Vehicle sound output device and vehicle sound propagation device

Abstract

A sound emitted from a sound emitting portion arranged inside a vehicle is prevented from passing through a panel opening portion and properly propagating from the inside of the vehicle to the outside of the vehicle. A sound output device for a vehicle (1) includes a sound emitting portion (10) that emits a sound of a predetermined frequency, a double wall (20) arranged more to the outside of the vehicle than the sound emitting portion (10) and composed of an inner wall portion (21) and an outer wall portion (22) separated from each other in a vehicle inside-outside direction, and an intermediate layer (30) formed in a closed space between the inner wall portion (21) and the outer wall portion (22) so as to allow the sound to pass through.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle sound output device mounted on a vehicle and a vehicle sound propagation device. BACKGROUND

[0002] Currently, a vehicle sound output device mounted on a vehicle or the like (for example, Patent Document 1) is known. The vehicle sound output device described in Patent Document 1 is a device that has a sound emitting portion such as a horn, a speaker, or the like, and makes a person around a vehicle hear a sound emitted from the sound emitting portion. The sound emitting portion is disposed more inside the vehicle than a radiator grille, a front bumper, or the like, which are outer panels of the vehicle.

[0003] In the above-described sound output device, the sound emitted from the sound emitting portion is released to the outside of the vehicle through an opening portion provided in the outer panel, a cover member, or the like. In particular, if the sound emitting portion is disposed more inside the vehicle than the opening portion of the outer panel or the like, the sound emitted from the sound emitting portion is easily released to the outside of the vehicle through the opening portion, and thus the sound is easily propagated over a wide range even with a small output. In this regard, as described above, if the opening portion is provided in the outer panel or the like, a person outside the vehicle is easily made to hear the sound emitted from the sound emitting portion.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-330852 SUMMARY

[0005] However, in recent years, with the development of EVs and the demand for improved fuel efficiency, the opening portion of the outer panel or the like is showing a tendency to be reduced in size. With a configuration in which the opening portion of the outer panel or the like is reduced in size or does not have an opening portion, as compared with a configuration in which the opening portion is large, the sound emitted from the sound emitting portion is easily reflected at the back of the outer panel or the like, and the sound that passes through the opening portion from the inside of the vehicle to the outside of the vehicle is reduced, and thus it can be difficult to make a person outside the vehicle hear the sound emitted from the sound emitting portion.

[0006] The present application has been made in view of the above, and aims to provide a vehicle sound output device and a vehicle sound propagation device that can appropriately propagate a sound emitted from a sound emitting portion disposed more inside a vehicle than an opening portion of a panel from the inside of the vehicle to the outside of the vehicle without the sound passing through the opening portion.

[0007] One embodiment of the present application is a vehicle sound output device including a sound emitting portion that emits a sound of a predetermined frequency, a double wall disposed more outside a vehicle than the sound emitting portion and composed of an inner wall portion and an outer wall portion that are separated from each other in a vehicle inside-outside direction, and an intermediate layer that forms a closed space between the inner wall portion and the outer wall portion so that the sound passes through.

[0008] According to this structure, the sound of a prescribed frequency emitted from the sound emitting portion resonates and transmits through the intermediate layer from the inner wall portion of the double wall to the outer wall portion, and propagates to a position further outside the vehicle than the outer wall portion. Therefore, the sound emitted from the sound emitting portion can be appropriately propagated from the inside of the vehicle to the outside of the vehicle without passing through the panel opening portion provided in the wall.

[0009] One embodiment of the present application is a vehicle sound propagating device including a double wall disposed further outside a vehicle than a sound emitting portion that emits a sound of a prescribed frequency, the double wall including an inner wall portion and an outer wall portion separated from each other in a vehicle inside-outside direction, and an intermediate layer that forms a sealed space between the inner wall portion and the outer wall portion, so that the sound transmits through the intermediate layer.

[0010] According to this structure, the sound of a prescribed frequency emitted from the sound emitting portion resonates and transmits through the intermediate layer from the inner wall portion of the double wall to the outer wall portion, and propagates to a position further outside the vehicle than the outer wall portion. Therefore, the sound emitted from the sound emitting portion can be appropriately propagated from the inside of the vehicle to the outside of the vehicle without passing through the panel opening portion provided in the wall. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a perspective view of a vehicle on which a vehicle sound output device and a vehicle sound propagating device according to a first embodiment of the present application are mounted.

[0012] Figure 2 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to the first embodiment.

[0013] Figure 3 is a graph comparing the frequency and the transmission loss of sound with respect to a double wall (solid line) and a single wall (dotted line).

