Acoustic vehicle alerting system

Abstract

To provide an acoustic vehicle alerting system that can generate alert sound that allows a pedestrian to easily distinguish whether a vehicle is moving toward the pedestrian or passing around the pedestrian.SOLUTION: An acoustic vehicle alerting system 10 includes: a diaphragm 210 disposed in an internal space and configured to generate sound; and a sound emitter 200 configured to output alert sound to the outside of a vehicle. A control device 100 controls the sound emitter 200. The sound emitter 200 includes: a first sound guide pipe 221 oriented to the front face of the vehicle; and a second sound guide pipe 222 and a third sound guide pipe 223 that are oriented to directions different from that of the first sound guide pipe 221. The first sound guide pipe 221, the second sound guide pipe 222, and the third sound guide pipe 223 resonate the sound emitted from the diaphragm 210 and thus amplitude the sound with frequency according to the pipeline length. The pipeline length of the first sound guide pipe 221 is different from the pipeline lengths of the second sound guide pipe 222 and the third sound guide pipe 223.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle approach notification device. [Background technology]

[0002] In recent years, vehicles capable of running without generating engine noise, such as electric vehicles and hybrid vehicles, are equipped with vehicle approach notification devices. The vehicle approach notification devices emit a notification sound toward the outside of the vehicle when the vehicle is running without generating engine noise. The emitted notification sound is used to notify the surroundings of the approach of the vehicle. Patent Document 1 discloses a technology for efficiently generating a notification sound by emitting the notification sound amplified by resonance from a sound emission hole toward the outside of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-150714 A Summary of the Invention [Problem to be solved by the invention]

[0004] Vehicles equipped with vehicle approaching notification devices can notify pedestrians of the approach of a vehicle. However, when a pedestrian hears the notification sound of a vehicle approaching notification device, it is difficult for the pedestrian, especially a pedestrian with impaired eyesight, to determine whether the vehicle is moving toward the pedestrian or passing by the side of the pedestrian. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. The vehicle approach notification device for solving the above problem is a vehicle approach notification device that is mounted on a vehicle and outputs a notification sound to notify a driver of the approach of the vehicle.

[0006] The vehicle approach notification device includes a control device that generates a sound signal that serves as the sound source of the notification sound, and a sound generator having a diaphragm that generates sound disposed in an internal space and a plurality of sound guide tubes that output the notification sound toward the outside of the vehicle.

[0007] The plurality of sound guide tubes include a first sound guide tube facing toward the front of the vehicle and a second sound guide tube facing in a different direction from the first sound guide tube. The plurality of sound guide tubes have a structure that resonates with the sound emitted from the diaphragm and amplifies the sound of a frequency according to the length of the tube.

[0008] The first sound-guide tube has a different path length from the second sound-guide tube. Effect of the Invention

[0009] The vehicle approach notification device can generate a notification sound that allows pedestrians to easily distinguish whether a vehicle is moving toward them or passing around them, and therefore the vehicle approach notification device can ensure the safety of pedestrians. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an embodiment of a vehicle approach notification device. [Diagram 2] FIG. 2 is a schematic diagram showing the resonance of sound through a sound guide tube. [Diagram 3] FIG. 3 is a schematic diagram showing an effective range of a notification sound in a vehicle to which an embodiment of a vehicle approach notification device is applied. [Figure 4] FIG. 4 is a schematic diagram showing a case where there is a position that is not included in the effective range of any of the notification sounds even in front of the vehicle. [Diagram 5] FIG. 5 is a schematic diagram showing the configuration of a vehicle approach notification device according to a modified example. [Figure 6] FIG. 6 is a schematic diagram showing an effective range of a notification sound in a vehicle to which an embodiment of a vehicle approach notification device according to a modified example is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a vehicle approach notification device will be described with reference to Figs. 1 to 3. <Structure of vehicle approach notification device 10> 1, the vehicle approach notification device 10 includes a control device 100 and a sound generator 200. The control device 100 is an electronic control device mainly composed of a microcomputer. The control device 100 controls the sound generator 200.

[0012] Sound generator 200 has sound-generating diaphragm 210 disposed in the internal space. Diaphragm 210 generates white noise with uniform sound pressure over a wide frequency range. In other words, diaphragm 210 generates complex sounds.

[0013] The sound generator 200 includes a plurality of sound guide tubes 220 that output a notification sound toward the outside of the vehicle 20. Each sound guide tube 220 has a spiral shell shape with the inside being a spiral duct. As shown in Fig. 3, the vehicle approach notification device 10 is mounted on a vehicle 20. The vehicle 20 is, for example, a hybrid vehicle or an electric vehicle. The vehicle approach notification device 10 generates a notification sound to notify surrounding pedestrians of the approach of the vehicle 20 when the vehicle 20 is running on an electric motor. Here, the area through which the vehicle 20 passes when traveling straight is defined as the area in front of the vehicle 20 (Fr).

