JPS6081437A - Fuel injection controller - Google Patents

Abstract

PURPOSE:To improve responsiveness, by selecting a parameter for fuel injection quantity operation according to whether or not a suction cylinder at the secondary side is used, in case of a device being constituted of forming the suction cylinder into a compound type having both primary and secondary sides in itself. CONSTITUTION:A primary side suction cylinder 2 being normally used is installed at the left of a throttle chamber 1, while a secondary side suction cylinder 3 being used in time of high output driving is installed at the right. At a driving range where the primary side is mainly used, a fuel injection quantity is calculated according to the throttle valve opening detected by a throttle sensor 10 and the engine speed detected by an engine speed detecting sensor. Likewise, at a driving range where also the secondary side is used besides the primary side, a suction air quantity is detected on the basis of the throttle valve opening and the engine speed or the suction pressure detected by the engine speed and a suction pressure sensor 12 whereby the fuel injection quantity is determined according to this suction air quantity. With this constitution, responsiveness is improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fuel injection control device, and more specifically, the present invention relates to a fuel injection control device, and more specifically, an intake cylinder is connected to a primary side that is always used and a secondary side that is used together with the primary side when the engine output is high. The present invention relates to a fuel injection control device for a dual-type engine having the following.

[Background of the invention]

In order to improve exhaust performance and fuel efficiency, fuel injection amount # (hereinafter referred to as E
(referred to as Gi) is becoming more and more popular. EGl is set to % in order to measure the intake air amount of the engine.
Vane type as in Publication No. 260 and JP-A No. 1185
A hot wire type air amount measuring device as disclosed in Japanese Patent No. 5-78164 is used.

In the former case, due to the inertia of the vanes, information that lags behind the actual change in the amount of intake air is produced, resulting in a lean air-fuel ratio during acceleration, which impairs drivability. Therefore, the acceleration state is detected and the amount of fuel is increased depending on the degree of acceleration, but if emphasis is placed on drivability, this will lead to overcorrection and worsen the exhaust performance and fuel ratio. Even when the latter hot wire type air amount measuring device is used, there is a problem that the heat capacity of the sensor section including the bobbin that constitutes the hot wire is often absorbed by the intake air, resulting in a reduction in maneuverability fuel efficiency and exhaust performance.

On the other hand, when a throttle valve is installed in a single intake cylinder, the rate of change in the ventilation area with respect to the throttle valve opening when the throttle valve is operated with the accelerator pedal is large, making smooth operation difficult. Reducing the diameter of the wax intake cylinder will improve this problem, but will increase intake air loss and reduce output. In addition, when the intake cylinder is made larger, drivability decreases, and when the differential pressure between the top and bottom of the throttle valve increases, such as during idling or deceleration operation, large bending stress is applied, causing deformation of the throttle valve and valve stem. There is a risk of

Furthermore, during operation with a small opening degree of the throttle valve, the mixing of the fuel supplied from the injection valve and the intake air deteriorates because the annular gap around the outer periphery of the throttle valve is small. That is, the fuel flows as a wall flow over the upper surface of the throttle valve, which has a relatively large area, and is sucked into the downstream side of the throttle valve. Therefore, the fuel particles supplied from the injection valve become liquid, and atomization is reduced.

[Purpose of the invention]

An object of the present invention is to provide a fuel injection control device that improves the responsiveness of intake air amount measurement.

[Summary of the invention]

The present invention integrally configures the intake cylinder as a dual type having a primary side and a secondary side, and in an operating range where the downstream side is mainly used, the secondary side is In the operating range where the engine is used, the amount of intake air is calculated from the throttle valve opening and engine speed, or from the engine speed and intake pressure.
This system is characterized in that the fuel injection amount is determined from this intake air amount.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

The fuel injection device according to the present invention has a primary side intake cylinder 2 that is always used on the left side of the throttle chamber 1, and a secondary side intake cylinder 3 that is used simultaneously with the primary side intake cylinder 2 during high output operation on the right side. It is composed of -In the next intake cylinder 2,
The throttle valve 4 is installed on the throttle valve 4 and opened and closed using the throttle lever 11 which is linked to the accelerator link. A throttle valve 5 is attached to the secondary intake cylinder 3 and operated by a secondary valve opening/closing device 9 that allows the throttle valve 5 to open from when the throttle valve 4 is about 1/2 open. The secondary valve opening/closing device 9 is configured by interlocking the throttle valve 4 and the throttle valve 5 by a link structure, or by controlling the intake air amount or by controlling the negative pressure of the pen 4 provided in a part of the intake cylinder. Drive and operate equipment. Further, the secondary valve opening/closing device 9 has a built-in valve opening sensor that detects that the throttle valve 5 is opened and transmits the information to the control circuit 13. Note that the intake air is supplied through an air cleaner attached to the 7-landing 8. An intake manifold 14 is connected downstream of the throttle chamber 1, and fuel is supplied from an injection valve 6 disposed above the throttle valve 4 and an injection valve 7 disposed above the throttle valve 5. Mixes air and supplies it to each cylinder of the engine.

