JP2018189006A - Muffler for blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a muffler for a blower which suppresses deterioration of muffling performance due to heat and moisture to the minimum and prevents incorporation of foreign matter to ejected air.SOLUTION: A muffler 20 for a blower fitted to an ejection port 12a of a vortex flow blower 10 includes: a tubular housing 30 which allows one end thereof to be fitted to the ejection port 12a of the vortex flow blower 10, allows the other end to be opened to an external part and has an air passage P along an axial direction C from one end side toward the other end side; and a plurality of sound absorbing packs 40 which are arranged in the tubular housing 30 and are stacked on a position which surrounds the air passage P and along the air passage P. Therein, the sound absorbing packs 40 are communicated with the air passage P and includes a recessed case 41 formed in a dish shape and a porous plate 42 provided on a position which blocks the opening side of the recessed case 41.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a silencer attached to a discharge port side or a suction port side of a blower such as a vortex blower.

  Conventionally, a silencer incorporated in a blower such as a vortex fan is known (for example, see Patent Documents 1 and 2). FIG. 9 is a diagram showing an example of such a silencer. That is, in these drawings, reference numeral 100 denotes an eddy current blower, and 110 denotes a silencer. The vortex blower 100 includes an electric motor 101 and a blower 102 driven by the electric motor 101. A silencer 110 is integrally attached to the discharge port 102 a of the blower 102.

  The silencer 110 has a cylindrical case 111. One end 112 of the case 111 is connected to the discharge port 102a of the blower 102, and the other end 113 side is open to the outside. A silencer 120 made of a porous synthetic resin is attached to the inner wall surface of the case 111. A ventilation path 121 is formed at the center of the sound deadening material 120 as shown in FIG. 10, and guides the high-pressure air discharged from the discharge port 102a to the outside along the direction of arrow F in FIG. A cylindrical wire mesh 122 is inserted into the muffler 120 as shown in FIG. 11 so that the ventilation path 121 is not deformed by dynamic pressure (wind pressure).

JP 7-42699 A JP-A-5-209600

  The above-described silencer for a blower has the following problems. That is, the air sent from the blower is high temperature and high speed, the sound deadening material 120 made of porous synthetic resin is gradually deteriorated, and the sound absorbing performance is lowered. Moreover, when the air which touches a sound deadening material contains a water | moisture content, the sound deadening material 120 absorbs water, hydrolysis occurs, and deterioration is accelerated. For this reason, the sound deadening material 120 is gradually decomposed and shattered, and there is a possibility that the powder blows out from the opening hole. For this reason, it has been necessary to install a filter for preventing foreign matters from being mixed or to periodically replace the filter.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a silencer for a blower that can minimize the deterioration of the silencing performance due to heat and moisture and can prevent foreign matter from being mixed into the discharged air.

  The silencer of the blower of the invention 1 is the silencer of the blower attached to the discharge port or the suction port of the blower, and one end is attached to the discharge port or the suction port of the blower, and the other end is opened to the outside. A cylindrical housing having a ventilation path along the axial direction from the one end side toward the other end side, and a position that is disposed in the cylindrical housing and surrounds the ventilation path, and the ventilation path A plurality of sound-absorbing packs arranged in a stack, and the sound-absorbing pack communicates with the ventilation path, and is provided at a position where the concave case formed in a dish shape and the opening side of the concave case are closed. Perforated plate. At this time, the invention 2 is arranged such that the concave case is positioned on the downstream side of the air flowing through the bottom plate, and the sound absorbing pack is formed of a water-resistant material. In the invention 4, the sound absorbing pack is formed of a heat-resistant material.

  According to the invention 1, since sound absorption is performed using a porous plate without using a porous resin, it is possible to prevent deterioration and destruction of the sound absorption effect due to deterioration over time, maintain the sound deadening performance, and discharge foreign matters. There is no problem. At this time, according to the second aspect, the sound absorption performance can be maximized because the air flow direction and the direction from the perforated plate into the air chamber coincide.

