JP5195572B2 - Ultrasonic sensor - Google Patents

Description

  The present invention relates to an ultrasonic sensor provided with an ultrasonic transducer having a piezoelectric element.

  Conventionally, as an ultrasonic sensor provided with an ultrasonic transducer having a piezoelectric element, for example, there is one disclosed in Patent Document 1 below. FIG. 4 is a cross-sectional view of the ultrasonic sensor 100 of Patent Document 1. 5 is an exploded perspective view of the ultrasonic sensor 100 of FIG. 4, (a) is a state before the ultrasonic transducer 10 is attached to the cylindrical elastic body 33, and (b) is a cylinder. A state is shown in which the ultrasonic transducer 10 having the elastic member 33 attached thereto is assembled to the case 30.

  In the ultrasonic sensor 100, the ultrasonic transducer (microphone) 10 vibrates when generating ultrasonic waves. For this reason, in order to prevent the vibration from being transmitted to the case 30, it is not directly fixed to the cylindrical opening 32 of the case 30, but is substantially cylindrical on the outer peripheral surface of the ultrasonic transducer 10. A cylindrical elastic body (silicon rubber) 33 is covered, and a substantially disc-shaped foamed elastic body (foam rubber) 34 is laid on the bottom surface opposite to the vibration surface 11b (see FIG. 4) to absorb vibration. This prevents vibrations from being transmitted to the case 30.

  The cylindrical elastic body 33 includes a projecting locking portion 33a disposed on the outer end side of the opening 32 of the case 30, an outer peripheral surface 33b that covers the outer peripheral surface of the ultrasonic transducer 10, and an outer peripheral surface 33b. In the second reference portion 33c provided on the outer surface, the locking portion 33d provided on the distal end side in the insertion direction of the cylindrical elastic body 33 into the opening 32 of the case 30, and the inner wall of the outer peripheral surface 33b, The notch part (33e) (not shown) provided corresponding to the 1st reference | standard part 14a formed in the sound wave vibrator 10 is provided.

  When the ultrasonic transducer 10 is inserted into the opening 32 of the case 30, the locking portion 33 a and the locking portion 33 d sandwich the wall surface of the opening 32 between the front end position and the rear end position in the insertion direction. belongs to. Specifically, the engaging portion 33d passes through a through hole 31b (see FIG. 5B) different from the positioning hole 31a provided in the guide surface 31 of the case 30, and the circuit board of the guide surface 31 is provided. The side wall (rear surface) is locked, and the wall surface of the opening 32 of the case 30 is held together with the locking portion 33a.

  The outer peripheral surface 33 b has an inner diameter that is equal to or slightly smaller than the diameter of the ultrasonic transducer 10, and has a structure that can be attached to the ultrasonic transducer 10 without any gap when the ultrasonic transducer 10 is accommodated. ing. The second reference portion 33 c is provided in parallel with the insertion direction of the case 30 into the opening 32, and the tip of the first reference portion 14 a is attached when the cylindrical elastic body 33 is attached to the ultrasonic transducer 10. Compared with the position, the height is set such that the protrusion of the ultrasonic transducer 10 in the radial direction is slightly smaller.

  A notch (33e) (not shown) is provided so that the first reference portion 14a is not obstructed when the cylindrical elastic body 33 is attached to the ultrasonic transducer 10. With such a configuration, the ultrasonic transducer 10 has a cylindrical shape so that the first reference portion 14a is arranged on the same straight line with respect to the second reference portion 33c in the insertion direction of the ultrasonic transducer 10. The elastic body 33 is attached.

  In this attached state, the first reference portion 14a of the ultrasonic transducer 10 and the second reference portion 33c of the cylindrical elastic body 33 are on the same straight line in the insertion direction, and the protruding tip of the first reference portion 14a. Are exposed from the outer peripheral surface 33 b of the cylindrical elastic body 33. Further, on the bottom surface opposite to the vibration surface 11 b of the ultrasonic transducer 10 on which the cylindrical elastic body 33 is attached, the protection portion 18 of the ultrasonic transducer 10 and the cylindrical elastic body 33 are substantially disc-shaped. A foamed elastic body 34 with holes formed so that the stop 33d penetrates is assembled (not shown in FIG. 5).

