JPH0583073A - Case for piezoelectric resonator - Google Patents

Abstract

PURPOSE:To prevent the position of an internal component such as a piezoelectric element from being deviated even when a terminal board is not tack welded by devising the terminal board to be simply and surely tentatively fastened to the case used for the piezoelectric resonator utilizing a thickness-shear vibration mode or the like. CONSTITUTION:The shape of a projection 10a of a case 10 is formed to be a mushroom and a terminal board fitted to the case 10 is engaged by the protruded part 10b and is not restored to the original position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case used for a piezoelectric resonator, and more particularly, to an improvement of a protrusion for fixing a terminal plate.

[0002]

2. Description of the Related Art Generally, a piezoelectric resonator is one that generates a stable frequency by utilizing a piezoelectric effect or selects a specific frequency, and uses various vibration modes depending on the frequency. , There are various forms.

As a piezoelectric resonator for generating a frequency of about 1 MHz, for example, there is a piezoelectric resonator 1 utilizing a contour sliding vibration mode as shown in FIG. The piezoelectric resonator 1 includes a piezoelectric element 2 having opposing electrodes 2b formed on both surfaces of a piezoelectric substrate 2a made of a piezoelectric ceramic, and an electrical connection to each of the opposing electrodes 2b without disturbing the vibration of the piezoelectric element 2. Two electrically conductive sheets 3 to be connected, a leaf spring 4 for fixing the piezoelectric element 2 at a predetermined position through one of the electrically conductive sheets 3, and the piezoelectric element 2, the electrically conductive sheet 3 and the leaf spring 4 are housed. Frame-shaped case 5 and conductive sheet 3
And a terminal plate 6 that is electrically connected to the counter electrode 2b of the piezoelectric element 2 via a leaf spring 4 and holds the piezoelectric element 2 therebetween.

The case 5 is made of a resin such as plastic, and the terminal board 6 is joined to four places on both sides.
A cylindrical protrusion 5a for fixing the terminal plate 6 is integrally formed. Further, in each of the terminal plates 6, a joining hole 6 is formed at a position corresponding to each of the projecting portions 5a of the case 5.
a is formed, and a terminal portion 6b for mounting the piezoelectric resonator 1 on a printed circuit board or the like is integrally formed. These projections 5a are passed through the joining holes 6a of the terminal plate 6 and melted, and the respective terminal plates 6 are welded to the case 5 and joined.

To manufacture such a piezoelectric resonator 1,
First, after welding and joining the terminal plate 6 to one surface of the case 5,
In the case 5, the conductive sheet 3, the piezoelectric element 2, the conductive sheet 3 and the leaf spring 4 are incorporated in order. Next, the terminal plate 6 is attached to the other surface of the case 5 so that the protruding portion 5a passes through the joint hole 6a of the terminal plate 6. FIG. 10 shows a state in which the terminal board 6 is attached. These terminal boards 6 are shown in FIG.
As shown in FIG. 1, a large number of hoop members 7 are arranged side by side to form a hoop shape, and the terminal plate 6 is attached to the case 5 while being attached to the hoop member 7. Then, as shown in FIG. 12, the protrusions 5 a are collectively melted by a pressing plate 8 with a heater for every fixed number, and the terminal plate 6 is welded and joined to the case 5.

Here, as shown in FIG. 10, when the terminal plate 6 is simply attached to the case 5, the terminal plate 6 is disengaged from the case 5 by the elastic force of the leaf spring 4, so that the protrusion 5a is removed. The terminal plates 6 were temporarily fixed to the case 5 by melting them one by one with a trowel or the like. That is, before the terminal plate 6 was completely welded to the case 5, it was temporarily welded.

[0007]

However, it is difficult to temporarily weld the case 5 and the terminal plate 6 in a state in which they are in close contact with each other, and normally, as shown in FIG.
The terminal plate 6 floats up and separates from the case 5 by the elastic force of. Therefore, the force for pressing the piezoelectric element 2 becomes weak, and the piezoelectric element 2, the conductive sheet 3, and the leaf spring 4 are displaced from a predetermined position during transportation until the terminal plate 6 is completely welded, resulting in a defect. There was something. Further, as shown in FIG. 11, the terminal plate 6 has a hoop shape. Therefore, if all the protrusions 5a are melted with a trowel or the like to temporarily fix them, there is a problem that it takes too much work time. ..

Therefore, the present inventor has accomplished the present invention as a result of intensive studies to solve such a problem.

