On-vehicle sensor installation structure and acoustic sensor device

Abstract

To provide an on-vehicle sensor installation structure or the like for enabling suitable attachment to an acoustic sensor device for detecting sound and vibration.SOLUTION: An on-vehicle sensor installation structure includes an external structure part 10 and an acoustic sensor device 100. The external structure part 10 has a plate-like shape and includes a rear outer surface 11 exposed to an outside of a vehicle Ve in a posture directed to a rear side of the vehicle Ve. The acoustic sensor device 100 includes a sensor housing 30 and MEMS microphones 70. The sensor housing 30 is held with respect to a rear inner surface 12 being a rear side of the rear outer surface 11 in the external structure part 10. The MEMS microphone 70 is stored in the sensor housing 30 in a posture where an outside-vehicle sound collection surface 71 for detecting sound coming from an outside of the vehicle Ve and a vibration inside the external structure part is directed toward the external structure part 10.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The disclosure in this specification relates to an acoustic sensor device that detects sounds and vibrations coming from outside a vehicle, and an installation structure thereof. [Background technology]

[0002] Patent Document 1 discloses a vehicle upper structure in which a surrounding information detection sensor is attached to the upper part of a vehicle. In this vehicle upper structure, a portion of a roof panel covering the surrounding information detection sensor that faces a detection unit of the surrounding information detection sensor is made of a material that transmits a detection medium. Patent Document 1 gives examples of detection media used by the surrounding information detection sensor, such as radio waves, light, and ultrasonic waves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-199129 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present disclosure have come up with the idea of ​​installing an acoustic sensor device in a vehicle to detect sounds and vibrations coming from outside the vehicle. The configuration for installing such an acoustic sensor device in a vehicle is not disclosed in Patent Document 1.

[0005] The present disclosure aims to provide an in-vehicle sensor installation structure that enables suitable mounting of an acoustic sensor device that detects sound and vibration, and the acoustic sensor device. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one disclosed embodiment is an on-vehicle sensor installation structure comprising: a plate-shaped external structure (10) having a rear outer surface (11) exposed to the outside of the vehicle in a position facing the rear of the vehicle (Ve); a sensor housing (30) held against a rear inner surface (12) that is the back side of the rear outer surface in the external structure; and an acoustic sensor device (100) having a sound detection sensor unit (70, 270) contained in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure.

[0007] In this embodiment, the acoustic sensor device is attached to the external structure of the vehicle with the external sound collecting surface facing the rear of the vehicle. Therefore, the acoustic sensor device can effectively collect sounds coming from the rear of the vehicle and vibrations within the external structure. Therefore, it is possible to mount the acoustic sensor device in a manner suitable for detecting sounds and vibrations.

[0008] One disclosed embodiment is an in-vehicle sensor installation structure including: a plate-shaped external structure (10) having an upper outer surface (13) exposed to the outside of the vehicle in a position facing upward of the vehicle (Ve); a sensor housing (30) held against an upper inner surface (14) that is the back side of the upper outer surface of the external structure; and a thin-film adhesive layer (20) that holds, on the upper inner surface, an acoustic sensor device (100) having a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure.

[0009] One disclosed embodiment is an in-vehicle sensor installation structure including a plate-shaped external structure (10) having an upper outer surface (13) exposed to the outside of the vehicle in a position facing upward of the vehicle (Ve), a sensor housing (30) held against an upper inner surface (14) that is the back side of the upper outer surface of the external structure, and a retainer member (60) that holds, on the upper inner surface, an acoustic sensor device (100) having a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure.

[0010] In these embodiments, the acoustic sensor device is attached to the external structure by holding the attachment surface of the sensor housing on the upper inner side surface by a thin-film adhesive layer or a retainer member. Therefore, the acoustic sensor device can be easily and reliably attached to external structures of various configurations. Therefore, it is possible to attach the acoustic sensor device in a manner suitable for detecting sound and vibration.

[0011] One disclosed embodiment is an acoustic sensor device that is held on a plate-shaped external structure (10) of a vehicle, and includes a sound detection sensor unit (70, 270) having a sound collection surface (71) that detects sound and vibrations within the external structure, and a sensor housing (30) that is held against an inner surface (12, 14) of the external structure by an adhesive layer (20) and that houses the sound detection sensor unit with the sound collection surface aligned along the inner surface.

[0012] In this embodiment, since the sensor housing has an attachment surface, the acoustic sensor device can be held over a wide area on the inner surface of the external structure by using double-sided tape, adhesive, or the like. As a result, the acoustic sensor device can be easily and reliably attached to external structures of various configurations. Therefore, an appropriate attachment for the acoustic sensor device that detects sound and vibration is possible.

[0013] In addition, the reference numbers in parentheses in the above and claims merely show an example of the correspondence with the specific configurations in the embodiments described below, and do not limit the technical scope in any way. In addition, claims that are not explicitly stated in the claims can be combined together as long as there is no particular problem with the combination. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram for explaining locations to which the vehicle-mounted sensor installation structure of the present disclosure can be applied. [Diagram 2] FIG. 1 is a diagram showing a basic configuration of an acoustic sensor device using a MEMS microphone. [Diagram 3] 1A to 1C are diagrams illustrating an assembly process of the acoustic sensor device. [Figure 4] 1 is a diagram illustrating a configuration of an acoustic sensor device according to a first embodiment. [Diagram 5] FIG. 2 is a plan view of a sensor housing that houses two MEMS microphones. [Figure 6] FIG. 2 is a bottom view of a sensor housing that houses two MEMS microphones. [Figure 7] FIG. 2 is a diagram showing the electrical configuration of an acoustic sensor device including two MEMS microphones and an ECU. [Figure 8] FIG. 1 is a diagram showing a basic configuration of an acoustic sensor device using a piezoelectric sensor. [Figure 9] 3A and 3B are diagrams for explaining a detailed configuration of a piezoelectric sensor. [Figure 10] 1A to 1C are diagrams illustrating an assembly process of the acoustic sensor device. [Figure 11] FIG. 11 is a diagram illustrating a configuration of an acoustic sensor device according to a second embodiment. [Figure 12] FIG. 2 is a bottom view of a sensor housing that houses four piezoelectric sensors. [Figure 13] FIG. 2 is a diagram showing the electrical configuration of an acoustic sensor device including four piezoelectric sensors and an ECU. [Figure 14] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a third embodiment. [Figure 15]FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a modified example of the third embodiment. [Figure 16] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a fourth embodiment. [Figure 17] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a fifth embodiment. [Figure 18] 13A to 13C are diagrams illustrating a mounting process of the acoustic sensor device of the sixth embodiment. [Figure 19] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a sixth embodiment. [Figure 20] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a modified example of the sixth embodiment. [Figure 21] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a seventh embodiment. [Figure 22] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to an eighth embodiment. [Diagram 23] 13A and 13B are diagrams illustrating an in-vehicle sensor installation structure according to a ninth embodiment. [Figure 24] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a tenth embodiment. [Diagram 25] FIG. 13 is a diagram illustrating a configuration of an acoustic sensor device according to a modified example of the tenth embodiment. [Figure 26] FIG. 23 is a diagram showing an in-vehicle sensor installation structure according to an eleventh embodiment. [Figure 27] 27 is a cross-sectional view taken along line XXVII-XXVII in FIG. 26. [Figure 28] 1A and 1B are diagrams illustrating an in-vehicle sensor installation structure and an acoustic sensor device according to a first modified example. [Figure 29] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a second modified example. FIG. [Diagram 30] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a third modified example. FIG. [Diagram 31] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a fourth modified example. FIG. [Diagram 32] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a fifth modified example. FIG. [Diagram 33] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a sixth modified example. FIG. [Diagram 34] FIG. 23 is a diagram showing a piezoelectric sensor of an acoustic sensor device according to a seventh modified example. [Diagram 35] FIG. 23 is a diagram showing a piezoelectric sensor of an acoustic sensor device according to Modification 8. [Diagram 36] FIG. 13 is a diagram showing a piezoelectric sensor of an acoustic sensor device according to a ninth modified example. [Figure 37] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a tenth modification. FIG. [Figure 38] 13 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to an eleventh modified example. FIG. [Figure 39] 15 is a diagram showing an in-vehicle sensor installation structure and an acoustic sensor device according to a twelfth modified example. FIG. [Diagram 40] FIG. 23 is a diagram showing the arrangement of an acoustic sensor device in a vehicle-mounted sensor installation structure according to a thirteenth modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a number of embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated descriptions may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0016] [Installation location of acoustic sensor device] The vehicle-mounted sensor installation structure according to the present disclosure can be applied to various locations in the vehicle Ve shown in Figures 1 and 2. The vehicle-mounted sensor installation structure can be provided on any of the front, side, rear, and top surfaces of the vehicle. This allows the acoustic sensor device 100 to be installed inside various locations exposed to the outside of the vehicle Ve.

[0017] In the vehicle Ve, the external structure 10 has a shape that combines smooth curved surfaces and flat surfaces to improve the design and aerodynamic characteristics. In addition, most of the external structure 10 is thin and plate-like to reduce weight. This plate-like part vibrates when it receives sound from the outside. In addition, vibrations transmitted from the road surface and vibrations generated when the vehicle collides are transmitted inside the external structure 10, causing the plate-like part to vibrate. The acoustic sensor device 100 measures this vibration and the sound re-emitted by the vibration, thereby indirectly detecting sound arriving from the outside and vehicle vibration.

[0018] The acoustic sensor device 100 is held by a plate-shaped external structure 10 of the vehicle Ve. The external structure 10 on the front side of the vehicle includes, for example, a front emblem Pf1, headlamps Pf2, front fog lamps Pf3, bumper corners Pf4, bumper sides Pf5, a front camera Pf6, a windshield Pf7, and a millimeter wave radar. The acoustic sensor device 100 installed on the external structure 10 on the front side of the vehicle is oriented so that the outside sound collecting surface 71 faces the front Ze of the vehicle Ve, and detects sounds coming from outside the vehicle Ve mainly from the front Ze.

[0019] The external structure 10 on the vehicle side is, for example, a side mirror Ps1, a side mirror cover Ps2, a door Ps3, each pillar (such as the B pillar Ps4), a side fender Ps5, a fender camera, a fender rider, a side step, and a tire house. The acoustic sensor device 100 installed on the side mirror Ps1 is oriented so that the external sound collecting surface 71 faces the rear Go of the vehicle Ve, and detects sounds coming from the rear Go outside the vehicle Ve. The acoustic sensor device 100 installed on the side mirror cover Ps2 is oriented so that the external sound collecting surface 71 faces the front Ze of the vehicle Ve, and detects sounds coming from the front Ze outside the vehicle Ve. The acoustic sensor device 100 installed on the external structure 10 on the other vehicle side is oriented so that the external sound collecting surface 71 faces the right Mi or left Hi of the vehicle Ve, and detects sounds coming mainly from the sides outside the vehicle Ve.

