JPH0248694Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intake device for an internal combustion engine (hereinafter also referred to as an engine) for controlling the intake air amount of an internal combustion engine (hereinafter also referred to as an engine) in an automobile or the like.

[Background Art] Conventionally, an engine intake device has a function of correcting the intake air amount to the engine, such as a low temperature start correction air amount control device, an idle rotation air amount control device, etc. For this reason, the intake passage is formed with a bypass passage that sucks intake air from an inlet on the upstream side wall of the throttle valve, bypasses the throttle valve, and causes it to flow out from an outlet on the downstream side wall. Note that such a configuration is, for example,
It is disclosed in Publication No. 161037.

[Problems to be Solved by the Invention] However, in the conventional device, the outlet surface of the bypass passage is flush with the wall surface of the intake passage. Therefore, as the throttle valve is opened and the amount of intake air increases, the wall flow of the intake air blows the exit of the bypass passage like a whistle, producing a whistling sound. Since the whistling sound has a high frequency, it causes discomfort to passengers in automobiles and the like.

An object of the present invention is to provide an intake system for an internal combustion engine that can prevent or reduce whistling noise generated at the exit of the bypass passage.

[Means for Solving the Problems] An intake system for an internal combustion engine according to the present invention that solves the above problems includes: a throttle body having an intake passage leading to the internal combustion engine; a throttle valve controlling the amount of intake air flowing through the intake passage; An intake system for an internal combustion engine, comprising: a bypass passage provided in the throttle body and having an inlet communicating with the intake passage on the upstream side of the throttle valve and an outlet communicating with the intake passage on the downstream side of the throttle valve. The outlet surface of the bypass passage is opened substantially parallel to the wall surface of the intake passage, and a protrusion is formed on the wall surface of the intake passage to interrupt the wall flow of intake air on the upstream side of the outlet of the bypass passage. It is.

[Function] According to the above means, the wall flow of intake air is blocked by the protrusion formed on the wall of the intake passage on the upstream side of the outlet of the bypass passage.

Further, since the outlet surface of the bypass passage is opened substantially parallel to the wall surface of the intake passage, backflow caused by engine blowback is difficult to enter the bypass passage.

[Embodiments] [First Embodiment] A first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, which shows a sectional view of an intake system for an internal combustion engine, a throttle body 1 has an intake passage 2 leading to the internal combustion engine. A shaft 3a of a throttle valve 3 that opens and closes an intake passage 2 is rotatably supported by the throttle body 1. The throttle valve 3 rotates to open and close the intake passage 2.
Controls the amount of intake air flowing through.

A bypass passage 4 that bypasses the throttle valve 3 is formed in the throttle body 1 . The bypass passage 4 has an inlet 4a that communicates with the intake passage 2 on the upstream side of the throttle valve 3, and an outlet 4b that communicates with the intake passage 2 on the downstream side of the throttle valve 3.

An adjuster screw 5 for changing the opening cross-sectional area of the bypass passage 4 is screwed onto the throttle body 1. Asiast Skrill 5
The amount of bypass air, that is, the amount of engine idle air is controlled by the adjustment by screwing forward and backward.

Thus, a protrusion 6 that forms the outlet 4b of the bypass passage 4 is formed on the wall surface 1a of the intake passage 2 of the throttle body 1. Projection part 6
The outlet 4b surface is opened substantially parallel to the wall surface 1a of the intake passage 2. Further, the upper half portion of the protrusion 6 serves to block the wall flow of intake air on the upstream side of the outlet 4b.

In the intake system for the internal combustion engine described above, when the throttle valve 3 is opened, intake air flows through the intake passage 2 from the top to the bottom in the drawing. Of the wall flow flowing along the wall surface 1a of the intake air, the wall flow passing near the outlet 4b of the bypass passage 4 is blocked by the upper half of the protrusion 6. Therefore, the occurrence of whistling noise caused by the wall flow blowing through the outlet 4b like a whistle is prevented or reduced.

