JP7284597B2 - resonator - Google Patents

Description

The present invention relates to a resonator mountable in a chamber or duct communicating with a noise source.

A resonator attachable to a chamber or duct communicating with a noise source such as an air conditioner is used to reduce sound transmitted from the noise source through the chamber or duct.

The resonator is branch-connected to the chamber or duct, and is configured to reduce an acoustic power level corresponding to the difference between the acoustic power level Lwi on the upstream side and the acoustic power level Lwo on the downstream side of the branch position. there is

This reduced acoustic power level, that is, the transmission loss TL of the resonator, becomes maximum at the resonance frequency determined according to the shape of the resonator, and gradually decreases on the low frequency side and the high frequency side from the resonance frequency. When the resonance frequency of the object changes, there are cases where a satisfactory silencing effect cannot be obtained.

In order to change the resonance frequency according to the change in the frequency to be silenced, Patent Document 1 discloses that a plurality of resonance chambers branched and connected to a duct are provided, and these resonance chambers are communicated with each other by a communicating pipe. In addition, a technique has been proposed for opening and closing an on-off valve provided in the communicating pipe in accordance with a change in the resonance frequency of an object to be silenced.

However, such a configuration for controlling the opening and closing of the on-off valve is complicated and expensive.

JP-A-60-22021

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resonator capable of easily changing the resonance frequency according to the frequency to be silenced.

The characteristic configuration of the resonator according to the present invention for achieving the above object is a cylindrical first resonance portion, and the first resonance portion along the direction of the cylinder axis of the first resonance portion. A cylindrical second resonance section arranged side by side and partitioned from the first resonance section by a partition wall, a chamber communicating with a noise generation source or a duct communicating with the noise generation source , and the first resonance. a first communicating pipe portion that communicates with the cylindrical side surface of the portion; and a second communicating pipe portion that communicates with the chamber or the duct and the cylindrical side surface of the second resonance portion. In the resonator , the length of the first communicating pipe portion and the length of the second communicating pipe portion are configured to be variable , and the length of the first communicating pipe portion and the length of the second communicating pipe portion are set to be greater than the central position of the first resonance portion in the axial direction of the cylinder. At a position near the partition wall, the first resonance portion communicates with the first communicating pipe portion, and at a position closer to the partition wall than the central position of the second resonance portion in the axial direction of the cylinder, the The point is that the second resonance portion communicates with the second communicating pipe portion .

Side view of a chamber fitted with a resonator according to the invention Front view of a chamber fitted with a resonator according to the present invention Side view of a resonator according to the present invention Front view of a resonator according to the present invention Explanatory diagram showing changes in relative sound pressure when the length of the communicating pipe is varied Side view of a resonator according to another embodiment Front view of a resonator according to another embodiment Explanatory diagram showing changes in transmission loss when the length of the communicating tube is changed Side view of a resonator according to another embodiment Front view of a resonator according to another embodiment Explanatory diagram showing changes in transmission loss when the length of the communicating tube is changed

An embodiment of a resonator according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a resonator 10 is attached to a chamber 2 that communicates with an air outlet of an air conditioner 1, which is a source of noise, in order to reduce the sound transmitted from the air conditioner 1. It is

[Example 1]
As shown in FIGS. 3 and 4, the resonator 10 includes a main body portion 20 having a cylindrical resonance chamber and a communication tube portion 30 communicating the main body portion 20 with the chamber 2 .

The body portion 20 is configured by closing both open ends of a hard PVC pipe (VU450) having a length of 940 mm by adhering a hard PVC plate having a thickness of 15 mm. The space constitutes a cylindrical resonance chamber 21 .

In this embodiment, the main body 20 is provided with one partition wall 20a which partitions the resonance chamber 21 into two cylindrical resonance portions 21a and 21b arranged in the axial direction. The partition wall 20a is provided at the center in the longitudinal direction, that is, at a position 470 mm from one end in the longitudinal direction. The partition wall 20a is also made of a rigid PVC plate having a thickness of 15 mm, and is fixed to the inner surface of the main body 20 by an adhesive, welding, or the like.

The communicating pipe portion 30 includes a one end side pipe portion 31 that communicates with the cylindrical side surface of the resonance chamber 21 and a second end side pipe portion 32 that can communicate with the chamber 2 .