[0020] The external structure 10 on the rear of the vehicle is, for example, a backup camera Pb1, a rear sight window Pb2, the rear surface of a back door or hatch, a reflector Pb3, a tail lamp module Pb4, an edge of the rear glass Pb5, an ADAS rear camera module, etc. A rear bumper, a rear emblem, etc. may also be used as the external structure 10 on the rear of the vehicle. The acoustic sensor device 100 installed on the external structure 10 on the rear of the vehicle is oriented so that the outside sound collecting surface 71 faces the rear Go of the vehicle Ve, and detects sounds coming mainly from the rear Go outside the vehicle Ve.

[0021] The external structure 10 on the upper surface of the vehicle is, for example, the four corners Pt1 or the center Pt2 of a roof panel (ceiling), the upper surface Pt3 of the trunk lid, a sunroof, a roof rail, a rear spoiler, a roof end spoiler, etc. A housing for an ADAS sensor (camera, lidar, etc.) module mounted on the roof panel may be the external structure 10 on the upper surface of the vehicle. The acoustic sensor device 100 installed on the external structure 10 on the upper surface of the vehicle is oriented so that the outside sound collecting surface 71 faces upward Ue of the vehicle Ve, and detects sounds coming from all four sides (front, back, left and right) of the vehicle Ve.

[0022] Here, the front-rear direction and the left-right direction in this disclosure are defined based on the vehicle Ve stationary on a horizontal plane. Specifically, the front-rear direction (forward Ze and backward Go) is defined along the longitudinal direction (direction of travel) of the vehicle Ve. The left-right direction (right Mi and left Hi) is defined along the width direction of the vehicle Ve. Furthermore, the up-down direction (upward Ue) is defined along the vertical direction of the horizontal plane that defines the front-rear direction and the left-right direction. For the sake of simplicity, the following description may omit the symbols indicating each direction as appropriate.

[0023] First embodiment The in-vehicle sensor installation structure according to the first embodiment of the present disclosure is applied to an external structure 10 on the rear surface of a vehicle. As shown in Fig. 2, the in-vehicle sensor installation structure is composed of the external structure 10, an adhesive layer 20, an acoustic sensor device 100, and the like.

[0024] The external structure 10 has a rear outer surface 11 exposed to the outside of the vehicle Ve in a position facing the rear Go of the vehicle Ve. The external structure 10 is, for example, the above-mentioned rear sight glass Pb2 (see FIG. 1 ) and is formed of plate-like glass. The external structure 10 may be flat or slightly curved. In the external structure 10, the back side of the rear outer surface 11 is a smooth rear inner surface 12 to which the adhesive layer 20 is attached. In a form in which the acoustic sensor device 100 is attached to the rear sight glass Pb2 or the edge Pb5 of the rear glass, the rear inner surface 12 is defined as an area in which a light-shielding black ceramic layer is formed.

[0025] The adhesive layer 20 is formed of a double-sided tape or an adhesive. The adhesive layer 20 holds the attachment surface 31 of the acoustic sensor device 100 against the rear inner surface 12 by bonding each surface to the rear inner surface 12 and the acoustic sensor device 100. The adhesive layer 20 is formed in a thin film that is thinner than the external structure 10, and transmits the sound that reaches the external structure 10 toward the acoustic sensor device 100. In a form in which a double-sided tape is used as the adhesive layer 20, one adhesive surface of the adhesive layer 20 is first attached to the attachment surface 31 of the acoustic sensor device 100. Then, the other adhesive surface of the adhesive layer 20 is attached to the rear inner surface 12. Through these steps, the acoustic sensor device 100 is fixed to the external structure 10.

[0026] [Basic configuration of acoustic sensor device] 2 and 3, the acoustic sensor device 100 includes a sensor housing 30, a MEMS microphone 70, and a circuit board 80. The sensor housing 30 houses the MEMS microphone 70 and the circuit board 80. The sensor housing 30 is provided with an attachment surface 31, a sealed space 34, an interior space 36, and a connector section 38.

[0027] The attachment surface 31 is a flat mounting surface provided on the sensor housing 30. The attachment surface 31 is attached to the rear inner surface 12 of the external structure 10 via the adhesive layer 20. In this way, the sensor housing 30 is held against the rear inner surface 12.

[0028] The sealed space 34 and the interior space 36 are storage spaces partitioned inside the sensor housing 30. The storage space of the sensor housing 30 is partitioned into the sealed space 34 and the interior space 36 by the circuit board 80. The sealed space 34 is formed on the attachment surface 31 side of the circuit board 80 (hereinafter, the exterior side SG). The interior space 36 is formed on the opposite side of the sealed space 34 across the circuit board 80 (hereinafter, the interior side SN).

[0029] The sealed space 34 is defined between the attachment surface 31 and the vehicle exterior sound collection surface 71 (described later) of the MEMS microphone 70. The sealed space 34 is a hollow space filled with air or an inert gas. The attachment surface 31 side of the sealed space 34 is made large in area within a range of dimensions smaller than half the wavelength of the highest frequency sound among the measurement targets, so that the sound re-radiated by the vibration of the external structure 10 can be collected with good sensitivity. In addition, the height of the sealed space 34, that is, the distance from the inner bottom wall surface 42 (described later) to the front surface of the circuit board 80, is made shorter than the wavelength of the highest frequency sound among the measurement targets. As a result, the sealed space 34 functions as a sound collection space that collects sound.

[0030] The sound-insulating filler 37 is accommodated in the interior space 36. The sound-insulating filler 37 is accommodated in the sensor housing 30 behind the circuit board 80, and is disposed on the opposite side of the sealed space 34 with the circuit board 80 in between (see FIG. 3). The sound-insulating filler 37 fills almost the entire interior space 36, and forms a sound-insulating structure for the interior SN of the circuit board 80. That is, the sound-insulating filler 37 exerts a sound-absorbing effect and a sound-insulating effect on the sound that arrives at the sensor housing 30 from the interior SN. In addition, the sound-insulating filler 37 suppresses the vibration of the MEMS microphone 70 and the circuit board 80. Furthermore, the sound-insulating filler 37 prevents the intrusion of air containing water vapor into the interior space 36, and suppresses the occurrence of condensation caused by temperature changes between day and night.

[0031] The sound-insulating filler 37 is formed of a soft elastic material such as urethane or silicone, or a porous soft elastic material such as sponge. Sound-absorbing materials such as nonwoven fabric or cotton may also be used as the sound-insulating filler 37. The sound-insulating filler 37 may be formed in advance and placed in the interior space 36, or may be formed by hardening urethane, silicone, or a foam thereof that has been filled (encapsulated) in the interior space 36. When a hardening type filler such as urethane or silicone is filled in the interior space 36, the circuit board 80 functions as a seal to prevent the sound-insulating filler 37 and its additives from entering the sealed space 34 before hardening.

[0032] The connector portion 38 is provided in a cylindrical shape on the side surface of the sensor housing 30. A plug portion of a wire harness is inserted into the connector portion 38. By connecting the plug portion to the connector portion 38, a detection signal from the MEMS microphone 70 can be output to an external configuration (such as an ECU 90 described below) through the wire harness.

[0033] The sensor housing 30 is composed of a housing body 40, a rear cover 50, etc. The sensor housing 30 has a flat rectangular prism or cylindrical shape as a whole. The housing body 40 and the rear cover 50 are mainly formed of a resin material. The housing body 40 has a mounting bottom wall 41 and a peripheral wall 44.

[0034] The mounting bottom wall 41 is the bottom wall of the sensor housing 30 that forms the attachment surface 31. On the opposite side of the mounting bottom wall 41 to the attachment surface 31, an inner bottom wall surface 42 that faces the sealed space 34 is formed. The inner bottom wall surface 42 has a porous structure made up of a large number (plurality) of recesses 43 (see also FIG. 6 ). The recesses 43 are arranged at intervals from each other on the inner bottom wall surface 42. The recesses 43 partially reduce the wall thickness of the mounting bottom wall 41. This structure makes it possible to improve the sound transmittance while suppressing a decrease in the strength of the mounting bottom wall 41.

[0035] The peripheral wall 44 stands from the periphery of the mounting bottom wall 41 toward the vehicle interior side SN. The peripheral wall 44 surrounds the entire periphery of the MEMS microphone 70 and the circuit board 80. The wall thickness of the peripheral wall 44 is sufficiently thicker than the wall thicknesses of the external structure 10 and the mounting bottom wall 41. With this configuration, the peripheral wall 44 prevents sound (vibration) from entering from the side. The connector portion 38 is provided on one outer wall surface of the peripheral wall 44. The peripheral wall 44 has an upper peripheral wall portion 44a that defines the sealed space 34 and a lower peripheral wall portion 44b that defines the vehicle interior side space 36. A step portion 44c facing the vehicle interior side SN is formed in an annular shape between the upper peripheral wall portion 44a and the lower peripheral wall portion 44b (see also FIG. 6).

[0036] The rear cover 50 has a rectangular plate shape as a whole. The rear cover 50, together with the housing body 40, forms the sealed space 34 and the vehicle interior space 36 as a sealed, liquid-tight storage space. The thickness of the rear cover 50 and the sound-insulating filler 37 is made thicker than the wall thickness of the mounting bottom wall 41. As a result, the sound absorption coefficient of the rear sound-absorbing structure formed by the rear cover 50 and the sound-insulating filler 37 is greater than the sound absorption coefficient of the external structure part 10 and the mounting bottom wall 41. The rear cover 50 is fixed to the top surface of the peripheral wall 44 by the adhesive part 55 while crushing the sound-insulating filler 37 between the rear surface of the circuit board 80 (see FIG. 3). The adhesive part 55 is formed by, for example, an adhesive material. The rear cover 50 may be joined to the housing body 40 by welding. The acoustic sensor device 100 attached to the external structure 10 can have directionality toward the rear outer surface 11 by blocking sounds coming from the sides with the peripheral wall 44, and from the rear with the rear cover 50 and sound-proof filler 37. Also, if the sound-proof filler 37 alone can provide sufficient sound insulation and is sufficiently airtight, the rear cover 50 is not necessary.

[0037] The MEMS (Micro Electro Mechanical Systems) microphone 70 is a microphone element that converts sound (air vibration) into an electric signal. The MEMS microphone 70 functions as a condenser microphone that outputs a change in capacitance caused by a thin diaphragm vibrating due to sound pressure as an electric signal (hereinafter, detection signal). The MEMS microphone 70 is mounted on the back surface of the circuit board 80. The MEMS microphone 70 has a diaphragm disposed in an internal space, and introduces sound from a sound hole provided on a sound collection surface (hereinafter, vehicle exterior sound collection surface 71). The vehicle exterior sound collection surface 71 is housed in the sensor housing 30 in a position facing the external structure 10. As a result, the MEMS microphone 70 effectively detects sound that arrives at the external structure 10 from the outside of the vehicle Ve and is transmitted to the sealed space 34. Note that an electret condenser microphone or the like can be adopted as the sound detection sensor unit instead of the MEMS microphone 70.

