JPS59175299A - Ultrasonic wave transceiver - Google Patents

Abstract

PURPOSE:To improve the amplitude of vibration of a diaphragm and also to prevent the vibration from the diaphragm from being delivered to a side plate by bending the ridge circumference part of the diaphragm and also forming a boundary part with the side plate as a pin corner. CONSTITUTION:The ridge circumferential part of the diaphragm 1a is curved and constitutes a case 1 together with a cylindrical side plate 1b having a diameter t2 smaller than the maximum diameter t1 of the diaphragm 1a. Further, the boundary 6 between the diaphragm 1a and the side plate 1b is formed as a pin corner. A piezoelectric element 2 is fitted in the inside face of the diaphragm 1a, a prescribed electric signal is impressed to the piezoelectric element 2 via terminals 4 and 4' and an electric signal is led out from the piezoelectric signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic transducer that converts electrical signals into ultrasonic waves or ultrasonic waves into electrical signals.

A conventional ultrasonic transducer will be explained with reference to FIGS. 1 and 2. In Fig. 1 and Fig. 2), l is a case in which one side is open end, with a diaphragm 1a and a side plate 1b.
The piezoelectric element 2 is bonded to the inner wall of the diaphragm 1a. 3 is an insulating terminal plate, 4.4' is a terminal, and 5.5' is a lead wire. The terminal 4 is electrically connected to an electrode attached to the surface of the piezoelectric element 2 by baking or other methods through a lead wire 5, and the terminal 4' is a ground terminal, and electrically conductive to the case 1 through a lead wire 5'. ing.

Now, when an electric signal with a predetermined resonant frequency is applied between the terminals 4 and 4', the piezoelectric element 2 operates as an electromechanical transducer, so the diaphragm 1a resonates, and the intensity changes according to the applied voltage. Generates ultrasonic waves. Conversely, when an ultrasonic wave having the resonant frequency is applied to the diaphragm 1a, an electric signal having the same frequency and a magnitude corresponding to the sound pressure is generated between the terminals 4 and 4'.

Here, as shown in FIG. 1, the diaphragm 1a and side plate 1 of case l
In the shape where the thickness of the side plate 1b is the same, the vibration is caused by the side plate 1b.
, and the actual vibration surface becomes larger. If this is fixed with side support, the sensitivity tends to decrease and vibration characteristics such as resonance frequency become unstable.

Figure 2 shows an improvement made to compensate for the above-mentioned drawbacks. By making the thickness of the side plate 1b sufficiently thicker than that of the diaphragm 1a, the interference of the vibration of the diaphragm 1a does not affect the side plate 1b. This is how it was done.

However, this has the disadvantage that the vibration amplitude becomes small and the output sound pressure or reception sensitivity decreases.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an ultrasonic transducer that does not transmit the vibration of the diaphragm to the side plate and does not reduce the vibration amplitude of the diaphragm. Our goal is to provide the following.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 3 is a sectional view showing one embodiment of the present invention, and parts having the same reference numerals as those in FIGS. 1 and 2 indicate the same or equivalent parts. As shown in FIG. 3, the periphery of the diaphragm 1a is curved, and forms the case 1 together with a cylindrical side plate lb having a diameter t2 smaller than the maximum diameter t1 of the diaphragm 1a. Further, the boundary portion 6 between the diaphragm 1a and the side plate 1b has a bin angle.

As exemplified in this embodiment, the present invention curves the edge of the diaphragm, so it is possible to reduce the mechanical impedance of the vibrating part and improve the vibration amplitude of the diaphragm. Since the boundary between the diaphragm and the side plate is configured to form a bin angle, vibrations from the diaphragm are less likely to be transmitted to the side plate.This prevents a decrease in sensitivity when the side plate is fixed, and stabilizes vibration characteristics such as resonance frequency. This has the excellent effect of making it possible to achieve

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of conventional ultrasonic transducers;
The figure is a sectional view of an ultrasonic transducer showing an embodiment of the present invention. ■...Case, la...Diaphragm, 1b...Side plate,
2... Piezoelectric element, 6... Boundary part. Representative Patent Attorney Takashi Okabe No. 11 No. 3 1g

Claims (1)

[Claims] In an ultrasonic transducer in which a piezoelectric element is arranged on the inner wall of the diaphragm in a case configured with a diaphragm and a side plate, the periphery of the diaphragm is curved, and the boundary with the side plate is curved. Ultrasonic transducer with pin angle.