JP2000073786A - Throttle valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throttle valve device in which the operation feeling in the low rotation area of an engine is improved. SOLUTION: In a carburettor type intake device in which a throttle valve is opened and closed by a throttle operation to control the air amount in a venturi passage 7, the throttle valve 9 is divided into two parts, and when the throttle is opened from the closed condition to a specific opening angle θ, only one side throttle valve 9b is opened, and when the throttle angle exceeds the specific opening angle θ, both throttle valves 9a and 9b are to be opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a throttle valve device.

[0002]

2. Description of the Related Art The output of an engine is controlled by increasing or decreasing the amount of air flowing through a venturi passage in a carburetor. For example, a throttle valve or a piston valve is provided in the venturi passage and these valves are controlled. Some open / close controls the air flow rate.

[0003]

However, in the case of a throttle valve, as shown by the solid line in FIG. 6, the change in the flow rate of the intake air with respect to the change in the throttle opening is large at a low throttle opening. As a result, the controllability of the engine in the low rotation range is deteriorated, and the operation feeling is not good.

[0004] The present invention has been made in view of the above circumstances, and has as its object to provide a throttle valve device that improves the operational feeling in a low engine speed range.

[0005]

In order to solve the above-mentioned problems, a throttle valve device according to the present invention opens and closes a throttle valve by operating a throttle to open air in a venturi passage. In a carburetor-type intake device for controlling a flow rate, the throttle valve is divided into two, only one of the throttle valves is opened from a closed state to a predetermined opening angle, and when the throttle exceeds a predetermined opening angle, both throttle valves are opened. It is configured to open a throttle valve.

In order to solve the above-mentioned problem, the carburetor has a piston valve inserted into a venturi passage in a direction orthogonal to the passage so as to be vertically movable. A constant negative pressure type variable venturi carburetor that automatically adjusts a venturi diameter by a pressure change in the venturi passage, wherein the piston valve opens a throttle valve that starts to open first among the two divided throttle valves. It is arranged on the starting side.

Further, in order to solve the above-mentioned problems,
As set forth in claim 3, in a fuel injection type intake apparatus for controlling the air flow rate in an intake passage through which fuel is injected by a fuel injector by opening and closing a throttle valve by a throttle operation, the throttle valve is divided into two parts, Only one throttle valve is opened from the closed state to a predetermined opening angle, and both throttle valves are opened when the throttle exceeds a predetermined opening angle. The throttle valve that starts to open first is disposed on the side of the fuel injector where the injection port is disposed.

[0008]

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

FIG. 1 shows a constant negative pressure (CV) to which the present invention is applied.
FIG. 1 is a longitudinal sectional view showing an example of an intake device using a (constant vacuum) type variable venturi-type carburetor 1.
The right side in the figure is the air cleaner side (not shown), and the left side is the engine side (not shown).

A throttle body 2, which is a main body of the carburetor 1, is formed by die-casting a light metal material such as aluminum, for example. The upper part in the figure is closed by a negative pressure chamber cap 3, and the inside thereof is negatively charged. The pressure chamber 4 is formed. A diaphragm device 5 is provided in the negative pressure chamber 4.
Is provided.

On the other hand, a float chamber 6 for storing fuel is provided below the throttle body 2 in the figure.
In the center of the throttle body 2, a venturi passage 7 is provided.
Are formed so as to penetrate in the lateral direction of the drawing.

The venturi passage 7 is provided with a piston valve 8 on the air cleaner side and a throttle valve 9 on the engine side. The piston valve 8 is inserted into the venturi passage 7 from above, for example in the drawing, of the throttle body 2 so as to be able to ascend and descend in a direction perpendicular to the passage. The ventilator 7 is controlled to move up and down by the operation of the diaphragm device 5 to automatically adjust the passage area (venturi diameter) of the venturi passage 7.

The diaphragm device 5 senses a pressure change in the venturi passage 7 due to a change in the opening of the throttle valve 9 due to the operation of a throttle (not shown), and moves the diaphragm 5a up and down to automatically raise and lower the piston valve 8. The change in pressure in the venturi passage 7 is transmitted to the diaphragm device 5 through a negative pressure port (not shown).

FIG. 2 is an enlarged vertical sectional view showing the vicinity of the throttle valve 9. FIG. 3 is a sectional view taken along line III-III in FIG. As shown in FIGS. 2 and 3, the throttle valve 9 has a disk shape substantially the same as the cross-sectional shape of the venturi passage 7, and a valve shaft 11 is disposed at the center thereof.

