JPS63280863A - Ignition timing controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To certainly prevent the excessive revolution by suspending ignition until the number of engine revolution reduces to a necessary value, preventing the continuation of ignition stop in two times in each cylinder and regenerating ignition in the number of cylinders at the delayed angle ignition timing. CONSTITUTION:A controller electrically controls the ignition timing according to the operation state of an internal combustion engine A. In this case, an ignition stop means B which stops the ignition in the internal combustion engine A and a delayed angle ignition means C which generates the delayed ignition timing are provided. A revolution-corresponding control means D which operates the means B and C alternately on each repetition in prescribed number of times in the case when the engine revolution speed is within a previously set range is provided. At this time, the suspension of ignition is continuously executed in the number of cylinders of the internal combustion engine A, and the delayed angle of the ignition timing is continuously executed over the number of cylinders. Therefore, stop of ignition and delayed angle ignition are repeated alternately, and the excessive revolution can be prevented without generating backfire.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition device for an internal combustion engine such as a gasoline engine, and more particularly to an ignition timing control device for an internal combustion engine that has a function of preventing engine overspeed. .

[Conventional technology]

If the engine is over-revved (so-called overrevving), especially in the case of a Renpro engine, pulp surge will occur and the durability of the engine will be impaired. For this reason, overspeed prevention mechanisms have conventionally been provided in ignition devices and fuel devices (for example, Japanese Patent Laid-Open No. 164077/1983). Furthermore, in engines using electronically controlled fuel injection, fuel injection is stopped. Also, in engines that use a carburetor, it is extremely difficult to completely stop the fuel supply.
It is necessary to stop the ignition.

[Problem that the invention seeks to solve]

By the way, when electronic power distribution (D-L・■) for the simultaneous ignition coil (W coil) is used in the carburetor, if the ignition is stopped to prevent over-speeding, unburned gas will be exhausted and the engine speed will drop. When the ignition is restored by
(occurs at the end of the exhaust process), which ignites unburned gas in the exhaust process. Therefore, when the intake pulp opens, the flame spreads to the unburned gas in the intake manifold, causing a packfire. When a packfire occurs, combustion and pressure rise occur inside the engine's intake system, causing damage to the intake system.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reliably prevent overspeeding without causing packfire even in an internal combustion engine using electronic power distribution for simultaneous ignition in a carburetor.

[Means for solving problems]

Therefore, as shown in FIG. 1, the present invention provides an ignition timing control device for a multi-cylinder internal combustion engine that electronically controls ignition timing according to the operating state of the internal combustion engine. rotation-responsive control that alternately operates the ignition stop means and the retard ignition means a predetermined number of times when the engine rotation speed is within a preset rotation speed range; An ignition timing control device for an internal combustion engine is provided.

(Function) As a result, first, ignition is stopped until the number of ignition stops is not repeated twice in each cylinder (and the engine speed decreases by the necessary amount. In other words, ignition is stopped for the number of cylinders. Then , the ignition is restored by a number of cylinders with the retarded ignition timing.

By performing this retarded ignition, sudden changes in torque can be suppressed and increases in rotation can be reduced. It is characterized by repeating this ignition stop and retarded ignition alternately.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The internal combustion engine ignition system according to the present invention will be described in detail below with reference to an illustrated embodiment.

FIG. 2 shows an embodiment of an ignition system using an electronic power distribution method using a simultaneous ignition coil and applied to a four-cylinder gasoline engine using a carburetor. In FIG. 2, 110 is a crank angle sensor that detects the rotational angular position of the engine, 120 is an ignition timing control unit, and 121 is a crank angle sensor 11.
122 is a microprocessor that calculates ignition timing, energization time, overspeed control, etc. based on the signal from the crank angle sensor 110, and outputs an ignition coil energization cutoff signal; 123; Reference numeral 124 indicates an ignition output interface composed of a power transistor, etc., which conducts energization/cutoff to the ignition coil based on a signal output from the microprocessor 122;
A power supply circuit supplies power from a battery 140 to 22 and other circuits, and 130 is an ignition coil of a simultaneous ignition type.

