Patent Application
20240292140
The present disclosure relates to a vehicular microphone placed on a vehicle body, and a vehicle.
A microphone that is placed outside of a vehicle and converts received sounds outside the vehicle to electrical signals has been used recently. A commonly used microphone has a problem of susceptibility to dirt, dust, water, etc. from outside of the vehicle.
To address such a problem, a protective film provided under a protective cap prevents water and foreign objects from getting into a microphone unit, in Patent Literature (hereinafter, referred to as PTL) 1 (WO 2020/127408). In PTL 2 (China Patent Application Publication No. 110418228), water is removed from the inside of a microphone by water boiling and gas expansion using a heater.
The technique of PTL 1, however, has such a problem that water and a foreign object got into a space between the protective cap and the protective film stays on the protective film, a vibration characteristic of the protective film when sound pressure is applied is changed, and the acoustic performance is significantly impaired, accordingly. The technique of PTL 2 has such a problem that it is difficult to miniaturize a microphone since a heater has to be provided.
The present disclosure is for addressing such problems and the object is to provide a vehicular microphone placed on a vehicle body, and a vehicle each capable of naturally removing water and a foreign object got into the microphone and miniaturizing the microphone.
To address the above problems, one aspect of a vehicular microphone according to the present disclosure includes: at least one microphone sensor that detects sound; a board that includes a first surface and a second surface, the first surface being a surface where the microphone sensor is provided, the second surface being opposite to the first surface; a cover that includes a bottom surface and a side surface; and a connector that is electrically connectable to a cable of a vehicle, wherein, the cover is provided with at least one first hole that opens toward the bottom surface of the cover to collect the sound to be detected by the microphone sensor.
Further, one aspect of a vehicle according to the present disclosure includes the vehicular microphone, wherein the vehicular microphone is installed so that the at least one first hole opens toward a lower side of a body of the vehicle.
According to the present disclosure, it is possible to naturally remove water and a foreign object got into a microphone and miniaturize the microphone.
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the embodiments described below are all specific examples of the present disclosure. Accordingly, the numerical values, the components, the arrangement of the components, the connection configuration, etc. in the following embodiments are merely examples, and it is not intended to limit the present disclosure. Thus, components not recited in the independent claims among the components in the following embodiments are described as optional components.
In addition, the drawings are schematic diagrams and not necessarily exactly illustrated. Note that substantially the same components are denoted by the same reference signs in the drawings, and redundant descriptions are omitted or simplified.
First, a configuration of vehicular microphone 1 according to the embodiment will be described with reference to
Vehicular microphone 1 is attached, for example, to surface 72 facing the ground at the rear of vehicle body 7. Bottom surface 21 of cover 2 of vehicular microphone 1 faces the ground. A portion of connector 6 of microphone 1 on the side of cover 2 is fixed to surface 72 of vehicle body 7 facing the ground. Connector 6 is placed inside of vehicle body 7, and cover 2 is placed outside of surface 72 of vehicle body 7 facing the ground.
First hole 22 is formed on the bottom surface of cover 2 to collect sound to be detected by a microphone sensor to be described later. It is thus possible to naturally remove water and a foreign object got into vehicular microphone 1 by placing vehicular microphone 1 so that first hole 22 opens downward from vehicle body 7. It is also possible to miniaturize vehicular microphone 1 since there is no need to provide a heater as in the prior art.
Further, first hole 22 is formed so as to open not only toward the bottom surface of cover 2 but also toward the side surface of cover 2. It is thus possible to prevent a foreign object such as water, mud, and dust splashed by a vehicle from getting into first hole 22 by placing vehicular microphone 1 so that first hole 22 opens toward side surface 71 of vehicle body 7.
Note that vehicular microphone 1 is not necessarily placed so that first hole 22 faces side surface 71 of vehicle body 7, but placing it in this way makes it possible to prevent water and a foreign object splashed by a vehicle from directly getting into first hole 22.
