JP2019127723A - Silencer - Google Patents

Silencer Download PDF

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Publication number
JP2019127723A
JP2019127723A JP2018009164A JP2018009164A JP2019127723A JP 2019127723 A JP2019127723 A JP 2019127723A JP 2018009164 A JP2018009164 A JP 2018009164A JP 2018009164 A JP2018009164 A JP 2018009164A JP 2019127723 A JP2019127723 A JP 2019127723A
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Japan
Prior art keywords
silencer
pipe
air
muffling
blower
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JP2018009164A
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Japanese (ja)
Inventor
秀明 高野
Hideaki Takano
秀明 高野
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Makita Corp
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Makita Corp
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Priority to JP2018009164A priority Critical patent/JP2019127723A/en
Priority to PCT/JP2018/036933 priority patent/WO2019146165A1/en
Publication of JP2019127723A publication Critical patent/JP2019127723A/en
Pending legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B5/00—Cleaning by methods involving the use of air flow or gas flow
    • B08B5/02—Cleaning by the force of jets, e.g. blowing-out cavities
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01H—STREET CLEANING; CLEANING OF PERMANENT WAYS; CLEANING BEACHES; DISPERSING OR PREVENTING FOG IN GENERAL CLEANING STREET OR RAILWAY FURNITURE OR TUNNEL WALLS
    • E01H1/00—Removing undesirable matter from roads or like surfaces, with or without moistening of the surface
    • E01H1/08—Pneumatically dislodging or taking-up undesirable matter or small objects; Drying by heat only or by streams of gas; Cleaning by projecting abrasive particles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/24—Silencing apparatus characterised by method of silencing by using sound-absorbing materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • A47L9/02—Nozzles
    • A47L9/08—Nozzles with means adapted for blowing

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Civil Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Architecture (AREA)
  • Chemical & Material Sciences (AREA)
  • Structural Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Cleaning Of Streets, Tracks, Or Beaches (AREA)
  • Electric Suction Cleaners (AREA)
  • Nozzles For Electric Vacuum Cleaners (AREA)
  • Cleaning In General (AREA)
  • Exhaust Silencers (AREA)

Abstract

To facilitate the reduction in air blow noise generated from an air passing through a blowing pipe.SOLUTION: A silencer 40 connected to an air blow pipe 30 of an air blow work machine 10 is provided with a silencer pipe 41 connected to the air blow pipe 30 and having a sound absorption material 42 arranged on the inner peripheral surface thereof, and a reflecting protrusion 43 provided to protrude inward from the inner peripheral surface of the silencer pipe 41 to reflect an air passing through the central portion in a radial direction of the silencer 41 so as to pass around the sound absorption material 42.SELECTED DRAWING: Figure 2

Description

本発明は、ブロワ等の送風作業機の送風管に接続して使用する消音器に関する。   BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a silencer used by being connected to an air duct of a blower working machine such as a blower.

特許文献１には空気を噴出させて落葉等を吹き集めるブロワが開示されている。ブロワは、背負フレームに搭載して空気を噴出させるブロワユニットと、ブロワユニットの送風ダクト部に接続した送風管とを備え、ブロワユニットから送り出した空気を送風管の先端から噴出させるようにしている。   Patent Document 1 discloses a blower that blows air and collects fallen leaves and the like. The blower includes a blower unit mounted on a back and forth frame to eject air, and an air duct connected to the air duct portion of the blower unit, so that the air delivered from the blower unit is ejected from the tip of the air duct. .

