JP2006086082A - Push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a push-button switch in which life prolongation is possible by preventing cracks of a movable contact caused by repeated key pressings. <P>SOLUTION: This push-button switch is provided with a movable contact 5 having a dome 5a which is composed of a thin metal plate and reversible by being pushed, a common contact 3 which is composed of a metal material and always connected to the movable contact 5, a fixed contact 4 which is arranged opposingly to the movable contact 5 which can be contacted and separated because the dome 5a is reversed, and a base pedestal 2 having a receiving face which supports the outer peripheral edge 5c of the dome 5a of the movable contact 5. The receiving face is formed of an insulating member composed of a material softer than the common contact 3, the fixed contact 4, and the movable contact 5, and at the outer peripheral part of the dome 5a which is different from the outer peripheral edge 5c of the movable contact 5 supported by the receiving face, a connection part to the common contact 3 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a push button switch that presses and reverses a movable contact to make contact with and away from a fixed contact, and more particularly to a push button switch used for an input operation unit of various electronic devices.

As a structure of a conventional pushbutton switch, a structure in which an outer peripheral edge portion of a dome-shaped movable contact is placed on an outer fixed contact made of a metal material is known (for example, see Patent Document 1).
The structure of this conventional push button switch is shown in FIG. FIG. 11 is a cross-sectional view of a conventional pushbutton switch. In FIG. 11, reference numeral 31 denotes an insulating resin box-shaped case in which outer fixed contacts 33A and 33B and a center fixed contact 35 are implanted on the inner bottom surface by insert molding. A dome-shaped movable contact 40 made of a thin elastic metal plate is placed on the outer fixed contacts 33A, 33B, and a switch contact for contacting and separating the outer fixed contacts 33A, 33B and the central fixed contact 35 through the dome-shaped movable contact 40 is provided. It is composed.

The operation body 37 is mounted on the upper surface of the dome-shaped movable contact 40 so that the pressing portion 37A is in contact with the upper surface of the dome-shaped movable contact 40. It protrudes from the center hole 38A of the cover 38 which covers the opening to the upper part, and becomes an operation part.
The shape of the dome-shaped movable contact 40 is a substantially spherical shape in which the outer peripheral portion 40A has a truncated cone shape, and the inner central portion 40B slightly swells upward, and the boundary between the two is connected by a smooth curve. In this way, the elastic metal thin plate is drawn.

  In the conventional push switch configured as described above, when the button portion 37B on the upper surface of the operation body 37 is pressed downward via the operation button of the electronic device used, the operation body 37 moves downward and the pressing portion 37A on the lower surface. When the dome-shaped movable contact 40 is pressed, the dome-shaped movable contact 40 reversely moves with a sense of moderation, and the space between the outer fixed contacts 33A and 33B and the central fixed contact 35 is electrically connected via the dome-shaped movable contact 40. Connected to.

  Thereafter, when the force pressing the button portion 37B on the upper surface of the operation body 37 is removed, the original state is restored by the elastic restoring force of the dome-shaped movable contact 40, and the space between the outer fixed contacts 33A, 33B and the central fixed contact 35 is reduced. It is configured to be open.

Japanese Patent Laid-Open No. 11-67002

  However, in the conventional pushbutton switch described above, the dome-shaped movable contact is formed by subjecting a thin metal plate to a dome-shaped drawing process, and the contact surface between the outer peripheral edge portion and the fixed contact is made uniform without any gap. Because it is difficult to form, the outer peripheral edge of the dome-shaped movable contact partially rubs against the hard fixed contact by repeating the keying of the movable contact, and the movable contact due to stress concentration at the non-uniform portion There is a problem in that cracks are likely to occur and the life cannot be extended.

  Accordingly, an object of the present invention is to provide a pushbutton switch that solves the above-described problems, prevents cracking of the movable contact due to repeated keystrokes, and can extend the life.

  In order to solve the above-mentioned problems, the present invention provides a first solving means comprising a movable contact made of a thin metal plate and having a dome portion that can be reversed by being pressed, and a common that is made of a metal material and is always connected to the movable contact. A fixed contact that is disposed opposite to the movable contact and that can be contacted and separated by reversing the dome, and a base having a receiving surface that supports an outer peripheral edge of the dome of the movable contact. The receiving surface is formed of an insulating member made of a material softer than the common contact, the fixed contact, and the movable contact, and is different from the outer peripheral edge of the movable contact supported by the receiving surface. A pushbutton switch characterized in that a connection portion with the common contact is formed on an outer peripheral portion.