[0038] The circuit board 80 is a glass epoxy board or the like, and has a rectangular plate shape as a whole. The circuit board 80 is accommodated in the sensor housing 30 in a posture along the mounting bottom wall 41, and is fixed to the step portion 44c of the peripheral wall 44 via a board fixing material 88 (see FIG. 3). The board fixing material 88 is formed in a thin film shape using a rubber packing, double-sided tape, adhesive material, or the like. The circuit board 80 divides the sealed space 34 and the vehicle interior space 36 in cooperation with the sensor housing 30. Furthermore, the circuit board 80 divides the sealed space 34 by making the board fixing material 88 function as a seal. For convenience, of both sides of the circuit board 80, one side facing the sealed space 34 is designated as the front side, and the opposite side is designated as the back side.

[0039] The MEMS microphone 70 is mounted on the back surface of the circuit board 80. A sound hole 81 is formed in a portion of the circuit board 80 between the vehicle exterior sound collecting surface 71 and the sealed space 34. The sound hole 81 is a through-hole that penetrates the circuit board 80 in the plate thickness direction. The sound hole 81 enables air vibrations in the sealed space 34 to be transmitted to the vehicle exterior sound collecting surface 71.

[0040] The circuit board 80 is provided with an amplifier circuit section 85 and a communication interface 86 (see FIG. 7). The amplifier circuit section 85 is electrically connected to the MEMS microphone 70, and amplifies the detection signal output from the MEMS microphone 70. The communication interface 86 outputs the detection signal amplified by the amplifier circuit section 85.

[0041] When the circuit board 80 is accommodated in the sensor housing 30, it is electrically connected to a plurality of connector insert pins 83. The connector insert pins 83 are formed of a metal material. An intermediate portion of the connector insert pins 83 is embedded in the peripheral wall 44 of the housing main body 40. One end of the connector insert pins 83 is exposed inside the connector portion 38. The connector insert pins 83 transmit detection signals and the like output from the communication interface 86 to wiring in the plug portion connected to the connector portion 38.

[0042] [Acoustic Sensor Device of First Embodiment] The acoustic sensor device 100 of the first embodiment shown in Figs. 4 to 6 is configured by combining a plurality (two) of the acoustic sensor devices 100 having the basic configuration shown in Fig. 2. The acoustic sensor device 100 houses two circuit boards 80 on which the MEMS microphones 70 are mounted. That is, the acoustic sensor device 100 has two MEMS microphones 70. By attaching the acoustic sensor device 100 to the rear inner surface 12, the two MEMS microphones 70 are arranged side by side in the horizontal direction of the vehicle Ve with the vehicle exterior sound collecting surface 71 facing the rear Go of the vehicle Ve. In the first embodiment, the MEMS microphones 70 are arranged side by side along the left-right direction of the vehicle Ve, with a distance of, for example, about several centimeters (for example, 5 cm). The two circuit boards 80 are electrically connected by a board connection line 84. The detection signals of the two MEMS microphones 70 are both output from a connector insert pin 83 exposed to the connector portion 38.

[0043] The attachment surface 31 formed on the sensor housing 30 has a rectangular shape with the longitudinal direction extending in the left-right direction (see FIG. 5). The inside of the sensor housing 30 is partitioned into two mutually independent sealed spaces 34 and two vehicle interior spaces 36 connected to each other by a space connection part 47. The sound-insulating filler 37 housed in the vehicle interior space 36 may be formed as a single unit, or may be divided into two.

[0044] The sensor housing 30 is provided with a shielding wall 45 and a shielding groove 46. The shielding wall 45 stands from the mounting bottom wall 41 toward the vehicle interior side SN, and divides the two sealed spaces 34. The shielding wall 45 extends along the short side direction of the sensor housing 30 so as to separate the two MEMS microphones 70 and the sealed spaces 34. The shielding wall 45 suppresses the transmission of sound (vibration) from one of the two sealed spaces 34 to the other. The shielding groove 46 is recessed from the top surface of the shielding wall 45 toward the vehicle exterior side SG. The shielding groove 46 forms a sound insulation space 46a in the shielding wall 45 that is hollow or filled with a sound insulation filler and separates the two MEMS microphones 70 and the sealed spaces 34. The formation of the sound insulation space 46a in the shielding wall 45 further suppresses the transmission of sound from one of the two sealed spaces 34 to the other. The sound-insulating filler used here is also silicone, urethane, or a foam of either of these. By connecting the interior space 36 and the shielding groove 46, it is possible to fill both the interior space 36 and the shielding groove 46 with sound-insulating filler in one filling operation. If the shielding wall 45 provides sufficient sound insulation, the shielding groove 46 may not be necessary.

[0045] [Electrical configuration of the acoustic sensor device] Next, the electrical configuration of the acoustic sensor device 100 and the ECU 90 will be described in detail with reference to FIG.

[0046] Each circuit board 80 of the acoustic sensor device 100 is provided with the above-mentioned amplifier circuit unit 85 and communication interface 86. One amplifier circuit unit 85 and one communication interface 86 are provided for each MEMS microphone 70. Each communication interface 86 outputs a detection signal of each MEMS microphone 70 to the ECU 90 individually.

[0047] The ECU 90 is a computing device mounted on the vehicle Ve. The ECU 90 is electrically connected to the acoustic sensor device 100 via a wire harness or the like, and functions as a signal processing device that processes a detection signal output by the acoustic sensor device 100. The ECU 90 has a signal receiving unit 91 and a signal processing unit 93.

[0048] The signal receiving units 91 are provided in the ECU 90 in a number corresponding to the number of MEMS microphones 70, in other words, the number of channels of detection signals input to the ECU 90. In a configuration in which two detection signals are input to the ECU 90, at least two signal receiving units 91 are provided in the ECU 90. Detection signals (see signals 1 and 2 in FIG. 7) output from the multiple MEMS microphones 70 are input to each signal receiving unit 91. The signal receiving unit 91 includes an FFT (Fast Fourier Transform) function, and provides a signal obtained by Fourier transforming the detection signal to the signal processing unit 93.

[0049] The signal processing unit 93 performs signal processing based on the signal differences between the multiple detection signals. The signal processing unit 93 calculates differences in physical quantities between the provided detection signals, such as a phase difference, a time difference, a sound pressure difference, and an amplitude product. The ECU 90 uses the calculated differences in physical quantities to calculate information related to the relative positions of the sound sources detected by each MEMS microphone 70, such as the direction of arrival of the sound and vibration. As an example, the signal receiving unit 91 estimates the direction of an emergency vehicle (such as an ambulance) approaching the vehicle Ve from the sound of the siren of the emergency vehicle.

[0050] [Summary of the first embodiment] In the first embodiment described above, the acoustic sensor device 100 is attached to the external structure 10 of the vehicle Ve with the vehicle exterior sound collecting surface 71 facing the rear of the vehicle Ve. Therefore, the acoustic sensor device 100 can effectively collect sounds coming from the rear of the vehicle Ve. Therefore, the acoustic sensor device 100 can be attached in a manner suitable for detecting sounds and vibrations.

[0051] More specifically, the acoustic sensor device 100 is attached to the rear inner surface 12 of the external structure 10 facing the rear Go of the vehicle Ve. With such an in-vehicle sensor installation structure, the sensor is less likely to be exposed to rain while driving, reducing rain noise. Therefore, surrounding sounds and vibrations can be effectively detected even during rainfall. Furthermore, emergency vehicles approaching from the rear Go of the vehicle Ve can be detected with high sensitivity.

[0052] In addition, the acoustic sensor device 100 is not exposed to the outside of the vehicle Ve. As a result, the design of the vehicle Ve is less likely to be impaired. Also, improved waterproofing and prevention of damage caused by chipping due to flying stones and the like are achieved. Furthermore, wind noise is less likely to occur near the acoustic sensor device 100. In addition, clogging of holes due to wax and water ingress due to high-pressure car washing are also prevented.

[0053] Moreover, the MEMS microphone 70 is housed in and protected by the sensor housing 30. With this configuration, the peripheral wall 44 of the sensor housing 30 blocks input of vibrations from other than the rear Go. As a result, the acoustic sensor device 100 can more effectively collect sounds arriving from the rear Go.

[0054] Furthermore, by being protected by the sensor housing 30, damage to the MEMS microphone 70 during transportation and storage can be prevented. Also, waterproofness and dustproofness can be improved, and condensation can be suppressed. In addition, if a characteristic inspection and a sealing inspection are performed before shipping at a sensor assembly factory where the acoustic sensor device 100 is assembled, it is difficult for moisture, foreign matter, and chemicals to enter the sealed sensor housing 30. Furthermore, by sealing an inert gas such as nitrogen in the sealed space 34, deterioration and characteristic fluctuation of the MEMS microphone due to moisture and oxygen in the air can be suppressed. Also, moisture and oxygen contained in the air may be removed by putting a moisture absorbent or an oxygen scavenger in the sealed space 34.

[0055] Additionally, in the first embodiment, the sensor housing 30 is provided with a flat attachment surface 31. The attachment surface 31 is held on the rear inner surface 12 by a thin-film adhesive layer 20. In this manner, with an in-vehicle sensor installation structure using the adhesive layer 20 such as double-sided tape or adhesive, processing of the external structure 10 is not required. That is, the acoustic sensor device 100 can be easily attached, and it is not necessary to provide the external structure 10 with a complicated structure such as a screw hole and a locking claw. Furthermore, the acoustic sensor device 100 can be attached anywhere on the external structure 10 that faces the outside air. Furthermore, repair (replacement) of the acoustic sensor device 100 in the market is also easy.

[0056] In the first embodiment, the external structure 10 is made of glass. It is difficult to provide screw holes and locking claws for mounting on the external structure 10 made of glass. Therefore, the vehicle-mounted sensor installation structure in which the acoustic sensor device 100 is attached by the adhesive layer 20 is particularly effective when the external structure 10 is made of glass. In addition, glass has a lower density and is thinner than iron, so it is easy for sound to pass through. Therefore, according to the vehicle-mounted sensor installation structure in which the acoustic sensor device 100 is attached to the glass, it is possible to detect sounds outside the vehicle Ve with high sensitivity. In addition, the rear glass is relatively far from the audio speaker. Therefore, by making the rear view window Pb2 the external structure 10, the acoustic sensor device 100 is less susceptible to audio noise.

[0057] Furthermore, in the first embodiment, the acoustic sensor device 100 has a plurality of MEMS microphones 70. By having a plurality of MEMS microphones 70 in this way, it becomes easy to ensure the area of ​​the attachment surface 31 of the sensor housing 30. As a result, even in an installation structure using the adhesive layer 20, it becomes possible to reliably fix the acoustic sensor device 100 to the external structure 10.

[0058] Additionally, in the first embodiment, the multiple (two) MEMS microphones 70 are arranged along the horizontal direction of the vehicle Ve. Then, the detection signals output from the MEMS microphones 70 are input to the ECU 90. The ECU 90 performs signal processing based on the signal difference between the multiple detection signals. This signal processing makes it possible to estimate the direction of a sound source approaching the vehicle Ve.