特開２０１５−０８３８１６号公報JP, 2015-083816, A

特許文献１のブロワのような送風作業機では、例えばブロワユニットの駆動源のエンジンを電動モータに代えて駆動音の低騒音化を図るようにしたり、送風管の内周面に吸音材を配設して送風管を通過する空気から生じる送風騒音の低減を図るようにして、送風作業機から発生する騒音をできるだけ小さくするようしたものが開発されている。しかし、送風管の内周面に吸音材を配設しても、送風管の内周面の周囲を通過する空気から生じる送風騒音を低減できるものの、送風管の径方向の中央部を通過する空気から生じる送風騒音を低減しきれなかった。本発明は、送風作業機の送風管を通過する空気から生じる送風騒音の低減化を図ることを目的とする。   In the blower work machine such as the blower of Patent Document 1, for example, the engine of the drive source of the blower unit is replaced with an electric motor to reduce the driving noise, or a sound absorbing material is disposed on the inner circumferential surface of the air duct. It has been developed to reduce the noise generated from the blower working machine as much as possible by installing it to reduce the noise generated by the air passing through the blower pipe. However, even if the sound absorbing material is disposed on the inner peripheral surface of the air blow pipe, although the air flow noise generated from the air passing around the inner peripheral surface of the air blow pipe can be reduced, it passes through the central portion in the radial direction of the air blow pipe. The blowing noise generated from the air could not be reduced. An object of this invention is to aim at reduction of the blowing noise which arises from the air which passes the blast pipe of a ventilation work machine.

上記課題を解決するために本発明は、送風作業機の送風管に接続される消音器であり、消音器は、送風管に接続されて内周面に吸音材が配設された消音管と、消音管の内周面から内側に突出して設けられて、消音管の径方向の中央部を通過する空気を吸音材の周囲を通過させるように反射させる反射突部を設けたことを特徴とする消音器を提供するものである。   In order to solve the above problems, the present invention is a silencer connected to a blower pipe of a blower working machine, and the silencer is connected to the blower pipe and a silencer pipe having a sound absorbing material disposed on an inner peripheral surface thereof. The reflection protrusion is provided so as to project inward from the inner peripheral surface of the silencer, and to reflect the air passing through the central portion in the radial direction of the silencer so as to pass around the sound absorbing material. A muffler is provided.

上記のように構成した消音器においては、送風管から送る空気を消音管を通過させたときに、消音管の内周面の周囲を通過する空気から生じる送風騒音を吸音材により低減できるだけでなく、消音管の径方向の中央部を通過する空気を反射突部によって吸音材の周囲を通過させるように反射させることで、送風騒音の低減効果を高めることができるようになった。   In the silencer configured as described above, when air sent from the air blowing pipe passes through the muffling pipe, not only the air blowing noise generated from the air passing around the inner peripheral surface of the muffling pipe can be reduced by the sound absorbing material By reflecting the air passing through the central portion in the radial direction of the sound deadening pipe so as to pass the periphery of the sound absorbing material by the reflecting protrusion, the effect of reducing the blowing noise can be enhanced.

上記のように構成した消音器においては、反射突部の消音管の軸線方向における長さを２００ｍｍ以上とするのが好ましい。反射突部を２００ｍｍ以上としたことで、この種の送風作業機で生じる波長が１９０〜２６０ｍｍ（ｆ＝１．３〜１．８ｋＨｚ）の騒音の音波を吸音材の周囲に反射できるようになった。なお、この消音器においては、反射突部を３００ｍｍ以下とするのが好ましい。   In the silencer configured as described above, it is preferable that the length of the reflection protrusion in the axial direction of the silencer tube is 200 mm or more. By setting the reflection protrusion to be 200 mm or more, it becomes possible to reflect sound waves of noise having a wavelength of 190 to 260 mm (f = 1.3 to 1.8 kHz) generated in this type of blower working machine around the sound absorbing material. It was. In addition, in this silencer, it is preferable to make a reflective protrusion 300 mm or less.

また、反射突部の送風管内の空気が流れる方向から見た最大投影面積を消音管の径方向の断面積の１０％〜３０％とするのが好ましい。また、反射突部を消音管の軸線方向に進むつれて幅を膨らませた後で再び細くするようにした紡錘形とするのが好ましい。このようにしたときには、消音管を通過する空気量を十分に確保したうえで、送風騒音を十分に低減させるようにすることができた。   Moreover, it is preferable that the maximum projected area seen from the direction in which the air in the blast pipe of the reflection projection flows is 10% to 30% of the cross-sectional area in the radial direction of the muffler pipe. In addition, it is preferable that the reflecting projection be formed into a spindle shape in which the width is expanded after advancing in the axial direction of the muffling pipe and then narrowed again. In this case, it is possible to sufficiently reduce the blowing noise while securing a sufficient amount of air passing through the muffle tube.