As a second solution, the base is made of synthetic resin, and the receiving surface is formed integrally with the base.
As a third solution, a connecting portion between the movable contact and the common contact is formed by a contact piece extending from an outer peripheral portion of the dome portion of the movable contact, and the contact piece is elastically applied to the common contact. The structure was in contact.
As a fourth solution, a connecting portion between the movable contact and the common contact is formed by a contact piece extending from a part of the common contact, and this contact piece is an outer periphery of the dome portion of the movable contact. The structure is elastically contacted with the part.

  As described above, the pushbutton switch of the present invention includes a movable contact made of a thin metal plate and having a dome portion that can be reversed by being pressed, a common contact made of a metal material and always connected to the movable contact, and a movable contact. A fixed contact that is arranged oppositely and can be contacted and separated by reversing the dome part, and a base having a receiving surface that supports the outer peripheral edge of the dome part of the movable contact, the receiving surface being a common contact and a fixed contact Since the insulating member is made of a material softer than the movable contact, and the outer peripheral portion of the dome portion is different from the outer peripheral edge portion of the movable contact supported by the receiving surface, the connection portion with the common contact is formed. The receiving surface made of a soft material is smoothed so that the gap with the outer peripheral edge of the movable contact is filled by keying, enabling uniform support, preventing cracking of the movable contact, and extending the service life. It made.

In addition, since the base is made of synthetic resin and the receiving surface is formed integrally with the base, the receiving surface made of a soft material can be formed integrally with the base, which facilitates manufacture.
In addition, the connecting part between the movable contact and the common contact is formed with a contact piece extending from the outer periphery of the dome part of the movable contact, and the contact piece is elastically contacted with the common contact. As a result, the assembly can be easily performed. In addition, since the fixed contact and the common contact can be formed on the same plane of the base, the degree of freedom of arrangement of the fixed contact, the common terminal, and the external terminal can be increased.
In addition, the connection part between the movable contact and the common contact is formed by a contact piece extending from a part of the common contact, and this contact piece is elastically contacted with the outer periphery of the dome part of the movable contact. Is formed separately from the movable contact, so that the degree of freedom in designing the movable contact as a reversing spring can be increased.

  Hereinafter, embodiments of the present invention are shown in FIGS. 1 is a plan view showing a pushbutton switch according to an embodiment of the present invention, FIG. 2 is a plan view showing a first housing, FIG. 3 is a plan view showing a second housing, and FIG. 4 is a plan view showing a movable contact. FIG. 5 is a diagram for explaining the operation of the pushbutton switch of the present invention, and FIG. 6 is a plan view showing a modification of the pushbutton switch using a movable contact different from that in FIG.

  1 to 5, the pushbutton switch according to the present invention includes a first housing 1 in which a common contact 3 is disposed, a second housing 2 in which a fixed contact 4 is disposed, and first and second housings. The movable contact 5 is housed in the housings 1 and 2 and connected to the common contact 3 and the fixed contact 4, and the insulator 6 is attached to the movable contact 5 and the upper portion of the first housing 1.

  The first housing 1 is made of an insulating material such as synthetic resin, has an outer shape formed in a rectangular shape, and has a rectangular opening 1a at the center. A common contact 3 made of a conductive metal material is integrally embedded in one side plate portion 1b of the first housing 1 by a method such as insert molding, and the common contact 3 is inserted into the opening 1a. A pair of contact pieces 3a, 3a are formed to extend. The tip of the contact piece 3a is bent slightly downward, and the bent portion 3b is in elastic contact with the outer peripheral portion of the dome portion 5a of the movable contact 5 described later. Further, both end sides of the common contact 3 protrude outward from both side portions of the first housing 1 and are provided with external terminals 3c and 3c.

  The second housing 2 serving as a base is also made of an insulating material such as synthetic resin, and has an outer shape that is rectangular. On one side of the second housing 2, a fixed contact 4 made of a conductive metal material is embedded integrally by a method such as insert molding. Further, in the center of the second housing 2, planar recesses 2a and 2b made of a circle and a rectangle are formed, and the contact 4a of the fixed contact 4 is formed in the center of the circular recess 2a. It is provided. Further, both ends of the fixed contact 4 protrude outward from both side portions of the second housing 2, and external terminals 4b and 4b are provided.

  The movable contact 5 is made of a conductive metal thin plate such as a phosphor bronze plate or a stainless steel plate, is formed in a disc shape, has a dome portion 5a that can be reversed at the center, and a skirt portion connected to the dome portion 5a on the outside. 5b and a circular outer peripheral edge 5c on the outer periphery of the skirt 5b. The movable contact 5 is housed in the recesses 2a and 2b of the second housing 2, the outer peripheral edge 5c of the skirt 5b is placed on the recesses 2a and 2b, and the top lower surface of the dome 5a is The fixed contact 4 is arranged to face the contact portion 4a. At this time, the movable contact 5 has a circular outer peripheral edge portion 5c supported by the plane of the planar depressions 2a and 2b, and the depressions 2a and 2b serve as receiving surfaces of the movable contact 5. .

