Ultrasonic sensor and sensor attachment

Abstract

A sensor attachment (8) comprises: a U-shaped attachment body (81) having a pair of extending portions (814), a connecting portion (812), and an opening portion (811); and an elastic portion (82) protruding from the attachment body. The sensor attachment is configured to be inserted into an attachment insertion groove (75b) in a housing component (7) by sliding along an attachment insertion direction (F), and thus held between a vehicle body component (V3) and a cylindrical portion (72) of the housing component by elastic force. The sensor attachment has a structure that allows the elastic force to be lower at an initial stage of the insertion into the attachment insertion groove than at any subsequent stages.

Description

Ultrasonic sensors and sensor mounting fixtures CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2022-205794, filed on December 22, 2022, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to ultrasonic sensors and sensor mounts used to mount such ultrasonic sensors to vehicle body parts.

[0003] The ultrasonic sensor described in Patent Document 1 is attached to a vehicle bumper and used as a rear sonar or corner sonar. Specifically, a sensor body integrated with a bezel is inserted into a hole in the bumper from the outside of the bumper. The bezel is a cylindrical member with a hollow portion and is made of synthetic resin or the like. A retainer is then attached to the back side of the bumper. The retainer is a member for holding the sensor body and bezel to the bumper and is made of synthetic resin or the like.

[0004] Specifically, a flange is formed at one end of the bezel. A sliding surface is formed at the end of the bezel opposite the flange. The sliding surface is configured as a surface facing the back surface of the bumper, and is formed symmetrically on both sides of the hollow portion of the bezel. For example, the sliding surface is configured by partially protruding the end of the bezel opposite the flange. A retainer is fitted between this sliding surface and the back surface of the bumper so as to be slidable.

[0005] The retainer has a U-shaped portion and an elastic portion. The U-shaped portion has a U-shape with a central recess so that the bezel fits into the central recess. Of the straight portions on both sides of the U-shaped portion, the inner surfaces of the U-shape abut against the outer wall surface of the bezel, and the surface of the U-shaped portion opposite the flange abuts against the sliding surface. An elastic portion is also disposed on the surface of the U-shaped portion facing the flange. An elastic portion is provided on each of the straight portions on both sides of the U-shaped portion. Each elastic portion is composed of two arch-shaped portions, one end of which is a fixed end supported by the U-shaped portion and the other end of which is a free end. Before the retainer is fitted between the sliding surface and the rear surface of the bumper, the height of each elastic portion is greater than the distance between the sliding surface and the rear surface of the bumper.

[0006] Using this retainer, the sensor body together with the bezel is fitted into the hole in the bumper, and then the retainer is slid between the sliding surface and the back surface of the bumper to firmly hold the sensor body and bezel to the bumper. Specifically, when the retainer is fitted between the sliding surface and the back surface of the bumper, the bulging portion of the elastic portion between the free end and the fixed end abuts against the back surface of the bumper, causing the elastic portion to elastically deform. As a result, the elastic force presses the U-shaped portion and the elastic portion against the sliding surface and the back surface of the bumper, making it possible to firmly hold the sensor body and bezel to the bumper.

[0007] Japanese Patent Application Laid-Open No. 2018-146564

[0008] In the configuration described in Patent Document 1, when the retainer is slid and fitted, a load must be applied to elastically deform the elastic portion of the retainer. In this regard, in the initial stage of fitting the retainer, the orientation of the retainer relative to the sensor body and the bezel is not determined, and the direction of the load is also unstable. Therefore, the configuration described in Patent Document 1 still leaves room for improvement in terms of ease of installation of the ultrasonic sensor to the bumper. The present disclosure has been made in light of the circumstances exemplified above. That is, the present disclosure provides a technology for improving ease of installation of the ultrasonic sensor to the bumper of a vehicle, for example.

[0009] According to one aspect of the present disclosure, a sensor attachment tool is used to attach an ultrasonic sensor to a plate-shaped vehicle body part, wherein the ultrasonic sensor comprises a cylindrical housing part having a tubular portion to be inserted into a through-hole formed in the vehicle body part, and a flange portion for preventing removal that protrudes radially away from a central axis at one end in an axial direction parallel to the central axis of the cylindrical portion, the cylindrical portion having a pair of attachment tool insertion grooves that open in the radial direction at the outer periphery of the cylindrical portion and extend in an attachment tool insertion direction that intersects the axial direction, and that are parallel to each other on both sides of the central axis, the pair of extension parts extending in the attachment tool insertion direction and arranged parallel to each other, a connecting portion that connects base ends of the pair of extension parts on the side opposite to the tip ends on the attachment tool insertion direction side, and an opening that opens at the tip end, an elastic portion that protrudes from the fixture main body along the axial direction and is formed to be elastically deformable along the axial direction, so that an elastic force is generated in an urging direction toward the vehicle body part when the tubular portion is inserted into the through hole and the fixture main body is inserted into the fixture insertion groove; and when the tubular portion is inserted into the through hole, the tubular portion is inserted into the fixture insertion groove so as to slide along the fixture insertion direction while being accommodated inside the opening, so that the vehicle body part and the tubular portion are held together by the elastic force, and the structure has such that the elastic force is lower in the initial stage of insertion into the fixture insertion groove than in subsequent stages.According to another aspect of the present disclosure, an ultrasonic sensor attached to a plate-shaped vehicle body part comprises: a cylindrical housing part having a tubular portion inserted into a through-hole formed in the vehicle body part, and a flange portion for preventing slip-out that protrudes radially away from a central axis at one end in an axial direction parallel to the central axis of the cylindrical portion; and a sensor attachment device configured to be attached to the housing part to hold the housing part to the vehicle body part, wherein the cylindrical portion has a pair of attachment device insertion grooves that open in the radial direction at the outer periphery of the cylindrical portion and extend in an attachment device insertion direction that intersects with the axial direction, and are parallel to each other on both sides of the central axis, and the sensor attachment device comprises: a U-shaped attachment device main body having a pair of extension portions that extend in the attachment device insertion direction and are arranged parallel to each other, a connecting portion that connects base ends of the pair of extension portions on the side opposite to the tip ends on the attachment device insertion direction side, and an opening that opens at the tip end; and an elastic portion that protrudes from the mounting fixture main body along the axial direction and is formed to be elastically deformable along the axial direction, so that when the tubular portion is inserted into the through hole and the mounting fixture main body is inserted into the mounting fixture insertion groove, an elastic force is generated in the biasing direction toward the vehicle body part; and when the tubular portion is inserted into the through hole, the tubular portion is inserted into the mounting fixture insertion groove so as to slide along the mounting fixture insertion direction while being accommodated inside the opening, so that the sensor mounting fixture is held between the vehicle body part and the tubular portion by the elastic force, and has a structure in which the elastic force is lower in the initial stage of inserting the sensor mounting fixture into the mounting fixture insertion groove than in subsequent stages.

[0010] In addition, in each section of the application documents, each element may be assigned a reference symbol in parentheses. In this case, the reference symbol merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present disclosure is not limited in any way by the description of the reference symbol.

[0011] 1 is a perspective view showing the appearance of a vehicle equipped with an ultrasonic sensor according to an embodiment. FIG. 1 is a plan view showing the ultrasonic sensor shown in FIG. 1 mounted on a vehicle. FIG. 2 is a plan view showing a schematic configuration of the sensor main body shown in FIG. 3. FIG. 3 is a partial cross-sectional view of the sensor main body shown in FIG. 4. FIG. 5 is a plan view showing an enlarged view of the anti-vibration spacer shown in FIG. 2. FIG. 5A is a front view of the anti-vibration spacer shown in FIG. 5A. FIG. 5B is a plan view showing a schematic configuration of a secondary assembly combining the sensor main body, anti-vibration spacer, and bezel shown in FIG. 2. FIG. 6 is an enlarged view of the bezel shown in FIG. 6. FIG. 7 is a rear view of the retainer shown in FIG. 2. FIG. 8 is a side view of the retainer shown in FIG. 8A. FIG. 8D is a side cross-sectional side view of the retainer shown in FIG. 8A. FIG. 8D is a side view showing a state where an ultrasonic sensor is attached to a bumper using a retainer of a comparative example.

[0012] (Embodiments) Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that if various modified examples applicable to one embodiment are introduced in the middle of a series of explanations related to the embodiment, it may hinder understanding of the embodiment. Therefore, the modified examples will not be introduced in the middle of a series of explanations related to the embodiment, but will be explained together after the series of explanations.

[0013] 1, in this embodiment, the ultrasonic sensor 1 has a configuration as an on-vehicle clearance sonar to be attached to a vehicle V. That is, the ultrasonic sensor 1 is configured to be mounted on the vehicle V and to be able to detect objects present around the vehicle V.

[0014] The vehicle V is a so-called four-wheeled automobile and has a box-shaped body V1. The body V1 has a body panel V2, a front bumper V3, and a rear bumper V4, which are plate-shaped body components that form the exterior panels. The front bumper V3 is provided at the front end of the body V1. The rear bumper V4 is provided at the rear end of the body V1. In this embodiment, the front bumper V3 and the rear bumper V4 are formed from metal plates.