  Note that the base 14, the cylindrical elastic body 33, and the foamed elastic body 34 of the ultrasonic transducer 10 are bonded and fixed to each other with a silicon-based adhesive. Then, the ultrasonic transducer 10 is inserted into the case 30 from the opening 32 in a state where the protruding tip of the first reference portion 14 a is guided by the groove-shaped third reference portion 38 provided in the case 30. Thus, the protection part 18 of the ultrasonic transducer 10 penetrates the positioning hole 31 a of the guide surface 31.

  Further, the connection pin 15 of the ultrasonic transducer 10 is inserted into the hole portion 21 a of the insert pin 21, and the locking portion 33 d of the cylindrical elastic body 33 passes through the through hole 31 b provided in the guide surface 31. Thus, the ultrasonic transducer 10 is fixed to the case 30 by the both locking portions 33a and 33d.

  Thereafter, the side of the case 30 partitioned by the guide surface 31 on which the circuit board 20 is disposed is filled with a moisture-proof member 35 such as silicon resin or urethane resin. Note that the reference numerals not described in FIG. 4 correspond to the reference numerals described in the embodiments of the present invention to be described later, and thus the description thereof is omitted here.

JP 2007-281999 A

  In recent years, while automatic assembly is progressing to reduce the cost of the ultrasonic sensor, the ultrasonic sensor 10 of Patent Document 1 described above includes a cylindrical elastic body 33 made of silicon rubber and a foamed elastic body 34 made of foam rubber. Since it is soft, automatic assembly to the ultrasonic transducer 10 is difficult. For this reason, since only the assembly of the cylindrical elastic body 33 and the foamed elastic body 34 is handled by manual assembly, it takes a number of manufacturing steps and becomes a bottleneck in reducing the cost of the ultrasonic sensor.

  In addition, due to assembly variations caused by manually assembling the cylindrical elastic body 33 and the foamed elastic body 34, the gap between the ultrasonic transducer 10 and the cylindrical elastic body 33 or between the cylindrical elastic body 33 and the case 30 is increased. There is also a problem that leakage of the moisture-proof member 35 occurs.

  The present invention has been made paying attention to such problems existing in the prior art, and an object of the present invention is to provide an ultrasonic sensor that can prevent leakage of moisture-proof members with a structure that can be easily assembled automatically. It is to provide.

In order to achieve the above object, the present invention employs the following technical means. That is, in the invention described in claim 1, the bottomed cylindrical housing (11), the piezoelectric element (12) fixed to the inner surface of the bottom (11a) of the housing (11), and the opening of the housing (11) An ultrasonic transducer (10) having a base (14) fitted and fixed to the side, and a cylindrical opening (32), and the ultrasonic transducer (10) is located outside the opening (32). A hollow case (30) inserted from the side and assembled into the opening (32), and a circuit board (20) disposed inside the case (30) and electrically connected to the piezoelectric element (12) And a moisture-proof member (35) filled inside the case (30) so as to enclose the circuit board (20),
A flexible thin plate portion (39) that is bent in contact with the outer peripheral surface of the ultrasonic transducer (10) is formed on the inner peripheral surface of the outer end of the opening (32), and the ultrasonic transducer ( 10) and a gap (S) between the opening (32) and a moisture-proof member (35) between the ultrasonic transducer (10) and the circuit board (20). Yes.

  According to the first aspect of the present invention, the moisture-proof member (35) for enclosing the circuit board (20) to be filled after assembling is filled up to the periphery of the ultrasonic transducer (10). . Since this moisture-proof member (35) serves as a cushioning member, a cushioning member such as a cylindrical elastic body or a foamed elastic body, which has conventionally been difficult to automatically assemble, becomes unnecessary, and its assembly is also unnecessary. A structure that facilitates automatic assembly.

