JPH0442771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piezoelectric relay using a piezoelectric element that generates strain when a voltage is applied.

[Conventional technology]

Conventionally, as this type of piezoelectric relay, one shown in FIG. 2 has been proposed. The box 10 is formed of a square-shaped outer frame 11 and a flat plate that is fixed to two opposing sides and one other side of the square-shaped outer frame 11 and partially closes one opening of the square shape. It has a mounting part 12 to which the contact drive part 20 is mounted and fixed. Contact drive unit 20
A piezoelectric drive body 41 is a drive unit in which a plurality of piezoelectric elements are integrally stacked such that internal electrodes are alternately located between them, and mechanical strain is generated in which the piezoelectric elements expand and contract in the stacking direction, that is, the longitudinal direction, due to an electric field. It has a child 42, a drive board 23, a fixed body 24, and a displacement magnification mechanism 25. The drive element 42 is fixed to one longitudinal end of the piezoelectric drive body 41, and the drive board 23 attaches and fixes the contact drive section 20 to the mounting plate 12. Fixed body 2
4 fixes the piezoelectric drive body 41 to the drive board 23.
The displacement magnifying mechanism 25 includes hinge springs 251, 252,
An arm body 253 that connects these hinge springs 251 and 252 and a driving protrusion 254 are provided in parallel. The hinge spring 251 is a leaf spring, and has one end fixed to the drive board 23 and the other end fixed to the arm body 253.
53 fulcrums are formed. The hinge spring 252 has both ends fixed to each arm body 253 and has the role of displacement transmission. One of the arm bodies 253 (in the case of multiple arms, one of the ends) has a drive protrusion 254 that contacts the drive element 22 at a fulcrum near the hinge spring 251 at the middle part and drives a contact at the other end. will be established. arm body 253
The hinge springs 251 and 252 are connected as lever fulcrums. The hinge springs 251 and 252 have central axes on approximately the same plane and leaf spring surfaces that are arranged in parallel to each other, and an arm body 253 that connects the hinge springs 251 and 252.
Together with this, a displacement amplifying mechanism 25 is formed. The contact assembly section 30 includes a movable contact spring 31 and a fixed contact holder 3.
It has 2. The movable contact spring 31 is a leaf spring,
One end is fixed to one of the lead-out terminals 14, and the other end has a movable contact and presses against the drive protrusion 254, so that the movable contact is moved by displacement of the drive protrusion 254. The fixed contact holder 32 has a fixed contact facing the movable contact and is fixed to the lead-out terminal 14 . The pull-out terminal 14 is inserted and fixed to one side of the outer frame 11 together with the input terminal 13, and the movable contact spring 31 is connected to the hinge spring 25.
1,252, and the central axis is also arranged and fixed on substantially the same plane. Therefore, the displacement magnifying mechanism 25 and the contact assembly section 30 are individually located inside the outer frame 11. The input terminal 13 and the pull-out terminal 14 are provided to protrude in the same direction, and an outer box (not shown) is tightly covered with the case 10 from the side opposite to the terminal insertion side in the terminal protrusion direction, and is attached to the outer frame 11. Glued.

[Problem that the invention seeks to solve]

The manufacturing of the drive board and displacement amplifying mechanism of the conventional piezoelectric relay described above includes the drive board 23, the arm body 25,
3 by fixing the hinge springs 251, 252 by welding or caulking, or by integrally machining a material having one thickness by punching, electric discharge machining, etc.; in the case of the former, the hinge springs There are many sticking points, making the manufacturing process complicated, and in the latter case, if a punching method is used, it is difficult to manufacture parts where the hinge spring has a thin plate, and if an electric discharge machining method is used, the number of man-hours spent on machining will be reduced. However, neither method satisfies both economical efficiency and manufacturability, and has the disadvantage that it is difficult to mass produce and is expensive.

Also, if the arms were made of metal, the mass would be large and the speed would be poor.

[Means for solving problems]

The piezoelectric relay of the present invention includes a drive board made of engineering plastic that fixes a fixing part of a piezoelectric drive body in which a plurality of piezoelectric elements are integrally laminated, has a driver at one end, and a fixing part at the other end. , one end of which is fixed to the drive board with a hinge spring, and the drive element is pressed against the middle part of an arm made of engineering plastic that is connected to the hinge spring, and the drive protrusion moves by magnifying the displacement of the drive element. a contact drive section including a displacement magnification mechanism having a displacement magnification mechanism at the bottom end; a contact assembly section consisting of a movable contact and a fixed contact that are opened and closed by displacement of the drive protrusion; and a piezoelectric drive body integrated with the drive board. It has an outer frame made of engineering plastic into which input terminals and output terminals are inserted, and an outer box from which the input terminals and output terminals protrude to the outside and which encloses a contact drive section and a contact assembly section.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention. Components that are the same as those in FIG. 2 are designated by the same reference numerals and their explanations will be omitted.