[0014] Figure 4 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to a second embodiment.

[0015] Figure 5 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to a third embodiment.

[0016] Figure 6 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to a first modified example.

[0017] Figure 7 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to a second modified example.

[0018] Figure 8 is a structural view of a vehicle sound output device including a vehicle sound propagating device according to a third modified example. Figure 7An exploded oblique view of a vehicle sound output device, which is a vehicle sound propagating device shown. DETAILED DESCRIPTION

[0019] Hereinafter, a detailed description will be given of a vehicle sound output device and a vehicle sound propagating device according to the present application.

[0020] [First Embodiment]

[0021] The vehicle sound output device 1 of the present embodiment is a device mounted on a vehicle 3 and configured to cause a person around the vehicle to hear a sound emitted from a sound emitting portion. In addition, the vehicle sound propagating device 2 is a device configured to propagate a sound generated from the sound emitting portion to a person around the vehicle. Further, the vehicle 3 on which the vehicle sound output device 1 is mounted can be a vehicle in which an opening portion for taking air into an engine room is provided in an outer panel, and particularly, can be an electric vehicle or the like in which the opening portion is not provided in the outer panel or in which the opening area of the opening portion is small even if the opening portion is provided (see Figure 1 ).

[0022] As shown in Figure 2 , the vehicle sound output device 1 has a sound emitting portion 10, a double wall 20, and an intermediate layer 30. In addition, the vehicle sound propagating device 2 is a device in which the sound emitting portion 10 is removed from the vehicle sound output device 1 and has the double wall 20 and the intermediate layer 30.

[0023] The sound emitting portion 10 is a device configured to emit a sound of a predetermined frequency to the outside of the vehicle. The sound emitting portion 10 is a horn configured to emit a warning sound to a person around the vehicle 3, a proximity notification device configured to notify a person approaching the vehicle 3 of the approach, a speaker configured to emit a human voice, a musical instrument sound, or the like as a sound, or the like. The sound emitting portion 10 is disposed more inward than an outer panel of the vehicle 3. The sound emitting portion 10 is capable of emitting a sound of a sound pressure level conforming to a regulation or the like. In addition, the sound emitting portion 10 emits a sound of a predetermined frequency that is predetermined in advance.

[0024] The predetermined frequency of the sound emitted from the sound emitting portion 10 is an audible sound region, i.e., a frequency between, for example, 20 Hz and 20,000 Hz. Further, the predetermined frequency of the sound emitted from the sound emitting portion 10 includes not only a fundamental frequency (fundamental frequency) of the sound emitted from the sound emitting portion 10 but also a frequency that is a positive multiple of the fundamental frequency by a number greater than or equal to 2. In the case where the sound emitting portion 10 is a horn, the fundamental frequency of the sound is, for example, predetermined to be between 270 Hz and 600 Hz, 370 Hz, 400 Hz, 480 Hz, 500 Hz, or the like. In addition, in the case where the sound emitting portion 10 emits a proximity notification sound, the fundamental frequency of the sound is, for example, predetermined to be between 20 Hz and 5,000 Hz.

[0025] The sound emitting portion 10 is mounted to the housing 11. The housing 11 is formed in a box shape (for example, a rectangular parallelepiped shape) capable of accommodating the sound emitting portion 10. The housing 11 is disposed to the vehicle 3 in a manner such that the sound emitted from the sound emitting portion 10 easily travels to the outside of the vehicle. The sound emitting portion 10 is disposed to the vehicle 3 in a state in which the housing 11 is disposed, and the sound emitted therefrom easily travels to the outside of the vehicle.

[0026] The double wall 20 is a wall that separates the sound emitting portion 10 from the outside of the vehicle. The double wall 20 is disposed further to the outside of the vehicle than the sound emitting portion 10. The double wall 20 is composed of an inner wall portion 21 and an outer wall portion 22. The inner wall portion 21 and the outer wall portion 22 are disposed apart from each other in the vehicle inside-outside direction. That is, the inner wall portion 21 is disposed on a side closer to the sound emitting portion 10 than the outer wall portion 22, and the outer wall portion 22 is disposed on a side farther from the sound emitting portion 10 than the inner wall portion 21. A hollow space 23 is formed between the inner wall portion 21 and the outer wall portion 22. The double wall 20 allows the sound of the sound emitting portion 10 to pass through from the inside of the vehicle to the outside of the vehicle by resonance of the inner wall portion 21 and the outer wall portion 22.