[0014] As shown in Fig. 1, the sound generator 200 has three sound guide tubes 220: a first sound guide tube 221, a second sound guide tube 222, and a third sound guide tube 223. The first sound guide tube 221 faces in the front direction Fr of the vehicle 20. The second sound guide tube 222 is provided in the sound generator 200 at an angle to the lateral side of the vehicle 20 with respect to the direction in which the first sound guide tube 221 faces. The third sound guide tube 223 is provided in the sound generator 200 at an angle to the lateral side opposite to the second sound guide tube 222 with respect to the direction in which the first sound guide tube 221 faces. The first sound guide tube 221 has a different tube length from the second sound guide tube 222 and the third sound guide tube 223.

[0015] <Sound resonance through the sound guide tube 220> 2, the resonance and amplification of sound by the sound guide tube 220 will be described using the L1 sound guide tube 220A and the L2 sound guide tube 220B as examples. In the following, subscripts will be written following "_".

[0016] The L1 sound guide tube 220A is a sound guide tube 220 with a tube length of L_1. An incident sound entering the L1 sound guide tube 220A from the sound generator 200 and a reflected sound reflected in the L1 sound guide tube 220A interfere with each other to form a standing wave with a wavelength of λ_1. The wavelength λ_1 of the standing wave formed by the L1 sound guide tube 220A is four times the tube length in the L1 sound guide tube 220A. Similarly, the wavelength λ_2 of the standing wave formed in the L2 sound guide tube 220B, whose tube length is L_2 shorter than L_1, is four times the tube length in the L2 sound guide tube 220B. That is, standing waves with different wavelengths are formed according to the tube length of the sound guide tube 220. As a result, resonance occurs at the frequency at which the standing wave is formed, and the sound pressure of the notification sound is amplified. By providing a plurality of sound guide tubes 220 with different tube lengths, notification sounds of different frequencies can be amplified.

[0017] 1, sound emitted by the diaphragm 210 resonates inside the first sound guide tube 221, the second sound guide tube 222, and the third sound guide tube 223. Due to the resonance, the first sound guide tube 221, the second sound guide tube 222, and the third sound guide tube 223 amplify the sound of a frequency according to the respective tube lengths. The amplified sound is emitted from the first sound guide tube 221, the second sound guide tube 222, and the third sound guide tube 223 as a notification sound.

[0018] <Effective range of warning sound> The range in which the sound pressure of the notification sound output from sound guide tube 220 is equal to or greater than the predetermined sound pressure is defined as the effective range of the notification sound.

[0019] 3, the effective range of the notification sound output from the first sound guide tube 221 is a first effective range Ar1. Similarly, the effective range of the notification sound output from the second sound guide tube 222 is a second effective range Ar2. And the effective range of the notification sound output from the third sound guide tube 223 is a third effective range Ar3.

[0020] In FIG. 3, point P1 is a point in front of the vehicle 20 Fr and within the first effective range Ar1. At point P1, only the notification sound emitted from the first sound guide tube 221 can be heard at a predetermined sound pressure or higher. Point P2 is a point on the side of the front of the vehicle 20 Fr where the first effective range Ar1 and the second effective range Ar2 partially overlap. At point P2, a mixed sound of the notification sound emitted from the first sound guide tube 221 and the notification sound emitted from the second sound guide tube 222 can be heard at a predetermined sound pressure or higher. That is, the notification sound heard by a pedestrian is different between point P1 located in front of the vehicle 20 Fr and point P2 located on the side of the front of the vehicle 20 Fr.

[0021] <Action of this embodiment> The vehicle approaching notification device 10 generates a notification sound toward the front Fr of the vehicle 20 through the first sound guide tube 221. The vehicle approaching notification device 10 generates a notification sound of a different frequency from the notification sound emitted toward the front Fr on both sides of the front Fr of the vehicle 20 through the second sound guide tube 222 and the third sound guide tube 223. Therefore, the sound heard in association with the approach of the vehicle 20 differs between a point P1 located in the front Fr of the vehicle 20 and a point P2 located to the side of the front Fr of the vehicle 20.

[0022] Therefore, it becomes easier for a pedestrian to determine whether the vehicle 20 equipped with the vehicle approach notification device 10 is proceeding toward him / her or passing by the side of him / her. At positions where the effective ranges overlap, the warning sound is a mixture of warning sounds of multiple frequencies. That is, the warning sound heard by pedestrians at point P2, where multiple effective ranges overlap, is different from the warning sound heard at point P1, where the effective ranges do not overlap.

