JP5858841B2 - In-vehicle audio equipment - Google Patents

Description

  The present invention relates to an on-vehicle audio device for installing a speaker on a ceiling of a vehicle such as an automobile.

  In a general acoustic device, a speaker is attached to a speaker box so that interference between a sound pressure emitted forward from the speaker and a sound pressure emitted backward from the speaker can be prevented.

  On the other hand, in the in-vehicle acoustic device, the speaker is attached to the rear panel of the automobile and the trunk space is used instead of the speaker box, or the speaker is attached to the interior panel of the door and the interior space of the door is used instead of the speaker box. used. However, since the driver's ear is far from the rear panel and is higher than the speaker installed on the door, the sound effect in the vehicle interior cannot be said to be sufficient only by the speaker attached to the rear panel or the door.

  It is known that the sound effect in the passenger compartment improves when the speaker is installed on the ceiling of the vehicle interior, but usually there is a sufficiently large space in the ceiling to replace the speaker box. In addition, it is difficult to install a speaker box having a sufficiently large internal volume. If a speaker box with a small internal volume is arranged on the ceiling, the sound pressure reaching the ears of the driver or the like is reduced by the damper action of the internal space of the speaker box, and the acoustic effect particularly in the low sound range is reduced.

  Patent Document 1 below discloses an in-vehicle speaker device in which a speaker is disposed between a ceiling portion and a rear window.

  This vehicle-mounted speaker device is provided with a speaker box on the ceiling and a horn that communicates with the internal space of the speaker box and extends forward. By providing this horn, we are trying to expand the bass.

Microfilm of Japanese Utility Model No. 61-167579 (Japanese Utility Model Application No. 63-72990)

  Since the in-vehicle speaker device described in Patent Document 1 is a combination of a speaker box and a horn, the structure is complicated, the height is large, and a large installation space is required on the ceiling. Further, since the speaker cannot be disposed on the seat, the acoustic effect in the passenger compartment cannot be sufficiently enhanced.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a vehicle-mounted acoustic device that can be thinly structured and can be provided with a speaker on a seat such as a driver's seat and that can enhance the acoustic effect. It is said.

The present invention relates to an in-vehicle acoustic device having a support body attached to a lower surface of a ceiling portion of a vehicle and a speaker attached to the support body.
The support body has a support plate portion that is installed at a distance from the lower surface of the ceiling portion , and a hole portion in which the speaker is attached downward is formed in the support plate portion, and an edge of the support plate portion An opening is formed between at least a part of the portion and the lower surface of the ceiling portion , and a space is formed between the support plate portion and the lower surface of the ceiling portion to communicate the back portion of the speaker and the opening portion. It is characterized by that. In addition, the said support plate part can be extended substantially parallel to the lower surface of a ceiling part, and the space between the said support plate part and the lower surface of a ceiling part can be connected with a vehicle interior by the said opening part.

  Since the on-vehicle acoustic device of the present invention has a thin structure, it can be attached to a ceiling portion in a vehicle compartment and a speaker can be installed on the seat. Since the distance of the sound pressure path from the opening formed between the support plate part and the ceiling part to the ear of the seated person of the seat is long, the sound pressure emitted from the front part of the speaker is not greatly attenuated. It is given to a person's ear and the acoustic effect with respect to a seated person, especially the acoustic effect of a low-frequency range can be heightened.

  In addition, the passenger's ears seated in a seat other than the seat under the speaker are given sound pressures that are emitted from the front and back of the speaker and whose phases are reversed to each other. Therefore, only a seated person located under the speaker can enjoy the sound.

In the present invention, it is preferable that the space between the support plate portion and the lower surface of the ceiling portion does not resonate with sound waves having a frequency of 200 Hz or less.

  With the above configuration, a low-frequency sound effect can be effectively given to a seated person in the seat under the speaker.

  In the present invention, it is preferable that the opening is formed at ¼ or more of the length of the edge of the support plate.

  Further, it is preferable that the support plate portion has a wide edge portion having a width dimension larger than the width dimension of the speaker installation portion in which the hole portion is formed, and the opening portion is formed in the wide edge portion, More preferably, the width of the support plate portion gradually increases from the speaker installation portion toward the wide edge portion.

  Since the in-vehicle acoustic device of the present invention has a thin structure, even if it is attached to the ceiling portion in the vehicle interior, the space in the vehicle interior is not reduced. Moreover, the acoustic effect with respect to the seated person of the seat under a speaker can be heightened, and it can suppress that a loud sound is transmitted to the passenger of the other seat.