[0027] The outer wall portion 22 is the outermost housing of the vehicle 3, and is an exterior panel or a cover member facing the outside of the vehicle. The outer wall portion 22 is formed in a plate shape with no opening portion or almost no opening portion. The outer wall portion 22 is, for example, a grill, a bumper, a fender, a cylinder head, a headlamp cover, a pillar, a roof, a rearview mirror cover, or the like. The outer wall portion 22 is formed of a resin material or a metal material. The outer wall portion 22 is mounted and fixed to a structure 3a, such as a frame, an exterior panel, a cover, or the like, provided to the vehicle 3. The outer wall portion 22 is disposed to close an opening 4 provided to the structure 3a.

[0028] The inner wall portion 21 is a plate-shaped member. The inner wall portion 21 is disposed further to the inside of the vehicle than the outer wall portion 22, and faces the outer wall portion 22 with the intermediate layer 30 described later interposed therebetween. The inner wall portion 21 is capable of vibrating with a predetermined frequency of the sound emitted from the sound emitting portion 10. The vibration of the inner wall portion 21 based on the sound is transmitted to the outer wall portion 22 with the intermediate layer 30 as a spring. The outer wall portion 22 is capable of vibrating in a manner resonating with the vibration of the inner wall portion 21.

[0029] The inner wall portion 21 is provided to the bracket 40. The bracket 40 is attached to the back surface (inner surface) of the outer wall portion 22. The bracket 40 is formed of a resin material or a metal material. The material of the bracket 40 can be the same as that of the outer wall portion 22. The inner wall portion 21 is formed in a thickness and a material that can vibrate due to the sound of the sound emitting portion 10. The thickness of the inner wall portion 21 is, for example, 2 mm to 5 mm. In addition, the outer wall portion 22 is formed in a thickness and a material that can vibrate in resonance due to the vibration of the inner wall portion 21. The thickness of the outer wall portion 22 can be the same as that of the inner wall portion 21, and is, for example, 2 mm to 5 mm. In the present embodiment, the inner wall portion 21 is integrated with the cover portion 42 described later as a part of the bracket 40, but can be provided separately from the bracket 40 and attached to the cover portion 42 of the bracket 40 to be integrated.

[0030] The bracket 40 has the inner wall portion 21, an attachment portion 41, and a cover portion 42. The attachment portion 41 is a through hole through which an attachment member 50 for attaching the bracket 40 to the back surface of the outer wall portion 22 penetrates. The attachment portion 41 is provided at the peripheral edge portion of the plate-shaped inner wall portion 21 at a plurality of positions.

[0031] The outer wall portion 22 has a fixing portion 22a in which the attachment member 50 is fixed. The fixing portion 22a is formed on the back surface side of the outer wall portion 22. The fixing portion 22a is an attachment hole formed by a protruding portion 22b protruding from the back surface of the outer wall portion 22 toward the inside of the vehicle. The attachment member 50 penetrates the attachment portion 41 and is fixed to the fixing portion 22a of the outer wall portion 22, whereby the bracket 40 is attached to the outer wall portion 22.

[0032] The protruding portion 22b is formed in a ring shape along the periphery of the inner wall portion 21. In a state in which the bracket 40 is attached to the outer wall portion 22, the hollow space 23 between the inner wall portion 21 and the outer wall portion 22 is surrounded by the ring-shaped protruding portion 22b over the entire periphery. That is, the hollow space 23 is closed by the surface of the inner wall portion 21, the back surface of the outer wall portion 22, and the inner side surface of the protruding portion 22b.

[0033] The cover portion 42 is a portion that surrounds the entire periphery of the above-described housing 11 (particularly, the sound emitting portion 10). The cover portion 42 extends in a cylindrical shape from the sound emitting portion 10 side to the vehicle inner surface side of the inner wall portion 21. The cover portion 42 has a bottom wall portion that closes the cylindrical end on the sound emitting portion 10 side, and an opening portion that opens the cylindrical end on the inner wall portion 21 side. The housing 11 is attached and fixed to the bottom portion of the vehicle inner end of the cover portion 42 in such a manner that the entire periphery thereof is surrounded by the cylindrical wall of the cover portion 42.

[0034] The housing 11 has a flange portion 11a extending from the outer peripheral surface toward the radially outer side. The flange portion 11a has a mounting portion 11b. The mounting portion 11b is a through-hole through which a mounting member 51 such as a bolt or a screw for mounting the housing 11 to the cover portion 42 is inserted. The flange portion 11a and the mounting portion 11b are provided at the entire circumference of the housing 11 at a plurality of positions.

