EP2495990B1

EP2495990B1 - Speaker device

Info

Publication number: EP2495990B1
Application number: EP09850859.1A
Authority: EP
Inventors: Takashi Yamamizu; Junichi Sato; Hirotaka Horiguchi
Original assignee: Tohoku Pioneer Corp; Pioneer Corp
Current assignee: Tohoku Pioneer Corp; Pioneer Corp
Priority date: 2009-10-30
Filing date: 2009-10-30
Publication date: 2016-07-13
Anticipated expiration: 2029-10-30
Also published as: EP2495990A1; JP5204313B2; WO2011052080A1; JPWO2011052080A1; EP2495990A4

Description

FIELD OF THE INVENTION

The present invention relates to a speaker device.

BACKGROUND OF THE INVENTION

In a speaker device equipped with a cabinet and a speaker unit, those which have a bass reflex type cabinet for actively utilizing the sound emitted from the rear side of a speaker unit (diaphragm) are known. A bass reflex type or an acoustimass (trademark owned by Bose Corporation) type cabinet forms a given volume of space on the rear side of a speaker unit, and has a duct in the space. One end of the duct is opened while the other end of the duct is opened toward the sound emission side.
A patent literature 1 that is shown below describes a small-sized and light-weight speaker device capable of reproducing a low frequency range, wherein a speaker unit is attached at the central part of the rear surface board of a speaker box, and a low-frequency reproduction duct is provided on the sound emission side of the speaker unit while a bass-reflex duct is provided on the rear side of the speaker unit, and the low-frequency reproduction duct is constituted of a first and a second duct parts, wherein the first duct part extends along the rear surface board and the upper surface board to open at the upper part on a front surface of the speaker unit while the second duct part extends along the rear surface board and the bottom surface board to open at the lower part on a front surface of the speaker box.
Further, a patent literature 2 that is shown below describes a speaker device comprising a first duct formed in the direction orthogonal to the emission direction of sound pressure that is emitted from the front side of a speaker unit and a second duct formed with one end being connected to the first duct, wherein the speaker unit is arranged at the connecting portion of the first duct and the second duct, and the sound pressure emitted from the rear side of the speaker unit is transmitted to the first duct side via the second duct, connected together with the sound pressure emitted from the front side of the speaker unit, and then released to the outside from the first duct.
Such a system is also disclosed in US 5475764 .

[Patent literature 1]Japanese laid-open patent publication 11-136786
[Patent literature 2]Japanese patent 3410206

DISCLOSURE OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

A speaker device equipped with the aforementioned cabinet is required to secure space for arranging a speaker device in accordance with the volume of the cabinet, whereby the installation position of a speaker device is subject to limitation. When adopting the aforementioned bass reflex type or acoustimass type cabinet, an air chamber is provided on the opposite side of the sound emission side of a speaker unit and a duct is required to be elongatedly formed from the air chamber toward the sound emission side, whereby it becomes difficult to install a speaker device in narrow space. In addition, when a plurality of speaker units is provided, in order to acquire a preferable acoustic characteristic in low frequency range, it is required to secure a sufficient volume of the air chamber, and thus the installation position of a speaker device is subjected to further limitation unless the speaker device is efficiently arranged.
When a speaker device is arranged in limited space such as the inside of a car, it is effective in improving utilization efficiency to arrange a speaker device by using space which is to be dead space under ordinary circumstances. When the space which is to be dead space under ordinary circumstances is utilized as an air chamber, the volume of the air chamber is subject to constraints, and therefore it becomes necessary to create an efficient way of making the partition of the cabinet and making the arrangements of the speaker unit and the duct.
For example, when a speaker device is arranged in a spare tire housed in a car body, constraints arise such that the outer diameter of the speaker device is required to be smaller than the inner diameter of the spare tire or smaller than the outer diameter of a wheel. Hereby, the outer diameter as well as the shape of a cabinet is necessarily subject to the constraints. In such a speaker device, for example, when an acoustimass type cabinet is employed, a preferable acoustic characteristic in a low frequency range cannot be acquired unless there is ingenuity in the arrangement of an air chamber or a duct on the front side and the rear side of the speaker unit. Further, when two or more speaker units are arranged, further efficient arrangements and configurations of an air chamber and a duct including the arrangements of the speaker units are required.
In a speaker device for low-frequency reproduction wherein a speaker unit is arranged in a cabinet, the diameter of the diaphragm of a speaker unit is subject to limitation due to the height of a cabinet, whereby the diameter of the diaphragm for acquiring desired large sound pressure may not be established depending on the installation space of the speaker device. In this case, when a large sound pressure is sought by increasing the amplitude of vibration of the diaphragm, creating a design for the support system and the drive system of a speaker unit becomes difficult. As a result a problem arises due to distortion that is frequently generated in the reproduced sound pressure.
Therefore, an object of the present invention is to address such a problem. That is, it is an object of the present invention to provide a speaker device wherein a preferable acoustic characteristic in a low frequency range can be acquired by effectively securing an air chamber and so forth in a cabinet even in limited installation space of the speaker device; a bass reflex type cabinet can be adopted by efficiently arranging an air chamber and a duct even when the outer diameter and the shape of a cabinet is limited and a comparatively large air chamber can be secured even when a plurality of speaker units is used while making efficient use of the space in the cabinet; and in a speaker device for low-frequency reproduction with a speaker unit being arranged in the cabinet, even when the diameter of the diaphragm is subject to limitation due to the installation space of the speaker device, large sound pressure as well as high-quality reproduced sound can be generated.

