JPS5910381Y2 - Resonant silencer - Google Patents

Description

[Detailed Description of the Invention] The present application relates to a resonant sounding device used in internal combustion engines and the like.

A resonant silencer consists of a box with a predetermined volume and an inner tube with small holes inserted inside the box, and is designed to absorb sound in a specific frequency band corresponding to the dimensions of the box. ing.

As shown in FIG. 1, in this type of conventional device, an inner tube 3 having a plurality of small holes 2 is inserted and fixed into a box body 1 having a chamber 4 of a predetermined capacity. It has a structure in which the chamber 4 and the chamber 4 are communicated with each other.

Incidentally, from the viewpoint of production or weight reduction measures, it is being considered to apply a molding method using a plastic material to the above-mentioned muffler.

However, the above structure, particularly the presence of the small hole 2 in the inner tube 3, makes it extremely difficult to mold the tube into an integral hollow mold made of plastic.

Therefore, the present application provides a first outer tube having a first inner tube and a second inner tube.
A second outer cylinder having an inner pipe is joined to form a hollow part inside, and the first and second inner pipes of the hollow part are made to face each other, and a gap is provided between them. The purpose of the present invention is to provide a resonance type muffler having a structure in which the inside of the pipe is communicated with a hollow part, and thereby it is possible to mold the muffler with a plastic material without reducing the muffling effect.

To describe an embodiment, FIG. 2 shows a resonance type muffler 10 of the present invention, which includes a first outer cylinder 11 made of plastic and a second outer cylinder 12 made of plastic.

The first and second outer tubes 11 and 12 have a symmetrical structure, and the first and second inner tubes 13. 14 integrally.

The first and second outer cylinders 13 and 14 have flange portions 15. 16 to form a cavity 17 with a predetermined volume V inside.

The end surfaces of the first and second inner tubes 13 and 14 of the cavity 17 face each other, and a predetermined gap d is formed between them.

The volume 1 of the cavity 17, the length of the gap d, etc. are set to predetermined values depending on the frequency band to be muted.

FIG. 3 shows another embodiment, which includes a first outer cylinder 21 and a second outer cylinder 22.

The first and second outer tubes 21 and 22 have first and second inner tubes 23, respectively.
, 24, which are joined at a joint 25 to form a cavity 26 inside.

The inner diameter of the second inner tube 24 is larger than that of the first inner tube 23, and the first inner tube 23 is inserted into the second inner tube 24 in the cavity 26, and the first inner tube 23 is inserted into the second inner tube 24. A gap d is formed between the outer wall of the second inner tube 23 and the inner wall of the second inner tube 24.

The resonance type muffler is used, for example, by being disposed in an intake system between an internal combustion engine and an air cleaner (both not shown).

Intake noise accompanying the introduction of intake air is absorbed while flowing through the silencer 10.

That is, the gap d in the resonance type muffler 10 corresponds to the small hole in the conventional muffler, and provides a predetermined sound muffling effect.

First and second inner tubes 13, 23, 14 without small holes.
24 allows the first and second outer cylinders 11, 12, 21, 22 to be integrally made of plastic material.

As described above, the resonance type muffler of the present invention has the first and second inner tubes separated and a gap is provided between them, so it is possible to maintain the silencing function by using plastic material. An integral mold is possible, which reduces weight and streamlines production.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional muffler, FIG. 2 is a sectional view of a resonance type muffler according to the present invention, and FIG. 3 is a sectional view of another embodiment. 11, 21...First outer cylinder, 12, 22...
...Second outer tube, 13,23...First inner tube,
14, 24... second inner tube, 17. 26...
...Cavity, d...Gap.

Claims (1)

[Scope of utility model registration request] A first outer tube made of plastic having a first inner tube and a second outer tube made of plastic having a second inner tube are joined together to form a cavity inside, and the first and second inner tubes in the cavity face each other. and a gap is provided between these inner tubes, and the inside of the first and second inner tubes are communicated with the cavity through the gap.