[0009]

SUMMARY OF THE INVENTION A gist of a case of a piezoelectric resonator according to the present invention is that a piezoelectric element in which counter electrodes are formed on both surfaces of a piezoelectric substrate and a counter electrode of the piezoelectric element are electrically connected to each other. The case of a piezoelectric resonator comprising a terminal plate that is connected to and that holds the piezoelectric element, and a case that has at least the piezoelectric element and that has a protrusion for fixing the terminal plate, The projecting portion of the case is formed with a locking means for locking the terminal plate.

[0010]

According to the case of such a piezoelectric resonator, the terminal plate attached to the case is positioned and fixed by the protrusion of the case, and is locked by the latching means formed on the protrusion. It is temporarily fixed in the state of being in close contact with the case. That is, the terminal plate attached to this case does not float up and separate from the case even if it is not temporarily welded. Therefore, the internal parts such as the piezoelectric element housed in the case are sufficiently pressed and held by the terminal plate temporarily fixed to the case, and are not displaced during transportation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the case of the piezoelectric resonator according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a case 10 of the piezoelectric resonator according to the present invention is provided with a mushroom-shaped protrusion 10a. The case 10 is used in place of the case 5 of the piezoelectric resonator 1 using the thickness shear vibration mode described in the related art, and is made of a resin such as plastic as in the case 5 of the related art, and includes the piezoelectric element 2. , For accommodating the conductive sheet 3 and the leaf spring 4. The protrusion 10a has a shape such that a hemisphere having a slightly larger diameter is attached to the upper surface of the cylinder, and a portion 10b protruding from the side surface of the cylinder hooks the terminal plate 6. It constitutes a stopping means. Although not shown, the protrusions 10a are provided not only at this location but also at a total of four locations on both sides to which the terminal board 6 is joined. Therefore, if this case 10 is used, as shown in FIGS. 2 and 3, the terminal plate 6 is positioned and fixed by the protrusion 10a, and
The protruding portion 10b is hooked so as not to return to the original.

In order to manufacture a piezoelectric resonator using the case 10, first, the terminal plate 6 is formed on one surface of the case 10 so that the protrusion 10a passes through the joint hole 6a of the terminal plate 6.
After being attached by pressing with tweezers or the like, the conductive sheet 3, the piezoelectric element 2, the conductive sheet 3 and the leaf spring 4 are sequentially incorporated in the case 10. Then, the terminal plate 6 is attached to the other surface of the case 10 by pressing it with tweezers or the like as in the previous case. Then, similarly to the method shown in FIG. 12, the protrusions 10 a are collectively melted in a fixed number by the pressing plate 8 with a heater, and the terminal plate 6 is welded and joined to the case 10.

As described above, even if the terminal plate 6 is not temporarily welded to the case 10, the terminal plate 6 can be securely fixed to the case 10 in a state where the terminal plate 6 is firmly attached to the case 10. Therefore, the terminal plate 6 does not float up and separate from the case 10 due to the elastic force of the leaf spring 4, so that the piezoelectric element 2, the conductive sheet 3, and the like can be used during transportation until the terminal plate 6 is welded to the case 10. The leaf spring 4 will not be displaced and the defects will be greatly reduced. Further, even with the hoop-shaped terminal plate 6 as shown in FIG. 11, it is possible to quickly temporarily temporarily fix all the protrusions 10a only by pressing the terminal plate 6 with tweezers or the like. Get better.

Although one embodiment of the case of the piezoelectric resonator according to the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment and can be implemented in other modes.

For example, as shown in FIG. 4, small protrusions 12b as hooking means may be formed on the cylindrical protrusion 12a at two opposite positions. Case 1 like this
If the above-mentioned terminal board 6 is attached to 2, the terminal board 6 can be temporarily fixed by these small protrusions 12b. Further, the small protrusions 12b may be formed only at one location of the protrusion 12a or at three or more locations.

Further, as shown in FIG. 5, a case 14 having an inverted L-shaped protrusion 14a may be used. This protrusion 14a
Has a shape in which two portions of a cylindrical body are cut out, and a portion 14b protruding inward of the case 14 is a terminal plate 16
It constitutes a locking means for locking. The joint hole 16a of the terminal plate 16 is formed in a semicircular shape so as to fit the protrusion 14a. When the case 14 is used, the projection 14a is slightly bent in the outer direction of the case 14 when being inserted into the joint hole 16a of the terminal plate 16, so that the terminal plate 16 can be easily attached.

Further, as shown in FIG. 6, the case 18 may be provided with a protrusion 18a having a bellows-like surface 18b.
In this case, the bellows-shaped surface 18b constitutes a locking means for locking the terminal plate. The terminal plate 6 described above can be used for the case 18.

