JPS62258152A - Method for controlling ignition timing of internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate misfire immediately after acceleration, prevent after burning, and improve operatability by delayingly carrying out the lag angle of ignition timing at the time of acceleration of an internal combustion engine by a defined number of misfire after detecting acceleration. CONSTITUTION:A control unit has an MPU 21, etc. and receives various detected signals from various detecting sensors 3, 25, 26, 27, 18, 19, 29 for detecting various operating conditions of an engine via an A/D converter and an input/ output circuit 24. And, after carrying out a certain arithmetic processing, it controls injectors 13, an ignition coil 29, and a fuel pump 10 in accordance with the operated result. In this case, when an ignition timing is gradually advanced after delaying the ignition timing at the time of accelerating an internal combustion engine, the delay of angle is carried out from after a defined number of ignition after the acceleration is detected. Thereby, misfire immediately after acceleration can be eliminated, preventing after burning.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ignition timing control method for an internal combustion engine.

In particular, the present invention relates to an ignition timing control method for an internal combustion engine suitable for reducing acceleration shock in an electronic fuel injection system.

[Conventional technology]

In a conventional method for controlling ignition timing of an internal combustion engine using an electronic fuel injection system, the ignition timing is retarded immediately after acceleration is detected during acceleration in order to reduce acceleration shock, as described in JP-A-59-162365, for example. Later, a control method was adopted that gradually advanced the ignition timing.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional technology does not take into account misfires that occur immediately after acceleration by retarding the ignition timing immediately after acceleration is detected during acceleration, so if the amount of retardation is increased to reduce acceleration shock, afterburn occurs. There was a point.

An object of the present invention is to provide an ignition timing control method for an internal combustion engine that reduces acceleration shock during acceleration and prevents afterburn.

[Means for solving problems]

The above objective was to focus on the fact that in conventional technology, the ignition timing during acceleration was retarded immediately after acceleration was detected, which resulted in misfires in cylinders that had not taken in the increased amount of fuel during acceleration, resulting in afterburn. According to the present invention, the ignition timing during acceleration is not retarded immediately after acceleration is detected, but the ignition timing during acceleration is retarded a predetermined number of times after acceleration is detected.

This is achieved by retarding the cylinder from which the increased amount of fuel is sucked in during acceleration and explodes.

[Effect]

In the ignition timing control method for an internal combustion engine using the above means, the ignition timing is retarded during acceleration a predetermined number of times after acceleration is detected.

Since the ignition timing is not retarded from the moment of acceleration until the fuel increased by acceleration correction is inhaled and explodes,
The cylinder will not misfire and cause afterburn.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

First, FIG. 2 is a system configuration diagram of an electronic fuel injection device showing an embodiment of the ignition timing control method for an internal combustion engine according to the present invention. In FIG. 2, 1 is an air cleaner, 2 is an air inlet, 3 is a hot wire air flow meter, 4 is a duct, 5 is a throttle body, 6 is a collector, 7 is an internal combustion engine, and 8 is an intake pipe. 9 is a fuel tank, 10 is a fuel pump, 11 is a fuel damper, 12 is a fuel filter, 13 is a fuel injection valve,
14 is a fuel pressure regulator. 15 is a control unit (electronic control circuit), 16 is a distribution user,
17 is the igniter, 18 is 02. The sensor 19 is a water temperature sensor (temperature detection means), and 20 is a spark plug.

In Fig. 2, intake air enters from an air inlet 2 of an air cleaner 1, which has a hot wire air flow meter (air flow rate detection means) 3 for detecting the amount of intake air, a duct 4, and a throttle valve for controlling the air flow rate. Through the throttle body 5, the collector 6
to go into. From this, the intake air is distributed to each intake pipe 8 communicating with the internal combustion engine 7 and sucked into the cylinder. One fuel is sucked and pressurized from the fuel tank 9 by the fuel pump 10, and is sent to the fuel damper 11, the fuel filter 2, and the injection valve 1.
3 and a fuel regulator 4 are supplied to the fuel system. From this, the pressure of the fuel is regulated to a constant pressure by the regulator 14, and the fuel is injected into the intake pipe 8 from the injection valve 13 provided in each intake pipe 8. Further, the air flow meter 3 outputs a signal for detecting the amount of intake air, and this output is input to the control unit 15. Distributor 1
6 has a crank angle sensor (rotation speed detection means).

