JPS61277872A - Ignition control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable continuance of normal running operation, by providing a high-reliable backup circuit which, even when a microcomputer is inoperative, maintains minimum ignition function and enables the performance of normal running operation. CONSTITUTION:In a backup signal generating circuit 6, a reference angle signal 3A and an angle signal 3B are inputted and a backup signal 6A with a specified pulse width is also outputted. A number coincidence detecting circuit 7 monitors operation of a microcomputer 4, and outputs a monitor signal 7A. A selection switching circuit 8 is atuated according to a monitor signal 7A, during normal operation, an ignition signal 4A from the microcomputer 4 is selected, and during abnormal operation, the backup signal 6A from the backup signal generating circuit 6 is selected to output an output ignition signal 8A to an igniting device 9. The signal 8A is energized to an ignition coil 10, and a generated high voltage is guided to an ignition plug 12 through a distributor 11 to ignite, in order, cylinders.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition control device for an internal combustion engine using a microcomputer, and more particularly to an ignition control device equipped with a back-up function of a microcomputer.

[Conventional technology]

In electronic ignition control devices using microcomputers,
The optimum ignition timing and ignition fill energization time are calculated based on engine rotation information such as the number of rotations of the engine, and operating information such as intake air volume, cooling water temperature, and idle detection that indicate the engine operating status, and the 5 giant fires are calculated. It is outputting a signal. This makes it possible to perform fine-grained ignition control that matches the operating conditions of the engine, which is useful for improving engine performance such as improving fuel efficiency.

However, since a microcomputer is used, the program may run out of control due to an abnormal drop in the power supply voltage, an abnormal value input due to external noise, etc., and the computer control may become impossible. Furthermore, the system may stop due to a failure of the microcomputer itself. Conventional devices have a problem in that in such a case, ignition cannot be started and the engine cannot be fully operated.

When such a problem occurs, P! Unexamined Japanese Patent Publication No. 57-103501 as a backup device that enables the return operation of the i-leap.
No. 57-193766, etc. have been proposed.

The former uses a microcomputer to determine that an abnormality has occurred in the engine's rotation angle detection signal and backs it up, and is of no use if the microcomputer itself malfunctions. The latter is a two-buff, one-buff circuit that fixes the ignition timing when the microcomputer is not in operation to the generation timing of the reference angle signal. The problem is that the operating performance of the engine is extremely deteriorated when the micro-funnel valve is activated because the engine must be set at a rank angle position where ignition is possible.
There is a

[Problem that the invention seeks to solve]

The present invention has been made in order to solve the above-mentioned problem α, and provides a highly reliable backup circuit that maintains the minimum ignition function even when the microcomputer is not activated and enables normal driving. Equipped with engine ignition control￥C
The purpose is to provide a

[Means for solving problems]

For two reasons, the PISl invention of the present invention includes a reference angle sensor that detects the rotation of the internal combustion engine and generates a reference angle signal at a specific rotation angle position of the cylinder, and a reference angle sensor that also detects the rotation of the engine and outputs an angle signal to a predetermined rotating paper. It is equipped with a control computer that calculates the ignition timing based on the generated angle sensor and the engine operating status information such as the +91 rotation angle information and the intake air amount based on the above two signals and outputs the first generation large signal. The ignition control device includes a monitor circuit that monitors the abnormal operation of the control computer and outputs a monitor signal, and a monitor circuit that counts the number of angle signals generated after inputting the reference angle signal, and the count value becomes a specific count value. a backup signal generation circuit capable of outputting a backup signal of a fixed time width in synchronization with an angle signal when An ignition control device for an internal combustion engine is provided, characterized in that it is equipped with a selection switching circuit that outputs an output to the ignition f& position by switching.

In the second invention, in addition to the configuration of the first invention, a count value switching circuit is added that selects and switches a specific count value of the angle signal that determines the aiming to output the backup signal according to the starting signal from the starter. An ignition control device for an internal combustion engine is provided.

[Effect]

According to the configuration of the first invention, the control computer outputs the ignition signal with the timing and pulse width calculated based on the rotation information and the operating state information, and the backup signal generation circuit outputs the ignition signal with a specific count of angle No. 43. A backup output signal with a constant pulse width is constantly output in synchronization with the value. During normal operation, the selection switching circuit outputs an ignition signal from the control computer to the ignition device, causing direct ignition. When an abnormality occurs such as when the control computer is not operating, the abnormality is detected by the monitor circuit, and the selection switching circuit selects the backup signal from the backup signal generation circuit in place of the ignition signal and outputs it to the ignition ii to ignite.

