JP2008145391A - Ultrasonic sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein it is difficult to carry out raising the output level of the transmission characteristics of ultrasonic waves or narrowing the directivity in a conventional ultrasonic transmitter, without impairing the appearance by placing the transmitter so that it is installed visible from the outside of bumper. <P>SOLUTION: An oscillator element constituted of a piezoelectric element and a cylindrical case with a bottom is bonded to the rear side of a bumper. A recessed section is further provided to the bumper section, with the oscillator element being constituted of the piezoelectric element and the cylindrical case having the bottom bonded thereto, and then the bumper is vibrated for transmission and reception of ultrasonic waves. The piezoelectric element is bonded directly to the rear side of the bumper, and then the bumper is vibrated for transmission and reception of ultrasonic waves. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic transducer that transmits and receives an ultrasonic frequency band.

In the ultrasonic transducer according to the conventional embodiment, when this is installed in a car bumper or the like, after making a through hole for mounting in the bumper or the like, the ultrasonic transducer main body is made of a resin case and Fix the bumper from the front and back sides using a bezel. The ultrasonic radiation surface of the ultrasonic transducer is installed so that it can be seen from the outside of the bumper. When high output of ultrasonic transmission / reception characteristics and sharpening of directivity are implemented, it is possible to increase the vibration surface of the ultrasonic transducer. However, since the ultrasonic transducer according to the conventional embodiment is installed so that it can be seen from the outside of the bumper, it is difficult to increase the output of ultrasonic transmission / reception characteristics and sharpen the directivity without impairing the appearance. There is a problem.
JP2004-251665A Tanikoshi Shinji “Ultrasound and its usage-Ultrasonic transducers and ultrasonic motors” Nikkan Kogyo Shimbun 1994

  With the conventional technology, it is difficult to increase the output of ultrasonic transmission / reception characteristics and sharpen directivity without impairing the appearance.

  A piezoelectric element and a vibrator comprising a bottomed cylindrical case are joined to the back side of the bumper. Further, a concave portion is provided in the bumper portion, and a vibrator comprising a piezoelectric element and a bottomed cylindrical case is joined thereto, and the bumper is vibrated to transmit / receive ultrasonic waves. Alternatively, a piezoelectric element is directly bonded to the back side of the bumper, and the bumper is vibrated to transmit / receive ultrasonic waves.

  According to the present invention, the size of the vibrator can be increased without impairing the appearance, so that high output and sharpening of directivity can be easily realized.

  When used in an in-vehicle corner sensor or the like, a unimorph vibrator or piezoelectric element comprising a piezoelectric element and a bottomed cylindrical case is directly joined to the back side of the bumper, and the bumper is vibrated to transmit and receive ultrasonic waves.

FIG. 1 is a schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of claim 1 of the present invention. In FIG. 1, a piezoelectric element 1 is bonded to the inside of the bottom surface of a bottomed cylindrical case 2 made of an aluminum material or the like to constitute a unimorph vibrator. This is joined and fixed to the bumper 3 from the back side using an epoxy adhesive or the like. The input / output lead 5a is taken out from the opposite surface of the piezoelectric element 1 to the bottomed cylindrical case 2 and the input / output lead 5b is taken out from the bottomed cylindrical case 2 by soldering or the like. The adhesive surface side of the piezoelectric element 1 with the bottomed cylindrical case 2 and the bottomed cylindrical case 2 are electrically connected. Further, the piezoelectric element 1, the input / output lead 5a, and the bottomed cylindrical case 2 are electrically connected. And the input / output lead 5b are electrically connected. A sound absorbing material 4 made of foamed silicone or the like is placed on the upper surface of the piezoelectric element 1, and the input / output leads 5a and 5b are soldered to the external leads 6a and 6b, respectively. The inside of the bottomed cylindrical case 2 is filled with a sealant 8 made of silicone or urethane having self-adhesiveness from the back opening of the bottomed cylindrical case.
FIG. 2 is a schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of claim 2 of the present invention.
In FIG. 2, the bumper 3 is partially thinned to provide a recess, and a unimorph vibrator similar to that shown in FIG. 1 is joined and fixed to the bottomed cylindrical case 2 and the bumper 3 using an epoxy adhesive or the like. To do. The thickness t of the bumper recess may be 0.1 mm or more, and preferably in the range of 0.2 mm to 0.5 mm.
FIG. 3 is a schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of claim 3 of the present invention.
In FIG. 3, a piezoelectric element 1 having a folded electrode is directly bonded to a bumper 3 to constitute a unimorph vibrator. The cylindrical case 7 is joined and fixed to the bumper 3 using an epoxy adhesive or the like so as to cover the outer peripheral portion of the piezoelectric element. The input / output leads 5a and 5b are respectively taken out from the electrodes 9a and 9b of the piezoelectric element by soldering or the like. A sound absorbing material 4 made of foamed silicone or the like is placed on the upper surface of the piezoelectric element 1, and a sealing agent 7 made of silicone or urethane having self-adhesive properties is placed inside the cylindrical case 2 from the back opening of the cylindrical case 2. Fill.

1 is a schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of the present invention. Schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of claim 2 of the present invention Schematic longitudinal sectional view of an ultrasonic transducer according to an embodiment of claim 3 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Bottomed cylindrical case 3 Bumper 4 Sound absorbing material 5a Input / output lead 5b Input / output lead
6a Input / output terminal 6b Input / output terminal 7 Cylindrical case 8 Sealant

Claims (3)

  In an ultrasonic transducer used for detecting obstacles by transmitting and receiving ultrasonic waves on a vehicle, a unimorph transducer consisting of a piezoelectric element and a bottomed cylindrical case is joined to the back of the bumper, and the bumper An ultrasonic transducer that transmits and receives ultrasonic waves by vibrating.   2. The ultrasonic transducer according to claim 1, wherein a concave portion is provided in the bumper portion, and a piezoelectric element and a vibrator comprising a bottomed cylindrical case are joined thereto.   An ultrasonic transducer having a piezoelectric element directly bonded to the back side of a bumper and vibrating the bumper to transmit / receive ultrasonic waves.

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