  The flexible thin plate portion (39) formed on the inner peripheral surface of the outer end of the opening (32) bends inward when the ultrasonic transducer (10) is inserted to hold the ultrasonic transducer (10). In addition, since the seal is formed with the outer peripheral surface of the contacting ultrasonic transducer (10), leakage of the moisture-proof member (35) can also be prevented.

  In the invention according to claim 2, in the ultrasonic sensor according to claim 1, when the ultrasonic transducer (10) is inserted into a predetermined position, the tip of the flexible thin plate portion (39) is The groove (11d) for entering is formed on the outer peripheral surface of the ultrasonic transducer (10).

  According to the second aspect of the present invention, the distal end portion of the flexible thin plate portion (39) bent inward at the time of press-fitting insertion of the ultrasonic transducer (10) enters the groove portion (11d) and is sealed. Becomes stable and holds the ultrasonic transducer (10) in a predetermined position. Further, when filling the moisture-proof member (35), the surface of the groove (11d) in contact with the pressure received by the tip of the flexible thin plate portion (39) from the moisture-proof member (35) is acceptable. Since the leading end of the flexible thin plate portion (39) is supported, leakage of the moisture-proof member (35) can be prevented.

  Further, in the invention according to claim 3, in the ultrasonic sensor according to claim 1 or 2, the flexible thin plate portion (39) is a softer material than the case (30), and the case (30) It is characterized by being integrally formed by two-color molding. According to the third aspect of the present invention, a stable sealing function can be exhibited.

  In the invention according to claim 4, in the ultrasonic sensor according to claim 1 or 2, the flexible thin plate portion (39) is made of the same material as the case (30), and is integrated with the case (30). It is characterized by being formed. According to the fourth aspect of the invention, the cost of the ultrasonic sensor can be reduced.

  In the invention according to claim 5, in the ultrasonic sensor according to any one of claims 1 to 4, the insertion depth of the ultrasonic transducer (10) and the circumference of the inner surface of the opening (32). A positioning convex portion (38) that regulates the orientation in the direction is formed, and a positioning concave portion (14a) that fits the positioning convex portion (38) is formed on the outer peripheral surface of the ultrasonic transducer (10). It is characterized by that. According to the fifth aspect of the present invention, the assembly of the ultrasonic transducer (10) can be facilitated.

  In addition, the code | symbol in the parenthesis as described in a claim and said each means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(A) is a cross-sectional view of the ultrasonic transducer 10, (b) is a back view of the housing 11 housing the piezoelectric element 12 provided in the ultrasonic transducer 10, and (c) is a back view of the entire ultrasonic transducer 10. It is. (A) is sectional drawing which shows the structure outline | summary of the ultrasonic sensor 1 in one Embodiment of this invention, (b) is the figure which looked at the ultrasonic sensor 1 of (a) from the downward direction. FIG. 3 is an exploded perspective view of the ultrasonic sensor 1 of FIG. 2 and shows a state in which an ultrasonic transducer 10 is assembled to a case 30. 1 is a cross-sectional view of an ultrasonic sensor 100 of Patent Document 1. FIG. FIG. 5 is an exploded perspective view of the ultrasonic sensor 100 of FIG. 4, where (a) shows a state before the ultrasonic transducer 10 is attached to the cylindrical elastic body 33, and (b) shows the cylindrical elastic body 33 covered. A state where the worn ultrasonic transducer 10 is assembled to the case 30 is shown.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. The ultrasonic sensor of this embodiment is attached to a bumper of a vehicle and used as a back sonar or a corner sonar, for example. First, FIG. 1 shows an ultrasonic transducer 10 constituting the ultrasonic sensor of the present embodiment. 1A is a cross-sectional view of the ultrasonic transducer 10, FIG. 1B is a rear view of the housing 11 housing the piezoelectric element 12 provided in the ultrasonic transducer 10, and FIG. It is a back view.

  As shown in FIGS. 1A to 1C, an ultrasonic transducer (hereinafter referred to as a microphone) 10 includes a housing 11, a piezoelectric element 12, a spacer 13, a base 14, and a connection pin 15. Has been. The housing 11 is formed of a member made conductive by forming a conductive film on the surface of a metal material or an insulating material. In addition, an internal space 16 is formed inside the housing 11 by having a bottomed cylindrical shape.

