WO2017037805A1

WO2017037805A1 - Speaker system for moving body

Info

Publication number: WO2017037805A1
Application number: PCT/JP2015/074530
Authority: WO
Inventors: 孝之根岸; 泰美梅津; 中村　徹; 鈴木　達也
Original assignee: パイオニア株式会社; 東北パイオニア株式会社
Priority date: 2015-08-28
Filing date: 2015-08-28
Publication date: 2017-03-09

Abstract

Provided is a speaker system that is for a moving body, that maintains the volume of the back surface side of a speaker unit, and that can be easily installed in a moving body. As a result of one end (5A) of a closed tube member (5) being connected to an enclosure (3) that accommodates the back surface of a speaker unit (2), the volume of the closed tube member (5) can be used in addition to the volume of the enclosure (3) as volume for the back surface side of the speaker unit (2), and it is thereby possible to maintain the volume of the back surface side of the speaker unit (2) while reducing the size of the enclosure (3). The closed tube member (5) offers a high degree of freedom with respect to the installation thereof. By using an empty space in a vehicle (C) to arrange the closed tube member (5), the speaker system (1A) for a moving body can be easily installed in the vehicle (C).

Description

Speaker system for moving objects

The present invention relates to a speaker system for a moving body.

2. Description of the Related Art Conventionally, a vehicle-mounted speaker device (speaker system for a moving body) using a sound radiated from the back side has been proposed (see, for example, Patent Document 1) while a speaker is disposed in an instrument panel of a vehicle. . In the conventional vehicle-mounted speaker device described in Patent Document 1, a speaker is installed with the upper surface of the instrument panel as the front side, and the speaker is accommodated in a cylindrical acoustic tube (tube member). Moreover, the low-frequency component of the sound generated on the back side of the speaker resonates in the acoustic tube and is emitted from the lower surface of the instrument panel.

Japanese Utility Model Publication No. 1-143595

However, in the vehicle-mounted speaker device described in Patent Document 1, the back surface of the speaker is accommodated in an acoustic tube, and this acoustic tube also functions as an enclosure (accommodating portion). The acoustic tube becomes large. When the acoustic tube becomes large, it becomes difficult to install the in-vehicle speaker device on the instrument panel. Further, in a vehicle as a moving body, it is difficult to secure a large installation space for the speaker device, not limited to the installation on the instrument panel. Therefore, it has been difficult to achieve both the securing of the volume on the back side of the speaker unit and the easy installation of the mobile speaker system on the mobile body.

Therefore, an object of the present invention is, for example, to provide a moving body speaker system that can secure the volume on the back side of the speaker unit and can be easily installed on the moving body.

In order to solve the above-described problems and achieve the object, a moving body speaker system according to a first aspect of the present invention includes a speaker unit that emits sound from the front surface toward a box-shaped space formed by the moving body. A housing portion for housing the back surface of the speaker unit, an open tube member having one end connected to the internal space of the housing portion and the other end opened in the box-shaped space, and one end connected to the internal space of the housing portion And at least one closed tube member whose other end is closed.

It is a side view which shows the mobile body provided with the speaker system for mobile bodies which concerns on the Example of this invention. It is a front view which shows the principal part of the tube member of the said speaker system for moving bodies. It is a perspective view which shows the said pipe member. It is a perspective view which shows a mode that the said mobile body speaker system was provided in the said mobile body. It is a graph which shows the frequency characteristic of the acoustic impedance of the speaker system for moving bodies concerning a comparative example. It is a graph which shows the frequency characteristic of the acoustic impedance of the speaker system for moving bodies which concerns on an Example. It is a graph which shows the frequency characteristic of the sound pressure in the speaker system for moving bodies of an Example and a comparative example. FIG. 5 is a side view showing a moving body speaker system according to first to third modifications of the present invention. It is a side view which shows the speaker system for moving bodies which concerns on the 4th modification of this invention. It is a side view which shows the speaker system for moving bodies which concerns on the 5th modification of this invention. It is a rear view which shows the speaker system for moving bodies which concerns on the 6th modification of this invention. It is a top view which shows the speaker system for moving bodies which concerns on the 7th modification of this invention. It is the perspective view and side view which show the speaker system for moving bodies which concerns on the 8th modification of this invention. It is a side view which shows the speaker system for moving bodies which concerns on the 9th modification of this invention.

Hereinafter, embodiments of the present invention will be described. The moving body speaker system according to the first embodiment of the present invention includes a speaker unit that emits sound from the front surface toward a box-shaped space formed by the moving body, a housing portion that houses the back surface of the speaker unit, and An open tube member having one end connected to the internal space of the housing portion and the other end opened in a box-shaped space; and at least one closed tube member having one end connected to the internal space of the housing portion and the other end closed. Prepare.

Since one end of the closed tube member is connected to the housing portion that houses the back surface of the speaker unit, not only the volume of the housing portion but also the volume of the closed tube member can be used as the volume on the back side of the speaker unit. The housing portion can be reduced in size while ensuring the volume on the back side. At this time, the closed tube member has a high degree of freedom of installation, and can be provided in an appropriate empty space in the moving body. Therefore, by providing the closed tube member, it is possible to easily install the moving body speaker system on the moving body while securing the volume on the back side of the speaker unit.

In addition, since one end of the open tube member is connected to the internal space of the housing portion (the space in which the speaker unit is housed), the sound corresponding to the length of the open tube member is reduced among the sounds generated on the back side of the speaker unit. The range component resonates in the open tube member and is emitted from the other end.

The open tube member is preferably longer than the closed tube member. As a result, the fundamental vibration frequencies of the open tube member and the closed tube member do not completely match, and the sound pressure of the sound radiated from the other end of the open tube member becomes too high or too low at a specific frequency. Can be suppressed.

