JPH04365968A - Fuel supply device of internal combustion engine - Google Patents

Abstract

PURPOSE:To inject fuel to a plurality of intake valves of an internal combustion engine, and to reduce fuel adhesion to the intake valves at the time of increasing fuel and so on. CONSTITUTION:A sleeve 620 for making an injected fuel fork in directions of two intake valves, is provided on an air assist fuel delivery valve 6, while assist air passages 624, 625 for injecting assist air are formed on the sleeve 620. When the assist air is not supplied, a fuel is supplied to each intake valve. When the assist air is supplied, the fuel passed through fuel passages 621, 622 is diffused, and the injection angle is regulated by a passage 631 of a socket 630, and the fuel is injected. By interrupting the assist air, atomization directed to each intake valve is turned into diffused atomization, and fuel adhesion to the intake valves at the time of increasing fuel and so on can thus be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device applied to an internal combustion engine, and is particularly designed to supply assist air to a fuel injection valve of the fuel injection valve to improve fuel atomization.

0002

[Prior Art] Conventionally, as a fuel injection device applied to an internal combustion engine equipped with a plurality of intake valves,
The one disclosed in Japanese Patent Application No. In the prior art disclosed in this publication, a fuel injection valve having two nozzle holes is used, and the injection direction of each nozzle hole is directed toward each intake valve to reduce fuel adhesion to the intake passage. Furthermore, in this prior art, auxiliary air (assist air) nozzle holes are formed in the same direction as each nozzle hole, and this auxiliary air is used to improve atomization of fuel directed toward each intake valve.

0003

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, the atomization of the fuel directed toward each intake valve is improved by supplying auxiliary air, but in order to direct the fuel toward each intake valve, The injection angle from each nozzle hole could not be made large, and there were limits to the atomization and atomization of the fuel.

In particular, when a large amount of fuel is required to be injected, such as when the internal combustion engine is under high load or at low temperatures immediately after starting, fuel injection is performed before the intake valve opens in order to lengthen the injection time of the fuel injection valve. I needed to start. However, if injection is started at a point where the intake air flow velocity is slow, the problem arises that the fuel is not sufficiently atomized and atomized with the small injection angle of the conventional technology, and that it adheres to the intake passage and intake valve. There was a point.

In view of the problems of the prior art as described above, the present invention aims to improve engine performance by injecting fuel toward the intake valve of an internal combustion engine, and to increase the injection angle to atomize the fuel and reduce fine particles. This was done with the aim of simultaneously improving engine performance by promoting fuel efficiency.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a fuel supply device provided in an intake passage of an internal combustion engine having a plurality of intake valves. A fuel injection valve that injects fuel, an assist air passage that injects assist air so as to intersect with an injection direction of fuel injected from the fuel injection valve toward each intake valve, and an assist air passage that injects assist air from the assist air passage. An internal combustion engine characterized by comprising an injection angle regulating means for regulating a fuel spray angle when fuel is injected, and an intermittent means for intermittent supply of assist air to the assist air passage depending on the operating state of the internal combustion engine. Adopting the technical means of fuel supply for the engine.

[0007]

[Operation] The operation of the configuration of the present invention described above will be explained. The fuel injection valve forms a plurality of fuel sprays with narrow injection angles toward each intake valve, and injects fuel toward each intake valve of the internal combustion engine. The intermittent means intermittents the supply of assist air to the assist air injection means according to the operating state of the internal combustion engine,
The injection of assist air from the assist air injection means is intermittent.

[0008] With this, when the supply of assist air is cut off depending on the operating state of the internal combustion engine, the fuel injected from the fuel injection valve becomes a plurality of fuel sprays at narrow injection angles toward each of the plurality of intake valves. This reduces fuel adhesion to the intake passage.

On the other hand, when assist air is supplied depending on the operating condition of the internal combustion engine, the fuel injected from the fuel injection valve collides with the assist air and is dispersed, but the injection angle is controlled by the injection angle regulating means. is regulated, the fuel spray shape has an appropriately wide injection angle, and atomization and atomization of the injected fuel in the intake passage are promoted.