In the present embodiment, the resonance chamber 21 is partitioned into two resonance portions 21a and 21b. are provided. The communicating pipe portions 30a and 30b are not provided at the center position along the axis of the cylinder on the side surfaces of the cylinders of the resonance portions 21a and 21b, but at positions close to the partition wall 20a. Specifically, it is provided at a position where the interval between the axial centers of the communicating pipe portions 30a and 30b is 100 mm.

Since the communicating pipe portions 30a and 30b have the same configuration, they will simply be referred to as the communicating pipe portion 30 unless it is necessary to distinguish between them in the following description. The same applies to each part constituting the communicating tube part 30 .

The one-end tube portion 31 is composed of a rigid PVC socket (VU100), and is inserted into the opening provided on the circumferential side surface of the body portion 20 so that the amount of protrusion from the surface of the body portion 20 is 50 mm. It is fixed by adhesive, welding, or the like.

An opening 3 having a counterbore is provided in the top surface of the chamber 2 , and the tip side of the one end side pipe portion 31 can be inserted into and removed from the opening 3 and inserted in a manner perpendicular to the airflow direction in the chamber 2 . ing. The depth of the counterbore is the insertion depth of the one end side pipe portion 31 into the top surface of the chamber 2 . The chamber 2 is partitioned into a plurality of (five in this embodiment) portions by a plurality of (four in this embodiment) partition plates so as to form a plane wave sound field at the resonance frequency of the resonator 10. A resonator 10 is provided for each partitioned portion.

The other-end-side pipe portion 32 is composed of a rigid PVC pipe (VU100) of a size that can be inserted into the one-end-side pipe portion 31, and when one end is inserted into the one-end-side pipe portion 31, , the other end is located inside the chamber 2 .

The other end side pipe portion 32 is composed of a plurality of rigid PVC pipes having different lengths. By changing the hard PVC pipe inserted into the one end side pipe portion 31, the distance between the one end side and the other end side of the communicating pipe portion 30 can be changed, and the resonance frequency of the resonator 10 can be changed.

Specifically, as shown in FIG. 5, compared to the case where the resonator 10 is not attached to the chamber 2 (see the solid line), the communicating tube portion 30 is inserted into the one end tube portion 31 at the other end tube portion 32. When the resonators 10 with different lengths are attached to the chamber 2 (see dashed line and one-dot chain line), the frequencies at which the relative sound pressure drops are different. It was confirmed that the muffled frequency changes according to the distance from the Note that the shorter the distance between the one end side and the other end side of the communicating tube portion 30, the higher the resonance frequency.

[Example 2]
As shown in FIGS. 6 and 7, in the second embodiment, the main body 20 is a hard PVC pipe (VU200) having a length of 550 mm, and a hard PVC plate having a thickness of 10 mm is adhered to both open ends. Inside the main body 20, three partition walls 20a, 20b, and 20c are provided at positions 140 mm, 275, and 410 mm from one end in the longitudinal direction. The partition walls 20a, 20b, and 20c are also made of rigid PVC plates having a thickness of 10 mm, and are fixed to the inner surface of the main body 20 by an adhesive, welding, or the like. Therefore, in the resonator 10 according to the second embodiment, the resonance chamber 21 is partitioned into four resonance portions 21a, 21b, 21c and 21d by the three partition walls 20a, 20b and 20c.

The one end side pipe portion 31 constituting the communication pipe portion 30 of the resonator 10 according to the second embodiment is composed of a hard polyvinyl chloride socket (VU75), and the other end side pipe portion 32 can be inserted into the one end side pipe portion 31. It is constructed from rigid PVC pipe (VU75) of size. The distance between the axes of the communicating pipe portions 30 is 135 mm.

As shown in FIG. 8, three other-end-side tube portions 32 having different lengths are sequentially inserted into the one-end-side tube portion 31, and the transmission loss before and after passing through the resonator 10 is measured. Accordingly, three peaks were confirmed (see solid line, dashed line, and dashed line). That is, it was confirmed that the muffled frequency varied according to the distance between the one end side and the other end side of the communicating tube portion 30 . Note that the shorter the distance between the one end side and the other end side of the communicating tube portion 30, the higher the resonance frequency.