Next, the operation of this embodiment will be explained according to the flowcharts shown in FIGS. 3 to 5. The flowchart in Figure 3 is a routine 2 in which an interrupt occurs every time ignition occurs, the timing to start energization for the next ignition is calculated, and the timing to start energization is set.
It is 00. First, in step 201, it is determined whether the over-rep flag is ON, that is, whether the current engine speed is within the over-speed control range, and if YES, the process moves to step 202. In step 202, it is determined whether the guard flag is ON, and if YES, the process branches to step 204. If the determination is NO, the process branches to step 203, and in step 203, the count value "" CIGC11 of the ignition stop counter is determined to be the number of ignition stops "KIG".
Determine whether it is larger than C". In this example, 4
Since the target engine is the cylinder, the number of ignition stops “”
KIGC" becomes 4. Therefore, if the number of ignition stops is 4 or less, the determination is No and the process branches to step 206.

In step 206, the count value "C" of the retard ignition counter is
IGR'" is cleared and the process moves to step 208. In step 208, the setting of the energization start timing is stopped in order to stop the next ignition. As a result, the ignition coil 130 is no longer energized, so the ignition is stopped. After that, the process moves to step 210, increments the count value "'CTGC" of the ignition stop counter by 1, and returns.The above steps are repeated until the number of ignition stops reaches the number of cylinders. When the number of stops reaches the number of cylinders, that is, when the ignition for four ignitions has been stopped, YES is determined in step 203 and the process branches to step 205.In step 205, the count value of the retard ignition counter is "'". CIGR''' is counted up by 1 and the process moves to step 207.

In step 207, it is determined whether the number of retarded ignitions is greater than the number of retarded ignitions 'KIGR''' which is set to be greater than or equal to the number of cylinders. Set it to a number that is greater than or equal to the number of cylinders and does not cause the engine speed to rise too much.For a 4-cylinder engine, set it to 4 or more.Also, by retarding the ignition timing, sudden torque fluctuations can be suppressed. The rotation should not increase too much.In this example, there were 4 ignitions.

If the determination in step 207 is No, that is, in the case of retarded ignition, the process branches to step 211.

In step 211, the energization timing is calculated, the energization timing is set, and the process returns. Repeat this for retarded ignition. If the retarded ignition is the last ignition that completes the predetermined circuit, the process branches to YES in step 207 and proceeds to step 209. In step 209, the count value "'CIGC" of the ignition stop counter is set to 1, and the process moves to step 211, whereupon the same control is performed.

In this way, when the engine speed is within the set speed of overrev, ignition stop and retarded ignition can be alternately repeated for each number of cylinders.

As a result, when viewed from a single cylinder, ignition stop and retarded ignition are alternately repeated.

Next, determination of overrev will be explained using FIG. 4. The flowchart shown in FIG. 4 is a routine 300 in which an interrupt occurs at the falling edge of the Ne signal output from the crank angle sensor 110. In step 301, it is determined whether the engine speed is greater than a first set rotation speed NeMIN, which is the lower limit of overrev control. If the engine rotational speed is smaller than the first set rotational speed Ne, . In step 302, the overrev flag is cleared, and in step 3
The process moves to 06, the guard flag is turned OFF, and the process returns. In this case, in step 201 of the flowchart of FIG.
If the result is determined to be O, the process branches to step 209, and the same processing as described above is performed, and ignition is not stopped or delayed ignition is performed.

N if it is determined in step 301 that the engine speed is greater than the first set rotation speed Ne□8.

The process branches to step 303. Step 303
Then, it is determined whether the engine rotation speed is higher than the second set rotation speed NeMAX, which is set to a rotation speed larger than the first set rotation speed Ne□8 (in this embodiment, the rotation speed is 1100 rp larger). If it is determined that the engine rotational speed is smaller than the second set rotational speed, the process branches to YES, moves to step 306, clears the guard flag, and returns. Therefore, the overrev flag and the guard flag maintain their previous states without changing. In step 303, the engine rotation speed is set to the second set rotation speed Ne.
N if determined to be larger than xax.