Further, as shown in FIG. 7, an inverted L-shaped projection 20a may be provided on the outer edge of the case 20. The protrusion 20a is different from the protrusion 14a shown in FIG.
The portion 20b protruding inward of 0 constitutes a locking means for locking the terminal plate 22. Case 2 like this
For 0, a terminal plate 22 in which a rectangular notch 22a is formed at a corresponding position of the protrusion 20a may be used. As is clear from this example, the shape of the terminal plate 22 may be appropriately changed depending on the case used, and may not be the hole like the joining holes 6a and 16a of the terminal plates 6 and 16 described above. Of.

Further, as shown in FIG. 8, it can be applied to a case 24 having a step 24a.
4a is provided with a hooking member 24b having a triangular prism shape. In the case 24, when the terminal plate 26 is fitted inside the step 24a, the terminal plate 26 is locked by the locking member 24b so as not to come off from the case 24. In this example, the outer peripheral portion 24c of the step 24a constitutes a protrusion for fixing the terminal plate 26, and the retaining member 24b constitutes a retaining means for retaining the terminal plate 26.

As described above, the shape of the case is not particularly limited. For example, although not shown, when the circular piezoelectric element is housed, it may be formed into a circular frame shape. Alternatively, the protrusions may be provided at eight locations,
The number of protrusions is not particularly limited.

In addition, the present invention can be applied to a case of a piezoelectric resonator in which a projection or the like is integrally provided on one side of a terminal plate, and a piezoelectric element is held by this terminal plate, and further, the contour sliding The present invention can be applied not only to the piezoelectric resonator utilizing the vibration mode but also to the case of the piezoelectric resonator utilizing various vibration modes such as the thickness-shear vibration mode, etc. ,
The present invention can be implemented with various improvements, modifications and variations based on the knowledge of those skilled in the art.

[0023]

In the case of the piezoelectric resonator according to the present invention, since the projection for fixing the terminal plate is formed with the latching means for latching the terminal plate, the terminal plate is temporarily welded. It is possible to temporarily and easily fix it without any trouble. Therefore, during transportation after temporarily fixing the terminal board,
Internal parts such as piezoelectric elements will not be displaced,
Defects are greatly reduced. Moreover, workability is improved because the terminal plate can be temporarily fixed by simply pressing it with tweezers or the like.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing an embodiment of a case of a piezoelectric resonator according to the present invention.

FIG. 2 is a partial cross-sectional view showing how a terminal plate is attached to the case of the piezoelectric resonator shown in FIG.

FIG. 3 is an enlarged cross-sectional view of an essential part of a state where a terminal plate is attached to the case of the piezoelectric resonator shown in FIG.

FIG. 4 is a sectional view of an essential part showing another embodiment of the case of the piezoelectric resonator according to the present invention.

FIG. 5 is a perspective view of an essential part showing another embodiment of the case of the piezoelectric resonator according to the present invention.

FIG. 6 is a main part perspective view showing another embodiment of the case of the piezoelectric resonator according to the present invention.

FIG. 7 is a main part perspective view showing another embodiment of the case of the piezoelectric resonator according to the present invention.

FIG. 8 is a main part perspective view showing another embodiment of the case of the piezoelectric resonator according to the present invention.

FIG. 9 is an exploded perspective view showing an example of a conventional piezoelectric resonator.

10 is a perspective view showing a state in which a terminal plate is attached in the manufacturing process of the piezoelectric resonator shown in FIG.

11 is an external view for explaining a terminal plate used in the piezoelectric resonator shown in FIGS. 9 and 10. FIG.

FIG. 12 is an explanatory diagram showing a manner of welding the terminal plate in the manufacturing process of the piezoelectric resonator shown in FIGS. 9 and 10;

FIG. 13 is a fragmentary sectional view for explaining a problem in the piezoelectric resonator shown in FIGS. 9 and 10.

[Explanation of symbols]

2; Piezoelectric element 2a; Piezoelectric substrate 2b; Counter electrode 6, 16, 22, 26; Terminal plate 10, 12, 14, 18, 20, 24; Case 10a, 12a, 14a, 18a, 20a, 24c; Protrusion 10b , 12b, 14b, 18b, 20b, 24b; locking means

Claims (1)

[Claims] 1. A piezoelectric element having opposing electrodes formed on both sides of a piezoelectric substrate, a terminal plate electrically connected to the opposing electrodes of the piezoelectric element and holding the piezoelectric element, and the terminal plate fixed. In the case of the piezoelectric resonator including a projection portion for holding the piezoelectric element and at least the case for housing the piezoelectric element, a locking means for locking the terminal plate is formed on the projection portion of the case. A case of a piezoelectric resonator, which is characterized in that