JPH0949473A - Throttle valve control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate control of a fuel injection valve and produce sufficient atomization, by increasing an amount of assist air supplied to the fuel injection valve, and obtaining a linear flow rate characteristic. SOLUTION: A throttle valve 2 is arranged rotatably by a throttle valve shaft 3 in a throttle body 1. An assist air passage port 4, supplying assist air to fuel injection valve parallelly along the periphery of the throttle valve 2 when it is closed, is formed in a slit shape in the throttle body 1. The assist air passage port 4 is formed in the slit shape of circular arc shape or in the slit shape of linear shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve control device for supplying and controlling assist air to a fuel injection valve for injecting fuel into an intake port of an engine.

[0002]

2. Description of the Related Art In recent automobile engines, in order to improve combustion efficiency, various information is processed and controlled by a computer to directly inject a minimum required amount of fuel into an intake port of the engine. Is being prepared.

Although the combustion efficiency has been greatly improved by mounting the fuel injection valve as compared with the conventional one, it is not easy to control the fuel injection valve, so that the atomization of fuel is not sufficiently performed. Was occurring. In order to solve the problem, assist air has been supplied to the fuel injection valve from the intake passage, and atomization has been promoted by mixing the injected air with the assist air.

As one of these, an apparatus as disclosed in Japanese Patent Laid-Open No. 6-317236 has been proposed. according to this,
As shown in FIG. 10, a throttle valve 22 is arranged in an intake passage pipe 21 of the engine, and a passage port 24 for assist air supplied to the fuel injection valve 20 is provided downstream of the throttle valve 22 in the intake passage pipe 21. Formed on the side. Then, the flow rate of the assist air is regulated by the throttle valve 22.

Further, in the known device as shown in FIG. 11, an assist for supplying assist air to the fuel injection valve 30 is provided in the vicinity of the throttle valve 32 disposed in the intake passage pipe 31 of the engine and assist air is supplied to the fuel injection valve 30. The air passage port 34 is formed, and when the throttle valve 32 rotates, the inner wall of the intake passage pipe 31 is formed into a spherical surface along the miracle of movement drawn by the throttle valve 32.

[0006]

However, in any of the above devices, the passage of the assist air is formed in a round shape having a small diameter as shown in FIG. The amount of assist air required for the opening cannot be obtained. Therefore, the linear flow rate characteristic of the total intake air amount cannot be obtained, and the fuel injection valve cannot be easily controlled. Then, the fuel injected from the fuel injection valve is not sufficiently atomized.

The present invention is to solve the above-mentioned problems, and facilitates control of the fuel injection valve by increasing the amount of assist air supplied to the fuel injection valve and obtaining a linear flow rate characteristic. An object of the present invention is to provide a throttle valve control device that can perform various atomizations.

[0008]

In the throttle valve control device according to the present invention, an assist air passage for mixing assist air into the fuel injection valve is provided between the fuel injection valve and the intake passage of the engine, A throttle valve control device for accelerating fuel atomization by disposing an assist air passage opening formed in the intake passage near a downstream side of a throttle valve arranged in the intake passage,
It is characterized in that the assist air passage opening is formed in a slit shape parallel to the outer circumference of the throttle valve when the throttle valve is closed.

Further, it is preferable that the slit shape of the assist air passage opening is linear.

Further, the slit shape of the assist air passage opening may be formed in an arc shape.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an intake passage T of the engine. The intake passage T is connected to an air cleaner (not shown) from the upper side (upstream side) in the figure, and a surge tank (not shown) on the lower side (downstream side). Connected to the intake port of the engine. 2 is a II-II cross section of FIG. 1, showing a cross section of the throttle valve 2 and the assist air passage port 4.

