JP2007138745A - Intake device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device of an internal combustion engine in which airflow noise is suppressed by reducing the amount of intake air without degrading the output of the internal combustion engine. <P>SOLUTION: In this intake device of the internal combustion engine, a throttle valve 1 is installed in the intake passage 3 of the intake device of the internal combustion engine. An inner diameter-increased part 4 is formed in the intake passage 3 on the downstream side of the peripheral edge portion 1a among the pair of peripheral edge portions 1a, 1b of the throttle valve on the side where the throttle valve is tilted to the upstream side when the throttle valve 1 is changed from a closed state to an open state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for suppressing airflow noise generated from a downstream side of a throttle valve provided for the purpose of adjusting an intake air amount in an intake device of an internal combustion engine such as an engine used in an automobile.

  An internal combustion engine such as an engine used in an automobile includes an intake device, and the intake device is provided with a throttle valve for the purpose of adjusting the intake air amount. As the throttle valve, a butterfly type is often used which opens and closes by swinging a disc-shaped valve around a swing shaft provided in the diameter direction. The butterfly type throttle valve is opened from a closed state. When this occurs, the air flows are turbulent and interact with each other when a plurality of airflows with different flow velocities merge on the downstream side of the throttle valve, thereby generating airflow noise. To do.

  In recent years, there has been a growing demand for quietness in the interior of automobiles, and measures for preventing noise generation and blocking the transmission path have been developed and applied to those with relatively high noise levels. Accordingly, the airflow noise having a relatively low noise level, which has not been a problem in the past, has become a problem.

As a means for suppressing such airflow noise, there is an airflow noise prevention device as described in, for example, Patent Document 1, which is formed by a butterfly throttle valve 51 as shown in FIG. Gap portions α and β where the flow is fast (a pair of gap portions formed between the peripheral portions 51a and 51b of the throttle valve at the position farthest from the swing shaft 52 of the throttle valve 51 and the intake passage inner wall 53) And a low-speed air flow that has passed through each of the other low-flow gap portions γ interact with each other when they merge downstream of the throttle valve 51, and Paying attention to the occurrence of unstable flow vortices, resistance means such as fins, dimples, and wires are provided downstream of the fast-flowing gap portion, and the airflow flowing through the gap portion is reduced. With reducing degree, their flow by shifting the point of confluence, by suppressing a large disturbance of flow, it has been proposed to suppress the airflow noises.
Japanese Patent Laid-Open No. 11-13500

  However, in such a device for preventing airflow noise, there is a problem that by providing the resistance means downstream of the throttle valve, the intake air amount is also reduced, leading to a decrease in the output of the internal combustion engine.

  An object of the present invention is to solve the above-described problem, and to provide an intake device for an internal combustion engine that can suppress airflow noise without reducing the intake air amount and lowering the output of the internal combustion engine. is there.

An airflow noise prevention device for an intake device of an internal combustion engine according to the present invention,
An intake passage through which air supplied to the internal combustion engine flows from the upstream side toward the downstream side;
A throttle valve rotatably provided in the intake passage via a swing shaft;
An intake device for an internal combustion engine comprising:
When the throttle valve is rotated to change the throttle valve from the closed state to the open state, an inner diameter enlarged portion is formed on the inner wall portion of the intake passage that faces the upstream portion of the peripheral portion of the throttle valve. Provided,
The inner diameter enlarged portion is provided on the downstream side of a peripheral portion of the throttle valve when the throttle valve is in a closed state.

  According to this, in the peripheral portion of the throttle valve, when the throttle valve is changed from the closed state to the open state, the inner diameter is increased in the intake passage located on the downstream side of the peripheral portion on the side inclined to the upstream side. By providing a portion, the peripheral edge on the side inclined to the downstream side is reduced by reducing the speed of the air flow passing through the gap formed between the peripheral edge portion on the side inclined to the upstream side and the intake passage. By reducing the difference in speed between the air flow passing through the gap formed between the air intake passage and the intake passage, a vortex is generated on the downstream side of the throttle valve by combining these air flows. This can be suppressed and airflow noise caused by vortices can be suppressed. In addition, it is possible to avoid providing resistance means such as fins, dimples, and wires that directly obstruct the flow of air flow in the intake passage as in the prior art. A reduction in fuel consumption can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the principle of an intake device for an internal combustion engine according to the present invention.
FIG. 2 is a schematic view showing an embodiment of an intake device for an internal combustion engine according to the present invention.

