JPH06288326A - Control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent deterioration of operation property due to flame out of an internal combustion engine just after full acceleration. CONSTITUTION:A control device for an internal combustion engine is provided with ignition coils 9, 10 for generating high voltage necessary for ignition of an engine, while one coil supplies ignition energy to at least ignition plugs of two cylinders at the same time so that + discharge ignition is carried out in at least one cylinder. A throttle opening sensor 16 for detecting operation state of the engine is provided together with an intake pressure sensor 15 for detecting accelerating state of the engine and ECU 1. After the idling state of the engine is kept for more than specified time (10sec.) by the throttle opening sensor 16, and when the engine is fully accelerated by the intake pressure sensor 15, and ECU 1 reduces the required voltage only of + discharge cylinder for a specified time (200ms).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, an ignition coil for generating a high voltage required for ignition of an engine is provided as an ignition device for an engine, and one coil simultaneously supplies ignition energy to ignition plugs of two cylinders. + In one cylinder
There are some which perform discharge ignition (for example, JP-A-54-33).
924).

[0003]

By the way, in such an engine ignition system, the required voltage (voltage required for discharging at the spark plug) is obtained when the engine is fully idle after the idle state is maintained for a long time. Becomes higher due to the shape of the plug electrode, especially in the + discharge cylinder, and there is a problem of misfire (discharging is impossible).

That is, in the ignition device of this type,
The pressure in the cylinder increases due to the increase in the charging efficiency immediately after the full-open acceleration after the idle state is maintained for a long time, or the active ion gas (HC , CO, etc.) concentration becomes low.
As a result, sparks may be less likely to fly particularly in the cylinder on the + discharge side where the spark plug discharges from a wide-area pole to a narrow-area pole.

Therefore, an object of the present invention is to provide a control device for an internal combustion engine which can prevent deterioration of drivability due to misfire of the internal combustion engine immediately after full-open acceleration.

[0006]

SUMMARY OF THE INVENTION The present invention is provided with an ignition coil for generating a high voltage required for ignition of an internal combustion engine, and one coil simultaneously supplies ignition energy to ignition plugs of at least two cylinders. In a control device for an internal combustion engine that supplies and performs + discharge ignition in at least one cylinder, an operating state detection unit that detects an operating state of the internal combustion engine, and an acceleration state detection unit that detects an acceleration state of the internal combustion engine, After the internal combustion engine is held in the idle state or the deceleration state for a predetermined time or more by the operating state detecting means, when fully accelerated by the acceleration state detecting means,
The gist is a control device for an internal combustion engine provided with a required voltage reducing means for reducing the required voltage only for a + discharge cylinder for a predetermined time.

Here, as the required voltage reduction means,
The required voltage may be reduced by ignition on the retard side from the compression top dead center (hereinafter referred to as TDC) by the ignition timing control means.

Further, as the required voltage reducing means, the required voltage may be reduced by increasing the amount of fuel only in the + discharge cylinder for a predetermined time by the fuel injection control means. Further, the required voltage reducing means may increase the fuel amount by the fuel injection control means by an amount corresponding to the idle holding time.

Further, as the required voltage reducing means, the opening timing of the intake valve may be delayed by the variable valve timing control means to increase the residual fuel gas in the cylinder to reduce the required voltage.

[0010]

The required voltage reduction means is such that when the internal combustion engine is held in the idle state or the decelerated state by the operation state detection means for a predetermined time or more and then fully accelerated by the acceleration state detection means, only the + discharge cylinders have the required voltage for the predetermined time. To reduce.
Therefore, only in the + discharge cylinder, the required voltage is reduced for a predetermined period, and deterioration of drivability due to misfire of the internal combustion engine is prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, it is used for a vehicle-mounted spark ignition type four cylinder gasoline engine.