上記のように構成した消音器においては、反射突部を消音管の周方向に複数配置してもよいし、この場合には、複数の反射突部を消音管の軸線方向に互いにずらして配置してもよい。   In the silencer configured as described above, a plurality of reflective protrusions may be arranged in the circumferential direction of the muffle tube, and in this case, the plurality of reflective protrusions are arranged mutually offset in the axial direction of the muffle tube May be.

本発明の消音器を用いたブロワの側面図である。It is a side view of the blower using the silencer of the present invention. 消音器の斜視図である。It is a perspective view of a silencer. 消音器の軸線方向の側面図である。It is an axial side view of a silencer. Ａ−Ａ断面図である。It is AA sectional drawing. 他の実施形態の消音器の斜視図である。It is a perspective view of the silencer of other embodiments. 図５の消音器の軸線方向からみた側面図である。It is the side view seen from the axial direction of the silencer of FIG.

以下、本発明の消音器を用いた可搬式の送風作業機の一実施形態である背負式ブロワの実施形態を添付図面を参照して説明する。図１に示したように、背負式ブロワ１０は、作業者が背負う背負フレーム１１と、背負フレーム１１に搭載したブロワユニット２０と、ブロワユニット２０の送風ダクト２１ａに接続した送風管３０と、送風管３０に介装された消音器４０とを備えている。背負フレーム１１は作業者がブロワユニット２０を背負って運ぶためのものである。背負フレーム１１は、作業者の背中に沿って配置される背板部１２と、背板部１２の下端から後方に延びる台座部１３とからなり、側面から見た形状がＬ字形をしている。背負フレーム１１の台座部１３には前側にボリュート２１が搭載されている。   Hereinafter, an embodiment of a back blower that is an embodiment of a portable blower working machine using the silencer of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the backpack blower 10 includes a backpack frame 11 carried by a worker, a blower unit 20 mounted on the backpack frame 11, a blower tube 30 connected to a blower duct 21 a of the blower unit 20, and a blower. And a silencer 40 interposed in the pipe 30. The backrest frame 11 is for the worker to carry the blower unit 20 on his back. The backrest frame 11 is composed of a back plate 12 disposed along the back of the worker and a pedestal 13 extending rearward from the lower end of the back plate 12 and is L-shaped when viewed from the side. . A volute 21 is mounted on the front side of the pedestal portion 13 of the backrest frame 11.

図１に示したように、ブロワユニット２０は、ボリュート２１と、ボリュート２１内に回転可能に設けた羽根車（図示省略）と、羽根車を回転させる原動機２２とを備えている。ボリュート２１の側部には送風ダクト２１ａが形成されており、ボリュート２１内にて羽根車の回転によって遠心方向に送り出される空気は送風ダクト２１ａから噴出される。   As shown in FIG. 1, the blower unit 20 includes a volute 21, an impeller (not shown) that is rotatably provided in the volute 21, and a prime mover 22 that rotates the impeller. An air duct 21 a is formed on the side of the volute 21, and the air sent out in the centrifugal direction by the rotation of the impeller in the volute 21 is ejected from the air duct 21 a.

図１に示したように、送風ダクト２１ａには送風管３０が接続されており、送風管３０は、送風ダクト２１ａに回転可能に接続されたエルボ管３１と、エルボ管３１に接続された蛇腹管３２と、消音器４０を介して蛇腹管３２に接続される真直管３３とを備えている。送風管３０には操作ハンドル３４が設けられており、操作ハンドル３４は送風管３０の操作可能としている、また、操作ハンドル３４にはスロットルレバー３４ａが設けられており、スロットルレバー３４ａの操作によって原動機２２の出力が調整される。なお、この実施形態では、操作ハンドル３４は消音器４０を介して送風管３０に取り付けられている。   As shown in FIG. 1, the air duct 30a is connected to the air duct 21a, and the air duct 30 is connected to the elbow pipe 31 rotatably connected to the air duct 21a and the bellows connected to the elbow pipe 31. A pipe 32 and a straight pipe 33 connected to the bellows pipe 32 via the silencer 40 are provided. An operation handle 34 is provided on the air duct 30, and the operation handle 34 is capable of operating the air duct 30, and a throttle lever 34a is provided on the operation handle 34. The motor can be operated by operating the throttle lever 34a. 22 outputs are adjusted. In this embodiment, the operation handle 34 is attached to the air duct 30 via the silencer 40.

