CN107438212B - Bass reflex port and acoustic apparatus - Google Patents
Bass reflex port and acoustic apparatus Download PDFInfo
- Publication number
- CN107438212B CN107438212B CN201710379202.5A CN201710379202A CN107438212B CN 107438212 B CN107438212 B CN 107438212B CN 201710379202 A CN201710379202 A CN 201710379202A CN 107438212 B CN107438212 B CN 107438212B
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- China
- Prior art keywords
- bass reflex
- reflex port
- wall surface
- end portion
- tubular member
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- 230000011514 reflex Effects 0.000 title claims abstract description 234
- 239000000463 material Substances 0.000 claims description 27
- 230000002159 abnormal effect Effects 0.000 description 21
- 238000000034 method Methods 0.000 description 10
- 230000000903 blocking effect Effects 0.000 description 7
- 230000008901 benefit Effects 0.000 description 6
- 239000011358 absorbing material Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2807—Enclosures comprising vibrating or resonating arrangements
- H04R1/2815—Enclosures comprising vibrating or resonating arrangements of the bass reflex type
- H04R1/2823—Vents, i.e. ports, e.g. shape thereof or tuning thereof with damping material
- H04R1/2826—Vents, i.e. ports, e.g. shape thereof or tuning thereof with damping material for loudspeaker transducers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2876—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of damping material, e.g. as cladding
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2884—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of the enclosure structure, i.e. strengthening or shape of the enclosure
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2430/00—Signal processing covered by H04R, not provided for in its groups
Abstract
The bass reflex port includes a tubular member. A portion of the wall of the tubular member has a stiffness less than the stiffness of the remainder of the tubular member. The rigidity of the wall surface of at least one end portion of the tubular member in the axial direction of the tubular member is smaller than the rigidity of the wall surface of the central portion of the tubular member in the axial direction.
Description
Technical Field
The present invention relates to a bass reflex port and an acoustic apparatus such as a bass reflex speaker.
Background
There has been proposed a bass reflex speaker which enhances the volume of low-pitched sound by using sound emitted from a speaker unit to the rear side of a cabinet of the bass reflex speaker. In the bass reflex speaker, a bass reflex port that communicates the inside and the outside of a housing (enclosure) with each other is provided. In the bass reflex speaker, abnormal sound (noise) is caused from the bass reflex port. Therefore, various techniques have been proposed to reduce abnormal sounds caused from the bass reflex port.
JP-UM-a-56-63182 discloses a loudspeaker system in which a sound absorbing material, such as glass wool, is attached to at least one opening of a bass reflex port. According to this technique, air eddies generated at the opening of the bass reflex port are suppressed by the sound absorbing material, thereby reducing abnormal sounds.
JP-UM-a-58-173989 discloses a bass reflex enclosure for a loudspeaker in which a cushioning material such as urethane is provided at a free end portion opposite to a fixed end portion fixed to the enclosure in a bass reflex port. The free end portion is not fixed to any portion. According to this technique, vibration at the free end of the bass reflex port becomes difficult to occur, thereby reducing abnormal sound.
However, although the technique disclosed in JP-UM-a-56-63182 or JP-UM-a-58-173989 is used, abnormal sound caused from the bass reflex port due to air flowing in the bass reflex port cannot be sufficiently reduced.
Disclosure of Invention
The present invention has been made in view of the above circumstances, and an object thereof is to reduce abnormal sound due to air flowing in a bass reflex port.
The invention provides a bass reflex port, which comprises a tubular member and is characterized in that the rigidity of one part of the wall surface of the tubular member is less than that of the other part. The present invention also provides an acoustic apparatus provided with a bass reflex port.
When air flows in the bass reflex port, a pressure distribution occurs in the enclosure (outside of the bass reflex port) and in the bass reflex port, and an air pressure difference is caused between the inside and the outside of the bass reflex port. In the bass reflex port according to the present invention, the portion having low rigidity on the wall surface moves according to the air pressure difference. As a result, the bass reflex port (in particular, a portion having low rigidity on the wall surface of the bass reflex port) is deformed. When the bass reflex port deforms according to the air pressure difference, the shape of the inner wall surface on the portion having low rigidity changes randomly at each position and at each timing. Thereby, the flow velocity distribution of air in the vicinity of the inner wall surface of the bass reflex port is disturbed, so that the position and timing at which the vortex occurs are randomly changed. Since the position and timing at which the vortex occurs are not concentrated but dispersed, in the present bass reflex port, the growth of the vortex can be suppressed, so that abnormal sound due to the vortex can be reduced. That is, according to the acoustic apparatus provided with the present bass reflex port, abnormal sound due to air flowing in the bass reflex port can be reduced.
