JPH06100177B2 - Internal combustion engine ignition device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition device for an internal combustion engine, and in particular, secures the ignitability of an ignition system in a partial load region, and provides high load characteristics and drivability at low temperatures. The present invention relates to an ignition device for an internal combustion engine, which prevents smoldering of a spark plug without deteriorating and suppresses electrode wear.

[Problems to be Solved by Prior Art and Invention]

Conventionally, as a measure against preignition or misfire of an internal combustion engine, a method of appropriately adjusting the heat value of an ignition plug has been adopted. Preignition easily occurs when the temperature of the spark plug rises under high load, and misfire occurs because carbon adheres to the spark plug due to combustion of the rich mixture at low temperature and ignition energy leaks through the carbon. Occurs in. Therefore, we have taken these measures by adjusting the above-mentioned heat value, but if the heat value of the spark plug is put too much emphasis on high load to avoid engine damage due to preignition, on the contrary, the spark plug at low temperature Smoldering is a problem.

Conventionally, in order to prevent the smoldering of this spark plug,
Although there is a problem of deteriorating drivability at low temperatures, a method of thinning the air-fuel mixture in order to suppress the amount of carbon generation or a method of burning off carbon adhering to the spark plug by a long-time discharge (for example, JP-A-57- 68562). In the latter method, only the discharge start timing (so-called ignition timing) is advanced to around 40 ° CA before top dead center to lengthen the discharge duration and burn out the carbon by the heat energy of the discharge energy. In this case, the discharge time is about 25 ms when starting.
ec in need.

On the other hand, the misfire rate when the ignition timing is advanced as described above increases as the ignition timing is advanced. Therefore, if the discharge duration is lengthened, the timing of igniting the air-fuel mixture greatly changes, which causes torque fluctuations and engine speed fluctuations, which deteriorates drivability. Also, according to experiments, unnecessary and long-time discharge in an ignitable atmosphere easily produces carbon in the vicinity of the spark plug, and this carbon is pushed into the pocket of the spark plug as the piston rises and is deposited on the insulator. Was found to progress further. Further, there is also a problem that the power consumed for a very long discharge is increased, so that the battery is significantly consumed.

Further, in the conventional internal combustion engine, a large amount of "exhaust gas recirculation" is performed if the air-fuel mixture is made lean at a partial load from the viewpoint of improving fuel efficiency, and thus the ignition performance of the ignition device becomes a problem. As a countermeasure for this, it is necessary to improve the spark energy (in particular, increase the discharge current). However, when the spark energy is increased, the electrode consumption of the spark plug is significantly increased, and the spark energy is increased. The heat generation of the igniter power transistor is also a problem.

[Means for solving problems]

An ignition device for an internal combustion engine according to a first aspect of the present invention includes an ignition plug installed according to a cylinder of the internal combustion engine, a first ignition coil for supplying discharge energy to the ignition plug, and a first ignition coil connected in parallel with the first ignition coil. A second ignition coil that is connected and supplies discharge energy to the ignition plug, an operating state detecting unit that detects an operating state of the internal combustion engine, and the internal combustion engine is set to a starting state based on the operating state detected by the operating state detecting unit. When it is determined that the ignition command is output to the first ignition tile at the end of the compression stroke of the internal combustion engine, and when it is determined that the internal combustion engine is in the cold operation state, the second ignition coil is provided at the end of the intake stroke of the internal combustion engine. The ignition command to the first and second ignition coils at the end of the compression stroke of the internal combustion engine, and the internal combustion engine is in the warm operation state and the light load operation state. When it is determined that the internal combustion engine is in the warm operation state and the high load operation state by outputting an ignition command to the first and second ignition coils at the end of the compression stroke of the internal combustion engine, Control means is provided for outputting an ignition command to the first ignition coil at the end of the compression stroke.

An ignition device for an internal combustion engine according to a second aspect of the present invention includes an ignition plug installed according to a cylinder of the internal combustion engine, an ignition coil that supplies discharge energy to the ignition plug, and power supply to the ignition coil that is connected to the ignition coil. A first igniter for controlling the internal combustion engine, a second igniter connected to the ignition coil in parallel with the first igniter for controlling power supply to the ignition coil, and an operating state detecting means for detecting an operating state of the internal combustion engine. When it is determined that the internal combustion engine is in the starting state based on the operating state detected by the operating state detecting means, an operation command is output to the first igniter at the end of the compression stroke of the internal combustion engine to bring the internal combustion engine into the cold operating state. When it is determined that there is, an operation command is output to the second igniter at the end of the intake stroke of the internal combustion engine, and the first and second igniters are output at the end of the compression stroke of the internal combustion engine. When it is determined that the internal combustion engine is in the warm operation state and the light load operation state, the operation instruction is output to the first and second igniters at the end of the compression stroke of the internal combustion engine. Is provided in the warm operation state and the high load operation state, the control means is provided for outputting an operation command to the first igniter at the end of the compression stroke of the internal combustion engine.