[0059] In the first embodiment, the sensor housing 30 is provided with a shielding wall 45 that separates the multiple MEMS microphones 70. Therefore, the MEMS microphones 70 are located in spaces independent of each other. In other words, sounds (vibrations) are less likely to mix inside the sensor housing 30, and the MEMS microphones 70 can be acoustically separated. As a result, it becomes possible to reliably detect the phase difference of sounds using the multiple MEMS microphones 70.

[0060] Furthermore, in the first embodiment, the hollow sound insulating spaces 46a that separate the multiple MEMS microphones 70 are provided in the shielding wall 45. The configuration in which the hollow sound insulating spaces 46a are provided in the shielding wall 45 can more reliably acoustically separate the MEMS microphones 70. As a result, detection of the phase difference of sounds using the multiple MEMS microphones 70 can also be more reliably performed.

[0061] Additionally, in the first embodiment, since the sensor housing 30 is provided with a flat attachment surface 31, the acoustic sensor device 100 can be held over a wide area on the rear outer surface 11 of the external structure 10 by using double-sided tape, adhesive, or the like. As described above, the acoustic sensor device 100 can be easily and reliably attached to external structures 10 of various configurations. Therefore, suitable attachment of the acoustic sensor device 100 for detecting sound and vibration is possible.

[0062] In the sensor housing 30 of the first embodiment, a hollow sealed space 34 is defined between the attachment surface 31 and the vehicle exterior sound collecting surface 71. By providing such a sealed space 34 and vibrating the air in the sealed space 34, the MEMS microphone 70 can effectively detect the sound (vibration) that arrives at the external structure 10 and is transmitted to the sensor housing 30.

[0063] Additionally, in the first embodiment, the plate-shaped circuit board 80 housed in the sensor housing 30 cooperates with the sensor housing 30 to define the sealed space 34. That is, the vehicle interior side SN of the sealed space 34 is sealed by the circuit board 80. With this configuration, it is possible to easily assemble the acoustic sensor device 100 without complicating the configuration of the sensor housing 30, and to define the sealed space 34 inside the sensor housing 30.

[0064] In the first embodiment, the MEMS microphone 70 is mounted on one of both sides of the circuit board 80, namely, on the rear side opposite the front side facing the sealed space 34. A sound hole 81 penetrating the circuit board 80 in the thickness direction is formed in a portion of the circuit board 80 between the exterior sound collecting surface 71 and the sealed space 34. In this configuration, vibrations in the sealed space 34 can be transmitted to the exterior sound collecting surface 71 through the sound hole 81. Therefore, even if the MEMS microphone 70 is mounted on the rear side of the circuit board 80, it can reliably detect sounds arriving at the external structure 10.

[0065] Furthermore, in the first embodiment, a sound-insulating filler 37 is disposed on the opposite side of the sealed space 34 with the circuit board 80 in between. The sound-insulating filler 37 is accommodated in the interior space 36 of the sensor housing 30, thereby blocking sound that enters the sensor housing 30 from the rear cover 50 side, making it difficult for the sound to be transmitted to the MEMS microphone 70. Due to the sound-insulating effect of the sound-insulating filler 37, the MEMS microphone 70 can more reliably detect sound from the outside of the vehicle Ve.

[0066] Additionally, in the first embodiment, a recess 43 is formed in the mounting bottom wall 41 of the sensor housing 30. The recess 43 faces the sealed space 34 and reduces the wall thickness of the mounting bottom wall 41. Due to the reduction in wall thickness caused by the recess 43, sound arriving at the external structure 10 is more likely to be transmitted to the sealed space 34. As a result, the MEMS microphone 70 can effectively detect sound from the outside of the vehicle Ve. Furthermore, the strength of the mounting bottom wall 41 can be ensured in the portion where the recess 43 is not formed. Furthermore, since the recess 43 has a non-penetrating structure, the sealability of the sensor housing 30 can be ensured.

[0067] In addition, in the first embodiment, an amplifier circuit unit 85, a communication interface 86, and the like are formed on the circuit board 80. In this manner, by processing the detection signal inside the acoustic sensor device 100, it is possible to improve noise resistance and improve the S / N ratio.

[0068] Furthermore, in the first embodiment, the peripheral wall 44 is formed to be thicker than the mounting bottom wall 41 and the rear cover 50. Therefore, the peripheral wall 44 can effectively block sound and vibration coming from the side of the sensor housing 30 along the external structure 10.

[0069] Additionally, in the first embodiment, the multiple vehicle interior spaces 36 are connected to one another via the spatial connection parts 47. Therefore, it becomes possible to electrically connect the multiple circuit boards 80 via the board connection lines 84 that pass through the spatial connection parts 47.

[0070] In the first embodiment, the rear inner surface 12 corresponds to the "inner surface", the sealed space 34 corresponds to the "hollow sound collection space", the sound insulating filler 37 corresponds to the "rear sound insulating material", the mounting bottom wall 41 corresponds to the "mounting wall", and the recess 43 corresponds to the "hole". In addition, the MEMS microphone 70 corresponds to the "sound detection sensor part", the outside sound collection surface 71 corresponds to the "sound collection surface", the sound hole 81 corresponds to the "through hole", and the ECU 90 corresponds to the "signal processing device".

[0071] Second Embodiment The vehicle-mounted sensor installation structure according to the second embodiment of the present disclosure is applied to an external structure 10 on the top surface of a vehicle. The external structure 10 has an upper outer surface 13 exposed to the outside of the vehicle Ve in a position facing the upward Ue of the vehicle Ve. The external structure 10 is, for example, the above-mentioned roof panel, and is formed from a plate-like metal material (iron, aluminum, etc.). The vehicle-mounted sensor installation structure according to the second embodiment is applicable to all external surface parts facing the upward Ue of the vehicle Ve.

[0072] In the external structure 10, the back side of the upper outer surface 13 is a smooth upper inner surface 14 to which the adhesive layer 20 is attached. The attachment surface 31 of the acoustic sensor device 100 is held against the upper inner surface 14 by the adhesive layer 20, and the acoustic sensor device 100 is fixed to the external structure 10.

[0073] [Basic configuration of acoustic sensor device] 8 to 10, the acoustic sensor device 100 of the second embodiment includes a piezoelectric sensor 270 as a sound detection sensor unit instead of the MEMS microphone 70 (see FIG. 2). The piezoelectric sensor 270 forms an outside-vehicle sound collecting surface 71, similar to the MEMS microphone 70, and converts sound into an electric signal. The piezoelectric sensor 270 is composed of a piezoelectric element 270a, a metal plate 275, and the like.

[0074] The piezoelectric element 270a is formed in a thin plate shape. A negative electrode 271n is formed on one surface (front surface) of the piezoelectric element 270a. A positive electrode 271p is formed on the other surface (rear surface) of the piezoelectric element 270a. A positive electrode wire 272p is connected to the positive electrode 271p by solder 273 (see FIG. 9). The piezoelectric element 270a generates a voltage between the negative electrode 271n and the positive electrode 271p according to the input stress.

[0075] The metal plate 275 is formed in a thin plate shape with an area larger than that of the piezoelectric element 270a. The metal plate 275 is joined to the surface of the piezoelectric element 270a on the negative electrode 271n side. A negative electrode wire 272n is connected to the metal plate 275 by solder 273 (see FIG. 9). The metal plate 275 is electrically connected to the GND potential of the circuit board 80 via the negative electrode wire 272n. The metal plate 275 vibrates together with the piezoelectric element 270a due to sound transmitted to the sensor housing 30. The front surface of the metal plate 275, which is opposite to the piezoelectric element 270a, becomes the vehicle exterior sound collecting surface 71 of the piezoelectric sensor 270.

[0076] The piezoelectric sensor 270 is accommodated in the sealed space 34. The piezoelectric sensor 270 is held against the mounting bottom wall 41 of the sensor housing 30 forming the attachment surface 31 by attaching the front surface of the metal plate 275 to the inner bottom wall surface 42 by a piezoelectric adhesive layer 276 (see FIG. 10). The piezoelectric adhesive layer 276 is formed by double-sided tape, adhesive material, or the like. The negative electrode wire 272n and the positive electrode wire 272p of the piezoelectric sensor 270 are connected to one end of each of a pair of middle insert pins 87 by soldering, welding, crimping, or the like. The middle insert pin 87 is formed by a metal material. The middle insert pin 87 is partially embedded in the housing body 40.

[0077] A vibration-damping filler 35 is disposed in the vehicle interior side SN of the piezoelectric sensor 270. The vibration-damping filler 35 is formed of urethane, silicone, sponge, or the like, similar to the sound-insulating filler 37. The vibration-damping filler 35 is disposed in the sealed space 34, thereby exerting functions such as preventing unnecessary air expansion and contraction, suppressing the occurrence of unnecessary resonance, and cutting high frequencies. In other words, the vibration-damping filler 35 attenuates the sound and vibration that have entered the sensor housing 30 from the vehicle interior side SN, and prevents unnecessary vibration and resonance from being observed.

[0078] The circuit board 80 is held on the step portion 44c via the board fixing material 88 while crushing the vibration-damping filler 35 between the piezoelectric sensor 270 and the circuit board 80 (see FIG. 10). When the circuit board 80 is accommodated in the sensor housing 30, it is electrically connected to the intermediate insert pins 87 and the connector insert pins 83. The intermediate insert pins 87 and the connector insert pins 83 are electrically connected to the circuit board 80 by soldering, welding, or the like. The piezoelectric sensor 270 is electrically connected to the amplifier circuit section 85 (see FIG. 13) on the circuit board 80 via the intermediate insert pins 87. Furthermore, a detection signal of the piezoelectric sensor 270 can be output to the outside from a plug section connected to the connector section 38.

[0079] A sound-insulating filler 37 is disposed on the vehicle interior side SN of the circuit board 80. The sound-insulating filler 37 is enclosed between the circuit board 80 and the rear cover 50 (see FIG. 10). The sound-insulating filler 37, together with the vibration-damping filler 35, suppresses vibrations entering the sensor housing 30 from the vehicle interior side SN, and prevents the vibrations from being transmitted to the piezo sensor 270.

[0080] [Acoustic sensor device of second embodiment] The acoustic sensor device 100 of the second embodiment shown in Figs. 11 and 12 is configured by combining a plurality (four) of the acoustic sensor devices 100 having the basic configuration shown in Fig. 8. The acoustic sensor device 100 houses four piezoelectric sensors 270 and four circuit boards 80. By attaching the acoustic sensor device 100 to the upper inner side surface 14, the four piezoelectric sensors 270 are arranged in a row in the horizontal direction of the vehicle Ve with the vehicle exterior sound collecting surface 71 facing the upper Ue of the vehicle Ve. In the second embodiment, the piezoelectric sensors 270 are arranged two by two along the left-right and front-rear directions of the vehicle Ve at a predetermined interval. By installing the acoustic sensor device 100 on the roof panel, it is possible to measure the sound around the vehicle Ve in a 360° direction.