According to the technique disclosed in JP-UM-a-56-63182, a sound absorbing material is attached to the bass reflex port, and according to the technique disclosed in JP-UM-a-58-173989, a cushioning material is attached to the bass reflex port. According to the techniques disclosed in JP-UM-a-56-63182 and JP-UM-a-58-173989, the bass reflex port is not deformed so that the position and timing at which vortex occurs cannot be dispersed. In contrast, in the present bass reflex port, the position and timing at which the vortex occurs can be dispersed as described above, so that the growth of the vortex can be suppressed. For this reason, according to the present bass reflex port, abnormal sounds caused from the bass reflex port due to air flowing in the bass reflex port can be sufficiently reduced as compared with the bass reflex ports disclosed in JP-UM-a-56-63182 and JP-UM-a-58-173989.
Further, according to the techniques disclosed in JP-UM-a-56-63182 and JP-UM-a-58-173989, since the position and timing at which the vortex occurs cannot be dispersed, even if the abnormal sound is reduced, only the sound of a specific frequency according to the material characteristics and the placement position of the sound absorbing material and the cushioning material is reduced. In contrast, in the present bass reflex port, the position and timing at which the vortex occurs dynamically change according to the air pressure difference, which also changes at timing. For example, at a certain time, the vortex occurs at a position near the center on the end portion of the bass reflex port, and at another time different from this, the vortex occurs at a position near the opening end on the end portion of the bass reflex port. The sound frequency due to the vortices at a position near the center on the end portion of the bass reflex port and the sound frequency due to the vortices at a position near the opening end on the end portion of the bass reflex port are different. As described above, in the present bass reflex port, since the positions and timings at which vortices occur are dispersed, abnormal sounds caused by concentrated occurrence of vortices at specific positions and timings never become conspicuous, so that abnormal sounds of a plurality of frequencies in a predetermined frequency range like a continuous spectrum can be reduced. In this regard, according to the present bass reflex port, abnormal sound caused from the bass reflex port due to air flowing in the bass reflex port can also be sufficiently reduced as compared with the bass reflex ports disclosed in JP-UM-a-56-63182 and JP-UM-a-58-173989.
Drawings
Fig. 1 is a sectional view showing the structure of an acoustic apparatus including a bass reflex port according to a first embodiment of the present invention.
Fig. 2 is a sectional view showing the structure of the bass reflex port.
Fig. 3 is a side view showing the structure of the bass reflex port.
Fig. 4 is a sectional view showing the structure of a bass reflex port 30A of an acoustic apparatus 1A provided with the bass reflex port 30A according to a second embodiment of the present invention.
Fig. 5 is a sectional view showing the structure of a bass reflex port 30B of an acoustic apparatus 1B provided with the bass reflex port 30B according to a third embodiment of the present invention.
Fig. 6 is a view showing the structure of a bass reflex port 30C of an acoustic apparatus 1C provided with the bass reflex port 30C according to a fourth embodiment of the present invention.
Fig. 7 is a sectional view showing the structure of a bass reflex port 30D of an acoustic apparatus 1D provided with the bass reflex port 30D according to a fifth embodiment of the present invention.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
< first embodiment >
Fig. 1 is a sectional view showing the structure of an acoustic apparatus 1 including a bass reflex port 30 according to a first embodiment of the present invention. The acoustic apparatus 1 emits sound in response to an acoustic signal supplied from an external apparatus, and specifically, the acoustic apparatus 1 is a bass reflex speaker. The acoustic apparatus 1 has an enclosure 10 (which is a housing of the acoustic apparatus 1), a bass reflex port 30, and a speaker unit 20 formed with a diaphragm, a voice coil, or the like.
The enclosure 10 is a hollow structure (generally, rectangular parallelepiped-shaped) formed by a plurality of plate members. The speaker unit 20 is fixed to the plate member 12 among the plate members constituting the enclosure 10. The plate member 12 serves as a barrier surface. The plate member 12 has a circular opening 14 through the plate member 12. Although the enclosure 10 in the present embodiment is formed with a plurality of plate members, the enclosure 10 may be a resin molded product formed by injection molding or the like. Moreover, although the opening 14 is provided on the plate member serving as the blocking surface (i.e., the plate member 12) in the acoustic apparatus 1 in the present embodiment, the opening 14 may be provided on a surface other than the blocking surface, such as the rear surface or the side surface of the enclosure 10. Also, the shape of the opening 14 is not limited to a circle and may be different shapes.
The bass reflex port 30 is a hollow and substantially cylindrical tube, and is provided in the enclosure 10. Both ends of the bass reflex port 30 are opened. One open end of the bass reflex port 30 is fixed to the rim of the opening 14 of the plate member 12. The other open end of the bass reflex port 30 is located in the enclosure 10. The space in the enclosure 10 and the space outside the enclosure 10 communicate through the bass reflex port 30 and the opening 14. For this reason, air inside and outside the enclosure 10 passes in the bass reflex port 30.