  Further, according to the invention 3, since the sound absorbing pack has water resistance, the deterioration does not proceed even if the air discharged from the blower contains moisture. Further, according to the invention 4, since the sound absorbing pack has heat resistance, the deterioration does not proceed even when the air discharged from the blower is at a high temperature.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a silencing device according to an embodiment of the present invention and a vortex blower incorporating the silencing device, partially cut away. Sectional drawing which cut | disconnected the said silencer by the AA line in FIG. 1, and looked at the arrow direction. The longitudinal cross-sectional view which shows the suction side silencing chamber integrated in the silencer. The longitudinal cross-sectional view which expands and shows the principal part of the discharge side silencing chamber incorporated in the silencer. The disassembled perspective view which shows the sound absorption pack integrated in the discharge side silencing chamber. The perspective view which cuts and shows the sound-absorbing pack incorporated in the discharge side silencing chamber. The perspective view which shows the sound absorption pack integrated in the silencer. Explanatory drawing which shows the silencing effect by the silencing apparatus. The side view which shows a general muffler and the eddy current blower in which this muffler was incorporated partially cut away. The disassembled perspective view which shows the sound deadening material. The perspective view which shows the sound deadening material.

  1 to 7 show an embodiment of the present invention. C in the figure indicates an axial direction of a cylindrical housing 30 described later. As shown in FIG. 1, the silencer 20 is integrated with the vortex blower 10. The vortex blower 10 includes an electric motor 11, an impeller housing 12, and an impeller 13 that is rotationally driven by the electric motor 11. The impeller housing 12 includes a discharge port 12a and a suction port 12b.

  The silencer 20 includes a cylindrical housing 30 having substantially the same overall length as the vortex blower 10. As shown in FIG. 2, a partition wall 31 is provided inside the cylindrical housing 30, and a discharge side silencing chamber 32 and a suction side silencing chamber 33 are formed.

  As shown in FIGS. 1 and 3, a plurality of sound absorbing packs (silencers) 40 are attached to the discharge side silencing chamber 32 and the suction side silencing chamber 33 along the axial direction of the cylindrical housing 30. The sound-absorbing pack 40 is formed in a dish shape and includes a metal-made concave case 41 and a metal-made porous plate 42 attached to cover the opening of the concave case 41. An air chamber 43 is formed between the concave case 41 and the porous plate 42. The metal material is preferably water-resistant and heat-resistant, for example, stainless steel or iron. The sound absorbing pack 40 is formed, for example, by pressing. Note that a 3D printer may be used.

  As shown in FIGS. 4 and 5, the concave case 41 has a surface orthogonal to the axial direction C, the periphery of which is in contact with the discharge-side silencing chamber 32, and the outer periphery of the bottom plate 41a in the axial direction. A collar 41b provided along C, an opening 41c provided in the center of the bottom plate 41a, and a small cylindrical part 41d provided along the axial direction C at a position facing the opening 41c. ing.

  Since the openings 41c described above are arranged in parallel along the axial direction C, a ventilation path P is formed, and the discharge air and the intake air flow through the ventilation path P.

  As shown in FIGS. 1 and 3, the concave case 41 installed in the discharge-side silencing chamber 32 and the suction-side silencing chamber 33 is positioned so that the bottom plate 41 a side is downstream with respect to the air flow direction. Has been placed. For this reason, when the discharge side silencing chamber 32 and the suction side silencing chamber 33 have the partition wall 31 symmetrical, the concave case 41 and the perforated plate 42 can be formed in the same shape, and parts can be shared. Can be achieved.

  When the surface of the bottom plate 41a is used as a reference, the height in the axial direction C of the flange portion 41b is the height in the axial direction C of the small cylindrical portion 41d and the height (thickness) in the axial direction C of the porous plate 42. It is formed larger than the added dimension. The dimensional difference is t (see FIG. 6). Therefore, when the concave cases 41 are stacked, the slits S are formed by the size difference t between the small cylindrical portion 41d and the bottom plate 41a of the adjacent concave case 41.

