk 8, and the waveforms of the N symbol and the G symbol shown in FIG. 4a and FIG. 4b, respectively, are obtained. The width and position of the slit are set accordingly. Note that the arrow in FIG. 3a indicates the rotation direction of the engine crankshaft.

Next, the normal operation (excluding startup) of the first embodiment will be explained with reference to FIG. CPU1
04 receives the load signal 3', correction signal 2', battery voltage signal 4', angle signal D, reference position signal C, etc., and determines the optimal control values (ignition timing and ignition coil energization time) for the current engine conditions. calculate. In this embodiment, one ignition coil is applied to each cylinder.
, the calculation output for four cylinders from the CPU 104 is sent to the multiplexer 106. Here, when the system is normal, the multiplexer 106 inputs the calculated ignition control signal, which is the calculated output of the CPU 104, to the bases of the power transistors 60 to 63 for driving the ignition coil.
The ignition coils 70 to 73 are sequentially controlled based on the calculation result of step 04. (For example, the ignition timing and ignition coil charging start timing are controlled for each cylinder by control values.) Next, the timing of starting the engine and the abnormality of the control device will be explained. In this case, in order to determine whether the system is normal (excluding when starting) or not (including when starting), the start determining circuit 101 receives the starter signal 1' and determines whether or not it is starting. If so, a high level signal is output to the OR circuit 107. On the other hand, if the CPU 104 determines that the peripheral circuits or sensors of the CPU 104 are malfunctioning, it sends a signal indicating that it is a fail time to the fail determination circuit 102.
2 is an OR circuit 10 that outputs a high level signal at the time of fail.
Output to 7. If the watchdog timer 103 determines that the CPU 104 itself is abnormal, it outputs a high level signal to the OR circuit 107 as the output of the watchdog timer 103. As described above, the ignition control is switched to the fixed control and the calculation ignition control is backed up at the time of starting, when there is an abnormality in the CPU 104 peripheral circuits and sensors, or when the CPU 104 itself is abnormal.

Next, the operation of the cylinder discrimination signal and fixed ignition control signal forming circuit 110 will be explained using FIGS. 2 and 4. When the G signal 5' and N signal 6' in Fig. 2 are passed through waveform shaping circuits 112 and 111, respectively, waveforms such as the E signal shown in Fig. 4b and the D signal shown in Fig. 4a are obtained, respectively. . When these two broken shapes are input to the AND circuit 113 and the logical sum of the two is taken, the waveform shown in Fig. 4c is obtained, which is a signal for each cylinder group.
A′ (group of 1st and 4th cylinders or 2nd cylinder group)
A signal for determining the cylinder and the third cylinder group is obtained. The output signal A' (waveform shown in FIG. 4c) of the AND circuit 113 and the signal E after waveform shaping of the G signal (waveform shown in FIG. 4b) are connected to the XOR circuit 11.
4, the waveform shown in FIG. 4d, that is, the B' signal for each cylinder group (a signal whose phase is shifted by 180 CA from the waveform shown in FIG. 4c) is obtained. These cylinder group signals A' and B' are sent to a variable pulse width circuit 116.
and 117, and change the pulse widths of the cylinder group signals A' and B' to appropriate pulse widths to obtain output signals A and B. (CPU10 from cylinder group signals A' and B'
In order to obtain an ignition signal waveform suitable for performing the backup of No. 4, it is necessary to vary the pulse width based on the engine rotation speed, battery voltage, etc. ) Next, the G signal and N required for calculation by the CPU
The signal is obtained by guiding the output signal of the waveform shaping circuit 111 to the reference position detection circuit 115. This signal is generated once every two revolutions of the engine (reference position signal C shown in Figs. 1, 2, and 4 e)
Using the angle signal D shown in FIG.
The CPU 104 calculates and outputs a necessary calculated ignition control signal.