[0015] The ultrasonic sensor 1 is attached to the front bumper V3 and is configured to detect objects present in front of and on the sides of the vehicle V. Similarly, the ultrasonic sensor 1 is attached to the rear bumper V4 and is configured to detect objects present behind and on the sides of the vehicle V. The state in which the ultrasonic sensor 1 is mounted on the vehicle V by being attached to the front bumper V3 and rear bumper V4 provided on the vehicle body V1 will hereinafter be referred to as the "vehicle-mounted state."

[0016] Specifically, in a vehicle-mounted state, a plurality of (e.g., four) ultrasonic sensors 1 are attached to the front bumper V3. The plurality of ultrasonic sensors 1 attached to the front bumper V3 are each arranged at different positions in the vehicle width direction. Similarly, a plurality of (e.g., four) ultrasonic sensors 1 are attached to the rear bumper V4. The front bumper V3 and the rear bumper V4 are provided with mounting holes V5, which are through-holes for mounting the ultrasonic sensors 1. Note that the ultrasonic sensors 1 can be attached to and detached from the front bumper V3 with the front bumper V3 removed from the vehicle body V1. Therefore, the "mounted state" in which the ultrasonic sensors 1 are attached to the front bumper V3 includes the "vehicle-mounted state." The same applies to the attachment and detachment of the ultrasonic sensors 1 to and from the rear bumper V4.

[0017] (Ultrasonic Sensor) FIG. 2 shows one of the ultrasonic sensors 1 mounted on the front bumper V3 in a vehicle-mounted state. The overall configuration of the ultrasonic sensor 1 according to this embodiment will be described below with reference to FIG. 2 . The ultrasonic sensor 1 can also be mounted on the rear bumper V4 in a similar manner. While the figure shows an example mounted on the front bumper V3, the present disclosure is not limited to this configuration. Therefore, while the front bumper V3 is illustrated in FIG. 2 and subsequent figures, the front bumper V3 and the rear bumper V4 will be collectively referred to simply as "bumpers" in the following description. For ease of explanation, a right-handed XYZ Cartesian coordinate system is set as shown in the figure, with the direction of gravity acting as the reference when the vehicle V is mounted on the vehicle. In the illustrated right-handed XYZ coordinate system, the upward direction along the vertical is defined as the positive Z-axis direction. The vertical upward direction refers to a direction parallel to and opposite to the direction of gravity when the vehicle V is stably placed on a horizontal plane in a drivable state. The upward direction is the same direction as the vertically upward direction or a direction that forms a predetermined small acute angle α with the vertically upward direction. α is, for example, 10 degrees or less. Therefore, depending on the shape of the bumper, the positive Z-axis direction may be the same direction as the vertically upward direction or a direction that intersects with the vertically upward direction. Similarly, the positive Y-axis direction may be the same direction as the horizontal direction or a direction that intersects with the horizontal direction.

[0018] The bumper has a bumper outer surface V31 and a bumper back surface V32. The bumper outer surface V31 is the outer surface of the bumper and is arranged to face the bumper outer space SG, which is the space outside the vehicle V when mounted on the vehicle. The bumper back surface V32 is the surface behind the bumper outer surface V31 and is arranged to face the bumper inner space SN, which is the space inside the vehicle V when mounted on the vehicle. The mounting hole V5 is opened on the bumper outer surface V31 and the bumper back surface V32, penetrating the bumper in the thickness direction. The mounting hole V5 is formed as a circular hole with a cylindrical space inside. In other words, the mounting hole V5 has an inner edge V51 with a cylindrical inner surface.

[0019] The ultrasonic sensor 1 is configured to transmit and receive ultrasonic waves. Specifically, the ultrasonic sensor 1 is configured to transmit ultrasonic probe waves along a central axis CL toward the bumper exterior space SG. The ultrasonic sensor 1 is also configured to receive received waves, including reflected waves of the probe waves from objects in the bumper exterior space SG, and generate and output a detection signal corresponding to the reception results of the received waves. As shown in FIG. 2 , in the illustrated right-handed XYZ coordinate system, the direction of transmission of the probe waves, parallel to the central axis CL that constitutes the directional axis of the ultrasonic sensor 1, is defined as the positive Y-axis direction. The "directional axis" is a virtual line extending from the ultrasonic sensor 1 along the direction of transmission and reception of ultrasonic waves and serves as a reference for the directional angle. The "directional axis" may also be referred to as the directional central axis or the detection axis. The positive Y-axis direction, parallel to the directional axis, is referred to as the "axial direction." Hereinafter, of the two axial ends of a member extending in the axial direction, the one on the positive Y-axis side may be referred to as the "axial tip end" and the one on the negative Y-axis side may be referred to as the "axial base end." Furthermore, the dimension of a certain member or part in the axial direction will hereinafter be simply referred to as the "axial dimension."

[0020] Any direction perpendicular to the axial direction will be referred to as the "in-plane direction." The "in-plane direction" is a direction parallel to the XZ plane. The shape of a certain part or component in a plane perpendicular to the central axis CL, i.e., the shape projected onto the XZ plane, may be referred to as the "in-plane shape." The "in-plane direction" includes the "radial direction" and the "circumferential direction." The "radial direction" is a direction extending radially from the central axis CL. That is, the "radial direction" is a direction perpendicular to the central axis CL and moving away from the central axis CL. Specifically, the "radial direction" is the direction in which a half-line extends when a virtual plane perpendicular to the central axis CL intersects with the central axis CL as its starting point. In other words, the "radial direction" is the radial direction of a virtual circle drawn in the virtual plane with the intersection of the virtual plane and the central axis CL as its center. The "circumferential direction" refers to the circumferential direction of the imaginary circle surrounding the central axis CL.

[0021] In this embodiment, the ultrasonic sensor 1 is mounted on the vehicle V so that, when mounted on the vehicle, the central axis CL is approximately parallel to the thickness direction of the bumper in the vicinity of the mounting position. The "mounting position" refers to the position where the ultrasonic sensor 1 is mounted on the bumper, and is typically the center position of the mounting hole V5. The center position of the mounting hole V5 is the center position of a circle that forms the intersection line between the inner edge V51 of the cylindrical inner surface of the mounting hole V5 and the bumper outer surface V31 or the bumper back surface V32. Alternatively, the center position of the mounting hole V5 is the position on the XZ plane of the central axis CL when mounted on the vehicle or mounted.

[0022] The sensor body 2, which forms the main body of the ultrasonic sensor 1, includes a sensor case 3, an ultrasonic microphone 4, and a cushion member 5. The sensor body 2 is attached to the bumper using an anti-vibration spacer 6, a bezel 7, and a retainer 8. That is, the ultrasonic sensor 1 in the vehicle-mounted state is made up of the sensor case 3, the ultrasonic microphone 4, the cushion member 5, the anti-vibration spacer 6, the bezel 7, and the retainer 8. The specific configuration of each part that makes up the ultrasonic sensor 1 will be described below.

[0023] (Sensor Case) The sensor case 3, which constitutes the housing of the ultrasonic sensor 1, i.e., the sensor body 2, is made of a hard synthetic resin such as polybutylene terephthalate, ABS resin, polypropylene, polycarbonate, or polystyrene. Figure 3 shows the state in which the secondary assembly, in which the retainer 8 has been removed from the ultrasonic sensor 1 in the installed state shown in Figure 2, has been removed into the bumper outer space SG, and the bezel 7 has been removed from the secondary assembly. The secondary assembly is an assembly in which the sensor body 2, which is the primary assembly consisting of the sensor case 3, ultrasonic microphone 4, and cushion member 5, is further assembled with the vibration-isolating spacer 6 and bezel 7. Hereinafter, the state in which such a secondary assembly is formed may be referred to as the "assembled state." The "installed state" and "vehicle-mounted state" also fall under the "assembled state."

[0024] Referring to Figure 3, the sensor case 3 has a box-shaped portion 31, a connector portion 32, and a microphone support portion 33. The box-shaped portion 31, the connector portion 32, and the microphone support portion 33 are seamlessly formed as a single unit by injection molding. The box-shaped portion 31 has a box-like outer shape that is longitudinal in the X-axis direction and thin in the Y-axis direction when installed. As shown in Figure 4, which is a partial cross-sectional view of Figure 3, a circuit board 34 is housed inside the box-shaped portion 31. The circuit board 34 is electrically connected to the ultrasonic microphone 4 via connection wiring 35.

[0025] The connector portion 32 is provided so as to extend substantially horizontally and diagonally rearward from one longitudinal end of the box-shaped portion 31 (i.e., the left end in FIGS. 3 and 4 ) when mounted on the vehicle. That is, the connector portion 32 extends in a direction away from the bumper when mounted. The connector portion 32 is configured as a receptacle connector that is detachable from a plug connector (not shown) provided at the end of a wire harness for electrical connection with an external device such as an ECU. ECU stands for Electronic Control Unit.