As described above, according to the present invention, depending on the operating condition of the internal combustion engine, a spray shape directed toward each intake valve and a diffused spray shape can be obtained, and engine performance can be improved depending on the operating condition of the internal combustion engine. is planned.

[0011]

[Example] Below, an example to which the present invention is applied is shown in Figs. 1 and 2.
, will be explained based on FIGS. 3, 4, and 5.

FIG. 1 is a block diagram showing a schematic structure of a first embodiment. The internal combustion engine 1 includes two intake valves 2 and two exhaust valves 3 for each cylinder. FIG. 1 shows one intake valve and one exhaust valve. An intake passage 4 is connected to the intake valve 2 of the internal combustion engine 1, and the intake passage 4 is provided with a throttle valve 5 for adjusting the intake air flow rate. Further, upstream of the intake passage 4, an intake flow rate measuring device and an air cleaner (not shown) are provided.

An air assist fuel injection valve 6 is provided between the throttle valve 5 and the intake valve 2 in the intake passage 4. The air assist fuel injection valve 6 includes a fuel injection hole through which fuel is injected, and an assist air injection hole through which assist air is injected toward the fuel injected from the fuel injection hole. Furthermore, this air assist fuel injection valve 6 is attached to the intake passage 4 so that the fuel injection hole faces the intake valve 2. The air-assist fuel injection valve 6 is supplied with fuel from a fuel tank (not shown), which is pressurized by a fuel pump and regulated to a predetermined pressure by a pressure control valve, and is controlled by a control device (not shown) according to the amount of fuel to be injected. A time control pulse is input. Further, assist air is introduced into the air assist fuel injection valve 6 from the intake passage 4 upstream of the throttle valve 5 through an assist air passage 7.

FIG. 2 is a sectional view showing the configuration of the air-assisted fuel injection valve 6. As shown in FIG. The air assist fuel injection valve 6 includes a fuel valve section 600, and a general fuel injection valve is used for this fuel valve section 600.

The fuel valve section 600 has a fuel nozzle hole 60 at its tip.
1 is formed, and a valve needle 603 for opening and closing the fuel injection hole 601 is housed in the valve housing 602. The valve housing 602 is the housing 60
4, an electromagnetic coil 605 is provided inside the housing 604, and a connector 60 is connected to the housing 604 from a control circuit (not shown).
It is energized via 6. An armature 607 is provided on the valve needle 603, and the valve needle 603 is moved by an electromagnetic force generated by energizing the electromagnetic coil 605. A stator 608 is fixed to the housing 604, and fuel is supplied to the upper end of the stator 608 from a fuel pump (not shown). When the electromagnetic coil 605 is energized and the valve needle 603 moves, the fuel injection hole 601 is opened and the fuel flows from the inside of the stator 608 to the inside of the armature 607 and then to the valve needle 603.
The fuel injection hole 60 passes between the valve housing 602 and the valve housing 602.
It is injected from 1.

The fuel valve section 600 is inserted into a case 610 that forms an assist air passage. A pipe 611 is provided in the case 610, and assist air is introduced into the case 610 from the assist air passage 7 through the pipe 611. Inside the case 610, a sleeve 620 is provided at the tip of the valve housing 602 of the fuel valve section 600, and a socket 630 is further provided. The sleeve 620 and the socket 630 are sandwiched and fixed between the fuel valve section 600 and the case 610 by inserting and fixing the fuel valve section 600 into the case 610.

The sleeve 620 has two fuel passages 621 and 622 through which fuel injected from the fuel injection hole 601 passes.
A partition wall 62 is formed between these fuel passages 621 and 622 to divide the fuel injected from the fuel injection hole 601 into two.
3 is provided. Two fuel passages 621, 622
is conical in shape, and its cross-sectional area decreases toward the downstream of the fuel spray.