In general, in a flow in a continuous pipe, the flow rate at any position in the flow direction is constant. Therefore, when the diameter of the pipe is increased and its cross-sectional area is increased from the middle as shown in FIG. The flow velocity of becomes smaller.
Based on this law, as shown in FIG. 2, a throttle valve 1 is provided in an intake passage 3 of an intake device of an internal combustion engine (not shown), and a pair of peripheral portions 1a and 1b that are farthest from the swing shaft 2 of the throttle valve 1 Among them, when the throttle valve 1 is changed from the closed state to the open state, the inner diameter enlarged portion 4 is provided in the intake passage 3 located on the downstream side of the peripheral edge portion 1a on the side inclined to the upstream side.
FIG. 2 shows a cross section including the central axis of the intake passage 3 and perpendicular to the swing shaft 2.

  According to this, of the pair of peripheral portions 1a and 1b farthest away from the swing shaft 2 of the throttle valve 1, when the throttle valve 1 is changed from the closed state to the open state, the side on the side inclined to the upstream side. By providing the inner diameter enlarged portion 4 in the intake passage 3 located on the downstream side of the peripheral portion 1a, it passes through the gap portion α formed between the peripheral portion 1a and the intake passage 3 on the side inclined to the upstream side. The air flow velocity Vα is reduced, and the velocity difference between the air flow velocity Vβ passing through the gap portion β formed between the peripheral edge portion 1b on the side inclined to the downstream side and the intake passage 3 is reduced. By doing so, it is possible to suppress the generation of vortices due to the merging of these air flows on the downstream side of the throttle valve 1, and to suppress airflow noise caused by the vortices. In addition, since it is possible to avoid providing resistance means that directly obstructs the flow of air flow in the intake passage 3 as in the prior art, it is possible to reduce the intake amount and reduce the fuel consumption of the internal combustion engine. Can be prevented.

In addition, the inner diameter of the intake passage 3 is gradually enlarged over the entire circumference from the position where the throttle valve 1 is provided to the upstream side and the downstream side, and the workability is improved when the throttle valve 1 is attached to the intake passage 3. ing.
Further, as shown in FIG. 2, the inner diameter enlarged portion 4 is provided on the downstream side of the gap portion α, but the upstream end A of the inner diameter enlarged portion 4 is provided adjacent to the downstream side of the installation position of the throttle valve 1. The position of the downstream end B of the inner diameter expanding portion 4 is determined by changing the inner diameter expanding portion 4 after the position where the inner diameter expanding portion 4 joins the air flow passing through the gap portion α and the air flow passing through the gap portion β. Since it is not necessary to install, the air flow rate is appropriately determined based on the amount of air flowing through the intake passage 3 and the velocity of the air flow passing through the gap portions α and β. For this reason, on the further downstream side of the inner diameter enlarged portion 4, the inner diameter of the intake passage 3 is returned in the same manner as the inner diameter at the circumferential position other than the gap portion α.

FIG. 3 is a schematic diagram showing a cross-sectional arrow view in the CC direction of FIG. 2.
The inner diameter enlarged portion 4 is formed on the downstream side of the gap portion α formed between the peripheral edge portion 1a on the side inclined to the upstream side and the intake passage 3 as described above. The length is also appropriately determined based on the amount of air flowing through the intake passage 3 and the velocity of the airflow passing through the gap portions α and β. Since the peripheral portion 1a is the position farthest from the swing shaft 2, naturally, the peripheral portion 1a is positioned on a plane D that is perpendicular to the swing shaft 2 and includes the direction of the central axis of the intake passage 3. The inner diameter enlarged portion 4 provided on the downstream side of the peripheral portion 1a is formed including the plane D.

FIG. 4 is a schematic view showing another embodiment of the intake device for an internal combustion engine according to the present invention.
As described above, in general, the inner diameter of the intake passage 3 is gradually enlarged over the entire circumference from the position where the throttle valve 1 is provided toward the upstream side and the downstream side, and the throttle valve 1 is attached to the intake passage 3. The workability is improved. Therefore, by utilizing the form of the original intake passage 3, the swing shaft of the throttle valve 1 when the inner diameter of the intake passage 3 is gradually expanded from the position where the throttle valve 1 is provided toward the downstream side. The inner diameter enlarged portion 4 is formed by increasing the diameter expansion amount of the portion located on the downstream side of the peripheral edge portion 1a on the side inclined from 2 to the upstream side (see claim 2). Equivalent).