  A piezoelectric element 12 is adhered to the inner surface of the bottom portion 11a of the housing 11, and the outer surface of the bottom portion 11a is a vibration surface 11b. In the present embodiment, aluminum is used as the conductive material, and the vibration surface 11b has a circular shape. Further, as shown in FIG. 1B, the upper surface shape of the internal space 16 is a rectangular shape in which the long side and the short side are different in length and the four corners are rounded.

  With the internal space 16 having such a shape, the directivity of the microphone 10 is different between the horizontal direction and the vertical direction. In FIG. 1B, the vertical direction corresponds to the vertical vertical direction with narrow directivity, and the horizontal direction corresponds to the horizontal horizontal direction with wide directivity. The piezoelectric element 12 is made of, for example, lead zirconate titanate piezoelectric ceramics, and includes electrodes (not shown) on both front and back surfaces.

  One electrode of the piezoelectric element 12 is electrically connected to one of the pair of connection pins 15 by a lead 17a, and the other electrode is adhered to the bottom 11a of the housing 11 by, for example, a conductive adhesive, and is electrically conductive. After being connected to the lead 17 b through the housing 11 made of a material, the lead 17 b is electrically connected to the other of the pair of connection pins 15. The inner space 16 of the housing 11 is filled with felt and silicon in order from the piezoelectric element 12 side through an injection port (not shown) provided in the spacer 13 and the base 14, and unnecessary vibration is generated from the vibration surface 11 b. Transmission to the connection pin 15 is suppressed.

  The spacer 13 is disposed between the opening of the housing 11 and the base 14. The spacer 13 is an elastic body for suppressing unnecessary vibration generated in the cylindrical portion 11 c of the housing 11 due to vibration of the bottom portion 11 a of the housing 11 from being transmitted to the base 14 to which the connection pin 15 is fixed. For example, it is made of silicon rubber. Here, the spacer 13 is disposed, but a configuration in which the spacer 13 is eliminated may be employed.

  The base 14 is fixed to the housing 11 by being fitted to the outer peripheral surface on the opening side of the housing 11 via the spacer 13. The base 14 is made of an insulating material made of synthetic resin such as ABS resin. A connection pin 15 is disposed through the base 14. When the base 14 is molded, the connection pins 15 are insert-molded so that a part of the connection pins 15 is embedded and fixed in the base 14.

  Further, the base 14 is provided with a protection portion 18 extending along the longitudinal direction of the connection pin 15, and the connection pin 15 drawn out of the housing 11 is predetermined from the base 14 toward the outer tip side. Covering range. A pair of connection pins 15 are integrally covered with the protection portion 18.

  The connection pin 15 is made of, for example, a conductive material whose main component is copper, and is composed of a rod-shaped member having a diameter of 0.5 mm, for example. In this embodiment, since the directivity of the microphone 10 is configured to be different between the horizontal direction and the vertical direction, the connection pin 15 and the protection unit 18 are arranged at the center of the microphone 10 as shown in FIG. It is provided at a position shifted from the axis.

  In the present embodiment, the protective portion 18 is configured by a part of the base 14, but the protective portion 18 may be configured as a member separate from the base 14. For example, the protection unit 18 may be fixed to the base 14 by adhesion or the like. Further, a configuration in which the pair of connection pins 15 are not integrally covered by the protection portion 18 and each of the connection pins 15 is covered and protected independently may be employed.

  Further, the through arrangement of the connection pin 15 with respect to the base 14 and the protection part 18 is not limited to the above-mentioned insert, and the connection pin 15 is inserted into a through hole provided in the base 14 and the protection part 18, It may be bonded and fixed in a predetermined arrangement. However, the configuration of this embodiment is effective in preventing the connection pin 15 from being bent or bent.