Further, the sleeve 620 is formed with two assist air passages 624 and 625 through which assist air passes. The upstream sides of the assist air passages 624 and 625 open toward the internal space of the case 610, and the downstream sides of the assist air passages 624 and 625 open to downstream parts of the fuel passages 621 and 622 of the sleeve 620, respectively. The axis of the assist air passage 624 intersects with the axis of the fuel passage 621, the axis of the assist air passage 625 intersects with the axis of the fuel passage 621, and the axes of the two assist air passages 624 and 625 intersect with the axis of the fuel passage 621. intersect at.

A conical passage 631 is formed in the socket 630 to regulate the injection angle of the fuel spray. In the air-assisted fuel injection valve 6 shown in FIG. 2, the axes of the two fuel passages 621 and 622 face each intake valve of the internal combustion engine, and the two fuel sprays injected from the two fuel passages 621 and 622 are It is attached to the intake passage 4 of the internal combustion engine so as to face the intake valve of the internal combustion engine.

FIGS. 3 and 4 are schematic diagrams showing the shape of spray from a fuel injection valve for each intake valve of an internal combustion engine. The internal combustion engine includes two intake valves 2a, 2b. In each intake valve, the intake passage 4 branches into two intake ports 4a and 4b,
Each communicates with two intake valves 2a, 2b. An intermediate wall 4c is provided between the two intake ports 4a, 4b. 3 and 4, the shape of the spray from the fuel injection valve 6 is shown as a hatched area, and the spray angle is shown as A or B.

Next, the operation of the above embodiment will be explained. In this embodiment, when the throttle valve 5 is open, the pressure difference in the assist air passage 7 disappears, the assist air is cut off, and the injection of assist air from the assist air passages 624 and 625 is stopped. When the electromagnetic coil 605 of the fuel valve section 600 is energized while the throttle valve 5 is open, fuel is injected from the fuel injection hole 601. The fuel injected from the fuel injection hole 601 flows through two fuel passages 621 and 622.
Divided into. The fuel that has passed through the two fuel passages 621 and 622 has two narrow injection angles A as shown in FIG.
The spray shape is as follows. These sprays with a narrow injection angle A pass through a passage 631, each of which is connected to two intake valves 2a, 2b.
Head to.

[0022] This prevents fuel from adhering to the inside of the intake passage 4 at high loads and high speeds when the throttle valve 5 is opened, and as a result, fuel can be reliably supplied to the combustion chamber, which improves the transient response of the engine, especially This will improve transient response when using heavy gasoline.

When the throttle valve 5 is closed, a pressure difference is generated in the assist air passage 7, and assist air is supplied into the case 610, and the assist air is injected from the assist air passages 624 and 625. When the electromagnetic coil 605 of the fuel valve section 600 is energized while the throttle valve 5 is closed, fuel is injected from the fuel injection hole 601. fuel injection hole 60
The fuel injected from 1 flows through two fuel passages 621 and 6.
Divided into 22. Then, the assist air is supplied to the fuel passage 62.
1 and 622, the fuel that has passed through the two fuel passages 621 and 622 collides with the assist air and is diffused. At this time, the spread of the fuel spray is restricted by the passage 631 formed in the socket 630, but one wide injection angle B as shown in FIG.
The fuel spray shape is as follows.

[0024] This promotes fuel atomization and atomization at low load and low rotation speeds when the throttle valve 5 is closed, making it possible to supply a high-quality air-fuel mixture, resulting in reduced emissions, combustion fluctuations, and transient response. The goal is to improve sexual performance, etc. Especially when the internal combustion engine is at a low temperature, in order to inject a large amount of fuel, the electromagnetic coil 605 is energized for a long time, and the intake valves 2a, 2b
If injection starts before the airflow rises at the seat part, the fuel spray angle will be large and the fuel will be atomized.
Since atomization is promoted, fuel adhesion to the intake passage 4 is reduced, and fuel can be reliably supplied to the combustion chamber.

As described above, according to this embodiment, fuel injection can be performed according to the operating condition of the internal combustion engine, and fuel adhesion to the intake passage, which occurs when increasing the amount of fuel when fuel is injected toward each intake valve, can be avoided. This reduces internal combustion engine emissions, reduces combustion fluctuations, and improves transient response.