[0081] Of the four circuit boards 80, a connector insert pin 83 is connected to one (hereinafter, output board) that is closest to the connector section 38. Meanwhile, the other three circuit boards 80 are each electrically connected to the output board by board connection insert pins 284. With this configuration, the outputs of the four piezoelectric sensors 270 can be output from the connector insert pins 83 exposed to the connector section 38.

[0082] The output board and the other circuit board 80 may be electrically connected by a board connection line 84 (see FIG. 4). Furthermore, the sensor housing 30 may be provided with a plurality of connectors 38 for outputting the detection signal of the piezoelectric sensor 270.

[0083] The interior of the sensor housing 30 is divided into four independent sealed spaces 34 and four interior spaces 36 connected to each other by space connecting parts 47 (see FIG. 12). A vibration-damping filler 35 is disposed on the interior side SN of the piezoelectric sensor 270 housed in each sealed space 34. Furthermore, each interior space 36 and the space connecting parts 47 are filled with urethane foam, silicone foam, or the like to form an integrated sound-proof filler 37.

[0084] The sensor housing 30 is provided with a shielding wall 45 and a shielding groove 46, as in the first embodiment. The shielding wall 45 divides the four sealed spaces 34. The shielding wall 45 extends in a cross shape so as to separate the four piezo sensors 270 and the sealed spaces 34. The shielding groove 46 is formed in a cross shape along the shielding wall 45, and divides a hollow sound insulation space 46a into the shielding wall 45 (see FIG. 12). By forming the shielding wall 45 and the sound insulation space 46a, the multiple sealed spaces 34 and the piezo sensors 270 are acoustically independent. The shielding groove 46 may be filled with a sound insulation filler. Since each vehicle interior space 36 and the shielding groove 46 are connected by a space connection portion 47, the sound insulation filler can be filled in one filling.

[0085] [Electrical configuration of the acoustic sensor device] 13, each circuit board 80 of the acoustic sensor device 100 is provided with the above-mentioned amplifier circuit unit 85 and communication interface 86. One amplifier circuit unit 85 and one communication interface 86 are provided for each piezoelectric sensor 270. Each communication interface 86 outputs a detection signal of each piezoelectric sensor 270 to the ECU 90 individually.

[0086] The ECU 90 has four signal receiving units 91 and one signal processing unit 93. Detection signals (see signals 1 to 4 in FIG. 13) output from a plurality of piezoelectric sensors 270 are input to each signal receiving unit 91. Each signal receiving unit 91 provides the signal processing unit 93 with a signal obtained by Fourier transforming each detection signal.

[0087] Information indicating the positional relationship in the front-rear and left-right directions of each piezoelectric sensor 270 is registered in advance in the signal processing unit 93. The signal processing unit 93 can estimate the arrival direction of the sound (vibration) detected by the piezoelectric sensor 270, in other words, the direction of the sound source as seen from the vehicle Ve, based on the signal differences, specifically, the phase difference, the time difference, and the sound pressure difference, of the four detection signals acquired from each signal receiving unit 91.

[0088] [Summary of the second embodiment] In the second embodiment described above, the flat attachment surface 31 provided on the sensor housing 30 is held on the upper inner surface 14 by the thin-film adhesive layer 20, and thus the acoustic sensor device 100 is attached to the external structure 10. Therefore, the acoustic sensor device 100 can be easily and reliably attached to external structures 10 of various configurations. Therefore, suitable attachment of the acoustic sensor device 100 for detecting sound and vibration is possible.

[0089] In detail, since the acoustic sensor device 100 is attached to the external structure 10 by the adhesive layer 20, there is no need to process the structure of the upper surface of the vehicle, such as the roof panel. Therefore, it is possible to detect sounds and vibrations coming from all around 360° with one acoustic sensor device 100 while suppressing the installation cost of the acoustic sensor device 100. In addition, the acoustic sensor device 100 can be installed on the vehicle Ve without being restricted by design. Also, since there is no structure protruding upward Ue from the roof panel, the generation of wind noise can be suppressed. Furthermore, since the external structure 10 faces upward Ue, snow accumulation on the upper outer surface 13 during driving is less likely to occur than on the front outer surface.

[0090] Additionally, in the second embodiment, the vehicle exterior sound collecting surface 71 that detects sound is formed by a piezoelectric sensor 270. The piezoelectric sensor 270 includes a monomorph diaphragm in which a metal plate 275 and a piezoelectric element 270a are bonded together. By using such a piezoelectric sensor 270, the sensitivity of sound detection can be improved. Furthermore, the metal plate 275 and the piezoelectric element 270a are less susceptible to changes in characteristics due to temperature than resin materials. Therefore, by using the piezoelectric sensor 270, it becomes possible to output a stable detection signal.

[0091] In the second embodiment, the intermediate insert pin 87 partially embedded in the sensor housing 30 electrically connects the piezoelectric sensor 270 and the circuit board 80. In this manner, the intermediate insert pin 87, which is held in the sensor housing 30 by being embedded, is interposed between the piezoelectric sensor 270 and the circuit board 80, which facilitates the process of electrically connecting the piezoelectric sensor 270 and the circuit board 80.

[0092] Furthermore, in the second embodiment, the acoustic sensor device 100 is provided with a plurality of (three or more) piezoelectric sensors 270 arranged in the horizontal direction of the vehicle Ve, along the front-rear and left-right directions of the vehicle Ve. Therefore, by comparing the detection signals of the piezoelectric sensors 270, it is possible to estimate the direction from which the sound (vibration) comes from within the entire 360° circumference of the vehicle Ve. In addition, the configuration in which detection signals are obtained from the plurality of piezoelectric sensors 270 makes it possible to improve the reliability and sensitivity of the detection results.

[0093] In addition, the piezoelectric sensor 270 of the second embodiment is connected via a negative wire 272n and a positive wire 272p. If the piezoelectric sensor 270 is firmly connected to the circuit board 80, a decrease in sensitivity or reception of unnecessary vibrations may occur. On the other hand, if the piezoelectric sensor 270 is electrically connected via a flexible wire, the decrease in sensitivity and reception of unnecessary vibrations are less likely to occur.

[0094] In the second embodiment, the multiple interior spaces 36 are connected to one another via the space connection parts 47. Therefore, it is possible to fill each of the interior spaces 36 with urethane foam or the like, which serves as the sound-insulating filler 37, all at once.

[0095] Furthermore, the piezoelectric sensor 270 of the second embodiment is attached to the inner bottom wall surface 42. With this arrangement, the piezoelectric sensor 270 can efficiently measure the sound transmitted to the external structure 10 and the mounting bottom wall 41.

[0096] In the second embodiment, the upper inner surface 14 further corresponds to the "inner surface", the intermediate insert pin 87 corresponds to the "connection portion", and the piezoelectric sensor 270 corresponds to the "sound detection sensor portion".

[0097] Third embodiment The third embodiment of the present disclosure shown in Fig. 14 is a modified example of the first embodiment. In the vehicle-mounted sensor installation structure of the third embodiment, the acoustic sensor device 100 includes an exterior acoustic sensor device 100a and an interior acoustic sensor device 100b. The exterior acoustic sensor device 100a has substantially the same configuration as the acoustic sensor device 100 installed on the rear inner surface 12 in the first embodiment, and includes two MEMS microphones 70 each having an exterior sound collecting surface 71.

[0098] The interior acoustic sensor device 100b has substantially the same configuration as the acoustic sensor device 100 having the basic configuration described in the first embodiment. The interior acoustic sensor device 100b is held relative to the exterior acoustic sensor device 100a in a position facing in the opposite direction to the exterior acoustic sensor device 100a. The interior acoustic sensor device 100b is arranged side by side with the exterior acoustic sensor device 100a in a direction perpendicular to the external structure 10 (hereinafter, the interior / exterior direction), and is located on the interior side SN of the exterior acoustic sensor device 100a.

[0099] The interior acoustic sensor device 100b includes one MEMS microphone 170. The MEMS microphone 170 is held on the back surface of the circuit board 80 with its sound collecting surface (hereinafter, interior sound collecting surface 73) facing the interior side SN of the vehicle. The interior sound collecting surface 73 detects sounds coming from inside the vehicle Ve (inside the vehicle).

[0100] The ECU 90 (see FIG. 7) includes three signal receiving units 91 and one signal processing unit 93. Each signal receiving unit 91 acquires two detection signals detected at each vehicle exterior sound collecting surface 71 and one detection signal detected at the vehicle interior sound collecting surface 73, and provides them to the signal processing unit 93. The signal processing unit 93 estimates the vehicle interior noise received at the vehicle exterior sound collecting surface 71 based on the vehicle interior sound measured at the vehicle interior sound collecting surface 73 and a transfer function measured in advance. The signal processing unit 93 cancels the vehicle interior noise included in the vehicle exterior sound by processing to subtract the vehicle interior noise from the detection signal of the vehicle exterior sound collecting surface 71.

[0101] The third embodiment described so far also has the same effect as the first embodiment, and allows suitable installation of the acoustic sensor device 100 for detecting sound and vibration. In addition, the acoustic sensor device 100 of the third embodiment includes an interior sound collection surface 73 for detecting sound coming from inside the vehicle Ve, in addition to the exterior sound collection surface 71 for detecting sound coming from outside the vehicle Ve. This configuration makes it possible to cancel noise inside the vehicle. As a result, the influence of interior sound on sound detection by the exterior sound collection surface 71 can be suppressed.

[0102] In the third embodiment, the MEMS microphone 70 of the exterior acoustic sensor device 100a corresponds to the "first sound detection sensor unit", and the MEMS microphone 170 of the interior acoustic sensor device 100b corresponds to the "second sound detection sensor unit".

[0103] 15, the exterior acoustic sensor device 100a may be configured to include only one MEMS microphone 70, similar to the interior acoustic sensor device 100b. Even in this configuration, a process of canceling the interior sound from the exterior sound measured by the MEMS microphone 70 can be performed using the detection signal of the interior sound collected by the MEMS microphone 170.

[0104] Fourth embodiment 16 is a modified example of the third embodiment. In the acoustic sensor device 100 of the fourth embodiment, a MEMS microphone 70 having an exterior sound collecting surface 71 and a MEMS microphone 170 having an interior sound collecting surface 73 are both housed in one sensor housing 30. The MEMS microphone 70 is mounted on the front surface of a circuit board 80 and housed in a sealed space 34.

[0105] The MEMS microphone 170 is mounted on the rear surface of the circuit board 80 and is housed in the vehicle interior space 36. A microphone housing hole 37a for housing the MEMS microphone 170 is formed in the sound insulating filler 37. A sound collection opening 53 for passing interior sounds is formed in the rear cover 50. The MEMS microphone 170 detects the interior sounds that have passed through the sound collection opening 53 and the microphone housing hole 37a on the interior sound collection surface 73.