MEANS FOR SOLVING THE PROBLEM

In order to achieve such an object, a speaker device according to claim 1 is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view illustrating the outer appearance of the configuration of a speaker device according to one embodiment of the present invention;
Fig. 2 is a view illustrating the internal structure of a speaker device according to one embodiment of the present invention;
Fig. 3 is a view illustrating a duct structure of a speaker device (perspective view of a speaker device 1 without a cap part) according to one embodiment of the present invention;
Fig. 4 is a view illustrating an attachment relationship between a housing part and a wall part in a speaker device according to an embodiment of the present invention;
Fig. 5 is a view illustrating a cap part of a speaker device according to an embodiment of the present invention (Fig. 5(a) is a plan view and Fig. 5(b) is a rear side perspective view);
Fig. 6 is a view illustrating a sound emitting part of a speaker device according to an embodiment of the present invention (Fig. 6(a) is a plan view and Fig. 6(b) is a rear side perspective view);
Fig. 7 is a view illustrating a speaker unit of a speaker device according to an embodiment of the present invention (Fig. 7(a) is a perspective view of the outer appearance and Fig. 5(b) is a cross-sectional perspective view);
Fig. 8 is a view illustrating an example of mounting a speaker device 1 according to an embodiment of the present invention; and
Fig. 9 is a view illustrating a vehicle equipped with a speaker device according to an embodiment of the present invention.