Next, a second embodiment to which the present invention is applied is shown in FIG.
and will be explained based on FIG. FIG. 1 is a configuration diagram showing a schematic configuration of a first embodiment. The assist air passage 7 is provided with a control valve 8 that connects and disconnects the passage. This control valve 8 connects and disconnects the assist air passage 7 in response to a signal from a control device 9. A signal is input to the control device 9 from an operating state detection means 10 that detects the operating state of the internal combustion engine 1, and the control device 9 controls the control valve 8 according to this operating state. In this embodiment, the operating state detection means 10 detects the low temperature state of the internal combustion engine 1 from the temperature of the cooling water of the internal combustion engine.

This second embodiment is the same as the first embodiment except for the configuration provided in the assist air passage 7. FIG. 6 is a flowchart showing the operation of the control device 9 of this second embodiment.

In step 101, the operating state detection means 10
Enter the cooling water temperature as the operating state of the internal combustion engine. In step 102, it is determined whether the cooling water temperature is a temperature indicating a low temperature state of the internal combustion engine, and if it is a low temperature state, YES is determined.
It branches to NO when the temperature is not low. In step 103, the control valve 8 is opened, and in step 104, the control valve 8 is closed.

According to this embodiment, assist air is supplied only when the internal combustion engine is in a low temperature state, promoting atomization and atomization of the fuel, reducing emissions of the internal combustion engine, reducing combustion fluctuations, and improving transient response. etc. will be planned.

[0030]Although in the second embodiment described above, the supply of assist air is intermittent depending on the temperature of the cooling water of the engine, it may also be intermittent depending on the operating state of the internal combustion engine, such as the operation of changing gears of the transmission. . Furthermore, by linking with a variable intake system that changes the intake valve operation timing of the internal combustion engine, the intake valve opening timing is retarded, and assist air is supplied only when fuel injection starts before the intake valve opens. However, atomization and atomization of the fuel may be promoted.

[0031]

According to the structure and operation of the present invention described above, it is possible to obtain a spray shape directed toward each intake valve and a diffused spray shape depending on the operating condition of the internal combustion engine. This has the effect of reducing fuel adhesion that occurs when fuel is increased, which occurs when fuel is injected toward the valve at a narrow injection angle, and improves engine performance depending on the operating state of the internal combustion engine.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a schematic configuration of a first embodiment to which the present invention is applied.

FIG. 2 is a cross-sectional view of an air-assisted fuel injection valve.

FIG. 3 is a schematic diagram showing the shape of spray from an air-assisted fuel injection valve.

FIG. 4 is a schematic diagram showing the shape of spray from an air-assisted fuel injection valve.

FIG. 5 is a configuration diagram showing a schematic configuration of a first embodiment to which the present invention is applied.

FIG. 6 is a flowchart showing the operation of the control device.

[Explanation of symbols]

1 Internal combustion engine 2, 2a, 2b Intake valve 3 Exhaust valve 4 Intake passage 5 Throttle valve 6 Air-assisted fuel injection valve 600 Fuel valve part 610 case 620 Sleeve 621, 622 Fuel passage 623 Partition wall 624, 625 Assist air passage 630 socket 631 Passage 7 Assist air passage 8 Control valve 9 Control device 10 Operating state detection means

Claims (1)

[Claims] 1. A fuel supply device provided in an intake passage of an internal combustion engine, which includes a plurality of intake valves, a fuel injection valve that injects fuel toward each intake valve of the internal combustion engine, and a fuel injection valve that injects fuel toward each intake valve of the internal combustion engine; an assist air passage for injecting assist air so as to intersect with an injection direction of fuel injected toward the valve; and an injection angle regulating means for regulating a fuel spray angle when assist air is injected from the assist air passage. A fuel supply device for an internal combustion engine, comprising: an intermittent means for intermittent supply of assist air to the assist air passage depending on the operating state of the internal combustion engine.