JPS56155598

Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPS56155598
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a conventional ultrasonic
ceramic microphone, FIG. 2 is a sectional view showing an embodiment of the ultrasonic ceramic
microphone according to the present invention, and FIG. 4 is a sensitivity-frequency
characteristic comparison diagram of the product of the present invention and the conventional
product. 5a · · · · · Metal diaphragm, 5b · · · · · · · · · Piezoelectric porcelain resonator, · · · · · · · · · · · · ·
· · · · · · · · · · · · · · · · · Bimorph oscillator, 7 · · · · · · · · · cylindrical case, 7a · · ·・ ・ ・ ・ ・ ・ ・ ・
・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・
・・・
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sensor for
transmitting and receiving ultrasonic waves, in particular, a drip-proof, dust-proof structure for
use outdoors: '7' F 曾? As an application product of this type of ultrasonic ceramic microphone
used in the outdoors, which is related to the ultrasonic ceramic microphone of No. 2, there is a
device for detecting various objects, taking a rear detection device of a car as an example. Here,
the peripheral configuration of the sensor, in which measures are taken according to the ambient
environment and mounting method, is an important issue. The above-mentioned automotive
applications are used in a structure that is resistant to vibrational impact, supported by an elastic
body so that the characteristics of the sensor do not change due to the support wedge, and
further the outer periphery thereof is held by a strong material. Therefore, a characteristic
change due to the side support is small, and a microphone that is resistant to vibrational impact
is required. The present invention provides an ultrasonic microphone having a structure that can
meet the above-mentioned requirements. A conventional embodiment will be described with
reference to FIG. The piezoelectric ceramic vibrator 1 is attached to the center inside the bottom
of the case 2 and the terminal plate 4 is attached to the pond end opening of the case 2, and the
elastic adhesive 3 is interposed between the case 32 and the terminal plate 4 It is a sealed
04-05-2019
1
structure. When supporting pressure is applied to the outer periphery of the case 2, the side
thickness is made thicker than the thickness of the bottom of the case 2 in order to reduce the
vibration damping of the vibrating portion formed on the bottom of the case 2. In such a
conventional structure, the thickness of the bottom and the side of the case 2 is different, so the
processing cost of the case 2 is high, and since the case 2 and the vibrating portion are
integrated, mechanical vibration and impact applied to the case 2 The noise was picked up by the
camera, and the motion damping was given. The present invention ameliorates these
conventional drawbacks and provides an ultrasonic ceramic microphone having high sensitivity
and wide band performance. Hereinafter, one embodiment of the present invention will be
described with reference to FIG. First, as shown in the figure, the piezoelectric ceramic vibrator
5b is bonded to the metal vibrating plate 6a to form the bimorph vibrator 6. Reference numeral 7
denotes a cylindrical case having a flange 7a. A support base 8 having a hole at the center is
inserted into the case 7 and fixed in contact with the flange 7a. Then, the bimorph oscillator 6 is
attached to the support 8 via the elastic adhesive 9 and at the same time the space between the
side 7 a of the case 7 and the oscillator 6 and the support 8 is sealed with the productivity
adhesive 9. doing. In the case of 1 °, the inner case supports the support 8 and the terminal
plate 11 is positioned at the other end opening of the case 7.
A reference numeral 12 is a gold-plated base incorporated in the terminal board 11. The metal
base 12 is electrically conducted to the case 7 and is electrically conducted to the i-core 13 & it
has an electrical shielding effect. 13b is a ■ terminal, 14a, 14b is a terminal 13a. It is a lead wire
which connects 13b and the said bimorph vibrator ¦ oscillator 60 both electrodes. As described
above, in the ultrasonic ceramic microphone according to the present invention, the bimorph
vibrator 6, that is, the vibrating portion is separated from the case 7, and the terminal is held
elastically in the support base 8 and the flange portion a of the case 7. Even if the side surface of
the case 7 is supported or held strong, the imaging motion of the vibrating portion is not
attenuated. Also, since the elastic body is used to fix the bimorph imaging moving member 6, the
vibration mode approximates to the free imaging mode. Therefore, it has sensitivity
characteristics. Further, since the component structure of the support base 8, the case 7 and the
terminal plate 11 is simple, it is possible to provide a structure which is low in component cost
and easy to assemble and which can be miniaturized. FIG. 3 shows another embodiment of the
present invention, in which 15 is a metal (or resin) conical resonator, and the metal conical
resonator 15 is disposed at the central portion of the bimorph actuator 6. The vertex is fixed. In
this embodiment f1, the holding of the bimorph oscillator 6 is transmitted to the metallic conical
resonator 15, the radiated sound wave strikes the upper surface of the terminal plate 11, and the
reflected acoustic wave is incident on the metallic conical resonator 15. Vibration amplification is
performed by resonating the metal cone conical resonator 16 with the sound wave. Therefore,
there is a need to set the distance between the terminal plate 11 and the gold / 1 conical
resonator 16 so that the number of standing wave resonances is easily generated. This distance
can be obtained by the following equation. --- L = integer multiple of A-integer multiple of p (鵡)
04-05-2019
2
44f 6f; frequency, C; speed of sound, λ; wavelength. As described above, by providing the
conical resonator 15, the Q of the imaging motion can be lowered even in the closed structure,
and high sensitivity and wide band characteristics can be obtained. Fig. 4 shows comparison data
of sensitivity-frequency characteristics between the product of the present invention and the
conventional product, where A is the conventional product, B is the product of the present
invention according to Fig. 2, and C is the embodiment of Fig. 3. The characteristics of the
product of the present invention are shown respectively, and the product of the present invention
has better characteristics. As described above, according to this study, the imaging unit is
elastically fixed, and by adding a lively function to the inside of the case, it is resistant to
vibrational impact, a high sensitivity, wide band ultrasonic ceramic microphone that entrusts the
application. Was able to develop.
And, according to this examination, it is expected to be applied as a sensor for automobile
inspection, especially as a microphone (sensor) of anti-corrosion, dust-proof and dust-proof type
used outdoors.
04-05-2019
3