Further, vehicular microphone 1 is not necessarily placed on surface 72 and may be placed at the front of vehicle body 7, on the bottom surface of a bumper, on a side mirror, or the like.
Cover 2 includes elliptical bottom surface 21 and side surface 23, and five first holes 22 are formed in a substantially straight portion of side surface 23. First holes 22 are formed on bottom surface 21 of cover 2 so as to open in a direction perpendicular to bottom surface 21.
First holes 22 are also formed on side surface 23 of cover 2 so as to open in a direction perpendicular to side surface 23. To be more specific, first holes 22 are each defined by two side surfaces 22a and surface 22b perpendicular to respective side surfaces 22a, and are each formed so as to open outward of cover 2 perpendicular to surface 22b.
The effect of preventing ingress of water and a foreign object can be obtained even when first holes 22 of cover 2 are provided so as to open toward only bottom surface 21 or side surface 23, but by forming first holes 22 on both bottom surface 21 and side surface 23, first holes 22 are less likely to be filled with mud splashed directly from below the vehicle compared with a case where first holes 22 are provided so as to open toward only bottom surface 21.
Further, water and a foreign object are easily discharged from first holes 22 as compared with the case where first holes 22 are provided so as to open toward only bottom surface 21. In addition, the sound hole diameter can be increased, thereby improving the acoustic performance (frequency performance).
The reason why there are five first holes 22 is that, even when some of first holes 22 can no longer be used due to dust, mud, etc. filled therein, the rest of first holes 22 can still detect sound. Note that the number of first holes 22 is not limited to five and may be another number.
Cover 2 is formed with substantially elliptical concavity 24 defined by bottom surface 21a and side surface 23a. In addition, elliptical flange surface 25 larger than bottom surface 21 is formed on the upper portion of cover 2. Further, surface 26, which is a surface one step down from flange surface 25, is formed inside cover 2 on the first hole 22 side.
Holder 3 includes bottom surface 31, inclined surface 32, and side surface 33, and first opening 34 serving as a path of sound collected by first holes 22 is formed on inclined surface 32. First opening 34 has a rectangular shape with rounded corners. First opening 34 is formed at an angle to bottom surface 31 of holder 3 from inclined surface 32. Surface 35 in contact with surface 26 of cover 2 is formed on the upper side of inclined surface 32.
Bottom surface 31 of holder 3 has a substantially elliptical shape, and holder 3 has concavity 36 inside. Cylindrical sealing rib 37 is placed above first opening 34 of concavity 36, and sealing rib 37 is formed with cylindrical second opening 34a through which sound collected by first holes 22 passes. Second opening 34a of sealing rib 37 and first opening 34 formed on inclined surface 32 are communicated with each other.
Protrusion 38 is formed around second opening 34a of sealing rib 37. Further, annular waterproof film 4 including second hole 41 through which sound collected by first holes 22 passes is placed at the upper portion of protrusion 38. Substantially elliptical flange surface 39 larger than bottom surface 31 is formed on the upper portion of side surface 33 of holder 3.
Bottom surface 31 and side surface 33 of holder 3 are fixed to concavity 24 of cover 2. Surface 35 of holder 3 is in contact with surface 26 of cover 2, and second opening 34a of holder 3 are communicated with first holes 22 of cover 2. Further, back side 39a of surface 39 of holder 3 is in contact with surface 25 of cover 2, and is joined by, for example, laser-welding.
The diameter of second hole 41 of waterproof film 4 is substantially the same as the diameter of the circle of second opening 34a. The diameter of annular part 42 of waterproof film 4 is substantially the same as the diameter of sealing rib 37.
Other electronic components, circuits, and the like are mounted on the front surface of board 5, and microphone sensor 51 is mounted above second opening 34a. On board 5, cylindrical third hole 52 for allowing sound to pass is formed in a position where microphone sensor 51 is placed. Board 5 has a rectangular shape and is formed so as to have rounded corners.
