Sound output device for vehicle

Abstract

To enable the output of sound waves at a prescribed frequency from the center of an imaginary circle to the outer side relative to an external member body even if the external member bodies have mutually different sizes and shapes.SOLUTION: A sound output device 10 includes an external member body 21, a vibrator 30 and coupling portions 22. The sound output device 10 causes the external member body 21 to vibrate through vibrations of the vibrator 30 propagating through the coupling portions 22, thereby outputting sound waves generated by the vibration of the external member body 21 to the outside of a vehicle. The coupling portions 22 are arranged on a circumference of an imaginary circle C located on a rear surface 21b of the external member body 21. A diameter R of the imaginary circle C and the frequency of vibration of the vibrator 30 are set so that vibrations propagating through the coupling portions 22 strengthen each other in the center of the imaginary circle C of the external member body 21.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a sound output device for a vehicle.

Background Art

[0002] Patent Document 1 describes an alarm sound generating device that emits an alarm sound around a vehicle. The alarm sound generating device described in Patent Document 1 includes a vibration unit attached to a body component member exposed outside the vehicle, and an acoustic signal supply means. The acoustic signal supply means supplies an acoustic electrical signal for alarm to the vibration unit. The vibration unit has a vibrator that converts the acoustic electrical signal into mechanical vibration. When the body component member vibrates due to the vibration of the vibrator, an alarm sound is radiated around the vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the alarm sound generating device described in Patent Document 1, when the vibration unit is attached to body component members having different sizes and shapes, even if the vibration frequencies of the vibration unit are the same, the vibration frequencies of the body component members may be different. For this reason, there arises a problem that the frequencies of the sound waves radiated along with the vibration of the exterior member are different.

Means for Solving the Problems

[0005] Each aspect of a sound output device for a vehicle for solving the above problems will be described. [Aspect 1] An exterior member main body that constitutes a part of the outer shell portion of a vehicle, a vibration device provided inside the vehicle relative to the exterior member main body and vibrating by energization, and a plurality of connecting portions that protrude from the inner surface of the exterior member main body and connect the exterior member main body and the vibration device. A vehicle sound output device that outputs sound waves generated along with the vibration of the exterior member main body to the outside of the vehicle by vibrating the exterior member main body by the vibration of the vibration device propagated through the connecting portion. The plurality of connecting portions are arranged on the circumference of a virtual circle located on the inner surface of the exterior member main body, and the diameter of the virtual circle and the frequency of the vibration by the vibration device are set so that the vibrations respectively propagated through the plurality of connecting portions overlap at the center of the virtual circle in the exterior member main body and strengthen each other. A vehicle sound output device.

[0006] According to the above configuration, vibrations of a predetermined frequency respectively propagated through each connecting portion overlap at the center of a virtual circle located on the inner surface of the exterior member main body and strengthen each other. At this time, the configuration outside the virtual circle in the exterior member main body has almost no influence on the vibration inside the virtual circle. Therefore, regardless of the exterior member main body having different sizes and shapes, sound waves of a predetermined frequency can be output from the center of the virtual circle outward from the exterior member main body.

[0007] [Aspect 2] The frequency is 100 Hz or more and 2000 Hz or less, and the diameter of the virtual circle is 50 mm or more and 250 mm or less. The vehicle sound output device according to [Aspect 1].

[0008] According to the above configuration, the sound output device can be embodied as a vehicle approach notification sound output device.

Effects of the Invention

[0009] According to the present invention, regardless of the exterior member main body having different sizes and shapes, sound waves of a predetermined frequency can be output.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, with reference to FIGS. 1 to 6, an embodiment of a sound output device for a vehicle will be described. The sound output device of this embodiment is a device that outputs an approach notification sound to a pedestrian or the like approaching a vehicle (hereinafter, the host vehicle) on which the sound output device is mounted.

