JPH0413919Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-frequency vibrator using a plurality of Languevin type vibrators or bolted Languevin type vibrators.

[Prior Art] In recent years, most fishing boats have been equipped with fish finders to improve their catch. A device that can generate ultrasonic waves of multiple frequencies is used.

[Problems that the invention aims to solve] However, in any case, the frequencies used are almost the same depending on the species of fish, so in fish farms where many fishing boats operate, interference can cause fish schools to become distorted. There is also the problem that the detector cannot fully demonstrate its original performance.

To solve these problems, devices equipped with multiple transducers with different frequencies or a single transducer containing multiple vibrators with different frequencies are used. This method has the disadvantage that the transducer becomes larger and the price becomes significantly higher.

In addition, one method is to use vibrations in the thickness direction, radial direction, and harmonics of these vibrations of a disc type piezoelectric vibrator, or to use vibrations in the thickness direction, radial direction, and harmonics of these vibrations of a ring type piezoelectric vibrator. A transducer that uses vibrations in the width direction and its harmonics is also known.

However, harmonic vibrations of piezoelectric vibrators can only effectively generate either even-order harmonics or odd-order harmonics depending on the vibration mode, and due to impedance, even with the method described above, one vibration There were at most three or four frequencies that could be used effectively by the child.

An object of the present invention is to provide a multi-frequency transducer that can arbitrarily input and output ultrasonic waves of a large number of different frequencies.

[Means for Solving the Problems] In order to achieve the above object, the present invention sandwiches a pair of piezoelectric elements each having an electrode from which a terminal is drawn out between three or more metal rods of the same length. It is a Languevin type vibrator in which the piezoelectric vibrator is either glued or screwed by passing a bolt through the piezoelectric element and the metal rod, and outputs an unspecified number of frequencies by electrically driving the piezoelectric vibrator in series or parallel. A multi-frequency resonator characterized by:

[Operation] According to the present invention, ultrasonic waves of a large number of different frequencies can be output by electrically driving one or more Languevin type vibrators or bolted Languevin type vibrators in series or parallel. I can do it.

[Embodiment] Referring to FIG. 1, in the multi-frequency vibrator according to the embodiment of the present invention, 1 and 2 are a pair of piezoelectric elements having electrodes 3 and 4 from which terminals 5 and 6 are drawn, respectively. Further, 7, 8, and 9 are metal rods of the same length provided on both sides of the pair of piezoelectric elements 1 and 2, respectively, and are connected by bolts passing through the piezoelectric elements 1 and 2.
These metal rods 7, 8, and 9 are screwed together.

The operation of the multi-frequency vibrator of this embodiment configured as described above will be explained. First, terminal 5 and metal rod 7
When a variable frequency power source is connected between A and A to drive the pair of piezoelectric elements 1, as shown in FIG.
(34.3KHz, 300Ω), B (73.68KHz, 22Ω), C
(88.83KHz, 427Ω), D (106.0KHz, 250Ω) E
(132.5KHz, 680Ω), F (155.88KHz, 480Ω), G
(167.54KHz, 154Ω)H (175.42KHz, 225Ω), J
Resonance is obtained at (198.97KHz, 580Ω) and the impedance is low.

Next, in the multi-frequency oscillator shown in Fig. 1,
Connect terminals 5 and 6 to one terminal of a variable frequency power supply,
When the other terminal is connected to any of the metal rods 7, 8, and 9, the piezoelectric elements 1 and 2 are driven in parallel, and as shown in FIG.
(87.88KHz, 71.5Ω), C (104.92KHz, 520Ω), D
(110.787KHz, 24.8Ω), E (154.7KHz, 78Ω), F
(171.256KHz, 37Ω), G (198.04KHz, 37Ω), H
(206.33KHz, 210Ω), resonance is obtained and the impedance is low.

Next, terminal 5 of the multi-frequency vibrator shown in FIG.
6 is connected to a variable frequency power supply, A (70.0KHz, 90Ω), B (111.9KHz,
640Ω), C (132.1KHz, 770Ω), but the frequency of A, which has a lower impedance, can be used.

In this way, by driving one or all of the pair of piezoelectric elements 1, 2 in series or in parallel, a large number of different frequencies can be used.

Referring to FIG. 5, in a multi-frequency vibrator according to another embodiment of the present invention, 1 and 2 are a pair of piezoelectric elements 7 and 8, each having electrodes 3 and 4 between which lead out terminals 5 and 6, respectively. Reference numeral 9 denotes metal rods of the same length provided on both sides of the pair of piezoelectric elements 1 and 2, and their configuration is the same as that of the multi-frequency vibrator of the embodiment shown in FIG. 1 above, so a description thereof will be omitted. but,
In this embodiment, the electrode 11 from which the terminal 12 is drawn out is
A pair of piezoelectric elements 10 and a metal rod 13 are provided.

