ULTRASCHALLSENSOR

Abstract

Ultrasonic sensor (1), comprising: - an ultrasonic element (5) configured to perform a conversion between an electrical signal and an ultrasonic oscillation; and - an element housing (6) having a cylindrical shape with a base and configured to house the ultrasonic element within the element housing housing, wherein - the element housing features: - a side plate section (61) formed into a cylindrical shape surrounding a directed central axis (DA) of the ultrasonic sensor, and - a base plate section (62) that closes an end side of the side plate section in an axial direction parallel to the directed central axis, - the side panel section has: - a thin section (611) having a circular cylindrical shape or a partial circular cylindrical shape having a predetermined thickness in a radial direction orthogonal to the directed central axis, and - a thick section (613) provided in a section of the thin section in a circumferential direction around the directed central axis and having a radial thickness greater than the predetermined thickness, - the ultrasonic element is attached to the base plate section, - the ultrasonic element and the element housing form an ultrasonic transceiver (4), and - the thick section is designed such that the ultrasonic transceiver (4) is provided with a first structural resonance frequency and a second structural resonance frequency, neither of which is a high-order resonance frequency of the other, by vibration of the ultrasonic element excited by input of the electrical signal.

Description

BACKGROUND [Technical Field]

[0001] The present disclosure relates to an ultrasonic sensor. [State of the art]

[0002] An ultrasonic transceiver (transmitter / receiver) that transmits and receives in the ultrasonic frequency band is used, for example, in industrial applications as an ultrasonic sensor, such as an onboard corner sensor. This type of ultrasonic transceiver consists of a cylindrical housing with a base and a piezoelectric element attached to a section of the base of the housing.

[0003] A technology is known for this type of ultrasonic transceiver in which a single transceiver has multiple resonant frequencies (see, for example, JP 5 276 352 B2). This technology can improve the functionality of the ultrasonic transceiver or of an ultrasonic sensor in conjunction with the transceiver. For example, a single transceiver can perform both near- and long-range detection.

[0004] In particular, the ultrasonic transceiver described in JP 5 276 352 B2 comprises two cylindrical housings with bases of different sizes. The ultrasonic transceiver is formed by a base face of a large cylindrical housing with a base and an opening section of a small cylindrical housing with a base, which are joined together, and a piezoelectric element attached to a base face of the small cylindrical housing with a base.

[0005] In conventional technology, where a single ultrasonic transceiver has multiple resonant frequencies, the shape of the housing containing ultrasonic elements such as the piezoelectric element becomes complex. This leads to problems regarding manufacturing costs and durability.

[0006] From DE 196 14 885 C1 a sensor for transmitting and / or receiving acoustic signals, in particular in the ultrasound range, is also known, which has a pot-shaped housing, on the bottom of which a vibrating element is arranged, which forms a vibrating diaphragm with it, and at least a thickening of the wall in the area of ​​the vibrating diaphragm, wherein the thickness of the wall is increased at a predetermined point such that the base area of ​​the vibrating diaphragm forms a circular segment.

[0007] DE 101 23 612 A1 relates to an ultrasonic wave transceiver that can be used, for example, as a distance sensor or rear sensor in a vehicle. DE 10 2004 031 310 A1 discloses a membrane housing for an ultrasonic transducer with a cavity for supporting a diaphragm that is electroplated, preferably with a chromium coating.

[0008] DE 10 2006 050 037 A1 relates to an ultrasonic transducer for a vehicle and a corresponding method for manufacturing such an ultrasonic transducer. JP 2004 040 614 A teaches an ultrasonic sensor for transmitting an ultrasonic signal and receiving a wave reflected by an obstacle in order to detect the presence of an obstacle, and in particular a drip-proof ultrasonic sensor suitable for a reversing sonar or a corner sonar of a motor vehicle.

[0009] WO 2016 / 147917 A1 relates to an ultrasonic sensor with a cylindrical housing with a closed end, a piezoelectric element connected to an inner bottom surface of the housing, and an associated conductive element. JP 2009 065380 A discloses an ultrasonic sensor for use in vehicles for obstacle detection, with direction-adjustment units arranged on the side opposite the piezoelectric element assembly in the main section to adjust the directionality of the ultrasonic waves.