The lengths of the open tube member and the closed tube member are set so that the frequency of the fundamental vibration in the closed tube member is greater than 0.75 times and less than 1.25 times the frequency of the fundamental vibration in the open tube member. It is preferable that When sound is emitted only to the open tube member, the sound pressure is reduced at a frequency 1.5 times and 2.5 times the fundamental vibration, and the sound pressure is increased at a frequency twice that of the basic vibration. On the other hand, when sound is emitted only to the closed tube member, the sound pressure is increased at the frequency of the fundamental vibration and three times the frequency, and the sound pressure is decreased at the twice the frequency. Since the frequency of the double vibration of the closed tube member is larger than 1.5 times the frequency of the basic vibration of the open tube member and smaller than 2.5 times, the sound pressure in the open tube member is between these frequencies. The frequency at which the sound pressure is minimized does not match the frequency at which the sound pressure is minimized in the closed tube member, and the sound pressure of the sound radiated from the other end of the open tube member is too low at a specific frequency. Can be suppressed.

It is preferable that the lengths of the open tube member and the closed tube member are set so that the frequency of the basic vibration in the open tube member is equal to the frequency of the basic vibration in the closed tube member. In the open tube member, the sound pressure is maximized at twice the vibration, and in the closed tube member, the sound pressure is maximized at the fundamental vibration and the triple vibration, and the sound pressure is minimized at a frequency twice the fundamental vibration. Therefore, the frequency at which the sound pressure is maximized in the open tube member is equal to the frequency at which the sound pressure is minimized in the closed tube member, and the sound pressure of the sound radiated from the other end of the open tube member is around this frequency. It can suppress that it changes greatly in.

The housing portion may be formed integrally with the open tube member or the closed tube member, or may be formed integrally so that the open tube member, the housing portion, and the closed tube member are formed into one tubular shape. Thereby, the number of parts can be reduced.

It is preferable that the other end of the open tube member opens toward an intersection where at least two of a plurality of surfaces surrounding the box-shaped space intersect. Here, the moving body forming the box-shaped space has a plurality of surfaces. For example, in the traveling direction of the moving body, the front surface, the rear surface, the left side surface, the right side surface, the lower surface (bottom surface), and the upper surface ( It has a top surface. Since the other end of the open tube member opens toward the intersection where at least two of the plurality of surfaces surrounding the space of the moving body intersect, the bass emitted from the other end is reflected by at least two surfaces. Therefore, it is easy to reverberate in the space of the moving body, and the acoustic characteristics such as the sound pressure in the low frequency range in the moving body speaker system can be improved.

The speaker unit is provided in the instrument panel so as to emit sound from the front side on the upper surface of the instrument panel of the moving body, the open tube member extends downward from the housing portion, and the closed tube member is at least one It is preferable that the part is provided in the pillar of the moving body. Thereby, the speaker unit is provided in the instrument panel, and the sound emitted from the front side on the upper surface of the instrument panel can be easily delivered to the passenger. Furthermore, since at least a part of the closed tube member is provided in the pillar, an empty space in the moving body can be used effectively.

In addition, the mobile body in the present embodiment includes the above mobile body speaker system. According to such a moving body, since the freedom degree of installation of the speaker system for moving bodies is high, it is easy to ensure the space for accommodating another member.

Hereinafter, examples of the present invention will be described in detail. FIG. 1 is a side view showing a vehicle C provided with a moving body speaker system 1A according to an embodiment of the present invention, and FIG. 2 shows a main part of an open tube member 4 of the moving body speaker system 1A. 3 is a front view, FIG. 3 is a perspective view showing the open tube member 4, FIG. 4 is a perspective view showing a state where the vehicle speaker system 1A is provided in the vehicle C, and FIG. FIG. 6 is a graph showing the frequency characteristics of the acoustic impedance of the mobile speaker system 1A according to the example. FIG. 6 is a graph showing the frequency characteristics of the acoustic impedance of the mobile speaker system 1A according to the example. It is a graph which shows the frequency characteristic of the sound pressure in the speaker system for moving bodies of an Example and a comparative example.

As shown in FIG. 1, the moving body speaker system 1 A is provided in a vehicle C as a moving body, and is connected to the speaker unit 2, an enclosure 3 as a housing portion that houses the speaker unit 2, and the enclosure 3. An open tube member 4 and a closed tube member 5 connected to the enclosure 3 are provided.

The vehicle C includes an inner surface of a windshield (front glass) W, an upper surface (top surface) S1 and a lower surface S2 of the vehicle body, a front surface S3 in the traveling direction of the vehicle C, and a pair of side surfaces S4 ( A box-shaped in-vehicle space A1 surrounded by a vehicle door) and a rear surface (not shown) in the traveling direction of the vehicle C is formed. In addition, an instrument panel I is provided on the front surface S3, and a seat (driver's seat and passenger seat) SH is provided so as to face the rear side of the instrument panel I. In the present embodiment, the moving body speaker system 1A is provided on the front side of the driver's seat, but may be provided on the front side of the passenger seat or may be provided on both sides.

The speaker unit 2 includes a diaphragm, a voice coil supported by the diaphragm, an edge that connects the diaphragm to the frame, a magnetic circuit that drives (vibrates) the voice coil, and a frame that connects the voice coil to the frame. And a damper that suppresses the natural vibration of the diaphragm. The speaker unit 2 may emit sound waves so that the sound pressure in the middle and high sound range (for example, 1000 to 10000 Hz) is higher than the sound pressure in the low sound region (for example, 10 to 1000 Hz). The diaphragm is installed such that the side (front side) from which the speaker unit 2 emits sound is directed upward of the vehicle C, and the magnetic circuit side (back side) is directed downward of the vehicle C. Further, the speaker unit 2 is attached to the instrument panel I so that the vibration direction (or sound radiation direction) of the diaphragm of the speaker unit 2 is inclined by a predetermined angle (for example, 30 °) with respect to the upper surface of the instrument panel I. May be provided. When the speaker unit is attached to the instrument panel with the diaphragm tilted with respect to the upper surface of the instrument panel I, the tilt angle of the diaphragm with respect to the upper surface of the instrument panel I is determined by the windshield W And the distance between the speaker unit 2 and the seat SH may be appropriately set as necessary, and the central axis or the diaphragm of the speaker unit 2 may not be inclined. When the central axis or the diaphragm of the speaker unit 2 is not inclined, the speaker unit 2 may be attached so that the diaphragm is disposed along the upper surface of the instrument panel I. Further, the central axis or the diaphragm of the speaker unit 2 may be directed to the driver seat or the passenger seat.