図１〜図４に示したように、消音器４０は送風管３０を通過する送風騒音を低減させるものであり、消音器４０は送風管３０の蛇腹管３２と真直管３３との間に介装された消音管４１を備えている。図４に示したように、消音管４１の内周面には吸音材４２が貼着されており、吸音材４２は消音管４１を通過する送風騒音を吸収して低減させる機能を有している。消音管４１の内周面に貼着された吸音材４２は１０ｍｍの厚さの発泡ポリウレタン材よりなり、吸音材４２の表面には１００μｍの厚みの滑面よりなる被膜が形成されている。消音管４１の吸音材４２が貼着されてないときの内径は９００ｍｍとなっており、消音管４１の吸音材４２を設けたときの内径は７００ｍｍとなっている。消音管４１の吸音材４２を設けた部分の内径は送風管３０の内径と実質的に同じとなっており、送風管３０から消音管４１を通過する送風の抵抗とならないようになっている。   As shown in FIGS. 1 to 4, the silencer 40 is for reducing the blowing noise passing through the blower tube 30, and the silencer 40 is interposed between the bellows tube 32 and the straight tube 33 of the blower tube 30. A muffler 41 is provided. As shown in FIG. 4, a sound absorbing material 42 is attached to the inner peripheral surface of the muffling pipe 41, and the sound absorbing material 42 has a function of absorbing and reducing the blowing noise passing through the muffling pipe 41. There is. The sound absorbing material 42 attached to the inner circumferential surface of the muffle tube 41 is made of a foamed polyurethane material having a thickness of 10 mm, and a coating having a smooth surface having a thickness of 100 μm is formed on the surface of the sound absorbing material 42. The inner diameter when the sound absorbing material 42 of the muffling pipe 41 is not attached is 900 mm, and the inner diameter when the sound absorbing material 42 of the muffling pipe 41 is provided is 700 mm. The inner diameter of the portion provided with the sound absorbing material 42 of the muffling pipe 41 is substantially the same as the inner diameter of the air blowing pipe 30, and does not serve as a resistance to air flowing from the air blowing pipe 30 through the muffling pipe 41.

図２〜図４に示したように、消音管４１には内側に突出する反射突部４３が設けられており、反射突部４３は消音管４１の径方向の中央部を通過する空気を消音管４１の内周面に設けた吸音材４２の周囲を通過させるように反射させるものである。反射突部４３は消音管４１の半径方向の両側に設けられており、反射突部４３は消音管４１の軸線方向に進むにつれて幅を膨らませた後で再び細くするようにした紡錘形をしてる。反射筒部４３の軸線方向における長さは２５０ｍｍとなっており、背負式ブロワ１０で生じる波長１９０〜２６０ｍｍ（ｆ＝１．３〜１．８ｋＨｚ）の騒音の音波を吸音材４２の周囲に反射させるようにしている。なお、反射突部４３の軸線方向の長さを２００ｍｍ以上で、さらに好ましくは３００ｍｍ以下とすることで、波長１９０〜２６０ｍｍ（ｆ＝１．３〜１．８ｋＨｚ）の騒音の音波を吸音材４２の周囲に反射させるのに好適である。   As shown in FIGS. 2 to 4, the muffling pipe 41 is provided with a reflecting protrusion 43 projecting inward, and the mottling protrusion 43 muffles the air passing through the radial center of the muffling pipe 41. It is reflected so as to pass around the sound absorbing material 42 provided on the inner circumferential surface of the tube 41. The reflecting projections 43 are provided on both sides in the radial direction of the muffling pipe 41, and the reflecting projections 43 have a spindle shape in which the width is expanded as it proceeds in the axial direction of the muffling pipe 41 and then narrowed again. The length in the axial direction of the reflective cylindrical portion 43 is 250 mm, and the sound wave of noise of wavelength 190 to 260 mm (f = 1.3 to 1.8 kHz) generated in the backpack type blower 10 is reflected around the sound absorbing material 42 I try to let them. In addition, the sound wave of the noise of wavelength 190-260 mm (f = 1.3-1.8 kHz) is absorbed by setting the length of the axial direction of the reflective protrusion 43 to 200 mm or more, preferably 300 mm or less. It is suitable to be reflected around the surroundings.

