JPS5827824A - Fuel supplier of internal combustion engine - Google Patents

Abstract

PURPOSE:To allow a fuel supplier to concurrently have functions of output control and fuel supply control by forming a throttle valve into a Venturi structure by contolling the air-fuel ratio using the negative pressure of the Venturi and its passage sectional area as parameters. CONSTITUTION:A fuel supplier is constituted by an air cleaner 1, a suction pipe 2, an accelerating pedal, a Venturi 4 varying its sectional area AT for limiting the suction air quantity in linkage with the accelerating pedal 3, a transducer 5 for supplying an electric signal in correspondence to the sectional area AT, a sensor 6 for sensing the negative pressure generating part, a fuel injector 7, a measurement control part 8 of the fuel quantity, a function generator 9, a pressure sensor 10 within the suction pipe 2, an engine 11 and a fuel supply part 12. By this arrangement, air-fuel ratio control which supplies the fuel corresponding to the air-flow quantity in linkage with the accelerating pedal 3 becomes possible, to improve the transient responce and simplify the entire device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply device for an internal combustion engine.
In particular, the throttle valve, which is used to control the output of internal combustion engines, has a fluid-dynamically low loss structure such as a venturi structure, and the air-fuel ratio is controlled using the pressure in the venturi section and the cross-sectional area of the intake pipe passage as parameters. The present invention relates to a fuel supply device.

Conventionally, fuel supply systems for internal combustion engines have been of the carburetor type or the fuel injection type, and the latter in particular utilizes the power equipment of microcomputers, which have developed rapidly in recent years, to perform complex and precise fuel control. It is becoming. In particular, from the perspective of exhaust gas regulations and fuel efficiency, it is becoming increasingly important to perform EGR (exhaust gas circulation II) and air-fuel ratio control in a complex, precise, and quick manner in accordance with various operating conditions.
Since then, control with a carburetor type has been extremely difficult due to problems such as mechanical precision and aging, so electronic fuel supply control devices have recently been increasingly put into practical use. Therefore, the electronic fuel supply system that is currently in practical use has an air flow meter at the input section and an electrically controlled fuel injection device at the output section as basic components, and controls the flow between the input and output sections. One of the features of this method is that the control part is configured with an electronic circuit including a microcomputer, but as can be seen from the configuration of the electronic fuel supply system that has been put into practical use, the electronic circuit that serves as one control unit is The input of the entire operation must correspond to the accuracy and speed, but in practice it may be difficult to use a complex, high precision, expensive air flow meter, or as a complement to this, some other The entire range of input parameters is carefully controlled.

Particularly in the case of in-vehicle internal combustion engines, in order to meet the demand for quick adjustment and reduction operations performed under arbitrary conditions according to the driver's will, new input elements such as detecting the opening degree of the throttle valve are added. Currently, deceleration correction is being performed.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional throttle valve in the intake pipe, which was conventionally used only for controlling the output of the engine. A structure in which the relationship between the flow rate and pressure passing through a passage is determined, for example, a venturi IJ with a variable passage cross-sectional area, and this venturi negative pressure is detected by a pressure sensor, and each pressure and passage cross-sectional area are used as parameters. It is an object of the present invention to provide a fuel supply device for an internal combustion engine that combines engine output control and fuel supply control, which is comprised of a fuel supply means capable of controlling the air-fuel ratio and supplies fuel according to the air flow rate at a time.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is an air cleaner that removes foreign matter in the outside air and guides the outside air to the intake pipe, 2 is the intake pipe, 3 is the accelerator, and 4 is the air cleaner.
works in conjunction with this accelerator to limit the amount of intake air,
Air flow passage cross-sectional area ATt - Variable vent I to change
J-15 is a pressure sensor that outputs an electric signal according to the passage cross-sectional area AT. A transducer 16 is a pressure sensor that detects the pressure PT of the negative pressure generation part of the venturi 4. 7 is a fuel injector. 8 is a fuel discharged from this injector 7. 9 is a function generator whose input parameters are the passage cross-sectional area AT and the pressure pT of the negative pressure generating part;
10 is a pressure sensor that detects the pressure inside the intake pipe 2; 11;
12 is an engine, and 12 is a fuel supply section.

Next, the operation will be explained. The air flow sucked through the air cleaner 1° and the intake pipe 2t is interlocked with the accelerator 3, and its flow rate is restricted at the venturi 4, and its flow velocity is accelerated. In other words, the pressure decreases due to fluid dynamics. Here, assuming that the intake air flow in the vicinity of the venturi 4 is an adiabatic laminar flow, the air flow rate G can be approximately expressed as follows. Here, Pl and γ1 are the pressure of the intake pipe 2 on the upstream side of the venturi 4, the air density, and the specific heat ratio of air, respectively, which is 1.4. AT is the passage cross-sectional area of the venturi 4, and PT is the pressure of the venturi. The above equation can be approximated very accurately when the air flow velocity in the intake pipe 2 is considerably smaller than the flow velocity in the venturi 4. In a typical internal combustion engine, the air flow velocity at the throttle valve part reaches the subsonic region and becomes turbulent.
The above approximations have sufficient accuracy. Further, the function generator generates a value divided by 141 for the inputs of AT and PT/P, and sends the output to the fuel quantity metering control section 8.

This control unit 8 is fuel driven reciprocally at a frequency proportional to the above output. This is a well-known device consisting of a pump, etc.

As described above, according to the present invention, the throttle valve, which is a means for controlling the amount of intake air for controlling the output of a conventional engine, has a venturi structure, and the air-fuel ratio is controlled using the negative pressure of the venturi and its passage cross-sectional area as parameters. As a result, the fuel supply amount can be changed directly in response to the throttle movement, which is the only means for changing the engine operating state from outside according to the driver's will, and therefore has excellent transient response. This has the effect of enabling fuel supply control.

Furthermore, since there are only two input parameters, pressure and passage cross-sectional area, calculations for control are simple and the entire device can be simplified.

[Brief explanation of drawings]

The drawing shows a fuel supply device showing one embodiment of the present invention.
This is the essential diagram. 1... Air cleaner, 2... Intake pipe, 3゛'° accelerator pedal, 4... Penduyu! J-15...transduyu? -, 6, 10...pressure sensor, 7...
・Injector, 8...Metric control unit, 9...Function generator〇Representative Shin Kuzuno -

Claims (1)

[Claims] A pressure sensor that detects the pressure PT at the negative pressure generating part of the venturi and the pressure Pt'fr in the intake pipe upstream of the venturi, and the passageway. Cross-sectional area AT and pressure PT of negative pressure generating section/intake pipe pressure Pxk
1. A fuel supply device for an internal combustion engine, comprising: a function generator that uses an input AI parameter; and a fuel discharge means that changes the amount of fuel discharged according to the output of the function generator.