Furthermore, since the outlet 4b surface of the bypass passage 4 is opened substantially parallel to the wall surface 1a of the intake passage 2, backflow due to engine blowback is difficult to enter the bypass passage. Therefore, problems such as a decrease in the amount of bypass air caused by carbon, oil mist, etc. contained in the backflow adhering to the wall surface of the bypass passage are improved.

Further, according to this example, out of the wall flow of the reverse flow due to engine blowback, the exit 4b of the bypass passage 4
The wall flow passing nearby is blocked by the lower half of the protrusion 6. Therefore, carbon, oil mist, etc. contained in the backflow are allowed to adhere to the side surface of the lower half of the protrusion 6, which is also advantageous in reducing intrusion of carbon, oil mist, etc. into the bypass passage 4.

[Second Embodiment] A second embodiment of the present invention will be described with reference to the drawings. Since this example is a partial modification of the first example, the same portions will be given the same reference numerals and the description thereof will be omitted, and only the different configurations will be described in detail.

FIG. 2 shows a plan view of an intake system of an internal combustion engine;
In FIG. 3 showing the cross-sectional view, the outlet 4b surface of the bypass passage 4 of this example is the wall surface 1 of the intake passage 2.
a, and is open flush with the wall surface 1a. The openings that are flush with the wall surface 1a also include openings that are substantially parallel in the present invention.

Further, a protrusion 7 is formed on the wall surface 1a of the intake passage 2 of the throttle body 1, and is located upstream of the outlet 4b. Note that this protrusion 7 is also located upstream of the end of the throttle valve 3. Further, in the figure, an outlet 4b is opened at the lower end surface of the throttle body 1, but the lower end surface of the outlet 4b is closed by the end surface of an engine or the like connected to the throttle body 1, although not shown in the drawings, as is well known.

This example also provides the same effects as the first example.

[Effects of the invention] According to the invention, the wall flow of intake air can be blocked by the protrusion formed on the wall of the intake passage, and the occurrence of whistling noise due to the wall flow is prevented or reduced.

In addition, since the outlet surface of the bypass passage is opened almost parallel to the wall surface of the intake passage, backflow caused by engine blowback is difficult to enter the bypass passage, and carbon, oil mist, etc. contained in the backflow enter the bypass passage. Problems such as a decrease in bypass air volume due to accumulation are improved. To explain this in detail, for example, as in JP-A-55-156240, an air pipe is connected to the outlet of the bypass passage and the tip of the air pipe is directed downstream at approximately the center of the intake passage. The backflow caused by engine blowback easily enters the bypass passage, and carbon, oil mist, etc. in the backflow adhere to the walls of the bypass passage, reducing the amount of bypass air. Problems like this will be improved.

Therefore, the present invention can effectively prevent or reduce the occurrence of whistling noise without causing problems such as a decrease in the amount of bypass air.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an intake system for an internal combustion engine showing a first embodiment of the present invention. 2 and 3 show a second embodiment of the present invention, in which FIG. 2 is a plan view of an intake system for an internal combustion engine, and FIG. 3 is a sectional view thereof. 1...Throttle body, 1a...Wall surface, 2...
...Intake passage, 3... Throttle valve, 4... Bypass passage, 4a... Inlet, 4b... Outlet, 6, 7...
...protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] A throttle body having an intake passage leading to an internal combustion engine, a throttle valve for controlling the amount of intake air flowing through the intake passage, and a throttle body provided in the throttle body and connected to the intake passage on the upstream side of the throttle valve. An intake system for an internal combustion engine, comprising: a bypass passage having a communicating inlet and an outlet communicating with the intake passage on the downstream side of a throttle valve, wherein an outlet surface of the bypass passage is substantially flush with a wall surface of the intake passage. An intake system for an internal combustion engine, characterized in that the intake passage has a protrusion that is opened in parallel and has a protrusion formed on the wall of the intake passage to interrupt the wall flow of intake air on the upstream side of the outlet of the bypass passage.