JPS6023502Y2 - intake resonator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake resonator in which a resonance chamber is communicated with an intake path in order to control intake noise.

As is well known, this type of intake resonator absorbs intake noise by resonance, so the amount of noise that can be suppressed is limited to a very narrow range determined by the resonance frequency of the resonator. While the noise suppression effect is remarkable, in the frequency range outside the resonant frequency, the resonator may have an adverse effect and slightly increase the noise level.

In view of these problems, an object of the present invention is to suppress an increase in the noise level in a frequency range outside the resonance frequency of the resonator.

Therefore, the present invention is characterized in that the resonance chamber of the resonator is communicated with the air cleaner interior space through a small hole.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In this embodiment, an air cleaner and a resonator are integrated.

The resonator built-in air cleaner 50 shown in FIG. 1 is composed of an air cleaner 20 and a resonator 30.

The air cleaner 20 includes a box-shaped casing 5 with one side (left side in FIG. 1) open, and a cylindrical element 8 housed within the casing 5.

Cylindrical bodies are fitted and fixed to the side walls 1 and 2 of the casing 5, forming an air inflow pipe 3 and an air outflow pipe 4, respectively.

The element 8 has one end (the right end in FIG. 1) supported by the air outflow pipe 4, and the other end supported by a protrusion 16 of the cover plate 15 of the resonator 30, which will be described later. It is room 13.

On the other hand, in the resonator 30, a resonance box 33 is constituted by a box-shaped casing 31 that is open on one side (the right side in FIG. 1) and a cover plate 15 fixed to this opening. This serves as a resonance chamber 35.

The resonator 30 is integrated with the air cleaner 20 by fitting the enlarged diameter portion 32 formed at the opening of the casing 31 into the flange portion 9 formed at the opening of the casing 5 and fixing it with a fastener (not shown). ing.

In this state, the gaskets 28, 29 and 42 keep the air cleaner 20 and the element 8 airtight, and at the same time prevent the element 8 from moving.

The resonance chamber 35 includes a cylindrical member 37 fixed to a side wall 36, a duct 38, and a cylindrical member 11 fixed to the air inflow pipe 3.
It is connected to the air inflow pipe 3 by.

In this embodiment, after the air flowing into the cleaner chamber 13 from the inflow pipe 3 is cleaned by the element 8,
Air is drawn into the engine from the outflow pipe 4 via a carburetor etc. At this time, air (intake air) pulsates in the intake path including the air cleaner 20, causing intake noise.

The frequency of intake noise changes depending on the engine rotation speed, etc., but certain frequency ranges that are especially annoying are known from experience.

According to the resonator built-in air cleaner shown here,
Sound in this specific frequency range can be resonantly absorbed.

FIG. 2 is a graph in which the sound pressure level of intake noise is measured for each frequency. A shows the case where no intake resonator is provided, and B shows the case where an intake resonator is provided.

As is clear from comparing A and B, the sound pressure level is significantly reduced near 90Hz, which is the resonance frequency of the resonator, but in the frequency range outside the resonance frequency, especially around 50Hz, On the contrary, the sound pressure level has increased.

Therefore, in the present invention, a small hole 17 is formed in a part of the cover plate 15, and the resonance chamber 35 is connected to the air cleaner 20 through the small hole 17.
It communicates with a space 14 on the upstream side of the air cleaner element 8.

The size and number of the small holes 17 are determined by the resonance chamber 35 of the resonator 30.
In the case of the embodiment shown in FIG. 1, the resonator 3
The capacity of the resonance chamber 35 of 0 is 2 and the resonance frequency of 1 is 90H2%.
The capacity of the air cleaner 20 is 5, and there is one small hole 17 with a diameter of 3 to 5 mm.

In this way, the resonance chamber 35 is connected to the space 1 upstream of the air cleaner element 8 of the air cleaner 20 through the small hole 17.
The sound pressure level measured by communicating with 4 is shown as C in FIG.

Looking at this, it can be seen that the sound pressure level near the resonant frequency of 90 Hz of the resonator 30 remains suppressed to a low level, but the sound pressure level in the vicinity of the resonant frequency of 90 Hz remains low, and the sound pressure level in the frequency range outside the resonant frequency, especially 50 Hz and 100 Hz
The sound pressure level in the vicinity could be kept lower than the level in B.

In the embodiments described above, the resonator and the air cleaner are integrated, but the present invention is not limited to this.

For example, a resonator is installed separately from the air cleaner, and a pipe is connected to a small hole drilled in the resonance chamber of the resonator, and the resonance chamber of the resonator is connected to the upstream side of the air cleaner element in the air cleaner through this pipe. It may also be connected to a space on the side.

As described above, the present invention enables resonance by communicating the resonance chamber of the resonator with the space upstream of the air cleaner element in the air cleaner, which is an expansion chamber, through a small hole smaller than the passage cross-sectional area of the duct. It is possible to suppress an increase in the noise level in a frequency range outside the resonance frequency without affecting the noise suppression function near the frequency.

Furthermore, even if outside air containing foreign matter such as dust flows into the linear cleaner through the small hole due to a malfunction such as the duct coming off or coming loose, the small hole is located upstream of the element, so the element can clean it. As a result, there is no risk of problems such as deterioration of engine performance due to contamination of foreign matter, and the reliability of the air cleaner is also improved.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention, and FIG. 2 is a graph showing the effects of the embodiment of FIG. 14... Space inside the air cleaner, 17...
・Small hole, 20...Stile aculina, 30...
・Resonator, 35...Resonance chamber, 38...
...Duct (connecting pipe).

Claims (1)

[Scope of utility model registration request] In the air inlet pipe of the air cleaner for engine intake air purification,
In an intake resonator in which a resonance chamber is communicated through a connecting pipe, the resonance chamber is communicated with a space upstream of the air cleaner element in the air cleaner through a small hole smaller than the cross-sectional area of the connecting pipe passage. Features an intake resonator.