The enclosure 3 is formed in a box shape having a top surface, a bottom surface, and four side surfaces. The enclosure 3 is provided in the instrument panel I, a frame for supporting the diaphragm is attached to the top surface thereof, and the speaker unit 2 is disposed in an internal space formed by a bottom surface and four side surfaces. A portion on the back side of 2 is accommodated in the enclosure 3. The enclosure 3 has an inclined surface on the top so that the sound wave radiated from the diaphragm is prevented from being reflected by a part of the enclosure 3 and the sound wave is radiated to the vehicle interior space A1. It may be provided. The enclosure 3 is disposed in the vicinity of the side surface S4 in the width direction. By accommodating the speaker unit 2 in such an enclosure 3, the speaker unit 2 is provided in the instrument panel I so as to emit sound waves from the front surface on the upper surface of the instrument panel I. In addition, sound waves generated on the back side of the speaker unit 2 are radiated toward the internal space of the enclosure 3.

The open tube member 4 is formed in a cylindrical shape having both ends opened using a known metal, resin, or the like. One end 4A is connected to the lower surface on the back side of the speaker unit 2 in the enclosure 3, and the other end 4B is It is located at the foot of the driver's seat (near the accelerator pedal). The cross-sectional shape and cross-sectional area of the open tube member 4 are substantially constant from one end 4A side to the other end 4B side, and a resonance frequency (for example, 30 to 100 Hz) corresponding to a standing wave formed in the vehicle interior space A1, as will be described later. It is formed in the length which has. The open tube member 4 is connected to the inner space of the enclosure 3 at one end 4 A by connecting one end 4 A to the bottom surface of the enclosure 3. Further, as shown in FIGS. 2 and 3, the other end 4B faces the corner C1 where the front surface S3, the lower surface S2, and the side surface S4 on the driver's seat cross below the instrument panel I, and enters the interior space A1. Open toward.

The open tube member 4 passes through the instrument panel I on one end 4A side, and protrudes to the outside of the instrument panel I on the other end 4B side. Further, the open tube member 4 extends from the one end 4A to the other end 4B in the width direction so as to be once separated from the side surface S4 on the driver's seat side, and then extends so as to approach the side surface S4 again. That is, when the open tube member 4 is viewed from the front-rear direction (the traveling direction of the vehicle C), it has a convexly curved shape toward the passenger seat side. Further, the open tube member 4 extends in the front-rear direction so as to go forward as it goes from the one end 4A to the other end 4B.

The closed tube member 5 is formed in a cylindrical shape with one end 5 A opened and the other end 5 B closed using an appropriate metal, resin, or the like, and the one end 5 A is the front side in the traveling direction of the vehicle C on the side surface of the enclosure 3. The other end 5 B is disposed in the pillar P of the vehicle C. The cross-sectional shape and cross-sectional area of the closed tube member 5 are substantially constant from one end 5A side to the other end 5B side. As will be described later, the length of the closed tube member 5 is substantially half of the length considering the open end correction of the open tube member 4 and the closed tube member 5. In addition, when a standing wave is formed in the open tube member 4 and the closed tube member 5, the opening becomes a free end and becomes an antinode, but the position of the antinode is located slightly outside the open end, The shift of the position between the end and the belly is called opening end correction. The closed tube member 5 is connected to the inner space of the enclosure 3 at one end 5A by connecting one end 5A to the front surface of the enclosure 3. The closed tube member 5 passes through the instrument panel I from one end 5 A, extends toward the side S 4 (i.e., the door body) on the driver's seat side, enters the pillar P, and extends along the pillar P. In this way, the enclosure 3 can be downsized using the internal space in the pillar P.

A description will be given of the progress and reflection of sound waves when the speaker unit 2 emits sound waves in the moving body speaker system 1A as described above. First, the sound wave radiated from the front side of the speaker unit 2 travels obliquely rearward according to the inclination of the diaphragm and heads near the headrest (driver's head) in the driver's seat. The sound wave radiated from the front side may be reflected by the windshield W or the upper surface (top surface) S1 of the vehicle C and directed toward the headrest.

The sound wave generated on the back side of the speaker unit 2 reverberates in the internal space of the enclosure 3, enters the open tube member 4 from one end 4 A, and travels through the open tube member 4. At this time, among the sound waves generated on the back side of the speaker unit 2, a low-frequency component corresponding to the length of the open tube member 4 and the close tube member 5 resonates in the open tube member 4. Therefore, the other end 4B of the open tube member 4 emits a sound wave mainly composed of a low frequency component. In other words, the sound wave radiated from the other end 4B of the open tube member 4 is cut in the mid-high range component. Specifically, the term “cut” means that the sound pressure of the medium and high frequency components is lower than the sound pressure of the low frequency components. The sound wave radiated from the other end 4B is reflected by the corner portion C1 and the surrounding surfaces S2 to S4, and is opposed to the corner portion C1 (the corner portion where the upper surface S1, the rear surface and the side surface on the passenger seat side intersect). ), Is reflected again at the opposite corner and its surroundings, and proceeds toward the corner C1. In this way, a standing wave having a wavelength corresponding to the distance between the corner C1 and the opposing corner is generated by the sound wave traveling from the corner C1 toward the opposing corner and the sound wave from the opposing corner toward the corner C1. It is formed. The frequency of this standing wave and the resonance frequency of the open tube member 4 are substantially the same, and the low frequency sound amplified by the open tube member 4 and radiated from the other end 4B generates a standing wave in the vehicle interior space A1. Form. As described above, since the open tube member 4 has a resonance frequency corresponding to the standing wave formed in the vehicle interior space A1, the resonated component of the sound wave emitted from the other end 4B is the standing wave. Form.