  As described above, the second housing 2 serving as a base is formed of an insulating material such as a synthetic resin, and the receiving surface of the movable contact 5 is formed integrally with the second housing 2, so that it is soft. A receiving surface made of a material can be formed integrally with the second housing 2, which facilitates manufacture.

  The first housing 1 is fitted on the upper surface side of the second housing 2, and at this time, the movable contact 5 is placed in the opening 1a so as to face the opening 1a. A pair of contact pieces 3a and 3a of the common contact 3 extending to the dome part 5a extend on the outer peripheral part of the dome part 5a, and the bent part 3b formed at the tip is a dome part 5a of the movable contact part 5a. It is electrically connected in elastic contact with the outer periphery of the.

  In this way, the connecting portion between the movable contact 5 and the common contact 3 is formed by the contact piece 3 a extending from a part of the common contact 3, and this contact piece 3 a is formed on the dome portion 5 a of the movable contact 5. Since the connection portion is formed separately from the movable contact 5 because it is elastically contacted with the outer peripheral portion, the degree of freedom in designing the movable contact 5 as a reversing spring can be increased.

  The insulator 6 is made of an insulating material sheet such as a synthetic resin having flexibility, and an adhesive layer made of an adhesive or the like is provided on the lower surface. The insulator 6 covers the opening 1a of the first housing 1 so as to cover the opening 1a. 1 is attached to the upper surface of the housing 1. At this time, the contact pieces 3a, 3a disposed in the opening 1a of the first housing 1 and the upper surface side of the dome portion 5a of the movable contact 5 are also simultaneously attached to the adhesive layer of the insulator 6. Thus, the contact between the contact piece 3a and the movable contact 5 is ensured, and the movable contact 5 is positioned. The insulator 6 prevents dust from entering the contact portion.

  Next, the operation of the pushbutton switch having the above configuration will be described with reference to FIGS. 5 (a) and 5 (b). First, in the initial state shown in FIG. 5A (the movable contact 5 is not pressed by the operating member 7), the movable contact 5 is electrically connected to the common contact 3 via the contact piece 3a. However, the outer peripheral edge portion 5c of the skirt portion 5b is placed in the recess portions 2a and 2b, and the top lower surface of the dome portion 5a is arranged to face the contact portion 4a of the fixed contact 4, and is separated from the fixed contact 4. The switch is off.

  From this state, as shown in FIG. 5 (b), when the dome portion 5a of the movable contact 5 is pressed by the operating member 7 via the insulator 6, the dome portion 5a is inverted downward and the top portion of the dome portion 5a. When the lower surface is in contact with the contact portion 4a of the fixed contact 4, the common contact 3 and the fixed contact 4 are electrically connected via the movable contact 5, and the switch is turned on.

  Thus, according to the above-described embodiment, the receiving surface of the outer peripheral edge portion 5c of the movable contact 5 is formed by the planar depressions 2a and 2b of the second housing 2, and the fixed contact 4 or the like. Since the insulating member such as a synthetic resin made of a material softer than the metal material is used, even if the movable contact 5 repeats the reversing operation by the pressing of the operating member 7, the outer peripheral edge portion 5c of the movable contact 5 is The receiving surface made of a soft material is smoothed so as to fill the gap, and it is possible to provide uniform support and prevent the movable contact 5 from cracking, so that the life of the switch contact portion can be extended. Yes.

  FIG. 6 shows a modified example of the movable contact mounted on the recesses 2a and 2b of the second housing 2. In this case, the movable contact 8 has a dome portion 8a at the center, but the outer shape is Instead of a circle, the opposing outer peripheral portions are formed in an elliptical shape cut into a straight line. Even in this case, the outer peripheral edge portion 8c of the skirt portion 8b excluding the linear cut portion 8d is placed on the planar hollow portions 2a and 2b of the second housing 2 and serves as a receiving surface. In this case, the same effect as in the above embodiment can be obtained. In the present embodiment, the movable contact can be downsized, and the entire switch can be downsized.