[0010] From DE 10 2015 217 778 A1 an acoustic sensor with a membrane and an electroacoustic transducer is known, and DE 10 2021 209 732 A1 relates to a sound transducer, which is in particular designed as an ultrasonic transducer, and to a method for manufacturing the sound transducer.

[0011] Another ultrasonic transducer for distance measurement is known from DE 199 12 772 A1. DE 199 17 862 A1 relates to an ultrasonic sensor for emitting and / or detecting ultrasonic energy and, in particular, to an ultrasonic sensor for detecting the existence of objects or measuring a distance to an object, which is used, for example, as an obstacle detection sensor, a vehicle reversing sonar, or a corner sonar. SUMMARY

[0012] The purpose of the present disclosure is to provide a configuration in which multiple resonant frequencies are provided, while avoiding complexity in the form as much as possible.

[0013] The problem is solved by the subject matter of the main claim. Advantageous further developments are specified in the dependent claims.

[0014] In the ultrasonic sensor according to the invention, when an electrical signal is applied to the ultrasonic element, which is housed on the inside of the cylindrical element housing with a base, the ultrasonic element vibrates in an ultrasonic manner to excite the element housing. An ultrasonic transceiver (transmitter-receiver) configured by the ultrasonic element and the element housing then vibrates in a predetermined vibration mode.

[0015] With regard to this point, in the configuration according to the invention, the side plate section, which is the cylindrical section of the cylindrical shape with a base, comprises the thin section and the thick section. The thick section is provided within a portion of the thin section in the circumferential direction. The thin section has a circular cylindrical shape or a partial circular cylindrical shape. The thick section has a radial thickness that is greater than the predetermined thickness of the thin section.

[0016] Consequently, in the ultrasonic transceiver, in addition to a normal oscillation mode when the thick section is absent, an additional oscillation mode is present, which is attributed to the presence of the thick section. This generates a second structural resonance frequency, in addition to a first structural resonance frequency caused by the normal oscillation mode, which is attributed to the occurrence of the additional oscillation mode. The first and second structural resonance frequencies have a ratio such that neither is a higher-order resonance frequency than the other.

[0017] In this way, due to the configuration according to the invention, the individual ultrasound transceiver can be provided with multiple structural resonance frequencies by a very simple change in shape, i.e., by the thick section within the thin section in the circumferential direction. Thus, the complexity of the shape of the ultrasound transceiver with multiple structural resonance frequencies can be avoided as much as possible.

[0018] Reference numerals in parentheses may be appended to elements in any section of the application documents. However, these reference numerals only show examples of corresponding relationships between the elements and specific means according to the embodiments described below. Therefore, the present disclosure is in no way limited by the reference numerals described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The attached drawings show: Fig. 1 a perspective view of the external appearance of a vehicle in which an ultrasonic sensor according to an embodiment is mounted; Fig. 2 a cross-sectional view of a schematic configuration of the in Fig. 1 ultrasonic sensor shown; Fig. 3 a perspective view of a schematic configuration of an ultrasound transceiver according to Fig. 2; Fig. 4 a diagram of an acoustic impedance of the in Fig. 3 ultrasound transceivers shown; Fig. 5 a top view of a schematic configuration of the ultrasound transceiver in a variation example; Fig. 6 a cross-sectional view along line VI-VI in Fig. 5; Fig. 7 a cross-sectional view of a schematic configuration of the ultrasound transceiver in another variation example; Fig. 8 a top view of a schematic configuration of the ultrasound transceiver in yet another variation example; Fig. 9 a cross-sectional view along line IX-IX in Fig. 8; Fig. 10A a perspective view of a schematic configuration of the ultrasound transceiver in yet another variation example; Fig. 10B a cross-sectional view of the in Fig. 10A ultrasound transceiver shown; Fig. 11 a perspective view of a schematic configuration of the ultrasound transceiver in yet another variation example; Fig. 12 a cross-sectional view of the in Fig. 11 ultrasonic sensor shown; and Fig. 13 a cross-sectional view along line XIII-XIII in Fig. 12. DESCRIPTION OF THE EXECUTION FORMS