Sectional drawing which shows the state by which the vehicle-mounted audio apparatus of the 1st Embodiment of this invention was attached to the motor vehicle, The perspective view of the vehicle-mounted audio apparatus shown in FIG. The top view which shows the state by which the vehicle-mounted audio apparatus of the 2nd Embodiment of this invention was attached to the motor vehicle, The top view which shows the state by which the vehicle-mounted audio apparatus of the 3rd Embodiment of this invention was attached to the motor vehicle, The perspective view which shows the vehicle-mounted audio apparatus of the 4th Embodiment of this invention, The diagram which shows the acoustic effect of the vehicle-mounted audio apparatus of 1st Embodiment,

  A vehicle 1 shown in FIG. 1 is an automobile, and a ceiling portion 2 and a windshield 3 are shown. An instrument panel 5 and a steering wheel 5a are provided in front of the passenger compartment 4. In the passenger compartment 4, a driver's seat 6 is provided in the front and a passenger seat 7 is provided in the rear.

  The in-vehicle audio device 10 according to the first embodiment of the present invention is installed under the ceiling 2. As shown in FIGS. 1 and 2, the in-vehicle acoustic device 10 has a support 11. The support body 11 includes a flat plate-like support plate portion 12 and a plurality of support columns 13 that support the support plate portion 12. The upper end portion of the support column 13 is fixed to the lower surface of the ceiling portion 2, and the support plate portion 12 is disposed substantially parallel to the ceiling portion 2 along the lower surface of the ceiling portion 2. The support plate portion 12 and the support column 13 are integrally formed of a synthetic resin material.

  A hole portion 14 is opened at a substantially central portion of the support plate portion 12, and a speaker 15 is attached to the hole portion 14. The front portion 15 a of the speaker 15 is directed to the lower side of the support plate portion 12, and the back portion 15 b of the speaker 15 is directed to the upper side of the support plate portion 12.

  As shown in FIG. 1, when the in-vehicle acoustic device 10 is attached to the ceiling portion 2, a space 16 is formed between the support plate portion 12 and the ceiling portion 2. Further, an opening 17 is formed between the edge 12 a of the support plate 12 and the ceiling 2. Since there are only four columns 13 between the support plate portion 12 and the ceiling portion 2, the opening 17 is formed in 80% or more of the total length of the edge portion 12 a of the support plate portion 12. . Further, it is more preferable that the opening 17 is formed in 90% or more.

  As shown in FIG. 1, the speaker 15 is located above the driver 8 who is seated in the driver's seat 6. Therefore, the sound pressure emitted from the front portion 15a due to the vibration of the diaphragm of the speaker 15 reaches the ear of the driver 8 by the route (i) at the shortest, but the sound pressure emitted from the back portion 15b of the speaker 15 is As shown by (ii), it passes through the space 16 and is transmitted to the driver's 8 ear through the opening 17.

  If the path (ii) is more than twice the path (i), the sound pressure of the path (ii) can be reduced by 6 dB or more with respect to the sound pressure of the path (i), and the phases are opposite to each other. The attenuation of the sound pressure due to the synthesis of the sound pressure of the path (i) and the sound pressure of the path (ii) can be suppressed to 1 dB or less. Therefore, a sufficiently large sound pressure can be given to the driver 8 by the sound pressure output from the front portion 15 a of the speaker 15.

  In order to make the path (ii) more than twice as long as the path (i), the shortest distance W from the center of the speaker 15 to the edge 12a of the support plate 12 shown in FIG. The diameter is preferably longer than the diameter of the diaphragm, and more preferably, W is 1.5 times or more the diameter of the diaphragm.

  On the other hand, the sound pressure emitted from the front portion 15a of the speaker 15 reaches the ear of the passenger 9 seated in the rear passenger seat 7 through the route (iii), and the sound pressure emitted from the back portion 15b. Arrives on route (iv). Since the difference in the distance between the route (iii) and the route (iv) is small with respect to the ear of the passenger 9, the sound pressure from the front portion 15a and the sound pressure from the back portion 15b, which are 180 degrees out of phase with each other, The ratio increases, and the sound pressure from the speaker 15 is greatly attenuated and transmitted to the passenger's 9 ear. Therefore, the sound from the speaker 15 is mainly transmitted to the driver 8 seated in the lower seat so that the passenger 9 can sit in a quiet environment.

  FIG. 6 shows the acoustic effect transmitted to the ear of the driver 8, where the horizontal axis is the vibration frequency (Hz) of the diaphragm of the speaker 15 and the vertical axis is the sound pressure (dB / m) felt by the ear. is there.

  The level line (a) shown in FIG. 6 is a result of using the vehicle-mounted acoustic device 10 shown in FIGS. 1 and 2. The length of one side of the square support plate portion 12 is 380 mm, and the diameter of the diaphragm of the speaker 15 used is 180 mm. Moreover, the shortest distance (distance of path | route (i)) from the front part 15a of the speaker 15 to the driver | operator 8 (listener) ear | edge was 200 mm.

