JPH09283885A - Piezoelectric transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the mounting on a printed board, by installing a piezoelectric transformer main body and a case for accommodating it, and forming an engaging pawl for mounting which has an engaging part at the tip, in the case. SOLUTION: Retaining pins 3, 3 serving as electrode terminals are formed on a piezoelectric ceramic element 1. A case 7 has a rectangular shallow box type form whose bottom part is opened, and engaging pawls 8, 8 for mounting are formed on the side parts of the case. Hook type engaging parts 8a, 8a are formed at the tips of the engaging pawls 8, 8. When a piezoelectric transformer is mounted, the retaining pins 3, 3 are inserted into engaging holes 10a, 10a of a printed board 10, and then the engaging pawls 8, 8 are inserted into engaging holes 10b, 10b. The engaging parts 8a, 8a of the engaging pawls 8, 8 engage with the back of the printed board 10 of the engaging holes 10a, 10a. The end portions of the retaining pins 3, 3 are soldered to the printed board 10.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a piezoelectric transformer.

[0002]

2. Description of the Related Art A piezoelectric transformer including a piezoelectric transformer main body and a case for accommodating the piezoelectric transformer main body is known. Generally, a mounting claw is formed on the case.
The mounting locking claws are inserted into the locking holes formed on the printed circuit board, and then the adhesive is injected into the locking holes or the mounting locking claws protruding through the locking holes to the back surface of the printed circuit board. By bending the tip, the piezoelectric transformer
It is mounted on a printed circuit board.

[0003]

It takes time and effort to inject an adhesive into the locking hole or to bend the tip of the mounting locking claw protruding through the locking hole to the back surface of the printed circuit board. The present invention has been made in view of the above problems,
It is an object of the present invention to provide a piezoelectric transformer that does not require mounting on a printed circuit board.

[0004]

In order to solve the above-mentioned problems, the present invention comprises a piezoelectric transformer main body and a case for accommodating the piezoelectric transformer main body, and the case has a hook-shaped engaging portion at its tip. Provided is a piezoelectric transformer, which has a mounting pawl for mounting. When the mounting locking claw is inserted into the locking hole formed on the printed circuit board, the hook-shaped locking part at the tip of the mounting locking claw that penetrates the locking hole and projects to the back surface of the printed circuit board is engaged. The piezoelectric transformer is mounted on the printed circuit board by engaging with the back surface of the printed circuit board around the stop hole. It is not necessary to inject an adhesive into the locking hole or bend the tip of the mounting locking claw protruding through the locking hole to the back surface of the printed circuit board. Therefore, the piezoelectric transformer according to the present invention is easy to mount on the printed circuit board.

In a preferred aspect of the present invention, the piezoelectric transformer body has a supporting member which also serves as an electrode terminal.
By integrating the electrode terminal and the support member, the structure of the piezoelectric transformer is simplified and the manufacturing cost of the piezoelectric transformer is reduced. In a preferred aspect of the present invention, the case has a box shape with one end open, and the case and a printed circuit board on which the piezoelectric transformer is mounted form an enclosure wall that surrounds the piezoelectric transformer body. By forming the case into a box shape with one end open, the height of the piezoelectric transformer mounted on the printed circuit board is reduced compared to the case where the case is closed into a box shape. Becomes smaller.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A piezoelectric transformer according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, a pair of input electrodes 2 and 2 are formed facing each other on the surface of a substantially half portion of the piezoelectric ceramic body 1 having a rectangular thin plate shape near one end in the longitudinal direction. A pair of support pins 3 and 3 having support arms 3a and 3a also serving as electrode terminals are soldered to the electrodes 2 and 2. An output electrode 4 is formed on the other end of the piezoelectric ceramic body 1 in the longitudinal direction. The output lead wire 5 is soldered to the output electrode 4. Support arm 6
A pair of support pins 6 and 6 having a and 6a are bonded and fixed to a substantially half portion of the piezoelectric ceramic body 1 near the other end in the longitudinal direction. The piezoelectric ceramic body 1, the support pins 3, 3 and the support pins 6, 6 are mounted on the support arms 3a, 3a, 6a, 6a of the support pins 3, 3, 6, 6 of the piezoelectric ceramic body 1. , Are joined by being supported by the support arms 3a, 3a, 6a, 6a. The support pins 3 and 3 are disposed at positions L / 4 (L is the length of the piezoelectric ceramic body 1) away from one end in the longitudinal direction of the piezoelectric ceramic body 1, and the support pins 6 and 6 are piezoelectric. It is arranged at a position separated from the other end of the ceramic body 1 in the longitudinal direction by L / 4. The piezoelectric ceramic body 1, the input electrodes 2, 2, the support pins 3, 3, the output electrode 4, the output lead wire 5, and the support pins 6, 6 form a piezoelectric transformer body.

