JPH055758Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The invention consists of an electrostrictive element sandwiched between a pair of metal blocks consisting of a front plate and a backing plate, and equipped with an ultrasonic irradiation surface that operates over a long and narrow area. The present invention relates to a Languevin type resonator.

``Prior art'' One disk-shaped electrostrictive porcelain plate is connected directly or a plurality of plates are connected mechanically in series and electrically in parallel via a terminal plate to form an electrostrictive element, and both main surfaces thereof A Languevin type vibrator, which is made by stacking and fixing a pair of metal blocks on top of each other, is widely used in various types of equipment that utilize ultrasonic vibration.

``Problem that the invention attempts to solve'' The Lange-Huvin type transducer mentioned above has a circular front plate that irradiates ultrasonic waves, so the shape of the irradiated surface is square.
Particularly in the case of a rectangular shape, it is difficult to apply uniform ultrasonic vibration to the entire surface.

"Means for solving the problem" An electrostrictive element is sandwiched between the electrostrictive elements, the total height is an integral multiple of λ/2, and the lateral dimension is square as shown in the figure. A front plate and a backing plate are laminated, and a notch is bored forward from a side surface of the electrostrictive element in the horizontal axis direction to suppress combined vibration in the horizontal axis direction of ultrasonic vibrations to be radiated forward from the front plate.

"Function" By making the front plate and the backing plate longer in the lateral direction and by providing notches from the side to the front of the vibrator, the coupled vibration in the lateral axis direction is suppressed, and the irradiated surface is rectangular, especially rectangular. Gives uniform ultrasonic vibration to the object.

``Example'' (1) Figure 1 shows the basic aspect of the Langillevin type vibrator of the present invention. In the figure, 1 is made of a lead zirconate titanate compound, and both main surfaces are coated with silver or the like. A pair of plate-shaped piezoelectric elements 11, 1 formed with metallized surfaces (not shown) and polarized.
1 are connected mechanically in series and electrically in parallel via a terminal piece 12 which is made of a thin metal plate and has a tongue-like conductive part 12a protruding from the edge to be connected to the lead wire L. A substantially square electrostrictive element is connected with the terminal piece 12 side as the positive electrode side, and 2 is one metal block that serves as a front plate that comes into contact with one main surface of the electrostrictive element and radiates the ultrasonic vibration forward. It has a long columnar shape with a width approximately equal to the opposite side of the electrostrictive element 2 and a lateral dimension that is three times or more as large as the opposite side. 3 designates the other metal block called a backing plate which is laminated with the electrostrictive element 1 sandwiched therebetween, and in the center in the horizontal axis direction, there is a metal block in the short axis direction perpendicular to the horizontal axis that presses the electrostrictive element 2 onto the front plate 1. A notched concave seating surface 31 is formed, and the total height of the front plate 2 and back plate 3, which are laminated with the electrostrictive element 1 sandwiched between them, is set to an integral multiple of λ/2, and the side surface of the electrostrictive element 1 in the horizontal axis direction is set to an integral multiple of λ/2. Cuts 4, 4 in the short axis direction are provided forwardly from the front plate 2 to suppress the combined vibration in the horizontal axis direction of the ultrasonic vibrations radiated forward from the front plate 2.

(2) Figure 2 shows multiple sets made using a long column-shaped front plate 2 and a backing plate 3 whose lateral dimensions are 5 times larger.
Here, three sets of electrostrictive elements 1, 1, 1 are connected to the front plate 2.
A mode is shown in which backing plates 3 having concave seating surfaces 31, 31, 31 cut out in the minor axis direction are laminated and fixed so as to be pressed together with intervals 5, 5, and in this case as well, the total height of the laminate is is set to an integral multiple of λ/2, and cuts in the short axis direction are made to suppress the combined vibration in the horizontal axis direction of the ultrasonic vibrations irradiated forward from the front plate 2 on the sides of the electrostrictive elements 1, 1, 1. 4, 4, 4,
4 will be provided.