The process branches to step 304. Step 304
Now turn on the overrep flag. Then step 3
05, the engine rotation speed is compared with the third set rotation speed Ne guard, which is set to the engine's allowable limit rotation speed. If it is determined in step 305 that the engine rotation speed is smaller than the third set rotation speed Ne guard, the process branches to YES, and if it is determined that the engine rotation speed is greater than the third set rotation speed Ne guard, the process branches to NO. At step 307, the guard flag is turned on and the process returns. Here, the operation when the guard flag is turned on will be explained using the flowchart of FIG. At step 202 in FIG. 3, it is determined whether the guard flag is ON. If it is ON, the process branches to YES and proceeds to step 204. In step 204, the count value "CrGC'" of the ignition stop counter is set to the value of the number of ignition stops "KIC,C". After that,
The process moves to step 206, and the same ignition stop processing as described above is performed.

Next, the ignition timing calculation routine 400 will be explained using the flowchart shown in FIG.

FIG. 5 shows the ignition timing calculation section of the main routine.

In step 401, the basic ignition timing (
The base θig) is read out from an ignition timing table provided corresponding to the engine speed and calculated. After that, the process moves to step 402 and the overrev flag is turned on.
If the overrev flag is OFF, the system returns as is. Overrev flag is O
If N, the process moves to step 403 and the retard amount (ΔθR) is subtracted from the basic ignition timing. In this embodiment, the retard amount (ΔθR) is set to a value such that the subtraction result is BTDC5°CA. Here, the basic ignition timing (θi
g) Instead of subtracting the retard amount (ΔθR), a value of the ignition timing retarded in advance may be used in place of the basic ignition timing.

Next, the actual operating state will be explained using the time charts shown in FIGS. 6 and 7. FIG. 6 and FIG. 7 show a state in which the engine is under no load and the overspeed control is operating. 6th
In the figure and FIG. 7, (a) indicates the third set rotation speed Ne
Guard, (b) is the second set rotation speed N e MAX %
(C) is the first set rotation speed NeMIH1 (d) is the engine rotation speed, (e) is the overrev flag, (f) is the count value "CIGC" of the ignition stop counter, (g) is the count of the retard ignition counter The values “”CIGR”, (5) and (i) are the current cutoff signal to the simultaneous ignition coil 130, (
j) is the ignition timing. In this embodiment, since four cylinders are used as an example, two simultaneous ignition coils 130 are used, and energization/cutoff signals are output to each of them.

First, when the engine speed (d) increases and exceeds the second set speed (g), the overrev flag (e) is set to O.
N is given. When the overrev flag (e) is turned on,
First, ignition is stopped. Next, the count value (f) of the ignition stop counter is counted up, and the energization signals (c) and (i) are stopped. The two energization signals are stopped for two ignitions each, and each cylinder is stopped for one ignition. The ignition timing (j) is set to a retarded ignition timing when the overrev flag is turned on.

When the count value "CIGC" (f) of the ignition stop counter reaches a predetermined number of times (four times in this embodiment) or more, the ignition is switched to retarded ignition. When switching to retard ignition, energization signals (h) and (i) to the ignition coil 130 are output, and the count value "CIGR" of the retard ignition counter is counted up.

When the count value "CIGR" of the retard ignition counter reaches a predetermined number of times (four or more ignitions in this embodiment), ignition is stopped again. This ignition stop and retarded ignition are performed as long as the engine speed (d) is within the overspeed control speed range, that is, the range of the first set number of times (C) and the third set speed (a). Repeat.

When the engine speed (d) decreases due to throttle operation or an increase in load and becomes smaller than the first set speed (C), the over-rep flag (e) is cleared and the ignition timing etc. return to the state.

Further, even with the above control, over-speed cannot be prevented, and the ignition is always stopped while the engine speed is higher than the third set speed Ne guard.

As described above, by repeating ignition stop and retarded ignition for each number of cylinders within a predetermined rotational speed range, over-speeding can be prevented and packfire can be prevented from occurring.

In addition, in the above-mentioned embodiment, overspeed prevention control was carried out only by repeating ignition stop and retard several times for the cylinders, but it is possible to perform the overspeed prevention control by adding other control methods to this control method. Needless to say.