BEST MODE FOR PRACTICING THE INVENTION

Hereinafter, an embodiment of the present invention is described with reference to the drawings. Although an embodiment of the present invention includes the contents shown in the drawings, it is not limited hereto. Fig. 1 is a view illustrating the outer appearance of the configuration of a speaker device 1 (perspective view) according to one embodiment of the present invention, and Fig. 2 is a view illustrating the internal structure of a speaker device 1 according to one embodiment of the present invention.
A speaker device 1 according to an embodiment of the present invention is provided with a cabinet 2 and a duct 4, and a speaker unit 3 (3₁, 3₂) is arranged inside the cabinet 2. The cabinet 2 is provided with at least a housing part 10 and a cap part 13, and a duct 4 is provided at the cabinet 2. In an example shown in the drawing, the cabinet 2 is formed with the housing part 10 and a sound emitting part 14 that is made of a member different from the housing part 10. The example shows that the duct 4 (4₁, 4₂) is provided at the sound emitting part 14, but not limited hereto, the duct 4 (4₁, 4₂) may be provided at the part integrally configured with the housing part 10 and the sound emitting part 14. The speaker device 1 is particularly suitable for low frequency reproduction, and sound emitted from a speaker unit that is driven in the cabinet 2 is released from the duct 4 (4₁, 4₂) to the outside. In the example shown in the drawing, the lateral shape of the housing part 10 forming the cabinet 2 is shown in a cylindrical shape as an example, but is not limited thereto, and various types of shapes such as a rectangular shape may be used. The shape of the cabinet 2 is determined according to the shape of space where the speaker device 1 is housed. The housing part 10, the sound emitting part 14, and the cap part 13 may be respectively formed with different members. Also, the housing part 10 and the sound emitting part 14 or the sound emitting part 14 and the cap part 13 can be integrally formed.
A wall part 15 is arranged in the cabinet 2 so as to extend from the central part 2c of the cabinet 2 toward different positions 2r₁, 2r₂ in the outer periphery part 2r, and the wall part 15 partitions the space 2S in the cabinet 2 into two spaces (one space 2S₁ and the other space 2S₂). In the example shown in the drawing, the wall part 15 is a plate shaped member and has planar parts 15A, 15B along the axial direction L of the cabinet 2. The planar parts 15A, 15B respectively extend in two directions R1, R2 orthogonally to the axial direction L of the cabinet 2. In the example shown in the drawing, the angle defined by the two directions R1, R2 of the planar parts 15A, 15B is less than 180 degrees and is in refractive state, and the wall part 15 is arranged in the cabinet 2 such that the volume of one partitioned space 2S₁ is larger than the volume of the other space 2S₂. The angle defined by the two directions R1, R2 of the planar parts 15A, 15B may be adjustable to 180 degrees as necessary.
Two speaker units 3 (a first speaker unit 3₁ and a second speaker unit 3₂) are arranged in the cabinet 2 (housing part 10) and the first speaker unit 3₁ and the second speaker unit 3₂ are attached to the wall part 15. The first speaker unit 3₁ and the second speaker unit 3₂ are attached respectively to the planar parts 15A, 15B, whereby the sound emission directions are directed to two directions orthogonally to the axial direction L of the cabinet 2. Further, the first speaker unit 3₁ is arranged in one space 2S₁ partitioned by the wall part 15 and the second speaker unit 3₂ is arranged in another space 2S₂ partitioned by the wall part 15, and the first speaker unit 31 and the second speaker unit 3₂ are arranged such that the sound emission surfaces 3a₁, 3a₂ are directed to mutually different spaces 2S₁, 2S₂. That is, the sound emission surface 3a1 of the first speaker unit 3₁ arranged in one space 2S₁ is directed to another space 2S₂, and the sound emission surface 3a₂ of the second speaker unit 3₂ arranged in another space 2S₂ is directed to one space 2S₁.
A controlling device 40 electrically connected to one or both of the speaker unit 31 and the second speaker unit 3₂ is arranged in one of the spaces 2S₁, 2S₂ in the cabinet 2 partitioned by the wall part 15. In the example shown in the drawing, the space 2S1 is formed larger than the space 2S₂ and the controlling device (amplifier) 40 is arranged in the larger space 2S₁. Further, one of the ducts 4 is arranged above the controlling device 40 as described later. A heat releasing fin 40a is provided on the controlling device 40 on the side of the first speaker unit 3₁ or the second speaker unit 3₂. The first speaker unit 3₁ and the second speaker unit 3₂ are driven by the controlling device 40 in substantially the same phase. Specifically, when the first speaker unit 3₁ emits a sound wave toward the other space 2S₂, the second speaker unit 3₂ also emits a sound wave toward the other space 2S₂. In other words, when the diaphragm of the first speaker unit 3₁ vibrates or is displaced toward the other space 2S₂, the diaphragm of the second speaker unit 3₂ also vibrates or is displaced toward the other space 2S₂.
In a speaker device 1 having such a structure, when the duct 4 is provided so as to communicate between only one of the partitioned spaces 2S₁ and 2S₂ and the outside, a bass reflected type cabinet system can be realized, and when two ducts 4₁, 4₂ are provided so as to communicate between each of the spaces 2S₁ and 2S₂ and the outside as described later, an acoustimass type cabinet system can be realized.
The cabinet 2 is covered with a cap part 13, and has the speaker units 3₁, 3₂ arranged in the cabinet, whereby the speaker units 3₁, 3₂ are not exposed, and thus the cabinet 2 is structured to substantially protect the speaker units 3₁, 3₂. Hereby, the speaker device 1 can be arranged with no relation to the surrounding condition of the installation space. The speaker device 1 can protect the speaker unit 3₁, 3₂ from being damaged even in the space where a movable object exists around or in the place where hand touching commonly occurs.
Further, in the speaker device 1, the ducts 4 (4₁, 4₂) are formed at the upper part of the housing part 10. As such, even when the lateral side of the housing part 10 is covered with a support body and so forth, the sound emitting opening of the ducts 4 (4₁, 4₂) can be effectively opened. Further, the ducts 4 (4₁, 4₂) are opened on the lateral side of the cabinet 2, whereby the sound emitting opening of the ducts 4 (4₁, 4₂) can be effectively opened even when the top of the cap part 13 is covered with some items placed on the cap part 13. Specifically, in the example shown in the drawing, since the upper face of the cap part 13 is formed in a planar shape, the upper face of the cap part 13 can be used for placing some items thereon.
The wall part 15 for partitioning the space inside the cabinet 2 partitions the space inside the tubular cabinet 2 along an axis of the tubular cabinet, whereby internal arrangement can be made effectively using the height of the cabinet 2. The speaker units 3₁, 3₂ are attached in the direction obliquely to the plane forming the wall part 15 having the planar parts 15A, 15B which are along the axis of the cabinet 2, specifically in substantially the orthogonal direction in the example shown in the drawing, whereby the speaker units 3₁, 3₂ can be arranged, having diameters in accordance with the height of the cabinet2.
The wall part 15 is provided with the planar parts 15A, 15B radially shaped from the central part 2c of the cabinet 2 toward the outer periphery part 2r of the cabinet 2, and by arbitrarily setting the angle of the planar parts 15A, 15B, the space in the cabinet 2 can be partitioned at any ratio. Hereby, the acoustic characteristic such as the lowest resonance frequency or the low frequency reproduction band can be adjusted.