As shown in FIGS. 1 and 2, the case 7 for accommodating the piezoelectric transformer main body has a rectangular shallow box shape with an open bottom. Inside the top wall of the case 7, the support pins 3, 3, 6, 6 are accommodated while the piezoelectric transformer main body is housed.
Support protrusions 7a, 7a are formed at positions aligned with each other. On the side of the case 7, two pairs of mounting locking claws 8, 8,
9 and 9 are formed. Mounting locking claws 8, 8, 9, 9
Hook-shaped locking portions 8a, 8a, 9a, 9a are formed at the tip of the. An output lead wire insertion hole 7b is formed at one end of the case 7.

A procedure for mounting the piezoelectric transformer according to this embodiment having the above structure on a printed circuit board will be described below. As shown in FIG. 2, the support pins 3, 3, 6, 6 of the piezoelectric transformer main body are inserted into the four locking holes 10a formed in the printed circuit board 10, and the printed circuit board 10 is penetrated through the locking holes 10a. Support pins 3, 3, 6, 6 protruding from the back of
Solder the end of the to the printed circuit board 10. After inserting the output lead wire 5 extending from the piezoelectric transformer main body from the inside to the outside of the case 7 through the output lead wire insertion hole 7b of the case 7, the four locking holes 10b formed in the printed circuit board 10 are inserted. , The mounting claws 8 for mounting the case 7,
Insert 9, 9. The hook-shaped locking portions 8a, 8a, 9a, 9a at the tips of the mounting locking claws 8, 8, 9, 9 protruding through the locking hole 10b to the back surface of the printed circuit board 10 are the locking holes 10a. The piezoelectric transformer is mounted on the printed circuit board 10 by engaging with the back surface of the printed circuit board 10 around it. Locking hole 10a
The ends of the support pins 3, 3, 6, 6 penetrating through and protruding to the back surface of the printed circuit board 10 are soldered to the printed circuit board 10.

When the piezoelectric transformer according to the present embodiment is mounted on the printed circuit board 10, an adhesive is injected into the locking hole 10b or the mounting is performed by penetrating the locking hole 10b and protruding to the back surface of the printed circuit board 10. It is not necessary to bend the tips of the locking claws 8, 8, 9, 9. Therefore, the piezoelectric transformer according to the present embodiment does not take time and effort to be mounted on the printed board.

The operation of the piezoelectric transformer according to this embodiment will be described below. An AC voltage having a frequency equal to the natural frequency of the two-node longitudinal vibration in the longitudinal direction of the piezoelectric ceramic body 1 is applied between the input electrodes 2 and 2. Two-node vertical vibration occurs in the piezoelectric ceramic body 1, and the piezoelectric ceramic body 1 vibrates in the longitudinal direction with a large amplitude. As a result, a high voltage AC voltage is generated at the output electrode 4. The high-voltage AC voltage generated at the output electrode 4 is taken out through the output lead wire 5. The two-node longitudinal vibration node of the piezoelectric ceramic body 1 is at a position L / 4 from both ends of the piezoelectric ceramic body 1 in the longitudinal direction. The piezoceramic body 1 includes support protrusions 7a, 7a formed on the case 7 and support arms 3a, 3a, 6a of support pins 3, 3, 6, 6 at a node position of two-node longitudinal vibration in the longitudinal direction. , 6a
Since it is supported by being sandwiched by and, it is possible to freely perform two-node longitudinal vibration in the longitudinal direction.