[0012] In the following, the front-rear direction of the vehicle will be simply referred to as the front-rear direction, and the up-down direction of the vehicle will be simply referred to as the up-down direction. Also, the front and rear in the front-rear direction will be simply referred to as the front and rear, respectively, and the upper and lower in the up-down direction will be simply referred to as the upper and lower.

[0013] As shown in FIGS. 1 to 3, a sound output device 10 is provided at the front part of the vehicle. The sound output device 10 includes an exterior member 20 and a vibration device 30. <Exterior member 20> As shown in FIGS. 1 to 3, the exterior member 20 constitutes a part of the outer shell portion of the vehicle. The exterior member 20 is, for example, a front cover made of a hard resin.

[0014] The exterior member 20 includes an exterior member body 21 having a front surface 21a that constitutes the design surface of the front of the vehicle and a rear surface 21b that is the surface opposite to the front surface 21a, and a plurality of connecting portions 22 protruding from the rear surface 21b.

[0015] The connecting portion 22 is integrally formed with the exterior member body 21. In the present embodiment, three connecting portions 22 are provided on the exterior member body 21. The connecting portion 22 has a first portion 23 and a second portion 24.

[0016] As shown in FIGS. 1 and 3, the first portion 23 protrudes from the rear surface 21b of the exterior member body 21. As shown in FIGS. 2 and 3, the first portion 23 is hollow and opens downward.

[0017] The second portion 24 protrudes from the rear end surface 23b of the first portion 23. A screw hole 24a that opens at the rear end surface 24b is provided in the second portion 24. As shown in FIG. 2, the centers of the screw holes 24a of the three connecting portions 22 are arranged on the circumference of a virtual circle C located on the rear surface 21b of the exterior member body 21. In the present embodiment, the three screw holes 24a are provided at 120-degree intervals, that is, at equal angular intervals, around the center of the virtual circle C.

[0018] <Vibration device 30> As shown in FIGS. 1 and 3, the vibration device 30 is provided behind the exterior member body 21.

[0019] The vibration device 30 includes a vibrator 31 that vibrates when energized and a fixing plate 32. The fixing plate 32 is substantially disc-shaped. The fixing plate 32 has substantially the same size as the virtual circle C. The fixing plate 32 is provided with a protruding portion 32b that protrudes from the outer peripheral side of the fixing plate 32 and is connected to the second portion 24 of the connecting portion 22. In a state where the protruding portion 32b is in contact with the rear end surface 24b of the second portion 24, a screw 40 is inserted through the through hole 32a of the protruding portion 32b and screwed into the screw hole 24a. Thereby, the fixing plate 32 is connected to the connecting portion 22.

[0020] A vibrator 31 is fixed to the central portion of the rear surface of the fixing plate 32. The vibrator 31 is fixed to the fixing plate 32 by, for example, an adhesive. The vibrator 31 is electrically connected to a control device (not shown). The vibration frequency of the vibrator 31 is controlled by the control device.

[0021] The sound output device 10 having such a configuration outputs, to the outside of the vehicle, sound waves generated along with the vibration of the exterior member main body 21 by vibrating the exterior member main body 21 by the vibration of the vibration device 30 propagated through the connecting portion 22.

[0022] The diameter R of the virtual circle C and the vibration frequency of the vibration device 30 are set so that the vibrations respectively propagated through the plurality of connecting portions 22 reinforce each other at the center of the virtual circle C in the exterior member main body 21.

[0023] The vibration frequency of the vibrator 31 is preferably 100 Hz or more and 2000 Hz or less. More preferably, the vibration frequency of the vibrator 31 is 500 Hz or more and 1000 Hz or less.

[0024] The diameter R of the virtual circle C is preferably 50 mm or more and 250 mm or less. More preferably, the diameter R of the virtual circle C is 70 mm or more and 130 mm or less. <Examples of the vibration device 30> (Example 1) The diameter R of the fixing plate 32 is 90 mm. The thickness of the fixing plate 32 is 4 mm. The fixing plate 32 is made of ABS resin.