Inside the throttle body 1, the throttle valve 2
Are arranged in substantially the same shape as the inner wall of the throttle body 1. The throttle valve 2 traverses the intake passage T, and the throttle valve 2
The throttle valve shaft 3 attached to the throttle body 1 rotatably supports the throttle body 1 so as to block or open the intake passage T. Also, the throttle valve 2
Is installed so as to be fully closed at a position (about 10 ° in this embodiment) slightly tilted in the direction of falling to the downstream with respect to the horizontal position, and the throttle is rotated as it rotates counterclockwise from the fully closed position. Valve 2 is opened.

Further, when the throttle valve 2 is fully closed, an assist air passage port 4 is formed in a slit shape in a part of the throttle body 1 substantially parallel to the outer circumference of the throttle valve 2. Therefore, as shown in FIG. 3, the assist air passage port 4 is formed in an arc shape with a width smaller than the thickness of the throttle valve 2. (Hereinafter, the assist air passage opening formed in the arc-shaped slit shape is referred to as passage opening 4A.)
The slit shape of the assist air passage port 4 may be linearly formed with a width smaller than the thickness of the throttle valve 2, as shown in FIG. (Hereinafter, the assist air passage opening formed in a linear slit shape is referred to as passage opening 4B.) In any case, when the throttle valve is fully closed, the passage opening 4A (4B) is closed by the throttle valve 2. When the throttle valve 2 is gradually opened, the passage opening 4A (4B) is formed so as to be gradually opened in the slit-like longitudinal direction. Therefore, a linear flow rate characteristic is obtained for the flow rate of the assist air.

Further, the passage port 4A of the throttle body 1
An air pipe 5 is connected to the outside on the (4B) side via a flange 6. The air pipe 5 is connected to a fuel injection valve (not shown) and supplies assist air to the fuel injection valve.

FIG. 5 shows a part 1 of the inner wall of the throttle body 11.
1a is formed into a spherical curved surface, and the throttle valve 2 is the same as in FIG. FIG. 6 shows the throttle valve 12
The outer peripheral part 12a is formed in a spherical curved surface, and the throttle body 1 is the same as in FIG. In either case, the assist air passage ports 4 and 14 formed in the throttle bodies 1 and 11 are circular along the outer circumferences of the throttle valves 12 and 2 in parallel when the throttle valves 12 and 2 are fully closed, as described above. It is formed in an arc shape or a linear slit shape.

Next, the passage opening 4A formed in a slit shape.
The operation of the throttle valve control device having (4B) will be described with reference to the flow rate characteristic graphs of FIGS. 7 and 8.

At the time of idling, the throttle valve 2 is fully closed and the passage port 4A (4B) is also fully closed by the throttle valve 2. In this case, the air is supplied to the engine by another circuit for idling. However, without providing a separate circuit for idling, the throttle valve 2
May be formed slightly smaller than the throttle body 1 so that it flows from the outer periphery of the throttle valve 2.

When the normal operating state is entered, the throttle valve 2 is gradually opened according to the running state, and the passage opening 4A (4B) is opened.
Gradually opens. In the case of the passage opening 4A, the passage opening 4A is fully opened by the opening of the throttle valve 2 of 1.5 °. At this time, since the passage port 4A is formed in parallel with the throttle valve 2 and in the shape of a slit, the assist air for the longitudinal direction of the passage port 4A is gradually constant with respect to the opening degree of the throttle valve 2. Will be increased. Therefore, the increasing tendency of the assist air appears linearly as shown in FIGS. 7 and 8. Further, the increase amount of the main air at this time is relatively small because the opening degree of the throttle valve 2 is small.

When the opening degree of the throttle valve 2 becomes 1.5 ° or more, the amount of assist air becomes constant and the amount of increase of main air becomes large because the passage opening 4A is fully opened.

When this is represented by the graph in FIG. 7, the total air amount obtained by adding the main air and the assist air has a linear flow rate characteristic. In this graph, (a) shows the intake air amount of assist air with respect to the opening of the throttle valve, (b) shows the intake air amount of main air, and (c) shows the intake air amount of total air.