  In the porous plate 42, a large number of holes 42b having an inner diameter of about 2 to 3 mm are formed in the metal plate 42a at intervals of several mm. The hole diameter has a silencing effect at 2000 to 4000 Hz. The inner diameter of the hole 42b may be appropriately changed depending on the frequency band to be silenced.

  In the silencer 20 configured as described above, the vortex fan 10 is silenced as follows. That is, when the electric motor 11 is energized, the impeller 13 rotates. As the impeller 13 rotates, the inside of the impeller housing 12 becomes negative pressure, and outside air is sucked into the impeller housing 12 through the suction-side silencing chamber 33. On the other hand, the air discharged at a high pressure by the impeller 13 in the impeller housing 12 is discharged to the outside through the discharge side silencing chamber 32. Such an air flow generates noise.

  As shown in FIG. 7, the high-speed air F flowing through the ventilation path P enters the concave case 41 through the slit S. This air enters the air chamber 43 through the hole 42b, as indicated by f in FIG. Since the pressure inside the air chamber 43 increases, the air in the air chamber 43 exits from the hole 42b. Then, since the inside of the air chamber 43 becomes a negative pressure, the air enters the air chamber 43 through the hole 42b again. By repeating this operation, friction between air is generated, energy loss is generated, and the sound is muted. As the number of sound absorbing packs 40 increases, the effective sound absorbing area can be increased, so that the silencing effect is enhanced.

  FIG. 8 is an explanatory diagram showing a silencing effect by the silencing device 20. When the noise was measured by actually operating a general vortex blower, the noise (A characteristic) could be reduced from 91 dB to 83 dB in the discharge fully closed operation at a frequency of 60 Hz. In particular, the annoying peak frequency of 2590 Hz could be lowered by 19 dB. Therefore, it can be seen that the silencing effect varies greatly depending on the presence or absence of the silencer 20.

  On the other hand, since the sound absorbing pack 40 is formed of the concave case 41 and the porous plate 42 made of a metal material, there is almost no deterioration over time and the sound deadening function can be maintained. In addition, there is no problem that the concave case 41 and the porous plate 42 are broken by heat or moisture, and a part thereof is powdered and discharged to the outside. Further, since it is made of a metal material like the vortex blower 10, it is considered that it has an equivalent life, so that it is not necessary to periodically replace the sound absorbing pack 40.

  According to the silencer 20 configured as described above, since the sound absorbing function is generated using the sound absorbing action in the metal porous plate 42, the sound absorbing function is deteriorated due to the deterioration of the sound absorbing pack 40. Does not occur. Moreover, since the concave case 41 and the porous plate 42 provided inside are metal materials, they have heat resistance and water resistance, are not broken, and a part thereof is powdered and discharged to the outside. There is no fear of such a situation, and stable performance can be maintained for many years.

  In the above-described embodiment, one perforated plate 42 is disposed for each concave case 41, but a plurality of sheets may be stacked and installed with an interval. In this case, by setting the inner diameter of the hole 42b provided in the porous plate 42 to a smaller diameter on the side close to the bottom plate 41a, it is possible to mute various frequency bands. Moreover, although the concave case 41 and the porous plate 42 are made of stainless steel, other metal materials may be used as long as they have heat resistance and water resistance. Furthermore, although the silencer 20 is attached to each of the discharge side and the suction side of the vortex blower 10, it may be installed only on one side.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and an effect can be obtained, the configuration from which the constituent requirements are deleted can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 10 ... Eddy current blower, 11 ... Electric motor, 12 ... Impeller housing, 12a ... Discharge port, 12b ... Suction port, 13 ... Impeller, 20 ... Silencer, 30 ... Cylindrical housing, 31 ... Partition wall, 32 ... Discharge side silence Chamber 33 ... Suction side silencer chamber 40 ... Sound absorbing pack (silencer) 41 ... Recessed case 41a ... Bottom plate 41b ... Saddle part 41c ... Opening part 41d ... Small cylindrical part 42 ... Perforated plate 42a ... Metal plate, 42b ... hole, 43 ... air chamber, S ... slit, P ... ventilation path, C ... axial direction.

