Air intake duct for motor vehicle

Abstract

The problem to be solved is to suppress airflow noise generated when air flows through a discharge hole of a resonator. To this end, the invention discloses an air intake duct for a motor vehicle with a resonator, in which the resonator has an outer wall enclosing an interior space, on the bottom surface of which is provided at least one discharge hole formed as a through-passage penetrating the outer wall, and the length of the through channel is extended by providing a thickened portion at least on the periphery of the discharge hole.

Description

Technical Field

[0001] This invention relates to an air intake pipe for motor vehicles. Background Technology

[0002] For the engine of a motor vehicle to operate, the intake manifold needs to supply outside air to the engine. When air flows through the intake manifold, intake noise may be generated due to inherent vibrations. This intake noise can cause discomfort to the vehicle driver; therefore, resonators have traditionally been installed in the intake manifold to reduce intake noise. Because the installation location and shape of the resonator may allow water to accumulate inside, the resonator is usually provided with an exhaust port (see, for example, Patent Documents 1 to 5). However, the air passing through this exhaust port generates airflow noise in the intake manifold at a certain airflow velocity. With the increasing demand for low noise in motor vehicles, it is necessary to suppress this airflow noise.

[0003] Traditionally, known methods for suppressing airflow noise generated by exhaust orifices involve adding tuning holes, protrusions, or slab shapes, or combinations thereof, to the resonator. However, these methods require significant modifications to the intake duct path and the internal shape of the resonator.

[0004] Related technical documents

[0005] [Patent Literature]

[0006] Patent Document 1: Japanese Utility Model Unexamined Publication H2-1460

[0007] Patent Document 2: Japanese Patent Unexamined Application 2000-240520

[0008] Patent Document 3: Japanese Patent Application 2010-144560 (Unexamined)

[0009] Patent Document 4: Japanese Patent Application 2014-118920 (Unexamined)

[0010] Patent Document 5: Japanese Patent Application 2022-144027 (Unexamined) Summary of the Invention

[0011] The purpose of this invention is to provide an intake duct that can easily suppress airflow noise generated by airflow through the exhaust port of a resonator.

[0012] Problem-solving methods

[0013] In one embodiment of the invention, this objective is achieved by an intake duct, wherein the resonator has an outer wall enclosing an internal space, and at least one exhaust hole is provided on the bottom surface of the outer wall as a through channel penetrating the outer wall, and the length of the through channel is extended by providing a thickened portion at least around the exhaust hole.

[0014] Therefore, exhaust vents can be installed where necessary, and airflow noise can be suppressed without being limited by the flow path of the intake duct or the internal shape of the resonator. Furthermore, the effect of suppressing airflow noise can be achieved simply by installing exhaust vents with extended through-channel lengths, without requiring significant modifications to the intake duct path or the internal shape of the resonator.

[0015] Preferably, the through passage has a radius at the entrance.

[0016] Preferably, the length of the through channel is twice the thickness of the outer wall. Attached Figure Description

[0017] Figure 1 This is a bottom view of the air intake pipe used in motor vehicles;

[0018] Figures 2(A) and 2(B) are cross-sectional views of the resonator; and

[0019] Figure 3 It is a graph depicting the effect of the resonator in suppressing airflow noise. Detailed Implementation

[0020] Next, various embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the drawings are schematic in the following description, and the dimensional relationships and proportions between elements may differ from actual conditions. The drawings may also include components with different dimensional relationships and proportions.

[0021] Figure 1 This is a bottom view of the air intake duct 10 for a motor vehicle. The arrows indicate the flow of outside air. Outside air introduced from outside the vehicle passes through the air intake duct 10 and is supplied to an air filter (not shown) for filtration. The filtered outside air is then guided downstream to the engine. Multiple resonators 20, 20', and 20" are provided on the bottom surface of the air intake duct 10 to suppress intake noise. The resonators 20, 20', and 20" function to suppress airflow noise generated by natural vibrations, etc., when outside air flows through the air intake duct 10. Figure 1 In the middle, resonators 20 and 20' each have a discharge hole 24, but resonator 20" does not have a discharge hole.

