JP2017068231A5 - - Google Patents

Description

Conventionally, as an active silencer having a duct structure, an internal original sound reference microphone 104 , a silencer speaker 105 , an error microphone, and the like, which are sequentially attached at appropriate intervals from the upstream side inside a rectangular duct 101 made of a thin steel plate, are provided. What is comprised from 106 and the arithmetic controller 102 each connected with them is known.

In this type of apparatus, the generated sound propagating in the rectangular duct 101 together with the airflow 103 is detected by the reference microphone 104 , and the frequency etc. is detected, and the arithmetic controller 102 creates a signal having a phase opposite to that of the original sound. The sound is emitted from the loudspeaker 105 into the rectangular duct 101 and the original sound is canceled and silenced. The error microphone 106 monitors the internal sound, and the computation controller 102 causes the noise mute speaker 105 115 so that the output of the error microphone 106 becomes zero. Is automatically adjusted.

As shown in FIG. 7 , the expansion chamber 111 is formed by expanding the cross-sectional area perpendicular to the airflow direction of a part of the wall surface of the duct 110 , and the microphone 112 is attached in the expansion chamber 111 . As a result, when the airflow flowing in the duct 110 reaches the expansion chamber 111 , the cross-sectional area perpendicular to the airflow direction increases, and the wind speed decreases. Furthermore, providing the microphone 112 in the expansion chamber 111 has an effect of preventing the vortex generated by separation near the wall surface of the duct 110 from reaching the microphone 112 . As a result, the influence of the airflow on the microphone 112 can be reduced, and it can be expected to suppress the deterioration of the silencing effect.

Japanese Utility Model Publication No. 5-11198 JP-A-7-162979

In order to achieve the above object, the present invention communicates a suction port for sucking air upstream, a discharge port for discharging air sucked from the suction port, and a suction port and a discharge port. An air passage section, an air blowing section that guides air from the suction port to the discharge opening inside the air passage section, an active silencing air path provided upstream of the air passage section, a reference microphone, and a speaker. An active silencing device for silencing the silencing air path, and the active silencing air path is a rectangular tube having a long side and a short side in the air path cross section, and a part of the side wall including the long side is the cylindrical body comprising a side space having a parallel protruding wall to the outer side, a reference microphone placed in the wall, a blower, wherein a distance to the side wall to an opposing wall surface is equal to the length of the long side, This achieves the intended purpose.

The blower according to the present invention includes a suction port that sucks air on the upstream side in the air flow direction, a discharge port that discharges air sucked from the suction port, and an air passage unit that communicates the suction port and the discharge port. An air blowing portion that guides air from the suction port to the discharge port inside the air passage portion, an active silencing air passage provided on the upstream side of the air passage portion, a reference microphone, and a speaker. An active silencer for silencing, and the active silencer air passage is a rectangular tube whose cross section has a long side and a short side, and a part of the side wall including the long side is parallel to the outside of the tube. comprising a side space having the wall surfaces protruding, a reference microphone placed in the wall, but the distance to the side wall to an opposing wall surface is equal to the length of the long side.

Another blowing device according to the present invention includes a suction port for sucking air at the upstream side in the air flow direction, a discharge port for discharging the sucked from suction plug mouth air and an exhaust outlet and suction plug mouth Yes and air passage portion, and a blower for guiding the air to the discharge outlet from the suction plug mouth inside the air path portion, and an active silencer air path provided on an upstream side of the air path portion, the reference microphone and speaker for communicating and a active silencer that performs mute performance dynamic muffler air passage, and capacity dynamic muffling air passage is a cylinder of elliptical air passage cross-section has a major axis and a minor axis, the side wall which does not intersect the major axis comprising a part of the side space having the wall surface protrudes outside the side of the cylindrical body, a's Reference microphone placed toward the wall surface to the long axis and the intersection of the minor axis, which passes opposite the intersection from the wall surface The distance to the side wall is equal to the length of the long axis.

The blower 5 includes a circular multi-blade fan 9, a motor (not shown) that rotates the multi-blade fan 9, a casing 10 that encloses the multi-blade fan 9, and a rotation shaft that is the center of rotation of the multi-blade fan 9. 11. The motor (not shown) is coaxial with the rotary shaft 11 and is arranged in a form embedded in the space inside the blower unit 5. Moreover, the rotating shaft 11 is arrange | positioned orthogonally with respect to the flow direction (from the downward direction of FIG. 1) of an airflow.

Claims (2)

And a suction port for sucking the air on the upstream side in the air flow direction,
A discharge port for discharging the air sucked from the empty suction port;
And air passage portion which communicates the front SL inlet and said outlet,
A blowing section for guiding air from the suction port inside the front Kifuro portion to the outlet,
An active silencer air path provided on an upstream side of the front Kifuro portion,
And a active silencer device comprising a's Reference microphone and speaker performs mute the active silencer air passage,
Before SL active silencer air passage, a square tube that the air passage cross section having long sides and short sides, having a wall portion of the side wall containing the long side is parallel to protrude to the outer side of the cylindrical body With side space,
The reference microphone placed in front Symbol wall,
Blowing device distance to the opposing side walls from before Symbol wall surface, characterized in that equal to the length of the long sides. And a suction port for sucking the air on the upstream side in the air flow direction,
And a discharge port for discharging the air sucked from the previous Symbol suction port,
And air passage portion which communicates the front SL inlet and said outlet,
A blowing section for guiding air from the suction port inside the front Kifuro portion to the outlet,
An active silencer air path provided on an upstream side of the front Kifuro portion,
And a active silencer device comprising a's Reference microphone and speaker performs mute the active silencer air passage,
Before SL active silencer air passage, a cylinder of elliptical with major and minor axes are air path cross section, have a wall portion of the side wall which does not intersect the major axis is protruded to the outer side of the cylindrical body Side space,
The pre-Symbol reference microphone placed toward the intersection of the minor axis and the major axis from said wall surface,
Blowing device distance from the previous SL wall to the sidewall of through opposite the intersection is equal to or equal to the length of the long axis.