Sensor device for detecting sound, in particular for detecting structure-borne sound on a vehicle

Abstract

Sensor device for detecting sound, in particular for detecting structure-borne sound on a vehicle, especially sound caused by environmental influences, comprising at least one sound sensor (1) and at least one housing (2) which surrounds the sound sensor (1) at least partially, wherein the housing (2) has at least one planar detection area (3), wherein the sound sensor (1) is connected to the detection area (3) in a structure-borne sound-conducting manner, and wherein the housing (2) has mounting sections (5) for mounting on an object (7), in particular for mounting on a vehicle. characterized by that at least one area (6) with reduced material thickness of the housing (2) is arranged between the flat detection area (3) and at least one fastening section (5) of the housing (2), that the side walls (4) of the housing (2) are arranged adjacent to the detection area (3) and that the side walls (4) have at least one material-reduced area (6) that surrounds the detection area (3) at least section by section for the mechanical decoupling of the sound sensor (1) from the object (7) on which the sensor device is arranged.

Description

[0001] The invention relates to a sensor device for detecting sound, in particular for detecting structure-borne sound on a vehicle, in particular sound caused by environmental influences, with at least one sound sensor and with at least one housing that surrounds the sound sensor at least in sections, wherein the housing has at least one flat detection area, wherein the sound sensor is connected to the detection area in a structure-borne sound-conducting manner and wherein the housing has fastening sections for fastening to an object, in particular for fastening to a vehicle.

[0002] Sensor devices of the type mentioned above are known and are used in a variety of vehicles. For example, the sensor devices can be used to detect road surface moisture or to detect environmental influences such as swirled-up loose chippings or similar. For example, swirled-up loose chippings or swirled-up spray water can generate sound signals, in particular structure-borne sound signals, on the outer shell of the vehicle. These structure-borne sound signals can be detected by sound sensors, in particular structure-borne sound sensors. A structure-borne sound sensor can be arranged in a housing, wherein the housing has a preferably flat detection area. For example, swirled-up spray water or dirt particles can hit the detection area and thus generate structure-borne sound signals in the detection area.At least one structure-borne sound sensor is connected to the detection area in a structure-borne sound-conducting manner in order to record the structure-borne sound signals generated by the external environmental influences.

[0003] In order to ensure that the recorded structure-borne sound signals are structure-borne sound signals resulting from environmental conditions and not, for example, structure-borne sound signals caused by driving, a mechanical decoupling of the structure-borne sound sensor is necessary.

[0004] DE 102015211539 A1 discloses a motor vehicle with an ultrasonic sensor arrangement for the contactless detection of objects in the vehicle's surroundings. Piezoelectric film sensors are used. Damping means are used to acoustically and electrically decouple the sensor areas of a sensor film with at least two separately usable sensor areas. The damping means for acoustically and electrically decoupling the sensor areas are arranged between the sensor areas. The damping means can, for example, be elastomer strips incorporated into the sensor film.

[0005] For example, DE 10 2011 076 395 A1 discloses an ultrasonic sensor comprising a substantially cylindrical housing having a bottom portion and a sidewall portion, and a plurality of members arranged within the housing. A reinforcement having a substantially annular shape is arranged on a thick segment within the housing in a position that is not in contact with an inner surface of a thin segment of the sidewall portion. A piezoelectric element is attached to an inner bottom surface of the housing.

[0006] Furthermore, an ultrasonic transducer is known from US 6 276 212 B1. This comprises a housing with an axis and a diaphragm centered at one end of the housing. A cylindrical oscillating mass is arranged in the housing and centered on the axis. The oscillating mass has a first end attached to an inner surface of the diaphragm and centered relative thereto, and an opposite second end. The oscillating mass can be set into vibration in a direction along the axis. A second cylindrical mass is arranged in the housing and centered on the axis. The second mass has a third end with a recess centered on the axis. The second end of the oscillating mass projects into the recess and is attached to the second mass.

[0007] Furthermore, US Pat. No. 5,636,182 A discloses a portable ultrasonic underwater sensor comprising a piezoelectric element arranged in a housing. The housing is designed as a cylinder and has a truncated cone, both of which are formed integrally and axially symmetrically to form a vibrator. A piezoelectric element and the vibrator are connected to one another, wherein a center of the piezoelectric element coincides with the center of a rear side of the truncated cone of the vibrator. As a result, the vibrator is fully resonant in a vibration mode in which the bending vibration has a maximum amplitude at the center of the truncated cone, and wherein means for holding the vibrator along a vibration node line are arranged on an outer side surface of the vibrator.