In this specification, a line as the center of the tube in the bass reflex port 30 will be referred to as a tube axis. Also, in the present specification, of both end portions of the bass reflex port 30, the end portion fixed to the rim of the opening 14 will be referred to as an outer side, and the end portion opened in the enclosure 10 will be referred to as an inner side. Also, in this specification, at each end of the bass reflex port 30, a region predetermined from the opening end in the tube axis direction will be referred to as an end portion. Also, a region predetermined at the center of the bass reflex port 30 in the tube axis direction will be referred to as a center portion.
Fig. 2 is a sectional view showing the structure of the bass reflex port 30. The bass reflex port 30 includes a first tube 32, a second tube 34, and a sheet member 36. The first pipe 32 is a tubular member of a cylindrical shape (hereinafter referred to as a tubular shape) in which an inner diameter and an outer diameter are kept substantially constant from one end to the other end thereof. The first tube 32 is, for example, a paper tube formed of a paper material (e.g., recycled paper). The constituent material of the first tube 32 is not limited to paper and may be resin or the like.
The second tube 34 is a tubular member having a straight tube shape with an inner diameter substantially equal to the outer diameter of the first tube 32. The material forming the second tube 34 is, for example, synthetic resin. The length of the second tube 34 is shorter than the length of the first tube 32. A flange 35 is provided at one end of the second pipe 34.
One end side of the first pipe 32 is accommodated in the second pipe 34, and is fixed to the second pipe 34 by an appropriate frictional force between an outer wall surface of the first pipe 32 and an inner wall surface of the second pipe 34. In the case where the first pipe 32 is fixed to the second pipe 34, the other end side of the first pipe 32 protrudes to the outside of the second pipe 34 from the end portion of the second pipe 34 opposite to the end portion where the flange 35 is provided. The flange 35 of the second pipe 34 is fixed to the rim of the opening 14 of the plate member 12 (blocking surface).
The first tube 32 is provided with a sheet member 36 that protrudes from an end 33 of the first tube 32 opposite to the blocking surface in the extending direction of the first tube 32. The material forming the sheet member 36 is, for example, felt, and the rigidity of the sheet member 36 is smaller than that of the first tube 32. The sheet member 36 extends in the circumferential direction (radial direction) of the first tube 32, and forms a tube that is disposed in a position where the first tube 32 extends.
The sheet member 36 is provided to cover the end 33 of the first tube 32. More specifically, the sheet member 36 is partially fixed to the inner wall surface of the first pipe 32. In the example of fig. 2, the sheet member 36 is fixed over the entire inner wall surface of the first pipe 32. The sheet member 36 extends so as to protrude from the end 33 of the first pipe 32 in the extending direction of the first pipe 32, and is folded back in such a manner that a space 38 is formed by the end 33 of the first pipe 32 and the sheet member 36, and the end of the extended portion thereof is fixed to the outer wall surface of the first pipe 32. An example of a method of fixing the sheet member 36 to the first tube 32 is a method using a double-sided adhesive tape. A binding tape or the like may be wound, as a supplement, so that the portion of the sheet member 36 adhered to the outer wall surface of the first tube 32 is not peeled off. As described above, in the bass reflex port 30, the sheet member 36 is fixed in such a manner as to protrude from the end portion 33 of the first tube 32 in the extending direction. Thus, in the bass reflex port 30, the portion of the sheet member 36 folded back toward the inside is the end portion of the bass reflex port 30.
The portion of the first tube 32 accommodated in the second tube 34 (more precisely, including the sheet member 36 fixed to the inner wall surface of the first tube 32) and the second tube 34 constitute the wall surface of the outer end portion of the bass reflex port 30. The portion of the first pipe 32 protruding from the second pipe 34 (more precisely, including the sheet member 36 fixed to the inner wall surface of the first pipe 32) constitutes a wall surface of the central portion of the bass reflex port 30. The portion of the sheet member 36 protruding from the first tube 32 constitutes a wall surface of the inner end portion of the bass reflex port 30. Since the rigidity of the sheet member 36 (felt) is smaller than that of the first tube 32 (paper tube) in the bass reflex port 30, the rigidity of the wall surface of the inner side end portion of the bass reflex port 30 is smaller than that of the wall surface of the central portion thereof. For this reason, in the bass reflex port 30, the wall surface of the inner side end portion is easily deformed.
In the bass reflex port 30, the sheet member 36 is folded back at the inner end. For this reason, at the turn-back portion, the bass reflex port 30 has an expanded shape (albeit slightly) in which the area of the region surrounded by the sheet member 36 increases toward the inside end.
Fig. 3 is a side view showing the structure of the bass reflex port 30. On a portion of the sheet member 36 serving as an outer wall surface (in other words, an outer layer portion of the sheet member 36 folded back into two layers), in the circumferential direction, more than one cut portion 39 in the extending direction of the first pipe 32 is provided. For this reason, when the bass reflex port 30 is manufactured, the sheet member 36 fixed to the inner wall surface is folded back toward the outer wall surface of the first tube 32 in order, and is easily fixed to the outer wall surface of the first tube 32. On the other hand, on the bass reflex port 30, a cut portion similar to the cut portion 39 of the portion serving as the outer wall surface is not provided on the inner wall surface serving as the sheet member 36 (in other words, the inner layer portion of the sheet member 36 folded back into two layers).
