JPS5960069A - Fuel supplying device for engine - Google Patents

Abstract

PURPOSE:To control the flow amount of fuel and promote the atomization of the fuel by a method wherein high-pressure gas is mixed and injected into the supplying system of high-pressure fuel. CONSTITUTION:The supplying system FS of the high-pressure fuel is provided with a high-pressure air injecting system AS, injecting the high-pressure air as the high-pressure gas, and a control mechanism C, controlling the condition of the air injected from the high-pressure air injecting system AS to control the flow amount of the fuel. Accordingly, the high-pressure air, whose condition such as the pressure, the flow amount of the like, for example, is regulated, is injected from an air injection unit 4a into a fuel supplying path 3 by an air pump 5 equipped with a flow amount control valve and, as a result, the high-pressure air may be mixed with the fuel. According to this method, the specific gravity of the fuel, mixed with the high-pressure air, may be changed and the flow amount of the fuel may be controlled.

Description

[Detailed description of the invention] The present invention relates to an engine fuel supply device.

Generally, when an air-fuel mixture is supplied to each cylinder of a multi-cylinder engine through the manifold, it is necessary to sufficiently atomize the fuel in order to make the air-fuel ratio uniform in each cylinder.

Therefore, in conventional engine fuel supply devices, various studies have been made, such as increasing the fuel pressure and injecting the fuel from minute holes, but there is still a problem that atomization of the fuel is insufficient.

The present invention aims to solve these problems, and in an apparatus that injects fuel at a fuel pressure higher than atmospheric pressure, the present invention controls the fuel flow rate by injecting a mixture of high-pressure gas into a high-pressure fuel supply system. It is an object of the present invention to provide a fuel supply device for an engine that is capable of promoting atomization of fuel.

Therefore, in an engine equipped with a high-pressure fuel supply system capable of supplying fuel at a fuel pressure higher than atmospheric pressure, the engine fuel supply device of the present invention injects high-pressure gas into the high-pressure fuel supply system to supply the same amount of fuel. It is characterized by having a high-pressure gas injection system that can mix high-pressure gas, and a control mechanism that can control the fuel flow rate by adjusting the state of the gas injected from the high-pressure gas injection system.

Hereinafter, a fuel supply system for an engine as an embodiment of the present invention will be explained with reference to the drawings. Fig. 1 is a schematic diagram showing the main parts thereof, and Fig. 2 is a spiral passage element interposed in the high-pressure fuel supply system. FIG.

As shown in FIG. 1, a high-pressure fuel supply system FS is provided that can supply fuel at a fuel pressure higher than atmospheric pressure.

The fuel injection nozzle 3a of the fuel supply passage B in the high-pressure fuel supply system FS is provided so as to open in a portion of the intake passage 1 of the engine upstream of the portion where the throttle valve 2 is disposed.

In addition, a high-pressure air injection system (high-pressure gas injection system) AS is provided that can inject high-pressure air as a high-pressure gas into the high-pressure fuel supply system FS and mix this high-pressure air with the supplied fuel. A control mechanism C is provided which can control the fuel flow rate by adjusting the condition of the injected air from the system As.

That is, a high-pressure air passage 4 is provided that supplies high-pressure air generated by the air pump 5 with a flow rate control valve, and the air injection portion 4a of this high-pressure air passage 4 is inserted into the fuel supply passage filter. .

Therefore, the high-pressure air whose conditions, such as pressure and flow rate, are adjusted by the air pump 5 with a flow rate control valve,
The air is injected from the air injection part 4a into the fuel supply passage 6, so that this high-pressure air can be mixed with the fuel. Thereby, the specific gravity of the fuel mixed with high-pressure air (hereinafter referred to as "air-mixed fuel") can be changed.

Incidentally, the fuel flow, amount G [this flow rate G is expressed in weight per unit time (K7). ] is known to be expressed by the following formula.

G-ζAJ]7T77下Here, ζ is the coefficient, A is the flow path cross-sectional area, 2 is the gravitational acceleration,
γ is the specific gravity of the air-mixed fuel, and ΔP is the difference between the fuel pressure and atmospheric pressure.

As can be seen from this equation, the fuel flow rate G can be changed by changing the specific gravity γ of the air-mixed fuel. That is, by adjusting the state of high-pressure air injected into the fuel supply passage 3, the specific gravity γ of the air-mixed fuel is changed,
This allows the fuel flow rate G to be controlled.

Note that the air injection part 4a may be a pipe in which many small holes with a diameter of 0.6 fl or less are formed, a porous ceramic pipe, a sintered metal pipe, or a cylindrical piece of fine wire mesh. A cylindrical body is used.

Further, in the portion of the fuel supply device B closer to the fuel injection nozzle 3a than the high-pressure air injection portion, there is a spiral passage element 7.
8 are interposed in series.

The spiral passage element 7 is a spiral passage 7 that rotates the air-mixed fuel clockwise, as shown in Fig. 1.2.
a, 7b, and the spiral passage element 8 is
As shown in FIG. 1, spiral passages 8a and sb are provided for rotating the air-mixed fuel counterclockwise, respectively.