[0008] Further prior art can be found in DE000003505872A1, DE 195 43 137 A1, DE197 44 229 A1, DE699 15 083 T2, DE 10 2006 021 492 A1, DE 10 2006 038 598 A1, DE 10 2007 045 809 A1, DE 10 2010 027 780 A1, DE 10 2015 107 899 A1, DE 10 2015 216 163 A1, DE 10 2015 217 778 A1 and JP H02 116 299 A, US 2012 / 0 056 511 A1.

[0009] The use of damping devices made of special damping material is complex and therefore time-consuming and costly to install.

[0010] The invention is based on the object of proposing a sensor device of the type mentioned above, in which a simple and cost-effective mechanical decoupling of the detection area is possible.

[0011] This object is achieved by a sensor device having the features of patent claim 1. Further developments and advantageous embodiments are specified in the subclaims.

[0012] In a sensor device for detecting sound, in particular for detecting structure-borne sound on a vehicle, in particular sound caused by environmental influences, with at least one sound sensor and with at least one housing that at least partially surrounds the sound sensor, wherein the housing has at least one flat detection area, wherein the sound sensor is connected to the detection area in a way that conducts structure-borne sound, and wherein the housing has fastening sections for fastening to an object, in particular for fastening to a vehicle, it is provided that between the flat detection area and at least one fastening section of the housing at least one area with reduced material thickness of the housing is arranged, that side walls of the housing are arranged adjacent to the detection area, and that the side walls have at least one material-reduced,have an area surrounding the detection area at least in sections for mechanically decoupling the sound sensor from the object on which the sensor device is arranged.,

[0013] The sensor device is intended for detecting sound, in particular for detecting structure-borne sound signals on a vehicle. In particular, the sensor device is intended for detecting structure-borne sound signals that are caused by environmental influences on the outer shell of a vehicle. Environmental influences that generate structure-borne sound signals on the vehicle's outer shell can be, for example, spray water stirred up by a wet roadway, stirred up loose chippings, or similar particles impacting the vehicle's outer shell. To detect the structure-borne sound signals, the sensor device has at least one sound sensor, in particular a structure-borne sound sensor. The structure-borne sound sensor can be connected in a signal-conducting manner to an evaluation device for evaluating the detected structure-borne sound signals. At least one structure-borne sound sensor is at least partially surrounded by a housing.The housing forms a preferably flat detection zone, in which structure-borne sound signals are generated by environmental influences, such as splashing water. The structure-borne sound sensor is connected to the detection zone of the housing in a conductive manner, so that the structure-borne sound signals generated in the detection zone can be detected by the structure-borne sound sensor.

[0014] In particular, the structure-borne sound sensor is arranged on one side of the detection area. Preferably, the structure-borne sound sensor is arranged on the side of the housing facing away from the ambient influences, i.e., protected from the ambient influences. Furthermore, the housing can have a cover for completely closing the housing. The housing can be arranged on the vehicle such that the side of the detection area not having a structure-borne sound sensor faces the ambient influences. The structure-borne sound sensor can, for example, be a piezoelectric film applied to one side of the detection area. The housing has fastening sections with which the housing can be fastened to the object to be monitored, in particular to a vehicle, for example to the vehicle's outer shell.Areas of reduced material thickness are arranged between the fastening sections of the housing and the flat detection area. This minimizes the transmission of vibrations that propagate on the object to which the housing is attached and that are not due to the environmental influences to be detected, from the object to the detection area. The areas of reduced material thickness of the housing can, for example, be formed by a reduction in the wall thickness of the housing, i.e. by areas in which the housing wall is thinner than in the other areas. With a thinner housing wall, vibrations from the object to which the housing is attached are transmitted to the detection surface to a lesser extent. Thus, vibrations that are not caused by environmental influences do not interfere with the detection of sound events that are caused by environmental influences.In addition, the detection surface is thus less flexible, allowing greater deflection, whereby environmental influences can lead to amplified structure-borne sound signals. Furthermore, the aforementioned detection area can be formed by an area of ​​thinner material, i.e., one that is less thick than the walls of the housing. By reducing the thickness compared to the walls, the detection area, and thus the structure-borne sound sensor arranged on the detection area, can be decoupled from the adjacent housing walls. For example, the sensor device can be used to detect precipitation on a roadway on which a vehicle is moving, by arranging the sensor device in the area of ​​the spray water stirred up by the vehicle's tires.The stirred up spray water can hit the detection area of ​​the sensor device and generate structure-borne sound signals that can be recorded. The driving of the vehicle can also cause vibrations that are transmitted to the housing of the sensor device and thus overlap with the vibrations generated by the impacting spray water. This overlap can make it more difficult to detect the spray water. The areas of thinner material that are arranged between the fastening sections of the housing and the detection area reduce the transmission of vibrations caused by driving operation. In addition, the areas of thinner material allow the detection area to oscillate more freely when the spray water hits, thus enabling more precise recording of the structure-borne sound vibrations generated by the impacting spray water.This provides a simple and cost-effective way to mechanically decouple the detection area and consequently the sound sensor arranged thereon from the object on which the sensor device is arranged.

