JP2001098959A - Throttle controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce velocity of an intake flow when mixed with air in a downstream of a valve by dividing the intake flow passing through a valve tip part using a straightening vane, and to make a noise hardly generated in a terminal of the vane even when the divided intake flows are joined again. SOLUTION: Each cross-sectional shape of the plural straightening vanes 3b provided in a valve rear face ranging over from an upper tip part 3a of the throttle valve 3 to a throttle shaft 2 is formed into an inversed trapezoid shape to widen its width toward a downstream, and the intake flow in an outlet 3e of the vane 3b is expansion-decelerated thereby to disperse energy of the flow, so as to reduce the noise when the divide intake flows are joined again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control device for an internal combustion engine, and more particularly to a structure for reducing noise generated when a throttle valve opens.

[0002]

2. Description of the Related Art Conventionally, noise generated when a throttle valve is rapidly opened from a fully closed state is caused by that an intake air flow passing through both ends of the throttle valve when the valve is opened is rapidly mixed with air downstream of the throttle valve. It is thought to occur by doing. In order to reduce this noise, as shown in FIG.
a to the throttle shaft 2 and from the downstream front end 13f of the throttle valve 13 to the throttle shaft 2 to reduce the noise by expanding the mixing area and reducing the speed of the intake air flow during mixing. A throttle control device provided with a plurality of rectifying plates 13b and 13g has been proposed. Before the throttle valve 13,
A plurality of straightening plates 13b and 13g provided on the rear surface divide the intake air passing through the front ends 13a and 13f of the throttle valve 13 into smaller pieces, and reduce the speed of mixing with the downstream air to reduce noise. Can be.

[0003]

However, the intake air flows subdivided by the flow straightening plate 13b are combined with each other by the flow straightening plate 13b.
At the downstream end 13c, the noises are merged again, and a slight noise is generated, so that the noise cannot be completely eliminated. The principle of the noise generation is shown in FIG.
This will be described in detail with reference to FIG. 4 shows a throttle valve having a configuration in which a straightening plate is provided only on the lower surface of the valve for easy understanding. FIG. 4 (a) is a top view as viewed from the upstream end portion, and FIG. 4 (b) is as viewed from the upstream side. It is a front view.
FIG. 5A is a schematic view showing a state where the divided intake air flows join at the end of the current plate, and FIGS. 5B, 5C, and 5D respectively show the front surface of the intake air flowing through the gap between the current plates. Figure, side view,
It is a rear view. The arrows indicate the flow of intake air. In FIG. 5, the intake air flow segmented by the current plate 13b joins again at the end 13c of the current plate 13b (shown by hatching). The intake air flow at the straightening plate inlet 13d shown in FIG.
As shown in FIG. 5 (c), it slightly spreads in the plate direction of the current plate 13b as it passes between the current plates 13b, but at the current plate exit 13e, as shown in FIG. Merges while having almost the same energy in area. For this reason, it is considered that noise is generated. Therefore, the present invention divides the intake air flow by the rectifier plate to subdivide the energy of the intake flow at the time of merging, and generates noise even if the subdivided intake air flows again at the end of the rectifier plate. It is an object to provide a throttle control device having a configuration that is difficult to perform.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention of claim 1 is directed to opening and closing an intake air by opening and closing a throttle valve fixed to a throttle shaft rotatably provided across an intake passage. In the throttle control device for adjusting the amount, the cross-sectional shape of the rectifying plate provided on the rear surface of the valve between the upstream end portion of the throttle valve and the throttle shaft has an inverted trapezoidal shape that becomes wider toward the downstream side. It is characterized by having been formed. Further, the invention of claim 2 is characterized in that the straightening plate is also provided on the front surface of the valve between the downstream end of the throttle valve and the throttle shaft.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. 1A and 1B show a state in which a throttle valve according to an embodiment of the present invention is in the middle of a rapid opening. FIG. 1A is a top view as viewed from an upstream end portion, and FIG. 1B is a front view as viewed from an upstream side. FIG. FIG. 2A is a schematic view showing a state in which the divided intake air flows merge at the end of the flow straightening plate, and FIGS. 2B, 2C, and 2D are front views of the intake air flowing through the gaps between the flow straightening plates. It is a figure, a side view, and a rear view. The arrows indicate the flow of intake air. In FIG. 1, a throttle valve 3 is fixed to a throttle shaft 2 rotatably provided across an intake passage 1a of a throttle body main body 1. The rotation of the throttle shaft 2 opens and closes the throttle valve 3 to adjust the amount of intake air. From the upstream end 3a of the throttle valve 3 to the vicinity of the throttle shaft 2, a plurality of rectifying plates 3b are erected integrally on the rear surface of the throttle valve 3 along the intake flow. Current plate 3
The cross-sectional shape in the direction perpendicular to the intake flow of b is formed in an inverted trapezoidal shape that becomes wider toward the downstream. Therefore,
Conversely, the cross-sectional shape of the gap between the flow straightening plates 3b exhibits a trapezoidal shape that becomes narrower toward the downstream.

