JPH04204017A - Ultrasonic transducer - Google Patents

Abstract

PURPOSE:To prevent delamination of an adhesive by absorbing the extension in the radial direction due to the temperature change by the groove part forming a groove part at an electrode of one end of an ultrasonic transducer or the adhesive face of a radiation plate, and making the groove part to be a non- adhesive part to the radiation plate. CONSTITUTION:A negative electrode 4 is deposited at one end face and a peripheral side face of a vibrator 2. A lattice-like groove part 41 is formed at the side of the adhesive face of a radiation plate to be used as the negative electrode 4. A non-adhesive member 7 is filled in the groove part 41. In this constitution, the extension in the radial direction due to the temperature change in the periphery of the adhesive part is absorbed by the groove part 41. As a result, the thermal distortion of the adhesive face between the radiation plate and the electrode is reduced, and an adhesive 5 is prevented from being separated by thermal stress. Moreover, since the member 7 is filled in the part 41, the vibration of the vibrator 2 can be positively transmitted to the radiation plate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultrasonic transducer used in ultrasonic flow rate meters of fluids, flowmeters, and the like.

[Conventional technology]

For example, as shown in FIG. 5, a conventional ultrasonic transducer of this type has a positive electrode 3 formed on one end surface of a ceramic vibrator 2, and a negative electrode 4 formed on the other end surface. is,
The negative electrode 4 includes, for example, a radiation plate 6 made of Teflon with a Franz
is fixed by adhesive 5. Further, an insulating member 11 is provided on the metal housing song 1, and a plug 12 is fitted and fixed to the insulating member 11. Then, the positive electrode 3 of the vibrator 2 is connected to the plug 12 via the metal conductive plate 9 and the compression coil spring 1o, the negative electrode 4 is connected to the housing song 1 via the coil spring 8, and the radiation plate 6 is connected to the A presser ring 14 was fixed to the housing l through a ring 13, and the vibrator 2 was housed in the housing l in a sealed state.

[Invention or problem to be solved]

However, in this conventional ultrasonic transducer, if the negative electrode 4 side of the adhesive 5 to which the radiation plate 6 is adhered is exposed to a large change in ambient temperature, the radiation plate 6, the adhesive 5, and the electrode 4 Thermal stress caused by the difference in thermal expansion coefficients could cause the film to peel off.

The present invention aims to provide an ultrasonic transducer that solves these conventional problems.

[Means for Solving the Problems] The present invention provides an ultrasonic transducer in which electrodes are formed on both end faces of a vibrator and a radiation plate is adhesively fixed to the one end side electrode. This ultrasonic transducer is characterized in that a groove is formed on the adhesive surface side of the ultrasonic transducer, and the groove is used as a non-bonded part with the radiation plate or the electrode.

[For production]

Since a groove is formed on the adhesive surface of the electrode on one end or the radiation plate, the expansion in the radial direction when there is a temperature change around the adhesive part is absorbed by the groove, and as a result, the adhesive surface between the radiation plate and the electrode is Thermal strain is reduced and adhesive delamination is prevented.

First, since the groove is filled with a non-adhesive member, the vibration of the vibrator is reliably transmitted to the radiation plate via the non-adhesive member. [Embodiment] An embodiment of the present invention will be explained based on FIGS. 1 and 2. The basic structure of the ultrasonic transducer is the same as the conventional example shown in FIG. A negative electrode 4 has a plurality of grooves formed in a lattice pattern on one end surface, a negative electrode 4 is deposited on the end surface and the circumferential surface, and a lattice-shaped groove portion 41 is formed on the side to which the radiation plate is bonded;
The groove portion 41 is filled with a non-adhesive member 7 (eg, Teflon).

Further, FIG. 3 shows a modified example of the groove portion of the negative electrode 4 of the vibrator 2,
A plurality of concentric grooves are formed on one end surface of the vibrator 2, a negative electrode 4 is deposited on the end surface and the circumferential surface, and a concentric groove portion 41 is formed on the adhesive surface side.

Furthermore, FIG. 4 also shows a modification example of the groove portion of the negative electrode 4 of the vibrator 2, in which a plurality of grooves are formed in parallel on one end surface of the vibrator 2, and the negative electrode 4 is deposited and bonded on the end surface and the circumferential surface. Parallel grooves 41 are formed on the surface side.

With such a configuration, the radial elongation due to temperature changes around the adhesive portion is absorbed by the groove portion 41, and as a result, thermal strain on the adhesive surface between the radiation plate and the electrode is reduced. Therefore, the ambient temperature changes are large (as a result, peeling of the adhesive 5 due to thermal stress is prevented).

Further, the groove portion 4. Since the non-adhesive member 7 is filled in,
The vibrations of the vibrator 2 are reliably transmitted to the radiation plate 6 via the non-adhesive member 7.

In the above embodiments, a groove is formed in the electrode at one end of the vibrator, but the groove may be provided in the radiation plate.

〔Effect of the invention〕

In the present invention, a groove is formed on the electrode at one end of the vibrator or on the adhesive surface of the radiation plate, and the groove is made into a non-adhesion part with the radiation plate, so that the expansion in the radial direction due to temperature changes is absorbed by the groove. This reduces thermal strain on the adhesive surface, preventing adhesive peeling due to thermal stress.

Furthermore, since the groove is filled with a non-adhesive member, the vibration of the vibrator is reliably transmitted to the radiation plate via the non-adhesive member.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 (1al) is a sectional view of a vibrator and an electrode, Fig. 2 (1)l is a left side view of the same, and Figs. 3 and 4 are negative views of the vibrator. Modified example diagram of the groove part of the electrode, No. 5
The figure is a sectional view showing a conventional example. 1... Housing, 2. Vibrator, 3 Positive electrode, 4...
- Negative electrode, 5... Adhesive, 6... Radiation plate, 7 Non-adhesive member, 8... Coil wing, 9 Metal conductive plate, 1°.
...Compression coil spring, 11...Insulating member, 12...
Plug, 13.0 ring, 14. Holder ring. Patent Applicant Kaiyo Denki Co., Ltd. Agent Patent Attorney Yakushi Minoru Patent Attorney Yori 1) Takajibe Agent Patent Attorney Tadashi Takagi Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) In an ultrasonic transducer in which electrodes are formed on both end surfaces of a vibrator and a radiation plate is adhesively fixed to the one end electrode, a groove is formed on the adhesive surface of the one end electrode or the radiation plate. An ultrasonic transducer characterized in that the groove portion is a non-bonded portion with a radiation plate or an electrode. (2) The ultrasonic transducer according to claim 1, wherein the groove portion is configured in a grid shape, concentric circle shape, or parallel shape. (3) The ultrasonic transducer according to claim 1, wherein the groove is filled with a non-adhesive member.