JPS5812017Y2 - Kiyomeigatashiyouonki - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of a silencer constructed using a perforated plate in which a large number of small holes of the same diameter are provided at the same pitch.
By inserting a partition plate into the cavity inside the silencer,
This is an attempt to expand the silencing frequency band.

An example of a conventional silencer will be explained with reference to FIG. 5. Reference numerals 1 and 2 are an inner cylinder button and an outer cylinder that are composed of a perforated plate in which a large number of small holes 3 of the same diameter are provided at the same pitch. A ventilation passage 4 is provided inside the inner cylinder 1, and the space formed by the inner cylinder 1 and the outer cylinder 2 is a cavity 5 whose upper and lower surfaces are closed.

The resonant frequency of the silencer configured in this way, i.e.
The center frequency muted by the muffler is expressed by equation (1).

Here, C is the speed of sound, (2) is the volume of the space 5, and n is the number of small holes 3, a value determined by the perforated plate used in the GU.

Generally, equation (1) is expressed as v/n for one small hole 3.
There is a volume behind the pore, one pore and v
/ A collection of n single resonators consisting of a volume of n,
It is understood that it constitutes a silencer.

Therefore, the resonance type muffler configured as shown in FIG. 5 has one resonance frequency, and is a muffler having a narrow muffling frequency band.

On the other hand, the silencer of the present invention has a partition plate 6 that divides the inside of the cavity 5 into two, as shown in FIG. 1.2, for example.
It is inserted concentrically with the inner cylinder 1 and outer cylinder 2 to divide the cavity 5 into an A chamber and a B chamber.

Note that the volume of chamber A is VA, the volume of chamber B is VB, and vA=
The partition plate 6 is inserted so that vB.

Now, the outer diameter of the inner cylinder 1 is D□, the inner diameter of the outer cylinder 2 is D2, the total number of small holes provided on the surface of the inner cylinder 1 is nl, and the number of small holes provided on the surface of the outer cylinder is If the total number is n2, the small holes 3 are provided at the same pitch and button, and nl<n2 because D□×D2.

Therefore, the resonance frequency caused by the volume of the small hole on the cylinder surface and the volume of chamber B, and the volume of the small hole on the outer cylinder surface and the volume of chamber A, is calculated as fA.
, fB, the following equation is obtained.

Here, since there is a relationship vA=VB, nl x n2, f
Since A > fB, the silencer shown in Figure 1 has two resonance frequencies, and there are two silencing frequency bands with fA and fB as the center frequencies, and the silencing frequency band has been expanded. It turns out.

In addition, as shown in FIG. 3, a partition plate 6 having a conical bottom shape
' is inserted into the cavity 5, the silencing frequency range can be further expanded and a wideband resonance type muffler can be obtained.

As shown in FIG. 3, the partition plate 6' is formed into a conical shape and is inserted so as to divide the cavity 5 into two chambers, A chamber and B chamber, so that the volume of each chamber is equal.

In this way, the small hole 3 provided in the inner cylinder 1 button and the outer cylinder 2
If the nth stage, for example the third stage, is n3, the resonant frequency of a single resonator composed of n3 and the volume behind the small hole will be different because each volume is different. becomes.

On the other hand, for example, if the seventh stage small hole is n7, the resonance frequency formed by the volume behind the small hole will be different from the resonance frequency at n3.

In this way, the volumes behind the small holes in each stage are all different, so the muffler is considered to be a collection of single resonators with different resonance frequencies. You will have bandwidth.

Figure 4 shows a hot water boiler as an application example of the silencer of the present invention.

In the figure, 7 is a can having a combustion chamber 8 and a hot water storage section 9 inside, 10 is a burner, 11 is an exhaust port, and D is a muffler.

The exhaust gas generated in the combustion chamber 8 by the burner 10 is passed through the air passage 4 of the muffler, the outer cylinder of the muffler, and the inner wall 12 of the can body.
It is released to the outside through the gap between the

- While the noise inside the baking chamber 8 is propagated to the exhaust port along with the exhaust gas, it is muffled in a wide frequency range by the muffling action of the muffler, and the noise emitted to the outside from the exhaust port is significantly reduced.

As described above, the present invention provides a resonance type muffler that has a sound-dampening effect.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view showing one embodiment of the silencer of the present invention;
The figure is a cross-sectional view of the same, Figure 3 is a longitudinal cross-sectional view of another embodiment, and Figure 4 is a vertical cross-sectional view of another embodiment.
The figure is a longitudinal sectional view of a hot water boiler using a muffler, and FIG. 5 is a longitudinal sectional view of a conventional muffler. 1... Inner cylinder, 2... Outer cylinder, 3...
...Small hole, 4...Vent passage, 5...Cavity, 6,6'...Partition plate.

Claims (1)

[Scope of utility model registration request] An inner cylinder and an outer cylinder having a large number of small holes with the same diameter, an air passage formed in the inner cylinder, and a cavity formed between the inner and outer cylinders, and the cavity is divided into a plurality of parts. A resonance type muffler characterized by having a partition plate.