  In this embodiment, the movable contact 8 has the dome portion 8a cut into an oval shape, and the cut portion 8d is bridged on an extended portion connected to the contact portion 4a of the fixed contact 4 of the recessed portion 2a. It is placed in a state. Since the outer peripheral edge 8c of the skirt portion 8b excluding the cut portion 8d is not on the extended portion connected to the contact portion 4a of the fixed contact 4 embedded in the second housing 2, the fixed contact 4 is extended. Even if the resin thickness on the part is reduced or the extended part is exposed on the surface of the recessed part 2a, the outer peripheral edge part 8c of the skirt part 8b of the movable contact 8 and the fixed contact 4 may come into contact with each other. Absent. For this reason, in the present embodiment, the second housing 2 can be thinned, and the entire switch can be thinned.

  7 to 10 show another embodiment of the push button switch of the present invention, FIG. 7 is a plan view of the push button switch, FIG. 8 is a plan view of the housing, FIG. 9A is a plan view of the movable contact, FIG. 9 (b) is a front view of the movable contact, and FIGS. 10 (a) and 10 (b) are diagrams for explaining the operation of the push button switch.

  In the figure, the pushbutton switch of this embodiment includes a housing 11 provided with a common contact 12 and a fixed contact 13, a movable contact 14 housed in the housing 11 and connected to the common contact 12 and the fixed contact 13, and a movable contact. It is mainly comprised from the insulator 15 stuck on the contact 14 and the housing 11 upper part.

  The housing 11 serving as a base is made of an insulating material such as a synthetic resin and has an outer shape that is rectangular. A common contact 12 made of a conductive metal material is integrally embedded on one side of the housing 11 by a method such as insert molding. Further, on the other side of the housing 11, a fixed contact 13 made of the same conductive metal material is also embedded integrally by a method such as insert molding. Further, in the center of the housing 11, planar hollow portions 11 a, 11 b, and 11 c are formed, each having a slightly small circle and a slightly large ellipse, and a long shape that connects both of them.

  Among these hollow portions, a contact portion 12a of the common contact 12 is provided at the center of the circular hollow portion 11a, and the fixed contact is formed at the center of the elliptical hollow portion 11b. Thirteen contact portions 13a are exposed and provided. Further, both ends of the common contact 12 protrude outward from both sides of the housing 11 to be provided with external terminals 12b and 12b, and both ends of the fixed contact 13 are similarly connected to the housing 11 External terminals 13b and 13b are provided so as to protrude outward from both side portions of the.

  The movable contact 14 is made of a conductive metal thin plate such as a phosphor bronze plate or a stainless steel plate, and is formed on the tip side from the inversion portion 14a through the elongate bar portion 14b from the inversion portion 14a. And a small circular contact piece 14c. In addition, the elliptical inversion part 14a has a dome part 14d that can be inverted at the center, and has a pair of skirt parts 14e that are connected to the dome part 14d on the opposite outer side, and a pair of skirt parts 14e on the outer periphery of the skirt part 14e. The outer peripheral edge portion 14f has a circular arc shape.

  The movable contact 14 has an elliptical inversion portion 14a housed in a recess 11b of the housing 11, an outer peripheral edge portion 14f of the skirt portion 14e is placed on the recess 11b, and the top lower surface of the dome portion 14d is The fixed contact 13 is arranged to face the contact portion 13a. At this time, the movable contact 14 has a pair of arc-shaped outer peripheral edge portions 14f supported by the plane of the planar depression 11b, and the depression 11b serves as a receiving surface for the movable contact 14. .

  Further, the elongated beam portion 14b is accommodated in the recess portion 11c, the small circular contact piece 14c is accommodated in the recess portion 14a, and the contact piece 14c is mounted on the contact portion 12a of the common contact 12. The contact piece 14c is arranged in an electrically connected state in elastic contact with the contact portion 12a by the elasticity of the crosspiece 14b.

  In this way, the connecting portion between the movable contact 14 and the common contact 12 is formed by the contact piece 14c extending from the outer periphery of the dome portion 14d of the movable contact 14, and the contact piece 14c is formed as the common contact. Since the contact piece 14c can be formed integrally with the movable contact 14, the assembly is facilitated. Further, since the fixed contact 13 and the common contact 12 can be formed on the same plane of the housing 11 serving as a base, the degree of freedom in arrangement of the fixed contact 13, the common terminal 12, and the external terminals 13b and 12b can be increased. ing.

  The insulator 15 is made of an insulating material sheet such as a synthetic resin having flexibility, and an adhesive layer made of an adhesive or the like is provided on the lower surface, so as to cover the recessed portions 11a, 11b, and 11c of the housing 11. Attached to the upper surface of the housing 11. At this time, the upper surface side of the dome portion 14d of the movable contact 14 and the upper surface side of the crosspiece portion 14b disposed in the recess portions 11a, 11b, and 11c of the housing 11 are also simultaneously attached to the adhesive layer of the insulator 15. Thus, the contact between the contact piece 14c and the contact portion 12a of the common contact 12 is ensured, and the movable contact 14 is positioned. The insulator 15 prevents dust from entering the contact portion.

