This is a national stage application filed under 35 U.S.C. § 371 of pending international application PCT/JP2018/005009 filed Feb. 14, 2018, which claims priority to Japanese Patent application JP 2017-026636, filed Feb. 16, 2017, the entirety of which applications are hereby incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a sound absorbing body that includes a structure for absorbing sound and to a sound absorbing structure.

BACKGROUND ART

As an example of the sound absorbing body, devices for reducing noise generated by a vehicle engine have been known (for example, refer to Patent Document 1). This kind of a sound absorbing body includes, for example, a sound absorbing material including non-woven fabric and cup-shaped cells, which are two-dimensionally arranged on a thin plate-like reflector. One of the openings of each cup-shaped cell is joined to a surface of the sound absorbing material, and the other one of the openings of the cup-shaped cell is joined to a surface of a plate member. The sound absorbing material is located to face the source of sound, so that the sound absorbing body absorbs the noise generated by the source of sound by the cooperation of the sound absorbing material and the cup-shaped cells.

PRIOR ART DOCUMENT

Patent Document

Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-31241

SUMMARY OF THE INVENTION

Problems that the Invention is to Solve

The frequency band of the sound that the sound absorbing body can absorb is determined to either a high-frequency band or a low-frequency band in accordance with the mass per unit area and the thickness of the sound absorbing material and the height and the opening size of the cup-shaped cells. Since the frequency band required to be absorbed by the sound absorbing body may range between both the high-frequency band and the low-frequency band, it is desirable to broaden the frequency band of the sound that can be absorbed by the sound absorbing body.

Accordingly, it is an objective of the present disclosure to provide a sound absorbing body that is capable of absorbing sound in a broad frequency band and a sound absorbing structure.

Means for Solving the Problems

In accordance with one aspect of the present disclosure, a sound absorbing body is provided that includes a cup-shaped main body and porous sheet. The cup-shaped main body includes an opening portion and a bottom portion. The porous sheet covers the opening portion. The main body includes, between the opening portion and the bottom portion, at least one hole that is larger than pores of the porous sheet and extends through the main body.

In accordance with another aspect, a sound absorbing structure is provided that includes cup-shaped main bodies, porous sheets, and a wall portion. Each main body includes an opening portion and a bottom portion. The porous sheets respectively cover the opening portions. The wall portion faces the bottom portions and is shared among the bottom portions. The main bodies each include, between the opening portion and the bottom portion, at least one hole that is larger than pores of the porous sheets and extends through the main body.