[0022] Figure 2 is a schematic cross-sectional view of the resonator 20 according to this embodiment. The resonator 20 has an outer wall 22 enclosing an internal space. At least one discharge hole 24 is provided on the bottom surface of the outer wall 22 to prevent the accumulation of water, etc. The discharge hole 24 can have any shape, but is preferably circular. The discharge hole 24 is formed as a through channel 26 penetrating the outer wall 22, and the length of the through channel 26 is extended by providing a thickened portion at least around its periphery. The thickened portion can be integrally formed with the outer wall, or it can be formed by post-processing by attaching the components surrounding the discharge hole 24 to the resonator with an adhesive or the like. The extended through channel 26 has the effect of suppressing airflow noise generated when air is drawn into the resonator 20 through the discharge hole 24.

[0023] The entrance to the through-channel 26 can be left un-chamfered as shown in Figure 2(A), or it can be chamfered with an R-shape as shown in Figure 2(B). Tests conducted by the inventors have shown that the through-channel 26 exhibits the same effect in suppressing airflow noise regardless of its shape.

[0024] Preferably, the length of the through channel 26 is twice the thickness of the outer wall 22. However, depending on factors such as the frequency of the airflow sound, the length of the through channel 26 can be set to be greater than or less than twice the thickness of the outer wall 22.

[0025] Figure 3 This is a graph depicting the effect of the resonator 20 according to this embodiment on suppressing airflow noise. The graph shows the spectrum of the airflow sound generated by one of the resonators 20 shown in Figure 2, where the horizontal axis represents frequency (Hz) and the vertical axis represents sound pressure (dB). Curve G1 in the graph corresponds to the airflow noise generated by a resonator with a common water drain hole, curve G2 corresponds to the airflow noise generated by a resonator with a water drain hole extending according to this embodiment, and curve G3 corresponds to the airflow noise generated by a resonator with the water drain hole completely blocked. The sound pressure value of curve G2 is significantly suppressed relative to the sound pressure value of curve G1 across almost the entire frequency range shown in the figure. It can also be seen that the sound pressure value of curve G2 is not significantly different from the sound pressure value of curve G3 when the drain hole is blocked in many frequency ranges. In this way, by forming the drain hole 24 of the resonator 20 as an extended through-channel 26, airflow noise can be significantly suppressed.

[0026] The extended through-hole in the resonator according to this embodiment can be used in combination with known tuning holes, protrusions, or baffle shapes that are also provided in the resonator.

[0027] In this embodiment, resonators 20 and 20' have a water drain hole 24 at each end in the flow direction of the intake duct 10. Thus, by separating the water drain hole 24 as far as possible from the neck of the resonators 20 and 20' (i.e., the flow path side of the intake duct), air flow through the water drain hole 24 through the resonators 20 and 20' is suppressed, thereby minimizing the occurrence of resonance noise caused by the water drain hole 24. It should be noted that only one hole is provided to suppress any reduction in resonator performance due to the presence of this hole.

[0028] In this embodiment, the discharge port 24 of the resonator 20 is provided with a thickened portion, but the discharge port 24 of the resonator 20' is not provided with a thickened portion. This is because actual measurements have confirmed that the resonator 20' is not affected by the resonance noise caused by the discharge port 24. Attached Figure Description

[0030] 10. Air intake pipe

[0031] 20, 20', 20” resonators

[0032] 22. Outer wall

[0033] 24. Drain port

[0034] 26. Through passage

Claims

1. An intake duct with a resonator for a motor vehicle, wherein, The resonator has an outer wall that encloses the internal space. At least one discharge hole is provided on the bottom surface of the outer wall, which is formed as a through channel penetrating the outer wall. The length of the through channel is extended by providing a thickened portion at least around the discharge hole.

2. The air intake pipe according to claim 1, wherein, The through passage has a radius R at its entrance.

3. The air intake pipe according to claim 1 or 2, wherein, The length of the through channel is twice the thickness of the outer wall.

4. The air intake pipe according to claim 1, wherein, Multiple resonators are provided on one side of the air intake pipe, and each resonator with a water drain hole has a water drain hole at one end.

5. The intake pipe according to claim 1 or 4, wherein, The thickened portion is only installed on the resonator that generates a large resonance sound due to the water discharge hole.

Images