JPH03107573A - Ignition time control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent aggravation in operating condition by selection-setting an ignition time for the low octane number at the time of using for high octane number fuel providing each of a based ignition time setting means for a high and low octane number and a based ignition time setting means for a high water temperature. CONSTITUTION:Each of based ignition time setting means 1, 2 for a high and low octane number are provide, while an ignition time setting means 3 for a high water temperature is provided in order to set the based ignition time according to an operation condition when the cooling water temperature on an internal combustion engine is at a prescribed temperature or more. One based ignition time of three based ignition times set by each setting means 1 to 3 is selected by a based ignition time selecting means 6 on the basis of a cooling water temperature detected by a water temperature detecting means 5 when generation of knocking in the internal combustion engine is detected by a knocking detection means 4. At the selected based ignition time, an ignition time correcting amount is applied by a correcting means 7 so as to decide a minimal ignition time. It is thus possible to control an ignition device 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an ignition timing control device for an internal combustion engine, and more particularly to an ignition timing control device that controls ignition timing in relation to the octane number of the fuel and the temperature of the cooling water of the internal combustion engine. It is related to.

Conventional technology There is a correlation between the octane number of gasoline and the occurrence of knocking, and it is well known that the higher the octane number, the less likely knocking will occur. Internal combustion engines have been developed that can use both gasoline (so-called regular gasoline) and high-octane gasoline (so-called high-octane gasoline).

In other words, it is determined whether the gasoline being used is Regicola or Bio-gasoline based on the state of knocking occurrence, and based on the determination result, either the basic ignition timing for Regicola gasoline or the basic ignition timing for high-octane gasoline is set. This selects the ignition timing and controls the ignition timing.

For example, Japanese Patent Application Laid-Open No. 60-104.774 discloses that a knock sensor is used to detect the occurrence of knock, and based on the detected value, it is determined whether the gasoline in use is Regicola kasoline or high-octane gasoline. An ignition timing control device is disclosed that automatically switches the ignition timing in accordance with the type of gasoline by setting the ignition timing to the advanced side or the retarded side based on the determination result.

Problem to be Solved by the Invention When knocking occurs due to the low octane number of gasoline, the occurrence of knocking can generally be suppressed by retarding the ignition timing, but even when the octane number of gasoline is high, various conditions may occur. Depending on the situation, knocking may occur. For example, this occurs when the temperature of the cooling water for the internal combustion engine rises and the internal combustion engine cannot be cooled appropriately, causing the temperature of the combustion gas to rise.

Then, if high-octane gasoline is used and knocking occurs due to the internal combustion engine's cooling water temperature = 3 degrees Celsius during continuous high-load operation, the above-mentioned conventional technology would not be able to adjust the ignition timing for the high-octane gasoline. The ignition timing will be switched to the ignition timing for gasoline and gasoline, and the ignition timing will be controlled to be delayed. However, if high-octane gasoline is used and the ignition timing for high-octane gasoline is switched to the ignition timing for regular gasoline, the following problems are likely to occur, such as deterioration of drivability. ■Output decreases.

■The combustion scum temperature rises further, resulting in overheating.

■Knocking becomes more intense as the driver presses the accelerator further as the output decreases.

In addition, there are some systems that detect the cooling water temperature of the internal combustion engine and make corrections to the selected 6 spark timings according to the cooling water temperature, but due to responsiveness and other reasons, the amount of correction cannot be increased. The disadvantage is that it is difficult to perform optimal correction.

Means for Solving the Problems This invention has been made to solve the above problems, and as shown in FIG. basic ignition timing setting means 2 for low octane fuel, which sets the basic ignition timing for low octane fuel according to operating conditions, and basic ignition timing setting means 2 for setting the basic ignition timing for low octane fuel when the temperature of the cooling water of the internal combustion engine is above a predetermined temperature. High water temperature ignition timing setting means 3 for setting ignition timing according to operating conditions; knocking detection means 4 for detecting the occurrence of knocking in the internal combustion engine; and water temperature detection means 5 for detecting the cooling water temperature of the internal combustion engine. , a basic ignition timing selection means 6 for selecting any one of the three basic ignition timings as a basic ignition timing based on the detected knocking occurrence state and the cooling water temperature; and the selected basic ignition timing. The ignition timing correction means 7 adds an ignition timing correction amount to the timing to determine the final ignition timing. In addition, 8 is the ignition timing correction means 7.
This is an ignition device that ignites according to the final ignition timing determined by.

