JPH03107571A - Ignition timing controller of internal combustion engine - Google Patents

Abstract

PURPOSE:To accurately judge used fuel by variably setting a judgement value of the used fuel in response to ambient air related to generation of knocking, in an internal combustion engine alternatively using two kinds of fuel which have different knocking characteristics. CONSTITUTION:In an internal combustion engine in which two kinds of fuel are variably used an ignition timing set means A which sets ignition timing in response to an engine operation condition with respect to used fuel is provided. Delay angle quantity of the ignition timing is set by a set means C when the knocking is detected by a knocking detection means B, and the ignition timing is compensated by a compensation means D in response to the delay angle quantity after the setting so as to control an ignition plug E by an ignition control means F. In this case, an ambient detection means G which detects the ambient air related to the generation of knocking is provided, and a judgement value of used fuel is judged by a set means H in response to the detected ambient air. The judgement value is compared with the delay angle quantity by the judgment means I so as to judge the used fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an ignition timing control device for an internal combustion engine, and particularly to one that switches between and uses two types of fuel.

<Prior Art> Conventional examples of this type of ignition timing control device include the following.

That is, engine operating conditions (e.g. engine speed and engine load)
The ignition timing ADV is set from the map according to the ignition timing ADV, and the ignition plug is operated to ignite at the set ignition timing ADV. Furthermore, when knocking occurs in a predetermined operating range, the ignition timing ADV is retarded by a predetermined amount (for example, 1°) to suppress the occurrence of knocking.

Further, when knocking does not occur, the ignition timing is retarded as much as possible near the knocking non-occurrence limit region to increase engine output (hereinafter referred to as knock control).

Here, the fuel used is gasoline with excellent anti-knock properties (
When switching between gasoline (hereinafter referred to as high-octane gasoline) and gasoline with poor anti-knock properties (hereinafter referred to as regular gasoline), the ignition timing is controlled as follows.

That is, ignition control is performed using dedicated ignition timing maps when using high-octane gasoline and when using regular gasoline.

The gasoline used is determined based on the amount of retardation during knock control. That is, when high-octane gasoline is currently being used, ignition control is performed by setting the ignition timing from a high-octane ignition timing map, and knock control is performed to suppress knocking based on the detection signal of the knocking sensor. Then, when the maximum retardation amount during knock control exceeds a certain determination value, it is determined that the gasoline used has been switched to regular gasoline, and then the ignition timing is set from the regular ignition timing map and ignition control is performed. At the same time, knock control is also performed.

Here, the judgment value is determined from atmospheric conditions such as intake temperature and engine oil temperature, octane number variations, and engine variations, and is particularly highly dependent on the atmospheric conditions.

<Problems to be Solved by the Invention> By the way, the above-mentioned constant judgment value is set to a large value taking into account atmospheric conditions, octane number variations, and engine variations. If such a determination is made, the gasoline used cannot be accurately determined, resulting in a problem that optimal ignition control cannot be performed in accordance with the gasoline used.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ignition timing control device that can accurately determine the fuel used and perform optimal ignition control.

Therefore, as shown in Fig. 1, the present invention uses two types of fuel with different knocking characteristics by switching between them, and the ignition timing is adjusted depending on the engine operating state. ignition timing correction means 8, which sets the ignition timing in accordance with An ignition timing correction means for correcting the ignition timing according to the amount of retardation, and an ignition control means F for controlling the ignition plug E according to the corrected ignition timing, which is related to the occurrence of knocking. Atmosphere detection means G for detecting the atmosphere; Judgment value setting means H for setting a judgment value of the fuel to be used according to the detected atmosphere; The present invention includes a used fuel determining means I for determining the fuel used.

<Operation> In this way, by variably setting the judgment value according to the atmosphere related to the occurrence of knocking, it is possible to accurately determine the fuel used from the retard amount and perform optimal ignition control according to the fuel used. I did it like that.

<Example> An example of the present invention will be described below with reference to FIGS. 2 and 3.

In FIG. 2, a control device 1 consisting of a microcomputer etc. receives a reference signal (corresponding to the engine rotational speed) and a position signal from a crank angle sensor 2.
An intake air flow rate detection signal from the air flow meter 3, a knocking detection signal from the knocking sensor 4 as a knocking detection means, a cooling water temperature detection signal from the water temperature sensor 5, and an intake temperature detection signal from the intake temperature sensor 6, An oil temperature detection signal from an oil temperature sensor 7 that detects the temperature of lubricating oil in the engine is input.