[0015] The housing walls can have material-reduced regions that surround the detection zone at least partially, preferably completely. These material-reduced regions reduce vibration transmission from the mounting sections to the detection zone, thus providing a simple way of mechanically decoupling the detection zone from the mounting sections.

[0016] In a further development of the invention, the sound sensor is arranged on one side of the detection area, and the detection area has a region of reduced material thickness that surrounds the sound sensor at least in sections. To detect sound events that are caused in the detection area, for example by environmental influences, the sound sensor, in particular a structure-borne sound sensor, is preferably arranged on one side of the detection area. In order to achieve the greatest possible mechanical decoupling of the detection area and thus the sound sensor from the adjacent sections of the housing, the detection area has a region of reduced material thickness. In this case, the region of reduced material thickness is arranged at least in sections, in particular completely, circumferentially around the sound sensor.This creates a zone of reduced material thickness between the sound sensor and the housing's mounting areas. This allows for mechanical decoupling of the sound sensor from the adjacent housing components.

[0017] In a further development of the invention, at least one region of reduced material thickness is formed by a groove. At least one region of reduced material thickness can be formed by a groove. A groove is an elongated recess, in particular an elongated, angled recess, that is formed in the housing. A groove can be subsequently introduced into the housing or already provided during the manufacturing process. A groove provides a defined region of reduced material thickness.

[0018] In a further development of the invention, at least two regions of reduced material thickness, in particular two grooves, are arranged at least approximately parallel to one another. Multiple regions of reduced material thickness can be provided on the housing. For example, two grooves arranged parallel to one another can be provided, which encircle the structure-borne sound sensor. The arrangement of multiple grooves arranged parallel to one another enables improved mechanical decoupling of the detection area.

[0019] In a further development of the invention, at least one groove is arranged on the side of the flat detection area that has the sound sensor and / or on the side of the detection area facing away from the sound sensor. The grooves for forming material-reduced areas can be arranged both on the side of the detection area on which the sound sensor, in particular the structure-borne sound sensor, is located, and on the side of the detection area facing away from the structure-borne sound sensor. Furthermore, grooves can be arranged on both sides. These can, for example, be arranged congruently, so that the material-reduced areas are formed by grooves introduced on both sides.

[0020] In a further development of the invention, the base area of ​​the detection area is circular, and at least one groove runs at least approximately parallel to the edge of the detection area. The base area of ​​the detection area is preferably circular. The sound sensor, in particular the structure-borne sound sensor in the form of an adhesively bonded piezoelectric film, is preferably arranged centrally on the circular base area. The circular base area enables simple arrangement of the sensor device in an opening, for example in an opening in the outer shell of a vehicle. At least one groove introduced into the base area of ​​the detection area, which is arranged parallel to the edges of the circular base area, enables mechanical decoupling of the structure-borne sound sensor from the adjacent housing parts.

[0021] In a further development of the invention, the material-reduced region is formed by a tapered wall thickness of the side walls. A material-reduced region can be incorporated into a wall of the housing adjacent to the detection area. For example, a material-reduced region can be formed by a tapered side wall. With a tapered region, the wall thickness of the side wall can, for example, decrease starting from the detection area or increase toward the detection area. A tapered region reduces the wall thickness and thus decouples the detection area.