In the first embodiment described above, the G signal and the N signal are transmitted using the light emitting diodes 7-1, 7-2 and phototransistors 7-3, 7-4 attached to the slit of the slit disk 8 and the stay 7. from the G signal and N signal, a cylinder discrimination signal and a fixed ignition timing signal are determined.
Group signals are formed, and fixed ignition control signals are divided into groups for the first and fourth cylinders, and the second and third cylinders via a multiplexer, and are used when starting the engine or backing up the engine. Therefore, even if a failure is detected in the arithmetic ignition control device that controls each cylinder individually or when the internal combustion engine is started, the fixed ignition control signal is used to group the internal combustion engine while the internal combustion engine rotates at least 1/2 revolution. This makes it possible to control the ignition coil and improve the startability of the internal combustion engine. Furthermore, since the internal combustion engine is controlled by group, the circuit configuration can be simplified compared to individual control, and reliability can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the N signal and the G signal are detected by magnetic means using a proximity switch composed of a signal rotor and a pickup coil. Figure 5a and Figure 5b, which is a side view of the same.
In the figure, 501 is a signal rotor for N signals, and 502 is a signal rotor for G signals. Further, 503 and 504 are pickup coils for detecting an N signal and a G signal, respectively. Protrusions corresponding to the N signal and G signal are provided on the outer peripheries of the signal rotors 501 and 502, respectively, and pickup coils 503 and 504 respond to the proximity of the protrusions to generate the waveforms of the D signal and E signal shown in FIGS. The purpose is to obtain the following.
Note that the arrow in the figure indicates the rotation direction of the signal rotor 501. Other configurations and operations are similar to those of the first embodiment. According to the second embodiment, the N signal and the G signal are detected by the magnetic detection means generated by the proximity of the signal rotor to the pickup coil.
Therefore, there is no detection error due to dust, etc., and the N
The signal and the G signal can be detected, and as a result, the reliability of the solid state ignition control device can be improved.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. In this embodiment, N signal, G signal,
The three signals of the first cylinder discrimination signal are connected to the slit disk 600.
and an optical sensor.
In FIG. 6, 600 is a slit disk;
A slit 601 for N signal detection is provided on the outer periphery of the slit disk, a slit 602 for G signal detection is provided inside the slit 601, and a slit 603 for determining the first cylinder is provided on the inner periphery. It is.
The above-mentioned signals are then detected by optical means (such as a combination of a light emitting diode and a phototransistor) using these slits, and are used as inputs to an ignition control device.

FIG. 7 shows a block diagram of the third embodiment, in which the first cylinder discrimination signal 603' is input to a fixed ignition control signal forming circuit 110'. Here the first
If the cylinder discrimination signal 603' becomes abnormal due to noise, disconnection, short circuit, etc., it is determined as a fail by the fixed ignition control signal forming circuit 110', and a fail signal is sent to the fail discrimination circuit 102. Further, a fixed ignition control signal forming circuit 110' forms a fixed ignition control signal based on the N signal and the G signal, and generates an ignition signal for each group of cylinders to control ignition. Other configurations and operations are similar to those of the first embodiment.

According to the third embodiment, since the N signal, the G signal, and the first cylinder discrimination signal are obtained by sensors, the fixed ignition control signal forming circuit 110' is more effective than the first and second embodiments. It gets easier. That is, in the first and second embodiments, a discrimination circuit was required to obtain a discrimination signal for the first cylinder contained in the N signal using the N signal and the G signal. In this way, in this third embodiment, the circuit configuration is simplified and reliability can be improved.

Next, individual ignition control and group-based ignition control by the microcomputer will be explained with reference to FIG. FIG. 8 shows a flowchart for switching between group-specific ignition control and individual ignition control. If the microcomputer starts based on the arithmetic processing of data and programs in RAM and ROM (not shown), In step 810, it is determined whether the internal combustion engine is starting. If it is the time of starting, select YES to proceed to step 820, perform group-specific ignition control, and return to step 850. step
If it is determined at 810 that the engine is not starting, the process proceeds to step 830 (NO), and it is determined whether or not the first cylinder has failed. If it fails, select YES to proceed to step 820 and receive group-specific ignition control. Unless it fails
If NO, proceed to step 840, receive individual ignition control, return, and repeat the same judgment and execution.

