JPH0445352Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an ultrasonic transducer used as a distance sensor or the like.

(Prior Art) An example of the structure of a conventional ultrasonic transducer is shown in FIG.

In the figure, 101 is a housing, and an ultrasonic transducer 103 is held within this housing 101 by a holder 102. Holder 102
is made of an elastic material such as rubber or felt.
A horn 104 is formed integrally with the housing 101 in front of the ultrasonic transducer 103.
Moreover, vibration-proof rubber is provided inside the ultrasonic transducer 103. Note that 105 in the figure is a terminal of the ultrasonic transducer 103.

In such a structure, when an electrical signal is input to the terminal 105, the ultrasonic vibrator 103 vibrates,
This vibration is transmitted into the atmosphere by the horn 104 as a transmitted wave having a predetermined beam shape. Conversely, the sound waves that have been reflected toward the horn 104 are converged by the horn 104, and the ultrasonic transducer 10
3 into an electrical signal. At this time, the reverberation that occurs in the ultrasonic transducer 103 is caused by
and is reduced by the anti-vibration rubber built into the ultrasonic transducer 103.

However, in such a structure, since the ultrasonic transducer 103 is held by the holder 102 and fixed behind the horn 104 in the housing 101, the ultrasonic transducer 101 is held against the horn 104. Positioning is not easy,
Since the positional relationship between the two tends to vary due to installation work, it is difficult to accurately set the directivity of the transmitted waves. Especially when used for both transmitting and receiving, horn 1
If the 04 and the holder 102 are not brought into close contact with each other properly, poor reverberation may occur, making it impossible to detect objects at close range. Further, since the holder 102 and the ultrasonic vibrator 103 are separately provided to the horn 104, the number of parts is large, assembly is difficult, and it is not advantageous in terms of manufacturing cost.

(Purpose of the invention) In view of the above circumstances, an object of the present invention is to provide an ultrasonic transducer that can achieve stable directivity, improved performance by preventing reverberation, and reduced manufacturing costs.

(Structure of the invention) The invention consists of an ultrasonic transducer, a holder for holding the ultrasonic transducer in a housing, a horn provided in front of the ultrasonic transducer, and a vibrator for vibration of the ultrasonic transducer. In this ultrasonic transducer, the holder, the horn, and the vibration isolator are integrally formed of the same elastic material.

According to such a configuration, since the horn, the holding body, and the vibration isolating material are integrally formed, there is no variation in the positional relationship between the ultrasonic transducer and the horn.
Poor matching between the holding body and the horn does not occur.

(Example) An example of the present invention will be described based on FIG.

In the figure, reference numeral 1 denotes a housing, and an ultrasonic transducer 3 is held within the housing 1 by an elastic body 2 made of an elastic material such as silicone rubber. The elastic body 2 includes a tapered portion 21 forming the horn 4, a holding portion (holding body) 22 surrounding the ultrasonic vibrator 3, and a vibration isolating portion (vibration isolating material) located directly below the ultrasonic vibrator 3. ) It consists of 23. The holding portion 22 has a plurality of protrusions 22 on its outer peripheral surface.
a, and is fitted into the housing 1 with the protrusion 22a in close contact with the inner circumferential surface 1a of the housing 1.

The case 3a of the ultrasonic transducer 3 is composed only of the upper part of the ultrasonic transducer 103 shown in FIG. . Electrode lead wires 6a, 6b are connected to the peripheral edges of the piezoelectric element 5 and the ultrasonic vibrator 3, respectively, and these lead wires 6a, 6b pass through communication holes 2a, 2b formed in the elastic body 2. It is guided inside the housing 1 and connected to terminals 7a and 7b.

A back chamber 23a is formed on the upper surface of the vibration isolating portion 23, that is, directly below the piezoelectric element 5, and the felt 8 is fitted into the back chamber 23a.

Next, the operation of the above structure will be explained. Said terminal 7
When an electric signal is input to a, 7b, the piezoelectric element 5
converts this into ultrasonic vibrations. This piezoelectric element 5
The vibrations are transmitted to the case 3a of the ultrasonic transducer 3, and are propagated into the air as ultrasonic waves while matching with the air. This ultrasonic wave is
A predetermined beam shape is formed by the action of , and the wave is transmitted. On the other hand, the sound waves that have been reflected toward the horn 4 are converged by the horn 4, received by the piezoelectric element 5 via the case 3a of the ultrasonic vibrator 3, and converted into electrical signals, and then 6a, 6
b and is output to an external circuit via terminals 7a and 7b. Furthermore, during such wave transmission and reception, acoustic reverberations of the ultrasonic transducer 3 caused by air vibrations are absorbed by the felt 8, and structural reverberations caused by the vibrations of the piezoelectric element 5 are absorbed by the vibration isolation part 23. Ru.

According to such a device, since the taper portion 21, the holding portion 22, and the vibration isolating portion 23 that form the horn 4 are integrated, there is no mismatching between the horn and the holding portion as in the past, and reverberation is reduced. The reduction will definitely be achieved. Moreover, the positional relationship between the horn 4 and the ultrasonic transducer 3 is already uniquely determined before they are attached to the housing 1, and there is no variation caused by the attachment work as in the conventional case. The beam shape can be set accurately, and the directivity can be set stably. Furthermore, since the number of parts is small and assembly is easy, it also leads to a reduction in manufacturing costs.

In the present invention, the shape of the holding portion 22 may be formed according to the shape of the housing 1 into which it is incorporated, and the protrusion 22a does not necessarily need to be provided.

(Effects of the invention) As described above, in the present invention, the holder for holding the ultrasonic vibrator, the horn, and the vibration isolating material are integrally formed from a single material. The positional relationship between the horn and the holder remains constant without variations due to installation work, and this provides stable directivity.Compared to the conventional structure in which the matching between the horn and the holder was unstable,
This has the effect of reducing reverberation more reliably. Furthermore, since the number of parts is small and assembly is easy, it can contribute to reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an ultrasonic transducer according to the present invention, and FIG. 2 is a sectional view of a conventional ultrasonic transducer. DESCRIPTION OF SYMBOLS 1... Housing, 2... Elastic body, 3... Ultrasonic vibrator, 4... Horn, 8... Filter, 21
... Tapered part, 22 ... Holding part (holding body), 23
...Vibration isolator (vibration isolator).

Claims (1)

[Scope of utility model registration request] The ultrasonic transducer includes an ultrasonic transducer, a holder for holding the ultrasonic transducer in a housing, a horn provided in front of the ultrasonic transducer, and a vibration isolating material for suppressing vibrations of the ultrasonic transducer. An ultrasonic transducer characterized in that the holding body, the horn, and the vibration isolating material are integrally formed of the same elastic material.