(3) In Figure 3, the front 2nd
A front plate with the same lateral dimensions as in the example is used, but there are multiple sets of electrostrictive elements, here 1, 1...1
For the 5 pairs, the intervals 5, 5... of the same example were not provided, and only cuts 4, 4... 4 were provided at four locations in the short axis direction to suppress the combined vibration of the ultrasonic vibration in the horizontal axis direction. A backing plate 3 is laminated to be arranged in parallel on the front plate 2, to sandwich the electrostrictive element in correspondence with the front plate, and to have a total height set to an integral multiple of λ/2.

In addition, in each example, each cut 4 in the short axis direction
The holes extend from the front plate 2 to the backing plate 3 along the side surface of the electrostrictive element 1 to form the through holes shown in each figure, but each cut 4 suppresses lateral coupled vibration on the front plate 2 side. , since the backing plate 3 side forms a concave seating surface 31 for seating the electrostrictive element 1 and insulates between the two electrostrictive elements, the inner wall surface of the notch 4 on the electrostrictive element side is the same. Although it is desirable to form a surface,
The other inner wall does not necessarily have to be on the same plane;
It is also possible to use stepped seating surfaces with different width dimensions.

Furthermore, in each example, the electrostrictive element, the front plate, and the backing plate were bonded together using an adhesive.
When notches 4, 4 and gaps 5, 5 are provided between the electrostrictive elements 1 and 1 as shown in the figure, the small hole 3a of the backing plate 3 is inserted through the gap 5 as shown in FIG. A tightening bolt 6 may be provided protruding from the front plate 2 and screwed into a nut 6a also seated on the backing plate 3 to tighten the electrostrictive element, as shown in FIG. A center hole 1a is formed in the element, protruding from the front plate 2,
A tightening bolt 6 that is insulated from the electrostrictive element by an insulating tube 13 made of rubber or the like and inserted through the center hole 1a of the electrostrictive element and the small hole 3a of the backing plate communicating with the center hole; The electrostrictive element 1 can also be fastened by a nut 6a that is screwed together and seated on the backing plate, and the electrostrictive element 1 is held between the front plate 2 and the backing plate 3. The means are not specified.

"Effects of the invention" As described above, the Languevent type transducer of the present invention has the front plate lengthened in the lateral direction, and has notches from the side of the ultrasonic transducer to suppress coupled vibration in the lateral axis direction. Uniform ultrasonic vibration is applied to a square, especially rectangular, irradiated surface, but the above-mentioned lateral length must be set to three times or more of one side of the square electrostrictive element to achieve a satisfactory effect. is not obtained. However, in the conventional Languevin type vibrator in which the cross-sectional shapes of the pair of metal blocks and the electrostrictive element were equal, the acoustic load on the front plate was too light and the loss was large. The effect can be increased by increasing the ratio of the front plate to the irradiated surface, and the one shown in Figure 3 greatly increases the output, and the electrostrictive element is divided into multiple parts. Since each electrostrictive element constituting each electrostrictive element is miniaturized to eliminate bending and distortion that occur during molding and firing, efficiency can be improved from this point of view as well, and output can be increased.

[Brief explanation of the drawing]

Fig. 1 shows the basic aspect of the Languevin type vibrator according to the present invention, Fig. A is a top view, Fig. B is a longitudinal cross-sectional view taken along the line A-I of Fig. A, and Fig. 2 shows a plurality of electrostrictive elements. Figure A is a top view, Figure B is a top view, and Figure B is a top view.
The figure is a longitudinal cross-sectional view taken along the Ro-Ro line in figure A, and FIG. 3 similarly shows another embodiment using a plurality of electrostrictive elements.
Figure A is a top view, Figure B is a vertical cross-sectional view taken along the line H - H in Figure A, and Figures 4 and 5 show the front plate and backing plate being tightened with bolts while holding the electrostrictive element in between. FIG. 2 is an enlarged vertical cross-sectional view of a main part of a worn state. 1... Electrostrictive element, 2... Front plate, 3... Backing plate, 4... Notch.

Claims (1)

[Scope of utility model registration request] A square electrostrictive element is sandwiched between a long front plate and a backing plate, the total height of which is an integral multiple of λ/2 and the lateral dimension of which is at least three times the side of the electrostrictive element. 1. A Languevent type vibrator, characterized in that a notch is carved forward from a side surface of the electrostrictive element to suppress lateral coupled vibration of ultrasonic vibration to be applied to the electrostrictive element.