Fail discrimination can be performed through such arithmetic processing by a microcomputer, and control of the ignition coils can be switched from individual control to group control.

As described above, according to the present invention, it is possible to maintain good engine startability even when the engine is started or when an abnormality occurs in the calculation ignition control means. Further, the circuit configuration is simple, yet the backup function can be reliably performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an ignition control device according to a first embodiment of the present invention. FIG. 2 is a block diagram of a cylinder discrimination signal and fixed ignition control signal forming device. Figures 3a and 3b are external views showing optical detection means for G and N signals.
FIG. 4 is a diagram showing a timing chart of an embodiment of the present invention. FIGS. 5a and 5b are diagrams showing a signal detection device of an ignition control device according to a second embodiment of the present invention. FIG. 6 is a diagram showing a signal detection device of an ignition control device according to a third embodiment of the present invention. 7th
This figure is a block diagram showing the configuration of an ignition control device according to a third embodiment of the present invention. FIG. 8 is a flowchart showing the logic of switching control by a computer. (Code number), 1... Starter switch, 2
... Correction device, 3 ... Load sensor, 4 ... Batch voltage detection device, 5 ... G (reference position) sensor,
5-1 to 5-4...G signal slit, 6...N
(Detection angle) sensor, 6-1 to 6-17...N signal slit, 7...detection section, 7-1, 7-2...
...Phototransistor, 7-3, 7-4...Light emitting diode, 8...Slit disk, 10...Signal section, 50...Ignition coil section, 60-63...Power transistor, 70-73...Ignition coil, 1
00...Control unit, 101...Start discriminator,
102...Fail discriminator, 103...Watchdog timer, 104...CPU, 106...Multiplexer, 110...Cylinder discrimination signal and fixed ignition control signal forming circuit, 110'...Fixed ignition control signal forming circuit , 501... Signal rotor for N signal, 502... Signal rotor for G signal, 50
3,504... Pick up coil, 600...
Slit disk, 601...Slit for N signal, 6
02...Slit for G signal, 603...Slit for determining the first cylinder.

Claims (1)

[Scope of Claims] 1. An ignition coil connected to each cylinder of a multi-cylinder internal combustion engine; an arithmetic ignition control means capable of controlling an energization start point and an energization end point of each of the ignition coils; and a group of the ignition coils. group-specific ignition control means for forming an ignition control signal for controlling the ignition of the ignition coils for each group; detection means for detecting a failure of the calculation ignition control means or a starting state of the internal combustion engine; means for switching between the arithmetic control means and the group-specific ignition control means to perform ignition control, and when the detection means detects a failure of the arithmetic ignition control means or a starting state of the internal combustion engine, An ignition control device characterized in that the ignition coils are controlled by group by group ignition control means, and in other cases the ignition coils are individually controlled by calculation ignition control means. 2. In the ignition control device according to claim 1, the group-specific ignition control means controls a slit disk that rotates in synchronization with the crankshaft of the internal combustion engine and a rotational position of the slit in the slit disk. A cylinder discrimination signal and a group-specific ignition control signal are formed using a G (reference position) signal and an N (detection angle) signal generated by an optical means for detection, and these signals are applied to a group of ignition coils. An ignition control device characterized in that it is used as a signal for controlling ignition by group. 3. In the ignition control device according to claim 1, the group-based ignition control means generates a magnetic field generated by a rotor that rotates in synchronization with the crankshaft of the internal combustion engine and a magnetic detection means that cooperates with the rotor. G to do
(reference position) signal and N (detection angle) signal to form a cylinder discrimination signal and group-specific ignition control signal, and use these signals as signals for controlling ignition of a group of ignition coils group-by-group. Characteristic ignition control device. 4. In the ignition control device according to claim 1, a group-specific ignition control signal is formed by a detection signal from a sensor that generates a G (reference position) signal, an N (detection angle) signal, and a cylinder discrimination signal, An ignition control device characterized in that it is used as a signal for controlling ignition of a group of ignition coils group by group.