Further, the sound wave generated on the back side of the speaker unit 2 and reverberating in the internal space of the enclosure 3 enters the closed tube member 5 from one end 5A. The sound wave that has entered the closed tube member 5 from the one end 5A travels toward the other end 5B, is reflected at the fixed end at the other end 5B that is blocked, and travels toward the one end 5A. Therefore, the traveling wave toward the other end 5B and the reflected wave toward the one end 5A are strengthened or weakened.

By radiating sound waves as described above, the vehicle interior space A1 is radiated from the other end 4B of the open tube member 4 with sound waves mainly composed of components in the middle and high frequencies radiated from the front side of the speaker unit 2. The sound wave mainly composed of the low-frequency component is reflected.

Here, the acoustic characteristics of the moving body speaker system 1A of the embodiment will be specifically described with reference to the moving body speaker system of the comparative example. First, the phase characteristics of acoustic impedance were obtained by simulation for the speaker systems for moving bodies of the comparative example and the example. The calculation conditions at this time are as follows. That is, in the speaker system for a moving body of the comparative example, the speaker unit is accommodated in a box-shaped enclosure having a volume (internal space volume) of 1 L, and opening end correction is considered on the side surface of the enclosure facing the back surface of the speaker unit. An open tube member having a length of 500 mm was connected, and no closed tube member was provided. On the other hand, in the moving body speaker system 1A of the embodiment, the open tube member 4 having a length of 500 mm in consideration of opening end correction and the closed tube member 5 having a volume of 1 L and a length of 250 mm are connected. The portion functions as an enclosure to accommodate the speaker unit, and the volume of the enclosure 3 is sufficiently small.

In the mobile speaker system of the comparative example, the frequency characteristics of acoustic impedance as shown in FIG. 5 were obtained. The horizontal axis in FIG. 5 represents the logarithm of the frequency, and the vertical axis represents the logarithm of the acoustic impedance. The acoustic impedance of the enclosure only monotonously decreased with increasing frequency as shown by the broken line. On the other hand, the acoustic impedance of only the open tube member becomes a minimum value at an integer n times (n ≧ 1) of the fundamental vibration frequency fo (about 340 Hz) in the natural vibration, as shown by a one-dot chain line, and is maximum at −fo / 2 + nfo. Value. That is, the maximum value and the minimum value were repeated every fo / 2.

The synthetic acoustic impedance (acoustic impedance of the entire mobile speaker system) of the enclosure and the open tube member in the comparative example is a maximum value at about 61 Hz, a minimum value at about 320 Hz, and a maximum value at about 340 Hz. After that, the minimum and maximum were repeated in the same manner. The maximum value of about 61 Hz is caused by the maximum value at fo / 2 of the open tube member, the minimum value of 320 Hz is caused by the minimum value at fo of the open tube member, and the maximum value of about 340 Hz is 3fo of the open tube member. This is thought to be due to the local maximum at / 2.

In the moving body speaker system of the example, the frequency characteristics of acoustic impedance as shown in FIG. 6 were obtained. The horizontal axis and horizontal axis in FIG. 6 are the same as those in FIG. As indicated by the broken line, the acoustic impedance of only the closed tube member becomes a minimum value at an odd number k times (k ≧ 1) of the fundamental vibration frequency fc (about 340 Hz) in the natural vibration, and is an even number m times fc (m ≧ 2). It became the maximum value at. That is, the maximum value and the minimum value were repeated for each fc. The acoustic impedance of the open tube member was the same as in the comparative example.

In the moving body speaker system of the example, the fundamental vibration frequency fo in the open tube member and the fundamental vibration frequency fc in the closed tube member were substantially equal. In addition, the frequency 2fo of the double vibration in the open tube member is substantially equal to the frequency 2fc intermediate between the fundamental vibration and the triple vibration in the closed tube member. That is, at the frequency 2fo (2fc), the acoustic impedance in the open tube member became a maximum value, and the acoustic impedance in the closed tube member became a minimum value.

Since the acoustic impedance of the closed tube member exhibited the above-described characteristics, the synthetic acoustic impedance in the example exhibited characteristics different from the synthetic acoustic impedance in the comparative example, as indicated by a solid line. That is, the synthesized acoustic impedance in the example has a maximum value at about 61 Hz, a minimum value at about 340 Hz (fo, fc), a maximum value at about 600 Hz, a minimum value at about 680 Hz, and a maximum value at about 740 Hz. Thereafter, the minimum and maximum were repeated in the same manner. Moreover, the maximum value of about 61 Hz is caused by the maximum value at fo / 2 of the open tube member, and the minimum value of about 340 Hz is caused by the minimum values at fo and fc of the open tube member and the closed tube member, and is a maximum value of about 600 Hz. Is caused by the maximum value at 3fo / 2 of the open tube member and the maximum value at 2fc of the closed tube member, the minimum value of about 680 Hz is caused by the minimum value at 2fo of the open tube member, and the maximum value of about 740 Hz is the open tube member This is considered to be caused by the local maximum value at 5 fo / 2 and the local maximum value at 2 fc of the closed tube member.

In the synthesized acoustic impedance of the example, the maximum value and the minimum value overlap each other at the frequency 2fo (2fc). Therefore, it is considered that the maximum value of the synthetic acoustic impedance of the comparative example at about 340 Hz has shifted to the high frequency side.

