JPS6088832A - Controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To facilitate the restarting of an engine, by maintaining sparks for a prescribed time even after turning off an ignition key. CONSTITUTION:When an ignition key 2 is turned off, the supply of fuel is stopped. However, an ignition circuit 5 is still connected to a power supply unit for a time determined by a delay circuit 4, to maintain sparks for the preset time even after the ignition key 2 is turned off. As a result, fuel remaining in a cylinder and an intake pipe is burned up to facilitate the restarting of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a control device for an internal combustion engine having an ignition system and a fuel system.

[Prior art and its problems]

Normally, when the ignition system (ignition circuit) stops in an internal combustion engine,
This is done by stopping the power supply. The specific means for stopping this power supply is the ignition key (
Hereinafter, it will also be referred to as ■yo or 1g key. ) is to be turned off. By the way, when the internal combustion engine is stopped in this way, the inside of the cylinder during the intake stroke or the inside of the cylinder before ignition during the compression stroke,
Alternatively, fuel may remain in the intake pipe, but the vaporization of the fuel in the cylinder is promoted by preheating the combustion chamber while the engine is stopped, and it also diffuses over time into the intake air warmed by residual heat. It is highly flammable. In this way, when the engine is restarted in a hot state, the cylinders that are prone to combustion will ignite before the engine speed has sufficiently increased immediately after starting the starter, and this will prevent the generation of the peak combustion pressure. If the engine reaches top dead center too early, it may prevent the engine from rotating, making it difficult to start. Incidentally, such a situation is likely to occur especially in the summer when the engine is restarted immediately after being stopped. Conventionally, this problem has been prevented by using a high-output starter, which has the drawbacks of increasing the weight of the engine, increasing the battery load, and increasing costs.

[Purpose of the invention]

This invention was made under these circumstances, and aims to enable smooth engine starting by preventing fuel from being combusted (ignited) until the engine speed has fully increased immediately after starting the starter. purpose.

[Key points of the invention]

The key point is that in an internal combustion engine consisting of an ignition system and a fuel system, a power supply means is provided that continues to supply power to the ignition system for a predetermined period of time even after the ignition key switch is released, and during this time, the inside of the cylinder or intake pipe is The main feature is that the fuel accumulated in the fuel tank is burned down to an amount below the flammable range in preparation for the next one. By doing so, premature ignition can be prevented when starting the starter for restart when the engine temperature is high, and the engine can be started reliably.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the invention, and FIG. 2 is a circuit diagram showing an example of the delay circuit shown in FIG. In Figure 1, 1 is the power supply (VB), 2 is the Ig key,
3 is representative of the fuel system; 4 is the delay circuit; 5 is the fuel system;
is the ignition system (ignition circuit).

For example, as shown in FIG. 2, the delay circuit 4 includes diodes DI, D2, a resistor R, a capacitor C, and a relay L.
etc. Note that the present invention is not limited to this, and various types of delay circuits may be used.

The operation will be explained below with reference to FIGS. 1 and 2.

Now, when the ■8 key 2 is operated, the power VB is supplied directly to the fuel system 6 and to the ignition circuit 5 via the delay circuit 4, thereby starting the fuel system 6 and the ignition system 5. However, at this time, the delay circuit 4 is
In order to rapidly move the relay L via the diode D1, starting is performed in the same manner as in the conventional case, and the subsequent operation begins.

On the other hand, when the ■2 key 2 is released, the fuel system 6 is immediately cut off and restored, but in the delay circuit 4, the energy stored in the capacitor C via the diode D2 is transferred to the relay L through the resistor R. Since the power supply VB is supplied, the power supply VB is held for a predetermined time determined by the time constant of this circuit.
Power supply to the ignition system 5 continues. In other words, even after the Ig key is turned off and the fuel supply stops, the ignition circuit 5
The ignition continues for a predetermined period of time, and the fuel accumulated in the cylinder and intake pipe is burned to an amount below the flammable range. If you set this to 5, even the cylinder that explodes first at the time of restart will start from the intake stroke first, so g660
There is a margin of one rotation of the crankshaft, and during this time the rotation of the engine increases as it is driven by the starter, and even if there is some resistance, it is possible to obtain enough inertia to start the engine. . In addition, in Fig. 1, the fuel system 3
However, in the event of a collision, etc., the I and key 2 cannot be operated immediately, and there is a risk of fuel leakage causing an accident such as a fire. In such cases, it can be linked to the operation of the engine.