Board 5 is placed on surface 39 of holder 3, and the center of third hole 52 of board 5 coincides with the center of second opening 34a of holder 3 and the center of second hole 41 of waterproof film 4.
As illustrated in
Forming the sound path straight as described above makes it possible to shorten the length of the path through which the sound passes as compared with a case where the sound path is stepped or curved, thereby improving the acoustic performance (frequency performance).
In addition, waterproof film 4 placed between holder 3 and board 5 prevents water and a foreign object from reaching microphone sensor 51 even if water and the foreign object reach third hole 52 of board 5; accordingly, microphone sensor 51 can be prevented from being destroyed by water and the foreign object.
Holder 3 including protrusion 38 is formed of an elastic body such as rubber or a soft material. Waterproof film 4 is formed of polytetrafluoroethylene (PTFE) or the like. When board 5 is held by holder 3, protrusion 38 is pressed and deformed by the pressure from board 5.
This reliably closes the space between holder 3 and board 5, thereby preventing water leakage and sound leakage that leads to deterioration of an acoustic characteristic. Further, even if rushing water gets into vehicular microphone 1, the waterproof film is less likely to peel off.
Note that waterproof film 4 is not necessarily formed of these materials, and other materials may be used. Alternatively, waterproof film 4 may be adhered to sealing rib 37 of holder 3 and board 5 by double-sided tape. Using sealing rib 37 as described above, however, reduces the number of manufacturing steps, and vehicular microphone 1 can be manufactured at a lower cost.
Connector 6 includes fixer 61, supporter 62, and storage 63. Fixer 61 is formed at a lower portion of connector 6, and fixes cover 2, holder 3, and board 5 with respect to connector 6. This seals between connector 6 and cover 2. Connector 6 is electrically connected to a cable that is a part of a vehicle.
Fixer 61 has elliptical bottom surface 64a, and bottom surface 64a fixes surface 25 of cover 2. In addition, fixer 61 includes side surface 65a and surface 64b perpendicular to side surface 65a inside. Side surface 65a fixes side surface 39b of holder 3 and surface 64b fixes surface 39 of holder 3.
Further, fixer 61 includes rectangular side surface 65b with rounded corners and surface 64c perpendicular to side surface 65b above side surface 65a. Side surface 65b fixes side surface 53a of board 5, and surface 64c fixes surface 53b of board 5.
As illustrated in
Storage 63 is a space provided inside connector 6 and accommodates board 5, two electrode rods 66, and the like. Electrode rods 66 penetrate two holes 54 formed on board 5, and their ends are fixed to fourth holes 31a formed on the front side of bottom surface 31 of holder 3.
Note that, in the present embodiment, one microphone sensor 51 on board 5 and one first opening 34 through which sound collected by first holes 22 passes are provided, but a plurality of microphone sensors may be provided on board 5, and only one hole serving as a sound path corresponding to all may be provided.
In addition, a plurality of microphone sensors may be provided on board 5, and a plurality of holes serving as sound paths corresponding to respective microphone sensors may be provided. Providing a plurality of sound paths improves accuracy of directivity synthesis as compared with a case where only one hole serving as a sound path is provided.
Further, in the present embodiment, vehicular microphone 1 is installed in vehicle body 7 so that the bottom surface of cover 2 formed with first holes 22 is parallel to the ground as illustrated in
To be more specific, vehicular microphone 1 may be installed in vehicle body 7 such that vehicular microphone 1 illustrated in
This allows vehicular microphone 1 to be placed on the side surface of vehicle body 7 while achieving the effects of naturally removing water and a foreign object got into the microphone and miniaturizing the microphone, which are the same effects as those of vehicular microphone I illustrated in
The disclosure of Japanese Patent Application No. 2023-028323, filed on Feb. 27, 2023, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-028323 | Feb 2023 | JP | national |
