1. Technical Field
The present disclosure relates to a loudspeaker device integrated in an interior member of an automobile and the like, and to device movable-body device equipped with the loudspeaker device.
2. Description of the Related Art
A loudspeaker device for reproducing low-pitched sounds requires a large volumetric capacity for enhancing the ability of the device to reproduce low-pitched sounds. Unfortunately, there is a limit to the space available for such a device in an automobile. Thus, Japanese Translation of PCT Publication No. 2012-503940 (Patent Literature 1, hereinafter), for example, proposes that a spare-wheel housing section, which is disposed in the interior of an automobile, is used as an enclosure of a loudspeaker.
The present disclosure is intended to provide a loudspeaker device which utilizes an interior member of a movable-body device such as an automobile, as an enclosure of the loudspeaker device. Such a loudspeaker device can feature compatibility between high sound quality in a vehicle interior and space saving of the vehicle interior.
The loudspeaker device according to the present disclosure includes a loudspeaker unit and an enclosure. The loudspeaker unit outputs sounds mainly in a first direction, upon receiving an electric signal. The enclosure is configured with at least a part of the interior member of the movable-body device, and secures and accommodates the loudspeaker unit in the inside of the enclosure. The interior member includes a body part, and an accommodation part that accommodates the loudspeaker unit therein. The accommodating part is formed integrally with the body part and is larger in dimension along the first direction than the body part. A part of the accommodation part faces the diaphragm of the loudspeaker unit.
A movable-body device according to the present disclosure includes a body, a drive unit, an amplifier, and the loudspeaker device described above. The drive unit and the amplifier are mounted in the body. The loudspeaker device is fed with an output from the amplifier.
Prior to descriptions of embodiments of the present disclosure, problems of the conventional loudspeaker device will be briefly described. According to the loudspeaker device disclosed in Patent Literature 1, a spare-wheel housing section in the vehicle interior is used as an enclosure of a loudspeaker without any modification. This causes variations in acoustic characteristics because the volumetric capacity of the enclosure varies depending on the model of the automobile and the situation whether or not a tire is being housed in the housing section. Moreover, such a spare-wheel housing section essentially requires no airtightness; therefore, sounds will leak from the spare-wheel housing section. Therefore, the spare-wheel housing section is unsuitable for use as the volumetric capacity of the enclosure of the loudspeaker device.
Hereinafter, an embodiment of the present disclosure will be specifically described with reference to the accompanying drawings.
The automobile as an example of a movable-body device shown in
As shown in
As shown in
A part of lid 1 functions as enclosures 3 of loudspeaker units 150. In more detail, lid 1 includes body part 10, and accommodation parts 2 integrally formed with body part 10. Each of loudspeaker unit 150 is accommodated in accommodation part 2. Lid 1 covers opening 76 of housing section 70. Lid 1 is an example of an interior member of the automobile.
Commonly, housing section 70 is disposed in the bottom of a trunk or luggage room which is disposed in the rearward of rear sheets of the automobile. Lid 1 is disposed such that the space above it can be used as a trunk or a luggage room capable of housing baggage after housing section 70 has housed spare tire 80 therein. Accordingly, lid 1 is necessary for housing section 70. Moreover, the lid preferably has a plane shape in the upper side without projections and depressions, for efficiently housing baggage.
Note that, lid 1 is commonly configured with a plane-shaped resin molding. Most lids have surfaces having been subjected to processing, such as flocking, for enhancing their external appearance quality.
As shown in
Spare tire 80 shown in
For functioning as enclosure 3, lid 1 includes plane plates 1A and 1B, and a plurality of reinforcing ribs 1C. Plates 1A and 1B are disposed to have a space therebetween, and each of reinforcing ribs 1C connects plate 1A to plate 1B. This configuration securely provides the space in the inside of lid 1. The dimension along first direction “S” of each of reinforcing ribs 1C is 3 cm to 4 cm, for example.
Lid 1 includes accommodation parts 2, allowing lid 1 to function as enclosure 3 of loudspeaker devices 100. Therefore, such an empty space which would not be used in the vehicle interior can be effectively utilized as enclosure 3. On top of that, it is possible to secure a sufficient internal volume of enclosure 3, resulting in an increase in quality of acoustic characteristics of the vehicle interior. Moreover, it is possible to reduce variations in acoustic characteristics depending on the model of the automobile, and to reduce a leakage of sounds and the like.