  Furthermore, the microphone 10 includes a foamed elastic body 19 made of, for example, foamed silicon. The foamed elastic body 19 functions as an elastic body that suppresses vibration on the base 14 facing the protection portion 18, and the connection pin 15 is disposed so as to penetrate the foamed elastic body 19. In addition, although it is set as the structure provided with the foaming elastic body 19 here, the structure which is not provided may be sufficient.

  The housing 11, the spacer 13, the base 14, and the foamed elastic body 19 are bonded to each other with, for example, a silicon-based adhesive, so that the microphone 10 having an integral structure is configured.

  2A and 2B are diagrams showing an outline of the structure of the ultrasonic sensor 1 provided with the microphone 10 shown in FIG. 1. FIG. 2A is a sectional view, and FIG. 2B is a circuit board 20 of the ultrasonic sensor 1. It is the figure which looked at the case 30 in which etc. are accommodated from the back surface side. In FIG. 2 (a), for convenience, electronic components constituting the circuit board 20 are omitted.

  The ultrasonic sensor 1 includes the above-described microphone 10 and a circuit board 20 that applies a driving voltage for generating ultrasonic waves to the microphone 10 and processes a voltage generated by the counter electromotive force effect from the microphone 10. Is assembled in a case 30.

  The case 30 is roughly divided into a substantially box-shaped main body portion in which the circuit board 20 is mainly accommodated, and an opening portion 32 in which the microphone 10 is accommodated by protruding in a cylindrical shape from the bottom surface portion of the box body to the opposite opening side. And a connector portion 37 protruding in a substantially long cylindrical shape from one side surface of the box. And the insert pin 21 which functions as a relay pin is provided in the bottom face part of the box. The insert pins 21 are provided in a number corresponding to the connection pins 15 and are paired in this embodiment.

  The insert pin 21 is integrated by being insert-molded with respect to the case 30, one end is exposed in the hollow of the case 30, and the end corresponds to the connection pin 15 in the microphone 10. Has been drawn to. At least an end portion of the insert pin 21 drawn out from the case 30 has a thin shape that is easily bent in the insertion direction of the microphone 10 into the case 30.

  A hole 21a is formed at the end of the insert pin 21, and the tip of the connection pin 15 is inserted into the hole 21a. The other end 21 b of the insert pin 21 is exposed in a hollow portion in the case 30 and is drawn out in parallel with the direction in which the circuit board 20 is inserted into the case 30. When the circuit board 20 is inserted into the case 30, the end 21 b is inserted into a through hole 20 a formed in the circuit board 20.

  The amount of protrusion from the case 30 at the end of the insert pin 21 on the side connected to the connection pin 15 can be set as appropriate, but the connection pin 15 is pushed in by the microphone 10 being pushed from the outside. It is sufficient that the end portion of the insert pin 21 bends and the stress when the connection pin 15 is pushed in can be absorbed. Further, an insert pin 36 that functions as an external input / output terminal is provided on the connector 37 side of the bottom of the box.

  The insert pins 36 are provided in a number corresponding to the input / output between the circuit board 20 and the outside, and in the present embodiment, six insert pins 36 are provided. The insert pin 36 is integrated by being insert-molded with respect to the case 30. One end of the insert pin 36 is exposed in the hollow of the connector portion 37, and the end thereof is at a position corresponding to an external connector (not shown). Has been pulled out.

  The other end 36 a of the insert pin 36 is exposed in a hollow portion in the case 30 and is drawn out in parallel with the direction in which the circuit board 20 is inserted into the case 30. When the circuit board 20 is inserted into the case 30, the end 36 a is inserted into a through hole 20 b formed in the circuit board 20.

  Next, the characteristic part of this embodiment is demonstrated. Seal ribs (flexible thin plate portions referred to in the present invention) 39 that are bent in contact with the outer peripheral surface of the microphone 10 are formed on the inner peripheral surface of the outer end of the opening 32 that is the insertion portion of the microphone 10. The seal rib 39 is made of a material softer than the case 30, such as an elastomer resin, and is integrally formed on the case 30 by two-color molding.