[0106] The fourth embodiment described above has the same effect as the third embodiment, and can cancel the noise inside the vehicle. As a result, the effect of the sound detection by the vehicle exterior sound collecting surface 71 on the sound detection can be suppressed.

[0107] Fifth embodiment The fifth embodiment of the present disclosure shown in Fig. 17 is a modified example of the second embodiment. In the on-vehicle sensor installation structure of the fifth embodiment, similarly to the third embodiment, an acoustic sensor device 100 including an exterior acoustic sensor device 100a and an interior acoustic sensor device 100b is attached to an external structure 10 of a vehicle Ve. The exterior acoustic sensor device 100a has substantially the same configuration as the acoustic sensor device 100 installed on the rear inner side surface 12 in the second embodiment, and includes two piezoelectric sensors 270 that form the exterior sound collecting surface 71.

[0108] The interior acoustic sensor device 100b has substantially the same configuration as the acoustic sensor device 100 having the basic configuration described in the second embodiment. The interior acoustic sensor device 100b is held relative to the exterior acoustic sensor device 100a in a posture opposite to that of the exterior acoustic sensor device 100a. In the interior acoustic sensor device 100b, the interior sound collecting surface 73 is formed by the piezoelectric sensor 370.

[0109] The fifth embodiment described so far also has the same effect as the third embodiment, and can cancel the noise inside the vehicle. As a result, the influence of the vehicle interior sound on the sound detection of the vehicle exterior sound collecting surface 71 can be suppressed. In the fifth embodiment, the piezo sensor 270 of the vehicle exterior acoustic sensor device 100a corresponds to the "first sound detection sensor unit", and the piezo sensor 370 of the vehicle interior acoustic sensor device 100b corresponds to the "second sound detection sensor unit". In addition, one of the two MEMS microphones 70 in the third and fourth embodiments may be the piezo sensor 270. Furthermore, one of the two piezo sensors 270 in the fifth embodiment may be the MEMS microphone 70.

[0110] Sixth Embodiment 18 and 19, the sixth embodiment of the present disclosure is yet another modified example of the first embodiment. In the vehicle-mounted sensor installation structure of the sixth embodiment, the acoustic sensor device 100 further includes a retainer member 60.

[0111] The retainer member 60 is made of a resin material and has a cylindrical shape that is flat in the axial direction. The retainer member 60 is held to the rear inner surface 12 (or the upper inner surface 14) of the external structure 10 by an adhesive layer 120. The adhesive layer 120, like the adhesive layer 20, is made of double-sided tape, adhesive material, or the like.

[0112] The retainer member 60 is provided with an enclosing wall 61 that encloses the sensor housing 30, and a holding portion 62 that is held against the external structure 10. The enclosing wall 61 is formed thicker than the peripheral wall 44 of the housing body 40. The enclosing wall 61 is formed with a notch 61a and an engagement groove 63. The notch 61a is a missing portion provided in the enclosing wall 61 to avoid the connector portion 38 protruding to the outer periphery of the housing body 40. The engagement groove 63 is a groove portion recessed from the inner periphery wall surface of the enclosing wall 61. The engagement groove 63 engages with the claw portion 48 formed in the housing body 40. The holding portion 62 is a brim-shaped portion that protrudes from the enclosing wall 61 to the outer periphery. The end face of the vehicle exterior side SG of the holding portion 62 is held to the rear inner surface 12 or the like via the adhesive layer 120.

[0113] The retainer member 60 is attached to the external structure 10 prior to the sensor housing 30. The sensor housing 30 is inserted into the surrounding wall 61 of the retainer member 60 attached to the external structure 10, and is held to the external structure 10 by the adhesive layer 20. Furthermore, the claws 48 provided on the outer circumferential wall surface of the peripheral wall 44 fit into the engagement grooves 63, so that the sensor housing 30 is also held by the retainer member 60.

[0114] The sixth embodiment described so far also has the same effects as the first embodiment, and allows suitable installation of the acoustic sensor device 100 that detects sound and vibration. Specifically, in the sixth embodiment, the acoustic sensor device 100 further includes a retainer member 60. The retainer member 60 is provided with a holding portion 62 that is held relative to the external structure 10. Therefore, the acoustic sensor device 100 can be fixed to the external structure 10 more reliably.

[0115] In addition, the retainer member 60 is provided with a surrounding wall 61 that is shaped to surround the sensor housing 30. Therefore, the surrounding wall 61 can more effectively block sound and vibration coming from the side of the sensor housing 30.

[0116] In addition, the retainer member 60 is attached to the external structure 10 prior to the sensor housing 30. This makes it possible to improve the accuracy of the positioning of the acoustic sensor device 100, improve the attachment strength, stabilize the thickness of the adhesive layer 20, and prevent air bubbles from being mixed into the adhesive layer 20.

[0117] Furthermore, as in a modified example of the sixth embodiment shown in FIG. 20, the acoustic sensor device 100 may be configured to include two MEMS microphones 70. In addition, the retainer member 60 may be configured to be attached to the external structure 10 after the sensor housing 30 is attached. The retainer member 60 in this form is provided with a pressing protrusion 64. The pressing protrusion 64 is formed at the end of the surrounding wall 61 on the vehicle interior side SN. The pressing protrusion 64 presses the sensor housing 30 toward the external structure 10 by attaching the holding portion 62 to the external structure 10 via the adhesive layer 120.

[0118] Seventh embodiment The seventh embodiment of the present disclosure shown in Fig. 21 is yet another modified example of the first embodiment. In an acoustic sensor device 100 according to the seventh embodiment, a plurality of MEMS microphones 70 are mounted on one circuit board 80. The circuit board 80 is provided with amplifier circuit units 85 (see Fig. 7) and communication interfaces 86 (see Fig. 7) in the same number as the number of mounted MEMS microphones 70. The circuit board 80 is disposed in the vehicle interior space 36 integrally formed with the sensor housing 30 so as to seal the plurality of sealed spaces 34 from the vehicle interior side SN.

[0119] As in the seventh embodiment, by connecting the circuit boards 80 to which the MEMS microphones 70 are connected, the configuration of the acoustic sensor device 100 can be simplified. As a result, it is possible to reduce the cost of the in-vehicle sensor installation structure. Note that the circuit boards 80 to which the piezoelectric sensor 270 (see FIG. 11) is connected may be connected to one another.

[0120] Eighth embodiment The eighth embodiment of the present disclosure shown in FIG. 22 is a modified example of the seventh embodiment. In the acoustic sensor device 100 according to the eighth embodiment, a large number of MEMS microphones 70 are mounted on one circuit board 80 at close intervals. The large number of MEMS microphones 70 may be arranged in a line or in a two-dimensional array. Also, instead of the MEMS microphones 70, a piezoelectric sensor 270 may be arranged on the sound collection surface of the sealed space. Furthermore, both the MEMS microphones 70 and the piezoelectric sensor 270 may be arranged together. For example, the MEMS microphones 70 may be arranged in odd-numbered rows of a two-dimensional array, and the piezoelectric sensor 270 may be arranged in even-numbered rows.

[0121] In the housing body 40, a large number of sealed spaces 34 corresponding to the arrangement of the MEMS microphones 70 are formed. As in the first embodiment, the sealed spaces 34 are sealed by the circuit board 80 and the board fixing material 88, and are acoustically independent from each other. In the circuit board 80, a plurality of sound holes 81 that are continuous with each sealed space 34 are formed in the portion of each exterior sound collecting surface 71 that is the exterior side SG of the vehicle. According to the configuration of the eighth embodiment, the direction of the sound source can be estimated with higher accuracy.

[0122] Ninth embodiment The ninth embodiment of the present disclosure shown in FIG. 23 is yet another modified example of the first embodiment. In the ninth embodiment, the connector portion 38 (see FIG. 2) is omitted. A detection signal of the MEMS microphone 70 is output to the ECU 90 (see FIG. 7) or the like via an output pin 184 and a wire harness 39 provided on the circuit board 80. The wire harness 39 is electrically connected to the output pin 184 by soldering, crimping, or the like. In addition to the output pin 184 and the wire harness 39 that output the detection signal, an output pin 184 and a wire harness 39 that are connected to a power supply line of the circuit board 80 and supply power may be further provided.

[0123] The on-vehicle sensor installation structure according to the ninth embodiment further includes a clamp member 160. The clamp member 160 is formed in a cylindrical shape from a resin material. The clamp member 160 is disposed near the acoustic sensor device 100 and is held by the external structure 10 together with the acoustic sensor device 100. The clamp member 160 is attached to the rear inner surface 12 or the upper inner surface 14 by an adhesive layer 120.

[0124] The clamp member 160 has a cylindrical clamp wall 161. A planar clamp attachment surface 162 is provided on the outer peripheral surface of the clamp wall 161. The clamp attachment surface 162 is held on the rear inner surface 12 or the upper inner surface 14 via an adhesive layer 120. The adhesive layer 120 is formed of a double-sided tape, an adhesive material, or the like, similar to the adhesive layer 20. A vibration-damping material 164 is arranged on the inner peripheral side of the clamp wall 161.

[0125] The vibration-damping material 164 is formed into a columnar shape and made of sponge or the like. The vibration-damping material 164 is in close contact with the inner circumferential side of the clamp wall 161. A harness hole 165 is provided in the vibration-damping material 164. The harness hole 165 is a long and thin through-hole that passes through the vibration-damping material 164 in the axial direction. A wire harness 39 for power supply and signal transmission is passed through the harness hole 165.

[0126] The clamp member 160 fixes the wire harness 39 to the external structure 10. The portion where the clamp member 160 and the wire harness 39 contact each other is a vibration-damping material 164. The vibration-damping material 164 exerts a sound absorbing effect and a vibration-damping effect on the wire harness 39. This can prevent vehicle vibrations and the like from being transmitted from the wire harness 39 to the circuit board 80 and being detected by the MEMS microphone 70.

[0127] Tenth embodiment The tenth embodiment of the present disclosure shown in Fig. 24 is yet another modified example of the first embodiment. In the acoustic sensor device 100 of the tenth embodiment, the sensor housing 30 includes a front cover 150 in addition to the housing main body 40 and the back cover 50. The front cover 150 is attached to the end face of the housing main body 40 on the vehicle exterior side SG by adhesive, welding, or the like. The front cover 150 is provided with a mounting bottom wall 41 and an attachment surface 31. The front cover 150, together with the housing main body 40 and the circuit board 80, defines an enclosed space 34.

[0128] The housing body 40 has a tapered upper peripheral wall portion 44a. The upper peripheral wall portion 44a reduces the cross-sectional area of ​​the sealed space 34 from the attachment surface 31 toward the vehicle exterior sound collecting surface 71. Due to the shape of the upper peripheral wall portion 44a, the sealed space 34 has a partial cone shape or a partial square pyramid shape.

[0129] In the tenth embodiment described so far, a horn structure is formed inside the sensor housing 30 by the tapered upper peripheral wall portion 44a. This makes it possible to direct the directionality of sound detection outward. As a result, external sounds are more effectively collected in the sealed space 34, and the sensitivity of the MEMS microphone 70 can be improved. In the tenth embodiment, the upper peripheral wall portion 44a corresponds to the "peripheral wall portion."