FIG. 1 shows an overall schematic diagram including an ignition timing control device in this embodiment. Electronic control unit (hereinafter E
A crank position sensor 2 and a reference position sensor 3 are connected to the (CU) 1. A signal for determining the position of the engine is input to the ECU 1 by the crank position sensor 2 and the reference position sensor 3. Then, the IGt for performing ignition from the ECU 1 at the optimum ignition timing in each cylinder
Signal and an IGd signal for distributing the cylinder groups. The IGt signal and the IGd signal are input to the igniter 4.

Further, an intake pressure sensor 15 and a throttle opening sensor 16 are connected to the ECU 1, and the ECU 1 inputs signals from both the sensors 15 and 16. And ECU1
Detects the intake pressure PM by the intake pressure sensor 15 and the throttle opening TA by the throttle opening sensor 16.

The igniter 4 includes an ignition distribution circuit 5 and transistors 6 and 7. The igniter 4 controls energization of the ignition coil group 8 so that ignition is appropriately performed at the ignition timing of each cylinder. That is, the transistor 6 is connected to the primary side of the ignition coil 9, and the transistor 7 is connected to the primary side of the ignition coil 10.

The ECU 1 uses the crank position sensor 2
The engine position is determined by the reference position sensor 3 and the reference position sensor 3 and the intake pressure P is determined by the position determination and the intake pressure sensor 15.
An ignition signal is output at an optimum position for each cylinder based on M and the throttle opening TA (engine state) by the throttle opening sensor 16.

In the case of a four-cylinder engine, it has two ignition coils 9 and 10. The ignition coils 9 and 10 supply ignition energy to the spark plugs 11, 12, 13, and 14 arranged in the combustion chambers of the two cylinders, respectively. At this time, the cylinder group is the first cylinder (hereinafter, #
No. 1 cylinder-No. 4 cylinder (hereinafter referred to as # 4) and No. 3 cylinder (hereinafter referred to as # 3) -No. 2 cylinder (hereinafter referred to as # 2).

Here, in the partial circuit of the ignition coil group 8, the # 1 spark plug and the # 4 spark plug, the current i flows in the order of # 4 spark plug-ignition coil- # 1 ignition coil. For this reason, in # 1, there is a positive discharge in which the spark plug has a large area pole and a narrow area pole.

Similarly, in # 3, + discharge is also performed. In the present embodiment, the intake pressure sensor 15 and the ECU 1
The acceleration state detecting means is constituted by and the throttle opening sensor 16 constitutes an operating state detecting means.

Next, the operation of the ignition timing control device thus constructed will be described. FIG. 2 shows a process (flowchart) executed by the ECU 1, and FIG. 3 shows a timing chart. In the embodiment, the retard control is performed in order to reduce the required voltage.

The flowchart of FIG. 2 is activated every 8 ms. In FIG. 2, the ECU 1 executes step 1
In 01, it is determined whether the process execution flag is ON. This processing execution flag is for determining whether or not the engine is in the idle state. Then, since the flag is initially OFF, the process proceeds to step 102. In FIG. 3, the throttle opening TA is “0” before the timing t1 and the engine is idle.

Then, the ECU 1 determines in step 102 whether the engine is in the idle state. Specifically, when the throttle opening TA is 2 ° or less (TA ≦ 2 °), it is determined that the engine is in the idle state.

When the engine is in the idle state with the throttle opening TA being "0" in step 102, the ECU 1 counts up the idle time counter and measures the idle holding time in step 103. Then E
The CU 1 turns off the process execution flag in step 104, and clears the process counter in step 105.

On the other hand, when the engine is no longer in the idle state (timing t1 in FIG. 3), the ECU 1 proceeds from step 102 to step 106 to make an acceleration determination. Specifically, the acceleration is determined to be acceleration when the time change rate ΔPM of the intake pressure PM is larger than “0” (ΔPM> 0).