By arranging the controlling device 40 in the space 2S₂ of the cabinet 2, the space in the cabinet 2 can be effectively used, and the speaker device 1 can be made compact. Further since the controlling device 40 is provided between the first speaker unit 3₁ and the second speaker unit 3₂, the controlling device 40 is cooled down by the airflow generated by the speaker units 3₁, 3₂, and thus the temperature of the entire controlling device 40 can be decreased. Here, by providing the heat releasing fin 40a, the airflow generated from the speaker units 3₁, 3₂ impinges on the heat releasing fin 40a, and thus the controlling device 40 can be further cooled down.
In the example shown in the drawing, by making an angle between the planar parts 15A, 15B of the wall part 15, one of the partitioned spaces 2S₁, 2S₂ becomes larger than the other in the cabinet 2, and by arranging the controlling device 40 in the larger space 2S₁, the utilization efficiency of the space in the cabinet 2 is increased while the volume of the air chamber in the cabinet 2 is sufficiently secured.
The diaphragms of the two speaker units 3₁, 3₂ are respectively driven substantially in the same phase. That is, the diaphragms of the two speaker units 3₁, 3₂ substantially vibrate simultaneously in the direction of entering the space 2S₂ and vibrate simultaneously in the direction of exiting from the space 2S₂, hereby, the speaker unit can generate larger sound pressure than in the case of a single speaker unit. When the cabinet 2 is provided in the limited space, although the height of the cabinet 2 may not be increased and the diameter of the diaphragm may not be increased, by driving the two speaker units 3₁, 3₂ substantially in the same phase, large sound pressure can be generated.
The reproduced sound pressure of a speaker unit is determined by the volume of air that a diaphragm discharges (in proportion to diaphragm area × amplitude of vibration). If the diaphragm area cannot be increased, when trying to increase the reproduced sound pressure by amplitude of vibration, it is difficult to design the support system and the drive system of a speaker unit, which can respond to the large amplitude of vibration. As a result, the reproduced sound pressure distortion may occur. When the two speaker units 3₁, 3₂ are driven substantially in the same phase as shown in the embodiment according to the present invention, the amplitude of vibration of a diaphragm required for generating substantially the same sound pressure can be halved, whereby high quality reproduced sound with reduced distortion can be acquired.
Further, when the two speaker units 3₁, 3₂ are driven substantially in the same phase, the diaphragm of the first speaker unit 3₁ vibrates or is displaced toward the other space 2S₂, while the diaphragm of the second speaker unit 3₂ also vibrates or is displaced toward the other space 2S₂.
When the diaphragms of the two speaker units 3₁, 3₂ substantially vibrate to simultaneously enter the space 2S₂ and vibrate in a direction simultaneously exiting the space 2S₂, the distortions of the support system or the drive system generated by each of the speaker units 3₁, 3₂ can cancel each other out, whereby high quality reproduced sound can be acquired.
Fig 3 is a view illustrating a duct structure of a speaker device according to an embodiment of the present invention (perspective view of a speaker device 1 when a cap part is removed). The two ducts 4 (first duct 4₁ and second duct 4₂) are provided in the cabinet 2. The space of the cabinet 2 is partitioned by the wall part 15. One space 2S₁ and outside are communicated by the first duct 41, and the other space 2S₂ and the outside are communicated by the second duct 42.
The two ducts 4 (the first duct 4₁ and the second duct 4₂) are provided on the sound emission sides of each of the two speaker units 3 (first speaker unit 3₁ or second speaker unit 3₂) and the first speaker unit 3₁ and the second speaker unit 3₂ are driven by the controlling device 40 substantially in the same phase as described above or the second speaker unit 3₂ may be configured with a passive unit (passive radiator). Further, when the second speaker unit 3₂ is a passive unit, a voice coil included in the second speaker unit 3₂ is short-circuited or a magnetic circuit is removed, and a dust cap and so forth is provided on the inner side of a voice coil or a voice coil support part supporting the voice coil, and a vibrating body (includes a diaphragm, an edge and a voice coil and also may include a voice coil support part) efficiently receiving air pressure released from the rear side of the first speaker unit 3₁ may be configured, or the voice coil may not be provided.
In the ducts 4 (first duct 4₁ and second duct 4₂), one end part 4a is arranged between the first speaker unit3₁ and the second speaker unit 3₂, and the other end part 4b is arranged near the outer periphery part 2r of the cabinet 2.
Further, the ducts 4 (first duct 4₁ and second duct 4₂) are configured from one end toward the other end such that one part extends in the axial direction (L direction) of the cabinet 2, and then the other part extends from the central part 2c toward the outer periphery part 2r of the cabinet 2 (R direction). That is, the end part 4a of the duct 4 is formed in the axial direction (L direction) of the cabinet 2 while the other part is formed in the direction along a planar face substantially orthogonal to the axial direction (L direction) and the end part 4b is directed to the outer periphery part 2r of the cabinet 2.
Further, at least one (the first duct 4₁ in the example shown in the drawing) of the ducts 4 (the first duct 4₁ and the second duct 4₂) is formed such that the part extending from the central part 2c through the outer periphery part 2r of the cabinet 2 is formed adjacently to the outer periphery part 2r of the cabinet 2.
The ducts 4 are formed within the cabinet 2, wherein the first duct 4₁ and the second duct 4₂ are provided within the space surrounded by the first speaker unit 3₁, the second speaker unit 3₂ and the cabinet 2. The ducts 4 are formed using a part of the space within the spaces 2S₁, 2S₂, and the bottom face part 4c of the first duct 41 and the second duct 4₂ is arranged in the position lower than the upper end part 3b of the first speaker unit 31 and the second speaker unit 3₂ in the axial direction (L direction) of the cabinet 2. The bottom face part 4c of the first duct 4₁ and the second duct 4₂ may be arranged in the position substantially the same as or higher than the upper end part 3b of the first speaker unit 3₁ and the second speaker unit 3₂ in the axial direction (L direction) of the cabinet 2.
As can be seen in the drawing, the first duct 4₁ through which the larger space 2S₁ of the spaces 2S₁, 2S₂ in the cabinet 2 partitioned by the wall part 15 communicates with the outside, is arranged so as to extend comparatively long and the second duct 4₂ through which the smaller space 2S₂ communicates with the outside, is arranged so as to extend comparatively short. Further the first duct 4₁ through which the larger space 2S₁ communicates with the outside is formed in a curved shape, whereby the effective length is made comparatively long. Further, in order to prevent the effective length of the duct from becoming shorter eventually by air as fluid flowing along the shortest path even if the duct is formed in a curved shape, the first duct 4₁ is adapted such that the exit cannot be viewed from the entrance, that is, a straight flow passage is not formed. By employing such a duct configuration, it becomes possible to lower the low-frequency reproduction limit frequencies, that is, to broaden the low-frequency reproduction band of the speaker device 1.