また、反射突部４３の軸線方向の略中央部が最も内側に突き出るようにした部分であり、この部分の幅の長さは３０ｍｍで高さが３０ｍｍとなっている。反射突部４３の送風管３０内の空気が流れる方向から見た最大投影面積は消音管２１の径方向の断面積の１０％の割合となっていて、消音管４１の半径方向の両側に２つ反射突部４３を設けたことで、反射突部４３の断面積は消音管２１の断面積の２０％の割合となっている。２つの反射突部４３の最大投影面積を消音管４１の断面積の２０％としたことで、消音管４１を通過する空気量を十分に確保したうえで、送風騒音を十分に低減させることができる。なお、反射突部４３の最大投影面積を消音管４１の径方向の断面積の１０％〜３０％にしたときに、消音管４１を通過する空気量を十分に確保したうえで、送風騒音を十分に低減させることができる。図５及び図６に示したように、半径方向の両側に配設された反射突部４３を互いに当接させるようにしたものであってもよい。また、この実施形態では２つの反射突部４３を消音管４１の軸線方向に同じ位置に配置したが、これに限られるわけでなく、２つの反射突部４３を消音管４１の軸線方向に互いに異なる位置に配置したものであってもよい。   In addition, a substantially central portion in the axial direction of the reflective protrusion 43 is a portion that protrudes inward most, and the width of this portion is 30 mm and the height is 30 mm. The maximum projected area of the reflective projection 43 as viewed in the flow direction of the air in the air blow pipe 30 is 10% of the cross sectional area of the sound deadening pipe 21 in the radial direction. The cross-sectional area of the reflective protrusion 43 is 20% of the cross-sectional area of the muffle tube 21 by providing the reflective protrusion 43. By setting the maximum projected area of the two reflecting projections 43 to be 20% of the cross-sectional area of the muffling pipe 41, the amount of air passing through the muffling pipe 41 can be sufficiently secured, and the blowing noise can be sufficiently reduced. it can. When the maximum projected area of the reflective projection 43 is 10% to 30% of the cross-sectional area of the muffling pipe 41 in the radial direction, the air volume passing through the muffling pipe 41 is sufficiently ensured, and the blowing noise is It can be sufficiently reduced. As shown in FIGS. 5 and 6, the reflecting projections 43 disposed on both sides in the radial direction may be in contact with each other. Further, in this embodiment, the two reflecting protrusions 43 are arranged at the same position in the axial direction of the muffling pipe 41, but the invention is not limited thereto. The two reflecting protrusions 43 are mutually arranged in the axial direction of the muffling pipe 41 It may be arranged at different positions.

上記のように構成した背負式ブロワ１０の作動について説明する。スロットルレバー３４ａの操作により原動機２２を駆動させると羽根車が回転し、ボリュート２１の前側の吸気開口部から吸い込まれた空気が回転する羽根車により遠心方向に噴き出され、噴き出された空気は渦形の送風路で昇圧されて送風ダクト２１ａに送られ、送風ダクト２１ａから噴き出された空気は送風管３０及び消音器４０を通って地面に噴き出される。作業者が送風管３０の操作ハンドル３４を把持して先端開口を作業者の前側で左右に揺動させると、地面に広範囲に散る落葉等が吹き集められるようになる。   The operation of the backpack type blower 10 configured as described above will be described. When the prime mover 22 is driven by the operation of the throttle lever 34a, the impeller rotates, and the air sucked from the intake opening on the front side of the volute 21 is ejected in the centrifugal direction by the rotating impeller and the ejected air is The pressure is increased in the vortex type air flow path and sent to the air flow duct 21 a, and the air blown out from the air flow duct 21 a is blown out to the ground through the air flow pipe 30 and the silencer 40. When the worker grips the operation handle 34 of the air duct 30 and swings the tip opening to the left and right on the front side of the worker, fallen leaves and the like widely scattered on the ground are blown and collected.