FIG. 7 shows the frequency characteristics (sound pressure characteristics) of the sound pressure in the speaker system for moving bodies of the examples and comparative examples. In the sound pressure characteristic in the mobile speaker system of the comparative example, as shown by the alternate long and short dash line, the minimum value was obtained at about 380 Hz. This is considered due to the maximum value of the synthesized acoustic impedance at about 340 Hz. On the other hand, in the sound pressure characteristics in the mobile speaker system of the example, the maximum value of about 340 Hz as in the comparative example is shifted to the high frequency side in the synthetic acoustic impedance, so that it does not become the minimum value around 380 Hz. It changed gradually.

Therefore, by providing the closed tube member and setting the length as described above, it is possible to suppress the sound pressure from being lowered at a specific frequency in the moving body speaker system of the embodiment. Furthermore, in the moving body speaker system of the comparative example, it is necessary to correct the input signal to the speaker unit in order to suppress the decrease in sound pressure around 380 Hz, whereas in the moving body speaker system of the embodiment, Sound pressure hardly changes around 380 Hz, and good acoustic characteristics can be obtained without correcting the input signal. .

With the above configuration, one end 5A of the closed tube member 5 is connected to the enclosure 3 that houses the back surface of the speaker unit 2, so that not only the volume of the enclosure 3 but also the volume of the closed tube member 5 is on the back side of the speaker unit 2. The enclosure 3 can be used as a volume, and the enclosure 3 can be downsized while ensuring the volume on the back side of the speaker unit 2. At this time, the closed tube member 5 has a high degree of freedom of installation, and an empty space in the vehicle C can be used effectively by providing the other end 5B side in the pillar. The moving body speaker system 1A can be easily installed in the vehicle C by downsizing the enclosure 3 and arranging the closed tube member 5 using an empty space.

Furthermore, the other end 4B of the open tube member 4 opens toward the corner C1 where three of the plurality of surfaces surrounding the vehicle interior space A1 intersect, so that the bass emitted from the other end 4B has three surfaces. And is easily reflected in the vehicle interior space A1, and the acoustic characteristics of the low frequency range in the moving body speaker system 1A can be improved.

Further, when the speaker unit 2 emits sound waves so that the sound pressure in the middle / high range is higher than the sound pressure in the low range, the amplitude of the voice coil or diaphragm of the speaker unit 2 is reduced. It is possible to suppress the generation of abnormal noise due to vibration transmitted to the vehicle body. In addition, by improving the acoustic characteristics in the low frequency range as described above, even when the small speaker unit 2 having a low sound pressure in the low frequency range is used, good acoustic characteristics can be obtained. Furthermore, since the sound pressure of the low sound emitted from the front surface of the speaker unit 2 is relatively low, the sound wave emitted from the front surface of the speaker unit 2 and the sound wave emitted from the other end 4B of the open tube member 4 in the low sound range. It is difficult to weaken each other.

In the moving body speaker system 1 A, sound waves in the middle / high range are mainly emitted from the front surface of the speaker unit 2, and mainly sound waves in the low range are emitted from the other end 4 B of the open tube member 4. The optimal emission position may be different between the mid-high range and the low range, but the position where the mid-high range sound wave is emitted and the position where the low-range sound wave is emitted are separated, Each of them can be arranged at an optimum position to obtain extremely good acoustic characteristics.

Further, when the other end 4B of the open tube member 4 opens toward the corner C1, a standing wave is formed between the corner C1 and the opposite corner by the sound wave radiated from the other end 4B. At this time, the distance between the corner C1 and the opposite corner is longer than the distance between a pair of opposing surfaces (upper surface S1 and lower surface S2, front surface S3 and rear surface, pair of side surfaces S4). A long standing wave can be formed, and bass can be efficiently reflected in the interior space A1.

When the speaker unit 2 and the enclosure 3 are provided in the instrument panel I and the open tube member 4 passes through the instrument panel I, the mobile speaker system 1A is provided in the vehicle C. Can be kept good.

In addition, this invention is not limited to the said Example, The other deformation | transformation etc. which can achieve the objective of this invention are included, and the following modifications etc. are also contained in this invention.

For example, in the above embodiment, the open tube member 4 and the closed tube member 5 are connected to the box-shaped enclosure 3, but the enclosure may be formed integrally with the open tube member or the closed tube member. For example, an open tube member and a closed tube member may be formed by one tubular member, and a speaker unit may be accommodated in a part (intermediate portion) of this tubular member. Further, as shown in FIG. 8A as a first modified example, a mobile speaker system 1B in which the speaker unit 2 is housed in a single tubular member having one end opened and the other end closed. Also good. In the moving body speaker system 1B, the open end side (right side in the figure) is the open tube member 4 and the closed end side (left side in the figure) is the closed tube member 5 when viewed from the speaker unit 2, and the open tube member 4 and the closed tube member are The boundary part with 5 becomes an accommodating part. That is, the open tube member 4, the closed tube member 5, and the housing portion are integrally formed to have a single tubular shape. According to such a configuration, the number of parts can be reduced as compared with a configuration in which the housing portion is formed separately from the open tube member and the closed tube member.

As a second modification, as shown in FIG. 8B, a single tubular member in which the open tube member 4, the closed tube member 5, and the housing portion are integrated is bent, and the speaker system for a moving body. It may be 1C. In the moving body speaker system 1C, the opening end and the closed end are bent in the same direction from the housing portion, but the bending position, direction, angle, and the like are appropriately set. It only has to be set. By bending one tubular member in this way, the degree of freedom of installation in the vehicle can be further improved.