  The seal rib 39 is formed at the outer end of the opening 32 so as to protrude thinly inward, and the inner diameter of the tip is set smaller than the outer diameter of the microphone 10. The part is in close contact with the outer peripheral surface of the microphone 10. The inner diameter of the opening 32 is formed to be larger than the outer diameter of the microphone 10, and when the microphone 10 is inserted into the opening 32 from the outside while bending the tip side of the seal rib 39, A predetermined gap S is formed between the inner peripheral surface and the outer peripheral surface of the microphone 10.

  Further, a groove portion 11 d into which the tip end portion of the seal rib 39 enters when the microphone 10 is inserted up to a predetermined position of the opening portion 32 is formed on the outer peripheral surface of the microphone 10. In FIG. 2A, the groove 11d is a rectangular groove, but it may be a triangular groove or a semicircular groove.

  Further, a positioning convex portion 38 for restricting the insertion depth of the microphone 10 and the relative position with respect to the case 30 in the circumferential direction is protruded inward on a part of the inner peripheral surface of the opening 32. At the same time, at least one positioning recess 14a (shown in FIG. 3) is formed on the outer peripheral surface of the microphone 10 in the circumferential direction.

  FIG. 3 is an exploded perspective view of the ultrasonic sensor 1 of FIG. 2 and shows how the microphone 10 is assembled to the case 30. The microphone 10 is assembled into the case 30 by being lightly press-fitted into the opening 32. At this time, the positioning convex portion 38 and the positioning concave portion 14a have a key-key groove relationship, and the insertion direction in the circumferential direction of the microphone 10 is determined.

  Further, the tip of the positioning protrusion 38 in the insertion direction and the bottom of the positioning recess 14 a come into contact with each other, whereby the microphone 10 is inserted to a predetermined position (depth), and the connection pin 15 is inserted into the hole 21 a of the insert pin 21. To be inserted. Further, the tip of the seal rib 39 is fitted into a groove 11d provided on the outer peripheral surface of the microphone 10, and the microphone 10 is fixed. In this state, the insert pin 21 and the connection pin 15 are soldered.

  Further, the circuit board 20 is disposed in the case 30. As a result, the end 21 b of the insert pin 21 is inserted into the through hole 20 a of the circuit board 20, and the tip 36 a of the insert pin 36 is also inserted into the through hole 20 b of the circuit board 20. Soldering is performed in this state, and electrical connection between the piezoelectric element 12 and the circuit board 20 through the insert pin 21 and electrical connection between the insert pin 36 and the circuit board 20 are performed.

  After that, in a substantially vacuum environment, the opening (the lower surface in FIG. 2A) of the main body (box) of the case 30 is oriented in the celestial direction, and the side on which the circuit board 20 is disposed. The case 30 is vacuum-filled with a silicon resin (moisture-proof member in the present invention) 35. In addition, a urethane resin or the like may be used as the moisture-proof member. The silicon resin 35 encloses the circuit board 20 and is also filled in the gap S between the microphone 10 and the opening 32 and between the microphone 10 and the circuit board 20 to serve as a cushioning material. Become.

  The vibration surface 11 b of the microphone 10 is exposed from the opening 32 of the case 30, and the ultrasonic wave emitted from the microphone 10 is transmitted to the outside of the case 30.

  Next, the features and effects of this embodiment will be described. First, a seal rib 39 that is bent in contact with the outer peripheral surface of the microphone 10 is formed on the inner peripheral surface of the outer end of the opening 32, and the gap S between the microphone 10 and the opening 32 and the microphone 10 are formed. And the circuit board 20 are filled with a silicon resin 35.

  According to this, the silicon resin 35 for enclosing the circuit board 20 to be filled after assembling is filled up around the microphone 10. Since this silicon resin 35 serves as a buffer member, a buffer member such as a cylindrical elastic body or foamed elastic body, which has conventionally been difficult to automatically assemble, is no longer necessary, and the assembly is also unnecessary. Structure. In addition to cost reduction by reducing parts such as a cylindrical elastic body and foamed elastic body, this eliminates the manual assembly process and enables full automation, thereby reducing the manufacturing cost.