Further, each of the first duct 4₁ and the second duct 4₂ is configured to have a constant cross-sectional shape (rectangular shape) along the length direction, and thus the occurrence of abnormal noises (wind noises) is prohibited. Further, the first duct 4₁ and the second duct 4₂ are configured to change the extending directions from the vertical direction (axial direction) to the horizontal direction (the direction orthogonal to the axis) and the flow passage of the duct is changed with the largest possible curvature at this direction changing part. Also by this configuration, the occurrence of abnormal noises can be prohibited.
Further, the bottom face part 4c of the first duct 4₁ and the second duct 4₂ is arranged in the position lower than the upper end part 3b of the first speaker unit 3₁ and the second speaker unit 3₂ in the axial direction (L direction) of the cabinet 2, and the first duct 4₁ and the second duct 4₂ are arranged, efficiently utilizing the upper part of the empty space in the cabinet 2 where no speaker units 3₁, 3₂ exist. Hereby, the ducts 4₁, 4₂ having desired diameters and the effective lengths can be formed in the limited space within the cabinet 2 while a comparatively large air chamber can be secured under the bottom face part 4c of the ducts 4₁, 4₂.
Fig. 4 is a view illustrating attachment relationship of a wall part 15 to a housing part 10 in a speaker device 1. The wall part 15 is provided with an attaching counterpart 15C to which a first speaker unit 3₁ and a second speaker unit 3₂ are attached. The aforementioned planar parts 15A, 15B form this attaching counterpart 15C. The attaching counterpart 15C has a central contact part 15D which comes into contact with the central part 2c of the cabinet 2, and both ends of the outer periphery part of the attaching counterpart 15C are formed integrally with a circumferential part 15E which is formed along the outer periphery part 2r of the cabinet 2. Further, the circumferential part 15E of the wall part15 is provided with an attachment part 15E1 attached to the outer periphery part 2r of the cabinet 2. The attachment part 15E1 is formed in a flange shape extending from the circumferential part 15E, and is mounted on a mounting face 2ra formed at the outer periphery part 2r of the cabinet 2 (housing part 10), and thereby the wall part 15 is attached to the cabinet 2.
The cabinet 2 has the aforementioned housing part 10 (first housing part 11) and a second housing part 12 is configured in the first housing part 11, wherein the second housing part 12 forms the aforementioned wall part 15. The second housing part 12 includes a bottom face part 12a and an outer periphery tubular part 12b. A reinforcing part 12c having protruding shape is formed in the second housing part 12 in the radial or circumferential direction of the cabinet 2. Further, a projection part (not shown, for example, having a shape like a projection part 2d) that supports the speaker unit 3₂, especially a magnetic circuit that is described later is provided at the bottom face part 12a of the second housing part. The projection part forms a gap between the magnetic circuit of the speaker unit 3₂ and the bottom face part 10a, whereby the occurrence of abnormal noises due to the speaker unit 3 coming into contact with the cabinet 2 is reduced. Further, the abnormal noises may be reduced by providing a buffer member (cushion member, damping member) between the projection part and the magnetic circuit of the speaker unit 3₂.
Further, a terminal part E1 is provided at the outer periphery part of the cabinet 2. The terminal part E₁ is provided at a sound emitting part 14 that is described later, and serves as a terminal part electrically connecting a controlling device that is described later to the outside.
A housing part 10 (first housing part 11) is provided with a bottom face part 10a and an outer periphery tubular part 10b that support the wall part 15, and a tubular part 10c is raised in the axial direction from the bottom face part 10a, forming a central part 2c. The projection part 2d is provided at the bottom face part 10a to support a second housing part 12. The protrusion part 2d forms a gap between the bottom face part 12a of the second housing part 12 and the bottom face part of the housing part 10 whereby the occurrence of abnormal noises due to the contact between the second housing part 12 and the housing part 10 is reduced. The abnormal noises may be reduced by providing a cushion member (cushion member, damping member) in between the projection part 2d and the second housing part 12.
The outer periphery part of a sound emitting part 14 as a separate member which is described later is arranged on a mounting face 2ra formed in the outer periphery part of the first housing part 11. A coupling part 2ra1 formed on the mounting surface 2ra is connected with the outer periphery part of the sound emitting part 14.
Further, the first cabinet 21 is formed as the first housing part 11 while the second cabinet 2₂ is formed with the wall part 15 and the second housing part 12, and the second cabinet 2₂ integrally formed with the first speaker unit 3₁ and the second speaker unit 3₂ can be separated from the first cabinet 21. Hereby, it becomes possible to easily attach the wall part 15 and two speaker units 3₁, 3₂ to the first cabinet 21.
As such, the speaker device 1 arranges the second cabinet 2₂ in the first cabinet 2₁ and the second cabinet 2₂ configures a volume on the one side in a cabinet of the acoustimass type. The second cabinet 2₂ is integrally formed with the first speaker unit 3₁ and the second speaker unit 3₂ by the second housing part 12 including the wall part 15 to which the first speaker unit 3₁ and the second speaker unit 3₂ are attached. The second cabinet 2₂ is formed with the integrally formed housing part 12, whereby it becomes easy to secure the sealing performance of the volume on the one side in the cabinet of the acoustimass type.
In the second cabinet 2₂, the wall part 15 along the axial direction of the cabinet 2 forms two baffle faces, to each of which the first speaker unit 3₁ and the second speaker unit 3₂ are attached. Since the baffle faces are integrally formed with the second cabinet 2₂ as described above, the strength of the baffle faces can be increased, and thus the first speaker unit 3₁ and the second speaker unit 3₂ can be firmly held when the speaker device 1 is driven. That is, owing to the integral structure of the second cabinet 2₂ the rigidity of the second housing part 12 is increased, and thus the vibration due to air pressure that the first speaker unit 3₁ and the second speaker unit 3₂ generate can be prohibited. Further, the vibrations caused when the first speaker unit 3₁ the second speaker unit 3₂ are driven can cancel each other out in the second housing part 12 without transmitting throughout the speaker device 1.
The central part of the wall part 15 in the second cabinet 2₂ is arranged so as to embrace the tubular part 10c standing at the central part 2c of the first cabinet 21(first housing part 11). Hereby, the wall part 15 to which the first speaker unit 3₁ and the second speaker unit 3₂ are attached is arranged radially (in the circumferential direction) from the central part 2c. The second cabinet 2₂ is positioned by the tubular part 10c and the inner face of the first housing part 11, whereby the second cabinet 2₂ substantially increases the strength of the tubular part 10c provided on the first cabinet 2₁. Since the tubular part 10c forms an attaching counterpart into which an attaching member is inserted, such a double cabinet structure contributes to improve the attachment strength of the cabinet 2.
Fig. 5 is a view illustrating a cap part 13 of the speaker device 1 according to an embodiment of the present invention (Fig. 5(a) is a plan view, and Fig. 5(b) is a rear side perspective view). The cap part 13 is formed with a tabular member which closes the upper face of the cabinet 2 described above. A hole part 13P is formed in the central part of the cap part 13, and the hole part 13P is formed in a surrounding recessed part 13P1. The recessed part 13P1 serves as space which receives the attaching member. A reinforcing part 13 having protruding shape is formed on the front face or the rear face of the cap part 13 in the radial direction or the circumferential direction of the cap part 13. Further, a plurality of connecting protrusions 13b are protruded from the rear face of the cap part 13 in order to connect with a sound emitting part which is described later.