In the above embodiment, one closed tube member 5 is connected to the enclosure 3, but a plurality of closed tube members may be connected to the enclosure 3. For example, as a third modification, as shown in FIG. 8C, a moving body speaker system 1D in which two closed tube members 6 and 7 are connected to the enclosure 3 may be used. According to such a configuration, the volumes of both the two closed tube members 6 and 7 can be used as the volume on the back side of the speaker unit 2. Therefore, even if there is no large empty space at one place in the vehicle, if there are small empty spaces at two places, the closed tube members 6 and 7 can be arranged respectively, and the volume on the back side of the speaker unit 2 is secured. However, the degree of freedom of installation on the vehicle can be further improved.

In the above embodiment, the speaker unit 2 and the enclosure 3 are provided on the instrument panel I. However, the speaker unit 2 and the enclosure 3 may be provided at other locations.

For example, as shown in FIG. 9 as a fourth modification, the speaker unit 2 and the enclosure 3 may be a moving body speaker system 1E provided below the seat SH of the vehicle C. The vehicle C provided with the moving body speaker system 1E is provided with an air conditioning duct D. The air conditioning duct D extends along the front-rear direction in order to send cold air or hot air from the air conditioner provided on the front side (for example, in the instrument panel) to the feet of the rear seat. As shown to C), it has the tubular channel | path part D0. The passage portion D0 includes a first passage D1 through which cold air or hot air passes and a second passage D2 by being partitioned by the partition portion D3. The second passage D2 is provided, for example, for reinforcing the first passage D1.

The open tube member 4 of the moving body speaker system 1E has one end 4A connected to the front surface of the enclosure 3 and extends forward, and is connected to the second passage D2. The second passage D2 functions as an open tube member. The second passage D2 is separated from the second passage D2 at the other end, and opens toward the front intersection or corner. That is, a portion between one end 4A and the other end of the open tube member 4 is formed integrally with the air conditioning duct D. The closed tube member 5 has one end 5A connected to the rear surface of the enclosure 3 and extends rearward. The closed tube member 5 is connected to the second passage D2 independently of the open tube member 4, and the second passage D2 functions as a closed tube member. The other end (not shown) is closed. The second passage may not be formed in the air conditioning duct D, and a part of the open tube member 4 and the closed tube member 5 may be formed integrally with the first passage D1.

According to the moving body speaker system 1E of the fourth modified example, the air conditioning duct D is used as the open tube member 4 and the closed tube member 5 to reduce the cost, and to pass the air conditioning duct D. A space formed in the vehicle C can be used. Furthermore, even if the installation space of the speaker unit 2 below the seat SH is narrow, the other end of the open tube member 4 is open toward the corner or the intersection, so that acoustic characteristics such as sound pressure in the low frequency range are obtained. Can be improved.

Further, as shown in FIG. 10A as a fifth modification, the speaker unit 2 and the enclosure 3F are formed as a part of a glove box G as a box portion provided in the instrument panel I of the vehicle C. Alternatively, the moving body speaker system 1F may be used. The instrument panel I of the vehicle C provided with the moving body speaker system 1F is provided with a rotation axis along the width direction, and the inside can be opened and closed by rotating around the rotation axis ( A glove box G is provided. The space on the lower side of the glove box G is partitioned from the other part G0 (a space in which an object can be accommodated), whereby the enclosure 3F is formed. The speaker unit 2 is housed in the enclosure 3F so that the front surface thereof faces the outside of the glove box G and the front surface faces the front side and the lower side. The open tube member 4 has one end 4A connected to the lower side of the enclosure 3F and the other end 4B opened toward the corner C1. One end 5A of the closed tube member 5 is connected to, for example, a portion of the enclosure 3F located on the upper side and the front side of the vehicle C, and is accommodated in the glove box G.

In addition, the other end 4B of the open tube member 4 may open toward the intersection where the front surface S3 and the lower surface S2 intersect. 10B, the front surface of the speaker unit 2 may face the rear side in the traveling direction of the vehicle C. Further, an enclosure 3F may be formed in an existing glove box G attached to the vehicle C to accommodate the speaker unit 2, or a glove box G in which the moving body speaker system 1F is provided in advance is produced. Also good. Alternatively, the glove box G may be divided into a plurality of spaces, and a closed space or a sealed space formed when the glove box G is closed may function as an enclosure. Further, the closed tube member 5 may be connected to an appropriate position of the enclosure 3F and extend in an appropriate direction.

According to the moving body speaker system 1F of the fifth modified example, the enclosure 3F is a part of the glove box G, so that the other end of the open tube member 4 can be easily directed to the corner portion C1. Moreover, even if the speaker unit 2 is downsized to suppress the narrowing of the space in the glove box G, the other end 4B of the open tube member 4 is open toward the corner C1 or the intersection, The acoustic characteristics such as the sound pressure in the low sound range can be improved. Furthermore, the closed tube member 5 may be disposed outside the glove box G. According to such a configuration, it is possible to suppress the narrowing of the glove box G while ensuring the volume on the back side of the speaker unit 2. it can.

Moreover, as shown in FIG. 11 as a sixth modification, the speaker unit 2 and the enclosure 3G may be a moving body speaker system 1G provided in the wheel T1 of the spare tire T accommodated in the vehicle interior space A1. . The spare tire T is accommodated in a tire accommodating portion formed on the rear side in the traveling direction of the vehicle C, for example, and includes a wheel T1 and a tire T2. The wheel T1 is formed with a recess T0 on the surface facing the inner side in the width direction when being attached to the vehicle C and used. The inner peripheral surface of the recess T0 is formed in a cylindrical shape, and the enclosure 3G is formed in a cylindrical shape whose outer peripheral size is the same as or slightly smaller than the recess T0. The enclosure 3G is accommodated in the recess T0.

