JPH0138987Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a support device for a tuning fork type filter used in the telecommunications industry, particularly in fields such as answering machines and public address radios.

Tuning fork type filters have excellent electrical characteristics and high reliability, and are also inexpensive, so in recent years they have been used mainly in the telecommunications industry, for TV audio multiplex broadcasting, as well as for answering machines, public information radio, etc. It is widely used in equipment.

With such widespread use, the current situation is that there is a growing demand for a tuning fork filter that is small, lightweight, and inexpensive.

In order to meet this demand, a number of ideas have been proposed to make tuning fork filters smaller and lighter while compensating for their disadvantage of being susceptible to external vibrations or external shocks.

For example, as shown in Figs. 1 and 2, a composite vibrator is composed of a U-shaped tuning fork vibrator a and a pair of piezoelectric ceramic plates b attached to its opposing outer surfaces, and the tuning fork vibrates. A support member c bent in the opposite direction to the longitudinal direction of the tuning fork vibrator a is attached to the U-shaped bottom of the child a, and a square hole is formed in the square member to support an elastic damper d. It was intended to be fitted and supported by c. Based on such a composite oscillator
To attach the damper to the top, as shown in FIG.
The structure was such that external vibrations and shocks were not directly transmitted to the composite oscillator.

The connection to the ground terminal g was made using an insulated lead wire h.

However, in the conventional method for supporting a tuning fork type filter as described above, the supporting member c is bent in the opposite direction in the longitudinal direction of the tuning fork vibrator a, and furthermore, the supporting member c is bent to the opposite side in the longitudinal direction of the tuning fork vibrator a. g and lead wire h
The composite oscillator is grounded, and this structure has been a major obstacle to miniaturizing tuning fork filters.

Furthermore, in the conventional tuning fork type filter, the input/output terminals i and k to the filter were arranged on both sides of the tuning fork vibrator a as shown in FIG. 2, so that the lateral dimension could not be reduced.

Furthermore, in terms of economy, manufacturing of the support member c and the damper d requires special molds, and costs such as soldering man-hours for connecting the ground terminal g and the support member c with the lead wire h, etc. It was also a disadvantageous structure.

This invention was devised in view of these problems, and its purpose is to provide a tuning fork type filter support device that has excellent electrical characteristics and reliability, is small, lightweight, and economically advantageous. There it is.

Preferred embodiments of the tuning fork type filter support device according to this invention will be described below with reference to the drawings.

FIG. 3 is an exploded perspective view showing the main parts of the tuning fork type filter support part according to this invention, and FIG. 4 is a perspective view showing the assembled state of the tuning fork type filter.

In this example, the constant elastic metal plate is
A composite vibrator 3 is constituted by a tuning fork vibrator 1 formed in a character shape and a pair of piezoelectric ceramic plates 2 made of lead zirconate titanate attached to opposing outer surfaces of the tuning fork vibrator 1. A support member 4 having a generally triangular tip with a wide width is provided on the U-shaped bottom of the tuning fork vibrator 1, and integrally with the tuning fork vibrator 1 in a direction perpendicular to the longitudinal direction of the tuning fork vibrator 1. A substantially elliptical through hole 5 is bored in the substantially triangular center of the tip. On the other hand, the ground terminal 6 of the tuning fork type filter has its tip formed into a wide rectangular shape and is connected to a receiving part 7.
The receiving part 7 is fitted into the substantially elliptical through hole 5 of the support member 4 in the substantially central part thereof, and prevents the composite vibrator 3 from coming off from the base support part described later. A convex, substantially elliptical protrusion 8 is formed to keep the composite vibrator 3 in a good grounding state and to prevent the composite vibrator 3 from swinging.

The grounding terminal 6 is bent into a crank shape in the middle in order to maintain compatibility with the terminal position of a conventional tuning fork filter and to ensure the longitudinal dimension of the tuning fork filter as effectively as possible while reducing its size. It has a unique structure.