Therefore, even when the $ control computer is inactive, the backup signal can maintain the minimum direct fire function. In addition, the backup signal is not synchronized with the reference angle signal, but is output in synchronization with the angle signal that corresponds to a specific count value counted from the reference angle signal. By setting the count value to correspond to the ignition timing suitable for driving, driving operation close to normal driving becomes possible. In addition, since the bank 1 signal is a pulse with a fixed time width, even if the engine stalls during the output of the backup signal, the energization to the Recca coil in the ignition system will not continue. There is no risk of burning out the ignition fill.

According to the configuration of the second invention, in addition to the effect of the first invention, the specific count value is switched at the time of starting (during cranking) by the count value switching circuit, and is different from that during operation. A back amplifier signal is output in synchronization with a specific count value. Therefore, it is possible to set specific count values corresponding to different ignition timings for starting, when a later ignition timing is appropriate, and during operation, when a more advanced direct ignition timing is appropriate. Even when the control computer is not operating, it is possible to operate the vehicle closer to normal operation.

〔Example〕

Embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the first invention.

The reference angle sensor 1 and the angle sensor 2 are electromagnetic pickup type detectors that are built into the distributor and detect the rotation angle of the crankshaft. The reference angle sensor 1 generates a reference angle signal at a specific crank angle advanced several degrees from the top dead center of each cylinder, and the angle sensor 2 generates an angle signal every 30° rotation of the crankshaft. Reference angle sensor 1 and angle sensor 2
The voltage signal from is led to the waveform shaping circuit 3, and outputted to the microcomputer 4 as a reference angle signal 3A and an angle signal 3B shaped into pulses.

The microcomputer 4 includes an air meter 51 for detecting the amount of intake air, a throttle sensor 52 for detecting the amount of throttle operation, a water temperature sensor 53 for detecting the cooling water temperature, a voltage sensor 54 for detecting the buffer voltage, etc. Each operating state sensor 5 is connected to input operating state information of the engine. The microcomputer 4 calculates the optimum ignition timing and energization time to the ignition coil based on the rotation angle information from the reference angle sensor and the angle sensor 2, and the operating state information from each operating state sensor 5, and outputs the ignition signal 4A. Output.

The backup signal generation circuit 6 receives the reference angle signal 3A and the angle signal 3B, and outputs a backup signal 6A of constant pulse +11i. A number coincidence detection circuit 7, which is an example of a monitor circuit, monitors the operation of the microcomputer 4 and outputs a monitor signal 7A. Then, in accordance with the monitor signal 7A, the selection switching circuit 8 selects the ignition signal 4A from the microcomputer 4 in normal conditions, selects the pickup signal 6A from the backup signal generation circuit 6 in abnormal conditions, and outputs the ignition signal to the ignition device 9. In the zero ignition system fi9 that outputs the signal 8A, the ignition coil 10 is energized by the output ignition signal 8A, and the high voltage generated when the energization is cut off is guided to a predetermined spark plug 12 via the distributor 11 11, and is sequentially applied to each cylinder. ignite.

The backup signal generation circuit 6 will be explained.

This circuit counts the number of generated angle signals 3B from the angle sensor 2, and counts the number of generated angle signals 3A from the reference angle sensor 1.
A counter 21 that is reset by a counter 21, a monostable multi-by-break 22 that is triggered by an angle 59 when its count value reaches a specific count value, a date circuit 23, 24, and a differential pulse that detects the rising edge of the input signal. and an edge detection circuit 25 that outputs. counter 21
is a six-step counter having six output terminals A, B%C1, .

Figure $2 is a timing chart illustrating the operation of the backup signal generation circuit 6.