The above is the configuration of the acoustic apparatus 1 having the bass reflex port 30.
When the air in the enclosure 10 is vibrated by the vibration of the diaphragm of the speaker unit 20, air pressure distribution occurs in the enclosure 10 (outside the bass reflex port 30) and the bass reflex port 30. Such air pressure distribution changes at every moment in accordance with the vibration of the diaphragm of the speaker unit 20. In the acoustic apparatus 1, since such air pressure distribution occurs, an air pressure difference is caused between the inside and the outside of the bass reflex port 30. Typically, a difference is created between the air pressure in the bass reflex port 30 and the air pressure in the enclosure 10. And air inside and outside the enclosure 10 passes in the bass reflex port 30.
As described above, in the bass reflex port 30, the rigidity of the wall surface of the inner side end portion is smaller than that of the wall surface of the central portion. For this reason, in the bass reflex port 30, the inner side end portion having low rigidity (especially the sheet member 36) is randomly moved in the radial direction, the circumferential direction, and the tube axis direction of the bass reflex port 30 and the resultant direction (synthetic direction) of these directions. As a result, the bass reflex port 30 (especially the sheet member 36) is deformed. When the bass reflex port 30 deforms according to the air pressure difference, the shape of the inner wall surface changes randomly at each position and at each time. Thereby, the air flow velocity distribution in the vicinity of the inner wall surface of the bass reflex port 30 is disturbed, so that the position and timing at which the vortex occurs are randomly changed. That is, in the bass reflex port 30, the position and timing of the vortex generated by the air pressure difference are not concentrated but dynamically dispersed. For this reason, the growth of the vortex can be suppressed in the bass reflex port 30 as compared with the conventional bass reflex port.
As described above, according to the bass reflex port 30, since the growth of the vortex can be suppressed by dynamically dispersing the position and timing at which the vortex occurs, compared to the conventional bass reflex port, the abnormal sound due to the vortex is sufficiently reduced. That is, according to the acoustic apparatus 1 provided with the bass reflex port 30, abnormal sound due to air flowing in the bass reflex port 30 can be sufficiently reduced.
In the bass reflex port 30 of the present embodiment, the position and timing at which the vortex occurs dynamically change according to the air pressure difference that changes from moment to moment. For example, at a certain timing, the swirl occurs at a position near the center on the end portion of the bass reflex port 30, and at a different timing from this, the swirl occurs at a position near the opening end on the end portion of the bass reflex port 30. The sound frequency caused by the vortices at a position near the center on the end portion of the bass reflex port 30 and the sound frequency caused by the vortices at a position near the opening end on the end portion of the bass reflex port 30 are different. As described above, in the bass reflex port 30 of the present embodiment, since the positions and timings at which vortices occur are dispersed, abnormal sounds due to the concentrated occurrence of vortices at specific positions and timings no longer become conspicuous, so that abnormal sounds at a plurality of frequencies in a predetermined frequency range similar to a continuous spectrum can be reduced. In this regard, according to the bass reflex port 30 of the present embodiment, abnormal sounds caused from the bass reflex port due to air flowing in the bass reflex port are also sufficiently reduced as compared with the conventional bass reflex port.
In the bass reflex port 30 of the present embodiment, the sheet member 36 protrudes from the end portion 33 of the first tube 32 in such a manner as to form the space 38. Thus, the wall surface inside the bass reflex port 30 can be made to have flexibility desired for appropriately deforming it in accordance with the air pressure difference.
In the sheet member 36 of the bass reflex port 30 of the present embodiment, a cut portion 39 is provided in a portion serving as an outer wall surface. In the bass reflex port 30, since these cut portions 39 are provided, not only an advantage that the sheet member 36 is easily fixed to the first tube 32 but also an advantage that the abnormal sound reduction effect can be enhanced because the sheet member 36 is easily deformed is obtained as compared with a case where the cut portions 39 are not provided.
Although felt is described as a preferable example of the sheet member 36 in the present embodiment, the sheet member 36 is not limited to felt but may be sheet-like resin or the like. Briefly, any pattern may be employed as long as the sheet member 36 is made of a material less rigid than that of the first tube 32. Also, although the sheet member 36 is fixed to the entire inner wall surface of the first pipe 32 in the present embodiment, the sheet member 36 may be fixed to a part of the inner wall surface of the first pipe 32. Also, the sheet member 36 folded back may be fixed to the entire outer wall surface of the first tube 32 instead of being fixed to a part of the outer wall surface of the first tube 32.
