JPH0218615B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support device for a piezoelectric electromechanical wave device (hereinafter referred to as a mechanical filter) in which a plurality of torsionally vibrating vibrators are mechanically connected in series using a coupler.

Generally, a vibrator that torsionally vibrates has a number of node points equal to the order of its vibration mode. For example, if the total length of the vibrator is l, there is one point at 1/2l in the primary vibration mode, and 1/2l in the secondary vibration mode.
There are two node points at 4l and 3/4l, and three node points at 1/6l, 3/6l and 5/6l in the tertiary vibration mode. In principle, this node point is a point that is not vibrating, so if the vibrator is supported at this point, vibration can be performed most smoothly.

Conventionally, such vibrators have been supported by welding metal wires or metal frames to the node points, but this method requires complicated support devices to avoid spurious vibrations and unnecessary coupling. In addition, external vibrations, shocks, etc. are easily transmitted directly to the vibrator, and the electrical characteristics are likely to be adversely affected.

Furthermore, in order to avoid such drawbacks, methods are used to store mechanical filters directly in boxes made of elastic cushioning material such as rubber, but in this case, vibrations and shocks from the outside are difficult to transmit. It tends to suppress even the necessary vibrations of the child,
This led to a decrease in the Qm of the vibrator, and a certain degree of deterioration in electrical characteristics had to be accepted. In addition, in this method, when the elastic cushioning material box (inner box) is stored in the outer box, both the inner box and the outer box are packed in order to reduce the variation in the pressure applied to the vibrator and make the electrical characteristics uniform. It was necessary to give strict precision to the machining dimensions.

The present invention was made to solve these problems, and it is difficult for external vibrations and shocks to be transmitted, prevents a decrease in the Qm of the vibrator, prevents deterioration of electrical characteristics, and has a structure that prevents the inner box from deteriorating. The present invention provides a mechanical filter having an inner box that reduces variations in the restraint force on the vibrator due to manufacturing errors in the outer box. This will be explained in detail below with reference to the drawings.

First, the mechanical filter supported by the support device of the present invention will be explained with reference to FIGS. 4 and 5. This mechanical filter consists of cylindrical oscillators 6, 6 each having a transducer T made of piezoelectric ceramic at both ends.
The oscillators 6, 6 are placed in parallel on two planes.
Between and on the above-mentioned plane, one or more cylindrical transducers 7 having substantially the same length l are provided with no transducer T, and the transducers 6 at both ends,
6 are arranged in parallel. This mechanical filter is in the third vibration mode, and the node points are 1/6l (point A in Figure 4) as explained above.
3/6l (point B in Figure 4) and 5/6l (point C in Figure 4)
It exists in three locations (point). Each vibrator 7, 7...
are arranged with their corresponding node points A, B, and C aligned substantially on a straight line, maintaining a predetermined interval. Then, for all of these oscillators 6 and 7, the optimum point of the amplitude of the oscillators in the vicinity of the node point A of 1/6l of the oscillator 7 is determined according to the characteristics of this mechanical filter (narrow and wide fractional band). connected by a linear connector 4, and a vibrator 7
They are connected to each other by a reinforcing wire 8 at a node point B of 3/6l. Note that lead wires 5 and 6 are connected to the end faces of the transducer T of the transducers 6, 6 at both ends, and to the end face of the transducer 6 on the opposite side to the transducer T side, for inputting and outputting electrical signals, respectively. 15 are connected.

Such a mechanical filter is assembled in the order shown in FIG. That is, the inner box 9 made of an elastic cushioning material shown in FIG. 1D is placed on the outer box substrate 12 shown in FIG. 1E, and the mechanical filter shown in FIG. is housed with the side where the connector 4 and reinforcing wire 8 are provided facing downward, and the lead wires 5 and 15 are connected to the terminal 13 of the outer box board 12, and then the inner box made of the elastic cushioning material shown in FIG. A box lid 2 is placed on top of the box lid 2, and the outer box 1 shown in FIG. A cross-sectional view of this state is shown in FIG.

The inner box lid 2 shown in B and the inner box 9 shown in D in FIG. 1 will be explained in more detail. The cross section of the inner box lid 2 is the second
As shown in Figure A, there are multiple jetties 2 on the upper side of the outer surface.
-1 is integrally provided, and a plurality of jetties 2-2 are integrally provided on the inner surface at positions to press the filter node points A, B, C of the vibrators 7, 7, . . . of the mechanical filters to be housed. In this embodiment, the number of jetties 2-2 is three. In this figure, the jetty 2-
2 and 2-1 are parallel, but may be provided in intersecting directions.

The cross section of the inner box 9 is shown in FIG. 2C, and one jetty 11 is integrally provided on the inside of the bottom surface. This position corresponds to the node point C of the vibrator 7 of the mechanical filter housed therein, and is also located at the node point C of the oscillator 7 of the mechanical filter housed therein.
It is at the 6l position. The height of this jetty 11 is approximately equal to the thickness of the connector 4. Note that the jetties 2-2 and 11 are formed so as not to contact the vibrators 6, 6 on both sides. Furthermore, this jetty 1
On the inside of the mutually opposing side surfaces parallel to 1,
A jetty 10 is provided in series at the end face of each vibrator 6 and 7 of the mechanical filter. Instead of this jetty 10, a projection may be provided independently at the position of the end face. The reason why there is only one jetty 11 on the bottom is that the connector 4 and reinforcing wire 8 are attached to the lower side of the vibrators 6 and 7.
Since these connectors 4 and reinforcing wires 8 serve as jetties, the vibrators 6 and 7 do not come into direct contact with the bottom surface.