[0025] (Example 2) The diameter R of the fixing plate 32 is 90 mm. The thickness of the fixing plate 32 is 2 mm. The fixing plate 32 is made of ABS resin.

[0026] (Example 3) The diameter R of the fixing plate 32 is 100 mm. The thickness of the fixing plate 32 is 1 mm. The fixing plate 32 is made of aluminum.

[0027] (Example 4) The diameter R of the fixing plate 32 is 100 mm. The thickness of the fixing plate 32 is 2 mm. The fixing plate 32 is made of aluminum.

[0028] (Example 5) The diameter R of the fixing plate 32 is 100 mm. The thickness of the fixing plate 32 is 3 mm. The fixing plate 32 is made of aluminum.

[0029] FIG. 5 shows the relationship between the frequency and sound pressure level of sound waves generated with the vibration of the exterior member body 21 when using a fixing plate 32 made of a hard resin. FIG. 6 shows the relationship between the frequency and sound pressure level of sound waves generated with the vibration of the exterior member body 21 when using a fixing plate 32 made of metal.

[0030] In FIGS. 5 and 6, the sound pressure level is the A-weighted sound pressure level. Note that FIGS. 5 and 6 show the simulation results using a square plate-shaped sample with a side length of 150 mm and a thickness of 3 mm as the exterior member body 21.

[0031] As shown in FIG. 5, in Example 1, the sound pressure level of sound waves in the frequency range of about 700 Hz to about 900 Hz is higher than that in Example 2 at the same frequency range. Also, in Example 1, the sound pressure level of sound waves in the frequency range of about 900 Hz to about 1100 Hz is higher than that in Example 2 at the same frequency range.

[0032] As shown in FIG. 6, in Example 4, the sound pressure level of sound waves in the frequency range of about 700 Hz to about 900 Hz is higher than that in Example 5 at the same frequency range. Also, in Example 4, the sound pressure level of sound waves in the frequency range of about 900 Hz to about 1100 Hz is higher than that in Example 5 at the same frequency range.

[0033] In Example 3, the sound pressure level of the sound wave at a frequency of about 700 Hz to about 900 Hz is higher than the sound pressure level of the sound wave at a frequency of about 700 Hz to about 900 Hz in Example 4. Also, in Example 3, the sound pressure level of the sound wave at a frequency of about 900 Hz to about 1100 Hz is higher than the sound pressure level of the sound wave at a frequency of about 900 Hz to about 1100 Hz in Example 4.

[0034] <Operation of this Embodiment> FIG. 4 shows the relationship between the diameter R of the virtual circle C and the frequency of the vibrator 31 and the distribution of the absolute value of the amplitude of the vibration of the exterior member main body 21. The fixing plate 32 is made of a hard resin. Note that FIG. 4 shows the simulation results using a square plate-shaped sample with a side length of 150 mm and a thickness of 3 mm as the exterior member main body 21.

[0035] When the vibration frequency of the vibrator 31 is 500 Hz, at the diameters R of 120 mm and 130 mm of the virtual circle C, the absolute value of the amplitude of the vibration is large at the center of the virtual circle C. Note that in FIG. 4, the higher the absolute value of the amplitude of the vibration, the higher the dot density is displayed.

[0036] When the vibration frequency of the vibrator 31 is 640 Hz, at the diameters R of 85 mm, 100 mm, 120 mm, and 130 mm of the virtual circle C, the absolute value of the amplitude of the vibration is large at the center of the virtual circle C. In particular, at the diameters R of 120 mm and 130 mm of the virtual circle C, the absolute value of the amplitude of the vibration is large at the center of the virtual circle C.

[0037] When the vibration frequency of the vibrator 31 is 800 Hz, at the diameters R of 70 mm, 85 mm, 100 mm, 120 mm, and 130 mm of the virtual circle C, the absolute value of the amplitude of the vibration is large at the center of the virtual circle C. In particular, at the diameters R of 100 mm, 120 mm, and 130 mm of the virtual circle C, the absolute value of the amplitude of the vibration is large at the center of the virtual circle C.