Fig. 6 is a view illustrating a sound emitting part 14 of a speaker device 1 according to an embodiment of the present invention (Fig. 6(a) is a plan view and Fig. 6(b) is a rear side perspective view). The sound emitting part 14 forms the aforementioned ducts 4 (first duct 4₁ and second duct 4₂) and can be formed integrally with the aforementioned cabinet 2. As shown in the drawing, the sound emitting part 14 can be also formed with a separate member. Such a sound emitting part 14 formed with a separate member is mounted on the housing part 10 (first housing part 11) thereby forming the first duct 4₁ and the second duct 4₂.
The sound emitting part 14 has a connecting face 14s formed on the top face which is connected to the aforementioned cap part 13, and the connecting face has a connecting hole 14p which is formed to fit the aforementioned coupling protrusion 13b of the cap part 13. Further, a terminal part provided at the sound emitting part is covered with a protection part 14t.
In the duct 4 (first duct 4₁, second duct 4₂) formed at the sound emitting part 14, the end part 4a is formed in the axial direction (L direction) and other parts are formed in the direction along a plane orthogonally to the axial direction (L direction) with the end part 4b extending the outer periphery part 14a of the sound emitting part 14. Further, the sound emitting part 14 is provided with an opening part 14b which is formed between the first duct 4₁ and the second duct 4₂. The cap part 13 is connected so as to close the opening part 14b and form the top faces of the first duct 4₁ and the second duct 4₂.
In the example shown in the drawing, the opening parts 4b of the first duct 4₁ and the second duct 4₂ are configured with the sound emitting part 14 and the cap part 13. The corner part of the opening part 4b formed on the side of the sound emitting part 14 is formed in a curved shape while the corner part of the opening part 4b on the side of the cap part 13 is formed in a rectangular shape. However, the corner part on the side of the cap part 13 may be formed in a curved shape, which is preferable to reduce the occurrence of abnormal noises (wind noises).
The cap part 13 is configured to be able to integrally connect the sound emitting part 14, and the sound emitting part 14 is configured to be able to integrally connect the second cabinet 2₂ including the first speaker unit 31 and the second speaker unit 3₂. Further, attachment parts 14c for attaching a controlling device 40 are provided at the bottom face 4c of the first duct 4₁ of the sound emitting part 14. As such, the cap part 13, the sound emitting part 14, the second cabinet 2₂ including the first speaker unit 3₁ and the second speaker unit 3₂ and the controlling device 40 can be integrally separated from the first cabinet 21 (first housing part 11) or attached to the first cabinet 2₁. Hereby, a wiring work and so forth for the controlling device 40 can be easily performed, and after thoroughly completing various adjustments of the speaker units 3₁, 3₂, other components can be integrally incorporated into the first cabinet 2₁ that is attached to an installation space, and thus the workability of component mounting is improved.
Fig. 7 is a view illustrating a speaker unit 3 of a speaker device 1 according to an embodiment of the present invention (Fig. 7(a) is an outer appearance perspective view and Fig. 7(b) is a cross-sectional perspective view along with an enlarged view of part A). The speaker unit 3 (first speaker unit 3₁ or second speaker unit 3₂) is provided with a static part 30 formed with a frame and so forth, a vibrating body 31 supported by the static part 30 and a magnetic circuit 38. The vibrating body 31 is provided with a diaphragm 32 and an edge 33 supporting the diaphragm 32 at the static part 30 and so forth. The magnetic circuit 38 is provided with a magnet 38A, a yoke 38B and a plate 38C.
The vibrating body 31 is provided with a voice coil 34 and a driving member 35 which transmits the vibration of the voice coil 34 to the diaphragm 32. In the example shown in the drawing, the driving member 35 is provided with a venting hole 35e. The voice coil 34 is wound around a voice coil support part (voice coil bobbin) 36 and vibrates integrally with the voice coil support part 36. In order to transmit the vibration of the voice coil 34 to the diaphragm 32 via the voice coil support part 36 and the driving member 35, one end part of the driving member 35 is connected to the diaphragm 32, and the other end of the driving member 35 is connected to the voice coil support part 36.
The venting hole 35e formed in the driving member 35 may be a hole part which communicates between the inside and outside spaces of the driving member 35 or may be a hole part as a through-hole for connecting a lead wire pulled out from the voice coil 34 to a terminal part arranged outside the driving member 35. Further, a plurality of venting holes 35e is provided such that the driving member 35 is provided with a hole part which communicates between the inside and outside spaces of the driving member 35 and a hole part as a through-hole.
The diaphragm 32 is tabularly formed and the outer edge part of the diaphragm 32 is connected to the inner edge part of the edge 33 directly or via another member, and the outer periphery part 33a of the edge 33 is connected to the static part (frame) 30. By forming the diaphragm 32 in a tabular shape, sound waves with substantially the same phase can be emitted from the entire diaphragm 32. In the example shown in the drawing, the outer edge part of the diaphragm 32 is attached to the inner edge part of the edge 33 via the outer edge part of the driving member 35.
The outer periphery part 35a of the driving member 35 is attached to the diaphragm 32 and a recessed part 35b is formed in the outer periphery part 35a of the driving member 35 on the side that faces the diaphragm 32 (see an enlarged view of part A in Fig. 7(b)). A protrusion part 35c that protrudes in the sound emission direction is provided in the outer periphery part 35a of the driving member 35 on the outside of the recessed part 35b and the outer periphery part of the diaphragm 32. The inner periphery part 33b of the edge 33 is attached to the face of the protrusion part 35c on the side of the magnetic circuit 38. In the outer periphery part 33a of the edge 33 the thickness of the outer side is formed larger than the thickness of the inner side, and a given gap t is formed between the outer periphery part 30a of the static part (frame) 30 and the outer periphery part 33a of the edge 33.
When connecting the diaphragm 32 and the driving member 35 with a connecting member, a recessed part 35b is formed in the outer periphery part 35a of the driving member 35 on the side that faces the diaphragm 32. The protrusion part 35c that protrudes in the sound emission direction is arranged outside the recessed part 35b and the outer periphery part of the diaphragm 32, whereby a connecting member (for example, adhesive and so forth) that connects the diaphragm 32 and the driving member 35 can be restrained from running down the inner face of the driving member 35 and dripping to a magnetic gap and so forth. Further, the connecting member pools in the recessed part 35b, thereby improving an adhesive force between the diaphragm 32 and the driving member 35, thus the diaphragm 32 can be accurately attached to the driving member 35.