[0020] An embodiment of the present disclosure is described below with reference to the drawings. Here, with regard to various variations applicable to an embodiment, the understanding of the embodiment may be hindered if the variations are presented within a series of descriptions related to the embodiment. Therefore, the variations are not included in the series of descriptions of the embodiment but are subsequently described collectively. (Form of execution)

[0021] As in Fig. Figure 1 shows a vehicle V, a so-called four-wheeled automobile with a box-shaped body V1. A front bumper V2 is mounted in a front end section of the body V1. A rear bumper V3 is mounted in a rear end section of the body V1. The front bumper V2 and the rear bumper V3 are body components.

[0022] Mounting holes V4 are formed in the front bumper V2 and the rear bumper V3. Mounting hole V4 is a through-hole used to mount an ultrasonic sensor 1. The ultrasonic sensor 1 is an onboard clearance sonar. The ultrasonic sensor 1 is mounted in the front bumper V2 and the rear bumper V3. (Ultrasonic sensor)

[0023] Fig. Figure 2 shows a schematic configuration of the ultrasonic sensor 1 in a state where the ultrasonic sensor 1 is mounted in the front bumper V2. For the sake of simplicity, in Fig. 2. A right-handed orthogonal XYZ coordinate system is determined such that a Z-axis runs parallel to a directed central axis DA (a central axis of directional action) of the ultrasonic sensor 1. At this time, a direction parallel to the directed central axis DA is called the axial direction. A top side in Fig. 2, i.e., a side with a positive direction on the Z-axis, is also referred to as the tip end face in the axial direction. Similarly, a bottom face in Fig. 2, i.e., a side with a negative direction on the Z-axis, also called the base end in the axial direction. Furthermore, any direction orthogonal to the axial direction is also called an in-plane direction. That is, the in-plane direction is a direction parallel to an XY plane in Fig. 2 proceeds.

[0024] As in Fig. As shown in Figure 2, the ultrasonic sensor 1 comprises a sensor housing 2, an elastic mounting element 3, and an ultrasonic transceiver (transmitter-receiver) (also called an ultrasonic transducer) 4. The ultrasonic transceiver 4 comprises an ultrasonic element 5 and an element housing 6. A configuration of each section that forms the ultrasonic sensor 1 is described below.

[0025] The sensor housing 2 forms a housing for the ultrasonic sensor 1. The sensor housing 2 is configured to hold the elastic retaining element 3. The elastic retaining element 3 comprises an elastic resin material, such as silicone rubber, which has insulating and elastic properties. The elastic resin material is also referred to as a viscoelastic material or elastomer. The elastic retaining element 3 is configured to elastically hold the ultrasonic transceiver 4 by covering the base end of the ultrasonic transceiver 4 in the axial direction while leaving the tip end exposed in the axial direction. That is, the ultrasonic transceiver 4 is held by the sensor housing 2 via the elastic retaining element 3.

[0026] The sensor housing 2 comprises a main housing body section 21, a connector section 22, and a housing cylinder section 23. The sensor housing 2 is integrally formed from a hard synthetic resin such as polypropylene.

[0027] The main housing body section 21 is a box-shaped section with an outer form approximately resembling a parallelepiped. The main housing body section 21 is formed into a cylindrical shape with a base that is open axially at the base end. The connector section 22 extends from a side wall section of the main housing body section 21 to an outer surface. The connector section 22 is designed to electrically connect the ultrasonic sensor 1 to external devices, such as an electronic control unit.

[0028] The housing cylinder section 23 is an approximately circular cylindrical section. The housing cylinder section 23 is designed to extend axially from the main housing housing section 21 to the tip end. The housing cylinder section 23 is configured to axially retain the base end section of the elastic retaining element 3. The elastic retaining element 3 is formed into an approximately circular cylindrical shape, with its directed central axis DA being an axial center. A cylindrical space on an inner surface of the housing cylinder section 23 is provided to communicate with an approximately rectangular parallelepiped space on an inner surface of the main housing body section 21. Hereinafter, the space on the inner surface of the housing cylinder section 23 and the space on the inner surface of the main housing body section 21 are collectively referred to as the space on an inner surface of the sensor housing 2.