[Action]

In the ignition device for an internal combustion engine according to the first aspect of the present invention, in an operating state where the ignitability deteriorates, two ignition coils connected in parallel are operated at the end of the compression stroke to supply increased energy to the spark plug. . Further, in an operating state in which carbon easily adheres to the spark plug, one of the ignition coils is operated at the end of the intake stroke to remove carbon. Further, in an operating state where no carbon is attached, ignition at the end of the intake stroke is prohibited to prevent electrode wear.

In the ignition device for the internal combustion engine according to the second aspect of the present invention, in an operating state where the ignitability deteriorates, the increased current is supplied to the ignition plug by increasing the current flowing through the ignition coil and operating it at the end of the compression stroke. . Further, in an operating state where carbon is likely to adhere to the spark plug, the ignition coil is operated at the end of the intake stroke to remove carbon. Further, in an operating state where no carbon is attached, ignition at the end of the intake stroke is prohibited to prevent electrode wear.

〔Example〕

FIG. 1 is a circuit diagram of an embodiment of an ignition device for an internal combustion engine according to the present invention. In FIG. 1, 1 is an engine control computer (EC) for electronically controlling the engine.
U), the engine speed detected by the rotation angle sensor 8, the engine cooling water temperature detected by the water temperature sensor 9, the engine start signal from the starter 10, and the intake air detected by the intake pressure sensor 11. The pipe pressure is taken in as an input signal, the clean discharge timing and the ignition discharge timing suitable for the operating conditions are calculated from these, and the control signal iG is supplied to the first igniter 21 and the second igniter 22 in the subsequent stage.
Outputs t ₁ and iGt ₂ from the first igniter 21 to the ignition coil
The ignition activation signal iGf produced by the collector voltage of the power transistor switching the primary current of 31,33 is returned.

The igniter control circuit 2 is composed of a first igniter control circuit and a second igniter control circuit, and performs switching of the primary side currents of the ignition coils 31 to 34 in the subsequent stage based on the signal of EUC1. 21 is for ignition and 22 is for cleaning. In the case of four cylinders, the ignition coil is provided with 31 to 34 ignition coils as shown in the figure. 31 and 33 serve as first ignition coils to carry an ignition discharge, and 32 and 34 serve as second ignition coils. Carries a discharge for spark plug cleaning. Incidentally, 31a to 34a are diodes for blocking backflow. Reference numeral 4 is a spark plug for each cylinder, and as shown in the figure, coils for No. 1 cylinder and No. 4 cylinder
31 and 32 are connected in parallel to operate as a wired OR,
The coils 33 and 34 are connected in parallel to the No. 2 cylinder and the No. 3 cylinder, and similarly operate as a wired OR.

In such a configuration, the control of the present invention performs the cleaning discharge and the ignition discharge at the time of starting, cold, and warm at the end of the compression stroke and the end of the intake stroke at the timings described in detail below. .

FIG. 2 is a signal timing chart of the apparatus shown in FIG.
In FIG. 2, first, as shown in (C), the starting state is detected by the starter 10 at the time of starting, and when the warm temperature is high, the water temperature sensor 9 detects that the cooling water temperature is 30 ° C. or higher. The intake pressure sensor 11 detects that the intake pipe pressure is a high load of −150 mmHg or higher, and based on these operating conditions, the ECU 1 sends the command signal iGt ₁ shown in g and the command signal iGt ₂ shown in h to the first Igniter 21 and second
To the igniter 22 of. In this case, iG
Since t ₂ (h) remains low level, the second igniter 22 does not operate and only the first igniter 21 is ignited at the ignition timing at the end of the compression stroke and is not discharged for cleaning. . i is the current waveform of the secondary coil, and the spark energy at this time is 40 mj. However, at high loads, an air-fuel mixture is rich, so an energy of 30 mj or more is sufficient. As a result, it is possible to suppress the electrode consumption under the condition of high heat load. This is because electrode consumption is proportional to the electrode temperature and the magnitude of spark energy.

Next, a description will be given of a warm light load. As shown in (B), the cooling water temperature 30
-150m as intake pipe pressure by intake pressure sensor 11 above ℃
iGt ₁ (d), iGt ₂ as shown in d and e at the same output timing from the ECU1 by detecting the operating condition under light load less than mHg
(E) is output to the first igniter 21 and the second igniter 22. Since iGt ₁ (d) and iGt ₂ (e) simultaneously activate the first ignition coil and the second ignition coil only at the end of the compression stroke, the spark energy becomes 80 mj, which is the sum of these as shown in the waveform of f, It is possible to improve the ignitability and prevent misfire under a condition where the air-fuel mixture is thin.