The outer periphery part 33a of the edge 33 is formed such that thickness of the outside is larger than thickness of the inside and a given gap t is formed between the outer periphery part 30a of the static part (frame) 30 and the outer periphery part 33a of the edge 33, whereby unwanted vibrations can be restrained from being transmitted from the diaphragm 32 to the static part 30 via the edge 33. Further, the outer periphery part 33a of the edge 33 comes into contact with the wall part 15, whereby air can be restrained from leaking out of the connecting face between the speaker unit 3 and the wall part 15, thus the occurrence of abnormal noises due to the leakage of air can be restrained.
The vibrating body 31 is provided with a damper 37 which supports the voice coil 34 at the static part (frame) 30. In the example shown in the drawing, the voice coil 34 is supported by the static part 30 via the voice coil support part 36 by the damper 37. The inner periphery part 35d of the driving member 35 and the inner periphery part 37a of the damper 37 are attached to the voice coil 34 or the voice coil support part 36, and an annular reinforcing part 39 which supports the inner periphery part 35d of the driving member 35 or the inner periphery part 37a of the damper 37 is connected to the outer periphery side face of the voice coil 34 or the voice coil support part 36.
In the speaker unit 3, a terminal part 41 is provided on the side part of the static part (frame) 30. Both end parts of the voice coil 34 are connected to respective terminals 41 a, 41b of the terminal part 41. Thus, the terminal parts 41a, 41b are connected to the connecting terminal of the controlling device 40.
Fig. 8 is a view illustrating an example of mounting a speaker device 1 according to an embodiment of the present invention. Here, a speaker device 1 is mounted within a wheel of a spare tire provided in a vehicle. Figs. 8 (a) to 8(c) show different structures of an attaching member.
The speaker device 1 (cabinet 2) has a prescribed shape corresponding to the inner side face of a wheel T1 of a spare tire T provided in a vehicle. Further, a hole part 2a into which a connecting tool M is inserted is formed in the central part 2c of the cabinet 2. The attaching member M is attached to a vehicle integrally with the spare tire T. The opening part 14b of the sound emitting part 14 shown in Fig. 6 configures the hole part 2a into which the attaching member M is inserted.
The speaker device 1 is mounted on a wheel K of the spare tire T, and the other end part of the connecting member M is inserted into the hole part 2a of the speaker device 1, the other end part of the attaching member M being fixed to an attaching counterpart N. Further, a fastening member V is provided at one end part of the connecting member M and by applying rotations and so forth to the fastening member V, speaker device 1 is fixed on the side of attaching counterpart N and is attached to the wheel K.
The aforementioned first duct 4₁ and second duct 42 is provided with a sound emitting hole (end part 4b) in the outer periphery side face of the cabinet 2, which faces the inner periphery side face of the wheel T 1 of the spare tire T. A gap K that guides to the outside sound waves emitted from the first duct 4₁ or second duct 4₂ is provided between the outer periphery side face of the cabinet 2 where the sound emitting hole is formed and the wheel T1 of the spare tire T. Such a structure can keep sounds from being cut off even when a floor mat or the like is placed on the cabinet 2, since the sound emitting holes of the first duct 4₁ and the second duct 4₂ are opened to the gap K by securing the gap K. Further, the gap K may also be a sound guide tube which guides sound waves emitted from the first duct 4₁ or the second duct 4₂ to the outside.
Fig. 9 is a view illustrating a vehicle equipped with a speaker device according to an embodiment of the present invention. A vehicle C is provided with a speaker device 1, a spare tire T in which the speaker device 1 is mounted, and an attaching counterpart N to which the spare tire T is attached, the speaker device 1 and the spare tire T are integrally attached to the attaching counterpart N with the attaching member M.
Here, the cabinet 2 is adapted to fit the wheel T 1 of the spare tire T, and the space in the wheel T1 of the spare tire T is effectively utilized so as to operate as the acoustic load of the speaker device 1. Further the cabinet 2 is adapted to fit the wheel shape of the spare tire T, whereby attachment can be effected with little looseness within the wheel T1. Owing to the shape of the cabinet 2 fitting the wheel T1, the volume of the cabinet attached within the wheel T1 can be secured to the maximum extent possible, and therefore low frequency reproduction is advantageously effected.
In order to attach the cabinet 2 to the wheel T 1 of the spare tire T, the outer diameter of the cabinet 2 is made smaller than the inner diameter of the wheel T1, and a gap may be formed between the outer periphery side face of the cabinet 2 and the inner periphery side face of the wheel. In this case, the bottom face part of the cabinet 2 is fixed to the wheel T1, whereby the occurrence of abnormal noises caused by the contact between the cabinet 2 and the wheel T1, specifically the contact between the outer periphery side face of the cabinet 2 and the inner diameter side face of the wheel T1 can be restrained.
The first duct 4₁ and the second duct 4₂ which respectively communicate between the two spaces 2S₁, 2S₂ in the cabinet 2 and the outside serve as a sound emitting part of an acoustimass type cabinet. Two spaces 2S₁, 2S₂ are formed by partitioning the wheel T1 in the axial direction of the wheel T1, and thus an acoustimass type cabinet is effectively formed by utilizing the space within the cylindrical wheel T1.
Notably, the wall part 15 for partitioning the spaces 2S₁, 2S₂ includes the attaching counterpart 15C ( planar parts 15A, 15B) that makes an angle, and the space 2S₂ surrounded by the planar parts 15A, 15B that makes an angle can collect sound waves emitted from the rear side of the second speaker unit 3₂ and efficiently guide the collected sound waves to the second duct 4₂,
Two speaker units 3₁, 3₂ arranged in the cabinet 2 are covered with the cap part 13, and thus are substantially protected. As such, even when tools and the like are arranged near the wheel T1, or a spare tire T is arranged together with other items in a trunk room, the speaker units 3₁, 3₂ that are in the cabinet 2 are not subject to damages. For example, if a speaker device 1 is a subwoofer for low frequency reproduction, a directional characteristic in a low frequency range is comparatively small, and thus even when the speaker device 1 is mounted in a spare tire wheel in a trunk room, it is possible to successfully provide reproduced sound to the entire room of a car.
Further, the sound emitting holes of the first duct 4₁ and the second duct 4₂ are provided near the opening part of the wheel T1 (upper part), whereby a rate of emitted sound waves interfering with the wheel T1 can be reduced. If the sound emitting holes of the duct 4 is arranged at the lower part, emitted sound waves are interrupted by the side face of the wheel T1 and are damped before emitted sound waves reach inside the room in a car. However, according to the speaker device 1, occurrence of such a problem is prohibited.
Further, a spare tire is arranged under the floor (under floor mat) in the trunk room of a vehicle and so forth, but is not limited thereto, and may be arranged anywhere in a vehicle as long as it has little effect on passengers.
As described above, an embodiment of the present invention has been described in detail with reference to the drawings. But a specific configuration is not limited to these embodiments, and any alterations in design, etc. without departing from the scope of the preset invention can be included in the present invention. In addition, each of the above-described embodiments can be combined by mutually using each technology unless there is a specific contradiction or problem in the purpose and configuration and so forth.

