JPS5928126Y2 - Resonant silencer - Google Patents

Description

[Detailed Description of the Invention] The present application relates to a resonance type muffler provided in an intake system of an internal combustion engine.

A resonant silencer consists of a tube with small holes and a box that forms a chamber of a predetermined volume, and produces a silencing effect by resonating and absorbing sound in a specific frequency band depending on the dimensions of the tube. be.

In such a muffler, the cross-sectional area of the tube may be made small in order to achieve a good muffling effect, but this results in a layer of resistance to fluid ventilation.

Therefore, the present application provides a resonant silencer consisting of a pipe with an opening and a box with a predetermined capacity, in which a constriction part is provided in a part of the pipe, and the apertures are drilled only in the constriction part, and the apertures are The purpose of the present invention is to provide a resonance type muffler that communicates with the inside of the box body, thereby improving the muffling effect in a specific frequency range with an extremely simple structure without significantly increasing ventilation resistance.

To describe an embodiment, FIG. 1 shows a resonance type muffler according to the present invention and an intake system equipped with the same, in which a resonance type muffler 3 is provided between an internal combustion engine 1 and an air cleaner 2.

The resonance type muffler 3 includes a box body 4 and an inner tube 5 having a predetermined volume.

The inner tube 5 passes through the box body 4 and has a constricted portion 6 within the box body 4, and a plurality of small holes 7 are bored on the same circumferential surface only in the constricted portion.

The muffler 3 has a unique resonance frequency determined by the area of the small hole 7, the volume of the box 4, etc.

FIG. 2 shows another embodiment of the present invention, in which, like FIG. 1, a resonant muffler 11 is provided between the internal combustion engine 1 and the air cleaner 2.

The muffler 11 includes a constricted portion 12 of a pipe 13 provided with a constricted portion 12.
A box body 14 having a predetermined capacity is disposed through a connecting pipe 15 in an opening 16 provided in the main body.

The opening 16 corresponds to the small hole 7 in FIG.

Intake air is supplied to the internal combustion engine 1 via an air cleaner 2 and a resonance muffler 3.11.

The intake noise generated at this time in a specific frequency band is muffled by the mufflers 3 and 11.

The constricted portions 6 and 12 provided in the inner tube 5 and tube 13 of the resonance type muffler 3 and 11 have small cross-sectional areas, increasing the silencing effect.

That is, the amount of sound pressure attenuation increases as the cross-sectional area of the tube decreases.

On the other hand, the diameter of the tube other than the constricted portions 6 and 12 is narrow, so that the ventilation resistance does not increase significantly.

To explain the effect of the silencer of the present invention using diagrams, Figure 3 shows the relationship between the pipe diameter and the sound pressure level. The sound pressure level is different between case B and case B, which indicates that case B, that is, the case of the present invention, is extremely good.

FIG. 4 shows the relationship between the pipe diameter and the ventilation resistance, and it can be seen that in the case of the present invention B, the ventilation resistance does not increase significantly even if the constricted portion is provided.

When the diameter is narrowed uniformly, the ventilation resistance increases significantly in case A.

As described above, the resonance type muffler of the present invention has a constriction part in a part of the pipe constituting the muffler, and an opening is provided to concentrate only on the constriction part, so that the sound in a specific frequency range can be suppressed. It is possible to effectively reduce the airflow resistance and to minimize the increase in ventilation resistance due to a reduction in cross-sectional area.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an intake system having a silencer of the present invention;
The figure is a sectional view showing another embodiment, FIG. 3 is a graph showing the pipe diameter and sound pressure level, and FIG. 4 is a graph showing the relationship between the pipe diameter and ventilation resistance. 3.11...Resonant silencer, 6...Aperture section, 4...Box body, 7...Small hole, 5.
...Inner tube.

Claims (1)

[Scope of utility model registration request] In a resonant silencer consisting of a pipe with an opening and a box with a predetermined capacity, a constriction part is provided in a part of the pipe, and the openings are concentrated only on the same circumferential surface of the constriction part, and the A resonant silencer with an opening that communicates with the inside of the box.