JPS6012339Y2 - piezoelectric tuning fork - Google Patents

Description

[Detailed Description of the Invention] The object of the present invention is to significantly reduce noise output due to external shocks and vibrations in a piezoelectric tuning fork having a structure in which a tuning fork is directly fixed to a ground terminal embedded in a terminal board.

Hereinafter, a conventional piezoelectric tuning fork will be shown together with FIG.

Reference numeral 1 denotes a tuning fork made of metal, and piezoelectric ceramics 3, 3' are bonded to vibrating pieces 2, 2' near the vibration nodes.

Further, a ground terminal 5 is fixed to the connecting portion 4 of the vibrating pieces 2, 2' by welding or the like, and this ground terminal 5 is implanted in a terminal plate 6.

Input and output terminals 7 and 8 are implanted in the terminal board 6.

Output terminals 7 and 8 are connected to piezoelectric ceramics 3 and 3' and lead wires 9 and 10.
has been contacted.

As shown in Fig. 1, in the past, the support of the tuning fork 1 was constructed integrally with the ground terminal 5, or even if it was constructed separately, it was directly implanted on the terminal board 6, so that vibrations and shocks from the outside were avoided. Case (not shown), terminals 5, 7.8 or terminal board 6
, the tuning fork 1 is excited through the ground terminal 5,
This causes noise output, which causes malfunction of the circuit.

In order to prevent this inconvenience, a structure has been proposed in which the terminal plate and the tuning fork support are attached via a cushioning material such as rubber, and the ground terminal and the tuning fork support are connected by a thin lead wire.

However, this structure has the disadvantage that it is difficult to mass produce and is expensive due to its complicated structure.

The object of the present invention is to eliminate the above-mentioned disadvantages, to obtain a piezoelectric tuning fork that has a simple structure, is easy to mass-produce, and has low noise output due to external shocks and vibrations.

An embodiment of the present invention will be described below with reference to FIG.

The configurations 1 to 10 shown in FIG. 2 are the same as those of the conventional example.

Reference numeral 11 denotes a protrusion provided on the terminal plate 6, which surrounds the ground terminal 5 at an appropriate distance and has a height that reaches near the lower end of the tuning fork 1.

Reference numeral 12 denotes a vibration absorbing material inserted between the protrusion 11 of the terminal plate 6 and the ground terminal 5, and a viscoelastic material such as butyl rubber is most suitable, but chloroprene rubber, silicone comb, etc. may also be used.

FIG. 3 shows another embodiment of the present invention, in which two protrusions 13.13 are provided on the terminal plate 6 at an appropriate distance from the ground terminal 5.
are provided at symmetrical positions, and this protrusion 13.13
A vibration absorbing material 14, 14' is compressed and inserted between ' and the ground terminal 5.

FIG. 4 shows still another embodiment of the present invention, which is similar to the embodiment shown in FIG. An arm portion 5'' is provided laterally from almost directly below the fixing portion to the arm portion 5''.
The lower part is embedded in the vibration absorbing material 12.

Note that the structure may be such that only one of the base portion 5' and the arm portion 5'' is provided.

The effects of the present invention are as follows.

(1) The tuning fork is directly fixed to the terminal board with a short ground terminal, and is further held by the protruding part of the terminal board via vibration absorbing material, so the support strength is strong and it can withstand strong vibrations and shocks. The support part will not be damaged.

(2) Vibration absorbing material is provided around the ground terminal, so vibrations and shocks applied from the outside are absorbed.
No noise output is generated by exciting the tuning fork.

(3) Since the vibration absorbing material is held around by the protruding parts provided on the terminal board, when vibration or impact is applied, the vibration absorbing material is compressed and expanded between the protruding parts of the ground terminal. .

Therefore, the displacement of the ground terminal becomes smaller, and vibrations are absorbed more effectively.

(4) In the embodiment shown in FIG. 4, the vicinity of the base of the ground terminal is made thinner, so that the degree to which vibrations and shocks are transmitted to the upper part of the ground terminal is even smaller.

Further, since the upper part of the ground terminal is thick, the contact area with the vibration absorbing material is large, and vibrations and shocks are suppressed more effectively than when the entire ground terminal is thin.

(5) As shown in Fig. 4, in the embodiment, since the arm portion is provided laterally than the ground terminal, not only the contact area between the ground terminal and the vibration absorbing material is expanded, but also the torsion applied to the ground terminal is increased. Power can also be effectively suppressed.

Therefore, it is almost impossible for the ground terminal to be twisted and the vibrating element to be excited by vibrations or shocks applied in the vibration direction of the vibrating element forming the tuning fork.

(6) Since the amount of vibration absorbing material can be regulated to a constant level by the protrusion of the terminal board, the amount and shape can be controlled to the optimum conditions even when liquid rubber is injected and cured.

Therefore, variations in noise output can be reduced and stabilized.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional piezoelectric tuning fork, Fig. 2 is a perspective view of an embodiment of the piezoelectric tuning fork according to the present invention, and Figs. 3 and 4 respectively show other embodiments of the present invention. FIG. 3 is a perspective view of main parts. 1...Tuning fork, 5...Ground terminal, 5'
...Near the base, 5z...Arm, 6...
...Terminal board, 11,13.13...Protrusion part,
12, 14, 14'... Vibration absorbing material.

Claims (3)

[Scope of utility model registration request] (1) A tuning fork is directly fixed by welding or the like to a ground terminal embedded in the terminal plate, and a protrusion of the terminal plate is provided so as to surround or surround the ground terminal at an appropriate distance. A piezoelectric tuning fork in which a vibration absorbing material made of rubber or the like is inserted between the part and the ground terminal. (2) The piezoelectric tuning fork according to claim (1) of the utility model registration, in which the vicinity of the base of the upper surface of the terminal plate of the ground terminal is thinner than other parts. (3) A utility model registered as claimed in claim (1) or in which an arm is provided horizontally from almost directly below the fixed part of the earth terminal with the tuning fork, and the lower part of the arm is embedded in a vibration absorbing material. (2) The piezoelectric tuning fork described in item (2).