  Further, the seal rib 39 formed on the inner peripheral surface of the outer end of the opening 32 bends inward when the microphone 10 is inserted to hold the microphone 10 and seals with the outer peripheral surface of the contacting microphone 10. Therefore, leakage of the silicon resin 35 can be prevented. Further, a groove portion 11 d into which the tip end portion of the seal rib 39 enters when the microphone 10 is inserted at a predetermined position is formed on the outer peripheral surface of the microphone 10.

  According to this, the tip end portion of the seal rib 39 that has been bent inward when the microphone 10 is press-fitted is inserted into the groove portion 11d to stabilize the seal and to hold the microphone 10 in a predetermined position. Further, when filling the silicon resin 35, the surface of the groove 11 d that is in contact with the pressure received by the tip of the seal rib 39 from the silicon resin 35 supports the tip of the seal rib 39. Can prevent leakage.

  The seal rib 39 is made of a material softer than the case 30 and is integrally formed with the case 30 by two-color molding. According to this, a stable sealing function can be exhibited. In addition, a positioning convex portion 38 that restricts the insertion depth of the microphone 10 and the direction in the circumferential direction is formed on the inner surface of the opening 32, and positioning that fits the positioning convex portion 38 on the outer peripheral surface of the microphone 10. A recess 14a is formed. According to this, the assembly of the microphone 10 can be facilitated.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows. For example, in the above-described embodiment, the seal rib 39 is formed in the case 30 so as to have two colors, but the seal rib 39 may be formed integrally with the case 30 with the same material as the case 30. This also can reduce the cost of the ultrasonic sensor.

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic sensor 10 ... Microphone (ultrasonic transducer)
DESCRIPTION OF SYMBOLS 11 ... Housing 11a ... Bottom part 11d ... Groove part 12 ... Piezoelectric element 14 ... Base 14a ... Positioning recessed part 20 ... Circuit board 30 ... Case 32 ... Opening part 35 ... Silicone resin (moisture-proof member)
38 ... Positioning convex part 39 ... Seal rib (flexible thin plate part)
S ... Gap

Claims (5)

A bottomed cylindrical housing (11), a piezoelectric element (12) fixed to the inner surface of the bottom (11a) of the housing (11), and a base (fitted and fixed to the opening side of the housing (11)) 14) an ultrasonic transducer (10) comprising:
A hollow case (having a cylindrical opening (32)) in which the ultrasonic transducer (10) is inserted from the outside of the opening (32) and assembled into the opening (32). 30),
A circuit board (20) disposed inside the case (30) and electrically connected to the piezoelectric element (12);
In the ultrasonic sensor comprising a moisture-proof member (35) filled in the case (30) so as to enclose the circuit board (20),
On the inner peripheral surface of the outer end of the opening (32), a flexible thin plate portion (39) that is bent in contact with the outer peripheral surface of the ultrasonic transducer (10) is formed.
The gap (S) between the ultrasonic transducer (10) and the opening (32), and the moisture-proof member (35) between the ultrasonic transducer (10) and the circuit board (20). ) Is filled with an ultrasonic sensor.   When the ultrasonic transducer (10) is inserted into a predetermined position, a groove (11d) into which the tip of the flexible thin plate portion (39) enters is formed on the outer peripheral surface of the ultrasonic transducer (10). The ultrasonic sensor according to claim 1, wherein:   The flexible thin plate portion (39) is made of a softer material than the case (30), and is formed integrally with the case (30) by two-color molding. 2. The ultrasonic sensor according to 2.   The ultrasonic wave according to claim 1 or 2, wherein the flexible thin plate portion (39) is made of the same material as the case (30) and is formed integrally with the case (30). Sensor.   On the inner surface of the opening (32), a positioning convex part (38) for restricting the insertion depth of the ultrasonic vibrator (10) and the direction in the circumferential direction is formed, and the ultrasonic vibrator (10 The ultrasonic sensor according to any one of claims 1 to 4, wherein a positioning concave portion (14a) that fits the positioning convex portion (38) is formed on an outer peripheral surface of the ultrasonic sensor.

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