For example, when a predetermined knocking condition is not detected, it is determined that high octane fuel is being used, and the high octane basic ignition timing set by the high octane basic ignition timing setting means 1 is selected. The final ignition timing obtained by adding a correction amount to this basic ignition timing by the ignition timing correction means 7 is given to the ignition device 8 to perform ignition. In this ignition timing setting state, if the cooling water temperature is below a predetermined temperature and a predetermined knocking state is detected, and the fuel used changes from a high octane number to a low octane number, the basic ignition timing setting means for low octane number The basic ignition timing for low octane number set by 2 is selected. In addition, when the cooling water temperature exceeds a predetermined temperature and a predetermined knocking state is detected, it is assumed that strong nogging has occurred due to the increase in the cooling water temperature, and the high water temperature set by the basic ignition timing setting means 3 for high water temperature is determined. The basic ignition timing is selected.

Embodiment FIG. 2 is a configuration explanatory diagram showing an embodiment in which the ignition timing control device according to the present invention is applied to an internal combustion engine with a supercharger.

11 is a cylinder block, 12 is a cylinder block 11
4 is an exhaust passage connected to the exhaust boat 15 of the cylinder block 11, 16 is an exhaust-driven supercharger, ] 7 is arranged upstream of the intake passage 12. It is an air cleaner.

A knocking sensor 8 and a water temperature sensor I9 are mounted on the side surface 11a of the cylinder block II. The knocking sensor I8 uses, for example, a piezoelectric element,
Mechanical vibration of the cylinder block 11 caused by knocking is detected. The water temperature sensor I9 is composed of, for example, a thermistor or a thermocouple, and detects the temperature of the cooling water flowing through the cylinder block II. Further, the cylinder head 20 has a spark plug 2 ignited by an ignition circuit 21.
2 is installed. The ignition circuit 2I is composed of an ignition coil, a power transformer, and the like.

The intake passage 12 includes an injector 23 that injects fuel toward the intake portion of the cylinder block 11, a throttle valve 24 for adjusting the amount of intake air, and a =1 valve for an alternator and air conditioner. A bypass passage 25 is provided for sending auxiliary air to each cylinder without passing through the throttle valve 24 when the load on the engine brake sensor increases. Further, an intake pressure sensor 26 for detecting intake pressure is disposed downstream of the snottle valve 24. This intake pressure sensor 26 is configured as a pressure sensor with a strain gauge attached to a pressure-sensitive tire flam.

The supercharger 16 includes a turbine 27 driven by exhaust gas, a compressor 28 that is driven by the turbine 27 and pressurizes air introduced through the air cleaner 17 and sends it to the intake passage 12, It is composed of a Guyafram type actuator and an etator 30 that open and close two waste gate valves and two waste gate valves for bypassing without going through the turbine 27.

31 is the ignition timing control circuit for the ignition plaque 22 described in -, and includes the knocking sensor +8 and water temperature sensor 1 described in -I-.
This circuit outputs an ignition timing signal to the ignition circuit 2I based on signals input from various sensors such as the intake pressure sensor 26 and the crank angle sensor 32 that detects the rotational position of the crankshaft of the internal combustion engine. Ignition timing control circuit 31
is an input/output port 33 for inputting and outputting each of the above-mentioned signals.
, a CPU 3/l that processes each signal according to the program;
ROM in which the program and fixed data are stored
35, I(ΔM) for temporarily storing variable data
It consists of 36 etc.

Next, the operation of the ignition timing control circuit 3I will be explained with reference to flowchart 1 in FIG.

Flowchart 1 in FIG. 3 shows the contents of a program for ignition timing control, and this program is executed, for example, every time each cylinder is ignited.

First, in step (2), it is determined based on the signal input from the knocking sensor 18 whether or not a predetermined knocking condition is occurring. This is determined by, for example, (1) whether strong knocking of a predetermined level or higher is detected, (2) whether the knocking continues for a predetermined period or more, and (2) whether the knocking correction amount described later is in a predetermined critical condition.

If it is determined in step 1 that the predetermined knocking condition has not occurred, the process proceeds to step 2, where the basic ignition timing for high octane number is set. The basic ignition timing for high octane fuel is the optimum ignition timing for high octane fuel, and is set theoretically or experimentally based on the engine speed and intake pressure that indicate the operating conditions, for example, as shown in Table 1 below. It is something that

Table 1 In Table 1, the numerical values shown as ignition timing indicate the advance angle from the top dead center of the piston. For example, when the rotation speed per minute is 2400 revolutions, the intake pressure is +200zπr (!?
If so, this indicates that the ignition timing is 18 degrees before the top dead center of the piston. As described above, in step 2, the basic ignition timing for high octane number is set according to the detected rotational speed and intake pressure.

If it is determined in step I that a predetermined knocking condition has occurred, the process proceeds to step 3, where it is determined whether the internal combustion engine cooling water temperature detected by the water temperature sensor I9 is below a predetermined temperature (for example, 1008C). be done. If the cooling water temperature is below the predetermined temperature in step 3, it is determined that knocking is occurring due to the low octane number of the fuel, and the process proceeds to step 4. If the cooling water temperature has undergone a predetermined temperature transformation, it is determined that the combustion gas temperature has risen due to the internal combustion engine not being cooled appropriately, and nogging is occurring, and the process proceeds to step 5.