  Next, the operation of the pushbutton switch having the above configuration will be described with reference to FIGS. 10 (a) and 10 (b). First, in the initial state shown in FIG. 10A (the movable contact 14 is not pressed by the operating member 7), the movable contact 14 is electrically connected to the common contact 12 via the contact piece 14c. However, the outer peripheral edge portion 14f of the skirt portion 14e is placed in the hollow portion 11b, and the top lower surface of the dome portion 14d is disposed to face the contact portion 13a of the fixed contact 13, and is separated from the fixed contact 13. The switch is off.

  From this state, as shown in FIG. 10 (b), when the dome portion 14d of the movable contact 14 is pressed by the operating member 7 via the insulator 15, the dome portion 14d is inverted downward and the top of the dome portion 14d. When the lower surface is in contact with the contact portion 13a of the fixed contact 13, the common contact 12 and the fixed contact 13 are electrically connected via the movable contact 14, and the switch is turned on.

  Thus, also in the present embodiment, the receiving surface of the outer peripheral edge portion 14f of the movable contact 14 is formed by the planar recess portion 11b of the housing 11, and compared with a metal material such as the fixed contact 13 or the like. Since it is formed of an insulating member such as a synthetic resin made of a soft material, even if the movable contact 14 repeats the reversing operation by the pressing of the operation member 7, the gap with the outer peripheral edge portion 14f of the movable contact 14 is filled by the keystroke. Since the receiving surface made of a soft material is smoothed, uniform support is possible, and cracking of the movable contact 14 can be prevented, so that the life of the switch contact portion can be extended.

It is a top view which shows the pushbutton switch which concerns on the Example of this invention. It is a top view which shows the 1st housing of this invention. It is a top view which shows the 2nd housing of this invention. It is a top view which shows the movable contact of this invention. It is operation | movement explanatory drawing of the pushbutton switch of this invention. It is a top view which shows the modification of the pushbutton switch using the movable contact different from FIG. 4 of this invention. It is a top view which shows the other Example of the pushbutton switch of this invention. It is a top view which shows the housing of the other Example of the pushbutton switch of this invention. It is the top view and front view which show the movable contact of the other Example of the pushbutton switch of this invention. It is operation | movement explanatory drawing of the other Example of the pushbutton switch of this invention. It is sectional drawing which shows the conventional pushbutton switch.

Explanation of symbols

1: 1st housing 1a: Opening part 1b: One side plate part 2: 2nd housing (base)
2a: hollow part (receiving surface)
2b: hollow part (receiving surface)
3: Common contact 3a: Contact piece 3b: Bending part 3c: External terminal 4: Fixed contact 4a: Contact part 4b: External terminal 5: Movable contact 5a: Dome part 5b: Skirt part 5c: Outer peripheral edge part 6: Insulator 7: Operating member 8: movable contact 8a: dome portion 8b: skirt portion 8c: outer peripheral edge portion 8d: cut portion 11: housing (base)
11a: hollow part 11b: hollow part (receiving surface)
11c: depression 12: common contact 12a: contact 12b: external terminal 13: fixed contact 13a: contact 13b: external terminal 14: movable contact 14a: reversing part 14b: crosspiece 14c: contact piece 14d: dome part 14e: Skirt part 14f: Outer peripheral edge part 15: Insulator

Claims (4)

  A movable contact made of a thin metal plate and having a dome portion that can be reversed by being pressed, a common contact made of a metal material, which is always connected to the movable contact, and the dome portion that is disposed facing the movable contact is reversed. And a base having a receiving surface that supports an outer peripheral edge of the dome portion of the movable contact, the receiving surface being the common contact, the fixed contact, and the movable contact. It is formed of an insulating member made of a softer material, and a connection portion with the common contact is formed on an outer peripheral portion of the dome portion different from an outer peripheral portion of the movable contact supported by the receiving surface. Push button switch.   2. The pushbutton switch according to claim 1, wherein the base is formed of a synthetic resin and the receiving surface is formed integrally with the base.   The connecting portion between the movable contact and the common contact is formed by a contact piece extending from the outer peripheral portion of the dome portion of the movable contact, and the contact piece is elastically contacted with the common contact. Item 3. A pushbutton switch according to item 1 or 2. A connecting portion between the movable contact and the common contact is formed by a contact piece extending from a part of the common contact, and the contact piece is elastically contacted with an outer peripheral portion of the dome portion of the movable contact. The pushbutton switch according to claim 1 or 2.

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