JPH0247050B2 - OSHIBOTAN SUITSUCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of the Invention The present invention relates to a push button switch that is attached to a keyboard and used as a keyboard switch.

(B) Background of the Invention Conventionally, as shown in FIG. 1, a push button switch attached to a keyboard has two movable pieces 1, 1 each having a contact mechanism formed of two thin metal plates, and a case 2. The switch operation was obtained by moving up and down the plunger 4, which was press-fitted into the plunger and had a cam 3 connected between the movable pieces 1 and 1.
Since the terminals 5, 5 protruding from the bottom of the case 2 are extensions of the thin movable pieces 1, 1, they are weak in strength and have the disadvantage of being bent when attached to a printed circuit board. Also, the plunger 4 and the movable piece 1,
Since the plunger 1 is configured to slide in direct contact with the plunger 4, there is a problem in that abrasion powder and dirt from the plunger 4 tend to get clogged between the contacts, resulting in poor contact.

(c) Purpose of the Invention The purpose of the present invention is to provide a push button switch which has increased terminal strength and prevents poor contact between contacts.

(d) Summary of the Invention This invention provides a switch unit operated by an elastic operating piece on one side of a plunger housed in a switch case so as to be movable up and down, and this switch unit is comprised of a unit case and a unit cover. An operating part that restores its original shape due to the elasticity of the material is molded on the inner surface of the unit body, which has an enclosed structure.A movable contact and a fixed contact are provided inside the unit body, and the operating part faces the movable contact. , one terminal with a fixed movable contact is provided at the bottom of the center, and the other terminal is connected to the fixed contact at the bottom of both sides.The fixed contact and three terminals are insert-molded in the unit case, and the three terminals are The terminal is a push button switch configured to protrude downward from the bottom of the switch case.

(E) Effects of the Invention According to the present invention, since the movable contacts are fixed to the central terminal and configured separately, each terminal can be formed thickly to provide strength, and the unit case is compact. Because it is insert-molded, sufficient strength can be obtained. In addition, the switch unit has an enclosed structure and is located on one side of the plunger, which prevents abrasion powder and dirt from the plunger from entering the contact area, thereby reliably preventing contact failure. can.

(F) Embodiment of the Invention An embodiment of the invention will be described in detail below based on the drawings.

The drawings show a push button switch, and in FIGS. 2 and 3, the push button switch 11 includes a key top 12, a switch cover 13, a plunger 14, a spring 15, a switch case 16, an operating piece 17, and a switch unit 18. It is structured as follows.

The aforementioned switch case 16 has a concave storage section 19.
A receiving portion 20 for the spring 15 is provided protruding from the center bottom of the inside. Further, guide rails 21 for guiding the vertical movement of the plunger 14 are integrally formed on opposing sides of the interior.
In addition, a guide rail 2 is attached to the side of the plunger 14.
A protrusion 22 guided by 1 is formed.

The aforementioned plunger 14 has a receiving recess 23 for the spring 15 formed on its bottom surface, and the spring 15 is interposed between this receiving recess 23 and the aforementioned receiving portion 20.

The above-mentioned switch cover 13 has an opening 24 formed in its upper central surface, and locking pieces 25, 25 extending downward are formed in series on opposing side edges. Locking holes 26, 26 are formed in the locking pieces 25, 25, and these locking holes 26, 26 are force-fitted into locking protrusions 27, 27 formed on the outer surface of the switch case 16. At this time, the switch cover 13 is fixed to the switch unit 18 by being engaged with each other.

The rim of the opening 24 of the switch cover 13 is provided with the protrusions 22, 22 of the plunger 14.
A regulating edge 28, 2 facing and abutting against the head of the
8, and these regulating edges 28, 28 regulate upward movement of the plunger 14 and prevent the plunger 14 from coming off.

The upper half of the plunger 14 is provided to protrude from the opening 24 of the switch cover 13, and a mounting hole 29 for the key top 12 is formed in the upper surface of the plunger 14. The section 30 is fitted. And key top 1
2, the plunger 14 is moved up and down.

Inside the switch case 16 on one side of the aforementioned plunger 14, a partition wall 31 whose upper end extends to approximately the middle position of the switch case 16 is connected to the bottom thereof, and between this partition wall 31 and the side wall, the above-mentioned switch unit is connected. 18 are arranged.

The aforementioned operation piece 17 is made of an elastic plate spring material, and has a locking part 32 on its upper part that is locked to the upper part of the switch unit 18, and also extends in an inclined shape toward the plunger 14 side. A bifurcated movable piece 3 that is in contact with the opposite lower edge of the plunger 14
3, and a protrusion 34 is formed on the back side thereof. This operation piece 17 is the plunger 14.
When the movable piece 33 is pressed down, the protrusion 34 is moved outward, and this movement causes the protrusion 34 to operate an operating section 38 of the switch unit 18, which will be described later.