In the multi-frequency vibrator of this embodiment configured in this way, the terminal 5 and the metal rods 7, 8, 9, 13
When a variable frequency power supply is connected between either of them and drives only the pair of piezoelectric elements 1, A (18.77KHz, 482Ω) and B (36.10KHz,
209Ω), resonance is obtained at C (49.51KHz, 133Ω), and the impedance becomes low. Note that in this case, only the pair of piezoelectric elements 10 may be driven.

Next, in the multi-frequency oscillator shown in Fig. 5,
A variable frequency vibration source is connected between the terminal 6 and one of the metal rods 7, 8, 9, 13, and the pair of piezoelectric elements 2
When only A is driven, as shown in FIG.
(18.37KHz, 250Ω), B (55.05KHz, 163Ω), C
Resonance is obtained at (67.91KHz, 317Ω) and the impedance is low.

Furthermore, in the multi-frequency oscillator shown in Fig. 5,
Connect the terminals 5, 6 or 12, 6 to one end of the variable frequency power supply, and connect the other end to the metal rods 7, 8, 9, 13.
When connected to one of the piezoelectric elements 1, 2 or 2, 10 in parallel, A (18.15KHz, 113Ω), B (30.06KHz,
270Ω), resonance is obtained and the impedance becomes low.

Furthermore, in the multi-frequency oscillator shown in Fig. 5,
Connect terminals 5 and 12 to one end of a variable frequency power supply,
When the other end is connected to one of the metal rods 7, 8, 9, and 13 and the paired piezoelectric elements 1 and 10 are driven in parallel, A (18.52KHz, 157Ω), B
Resonance is obtained at (53.79KHz, 51Ω) and the impedance is low.

Next, in the multi-frequency oscillator shown in Fig. 5,
When terminals 5, 6, and 12 are connected to one end of a variable frequency power source and the other end is connected to one of metal rods 7, 8, 9, and 13, and the pair of piezoelectric elements 1, 2, and 10 are driven in parallel, the As shown in Figure 10, A (17.93KHz,
69Ω), resonance is obtained and the impedance is low.

In this way, in the multi-frequency vibrator of this embodiment, any one of the paired piezoelectric elements 1, 2, 10,
Alternatively, by driving two or even three in parallel, ultrasonic waves of different frequencies can be input and output.

In addition, in the embodiments shown in FIGS. 1 and 5, a bolted lunge-type vibrator was used in which the pair of piezoelectric elements 1, 2, and 10 with electrodes sandwiched therebetween were screwed together so as to be fixed from both sides. A similar effect can be obtained by connecting a plurality of Languevin type vibrators in which metal rods of the same length are bonded to both sides of one piezoelectric element. Further, in the above embodiments, an example in which two or three vibrators are used has been described, but the same implementation is possible even if four or more vibrators are used.

[Effects of the invention] As explained above, according to the present invention, a Languevin type vibrator in which metal bars are provided on both sides of one piezoelectric element or a single piezoelectric element in which an electrode from which a terminal is drawn out is provided.
A plurality of bolted Languevin vibrators in which pairs of piezoelectric elements are screwed together with metal rods are mechanically arranged in series, and one or more Languevin vibrators or bolted Languevin vibrators are connected in series or in parallel. Since the transducer is driven, there is an advantage that ultrasonic waves of a plurality of different frequencies can be input and output using one transducer.

[Brief explanation of the drawing]

FIG. 1 is a side view of a multi-frequency vibrator according to an embodiment of the present invention, FIGS. 2 to 4 are explanatory diagrams of the operation of FIG. 1, and FIG. 5 is a multi-frequency vibrator according to another embodiment of the present invention. The side view of FIG. 6 to FIG. 10 are explanatory diagrams of the operation of FIG. 1, 2, 10...Pair of piezoelectric elements, 3, 4, 11
... Electrode, 5, 6, 12 ... Terminal, 7, 8, 9,
13...Metal rod.

Claims (1)

[Scope of utility model registration request] A lunge van in which a pair of piezoelectric elements each having an electrode for drawing out a terminal is sandwiched and glued between three or more metal rods of the same length, or a bolt is passed through the piezoelectric element and the metal rod and screwed together. 1. A multi-frequency vibrator, which is a type vibrator, and is characterized in that the piezoelectric vibrator is electrically driven in series or parallel to output an unspecified number of frequencies.