close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPH05137197

код для вставкиСкачать
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 JPH05137197
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
vibration isolation structure of a transducer in an apparatus for transmitting and receiving sound
waves.
[0002]
2. Description of the Related Art As shown in FIG. 2, the vibration isolation structure of a
conventional transducer of this type accommodates a transducer unit 7 for sound wave
transmission and reception, and has a cap-like acoustic rubber covered on the front surface. A
resilient vibration-proof material 9 is interposed between the waver housing 5 and a mount 6 for
holding the same. By setting the length L of the vibration-proof material 9 to be a quarter of the
used sound wave, for example, when mounted on a vehicle, even if vibration of the same
frequency as the used sound wave is applied to the gantry 6, the phase is set. Can be inverted by
the anti-vibration material 9 and transmitted to the transducer housing 5 to reduce the
transmission of the vibration to the vibrator portion 7.
[0003]
However, in this conventional vibration isolation structure of a transducer, since the sound wave
frequency that can be transmission-suppressed by the vibration insulation material 9 is limited to
the vicinity of one frequency, the frequency of the transmitted and received sound waves can be
varied. In this way, the transmission of the vibration of the gantry 6 to the transducer housing 5
13-04-2019
1
can not be sufficiently suppressed.
[0004]
SUMMARY OF THE INVENTION The structure of the present invention has a construction in
which a vibration-proof material is interposed between a transmitter-receiver housing containing
a transducer unit for sound transmission and reception and a mount on which the transmitterreceiver housing is mounted. In the vibration-proof structure of a transducer, the vibration-proof
material is a thermoplastic resin in which a temperature sensing thermistor and a heating wire
are embedded, and the heat wire according to the temperature detected by the thermistor. It is
characterized by comprising a feedback circuit which variably controls the power supplied to the
circuit.
[0005]
Next, the present invention will be described with reference to the drawings.
[0006]
FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.
In the figure, a thermoplastic resin 1 is interposed between the transducer housing 5 and the
frame 6, and the heating wire 2 and the thermistor 3 are embedded therein, and both are
connected to the feedback circuit 4.
In order to attenuate the vibration transmitted from the gantry 6 to the transducer housing 5, the
length L of the thermoplastic resin 1 may be set to a value corresponding to one fourth of the
wavelength λ of the sound wave used for transmission and reception. .
The thermoplastic resin 1 has a characteristic that the acoustic impedance I decreases as the
temperature rises. Assuming that the density of the thermoplastic resin 1 is ρ, the following
equation is established.
[0007]
13-04-2019
2
L = λ / 4 = I / (4 f)) where f is the frequency of the sound wave used for transmission and
reception. The feedback circuit 4 detects the temperature of the thermoplastic resin 1 by
detecting the resistance value of the thermistor 3, and the electrical impedance I of the
thermoplastic resin 1 at this temperature becomes a value satisfying the above equation. The
voltage applied to the heating wire 2 is variably controlled.
[0008]
As described above, since the acoustic impedance I can be varied by variably controlling the
temperature without changing the length L of the thermoplastic resin 1, the acoustic impedance I
can be varied even when the acoustic wave frequency f is changed. Control can be used to
significantly reduce the vibrational transmission from the cradle 6 to the transducer housing 5.
[0009]
As described above, according to the present invention, the temperature is feedback-controlled
by using a thermoplastic resin in which a thermosensitive thermistor and a heating wire for
heating are embedded as an anti-vibration material. Thus, even if the frequency of the sound
wave used by the transducer is increased, it is possible to reverse the phase of the vibration
transmitted from the mount at the thermoplastic resin and reduce the vibration transmission to
the transducer portion.
13-04-2019
3
Документ
Категория
Без категории
Просмотров
0
Размер файла
10 Кб
Теги
description, jph05137197
1/--страниц
Пожаловаться на содержимое документа