Claims

A speaker device (1) comprising:
a cylindrical cabinet (2) configured with a housing part (10) and a cap part (13);

a wall part (15) arranged in said cabinet (2), partitioning a space (2S) in said cabinet (2) by extending from a central part (2c) toward two different positions (2r1, 2r2) in an outer periphery part (2r) of said cabinet (2), wherein the central part (2c) is formed by a tubular part (10c), which is erected in the axial direction (L) from a bottom face part (10a) of the housing part (10); and

a plurality of speaker units (3, 31, 32) arranged in said cabinet (2) and attached to said wall part (15), wherein

a first speaker unit (31) is arranged in one space (2S1) partitioned by said wall part (15) with a sound emission surface (3a1) of said first speaker unit (31) being directed to the other space (2S2) partitioned by said wall part (15), and

a second speaker unit (32) is arranged in the other space (2S2) with said sound emission surface (3a2) of said second speaker unit (32) being directed to said one space (2S1), and

a duct (4, 41, 42) is provided at said cabinet (2) to communicate between said space (2S) and the outside.
The speaker device according to claim 1, wherein said duct (4) has a first duct (41) communicating between said one space (2S1) and the outside, and a second duct (42) communicating between said other space (2S2) and the outside.
The speaker device according to claim 2, wherein said speaker unit (3, 31, 32) directed to one of said first or second duct (41, 42) is a passive unit.
The speaker device according to claim 2, wherein one end part (4a, 4b) of said first duct (41) and said second duct (42) are arranged between said first speaker unit (31) and said second speaker unit (32), and
the other end part (4a, 4b) of said first duct (41) and said second duct (42) are arranged near said outer periphery part (2r) of said cabinet (2), and
one part of said first duct (41) and said second duct (42) extend in the axial direction (L) of said cabinet (2) from said one end towards the other end, and the other parts of said first duct (41) and said second duct (42) extend in the direction from said central part (2c) towards said outer periphery part (2r) of said cabinet (2).
The speaker device according to claim 2, wherein a portion provided in one of said ducts (4, 41, 42) and extending from said central part (2c) towards said outer periphery part (2r) of said cabinet (2) is formed adjacently to said outer periphery part (2r) of said cabinet (2).
The speaker device according to claim 5, wherein said first duct (41) and said second duct (42) are provided in the space surrounded by said first speaker unit (31), said second speaker unit (32) and said cabinet (2).
The speaker device according to claim 6, wherein a bottom face part (4c) of said first duct (41) and said second duct (42) is lower than an upper end part (3b) of said first speaker unit (31) and said second speaker unit (32) in the axial direction (L) of said cabinet (2).
The speaker device according to claim 7, wherein said wall part (15) includes an attaching counterpart (15C) attaching said first speaker unit (31) and said second speaker unit (32), and
a circumferential part (15E) is provided at said outer periphery part of said attaching counterpart formed along said outer periphery part (2r) of said cabinet (2).
The speaker device according to claim 8, wherein said circumferential part (15E) of said wall part (15) has an attachment part (15E1) attached to said outer periphery part (2r) of said cabinet (2).
The speaker device according to claim 9, wherein a second housing part (12) is configured in said housing part (10) of said cabinet (2) defined as a first housing part (11), and
said second housing part (12) includes a bottom face part (12a) and an outer periphery tubular part (12b), and
said second housing part (12) forms said wall part (15).
The speaker device according to claim 10, wherein said cabinet (2) configured with said first housing part (11) is defined as a first cabinet (21), and
said second housing part (12) configures a second cabinet (22) formed in said first cabinet (21), and
said second cabinet (22) is separated from said first cabinet (12) integrally with said first speaker unit (31) and said second speaker unit (32).
The speaker device according to claim 11, wherein a reinforcing part (12c) having protruding shape is formed at said second housing part (12) in the radial or circumferential direction of said first cabinet (21).
The speaker device according to claim 12, wherein said first housing part (11) includes a bottom face part (10a) supporting said wall part (15), and an outer periphery tubular part, and
said cap part (13) is formed in a tabular shape.
The speaker device according to claim 13, wherein a sound emitting part (14) including said first duct (41) and said second duct (42) is arranged between said first housing part (11) and said cap part (13), and
said outer periphery part (14a) of said sound emitting part (14) is arranged on said outer periphery part of said first housing part, and
said first housing part, said cap part (13) and said sound emitting part (14) are formed with different members.
A vehicle comprising:
a speaker device according to claim 1,

a spare tire (T1), and

an attaching counterpart (N), wherein

said speaker device (1) is mounted at said spare tire (T1).
The speaker device according to claim 1, comprising
planar parts (15A, 15B), which are along the axis of the cabinet (2), specifically in substantially the orthogonal direction, and which
extend in two directions (R1, R2) orthogonally to the axial direction (L) of the cabinet (2).