What is shown in FIG. 2B is a side view of the mechanical filter of FIG. 1C as viewed from the direction of the connector 4 and reinforcing wire 8. The inner box 9, the mechanical filter, and the inner box lid 2 are stacked in the order of B and A on C in FIG. 2, and the portion of FIG. It is.

Among the above members, the inner box lid 2 and the inner box 9, which are important components of the present invention, are made of materials that are easy to mold and have appropriate hardness, such as silicone rubber. Just do it. If such an elastic cushioning material of appropriate hardness is used, each vibrator 6 and 7 is supported at a node point that hardly vibrates, and the outside only lightly contacts the jetty 10 or protrusion on the side. of each vibrator 7.
Not enough pressure is applied to reduce Qm.
Also, the connector 4 is in contact with the bottom surface of the inner box 9,
The vibration mode of the connector 4 is longitudinal vibration, which is relatively hard to be restrained, and the contact area is small and the contact is light, so there is little effect on the reduction of Qm.

In addition, the outer jetty 2-1 of the inner box lid 2 is used to reduce variations in the pressing force on the mechanical filter caused by manufacturing errors of the inner box 9, outer box 1, etc. Each member is manufactured with dimensions such that the tip is slightly crushed. For this reason, the influence of dimensional errors of each member is
The amount by which the tip of the filter is crushed changes only slightly, but the pressing force on the mechanical filter is not substantially affected, and the characteristics of the mechanical filter are not affected.

As described above, the mechanical filter support device of the present invention has a simple structure, is easy to assemble, and does not cause deterioration of the characteristics of the mechanical filter, so it is extremely effective in practical use.

[Brief explanation of drawings]

Fig. 1 is an exploded view showing the entire structure including the mechanical filter support device of the present invention, Fig. 2 is an exploded sectional view of the mechanical filter support device of the present invention including the mechanical filter, and Fig. 3 is an exploded view showing the entire structure including the mechanical filter support device of the present invention. 4 is a plan view of the mechanical filter after assembly, and FIG. 5 is a front view thereof. In the figure, 1 is an outer box, 2 is an inner box lid, 4 is a connector, 6 and 7 are vibrators, 8 is a reinforcing wire, 9 is an inner box, 1
0 is a jetty on the side of the inner box, 11 is a jetty on the bottom of the inner box, 1
2 is an outer box board.

Claims (1)

[Scope of Claims] 1 A plurality of cylindrical torsional oscillators are mechanically cascade-connected by a linear coupler with their corresponding vibration node points aligned substantially in a straight line, and the oscillators at both ends This is a support device for a piezoelectric electromechanical filter, which is configured by providing a piezoelectric electromechanical transducer in a piezoelectric electromechanical transducer, and includes an inner box made of an elastic cushioning material and having a recess for accommodating the electromechanical filter; The box includes an inner box lid made of an elastic cushioning material that covers the top surface of the box, and an outer box that covers the outer periphery of the inner box and the inner box lid. A piezoelectric device characterized in that both sides are integrally provided with a jetty corresponding to a node point at a predetermined position among the node points of the plurality of torsional oscillators, and the electromechanical transducer is held between the jetties. Shaped electromechanical filter support device. 2. A plurality of cylindrical torsional oscillators are mechanically connected in cascade by a linear coupler with their corresponding vibration node points aligned almost in a straight line, and piezoelectric electromechanical transducers are connected to the oscillators at both ends. A supporting device for a piezoelectric electromechanical filter, which includes an inner box made of an elastic cushioning material and having a recess for accommodating the electromechanical filter, and an elastic material that covers the upper surface of the inner box. The inner box lid includes an inner box lid made of a cushioning material, and an outer box that covers the outer periphery of the inner box and the inner box lid. Jetties are integrally provided corresponding to nodes at predetermined positions among the node points of the torsional oscillator, and these jetties sandwich the electromechanical converter, and a set of opposing recesses in the inner box A support device for a piezoelectric electromechanical filter, characterized in that a side wall surface is provided with partial contact means for positioning the electromechanical filter by partially contacting an end surface of the torsional vibrator. 3. The support device according to claim 2, wherein the partial contact means comprises a jetty provided integrally with the inner wall surface of the inner box and parallel to the bottom surface of the recess. 4. The support device according to claim 2, wherein the partial contact means comprises a projection integrally provided on the inner wall surface of the inner box at a position facing the end surface of the torsional vibrator. 5 A plurality of cylindrical torsional oscillators are mechanically connected in cascade by a linear coupler with their corresponding vibration node points aligned almost in a straight line, and the oscillators at both ends have piezoelectric electromechanical transducers. A supporting device for a piezoelectric electromechanical filter, which includes an inner box made of an elastic cushioning material and having a recess for accommodating the electromechanical filter, and an elastic material that covers the upper surface of the inner box. The inner box lid includes an inner box lid made of a cushioning material, and an outer box that covers the outer periphery of the inner box and the inner box lid. Projections are integrally provided corresponding to node points at predetermined positions among the node points of the torsional oscillator, and the electromechanical converter is held between the jetties, and a tip portion is attached to the upper surface of the inner box lid. A support device for a piezoelectric electromechanical filter, characterized in that a jetty having a height that is pressed by the inner surface of the outer box is integrally provided.