Further, the cold state will be described. As shown in (A),
A command signal iGt for detecting that the cooling water temperature is lower than 30 ° C by the water temperature sensor 9 and discharging only at the end of the compression stroke.
₁ (a) is input to the first igniter 21, and a signal iGt ₂ (b) for discharging twice at the end of the intake stroke and the end of the compression stroke is input to the second igniter from the ECU 1, and the first ignition coil and the first ignition coil are connected. Two
Since the ignition coil operates, the spark energy is discharged at 40 mj at the end of the intake stroke as shown by C, the carbon adhering to the spark plug 4 is oxidized and cleaned, and then the spark energy at the ignition timing at the end of the compression stroke. As shown in C
It is done with an ignition discharge of 80 mj. As a result, it is possible to prevent a start-up failure due to smoldering of the spark plug and deterioration of drivability in the cold state, and since the spark energy is large, it is possible to thin the air-fuel mixture in the cold state and improve fuel efficiency.

FIG. 3 is another embodiment of the signal timing chart shown in FIG. As shown in (A), there is no change from the waveform in FIG. 2 (B) at the time of warm low speed light load. It changes as shown in (B) at the time of warm high speed and light load. That is, the water temperature sensor 9 detects that the cooling water temperature is 30 ° C. or higher,
If the intake pressure sensor 11 detects that the intake pipe pressure is a light load of less than −150 mmHg, and the rotation angle sensor 8 detects a low speed region of less than 300 rpm, the second
Similar to the illustrated embodiment, the first and second igniters 21, 22
3 (A) and 2 (B) because they operate simultaneously
The spark current at the spark plug 4 is doubled (80 mj), as shown in f, and the spark duration does not change. On the other hand, in the high speed range of 3000 rpm or more, as shown in FIG.
Timing IGT ₂ of the second igniter 22 to the timing of the IGT ₂ to be able to extend the spark duration by about 1msec delay. As a result, it is possible to prevent misfire due to blowout of the arc under conditions of strong turbulence in the combustion chamber at high speed and light load. In this case, for example, the spark currents of the first ignition coil and the second ignition coil are both 40 mA, and the spark durations are both 1.6 msec.

In the present embodiment, it is possible to oxidize and clean the carbon attached to the spark plug by the discharge in the oxidizing atmosphere at the end of the intake stroke, and the drivability is improved because the spark energy can be increased during cold and warm. As well as improving the fuel efficiency, it becomes possible to make the air-fuel mixture leaner or to carry out a large amount of "exhaust gas recirculation". Further, the spark energy under high load can be reduced, high energy discharge can be avoided under the condition that the electrode temperature of the spark plug is high, and the electrode consumption can be prevented from increasing, and further, each igniter and ignition can be prevented. Since the heat load on the coil can be suppressed small, the reliability of the igniter and the ignition coil can be improved.

FIG. 4 is a circuit diagram of another embodiment of the ignition device for an internal combustion engine according to the present invention. The difference from the embodiment shown in FIG. 1 is that one coil serves both cleaning and ignition of the ignition coil.
That is, similarly to the embodiment of FIG. 1, the engine angle is input from the rotation angle sensor 8, the intake pipe pressure is input from the intake pressure sensor 9, the engine cooling water temperature is input from the water temperature sensor 10, and the start signal is input from the starter 10. Then, the ignition timing and clean discharge timing according to each operating condition are calculated from these, and the discharge control signal (iG
t ₁ and iGt ₂ ) and the distribution signals (iGdA ₁ , iGdB ₁ , iGdA ₂ and iGdB ₂ ) are output to the first igniter 21 and the second igniter 22 provided in the subsequent stage. These igniters 2
1,22 perform switching of the primary currents of the ignition coils 31,32 based on the control signals a, b from the ECU 1, and the high voltage cord 7
A spark discharge is generated in the spark plugs 41 to 44 via 1 to 74.

FIG. 5 is a signal timing chart of the apparatus shown in FIG.
In FIG. 5, (A) is a signal timing chart at the time of cold, and (B) is a signal timing chart at the time of starting and warm. Cooling water temperature is 30
Second igniter 22 is actuated during the intake stroke at the time of between less than ℃ cold by the output IGT _second ECU 1, also by IGT ₁ first
Since the igniter 21 operates during the compression stroke, the ignition coil
The primary current of 31 is as shown by a, and as is clear from this waveform, as shown by c, after the clean discharge at the end of the intake stroke, the discharge for ignition is performed at the ignition timing at the end of the compression stroke. The distribution signal (iGdA ₁ , i
GdB ₁ , iGdA ₂ , iGdB ₂ ) provides a phase of 180 ° with the ignition coil 31 and similar discharge is performed.

