WO2021256189A1 - Ultrasonic sensor - Google Patents

Ultrasonic sensor Download PDF

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Publication number
WO2021256189A1
WO2021256189A1 PCT/JP2021/019776 JP2021019776W WO2021256189A1 WO 2021256189 A1 WO2021256189 A1 WO 2021256189A1 JP 2021019776 W JP2021019776 W JP 2021019776W WO 2021256189 A1 WO2021256189 A1 WO 2021256189A1
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WO
WIPO (PCT)
Prior art keywords
ultrasonic
plate portion
top plate
ultrasonic sensor
sensor according
Prior art date
Application number
PCT/JP2021/019776
Other languages
French (fr)
Japanese (ja)
Inventor
永児 小島
哲弥 加藤
厚司 水谷
格 石井
友貴 種村
達也 神谷
Original Assignee
株式会社デンソー
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社デンソー filed Critical 株式会社デンソー
Publication of WO2021256189A1 publication Critical patent/WO2021256189A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
    • B60S1/00—Cleaning of vehicles
    • B60S1/02—Cleaning windscreens, windows or optical devices
    • B60S1/56—Cleaning windscreens, windows or optical devices specially adapted for cleaning other parts or devices than front windows or windscreens
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
    • B60S1/00—Cleaning of vehicles
    • B60S1/02—Cleaning windscreens, windows or optical devices
    • B60S1/56—Cleaning windscreens, windows or optical devices specially adapted for cleaning other parts or devices than front windows or windscreens
    • B60S1/60—Cleaning windscreens, windows or optical devices specially adapted for cleaning other parts or devices than front windows or windscreens for signalling devices, e.g. reflectors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/93—Sonar systems specially adapted for specific applications for anti-collision purposes
    • G01S15/931—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/521—Constructional features
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein

Definitions

  • This disclosure relates to ultrasonic sensors.
  • the ultrasonic sensor described in Patent Document 1 is disposed in a case having a cylindrical shape with one bottom surface open, a plate disposed in the opening of this case, and substantially in the center of the other bottom surface in the case. It is composed of a sensor unit.
  • the plate is formed with a concentric pattern consisting of an annular region that allows ultrasonic waves to pass through and an annular region that does not allow ultrasonic waves to pass through.
  • ultrasonic sensors are: A cylindrical side plate portion that surrounds the central axis, and a plate-shaped portion that has a plate thickness direction in the axial direction parallel to the central axis and is provided so as to close one end of the side plate portion in the axial direction.
  • a microphone case having a top plate portion formed so that a transmitted wave, which is an ultrasonic wave, can pass through, and a microphone case.
  • a transmission unit that transmits the transmission wave and is housed in the microphone case in a state of being separated from the top plate portion.
  • An exciting unit that excites the microphone case so that foreign matter adhering to the top plate can be removed. It is equipped with.
  • each element may have a reference code in parentheses.
  • the reference numeral indicates only an example of the correspondence between the same element and the specific configuration described in the embodiment described later. Therefore, the present disclosure is not limited to the description of the reference numeral.
  • FIG. 1 It is a perspective view which shows the appearance of the vehicle which mounted the ultrasonic sensor which concerns on embodiment. It is a partial cross-sectional view showing the circumference of the ultrasonic sensor shown in FIG. 1 in an enlarged manner. It is sectional drawing which shows the schematic structure in 1st Embodiment of the ultrasonic microphone shown in FIG. It is a graph which shows the result of having examined the foreign matter adhesion state in the ultrasonic microphone shown in FIG. It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 3rd Embodiment. It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 4th Embodiment. It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 5th Embodiment. It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 6th Embodiment. It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on the modification.
  • the ultrasonic sensor 1 has a configuration as an in-vehicle sonar to which a vehicle V is mounted. That is, the ultrasonic sensor 1 is configured to be able to detect an object existing around the vehicle V by being mounted on the vehicle V.
  • the vehicle V is a so-called four-wheeled vehicle and has a box-shaped vehicle body V1.
  • the vehicle body V1 includes a vehicle body panel V2, a front bumper V3, and a rear bumper V4 as vehicle body parts constituting the outer panel.
  • the front bumper V3 is provided at the front end portion of the vehicle body V1.
  • the rear bumper V4 is provided at the rear end portion of the vehicle body V1.
  • the ultrasonic sensor 1 is configured to be mounted on the front bumper V3 and the rear bumper V4 to detect objects existing in front of and behind the vehicle V.
  • a state in which an ultrasonic sensor 1 is mounted on a front bumper V3 or a rear bumper V4 provided on a vehicle body V1 in a vehicle V is hereinafter referred to as an "in-vehicle state".
  • a plurality of (for example, four) ultrasonic sensors 1 are mounted on the front bumper V3 in an in-vehicle state.
  • a plurality of ultrasonic sensors 1 mounted on the front bumper V3 are arranged at different positions in the vehicle width direction.
  • a plurality of (for example, four) ultrasonic sensors 1 are mounted on the rear bumper V4.
  • the front bumper V3 and the rear bumper V4 are provided with mounting holes V5 for mounting the ultrasonic sensor 1.
  • the mounting hole V5 is formed in a round hole shape that penetrates the front bumper V3 and the rear bumper V4 in the thickness direction in the plate-shaped front bumper V3 and the rear bumper V4.
  • FIG. 2 shows one of a plurality of ultrasonic sensors 1 attached to the front bumper V3 in an in-vehicle state.
  • the configuration of the ultrasonic sensor 1 according to the first embodiment will be described with reference to FIGS. 2 and 3.
  • the front bumper V3 has a bumper outer surface V31 and a bumper back surface V32.
  • the bumper outer surface V31 is an outer surface of the front bumper V3 and is provided so as to face the vehicle body outer space SG, which is a space outside the vehicle V.
  • the bumper back surface V32 is a surface on the back side of the bumper outer surface V31 and is provided so as to face the vehicle body V, that is, the space inside the vehicle body SN, which is the space inside the front bumper V3.
  • the mounting hole V5 is provided so as to penetrate the front bumper V3 in the thickness direction by opening at the bumper outer surface V31 and the bumper back surface V32.
  • the ultrasonic sensor 1 is configured to be capable of transmitting and receiving ultrasonic waves. That is, the ultrasonic sensor 1 is configured to transmit an ultrasonic transmitted wave toward the vehicle body outer space SG along the central axis DA corresponding to the directional axis.
  • the "directivity axis" is a virtual straight line extending from the ultrasonic sensor 1 along the transmission / reception direction of ultrasonic waves, and serves as a reference for the directivity angle.
  • the "directional axis" may also be referred to as a directional central axis or a detection axis.
  • the ultrasonic sensor 1 receives a received wave including a reflected wave of the transmitted wave by an object existing outside, that is, around the vehicle V, from the vehicle body outer space SG, and generates an output signal corresponding to the reception state of the received wave. It is configured to do.
  • the right-handed XYZ Cartesian coordinate system is set so that the Y axis is parallel to the horizontal direction and the Z axis is parallel to the central axis DA as shown in the figure.
  • the direction parallel to the central axis DA is referred to as "axial direction".
  • the "tip side in the axial direction” is the transmission direction side of the transmitted wave, and corresponds to the upper side in FIGS. 2 and 3, that is, the Z-axis positive direction side.
  • the "base end side in the axial direction” corresponds to the lower side in FIGS. 2 and 3, that is, the negative direction side of the Z axis.
  • the end portion on the proximal end side in the axial direction of a certain component is referred to as “base end portion”, and the end portion on the distal end side in the axial direction is referred to as "tip portion”.
  • an arbitrary direction orthogonal to the axial direction is referred to as an "in-plane direction”.
  • the "in-plane direction” is a direction parallel to the XY plane in FIGS. 2 and 3.
  • the "in-plane direction” may also be referred to as the "diameter direction” in some cases.
  • the "diametrical direction” is a direction that is orthogonal to the central axis DA and is separated from the central axis DA.
  • the "diameter direction” is a direction in which the half straight line extends when a half straight line is drawn in the virtual plane starting from the intersection of the virtual plane orthogonal to the central axis DA and the central axis DA.
  • the "radial direction” is the radial direction of the circle when a circle is drawn in the virtual plane about the intersection of the virtual plane orthogonal to the central axis DA and the central axis DA.
  • the sensor case 2 constituting the housing of the ultrasonic sensor 1 has a case main body portion 2a, a sensor-side connector 2b, and a microphone accommodating portion 2c.
  • the sensor case 2 is integrally formed of an insulating synthetic resin.
  • the case body 2a is formed in a box shape.
  • a control circuit board (not shown) or the like is housed inside the case body 2a.
  • the sensor-side connector 2b extends from the case body 2a in a direction intersecting the central axis DA.
  • the sensor-side connector 2b is configured to be detachable from a wire-side connector (not shown) provided in a wire harness for electrical connection to an external device such as an ECU.
  • ECU is an abbreviation for Electronic Control Unit.
  • the microphone accommodating portion 2c is a substantially cylindrical portion surrounding the central axis DA, and projects from the case main body portion 2a toward the tip end side in the axial direction. In the vehicle-mounted state, the tip portion of the microphone accommodating portion 2c in the axial direction is accommodated in the mounting hole V5.
  • An ultrasonic sensor 1 includes a sensor case 2 and an ultrasonic microphone 3.
  • the ultrasonic microphone 3 is configured to have a substantially cylindrical outer shape with the central axis DA as the central axis.
  • the ultrasonic microphone 3 is housed in the microphone accommodating portion 2c so that the exposed surface 3a, which is the end surface on the distal end side in the axial direction, faces the vehicle body outer space SG in the vehicle-mounted state.
  • the exposed surface 3a is formed in a plane shape with the central axis DA as a normal.
  • the exposed surface 3a has a substantially circular shape when viewed from the outside space SG side of the vehicle body with a line of sight parallel to the central axis DA.
  • FIG. 3 shows a state in which the ultrasonic microphone 3 is taken out from the ultrasonic sensor 1 shown in FIG.
  • the ultrasonic microphone 3 has a microphone case 4 and a transmission unit 5.
  • the microphone case 4 constituting the housing of the ultrasonic microphone 3 is formed in a box shape having a substantially columnar outer shape.
  • the microphone case 4 is configured to accommodate the transmission unit 5 in the internal space SI, which is the space inside the microphone case 4.
  • the microphone case 4 has a side plate portion 41 formed in a cylindrical shape surrounding the central axis DA.
  • the side plate portion 41 is made of a metal material such as aluminum, which does not have ultrasonic transmission.
  • the side plate portion 41 is formed in a cylindrical shape having a central axis substantially parallel to the central axis DA. That is, the side outer wall surface 41a of the side plate portion 41, which is the outer wall surface facing the outer space SD, which is the space outside the microphone case 4, is formed in a cylindrical surface shape substantially parallel to the central axis DA. Further, the side inner wall surface 41b, which is an inner wall surface facing the internal space SI in the side plate portion 41, is formed in the shape of a cylindrical inner surface surrounding the central axis DA.
  • the microphone case 4 also has a top plate portion 42 which is a plate-shaped portion having a plate thickness direction in the axial direction.
  • the top plate portion 42 is provided so as to close the tip portion of the side plate portion 41 in the axial direction.
  • the top plate portion 42 is formed in a flat plate shape having a substantially constant plate thickness.
  • the top plate portion 42 is formed to have a plate thickness t of 0.4 mm or more, more specifically 0.4 to 10 mm. Further, the top plate portion 42 is seamlessly and integrally formed with the side plate portion 41 by using the same material as the side plate portion 41.
  • the top plate portion 42 has an outer surface 42a and an inner surface 42b.
  • the outer surface 42a is one of the pair of main surfaces of the top plate portion 42 that constitutes the exposed surface 3a, and is formed in a planar shape with the axial direction as the normal direction.
  • a "main surface” is a surface of a plate-shaped portion or member that is orthogonal to the plate thickness direction.
  • the inner surface 42b is one of the pair of main surfaces of the top plate portion 42 facing the internal space SI, and is formed in a planar shape with the axial direction as the normal direction.
  • the top plate portion 42 has a through hole 42c penetrating in the plate thickness direction.
  • the through hole 42c is provided along the axial direction so as to open at the outer surface 42a and the inner surface 42b. That is, the top plate portion 42 is formed so that the transmitted wave, which is an ultrasonic wave, passes through the through hole 42c so that the transmitted wave can be substantially transmitted.
  • the through hole 42c is formed in a round hole shape having an inner wall surface parallel to the central axis DA. That is, the through hole 42c is formed so that the cross-sectional shape having a cross section orthogonal to the central axis DA is circular. In the present embodiment, the through hole 42c is formed to have an inner diameter ⁇ of 0.8 mm or less, more specifically 0.01 to 0.8 mm.
  • the microphone case 4 also has a bottom plate portion 43.
  • the bottom plate portion 43 is provided so as to close the base end side of the side plate portion 41 in the axial direction.
  • the bottom plate portion 43 is formed of an insulating synthetic resin.
  • the bottom surface 43a which is an end surface facing the external space SD on the base end side in the axial direction of the bottom plate portion 43, is formed in a planar shape with the axial direction as the normal direction.
  • the connection terminal 43b extends from the bottom surface 43a toward the base end side in the axial direction.