The counter 21 is reset with the reference angle signal 3A, and the counter outputs 21A to 21FIJ are output every time the angle signal 3B is input thereafter.
f changes sequentially and becomes high level. Is the last counter output 21F OR? -) Since the circuit configuration is such that the counter 21 is reset together with the reference angle signal 3A by the counter 24, the counter output 21F is reset by its own output and becomes a spike-like pulse. Counter output 21A, 21B,...
・, 21F each have a cafunto value of the angle signal of 1.2,
. . . indicates that it is 6. As mentioned above, the angle signal 3B is a 30° crank angle (hereinafter referred to as CA).
Since the angle signal immediately after the reference angle signal 3A is generated is generated at the top dead center (TDC) position of the cylinder, the rising point of the counter output 21A, which is the count value 1, is at the crank angle. Top dead center position, counter output 21
The rising time of B, 21C, and 21D is 3 after top dead center, respectively.
The positions of 0°CA, 60”CA, and 90°CA are shown.

The counter output 21E and the angle signal 3B are ANDed by the AND date 23 and sent to the monostable multi-bi break 22 as a date output 23A. Date output 23
A is synchronized with the angle signal 3B input five times after the reference angle signal 3A is input. Monostable multivibrator 2
2 is triggered by the date output 23A and has a certain time width (
τ) bank up signal 6A is output. The pick-up signal 6A is a pulse signal with a constant time width (τ) that is synchronized 30″CA before the top dead center position of the next cylinder.

The number match detection circuit 7, which is an example of a monitor circuit, will be described.

This circuit receives the ignition signal 4 from the microcomputer 4.
R87 lip 70 knob 31 which is set by A and reset in synchronization with the angle signal corresponding to a specific rotation angle, D type 7 lip 70 knob 32, 33 which holds the output of R37 lip 70 knob, and D type 7 Lip Prop 32.3
OR date 34 that merges the outputs of 3 and outputs a monitor signal
The ignition signal 4A is input to the set terminal of the 6R87 lip 70/knob 31 consisting of the edge detection circuit 35 and the edge detection circuit 35, and the counter output 21C from the backup signal generation circuit 6 is input to the reset terminal. As mentioned above, the counter output 21C is 60° after the top dead center of the cylinder.
It is generated in synchronization with the angle signal 3B at the GA position.

D type 7 lip 70 knob 32.33 has R, S
The signals to the set terminal and reset terminal of the 71J knob 702 and 31 are input as clocks, and the output (Q) 31A of the R87 lip 70 knob 31 and the inversion ratio knob Q
)31B is input as data. Therefore, R37
4i to set terminal and reset terminal of lip 707p31
D type 7 lips 70 tongues 32 as long as the number is manually operated alternately
．． Both outputs 32A and 33A of 33 remain at low level.

When the signals are no longer input alternately and No. 48 is continuously input to one terminal, the output of the D-type 7-lip 70 tube driven by the continuously input signals becomes high level.

FIG. 3 shows the operation of the number coincidence detection circuit 7 and the output ignition signal 8.
It is a timing chart explaining A.

During normal operation of the microcomputer 4, the ignition signal 4
A and the counter output 21C corresponding to the angle signal at top dead and 60°GA position 1 after α are input alternately, and the R87 lip 7
The 0-tube 31 is repeatedly set and reset, and the outputs 32A and 33A of the D-type 7-lip 70 tubes 32 and 33 both remain at the low level.

If an abnormality occurs in the microcomputer 4 and, for example, the ignition signal 4A is no longer generated as shown in the figure, the RS7
Lip 70? The knob 31 remains reset by the counter output 21C, and the output 33A of the D-type 7-rip 70 knob 33 becomes high level. Then, the monitor signal 7A, which is the output of the OR date 34, becomes high level to notify that the microcomputer 4 is malfunctioning.

In the selection switching circuit 8, when the monitor signal 7A is at a low level, the ignition signal 4A from the microcomputer 4 is outputted to the ignition device 9 as an output ignition signal 8A, and when the monitor signal 7A is at a high level, it is output as a backup signal. A backup signal 6A from the generation circuit 6 is output.

In this way, even in the event of an abnormality such as when the microcomputer 4 is inoperative, the ignition function can be maintained by the backup signal and the engine can continue to operate.

In addition, since the backup signal generating circuit 6 has a simple circuit configuration with the counter 21 and the monostable multivibrator 22 as main elements, it has the advantage of high reliability.

FIG. 4 is a circuit diagram showing an embodiment of the second invention.

The basic circuit hv configuration is the same as that of the first embodiment of the invention explained in FIG. The difference is in the backup signal generation circuit 14 to which the starting signal 13A from the starter 13 is input, and the timer circuit 15 as a monitor circuit.