As shown in FIG. 2, the amount of intake air into each cylinder of the engine is determined by the engine speed detected from an engine speed sensor (not shown) and the intake pressure from a pressure sensor 12 attached to the intake manifold 14. There is a way to measure it.

The pressure sensor 12 has low responsiveness because it obtains a signal after the pressure changes due to an increase/decrease in the amount of intake air, which is a signal obtained by amplifying the distortion due to the differential pressure in the sensor section. This decrease in responsiveness is particularly significant in cold weather. Furthermore, there is also a risk that a peculiar liquid in which overpressure has occurred in the intake manifold 14 may intervene and generate an abnormal signal.

On the other hand, as shown in FIG. 3, there is a method of measuring the amount of intake air based on the engine speed and throttle valve opening. In this case, if the opening of the throttle valve is large, the amount of intake air changes greatly with respect to the opening of the throttle valve, and the detection accuracy of the throttle valve opening becomes important as shown by the dotted line.

In this embodiment, since the throttle sensor 10 integrally attached to the throttle valve 4 for the primary intake cylinder 2 with a relatively small diameter detects the intake air amount relative to the opening degree of the throttle valve 4. As shown by the solid line in FIG. 3, the change in the amount of time is large, as shown by the solid line in FIG. 3, and sufficient measurement accuracy can be ensured without particularly improving the accuracy of the throttle sensor 10. Note that the accuracy can be further improved by interposing an amplifying function (gear, cam, link, etc.) between the throttle valve shaft and the throttle sensor 10.

When increasing the rate of increase in the amount of intake air from a relatively small amount of intake air to the engine, such as when transmitting at an intersection or driving in a city area, the pressure sensor 1 of the second pressure is used.
2, the correct increase in intake air amount cannot be detected because the response is low. However, in this embodiment, since a change in the opening degree of the throttle valve 4 is immediately detected by the throttle sensor 10, a change in the opening degree of the throttle valve 4 is detected simultaneously with a change in the intake air amount by the control circuit 10, as shown in FIG. transmitted to. Furthermore, when the engine is operated at high output, the amount of intake air is large, so even if the signal from the pressure sensor is delayed, the degree of deterioration of drivability is small. The throttle sensor 10 is designed to improve output characteristics in the low opening range of the throttle valve 4, and the pressure sensor 12 is
The accuracy of measuring the amount of intake air can be improved by setting each so that the feeling is better on the side where the intake pressure is higher.

In addition, in the embodiment, a failure diagnosis circuit for the throttle sensor 10 and the pressure sensor 12 is provided and added to the control circuit 13, so that when one of these sensors fails, the other sensor takes over. The amount of intake air can be easily measured.

In addition, when performing exhaust gas recirculation (EGR) as an exhaust performance measure, if the intake air amount is measured using the method shown in Figure 2, the intake air pressure will increase along with the EGR amount, and the true intake air amount cannot be detected. However, in most cases, EGR is performed during the opening operation of the throttle valve 4 in the downstream side intake cylinder 2, and the effectiveness of the present invention can also be demonstrated in this respect.

〔Effect of the invention〕

According to the present invention, the responsiveness of intake air amount measurement can be improved, so that the air-fuel ratio in each cylinder of the engine can be optimally controlled.

In this embodiment, the injection valve is arranged upstream of the throttle valve, but the same effect can be obtained when the injection valve is arranged downstream or in EGi installed in each cylinder. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the fuel injection control device according to the present invention, FIG. 2 is a characteristic diagram showing the relationship between engine speed and intake air amount using intake pressure as a parameter, and FIG. A characteristic diagram showing the relationship between engine speed and intake air amount using throttle valve opening as a parameter. Figure 4 shows a comparison of the detection response of intake pressure and throttle valve opening during acceleration/deceleration operation. This is a diagram. 1.5... Throttle valve, 6,7. ...Injection valve, 9...Secondary valve separation device, 10...Throttle sensor, 12...
・Pressure unit, 13...control device. Technology / - Leather Sports Association 4 Figure Time

Claims (1)

[Claims] 1. An engine rotation speed sensor that detects the engine rotation speed in an engine having a dual intake cylinder having a primary side that is always used and a secondary side that is used together with the primary side when the engine output is high. When a throttle sensor detects the opening of the throttle valve on the primary side of the intake cylinder, a pressure sensor detects the intake pressure in the intake manifold, and a throttle valve detects the opening of the throttle valve on the primary side of the intake cylinder to a predetermined value. The output signals of the secondary valve opening/closing device, which opens the throttle valve on the secondary side when the above conditions are reached, and the output signals of each Kaede sensor and the secondary valve opening/closing device are input, and the operation range is mainly centered on the - downstream side. Then, the intake air amount is calculated from the throttle valve opening and the engine speed, and in the operating range where the secondary side is also used, the intake air amount is calculated from the throttle valve opening and the engine speed, or the engine speed and intake pressure. A fuel injection control device comprising a control circuit that determines a fuel injection amount from this intake air amount. 2. The fuel injection control device according to claim 1, wherein the control circuit calculates the intake air amount from the engine speed and intake pressure when the throttle sensor fails. 3. The fuel injection control device according to claim 1, wherein the control circuit calculates the intake air amount from the engine speed and the throttle valve opening when the pressure sensor fails.