< second embodiment >
Fig. 4 is a sectional view showing the structure of a bass reflex port 30A of an acoustic apparatus 1A provided with the bass reflex port 30A according to a second embodiment of the present invention. The acoustic apparatus 1A is similar to the acoustic apparatus 1 of the first embodiment except for the bass reflex port 30A.
The bass reflex port 30A has a straight pipe shape where the area of the region surrounded by the inner wall surface is kept substantially fixed from the outer end to the inner end. The bass reflex port 30A includes a first tube 32A and a second tube 36A. The first pipe 32A constitutes a wall surface outside and a wall surface in the central portion of the bass reflex port 30A. The second tube 36A constitutes an inner wall surface. The material forming the first tube 32A and the material forming the second tube 36A are the same, and the first tube 32A and the second tube 36A are formed, for example, by integral molding. The thickness of the wall surface of the second pipe 36A is smaller than that of the first pipe 32A. That is, in the bass reflex port 30A, the rigidity of the wall surface of the inner end portion is made smaller than that of the center portion by making the thickness of the wall surface of the inner end portion smaller than the material of the wall surface of the center portion.
The bass reflex port 30A is not provided with the sheet member 36 of the first embodiment. However, the bass reflex port 30A is similar to the bass reflex port 30 in that the rigidity of the wall surface of the inner side end portion is smaller than that of the wall surface of the central portion. For this reason, in the bass reflex port 30A, as in the bass reflex port 30, the inner side end portion moves randomly according to the air pressure difference, so that the bass reflex port 30A is deformed. Therefore, in the present embodiment, advantages similar to those of the first embodiment are achieved. In the present embodiment, by forming the first tube 32A and the second tube 36A with the same material and making the thickness of the wall surface of the second tube 36A smaller than that of the first tube 32A, the rigidity of the wall surface of the inner side end portion of the bass reflex port 30A is made smaller than that of the wall surface of the central portion. However, if the rigidity of the wall surface of the inner end portion of the bass reflex port 30A is made smaller than the rigidity of the wall surface of the central portion by making the thickness of the wall surface of the second tube 36A smaller than the thickness of the wall surface of the first tube 32A, the constituent material of the first tube 32A and the constituent material of the second tube 36A may be different.
< third embodiment >
Fig. 5 is a sectional view showing the structure of a bass reflex port 30B of an acoustic apparatus 1B provided with the bass reflex port 30B according to a third embodiment of the present invention. The acoustic apparatus 1B is similar to the acoustic apparatus 1 of the first embodiment except for the bass reflex port 30B.
Similarly to the bass reflex port 30A of the second embodiment, the bass reflex port 30B has a straight tube shape from the outside end portion to the inside end portion. The bass reflex port 30B has a first tube 30B and a second tube 36B. The first tube 30B constitutes a wall surface of an outer end portion and a wall surface of a central portion of the bass reflex port 30B. The second tube 36B constitutes an inner wall surface. The wall surface of the first tube 32B and the wall surface of the second tube 36B have the same thickness. The second tube 36B is formed of a material that is more flexible than the material forming the first tube 32B. The second tube 36B is fixed to the first tube 32B by an adhesive or the like. That is, in the bass reflex port 30B, the rigidity of the wall surface of the inner end portion is made smaller than that of the wall surface of the central portion by making the material of the wall surface forming the inner end portion more flexible than the material of the wall surface forming the central portion.
In the bass reflex port 30B, as in the second embodiment, the sheet member 36 of the first embodiment is not provided. However, like the second embodiment, the bass reflex port 30B is similar to the bass reflex port 30 of the first embodiment in that the rigidity of the wall surface of the inner side end portion is made smaller than the rigidity of the wall surface of the central portion. For this reason, in the bass reflex port 30B, as in the bass reflex port 30, the inner side end portion moves randomly according to the air pressure difference, so that the bass reflex port 30B is deformed. Therefore, in the present embodiment, advantages similar to those of the first embodiment are achieved.
< fourth embodiment >
Fig. 6 is a view showing the structure of a bass reflex port 30C of an acoustic apparatus 1C provided with the bass reflex port 30C according to a fourth embodiment of the present invention. The acoustic apparatus 1C is similar to the acoustic apparatus 1 of the first embodiment except for the bass reflex port 30C.
Similarly to the bass reflex port 30A and the bass reflex port 30B, the bass reflex port 30C has a straight tube shape from the outside end portion to the inside end portion. The bass reflex port 30C has a first tube 32C and a second tube 36C. The first pipe 30C constitutes a wall surface of an inner end portion and a wall surface of a central portion of the bass reflex port 30C. The second tube 36C constitutes a wall surface of the outer end portion. The second tube 36C is fixed to the edge of the opening 14 of the plate member 12 by an adhesive or the like. The wall surface of the first tube 32C and the wall surface of the second tube 36C have the same thickness. The second tube 36C is formed of a material that is more flexible than the material forming the first tube 32C. The second tube 36C is fixed to the first tube 32C by an adhesive or the like. That is, in the bass reflex port 30C, the rigidity of the wall surface of the outer end portion is made smaller than the rigidity of the wall surface of the central portion by making the material of the wall surface forming the outer end portion more flexible than the material of the wall surface forming the central portion.
