JPH07324666A - Fuel injection device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve engine output in the high rotation range by decreasing intake resistance as well as to improve riding comfort by improving combustibility, by changing the attaching position of a fuel injection valve to be attached to a throttle body. CONSTITUTION:A fuel injection valve 16 is made to point to the downstream from a throttle valve 12 and to an intake passage lower side inner wall surface 20 of an intake manifold 4, so as to be integrally formed on a throttle body 8.

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 for an internal combustion engine, and more particularly, by changing the mounting position of a fuel injection valve mounted on a throttle body, the combustibility is improved and the riding comfort is improved. The present invention relates to a fuel injection device for an internal combustion engine that can reduce intake resistance and improve engine output in a high engine speed range.

[0002]

2. Description of the Related Art Some internal combustion engines of vehicles are equipped with a fuel injection device for controlling the amount of fuel injection from a fuel injection valve as a measure against the problems of harmful exhaust gas and fuel consumption.

This fuel injection device includes a so-called single point injection system having a unique fuel injection valve in the throttle body.

As a fuel injection device of this single point injection type, there is one shown in FIGS. That is, in FIG. 10, 102 is an internal combustion engine, 10
Reference numeral 4 is an intake manifold, 106 is an intake passage, 108 is a throttle body, 110 is a body intake passage, 112 is an intake pipe, 114 is an intake pipe, and 116 is an air cleaner.
The throttle body 108 is connected to the upstream side of the intake manifold 104. A throttle valve 118 and a fuel injection valve 120 upstream of the throttle valve 118 are arranged in the body intake passage 110 of the throttle body 108. Fuel is supplied from the fuel supply pipe 124 of the fuel supply device 122 to the fuel injection valve 120.

The fuel injection valve 120, as shown in FIGS. Body intake passage 1 upstream of the throttle valve 118
It is located approximately in the center of 10. As a result, a body intake port 126 is formed around the fuel injection valve 120 on the upstream side in the body intake passage 110.

Further, as the structure of the throttle body to which the fuel injection valve is attached in this way, for example, the actual open sho 59
-135381, Japanese Utility Model Laid-Open No. 63-57369, and Japanese Patent Laid-Open No. 64-56965.
The one described in Japanese Utility Model Laid-Open No. 59-135381 has a fuel injection valve attached to a throttle body downstream of the throttle valve. In Japanese Utility Model Laid-Open No. 63-57369, fuel injection valves are mounted in both fuel injection passages so that the circumferential positions of both fuel injection passages with respect to the axis of the body are aligned with each other, and The angle of inclination with respect to the axis of the body is substantially the same. In the one disclosed in JP-A-64-56965, the injection direction of the injection valve is orthogonal to the axis parallel to the valve axes of the air valve and the throttle valve, and when the air valve and the throttle valve are fully opened, The front edges of both valves are located on the opposite side of the injection valve and the rear edges are located on the same side as the injection valve, and both valves open in the direction in which the rear edges of both valves are separated from the nozzle tip of the injection valve. It is a constitution to be valved.

[0007]

However, in the conventional single-point injection type fuel injection device, the fuel injection valve is arranged upstream of the throttle valve, and therefore, in particular, from a small opening of the throttle valve. During acceleration, etc., the fuel from the fuel injection valve collides with the throttle valve and rebounds, then reaches the intake passage and is supplied to the internal combustion engine. Therefore, the loss time of the fuel supply is large, and as shown in FIG. However, there are inconveniences that a lean air-fuel mixture (lean) is likely to occur, the combustibility is deteriorated, and the followability and response of the internal combustion engine are poor. In other words, when the throttle valve is suddenly fully opened, the amount of air increases in a moment, but the specific gravity of the fuel is large, and the ratio of adhering to the inner wall surface of the intake passage to form a wall flow is high, and the fuel immediately Since it is not sucked in, it takes a considerable amount of time for the internal combustion engine to guide the fuel required at that time to the combustion chamber, and depending on the opening state of the throttle valve, it functions as a baffle that prevents the fuel supply. Therefore, as shown in FIG. 13, the lean air-fuel mixture is likely to occur during this period, the air-fuel ratio becomes lean, and the combustibility deteriorates.
The responsiveness becomes poor and the riding feeling is reduced.