[0035] The cover portion 42 has a fixing portion 42a to which the mounting member 51 is fixed. The fixing portion 42a is formed on the surface side of the cover portion 42. The fixing portion 42a is a mounting hole formed by a protruding portion 42b protruding from the surface of the cover portion 42 toward the vehicle outer side. The mounting member 51 is inserted through the mounting portion 11b and fixed to the fixing portion 42a of the cover portion 42, whereby the housing 11 is mounted to the cover portion 42. The fixing portion 42a and the protruding portion 42b are provided at a plurality of positions of the cover portion 42 corresponding to the flange portion 11a and the mounting portion 11b of the housing 11.

[0036] The cover portion 42 is fixed and mounted to the inner wall portion 21 to be integrated. The cover portion 42 is engaged with the inner wall portion 21 in a detachable manner in a state where the housing 11 is fixed and mounted. If the cover portion 42 is mounted to the inner wall portion 21 in a state where the housing 11 is fixed and mounted to the cover portion 42, the housing 11, and further the sound emitting portion 10 mounted to the housing 11, are disposed in the space 49 sealed by the inner wall portion 21 and the cover portion 42. This sealed space 49 is a guide path for guiding the sound emitted from the sound emitting portion 10 toward the double wall 20.

[0037] The cover portion 42 and the inner wall portion 21 have engagement portions 43 and 44 that are engaged with each other. The engagement portion 43 of the cover portion 42 is an engagement protrusion for engaging the engagement portion 44 of the inner wall portion 21. The engagement portion 43 is formed on the cylindrical side wall of the cover portion 42 so as to protrude from the outer peripheral surface toward the radially outer side. The engagement portion 44 of the inner wall portion 21 is an engagement hole into which the engagement portion 43 is engaged. The engagement portion 44 is formed on the back surface side of the inner wall portion 21. The engagement portion 44 is formed on the protruding portion 45 protruding from the back surface of the inner wall portion 21 toward the vehicle inner side in a manner of penetrating in the radial direction. The engagement portion 43 of the cover portion 42 and the engagement portion 44 of the inner wall portion 21 are provided at a plurality of positions corresponding to each other.

[0038] Furthermore, as a method of mounting the bracket 40 to the outer wall portion 22, mounting parts 50 such as bolts and small screws are used. However, if the bracket 40 is tightly attached to the outer wall portion 22, thus sealing the hollow space 23, the above mounting method can be replaced by fixing with double-sided tape, heat fusion, or ultrasonic welding. Additionally, as a method of mounting the housing 11 to the covering portion 42 of the bracket 40, mounting parts 51 such as bolts and small screws are used, but this mounting method can also be replaced by fixing with double-sided tape, heat fusion, or ultrasonic welding. Furthermore, as a method of mounting the covering portion 42 to the inner wall portion 21 of the bracket 40, interlocking engaging parts 43 and 44 are used, but this mounting method can also be replaced by detachable threaded fasteners.

[0039] The intermediate layer 30 is the air layer between the inner wall portion 21 and the outer wall portion 22 of the double wall 20. That is, the intermediate layer 30 is the hollow space 23 itself. The thickness (i.e., the width in the inward and outward directions) or volume of the intermediate layer 30 is set to produce a resonant transmission phenomenon (see reference) that corresponds to the frequency of the sound emitted by the sound-emitting part 10, allowing the sound to pass through from the inner wall portion 21 to the outer wall portion 22. Figure 3 Specifically, the intermediate layer 30 is defined according to the following formula (1).

[0040]

Mathematical Formula 1

[0041]

[0042] Among them, f rmd d is the frequency of the sound emitted by the sound-emitting part 10 [Hz], d is the thickness of the intermediate layer 30 [mm], and ρ is the density of the gas sealed in the intermediate layer 30 [kg / m³]. 3 c is the speed of sound of the gas in the intermediate layer 30 [m / s], and m1 is the surface density of the inner wall 21 [kg / m³]. 2 m2 is the areal density of the outer wall portion 22 [kg / m³]. 2 Furthermore, the intermediate layer 30 is an air layer, therefore ρ is 1.2 [kg / m]. 3 ], c is 343.7 [m / s].

[0043] Next, the operation of the vehicle sound output device 1, including the vehicle sound transmission device 2, will be explained.

[0044] The sound-emitting part 10 emits a sound of a predetermined frequency. The sound of the predetermined frequency emitted by the sound-emitting part 10 propagates within the space 49 of the bracket 40 and reaches the inner wall 21. The sound reaching the inner wall 21 resonates and passes through the intermediate layer 30 to the outer wall 22, propagating to a position further outward than the outer wall 22. Therefore, the sound emitted by the sound-emitting part 10 of the vehicle 3 can be easily heard by people around the vehicle 3, and the sound emitted by the sound-emitting part 10 can be used to attract attention.