Next, a case where the composite vibrator 3 is installed on the base 9 will be explained. A accommodating portion 10 is provided at one end of the base 9 to accommodate the support member 4, the ground terminal 6, etc., which are integrally formed with the base 9.
The through hole 5 of the support member 4 and the protrusion 8 of the receiving pad 7 are inserted into the accommodation portion 10 in a fitted state, and are held between the receiving pad 7 and a shock absorbing damper 11 having a predetermined shape. The composite vibrator 3 is firmly held on the base 9. With this configuration, externally applied vibrations and
The damper 11 acts effectively against impact,
Vibrations and shocks will not be directly transmitted to the composite vibrator.

Further, in this embodiment, the distal end of the support member 4 is formed into a wide substantially triangular shape, and the accommodating portion 10
However, the shape of the support part 4 is not limited to this, and the same effect can be obtained by making it square, for example, and adding a taper to the tip. Further, an input/output terminal 12 is located on the line where the substantially central portion of the base 9, that is, the substantially central portion of the U-shape of the tuning fork vibrator 1 is located when the composite vibrator 3 is placed on the base 9. , 13 penetrate through the base 9, are installed substantially in line with the ground terminal 6 at a predetermined interval, and are connected to the pair of piezoelectric ceramic plates 2 by soldering or the like using lead wires 14 each made of a covered electric wire. .
By arranging the input/output terminals in this manner, it is also possible to reduce the lateral dimension.

As described above, the tuning fork type filter support device according to this invention has a tuning fork vibrator formed by forming a constant elastic metal plate into an elongated U-shape, and a lead zirconate titanate etc. on the opposing outer surfaces of the tuning fork vibrator. In a tuning fork type filter in which a pair of piezoelectric ceramic plates made of A through hole is formed in the approximate center of the support member, the tip of the ground terminal of the tuning fork filter is made wide to serve as a receiving part, and a convex projection is provided in the approximate center of the receiving part. The through hole is fitted into the protrusion, and the support member is held between the receiving part and a damper formed in a predetermined shape to support the composite vibrator. The damper effectively absorbs external vibrations and shocks, which are the weak points of
While maintaining earthquake resistance and impact resistance similar to conventional support devices of this type, the contact between the composite vibrator and the ground terminal is firmly held between the receiving part and the damper, so it is held well and Unlike tuning fork filters, there is no need to connect with lead wires, and detachment of the composite vibrator can be effectively dealt with by fitting the through holes and protrusions, making it compact and excellent in electrical characteristics and reliability. A lightweight and inexpensive tuning fork type filter support device can be provided, and its technical and economical effects are significant.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a composite vibrator of a conventional tuning fork filter, and FIG. 2 is an assembled perspective view of the conventional tuning fork filter. FIG. 3 is an exploded perspective view showing the composite vibrator of the tuning fork type filter and its support device according to this invention, and FIG. 4 is an assembled perspective view of this tuning fork type filter. In FIGS. 3 and 4, 1...a tuning fork vibrator,
2...Piezoelectric ceramic plate, 3...Composite vibrator, 4...Supporting member, 6...Grounding terminal, 7...Receiving part, 9
...Base, 10...Accommodation section, 11...Damper.

Claims (1)

[Scope of utility model registration request] A constant elastic metal plate is formed into an elongated U-shape to form a tuning fork vibrator, and a pair of piezoelectric ceramic plates made of lead zirconate titanate are attached to the opposing outer surfaces of the tuning fork vibrator to form a composite vibrator. In the tuning fork type filter, a support member is integrally provided with the tuning fork vibrator and is provided on the U-shaped bottom of the tuning fork vibrator in a direction perpendicular to the longitudinal direction of the tuning fork vibrator, and a through hole is formed approximately in the center of the support member. The tip of the ground terminal of the tuning fork type filter is formed wide to serve as a receiving part, a convex projection is formed approximately in the center of the receiving part, and the through hole is fitted into the projection. A tuning fork type filter support device characterized in that the supporting member is held between the receiving part and a damper formed in a predetermined shape to support the composite vibrator.