Accommodation part 2 not only secures and accommodates loudspeaker unit 150 therein, but also provides an acoustic space for sounds radiated from loudspeaker unit 150. For a sound radiated in the front direction (first direction “S”) of loudspeaker unit 150 and a sound radiated in the rear direction of loudspeaker unit 150, enclosure 3 also has a role in acoustically intercepting these sounds from each other, which prevents these sounds from cancelling each other, thereby preventing a reduction in their sound pressures.
Note that lid 1 may further include duct part 4 that connects accommodation part 2 to the vehicle interior (an example of the inside of the movable-body device). Generally, the larger the volume of an acoustic space is, the smaller the sound radiation resistance becomes, tending to provide better acoustic characteristics. The sound radiated in the inside of accommodation part 2 travels, through duct part 4, toward the upper side of lid 1 (in the positive direction of the Z-axis shown in
As shown in
Duct part 4 is configured in this way, so that sound waves with short wavelengths in a high frequency range are attenuated and sound waves with long wavelengths in a low frequency range can be selectively taken out. Therefore, duct part 4, having such a shape, can function as a mechanical filter, which allows sounds in a middle- to high-tone range to be naturally attenuated without use of a network circuit or an equalizer circuit. Accordingly, sound waves containing deep bass sounds reproduced with high fidelity reach passengers present in the vehicle interior. The passengers can enjoy music and the like with high sound quality particularly regarding deep bass sounds. At the same time, of course, middle to high-pitched sounds other than the deep bass sounds are reproduced by already-existing speakers. Such already-existing speakers are often disposed in doors, a rear tray, or in the vicinity of an instrument panel in the front. Then, resulting from the effect of duct part 4 as described above, middle to high-pitched sounds output from loudspeaker unit 150 are not radiated directly into the vehicle interior. This prevents sound waves in a high frequency range emitted from different speakers from causing interference between them that would reduce sound quality.
As shown in
Note that loudspeaker unit 150 mainly reproduces deep bass sounds. That is, the major reproduction range of loudspeaker unit 150 is 300 Hz or less. Loudspeaker unit 150 of this type is generally called a woofer. Moreover, a so-called super woofer for a major reproduction range of 100 Hz or less may be equipped as loudspeaker unit 150. Such deep bass sounds can be provided even without duct part 4, through vibrations of lid 1 as a whole. Therefore, duct part 4 is not always essential in accordance with applications.
Loudspeaker unit 150 includes frame 151, supporting part 152, magnetic circuit 153, diaphragm 154, and voice coil 155. Supporting part 152 is disposed in a center portion of frame 151. Magnetic circuit 153 of an outer magnet-type is provided with magnetic gap 156. The front face of magnetic circuit 153 is bonded to the rear face of supporting part 152. The outer peripheral end of diaphragm 154 is coupled to the outer peripheral end portion of frame 151. A first end portion of voice coil 155 is bonded to a center portion of diaphragm 154. Then, a second end portion of voice coil 155 is inserted into magnetic gap 156. Note that, as shown in
Loudspeaker unit 150 may include dust cap 158. In this case, dust cap 158 is bonded to the center portion of diaphragm 154. Then, dust cap 158 protrudes from the front face of diaphragm 154. Moreover, frame 151 is preferably provided with holes 151A. In this case, sounds output from the rear face of diaphragm 154 pass through holes 151A to be output to the outside of loudspeaker unit 150. Loudspeaker unit 150 works in such a way that voice coil 155 vibrates to cause diaphragm 154 to vibrate, thereby outputting sounds in both the forward and backward directions of loudspeaker unit 150. The vibration of voice coil 155 is caused by a magnetic force generated by magnetic circuit 153.
Magnetic circuit 153 includes yoke 153A, magnet 153B, upper plate 153C, and center pole 153D. Note that center pole 153D is a projection formed in a center portion of yoke 153A. Upper plate 153C is bonded to the front face of magnet 153B. Magnet 153B is bonded to the front face of yoke 153A. Accordingly, the front face of upper plate 153C is bonded to the rear face of supporting part 152. Note that center pole 153D passes through a hole that is formed in both the center portion of magnet 153B and the center portion of upper plate 153C. With this configuration, magnetic gap 156 is formed in a region where upper plate 153C faces center pole 153D.