[0022] In one development of the invention, the housing is designed to be accommodated in an opening in the outer shell of a vehicle. The housing of the sensor device can be designed to be accommodated in an opening in the outer shell of a vehicle. In particular, the sensor device can be accommodated in the opening such that the detection area is arranged flush with the outer shell of the vehicle. Thus, for example, splash water striking the outer shell can be detected by the structure-borne sound signals generated in the detection area by the splash water. In order to minimize falsification of the measurement results by vibrations of the vehicle during driving, areas of reduced material thickness are arranged between the detection area and the fastening sections of the housing.

[0023] In a further development of the invention, the side walls are flange-like, designed for insertion into an opening in the vehicle's outer shell. The housing of the sensor device can be designed for reception in an opening in the vehicle's outer shell and, for this purpose, can have flange-like side walls. In particular, the side walls of the housing can be arranged adjacent to the detection area and, at their end facing away from the detection area, can have a collar-like, radially outward-pointing projection, such that the side walls are flange-like. In particular, the collar-like projection enables insertion into an opening, for example into the opening in the outer shell of a vehicle, and corresponding fastening to the inner sides of the outer shell. The fastening sections of the housing are formed by the flange-like side walls, in particular by the collar-shaped projection of the flange-like side walls.

[0024] A further aspect of the invention relates to a vehicle with a sensor device according to the invention, wherein it is provided essential to the invention that the sensor device is connected by means of the fastening sections to the outer shell of the vehicle and / or to at least one component adjacent to the sensor device. In particular in vehicles, a sensor device according to the invention can be used to detect environmental influences, for example to detect the degree of wetting of a road surface with moisture. The degree of wetting of a road surface can be detected by swirling up spray water that strikes the detection area of ​​the sensor device. In particular, the structure-borne sound generated by the water droplets striking the detection device is detected by the structure-borne sound sensor.The arrangement of the reduced-thickness areas of the housing between the detection zone and the housing's mounting sections provides mechanical decoupling of the detection zone from the rest of the vehicle. This reduces the transmission of vibrations generated by the vehicle, for example, during driving, to the detection zone, allowing the measurement of the structure-borne sound signals generated by the water droplets without interference from the vibrations generated by the vehicle.

[0025] In a further development of the invention, the sensor device is accommodated, at least in sections, in an opening in the vehicle's outer shell. The vehicle's outer shell can have an opening into which the sensor device is accommodated, at least in sections. In particular, the sensor device can be accommodated in the opening such that the detection area is aligned flush with the vehicle's outer shell. For example, a wheel house liner can have an opening into which the sensor device can be accommodated. Thus, the detection area is arranged in the area of ​​the spray water stirred up by the tires, so that structure-borne sound signals generated by the spray water on the detection area can be detected.

[0026] In one embodiment of the invention, the sensor device is arranged on the side of the vehicle's outer shell facing away from the environment. The sensor device can be arranged on the inside of the outer shell, i.e., on the side of the vehicle's outer shell facing away from the environmental influences. In particular, the sensor device can be connected to the inside of the outer shell by means of the fastening sections. By being arranged on the inside of the outer shell, the sensor device is protected from environmental influences, such as weather.

[0027] The invention is further explained below with reference to an exemplary embodiment illustrated in the drawing. The schematic representation shows in detail: Fig. 1: a sensor device with a housing in a cross-section.