In step 4, the basic ignition timing for low octane number is set, and in step 5, the basic ignition timing 1 for high temperature water is set. The basic ignition timing for low octane number is the optimum ignition timing for low octane fuel.Similar to the above-mentioned basic ignition timing for high octane number, the basic ignition timing for low octane number is the theoretical or This has been set experimentally in advance.

This basic ignition timing for low octane numbers is generally set to be more retarded than the above-mentioned basic ignition timing for high octane numbers (some settings may be advanced depending on operating conditions).

The basic ignition timing for high-temperature water is the optimum ignition timing when the internal combustion engine is not sufficiently cooled due to continuous high-load operation. ) has been determined in advance theoretically or experimentally.

This basic ignition timing for high-temperature water is set approximately halfway between the above-mentioned basic ignition timing for high octane numbers and basic ignition timing for low octane numbers for boat fishing (depending on operating conditions, there may be setting values that are not in the middle). .

Step 2. Step 4. When any step in Step 5 is completed, the process proceeds to Step 6, where a knocking correction amount and the like are added to the basic ignition timing set in the previous step, and the final ignition timing is set. This knocking correction amount is a correction amount that is gradually applied to the retard side if knocking occurred during the previous ignition, and to the advanced side if knocking did not occur. By adding this knocking correction amount to the basic ignition timing, the final ignition timing is set so that it is always near the trace knock point (knock occurrence limit). Then, a final ignition timing signal is given to the ignition circuit 2I based on the rotational position of the crankshaft detected by the crank angle sensor 32, and the ignition plaque 22 is ignited.

As described above, the ignition timing control program is executed in the ignition timing control circuit 31, but the basic ignition timing setting operation is performed by pre-memorizing two sets of three types of basic ignition timing corresponding to the addresses, and detecting them. It is a simple process of selecting the address depending on the operating conditions and extracting the optimal ignition timing data that takes into consideration the state of knocking, internal combustion engine cooling water temperature, and operating conditions (rotational speed and intake pressure).
Thus, in this embodiment, when a predetermined knocking condition is detected due to an increase in internal combustion engine coolant temperature while using high octane fuel, Since the basic ignition timing for high water temperatures is selected without selecting the basic ignition timing for low octane numbers, excessive retardation can cause problems such as deteriorating driving conditions or causing the driver to operate the accelerator incorrectly. It will no longer occur.

In the above embodiment, the intake pressure is used as the load of the internal combustion engine, but by providing an air flow meter downstream of the air cleaner, the intake air amount can be detected and used as a parameter indicating the load.

Further, although this embodiment uses an internal combustion engine with a supercharger, it goes without saying that the present invention can also be implemented with an internal combustion engine without a supercharger.

Effects of the Invention As is clear from the above explanation, according to the ignition timing control device for an internal combustion engine according to the present invention, in addition to the basic ignition timing setting means for high octane numbers and the basic ignition timing setting means for low octane numbers, The basic ignition timing setting means for high water temperature is set to 6111, and when knocking occurs due to a rise in the cooling water temperature of the internal combustion engine, the basic ignition timing for high water temperature is selected and set, so that high octane fuel is used. This eliminates inconveniences that worsen driveability, such as selecting and setting the ignition timing for low octane numbers even when the vehicle is in use, further worsening the driving condition, or causing the driver to operate the accelerator incorrectly.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram showing the configuration of an ignition timing control device according to the present invention, and FIG. 2 is a configuration explanatory diagram showing an embodiment in which the ignition timing control device according to the present invention is applied to a supercharged internal combustion engine. , FIG. 3 is a flowchart showing the processing contents of the ignition timing control program in this embodiment. ■... Basic ignition timing setting means for high octane number, 2. Basic ignition timing setting means for low octane number, 3. Basic ignition timing setting means for high water temperature, 4. Knocking detection means 6. Mountain means, Water temperature detection means, Basic ignition timing selection. Means, . . . Ignition timing correction means, 8. Ignition device.

Claims (1)

[Claims] (1) Basic ignition timing setting means for high octane fuel that sets the basic ignition timing for high octane fuel according to operating conditions, and basic ignition timing for low octane fuel that sets basic ignition timing for low octane fuel according to operating conditions. timing setting means; high water temperature ignition timing setting means for setting basic ignition timing when the cooling water temperature of the internal combustion engine is higher than a predetermined temperature according to operating conditions; and knocking detection for detecting occurrence of knocking in the internal combustion engine. means, a water temperature detection means for detecting a cooling water temperature of the internal combustion engine, and basic ignition of any one of the three basic ignition timings as a basic ignition timing based on the detected knocking occurrence state and the cooling water temperature. An ignition timing control device for an internal combustion engine, comprising a basic ignition timing selection means for selecting a timing, and an ignition timing correction means for adding an ignition timing correction amount to the selected basic ignition timing to determine a final ignition timing.