The above-mentioned switch unit 18 has a unit case 35 and a unit cover 36 as shown in FIG.
As a result, a unit body 37 having an enclosed structure is formed, and this unit body 37 is made of a resin material.
The operation section 38 is formed by cutting out both sides and the upper three sides of the operation section 38 so as to be continuous so as to be restored by utilizing the elasticity of the material.

The above-mentioned unit case 35 has three terminals 3.
9, 40, and 40 are formed as inserts, and the central terminal 39 has a connecting portion 41 exposed at the center inside the unit case 35, and the lower end of the movable contact 42 is caulked to this connecting portion 41. Fixed. Further, the left and right terminals 40, 40 are connected at the upper part inside the unit case 35, and
A fixed contact 43 is formed by being exposed at a position facing the upper end contact portion of the movable contact 42, and the movable contact 4
2 and the fixed contact 43 are normally separated from each other, and the movable contact 42 can come into contact with the fixed contact 43 by pressing the aforementioned operating section 38 inside the unit.

Then, the unit case and unit cover 36
It is fitted and fixed as appropriate.

Further, when the switch unit 18 is housed in the partition wall 31 of the switch case 16, the three terminals 39, 40, 40 extending downward protrude downward through the insertion hole 44 formed at the bottom of the switch case 16. , and the operation section 3 of the switch unit 18
8 is stored facing the plunger 14 side.

Push button switch 11 configured in this way
Since the plunger 14 is urged upward by the spring 15, the key top 12 is normally positioned upward as shown in FIG.

As shown in FIG. 5, when the key top 12 is pressed down, the lower edge of the plunger 14 facing the operating piece 17 presses down the movable piece 33 of the operating piece 17, moving it toward the switch unit 18, and this movement The protrusion 34 of the movable piece 33 is connected to the switch unit 18.
This operation pushes down the internal movable contact 42, and this movable contact 42 connects to the fixed contact 4.
The switch is operated in contact with 3.

In the above-mentioned operation, even if abrasion powder is generated due to the vertical movement of the plunger 14, the switch unit 18 has an enclosed structure, so it will not enter the internal contact area, and therefore this abrasion powder and dirt will not be generated. This will not cause poor contact of the contacts.

Also, when soldering this push button switch 11 to a printed circuit board, each terminal 39, 40, 40
By soaking it in solder flux,
Switch case 1 when solder flux is caused by capillary action
6 through the insertion hole 44 and each terminal 39, 40, 40, but the partition wall 31 prevents the solder flux from penetrating into the plunger 14 side, and the vertical movement of the plunger 14 is prevented by the solder flux. damage is prevented.

FIG. 6 shows a case where a keyboard matrix 45 is assembled by the above-mentioned push button switch 11, and this push button switch 11 has three terminals 3
9, 40, 40, the column drive line 46 connects each central terminal 39 in series, and the horizontal sense line 47 connects each side terminal 40, 40 in series.

When connected in this way, as shown in FIG. 7, the jumper wire 48 that has been used in the past becomes unnecessary, and the wiring connection is simplified.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional push button switch. The following shows one embodiment of the present invention, and FIG. 2 is an exploded perspective view of a push button switch. Figure 3 is a longitudinal cross-sectional view. FIG. 4 is an exploded perspective view of the switch unit. FIG. 5 is a longitudinal sectional view showing the operating state of the push button switch. FIG. 6 is a block diagram of a matrix assembled with push button switches according to the present invention. FIG. 7 is a block diagram of a conventional matrix. DESCRIPTION OF SYMBOLS 11...Push button switch, 13...Switch cover, 15...Spring, 16...Switch case, 17...Operation piece, 18...Switch unit, 1
9...Storage part, 35...Unit case, 36...Unit cover, 37...Unit main body, 38...Operation section, 39, 40...Terminal, 42...Movable contact, 43...
Fixed contact.

Claims (1)

[Claims] 1. A switch case having a concave storage portion;
a plunger that is housed in a housing section of the switch case and can slide vertically; a spring that biases the plunger upward; and a spring that covers the upper part of the switch case with the upper part of the plunger protruding; A switch cover that regulates upward movement, and an operating section that is located on one side of the plunger and that is enclosed by the unit case and the unit cover, is connected to the inner surface of the unit body and that is restored by the elasticity of the material. The inside of the unit main body is provided with a movable contact and a fixed contact that face each other, the operating part faces the movable contact, one terminal to which one end of the movable contact is fixed is located below the center, and a terminal is provided below on both sides. a switch unit each comprising the other terminal connected to the fixed contact, the fixed contact and the three terminals being insert-molded in a unit case, and the three terminals protruding downward from the bottom of the switch case; A push button switch comprising an elastic operation piece interposed between the switch unit and the plunger and pressed down by the movement of the plunger to operate the operation section of the switch unit.