As a result, the air-mixed fuel first swirls clockwise, then counterclockwise, and is then injected into the intake passage 1 through the fuel injection nozzle 3a, which significantly improves the atomization of the fuel. can be promoted.

Note that the reference numeral 6 in FIG. 1 indicates a check valve consisting of a valve body 6a and a return spring 6b.

FIG. 6 is a schematic diagram showing main parts of an engine fuel supply system as another embodiment of the present invention, and in FIG.
The same reference numerals as in FIG. 2 indicate almost the same parts.

In this embodiment, a variable venturi 9 is provided in the intake passage 1, and a fuel injection nozzle 6a for injecting air-mixed fuel is provided at the narrowest part of the variable venturi 9.

That is, as shown in FIG. 3, a differential pressure responsive motor 10 is attached to the outer wall of the venturi portion of the carburetor. chamber 16
The diaphragm 12 is displaced by the differential pressure generated by the pressure (negative pressure) in the intake passage 1 acting on the chamber 1 and the atmospheric pressure acting on the other chamber 14, and the biasing force of the spring 15 in the chamber 16. However, a movable portion 11 is attached to this diaphragm 12, which projects and retracts toward the intake passage 1 when the diaphragm 12 is displaced.

Note that a space 11a with a vent opening to the intake passage 1 is formed in the movable part 11, and this space 11a is provided in the diaphragm 12 to allow ventilation from this space 11a to the chamber 13. check valve 17 in the diaphragm 12;
It communicates with the chamber 1B via an orifice 18 provided in parallel with the chamber 1B.

Further, the chamber 14 communicates with the atmosphere via a passage 16.

In this way, the movable part 11
is displaced to form the variable venturi 9, and the manner in which the movable portion 11 is displaced at this time is adjusted so that the gas flow rate passing through the venturi 9 is always approximately constant.

Note that a potentiometer used for feedback control of the position of the variable venturi 9 may be attached to the motor 10.

Further, on the venturi wall facing the movable part 11, a fuel injection nozzle loa a of the high-pressure fuel supply system FS is installed so that the air-mixed fuel can be injected from an outward direction approximately perpendicular to the air flow flowing in the intake passage 1. A fuel supply passage 6 into which high pressure air is injected is connected to this nozzle 6a.

With the above-described configuration, the air-mixed fuel whose flow rate is controlled by adjusting the condition of the injected air is injected from the fuel injection nozzle 3a into the narrowest part of the variable venturi 9, and in this case as well, it is similar to the embodiment described above. Similarly-1, atomization of fuel can be promoted.

In this embodiment, the spiral passage element 7.
Although elements 7 and 8 are omitted, these elements 7 and 8 may be installed in the fuel supply device B, as in the previous embodiment.

Furthermore, in each embodiment more than one set of spiral passage elements 7.8 may be provided.

As detailed above, according to the engine fuel supply device of the present invention, in an engine equipped with a high-pressure fuel supply system capable of supplying fuel at a fuel pressure higher than atmospheric pressure, high-pressure gas is injected into the high-pressure fuel supply system. A simple system includes a high-pressure gas injection system that can mix the high-pressure gas with the fuel, and a control mechanism that can adjust the state of the gas injected from the high-pressure gas injection system to control the fuel flow rate. In the configuration,
This has the advantage of greatly promoting fuel atomization.

[Brief explanation of drawings]

Figures 1 and 2 show a fuel supply system for an engine as an embodiment of the present invention, Figure 1 is a schematic diagram showing its main parts, and Figure 2 is a diagram showing the main parts of the engine fuel supply system as an embodiment of the present invention. FIG. 3 is a perspective view showing a spiral passage element, and FIG. 3 is a schematic diagram showing main parts of an engine fuel supply system as another embodiment of the present invention. 1. Intake passage, 2. Throttle valve, 3. Fuel Supply passage, 6a...Fuel injection nozzle, 4...High pressure air passage,
4a...Air injection unit, 5...Air pump with flow rate control valve, 6...Check valve, 6a...Valve body, 6b...Return spring, 7.8...Spiral passage element, 7a, 7b. 8a, 8b...Spiral passage, 9...Variable venturi, 10
・・Differential pressure responsive motor, 11・・Movable part, 11a・・Space with vent, 12・・Diaphragm, 13.14
...Chamber, 15...Spring, 16...Passway, 17...
Check valve, 18... Orifice, FS... High pressure fuel supply system, AS... High pressure air injection system as a high pressure gas injection system, C... Control mechanism. Sub-Agent Patent Attorney Yoshihiko Iinuma

Claims (1)

[Claims] In an engine equipped with a high-pressure fuel supply system that can supply fuel at a fuel pressure higher than atmospheric pressure, a high-pressure gas injection system is provided that can inject high-pressure gas into the high-pressure fuel supply system and mix the high-pressure gas with the fuel. A fuel supply device for an engine, further comprising a control mechanism that can control the fuel flow rate by adjusting the state of the gas injected from the high-pressure gas injection system.