[0029] A printed circuit board 24, a wiring section 25, and a shielding section 26 are housed in the space on the inside of the sensor housing 2. The printed circuit board 24, which controls the operations of the ultrasonic sensor 1, is located in the main body section 21 of the housing. The wiring section 25 is provided for electrically connecting the ultrasonic transceiver 4 and the printed circuit board 24. The shielding section 26 is attached to an inner surface of the sensor housing 2 to provide electromagnetic shielding to the printed circuit board 24 and the wiring section 25 by covering them.

[0030] A damping element 27 is a circular, disc-shaped element. The damping element 27 has an outer diameter that corresponds to an inner diameter of the elastic retaining element 3. That is, the damping element 27 is fitted into a cylindrical space on an inner side of the elastic retaining element 3, further axially towards the base end than the ultrasonic transceiver 4. The damping element 27 is designed to suppress the transmission of vibrations from the ultrasonic transceiver 4 to the sensor housing 2. In particular, the damping element 27 is formed by a foamed elastic body made of foamed silicone or the like, which has insulating and elastic properties.

[0031] The space on the inside of the sensor housing 2 is filled with a filler material 28. The filler material 28 is made of a synthetic resin material with insulating and elastic properties, such as silicone rubber. (Ultrasonic transceiver)

[0032] According to the present embodiment, the ultrasonic transceiver 4, formed by the ultrasonic element 5 and the element housing 6, performs the function of an ultrasonic transceiver. That is, the ultrasonic transceiver 4 is configured to transmit and receive ultrasonic waves.

[0033] In other words, the ultrasound transceiver 4 is configured to transmit ultrasound waves (test waves) along the directed center axis DA, based on a drive signal applied to the ultrasound transceiver 4. The directed center axis DA is a virtual semiline extending from the ultrasound transceiver 4 along a transmit / receive direction of the ultrasound waves. The directed center axis DA serves as a reference for the aiming angle. The directed center axis DA is also referred to as the detection axis. Furthermore, the ultrasound transceiver 4 is configured to receive ultrasound waves reflected from an object located at its periphery and to generate a received signal.

[0034] The ultrasonic element 5 is configured to convert an electrical signal into an ultrasonic vibration. The ultrasonic element 5 converts an electrical signal corresponding to the applied control signal into an ultrasonic vibration, thereby emitting the ultrasonic waves, and converts ultrasonic vibrations caused by received ultrasonic waves into the received signal. According to the present embodiment, the ultrasonic element 5 is a piezoelectric element and is formed into a thin film whose thickness direction is axial. (Element housing)

[0035] The element housing 6 has a cylindrical shape with a base, where the directed central axis DA is the axial center. The element housing 6 is configured to accommodate the ultrasonic element 5 inside the element housing 6. The configuration of the element housing is shown below with reference to the Fig. 2 and Fig. 3 described in more detail. Here, this corresponds to the in Fig. 3 right-handed orthogonal XYZ coordinate systems shown in the Fig. 2 right-handed orthogonal XYZ coordinate system shown.

[0036] The element housing 6 comprises a side plate section 61 and a base plate section 62. The side plate section 61 and the base plate section 62 are made of the same material. According to the present embodiment, the element housing 6 is seamlessly formed integrally from a metal, such as aluminum.

[0037] The side plate section 61 is formed into a cylindrical shape that surrounds the directed central axis DA. According to the present embodiment, the side plate section 61 is formed into a circular cylindrical shape that has an axial centerline that runs approximately parallel to the directed central axis DA.

[0038] The base plate section 62 is a flat plate- or thin-film-like section with a thickness direction running axially. The base plate section 62 is designed to close one end face of the side plate section 61 in the axial direction. In particular, the base plate section 62 is seamlessly and integrally connected to the tip end face of the side plate section 61 in the axial direction.

[0039] The ultrasonic element 5 is attached to the base plate section 62. That is, the ultrasonic element 5 is connected to the base plate section 62 while being housed in an interior space 63, which is a space on an inner side of the side plate section 61. When the ultrasonic element 5 transmits or receives ultrasonic waves, the base plate section 62 vibrates ultrasonically in the axial direction as it flexes, with an outer edge section of it, connected to the side plate section 61, serving as a fixed end.