The bass reflex port 30C is similar to the bass reflex ports 30 to 30B of the first to third embodiments in that the rigidity of the wall surface of the end portion of the bass reflex port 30C in the vicinity of the boundary between the inside and the outside of the bass reflex port 30C is smaller than the rigidity of the wall surface of the central portion. For this reason, in the bass reflex port 30C, as in the bass reflex port 30, the outside end portion moves randomly according to the air pressure difference, so that the bass reflex port 30C is deformed. Therefore, in the present embodiment, advantages similar to those of the first embodiment are achieved.
For example, the wall surface of the second pipe 36C of the bass reflex port 30C can be deformed in accordance with the air pressure difference and has rigidity to such an extent that the bass reflex port 30C remains self-sustainable with respect to the plate member 12.
The second tube 36C may have a structure in which a first stiffness region having a stiffness smaller than the height of the wall surface of the central portion and a second stiffness region having a stiffness larger than that of the first stiffness region are repeated in the circumferential direction of the second tube 36C. According to this embodiment, the portions of the first rigidity region of the second duct 36C move randomly according to the air pressure difference so that the bass reflex port 30C can be deformed, and the bass reflex port 30C can be kept self-sustaining by some portions of the second rigidity region of the second duct 36C.
< fifth embodiment >
Fig. 7 is a sectional view showing the structure of a bass reflex port 30D of an acoustic apparatus 1D provided with the bass reflex port 30D according to a fifth embodiment of the present invention. The acoustic apparatus 1D is similar to the acoustic apparatus 1 of the first embodiment except for the bass reflex port 30D.
The bass reflex port 30D is different from the bass reflex port 30 of the first embodiment in that it has a sheet member 36D in place of the sheet member 36. The sheet member 36D is partially fixed to the inner wall surface of the first tube 32, and extends to protrude from the end portion 33 of the first tube 32 in the extending direction of the first tube 32. In the bass reflex port 30D, an end of the protruding portion of the sheet member 36D is an inner side end of the bass reflex port 30D. The portion of the sheet member 36D protruding from the first tube 32 constitutes a wall surface of the inner side end portion of the bass reflex port 30D.
In the bass reflex port 30D, the sheet member 36D is not folded back at the inner side end. However, the bass reflex port 30D is similar to the bass reflex port 30 in that the wall surface of the inner side end portion is formed with a sheet member 36D, and the sheet member 36D protrudes from the end 33 of the first tube 32 to thereby make the rigidity of the wall surface of the inner side end portion smaller than that of the wall surface of the central portion. For this reason, in the bass reflex port 30D, as in the bass reflex port 30, the sheet member 36D on the inner side end portion moves randomly according to the air pressure difference, so that the bass reflex port 30D is deformed. Therefore, in the present embodiment, advantages similar to those of the first embodiment are achieved.
< other examples >
Although the first to fifth embodiments of the present invention are described above, other embodiments of the present invention are also contemplated, for example, as follows:
(1) in the bass reflex ports 30B and 30D of the first to third and fifth embodiments, the rigidity of the wall surface of the inner side end portion is smaller than that of the wall surface of the central portion, and in the bass reflex port 30C of the fourth embodiment, the rigidity of the wall surface of the outer side end portion is smaller than that of the wall surface of the central portion. However, the positions where the rigidity is low are not limited to these positions. That is, in the bass reflex port according to the present invention, it is only necessary that at least a part of the wall surface has a rigidity smaller than that of the remaining part. This is because, if the rigidity of at least a part of the wall surface is low, the part having low rigidity moves according to the air pressure difference, so that the bass reflex port is deformed. And if the portion having low rigidity is deformed, the distribution of the flow velocity of air in the vicinity of the inner wall surface of the portion having low rigidity is dynamically disturbed so that the position and timing at which the vortex occurs are not concentrated but dispersed. As described above, by making the rigidity of at least a part of the wall surface of the bass reflex port smaller than the rigidity of the remaining part, as in the other embodiments, the abnormal sound due to the air flowing in the bass reflex port is reduced.