In the case of the passage port 4B, the throttle body 1
However, since it is formed in an arc shape relatively to the outer circumference of the throttle valve 2, the passage port 4B is formed at an opening of the throttle valve of 1.5 °.
Does not become fully open, but becomes fully open around 2.6 °. The tendency of the increase amount of this assist air is as shown in FIG.

FIG. 8 shows that the shape of the assist air passage port is
6 is a graph comparing the amount of assist air intake air in three types of arc-shaped slit shape, linear slit shape, and conventional round shape.

According to this, in the case of the assist air passage port formed by the arc-shaped slit shape and the linear slit shape, the intake amount of the assist air has a large flow rate change and the throttle valve opening degree of 2.6 °. Around the same amount, the flow rate change is small in the case of the round shaped assist air passage port, and at the throttle valve opening of 3.0 °,
It can be seen that it is less than half of the slit-shaped assist air passage opening. Then, in the case of the assist air passage port formed in a round shape, it is understood that the fully open state of the assist air passage port is the throttle valve opening of 3.0 or more.

Further, in the case of the arc slit shape and the linear slit shape, the increasing tendency at the time of rising increases rapidly in the arc slit shape, so ideally the arc slit shape Things are easier to control.

FIG. 9 is a flow rate characteristic graph when the throttle body 11 and the throttle valve 12 shown in FIGS. 5 and 6 are used. (a) 'shows the intake air amount of assist air with respect to the opening of the throttle valve, (b)' shows the intake air amount of main air with respect to the opening of the throttle valve, (c)
′ Indicates the intake air amount of total air with respect to the opening of the throttle valve. According to this, when the opening of the throttle valve is small, the intake air amount of main air is less than the intake air amount of assist air, After the passage opening is fully opened, the air amount becomes larger than the assist air amount. However, also in this case, since the flow rate characteristic of the assist air is similar to the graph shown in FIG. 7, the linear flow rate characteristic of the total air amount can be obtained.

[0027]

As described above, according to the present invention, since the shape of the assist air passage opening is formed in a slit shape in parallel along the outer periphery of the throttle valve when the throttle valve is closed, the throttle valve is opened. The amount of assist air for each degree is obtained and the characteristic of the total air including the main air becomes linear, so that the control of the fuel injection valve becomes easy and sufficient atomization of the fuel injected from the fuel injection valve is achieved. As a result, the combustion efficiency is further improved.

[Brief description of drawings]

FIG. 1 is a throttle valve control device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an assist air passage opening formed in the shape of an arc slit in FIG.

FIG. 4 is an assist air passage opening formed in a linear slit shape in FIG.

FIG. 5 is another throttle valve control device according to the present invention

FIG. 6 is another throttle valve control device according to the present invention

7 is a flow rate characteristic graph of the throttle valve control device of FIG.

FIG. 8 is a graph showing a comparison of assist air amounts in assist air passage openings of various shapes.

FIG. 9 is a flow rate characteristic graph of the throttle valve control device of FIGS.

FIG. 10: Conventional throttle valve control device

FIG. 11: Conventional throttle valve control device

FIG. 12 is an assist air passage opening of a conventional throttle valve control device.

[Explanation of symbols]

 1 ... Throttle body 2 ... Throttle valve 4 ... Assist air passage port

Claims (3)

[Claims] 1. An assist air passage for mixing assist air into a fuel injection valve is provided between the fuel injection valve and an intake passage of an engine, and an assist air passage opening formed in the intake passage is In a throttle valve control device for accelerating fuel atomization by disposing the throttle valve near the throttle valve disposed in the intake passage, the shape of the assist air passage port is A throttle valve control device, characterized in that the throttle valve control device is formed in a slit shape parallel to the outer circumference of the throttle valve. 2. The throttle valve control device according to claim 1, wherein the slit shape of the assist air passage opening is formed in a straight line shape. 3. The throttle valve control device according to claim 1, wherein a slit shape of the assist air passage opening is formed in an arc shape.