  Even in this case, when the throttle valve 1 is changed from the closed state to the open state among the pair of peripheral portions 1a and 1b farthest from the swing shaft 2 of the throttle valve 1 without reducing the intake air amount, By providing the inner diameter enlarged portion 4 in the intake passage 3 located on the downstream side of the peripheral edge portion 1 a on the side inclined to the side, the intake passage 3 is provided between the peripheral edge portion 1 a on the side inclined on the upstream side and the intake passage 3. The velocity Vα of the airflow that has passed through the formed gap portion α is reduced, and the airflow that passes through the gap portion β formed between the peripheral edge portion 1b and the intake passage 3 on the side inclined to the downstream side is reduced. By reducing the speed difference with the speed Vβ, it is possible to suppress the generation of vortices due to the merging of these air flows on the downstream side of the throttle valve, and to suppress the airflow noise caused by the vortices. .

  Further, in FIG. 4, when the inner diameter of the intake passage 3 is gradually enlarged from the position where the throttle valve 1 is provided to the downstream side, the inner side of the throttle valve 1 is inclined to the downstream side. The diameter expansion amount of the portion located on the downstream side of the peripheral portion 1b is made smaller than the diameter expansion amount other than the portion (corresponding to claim 3).

  According to this, the velocity Vβ of the air flow passing through the gap portion β formed between the peripheral edge portion 1b on the side inclined to the downstream side and the intake passage 3 without reducing the intake amount is set to the throttle. By reducing the inner diameter of the intake passage 3 located on the downstream side of the peripheral portion 1b of the valve 1, it can be increased conversely, the speed difference between the speed Vα and the speed Vβ can be further reduced, and further effects are achieved. In particular, on the downstream side of the throttle valve, it is possible to suppress the generation of vortices due to the merging of these air flows, thereby suppressing airflow noise caused by the vortices.

FIG. 5 is a schematic view showing still another embodiment of the intake device for an internal combustion engine according to the present invention.
As described above, in general, the inner diameter of the intake passage 3 is gradually enlarged over the entire circumference from the position where the throttle valve 1 is provided to the upstream side and the downstream side, and the throttle valve 1 is attached to the intake passage 3. The workability is improved. Therefore, by utilizing the form of the original intake passage 3, the central axis F of the intake passage 3 is tilted from the position where the throttle valve 1 is provided to the downstream side and from the swing shaft 2 to the upstream side. The inner diameter enlarged portion 4 is formed by offsetting in the direction toward the peripheral portion 1a on the side (corresponding to claim 4).

  Even in this case, when the throttle valve 1 is changed from the closed state to the open state among the pair of peripheral portions 1a and 1b farthest from the swing shaft 2 of the throttle valve 1 without reducing the intake air amount, By providing the inner diameter enlarged portion 4 in the intake passage 3 located on the downstream side of the peripheral edge portion 1 a on the side inclined to the side, the intake passage 3 is provided between the peripheral edge portion 1 a on the side inclined on the upstream side and the intake passage 3. The velocity Vα of the airflow that has passed through the formed gap portion α is reduced, and the airflow that passes through the gap portion β formed between the peripheral edge portion 1b and the intake passage 3 on the side inclined to the downstream side is reduced. By reducing the speed difference with the speed Vβ, it is possible to suppress the generation of vortices due to the merging of these air flows on the downstream side of the throttle valve, and to suppress the airflow noise caused by the vortices. .

FIG. 6 is a schematic view showing still another embodiment of the intake device for an internal combustion engine according to the present invention.
The inner diameter enlarged portion 4 can take various forms as shown in FIG. 6 in addition to the form described above.
As shown in FIG. 6 (a), the inner diameter enlarged portion 4 is formed by gradually increasing the diameter from the swinging shaft 2 of the throttle valve 1 toward the downstream side and then sharply reducing the diameter further downstream. Alternatively, as shown in FIG. 6 (b), downstream from the swinging shaft 2 of the throttle valve 1 in a form that continues from the throttle valve of the original intake passage 3 toward the downstream side. The inner diameter enlarged portion 4 can also be formed by gradually increasing the diameter to the side and further reducing the diameter sharply on the downstream side.

Further, as shown in FIG. 6 (c), the diameter is increased sharply from the swing shaft 2 of the throttle valve 1 toward the downstream side, and further gradually reduced in diameter on the downstream side, so that the inner diameter enlarged portion 4 is formed. As shown in FIG. 6 (d), the diameter of the throttle valve 1 is rapidly increased from the swinging shaft 2 toward the downstream side, and the diameter thereof is gradually reduced in a curved line on the further downstream side. In this way, the inner diameter enlarged portion 4 can be formed.
These various forms can be appropriately selected in consideration of the ease of forming the inner diameter enlarged portion 4.

  In addition, as shown in FIG. 6 (a), an exhaust pipe 5 for removing moisture condensed in the intake passage 3 can be provided in the inner diameter enlarged portion 4.