[0045] In the above-described vehicle sound output device 1 and vehicle sound propagation device 2, the sound emitted from the sound emitting portion 10 disposed inside the vehicle resonates and transmits through the double wall 20 to the outside of the vehicle. At this time, the sound insulation performance of the double wall 20 is greatly reduced. Therefore, the sound of a predetermined frequency emitted from the sound emitting portion 10 can be properly transmitted from the inside of the vehicle to the outside of the vehicle without passing through the opening portion through which sound easily passes.

[0046] Therefore, even in an electric vehicle or the like in which the outer panel, the cover member (i.e., the outer wall portion 22) of the vehicle 3 is not provided with an opening portion, or in which the opening portion is provided but has a small opening area, the sound emitting portion 10 can be disposed inside the vehicle so that the sound of a predetermined frequency emitted from the sound emitting portion 10 is heard by people around the vehicle 3, and thus it is not necessary to secure an opening portion through which sound easily passes, and it is possible to balance the propagation of sound and the freedom of mounting the sound emitting portion 10.

[0047] In addition, the sound emitting portion 10 is surrounded by the cover portion 42 over the entire circumference, and is disposed in the space 49 that is sealed by the inner wall portion 21 and the cover portion 42. In this configuration, the sound emitted from the sound emitting portion 10 can be enclosed in the space 49 and is not easily leaked from the space 49, and most of the sound can reach the inner wall portion 21. Therefore, the sound emitted from the sound emitting portion 10 can be effectively propagated to the double wall 20, and the resonant transmission phenomenon can occur in the double wall 20 and the intermediate layer 30.

[0048] In addition, the sound emitting portion 10 is mounted to the housing 11 that is fixedly mounted to the bracket 40 mounted to the outer wall portion 22 that constitutes the double wall 20. That is, the sound emitting portion 10 is fixed to the back surface of the double wall 20. In this configuration, the sound emitting portion 10 can be disposed close to the double wall 20.

[0049] [Second Embodiment]

[0050] In the above-described first embodiment of the vehicle sound output device 1, the inner wall portion 21 and the cover portion 42 of the bracket 40 are integrated with each other by being engaged with each other, and the sound emitting portion 10 is disposed opposite to the inner wall portion 21 at a position closer to the inside of the vehicle than the inner wall portion 21 in a state of being mounted to the cover portion 42 of the bracket 40. In addition, the sound emitting portion 10 is housed in the housing 11, and further, the sound emitting portion 10 is fixed to the double wall 20 side.

[0051] On the contrary, in the vehicle sound output device 100 of the present embodiment, as Figure 4As shown, the sound emitting portion 10 is arranged closer to the inner side of the vehicle than the inner wall portion 21, but is arranged further away from the inner wall portion 21, and a guide path that guides the sound emitted from the sound emitting portion 10 toward the double wall 20 is formed between the sound emitting portion 10 and the inner wall portion 21. In addition, the sound emitting portion 10 is not fixed to the double wall 20 side, but is fixed to the structure 3b on the inner side of the vehicle 3. Further, in the Figure 4 embodiment, the same components as the structural components shown in Figure 2 the same reference numerals are attached to the same components, and the description thereof is omitted or simplified.

[0052] The vehicle sound output device 100 has a guide wall 110. The guide wall 110 is a guide wall that forms a guide path 111 that guides the sound of the prescribed frequency emitted from the sound emitting portion 10 toward the double wall 20. The guide wall 110 extends in a cylindrical shape from the sound emitting portion 10 side to the inner surface side of the inner wall portion 21. As shown in Figure 4 the sound emitting portion 10 is not opposed to the inner wall portion 21, the guide wall 110 and the guide path 111 are formed in a curved manner from the sound emitting portion 10 to the inner wall portion 21.

[0053] The guide wall 110 is mounted to the back surface of the inner wall portion 21, and is integrated with the inner wall portion 21. The guide wall 110 is mounted to the inner wall portion 21 by claw fitting, bolt fastening, or the like. In addition, the sound emitting portion 10 is not mounted to the guide wall 110, but is mounted to the structure 3b on the inner side of the vehicle 3 via the mounting bracket 120 by bolt fastening or the like. Further, with respect to the sound emitting portion 10, if the emitted sound is caused to efficiently propagate in the guide path 111, as shown in Figure 4 the sound emitting portion 10 can be arranged to enter a position closer to the inner side of the guide path 111 than the sound inlet end of the guide wall 110, or can be arranged to deviate further to the outer side of the guide path 111 than the sound inlet end of the guide wall 110.

