JPH05332180A - Electronically controlled fuel injection device - Google Patents

Abstract

(57) [Summary] [Purpose] To suppress a sudden change in the torque generated by the engine when the vehicle is decelerated while the vehicle drive wheels and engine are connected. [Structure] When the throttle valve is fully closed and the engine speed at this time is higher than a predetermined high-speed side judgment rotation speed, or when the engine speed becomes lower than the high-speed side judgment rotation speed, a certain time has elapsed. If so, the electronic control unit enters the deceleration running mode. In the deceleration traveling mode, the electronic control unit performs fuel control completely independent of the fuel control in the steady traveling mode. That is, the deceleration traveling pulse width P1 corresponding to the engine speed is obtained, and the atmospheric pressure correction is performed on the deceleration traveling pulse width P1 to obtain the deceleration traveling pulse width P1 completely independently of the determination of the injection pulse width in the steady traveling mode. After setting P2, the invalid pulse width P3 is added to determine the output pulse width P4, and the valve opening time of the fuel injection valve is controlled based on this.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled fuel injection device for supplying fuel to a 4-cycle gasoline engine mounted on a motorcycle, for example.

[0002]

2. Description of the Related Art Generally, in an electronically controlled fuel injection system for an engine mounted on a vehicle, the vehicle is decelerated while the drive wheels of the vehicle and the engine are connected for the purpose of improving fuel efficiency and purifying exhaust gas. The fuel cut during deceleration is performed during traveling, that is, during deceleration traveling of the vehicle in which the clutch is engaged and the throttle valve is fully closed (that is, the idle opening degree). Conventionally, as an electronically controlled fuel injection device that performs fuel cut during deceleration, if the throttle valve fully closed duration is a certain time or more and the engine speed at that time is higher than a predetermined fuel cut speed, the fuel cut When the engine speed drops below a predetermined fuel return speed after starting the engine, the fuel cut is stopped and the fuel is injected again (see Japanese Patent Laid-Open No. 60-125747).

[0003]

In the above-mentioned conventional electronically controlled fuel injection device, when the vehicle is decelerated and the fuel cut is started, the torque generated by the engine rapidly changes. Further, when the fuel is injected again, a rapid torque fluctuation occurs. This abrupt torque fluctuation does not cause any particular problem when the vehicle is a four-wheeled vehicle whose vehicle weight is relatively large relative to the engine output, but when the vehicle is a two-wheeled vehicle whose vehicle weight is small relative to the engine output. However, there is a problem that fluctuations in the torque of the engine drastically change the behavior of the vehicle, resulting in deterioration of steering stability and the like. The present invention is
When the vehicle is decelerated while the drive wheels of the vehicle and the engine are connected, it is possible to prevent the torque generated by the engine from fluctuating abruptly, thereby improving the steering stability of the vehicle. An object of the present invention is to provide an electronically controlled fuel injection device that can be used.

[0004]

An electronically controlled fuel injection system according to the present invention is a fuel injection valve, a detection means for detecting an operating state of an engine mounted on a vehicle, and a fuel injection based on the detection of the detection means. The control means controls the fuel injection by the valve, and the control means controls the fuel injection amount at the time of decelerating traveling of the vehicle in a state where the drive wheels of the vehicle and the engine are connected, completely independently of the steady traveling. It is characterized by doing.

[0005]

The present invention will be described below with reference to the illustrated embodiments.
FIG. 1 is a schematic diagram showing a control system of a motorcycle 4-cycle gasoline engine (hereinafter simply referred to as an engine) to which an electronically controlled fuel injection device according to an embodiment of the present invention is applied. In this figure, an electronic control unit (ECU) 10
Is an engine speed N, throttle opening, atmospheric pressure, engine cooling water temperature (hereinafter simply referred to as water temperature), and the like, and obtains an injection pulse width based on various sensor information 20, and based on this injection pulse width, the fuel injection valve The valve opening time of 11 is controlled to inject a required amount of fuel into the intake manifold 12. The fuel injected from the fuel injection valve 11 is sucked into the cylinder 14 together with the air sucked through the air cleaner 13, and after combustion, is discharged from the exhaust manifold 15 into the atmosphere as exhaust gas through a catalytic converter, a muffler and the like (not shown). It

Of the information on the operating state of the engine sent to the electronic control unit 10, the engine speed N is calculated from the ignition pulse P sent from the ignition unit 16. The throttle opening degree is detected by a throttle opening degree sensor 17 provided near the throttle valve 21. The atmospheric pressure is detected by the atmospheric pressure sensor 18.
The water temperature is detected by a water temperature sensor 19 provided near the cooling water passage (not shown).

The operation of this embodiment will be described with reference to FIGS. When the throttle valve 21 is not fully closed,
The electronic control unit 10 enters the steady running mode and determines the injection pulse width based on engine speed N, throttle opening, atmospheric pressure, water temperature, and various other sensor information. Then, the valve opening time of the fuel injection valve 11 is controlled on the basis of this injection pulse width to inject a required amount of fuel.