-”] is built-in, and outputs signals to detect reference number i for fuel injection timing and ignition timing, as well as internal combustion engine rotation speed.
It is input to the control unit 15.

In addition, signals detected by the water temperature sensor 9 and the 02 sensor 18 are input to the control unit 15.

FIG. 3 is a block diagram of the control system of the control unit 15 shown in FIG. 2. In fig.

Control unit (electronic control circuit) 15 is MPU
(Microprocessor) 21, EPROM 22, RAM 23, and an arithmetic unit including an A/D converter and an input/output circuit 24. control unit 15
includes an air flow meter (air flow sensor) 3, a crank angle sensor 25 in the distributor 16, an idle switch 26, a starter switch 27, and an 02 sensor 1.
8, a water temperature sensor 19 that detects the temperature of the internal combustion engine, and output signals such as a battery voltage 28 are inputted via an A/D converter and an input/output circuit 24. The control unit 15 performs predetermined calculation processing based on these required signals, and operates each injection valve (injector) 13 with the required injection pulse width based on the output signal of the calculation result to inject the required amount of fuel into each intake pipe 8. At the same time as spraying, igniter 1
The ignition timing of each spark plug 20 is controlled by sending a signal to the power transistor 7 to turn on/off the ignition coil 29 of the distributor 16. It also controls the fuel pump 10, etc.

Next, FIG. 1 is an ignition timing diagram of FIGS. 2 and 3 showing an embodiment of the ignition timing control method for an internal combustion engine according to the present invention. In FIG. 1, the stroke of the internal combustion engine in FIGS. 2 and 3, the fuel injection timing, and the air flow rate Q1
The relationship between 1 and 1 ignition timing is illustrated. NG in Figure 1
For cylinders 1 to N (14 cylinders, fuel is injected from the synchronous injection pulse injection valve 13 at a constant air flow rate Q&. When the throttle valve of the throttle body 5 is opened to accelerate from this state, the air flow rate Q & increase as follows.

When the amount of change ΔQ& in the air flow rate exceeds a predetermined value, this acceleration state is detected, and fuel is injected from the injection valve 13 using an asynchronous injection pulse. As a result, fuel is first sucked into the Nα4 cylinder as shown in the figure, and the fuel mixture explodes at the 3-ignition port 103 after acceleration is detected.
6 In the embodiment according to the present invention, the ignition timing is retarded during acceleration from the three ignition ports 103 after the acceleration is detected, as shown in the figure, and then the ignition timing is gradually advanced. Therefore, the ignition timing is not retarded in the first ignition interval 101 and the second ignition port 102 immediately after acceleration detection in which a lean air-fuel mixture explodes, so misfires do not occur and afterpan does not occur.

FIG. 4 is an arithmetic processing flowchart of the control unit 15 of FIGS. 2 and 3, showing an embodiment of the ignition timing control method for an internal combustion engine according to the present invention. In FIG. 4, in step 111, signals of air flow rate Q & or throttle opening 0 and reference ignition timing ADVM are read, and in step 112, acceleration detection is performed using air flow rate change amount ΔQ a
> X (predetermined value) or throttle opening change amount Δθ
If ih>Y (predetermined value), then when acceleration is detected, in step 113, a table search is performed for the retard amount ΔADV corresponding to the number of ignitions after acceleration detection, and the ignition timing ADV=A
Calculate DVM-ΔADV. The ignition timing of the internal combustion engine 15 is controlled based on this calculation result. Further, in step 114, the reference ignition timing ADVM and the ignition timing ADV of the calculation result are determined.
is stored at a predetermined address. FIG. 5 is an explanatory diagram of an example of an ignition timing retard amount table of the control unit 15. In FIG. 5, the retard amount Δ corresponds to the number of ignitions 1 to n after acceleration detection, with the number of ignitions being 0 as the acceleration detection position.
ADV will be displayed. In this embodiment, as shown in the figure, after acceleration is detected, the ignition is delayed by two ignitions, the ignition is retarded from the third ignition, and then the ignition is gradually advanced. Further, FIG. 6 is a flowchart of the calculation processing of the control unit 15 showing another embodiment. In FIG. 6, after acceleration detection, step 11
In step 2a, count the number of ignitions ADVC, and calculate the number of ignitions A.
The operation in other steps, in which the ignition timing is retarded from a predetermined ignition position at DVC=Z (a predetermined number of times), is the same as that shown in FIG.