[0054] In the vehicle sound output device 100, the sound of the prescribed frequency emitted from the sound emitting portion 10 propagates in the guide path 111 in the guide wall 110 to reach the inner wall portion 21. The sound that reaches the inner wall portion 21 resonantly transmits from the inner wall portion 21 toward the outer wall portion 22 via the intermediate layer 30, and propagates to a position closer to the outer side of the vehicle than the outer wall portion 22. Therefore, in the vehicle sound output device 100, it is also possible to cause the people around the vehicle 3 to easily hear the sound emitted from the sound emitting portion 10 of the vehicle 3, and to arouse attention using the sound emitted from the sound emitting portion 10. Therefore, it is possible to appropriately propagate the sound of the prescribed frequency emitted from the sound emitting portion 10 from the inner side of the vehicle to the outer side of the vehicle without causing the sound to pass through the opening portion through which the sound easily passes, and it is possible to obtain the same effects as the first embodiment described above.

[0055] Further, the sound emitting portion 10 is arranged so as to be apart from the inner wall portion 21 of the double wall 20, and the sound emitted from the sound emitting portion 10 is propagated through the guide path 111 of the guide wall 110 and conducted to the double wall 20. Therefore, even when the sound emitting portion 10 has to be arranged apart from the double wall 20, the sound emitted from the sound emitting portion 10 can be guided to the double wall 20 through the guide path 111 and resonated to be transmitted.

[0056] Further, in the above-described second embodiment, the guide wall 110 is separate from the inner wall portion 21 and is integrated by being attached to the back surface of the inner wall portion 21. However, the present disclosure is not limited to this, and the guide wall 110 and the inner wall portion 21 can be integrally formed.

[0057] [Third Embodiment]

[0058] In the above-described second embodiment, the guide wall 110 is attached to the back surface of the inner wall portion 21 without a gap, and the sound outlet end of the guide path 111 is in contact with the back surface of the inner wall portion 21.

[0059] On the contrary, in the vehicle sound output device 200 of the present embodiment, as shown in FIG. 2, the guide wall 210 is arranged apart from the back surface of the inner wall portion 21, and a gap is formed between the sound outlet end of the guide path 211 and the back surface of the inner wall portion 21. Further, in the present embodiment, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals and the description thereof is omitted or simplified. Figure 5 Figure 5 Figure 2 Figure 4

[0060] The vehicle sound output device 200 has a guide wall 210. The guide wall 210 is a guide wall that forms a guide path 211 that guides sound of a predetermined frequency emitted from a sound emitting portion 10 to a double wall 20. The guide wall 210 extends in a cylindrical shape from the sound emitting portion 10 side to the vehicle inner surface side of the inner wall portion 21. In a case where the sound emitting portion 10 is not opposed to the inner wall portion 21 as shown in FIG. 2, the guide wall 210 and the guide path 211 are curved from the sound emitting portion 10 to the inner wall portion 21. Figure 5

[0061] ​​​​​The guide wall 210 is configured to be separated from the back surface of the inner wall portion 21 toward the vehicle inner side. The guide wall 210 is attached to the structure 3c on the inner side of the vehicle 3 via the mounting bracket 220 by screw fastening or the like. Further, the gap distance of the guide wall 210 from the back surface of the inner wall portion 21 is only required to be such that the sound emitted from the sound emitting portion 10 effectively reaches the inner wall portion 21 and resonates through the double wall 20. In addition, the sound emitting portion 10 is not attached to the guide wall 210, but is attached to the structure 3b on the inner side of the vehicle 3 via the mounting bracket 120. Further, with respect to the sound emitting portion 10, if the emitted sound is caused to effectively propagate in the guide path 211, it can be configured to enter a position further toward the inner side of the guide path 211 than the sound inlet end of the guide wall 210, or, as shown in Figure 5

[0062] In the vehicle sound output device 200, the sound of the prescribed frequency emitted from the sound emitting portion 10 propagates in the guide path 211 in the guide wall 210 to reach the inner wall portion 21. The sound reaching the inner wall portion 21 resonates through the intermediate layer 30 from the inner wall portion 21 to the outer wall portion 22, and propagates to a position further toward the vehicle outer side than the outer wall portion 22. Thus, in the vehicle sound output device 200, it is also possible to cause people around the vehicle 3 to easily hear the sound emitted from the sound emitting portion 10 of the vehicle 3, and to arouse attention using the sound emitted from the sound emitting portion 10. Thus, it is possible to appropriately propagate the sound of the prescribed frequency emitted from the sound emitting portion 10 from the vehicle inner side to the vehicle outer side without causing the sound to pass through the opening portion through which sound easily passes, and to obtain the same effects as in the first and second embodiments described above.