FIG. 7 is a schematic diagram showing still another embodiment of the intake device for an internal combustion engine according to the present invention, as viewed in the direction of the arrow CC in FIG.
The shape of the inner diameter enlarged portion 4 as viewed in the direction of the arrow CC in FIG. 2 is, as shown in FIG. 7 (a), between the inner diameter enlarged portion 4 and the intake passage 3 as shown in FIG. Smoothly, the intake passage 3 and the inner diameter enlarged portion 4 can be formed seamlessly.

  Further, as shown in FIG. 7 (b), the bottom portion of the inner diameter enlarged portion 4 can be made smooth to form the bottom portion seamlessly. In addition, as shown in FIG. 7C, the shape of the joint between the bottom of the inner diameter enlarged portion 4 and the other portion can be smoothed, and the entire inner diameter enlarged portion 4 can be formed seamlessly.

  In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible. For example, in the above embodiment, the inner diameter enlarged portion 4 is provided in the intake passage 3 located on the downstream side of the peripheral edge portion 1a farthest from the swing shaft 2, but instead of this, the intake passages 3b and 3c (see FIG. 2) may be provided downstream of the peripheral edge.

  The intake device for an internal combustion engine according to the present invention is particularly suitable for use in a passenger car in which quietness is a problem, and effectively suppresses airflow noise to increase the quietness in the vehicle and enhance comfort. It can be done.

It is a schematic diagram which shows the principle of the intake device of the internal combustion engine which concerns on this invention. 1 is a schematic diagram showing an embodiment of an intake device for an internal combustion engine according to the present invention. It is a schematic diagram which shows the cross-section arrow of the CC direction of FIG. It is a schematic diagram which shows other embodiment of the intake device of the internal combustion engine which concerns on this invention. FIG. 6 is a schematic diagram showing still another embodiment of an intake device for an internal combustion engine according to the present invention. FIG. 6 is a schematic diagram showing still another embodiment of an intake device for an internal combustion engine according to the present invention. FIG. 6 is a schematic view showing still another embodiment of the intake device for an internal combustion engine according to the present invention as seen in the direction of the arrow C-C shown in FIG. 2. It is a schematic diagram which shows the air flow near the throttle valve of the intake device of a general internal combustion engine. It is a schematic diagram which shows the air flow near the throttle valve of the intake device of a general internal combustion engine.

Explanation of symbols

1 Throttle valve 2 Oscillating shaft 3 Intake passage 4 Inner diameter expansion part

Claims (5)

An intake passage through which air supplied to the internal combustion engine flows from the upstream side toward the downstream side;
A throttle valve rotatably provided in the intake passage via a swing shaft;
An intake device for an internal combustion engine comprising:
When the throttle valve is rotated to change the throttle valve from the closed state to the open state, an inner diameter enlarged portion is formed on the inner wall portion of the intake passage that faces the upstream portion of the peripheral portion of the throttle valve. Provided,
The intake device for an internal combustion engine, wherein the inner diameter enlarged portion is provided on the downstream side of a peripheral portion of the throttle valve when the throttle valve is closed.   The inner diameter of the intake passage is gradually increased over the entire circumference from the position where the throttle valve is provided toward the upstream side and the downstream side, and the inner diameter of the intake passage is directed toward the downstream side from the position where the throttle valve is provided. By gradually increasing the diameter expansion amount of the portion located on the downstream side of the peripheral portion on the side inclined to the upstream side from the swinging shaft of the throttle valve, by increasing the diameter expansion amount other than that portion. The intake device for an internal combustion engine according to claim 1, wherein an inner diameter enlarged portion is formed.   When the inner diameter of the intake passage is gradually enlarged from the position where the throttle valve is provided toward the downstream side, the portion of the portion located on the downstream side of the peripheral portion of the throttle valve tilting toward the downstream side is inclined. The intake device for an internal combustion engine according to claim 2, wherein the amount of diameter expansion is made smaller than the amount of diameter expansion other than that portion.   The inner diameter of the intake passage is gradually enlarged over the entire circumference from the position where the throttle valve is provided toward the upstream side and the downstream side, and the central axis of the intake passage is moved downstream from the position where the throttle valve is provided. 2. The intake device for an internal combustion engine according to claim 1, wherein the inner diameter enlarged portion is formed by being offset toward the peripheral portion on the side inclined to the upstream side from the swing shaft. .   The said inner diameter enlarged part is provided in the said downstream of the said inner wall part facing the peripheral part most spaced apart from the said rocking | fluctuation axis | shaft among the peripheral parts of the said throttle valve. Intake device for internal combustion engine.

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