[0040] The side plate section 61 comprises a thin section 611, a directional adjustment section 612, and a thick section 613. The thin section 611 is formed into a partial circular cylinder shape, having a predetermined thickness in a radial direction orthogonal to the directed central axis DA. The radial direction is a direction extending radially from the directed central axis DA. That is, the radial direction is the radial direction of a virtual circle when the virtual circle is drawn on a plane whose normal is the directed central axis DA. In this case, the center of the virtual circle is an intersection between the plane and the directed central axis DA. Furthermore, the radial thickness (radial directional dimension) of each section of the side plate section 61 can be referred to as its thickness.In other words, the thin section 611 has a fixed thickness that is thinner than the directional matching section 612 and the thick section 613.

[0041] According to the present embodiment, the predetermined thickness of the thin section 611 has a dimension that is closest to the thickness of the base plate section 62 in the axial direction, and to the dimensions of the side plate section 61 and the base plate section 62 in the radial and axial directions. In particular, the thin section 611 is shaped to have a thickness that is 0.3 to 2.0 times, preferably 0.5 to 1.5 times, and most preferably 0.7 to 1.2 times the thickness, i.e., an axial dimension, of the base plate section 62. The thin section 611 can typically be shaped to have a thickness that is approximately identical to that of the base plate section 62.

[0042] The directional adjustment section 612 has a thickness, i.e., a radial thickness (radial directional dimension), that is greater than that of the thin section 611. In particular, according to the present embodiment, when viewed from a line of sight parallel to the directed central axis DA, the directional adjustment section 612 is shaped into an arc surrounded by a support flange extending along the X-axis direction and an arc. Furthermore, the directional adjustment section 612 is arranged circumferentially around the directional central axis DA adjacent to the thin section 611. The circumferential direction is a circumferential direction of the virtual circle described above.

[0043] According to the present embodiment, a pair of thin sections 611 are arranged to face each other across the directed central axis DA. Similarly, a pair of directional matching sections 612 are arranged to face each other across the directed central axis DA. That is, when viewed from a line of sight parallel to the directed central axis DA, the interior 63 is formed into a rectangular shape with rounded corners, defined by a pair of semicircles and a pair of line segments, or an elliptical shape. Furthermore, the side plate section 61 includes the pair of thin sections 611 arranged according to the semicircles and the pair of directional matching sections 612 arranged according to the line segments. As a result, the ultrasonic transceiver 4 is configured to have a directional angle that is smaller in the Y-axis direction than in the X-axis direction.

[0044] The thick section 613 has a thickness, i.e., a radial thickness (radial dimension), that is greater than the predetermined thickness of the thin section 611. The thick section 613 is arranged in a position corresponding to the thin section 611 in the circumferential direction. Furthermore, the thick section 613 is provided in a section of the thin section 611 in the circumferential direction. Meanwhile, the thick section 613 is provided in at least one section of the thin section 611 in the axial direction.

[0045] That is, the thick section 613 is configured such that the ultrasonic transceiver 4 is provided with a first structural resonance frequency and a second structural resonance frequency resulting from the vibration of the ultrasonic element 5, which is excited by the input of an electrical signal. The first structural resonance frequency and the second structural resonance frequency both lie within an ultrasonic range. The first structural resonance frequency and the second structural resonance frequency have a ratio such that neither is a higher-order resonance frequency than the other. In particular, F2 ≠ n × F1 and F2 ≠ (r / s) × F1, where: F1 is the first structural resonance frequency; F2 is the second structural resonance frequency; F1 < F2; n is a natural number; and r and s are arbitrary single-digit natural numbers.

[0046] In particular, the thick section 613 is shaped such that it has a thickness greater than or equal to 1.1 times, preferably greater than or equal to 1.2 times, and especially preferably greater than or equal to 2 times the thickness of the thin section 611. Furthermore, the thick section 613 is preferably shaped such that it has a thickness less than or equal to 5 times the thickness of the thin section 611. Finally, the thick section 613 is shaped such that a width or circumferential dimension is greater than or equal to half (i.e., 1 / 2) of the thickness dimension of the thick section 613.