When the throttle valve 21 is fully closed and the engine speed N at this time is higher than a predetermined high speed side determination speed N1, or the engine speed N is lower than the high speed side determination speed N1. The electronic control unit 10 enters the deceleration running mode when a certain time has elapsed since the start. In the deceleration running mode, the electronic control unit 10
Fuel control is performed completely independently of the fuel control in the steady running mode. That is, in the deceleration traveling mode,
As shown in, the deceleration traveling pulse width P1 corresponding to the engine speed N is obtained, and the atmospheric pressure correction is performed to the deceleration traveling pulse width P1 to obtain a large value, independently of the determination of the injection pulse width in the steady traveling mode. After setting the atmospheric pressure correction pulse width P2, the invalid pulse width P3 is added to determine the output pulse width P4. Then, the valve opening time of the fuel injection valve 11 is controlled based on the output pulse width P4 to inject a required amount of fuel. In addition,
The deceleration traveling pulse width P1 is determined by the actual vehicle traveling test, and its value is smaller than the injection pulse width in the steady traveling mode.

When a certain period of time elapses after the vehicle speed decreases and the engine speed N becomes lower than the high speed side determination speed N1, or when the engine speed N is a predetermined low speed side determination speed. When it becomes lower than the number N2, the electronic control unit 10 exits the deceleration traveling mode and returns to the steady traveling mode again.

FIG. 5 is a flowchart for selecting a traveling mode in the electronic control unit 10.

The process of selecting the driving mode will be described with reference to this figure. In step S1, it is determined whether or not the throttle valve 21 is fully closed. Step S
When the throttle valve 21 is not fully closed in step 1, the routine proceeds to step S2 to enter the steady running mode, and when the throttle valve 21 is fully closed, the routine proceeds to step S3.

In step S3, it is determined whether the engine speed N is higher than a predetermined high speed side determination speed N1. When the engine speed N is higher than the high speed side determination speed N1 in step S3, step S3
When the engine speed N is lower than the high speed side determination speed N1, the process proceeds to step S5.

In step S5, it is determined whether the engine speed N is lower than a predetermined low speed side determination speed N2. In step S5, the engine speed N
Is lower than the low rotation side determination rotation speed N2, the routine proceeds to step S2, and the steady running mode is entered. If the engine rotation speed N is higher than the low rotation side determination rotation speed N2, the routine proceeds to step S6.

In step S6, it is determined whether or not a predetermined time has elapsed since the engine speed N became lower than the high speed side determination speed N1. In step S6, if the fixed time has elapsed, the process proceeds to step S2 to enter the steady traveling mode, and if the constant time has not elapsed, the process proceeds to step S4 to enter the deceleration traveling mode. After that, the determination is repeated in the same manner as described above.

As described above, according to the above embodiment, the fuel cut is performed when the two-wheeled vehicle is decelerated while the engine and the drive wheels are connected, that is, when the two-wheeled vehicle is decelerated when the engine is braked. Without performing it, the fuel is injected by setting the air-fuel ratio completely independently of the steady running, so it is possible to suppress the rapid torque fluctuation of the engine during decelerating running, which improves the steering stability of the motorcycle. Can be planned. Further, by appropriately performing the air-fuel ratio control during deceleration traveling, it is possible to reliably suppress the occurrence of afterburn.

In the above embodiment, the throttle valve 2
1 is in a fully closed state, the engine speed N is higher than a predetermined high rotation side determination rotation speed N1, or a certain time has elapsed since the engine rotation speed N was higher than the high rotation side determination rotation speed N1. Although the lapse of time is the condition for the electronic control unit 10 to enter the deceleration traveling mode, in addition to these,
The condition may be that the warm-up operation of the engine has ended, that is, the water temperature detected by the water temperature sensor 19 has reached a specified value.

Further, in the above embodiment, the electronically controlled fuel injection device applied to the engine mounted on the two-wheeled vehicle is used, but if the vehicle has a large engine output compared to the vehicle weight, it is mounted on any vehicle such as a four-wheeled vehicle. It has a good effect even when applied to the engine.

[0018]

As described above, according to the present invention, it is possible to suppress a sudden change in the torque generated by the engine when the vehicle is decelerated while the drive wheels of the vehicle and the engine are connected. As a result, it is possible to improve the steering stability and the like of the vehicle.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a control system of an engine to which an electronically controlled fuel injection device according to an embodiment of the present invention is applied.

FIG. 2 is a diagram for explaining determination of a decelerated traveling state.

FIG. 3 is a diagram for explaining a pulse width calculation in a deceleration running mode.

FIG. 4 is a diagram showing each pulse width in a deceleration running mode.

FIG. 5 is a flowchart for selecting a driving mode in the electronic control unit.

[Explanation of symbols]

 10 Electronic Control Unit (Control Means) 17 Throttle Opening Sensor (Detection Means) 18 Atmospheric Pressure Sensor (Detection Means) 19 Water Temperature Sensor (Detection Means) P Ignition Pulse

Claims (2)

[Claims] 1. A control means comprising a fuel injection valve, a detection means for detecting an operating state of an engine mounted on a vehicle, and a control means for controlling fuel injection by the fuel injection valve based on the detection of the detection means. The electronically controlled fuel injection device is characterized in that, during deceleration traveling of a vehicle in a state where the drive wheels of the vehicle and the engine are connected, the fuel injection amount is controlled completely independently of the steady traveling. 2. The detecting means detects at least an engine speed and a throttle opening as an operating state of the engine, and the control means has a throttle opening being an idle opening and the engine speed. Is higher than a prescribed number of revolutions, or if a certain time has elapsed since the number of revolutions of the engine was lower than a prescribed number of revolutions, the vehicle decelerates while the drive wheels of the vehicle and the engine are connected. 2. The electronically controlled fuel injection device according to claim 1, wherein it is determined that it is time, and the fuel injection amount is controlled completely independently of during steady running.