Then, the ECU 1 determines in step 107 whether or not the acceleration is at full opening. Specifically, the throttle opening TA
When the time change rate ΔTA of 30 ° / 100 ms or more and the intake pressure PM is 88 KPa or more, it is determined that the acceleration is fully open (ΔTA ≧ 30 ° / 100 ms, PM ≧ 8.
8 KPa). Further, when the ECU 1 determines that the full-open acceleration is performed, it determines in step 108 whether the idle time counter is equal to or greater than a predetermined value. Specifically, it is 10 s when the value is equal to or larger than the predetermined value.
ec or more (idle time counter ≧ 10 sec). When the ECU 1 determines that the idle time counter is equal to or greater than the predetermined value, the process counter is set to 200 ms in step 109.
If it is less than 200 ms, step 1
Go to 10. Steps 110 to 112 are ignition timing retard processing for reducing the required voltage.

Here, if the ECU 1 determines in step 102 that the vehicle is not in the idle state, but in step 106 that it is not in the acceleration state (constant speed state or deceleration state), it also determines in step 107 that the accelerator is fully open. If it is determined that it is not, the process proceeds to step 113. Similarly, in step 108, the idle holding time is set to a predetermined value (10se
If it is determined to be shorter than c), the idle time counter is cleared in step 113 for the next process, the process execution flag is turned off in step 104, and the process counter is cleared in step 105.

In the retarding process for reducing the required voltage, the process execution flag is turned on in step 110, and the process counter for measuring the process duration time is counted up in step 111. Then, in step 112, the ignition timing is fixed at ATDC 15 ° C. only in the + discharge cylinder, and in the + discharge cylinder, the ignition timing at which the required voltage becomes high, that is, by avoiding the vicinity of TDC where the compression pressure is highest, the required voltage is reduced. To do.

Further, once the required voltage process is started, the process execution flag is turned on in step 101 in the next process, so the determination of the process execution condition is stopped, and the process proceeds from step 101 to step 109 to proceed to the process counter. ≧
The process is continued until it reaches a predetermined value (200 ms) (Fig. 3
T1 timing to t2 timing).

After the required voltage reduction processing is continued for a predetermined time (200 ms), step 109 to step 1
In step 104, the idle time counter is cleared and the process execution flag is turned off in step 104.
At 5, the processing counter is cleared. As a result, the processing is not performed until the idle time reaches the full-open acceleration after the predetermined value (10 sec).

As described above, after the idle state is maintained for a predetermined period of time or more, when full-open acceleration is performed, only the + discharge cylinder is ignited on the retard side of TDC for reducing the required voltage for a predetermined period of time. .

Explaining in detail with reference to FIG. 3, the idle holding time is measured in the idle state before the timing of t1. After the idle state is maintained for 10 seconds or more, when full-open acceleration is performed after timing t1, the ignition timing in the + discharge cylinder is immediately delayed by ATDC15 ° C.
Fixed to. This required voltage reduction processing is 2 from the start of acceleration.
It is continued for 00 ms, and thereafter ignition timing control is performed as usual.

In this way, it is possible to reduce the high required voltage in the + discharge cylinder immediately after full-open acceleration after holding the idle state for a long time, and prevent deterioration of drivability and damage to the ignition device due to engine misfire. .

As described above, in this embodiment, the ignition coils 9 and 10 for generating the high voltage necessary for ignition of the engine (internal combustion engine) are provided, and one coil is used for at least two cylinders of the ignition plugs. It is a control device for an internal combustion engine that supplies ignition energy simultaneously to the engine and performs + discharge ignition in at least one cylinder. A throttle opening sensor 16 (operating state detecting means) for detecting an operating state of the engine is provided, and an intake pressure sensor 15 for detecting an accelerating state of the engine, ECU 1 (accelerating state detecting means).
To provide. Further, when the engine is held idle by the throttle opening sensor 16 for a predetermined time (10 sec) or more and then fully accelerated by the intake pressure sensor 15 and the ECU 1, the ECU 1 (required voltage reducing means) only + discharges the cylinder for a predetermined time. (200 ms), the required voltage is reduced. Therefore, only + discharge cylinder for a predetermined period (200 ms),
The required voltage is lowered, and deterioration of drivability due to engine misfire is prevented.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the ignition timing is retarded to avoid ignition in a high cylinder pressure state as the required voltage reduction process. You may perform by the other method shown below.