[0023] In this embodiment, the point P1 where the effective ranges do not overlap is set in front of the vehicle 20. In this case, a pedestrian can understand the relationship between the traveling direction of the vehicle 20 and his / her own position by the change in the notification sound that he / she hears.

[0024] <Effects of this embodiment> (1) The vehicle approaching notification device 10 can generate a notification sound that allows a pedestrian to easily distinguish whether the vehicle 20 is moving toward the pedestrian or whether the vehicle 20 is passing around the pedestrian. Therefore, the vehicle approaching notification device 10 can ensure the safety of the pedestrian.

[0025] (2) The vehicle approaching notification device 10 includes, as the multiple sound guide tubes 220, a first sound guide tube 221 and a second sound guide tube 222 provided in the sound generator 200 at an angle to the side of the vehicle 20 with respect to the direction in which the first sound guide tube 221 is facing. The vehicle approaching notification device 10 includes, as the multiple sound guide tubes 220, a third sound guide tube 223 provided in the sound generator 200 at an angle to the side opposite the second sound guide tube 222 with respect to the direction in which the first sound guide tube 221 is facing. The duct length of the first sound guide tube 221 is different from the duct length of the second sound guide tube 222. The duct length of the first sound guide tube 221 is different from the duct length of the third sound guide tube 223.

[0026] The vehicle approaching notification device 10 generates a notification sound toward the front Fr of the vehicle 20 through the first sound guide tube 221. The vehicle approaching notification device 10 generates a notification sound of a different frequency from the notification sound emitted toward the front Fr on both sides of the front Fr of the vehicle 20 through the second sound guide tube 222 and the third sound guide tube 223. Therefore, a pedestrian located in front of the front Fr of the vehicle 20 and a pedestrian located to the side of the front Fr of the vehicle 20 hear different sounds associated with the approach of the vehicle 20. Therefore, it becomes easier for a pedestrian to determine whether the vehicle 20 equipped with the vehicle approaching notification device 10 is proceeding toward them or passing by their side.

[0027] (3) Sound guide tube 220 has a spiral shell shape with a helical duct inside. Sound guide tube 220, which produces a resonance phenomenon, requires a duct length according to the frequency of the notification sound to be output. By adopting a spiral shell-shaped sound guide tube 220 with a helical duct inside as in the above configuration, sound guide tube 220 with the required duct length can be realized in a smaller space than with a straight cylindrical duct. This allows vehicle approach notification device 10 to be made smaller in size.

[0028] (4) The vehicle approach notification device 10 generates white noise in a wide frequency band from the diaphragm 210. When white noise that does not have a specific peak frequency is generated from the diaphragm 210, the vehicle approach notification device 10 can generate a resonant sound according to the duct length of the sound guide tube 220 by changing the duct length of the sound guide tube 220. In other words, by providing multiple sound guide tubes 220 with different duct lengths, different resonant sounds can be generated. This makes it possible to generate multiple different resonant sounds with one sound generating body.

[0029] (5) As shown in FIG. 4, assume that even in the front Fr of the vehicle 20, there exists a point P1 that is within the effective range of the notification sound and a point P2 that is not included in the effective range of the notification sound. In this case, a pedestrian standing at the point P1 hears the notification sound output from the first sound guide tube 221 with a predetermined sound pressure or more. When the vehicle 20 moves straight toward the pedestrian standing at the point P1, the relative position of the pedestrian with respect to the vehicle 20 approaches the vehicle 20. When the relative position of the pedestrian with respect to the vehicle 20 becomes point P2, the notification sound heard by the pedestrian becomes equal to or lower than the predetermined sound pressure, even though the vehicle 20 and the pedestrian are approaching each other. If the audible notification sound becomes smaller, the pedestrian may mistakenly believe that the vehicle 20 has moved away, even though the vehicle 20 is approaching the pedestrian.

[0030] In the vehicle approach notification device 10, the multiple sound guide tubes 220 are provided so that the multiple effective ranges of the multiple notification sounds output from the multiple sound guide tubes 220 partially overlap. By providing the multiple sound guide tubes 220 so that the effective ranges overlap, the vehicle approach notification device 10 can eliminate a range in which the notification sounds become small in the front Fr of the vehicle 20. In other words, the vehicle approach notification device 10 can prevent pedestrians from mistakenly thinking that the vehicle 20 has left.