As shown in (B), the discharge control signal iGt ₂ from the ECU 1 is not output at the time of starting and during warming (cooling water temperature of 30 ° C. or higher),
Since it has fallen to the low level, the second igniter 22 does not operate at all, and only the first igniter 21 by iGt ₁ causes the primary currents of the ignition coils 31 and 32 to look like a ', resulting in c'.
As shown by, the discharge is performed only at the ignition timing at the end of the compression stroke.

In this embodiment, since the cleaning ignition coil and the ignition coil are commonly used as described above, the engine can be easily mounted on the engine, the weight can be reduced, and the wired OR connection of the secondary high-voltage cord is unnecessary. It is possible to reduce the cost, improve the reliability, shorten the high-voltage cord, and reduce the radio noise. further,
It is also possible to significantly reduce the cost by reducing the number of ignition coils, reducing the number of stays for attaching the ignition coil, and eliminating the high voltage diode in the ignition coil.

〔The invention's effect〕

According to the ignition device for an internal combustion engine according to the first aspect of the present invention, the ignition plug is ensured when the internal combustion engine is cold and when the load is light, and the ignition plug does not deteriorate the high load characteristics and the drivability at low temperatures. It is possible to prevent smoldering of the electrode and consumption of the electrode.

According to the ignition device for an internal combustion engine of the second invention, in addition to the above, only one ignition coil can be provided, and the configuration can be simplified and the economical efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of an ignition device according to the present invention, FIG. 2 is an example of a signal timing chart of the device shown in FIG. 1, and FIG. 3 is another example of a signal timing chart of the device shown in FIG. FIG. 4 is a circuit diagram of another embodiment of the ignition device according to the present invention, and FIG. 5 is a signal timing chart of the device of FIG. (Explanation of symbols) 1 ... Engine control computer, 2,21,22 ... Igniter, 3,31-34 ... Ignition coil, 4 ... Spark plug, 7 ... High-voltage cord, 8 ... Rotation angle Sensor, 9 ... Water temperature sensor, 10 ... Starter switch, 11 ... Intake pressure sensor.

Claims (2)

[Claims] 1. A spark plug installed according to a cylinder of an internal combustion engine, a first ignition coil for supplying discharge energy to the spark plug, and a spark plug connected in parallel to the first ignition coil. It is determined that the internal combustion engine is in the starting state based on the second ignition coil that supplies the discharge energy, the operating state detecting means that detects the operating state of the internal combustion engine, and the operating state detected by the operating state detecting means. When the internal combustion engine is judged to be in a cold operation state, the second ignition is output at the end of the intake stroke of the internal combustion engine. An ignition command is output to the coil and an ignition command is output to the first and second ignition coils at the end of the compression stroke of the internal combustion engine, and the internal combustion engine is in a warm operation state and a light load operation state. When it is determined that the internal combustion engine is in the warm operation state and the high load operation state, the ignition command is output to the first and second ignition coils at the end of the compression stroke of the internal combustion engine. The ignition device for an internal combustion engine, comprising: a control means for outputting an ignition command to the first ignition coil at the end of the compression stroke of the internal combustion engine. 2. A spark plug installed according to a cylinder of an internal combustion engine, an ignition coil for supplying discharge energy to the spark plug, and a spark coil connected to the spark coil for controlling power supply to the spark coil. An igniter, a second igniter that is connected to the ignition coil in parallel with the first igniter, and controls power supply to the ignition coil, and an operating state detection unit that detects an operating state of an internal combustion engine. When it is determined that the internal combustion engine is in the starting state based on the operating state detected by the operating state detecting means, the internal combustion engine outputs an operation command to the first igniter at the end of the compression stroke of the internal combustion engine, When it is determined that the engine is in the cold operation state, an operation command is output to the second igniter at the end of the intake stroke of the internal combustion engine, and at the end of the compression stroke of the internal combustion engine. When it is determined that the operation command is output to the first and second igniters and the internal combustion engine is in a warm operation state and a light load operation state, the first and second compression strokes of the internal combustion engine are completed. When the internal combustion engine is determined to be in the warm operation state and the high load operation state, the operation command is output to the igniter of No. 1, and the operation command is output to the first igniter at the end of the compression stroke of the internal combustion engine. An ignition device for an internal combustion engine, comprising: