Patent Publication Number: US-2023162716-A1

Title: Noise suppressor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2021-188606 filed in Japan on Nov. 19, 2021. 
     FIELD 
     The present disclosure relates to a noise suppressor. 
     BACKGROUND 
     In an apparatus that generates noise, such as a power generator engine, there has been a known configuration for reducing the noise by installing a sound absorber, such as a vent, to a part where sound is emitted (see Patent Literature 1, for example). 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Utility Model Application Laid-open No. H4-125620 
       
    
     SUMMARY 
     Technical Problem 
     An apparatus that generates noise, such as a power generator engine mentioned above, requires a configuration for suppressing the generated noise appropriately. 
     The present disclosure has been made in view of the foregoing, and an object thereof is to provide a noise suppressor capable of suppressing the noise appropriately in power generator equipment provided with a power generator unit that is covered with an enclosure. 
     Solution to Problem 
     A noise suppressor according to the present disclosure is removably installed in power generator equipment including an enclosure and a power generator unit. The enclosure includes at least one of an air intake port and an air discharge port that are vents. The power generator unit is covered with the enclosure. The noise suppressor includes a tubular member having a first opening that opens to a direction different from the vent and a second opening that opens to the vent, forming a channel for gas leading from the first opening to the second opening, and provided with an acoustic liner inside the channel. The tubular member has such a shape that the channel bends at a plurality of points. 
     Advantageous Effects of Invention 
     According to the present disclosure, it is possible to appropriately suppress the noise in power generator equipment that includes a power generator unit that is covered with an enclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic perspective view of an example of power generator equipment to which noise suppressors are applied. 
         FIG.  2    is a schematic illustrating an example of the noise suppressors, viewing a casing from a −Y side. 
         FIG.  3    is a schematic illustrating a configuration on the cross section A-A in  FIG.  2   . 
         FIG.  4    is a schematic illustrating a configuration of the noise suppressor according to one modification. 
         FIG.  5    is a schematic illustrating a configuration of a noise suppressor according to another modification. 
         FIG.  6    is a schematic illustrating a configuration of a noise suppressor according to another modification. 
         FIG.  7    is a schematic illustrating an example of the noise suppressor, viewing the casing from a +Z side. 
         FIG.  8    is a schematic illustrating a configuration on the cross section B-B in  FIG.  7   . 
         FIG.  9    is a schematic illustrating a configuration on the cross section C-C in  FIG.  7   . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of a noise suppressor according to the present disclosure will now be explained with reference to the drawings. However, this embodiment is not intended to limit the scope of the present disclosure in any way. In addition, the following embodiment includes elements that are replaceable or that are easy to replace for those skilled in the art, or those that are substantially the same. 
       FIG.  1    is a perspective view of an example of power generator equipment  100  using noise suppressors  30  and  40 . In the following explanation, the longitudinal direction of the power generator equipment  100  (left-to-right direction in  FIG.  1   ) will be explained as an X direction, the short-hand direction of the power generator equipment  100  (depth direction in  FIG.  1   ) will be explained as a Y direction, and the height direction of the power generator equipment  100  (vertical direction in  FIG.  1   ) will be explained as a Z direction. In each of these coordinates, the direction to which the arrow points will be explained as a + direction, and the direction opposite to that to which the arrow points will be explained as a −direction. 
     As illustrated in  FIG.  1   , the power generator equipment  100  includes an enclosure  10  and a power generator unit  20 . The power generator unit  20  is disposed inside of the enclosure  10 , and is covered with the enclosure  10 . 
     The enclosure  10  includes a base plate  11 , a casing  12 , an air intake duct  13 , and an air discharge duct  14 . The base plate  11  has a rectangular plate-like shape in a plan view, and is installed on a floor surface F. The casing  12  has a rectangular box-like shape, for example. 
     The air intake duct  13  draws the air from the outside of the enclosure  10  into the inside of the enclosure  10 . The air intake duct  13  has air intake ports  13   a  facing outside. The air intake ports  13   a  are disposed on a −Y-side face  12   a  of the casing  12 , for example. 
     The air inside of the enclosure  10  is discharged through the air discharge duct  14  to the outside of the enclosure  10 . The air discharge duct  14  has an air discharge port  14   a  facing the outside. The air discharge port  14   a  is disposed on a face  12   b  corresponding to the ceiling (the +Z-side face) of the casing  12 , for example. 
     The power generator unit  20  is provided with a power generator  21  and a power-generating source  22 . The power generator  21  and the power-generating source  22  are disposed on the base plate  11 , for example. The power-generating source  22  has an engine, such as a diesel engine. The power generator  21  is coupled in a manner driven by the engine included in the power-generating source  22 . The rotational driving power of the engine is transmitted to the power generator  21  and drives the power generator  21 , and electric power is generated thereby. 
     The air comes into the enclosure  10  through the air intake ports  13   a  of the air intake duct  13 , passes through the power generator unit  20 , and is discharged from the air discharge port  14   a  on the air discharge duct  14 . In the enclosure  10 , an air channel is formed between the air intake ports  13   a  and the air discharge port  14   a . The air intake ports  13   a  and the air discharge port  14   a  serve as vents  15 . 
     Noise suppressors  30  are disposed in a manner surrounding the respective air intake ports  13   a . The noise suppressors  30  suppress the noise emitted from the air intake ports  13   a .  FIG.  2    is a diagram schematically illustrating an example of the noise suppressors  30 , viewing the casing  12  from the −Y side.  FIG.  2    illustrates the −Y-side surface as transparent so that the internal structure is visible.  FIG.  3    is schematic illustrating the configuration on a cross section A-A in  FIG.  2   . As illustrated in  FIGS.  2  and  3   , each of the noise suppressors  30  includes tubular members  31  and acoustic dampers  32 . 
     Each of the tubular members  31  has a first opening  31   a  and a second opening  31   b . The first opening  31   a  opens to a direction different from the air intake port  13   a . The second opening  31   b  opens to the air intake port  13   a . The tubular member  31  has walls  33 . The walls  33  of the tubular member  31  form a channel R 1  for gas, the channel leading from the first opening  31   a  to the second opening  31   b . The tubular member  31  has such a shape that the channel R 1  bends at a plurality of points. 
     The tubular members  31  are disposed at positions surrounding the air intake port  13   a , when viewed in a direction perpendicular to the −Y-side face  12   a  (surface) of the casing  12  included in the enclosure  10 . In this embodiment, the noise suppressor  30  is arranged in a rectangular annular shape, in a manner surrounding the four sides of the rectangular air intake port  13   a.    
     The tubular member  31  is provided in plurality, for example. In this embodiment, the noise suppressor  30  includes a tubular member  31  disposed on the upper left side of the air intake port  13   a  in  FIG.  3    (hereinafter, referred to as a tubular member  34 ), a tubular member  31  disposed on the upper right side of the air intake port  13   a  in  FIG.  3    (hereinafter referred to as a tubular member  35 ), a tubular member  31  disposed on the lower left side of the air intake port  13   a  in  FIG.  3    (hereinafter referred to as a tubular member  36 ), and a tubular member  31  disposed on the lower right side of the air intake port  13   a  in  FIG.  3    (hereinafter, referred to as a tubular member  37 ). 
     The tubular member  34  has a second opening  34   b  opening to the −Z direction and to the air intake port  13   a.    
     The tubular member  34  linearly extends along the face  12   a , from the second opening  34   b  to the +Z direction, bends toward a −X direction, and folds back to a −Z direction. The tubular member  34  has a first opening  34   a  that opens to the −X direction on one tip end portion of the folded-back portion. The tubular member  34  has a configuration in which the part extending from the second opening  31   b  to the +Z direction (the part including the +Z-side end) and the folded-back portion are positioned adjacently to each other with the walls  33  interposed therebetween. 
     The tubular member  35  has a second opening  35   b  that opens to the air intake port  13   a  in the −Z direction. The tubular member  35  linearly extends along the face  12   a , from the second opening  35   b  to the +Z direction, bends toward the +X direction, and folds back to the −Z direction. The tubular member  35  has a first opening  35   a  that opens to the +X direction on one tip end portion of the folded-back portion (the −Z side end). The tubular member  35  has a configuration in which the part extending from the second opening  35   b  to the +Z direction (the part including the +Z-side end) and the folded-back portion are positioned adjacently to each other with the walls  33  interposed therebetween. The tubular member  34  and the tubular member  35  have configurations in which their respective parts extending in the +Z direction from the second opening  34   b  and the second opening  35   b  are positioned adjacently to each other with the walls  33  interposed therebetween. 
     The tubular member  36  has a second opening  36   b  that opens to the +Z direction and to the air intake port  13   a . The tubular member  36  linearly extends along the face  12   a , from the second opening  36   b  to the −Z direction, bends toward the −X direction, and folds back to the +Z direction. The tubular member  36  has a first opening  36   a  that opens to the −X direction on a part (the +Z-side tip end portion) of the folded-back portion. The tubular member  36  has a configuration in which the part extending from the second opening  36   b  to the +Z direction (the part including the +Z-side end) and the folded-back portion are positioned adjacently to each other with the walls  33  interposed therebetween. The tubular member  36  also has a configuration in which a part of the folded-back portion (the part including the +Z-side tip end portion) and a part of the tubular member  34  (a part of the folded-back portion on the side of the second opening  34   b ) are positioned adjacently to each other with the walls  33  interposed therebetween. 
     The tubular member  37  has a second opening  37   b  that opens to the +Z direction and to the air intake port  13   a . The tubular member  37  linearly extends along the face  12   a , from the second opening  37   b  to the −Z direction, bends toward the +X direction, and folds back to the +Z direction. The tubular member  37  has a first opening  37   a  that opens to the +X direction on one tip end portion of the folded-back portion. The tubular member  37  has a configuration in which the part extending from the second opening  37   b  to the −Z direction (the part including the +Z-side end) and the folded-back portion are positioned adjacently to each other with the wall  33  interposed therebetween. The tubular member  36  and the tubular member  37  have configurations in which their respective parts extending in the −Z direction from the second opening  36   b  and the second opening  37   b  are positioned adjacently to each other with the walls  33  interposed therebetween. 
     All of the tubular members  31  extend from the second opening  31   b  in directions along the face  12   a . In other words, each of the tubular members  31  extends from the second opening  31   b  to the X direction, to the Z direction, or to a direction of the resultant force of the X direction and the Z direction. This configuration keeps the size of the tubular member  31  in the Y-direction small. 
     The tubular members  31  may be arranged at symmetrical positions with respect to the air intake port  13   a , for example, viewing from a direction perpendicular to the face  12   a . In such a case, for example, the tubular members  31  may be arranged at positions symmetrical to one another in the X direction, or positions symmetrical to one another in the X direction and the Y direction, with respect to the air intake port  13   a.    
     Each of the tubular members  31  has an acoustic liner  38  formed by a plurality of pass-through holes  31   c  provided along the channel R 1 . Each of the pass-through holes  31   c  has a circular shape, for example, and the pass-through holes  31   c  are provided across the entire tubular member  31 . 
     The acoustic dampers  32  are disposed along the tubular members  31 . In this embodiment, the acoustic dampers  32  are provided on the walls  33  of the tubular members  31 , respectively. Specifically, hollow sections  31   d  are provided inside the walls  33 . The hollow sections  31   d  have closed ends on the side of the first opening  31   a  of the corresponding tubular member  31 , and their ends on the side of the second opening  31   b  of the tubular members  31  are connected to the channel R 1 . With this configuration, the walls  33  serve as the acoustic dampers  32 . In this embodiment, the hollow sections  31   d  are formed in such a manner that the cross-sectional area is constant or nearly constant, across the range from the side of the second opening  31   b  to the side of the first opening  31   a  of the tubular member  31 . Alternatively, the acoustic dampers  32  may also be provided separately from the walls  33 . In such a case, the acoustic damper  32  may be disposed along the walls  33 , on both sides of the direction in which the channel R 1  extends, either on the outside or the inside of the tubular member  31 . 
       FIG.  4    is a schematic illustrating a configuration of a noise suppressor  30 A according to one modification. In  FIG.  4   , only the configuration of a tubular member  31 A on the upper left side is illustrated, but the same explanation is also applicable to the other tubular members. The noise suppressor  30 A illustrated in  FIG.  4    has such a shape that the cross-sectional area of the hollow section  31   d  inside a wall  33 A changes in the direction along the channel R 1 . In this configuration, it is possible to increase the band of absorbable frequencies of the noise emitted from the air intake port  13   a , compared with that in the noise suppressor  30  described above. 
       FIG.  5    is a schematic illustrating a configuration of a noise suppressor  30 B according to another modification. In  FIG.  5   , only the configuration of a tubular member  31 B on the upper left side is illustrated, but the same explanation is applicable to the other tubular members. In the noise suppressor  30 B illustrated in  FIG.  5   , each wall  33 B of the tubular member  31 B has a plate-like shape and a solid structure without the hollow section  31   d . The tubular member  31 B has partitions  31   e  that partition the channel R 1  at a plurality of respective points in the direction along the channel R 1 . The partitions  31   e  partition the channel R 1  inside of the tubular member  31 B into a plurality of spaces  31   s . Each of the partitions  31   e  is provided with a connecting hole  31   f . The connecting holes  31   f  connect the spaces  31   s  adjacent to each other. By partitioning the channel R 1  into a plurality of spaces  31   s  with the partitions  31   e , and connecting the spaces  31   s  with the connecting holes  31   f  provided to the partitions  31   e , an acoustic damper  32  can be provided inside the channel R 1 . 
       FIG.  6    illustrates the configuration of the noise suppressor  30 C according to another modification. In  FIG.  6   , only the configuration of a tubular member  31 C on the upper left side is illustrated, but the same explanation is applicable to the other tubular members. In the noise suppressor  30 C illustrated in  FIG.  6   , the wall  33 C of the tubular member  31 C has a plate-like shape and a solid structure without the hollow sections  31   d . The tubular member  31 C has a structure with a perforated plate  39  placed on the inner surface of the wall  33 C. With this configuration, noise can be reduced efficiently. 
     The noise suppressors  30 ,  30 A,  30 B described above may be configured to be removable from the casing  12  of the enclosure  10  using an attachment, not illustrated, such as a magnet. 
     Returning to  FIG.  1   , the noise suppressor  40  is disposed in the air discharge port  14   a . The noise suppressor  40  suppresses the noise emitted from the air discharge port  14   a .  FIG.  7    is a schematic illustrating an example of the noise suppressor  40 , viewing the casing  12  from the +Z side.  FIG.  8    is a schematic illustrating the configuration on the cross section B-B in  FIG.  7   .  FIG.  9    is a schematic illustrating the configuration on the cross section C-C in  FIG.  7   . As illustrated in  FIGS.  7  to  9   , the noise suppressor  40  has a tubular member  41 , a cover member  42 , and an acoustic damper  43 . 
     The tubular member  41  is cylindrical, for example, and has a first opening  41   a  and a second opening  41   b . The first opening  41   a  opens to a direction different from the air discharge port  14   a . The second opening  41   b  opens to the air discharge port  14   a . The tubular member  41  has a round-tube like wall  44 . The wall  44  of the tubular member  41  forms a channel R 2  for gas, the channel leading from the first opening  41   a  to the second opening  41   b . The channel R 2  is a channel that is an extension of the channel provided inside the air discharge duct  14 , to the outside of the air discharge duct  14  (the outside of the enclosure  10 ). The tubular member  41  has such a shape that the channel bends at a plurality of points. The second opening  41   b  is provided to an area overlapping with a part of the air discharge port  14   a , in a view from the +Z direction. Part of the gas discharged from the air discharge port  14   a  flows into the tubular member  41  through the second opening  41   b.    
     In the tubular member  41 , the second opening  41   b  opens to the −Z direction, in a manner facing the air discharge port  14   a . The tubular member  41  extends in the +Z direction from the second opening  41   b , and is bent toward the +X direction, and bent again toward the +Z direction. In this manner, the tubular member  41  is provided in a manner extending in the +Z direction and the +X direction, alternatingly. The first opening  41   a  opens to a direction different from the air discharge port  14   a , e.g., to the +Z direction. 
     The tubular member  41  has an acoustic liner  49  having a plurality of pass-through holes  41   c  that are provided along the channel R 2 . Each of the pass-through holes  41   c  has a circular shape, for example, and the pass-through holes  41   c  are provided across the entire tubular member  41 . 
     The cover member  42  has an outer shell  45  and an inner wall  46 . The outer shell  45  is disposed on the area covering a part of the face  12   b  of the casing  12  of the enclosure  10  that includes the air discharge port  14   a . The outer shell  45  has a shape of a rectangular box, for example. The outer shell  45  has a duct-side opening  45   a  and an outer-side opening  45   b . The duct-side opening  45   a  is provided on the −Z side face of the outer shell  45  across the area facing the air discharge port  14   a . The outer-side opening  45   b  is provided to the +Z side face of the outer shell  45 , on the end of the +X side, in a manner facing the +Z direction. 
     The inner wall  46  partitions the inside of the outer shell  45 . The inner wall  46  includes walls  46   a  and  46   b  making up the acoustic damper  43  for the tubular member  41  described above, a wall  46   c  that defines a channel R 3  for distributing the gas discharged via the air discharge port  14   a  from routes other than the tubular member  41 , and a wall  46   d  making up an acoustic damper  43  (rectangular-tube-side damper  48 ) corresponding to the channel R 3 . The tubular member  41  described above is partly housed in the space defined by the walls  46   a ,  46   b , and  46   f , and the outer shell  45 . The channel R 3  is partitioned by the wall  46   b  and the wall  46   c  mentioned above, and the −Z-side face and the +Y-side face of the outer shell  45 . The channel R 3  is connected to the outer-side opening  45   b  of the outer shell  45 . The configuration of the inner walls  46 , such as the arrangement of the walls  46   a ,  46   b ,  46   c ,  46   d , for example, is not limited to that described above, and may be any other configurations. 
     The acoustic damper  43  includes a round-tube-side damper  47  corresponding to the channel R 2  (tubular member  41 ), and the rectangular-tube-side damper  48  corresponding to the channel R 3 . The round-tube-side damper  47  and the rectangular-tube-side damper  48  have first damper sections  47   a ,  48   a , respectively, and second damper sections  47   b ,  48   b , respectively, the first and the second damper sections being designed for different frequencies, respectively. These different frequencies may be, for example, frequencies corresponding to the first-order and second-order resonance frequencies of the noise emitted from the power-generating source  22 , respectively. 
     As described above, the noise suppressor  30 ,  40  according to this embodiment is a noise suppressor  30 ,  40  that is removably installed in the power generator equipment  100  including an enclosure  10  that includes at least one of the air intake port  13   a  and the air discharge port  14   a  that are the vents  15 , and the power generator unit  20  that is covered with the enclosure  10 , the noise suppressor  30 ,  40  including: the tubular member  31 ,  41  that has the first opening  31   a ,  41   a  that opens to a direction different from the vent  15 , and the second opening  31   b ,  41   b  that opens to the vent  15 , that forms the channel R 1 , R 2  for gas, the channel leading from the first opening  31   a ,  41   a  to the second opening  31   b ,  41   b  and that is provided with the acoustic liner  38  inside the channel, wherein the tubular member  31 ,  41  has such a shape that the channel R 2 , R 3  bends at a plurality of points. 
     Therefore, it becomes possible to suppress the noise appropriately in the power generator equipment  100  provided with the power generator unit  20  that is covered with the enclosure  10 , while enabling the noise suppressor  30 ,  40  to be handled easily, e.g., attached or removed to or from the enclosure  10  easily, and achieving space saving, compared with a configuration including the linear tubular members  31  and  41 . 
     In the noise suppressor  30 ,  40  according to the embodiment described above, the tubular member  31 ,  41  includes an acoustic liner formed by the pass-through holes  31   c ,  41   a  provided along the channel. Therefore, the noise can be reliably suppressed in the tubular member  31 ,  41 . 
     In the noise suppressor  30  according to the embodiment described above, the enclosure  10  has the air intake ports  13   a , the second opening  31   b  opens to the air intake port  13   a  in the direction along the face  12   a , and the tubular member  31  extends from the second opening  31   b  in a direction along the face  12   a . Therefore, the size in a direction perpendicular to the face  12   a  can kept small, and compactness can be ensured. 
     In the noise suppressor  30  according to the embodiment described above, the tubular member  31  is positioned in a manner surrounding the air intake port  13   a , in a view from a direction perpendicular to the face  12   a . Thus, the noise emitted from the air intake ports  13   a  can be efficiently reduced. 
     In the noise suppressor  30  according to the embodiment described above, the tubular members  31  are arranged symmetrically with respect to the air intake port  13   a  in a view from a direction perpendicular to the face  12   a . Thus, the noise emitted from the air intake ports  13   a  can be efficiently reduced. 
     In the noise suppressor  40  according to the embodiment described above, the enclosure  10  has the air discharge port  14   a , the second opening  41   b  is positioned facing the air discharge port  14   a , and the tubular member  41  extends from the second opening  41   b  in a direction separating from the face  12   b . Therefore, it is possible to suppress the noise emitted from the air discharge port  14   a , while ensuring that the gas discharged from the air discharge port  14   a  is supplied into the tubular member  41 . 
     The noise suppressor  30 ,  40  according to the embodiment described above also includes the acoustic damper  32 ,  43  disposed along the tubular member  31 ,  41 . Thus, the noise emitted from the air intake port  13   a  and the air discharge port  14   a  can be efficiently reduced. 
     In the noise suppressor  30  according to the embodiment described above, the acoustic damper  32  is formed by providing the tubular member  31  with the wall  33  that partitions the channel R 1 , by providing the wall  33  with the hollow section  31   d  inside, and by connecting an end of the hollow section  31   d  to the channel R 1 , the end being on the side of the second opening  31   b . Thus, the noise emitted from the air intake ports  13   a  can be efficiently reduced. 
     In the noise suppressor  30 A according to the embodiment described above, the hollow section  31   d  has such a shape that the cross-sectional area thereof changes in the direction along the channel. Thus, it is possible to increase the band of frequencies of noise that can be suppressed. 
     In the noise suppressor  30 B according to the embodiment described above, the tubular member  31  has the partitions  31   e  that partition the channel at a plurality of points in the direction along the channel R 1  and is formed as the acoustic damper  32  by providing the partitions  31   e  with the connecting holes  31   f  connecting the spaces  31   s  adjacent to each other. Thus, the noise emitted from the air intake ports  13   a  can be efficiently reduced. 
     In the noise suppressor  30 C according to the embodiment described above, the perforated plate  39  is disposed on the inner surface of the tubular member  31 . Thus, the noise emitted from the air intake ports  13   a  can be efficiently reduced. 
     The technical scope of the present invention is not limited to the embodiment described above, and changes may be made as appropriate, within the scope not deviating from the gist of the present invention. For example, the configurations of the noise suppressors  30 A,  30 B, and  30 C may be applied to the noise suppressor  40 . 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  Enclosure 
               11  Base plate 
               12  Casing 
               12   a ,  12   b  Face 
               13  Air intake duct 
               13   a  Air intake port 
               14  Air discharge duct 
               14   a  Air discharge port 
               15  Vent 
               20  Power generator unit 
               21  Power generator 
               22  Power-generating source 
               30 ,  30 A,  30 B,  30 C,  40  Noise suppressor 
               31 ,  31 B,  34 ,  35 ,  36 ,  37 ,  41  Tubular member 
               31   a ,  34   a ,  35   a ,  36   a ,  37   a ,  41   a  First opening 
               31   b ,  34   b ,  35   b ,  36   b ,  37   b ,  41   b  Second opening 
               31   c ,  41   a ,  41   c  Pass-through hole 
               31   d  Hollow section 
               31   e  Partition 
               31   f  Connecting hole 
               31   s  Space 
               32 ,  43  Acoustic damper 
               33 ,  33 A,  33 B,  44 ,  46   a ,  46   b ,  46   c ,  46   d  Wall 
               38  Acoustic liner 
               39  Perforated plate 
               42  Cover member 
               45  Outer shell 
               45   a  Duct-side opening 
               45   b  Outer-side opening 
               46  Inner wall 
               47  Round-tube-side damper 
               47   a ,  48   a  First damper section 
               47   b ,  48   b  Second damper section 
               48  Rectangular-tube-side damper 
               100  Power generator equipment 
             F Floor surface 
             R 1 , R 2 , R 3  Channel