このように構成した背負式ブロワ１０の送風管３０には消音器４０が介装されており、この消音器４０は送風管３０に接続されて内周面に吸音材４２が配設された消音管４１と、消音管４１の内周面から内側に突出して設けられて、消音管４１の径方向の中央部を通過する空気を吸音材４２の周囲を通過させるように反射させる反射突部４３を設けたものである。送風管３０の蛇腹管３２から送る空気を消音管４１を通過させたときに、消音管４１の内周面の周囲を通過する空気から生じる送風騒音を吸音材４２により低減できるだけでなく、消音管４１の径方向の中央部を通過する空気を反射突部４３によって吸音材４２の周囲を通過させるように反射させて、送風騒音の低減効果を高めることができるようになった。このように、消音器４０は消音管４１の内周面の周囲を通過する空気から生じる送風騒音だけでなく、径方向の中央部を通過する空気から生じる送風騒音を低減させることができるので、送風騒音の低減効果を高めることができるようになった。   A silencer 40 is interposed in the blower pipe 30 of the back blower 10 constructed as described above, and the silencer 40 is connected to the blower pipe 30 and has a sound absorbing material 42 disposed on the inner peripheral surface thereof. A pipe 41 and a reflection projection 43 which protrudes inward from the inner peripheral surface of the muffling pipe 41 and reflects air passing through the central portion in the radial direction of the muffling pipe 41 so as to pass the periphery of the sound absorbing material 42 Is provided. When the air sent from the bellows tube 32 of the air duct 30 passes through the muffling pipe 41, not only the air noise generated from the air passing around the inner peripheral surface of the muffling pipe 41 can be reduced by the sound absorbing material 42, but The air passing through the central portion in the radial direction 41 is reflected by the reflective projection 43 so as to pass the periphery of the sound absorbing material 42, so that the reduction effect of the blowing noise can be enhanced. Thus, the silencer 40 can reduce not only the blowing noise generated from the air passing around the inner peripheral surface of the muffle tube 41 but also the blowing noise generated from the air passing through the central portion in the radial direction, It became possible to enhance the effect of reducing blowing noise.

この消音器４０は、反射突部４３の消音管４１の軸線方向における長さを２５０ｍｍとして、反射突部を２００ｍｍ以上で、さらに好ましい範囲で３００ｍｍ以下に設定したので、この種の送風作業機で生じる波長が１９０〜２６０ｍｍ（ｆ＝１．３〜１．８ｋＨｚ）の騒音の音波を吸音材４２の周囲に反射できるようになり、送風騒音の低減効果を高めることができるようになる。   In this silencer 40, the length of the reflection projection 43 in the axial direction of the silencer tube 41 is set to 250 mm, and the reflection projection is set to 200 mm or more, and more preferably to 300 mm or less. The sound wave of noise having a generated wavelength of 190 to 260 mm (f = 1.3 to 1.8 kHz) can be reflected around the sound absorbing material 42, and the effect of reducing blowing noise can be enhanced.

この消音器４０では、２つの反射突部４３の送風管３０（消音管４１）内の空気が流れる方向から見た最大投影面積を消音管４１の径方向の断面積の２０％として、１０％〜３０％の範囲に含まれるように設定している。また、反射突部４３を消音管４１の軸線方向に進むつれて幅を膨らませた後で再び細くするようにした紡錘形としている。これらにより、消音管４１を通過する空気量を十分に確保したうえで、送風騒音を十分に低減させるようにすることができた。   In this silencer 40, the maximum projected area of the two reflecting projections 43 as viewed from the flow direction of the air in the air blowing tube 30 (muffler tube 41) is 10% as 20% of the cross-sectional area of the muffling tube 41 in the radial direction It is set to be included in a range of ˜30%. In addition, the reflecting protrusion 43 is formed into a spindle shape which is narrowed in the axial direction of the muffling pipe 41 and expanded again after the width thereof is expanded. As a result, after sufficiently securing the amount of air passing through the muffle tube 41, the blowing noise can be sufficiently reduced.