[0063] However, in the first to third embodiments described above, the frequency of the sound emitted from the sound emitting portion 10 is set to a frequency within a prescribed range. However, the present application is not limited thereto, and the sound emitted from the sound emitting portion 10 can be a mixture of a plurality of frequencies (for example, two frequencies of 400 Hz and 480 Hz) within a prescribed range. In this case, the various sounds of the plurality of frequencies can be emitted simultaneously or at different times from one sound emitting portion 10, or can be emitted from sound emitting portions 10 separated from each other as shown in Figure 6

[0064] Further, in the case where a plurality of frequencies of sound are emitted from the sound emitting portion 10 as described above, it is preferable that the double wall 20 and the intermediate layer 30 be provided in multiple sets. For example, as shown in Figure 6 ​​As shown, the first group A of the double wall 20A and the intermediate layer 30A, and the second group B of the double wall 20B and the intermediate layer 30B are provided. In the group A, the double wall 20A and the intermediate layer 30A are configured to transmit only the sound of the assigned frequency in resonance. In the group B, the double wall 20B and the intermediate layer 30B are configured to transmit only the sound of the assigned frequency in resonance. Specifically, in the group A and the group B, the thickness of the intermediate layer 30A and the thickness of the intermediate layer 30B are configured to be different from each other in correspondence with the frequency of the sound generated.

[0065] Further, in Figure 6 , the first group A side sound generating portion 10A and the second group B side sound generating portion 10B are shown as being provided separately. In addition, in Figure 6 , the outer wall portion 22 of the double wall 20A of the first group A and the outer wall portion 22 of the double wall 20B of the second group B are shown as being common.

[0066] In Figure 6 , in the first group A side and the second group B side, the sound generating portions 10A, 10B respectively emit sound of corresponding frequencies, the double wall 20A and the intermediate layer 30A transmit only the sound of the corresponding frequency among the plurality of frequencies in resonance, and the double wall 20B and the intermediate layer 30B transmit only the sound of the corresponding frequency among the plurality of frequencies in resonance. In this structure, in the first group A side and the second group B side, sound of different frequencies can be respectively transmitted from the inside of the vehicle to the outside of the vehicle.

[0067] In addition, in the above first to third embodiments, the hollow space 23 (further, the intermediate layer 30) between the inner wall portion 21 and the outer wall portion 22 is entirely surrounded by the protruding portion 22b formed in a ring shape on the back surface side of the outer wall portion 22. However, the present application is not limited thereto, and as shown in Figure 7 and Figure 8 , the hollow space 23 (further, the intermediate layer 30) can be entirely surrounded by the protruding portion 21a formed in a ring shape on the surface side of the inner wall portion 21.

[0068] The protruding portion 21a of the inner wall portion 21 protrudes in a ring shape from the peripheral portion of the surface of the inner wall portion 21 to the back surface of the outer wall portion 22. Thereby, the hollow space 23 (further, the intermediate layer 30) is entirely surrounded. Further, in order to ensure the airtightness of the hollow space 23 (further, the intermediate layer 30), it is preferable to provide a member (cushion member) 60 having a cushioning property between the front end of the protruding portion 21a of the inner wall portion 21 and the back surface of the outer wall portion 22. According to this structure, the sound emitted from the sound generating portion 10 can be effectively propagated in the double wall 20 without easily leaking from the hollow space 23.

[0069] In addition, in the above-described modification, the inner wall portion 21 and the hollow cylindrical duct 70 that guides the sound emitted from the sound emitting portion 10 to the inner wall portion 21 can be attached to the structure (so-called yagura or the like) 22d provided on the back surface side of the outer wall portion 22. In addition, as the attachment method, the attachment member 52 such as a bolt or a small screw can be used. In this configuration, the attachment member 52 is fastened to the spring nut 53 with the attachment hole 21c provided in the flange portion 21b of the inner wall portion 21, the attachment hole 70b provided in the flange portion 70a of the duct 70, and the attachment hole 22e provided in the structure 22d of the outer wall portion 22 being penetrated.