The control device 1 operates according to the flowchart shown in FIG. 3, and outputs an ignition signal to the ignition plug 9 at a set ignition timing via an ignition device 8 consisting of an ignition coil, a power transistor, etc., and performs an ignition operation. It has become.

Here, the control device 1 constitutes an ignition timing setting means, a retard amount setting means, an ignition timing correction means, a determination value setting means, and a fuel usage determination means. Further, the control device 1 and the ignition device 8 constitute ignition control means.

Further, the water temperature sensor 5, the intake temperature sensor 6, and the oil temperature sensor 7 constitute atmosphere detection means.

Next, the operation will be explained according to the flowchart shown in FIG. In terms of operation, an example will be explained in which high-octane gasoline and regular gasoline are switched and used, and a case where high-octane gasoline is currently being used will be explained.

First, to explain normal ignition timing control, for example, ignition timing is searched from a high-octane ignition timing map based on engine speed and engine load such as basic injection amount, and an ignition signal is sent to the ignition device at the searched ignition timing. The signal is outputted to the spark plug 9 via the ignition plug 8 for ignition operation. Furthermore, in a predetermined operating range (for example, medium speed/high load operating range), when knocking occurs, the ignition timing is retarded by a predetermined amount (for example, 1°) to suppress the occurrence of knocking, while when knocking does not occur, the ignition timing is retarded by a predetermined amount (for example, 1°). Knock control is performed to advance the ignition timing as much as possible near the knock-free limit region.

During this control, a routine shown in the flowchart of FIG. 3 is executed.

That is, in Sl, various signals from the water temperature sensor 5 and the like are read.

In S2, it is determined whether or not knock control is currently being performed. If YES, the process proceeds to S3; if NO, the routine is ended.

In S3, a water temperature dependent determination value al is searched from the map based on the cooling water temperature detected by the water temperature sensor 5. The water temperature dependent determination value a is set to increase as the cooling water temperature increases. This is because the higher the cooling water temperature, the more likely knocking will occur.

In S4, the intake temperature dependence determination value a2 is searched from the map based on the intake air temperature detected by the intake air temperature sensor 6.

The intake air temperature dependent determination value a2 is set to decrease as the intake air temperature increases. This is because the lower the intake air temperature, the more likely knocking will occur.

In S5, the oil temperature dependence determination value a3 is searched from the map based on the engine oil temperature detected by the oil temperature sensor 7.

In S6, a determination value α is calculated using the following equation based on the retrieved water temperature dependency determination value a, intake temperature dependency determination value a2, and oil temperature dependency determination value a3.

cx=a, +a2+a3+b+c b is a determination value corresponding to octane number variation, and C is a determination value corresponding to engine variation.

In S7, it is determined whether the calculated determination value α is larger than the maximum retardation amount of the ignition timing during knock control, and YE
When the answer is S, the process proceeds to S8, and when the answer is NO, the process proceeds to SIO.

In S8, the currently used gasoline is determined to be high-octane gasoline, and in S9, a high-octane ignition timing map is selected.

At step 310, it is determined that the gasoline used has been switched to regular gasoline, and the regular ignition timing map is selected at Sll.

Ignition control is performed based on the ignition timing map selected in this way.

As explained above, the judgment value α for determining the gasoline used
Cooling water temperature related to the occurrence of knocking.

Since the settings are set variably according to the intake air temperature and oil temperature, the gasoline used can be accurately determined regardless of changes in the atmosphere.
This allows optimal ignition control to be performed depending on the gasoline used.

Note that the humidity or water vapor partial pressure of the intake air may be used as a parameter for determining the determination value.

<Effects of the Invention> As explained above, the present invention allows the judgment value of the fuel to be used to be variably set depending on the atmosphere related to knocking, so that the fuel to be used can be accurately determined and can be adapted to the fuel to be used. optimum ignition control.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram of the present invention, FIG. 2 is a configuration diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart of the same.

Claims (1)

[Claims] An ignition timing setting means for switching between two types of fuel having different knocking characteristics and setting the ignition timing in accordance with the fuel used according to the engine operating state; and a knocking detection means for detecting knocking. a retard amount setting means for setting a retard amount of ignition timing in accordance with detected knocking; an ignition timing correction means for correcting the ignition timing in accordance with the set retard amount; An ignition timing control device for an internal combustion engine, comprising: an ignition control means for controlling an ignition plug according to the atmosphere, an atmosphere detection means for detecting an atmosphere related to the occurrence of knocking, and a determination value for the fuel to be used according to the detected atmosphere. An ignition timing control device for an internal combustion engine, comprising: a determination value setting means for setting the retardation amount; and a fuel usage determination means for determining the fuel to be used by comparing the set determination value with the retard amount. .