  • the connection terminal 43b is a terminal member for electrically connecting the ultrasonic microphone 3 and a control circuit board (not shown) provided inside the case main body 2a, and is formed in a rod shape along the axial direction. ..
  • the outer edge portion in the radial direction of the upper surface 43c which is the end surface facing the internal space SI on the distal end side in the axial direction of the bottom plate portion 43, is joined to the side plate portion 41 via an adhesive layer (not shown).
  • the bottom plate portion 43 has a substrate support portion 43d.
  • the substrate support portion 43d extends from the upper surface 43c toward the tip end side in the axial direction.
  • the substrate support portion 43d has a recess 43e that supports the transmission portion 5 by opening toward the tip end side in the axial direction.
  • the transmitting unit 5 is housed in the microphone case 4 in a state of being separated from the top plate unit 42.
  • the transmission unit 5 is provided at a position facing the top plate unit 42. That is, the transmission unit 5 is arranged to face the top plate unit 42 with the internal space SI interposed therebetween. Specifically, the transmission unit 5 is provided so as to face the top plate unit 42.
  • the transmission unit 5 is configured to transmit the transmitted wave in the axial direction toward the top plate unit 42.
  • the transmission unit 5 has an ultrasonic element 51.
  • the ultrasonic element 51 is composed of an electric-mechanical conversion element such as a piezoelectric element that converts an electric signal and ultrasonic vibration.
  • the transmission unit 5 is configured so that the frequency of the transmitted wave is 20 kHz to 100 kHz.
  • the transmission unit 5 has a configuration as a transmission / reception unit that generates an output signal corresponding to the reception state of the received wave.
  • the ultrasonic element 51 has a configuration as a MEMS type piezoelectric transducer provided on the semiconductor substrate 52.
  • MEMS is an abbreviation for Micro Electro Mechanical System.
  • the semiconductor substrate 52 is supported by the substrate support portion 43d while being housed in the recess 43e.
  • the substrate bottom surface 53 which is one of the pair of main surfaces of the semiconductor substrate 52, is joined to the substrate support portion 43d.
  • the substrate upper surface 54 which is the other of the pair of main surfaces in the semiconductor substrate 52, is provided so as to face the top plate portion 42.
  • An ultrasonic element 51 is provided on the upper surface 54 of the substrate.
  • the ultrasonic microphone 3 is configured to be able to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the microphone case 4 with ultrasonic waves.
  • the ultrasonic element 51 provided so as to transmit the transmitted wave in the transmitting unit 5 excites the microphone case 4 for removing foreign matter in the top plate portion 42. It is configured to function as a part.
  • the ultrasonic element 51 is provided so as to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the top plate portion 42 with a transmitted wave.
  • the microphone case 4 is formed so as to have a resonance frequency higher than the frequency in the transmitted wave in a clean state in which foreign matter does not adhere to the top plate portion 42. More specifically, the top plate portion 42 has a resonance frequency higher than the frequency in the transmitted wave in a clean state.
  • the ultrasonic sensor 1 executes transmission / reception of ultrasonic waves at a predetermined timing set by an external device such as an ECU (not shown). That is, the ultrasonic sensor 1 transmits a transmitted wave, which is an ultrasonic wave, toward the vehicle body outer space SG. Further, the ultrasonic sensor 1 receives a received wave including a reflected wave of a transmitted wave by an object existing around the vehicle V.
  • an external device such as an ECU (not shown). That is, the ultrasonic sensor 1 transmits a transmitted wave, which is an ultrasonic wave, toward the vehicle body outer space SG. Further, the ultrasonic sensor 1 receives a received wave including a reflected wave of a transmitted wave by an object existing around the vehicle V.
  • the ultrasonic element 51 is excited by the input of the input signal to the connection terminal 43b, so that the transmitted wave is transmitted from the ultrasonic element 51.
  • the transmitted wave transmitted from the ultrasonic element 51 reaches the top plate portion 42 while propagating in the internal space SI along the axial direction.
  • the transmitted wave that has reached the top plate portion 42 propagates to the vehicle body outer space SG by passing through the through hole 42c provided in the top plate portion 42. That is, the transmitted wave passes through the top plate portion 42 having the through hole 42c. In this way, the transmitted wave is transmitted toward the vehicle body outer space SG.
  • the received wave propagates to the internal space SI by passing through the through hole 42c provided in the top plate portion 42. That is, the received wave passes through the top plate portion 42 having the through hole 42c.
  • an electric signal corresponding to the excitation state is generated in the ultrasonic element 51.
  • the output signal generated by executing signal processing such as amplification on the semiconductor substrate 52 for such an electric signal is output via the connection terminal 43b.
  • the outer surface 42a of the top plate portion 42 which constitutes the exposed surface 3a of the ultrasonic microphone 3, is exposed to the vehicle body outer space SG in the vehicle-mounted state. Therefore, foreign matter such as mud may adhere to the exposed surface 3a, that is, the outer surface 42a while the vehicle V is traveling.
  • the ultrasonic sensor 1 is mounted on the front bumper V3 or the rear bumper V4, the mounting height of the ultrasonic sensor 1 is low. In this case, foreign matter is likely to adhere to the outer surface 42a of the top plate portion 42.
  • the foreign matter adhering to the top plate portion 42 is satisfactorily removed by exciting the microphone case 4 with ultrasonic waves.
  • the occurrence of problems such as deterioration of detection performance due to adhesion of foreign matter is suppressed as much as possible. Therefore, according to such a configuration, the reliability of the ultrasonic sensor 1 is improved.
  • the excitation of the microphone case 4 for removing foreign matter is performed by using the transmitted wave transmitted from the ultrasonic element 51. Therefore, the foreign matter adhering to the top plate portion 42 can be satisfactorily removed by a simple apparatus configuration.
  • the foreign matter adhesion state in the top plate portion 42 may differ depending on the structure of the top plate portion 42 even if the foreign matter adhesion conditions such as running conditions are the same. Therefore, in the foreign matter removing configuration in the present embodiment in which the microphone case 4 is excited by ultrasonic waves to remove foreign matter, foreign matter easily adheres to the top plate portion 42, or foreign matter adheres to the top plate portion 42 is another. It is effective when it is difficult to remove depending on the removing means.
  • the outer surface 42a of the top plate portion 42 constituting the exposed surface 3a is matted to match the painted surface of the vehicle body panel V2
  • foreign matter such as mud easily adheres to the outer surface 42a.
  • an antifouling coating is repeatedly applied to the painted surface of the vehicle body panel V2 at regular intervals (for example, during periodic inspection of the vehicle V).
  • FIG. 4 shows the result of experimentally examining the influence on the foreign matter adhesion state due to the dimensional change of the plate thickness t of the top plate portion 42 and the inner diameter ⁇ of the through hole 42c.
  • the lower limit of the inner diameter ⁇ may be, for example, about 0.01 mm in consideration of processing restrictions and the like.
  • the plate thickness t when the plate thickness is 0.4 mm or more, wax clogging in the through hole 42c occurs remarkably, and it is necessary to remove it by excitation.
  • the upper limit of the plate thickness t may be, for example, about 10 mm in consideration of restrictions on the physique of the ultrasonic sensor 1.
  • the microphone case 4 has a resonance frequency higher than the frequency in the transmitted wave in a clean state in which foreign matter does not adhere to the top plate portion 42.
  • the resonance frequency in the microphone case 4 does not match the frequency in the transmitted wave in a clean state in which no foreign matter adheres to the top plate portion 42.
  • the resonance frequency in the microphone case 4 drops from the clean state and coincides with the frequency in the transmitted wave.
  • the microphone case 4 is automatically excited to the extent that foreign matter can be removed in the non-clean state. Then, when the foreign matter is removed and the state becomes clean, the excitation in the microphone case 4 is settled. Therefore, according to such a configuration, the microphone case 4 can be appropriately excited according to the foreign matter adhering state.
  • the schematic configuration of the ultrasonic microphone 3 according to this embodiment is the same as that in FIG. That is, also in the present embodiment, in the ultrasonic microphone 3, the ultrasonic element 51 provided so as to transmit the transmitted wave at the transmitting unit 5 excites the microphone case 4 for removing foreign matter at the top plate portion 42. It is configured to function as an exciting part.
  • the ultrasonic element 51 is provided so as to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the side plate portion 41 with a transmitted wave.
  • the ultrasonic microphone 3 is configured to excite the side plate portion 41 by using a portion outside the FOV, that is, a side lobe in the transmitted wave transmitted from the transmitting unit 5.
  • FOV is an abbreviation for Field of View.
  • the transmission unit 5 includes an additional ultrasonic element 55 in addition to the ultrasonic element 51.
  • the additional ultrasonic element 55 is composed of an electric-mechanical conversion element such as a piezoelectric element that converts an electric signal and ultrasonic vibration.
  • the additional ultrasonic element 55 has a configuration as a MEMS type piezoelectric transducer provided on the semiconductor substrate 52, and is provided on the upper surface 54 of the substrate.
  • the transmission unit 5 includes a plurality of electric-mechanical conversion elements, that is, an ultrasonic element 51 and an additional ultrasonic element 55, which convert an electric signal and ultrasonic vibration.
  • the ultrasonic element 51 which is one of the plurality of electric-mechanical conversion elements, is provided so as to transmit a transmitted wave.
  • the additional ultrasonic element 55 which is another one of the plurality of electric-mechanical conversion elements, is provided to function as an exciting unit that excites the microphone case 4 for removing foreign matter in the top plate portion 42. ..
  • the fourth embodiment will be described with reference to FIG.
  • the case exciting element 61 is fixed to the microphone case 4.
  • the case excitation element 61 is an electric-mechanical conversion element that converts an electric signal and ultrasonic vibration, and is configured to excite the microphone case 4 by applying a drive signal.
  • the case exciting element 61 is joined on the inner surface 42b of the top plate portion 42 at a position where the through hole 42c is not provided in the in-plane direction.
  • the case exciting element 61 is provided so as to function as an exciting unit for exciting the microphone case 4 for removing foreign matter in the top plate portion 42, separately from the transmitting unit 5 that transmits the transmitted wave. There is. Therefore, according to such a configuration, it is possible to execute the foreign matter removing operation without affecting the object detection operation timing by transmitting and receiving the transmitted wave in the transmitting unit 5. Further, the case exciting element 61 is fixed to the microphone case 4 so as to directly excite the microphone case 4. Therefore, according to such a configuration, good foreign matter removing performance can be realized.
  • the ultrasonic element 51 provided so as to transmit the transmitted wave by the transmitting unit 5 is used. It is configured to function as an exciting unit that excites the microphone case 4 for removing foreign matter in the top plate portion 42.
  • the transmitting unit 5 excites the side plate portion 41 by the transmitted wave so as to remove foreign substances such as mud adhering to the top plate portion 42. It is provided.
  • the microphone case 4 has a side plate resonance portion 411 as a resonance portion that resonates with ultrasonic waves transmitted from the transmission unit 5.
  • the side plate resonance portion 411 is provided in the side plate portion 41.
  • the side plate resonance portion 411 has a structure as a thin-walled portion or a thick-walled portion that adjusts the resonance frequency in the side plate portion 41. According to such a configuration, the side plate portion 41 can be efficiently excited for removing foreign matter by using the transmission unit 5.
  • the transmission unit 5 is provided so as to remove foreign matter such as mud adhering to the top plate portion 42 by exciting the top plate portion 42 by the transmitted wave. Has been done.
  • the microphone case 4 has a top plate resonance portion 412 as a resonance portion that resonates by the ultrasonic wave transmitted from the transmission unit 5.
  • the top plate resonance portion 412 is provided on the top plate portion 42.
  • the top plate resonance portion 412 has a structure as a thin-walled portion or a thick-walled portion that adjusts the resonance frequency of the top plate portion 42.
  • the top plate resonance portion 412 is arranged outside the region where the through hole 42c is provided in the radial direction. According to such a configuration, the top plate portion 42 can be efficiently excited for removing foreign matter by using the transmission unit 5.
  • the mounting target of the ultrasonic sensor 1 is not limited to the front bumper V3 and the rear bumper V4.
  • the ultrasonic sensor 1 may be mounted on the vehicle body panel V2. That is, the mounting hole V5 may also be provided in the vehicle body panel V2.
  • the ultrasonic sensor 1 is not limited to a configuration capable of transmitting and receiving ultrasonic waves. That is, for example, the ultrasonic sensor 1 may have a configuration capable of transmitting only ultrasonic waves. Alternatively, the ultrasonic sensor 1 may have only a function of receiving a reflected wave of a transmitted wave, which is an ultrasonic wave transmitted from another ultrasonic transmitter, by an object existing in the surroundings.
  • each part of the ultrasonic sensor 1 is not limited to the above specific example.
  • the outer shape of the ultrasonic microphone 3, that is, the microphone case 4 is not limited to a substantially columnar shape, and may be a substantially regular hexagonal columnar shape, a substantially regular octagonal columnar shape, or the like. Further, the microphone case 4 may be formed in a substantially columnar shape or a substantially frustum shape.
  • the side plate portion 41 and the top plate portion 42 may be seamlessly and integrally formed of the same material as described above.
  • the side plate portion 41 and the top plate portion 42 may be formed of different materials.
  • the top plate portion 42 may be formed of a porous material such as porous ceramics.