[Example 3]
As shown in FIGS. 9 and 10, in the third embodiment, the main body 20 is formed by bonding a rigid PVC pipe (VU150) having a length of 550 mm to both open ends and a rigid PVC plate having a thickness of 10 mm. Inside the main body 20, three partition walls 20a, 20b, and 20c are provided at positions 140 mm, 275, and 410 mm from one end in the longitudinal direction. The partition walls 20a, 20b, and 20c are also made of rigid PVC plates having a thickness of 10 mm, and are fixed to the inner surface of the main body 20 by an adhesive, welding, or the like. Therefore, in the resonator 10 according to the third embodiment, similarly to the second embodiment, the resonance chamber 21 is partitioned into four resonance portions 21a, 21b, 21c, and 21d by the three partition walls 20a, 20b, and 20c. there is

The one end side pipe portion 31 constituting the communication pipe portion 30 of the resonator 10 according to the third embodiment is composed of a hard polyvinyl chloride socket (VU75), and the other end side pipe portion 32 can be inserted into the one end side pipe portion 31. It is constructed from rigid PVC pipe (VU75) of size. The distance between the axes of the communicating pipe portions 30 is 135 mm.

As shown in FIG. 11, three other-end-side tube portions 32 having different lengths are sequentially inserted into the one-end-side tube portion 31, and the transmission loss before and after passing through the resonator 10 is measured. Accordingly, three peaks were confirmed (see solid line, dashed line, and dashed line). In other words, it was confirmed that the muffled frequency varied according to the distance between the one end side and the other end side of the communicating tube portion 30 . Note that the shorter the distance between the one end side and the other end side of the communicating tube portion 30, the higher the resonance frequency.

In the above-described embodiment, the communicating pipe section includes a plurality of rigid PVC pipes of different lengths, and the configuration in which the resonance frequency of the resonator is changed by changing the rigid PVC pipe inserted into the rigid PVC socket has been described. However, it is not limited to this.

For example, both the one end side tube part and the other end side tube part are configured telescopically using a rigid PVC pipe of a size that allows one to be inserted into the other, and the insertion depth of one to the other is changed. may change the resonance frequency of the resonator.

As described above, the resonator 10 is realized that can easily change the resonance frequency according to the frequency to be silenced. In any of the above-described embodiments, the resonance chamber is partitioned into a plurality of resonance portions by partition walls, but the number of partition walls is an example and may be omitted or may be two or more. good too. Moreover, the above dimensions are examples and are not limited to these.

Moreover, in the above-described embodiment, the configuration in which the resonator 10 is attached to the chamber 2 has been described, but the resonator 10 may be attached to a duct that communicates with the noise source.

All of the above-described embodiments are examples of the present invention, and the present invention is not limited by the description, and the specific configuration of each part can be appropriately changed and designed within the scope of the effects of the present invention. be.

1: Air conditioner (noise source)
2: Chamber 3: Opening 10: Resonator 20: Body 20a: Partition wall 20b: Partition wall 20c: Partition wall 21: Resonance chamber 21a: Resonance part 21b: Resonance part 21c: Resonance part 21d: Resonance part 30: Communicating pipe Part 31: One end side pipe part 32: Other end side pipe part

Claims (2)

a cylindrical first resonance portion;
a cylindrical second resonance portion arranged in parallel with the first resonance portion along the direction of the axis of the cylinder of the first resonance portion and partitioned from the first resonance portion by a partition wall;
a first communicating pipe portion communicating between a chamber communicating with a noise generating source or a duct communicating with the noise generating source and a cylindrical side surface of the first resonance portion;
A resonator comprising a second communicating pipe portion communicating between the chamber or the duct and the cylindrical side surface of the second resonance portion ,
The length of the first communicating pipe portion and the length of the second communicating pipe portion are configured to be variable ,
the first resonance portion communicates with the first communicating pipe portion at a position closer to the partition wall than the central position of the first resonance portion in the axial direction of the cylinder;
A resonance characterized in that the second resonance portion communicates with the second communicating pipe portion at a position closer to the partition wall than a central position of the second resonance portion in the axial direction of the cylinder. vessel. The first communicating pipe portion includes a first one end side pipe portion communicating with the first resonance portion , and a first one end side pipe portion communicating with the chamber or the duct and capable of being inserted into the first one end side pipe portion. and the other end side tube portion, and the length of inserting the first other end side tube portion into the first one end side tube portion is variable,
The second communicating pipe portion includes a second one end side pipe portion communicating with the second resonance portion, and a second one end side pipe portion communicating with the chamber or the duct and capable of being inserted into the second one end side pipe portion. 2. The length of inserting the second other end side tube portion into the second one end side tube portion is variable. resonator.

Images