As shown in
Note that, as shown in
Note that, in the embodiment, the two of accommodation parts 2 are disposed; however, the number of accommodation parts 2 is not limited to two. A plurality, more than two, of accommodation parts 2 may be disposed in lid 1 and that loudspeaker units 150 identical in number to accommodation parts 2 are accommodated in accommodation parts 2, one for each. In this case as well, it is only required for the plurality of accommodation parts 2 to be configured such that the inner side face of each of accommodation parts 2 is of a circular arc shape and the inner side face forms a corresponding part of an identical circle, as viewed from the opposite direction of first direction “S.” That is, three of accommodation parts 2 may be disposed in lid 1 or, alternatively, four of accommodation parts 2 may be disposed. For example, when accommodation parts 2 are disposed at four positions around the periphery of spare tire 80, a sufficient volumetric capacity for enclosure 3 can be ensured and accommodation parts 2 function as a guide for supporting spare tire 80 not to move. Note that, in general, sounds of music and the like are reproduced in stereo. In such applications, an even number of loudspeaker units 150 are disposed in the same even number of accommodation parts 2, respectively.
Moreover, in a case where a super woofer is used as loudspeaker unit 150, it may not be required that bass sounds be reproduced in stereo. In such applications, one loudspeaker unit 150 is disposed in one accommodation part 2.
Note that duct part 4 shown in
Parts of the section of the inner wall of duct part 4 shown in
Moreover, the depth (the distance between the highest and lowest points on the surface in the direction of thickness of the inner wall) of uneven surface 44 is preferably in a range from 0.5 mm to 2 mm, inclusive. With heights smaller than 0.5 mm, the function of regulating an air stream is restricted. With heights exceeding 2 mm, there are cases where uneven surface 44 becomes a factor in causing air strain.
The configuration described above provides loudspeaker device 100 that features compatibility between the high sound quality in an vehicle interior and the efficient use of the space of the vehicle interior. In the embodiment, lid 1 has been described as an example of the interior member functioning as enclosure 3, of the automobile; however, the interior member is not limited to this. In
As described above, installing loudspeaker device 100 into a movable-body device such as an automobile allows the effective utilization of a surplus space in the interior of the movable-body device, and provides the sufficient volumetric capacity of enclosure 3. This can provide the movable-body device that achieves high sound quality in the interior thereof.
Therefore, it is possible to implement the movable-body device that achieves high sound quality in the interior thereof, without any increase in cost for extra members and in weight accompanying the extra members.
On top of that, since enclosure 3 of loudspeaker device 100 is configured utilizing an interior member of an automobile or the like, the need for introducing additional members is eliminated for configuring enclosure 3. This can achieve a reduction in count and weight of its parts simultaneously, which in turn achieves low price and fuel saving, via reduced weight, of the automobile or the like.
As described earlier, according to Patent Literature 1, a space such as a spare-wheel housing section is used; however, the space essentially requires no airtightness. This causes a sound leakage, resulting in a decrease in sound quality. On the other hand, although loudspeaker device 100 is configured using an interior member of an automobile, loudspeaker device 100 is completed as an acoustic system by itself. For this reason, this reduces such a decrease in sound quality as observed in the case of Patent Literature 1.
As described above, the loudspeaker device according to the present disclosure is useful for use in vehicles. Note that the movable-body device is not limited to an automobile. The loudspeaker device according to the present disclosure is applicable to movable-body devices, such as a ship and a train, each of which has a space therein where sounds are output.
Number | Date | Country | Kind |
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2017-084127 | Apr 2017 | JP | national |
Number | Name | Date | Kind |
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4572326 | Hutchins | Feb 1986 | A |
4819761 | Dick | Apr 1989 | A |
20100074453 | Ludwig et al. | Mar 2010 | A1 |
20150158432 | O'Neal | Jun 2015 | A1 |
20180020290 | Ludwig | Jan 2018 | A1 |
Number | Date | Country |
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1713297 | Oct 2006 | EP |
8-140177 | May 1996 | JP |
2012-503940 | Feb 2012 | JP |
Number | Date | Country | |
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20180310084 A1 | Oct 2018 | US |