The backup signal generation circuit 14 will be explained. In the bank-up signal generation circuit 6 shown in FIG.
The angle signal corresponding to the 0'CA position (30' BTDC) was fixed, but this backup signal generation circuit 1
4, the count value is selected and switched in accordance with a starting signal 13A from the starter 13.

Count value recovery circuit 16 consisting of AND and OR dates
is inserted between the counter 21 and the AND date 23, and the counter output 21 corresponding to the count value 5 of the counter 21
E and counter output 21D corresponding to count value 4 are the beginning! Selected according to IJm No. 13A AND5'-)
23. The starting signal 13A can be obtained from the contactor contact of the starter 13, α, etc.

f:tS5 is a timing chart explaining the operation of the backup signal generating circuit 14.

While the engine is operating, the starting signal 13A from the starter 13 is at a high level, and the counter output 21E is selected by the counter value switching circuit 16 to become the switching circuit output 16A.

Then, the synchronizing signal 3B inputted to the AND date 23 after the ζ counter output 21E becomes high level, that is, the angle signal corresponding to the 3° CA position before the top dead center of the cylinder, is outputted to the monostable multivibrator 22 as the date output 23A. sent to. In monostable multivibrator 22, date output jJ
23A and outputs a backup compensation code 14A having a constant time width (τ) to the selection switching circuit 8.

When the engine has finished starting, the starting signal 13A becomes low level, and the counter value switching circuit 16 changes the counter output 21.
D is selected and becomes the switching circuit output 16A. Then, the synchronizing signal 3B input after the counter output 21D becomes high level, that is, the angle signal corresponding to the cylinder top dead center rrtI60° CA position, is sent to the monostable multivibrator 22 as the date output 23A, and the date output 23A Backup signal 14 for a certain period of time fi(τ)
Output A.

In this way, the bank-up signal generating circuit 14 outputs a backup signal with a fixed time width synchronized with the top dead center position of the cylinder during normal operation, and during starting (during cranking) by the starter 13, the backup signal is output from the bank up signal generating circuit 14. After the point, a backup signal with a constant time width synchronized with the 30° CA position is output. ' The timer circuit 15, which is an example of a monitor circuit, will be explained.

This circuit is a so-called watchdog timer that monitors whether or not the clock signal 4B is constantly output from the microcomputer 4. Oneshi B who gets IJ
7) Consists of a circuit 41, a transistor 43 driven by the one-shot pulse to discharge the capacitor 42, a comparator 44 whose output is inverted depending on the voltage of the capacitor 42, and the like.

From the microcomputer 4, for example, the internal A/D
A clock signal 4B having a constant period is constantly output every time conversion is performed. Every time the clock signal 4B is input to the timer circuit 15, a one-shot pulse with a constant pulse width is output from the 772571 circuit 41, and the charge stored in the capacitor 42 is discharged. While the clock signal 4B is constantly being input, the voltage of the capacitor 42 does not rise, and the monitor signal 15A, which is the output of the humparator 44, becomes low level. If the microcomputer 4 does not operate normally due to a runaway program due to a drop in the voltage of the power supply 4B, the clock output 4B will no longer be able to be output.

Then, since the charge in the capacitor 42 is not discharged, the voltage rises, and the humpator 44 is reversed, so that the monitor 1%15
A hits high level 1. In this way, the operation of the microcomputer 4 is constantly monitored.

The selection switching circuit 8 outputs the ignition signal 4A from the microcomputer 4 as the output ignition signal 8A to the ignition 5 IC 9 when the monitor signal 15A is at a low level, and outputs it to the backup signal generation circuit 14 when the monitor signal 15A is at a high level. A backup signal 14A from the ignition device 9 is output to the ignition device 9.

In this way, even in the event of an abnormality such as when the microcomputer 4 is inoperative, the ignition device 129 is activated by the backup signal.
It can drive and maintain vast functionality. Furthermore, in this embodiment, at the time of starting when the ignition timing that is delayed from that during operation is set as escape, a backup signal (i) synchronized with the delayed crank angle position is output. During starting, the power supply voltage drops temporarily due to the drive current of the starter, and noise is likely to occur, so the microcomputer 4 may not operate properly.
This advantage of being able to reliably use the back 7 knobs at times is great.