For example, examples thereof are shown in FIGS. 8 and 9. FIG. 8 shows a flow chart of this example, and FIG. 9 shows its timing chart.

FIG. 8 shows the Ne signal interrupt routine in FIG. 4, in which if the determination in the rotation speed determination step 303 is YES, the process proceeds to a newly added step 308 and turns on the mode 2 flag.
Make it. When this mode 2 flag is ON, control using both ignition stop and ignition retardation is performed, but when the mode 2 flag is OFF and the overrev flag is ON, only ignition retardation is performed. Further, in step 302, both the overrev flag and the mode 2 flag are turned off.

FIG. 9 is a timing chart thereof, and the first control section, that is, N e MIN < N e < N e
At MAX, only the ignition timing is retarded. By adding this control to the above-mentioned control, the shock caused by sudden torque fluctuations when overspeed control is entered can be alleviated.

Note that symbols (a) to (j) in Figure 9 are the same as those in Figures 6 and 7.
It is the same as the figure, and (2) indicates the mode 2 flag.

According to the embodiment described above, when the engine speed is within the overspeed control range, ignition stop and retarded ignition are repeated for each number of cylinders of the engine (four cylinders in this embodiment). In the case of a single cylinder, ignition stop and retarded ignition are alternately repeated. Even if unburned gas is generated in the exhaust process due to the ignition stop, if the unburned gas is caused by - times of misfires, it will not be ignited due to residual gas etc. in the exhaust process caused by the simultaneous ignition coil 130.
-It disappears. Therefore, it is possible to prevent over-rotation without causing backfire. Furthermore, when the ignition is restored, ignition is performed at a retarded ignition timing, which prevents sudden changes in engine torque and prevents the engine speed from rapidly increasing, thereby reducing vibrations caused to the engine and shocks to driving. be able to.

In addition, in the present invention, the number of times the ignition is continuously stopped is not limited to the same number as the number of cylinders, but may be one time as long as it is less than the number of cylinders, and the number of times the ignition timing is continuously retarded is also the same as the number of cylinders. It is not limited to the same number of times, but it is sufficient that the number of times is equal to or greater than the number of cylinders, and it is sufficient that the ignition of the same cylinder is not stopped continuously.

Furthermore, the present invention is not applicable only to internal combustion engines using a carburetor and simultaneous ignition coils, but also to internal combustion engines using electronically controlled fuel injection, and those having an ignition coil for each cylinder. Even with a distributor, the effect of preventing overspeed can be obtained, so it is applicable.

〔Effect of the invention〕

As described above, according to the present invention, even when an electronic power distribution ignition system using a simultaneous ignition coil is used in an internal combustion engine using a carburetor (although not limited to this), the engine This has excellent effects in that over-speed can be reliably prevented and the engine can be prevented from being damaged by backfire or the like.

[Brief explanation of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a block diagram showing an embodiment of the ignition timing control device for an internal combustion engine according to the present invention, FIGS. 3 to 5 are flowcharts explaining its operation, and FIG. 6 and 7 are timing charts showing the operating state thereof, FIG. 8 is a flow chart of another embodiment of the device of the present invention, and FIG. 9 is a timing chart showing the operating state. 110... Crank angle sensor, 120... Ignition timing control unit h, 121... Waveform shaping circuit, 122...
- Microprocessor, 123... Output interface, 124... Power supply circuit, 130... Simultaneous ignition coil.

Claims (2)

[Claims] (1) In an ignition timing control device for a multi-cylinder internal combustion engine that electronically controls ignition timing according to the operating state of the internal combustion engine, an ignition stop means that stops ignition and a retard ignition that provides retarded ignition timing and rotation-responsive control means for alternately and repeatedly operating the ignition stop means and the retarded ignition means a predetermined number of times when the engine rotation speed is within a preset rotation speed range. Timing control device. (2) The ignition stop by the ignition stop means is performed continuously by the number of cylinders, and the ignition timing retard by the retard ignition means is performed continuously by the number of cylinders or more.
The ignition timing control device for an internal combustion engine as described in .