The valve shaft 11 is composed of a pipe-shaped outer shaft 11a and an inner shaft 11b disposed in the outer shaft 11a coaxially with the outer shaft 11a. The throttle valve 9 is divided into a semi-disc-shaped first valve 9a and a second valve 9b with a valve shaft 11 as a boundary. One of the first valve 9a is connected to the outer shaft 11a, and the other is connected to the second shaft 9a. The valves 9b are fixed to the inner shaft 11b, respectively. And, the outer shaft 11a
Is formed with a notch 12 extending in the axial direction.
The inner shaft 11b to which b is fixed can be held inside.

Incidentally, the second valve 9b is arranged on the side where the piston valve 8 starts to open, in the present embodiment, on the lower half side of the venturi passage 7 in the drawing.

Both ends of the inner shaft 11b are rotatably supported by the venturi passage wall 7a of the throttle body 2. One end of the inner shaft 11b is
a, a throttle pulley 13 is integrally provided at one end thereof. Further, a return spring 14 is provided on a protruding portion of the inner shaft 11b, and urges the second valve 9b to a normally closed position (solid line in FIG. 2). The second valve 9b is operated in accordance with the operation of a throttle (not shown) via a transmission means such as a throttle cable or a throttle rod (not shown) connected to the throttle pulley 13.
Is rotated in the direction of the arrow shown in FIG.

On the other hand, both ends of the outer shaft 11a are also rotatably supported by the venturi passage wall 7a of the throttle body 2. Also, the inner shaft 11b
One end of the outer shaft 11a on the side opposite to the projecting portion projects outside the passage wall 7a, and a support plate 15 is provided at the end. Further, a return spring 16 is provided at a protruding portion of the outer shaft 11a, and the first valve 9
a is urged to the normally closed position (solid line in FIG. 2).

Here, since the transmission means of the throttle operation is not connected to the outer shaft 11a, a direct rotation operation by the operation of the throttle is not performed, but the first valve is opened after the inner shaft 11b opens the predetermined angle θ. 9a
Abuts against the edge of the notch 12 formed in the outer shaft 11a, the first valve 9a is pushed by the second valve 9b and rotates in conjunction therewith.

FIGS. 4 (a), (b), (c) and (d) show specific operations of the first valve 9a and the second valve 9b.
This will be described with reference to FIG.

FIG. 4A shows a state in which the throttle valve 9 is completely closed and the first valve 9a and the second valve 9b
Is held in the closed position by the urging forces of both return springs 14 and 16. When the operation of the throttle is started, the second valve 9b gradually starts to open, but the first valve 9a is held in the closed position until the second valve 9b reaches a predetermined opening angle θ (see FIG. 4B). ).

When the second valve 9b is further opened by the throttle operation and reaches a predetermined opening angle θ (see FIG. 4 (c)), the second valve 9b is inserted into the edge of the notch 12 formed in the outer shaft 11a. Then, as shown in FIG. 4D, the first valve 9a is linked and opened.

On the other hand, when the throttle valve 9 is closed, the above operation is performed in reverse. That is, when the throttle operation is released (returned), the first valve 9a and the second valve 9b are simultaneously rotated toward the closed position by the urging forces of both the return springs 14 and 16. When the first valve 9a stops rotating at the fully closed position, only the second valve 9b continues to rotate toward the closed position, and finally the throttle valve 9 is completely closed.

By the way, in the embodiment described above, an example is shown in which the throttle valve 9 is provided in the venturi passage 7 of the carburetor 1, but the throttle valve 9 according to the present invention is provided.
Can be provided in the intake passage of the fuel injection type intake device, and an example thereof is shown in FIG. 5 as a second embodiment. In the intake passage shown in FIG. 5, the right side in the figure is the air cleaner side (not shown) and the left side is the engine side (not shown).

The fuel injector 21 of the fuel injection device 20 is mounted on an intake pipe 22 connecting the engine and the air cleaner at an angle so that the injection port 21a is directed toward the engine. A throttle valve 24 composed of a first valve 24a and a second valve 24b is openable and closable on the upstream side (air cleaner) of the fuel injection port 21a of the fuel injector 21 in an intake passage 23 formed in the intake pipe 22. And the intake passage 23
Regulates the flow rate of air flowing into the inside. Since the structure of the throttle valve 24 is the same as the structure of the throttle valve 9 provided in the carburetor 1, the detailed description of the structure is omitted.

The second valve 24b of the throttle valve 24 is connected to the injection port 2 of the fuel injector 21.
1a, the intake passage 2 in the present embodiment.
3 is arranged on the lower half side.

