Open air layer-type vibration reduction structure
The open air layer-type vibration reduction structure is provided with at least one plate-like member of which the obverse surface faces toward the open space side; and a frame spaced at an interval from the reverse surface of the plate-like member, and an air layer is formed between the plate-like member and the frame. An air-permeable ventilation portion is formed at least one of the plate-like member and the frame, such that the average value of the flow resistance on the surface of at least one of the plate-like member and the frame, which forms an air layer, is in a range greater than 0 N·s/m 3 and equal to or less than 1,000 N·s/m 3 . The ventilation portion may be configured such that the sound pressure level generated within the air layer by applying an external force to the air layer is reduced by 3 dB or more.
1. An open air layer-type vibration reduction structure comprising:
at least one plate-like member arranged such that an obverse surface thereof faces an open space; and
a frame arranged with an interval from a reverse surface of the plate-like member that opposes the obverse surface of the plate-like member;
wherein an air layer is formed between the plate-like member and the frame;
wherein the at least one plate-like member can move toward the open space and the air layer in relation to the frame;
wherein at least one vibration proof rubber is arranged between the at least one plate-like member and the frame so as to support the at least one plate-like member; and
wherein ventilation portions having air permeability are formed by at least one of the at least one plate-like member and the frame such that an average value of flow resistance on a surface of at least one of the at least one plate-like member and the frame, which forms the air layer, is in a range greater than 0N·s/m 3 and equal to or less than 1,000 N·s/m 3 .
2. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the ventilation portions are further configured such that a sound pressure level generated within the air layer by applying an external force to the air layer, is reduced by 3 dB or more in a dominant frequency, in comparison with a case in which the at least one plate-like member and the frame have no air permeability, the dominant frequency being that in which amplitude based on characteristics of a series of systems including the at least one plate-like member, the frame, the at least one vibration proof rubber, and the air layer, is maximum.
3. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the ventilation portions are formed by providing air holes in an entirety of the at least one plate-like member or a part of the at least one plate-like member.
4. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the ventilation portions are formed by providing air holes in an entirety of the frame or a part of the frame.
5. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the at least one plate-like member conjures a plurality of plate-like members,
wherein the plurality of plate-like members is arranged adjacent to one another, and
wherein the ventilation portions are formed by providing a clearance between mutually adjacent plate-like members.
6. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the at least one plate-like member conjures a plurality of plate-like members,
wherein the plurality of plate-like members is arranged adjacent to one another, and
wherein mutually adjacent plate-like members are connected to one another by using a vibration insulation material.
7. The open air layer-type vibration reduction structure according to claim 1 ,
wherein an acoustically transparent member is arranged in the ventilation portion, the acoustically transparent member having a sound insulation performance of reducing the sound pressure level by 0 dB to 2 dB in a frequency domain of 30 Hz to 300 Hz.
8. The open air layer-type vibration reduction structure according to claim 1 ,
wherein a load from the at least one plate-like member toward the frame is applied to a peripheral portion of the at least one plate-like member.
9. The open air layer-type vibration reduction structure according to claim 1 ,
wherein the ventilation portions are formed by providing air holes in an entirety of the frame or a part of the frame.
10. An open air layer-type vibration reduction structure comprising:
at least one plate-like member arranged such that an obverse surface thereof faces an open space; and
a frame spaced at an interval from a reverse surface of the at least one plate-like member that opposes the obverse surface of the at least one plate-like member;
wherein an air layer is formed between the at least one plate-like member and the frame;
wherein the at least one plate-like member can move toward the open space and the air layer in relation to the frame;
wherein at least one vibration proof rubber is arranged between the at least one plate-like member and the frame so as to support the at least one plate-like member; and
wherein ventilation portions are provided in at least one of the at least one plate-like member and the frame such that a sound pressure level generated within the air layer by applying an external force to the air layer, is reduced by 3 dB or more in a dominant frequency, in comparison with a case in which the at least one plate-like member and the frame have no air permeability, the dominant frequency being that in which amplitude based on characteristics of a series of systems including the at least one plate-like member, the frame, the at least one vibration proof rubber, and the air layer, is maximum.
11. The open air layer-type vibration reduction structure according to claim 10 ,
wherein the ventilation portions are formed by providing air holes in an entirety of the at least one plate-like member or a part of the at least one plate-like member.
12. The open air layer-type vibration reduction structure according to claim 10 ,
wherein the at least one plate-like member conjures a plurality of plate-like members,
wherein the plurality of plate-like members is arranged adjacent to one another, and
wherein the ventilation portions are formed by providing a clearance between the mutually adjacent plate-like members.
13. The open air layer-type vibration reduction structure according to claim 10 ,
wherein the at least one plate-like member conjures a plurality of plate-like members,
wherein the plurality of plate-like members is arranged adjacent to one another, and
wherein mutually adjacent plate-like members are connected to one another by using a vibration insulation material.
14. The open air layer-type vibration reduction structure according to claim 10 ,
wherein an acoustically transparent member is arranged in the ventilation portion, the acoustically transparent member having a sound insulation performance of reducing the sound pressure level by 0 dB to 2 dB in a frequency domain of 30 Hz to 300 Hz.
15. The open air layer-type vibration reduction structure according to claim 10 ,
wherein a load from the at least one plate-like member toward the frame is applied to a peripheral portion of the at least one plate-like member.