  • the top plate portion 42 has passability or transparency of the transmitted wave and the received wave even if the through hole 42c shown in FIG. 3 or the like is not provided. Therefore, according to such a configuration, by omitting the through hole 42c shown in FIG. 3 and the like, the waterproof and dustproof properties of the ultrasonic microphone 3 are improved.
  • the top plate portion 42 may have a mesh-like structure, a grid structure, an isogrid structure, or a honeycomb structure.
  • the through hole 42c may have a polygonal cross-sectional shape due to a cross section orthogonal to the central axis DA.
  • the inner diameter in this case is the maximum diameter, that is, the diameter of the circumscribed circle in the polygonal shape.
  • the ultrasonic element 51 is not limited to the PMUT as in each of the above embodiments.
  • PMUT is an abbreviation for Piezoelectric Micro-machined Ultrasonic Transducers.
  • the ultrasonic element 51 may have a configuration as a CMUT.
  • CMUT is an abbreviation for Capacitive Micro-machined Ultrasound Transducer.
  • the ultrasonic element 51 may have a bulk type configuration.
  • the transmission direction of the transmitted wave in the transmitting unit 5 is the axial direction toward the top plate unit 42.
  • the present disclosure is not limited to such embodiments. That is, for example, the transmission direction of the transmitted wave in the transmitting unit 5 may be a direction (for example, an in-plane direction) that intersects the axial direction toward the top plate unit 42.
  • a plurality of embodiments can be combined with each other as long as there is no technical contradiction.
  • the additional ultrasonic element 55 according to the third embodiment shown in FIG. 5 may be provided so as to excite the side plate portion 41. That is, the second embodiment and the third embodiment can be combined with each other.
  • the additional ultrasonic element 55 in the third embodiment shown in FIG. 5 can also be provided in the configuration of the fourth embodiment shown in FIG. That is, the third embodiment and the fourth embodiment can be combined with each other.
  • the additional ultrasonic element 55 in the third embodiment shown in FIG. 5 can be provided in the configuration of the sixth embodiment shown in FIG. That is, the third embodiment and the sixth embodiment can be combined with each other.
  • the plurality of components that are seamlessly and integrally formed with each other may be formed by laminating separate members from each other.
  • a plurality of components formed by laminating separate members may be seamlessly and integrally formed with each other.
  • the plurality of components formed of the same material may be formed of different materials.
  • a plurality of components that were formed of different materials may be formed of the same material.
  • the modified example is not limited to the above example. That is, for example, any one of the plurality of embodiments and any one of the plurality of modifications can be combined with each other as long as there is no technical conflict. Similarly, one of the variants and the other can be combined with each other as long as there is no technical conflict.

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Abstract

An ultrasonic sensor comprises a microphone case (4), a transmission unit (5), and an excitation unit (51). The microphone case has a side plate part (41) and a top plate part (42). The side plate part is formed in a tubular shape surrounding a center axis (DA). The top plate part is a plate-shaped part having a thickness direction in an axial direction parallel to the center axis, being provided so as to close one end part of the side plate part in the axial direction, and being formed so as to be able to transmit transmission waves, which are ultrasonic waves. The transmission unit that transmits the transmission waves is contained in the microphone case in a state separated from the top plate part. The excitation unit excites the microphone case so as to be able to remove foreign matter that has adhered to the top plate part.

Description

超音波センサUltrasonic sensor 関連出願への相互参照Cross-reference to related applications
　本出願は、２０２０年６月１６日に出願された日本特許出願番号２０２０－１０３７８２号に基づくもので、ここにその記載内容が参照により組み入れられる。 This application is based on Japanese Patent Application No. 2020-103782 filed on June 16, 2020, the contents of which are incorporated herein by reference.
　本開示は、超音波センサに関する。 This disclosure relates to ultrasonic sensors.
　特許文献１に記載の超音波センサは、一底面が開口した円筒の形状を有するケースと、このケースの開口部に配設されたプレートと、ケース内の他の底面のほぼ中央に配設されたセンサ部とから構成される。プレートには、超音波を透過させる環状領域と、透過させない環状領域とからなる、同心円状のパターンが形成されている。 The ultrasonic sensor described in Patent Document 1 is disposed in a case having a cylindrical shape with one bottom surface open, a plate disposed in the opening of this case, and substantially in the center of the other bottom surface in the case. It is composed of a sensor unit. The plate is formed with a concentric pattern consisting of an annular region that allows ultrasonic waves to pass through and an annular region that does not allow ultrasonic waves to pass through.
特開平５－２３２２４１号公報Japanese Unexamined Patent Publication No. 5-232241
　特許文献１に記載の超音波センサのように、ケースの天板部を超音波が通過あるいは透過する構成の超音波センサにおいて、天板部に異物が付着することがあり得る。かかる異物の付着により、検知性能低下等の不具合が発生するおそれがある。
　本開示は、上記に例示した事情等に鑑みてなされたものである。すなわち、本開示は、例えば、ケースの天板部を超音波が通過あるいは透過する構成の超音波センサにおいて、天板部に付着した異物を良好に除去可能な構成を提供する。 In an ultrasonic sensor having a structure in which an ultrasonic wave passes or passes through a top plate portion of a case like the ultrasonic sensor described in Patent Document 1, foreign matter may adhere to the top plate portion. Adhesion of such foreign matter may cause problems such as deterioration of detection performance.
This disclosure has been made in view of the circumstances exemplified above. That is, the present disclosure provides, for example, a configuration capable of satisfactorily removing foreign matter adhering to the top plate portion of an ultrasonic sensor having a configuration in which ultrasonic waves pass or pass through the top plate portion of the case.
　本開示の１つの観点によれば、超音波センサは、
　中心軸を囲む筒状に形成された側板部と、前記中心軸と平行な軸方向に板厚方向を有し前記軸方向における前記側板部の一端部を閉塞するように設けられた板状部であって超音波である送信波が通過可能に形成された天板部と、を有するマイクケースと、
　前記天板部から離隔した状態で前記マイクケースに収容された、前記送信波を発信する送信部と、
　前記天板部に付着した異物を除去可能に、前記マイクケースを励振する励振部と、
　を備えている。 According to one aspect of the present disclosure, ultrasonic sensors are:
A cylindrical side plate portion that surrounds the central axis, and a plate-shaped portion that has a plate thickness direction in the axial direction parallel to the central axis and is provided so as to close one end of the side plate portion in the axial direction. A microphone case having a top plate portion formed so that a transmitted wave, which is an ultrasonic wave, can pass through, and a microphone case.
A transmission unit that transmits the transmission wave and is housed in the microphone case in a state of being separated from the top plate portion.
An exciting unit that excites the microphone case so that foreign matter adhering to the top plate can be removed.
It is equipped with.
　なお、出願書類中の各欄において、各要素に括弧付きの参照符号が付されている場合がある。この場合、参照符号は、同要素と後述する実施形態に記載の具体的構成との対応関係の単なる一例を示すものである。よって、本開示は、参照符号の記載によって、何ら限定されるものではない。 In each column of the application documents, each element may have a reference code in parentheses. In this case, the reference numeral indicates only an example of the correspondence between the same element and the specific configuration described in the embodiment described later. Therefore, the present disclosure is not limited to the description of the reference numeral.
実施形態に係る超音波センサを搭載した車両の外観を示す斜視図である。It is a perspective view which shows the appearance of the vehicle which mounted the ultrasonic sensor which concerns on embodiment. 図１に示された超音波センサの周囲を拡大して示す部分断面図である。It is a partial cross-sectional view showing the circumference of the ultrasonic sensor shown in FIG. 1 in an enlarged manner. 図２に示された超音波マイクロフォンの第一実施形態における概略構成を示す断面図である。It is sectional drawing which shows the schematic structure in 1st Embodiment of the ultrasonic microphone shown in FIG. 図３に示された超音波マイクロフォンにおける異物付着状態を検討した結果を示すグラフである。It is a graph which shows the result of having examined the foreign matter adhesion state in the ultrasonic microphone shown in FIG. 第三実施形態に係る超音波マイクロフォンの概略構成を示す断面図である。It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 3rd Embodiment. 第四実施形態に係る超音波マイクロフォンの概略構成を示す断面図である。It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 4th Embodiment. 第五実施形態に係る超音波マイクロフォンの概略構成を示す断面図である。It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 5th Embodiment. 第六実施形態に係る超音波マイクロフォンの概略構成を示す断面図である。It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on 6th Embodiment. 変形例に係る超音波マイクロフォンの概略構成を示す断面図である。It is sectional drawing which shows the schematic structure of the ultrasonic microphone which concerns on the modification.
　（実施形態）
　以下、本開示の実施形態を、図面に基づいて説明する。なお、一つの実施形態に対して適用可能な各種の変形例については、当該実施形態に関する一連の説明の途中に挿入されると、当該実施形態の理解が妨げられるおそれがある。このため、変形例については、当該実施形態に関する一連の説明の途中には挿入せず、その後にまとめて説明する。 (Embodiment)
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. If various modifications applicable to one embodiment are inserted in the middle of a series of explanations regarding the embodiment, the understanding of the embodiment may be hindered. Therefore, the modified examples will not be inserted in the middle of the series of explanations regarding the embodiment, but will be described collectively thereafter.
　（車載構成）
　図１を参照すると、本実施形態においては、超音波センサ１は、車両Ｖを装着対象とする車載型ソナーとしての構成を有している。すなわち、超音波センサ１は、車両Ｖに搭載されることで、当該車両Ｖの周囲に存在する物体を検知可能に構成されている。 (In-vehicle configuration)
Referring to FIG. 1, in the present embodiment, the ultrasonic sensor 1 has a configuration as an in-vehicle sonar to which a vehicle V is mounted. That is, the ultrasonic sensor 1 is configured to be able to detect an object existing around the vehicle V by being mounted on the vehicle V.
　車両Ｖは、いわゆる四輪自動車であって、箱状の車体Ｖ１を有している。車体Ｖ１は、その外板を構成する車体部品としての、車体パネルＶ２、フロントバンパーＶ３、およびリアバンパーＶ４を備えている。フロントバンパーＶ３は、車体Ｖ１における前端部に設けられている。リアバンパーＶ４は、車体Ｖ１における後端部に設けられている。 The vehicle V is a so-called four-wheeled vehicle and has a box-shaped vehicle body V1. The vehicle body V1 includes a vehicle body panel V2, a front bumper V3, and a rear bumper V4 as vehicle body parts constituting the outer panel. The front bumper V3 is provided at the front end portion of the vehicle body V1. The rear bumper V4 is provided at the rear end portion of the vehicle body V1.
　超音波センサ１は、フロントバンパーＶ３およびリアバンパーＶ４に装着されることで、車両Ｖの前方および後方に存在する物体を検知するように構成されている。超音波センサ１が、車両Ｖにおける車体Ｖ１に設けられたフロントバンパーＶ３またはリアバンパーＶ４に装着された状態を、以下「車載状態」と称する。 The ultrasonic sensor 1 is configured to be mounted on the front bumper V3 and the rear bumper V4 to detect objects existing in front of and behind the vehicle V. A state in which an ultrasonic sensor 1 is mounted on a front bumper V3 or a rear bumper V4 provided on a vehicle body V1 in a vehicle V is hereinafter referred to as an "in-vehicle state".
　具体的には、車載状態にて、フロントバンパーＶ３には、複数（例えば４つ）の超音波センサ１が装着されている。フロントバンパーＶ３に装着された複数の超音波センサ１は、それぞれ、車幅方向における異なる位置に配置されている。同様に、リアバンパーＶ４にも、複数（例えば４つ）の超音波センサ１が装着されている。 Specifically, a plurality of (for example, four) ultrasonic sensors 1 are mounted on the front bumper V3 in an in-vehicle state. A plurality of ultrasonic sensors 1 mounted on the front bumper V3 are arranged at different positions in the vehicle width direction. Similarly, a plurality of (for example, four) ultrasonic sensors 1 are mounted on the rear bumper V4.
　フロントバンパーＶ３およびリアバンパーＶ４には、超音波センサ１を装着するための装着孔Ｖ５が設けられている。装着孔Ｖ５は、板状のフロントバンパーＶ３およびリアバンパーＶ４における厚さ方向にフロントバンパーＶ３およびリアバンパーＶ４を貫通する丸孔状に形成されている。 The front bumper V3 and the rear bumper V4 are provided with mounting holes V5 for mounting the ultrasonic sensor 1. The mounting hole V5 is formed in a round hole shape that penetrates the front bumper V3 and the rear bumper V4 in the thickness direction in the plate-shaped front bumper V3 and the rear bumper V4.
　（第一実施形態）
　図２は、フロントバンパーＶ３に取り付けられた複数の超音波センサ１のうちの１つを、車載状態にて示している。以下、図２および図３を参照しつつ、第一実施形態に係る超音波センサ１の構成について説明する。 (First Embodiment)
FIG. 2 shows one of a plurality of ultrasonic sensors 1 attached to the front bumper V3 in an in-vehicle state. Hereinafter, the configuration of the ultrasonic sensor 1 according to the first embodiment will be described with reference to FIGS. 2 and 3.