The throttle valves 9 and 24 having the above-described configuration are used.
, The predetermined opening angle θ at the time of low throttle opening
Until then, only a part of the throttle valves 9 and 24, in this embodiment, only the second valves 9b and 24b are opened, so that the intake air amount is smaller than that of the conventional one. as a result,
The change in the flow rate of the intake air with respect to the amount of change in the throttle opening does not rise rapidly immediately after the throttle opening operation, but forms a gentle rising line as shown by the dashed line in FIG. Is very good and the engine feel is improved and it is easy to handle.

The first one of the throttle valves 9 and 24 which starts to open, in the present embodiment, the second valve 9
b, 24b on the side where the piston valve 8 starts to open, in the first embodiment the lower half of the venturi passage 7 and on the side where the injection port 21a of the fuel injector 21 is arranged, in the second embodiment the intake passage 23, the air flow becomes linear when the throttle opening is low, the intake resistance is reduced, and the response of the engine corresponding to the throttle operation, that is, the pickup is improved.

[0029]

As described above, according to the throttle valve device of the present invention, in the carburetor type intake device for controlling the air flow rate in the venturi passage by opening and closing the throttle valve by the throttle operation, Divide into two, open only one throttle valve from the closed state to a predetermined opening angle,
Since both throttle valves are opened when the throttle exceeds a predetermined opening angle, the amount of intake air at the time of a low throttle opening is reduced, and the controllability in a low engine speed range is improved.

In the carburetor, a piston valve is inserted into a venturi passage so as to be vertically movable in a direction perpendicular to the passage, and the piston valve automatically adjusts a venturi diameter by a pressure change in the venturi passage. In the variable pressure venturi type carburetor, the throttle valve that starts to open first among the two divided throttle valves is disposed on the side where the piston valve starts to open, so that the engine response corresponding to the throttle operation is improved.

Further, in a fuel injection type intake apparatus for controlling the flow rate of air in an intake passage through which fuel is injected by a fuel injector by opening and closing a throttle valve by operating a throttle, the throttle valve is divided into two parts and the throttle is closed. From the state to the predetermined opening angle, only one throttle valve is opened, and when the throttle exceeds the predetermined opening angle, both throttle valves are opened, and the first of the two divided throttle valves is opened. Since the starting throttle valve is located on the side where the fuel injector injection port is located, the amount of intake air at the time of low throttle opening is reduced, improving controllability in the low engine speed range and improving throttle operation. The corresponding engine response also improves.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an intake device using a constant negative pressure type variable Venturi carburetor showing one embodiment of a throttle valve device according to the present invention.

FIG. 2 is an enlarged vertical sectional view near a throttle valve.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIGS. 4A, 4B, 4C, and 4D are diagrams showing specific operations of a throttle valve.

FIG. 5 is a longitudinal sectional view of an intake device having a fuel injection device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a change in the flow rate of intake air with respect to a change amount of a throttle opening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carburetor 7 Venturi passage 8 Piston valve 9, 24 Throttle valve 9a, 24a First valve 9b, 24b Second valve 11 Valve shaft 11a Outer shaft 11b Inner shaft 12 Notch 20 Fuel injector 21 Fuel injector 21a Fuel injector injection port 22 Intake pipe 23 Intake passage θ Predetermined opening angle

Claims (3)

[Claims] 1. A carburetor-type intake device in which a throttle valve is opened and closed by a throttle operation to control an air flow rate in a venturi passage.
Is divided into two, and only one throttle valve 9b is opened from the closed state to a predetermined opening angle θ, and both throttle valves 9a and 9b are opened when the throttle exceeds the predetermined opening angle θ. A throttle valve device comprising: 2. In the carburetor 1, a piston valve 8 is inserted into a venturi passage 7 in a direction perpendicular to the passage so as to be able to move up and down, and the piston valve 8 automatically adjusts the venturi diameter by a pressure change in the venturi passage 7. 2. A constant negative pressure type variable venturi-type carburetor, wherein a throttle valve 9b which starts to open first among the two divided throttle valves 9a and 9b is disposed on a side where the piston valve 8 starts to open. The throttle valve device as described. 3. A fuel injection type intake system in which a throttle valve controls opening and closing of a throttle valve to control an air flow rate in an intake passage through which fuel is injected by a fuel injector. Only one throttle valve 24b is opened from the closed state to a predetermined opening angle θ, and both throttle valves 24a and 24b are opened when the throttle exceeds a predetermined opening angle θ, and the throttle valve 24b is divided into two. A throttle valve device, wherein the throttle valve 24b, which starts to open first among the throttle valves 24a and 24b, is arranged on the side of the fuel injector 21 where the injection port 21a is arranged.