Further, since the fuel injection valve is arranged on the upstream side of the throttle valve, it occupies most of the body intake port, which increases intake resistance and lowers the output in the high speed region. There was an inconvenience.

Further, in the structure described in the above publication, since the fuel is simply injected to the center side of the body intake passage of the throttle body, it is possible to obtain sufficient fuel atomization and distribution performance. There was an inconvenience that I could not do it.

[0010]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention attaches a fuel injection valve for injecting fuel to an internal combustion engine to a throttle body connected to an upstream side of an intake manifold. In a fuel injection device for an internal combustion engine in which a throttle valve is arranged in a body intake passage of a throttle body, the fuel injection valve is directed toward a downstream side of the throttle valve and an inner wall surface of an intake passage lower side of the intake manifold. It is characterized in that it is provided integrally with the throttle body.

[0011]

According to the structure of the present invention, the fuel is injected from the fuel injection valve toward the inner wall surface on the downstream side of the intake passage, is mixed with the air from the throttle valve side by the suction force of the internal combustion engine, and is supplied to the internal combustion engine side. To be done. Therefore, the fuel is quickly supplied to the internal combustion engine without being obstructed by the throttle valve, so there is no risk of becoming a lean mixture, and the combustibility is improved to improve the followability and responsiveness of the internal combustion engine. As a result, it is possible to improve the riding feeling, reduce the intake resistance to improve the output in the high rotation speed range, promote the atomization of the fuel, and improve the distribution performance.

[0012]

Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 8 show an embodiment of the present invention. In FIG. 1, 2 is an internal combustion engine, 4 is an intake manifold, and 6 is an intake passage formed in the intake manifold 4. A manifold upstream end 4a on the upstream side of the intake manifold 4 is bent and formed substantially at a right angle to the center of the intake passage 6c and is directed upward.

At the manifold upstream end 4a of the intake manifold 4, the body downstream end 8b of the throttle body 8 is provided.
Are lined up.

The throttle body 8 has an intake passage 6
A body intake passage 10 is formed to communicate with. A throttle valve 12 is provided in the body intake passage 10, and a body intake port 14 is formed at the upstream body upstream end portion 8a.

As a result, the center line 6c of the intake passage 6 and the center line 10c of the body intake passage 10 are substantially orthogonal to each other.

A fuel injection valve 16 of a fuel injection device (not shown) is provided at a body downstream end 8b of the throttle body 8.
Is integrated and installed.

The center line 16c of the fuel injection valve 16 is substantially parallel to the center line 10c of the body intake passage 10, so that the center line 16c is substantially orthogonal to the center line 6c of the intake passage 6,
Moreover, it is arranged close to the internal combustion engine 2 side.

Further, in the fuel injection valve 16, the injection port portion 16a extends from the intake passage upstream inner wall surface 18 side to the intake passage lower inner wall surface 20.
Is attached to the valve mounting portion 22 of the body downstream end 8b.

Therefore, the fuel from the fuel injection valve 16 is provided on the downstream side of the throttle valve 12 and at the collecting portion 24 of the intake passage 6.
At, the fuel is injected from the intake passage upstream inner wall surface 18 toward the intake passage downstream inner wall surface 20.

Further, the intake manifold 4 has a collecting portion 24.
A cooling water passage 26 is formed below.

Next, the operation of this embodiment will be described.