(2) Although it is only necessary according to the present invention that the rigidity of at least a part of the wall surface is lower than the rigidity of the remaining part in the bass reflex port, it is preferable that the rigidity of the wall surface of at least one end part of the bass reflex port is lower than the rigidity of the wall surface of the center part. The first reason is that the portion having low rigidity is more easily moved when the portion having low rigidity is located on the end portion than when the portion having low rigidity is located on the central portion. The second reason is that the vortex tends to easily occur on the end portion where the air flows outward from the bass reflex port, as compared with the vortex occurring on the central portion, and the dispersion effect of the position and timing at which the vortex occurs is better on the end portion than on the center. In addition, compared to the mode in which the rigidity of the wall surface of the outer end portion is lower than that of the wall surface of the central portion, the effect of reducing abnormal sounds is better in the mode in which the rigidity of the wall surface of the inner end portion is lower than that of the wall surface of the central portion. The first reason is that the inner end portion is easy to move compared to the outer end portion because the inner end portion is not supported by the blocking surface. The second reason is that swirl tends to easily occur on the inside end portion (which is not continuous with the blocking surface) and the dispersion effect at the position and timing at which swirl occurs is better than on the outside end portion (which is continuous with the blocking surface). Moreover, the bass reflex port according to the present invention is not limited to a mode in which the rigidity of the wall surface of the one end portion is smaller than the rigidity of the wall surface of the central portion; but the rigidity of the wall surfaces of both end portions may be less than that of the wall portion of the central portion.
(3) The specific mode in which the rigidity is low is not limited to the mode of the embodiment. For example, in the bass reflex port 30 of the first embodiment, the cut portion 39 of the sheet member 36 may be provided not only on the portion serving as the outer wall but also on the portion serving as the inner wall. According to this mode, the rigidity of the wall surface of the sheet member 36 is smaller than that in the first embodiment, which should take into consideration that the sheet member 36 is more easily deformed.
(4) A cut portion 39 is provided at the outer wall of the sheet member 36 serving as the bass reflex port 30 of the first embodiment. However, such a cutting portion 39 is not essential.
(5) In the bass reflex port, a structure of a portion constituting a wall surface of the end portion having low rigidity may be provided to be detachably attached to the center portion having high rigidity.
(6) The bass reflex port 30 of the first embodiment has a straight tube shape except for the folded-back portion of the sheet member 36. However, the inner end portion of the bass reflex port 30 may have a flared shape from the end 33 of the first tube 32 to the inner end. Also, not only the inner side end portion of the bass reflex port 30 but also the outer side end portion of the bass reflex port 30 may have an expanded shape. Also, not only one end portion but also both end portions of the bass reflex port 30 may have an expanded shape. Also, in the bass reflex ports 30A to 30D of the second to fifth embodiments, the end portions of the inner and outer sides of the bass reflex ports 30A to 30D may similarly have an expanded shape.
(7) The wall surface of the end portion of the bass reflex port may have a multilayer structure formed of an inner layer member constituting the inner wall surface and an outer layer member constituting the outer wall surface. In this case, the rigidity of at least the inner layer member is made smaller than the rigidity of the wall surface of the central portion, so that at least the inner layer member moves in accordance with the air pressure difference to make the bass reflex port deformable.
(8) The technical features of the embodiments may be combined as appropriate.
(9) In addition to the audio apparatuses of the embodiments being provided to the market, the bass reflex port employed in the audio apparatuses of the embodiments may also be provided to the market separately. This is because the acoustic apparatus of these embodiments can be realized by attaching the bass reflex port to the acoustic apparatus. Also, the acoustic apparatus of these embodiments can be offered to the market in a state of being mounted on a musical instrument (e.g., an electronic keyboard).
Here, the details of the above embodiment are summarized as follows.
[1] The present invention provides a bass reflex port, comprising:
the tubular member is provided with a tubular shape member,
wherein a portion of the wall surface of the tubular member has a stiffness less than a stiffness of the remaining portion of the tubular member.
[2] For example, the rigidity of the wall surface of at least one end portion of the tubular member in the axial direction of the tubular member is smaller than the rigidity of the wall surface of the central portion of the tubular member in the axial direction
[3] For example, the thickness of the at least one end portion in the radial direction of the tubular member is smaller than the thickness of the central portion in the radial direction, which is perpendicular to the axial direction.
[4] For example, the at least one end portion and the central portion are formed as an integral component.
[5] For example, at least one end portion and the central portion are formed as separate members, and the rigidity of the member for the at least one end portion is smaller than the rigidity of the member for the central portion.
[6] For example, the means for the at least one end is a sheet member.
[7] For example, the inner wall surface of the at least one end portion is flush with the inner wall surface of the central portion, and the outer wall surface of the at least one end portion is continuous with the inner wall surface of the central portion via the step portion.
[8] For example, the wall surface of the at least one end portion may be formed of a material that is more flexible than the material of the wall surface of the central portion.
[9] For example, the bass reflex port further includes:
a sheet member, which is less rigid than the tubular member,
wherein the sheet member is fixed to the tubular member and protrudes from one end of the tubular member in an extending direction of the tubular member.
[10] For example, the sheet member is partially fixed to the inner wall surface of the tubular member, extends to protrude from one end portion of the tubular member in the extending direction of the tubular member, and then is folded back so that a space is formed by the end portion of the tubular member and the sheet member.