[0047] The width of the thick section 613 is a dimension of the thick section 613 in a direction orthogonal to both the axial and radial directions. Similarly, the thick section 613 is configured such that an axial dimension is greater than or equal to half (i.e., 1 / 2) of the thickness dimension of the thick section 613. The thick section 613 typically has a width and an axial dimension that is greater than or equal to twice the thickness of the thin section 611. According to the present embodiment, the thick section 613 extends over the entire length of the thin section 611 in the axial direction. In the Fig. In the example shown in Figure 3, the thick section 613 has a shape in which an octagonal prism extending in the axial direction is bisected along the axial direction.

[0048] According to the present embodiment, the thick section 613 is arranged circumferentially in an approximately central section of the thin section 611. Furthermore, the thick section 613 projects towards the side of the directed central axis DA. That is, to realize the structural resonance frequencies as described above, the thick section 613 is provided as a projecting section extending from the thin section 611 towards the directed central axis DA. A pair of thick sections 613 are also arranged to face each other along the directed central axis DA. (Effects)

[0049] The effects achieved by the present embodiment are described below with reference to the drawings.

[0050] In the ultrasonic sensor 1 configured according to the description above, the ultrasonic element 5 vibrates in an ultrasonic manner when an electrical signal is applied to the ultrasonic element 5, which is located on the inside of the element housing 6, which has a cylindrical shape with a base. This excites the element housing 6. The ultrasonic transceiver 4, formed by the ultrasonic element 5 and the element housing 6, then vibrates in a predetermined vibration mode.

[0051] With regard to this point, in the configuration described above, the side plate section 61, which is the cylindrical section of the cylindrical shape with a base, has the thin sections 611 and the thick sections 613. The thick section 613 is provided in a section of the thin section 611 in the circumferential direction. The thin section 611 has a partially circular cylindrical shape. The thick section 613 has a radial thickness (radial dimension) that is greater than the predetermined thickness of the thin section 611. Furthermore, the thick section 613 is provided in at least one section of the thin section 611 in the axial direction.

[0052] Therefore, in the ultrasonic transceiver 4, in addition to a normal vibration mode when the thick sections 613 are absent, an additional vibration mode occurs, which is due to the presence of the thick sections 613. This generates, alongside the first structural resonance frequency caused by the normal vibration mode, a second structural resonance frequency, which is attributed to the occurrence of the additional vibration mode. The first structural resonance frequency and the second structural resonance frequency have a ratio such that neither is a higher-order resonance frequency than the other.

[0053] Fig. Figure 4 shows the results of a computational simulation of a vibrational state of the in Fig. 3 ultrasound transceivers shown 4. In Fig. Figure 4 shows a horizontal axis F representing the frequency and a vertical axis Ω representing the acoustic impedance. As in Fig. 4 shown, are in the Fig. The ultrasonic transceiver 4 shown in Figure 3 generates two noticeable structural resonance frequencies in a range of 10 to 100 kHz. One structural resonance frequency, generated at approximately 52 kHz, corresponds to the normal vibration mode when the thick sections 613 are absent. The other structural resonance frequency, generated at approximately 67 kHz, is due to the occurrence of the additional vibration mode. Specifically, the additional vibration mode is estimated to be a combination of vibration waves from the normal vibration mode and waves reflected from the thick section 613.

[0054] That is, the thick section 613 is not merely a tiny protrusion used for positioning between components and the like. In particular, the thick section 613 has a size of a predetermined magnitude such that the first structural resonant frequency and the second structural resonant frequency, neither of which is a high-order resonant frequency of the other, are noticeably generated.

[0055] In this way, the individual ultrasound transceiver 4, due to the configuration described above, can be provided with multiple structural resonance frequencies by a very simple change in shape, i.e., by providing the thick section 613 within a section of the thin section 611 in the circumferential direction. Thus, the complexity of the shape of the ultrasound transceiver 4 with multiple structural resonance frequencies can be avoided as much as possible. (Examples of variations)

[0056] The present disclosure is not limited to the embodiment described above. Therefore, modifications may be made to the embodiment described above, as applicable. The descriptions of the following variation examples set forth the essential differences from the embodiment described above. Furthermore, sections according to the embodiment described above and in the variation examples that are identical or equivalent are provided with the same reference numerals. Therefore, in the descriptions of the following variation examples, the descriptions according to the embodiment described above apply to the components whose reference numerals correspond to those of the embodiment described above, unless there are technical inconsistencies or, in particular, additional descriptions are given.