Also, the height of the enclosure 3G is larger than the depth of the recess T0, a part (lower part) of the enclosure 3G is accommodated in the recess T0, and the other part (upper part) protrudes from the recess T0. The entire enclosure 3G may be accommodated in the recess T0 in the vertical direction of the vehicle C. One end 4A of the open tube member 4 and one end 5A of the closed tube member 5 are connected to the enclosure 3G. The other end 4B of the open tube member 4 is open toward the corner C2 where one side S4, the lower surface S2, and the rear surface of the vehicle C intersect, but the angle at which the side S4 intersects the upper surface and the rear surface. It may be open toward the portion, or may be open toward the intersection where the rear surface and another surface (side surface S4, lower surface S2 or upper surface) intersect. The closed tube member 5 extends toward the other side surface S4.

In addition, unevenness is formed on the surface of the lower surface S2 of the vehicle by reinforcing ribs RB extending in the front-rear direction or the width direction, and a flat cover portion may be provided on this surface. You may utilize the clearance gap formed between this unevenness | corrugation and a cover part as an open tube member or a closed tube member.

According to the moving body speaker system 1G of the sixth modified example as described above, even if the speaker unit 2 is downsized to be accommodated in the recess T0 of the spare tire T, the other end 4B of the tube member 4 has the corner portion C2. Or by opening toward the intersection, it is possible to improve acoustic characteristics such as sound pressure in the low frequency range. Further, since the closed tube member 5 is provided, the volume on the back side of the speaker unit 2 can be secured.

Further, as a seventh modification, as shown in FIG. 12A, the speaker unit 2 and the enclosure 3H may be a mobile speaker system 1H provided at the center in the width direction of the vehicle C. The speaker unit 2 and the enclosure 3H are provided between the two seats SH on the front side and below, the ends 4A of the two open tube members 4 are connected to the front surface of the enclosure 3H, and closed on both sides in the width direction. The member 5 is connected. One of the two open tube members 4 extends to the right side with respect to the traveling direction, and the other extends to the left side, that is, extends toward opposite sides in the width direction. Further, the other ends 4B of the two open tube members 4 open toward the left and right corners C1, respectively. The closed tube member 5 is assumed to extend along the width direction, but the position where the closed tube member 5 is connected to the enclosure 3H and the extending direction may be set as appropriate.

In addition, the other end 4B of the open tube member 4 may open toward the intersection where the side surface S4 and the lower surface S2 of the vehicle C intersect. Also, as shown in FIG. 12B, two speaker units 2 are accommodated in the enclosure 3F, one speaker unit 2 radiates sound waves to the front side, and the other speaker unit 2 radiates sound waves to the rear side. It is good also as composition to do. According to such a configuration, the sound waves emitted from the back side of the two speaker units 2 are weakened, and the enclosure 3 can be prevented from vibrating during sound emission.

According to the moving body speaker system 1H of the seventh modified example, the space between the two seats SH on the front side and the lower side can be used. Moreover, even if the installation space in this space is narrow, the other end 4B of the open tube member 4 is open toward the corner C1 or the intersection, thereby improving acoustic characteristics such as sound pressure in the low frequency range. Can do. Further, since the closed tube member 5 is provided, the volume on the back side of the speaker unit 2 can be secured. Furthermore, the low-frequency sound radiated from the other end 4B of the open tube member 4 is reflected on both sides in the width direction, so that a reproduced sound that is powerful for the passenger can be obtained.

Further, as shown in FIG. 13 as an eighth modified example, a speaker unit 2I and an enclosure 3I for bass reproduction are provided on the rear side in the traveling direction of the vehicle C, and an upper surface S1 and a rear surface S5 of the vehicle C are provided. It is good also as the speaker system 1I for moving bodies provided in the crossing part CR1 vicinity which cross | intersects, and the open tube member 4 passes the inner side of the side sill SS of the vehicle C, and extends toward the front corner | angular part C1. The enclosure 3I is provided at the center of the width direction and behind the headrest of the seat SH on the rear side. The speaker unit 2I is accommodated with the front surface facing upward, and one end 4A of the open tube member 4 and the closed tube are disposed on the lower surface of the enclosure 3I. One end 5A of the member 5 is connected. The open tube member 4 extends downward from the lower surface of the speaker unit 2I toward one side surface of the vehicle C, passes through the inside of the side sill SS extending in the front-rear direction below the door body of the vehicle C, and toward the front side. Extend. Further, the open tube member 4 is directed forward from the side sill SS to the upper side and then toward the lower side, so that the other end 4B is opened toward the corner C1. Further, the closed tube member 5 extends downward.

The sound wave radiated from the speaker unit 2I is directed to the intersection CR1, and the sound wave radiated from the other end of the open tube member 4 is directed to the corner C1. The enclosure may be arranged on either the left or right side in the width direction, and the sound wave emitted from the speaker unit may be directed to the corner where the upper surface S1, the side surface S4, and the rear surface S5 intersect. Moreover, the other end 4B of the open tube member 4 should just open toward the crossing part of the front side rather than the side sill SS, and may face the crossing part where the front surface S3 and the lower surface S2 cross, You may face the cross | intersection part where the part ahead of the side sill SS in S4 and lower surface S2 cross.

According to the moving body speaker system 1I of the eighth modification as described above, the bass emitted by the speaker unit 2I and the other end 4B of the open tube member 4 is reflected at the front and rear corners or intersections, and the bass range. The acoustic characteristics such as the sound pressure can be further improved.

Further, as shown in FIG. 14 as a ninth modification, the mobile speaker is formed in a single tube as in the first and second modifications, and a part thereof is accommodated in the side sill SS. The system 1J may be used. The moving body speaker system 1J is formed by integrating the open tube member 4, the housing portion, and the closed tube member 5, and a part of the open tube member 4 is a side sill SS as in the open tube member 4 in the eighth embodiment. Is passing inside. Further, when the speaker unit 2 is provided in the side sill SS as shown in the figure, a sound guide hole is formed in the side sill SS so that the sound wave radiated from the front surface of the speaker unit 2 reaches the vehicle interior space A1. Shall. The single tubular member in which the open tube member 4, the housing portion, and the closed tube member 5 are integrated is not limited to the side sill SS and forms a body of the vehicle C and has a space inside. It may be provided inside.