[0031] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0032] The vehicle approach notification device 10 may have two sound guide tubes 220, if sounds of different frequencies can be generated in the traveling direction of the vehicle 20 and around the vehicle 20. For example, as shown in Fig. 5, the first sound guide tube 221 may be installed facing the front Fr of the vehicle 20, and the second sound guide tube 222 may be installed facing the road surface 300. In this case, as shown in Fig. 6, the vehicle approach notification device 10 can generate sounds of different frequencies in the front Fr of the vehicle 20 and around the vehicle 20. At this time, in the front Fr of the vehicle 20, a first effective range Ar1 of the notification sound output from the first sound guide tube 221 and a second effective range Ar2 of the notification sound output from the second sound guide tube 222 overlap. Therefore, at point P1 within the range where the first effective range Ar1 and the second effective range Ar2 overlap, both the notification sound output from the first sound guide tube 221 and the notification sound output from the second sound guide tube 222 can be heard at a predetermined sound pressure or higher. On the other hand, at point P2 where the first effective range Ar1 and the second effective range Ar2 do not overlap, only the notification sound output from the second sound guide tube 222 can be heard at a predetermined sound pressure or higher. In this way, even if the range where the effective ranges overlap is set to the front Fr of the vehicle 20, a pedestrian can grasp the relationship between the traveling direction of the vehicle 20 and his or her own position from the change in the notification sound that he or she hears.

[0033] The diaphragm 210 of the vehicle approaching notification device 10 may emit a sound other than white noise. In that case, the diaphragm 210 of the vehicle approaching notification device 10 may generate a sound of a frequency that resonates in all of the sound guide tubes 220 provided in the sound generator 200.

[0034] The sound guide tube 220 of the vehicle approaching notification device 10 does not have to be in a spiral shell shape with a spiral passage inside. For example, the sound guide tube 220 may be in a cylindrical shape that allows resonance inside.

[0035] The vehicle approaching notification device 10 may be provided with four or more sound guide pipes 220. In this case, the vehicle approaching notification device 10 can generate resonant sounds at four or more frequencies. The sound guide tube 220 of the vehicle approaching notification device 10 may emit a directional sound. In that case, the sound guide tube 220 of the vehicle approaching notification device 10 may be provided so that there is no range in front of the vehicle 20 Fr and on both sides of the front of the vehicle 20 Fr where the notification sound is equal to or lower than a predetermined sound pressure.

[0036] The effective ranges of the multiple notification sounds in the multiple sound guide tubes 220 of the vehicle approach notification device 10 do not have to overlap. In this case, it is preferable that the sound guide tubes 220 of the vehicle approach notification device 10 are arranged so that there is no range in front of the vehicle 20 Fr and on both sides of the front of the vehicle 20 Fr where the notification sounds are equal to or lower than a predetermined sound pressure, or the range is minimized as much as possible. [Explanation of symbols]

[0037] Reference Signs List 10... vehicle approach notification device, 20... vehicle, 100... control device, 200... sound generator, 210... diaphragm, 220... sound guide tube, 220A... L1 sound guide tube, 220B... L2 sound guide tube, 221... first sound guide tube, 222... second sound guide tube, 223... third sound guide tube, 300... road surface, Ar1... first effective range, Ar2... second effective range, Ar3... third effective range, Fr... front

Claims

1. A vehicle approach notification device that is mounted on a vehicle and outputs a notification sound to notify an approach of the vehicle, The sound-generating diaphragm is placed in the internal space, a sound generator having a plurality of sound guide tubes for outputting the notification sound toward the outside of the vehicle; A control device that controls the sound generator, the plurality of sound guide tubes include a first sound guide tube directed toward a front of the vehicle and a second sound guide tube directed in a direction different from that of the first sound guide tube, The plurality of sound guide tubes have a structure that resonates the sound emitted from the diaphragm and amplifies the sound of a frequency according to the length of the tube, The first sound-guiding tube has a length different from the length of the second sound-guiding tube. Vehicle approach notification device.

2. The plurality of sound guide tubes include The first sound-guiding tube; the second sound-guiding tube is provided in the sound generator at an angle toward a lateral side of the vehicle with respect to a direction in which the first sound-guiding tube is oriented; a third sound guide tube provided in the sound generator at an angle to a side opposite to the second sound guide tube with respect to a direction in which the first sound guide tube is oriented, The first sound-guiding tube has a length different from the length of the third sound-guiding tube. The vehicle approach notification device according to claim 1.

3. The sound guide tube is in the shape of a spiral shell, with the inside of the tube being a spiral passage. The vehicle approach notification device according to claim 1.

4. Generates white noise over a wide frequency range from the diaphragm The vehicle approach notification device according to claim 1.

5. When a range in which the sound pressure of the notification sound output from the sound guide tube is equal to or higher than a predetermined sound pressure is defined as an effective range of the notification sound, The effective ranges of the notification sounds output from the sound guide tubes are The plurality of sound guide tubes are provided so as to overlap in part. The vehicle approach notification device according to claim 1.

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