[0057] The ultrasonic sensor 1 is not limited to being mounted on a vehicle. That is, the ultrasonic sensor 1 can be used for various purposes, in addition to its use as an onboard clearance sonar (distance sonar), corner sensor, and the like.

[0058] The ultrasonic sensor 1 is not limited to a configuration in which it is capable of both transmitting and receiving ultrasonic waves. For example, the ultrasonic sensor 1 can be configured to transmit only ultrasonic waves. Alternatively, the ultrasonic sensor 1 can be equipped with a function to receive only reflected waves from objects in the periphery, where the reflected waves are those of test waves emitted by another ultrasonic transmitter. In other words, the ultrasonic transceiver 4 can be used for transmitting and receiving as described above. Alternatively, the ultrasonic transceiver 4 can be used for transmitting (e.g., as an ultrasonic transmitter or ultrasonic speaker). As a further alternative, the ultrasonic transceiver 4 can be used for receiving (e.g., as an ultrasonic receiver or ultrasonic microphone).

[0059] The configuration of the sections of the ultrasonic transceiver 4 is also not limited to the specific example described above. In particular, for example, the external shape of the ultrasonic transceiver 4, i.e., the element housing 6, is not limited to an approximately circular column shape and can be an approximately hexagonal column shape, an approximately octagonal column shape, or the like.

[0060] The directional adjustment section 612 can be omitted. That is, the thin section 611 can be shaped into a circular cylinder with a fixed thickness that surrounds the directed central axis DA.

[0061] The shape of the thick section 613 is also not limited to the specific example described above. That is, as, for example, in the Fig. 5 and Fig. As shown in Figure 6, the thick section 613 can be shaped into a rectangular column extending in the axial direction.

[0062] The thick section 613 can be provided within a section of the thin section 612 in the axial direction. In particular, for example, as shown in Fig. As shown in Figure 7, the thick section 613 is designed to be separated from the base plate section 62.

[0063] Alternatively, as in the Fig. 8 and Fig. As shown in Figure 9, the thick section 613 is provided adjacent to the base plate section 62. In this case, the thick section 613 can be seamlessly and integrally connected to the base plate section 62.

[0064] Alternatively, as in the Fig. 10A and Fig. As shown in Figure 10B, the thick section 613 can be provided at an intermediate position of the thin section 6 in the axial direction. That is, the thick section 613 can be arranged at a position separated by a predetermined distance from both ends of the thin section 611 in the axial direction. In this case, the thin section 611 is formed in the axial direction on both the tip end face and the base end face of the thick section 613.

[0065] According to the embodiment described above and in the variation examples, the thickness, i.e., the radial thickness of the thick section 613, is fixed. However, the present disclosure is not limited to this. That is, the thick section 613 can be shaped such that its radial thickness changes along the axial direction.

[0066] The Fig.Figures 11 to 13 show an example of the preceding variation. In this variation, the thin section 611 is formed into a circular cylinder shape having a fixed thickness and surrounding the directed central axis DA. Furthermore, the thick section 613 extends axially over the entire thin section 611. In addition, the thick section 613 has a small projecting section 614, a large projecting section 615, and a dimensional change section 616.

[0067] The small projecting section 614 is provided at each end of the thick section 613 in the axial direction. The large projecting section 615 has a greater radial thickness than the small projecting section 614. The large projecting section 615 is located between the pair of small projecting sections 614. That is, the large projecting section 615 is located at an intermediate position of the thick section 613 in the axial direction. The dimensional change section 616 is a section in which the radial thickness changes. The dimensional change section 616 is located between the small projecting section 614 and the large projecting section 615.

[0068] Here, the small projecting section 614 can only be provided on one end face of the thick section 613 in the axial direction. In this case, the large projecting section 615 can be provided on the other end face of the side plate section 61 in the axial direction. In particular, for example, the large projecting section 615 can be seamlessly and integrally connected with the base plate section 62.