Silencer of the invention the first blower, in the noise suppressor of the attached blower discharge port or suction port of the vortex blower, one end attached to the discharge port or suction port of the vortex blower, and the other end is opened to the outside A cylindrical housing having a ventilation path along the axial direction from the one end side toward the other end side, and a position that is disposed in the cylindrical housing and surrounds the ventilation path, and A plurality of sound-absorbing packs arranged in a stack along the ventilation path, the sound-absorbing pack communicating with the ventilation path, and a concave case made of a metal material having water resistance and heat resistance formed in a dish shape; , and a metal material made of a multi-hole plate having a water resistance and heat resistance is provided in a position for closing the opening side of the concave case. At this time, the invention 2 is arranged such that the concave case is positioned on the downstream side of the air flowing through the bottom plate thereof, and the invention 3, the concave case has a surface orthogonal to the axial direction. A bottom plate inscribed around the cylindrical housing, a flange provided along the axial direction on the outer periphery of the bottom plate, an opening provided in a central portion of the bottom plate, and the opening A small cylindrical portion provided along the axial direction at a position facing the portion, and when the surface of the bottom plate is used as a reference, the axial height of the flange portion is the axis of the small cylindrical portion. Between the small cylindrical portion and the bottom plate of the concave case adjacent to the upstream side of the air flowing through the ventilation path, which is larger than the dimension obtained by adding the height in the direction and the axial height of the porous plate. A slit is formed.

In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, also be removed several of the constituent elements disclosed in the embodiment, the problem can be solved, if the effect is obtained, it that could be extracted as an invention arrangement from which these constituent elements are deleted .
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1] In the silencer for a blower attached to the discharge port or suction port of the blower, one end is attached to the discharge port or suction port of the blower, the other end is opened to the outside, and the other end from the one end side to the other end A cylindrical housing having a ventilation path along the axial direction toward the side, and disposed in the cylindrical housing, and is positioned so as to surround the ventilation path and stacked along the ventilation path A plurality of sound absorbing packs, wherein the sound absorbing packs communicate with the ventilation path, and have a concave case formed in a dish shape and a perforated plate provided at a position to close the opening side of the concave case. A silencer for the blower.
[2] The silencer for a blower according to [1], wherein the concave case is disposed with a bottom plate positioned on the downstream side of the air flowing through the ventilation path.
[3] The silencer for a blower according to [1], wherein the sound absorption pack is formed of a material having water resistance.
[4] The silencer for a blower according to [1], wherein the sound absorption pack is formed of a material having heat resistance.

Claims (4)

In the silencer of the blower attached to the discharge port or suction port of the blower,
One end is attached to the discharge port or the suction port of the blower, the other end is opened to the outside, and a cylindrical housing having a ventilation path along the axial direction from the one end side toward the other end side;
A plurality of sound absorbing packs disposed in the cylindrical housing and surrounding the ventilation path and arranged in a stack along the ventilation path,
The sound absorption pack is a silencer for a blower having a concave case formed in a dish shape and a perforated plate provided at a position to close the opening side of the concave case while communicating with the ventilation path.   2. The silencer for a blower according to claim 1, wherein the concave case is disposed with its bottom plate positioned on the downstream side of the air flowing through the ventilation path. 3.   The silencer for a blower according to claim 1, wherein the sound absorption pack is formed of a material having water resistance.   The said sound-absorbing pack is a silencer of the air blower of Claim 1 currently formed with the material which has heat resistance.