  The level line (b) shown in FIG. 6 is the result of an experiment in which the same speaker as the level line (a) was attached to a sealed speaker box having an internal volume of 5 liters. The shortest distance from the front portion 15a of the speaker 15 to the driver 8 (listener) ear is the same as the level line (a).

  The speaker box with a capacity of 5 liters has a considerably large capacity, but the sound pressure in the speaker box is still suppressed by the damper action of the sound pressure in the speaker box, and the sound pressure is lowered as a whole. On the other hand, in the level line (a) measured using the in-vehicle acoustic device 10 according to the first embodiment of the present invention, the sound pressure is high in the entire region, and the sound pressure is large and small in the wide low frequency band. The difference between is narrowing.

  In the in-vehicle acoustic device 10 shown in FIGS. 1 and 2, since the opening 17 is formed in a range of 80% or more of the total length of the edge 12 a of the support plate 12, the support plate 12, the ceiling 2, It becomes difficult for the sound pressure to resonate in the space 16 between them, and a decrease in the sound pressure can be prevented.

  In the sound device using the speaker 15, the resonance of the sound pressure in the speaker box is suppressed by inserting a sound absorbing material in the speaker box or changing the shape of the speaker box in the middle to high sound range. However, it is difficult to suppress resonance of sound pressure generated in the speaker box in a low sound range of 200 Hz or less or 400 Hz or less.

  However, as shown in FIGS. 1 and 2, by providing the opening 17 in a wide area, resonance of sound pressure at a frequency of 200 Hz or less (10 Hz or more) does not occur, and further 400 Hz or less (10 Hz or more). Resonance of sound pressure at frequency does not occur. As a result, the damper action in the space 16 can be suppressed, and the bass sound pressure transmitted to the viewer located below the speaker 15 in the bass range can be increased.

  The in-vehicle acoustic device 101 according to the second embodiment of the present invention shown in FIG. 3 has a rectangular support 111. The support 111 has a rectangular support plate portion 112 and a wall portion 113 that rises integrally from the edge of the support plate portion 112.

  The support plate portion 112 has a rectangular shape and extends from the front driver seat 6a to the front passenger seat 6b. In the support plate portion 112, the speaker 15 is installed on the driver's seat 6a, and the speaker 15 is also installed on the passenger seat 6b.

  The wall portion 113 rises from a part of the front edge 112a which is the long side of the support plate portion 112 and the side edges 112b and 112b which are short sides. The upper end portion of the wall portion 113 is in close contact with the lower surface of the ceiling portion 2 in its entire length, and the space between the support plate portion 112 and the ceiling portion 2 is the entire length of the front edge 112a and part of both side edges 112b and 112b. It is blocked by. An opening 117 is formed between the support plate portion 112 and the ceiling portion 2 along the entire length of the rear edge 112c. That is, the opening 117 is formed at ¼ or more of the entire length of the edge portion of the support plate portion 112.

  The relationship between the shortest distance from the center of each speaker 15 to the edge (rear edge 112c) where the wall 113 of the support plate 112 is not formed and the diameter of the diaphragm of the speaker 15 is shown in FIG. This is the same as the relationship between the distance W and the diameter of the diaphragm.

  In the in-vehicle acoustic device 101 shown in FIG. 3, the support plate portion 112 and the ceiling portion 2 are substantially parallel, and the thickness dimension of the space 116 formed between the support plate portion 112 and the ceiling portion 2 is constant. is there. Further, the space 116 communicates with a constant thickness from the back portion 15b of the speaker 15 to the opening 117, and there is no shielding object therebetween.

  Also in this in-vehicle acoustic device 101, the sound pressure emitted from the front portion 15a of the speaker 15 is effectively transmitted to the driver and the passenger seated under the speaker 15, and is transmitted to the rear seats 7a and 7b. The sound of the speaker 15 is transmitted to the passenger's ear because the sound pressures of the opposite phases from the front portion 15a and the back portion 15b are transmitted to the seated passenger's ear through a path having substantially the same length. The rear seats 7a and 7b can be set in a quiet environment.

  The in-vehicle acoustic device 101A according to the third embodiment of the present invention shown in FIG. 4 has a support 111A. The support 111A has the same shape as the support 111 shown in FIG. 3 cut in half.

  In the support 111A, a support plate portion 112A and a wall portion 113A are integrally formed. The top edge 112a of the support plate portion 112A and the side edge 112b on the door side are closed by the wall portion 113A, and the opening 117A is formed on the side edge 112d and the rear edge 112c of the support plate portion 112A on the passenger seat 6b side. Is formed. In the support 111A, an opening 117A is formed in a range that is 1/2 or more of the entire length of the edge of the support plate portion 112A.

  Also in the support 111A shown in FIG. 4, the distance from the center of the speaker 15 to the edge portions 112c and 112d is longer than the diameter of the diaphragm of the speaker 15, and preferably 1.5 times the diameter or more.