In the piezoelectric transformer according to this embodiment,
Since the electrode terminal and the supporting member are integrated with the pair of supporting pins 3, 3 which also serve as the electrode terminal, the structure of the piezoelectric transformer is simplified as compared with the case where the supporting member and the electrode terminal are separately arranged. The manufacturing cost of the piezoelectric transformer is reduced.

In the piezoelectric transformer according to this embodiment,
The case 7 has a box shape with one end open,
The printed circuit board 10 on which the piezoelectric transformer is mounted forms an enclosure wall that surrounds the piezoelectric transformer body. By making the case 7 a box shape with one end open,
The height of the piezoelectric transformer mounted on the printed circuit board 10 is reduced by one enclosure wall as compared with the case where the case 7 has a closed box shape, and the device including the piezoelectric transformer is downsized.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Instead of forming the locking hole 10b in the printed circuit board 10, the locking portions 8a, 8a, 9a, 9a of the mounting locking claws of the case 7 may be engaged with the side edges of the printed circuit board 10. In the above embodiments, it is assumed that the piezoelectric ceramic body 1 is subjected to longitudinal two-node vibration when the piezoelectric transformer is in operation. When three-node longitudinal vibration in the longitudinal direction occurs in the piezoelectric ceramic body 1 during operation of the piezoelectric transformer, the supporting projection of the case 7 and the supporting pin are separated by three.
It may be arranged at the position of the node of longitudinal vibration.

[0014]

As described above, in the piezoelectric transformer according to the present invention, when the mounting locking claw is inserted into the locking hole formed in the printed board, the mounting hole of the printed board is penetrated through the locking hole. The hook-shaped locking portion at the tip of the mounting locking claw protruding to the back surface engages with the back surface of the printed circuit board around the locking hole, and the piezoelectric transformer is mounted on the printed circuit board. It is not necessary to inject an adhesive into the locking hole or bend the tip of the mounting locking claw protruding through the locking hole to the back surface of the printed circuit board.
Therefore, the piezoelectric transformer according to the present invention is easy to mount on the printed circuit board.

By integrating the electrode terminal and the support member, the structure of the piezoelectric transformer is simplified and the manufacturing cost of the piezoelectric transformer is reduced. By forming the case into a box shape with one end open, the height of the piezoelectric transformer mounted on the printed circuit board is reduced compared to the case where the case is closed into a box shape. Becomes smaller.

[Brief description of drawings]

FIG. 1 is a perspective view of a piezoelectric transformer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a piezoelectric transformer according to an embodiment of the present invention at a support pin position that also serves as an electrode terminal when mounted on a printed circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric ceramic body 2 Input electrode 3 Support pin also serving as an electrode terminal 4 Output electrode 5 Output lead wire 6 Support pin 7 Case 7a Support protrusion 8 and 9 Mounting locking claws 8a and 9a Hook type locking part 10 Printed board

Claims (3)

[Claims] 1. A piezoelectric transformer, comprising: a piezoelectric transformer main body; and a case for accommodating the piezoelectric transformer main body, wherein the case has a mounting locking claw having a hook-shaped locking portion at its tip. Trance. 2. The piezoelectric transformer according to claim 1, wherein the piezoelectric transformer main body has a support member that also serves as an electrode terminal. 3. The case has a box shape whose one end is open, and an enclosure wall surrounding the piezoelectric transformer main body is formed by the case and a printed circuit board on which the piezoelectric transformer is mounted. Alternatively, the piezoelectric transformer described in 2.