[0028] In Fig.1 shows a cross-sectional view of a sensor device for detecting sound, in particular structure-borne sound signals, comprising a structure-borne sound sensor 1 arranged in a housing 2. The housing 2 has a flat detection area 3. The structure-borne sound sensor 1 is arranged on the side of the detection area 3 facing the interior of the housing 2. In particular, the structure-borne sound sensor 1 can be designed as a piezoelectric film and can be connected to the detection area 3 in a flat manner. The structure-borne sound sensor 1 is thus protected from environmental influences by the housing 2 and is designed to detect structure-borne sound signals that propagate across the detection area 3. The flat detection area 3 is surrounded by side walls 4. The side walls 4 have fastening sections 5 for fastening to an object, in particular to a vehicle.The housing 2 with the side walls 4 and the fastening sections 5 is thus designed like a flange. In particular, the detection area 3 can be circular. The housing 2 with the fastening sections 5 is designed to be received in an opening of a vehicle, in particular in an opening in the outer shell 7 of a vehicle. In particular, the housing 2 with the fastening sections 5 can be arranged on the outer shell 7 of a vehicle such that the detection area 3 is arranged flush with the outer shell 7 of the vehicle. In particular, the housing 2 can be accommodated in an opening in a wheel arch of a vehicle. Environmental influences, in particular impinging splash water, can generate structure-borne sound signals in the detection area 3, which can be detected by the structure-borne sound sensor 1.The spray water can be spray water stirred up from a road surface by vehicle tires, so that the degree of wetting of a road surface with moisture can be determined using the structure-borne sound signals generated by the spray water. To prevent the measurements of the structure-borne sound signals generated by environmental influences from being disrupted by inherent vibrations of the object, in particular of the vehicle, for example vibrations during vehicle operation, by transmitting the vibrations to the detection area 3, the detection area 3 is mechanically decoupled from the fastening sections 5. For this purpose, areas of reduced material thickness 6 are arranged between the detection area 3 and the fastening sections 5. The areas of reduced material thickness 6 are formed in particular by grooves in the housing walls.The areas of reduced material thickness 6, for example, have a thinner wall thickness than the remaining areas of the housing 2, so that a lower transmission of vibrations can be expected than with a full wall thickness of the housing. Furthermore, due to the areas of reduced material thickness 6, the detection area 3 is more easily excited to vibration by environmental influences, thus enabling more sensitive detection of structure-borne sound signals in the detection area 3 by the structure-borne sound sensor 1. The areas of reduced material thickness 6 provide a mechanical decoupling of the detection area 3 from the fastening sections 5 or the object to which the housing 2 is attached.

[0029] All features mentioned in the above description and in the claims can be combined in any desired manner with the features of the independent claims. The disclosure of the invention is therefore not limited to the described or claimed feature combinations; rather, all feature combinations that are meaningful within the scope of the invention are to be considered disclosed.

Claims

[1] Sensor device for detecting sound, in particular for detecting structure-borne sound on a vehicle, in particular sound caused by environmental influences, with at least one sound sensor (1) and with at least one housing (2) surrounding the sound sensor (1) at least in sections, wherein the housing (2) has at least one flat detection area (3), wherein the sound sensor (1) is connected to the detection area (3) in a structure-borne sound-conducting manner and wherein the housing (2) has fastening sections (5) for fastening to an object (7), in particular for fastening to a vehicle, characterized by , that between the flat detection area (3) and at least one fastening section (5) of the housing (2) at least one area (6) with reduced material thickness of the housing (2) is arranged, that side walls (4) of the housing (2) are arranged adjacent to the detection area (3) and that the side walls (4) have at least one material-reduced region (6) which surrounds the detection region (3) at least in sections for mechanically decoupling the sound sensor (1) from the object (7) on which the sensor device is arranged. [2] Sensor device according to claim 1, characterized by that the sound sensor (1) is arranged on one side of the detection area (3) and that the detection area (3) has an area (6) with reduced material thickness that surrounds the sound sensor (1) at least in sections. [3] Sensor device according to one of claims 1 or 2, characterized by that at least one region (6) of reduced material thickness is formed by a groove. [4] Sensor device according to one of claims 1 to 3, characterized bythat at least two regions (6) of reduced material thickness, in particular two grooves, are arranged at least approximately parallel to one another. [5] Sensor device according to one of claims 1 to 4, characterized by that at least one groove is arranged on the side of the flat detection area (3) having the sound sensor (1) and / or on the side of the detection area (3) facing away from the sound sensor (1). [6] Sensor device according to one of claims 1 to 5, characterized by that the base area of ​​the detection area (3) is circular and that at least one groove runs at least approximately parallel to the edge of the detection area (3). [7] Sensor device according to one of claims 1 to 6, characterized by that at least one material-reduced region (6) is formed by a tapering of the wall thickness of the side walls (4). [8] Sensor device according to one of claims 1 to 7, characterized by that the housing (2) is designed to be received in an opening in the outer shell (7) of a vehicle. [9] Sensor device according to claim 8, characterized by that the side walls (4) are designed like a flange for insertion into an opening in the outer shell (7) of a vehicle. [10] Vehicle with a sensor device according to one of claims 1 to 9, characterized by that the sensor device is connected by means of the fastening areas (5) to the outer shell (7) of the vehicle and / or to at least one component adjacent to the sensor device. [11] Vehicle according to claim 10, characterized by that the sensor device is at least partially accommodated in an opening of the outer shell (7) of a vehicle. [12] Vehicle according to claim 10, characterized by that the sensor device is arranged on the side of the outer shell (7) of the vehicle facing away from the surroundings.

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