[0026] The microphone support portion 33 extends in the axial direction from the other longitudinal end portion of the box-shaped portion 31 (i.e., the right end portion in FIGS. 3 and 4 ). The microphone support portion 33 has a cylindrical shape that surrounds the central axis line CL. In this embodiment, the microphone support portion 33 is formed in a cylindrical shape with the central axis line CL as its axis center.

[0027] A cushion locking protrusion 36 and a bezel locking protrusion 37 are provided at the axial tip of the microphone support portion 33. The cushion locking protrusion 36 is a protrusion that protrudes toward the central axis CL from the cylindrical inner wall surface of the microphone support portion 33 that surrounds the central axis CL and extends circumferentially. The bezel locking protrusion 37 is a small protrusion that protrudes radially from the cylindrical outer wall surface of the microphone support portion 33 that surrounds the central axis CL, and a plurality of bezel locking protrusions 37 are formed in an array along the circumferential direction.

[0028] (Ultrasonic Microphone) Referring to Fig. 4, the ultrasonic microphone 4 has a columnar outer shape extending along the axial direction. Specifically, in this embodiment, the ultrasonic microphone 4 is formed in a substantially cylindrical shape with the central axis line CL as its axis center. The ultrasonic microphone 4 includes an ultrasonic element 41 and a microphone case 42. The ultrasonic element 41 is a so-called electromechanical conversion element, and is formed by a thin-film piezoelectric element or the like. The ultrasonic element 41 is housed inside the microphone case 42.

[0029] The microphone case 42 constituting the housing of the ultrasonic microphone 4 is formed into a cylindrical shape with a bottom from a metal material such as aluminum. Specifically, the microphone case 42 has a diaphragm 43 and a side plate portion 44. The diaphragm 43 is formed into a thin plate having a thickness in the axial direction. The diaphragm 43 is provided so as to close the axial tip end of the side plate portion 44. The outer surface of the diaphragm 43 that faces the bumper outer space SG when attached or mounted on the vehicle is formed into a smooth, flat surface. The ultrasonic element 41 is fixed to the inner surface of the diaphragm 43 behind the outer surface.

[0030] The side plate portion 44, which is a substantially cylindrical portion of the microphone case 42, extends in the axial direction. The side plate portion 44, i.e., the side surface 44a that constitutes the outer wall surface of the ultrasonic microphone 4, is formed in a cylindrical shape with the central axis line CL as its axis center. A pair of engagement grooves 45 is formed in the side surface 44a of the side plate portion 44. The engagement grooves 45 are square grooves that extend parallel to the Z-axis direction in the figure. The pair of engagement grooves 45 are arranged symmetrically with the central axis line CL in between.

[0031] (Cushion Member) The cushion member 5 is seamlessly formed as a single piece from a synthetic resin-based elastic material such as silicone rubber. In this embodiment, the cushion member 5 is attached to the sensor body 2, which is a primary assembly, together with the ultrasonic microphone 4 as a component constituting the sensor body 2. The cushion member 5 is formed in a tubular shape surrounding the central axis CL. Specifically, in this embodiment, the cushion member 5 has a substantially cylindrical shape with the central axis CL as its axis center, an outer diameter substantially equal to the outer diameter of the microphone support portion 33, and an inner diameter substantially equal to the outer diameter of the side plate portion 44. The cushion member 5 is also formed to have a larger axial dimension than the ultrasonic microphone 4.

[0032] The cushion member 5 is fixed to the microphone support portion 33 at a supported portion 51, which is a base end portion in the axial direction. Specifically, the supported portion 51 is provided with a locking groove 52 that opens radially. The locking groove 52 is a groove shaped to engage with the cushion locking protrusion 36 provided in the microphone support portion 33 and extends circumferentially. The microphone housing portion 53, which is a portion of the cushion member 5 further toward the tip end in the axial direction than the supported portion 51, is configured to house the ultrasonic microphone 4 over almost the entire axial direction. That is, the microphone housing portion 53 has a columnar internal space corresponding to the outer shape of the ultrasonic microphone 4 so as to cover the side surface 44a of the ultrasonic microphone 4. The microphone housing portion 53 is provided with a pair of locking protrusions 54. The pair of locking protrusions 54 are arranged symmetrically and opposite to each other across the central axis CL. The engaging protrusion 54 is a ridge portion that is rectangular in cross section and protrudes toward the central axis CL and has a shape that fits into the engaging groove 45, which is a square groove, and extends in the Z-axis direction in the figure. The microphone housing portion 53 of the cushion member 5 is formed so that the outer diameter of a tip portion 55 in the axial direction decreases toward the tip side in the axial direction.

[0033] In this way, the cushion member 5 is fixed to the sensor case 3 at the base end side in the axial direction and is provided to elastically support the ultrasonic microphone 4. That is, the ultrasonic sensor 1 in this embodiment is configured to suppress vibration transmission between the sensor case 3 and the ultrasonic microphone 4 by elastically supporting the ultrasonic microphone 4 on the sensor case 3 via the cushion member 5. Furthermore, the cushion member 5 is provided on the ultrasonic sensor 1 so as to be interposed between the ultrasonic microphone 4 and the bezel 7, which is provided to surround the side surface 44a of the ultrasonic microphone 4, when the ultrasonic sensor 1 is mounted in a vehicle. That is, the cushion member 5 is interposed between the ultrasonic microphone 4 and the bumper and is configured to suppress vibration transmission between the ultrasonic microphone 4 and the bumper.

[0034] 5A and 5B, the vibration-damping spacer 6 is a thin, ring-shaped member having a thickness in the axial direction, and is made of a synthetic resin-based elastic material such as silicone rubber. Specifically, in this embodiment, the vibration-damping spacer 6 has a shape in which a circular spacer through-hole 61, which is a through-hole, is drilled at the center of a disc-shaped member. As shown in FIG. 2, the vibration-damping spacer 6 is provided between the bumper and a flange portion 71 (described below) of the bezel 7 when mounted on a vehicle, so as to suppress vibration transmission between the bezel 7 and the bumper. That is, when mounted, the vibration-damping spacer 6 is sandwiched between the bumper outer surface V31 and a back surface 71a, which is the surface of the flange portion 71 of the bezel 7 that faces the bumper.

[0035] (Bezel) FIG. 6 shows the above-described secondary assembly. In such a secondary assembly or the ultrasonic sensor 1 shown in FIG. 2, the bezel 7, together with the sensor case 3, constitutes a housing. FIG. 7 shows an enlarged view of the bezel 7 shown in FIG. 6. The bezel 7 is a component used to attach the ultrasonic sensor 1 to a bumper, which is a plate-shaped vehicle body component, and is formed into a cylindrical shape from a hard synthetic resin. Below, the configuration of the bezel 7 as a housing component of the present disclosure will be described with the central axis of the cylindrical shape of the bezel 7 aligned with the central axis line CL as shown in FIGS. 2, 6, and 7.

[0036] A flange portion 71 is provided at the tip, which is one end in the axial direction, of the bezel 7. The flange portion 71 is a protrusion provided to prevent the secondary assembly from slipping out when it is inserted into the mounting hole V5 and attached to the bumper, and protrudes radially like a canopy. Specifically, the flange portion 71 is formed in a ring shape with its thickness oriented in the axial direction. The flange portion 71 has an outer diameter larger than the inner diameter of the mounting hole V5. That is, as shown in FIG. 2 , the flange portion 71 is provided so as to face the portion of the bumper outer surface V31 surrounding the mounting hole V5 with the vibration-damping spacer 6 sandwiched therebetween in the attached state. The back surface 71a of the flange portion 71 is formed in a flat, planar shape.

[0037] A spacer accommodating groove 71b for accommodating the anti-vibration spacer 6 is provided so as to open in the radial direction at a position adjacent to and closer to the flange portion 71 in the axial direction. The spacer accommodating groove 71b has a width (i.e., axial dimension) corresponding to the thickness of the anti-vibration spacer 6, and a depth (i.e., radial dimension) corresponding to the diameter of the spacer through-hole 61 in the anti-vibration spacer 6. The spacer accommodating groove 71b extends over the entire bezel 7 in the circumferential direction.

[0038] The spacer accommodating groove 71b is provided between the flange portion 71 and the cylindrical portion 72. That is, the flange portion 71 protrudes radially from one end, i.e., the tip, of the cylindrical portion 72, which extends axially. The flange portion 71 and the cylindrical portion 72 are seamlessly formed integrally from the same material. The cylindrical portion 72 is configured to be inserted into the mounting hole V5 while surrounding the ultrasonic microphone 4 and the cushion member 5 in the assembled and attached state. The cylindrical portion 72 has an outer diameter slightly smaller than the inner diameter of the mounting hole V5 and an inner diameter slightly larger than the outer diameters of the microphone support portion 33 and the cushion member 5.

[0039] The main body 73, including the axial center of the cylindrical portion 72, extends along the central axis CL. The main body 73 is provided with a sensor locking piece 74. The sensor locking piece 74 is a cantilever-shaped tongue having a thickness in the radial direction, and extends from the distal end to the proximal end of the main body 73 in the axial direction. That is, the sensor locking piece 74 is elastically deformable with its distal end as a fixed end and its proximal end as a free end, allowing the free end to move radially. A locking hole 74a is provided at the free end of the sensor locking piece 74, penetrating the sensor locking piece 74 in the thickness direction. The locking hole 74a is formed so as to detachably engage with a bezel locking protrusion 37 provided on the microphone support portion 33 in an assembled state. The same number of sensor locking pieces 74 as the number of bezel locking protrusions 37 are arranged circumferentially on the main body 73.

[0040] A base-end protrusion 75 protrudes radially from the base end of the main body 73 in the axial direction while being integrally connected to the main body 73. In this embodiment, the main body 73 and the base-end protrusion 75 are seamlessly formed integrally from the same material. A retainer abutment surface 75a, which is the end face on the tip side of the base-end protrusion 75 in the axial direction, is formed as a smooth plane having a normal direction parallel to the central axis CL.

[0041] The retainer abutment surface 75a is formed as one axial end face of the retainer insertion groove 75b, i.e., the end face on the base-end protrusion 75 side. The retainer insertion groove 75b, which serves as a mounting fixture insertion groove in the present disclosure, opens radially on the outer periphery of the tubular portion 72 and extends in the Z-axis direction in the figure, which is the retainer insertion direction (i.e., the mounting fixture insertion direction) that intersects the axial direction. Specifically, the retainer insertion groove 75b is formed as a square groove extending in the Z-axis direction in the figure so that the retainer 8 can be inserted when mounting the ultrasonic sensor 1 to a bumper. The pair of retainer insertion grooves 75b are parallel to each other on both sides of the central axis CL, more specifically, symmetrically disposed about the central axis CL. The base-end protrusion 75 is formed so that, in the mounted state, the retainer 8 inserted into the retainer insertion groove 75b is sandwiched between the base-end protrusion 75 and the bumper back surface V32.

[0042] The tubular portion 72 has a temporary assembly piece 76. The temporary assembly piece 76 is a cantilever-shaped tongue piece having a radial thickness and extending axially from the base-end protruding portion 75 toward the flange portion 71. That is, the temporary assembly piece 76 is elastically deformable with its axial base end as a fixed end and its axial tip end as a free end, with the free end moving radially. Specifically, a radially protruding temporary assembly protrusion 76a is provided at the free end of the temporary assembly piece 76, i.e., the axial tip end. The temporary assembly protrusion 76a is configured to hold the secondary assembly in a temporary assembled state. The temporary assembled state is a state in which the secondary assembly is temporarily held by the bumper in a predetermined temporary assembled position by inserting the bezel 7 of the secondary assembly into the mounting hole V5. The temporary assembled position is a position of the secondary assembly in which the vibration-proof spacer 6 contacts or closely faces the bumper outer surface V31 and the connector portion 32 extends in the negative X-axis direction as shown in FIG. 2 . The provisionally assembled state corresponds to a state in which the retainer 8 is removed from the ultrasonic sensor 1 that is mounted on the vehicle or installed.

[0043] A tip-side protrusion 77 is integrally connected to the main body 73 at the axial tip of the main body 73 and protrudes radially. The tip-side protrusion 77 is the axially most distal portion of the tubular portion 72 and extends circumferentially. In this embodiment, the main body 73 and the tip-side protrusion 77 are seamlessly formed integrally from the same material. The tip-side protrusion 77 is located axially between the spacer accommodating groove 71b and the retainer insertion groove 75b. That is, the tip-side protrusion 77 is located adjacent to the spacer accommodating groove 71b and the retainer insertion groove 75b. Therefore, the spacer accommodating groove 71b is defined by a gap between the flange portion 71 and the tip-side protrusion 77. Meanwhile, the retainer insertion groove 75b is defined by a space between the base-end protrusion 75 and the tip-side protrusion 77. In the mounted state, the tip-side protrusion 77 faces the inner edge V51 of the mounting hole V5, and is accommodated within the mounting hole V5.

[0044] (Retainer) Referring again to FIG. 2, the retainer 8 serving as the sensor mounting fixture of the present disclosure is a component used to mount the ultrasonic sensor 1 to a bumper, which is a plate-shaped vehicle body component, and is formed seamlessly and integrally from a hard synthetic resin. FIGS. 8A to 8D show a schematic configuration of the retainer 8. FIG. 9 shows the state in which the retainer 8 is attached to a secondary assembly in a provisionally assembled state. Below, the specific configuration of the retainer 8 according to this embodiment will be described with reference to FIGS. 8A to 8D and 9 in addition to FIG. 2. Note that in FIGS. 2 and 9, the retainer insertion direction is indicated by arrow D.

[0045] The retainer 8 is configured to be attached to a secondary assembly in a provisionally assembled state inserted through the mounting hole V5, thereby fixing the ultrasonic sensor 1 to the bumper. Specifically, the retainer 8 is inserted between the bumper and the base-end protruding portion 75 of the cylindrical portion 72 with the cylindrical portion 72 inserted through the mounting hole V5, so that the retainer 8 is sandwiched between the cylindrical portion 72 and the bumper when mounted on the vehicle.

[0046] The retainer 8 has a retainer main body 81 and an elastic portion 82. As shown in FIG. 8A , the retainer main body 81, which serves as the mounting device main body of the present disclosure, is formed in a U-shape with an opening 811 that opens toward the positive direction of the Z axis in the figure. A connecting portion 812 on the opposite side of the opening 811 extends in the X-axis direction in the figure, which is the width direction of the retainer main body 81. The connecting portion 812 is provided with a gripping rib 813 that functions as a reinforcing rib that reinforces the retainer 8 and can be grasped by an operator when attaching or detaching the retainer 8. The gripping rib 813 protrudes from the connecting portion 812 in the negative Y-axis direction in the figure and extends in the width direction of the retainer main body 81. The retainer 8 is formed symmetrically with respect to a plane that passes through the center in the width direction of the U-shaped retainer main body 81 and is parallel to the YZ plane. FIG. 8C is a cross-sectional view taken along this plane.

[0047] The retainer body 81 has a connecting portion 812, a gripping rib 813, and a pair of extension portions 814. The pair of extension portions 814, which are linear portions on both sides of the U-shaped portion, extend from both ends of the connecting portion 812 in the Z-axis direction in the figure. That is, the opening 811 is provided at the tip end of the pair of extension portions 814. Meanwhile, the base end portions of the pair of extension portions 814 are connected to each other by the connecting portion 812. The pair of extension portions 814 are also arranged parallel to each other. In this way, the U-shape of the retainer body 81 is formed by the pair of extension portions 814 and the connecting portion 812, which extend in a direction intersecting the central axis CL and are arranged opposite each other across the central axis CL. Furthermore, as shown in FIGS. 8B and 8C , the retainer body 81 is formed into a generally J-shape or a generally L-shape in side view by the gripping rib 813 and the extension portions 814. The retainer main body 81 is configured to accommodate the cylindrical portion 72 of the bezel 7 in an inner space formed between a pair of extension portions 814 and opening at the opening 811, while clamping the cylindrical portion 72.

[0048] The extension portion 814 has a flat base plate portion 814a having a thickness in the axial direction, and a first reinforcing rib 814b and a second reinforcing rib 814c that reinforce the base plate portion 814a. The first reinforcing rib 814b is a rib that protrudes in the same direction as the gripping rib 813 and extends along the extension direction of the extension portion 814. The extension direction of the extension portion 814 is hereinafter simply referred to as the "extension direction." This extension direction is the positive direction of the Z axis in the drawings. The second reinforcing rib 814c is a rib that protrudes in the same direction as the first reinforcing rib 814b and extends from the first reinforcing rib 814b outward in the width direction of the extension portion 814.

[0049] The extension portion 814 has a guide portion 815. As shown in Figures 8A and 8D, the guide portion 815 is provided more inward than the first reinforcing rib 814b in the width direction of the retainer body 81. The guide portion 815 is a thin plate-like portion having a thickness along the axial direction, and is formed to guide the insertion of the extension portion 814 into the retainer insertion groove 75b when the retainer 8 is attached to the bezel 7 while being moved in the retainer insertion direction. In other words, the guide portion 815 protrudes from the first reinforcing rib 814b toward the above-mentioned internal space that opens at the opening 811.

[0050] In this embodiment, the retainer 8 has a structure in which the elastic force is lower during the initial stage of insertion into the retainer insertion groove 75b, i.e., the space between the retainer abutment surface 75a and the bumper back surface V32, than during subsequent stages. Specifically, the guide portion 815 includes an initial insertion portion 816, an elastic force generating portion 817, and a holding portion 818. The initial insertion portion 816, the elastic force generating portion 817, and the holding portion 818 are arranged in this order along the extension direction. The initial insertion portion 816 is provided at the tip end in the extension direction. Furthermore, the initial insertion portion 816 is formed so that the amount of elastic deformation of the elastic portion 82 when inserted into the retainer insertion groove 75b and facing the retainer abutment surface 75a in the axial direction is smaller than that of the elastic force generating portion 817. Specifically, the initial insertion portion 816 is offset from the holding portion 818 in the positive Y-axis direction, i.e., toward the bumper. Therefore, a step is formed in the axial direction between the initial insertion portion 816 and the holding portion 818 .

[0051] The elastic force generating portion 817 is provided closer to the base end in the extension direction than the initial insertion portion 816. The elastic force generating portion 817 is configured to generate an elastic force in the elastic portion 82 when the retainer 8 is attached to the bezel 7 while being moved in the retainer insertion direction. Specifically, the elastic force generating portion 817 is formed in the shape of an inclined plate that connects the step between the initial insertion portion 816 and the holding portion 818. The holding portion 818 is formed in the shape of a flat plate whose thickness direction is in the axial direction. In the attached state, the holding portion 818 is configured to abut against a retainer abutment surface 75a provided on the bezel 7, thereby maintaining the retainer 8 attached to the bezel 7.

[0052] The guide portion 815 has a bezel abutment surface 819, which is a surface exposed on the side opposite to the side from which the elastic portion 82 protrudes (i.e., the negative Y-axis direction in the figure). The bezel abutment surface 819, which serves as a housing abutment surface in the present disclosure, is provided so as to be able to abut against the retainer insertion groove 75b, i.e., the retainer abutment surface 75a, in the axial direction when the retainer 8 is attached to the bezel 7 while being moved in the retainer insertion direction. The bezel abutment surface 819 has an initial insertion surface 819a, an inclined portion 819b, and a flat portion 819c.

[0053] An initial insertion surface 819a is provided at the tip of the bezel abutment surface 819 in the extension direction, and is disposed at a position corresponding to the initial insertion portion 816 in the extension direction. The initial insertion surface 819a is offset from the flat portion 819c toward the positive Y-axis direction in the figure (i.e., toward the biasing direction F shown in FIG. 9). The initial insertion surface 819a is also provided along the extension direction, i.e., the retainer insertion direction. Specifically, the initial insertion surface 819a is formed as an inclined surface that inclines so as to move away from the flat portion 819c in the axial direction (i.e., toward the biasing direction F) as it moves in the extension direction.

[0054] The inclined portion 819b is located at an intermediate position in the extension direction of the bezel abutment surface 819, i.e., between the initial insertion surface 819a and the flat portion 819c, at a position corresponding to the elastic force generating portion 817 in the extension direction. The inclined portion 819b is formed as an inclined surface connecting the step between the initial insertion surface 819a and the flat portion 819c. That is, the inclined portion 819b is formed so as to be in the biasing direction F as it approaches the initial insertion surface 819a. Specifically, the inclined portion 819b is formed so as to be steeper in slope than the initial insertion surface 819a. As shown in FIGS. 8A and 8C , a first bent portion 819d formed in a concave shape due to the change in slope is provided at the connection between the initial insertion surface 819a and the inclined portion 819b.

[0055] The flat portion 819c is located closer to the base end of the extension portion 814 than the initial insertion surface 819a. The flat portion 819c is located along the attachment insertion direction. The flat portion 819c is a surface that abuts against the retainer abutment surface 75a of the bezel 7 when the attachment state is formed, and is formed as a smooth plane having a normal direction parallel to the central axis CL in the attachment state. Specifically, the flat portion 819c is located approximately parallel to the attachment insertion direction. As shown in FIGS. 8A and 8C , the connection between the inclined portion 819b and the flat portion 819c is provided with a second bent portion 819e that is formed in a convex shape due to a change in inclination. That is, the inclined portion 819b is located between the first bent portion 819d and the second bent portion 819e.

[0056] The elastic portion 82 is a cantilever-shaped leaf spring portion that protrudes in the axial direction from the extension portion 814 of the retainer main body 81. The elastic portion 82 is configured to elastically deform while abutting against the bumper back surface V32 when the retainer 8 is in an attached state in which it is sandwiched between the retainer abutment surface 75a of the bezel 7 and the bumper back surface V32. Specifically, the elastic portion 82 is configured to protrude toward the positive Y-axis direction in the figure, i.e., in the direction opposite to the protruding direction of the gripping rib 813 and the first reinforcing rib 814b. Thus, the elastic portion 82 is configured to generate an elastic force in the positive Y-axis direction in the figure (i.e., the biasing direction F shown in FIG. 9 ) by being pressed toward the negative Y-axis direction in the figure and elastically deforming along the axial direction.

[0057] In this way, the elastic portion 82 is formed to generate an elastic force in a direction toward the bumper when the cylindrical portion 72 of the bezel 7 is inserted into the mounting hole V5 and the retainer body 81 is inserted into the retainer insertion groove 75b. The retainer 8 is configured to be held between the bumper and the cylindrical portion 72 by the elastic force when the retainer 8 is inserted into the retainer insertion groove 75b so as to slide along the mounting tool insertion direction while accommodating the cylindrical portion 72 inside the opening 811.

[0058] In this embodiment, the elastic portions 82 extend in a direction inclined with respect to the Y axis from approximately the center of the extension portion 814 in the extension direction. Furthermore, a pair of elastic portions 82 is provided on each extension portion 814 in a gull-wing shape in side view. That is, the retainer 8 has four elastic portions 82. More specifically, the retainer 8 includes a pair of front elastic portions 821 and a pair of rear elastic portions 822. The front elastic portions 821 extend in the positive Z-axis direction and the positive Y-axis direction from approximately the center of the extension portion 814 in the extension direction. The rear elastic portions 822 extend in the negative Z-axis direction and the positive Y-axis direction from approximately the center of the extension portion 814 in the extension direction. The front elastic portions 821 and the rear elastic portions 822 are formed in an arch shape that bulges toward the biasing direction F slightly closer to the fixed end than the free end.

[0059] (Effects) The method and state of mounting the ultrasonic sensor 1 to the bumper will be described below with reference to the drawings, along with the effects achieved by the configuration of this embodiment. For simplicity's sake, the following mounting method and mounting process will be described using a right-handed XYZ Cartesian coordinate system based on the vehicle-mounted state, as shown in the drawings. However, as mentioned above, the ultrasonic sensor 1 can be attached to or detached from the bumper after the bumper has been removed from the vehicle body V1. Therefore, in the actual mounting method or mounting process, the positive Z-axis direction may differ from the upward direction.

[0060] First, the sensor main body 2 shown in FIG. 3 is formed. The anti-vibration spacer 6 shown in FIGS. 5A and 5B is fitted into the spacer receiving groove 71b shown in FIG. 7 and attached to the bezel 7. The ultrasonic microphone 4 and cushion member 5 of the sensor main body 2 are then inserted into the cylindrical interior of the bezel 7 to which the anti-vibration spacer 6 is attached. The bezel 7 is then assembled to the sensor main body 2 by engaging the engagement holes 74a of the sensor engagement pieces 74 provided on the cylindrical portion 72 with the bezel engagement protrusions 37 provided on the microphone support portion 33. By assembling the bezel 7 with the anti-vibration spacer 6 attached to the sensor main body 2 in this manner, the secondary assembly shown in FIG. 6 is formed. In this secondary assembly, the cushion member 5 is accommodated in the cylindrical portion 72 of the bezel 7 while surrounding the ultrasonic microphone 4.

[0061] The secondary assembly shown in FIG. 6 is inserted into the mounting hole V5 from the bumper outer space SG side, starting with the connector portion 32, until the vibration-damping spacer 6 abuts against the bumper outer surface V31. At this time, as the tubular portion 72 of the bezel 7 is inserted into the mounting hole V5, the temporary assembly protrusion 76a abuts against the inner edge V51 of the mounting hole V5. This causes the free end of the temporary assembly piece 76 to elastically deform inward, i.e., in a direction approaching the central axis CL. Then, when the temporary assembly protrusion 76a passes through the mounting hole V5, the elastic deformation of the temporary assembly piece 76 is restored. Then, as shown in FIG. 9, the bezel 7 is held to the bumper by the flange portion 71 and the temporary assembly protrusion 76a, and the secondary assembly is in a temporary assembled state.

[0062] After the secondary assembly is brought into a provisionally assembled state as described above, the retainer 8 is placed in the attachment / detachment position on the bumper interior space SN side as shown in Fig. 9. The attachment / detachment position is a position in which the opening 811 opens toward the positive direction of the Z axis in the drawing and the elastic portion 82 faces the bumper rear surface V32 before the retainer 8 is attached to the bezel 7, i.e., the secondary assembly.

[0063] When the retainer 8 in the attachment / detachment position is moved in the retainer insertion direction indicated by arrow D in the figure, the bezel 7 in the secondary assembly in a provisionally assembled state is first inserted into the opening 811. The retainer 8 is then pushed in the retainer insertion direction until the bezel 7 and the connecting portion 812 of the retainer 8 abut or come close to each other. Then, the extension portion 814 of the retainer 8 is slid in the retainer insertion direction and fitted into the retainer insertion groove 75b provided in the bezel 7 in the secondary assembly, or more precisely, into the space between the retainer abutment surface 75a and the bumper back surface V32. Specifically, the initial insertion portion 816, the elastic force generating portion 817, and the holding portion 818 of the extension portion 814 are inserted into the retainer insertion groove 75b in this order.

[0064] 9 , the distance in the biasing direction F between the surface of the elastic portion 82 in its natural, unelastically deformed state that abuts against the bumper rear surface V32 and the bezel abutment surface 819 is defined as the abutment surface height H. The height of the retainer insertion groove 75b, i.e., the distance between the retainer abutment surface 75a and the bumper rear surface V32, is defined as the groove height H0. In this case, the abutment surface height H of the holding portion 818, i.e., the flat surface 819c, is expressed as H1 > H0. Therefore, in order to bring the retainer abutment surface 75a into abutment with the flat surface 819c and stably hold the retainer 8 in the provisionally assembled secondary assembly, it is necessary to elastically deform the elastic portion 82 to a predetermined degree.

[0065] In this regard, the contact surface height H changes from H<H0 to H>H0 at the elastic force generating portion 817. Therefore, when the elastic force generating portion 817 is inserted into the retainer insertion groove 75b, the inclined portion 819b of the bezel contact surface 819 comes into contact with the retainer contact surface 75a, thereby biasing the retainer body 81 in the biasing direction F. This causes the elastic portion 82 to elastically deform so that the free end moves in the direction opposite to the biasing direction F, and as a reaction force, an elastic force is generated in the elastic portion 82 in the biasing direction F. Then, when the retainer 8 is pushed in until the flat portion 819c of the bezel contact surface 819 stably contacts the retainer contact surface 75a, the retainer 8 is clamped between the base-end protrusion 75 of the bezel 7 and the bumper back surface V32 by the action of the elastic force of the elastic portion 82. In this way, by attaching the retainer 8 to the secondary assembly in a provisionally assembled state, the ultrasonic sensor 1 is realized in an attached state or vehicle-mounted state in which it is attached to the front bumper V3, as shown in Figure 2. The ultrasonic sensor 1 is attached to the rear bumper V4 in the same manner.

[0066] FIG. 10 shows a comparative example in which the extension portion 814 does not have an initial insertion portion 816. In this case, an elastic force generating portion 817 for elastically deforming the elastic portion 82 is provided at the tip of the extension portion 814. In this configuration, in order to insert the tip of the extension portion 814 into the retainer insertion groove 75b, the retainer 8 must be tilted in the attachment / detachment position so that the tip of the extension portion 814 approaches the bumper back surface V32, as indicated by the two-dot chain line in the figure. Then, in the attachment / detachment position in which the extension direction of the extension portion 814 is tilted relative to the retainer insertion direction, the retainer 8 is pushed in the retainer insertion direction while elastically deforming the elastic portion 82. In this attachment / detachment position, the tilt of the retainer 8 is unstable, and therefore the direction of load application for elastically deforming the elastic portion 82 is also unstable. This can lead to workers mistaking the load application direction or applying an unnecessarily large load, leaving room for improvement in workability.

[0067] In contrast, in this embodiment, as shown in FIG. 9 , the initial insertion portion 816 is provided further distally than the elastic force generating portion 817, which elastically deforms the elastic portion 82. The initial insertion portion 816 has a portion where the abutment surface height H is smaller than that of the elastic force generating portion 817. That is, the retainer 8 is configured such that the elastic force of the elastic portion 82 is lower at the initial stage of inserting the initial insertion portion 816 into the retainer insertion groove 75b than at the stage of subsequent insertion of the elastic force generating portion 817. In other words, the extension portion 814, i.e., the guide portion 815, is configured to generate the elastic force of the elastic portion 82 in multiple stages by the initial insertion portion 816, the elastic force generating portion 817, and the holding portion 818. Specifically, the initial insertion surface 819a of the initial insertion portion 816 is positioned closer to the bumper back surface V32 in the attachment / detachment posture than the inclined portion 819b of the elastic force generating portion 817. Preferably, the guide portion 815 is formed so that even when the retainer 8 is pushed in the retainer insertion direction while the elastic portion 82 is in contact with the bumper back surface V32 in the attachment / detachment posture, the initial insertion portion 816 does not generate an elastic force of the elastic portion 82. Specifically, the initial insertion portion 816 is offset in the axial direction from the holding portion 818 by a sufficient amount so that the entire initial insertion portion 816 satisfies H<H0 and the elastic force of the elastic portion 82 is not generated even when the initial insertion portion 816 is inserted into the retainer insertion groove 75b.

[0068] With this configuration, the angle at which the retainer 8 is tilted can be reduced in the mounting / removal position. More preferably, as shown in FIG. 9, for example, there is no need to tilt the retainer 8 in the mounting / removal position. This reduces the applied load in the initial stage of inserting the retainer 8 into the retainer insertion groove 75b. Then, by pushing the retainer 8 in the retainer insertion direction in a stable position, the retainer 8 is properly attached. At this time, the load required to elastically deform the elastic portion 82 is kept to a minimum. Therefore, according to this embodiment, it is possible to improve the workability when mounting the ultrasonic sensor 1 to the bumper of the vehicle V.

[0069] In the mounted or vehicle-mounted state, a cushion member 5, an anti-vibration spacer 6, and a bezel 7 are interposed between the ultrasonic microphone 4 and the bumper. Specifically, the cushion member 5 is sandwiched between the ultrasonic microphone 4 and the bezel 7. The anti-vibration spacer 6 is sandwiched between the flange portion 71 of the bezel 7 and the bumper. Furthermore, by providing the initial insertion portion 816, the retainer 8 is efficiently attached to the secondary assembly in a provisionally assembled state, and then the mounted or vehicle-mounted state is favorably maintained by the elastic pressure contact between the holding portion 818 and the retainer abutment surface 75a by the elastic portion 82. Therefore, according to this embodiment, when the bumper is formed of a metal plate material with high vibration transmission properties, the occurrence of erroneous detection due to vibration transmission can be favorably suppressed.

[0070] (Modifications) The present disclosure is not limited to the above-described embodiment. Therefore, the above-described embodiment can be modified as appropriate. Representative modifications will be described below. In the following description of the modifications, differences from the above-described embodiment will be mainly described. Furthermore, the same reference numerals are used for parts that are identical or equivalent to each other in the above-described embodiment and the modifications. Therefore, in the following description of the modifications, the description of the above-described embodiment can be used as appropriate for components that have the same reference numerals as the above-described embodiment, unless there is a technical contradiction or special additional explanation.

[0071] In the above embodiment, for the sake of simplicity, the ultrasonic sensor 1 is illustrated and described as being attached to the front bumper V3. However, the present disclosure is not limited to this. That is, the ultrasonic sensor 1 attached to the rear bumper V4 and the configuration of each part thereof can also be easily understood from the description of the above embodiment.

[0072] The ultrasonic sensor 1 may be mounted on a vehicle body panel V2, but is not limited to the front bumper V3 and the rear bumper V4. Specifically, the ultrasonic sensor 1 may also be mounted on the vehicle body panel V2. That is, the mounting hole V5 may also be provided in the vehicle body panel V2.

[0073] 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 only transmitting ultrasonic waves. Alternatively, the ultrasonic sensor 1 may have only a receiving function of receiving a search wave, which is an ultrasonic wave transmitted from another ultrasonic transmitter, reflected by an object present in the vicinity.

[0074] The configuration of each part of the ultrasonic sensor 1 is not limited to the above specific example. Specifically, for example, the material constituting each part may also be changed as appropriate from the above specific example. Furthermore, multiple components that were previously made of the same material may be made of different materials. Similarly, multiple components that were previously made of different materials may be made of the same material. Furthermore, multiple components that were previously formed integrally and seamlessly may be formed by bonding separate members together. Similarly, multiple components that were previously formed by bonding separate members together may be formed integrally and seamlessly.

[0075] The specific configuration of the sensor case 3 is not limited to the above example. That is, for example, the structure and extension direction of the connector portion 32 may be changed as appropriate. Furthermore, the shape of the microphone support portion 33 is not limited to a substantially cylindrical shape, and may be a substantially elliptical cylindrical shape, a substantially elongated cylindrical shape, a substantially polygonal cylindrical shape, or the like.

[0076] The external shape of the ultrasonic microphone 4, i.e., the microphone case 42, is not limited to a substantially cylindrical shape, but may be a substantially elliptical cylinder, a substantially regular polygonal prism, etc. The electromechanical conversion element constituting the ultrasonic element 41 is also not limited to a piezoelectric element.

[0077] The specific configuration of the cushion member 5 is not limited to the above specific example. That is, for example, the shape of the cushion member 5 is not limited to a substantially cylindrical shape, but may be a substantially elliptical cylindrical shape, a substantially elongated cylindrical shape, a substantially polygonal cylindrical shape, or the like.

[0078] Similar to the bezel 7, the cushion member 5 may be configured to form a secondary assembly by being later attached to the sensor main body 2, which is the primary assembly. In this case, for example, the ultrasonic microphone 4 is supported by the microphone support portion 33 of the sensor case 3 without the cushion member 5. The cushion member 5 is formed in a cylindrical shape having an axial dimension that is approximately the same as the axial dimension of the ultrasonic microphone 4, i.e., the microphone case 42.

[0079] The specific configurations of the bezel 7 and the retainer 8, which are components for attaching the ultrasonic sensor 1 to a plate-shaped vehicle body part (e.g., the front bumper V3), are not limited to the above specific example. Specifically, for example, the detailed configuration of the bezel 7 and / or the retainer 8 may be modified as appropriate from the above specific example. Furthermore, the present disclosure is not limited to a configuration in which the sensor main body 2 is attached to a vehicle body part using the bezel 7 and the retainer 8. That is, for example, the bezel 7 may be integral with the sensor main body 2 and not detachable from it. In other words, the present disclosure may also be suitably applied to a so-called bezel-less configuration.

[0080] Making the elastic force of the front elastic portion 821 smaller than that of the rear elastic portion 822 can also stabilize the posture of attachment and detachment of the retainer 8 and improve workability. Specifically, for example, the front elastic portion 821 can be formed thinner and / or narrower than the rear elastic portion 822. "Thinner" refers to a smaller dimension in the X-axis direction in the figures. "Thinner" refers to a smaller width dimension of the front elastic portion 821 in the side views shown in FIGS. 8B, 9, and 10. The width dimensions of the front elastic portion 821 and the rear elastic portion 822 are dimensions perpendicular to the tangent direction of the elastic portion center line and perpendicular to the X-axis. The elastic portion center line is a virtual curve that passes through the center of the front elastic portion 821 or the rear elastic portion 822 along the arch shape of the front elastic portion 821 or the rear elastic portion 822 extending from the fixed end to the free end. Alternatively, for example, the front elastic portion 821 may be formed so that the length from the fixed end to the contact portion with the bumper rear surface V32 is longer than that of the rear elastic portion 822. These configurations may also be applied to a configuration that does not have an initial insertion portion 816, as shown in FIG.

[0081] It goes without saying that the elements constituting the above-described embodiments are not necessarily essential unless expressly stated as essential or clearly considered essential in principle. Furthermore, when numerical values ​​such as the number, value, amount, and range of components are mentioned, the present disclosure is not limited to those specific numbers unless expressly stated as essential or clearly limited to a specific number in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present disclosure is not limited to those shapes, directions, positional relationships, etc. unless expressly stated as essential or clearly limited to a specific shape, direction, positional relationship, etc. in principle.

[0082] The modified examples are not limited to the above examples. For example, other than those exemplified above, multiple embodiments may be combined with each other as long as there is no technical contradiction. Similarly, multiple modified examples may be combined with each other as long as there is no technical contradiction.

[0083] (Disclosure) As is clear from the description of the above-described embodiments and modifications, this specification discloses at least the following matters. [Viewpoint 1-1] In a sensor attachment (8) used to attach an ultrasonic sensor (1) to a plate-shaped vehicle body part (V3), the ultrasonic sensor comprises a cylindrical housing part (7) having a cylindrical portion (72) inserted into a through-hole (V5) formed in the vehicle body part, and a flange portion (71) for preventing the ultrasonic sensor from coming off, which protrudes radially from one end in an axial direction parallel to a central axis (CL) of the cylindrical portion and is spaced apart from the central axis, the cylindrical portion is provided with a pair of attachment tool insertion grooves (75b) that are open in the radial direction at the outer periphery of the cylindrical portion and extend in an attachment tool insertion direction (D) that intersects with the axial direction, and are parallel to each other on both sides of the central axis, and the sensor attachment comprises a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction, so as to generate an elastic force in an urging direction (F) toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; and configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, The sensor attachment tool has a structure in which the elastic force is lower in the initial stage of insertion of the sensor attachment tool into the attachment tool insertion groove than in subsequent stages. [Aspect 1-2] In Aspect 1-1, the extension part has an initial insertion part (816) provided at the tip end, and an elastic force generating part (817) provided closer to the base end than the initial insertion part, and the initial insertion part is formed so that the amount of elastic deformation of the elastic part is smaller than that of the elastic force generating part. [Aspect 1-3]In a sensor attachment tool (8) used for attaching an ultrasonic sensor (1) to a plate-shaped vehicle body part (V3), the ultrasonic sensor comprises a cylindrical housing part (7) having a cylindrical portion (72) inserted into a through-hole (V5) formed in the vehicle body part, and a flange portion (71) for preventing removal, which protrudes radially from one end in an axial direction parallel to a central axis (CL) of the cylindrical portion and is spaced apart from the central axis, and the cylindrical portion is provided with a pair of attachment tool insertion grooves (75b) on the outer periphery of the cylindrical portion, which are open in the radial direction and extend in an attachment tool insertion direction (D) intersecting the axial direction, and which are parallel to each other on both sides of the central axis, and the sensor attachment tool is a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction so as to generate an elastic force in an urging direction (F) toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove, and configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, and the extension section has: an initial insertion section (816) provided at the tip end; an elastic force generating section (817) provided closer to the base end than the initial insertion section, and the initial insertion section is formed so that the amount of elastic deformation of the elastic section is smaller than that of the elastic force generating section. [Aspect 1-4] In Aspects 1-1 to 1-3, the attachment main body has a housing abutment surface (819) provided so as to abut against the attachment insertion groove in the axial direction, and the housing abutment surface comprises: an initial insertion surface (819a) provided at the tip end, a flat section (819b) provided closer to the base end than the initial insertion surface, and an inclined section (819c) provided between the initial insertion surface and the flat section,a mounting fixture (8) for mounting an ultrasonic sensor (1) to a plate-shaped vehicle body part (V3), the ultrasonic sensor comprising a cylindrical housing part (7) having a cylindrical portion (72) inserted into a through-hole (V5) formed in the vehicle body part, and a retaining flange portion (71) projecting radially from one end of the cylindrical portion in an axial direction parallel to a central axis (CL) of the cylindrical portion and spaced apart from the central axis, the cylindrical portion having a pair of mounting fixture insertion grooves (75b) extending in a mounting fixture insertion direction (D) intersecting the axial direction and opening in the radial direction at an outer periphery of the cylindrical portion, the pair of mounting fixture insertion grooves (75b) being parallel to each other on both sides of the central axis, the pair of mounting fixture insertion grooves (75b) being open radially at an outer periphery of the cylindrical portion and extending in a mounting fixture insertion direction (D) intersecting the axial direction, the sensor mounting fixture comprising: a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction, so as to generate an elastic force in an urging direction (F) toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; and configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, The attachment main body has a housing abutment surface (819) provided so as to abut against the attachment insertion groove in the axial direction, and the housing abutment surface has an initial insertion surface (819a) provided at the tip end, a flat portion (819b) provided closer to the base end than the initial insertion surface, and an inclined portion (819c) provided between the initial insertion surface and the flat portion,The initial insertion surface and the flat portion are arranged along the attachment insertion direction, the initial insertion surface is arranged offset in the urging direction from the flat portion, and the inclined portion is arranged to face the urging direction as it approaches the initial insertion surface. [Viewpoint 2-1] An ultrasonic sensor (1) to be attached to a plate-shaped vehicle body part (V3) comprises: a cylindrical housing part (7) having a cylindrical part (72) to be inserted into a through-hole (V5) formed in the vehicle body part, and a flange part (71) for preventing the cylindrical part from coming off and projecting in a radial direction away from a central axis (CL) at one end in an axial direction parallel to the central axis; and a sensor attachment (8) configured to be attached to the housing part to hold the housing part to the vehicle body part, wherein the cylindrical part has a pair of attachment tool insertion grooves (75b) that are open in the radial direction at an outer periphery of the cylindrical part and extend in an attachment tool insertion direction that intersects with the axial direction, and are parallel to each other on both sides of the central axis, and the sensor attachment a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction, so as to generate an elastic force in an urging direction toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; and configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, The sensor attachment tool has a structure in which the elastic force is lower in the initial stage of insertion of the sensor attachment tool into the attachment tool insertion groove than in subsequent stages. [Aspect 2-2] In Aspect 2-1, the extension part has an initial insertion part (816) provided at the tip end part, and an elastic force generating part (817) provided closer to the base end part than the initial insertion part,The initial insertion portion is formed so that the amount of elastic deformation of the elastic portion is smaller than that of the elastic force generating portion. [Viewpoint 2-3] An ultrasonic sensor (1) to be attached to a plate-shaped vehicle body part (V3) comprising: a cylindrical housing part (7) having a cylindrical portion (72) to be inserted into a through hole (V5) formed in the vehicle body part, and a flange portion (71) for preventing slip-out, the flange portion protruding in a radial direction away from a central axis (CL) of the cylindrical portion at one end in an axial direction parallel to the central axis, the flange portion (71) being used for preventing slip-out; and a sensor attachment (8) configured to be attached to the housing part to hold the housing part to the vehicle body part, wherein the cylindrical portion has a pair of attachment tool insertion grooves (75b) on an outer periphery of the cylindrical portion that are open in the radial direction and extend in an attachment tool insertion direction that intersects the axial direction, and the pair of attachment tool insertion grooves (75b) are provided parallel to each other on both sides of the central axis, and the sensor attachment a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction so as to generate an elastic force in an urging direction toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove, and is configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, and the extension section has: an initial insertion section (816) provided at the tip end; and an elastic force generating section (817) provided closer to the base end than the initial insertion section, and the initial insertion section is formed so that the amount of elastic deformation of the elastic section is smaller than that of the elastic force generating section. [Aspect 2-4] In Aspects 2-1 to 2-3, the attachment main body has a housing abutment surface (819) provided so as to abut against the attachment insertion groove in the axial direction, and the housing abutment surface isThe connector has an initial insertion surface (819a) provided at the tip end, a flat portion (819c) provided closer to the base end than the initial insertion surface, and an inclined portion (819b) provided between the initial insertion surface and the flat portion, wherein the initial insertion surface and the flat portion are provided along the attachment insertion direction, the initial insertion surface is offset in the biasing direction from the flat portion, and the inclined portion is provided so as to point in the biasing direction as it approaches the initial insertion surface. [Viewpoint 2-5] An ultrasonic sensor (1) to be attached to a plate-shaped vehicle body part (V3) comprises: a cylindrical housing part (7) having a cylindrical part (72) to be inserted into a through-hole (V5) formed in the vehicle body part, and a flange part (71) for preventing the cylindrical part from coming off and projecting in a radial direction away from a central axis (CL) at one end in an axial direction parallel to the central axis; and a sensor attachment (8) configured to be attached to the housing part to hold the housing part to the vehicle body part, wherein the cylindrical part has a pair of attachment tool insertion grooves (75b) that are open in the radial direction at an outer periphery of the cylindrical part and extend in an attachment tool insertion direction that intersects with the axial direction, and are parallel to each other on both sides of the central axis, and the sensor attachment is a U-shaped mounting tool main body (81) having a pair of extension sections (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting section (812) connecting base ends of the pair of extension sections on the opposite side to the tip ends on the mounting tool insertion direction side, and an opening (811) opening at the tip end; and an elastic section (82) protruding from the mounting tool main body along the axial direction and formed to be elastically deformable along the axial direction, so as to generate an elastic force in an urging direction toward the vehicle body part when the tubular section is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; and configured so that when the tubular section is inserted into the through hole, the tubular section is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, and is held between the vehicle body part and the tubular section by the elastic force, The fixture body has a housing abutment surface (819) provided to abut against the fixture insertion groove in the axial direction,The housing abutment surface has an initial insertion surface (819a) provided at the tip end, a flat portion (819c) provided closer to the base end than the initial insertion surface, and an inclined portion (819b) provided between the initial insertion surface and the flat portion, wherein the initial insertion surface and the flat portion are provided along the attachment insertion direction, the initial insertion surface is offset in the biasing direction from the flat portion, and the inclined portion is provided so as to point in the biasing direction as it approaches the initial insertion surface.

Claims

1. A sensor attachment tool (8) used for attaching an ultrasonic sensor (1) to a plate-shaped vehicle body part (V3), comprising: The ultrasonic sensor includes a cylindrical housing part (7) having a cylindrical portion (72) inserted into a through hole (V5) formed in the vehicle body part, and a flange portion (71) for preventing the cylindrical portion from coming off and projecting in a radial direction away from a central axis (CL) at one end in an axial direction parallel to the central axis (CL), A pair of mounting tool insertion grooves (75b) are provided in the cylindrical portion on both sides of the central axis, the mounting tool insertion grooves (75b) extending in a mounting tool insertion direction (D) intersecting the axial direction while opening in the radial direction at the outer periphery of the cylindrical portion, a U-shaped mounting tool main body (81) having a pair of extension parts (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting part (812) connecting base ends of the pair of extension parts on the opposite side to the tip ends in the mounting tool insertion direction, and an opening part (811) that opens at the tip end; an elastic portion (82) that protrudes from the mounting tool main body along the axial direction and is formed to be elastically deformable along the axial direction so as to generate an elastic force in a biasing direction (F) toward the vehicle body part when the tubular portion is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; having With the tubular portion inserted into the through hole, the tubular portion is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, whereby the vehicle body part is held between the tubular portion by the elastic force, The mounting body has a housing abutment surface (819) provided to abut against the mounting insertion groove in the axial direction, The housing abutment surface is An initial insertion surface (819a) provided at the tip portion; A flat surface (819c) provided on the base end side of the initial insertion surface; An inclined portion (819b) provided between the initial insertion surface and the flat portion; having the initial insertion surface and the flat surface portion are provided along the attachment tool insertion direction, the initial insertion surface is offset from the flat surface in the biasing direction, the inclined portion is provided so as to be inclined in the biasing direction as it approaches the initial insertion surface, Sensor mounting fixture.

2. The extension portion is An initial insertion portion (816) provided at the tip portion; An elastic force generating portion (817) provided on the base end side of the initial insertion portion; having The initial insertion portion is formed so that the elastic deformation amount of the elastic portion is smaller than that of the elastic force generating portion. The sensor fixture of claim 1 .

3. The initial insertion surface is provided in the initial insertion portion, The inclined portion is provided on the elastic force generating portion, a distance between a surface (V32) of the vehicle body part that abuts against the elastic force generating portion and a retainer abutment surface (75a) that is an end face on the other end side of the mounting tool insertion groove in the axial direction when the cylindrical portion is inserted into the through hole is defined as H0; When the elastic portion is in a natural state without elastic deformation and in contact with the surface, the distance between the retainer contact surface and the housing contact surface (819) is defined as H. At the initial insertion surface, H<H0; At the inclined portion, H<H0 changes to H>H0, H>H0 in the planar portion; The sensor fixture of claim 2 .

4. The initial insertion portion is formed to extend from the elastic force generating portion along the mounting tool insertion direction so that the initial insertion surface has a gentler inclination than the inclined portion. The sensor fixture of claim 3.

5. An ultrasonic sensor (1) attached to a plate-shaped vehicle body part (V3), a cylindrical housing part (7) having a cylindrical portion (72) inserted into a through hole (V5) formed in the vehicle body part, and a flange portion (71) for preventing the cylindrical portion from coming off and projecting in a radial direction away from a central axis (CL) at one end in an axial direction parallel to the central axis (CL); a sensor attachment (8) configured to be attached to the housing part to hold the housing part to the vehicle body part; Equipped with A pair of mounting tool insertion grooves (75b) are provided in parallel to each other on both sides of the central axis in the cylindrical portion, the mounting tool insertion grooves (75b) extending in a mounting tool insertion direction intersecting the axial direction while opening in the radial direction at the outer periphery of the cylindrical portion, The sensor attachment includes: a U-shaped mounting tool main body (81) having a pair of extension parts (814) extending in the mounting tool insertion direction and arranged parallel to each other, a connecting part (812) connecting base ends of the pair of extension parts on the opposite side to the tip ends in the mounting tool insertion direction, and an opening part (811) that opens at the tip end; an elastic portion (82) that protrudes from the mounting tool main body in the axial direction and is formed to be elastically deformable along the axial direction so as to generate an elastic force in a biasing direction toward the vehicle body part when the tubular portion is inserted into the through hole and the mounting tool main body is inserted into the mounting tool insertion groove; having With the tubular portion inserted into the through hole, the tubular portion is inserted into the mounting tool insertion groove so as to slide along the mounting tool insertion direction while being accommodated inside the opening, whereby the vehicle body part is held between the tubular portion by the elastic force, The mounting body has a housing abutment surface (819) provided to abut against the mounting insertion groove in the axial direction, The housing abutment surface is An initial insertion surface (819a) provided at the tip portion; A flat surface (819c) provided on the base end side of the initial insertion surface; An inclined portion (819b) provided between the initial insertion surface and the flat portion; having the initial insertion surface and the flat surface portion are provided along the attachment tool insertion direction, the initial insertion surface is offset from the flat surface in the biasing direction, the inclined portion is provided so as to be inclined in the biasing direction as it approaches the initial insertion surface, Ultrasonic sensor.

6. The extension portion is An initial insertion portion (816) provided at the tip portion; An elastic force generating portion (817) provided on the base end side of the initial insertion portion; having The initial insertion portion is formed so that the elastic deformation amount of the elastic portion is smaller than that of the elastic force generating portion.

6. The ultrasonic sensor according to claim 5.

7. The initial insertion surface is provided in the initial insertion portion, The inclined portion is provided on the elastic force generating portion, a distance between a surface (V32) of the vehicle body part that abuts against the elastic force generating portion and a retainer abutment surface (75a) that is an end face on the other end side of the mounting tool insertion groove in the axial direction when the cylindrical portion is inserted into the through hole is defined as H0; When the elastic portion is in a natural state without elastic deformation and in contact with the surface, the distance between the retainer contact surface and the housing contact surface (819) is defined as H. At the initial insertion surface, H<H0; At the inclined portion, H<H0 changes to H>H0, H>H0 in the planar portion; 7. The ultrasonic sensor according to claim 6.

8. The initial insertion portion is formed to extend from the elastic force generating portion along the mounting tool insertion direction so that the initial insertion surface has a gentler inclination than the inclined portion.

8. The ultrasonic sensor according to claim 7.