The difference between FIG. 1 and FIG. 2 is that the drive board 43 and outer frame 46 of the contact drive unit 40 are integrated and made of engineering plastic. In addition, displacement magnification mechanism 4
The hinge spring 452 in No. 5 is made of a metal material, and is obtained by being fixed to the contact drive part 40 together with the hinge spring 451 and arm body 453 made of engineering plastic by an insert molding method. At this time, a contact assembly 30 is installed on the lead-out terminal 14 inserted at the same time, and a piezoelectric drive body 41 having a driver 42 fixed to one end is fixed to a drive board 43 by a fixing member 44 to form a piezoelectric relay. The fixing body is made of engineering plastic and is fixed to the drive board by heat caulking, fitting, pressure bonding, or the like. The driving protrusion 454 is molded integrally with one end of the arm body 453.

Further, although the hinge spring 451 in FIG. 1 is made of engineering plastic, it may be made of a metal material.

In FIG. 1, the outer box and the input lead wire for driving the piezoelectric drive body are omitted.

〔Effect of the invention〕

As explained above, the present invention includes a drive board made of engineering plastic, an outer frame integrated with the drive board, an arm body, a pullout terminal made of metal material, an input terminal, and a part of the hinge spring by insert molding. To provide a piezoelectric relay which can be produced in bulk, reduces the number of parts, is easy to assemble, is inexpensive, and can be mass-produced. Furthermore, since the arm of the displacement magnification mechanism is made of lightweight engineering plastic, the natural frequency is increased, and earthquake resistance, impact resistance, and high-speed response can be improved. Furthermore, since the piezoelectric driver, which is the drive source, and the contact assembly are completely isolated by the engineering plastic, which is an insulator, the dielectric strength is improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the piezoelectric relay of the present invention, and FIG. 2 is a perspective view showing the configuration of a conventional piezoelectric relay. 41... Piezoelectric drive body, 23, 43... Drive board, 451, 452, 251, 252... Hinge spring, 453, 253... Arm body, 42... Drive element, 454, 254... Drive protrusion, 45 ,25...
...Displacement magnification mechanism, 40, 20...Contact drive unit, 3
1...Movable contact spring, 32...Fixed contact holder,
30...Contact assembly part, 13...Input terminal, 14...
...Output terminal, 46, 11...Outer frame, 12...Mounting portion, 10...Box.

Claims (1)

[Scope of Claims] 1 A plurality of piezoelectric elements are integrally stacked such that internal electrodes are alternately located between them, and an electric field causes mechanical strain in which these piezoelectric elements expand and contract in the stacking direction, and one end a piezoelectric drive body having a drive element at one end and a fixing part at the other end; a drive board fixing the fixing part of the piezoelectric drive body; one end fixed to the drive board with a hinge spring; A contact drive comprising: a displacement magnification mechanism having a drive protrusion at the other end that presses the drive element against the middle part of the arm body to be connected, and moves by magnifying the displacement of the piezoelectric drive body via the drive element based on this principle; a movable contact spring mechanism having a movable contact spring that moves the movable contact by displacement of the drive protrusion to open and close an electric circuit with the fixed contact; and a fixed contact holder having the fixed contact; a contact assembly section juxtaposed in the section; an outer frame into which a drive input terminal of the piezoelectric drive body and a draw-out terminal for fixing and holding the contact assembly section and drawing out an electric circuit are inserted; and a mounting section for fixing and holding the contact drive section. and an outer box of the box that projects the input terminal and the extraction terminal to the outside and encloses the contact drive part and the contact assembly part, the drive board and the outer frame are integrated, and the drive board and the outer frame are integrated. The hinge spring includes a first hinge spring that connects the outer frame and one of the arm bodies, and a second hinge spring other than the first hinge spring, and the arm body, the drive board, and the outer frame. is made of engineering plastic, the pull-out terminal, input terminal and second hinge spring are made of metal, and the drive board, outer frame and arms are made of engineering plastic, and the pull-out terminal, input terminal and second hinge spring are made of metal. A piezoelectric relay characterized in that the hinge spring of No. 2 is fixed by an insert molding method. 2. The piezoelectric relay according to claim 1, wherein the first hinge spring is made of engineering plastic.