上記の実施形態では、消音器４０を送風作業機の一例である背負式ブロワに適用した実施形態で説明したが、本発明の消音器４０は他の送風作業機として背負式集塵機、手持式送風機または手持式集塵機に適用したものであってもよい。   In the above embodiment, although the silencer 40 is described as an embodiment of the blower type work machine which is an example of the blower working machine, the silencer 40 of the present invention is another kind of blower work machine like a dust collector, hand-held blower Or you may apply to a hand-held dust collector.

１０…送風作業機、３０…送風管、４０…消音器、４１…消音管、４２…吸音材、４３…反射突部。   DESCRIPTION OF SYMBOLS 10 ... Blower working machine, 30 ... Air duct, 40 ... Silencer, 41 ... Silence pipe, 42 ... Sound absorption material, 43 ... Reflection protrusion

Claims (7)

送風作業機の送風管に接続される消音器であり、
前記消音器は、前記送風管に接続されて内周面に吸音材が配設された消音管と、前記消音管の内周面から内側に突出して設けられて、前記消音管の径方向の中央部を通過する空気を前記吸音材の周囲を通過させるように反射させる反射突部を設けたことを特徴とする消音器。 It is a silencer connected to the blast tube of the blower work machine,
The silencer is provided with a muffling pipe connected to the air blowing pipe and having a sound absorbing material disposed on the inner circumferential surface, and is provided so as to protrude inward from the inner circumferential surface of the muffling pipe. A silencer having a reflective projection for reflecting air passing through the central portion to pass around the sound absorbing material. 請求項１に記載の消音器において、
前記反射突部の前記消音管の軸線方向における長さを２００ｍｍ以上としたことを特徴とする消音器。 In the silencer according to claim 1,
The silencer having a length of 200 mm or more in the axial direction of the muffling pipe of the reflection protrusion. 請求項２に記載の消音器において、
前記反射突部の前記消音管の軸線方向における長さを３００ｍｍ以下としたことを特徴とする消音器。 In the silencer according to claim 2,
The silencer having a length of 300 mm or less in the axial direction of the muffling pipe of the reflection protrusion. 請求項１〜３の何れか１項に記載の消音器において、
前記反射突部の前記送風管内の空気が流れる方向から見た最大投影面積を前記消音管の径方向の断面積の１０％〜３０％としたことを特徴とする消音器。 The silencer according to any one of claims 1 to 3,
A muffler characterized in that the maximum projected area of the reflection protrusion as viewed from the direction in which the air in the air duct flows is 10% to 30% of the cross-sectional area in the radial direction of the muffler tube. 請求項１〜４の何れか１項に記載の消音器において、
前記反射突部を前記消音管の軸線方向に進むつれて幅を膨らませた後で再び細くするようにした紡錘形としたことを特徴とする消音器。 The muffler according to any one of claims 1 to 4,
A silencer having a spindle shape in which the reflecting projection is expanded in the axial direction of the muffling pipe to expand and then narrow again. 請求項１〜５の何れか１項に記載の消音器において、
前記反射突部を前記消音管の周方向に複数配置したことを特徴とする消音器。 The muffler according to any one of claims 1 to 5,
A silencer, wherein a plurality of the reflection protrusions are arranged in the circumferential direction of the muffling pipe. 請求項６に記載の消音器において、
前記複数の反射突部を前記消音管の軸線方向に互いにずらして配置したことを特徴とする消音器。 In the silencer according to claim 6,
A silencer, wherein the plurality of reflecting protrusions are arranged mutually offset in the axial direction of the muffling pipe.
JP2018009164A 2018-01-23 2018-01-23 Silencer Pending JP2019127723A (en)

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CN111749178A (en) * 2020-07-07 2020-10-09 扬州大学 Combined washing and sweeping vehicle noise reduction suction port, machining die and use method of machining die

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US5979013A (en) * 1998-03-10 1999-11-09 The Toro Company Portable blower with noise reduction
JP3043740B1 (en) * 1999-02-01 2000-05-22 埼玉日本電気株式会社 Soundproof hood structure for communication equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111749178A (en) * 2020-07-07 2020-10-09 扬州大学 Combined washing and sweeping vehicle noise reduction suction port, machining die and use method of machining die
CN111749178B (en) * 2020-07-07 2021-08-06 扬州大学 Combined washing and sweeping vehicle noise reduction suction port, machining die and use method of machining die

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