[0069] The ultrasonic element 5 is not limited to the piezoelectric element. That is, for example, a so-called capacitive element can be used as the ultrasonic element 5.

[0070] In the preceding descriptions, multiple components designed to be seamlessly integrated can be formed by joining individual components together. Similarly, multiple components formed by joining individual components can be seamlessly integrated.

[0071] In the descriptions above, several components that appear to be made of the same material may actually be made of different materials. Similarly, several components that appear to be made of different materials may actually be made of the same material.

[0072] Except in cases where an element forming the embodiment described above is clearly described as particularly necessary, is generally considered necessary, or the like, it is understood that the elements forming the embodiment described above are not strictly necessary. Furthermore, the present disclosure is not limited to specific numbers when a numerical value, such as a quantity, a numerical value, an amount, a range, or the like, of a component is mentioned, except in cases where the numerical value is clearly described as particularly necessary, is generally considered necessary, or the like.

[0073] Similarly, where a shape, direction, positional relationship or the like of a component or the like is mentioned, except in cases where the shape, direction, positional relationship or the like is clearly described as being particularly necessary, is generally clearly limited to a specific shape, direction, positional relationship or the like, or the like, the present disclosure is not limited to the shape, direction, positional relationship or the like.

[0074] The possible variations are not limited to those described above. Furthermore, several variations can be combined. Additionally, the embodiment described above can be combined, in whole or in part, with a variation, in whole or in part.

Claims

[1] Ultrasonic sensor (1) comprising: - an ultrasonic element (5) configured to perform a conversion between an electrical signal and an ultrasonic oscillation; and - an element housing (6) having a cylindrical shape with a base and configured to house the ultrasonic element within the element housing housing, wherein - the element housing has: - a side plate section (61) formed into a cylindrical shape surrounding a directed central axis (DA) of the ultrasonic sensor, and - a base plate section (62) that closes an end side of the side plate section in an axial direction parallel to the directed central axis, - the side panel section has: - a thin section (611) having a circular cylindrical shape or a partial circular cylindrical shape having a predetermined thickness in a radial direction orthogonal to the directed central axis, and - a thick section (613) provided in a section of the thin section in a circumferential direction around the directed central axis and having a radial thickness greater than the predetermined thickness, - the ultrasonic element is attached to the base plate section, - the ultrasonic element and the element housing form an ultrasonic transceiver (4), and - the thick section is designed such that the ultrasonic transceiver (4) is provided with a first structural resonance frequency and a second structural resonance frequency, neither of which is a high-order resonance frequency of the other, by vibration of the ultrasonic element excited by input of the electrical signal. [2] Ultrasonic sensor according to claim 1, wherein the predetermined thickness of the thin section has a dimension which is closest to a thickness of the base plate section in the axial direction, with dimensions of the side plate section and the base plate section in the radial and axial directions. [3] Ultrasonic sensor according to claim 1 or 2, wherein the thick section is provided to project to the side of the directed central axis. [4] Ultrasonic sensor according to any one of claims 1 to 3, wherein - the side plate section further comprises a directional matching section (612) which has a radial thickness greater than the thin section and is arranged circumferentially adjacent to the thin section; and - the thin section is shaped into a partial circular cylindrical shape. [5] Ultrasonic sensor according to claim 4, wherein - an interior space (63) in which the element housing is formed, wherein the interior space is a space on an inside of the side plate section and is formed into a rectangular shape with rounded corners or an elliptical shape formed by a pair of semicircles and a pair of line segments, when viewed from a line of sight parallel to the directed central axis; - the thin section comprises a pair of thin sections corresponding to the pair of semicircles arranged so that they are opposite each other about the directed central axis; and - the directional adjustment section comprises a pair of directional adjustment sections corresponding to the pair of line segments arranged so that they are opposite each other about the directed central axis. [6] Ultrasonic sensor according to one of claims 1 to 5, wherein the thick section is provided in at least one section of the thin section in the axial direction. [7] Ultrasonic sensor according to any one of claims 1 to 6, wherein the thick section is formed such that the radial thickness changes along the axial direction.

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