[0070] In addition, in the attachment configuration using the above-described attachment member 52, in order to absorb the vibration propagated between the inner wall portion 21 and the duct 70 (particularly, the vibration from the inner wall portion 21 to the duct 70), a member having a buffering property (buffer member) 61 can be arranged between the flange portion 21b of the inner wall portion 21 and the flange portion 70a of the duct 70. According to this configuration, the vibration is less likely to propagate between the inner wall portion 21 and the duct 70, and the influence of the resonance transmission of the vibration on the sound emitted from the sound emitting portion 10 can be avoided.

[0071] Further, in the configuration in which the hollow duct 70 guides the sound emitted from the sound emitting portion 10 to the inner wall portion 21 as described above, in order to suppress the vibration of the duct 70 due to the sound emitted from the sound emitting portion 10, a member having a buffering property (buffer member) 62 can be arranged on the inner surface of the duct 70 (for example, on one of the four inner surfaces of the cylinder in the example shown in FIG. 8; however, it is preferable that all of the four inner surfaces of the cylinder be targeted). According to this configuration, the vibration of the duct 70 due to the sound emitted from the sound emitting portion 10 is less likely to occur, and the sound can be effectively guided to the double wall 20. Figure 7 Figure 8 Further, in the configuration in which the hollow duct 70 guides the sound emitted from the sound emitting portion 10 to the inner wall portion 21 as described above, in order to suppress the vibration of the duct 70 due to the sound emitted from the sound emitting portion 10, a member having a buffering property (buffer member) 62 can be arranged on the inner surface of the duct 70 (for example, on one of the four inner surfaces of the cylinder in the example shown in FIG. 8; however, it is preferable that all of the four inner surfaces of the cylinder be targeted). According to this configuration, the vibration of the duct 70 due to the sound emitted from the sound emitting portion 10 is less likely to occur, and the sound can be effectively guided to the double wall 20.

[0072] In addition, in the above-described first to third embodiments, the intermediate layer 30 formed in the sealed hollow space 23 between the inner wall portion 21 and the outer wall portion 22 of the double wall 20 is an air layer. However, the present application is not limited thereto, and the intermediate layer 30 can be a layer in which argon gas, a liquid, or the like is enclosed in the hollow space 23, or the intermediate layer 30 in which argon gas, a liquid, or the like is enclosed in a bag shape can be inserted and arranged in the hollow space 23, if the intermediate layer 30 transmits the sound emitted from the sound emitting portion 10.

[0073] Further, the present application is not limited to the above-described embodiments and modifications, and various modifications can be made within the scope of the gist of the present application.

[0074] Explanation of Reference Numerals

[0075] ​1, 100, 200: vehicle sound output device, 2: vehicle sound propagation device, 3: vehicle, 10: sound generating portion, 11: housing, 20: double wall, 21: inner wall portion, 22: outer wall portion, 23: hollow space, 30: intermediate layer, 40: bracket, 42: covering portion, 110, 210: guide wall, 111, 211: guide path.

Claims

1. A sound output device for a vehicle, wherein the sound output device for a vehicle has: a sound emitting portion that emits a sound of a prescribed frequency; a double wall that is disposed apart from the sound emitting portion on a vehicle outer side than the sound emitting portion, and is composed of an inner wall portion and an outer wall portion that are separated from each other in a vehicle inside and outside direction; an intermediate layer that is formed in a closed space between the inner wall portion and the outer wall portion so that the sound is transmitted therethrough; and a guide wall that extends in a cylindrical shape from the sound emitting portion side to the vehicle inside surface side of the inner wall portion, and forms a guide path that guides the sound toward the double wall, the guide wall has: a bottom wall portion that closes one cylinder end; and an opening portion that opens the other cylinder end, the sound emitting portion is installed on the bottom wall portion side of the guide wall in a manner that emits the sound toward the opening portion side of the guide wall, the guide path is closed by the inner wall portion and the guide wall.

2. The sound output device for a vehicle according to claim 1, wherein the intermediate layer has a thickness, a density, or a volume that causes a resonance transmission phenomenon of the sound from the inner wall portion to the outer wall portion.

3. The sound output device for a vehicle according to claim 1, wherein the intermediate layer is an air layer.

4. The sound output device for a vehicle according to claim 1, wherein the prescribed frequency includes a plurality of frequencies that are different from each other, the double wall and the intermediate layer are provided in a plurality of groups, each of the intermediate layers respectively causes the sound of a corresponding frequency among the plurality of frequencies to be transmitted therethrough.

5. The sound output device for a vehicle according to claim 1, wherein the prescribed frequency includes a fundamental frequency that is prescribed between 270 Hz and 600 Hz.

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