FIG. 7 is an explanatory diagram of test results of an embodiment of the ignition timing control method for an internal combustion engine according to the present invention. Further, FIG. 8 is an explanatory diagram of test results of an example of the conventional ignition timing control method for an internal combustion engine according to the present invention. In an example of the conventional method shown in Fig. 8, the ignition timing ADV is retarded immediately after acceleration due to the change amount ΔQa in the air flow rate Q&, and misfire occurs immediately after acceleration, so the internal combustion engine rotation speed N changes after acceleration. On the other hand, in one embodiment of the method according to the present invention shown in FIG. 7, after acceleration is detected based on the amount of change ΔQ& in the air flow rate Q&, ignition is delayed by two ignitions, and the ignition timing ADV is retarded from the third ignition. Since a misfire does not occur immediately after second acceleration, fluctuations in the internal combustion engine rotational speed N after acceleration are also smaller.

As described above, according to this embodiment, the air flow meter or throttle opening sensor has an injection valve that supplies fuel to the internal combustion engine, detects the intake air amount of the internal combustion engine, and detects the rotation speed of the internal combustion engine. An electronic control unit consisting of a controller unit that includes an electronic control circuit that calculates the injection pulse width of the injector and determines the ignition timing based on signals from a crank angle sensor that detects the temperature of the internal combustion engine, and a water temperature sensor that detects the temperature of the internal combustion engine. In a type fuel injection system, during ignition timing control that retards the ignition timing when the internal combustion engine accelerates and then gradually advances the ignition timing, retards the ignition timing after a predetermined number of ignitions after detecting acceleration. By.

Since there is no misfire immediately after acceleration, it is possible to prevent an accident.

〔Effect of the invention〕

As described above, according to the present invention, the ignition timing is retarded when the internal combustion engine accelerates by a predetermined number of misfires after acceleration is detected, thereby eliminating misfires immediately after acceleration and preventing afterburn. , which has the effect of improving drivability.

[Brief explanation of drawings]

Fig. 1 is an ignition timing diagram showing an embodiment of the ignition timing control method for an internal combustion engine according to the present invention, Fig. 2 is a system diagram of an electronic fuel injection device, and Fig. 3 is a block diagram of the control system shown in Fig. 2. Figure 4 is the process flowchart of Figure 2 (Figure 3), Figure 5 is an example of the ignition timing retard amount table, Figure 6 is another process flowchart, and Figure 7 is the test result. 8 are test results diagrams of the conventional example. DESCRIPTION OF SYMBOLS 1... Air cleaner, 3... Air flow meter (air flow rate detection means), 5... Throttle body, 7... Internal combustion engine. 8...Intake pipe, 9...Fuel tank, 10...Fuel pump. 13... Injection valve, 15... Control unit (
electronic control circuit), 16... distributor (including rotation speed detection means), 19... water temperature sensor (temperature detection means), 2o... spark plug.

Claims (1)

[Claims] 1. An injection valve that supplies fuel to the internal combustion engine, an air flow rate detection device that detects the amount of intake air to the internal combustion engine, a rotation speed detection device that detects the rotation speed of the internal combustion engine, and a temperature detection device that detects the temperature of the internal combustion engine. ignition at the time of acceleration of an electronic fuel injection device consisting of a thermal decomposition detection means and an electronic control circuit that calculates and controls the injection pulse width of the injection valve and the ignition timing of the internal combustion engine based on the detection signals of the respective detection means. In an ignition timing control method for an internal combustion engine in which the timing is retarded and then gradually advanced,
An ignition timing control method for an internal combustion engine, characterized in that the retardation is performed after a predetermined number of ignitions after detecting acceleration during the acceleration.