[11] For example, a plurality of cut portions extending in the axial direction are provided in a fold-back sheet member fixed to the outer wall surface of the tubular member.
[12] For example, the sheet member is folded back so that the space in the cross-sectional area having the axial direction becomes larger as extending in the extending direction.
[13] For example, the acoustic device includes:
a bass reflex port according to any one of items [1] to [12 ]; and
a shell body with an opening is arranged in the shell body,
wherein the bass reflex port is provided in the housing and one end of the bass reflex port is fixed to an edge of the opening.
[14] For example, in the end portion of the tubular member of the bass reflex port, the rigidity of the wall surface near the end portion of the opening is smaller than the rigidity of the wall surface of the central portion of the tubular member of the bass reflex port.
Claims (11)
1. A bass reflex port comprising:
the tubular member is provided with a tubular shape member,
wherein a portion of the wall surface of the tubular member has a stiffness less than a stiffness of the remaining portion of the tubular member;
wherein a rigidity of a wall surface of at least one end portion of the tubular member in an axial direction of the tubular member is smaller than a rigidity of a wall surface of a central portion of the tubular member in the axial direction;
wherein the thickness of the at least one end portion in a radial direction of the tubular member is smaller than the thickness of the central portion in the radial direction, the radial direction being perpendicular to the axial direction;
the bass reflex port further includes:
a sheet member, which is less rigid than the tubular member,
wherein the sheet member is fixed to the tubular member and protrudes from one end of the tubular member in an extending direction of the tubular member.
2. The bass reflex port as set forth in claim 1, wherein the at least one end portion and the central portion are formed as an integral component.
3. The bass reflex port as set forth in claim 1, wherein the at least one end portion and the central portion are formed as separate components; and
wherein the stiffness of the member for the at least one end portion is less than the stiffness of the member for the central portion.
4. The bass reflex port as claimed in claim 3, wherein the means for the at least one end portion is a sheet member.
5. The bass reflex port as set forth in claim 1, wherein an inner wall surface of the at least one end portion is flush with an inner wall surface of the central portion; and
wherein an outer wall surface of the at least one end portion is continuous with an inner wall surface of the central portion via a step portion.
6. The bass reflex port as claimed in claim 1, wherein a material of the wall surface forming the at least one end portion is more flexible than a material of the wall surface forming the central portion.
7. The bass reflex port as claimed in claim 1, wherein the sheet member is partially fixed to an inner wall surface of the tubular member, extends to project from one end portion of the tubular member in an extending direction of the tubular member, and then is folded back so that a space is formed by the end portion of the tubular member and the sheet member; and
wherein the end of the folded sheet member is fixed to the outer wall surface of the tubular member.
8. The bass reflex port as claimed in claim 7, wherein a plurality of cut portions extending in the axial direction are provided in a turn-back sheet member fixed to an outer wall surface of the tubular member.
9. The bass reflex port as claimed in claim 7 or 8, wherein the sheet member is folded back such that a space in a cross-sectional area having the axial direction becomes larger as extending in the extending direction.
10. An audio device comprising:
the bass reflex port as claimed in any one of claims 1 to 9; and
a shell body with an opening is arranged in the shell body,
wherein the bass reflex port is provided in the housing and one end of the bass reflex port is fixed to an edge of the opening.
11. The acoustic apparatus according to claim 10, wherein in an end portion of the tubular member of the bass reflex port, a wall surface near the end portion of the opening has a rigidity smaller than that of a wall surface of a central portion of the tubular member of the bass reflex port.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016-104627 | 2016-05-25 | ||
| JP2016104627A JP6709537B2 (en) | 2016-05-25 | 2016-05-25 | Bass reflex port and audio equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107438212A CN107438212A (en) | 2017-12-05 |
| CN107438212B true CN107438212B (en) | 2019-12-27 |
Family
ID=58772745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710379202.5A Active CN107438212B (en) | 2016-05-25 | 2017-05-25 | Bass reflex port and acoustic apparatus |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP3249947B1 (en) |
| JP (1) | JP6709537B2 (en) |
| CN (1) | CN107438212B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7066372B2 (en) | 2017-11-02 | 2022-05-13 | シャープ株式会社 | Terminal equipment, base station equipment, and communication methods |
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- 2017-05-25 CN CN201710379202.5A patent/CN107438212B/en active Active
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| EP0361445A2 (en) * | 1988-09-28 | 1990-04-04 | Yamaha Corporation | Acoustic apparatus |
| JPH05268686A (en) * | 1992-03-17 | 1993-10-15 | Matsushita Electric Ind Co Ltd | Bass reflex port |
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Also Published As
| Publication number | Publication date |
|---|---|
| EP3249947A1 (en) | 2017-11-29 |
| JP6709537B2 (en) | 2020-06-17 |
| JP2017212606A (en) | 2017-11-30 |
| CN107438212A (en) | 2017-12-05 |
| EP3249947B1 (en) | 2021-04-07 |
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