[0130] In addition, in the acoustic sensor device 100 according to a modified example of the tenth embodiment shown in FIG. 25, a piezoelectric sensor 270 is mounted on the front surface of the circuit board 80 instead of the MEMS microphone 70 (see FIG. 24). In addition, an acoustic matching material 135 formed in a partial cone shape or a partial square pyramid shape is housed in the sealed space 34. The acoustic matching material 135 can transmit sound or vibration transmitted to the mounting bottom wall 41 to the vehicle exterior sound collecting surface 71 more efficiently than air. Therefore, even in the eleventh embodiment, effective sound collection in the sealed space 34 is possible, and therefore the sensitivity of the piezoelectric sensor 270 can be improved.

[0131] Eleventh Embodiment The eleventh embodiment of the present disclosure shown in Fig. 26 and Fig. 27 is yet another modified example of the first embodiment. The vehicle-mounted sensor installation structure of the eleventh embodiment is provided on the side mirror Ps1 of a vehicle Ve. The acoustic sensor device 100 is accommodated in a housing 15 of the side mirror Ps1. The acoustic sensor device 100 is attached to the back surface (rear inner surface 12) of the mirror member of the side mirror Ps1, which serves as an external structure 10.

[0132] As in the eleventh embodiment, by using a hard glass mirror member as the external structure 10, the mirror member functions as an antenna for receiving sound from the rear Go. As a result, the sensitivity of the piezoelectric sensor 270 (or the MEMS microphone 70, see FIG. 2) is improved. Therefore, the in-vehicle sensor installation structure in which the mirror member is the external structure 10 is a suitable mounting structure for the acoustic sensor device 100 that detects sound and vibration.

[0133] (Other embodiments) Although several embodiments of the present disclosure have been described above, the present disclosure should not be construed as being limited to the above-described embodiments, and can be applied to various embodiments and combinations within the scope not departing from the gist of the present disclosure.

[0134] In the modified example 1 of the second embodiment shown in FIG. 28, the roof panel of the vehicle Ve, which is the external structure 10, is curved in a shape that is convex upward Ue (the vehicle outer side SG) for drainage. In the vehicle-mounted sensor installation structure of the modified example 1, two acoustic sensor devices 100 having the basic configuration of the first embodiment are lined up in the left-right direction. The attachment surface 31 of each acoustic sensor device 100 is attached to the upper inner surface 14 in an attitude inclined with respect to the horizontal direction in accordance with the curvature of the external structure 10. At least a part of the gap generated between the planar attachment surface 31 and the curved upper inner surface 14 is filled by the deformation of the adhesive layer 20. According to the modified example 1 described above, it is possible to firmly install the acoustic sensor device 100 on the external structure 10 having a curved shape without performing special processing.

[0135] Furthermore, in the vehicle-mounted sensor installation structure of Modification 2 shown in Fig. 29, two acoustic sensor devices 100 are connected by one adhesive layer 20 made of double-sided tape or the like. Moreover, in the vehicle-mounted sensor installation structure of Modification 3 shown in Fig. 30, two acoustic sensor devices 100 are connected by one adhesive layer 20 and a flexible connecting member 22. In these vehicle-mounted sensor installation structures of Modifications 2 and 3, the adhesive layer 20 and the connecting member 22 bend between the two acoustic sensor devices 100, so that each attachment surface 31 can be made to conform to the curved external structure 10 (see Fig. 28).

[0136] In the on-vehicle sensor installation structures of Modified Examples 4 and 5 shown in Figs. 31 and 32, the sensor housing 30 is fixed to the curved external structure 10 via a retainer member 60. The retainer member 60 is attached to the upper inner surface 14 by an adhesive layer 20. The back space 16 generated between the mounting bottom wall 41 and the upper inner surface 14 is divided into multiple spaces and sealed by a sealing member 24. The sealing member 24 is made of rubber, a foam material, or the like. The sealing member 24 prevents water and the like from entering the back space 16.

[0137] The acoustic sensor device 100 of the fourth modification shown in Fig. 31 includes a plurality of MEMS microphones 70. A recess 43 formed in the mounting bottom wall 41 of the sensor housing 30 penetrates the mounting bottom wall 41 in the thickness direction. The recess 43 functions as a sound hole connecting the sealed space 34 and the back space 16. The sound hole formed by the recess 43 may be provided with a membrane or the like that transmits sound but does not transmit air or moisture.

[0138] The acoustic sensor device 100 of the fifth modified example shown in Fig. 32 includes a plurality of piezoelectric sensors 270. The mounting bottom wall 41 to which the piezoelectric sensors 270 are attached does not have a recess 43 (see Fig. 31). The rear space 16 defined between the mounting bottom wall 41 and the rear inner surface 12 contains an acoustic matching material 17. The acoustic matching material 17 can transmit sound or vibration transmitted to the external structure 10 to the mounting bottom wall 41 more efficiently than air. Note that the rear space 16 may be filled with an adhesive or the like instead of the acoustic matching material 17.

[0139] In the on-vehicle sensor installation structure of Modification 6 shown in Fig. 33, multiple sensor housings 30 are fixed to a curved external structure portion 10 via a retainer member 60. The retainer member 60 is attached to the upper inner surface 14 by an adhesive layer 120. Each sensor housing 30 is inserted into a fixing hole 18 defined by the retainer member 60 and the sealing member 24, and is held in the fixing hole 18 on the upper inner surface 14 via the adhesive layer 20.

[0140] In a seventh modification of the second embodiment shown in Fig. 34, the configuration of the piezoelectric sensor 270 is changed. In the piezoelectric sensor 270 of the seventh modification, the metal plate 275 (see Fig. 9) is omitted. The piezoelectric element 270a of the piezoelectric sensor 270 is housed in the sealed space 34 and is attached to the inner bottom wall surface 42 of the mounting bottom wall 41 with double-sided tape or the like.

[0141] In addition, in variant example 8 shown in FIG. 35, a piezoelectric sensor 270 including a monomorph vibration plate made up of a piezoelectric element 270a and a metal plate 275 is attached to a step portion 44c spaced apart from the mounting bottom wall 41 by an adhesive such as double-sided tape.

[0142] 36, a metal plate 275 of the piezoelectric sensor 270 forms the mounting bottom wall 41. The metal plate 275 covers an opening provided in the housing body 40, and constitutes the sensor housing 30 together with the housing body 40 and the like. The metal plate 275 is exposed from the sensor housing 30, and is directly attached to the external structure 10 via double-sided tape or the like. In this type of modification 9, sound is efficiently transmitted from the external structure 10 to the vehicle exterior sound collecting surface 71, so that the sensitivity of the piezoelectric sensor 270 can be improved.

[0143] In the modified example 10 shown in FIG. 37, the adhesive layer 20 is divided to form a back space 16 between the mounting bottom wall 41 and the rear inner surface 12. The back space 16 is sealed by the adhesive layer 20. The adhesive layer 20 can prevent water and the like from entering the back space 16. The recess 43 is a through hole penetrating the mounting bottom wall 41, as in the modified example 4 (see FIG. 1). The recess 43 communicates the back space 16 with the sealed space 34, and functions as a sound hole. The modified example 10 also makes it possible to improve the sensitivity of the MEMS microphone 70. In addition, instead of the mounting bottom wall 41 having a large number of sound holes, the mounting bottom wall 41 may be formed of a fiber material that transmits sound but does not transmit water, in other words, a fiber material that is both waterproof and moisture permeable (for example, Gore-Tex, registered trademark).

[0144] 38, a thin-film protective sheet 42a made of fiber, rubber, resin, or the like that is permeable to sound but impermeable to water and dust may be attached to the inner bottom wall surface 42. The protective sheet 42a covers the inside of the recess 43. With this configuration, it is possible to prevent water, dust, and the like from entering the sealed space 34 before attachment to the external structure 10.

[0145] Furthermore, as in a modification 12 shown in FIG. 39, the outside of the recess 43 which is a through hole may be sealed with an adhesive layer 20 made of a double-sided tape or the like.

[0146] Furthermore, in the vehicle-mounted sensor installation structure according to Modification 13 of the second embodiment shown in Fig. 40, three acoustic sensor devices 100 are arranged in a front-rear and left-right direction. If three or more acoustic sensor devices 100 (sound detection sensor units) are positioned with a mutual shift in the front-rear and left-right directions as in Modification 13, it becomes possible to estimate the direction of the sound source.

[0147] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. Furthermore, some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. The claims described in these multiple dependent forms define multiple technical ideas.