According to the moving body speaker system 1J of the ninth modified example, the single tubular member in which the open tube member 4, the housing portion, and the closed tube member 5 are integrated is a vehicle C such as a side sill SS. By being provided inside the component parts of the body, an empty space in the vehicle C can be used effectively. Furthermore, the open tube member 4 is routed in the components of the body and pulled out into the vehicle interior space A1 at an appropriate position, so that the other end 4B can be placed at a position where the bass is likely to reverberate to emit sound waves. .

In the embodiment, the frequency fo of the fundamental vibration in the open tube member and the frequency fc of the fundamental vibration in the closed tube member are substantially equal, and each synthesized acoustic impedance has a maximum value and a minimum value at the frequency 2fo (2fc). Although the length of the closed tube member is set to be approximately half the length of the open tube member so as to overlap, the lengths of the open tube member and the closed tube member may be set as appropriate. For example, the lengths of the open tube member and the closed tube member may be set so that the fundamental vibration frequency fo of the open tube member and the fundamental vibration frequency fc of the closed tube member are slightly different. If the frequency fc of the fundamental vibration in the closed tube member is larger than 0.75 times the fundamental frequency fo in the open tube member and smaller than 1.25 times, a decrease in sound pressure at a specific frequency is suppressed. can do.

In addition, the frequency fo of the basic vibration in the open tube member and the frequency fc of the basic vibration in the closed tube member are set so as to suppress a decrease in sound pressure due to other frequencies at which the acoustic impedance of the open tube member becomes maximum. It may be. Further, the frequency fo and the frequency fc may be set so as to suppress an increase in sound pressure due to the acoustic impedance of the open tube member being minimized.

Moreover, in the said Example, although the other end 4B of the pipe member 4 shall open toward the corner | angular part C1 where the front surface S3, the lower surface S2, and the side surface S4 by the side of a driver | operator cross, an other end is vehicle interior space. Corner portions (corner portions C1 to C3 shown in FIG. 3) where any three of the plurality of surfaces (inner surface of windshield W, upper surface S1, lower surface S2, front surface S3, pair of side surfaces S4, rear surface) that surround A1 intersect. It only needs to be open facing. Further, the other end of the tube member may be open toward an intersection (R1 to R8 shown in FIG. 3) where two of the plurality of surfaces intersect, or open so as to face one surface. Or may be along a surface.

The corner portion C1 is a corner portion where the front surface S3, the lower surface S2 and the side surface S4 of the vehicle C intersect, and the corner portion C2 is a corner portion where the rear surface S5, the lower surface S2 and the side surface S4 of the vehicle C intersect. The corner C3 is a corner where the rear surface S5, the upper surface S1, and the side surface S4 of the vehicle C intersect. The intersection R1 is an intersection where the front surface S3 and the lower surface S2 of the vehicle C intersect, and the intersection R2 is an intersection where the lower surface S2 and the side surface S4 of the vehicle C intersect, and the intersection R3 is The intersection portion R4 intersects the front surface S3 and the side surface S4 of the vehicle C, the intersection portion R4 intersects the rear surface S5 of the vehicle C and the lower surface S2, and the intersection portion R5 is the rear surface S5 of the vehicle C. And the side S4 intersect, the intersection R6 is the intersection where the front surface S3 and the upper surface S1 of the vehicle C intersect, and the intersection R7 intersects the upper surface S1 and the side S4 of the vehicle C. The intersection R8 is an intersection where the rear surface S5 of the vehicle C and the upper surface S1 intersect.

In addition, the best configuration and method for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the present invention has been illustrated and described primarily with respect to particular embodiments, but is not limited to the embodiments described above without departing from the scope and spirit of the present invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations. Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

DESCRIPTION OF SYMBOLS 1 Speaker system for moving bodies 2 Speaker unit 3 Enclosure (housing part)
4 Open tube member 5 Closed tube member 4A One end 4B The other end 5A One end 5B The other end A1 Car interior space (space)
C Vehicle (moving body)
I Instrument panel CR1 Intersection P Pillar

Claims

A speaker unit that emits sound from the front toward the box-shaped space formed by the moving body;
An accommodating portion for accommodating a rear surface of the speaker unit;
An open tube member having one end connected to the internal space of the housing and the other end opened in the box-shaped space;
A moving body speaker system comprising: at least one closed tube member having one end connected to the internal space of the housing portion and the other end closed.
The mobile speaker system according to claim 1, wherein the open tube member is longer than the closed tube member.
The frequency of the fundamental vibration in the closed tube member is greater than 0.75 times and less than 1.25 times the frequency of the fundamental vibration in the open tube member, and the open tube member and the closed tube member are The mobile speaker system according to claim 2, wherein a length is set.
The length of the open tube member and the closed tube member is set so that the frequency of the basic vibration in the open tube member and the frequency of the basic vibration in the closed tube member are equal. The speaker system for moving bodies according to 2.
The moving body speaker system according to claim 1, wherein the housing portion is formed integrally with the open tube member or the closed tube member.
The mobile speaker system according to claim 1, wherein the open tube member, the accommodating portion, and the closed tube member are integrally formed so as to form one tube.
2. The mobile speaker system according to claim 1, wherein the other end of the open tube member opens toward an intersection where at least two of a plurality of surfaces surrounding the space intersect.
The speaker unit is provided in the instrument panel so as to emit sound from the front side on the upper surface of the instrument panel of the moving body,
The open tube member extends downward from the housing portion,
2. The moving body speaker system according to claim 1, wherein at least a part of the closed tube member is provided in a pillar of the moving body.
A moving body comprising the speaker system for a moving body according to claim 1.