FIG. 3 is a configuration diagram showing an example in which the present invention is applied to a gasoline engine with a single carburetor. 10 is an ignition coil, 11 is a distributor, and 12 is a spark plug, which constitute an ignition system. The delay circuit 4 as described above is provided between the ignition system and the power source, and the above-described operation is performed. 'L. In addition, 15 is an engine compartment, 13 is a slow cut solenoid, 14 is an intake pipe, 1
6 is a float chamber, and these 13, 14, 16, etc. constitute a fuel system.

FIG. 4 is a block diagram showing an example of application to an electronically controlled fuel injection type engine, in which the fuel system, delay circuit, and ignition system are given the same reference numerals as in FIG. 1.

In addition, 17 is an electronic control unit, which includes a delay circuit 4.
A power supply VB is supplied through the terminal, and a key signal is also input. Therefore, the control unit 17 monitors the Ig key signal and immediately stops power supply to the fuel system 6 when it turns off. Then, after a predetermined period of time, the power supply from the delay circuit 4 is also stopped, so the operation of the electronic control unit 17 and the ignition system 5 is also stopped.

Incidentally, the above-mentioned operation is shown in a flowchart as shown in FIG.

The delay time of the delay circuit is set appropriately, but this time can be made a function of the temperature of the engine cooling water.
Further, when the electronically controlled fuel injection engine shown in FIG. 4 has an electronic control unit, the unit itself may be provided with a delay function. Furthermore, if the engine speed rises slowly after starting the starter, a time delay may be added to the start of fuel supply, and the delay time may be a function of the engine coolant temperature or carrot rotation speed. be able to.

〔Effect of the invention〕

According to this invention, since the ignition is maintained for a predetermined period of time even after the ignition key is released, it is possible to burn out the remaining fuel in the cylinder and intake pipe and prepare for the next time. Therefore, even if the engine is restarted at a high temperature, the engine will start easily and reliably, so there is no need to use a starter with an unnecessarily large capacity as in the past, and as a result, the battery ( This has the advantage of reducing the capacity of the power source (power source) and reducing the weight of the engine, thereby reducing costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of the delay circuit shown in FIG. 1, and FIG. 6 is a configuration diagram showing an example of application to a gasoline engine with a carburetor set. FIG. 4 is a block diagram showing an example of application to an electronically controlled fuel injection type engine, and FIG. 5 is a flowchart explaining the operation of the electronic control unit in FIG. 4. Code explanation 1... Power supply (VB), 2... Ignition key (eng), 3... Fuel system, 4...
...Delay circuit, death...--Ignition system (ignition circuit), 10
...Ignition coil, 11...Distributor, 12...Spark plug, 16...
...Slow cut solenoid, 14...-
Intake pipe, 15... Combustion chamber, 16... Float chamber, 17... Electronic control unit, Di
p D2...Diode, R...-Resistor, C...Capacitor, L...Relay Agent Patent Attorney Kiyoshi Matsuzaki

Claims (1)

[Claims] In an internal combustion engine that is equipped with at least an ignition system that supplies and stops power by opening and closing an ignition key switch, there is a fuel system that responds to the operation of the internal combustion engine, and a fuel system that responds to the operation of the internal combustion engine for a predetermined period of time after the key switch is opened. 1. A control device for an internal combustion engine, comprising: a holding means for continuing power supply to an ignition system; and at least a timing for stopping power supply to the ignition system is delayed compared to a time for stopping power supply to the fuel system.