[0148] (Technical thought 1) an external structural portion (10) having a plate-like shape and a rear outer surface (11) exposed to the outside of the vehicle (Ve) in a position facing the rear of the vehicle; an acoustic sensor device (100) including: a sensor housing (30) held against a rear inner surface (12) of the external structure that is the reverse side of the rear outer surface; and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; An in-vehicle sensor installation structure comprising: (Technical thought 2) The sensor housing is provided with a flat attachment surface (31), The vehicle-mounted sensor installation structure described in Technical Idea 1 further includes a thin-film adhesive layer (20) that holds the attachment surface against the rear inner surface. (Technical Thought 3) The vehicle-mounted sensor installation structure according to Technical Idea 2, wherein the external structural portion is formed of glass. (Technical Thought 4) An external structural portion (10) having a plate-like shape and an upper outer surface (13) exposed to the outside of the vehicle (Ve) in a position facing upward of the vehicle (Ve); a thin-film adhesive layer (20) for holding an acoustic sensor device (100) on the upper inner surface of the external structure, the acoustic sensor device having a sensor housing (30) held against an upper inner surface (14) that is the reverse side of the upper outer surface of the external structure, and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; and An in-vehicle sensor installation structure comprising: (Technical Thought 5) The sensor housing is provided with an attachment surface (31), The vehicle-mounted sensor installation structure described in Technical Idea 4, wherein the adhesive layer holds the attachment surface against the upper inner surface. (Technical Thought 6) An external structural portion (10) having a plate-like shape and an upper outer surface (13) exposed to the outside of the vehicle (Ve) in a position facing upward of the vehicle (Ve); a retainer member (60) for holding an acoustic sensor device (100) on the upper inner surface of the external structure, the acoustic sensor device having a sensor housing (30) held against an upper inner surface (14) that is the reverse side of the upper outer surface of the external structure, and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; and An in-vehicle sensor installation structure comprising: (Technical Thought 7) The on-vehicle sensor installation structure according to any one of Technical Concepts 1 to 6, wherein the acoustic sensor device has a plurality of the sound detection sensor portions. (Technical Thought 8) The on-vehicle sensor installation structure according to any one of Technical Ideas 1 to 7, wherein the acoustic sensor device has a plurality of the sound detection sensor parts arranged along the horizontal direction of the vehicle. (Technical Thought 9) The detection signals output from the plurality of sound detection sensor units are input to a signal processing device (90), The vehicle-mounted sensor installation structure according to Technical Idea 7 or 8, wherein the signal processing device performs signal processing based on a signal difference between the plurality of detection signals. (Technical Thought 10) The vehicle-mounted sensor installation structure according to any one of Technical Concepts 7 to 9, wherein the sensor housing is provided with a shielding wall (45) that separates the plurality of sound detection sensor units. (Technical Thought 11) The vehicle-mounted sensor installation structure according to Technical Idea 10, wherein the shielding wall is provided with a sound insulation space (46a) that is hollow or filled with sound-absorbing material to separate the plurality of sound detection sensor units. (Technical Thought 12) The acoustic sensor device includes: A first sound detection sensor unit which is the sound detection sensor unit; a second sound detection sensor unit (170, 370) including an interior sound collecting surface (73) for detecting a sound coming from inside the vehicle; The vehicle-mounted sensor installation structure according to any one of Technical Ideas 1 to 9. (Technical Thought 13) The acoustic sensor device further includes a retainer member (60) including a surrounding wall (61) surrounding the sensor housing and a retaining portion (62) that is held against the external structural portion, the vehicle-mounted sensor installation structure being described in any one of Technical Ideas 1 to 10. (Technical Thought 14) An acoustic sensor device that is held on a plate-shaped external structural portion (10) of a vehicle, a sound detection sensor unit (70, 270) having a sound collection surface (71) for detecting sound and vibrations within the external structure; a sensor housing (30) that is held against the inner surfaces (12, 14) of the external structure by an adhesive layer (20) and that houses the sound detection sensor unit with the sound collecting surface aligned along the inner surfaces; An acoustic sensor device comprising: (Technical Thought 15) The sensor housing is provided with an attachment surface (31), The acoustic sensor device according to technical idea 14, wherein the adhesive layer is a thin film and the attachment surface is held on the inner surface (12, 14) of the external structure. (Technical Thought 16) The acoustic sensor device according to Technical Idea 15, wherein the sensor housing defines a hollow sound collection space (34) between the attachment surface and the sound collection surface. (Technical Thought 17) The sound detection sensor unit is mounted on a plate-shaped circuit board (80) that is housed in the sensor housing. The acoustic sensor device according to Technical Idea 16, wherein the circuit board cooperates with the sensor housing to define the hollow sound collection space. (Technical Thought 18) The sound detection sensor unit is mounted on a rear surface of the circuit board opposite to a front surface facing the hollow sound collection space, The acoustic sensor device according to Technical Idea 16, wherein a through hole (81) penetrating the circuit board in the thickness direction is formed in the portion of the circuit board between the sound collecting surface and the hollow sound collecting space. (Technical Thought 19) The acoustic sensor device according to Technical Idea 17 or 18, further comprising a rear sound insulation material (37) housed in the sensor housing and arranged on the opposite side of the hollow sound collection space with the circuit board in between. (Technical Thought 20) The acoustic sensor device according to any one of Technical Ideas 16 to 19, wherein the sensor housing has a tapered peripheral wall portion (44a) that reduces the cross-sectional area of ​​the hollow sound collection space from the attachment surface toward the sound collection surface. (Technical Thought 21) The sensor housing has a mounting wall (41) that forms the attachment surface, 20. The acoustic sensor device according to any one of Technical Ideas 16 to 19, wherein the mounting wall is formed with a hole (43) that faces the hollow sound collection space and reduces a wall thickness of the mounting wall. (Technical Thought 22) The acoustic sensor device according to any one of Technical Ideas 16, 18, and 19, wherein the sound detection sensor portion includes a piezoelectric element (270a) and is held against a mounting wall (41) of the sensor housing that forms the attachment surface. (Technical Thought 23) a plate-shaped circuit board (80) that is accommodated in the sensor housing and cooperates with the sensor housing to define the hollow sound collection space; The acoustic sensor device according to Technical Idea 22, further comprising a connection portion (87) that is partially embedded in the sensor housing and electrically connects the piezoelectric element and the circuit board. [Explanation of symbols]

[0149] Ve vehicle, 10 external structural part, 11 rear outer surface, 12 rear inner surface (inner surface), 13 upper outer surface, 14 upper inner surface (inner surface), 20 adhesive layer, 30 sensor housing, 31 attachment surface, 34 sealed space (hollow sound collection space), 37 sound insulation filler (rear sound insulation material), 41 mounting bottom wall (mounting wall), 43 recess (hole), 44a upper peripheral wall part (peripheral wall part), 45 shielding wall, 46a sound insulation space, 47 space connection part, 60 retainer member, 61 surrounding wall, 62 holding part, 70 MEMS microphone (sound detection sensor part, first sound detection sensor part), 170 MEMS microphone (second sound detection sensor part), 270 piezo sensor (sound detection sensor part, first sound detection sensor part), 370 Piezo sensor (second sound detection sensor part), 270a piezoelectric element, 71 vehicle exterior sound collection surface (sound collection surface), 73 vehicle interior sound collection surface (sound collection surface), 80 circuit board, 81 sound hole (through hole), 87 intermediate insert pin (connection part), 90 ECU (signal processing device), 100 acoustic sensor device

Claims

1. An external structure (10) having an outer surface (11) exposed to the outside of a vehicle (Ve) and having a plate-like shape; an acoustic sensor device (100) including a sensor housing (30) held against an inner surface (12) that is the reverse side of the outer surface of the external structure, and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; An in-vehicle sensor installation structure comprising:

2. The sensor housing is provided with an attachment surface (31), The vehicle-mounted sensor installation structure according to claim 1 , further comprising a thin-film adhesive layer (20) for holding the attachment surface to the inner surface.

3. An on-vehicle sensor installation structure as described in claim 1, further comprising a thin-film adhesive layer (20) that holds an attachment surface (31) provided on the sensor housing to the inner surface.

4. 4. The vehicle-mounted sensor installation structure according to claim 2, wherein the external structure is made of glass.

5. An external structural portion (10) having a plate-like shape and an upper outer surface (13) exposed to the outside of the vehicle (Ve) in a position facing upward of the vehicle (Ve); a thin-film adhesive layer (20) for holding an acoustic sensor device (100) on the upper inner surface of the external structure; the acoustic sensor device (100) having a sensor housing (30) held against an upper inner surface (14) that is the reverse side of the upper outer surface of the external structure; and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; and An in-vehicle sensor installation structure comprising:

6. The sensor housing is provided with an attachment surface (31), The vehicle-mounted sensor installation structure according to claim 5 , wherein the adhesive layer holds the attachment surface against the upper inner surface.

7. An external structural portion (10) having a plate-like shape and an upper outer surface (13) exposed to the outside of the vehicle (Ve) in a position facing upward of the vehicle (Ve); a retainer member (60) for holding an acoustic sensor device (100) on the upper inner surface of the external structure, the acoustic sensor device having a sensor housing (30) held against an upper inner surface (14) that is the reverse side of the upper outer surface of the external structure, and a sound detection sensor unit (70, 270) housed in the sensor housing with an exterior sound collecting surface (71) that detects sound coming from outside the vehicle and vibrations within the external structure facing the external structure; and An in-vehicle sensor installation structure comprising:

8. The vehicle-mounted sensor installation structure according to claim 1 , 5 or 7 , wherein the acoustic sensor device includes a plurality of the sound detection sensor portions.

9. The vehicle-mounted sensor installation structure according to claim 1 , wherein the acoustic sensor device includes a plurality of the sound detection sensor units arranged along a horizontal direction of the vehicle.

10. The detection signals output from the plurality of sound detection sensor units are input to a signal processing device (90), The vehicle-mounted sensor installation structure according to claim 8 , wherein the signal processing device performs signal processing based on a signal difference between the plurality of detection signals.

11. 9. The vehicle-mounted sensor installation structure according to claim 8, wherein the sensor housing is provided with a shielding wall (45) that separates the plurality of sound detection sensor units.

12. 12. The vehicle-mounted sensor installation structure according to claim 11, wherein the shielding wall is provided with sound insulating spaces (46a) that are hollow or filled with a sound absorbing material and separate the plurality of sound detection sensor units.

13. The acoustic sensor device includes: A first sound detection sensor unit which is the sound detection sensor unit; A second sound detection sensor unit (170, 370) including an interior sound collection surface (73) that detects sound coming from inside the vehicle; The vehicle-mounted sensor installation structure according to any one of claims 1, 5 and 7, further comprising:

14. The acoustic sensor device further includes a retainer member (60) including a surrounding wall (61) surrounding the sensor housing and a holding portion (62) held against the external structural portion. The vehicle-mounted sensor installation structure according to any one of claims 1, 5 and 7.

15. An acoustic sensor device that is held on a plate-shaped external structural portion (10) of a vehicle, A sound detection sensor unit (70, 270) having a sound collection surface (71) for detecting sound and vibrations within the external structure; a sensor housing (30) that is held against the inner surface (12, 14) of the external structure by an adhesive layer (20) and that houses the sound detection sensor unit with the sound collection surface aligned along the inner surface; An acoustic sensor device comprising:

16. The sensor housing is provided with an attachment surface (31), The acoustic sensor device according to claim 15, wherein the adhesive layer is in the form of a thin film and holds the attachment surface to the inner surface (12, 14) of the external structure.

17. The acoustic sensor device according to claim 16, wherein the sensor housing defines a hollow sound collection space (34) between the attachment surface and the sound collection surface.

18. The sound detection sensor unit is mounted on a plate-shaped circuit board (80) housed in the sensor housing, The acoustic sensor device according to claim 17 , wherein the circuit board defines the hollow sound collection space in cooperation with the sensor housing.

19. The sound detection sensor unit is mounted on a rear surface of the circuit board opposite to a front surface facing the hollow sound collection space, The acoustic sensor device according to claim 18, wherein a through hole (81) penetrating the circuit board in a plate thickness direction is formed in a portion of the circuit board between the sound collecting surface and the hollow sound collecting space.

20. The acoustic sensor device according to claim 18, further comprising a rear sound insulation material (37) housed in the sensor housing and arranged on the opposite side of the hollow sound collection space with the circuit board in between.

21. The acoustic sensor device according to claim 17, wherein the sensor housing has a tapered peripheral wall portion (44a) in which a cross-sectional area of ​​the hollow sound collection space decreases from the attachment surface toward the sound collection surface.

22. The sensor housing has a mounting wall (41) that forms the attachment surface, The acoustic sensor device according to claim 17, wherein the mounting wall is formed with a hole portion (43) that faces the hollow sound collection space and reduces a wall thickness of the mounting wall.

23. 21. The acoustic sensor device according to claim 17, wherein the sound detection sensor portion includes a piezoelectric element (270a) and is held against a mounting wall (41) of the sensor housing that forms the attachment surface.

24. A plate-shaped circuit board (80) that is accommodated in the sensor housing and cooperates with the sensor housing to define the hollow sound collection space; The acoustic sensor device according to claim 23, further comprising a connection portion (87) that is partially embedded in the sensor housing and electrically connects the piezoelectric element and the circuit board.

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