In the embodiments described above, the number coincidence detection circuit 7 is used as the monitor circuit in the embodiment of the first invention, and the timer circuit 15 is used in the embodiment of the second invention, but either of the circuits can be used as the monitor circuit. It is possible.

〔Effect of the invention〕

As explained above, the present invention counts the number of angle signals generated after inputting the reference angle signal, and generates a backup signal of a certain time width in synchronization with the angle signal when the count value reaches a specific count value. Since the configuration includes a backup signal generation circuit that outputs a There is.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the first invention, FIGS. 2 and 3 are timing charts explaining the operation, and FIG. 4 is a circuit diagram showing an embodiment of the second invention. FIG. 5 is a timing chart explaining the operation. 1... Reference angle sensor, 2... Angle sensor, 4...
Microcomputer, 6... Backup signal generation circuit, 7... Number matching detection circuit, 8... Selection switching circuit, 9... Ignition device, 11... Distributor, 12... Spark plug, 13 ...Starter, 14.
... Backup signal generation circuit, 15 ... Timer circuit, 16 ... Count value switching circuit, 21 ... Counter, 22 ... Monostable multipipe rake. To,”′・,(,,,,,,: :’(Representative Patent Attorney Isamu Goto, ,“2);”,
j, (′″4゜−′1.・, (f−2?7−1,000 uchi)

Claims (1)

[Scope of Claims] 1. A reference angle sensor that detects the rotation of the internal combustion engine and generates a reference angle signal at a specific rotation angle position of the cylinder, and an angle sensor that also detects the rotation of the engine and generates an angle signal at every predetermined rotation. and a control computer that calculates ignition timing and outputs an ignition signal based on engine rotation angle information and engine operating state information such as intake air amount based on the two signals, wherein the ignition control device comprises: A monitor circuit that monitors computer malfunctions and outputs a monitor signal, and a monitor circuit that counts the number of angle signals generated after inputting the reference angle signal and synchronizes with the angle signal when the count value reaches a specific count value. a backup signal generation circuit capable of outputting a backup signal with a fixed time width; and a selection for selecting and switching between an ignition signal from the control computer and a backup signal from the backup signal generation circuit and outputting the selected signal to the ignition device according to the monitor signal. An ignition control device for an internal combustion engine, comprising a switching circuit. 2. Claims characterized in that the monitor circuit is a number coincidence detection circuit that confirms and detects that the angle signal corresponding to a specific rotation angle and the ignition signal from the control computer are alternately output. The ignition control device for an internal combustion engine according to item 1. 3. Claim 1, wherein the monitor circuit is a timer circuit that monitors a clock signal output from a control computer at regular intervals and detects that the clock signal is interrupted for a predetermined period of time or more. Ignition control device for the internal combustion engine described. 4. A reference angle sensor that detects the rotation of the internal combustion engine and generates a reference angle signal at a specific rotation angle position of the cylinder, an angle sensor that also detects the rotation of the engine and generates an angle signal at every predetermined rotation, and the above two signals. In an ignition control device comprising a control computer that calculates ignition timing based on engine rotation angle information and engine operating state information such as intake air amount and outputs an ignition signal, the control computer monitors for abnormal operation of the control computer. and a monitor circuit that outputs a monitor signal, and a monitor circuit that counts the number of angle signals generated after inputting the reference angle signal, and outputs a signal over a certain time width in synchronization with the angle signal when the count value reaches a specific count value. a backup signal generation circuit capable of outputting a backup signal; a count value switching circuit that selects and switches the specific count value according to a starting signal from the starter; and an ignition signal and backup signal generation circuit that generates an ignition signal from a control computer according to the monitor signal. 1. An ignition control device for an internal combustion engine, comprising a selection switching circuit that selects and switches between a backup signal from a backup signal and outputs the selected signal to an ignition device. 5. Claims characterized in that the monitor circuit is a number coincidence detection circuit that confirms and detects whether the angle signal corresponding to a specific rotation angle and the ignition signal from the control computer are alternately output. The ignition control device for an internal combustion engine according to item 4. 6. Claim 4, characterized in that the monitor circuit is a timer circuit that monitors a clock signal output from a control computer at regular intervals and detects that the clock signal is interrupted for a predetermined period of time or more. Ignition control device for the internal combustion engine described.