　図２を参照すると、フロントバンパーＶ３は、バンパー外面Ｖ３１とバンパー裏面Ｖ３２とを有している。バンパー外面Ｖ３１は、フロントバンパーＶ３の外表面であって、車両Ｖの外側の空間である車体外空間ＳＧに面するように設けられている。バンパー裏面Ｖ３２は、バンパー外面Ｖ３１の裏側の面であって、車両ＶすなわちフロントバンパーＶ３の内側の空間である車体内空間ＳＮに面するように設けられている。装着孔Ｖ５は、バンパー外面Ｖ３１およびバンパー裏面Ｖ３２にて開口することで、フロントバンパーＶ３を厚さ方向に貫通するように設けられている。 Referring to FIG. 2, the front bumper V3 has a bumper outer surface V31 and a bumper back surface V32. The bumper outer surface V31 is an outer surface of the front bumper V3 and is provided so as to face the vehicle body outer space SG, which is a space outside the vehicle V. The bumper back surface V32 is a surface on the back side of the bumper outer surface V31 and is provided so as to face the vehicle body V, that is, the space inside the vehicle body SN, which is the space inside the front bumper V3. The mounting hole V5 is provided so as to penetrate the front bumper V3 in the thickness direction by opening at the bumper outer surface V31 and the bumper back surface V32.
　超音波センサ１は、超音波を送受信可能に構成されている。すなわち、超音波センサ１は、超音波である送信波を、指向軸に対応する中心軸ＤＡに沿って車体外空間ＳＧに向けて発信するように構成されている。「指向軸」は、超音波センサ１から超音波の送受信方向に沿って延びる仮想直線であって、指向角の基準となるものである。「指向軸」は、指向中心軸あるいは検出軸とも称され得る。また、超音波センサ１は、外部すなわち車両Ｖの周囲に存在する物体による送信波の反射波を含む受信波を車体外空間ＳＧから受信して、受信波の受信状態に対応する出力信号を生成するように構成されている。 The ultrasonic sensor 1 is configured to be capable of transmitting and receiving ultrasonic waves. That is, the ultrasonic sensor 1 is configured to transmit an ultrasonic transmitted wave toward the vehicle body outer space SG along the central axis DA corresponding to the directional axis. The "directivity axis" is a virtual straight line extending from the ultrasonic sensor 1 along the transmission / reception direction of ultrasonic waves, and serves as a reference for the directivity angle. The "directional axis" may also be referred to as a directional central axis or a detection axis. Further, the ultrasonic sensor 1 receives a received wave including a reflected wave of the transmitted wave by an object existing outside, that is, around the vehicle V, from the vehicle body outer space SG, and generates an output signal corresponding to the reception state of the received wave. It is configured to do.
　説明の便宜上、図示の如く、Ｙ軸が水平方向と平行となり且つＺ軸が中心軸ＤＡと平行となるように、右手系ＸＹＺ直交座標系を設定する。このとき、中心軸ＤＡと平行な方向を「軸方向」と称する。「軸方向における先端側」は、送信波の発信方向側であり、図２および図３における上側すなわちＺ軸正方向側に対応する。これに対し、「軸方向における基端側」は、図２および図３における下側すなわちＺ軸負方向側に対応する。 For convenience of explanation, the right-handed XYZ Cartesian coordinate system is set so that the Y axis is parallel to the horizontal direction and the Z axis is parallel to the central axis DA as shown in the figure. At this time, the direction parallel to the central axis DA is referred to as "axial direction". The "tip side in the axial direction" is the transmission direction side of the transmitted wave, and corresponds to the upper side in FIGS. 2 and 3, that is, the Z-axis positive direction side. On the other hand, the "base end side in the axial direction" corresponds to the lower side in FIGS. 2 and 3, that is, the negative direction side of the Z axis.
　或る構成要素の軸方向における基端側の端部を「基端部」と称し、軸方向における先端側の端部を「先端部」と称する。また、軸方向と直交する任意の方向を「面内方向」と称する。「面内方向」は、図２および図３における、ＸＹ平面と平行な方向である。「面内方向」は、場合によっては、「径方向」とも称され得る。「径方向」は、中心軸ＤＡと直交しつつ当該中心軸ＤＡから離隔する方向である。すなわち、「径方向」は、中心軸ＤＡと直交する仮想平面と中心軸ＤＡとの交点を起点として当該仮想平面内に半直線を描いた場合に、当該半直線が延びる方向である。換言すれば、「径方向」は、中心軸ＤＡと直交する仮想平面と中心軸ＤＡとの交点を中心として当該仮想平面内に円を描いた場合の、当該円の半径方向である。 The end portion on the proximal end side in the axial direction of a certain component is referred to as "base end portion", and the end portion on the distal end side in the axial direction is referred to as "tip portion". Further, an arbitrary direction orthogonal to the axial direction is referred to as an "in-plane direction". The "in-plane direction" is a direction parallel to the XY plane in FIGS. 2 and 3. The "in-plane direction" may also be referred to as the "diameter direction" in some cases. The "diametrical direction" is a direction that is orthogonal to the central axis DA and is separated from the central axis DA. That is, the "diameter direction" is a direction in which the half straight line extends when a half straight line is drawn in the virtual plane starting from the intersection of the virtual plane orthogonal to the central axis DA and the central axis DA. In other words, the "radial direction" is the radial direction of the circle when a circle is drawn in the virtual plane about the intersection of the virtual plane orthogonal to the central axis DA and the central axis DA.
　図２を参照すると、超音波センサ１の筐体を構成するセンサケース２は、ケース本体部２ａと、センサ側コネクタ２ｂと、マイクロフォン収容部２ｃとを有している。センサケース２は、絶縁性合成樹脂によって一体に形成されている。 Referring to FIG. 2, the sensor case 2 constituting the housing of the ultrasonic sensor 1 has a case main body portion 2a, a sensor-side connector 2b, and a microphone accommodating portion 2c. The sensor case 2 is integrally formed of an insulating synthetic resin.
　ケース本体部２ａは、箱状に形成されている。ケース本体部２ａの内側には、不図示の制御回路基板等が収容されている。センサ側コネクタ２ｂは、ケース本体部２ａから中心軸ＤＡと交差する方向に延設されている。センサ側コネクタ２ｂは、ＥＣＵ等の外部装置に対する電気接続用ワイヤハーネスに設けられた不図示のワイヤ側コネクタと着脱可能に構成されている。ＥＣＵはElectronic　Control　Unitの略である。 The case body 2a is formed in a box shape. A control circuit board (not shown) or the like is housed inside the case body 2a. The sensor-side connector 2b extends from the case body 2a in a direction intersecting the central axis DA. The sensor-side connector 2b is configured to be detachable from a wire-side connector (not shown) provided in a wire harness for electrical connection to an external device such as an ECU. ECU is an abbreviation for Electronic Control Unit.
　マイクロフォン収容部２ｃは、中心軸ＤＡを囲む略円筒状の部分であって、ケース本体部２ａから軸方向における先端側に向かって突設されている。車載状態にて、マイクロフォン収容部２ｃの軸方向における先端部は、装着孔Ｖ５内に収容されている。 The microphone accommodating portion 2c is a substantially cylindrical portion surrounding the central axis DA, and projects from the case main body portion 2a toward the tip end side in the axial direction. In the vehicle-mounted state, the tip portion of the microphone accommodating portion 2c in the axial direction is accommodated in the mounting hole V5.
　（超音波マイクロフォン）
　超音波センサ１は、センサケース２と超音波マイクロフォン３とを備えている。本実施形態においては、超音波マイクロフォン３は、中心軸ＤＡを中心軸とする略円柱状の外形形状を有するように構成されている。 (Ultrasonic microphone)
An ultrasonic sensor 1 includes a sensor case 2 and an ultrasonic microphone 3. In the present embodiment, the ultrasonic microphone 3 is configured to have a substantially cylindrical outer shape with the central axis DA as the central axis.
　超音波マイクロフォン３は、軸方向における先端側の端面である露出面３ａが車載状態にて車体外空間ＳＧに面するように、マイクロフォン収容部２ｃに収容されている。露出面３ａは、中心軸ＤＡを法線とする平面状に形成されている。露出面３ａは、中心軸ＤＡと平行な視線で車体外空間ＳＧ側から見た正面視にて、略円形状を有している。 The ultrasonic microphone 3 is housed in the microphone accommodating portion 2c so that the exposed surface 3a, which is the end surface on the distal end side in the axial direction, faces the vehicle body outer space SG in the vehicle-mounted state. The exposed surface 3a is formed in a plane shape with the central axis DA as a normal. The exposed surface 3a has a substantially circular shape when viewed from the outside space SG side of the vehicle body with a line of sight parallel to the central axis DA.
　図３は、図２に示された超音波センサ１から、超音波マイクロフォン３を取り出した状態を示している。図３を参照すると、超音波マイクロフォン３は、マイクケース４と送信部５とを有している。 FIG. 3 shows a state in which the ultrasonic microphone 3 is taken out from the ultrasonic sensor 1 shown in FIG. Referring to FIG. 3, the ultrasonic microphone 3 has a microphone case 4 and a transmission unit 5.
　以下、超音波マイクロフォン３を構成する各部について説明する。なお、図示および説明の簡略化のため、超音波マイクロフォン３の内部における配線等の電気接続構造については、図示および説明を省略する。かかる電気接続構造については、いうまでもなく、本願の出願時点の技術常識に基づき、適宜形成することが可能である。 Hereinafter, each part constituting the ultrasonic microphone 3 will be described. For the sake of simplification of illustration and description, the illustration and description of the electrical connection structure such as wiring inside the ultrasonic microphone 3 will be omitted. Needless to say, such an electrical connection structure can be appropriately formed based on the common general technical knowledge as of the filing of the present application.
　超音波マイクロフォン３の筐体を構成するマイクケース４は、略円柱状の外形形状を有する箱状に形成されている。マイクケース４は、その内側の空間である内部空間ＳＩ内に送信部５を収容するように構成されている。 The microphone case 4 constituting the housing of the ultrasonic microphone 3 is formed in a box shape having a substantially columnar outer shape. The microphone case 4 is configured to accommodate the transmission unit 5 in the internal space SI, which is the space inside the microphone case 4.
　マイクケース４は、中心軸ＤＡを囲む筒状に形成された側板部４１を有している。本実施形態においては、側板部４１は、超音波透過性を有しない、アルミニウム等の金属材料によって形成されている。 The microphone case 4 has a side plate portion 41 formed in a cylindrical shape surrounding the central axis DA. In the present embodiment, the side plate portion 41 is made of a metal material such as aluminum, which does not have ultrasonic transmission.
　側板部４１は、中心軸ＤＡと略平行な中心軸線を有する円筒状に形成されている。すなわち、側板部４１における、マイクケース４の外側の空間である外部空間ＳＤに面する外壁面である側方外壁面４１ａは、中心軸ＤＡと略平行な円柱面状に形成されている。また、側板部４１における、内部空間ＳＩに面する内壁面である側方内壁面４１ｂは、中心軸ＤＡを囲む円筒内面状に形成されている。 The side plate portion 41 is formed in a cylindrical shape having a central axis substantially parallel to the central axis DA. That is, the side outer wall surface 41a of the side plate portion 41, which is the outer wall surface facing the outer space SD, which is the space outside the microphone case 4, is formed in a cylindrical surface shape substantially parallel to the central axis DA. Further, the side inner wall surface 41b, which is an inner wall surface facing the internal space SI in the side plate portion 41, is formed in the shape of a cylindrical inner surface surrounding the central axis DA.
　マイクケース４は、また、軸方向に板厚方向を有する板状部である天板部４２を有している。天板部４２は、軸方向における側板部４１の先端部を閉塞するように設けられている。具体的には、天板部４２は、板厚が略一定の平板状に形成されている。本実施形態においては、天板部４２は、板厚ｔが、０．４ｍｍ以上、より詳細には０．４～１０ｍｍに形成されている。また、天板部４２は、側板部４１と同一の材料によって、側板部４１と継ぎ目無く一体に形成されている。 The microphone case 4 also has a top plate portion 42 which is a plate-shaped portion having a plate thickness direction in the axial direction. The top plate portion 42 is provided so as to close the tip portion of the side plate portion 41 in the axial direction. Specifically, the top plate portion 42 is formed in a flat plate shape having a substantially constant plate thickness. In the present embodiment, the top plate portion 42 is formed to have a plate thickness t of 0.4 mm or more, more specifically 0.4 to 10 mm. Further, the top plate portion 42 is seamlessly and integrally formed with the side plate portion 41 by using the same material as the side plate portion 41.
　天板部４２は、外側表面４２ａと内側表面４２ｂとを有している。外側表面４２ａは、天板部４２における一対の主面のうちの、露出面３ａを構成する一方であって、軸方向を法線方向とする平面状に形成されている。「主面」は、板状の部分または部材における、板厚方向と直交する表面である。内側表面４２ｂは、天板部４２における一対の主面のうちの、内部空間ＳＩに面する一方であって、軸方向を法線方向とする平面状に形成されている。 The top plate portion 42 has an outer surface 42a and an inner surface 42b. The outer surface 42a is one of the pair of main surfaces of the top plate portion 42 that constitutes the exposed surface 3a, and is formed in a planar shape with the axial direction as the normal direction. A "main surface" is a surface of a plate-shaped portion or member that is orthogonal to the plate thickness direction. The inner surface 42b is one of the pair of main surfaces of the top plate portion 42 facing the internal space SI, and is formed in a planar shape with the axial direction as the normal direction.
　天板部４２は、板厚方向に貫通する貫通孔４２ｃを有している。貫通孔４２ｃは、外側表面４２ａおよび内側表面４２ｂにて開口するように、軸方向に沿って設けられている。すなわち、天板部４２は、超音波である送信波が貫通孔４２ｃを通過することで、実質的に送信波が透過可能に形成されている。 The top plate portion 42 has a through hole 42c penetrating in the plate thickness direction. The through hole 42c is provided along the axial direction so as to open at the outer surface 42a and the inner surface 42b. That is, the top plate portion 42 is formed so that the transmitted wave, which is an ultrasonic wave, passes through the through hole 42c so that the transmitted wave can be substantially transmitted.
　貫通孔４２ｃは、中心軸ＤＡと平行な内壁面を有する丸孔状に形成されている。すなわち、貫通孔４２ｃは、中心軸ＤＡと直交する断面による断面形状が円形となるように形成されている。本実施形態においては、貫通孔４２ｃは、内径φが、０．８ｍｍ以下、より詳細には０．０１～０．８ｍｍに形成されている。 The through hole 42c is formed in a round hole shape having an inner wall surface parallel to the central axis DA. That is, the through hole 42c is formed so that the cross-sectional shape having a cross section orthogonal to the central axis DA is circular. In the present embodiment, the through hole 42c is formed to have an inner diameter φ of 0.8 mm or less, more specifically 0.01 to 0.8 mm.
　マイクケース４は、また、底板部４３を有している。底板部４３は、側板部４１の軸方向における基端側を閉塞するように設けられている。本実施形態においては、底板部４３は、絶縁性の合成樹脂によって形成されている。 The microphone case 4 also has a bottom plate portion 43. The bottom plate portion 43 is provided so as to close the base end side of the side plate portion 41 in the axial direction. In the present embodiment, the bottom plate portion 43 is formed of an insulating synthetic resin.
　底板部４３の軸方向における基端側にて外部空間ＳＤに面する端面である底面４３ａは、軸方向を法線方向とする平面状に形成されている。底面４３ａから軸方向における基端側に向かって、接続端子４３ｂが延設されている。接続端子４３ｂは、超音波マイクロフォン３とケース本体部２ａの内側に設けられた不図示の制御回路基板とを電気接続するための端子部材であって、軸方向に沿った棒状に形成されている。 The bottom surface 43a, which is an end surface facing the external space SD on the base end side in the axial direction of the bottom plate portion 43, is formed in a planar shape with the axial direction as the normal direction. The connection terminal 43b extends from the bottom surface 43a toward the base end side in the axial direction. The connection terminal 43b is a terminal member for electrically connecting the ultrasonic microphone 3 and a control circuit board (not shown) provided inside the case main body 2a, and is formed in a rod shape along the axial direction. ..
　底板部４３の軸方向における先端側にて内部空間ＳＩに面する端面である上面４３ｃの、径方向における外縁部は、不図示の接着層を介して側板部４１と接合されている。底板部４３は、基板支持部４３ｄを有している。基板支持部４３ｄは、上面４３ｃから軸方向における先端側に向かって延設されている。基板支持部４３ｄは、軸方向における先端側に向かって開口することで送信部５を支持する凹部４３ｅを有している。 The outer edge portion in the radial direction of the upper surface 43c, which is the end surface facing the internal space SI on the distal end side in the axial direction of the bottom plate portion 43, is joined to the side plate portion 41 via an adhesive layer (not shown). The bottom plate portion 43 has a substrate support portion 43d. The substrate support portion 43d extends from the upper surface 43c toward the tip end side in the axial direction. The substrate support portion 43d has a recess 43e that supports the transmission portion 5 by opening toward the tip end side in the axial direction.
　送信部５は、天板部４２から離隔した状態で、マイクケース４に収容されている。本実施形態においては、送信部５は、天板部４２に面する位置に設けられている。すなわち、送信部５は、内部空間ＳＩを挟んで、天板部４２と対向配置されている。具体的には、送信部５は、天板部４２に正対するように設けられている。 The transmitting unit 5 is housed in the microphone case 4 in a state of being separated from the top plate unit 42. In the present embodiment, the transmission unit 5 is provided at a position facing the top plate unit 42. That is, the transmission unit 5 is arranged to face the top plate unit 42 with the internal space SI interposed therebetween. Specifically, the transmission unit 5 is provided so as to face the top plate unit 42.
　送信部５は、送信波を天板部４２に向かう軸方向に発信するように構成されている。具体的には、送信部５は、超音波素子５１を有している。超音波素子５１は、電気信号と超音波振動とを変換する、圧電素子等の電気－機械変換素子によって構成されている。本実施形態においては、送信部５は、送信波における周波数が２０ｋＨｚ～１００ｋＨｚとなるように構成されている。また、送信部５は、受信波の受信状態に対応する出力信号を生成する送受信部としての構成を有している。 The transmission unit 5 is configured to transmit the transmitted wave in the axial direction toward the top plate unit 42. Specifically, the transmission unit 5 has an ultrasonic element 51. The ultrasonic element 51 is composed of an electric-mechanical conversion element such as a piezoelectric element that converts an electric signal and ultrasonic vibration. In the present embodiment, the transmission unit 5 is configured so that the frequency of the transmitted wave is 20 kHz to 100 kHz. Further, the transmission unit 5 has a configuration as a transmission / reception unit that generates an output signal corresponding to the reception state of the received wave.
　本実施形態においては、超音波素子５１は、半導体基板５２に設けられたＭＥＭＳ型の圧電トランスデューサとしての構成を有している。ＭＥＭＳはMicro　Electro　Mechanical　Systemの略である。半導体基板５２は、凹部４３ｅに収容されつつ、基板支持部４３ｄにより支持されている。具体的には、半導体基板５２における一対の主面のうちの一方である基板底面５３は、基板支持部４３ｄに接合されている。半導体基板５２における一対の主面のうちの他方である基板上面５４は、天板部４２と正対するように設けられている。基板上面５４には、超音波素子５１が設けられている。 In the present embodiment, the ultrasonic element 51 has a configuration as a MEMS type piezoelectric transducer provided on the semiconductor substrate 52. MEMS is an abbreviation for Micro Electro Mechanical System. The semiconductor substrate 52 is supported by the substrate support portion 43d while being housed in the recess 43e. Specifically, the substrate bottom surface 53, which is one of the pair of main surfaces of the semiconductor substrate 52, is joined to the substrate support portion 43d. The substrate upper surface 54, which is the other of the pair of main surfaces in the semiconductor substrate 52, is provided so as to face the top plate portion 42. An ultrasonic element 51 is provided on the upper surface 54 of the substrate.
　超音波マイクロフォン３は、超音波によりマイクケース４を励振することで、天板部４２に付着した泥等の異物を除去可能に構成されている。本実施形態においては、超音波マイクロフォン３は、送信部５にて送信波を発信するように設けられた超音波素子５１が、天板部４２における異物除去のためにマイクケース４を励振する励振部として機能するように構成されている。 The ultrasonic microphone 3 is configured to be able to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the microphone case 4 with ultrasonic waves. In the present embodiment, in the ultrasonic microphone 3, the ultrasonic element 51 provided so as to transmit the transmitted wave in the transmitting unit 5 excites the microphone case 4 for removing foreign matter in the top plate portion 42. It is configured to function as a part.
　具体的には、超音波素子５１は、送信波により天板部４２を励振することで、天板部４２に付着した泥等の異物を除去するように設けられている。また、マイクケース４は、天板部４２に異物が付着していない清浄状態にて、送信波における周波数よりも高い共振周波数を有するように形成されている。より詳細には、天板部４２は、清浄状態にて、送信波における周波数よりも高い共振周波数を有している。 Specifically, the ultrasonic element 51 is provided so as to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the top plate portion 42 with a transmitted wave. Further, the microphone case 4 is formed so as to have a resonance frequency higher than the frequency in the transmitted wave in a clean state in which foreign matter does not adhere to the top plate portion 42. More specifically, the top plate portion 42 has a resonance frequency higher than the frequency in the transmitted wave in a clean state.
　（効果）
　以下、本実施形態の構成による動作概要を、同構成により奏される効果とともに、各図面を参照しつつ説明する。 (effect)
Hereinafter, an outline of the operation according to the configuration of the present embodiment will be described with reference to each drawing together with the effects produced by the configuration.
　図１および図２を参照すると、超音波センサ１は、不図示のＥＣＵ等の外部装置によって設定された所定タイミングにて、超音波の送受信を実行する。すなわち、超音波センサ１は、超音波である送信波を、車体外空間ＳＧに向けて送信する。また、超音波センサ１は、車両Ｖの周囲に存在する物体による送信波の反射波を含む受信波を受信する。 Referring to FIGS. 1 and 2, the ultrasonic sensor 1 executes transmission / reception of ultrasonic waves at a predetermined timing set by an external device such as an ECU (not shown). That is, the ultrasonic sensor 1 transmits a transmitted wave, which is an ultrasonic wave, toward the vehicle body outer space SG. Further, the ultrasonic sensor 1 receives a received wave including a reflected wave of a transmitted wave by an object existing around the vehicle V.
　具体的には、図３を参照すると、接続端子４３ｂへの入力信号の入力により超音波素子５１が励振されることで、超音波素子５１から送信波が発信される。超音波素子５１から発信された送信波は、内部空間ＳＩ内を軸方向に沿って伝播しつつ、天板部４２に到達する。天板部４２に到達した送信波は、天板部４２に設けられた貫通孔４２ｃを通過することで、車体外空間ＳＧに伝播する。すなわち、送信波は、貫通孔４２ｃを有する天板部４２を透過する。このようにして、送信波が、車体外空間ＳＧに向けて送信される。 Specifically, referring to FIG. 3, the ultrasonic element 51 is excited by the input of the input signal to the connection terminal 43b, so that the transmitted wave is transmitted from the ultrasonic element 51. The transmitted wave transmitted from the ultrasonic element 51 reaches the top plate portion 42 while propagating in the internal space SI along the axial direction. The transmitted wave that has reached the top plate portion 42 propagates to the vehicle body outer space SG by passing through the through hole 42c provided in the top plate portion 42. That is, the transmitted wave passes through the top plate portion 42 having the through hole 42c. In this way, the transmitted wave is transmitted toward the vehicle body outer space SG.
　受信波は、天板部４２に設けられた貫通孔４２ｃを通過することで、内部空間ＳＩに伝播する。すなわち、受信波は、貫通孔４２ｃを有する天板部４２を透過する。天板部４２を透過した受信波により超音波素子５１が励振されることで、超音波素子５１にて、励振状態に応じた電気信号が発生する。かかる電気信号に対して半導体基板５２にて増幅等の信号処理を実行することで生成した出力信号は、接続端子４３ｂを介して出力される。 The received wave propagates to the internal space SI by passing through the through hole 42c provided in the top plate portion 42. That is, the received wave passes through the top plate portion 42 having the through hole 42c. When the ultrasonic element 51 is excited by the received wave transmitted through the top plate portion 42, an electric signal corresponding to the excitation state is generated in the ultrasonic element 51. The output signal generated by executing signal processing such as amplification on the semiconductor substrate 52 for such an electric signal is output via the connection terminal 43b.
　ここで、超音波マイクロフォン３における露出面３ａを構成する、天板部４２における外側表面４２ａは、車載状態にて車体外空間ＳＧに露出される。このため、車両Ｖの走行中等において、露出面３ａすなわち外側表面４２ａに、泥等の異物が付着することがある。特に、超音波センサ１がフロントバンパーＶ３あるいはリアバンパーＶ４に装着されている場合、超音波センサ１の搭載高は低くなる。この場合、天板部４２における外側表面４２ａには、異物が付着しやすい。 Here, the outer surface 42a of the top plate portion 42, which constitutes the exposed surface 3a of the ultrasonic microphone 3, is exposed to the vehicle body outer space SG in the vehicle-mounted state. Therefore, foreign matter such as mud may adhere to the exposed surface 3a, that is, the outer surface 42a while the vehicle V is traveling. In particular, when the ultrasonic sensor 1 is mounted on the front bumper V3 or the rear bumper V4, the mounting height of the ultrasonic sensor 1 is low. In this case, foreign matter is likely to adhere to the outer surface 42a of the top plate portion 42.
　この点、本実施形態の構成においては、超音波によりマイクケース４を励振することで、天板部４２に付着した異物が良好に除去される。これにより、異物付着に伴う検知性能低下等の不具合の発生が、可及的に抑制される。したがって、かかる構成によれば、超音波センサ１の信頼性が向上する。 In this respect, in the configuration of the present embodiment, the foreign matter adhering to the top plate portion 42 is satisfactorily removed by exciting the microphone case 4 with ultrasonic waves. As a result, the occurrence of problems such as deterioration of detection performance due to adhesion of foreign matter is suppressed as much as possible. Therefore, according to such a configuration, the reliability of the ultrasonic sensor 1 is improved.
　また、本実施形態の構成においては、異物除去のためのマイクケース４の励振は、超音波素子５１から発信された送信波を利用して行われる。したがって、天板部４２に付着した異物の除去が、簡略な装置構成により良好に行われ得る。 Further, in the configuration of the present embodiment, the excitation of the microphone case 4 for removing foreign matter is performed by using the transmitted wave transmitted from the ultrasonic element 51. Therefore, the foreign matter adhering to the top plate portion 42 can be satisfactorily removed by a simple apparatus configuration.
　ところで、天板部４２における異物付着状態は、走行条件等の異物付着条件が同じであっても、天板部４２の構造によって異なり得る。このため、超音波によりマイクケース４を励振して異物を除去する、本実施形態における異物除去構成は、天板部４２に異物が付着しやすかったり、天板部４２に付着した異物が他の除去手段によっては除去しづらかったりする場合に効果的である。 By the way, the foreign matter adhesion state in the top plate portion 42 may differ depending on the structure of the top plate portion 42 even if the foreign matter adhesion conditions such as running conditions are the same. Therefore, in the foreign matter removing configuration in the present embodiment in which the microphone case 4 is excited by ultrasonic waves to remove foreign matter, foreign matter easily adheres to the top plate portion 42, or foreign matter adheres to the top plate portion 42 is another. It is effective when it is difficult to remove depending on the removing means.
　例えば、露出面３ａを構成する、天板部４２における外側表面４２ａが、車体パネルＶ２の塗装面にあわせてマット塗装されている場合、泥等の異物が外側表面４２ａに付着しやすい。車体パネルＶ２の塗装面には、多くの場合、防汚コーティングが定期的（例えば車両Ｖの定期点検時）に繰り返し施工される。一方、超音波センサ１の露出面３ａは、車体パネルＶ２の塗装面と同様の防汚コーティングを施工することが困難である。よって、この場合、マイクケース４を励振して異物を除去する、本実施形態における異物除去構成は、非常に有効である。 For example, when the outer surface 42a of the top plate portion 42 constituting the exposed surface 3a is matted to match the painted surface of the vehicle body panel V2, foreign matter such as mud easily adheres to the outer surface 42a. In many cases, an antifouling coating is repeatedly applied to the painted surface of the vehicle body panel V2 at regular intervals (for example, during periodic inspection of the vehicle V). On the other hand, it is difficult to apply the same antifouling coating as the painted surface of the vehicle body panel V2 on the exposed surface 3a of the ultrasonic sensor 1. Therefore, in this case, the foreign matter removing configuration in the present embodiment, in which the microphone case 4 is excited to remove the foreign matter, is very effective.
　また、例えば、天板部４２の板厚ｔおよび／または貫通孔４２ｃのサイズによっては、異物が貫通孔４２ｃに詰まりやすくなることがあり得る。図４は、天板部４２の板厚ｔおよび貫通孔４２ｃの内径φの寸法変化による、異物付着状態に対する影響を、実験により検討した結果を示す。 Further, for example, depending on the plate thickness t of the top plate portion 42 and / or the size of the through hole 42c, foreign matter may be easily clogged in the through hole 42c. FIG. 4 shows the result of experimentally examining the influence on the foreign matter adhesion state due to the dimensional change of the plate thickness t of the top plate portion 42 and the inner diameter φ of the through hole 42c.
　実験条件は以下の通りである。まず、市販の自動車用固形ワックスを、ワックス付属のスポンジにより、天板部４２における外側表面４２ａに一様に塗布する。次に、塗布したワックスを、パイル地のワックス拭き取り用タオルで１方向に１回拭き取る。その後、ワックスの残留状態を、目視で観察する。図４を参照すると、実験は、内径φ［ｍｍ］＝０．５，０．８４，１．３２，１．８６，２．３４、板厚ｔ［ｍｍ］＝０．２，０．４，０．６，０．８について行った。 The experimental conditions are as follows. First, a commercially available solid wax for automobiles is uniformly applied to the outer surface 42a of the top plate portion 42 by a sponge attached to the wax. Next, the applied wax is wiped once in one direction with a towel for wiping off the wax on the pile fabric. Then, the residual state of the wax is visually observed. With reference to FIG. 4, in the experiment, the inner diameter φ [mm] = 0.5,0.84,1.32,1.86,2.34, the plate thickness t [mm] = 0.2,0.4, It was about 0.6 and 0.8.
　図４においては、２つの矩形の間の空間によって、貫通孔４２ｃが表されている。また、貫通孔４２ｃの周囲におけるワックスの付着状態が、図４にて概略的に示されている。例えば、φ＝２．３４，ｔ＝０．８の例は、拭き取りにより、ワックスが、貫通孔４２ｃ内には詰まらず、貫通孔４２ｃを通過して内側表面４２ｂ側に回り込んでいる状態を示す。図４における「領域１」は、ワックス拭き取り後に、貫通孔４２ｃにワックスが詰まっていた領域を示す。同図における「領域２」は、ワックス拭き取り後に、貫通孔４２ｃにワックスが詰まっていなかった領域を示す。 In FIG. 4, the through hole 42c is represented by the space between the two rectangles. Further, the state of adhesion of wax around the through hole 42c is schematically shown in FIG. For example, in the example of φ = 2.34 and t = 0.8, the wax does not get stuck in the through hole 42c by wiping, but passes through the through hole 42c and wraps around to the inner surface 42b side. show. “Region 1” in FIG. 4 indicates a region where the through hole 42c is filled with wax after the wax is wiped off. “Region 2” in the figure indicates a region in which the through hole 42c is not clogged with wax after wiping off the wax.
　図４から明らかなように、内径φについては、０．８ｍｍ以下の場合に、貫通孔４２ｃにおけるワックス詰まりが顕著に発生し、励振による除去が必要となる。なお、内径φの下限については、加工上の制約等を考慮して、例えば、０．０１ｍｍ程度とされ得る。 As is clear from FIG. 4, when the inner diameter φ is 0.8 mm or less, wax clogging in the through hole 42c occurs remarkably, and it is necessary to remove it by excitation. The lower limit of the inner diameter φ may be, for example, about 0.01 mm in consideration of processing restrictions and the like.
　また、板厚ｔについては、０．４ｍｍ以上の場合に、貫通孔４２ｃにおけるワックス詰まりが顕著に発生し、励振による除去が必要となる。なお、板厚ｔの上限については、超音波センサ１の体格上の制約等を考慮して、例えば、１０ｍｍ程度とされ得る。 Further, regarding the plate thickness t, when the plate thickness is 0.4 mm or more, wax clogging in the through hole 42c occurs remarkably, and it is necessary to remove it by excitation. The upper limit of the plate thickness t may be, for example, about 10 mm in consideration of restrictions on the physique of the ultrasonic sensor 1.
　また、本実施形態においては、マイクケース４は、天板部４２に異物が付着していない清浄状態にて、送信波における周波数よりも高い共振周波数を有している。かかる構成においては、天板部４２に異物が付着していない清浄状態では、マイクケース４における共振周波数は、送信波における周波数とは一致しない。これに対し、天板部４２に異物が所定程度付着した非清浄状態では、マイクケース４における共振周波数が清浄状態から低下して、送信波における周波数と一致する。 Further, in the present embodiment, the microphone case 4 has a resonance frequency higher than the frequency in the transmitted wave in a clean state in which foreign matter does not adhere to the top plate portion 42. In such a configuration, the resonance frequency in the microphone case 4 does not match the frequency in the transmitted wave in a clean state in which no foreign matter adheres to the top plate portion 42. On the other hand, in the unclean state in which foreign matter adheres to the top plate portion 42 to a predetermined degree, the resonance frequency in the microphone case 4 drops from the clean state and coincides with the frequency in the transmitted wave.
　このため、清浄状態とは異なり、非清浄状態では、マイクケース４が、異物除去が可能な程度まで自動的に励振される。そして、異物が除去されて清浄状態となると、マイクケース４における励振が収まる。したがって、かかる構成によれば、マイクケース４が、異物付着状態に応じて適切に励振され得る。 Therefore, unlike the clean state, the microphone case 4 is automatically excited to the extent that foreign matter can be removed in the non-clean state. Then, when the foreign matter is removed and the state becomes clean, the excitation in the microphone case 4 is settled. Therefore, according to such a configuration, the microphone case 4 can be appropriately excited according to the foreign matter adhering state.
　（第二実施形態）
　以下、第二実施形態について説明する。なお、以下の第二実施形態の説明においては、主として、上記第一実施形態と異なる部分について説明する。また、第一実施形態と第二実施形態とにおいて、互いに同一または均等である部分には、同一符号が付されている。したがって、以下の第二実施形態の説明において、第一実施形態と同一の符号を有する構成要素に関しては、技術的矛盾または特段の追加説明なき限り、上記第一実施形態における説明が適宜援用され得る。後述の他の実施形態についても同様である。 (Second embodiment)
Hereinafter, the second embodiment will be described. In the following description of the second embodiment, the parts different from the first embodiment will be mainly described. Further, in the first embodiment and the second embodiment, the same or equal parts are designated by the same reference numerals. Therefore, in the following description of the second embodiment, the description in the first embodiment may be appropriately incorporated with respect to the components having the same reference numerals as those in the first embodiment, unless there is a technical contradiction or a special additional explanation. .. The same applies to other embodiments described later.
　本実施形態に係る超音波マイクロフォン３の概略構成は、図３と同様である。すなわち、本実施形態においても、超音波マイクロフォン３は、送信部５にて送信波を発信するように設けられた超音波素子５１が、天板部４２における異物除去のためにマイクケース４を励振する励振部として機能するように構成されている。 The schematic configuration of the ultrasonic microphone 3 according to this embodiment is the same as that in FIG. That is, also in the present embodiment, in the ultrasonic microphone 3, the ultrasonic element 51 provided so as to transmit the transmitted wave at the transmitting unit 5 excites the microphone case 4 for removing foreign matter at the top plate portion 42. It is configured to function as an exciting part.
　本実施形態においては、超音波素子５１は、送信波により側板部４１を励振することで、天板部４２に付着した泥等の異物を除去するように設けられている。具体的には、超音波マイクロフォン３は、送信部５から発信される送信波におけるＦＯＶ外の部分すなわちサイドローブを用いて、側板部４１を励振するように構成されている。ＦＯＶはField　of　Viewの略である。 In the present embodiment, the ultrasonic element 51 is provided so as to remove foreign substances such as mud adhering to the top plate portion 42 by exciting the side plate portion 41 with a transmitted wave. Specifically, the ultrasonic microphone 3 is configured to excite the side plate portion 41 by using a portion outside the FOV, that is, a side lobe in the transmitted wave transmitted from the transmitting unit 5. FOV is an abbreviation for Field of View.
　かかる構成においては、ＦＯＶに対応するメインローブの天板部４２における通過性あるいは透過性を高く保持することで、車体外空間ＳＧ側に発信される送信波の音圧ロスが良好に回避され得る。これに併せて、ＦＯＶ外のサイドローブを有効活用してマイクケース４を励振することで、異物除去が良好に行われる。すなわち、かかる構成によれば、送信部５を用いた異物除去が、物体検知特性を低下させることなく良好に実現され得る。 In such a configuration, by maintaining high passability or transparency in the top plate portion 42 of the main lobe corresponding to the FOV, the sound pressure loss of the transmitted wave transmitted to the outside space SG side of the vehicle body can be satisfactorily avoided. .. At the same time, by effectively utilizing the side lobes outside the FOV to excite the microphone case 4, foreign matter can be satisfactorily removed. That is, according to such a configuration, foreign matter removal using the transmission unit 5 can be satisfactorily realized without deteriorating the object detection characteristics.
　（第三実施形態）
　以下、第三実施形態について、図５を参照しつつ説明する。本実施形態においては、図５に示されているように、送信部５は、超音波素子５１に加えて、追加超音波素子５５を備えている。 (Third embodiment)
Hereinafter, the third embodiment will be described with reference to FIG. In the present embodiment, as shown in FIG. 5, the transmission unit 5 includes an additional ultrasonic element 55 in addition to the ultrasonic element 51.
　追加超音波素子５５は、電気信号と超音波振動とを変換する、圧電素子等の電気－機械変換素子によって構成されている。具体的には、本実施形態においては、追加超音波素子５５は、半導体基板５２に設けられたＭＥＭＳ型の圧電トランスデューサとしての構成を有していて、基板上面５４に設けられている。 The additional ultrasonic element 55 is composed of an electric-mechanical conversion element such as a piezoelectric element that converts an electric signal and ultrasonic vibration. Specifically, in the present embodiment, the additional ultrasonic element 55 has a configuration as a MEMS type piezoelectric transducer provided on the semiconductor substrate 52, and is provided on the upper surface 54 of the substrate.
　すなわち、本実施形態においては、送信部５は、超音波素子５１および追加超音波素子５５という、電気信号と超音波振動とを変換する複数の電気－機械変換素子を備えている。複数の電気－機械変換素子のうちの一つである超音波素子５１は、送信波を発信するように設けられている。複数の電気－機械変換素子のうちの他の一つである追加超音波素子５５は、天板部４２における異物除去のためにマイクケース４を励振する励振部として機能するように設けられている。 That is, in the present embodiment, the transmission unit 5 includes a plurality of electric-mechanical conversion elements, that is, an ultrasonic element 51 and an additional ultrasonic element 55, which convert an electric signal and ultrasonic vibration. The ultrasonic element 51, which is one of the plurality of electric-mechanical conversion elements, is provided so as to transmit a transmitted wave. The additional ultrasonic element 55, which is another one of the plurality of electric-mechanical conversion elements, is provided to function as an exciting unit that excites the microphone case 4 for removing foreign matter in the top plate portion 42. ..
　かかる構成においては、超音波素子５１による送信波の天板部４２における通過性あるいは透過性を高く保持することで、車体外空間ＳＧ側に発信される送信波の音圧ロスが良好に回避され得る。これに併せて、追加超音波素子５５から発信される超音波によりマイクケース４を励振することで、異物除去が良好に行われる。すなわち、かかる構成によれば、送信部５を用いた異物除去が、物体検知特性を低下させることなく実現され得る。また、送信波を発信する超音波素子５１とは別個に、異物除去用の追加超音波素子５５を設けることで、送信波の送受信による物体検知動作タイミングに影響を与えることなく異物除去動作を実行することが可能となる。 In such a configuration, by maintaining high passability or transparency in the top plate portion 42 of the transmitted wave by the ultrasonic element 51, the sound pressure loss of the transmitted wave transmitted to the outside space SG side of the vehicle body is satisfactorily avoided. obtain. At the same time, the microphone case 4 is excited by the ultrasonic waves transmitted from the additional ultrasonic element 55, so that foreign matter can be removed satisfactorily. That is, according to such a configuration, foreign matter removal using the transmission unit 5 can be realized without deteriorating the object detection characteristics. Further, by providing an additional ultrasonic element 55 for removing foreign matter separately from the ultrasonic element 51 that transmits the transmitted wave, the foreign matter removing operation is executed without affecting the object detection operation timing by transmitting and receiving the transmitted wave. It becomes possible to do.
　（第四実施形態）
　以下、第四実施形態について、図６を参照しつつ説明する。本実施形態においては、図６に示されているように、マイクケース４には、ケース励振素子６１が固定されている。 (Fourth Embodiment)
Hereinafter, the fourth embodiment will be described with reference to FIG. In the present embodiment, as shown in FIG. 6, the case exciting element 61 is fixed to the microphone case 4.
　ケース励振素子６１は、電気信号と超音波振動とを変換する電気－機械変換素子であって、駆動信号の印加によりマイクケース４を励振するように構成されている。図６に示された具体例においては、ケース励振素子６１は、面内方向における貫通孔４２ｃが設けられていない位置にて、天板部４２における内側表面４２ｂ上に接合されている。 The case excitation element 61 is an electric-mechanical conversion element that converts an electric signal and ultrasonic vibration, and is configured to excite the microphone case 4 by applying a drive signal. In the specific example shown in FIG. 6, the case exciting element 61 is joined on the inner surface 42b of the top plate portion 42 at a position where the through hole 42c is not provided in the in-plane direction.
　かかる構成においては、送信波を発信する送信部５とは別個に、ケース励振素子６１が、天板部４２における異物除去のためにマイクケース４を励振する励振部として機能するように設けられている。したがって、かかる構成によれば、送信部５における送信波の送受信による物体検知動作タイミングに影響を与えることなく異物除去動作を実行することが可能となる。また、ケース励振素子６１は、マイクケース４を直接励振するように、マイクケース４に固定されている。したがって、かかる構成によれば、良好な異物除去性能が実現され得る。 In such a configuration, the case exciting element 61 is provided so as to function as an exciting unit for exciting the microphone case 4 for removing foreign matter in the top plate portion 42, separately from the transmitting unit 5 that transmits the transmitted wave. There is. Therefore, according to such a configuration, it is possible to execute the foreign matter removing operation without affecting the object detection operation timing by transmitting and receiving the transmitted wave in the transmitting unit 5. Further, the case exciting element 61 is fixed to the microphone case 4 so as to directly excite the microphone case 4. Therefore, according to such a configuration, good foreign matter removing performance can be realized.
　（第五実施形態）
　以下、第五実施形態について、図７を参照しつつ説明する。本実施形態においては、上記の第一実施形態および／または第二実施形態と同様に、超音波マイクロフォン３は、送信部５にて送信波を発信するように設けられた超音波素子５１が、天板部４２における異物除去のためにマイクケース４を励振する励振部として機能するように構成されている。 (Fifth Embodiment)
Hereinafter, the fifth embodiment will be described with reference to FIG. 7. In the present embodiment, similarly to the first embodiment and / or the second embodiment described above, in the ultrasonic microphone 3, the ultrasonic element 51 provided so as to transmit the transmitted wave by the transmitting unit 5 is used. It is configured to function as an exciting unit that excites the microphone case 4 for removing foreign matter in the top plate portion 42.
　また、本実施形態においては、上記第二実施形態と同様に、送信部５は、送信波により側板部４１を励振することで、天板部４２に付着した泥等の異物を除去するように設けられている。具体的には、図７に示されているように、マイクケース４は、送信部５から発信された超音波により共振する共振部としての側板共振部４１１を有している。 Further, in the present embodiment, as in the second embodiment, the transmitting unit 5 excites the side plate portion 41 by the transmitted wave so as to remove foreign substances such as mud adhering to the top plate portion 42. It is provided. Specifically, as shown in FIG. 7, the microphone case 4 has a side plate resonance portion 411 as a resonance portion that resonates with ultrasonic waves transmitted from the transmission unit 5.
　側板共振部４１１は、側板部４１に設けられている。具体的には、側板共振部４１１は、側板部４１における共振周波数を調整する薄肉部または厚肉部としての構造を有している。かかる構成によれば、送信部５を用いた異物除去のための、側板部４１の励振が、効率的に行われ得る。 The side plate resonance portion 411 is provided in the side plate portion 41. Specifically, the side plate resonance portion 411 has a structure as a thin-walled portion or a thick-walled portion that adjusts the resonance frequency in the side plate portion 41. According to such a configuration, the side plate portion 41 can be efficiently excited for removing foreign matter by using the transmission unit 5.
　（第六実施形態）
　以下、第六実施形態について、図８を参照しつつ説明する。本実施形態においては、上記第一実施形態と同様に、送信部５は、送信波により天板部４２を励振することで、天板部４２に付着した泥等の異物を除去するように設けられている。 (Sixth Embodiment)
Hereinafter, the sixth embodiment will be described with reference to FIG. In the present embodiment, as in the first embodiment, the transmission unit 5 is provided so as to remove foreign matter such as mud adhering to the top plate portion 42 by exciting the top plate portion 42 by the transmitted wave. Has been done.
　また、本実施形態においては、図８に示されているように、マイクケース４は、送信部５から発信された超音波により共振する共振部としての天板共振部４１２を有している。天板共振部４１２は、天板部４２に設けられている。具体的には、天板共振部４１２は、天板部４２における共振周波数を調整する薄肉部または厚肉部としての構造を有している。また、天板共振部４１２は、貫通孔４２ｃが設けられている領域よりも径方向における外側に配置されている。かかる構成によれば、送信部５を用いた異物除去のための、天板部４２の励振が、効率的に行われ得る。 Further, in the present embodiment, as shown in FIG. 8, the microphone case 4 has a top plate resonance portion 412 as a resonance portion that resonates by the ultrasonic wave transmitted from the transmission unit 5. The top plate resonance portion 412 is provided on the top plate portion 42. Specifically, the top plate resonance portion 412 has a structure as a thin-walled portion or a thick-walled portion that adjusts the resonance frequency of the top plate portion 42. Further, the top plate resonance portion 412 is arranged outside the region where the through hole 42c is provided in the radial direction. According to such a configuration, the top plate portion 42 can be efficiently excited for removing foreign matter by using the transmission unit 5.
　（変形例）
　本開示は、上記実施形態に限定されるものではない。故に、上記実施形態に対しては、適宜変更が可能である。以下、代表的な変形例について説明する。以下の変形例の説明においては、上記実施形態との相違点を主として説明する。また、上記実施形態と変形例とにおいて、互いに同一または均等である部分には、同一符号が付されている。したがって、以下の変形例の説明において、上記実施形態と同一の符号を有する構成要素に関しては、技術的矛盾または特段の追加説明なき限り、上記実施形態における説明が適宜援用され得る。 (Modification example)
The present disclosure is not limited to the above embodiment. Therefore, the above embodiment can be changed as appropriate. Hereinafter, a typical modification will be described. In the following description of the modification, the differences from the above embodiment will be mainly described. Further, in the above-described embodiment and the modified example, the same or equal parts are designated by the same reference numerals. Therefore, in the following description of the modification, the description in the above embodiment may be appropriately incorporated with respect to the components having the same reference numerals as those in the above embodiment, unless there is a technical contradiction or a special additional explanation.
　超音波センサ１の装着対象は、フロントバンパーＶ３およびリアバンパーＶ４に限定されない。具体的には、例えば、超音波センサ１は、車体パネルＶ２にも装着され得る。すなわち、装着孔Ｖ５は、車体パネルＶ２にも設けられ得る。 The mounting target of the ultrasonic sensor 1 is not limited to the front bumper V3 and the rear bumper V4. Specifically, for example, the ultrasonic sensor 1 may be mounted on the vehicle body panel V2. That is, the mounting hole V5 may also be provided in the vehicle body panel V2.
　超音波センサ１は、超音波を送受信可能な構成に限定されない。すなわち、例えば、超音波センサ１は、超音波の発信のみが可能な構成を有していてもよい。あるいは、超音波センサ１は、他の超音波発信器から発信された超音波である送信波の、周囲に存在する物体による反射波を受信する機能のみを有するものであってもよい。 The ultrasonic sensor 1 is not limited to a configuration capable of transmitting and receiving ultrasonic waves. That is, for example, the ultrasonic sensor 1 may have a configuration capable of transmitting only ultrasonic waves. Alternatively, the ultrasonic sensor 1 may have only a function of receiving a reflected wave of a transmitted wave, which is an ultrasonic wave transmitted from another ultrasonic transmitter, by an object existing in the surroundings.
　超音波センサ１における各部の構成も、上記具体例に限定されない。具体的には、例えば、超音波マイクロフォン３すなわちマイクケース４の外形形状は、略円柱状に限定されず、略正六角柱状、略正八角柱状、等であってもよい。また、マイクケース４は、略柱状あるいは略錐台状に形成され得る。 The configuration of each part of the ultrasonic sensor 1 is not limited to the above specific example. Specifically, for example, the outer shape of the ultrasonic microphone 3, that is, the microphone case 4 is not limited to a substantially columnar shape, and may be a substantially regular hexagonal columnar shape, a substantially regular octagonal columnar shape, or the like. Further, the microphone case 4 may be formed in a substantially columnar shape or a substantially frustum shape.
　マイクケース４の構造についても、技術的な不都合が生じない限り、特段の限定はない。具体的には、例えば、側板部４１と天板部４２とは、上記のように、同一材料によって継ぎ目なく一体に形成されていてもよい。あるいは、側板部４１と天板部４２とは、互いに異なる材料によって形成されていてもよい。マイクケース４を構成する材料についても、特段の限定はない。すなわち、例えば、側板部４１および／または天板部４２は、合成樹脂によって形成されていてもよい。 There are no particular restrictions on the structure of the microphone case 4 as long as there are no technical inconveniences. Specifically, for example, the side plate portion 41 and the top plate portion 42 may be seamlessly and integrally formed of the same material as described above. Alternatively, the side plate portion 41 and the top plate portion 42 may be formed of different materials. There are no particular restrictions on the materials that make up the microphone case 4. That is, for example, the side plate portion 41 and / or the top plate portion 42 may be formed of a synthetic resin.
　図９に示されているように、天板部４２は、多孔質セラミックス等の多孔質材料によって形成されていてもよい。かかる構成においては、天板部４２は、図３等に示された貫通孔４２ｃを設けなくても、送信波および受信波の通過性あるいは透過性を有する。したがって、かかる構成によれば、図３等に示された貫通孔４２ｃを省略することで、超音波マイクロフォン３における防水性および防塵性が向上する。但し、多孔質材料によって形成された天板部４２に、図３等に示された貫通孔４２ｃを設けることは、差し支えない。 As shown in FIG. 9, the top plate portion 42 may be formed of a porous material such as porous ceramics. In such a configuration, the top plate portion 42 has passability or transparency of the transmitted wave and the received wave even if the through hole 42c shown in FIG. 3 or the like is not provided. Therefore, according to such a configuration, by omitting the through hole 42c shown in FIG. 3 and the like, the waterproof and dustproof properties of the ultrasonic microphone 3 are improved. However, it is permissible to provide the through hole 42c shown in FIG. 3 or the like in the top plate portion 42 formed of the porous material.
　天板部４２は、メッシュ状構造、グリッド構造、アイソグリッド構造、あるいはハニカム構造を有していてもよい。貫通孔４２ｃは、中心軸ＤＡと直交する断面による断面形状が多角形状であってもよい。この場合の内径は、最大径、すなわち、多角形状における外接円の直径となる。 The top plate portion 42 may have a mesh-like structure, a grid structure, an isogrid structure, or a honeycomb structure. The through hole 42c may have a polygonal cross-sectional shape due to a cross section orthogonal to the central axis DA. The inner diameter in this case is the maximum diameter, that is, the diameter of the circumscribed circle in the polygonal shape.
　超音波素子５１の種類を含む、送信部５の構成についても、特段の限定はない。すなわち、例えば、超音波素子５１は、上記各実施形態のようなＰＭＵＴに限定されない。ＰＭＵＴはPiezoelectric　Micro-machined　Ultrasonic　Transducersの略である。具体的には、超音波素子５１は、ＣＭＵＴとしての構成を有していてもよい。ＣＭＵＴはCapacitive　Micro-machined　Ultrasound　Transducerの略である。あるいは、例えば、超音波素子５１は、バルク型の構成を有していてもよい。 There are no particular restrictions on the configuration of the transmitter 5, including the type of ultrasonic element 51. That is, for example, the ultrasonic element 51 is not limited to the PMUT as in each of the above embodiments. PMUT is an abbreviation for Piezoelectric Micro-machined Ultrasonic Transducers. Specifically, the ultrasonic element 51 may have a configuration as a CMUT. CMUT is an abbreviation for Capacitive Micro-machined Ultrasound Transducer. Alternatively, for example, the ultrasonic element 51 may have a bulk type configuration.
　上記各実施形態においては、送信部５における送信波の発信方向が、天板部４２に向かう軸方向となっていた。しかしながら、本開示は、かかる態様に限定されない。すなわち、例えば、送信部５における送信波の発信方向は、天板部４２に向かう軸方向と交差する方向（例えば面内方向）であってもよい。 In each of the above embodiments, the transmission direction of the transmitted wave in the transmitting unit 5 is the axial direction toward the top plate unit 42. However, the present disclosure is not limited to such embodiments. That is, for example, the transmission direction of the transmitted wave in the transmitting unit 5 may be a direction (for example, an in-plane direction) that intersects the axial direction toward the top plate unit 42.
　複数の実施形態同士は、技術的に矛盾しない限り、互いに組み合わされ得る。例えば、図５に示された第三実施形態における追加超音波素子５５は、側板部４１を励振するように設けられ得る。すなわち、第二実施形態と第三実施形態とは、互いに組み合わせられ得る。 A plurality of embodiments can be combined with each other as long as there is no technical contradiction. For example, the additional ultrasonic element 55 according to the third embodiment shown in FIG. 5 may be provided so as to excite the side plate portion 41. That is, the second embodiment and the third embodiment can be combined with each other.
　また、例えば、図５に示された第三実施形態における追加超音波素子５５は、図６に示された第四実施形態の構成においても設けられ得る。すなわち、第三実施形態と第四実施形態とは、互いに組み合わせられ得る。 Further, for example, the additional ultrasonic element 55 in the third embodiment shown in FIG. 5 can also be provided in the configuration of the fourth embodiment shown in FIG. That is, the third embodiment and the fourth embodiment can be combined with each other.
　同様に、例えば、図５に示された第三実施形態における追加超音波素子５５は、図８に示された第六実施形態の構成においても設けられ得る。すなわち、第三実施形態と第六実施形態とは、互いに組み合わせられ得る。 Similarly, for example, the additional ultrasonic element 55 in the third embodiment shown in FIG. 5 can be provided in the configuration of the sixth embodiment shown in FIG. That is, the third embodiment and the sixth embodiment can be combined with each other.
　上記の説明において、互いに継ぎ目無く一体に形成されていた複数の構成要素は、互いに別体の部材を貼り合わせることによって形成されてもよい。同様に、互いに別体の部材を貼り合わせることによって形成されていた複数の構成要素は、互いに継ぎ目無く一体に形成されてもよい。 In the above description, the plurality of components that are seamlessly and integrally formed with each other may be formed by laminating separate members from each other. Similarly, a plurality of components formed by laminating separate members may be seamlessly and integrally formed with each other.
　上記の説明において、互いに同一の材料によって形成されていた複数の構成要素は、互いに異なる材料によって形成されてもよい。同様に、互いに異なる材料によって形成されていた複数の構成要素は、互いに同一の材料によって形成されてもよい。 In the above description, the plurality of components formed of the same material may be formed of different materials. Similarly, a plurality of components that were formed of different materials may be formed of the same material.
　上記実施形態を構成する要素は、特に必須であると明示した場合および原理的に明らかに必須であると考えられる場合等を除き、必ずしも必須のものではないことは言うまでもない。また、構成要素の個数、量、範囲等の数値が言及されている場合、特に必須であると明示した場合および原理的に明らかに特定の数値に限定される場合等を除き、その特定の数値に本開示が限定されることはない。同様に、構成要素等の形状、方向、位置関係等が言及されている場合、特に必須であると明示した場合および原理的に特定の形状、方向、位置関係等に限定される場合等を除き、その形状、方向、位置関係等に本開示が限定されることはない。 It goes without saying that the elements constituting the above embodiment are not necessarily essential except when it is clearly stated that they are essential or when they are clearly considered to be essential in principle. In addition, unless the numerical values such as the number, amount, range, etc. of the components are mentioned, when it is clearly stated that they are indispensable, or when the numerical values are clearly limited to specific numerical values in principle, the specific numerical values are used. This disclosure is not limited to. Similarly, except when the shape, direction, positional relationship, etc. of the components, etc. are mentioned, when it is clearly stated that it is particularly essential, or when it is limited to a specific shape, direction, positional relationship, etc. in principle. The present disclosure is not limited to the shape, direction, positional relationship, and the like.
　変形例も、上記の例示に限定されない。すなわち、例えば、複数の実施形態のうちの任意の１つと、複数の変形例のうちの任意の１つとが、技術的に矛盾しない限り、互いに組み合わされ得る。同様に、複数の変形例のうちの１つと他の１つとが、技術的に矛盾しない限り、互いに組み合わされ得る。 The modified example is not limited to the above example. That is, for example, any one of the plurality of embodiments and any one of the plurality of modifications can be combined with each other as long as there is no technical conflict. Similarly, one of the variants and the other can be combined with each other as long as there is no technical conflict.

Claims (15)

  1. 　超音波センサ（１）であって、
    　中心軸（ＤＡ）を囲む筒状に形成された側板部（４１）と、前記中心軸と平行な軸方向に板厚方向を有し前記軸方向における前記側板部の一端部を閉塞するように設けられた板状部であって超音波である送信波が通過可能に形成された天板部（４２）と、を有するマイクケース（４）と、
    　前記天板部から離隔した状態で前記マイクケースに収容された、前記送信波を発信する送信部（５）と、
    　前記天板部に付着した異物を除去可能に、前記マイクケースを励振する励振部（５１；５５；６１）と、
    　を備えた超音波センサ。     An ultrasonic sensor (1)
    The side plate portion (41) formed in a cylindrical shape surrounding the central axis (DA) and the side plate portion having a plate thickness direction in the axial direction parallel to the central axis so as to close one end of the side plate portion in the axial direction. A microphone case (4) having a top plate portion (42), which is a plate-shaped portion provided so that a transmitted wave which is an ultrasonic wave can pass through, and a microphone case (4).
    A transmission unit (5) that transmits the transmission wave and is housed in the microphone case in a state of being separated from the top plate portion.
    An exciting unit (51; 55; 61) that excites the microphone case so that foreign matter adhering to the top plate can be removed.
    Ultrasonic sensor with.
  2. 　前記励振部は、前記送信部にて前記送信波を発信するように設けられた、電気信号と超音波振動とを変換する超音波素子（５１）である、
    　請求項１に記載の超音波センサ。     The excitation unit is an ultrasonic element (51) for converting an electric signal and ultrasonic vibration, which is provided at the transmission unit so as to transmit the transmission wave.
    The ultrasonic sensor according to claim 1.
  3. 　前記送信部は、電気信号と超音波振動とを変換する超音波素子（５１，５５）を複数備え、
    　複数の前記超音波素子のうちの一つ（５１）は、前記送信波を発信するように設けられ、
    　前記励振部は、複数の前記超音波素子のうちの他の一つ（５５）である、
    　請求項１に記載の超音波センサ。     The transmission unit includes a plurality of ultrasonic elements (51, 55) that convert an electric signal and ultrasonic vibration.
    One of the plurality of ultrasonic elements (51) is provided so as to transmit the transmitted wave.
    The excitation unit is another one (55) of the plurality of ultrasonic elements.
    The ultrasonic sensor according to claim 1.
  4. 　前記励振部は、前記側板部を励振するように構成された、
    　請求項２または３に記載の超音波センサ。     The exciting portion is configured to excite the side plate portion.
    The ultrasonic sensor according to claim 2 or 3.
  5. 　前記マイクケースは、前記励振部から発信された超音波により共振する共振部（４１１；４２１）を有する、
    　請求項２～４のいずれか１つに記載の超音波センサ。     The microphone case has a resonance portion (411; 421) that resonates with ultrasonic waves transmitted from the excitation portion.
    The ultrasonic sensor according to any one of claims 2 to 4.
  6. 　前記共振部は、前記側板部に設けられた、
    　請求項５に記載の超音波センサ。     The resonance portion is provided on the side plate portion.
    The ultrasonic sensor according to claim 5.
  7. 　前記マイクケースは、前記天板部に前記異物が付着していない状態にて、前記励振部から発信された超音波における周波数よりも高い共振周波数を有するように構成された、
    　請求項２～６のいずれか１つに記載の超音波センサ。     The microphone case is configured to have a resonance frequency higher than the frequency of the ultrasonic wave transmitted from the excitation unit in a state where the foreign matter does not adhere to the top plate portion.
    The ultrasonic sensor according to any one of claims 2 to 6.
  8. 　前記励振部は、前記マイクケースに固定された、電気信号と超音波振動とを変換する超音波素子（６１）である、
    　請求項１に記載の超音波センサ。     The excitation unit is an ultrasonic element (61) fixed to the microphone case that converts an electric signal and ultrasonic vibration.
    The ultrasonic sensor according to claim 1.
  9. 　前記天板部は、前記板厚方向に貫通する貫通孔（４２ｃ）を有する、
    　請求項１～８のいずれか１つに記載の超音波センサ。     The top plate portion has a through hole (42c) penetrating in the plate thickness direction.
    The ultrasonic sensor according to any one of claims 1 to 8.
  10. 　前記貫通孔は、内径が０．８ｍｍ以下に形成された、
    　請求項９に記載の超音波センサ。     The through hole has an inner diameter of 0.8 mm or less.
    The ultrasonic sensor according to claim 9.
  11. 　前記天板部は、板厚が０．４ｍｍ以上に形成された、
    　請求項１～１０のいずれか１つに記載の超音波センサ。     The top plate portion is formed to have a plate thickness of 0.4 mm or more.
    The ultrasonic sensor according to any one of claims 1 to 10.
  12. 　前記天板部は、多孔質材料によって形成された、
    　請求項１～１１のいずれか１つに記載の超音波センサ。     The top plate portion is formed of a porous material.
    The ultrasonic sensor according to any one of claims 1 to 11.
  13. 　前記送信部は、外部の物体による前記送信波の反射波を含む受信波の受信状態に対応する出力信号を生成する送受信部としての構成を有する、
    　請求項１～１２のいずれか１つに記載の超音波センサ。     The transmission unit has a configuration as a transmission / reception unit that generates an output signal corresponding to a reception state of a reception wave including a reflected wave of the transmission wave by an external object.
    The ultrasonic sensor according to any one of claims 1 to 12.
  14. 　前記送信波における周波数が２０ｋＨｚ～１００ｋＨｚとなるように構成された、
    　請求項１～１３のいずれか１つに記載の超音波センサ。     The frequency of the transmitted wave is configured to be 20 kHz to 100 kHz.
    The ultrasonic sensor according to any one of claims 1 to 13.
  15. 　車両（Ｖ）における車体（Ｖ１）の外板を構成する車体部品（Ｖ３）に装着されるように構成された、
    　請求項１～１４のいずれか１つに記載の超音波センサ。     It is configured to be mounted on a vehicle body component (V3) constituting the outer panel of the vehicle body (V1) in the vehicle (V).
    The ultrasonic sensor according to any one of claims 1 to 14.
PCT/JP2021/019776 2020-06-16 2021-05-25 Ultrasonic sensor WO2021256189A1 (en)

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JPH05157849A (en) * 1991-04-26 1993-06-25 Matsushita Electric Works Ltd Ultrasonic sensor
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JP2002044784A (en) * 2000-07-21 2002-02-08 Amca:Kk Open air ultrasonic sensor
WO2010005130A1 (en) * 2008-07-07 2010-01-14 Hagisonic Co., Ltd. Ultrasonic sensor with water repellent function
JP2012217036A (en) * 2011-03-31 2012-11-08 Nec Casio Mobile Communications Ltd Oscillation device and electronic device
JP2019140672A (en) * 2018-02-05 2019-08-22 株式会社デンソー Ultrasonic sensor

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6327784A (en) * 1986-07-22 1988-02-05 Matsushita Electric Works Ltd Obstacle detector for vehicle
JPH05157849A (en) * 1991-04-26 1993-06-25 Matsushita Electric Works Ltd Ultrasonic sensor
JP2000023296A (en) * 1998-07-01 2000-01-21 Murata Mfg Co Ltd Ultrasonic wave sensor
JP2002044784A (en) * 2000-07-21 2002-02-08 Amca:Kk Open air ultrasonic sensor
WO2010005130A1 (en) * 2008-07-07 2010-01-14 Hagisonic Co., Ltd. Ultrasonic sensor with water repellent function
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