[0038] Also, when the frequency of the vibration of the vibrator 31 is 1000 Hz, the absolute value of the vibration amplitude at the center of the virtual circle C increases at each of the diameters R of the virtual circle C being 70 mm, 85 mm, 100 mm, 120 mm, and 130 mm. In particular, when the diameter R of the virtual circle C is 85 mm and 100 mm, the absolute value of the vibration amplitude at the center of the virtual circle C increases.

[0039] According to the sound output device 10 of the present embodiment, the vibrations respectively propagated through the plurality of connecting portions 22 overlap and reinforce each other at the center of the virtual circle C located on the rear surface 21b of the exterior member main body 21. At this time, the configuration of the exterior member main body 21 outside the virtual circle C hardly affects the vibration inside the virtual circle C.

[0040] <Effects of the present embodiment> (1) The diameter R of the virtual circle C and the frequency of the vibration by the vibration device 30 are set so that the vibrations respectively propagated through the plurality of connecting portions 22 reinforce each other at the center of the virtual circle C in the exterior member main body 21.

[0041] According to such a configuration, since the above-described operation is achieved, regardless of the exterior member main body 21 having different sizes and shapes, sound waves of a predetermined frequency can be output from the center of the virtual circle C outward from the exterior member main body 21.

[0042] (2) The frequency of the vibrator 31 is 100 Hz or more and 2000 Hz or less. The diameter R of the virtual circle C is 50 mm or more and 250 mm or less. According to such a configuration, the sound output device 10 can be embodied as a vehicle approach notification sound output device.

[0043] <Modification example> The present embodiment can be implemented with the following modifications. The present embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0044] · The fixing plate 32 is not limited to being made of a hard resin and may be made of metal. · In this embodiment, a plurality of connecting portions 22 are arranged at equal intervals on the virtual circle C. However, as long as it is on the virtual circle C, the positions of the plurality of connecting portions 22 may be changed as appropriate.

[0045] · In this embodiment, three connecting portions 22 are provided. However, the number of connecting portions 22 may be two or four or more. · The shape of the fixing plate 32 is not limited to a substantially circular shape, and may be a polygon such as a quadrilateral. In this case, it is preferable that each vertex of the polygon is located on the same circle. Further, it is preferable that connecting portions 22 are respectively provided at positions corresponding to each vertex of the polygon.

[0046] · The exterior member 20 is not limited to the front cover, and may be any part that constitutes a part of the outer shell of the vehicle such as a back door, a fender panel, a bumper, or a roof.

Explanation of Reference Numerals

[0047] 10… Sound output device 20… Exterior member 21… Exterior member body 21a… Front surface 21b… Rear surface 22… Connecting portion 23… First portion 23b… Rear end surface 24… Second portion 24a… Screw hole 24b… Rear end surface 30… Vibration device 31… Vibrator 32… Fixing plate 32a… Through hole 32b… Protrusion 40… Screw

Claims

1. An exterior member main body that constitutes a part of the outer shell of the vehicle; A vibration device that is provided inside the vehicle with respect to the exterior member main body and vibrates when electricity is applied; A plurality of connecting portions protruding from an inner surface of the exterior member main body and connecting the exterior member main body and the vibration device, A sound output device for a vehicle that outputs sound waves generated by the vibration of the exterior member main body to the outside of the vehicle by vibrating the exterior member main body with the vibration of the vibration device propagated through the connecting portion, The plurality of connecting portions are arranged on the circumference of a virtual circle located on the inner surface of the exterior member main body, The diameter of the virtual circle and the frequency of the vibration by the vibration device are set so that the vibrations respectively propagated through the multiple connecting portions overlap at the center of the virtual circle in the exterior member main body and reinforce each other. Vehicle sound output device.

2. The frequency is 100 Hz or more and 2000 Hz or less, The diameter of the virtual circle is 50 mm or more and 250 mm or less. The vehicle sound output device according to claim 1 .

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