Next, the operation of the present embodiment will be described with reference to FIG. In FIG. 2A, the intake air flow (arrow) subdivided by the current plate 3b is the end 3c of the current plate 3b.
Merge again (indicated by diagonal lines). The intake flow at the inlet 3d of the straightening plate shown in FIG. 2B is formed in an inverted trapezoidal shape in which the cross-sectional shape of the straightening plate 3b becomes wider toward the downstream, and the gap between the straightening plates 3b becomes narrower toward the downstream. As shown in FIG. 2 (c), as shown in FIG. 2 (c), it rapidly expands in the plate direction of the current plate 3b as it passes between the current plates 3b, and at the current plate exit 3e, as shown in FIG. 2 (d). Since the flow changes to a vertically long and narrow shape, the flow is expanded and decelerated, and the energy is dispersed, so that noise generated at the time of re-merging is greatly reduced. The current plate 3b according to the present embodiment
Is basically provided on the rear surface on the upstream end portion 3a side where noise is generated. However, if it is also provided on the front surface on the downstream end portion 3f side (not shown), the noise reduction effect is further increased.

[0007]

The present invention has the following effects because it is configured as described above. That is, since the cross-sectional shape of the rectifying plate provided on the rear surface of the throttle valve from the upstream end portion of the throttle valve to the throttle shaft is formed in an inverted trapezoidal shape that becomes wider toward the downstream, the intake air flow at the outlet of the rectifying plate is reduced. Is expanded and decelerated to disperse the energy of the flow, so that it is possible to reduce noise at the time of re-merging of the intake air flow. Further, by providing the rectifying plate also on the front surface of the valve between the downstream end portion and the throttle shaft, a further noise reduction effect can be obtained.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a throttle control device according to an embodiment of the present invention, and is a top view of a throttle valve viewed from an upstream end portion. FIG. 1B is a front view of the throttle valve viewed from the upstream side.

FIG. 2 (a) is a schematic view showing a state in which the divided intake air flows join at the end of the current plate of the present invention. FIG.
(B) is a front view of the intake airflow flowing through the inlet of the current plate.
FIG. 2C is a side view of the intake airflow flowing through the gap between the flow straightening plates. FIG. 2D is a rear view of the intake air flowing through the outlet of the current plate.

FIG. 3 (a) is a cross-sectional view of a throttle control device showing a conventional technique, and is a side view of a throttle valve as viewed from an axial direction of a throttle shaft. FIG. 3B is a rear view of the throttle valve viewed from the downstream side. FIG. 3C is a side view thereof.

FIG. 4 (a) is a cross-sectional view of a throttle control device showing a conventional technique, and is a top view of a throttle valve viewed from an upstream end portion side. FIG. 4B is a front view of the throttle valve viewed from the upstream side.

FIG. 5 (a) is a schematic diagram showing a state in which the subdivided intake air flows merge at the end of a conventional straightening vane. FIG. 5 (b)
FIG. 4 is a front view of the intake airflow flowing through the inlet of the current plate. FIG.
(C) is a side view of the intake airflow flowing through the gap of the current plate.
FIG. 5D is a rear view of the intake air flowing through the outlet of the current plate.

[Explanation of symbols]

 2 Throttle shaft 3 Throttle valve 3a Upstream tip 3b Rectifier plate 3f Downstream tip

Claims (2)

[Claims] 1. A throttle control device for adjusting an intake air amount by opening and closing a throttle valve fixed to a throttle shaft rotatably provided across an intake passage. A throttle control device for an internal combustion engine, characterized in that a cross-sectional shape of a straightening plate provided on a rear surface of the valve up to the reverse side is formed in an inverted trapezoidal shape that becomes wider toward a downstream side. 2. The throttle control device for an internal combustion engine according to claim 1, wherein said rectifying plate is also provided on a valve front surface between a downstream end portion of said throttle valve and said throttle shaft.