As shown in FIG. 6, when the fuel from the fuel injection valve 16 is injected toward the inner wall surface 20 on the downstream side of the intake passage in the collecting portion 24, the suction force of the negative pressure generated by the operation of the internal combustion engine 2 causes the throttle to move. It is mixed with the air from the valve 12 side, sucked to the internal combustion engine 2 side, and supplied to the internal combustion engine 2.

Therefore, the flow of the fuel from the fuel injection valve 16 is not obstructed by the throttle valve 12, and the fuel injection valve 16 is provided close to the internal combustion engine 2 side, so that the fuel can be quickly supplied. Even if the throttle valve 12 is supplied to the internal combustion engine 2 and the throttle valve 12 is suddenly opened from a small opening as shown in FIG. 7, there is no possibility of becoming a lean air-fuel mixture (lean) in the internal combustion engine 2. It is possible to improve the followability and responsiveness of the internal combustion engine and improve the riding feeling.

Further, the fuel injection valve 16 is connected to the body suction port 1
Since it does not exist in No. 4 and does not become intake resistance, as shown in FIG. 8, the output in the high rotation range can be made higher than in the conventional case, and the output can be improved.

Further, since the fuel injected from the fuel injection valve 16 is evenly mixed with air in the collecting portion 24, atomization can be promoted and the distribution performance to each cylinder can be improved.

Furthermore, since the fuel injection valve 16 is integrally built in the throttle body 8, the cost can be suppressed.

FIG. 9 shows another embodiment of the present invention.

In the other embodiments, the portions having the same functions as those of the above-mentioned embodiments are designated by the same reference numerals.

Another feature of this embodiment is that the fuel injection valve 16 is connected to the body intake passage 10 of the throttle body 8.
On the center line 10c and on the downstream side of the throttle valve 12 toward the inner wall surface 20 of the intake passage downstream.

According to the configuration of the other embodiment, the same effect as the above-mentioned embodiment can be obtained.

[0031]

As is apparent from the above detailed description, according to the present invention, the fuel injection valve is directed downstream of the throttle valve and toward the inner wall surface of the intake manifold below the intake passage so as to be integrated with the throttle body. By providing the fuel quickly to the internal combustion engine, eliminating the risk of becoming a lean mixture, improving the combustibility to improve the followability and responsiveness of the internal combustion engine, improve the riding feeling, and The intake resistance is reduced to improve the output in the high speed range, further promote the atomization of the fuel, improve the distribution performance, and further integrate the fuel injection valve in the throttle body, The cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of an intake system of an internal combustion engine.

FIG. 2 is a plan view of a throttle body.

FIG. 3 is an enlarged plan view of an essential part of FIG.

FIG. 4 is an enlarged sectional view of a throttle body.

5 is an enlarged plan view of an essential part of FIG.

FIG. 6 is a sectional view of an intake system for explaining a fuel injection state.

FIG. 7 is a diagram illustrating the behavior of the air-fuel ratio.

FIG. 8 is a diagram illustrating output comparison.

FIG. 9 is a sectional view of an intake system according to another embodiment of the present invention.

FIG. 10 is a system configuration diagram of a conventional fuel injection device.

FIG. 11 is a plan view of a conventional throttle body.

FIG. 12 is a sectional view of a conventional throttle body.

FIG. 13 is a diagram illustrating a conventional air-fuel ratio behavior.

[Explanation of symbols]

 2 internal combustion engine 4 intake manifold 8 throttle body 10 body intake passage 12 throttle valve 16 fuel injection valve 20 inner wall surface of intake passage

Claims (1)

[Claims] 1. A fuel for an internal combustion engine in which a fuel injection valve for injecting fuel into an internal combustion engine is mounted on a throttle body connected to an upstream side of an intake manifold and a throttle valve is arranged in a body intake passage of the throttle body. In the injector, the fuel injection valve for the internal combustion engine is characterized in that the fuel injection valve is provided downstream of the throttle valve and toward an inner wall surface of an intake manifold lower side of the intake manifold so as to be integrated with the throttle body. apparatus.