As a method of increasing the active ion gas concentration in the cylinder and reducing the electric resistance near the spark plug during sparking, fuel injection in which the fuel injection amount and injection timing can be controlled for each cylinder according to the engine state It is provided with a control means. Then, at the time of full-open acceleration after the idle state of the engine has continued for a predetermined value or more, by supplying a predetermined amount of fuel increase to the discharge cylinder for a predetermined time, CO and H ₂ are increased in the fuel chamber of the + discharge cylinder. The required voltage is reduced by using the contained residual gas.

Further, as the fuel increase amount for reducing the required voltage, the fuel increase coefficient corresponding to the length of the idle holding time is controlled by using the predetermined amount selected by the map interpolation to control the excess fuel supply. Can be prevented.

Further, a means (for example, disclosed in Japanese Utility Model Laid-Open No. 56-65139) which can arbitrarily select the opening / closing timing of the intake / exhaust valve of the engine according to the engine state is provided. After the engine idle state continues for a predetermined value or more, the intake timing is delayed from the normal timing for a predetermined time in at least the + discharge cylinder at the time of full-open acceleration, so that more fuel gas remains in the cylinder and the required voltage is reduced. .

As another aspect, in the above embodiment, after the idle state of the engine is maintained for a predetermined time or more,
Although the required voltage is reduced only for the + discharge cylinder for a predetermined time when the full-open acceleration is performed, the deceleration state may be set instead of the idle state.

[0038]

As described above in detail, according to the present invention,
The excellent effect of preventing deterioration of drivability due to misfire of the internal combustion engine immediately after full-open acceleration is exhibited.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram including an ignition timing control device for an engine in an embodiment.

FIG. 2 is a flowchart of a control method in the embodiment.

FIG. 3 is a timing chart when this control is performed based on a flowchart.

[Explanation of symbols]

1 ECU which constitutes acceleration state detection means 9,10 Ignition coil 11, 12, 13, 14 Spark plug 15 Intake pressure sensor which constitutes acceleration state detection means 16 Throttle opening sensor which constitutes operation state detection means

Claims (5)

[Claims] 1. An ignition coil for generating a high voltage required for ignition of an internal combustion engine is provided, and one coil supplies ignition energy to ignition plugs of at least two cylinders at the same time. In a control device for an internal combustion engine that performs + discharge ignition, an operating state detection unit that detects an operating state of the internal combustion engine, an acceleration state detection unit that detects an acceleration state of the internal combustion engine, and the internal combustion engine by the operating state detection unit. When the engine is held in the idle state or the deceleration state for a predetermined period of time or longer, and when the acceleration state detecting unit fully accelerates the engine, the required voltage reducing unit is provided for reducing the required voltage only for the + discharge cylinder for a predetermined period of time. A control device for an internal combustion engine. 2. The internal combustion engine control device according to claim 1, further comprising ignition timing control means for outputting an ignition signal at an optimum position for each cylinder based on a position determination signal and an engine state, and the required voltage reduction. The control means for an internal combustion engine is characterized in that the means ignites on the retard side from the compression top dead center by the ignition timing control means to reduce the required voltage. 3. The control device for an internal combustion engine according to claim 1, further comprising a fuel injection control unit capable of controlling a fuel injection amount for each cylinder according to a state of the internal combustion engine, wherein the required voltage reduction unit is the fuel. A control device for an internal combustion engine, wherein the injection control means is configured to increase the amount of fuel and reduce the required voltage only for a + discharge cylinder for a predetermined time. 4. The control device for an internal combustion engine according to claim 3, wherein the required voltage reduction means increases the fuel amount by the fuel injection control means by an amount according to an idle holding time. Control device for internal combustion engine. 5. The control device for an internal combustion engine according to claim 1, further comprising variable valve timing control means capable of arbitrarily selecting opening / closing timings of intake / exhaust valves of the internal combustion engine, wherein the required voltage reducing means is the variable valve. A control device for an internal combustion engine, characterized in that the timing control means delays the opening timing of the intake valve to increase the residual fuel gas in the cylinder to reduce the required voltage.