  In the in-vehicle acoustic device 101A shown in FIG. 4, the sound pressure from the front portion 15a of the speaker 15 is effectively transmitted to the driver seated in the driver's seat 6a located under the speaker 15, but the assistant Since the passengers seated in the seat 6b and the rear seats 7a and 7b are given sound pressures of opposite phases emitted from the front portion 15a and the back portion 15b of the speaker 15, the sound emitted from the speaker 15 is attenuated. You can set up a quiet sitting environment.

  The support 111 shown in FIG. 3 has an opening 117 formed in a range of 1/4 or more of the entire length of the edge of the support plate 112, and the support 111A shown in FIG. 4 has an edge of the support plate 112A. 117 A of opening parts are formed in the range more than 1/2 of full length. Therefore, resonance of sound pressure at a frequency of 200 Hz or less (10 Hz or more) in the sound range emitted from the speaker 15 does not occur, and preferably resonance of sound pressure at a frequency of 400 Hz or less (10 Hz or more) does not occur.

  Therefore, sound pressure, particularly low-range sound pressure can be effectively applied to the seated person's ears under the speaker 15.

  The on-vehicle acoustic device 201 according to the fourth embodiment of the present invention shown in FIG. The support body 211 has a support plate portion 212 and a wall portion 213 rising from the support plate portion 212.

  One end portion of the support plate portion 212 is a speaker installation portion 212 a, a hole portion 114 is formed therein, and the speaker 15 is attached to the hole portion 114. The front portion 15 a of the speaker 15 is directed below the support plate portion 212, and the back portion 15 b of the speaker 15 is directed to a space 116 formed between the support plate portion 212 and the ceiling portion 2.

  A wide edge portion 212 b is formed on the side of the support plate portion 212 opposite to the speaker installation portion 121 a, and an opening 117 is formed between the wide edge portion 212 b and the ceiling portion 2.

  A wall portion 213 rises integrally from an edge portion of the support plate portion 212 other than the wide edge portion 212b. The space 216 sandwiched between the wall portions 213 is gradually widened from the width Wa at the speaker installation portion 121a toward the width Wb at the wide edge portion 212b.

  Therefore, resonance of sound pressure at a frequency of 200 Hz or less (10 Hz or more) in the sound range emitted from the speaker 15 does not occur, and preferably, resonance of sound pressure at a frequency of 400 Hz or less (10 Hz or more) does not occur.

  The distance from the center of the speaker 15 to the wide edge portion 212b is longer than the diameter of the diaphragm of the speaker 15, and is preferably 1.5 times the diameter or more.

  Therefore, sound pressure, particularly low-range sound pressure, can be effectively applied to the ear of the seated person under the speaker 15, while the passenger sitting on the seat to which the opening 117 is directed. Can set a quiet environment.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Ceiling part 6,6a Driver's seat 10 Car-mounted audio apparatus 11 Support body 12 Support plate part 13 Support | pillar 14 Hole part 15 Speaker 15a Front part 15b Back part 16 Space 17 Opening part 101,101A Car-mounted audio apparatus 111,111A Support Body 112, 112A Support plate portion 113, 113A Wall portion 116 Space 117, 117A Opening portion 121b Wide edge portion 201 In-vehicle acoustic device 212 Support plate portion 212a Speaker installation portion 213 Wall portion

Claims (6)

In a vehicle-mounted acoustic device having a support attached to the lower surface of the ceiling of the vehicle and a speaker attached to the support,
The support body has a support plate portion that is installed at a distance from the lower surface of the ceiling portion , and a hole portion in which the speaker is attached downward is formed in the support plate portion, and an edge of the support plate portion An opening is formed between at least a part of the portion and the lower surface of the ceiling portion , and a space is formed between the support plate portion and the lower surface of the ceiling portion to communicate the back portion of the speaker and the opening portion. A vehicle-mounted acoustic device. The in-vehicle acoustic device according to claim 1, wherein the space between the support plate portion and the lower surface of the ceiling portion does not resonate with sound waves having a frequency of 200 Hz or less.   The in-vehicle acoustic device according to claim 1 or 2, wherein the opening is formed at ¼ or more of the length of the edge of the support plate.   The said support plate part has a wide edge part whose width dimension is larger than the width dimension of the speaker installation part in which the said hole part was formed, The said opening part is formed in the said wide edge part. In-vehicle acoustic device.   The on-vehicle acoustic device according to claim 4, wherein the support plate portion gradually increases in width from the speaker installation portion toward the wide edge portion.   The said support plate part is extended substantially parallel to the lower surface of a ceiling part, and the space between the said support plate part and the lower surface of a ceiling part is connected with the vehicle interior by the said opening part. The on-vehicle acoustic device according to claim 1.