JP2002324454A - Push-button switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a normally closed push-button switch that has a simple structure equal to that of a usual normally open switch and that can achieve small-size and low-cost. SOLUTION: This push-button switch is equipped with a housing 1 having a housing part 1a, fixed contacts 2a, 2b arranged on the inner bottom in the housing part 1a, a movable contact 4 placed on the fixed contacts 2a, 2b and a stem 5 that brings the movable contact 4 into contact with/separates from the fixed contacts 2a, 2b by pushing the movable contact 4. In the movable contact 4, there are formed a bulge 4a where the top bulges upward, slits 4b that are set in parallel with the top of the bulge 4a in-between and supporting pieces 4c that are set on both peripheral edges of the bulge 4a via the slits 4b. Both ends of the bulge 4a are contacted always with the fixed contacts 2a, 2b in the extended direction of the slits 4b, and by pushing and reversing the bulge 4a of the movable contact 4 accompanying pushing of the stem 5, both ends of the movable contact 4 part from the fixed contacts 2a, 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push-button switch used as an operation switch for various electronic devices, and more particularly to a normally closed contact structure in which a contact is turned off when pressed.

[0002]

2. Description of the Related Art As a structure of a conventional push button switch, a structure shown in FIGS. 6 and 7 is known. FIG. 6 is a sectional view of the push button switch, and FIG. 7 is a partial sectional view showing a state in which the stem is pressed similarly.

The conventional push button switch comprises a housing 11 having a storage portion 11a in which a plurality of fixed contacts 12a and 12b are provided, and a fixed contact 12 of the housing 11.
a movable contact 14 disposed in the storage portion 11a in opposition to the fixed contact 12a, the movable contact 14 being disposed on the movable contact 14 and being pressed to bend the movable contact 14 downward. , 12b, and a cover 16 that covers the storage portion 11a.

[0004] The housing 11 is formed of an insulating material such as a synthetic resin into a rectangular box shape having a storage portion 11a. The fixed contacts 12a and 12b made of a conductive metal plate are arranged at a constant interval on the inner bottom surface of the housing 11a. At the upper end side of the opening of the housing 11, a locking projection 11b that protrudes outward and locks the cover 16 is provided.

The movable contact 14 is formed of a conductive metal plate, and is formed in an arc shape in which the top is bulged upward at both ends. The movable contact 14 is placed on the fixed contacts 12a and 12b with the center part facing the fixed contact 12a with both ends in contact with the fixed contact 12b. Note that when the stem 15 is not pressed, the central contact portion 14a is separated and the switch is off.

The stem 15 is formed of an insulating material such as a synthetic resin in a substantially columnar shape. The stem 15 has an operating portion 15a protruding outside the housing 11 and an operating portion 1a.
Pressing projections 15b projecting below 5a and contacting the top of the movable contact 14 to press the movable contact 14 downward are formed. Also, at the lower end of the peripheral surface of the operation unit 15a,
A flange 15c is provided to contact the inner surface of the cover 16 and prevent the cover 16 from jumping out of the housing 11.

[0007] The cover 16 is made of a thin metal plate.
It is formed in a substantially square shape. In the center of the cover 16, a through hole 16a from which the operation portion 15a of the stem 15 projects is provided.
In the four corners, insertion holes (not shown) for inserting and locking the locking projections 11b of the housing 11 are formed. Note that the locking projection 11b is fixed after being inserted into the insertion hole by caulking with a press or the like.

In the push button switch, when the operating portion 15a of the stem 15 is pressed, the pressing projection 15b of the stem 15 presses the top of the movable contact 14 to push it down. At this time, the bulging portion is bent downward, so that a central contact portion 14 of the movable contact 14 is formed.
a contacts the fixed contact 12a, and
The switches a and 12b are connected to each other via the movable contact 14, and the switch is turned on.

In this state, when the pressing force of the stem 15 is released, the bulging portion of the movable contact 14 returns to the initial state by the urging force generated at the time of bending, and the stem 15 is pressed upward to push the stem 15 upward. 15 returns to the initial position. At this time, the switch is turned off when the central contact portion 14a of the movable contact 14 is separated from the fixed contact 12a. In the above configuration, the stem 15
Has a normally open type switch structure in which the switch is turned off when not pressed.

[0010]

However, in the structure of the conventional push-button switch described above, it is necessary to keep the switch on at all times and to switch off the switch when the stem is pressed. There was a problem that it could not be used as a device.

In order to obtain a normally closed type, fixed contacts are arranged above and below the housing with the movable contact interposed therebetween, and when not operated, the movable contact is electrically connected to the upper and lower fixed contacts to keep the switch on. A structure in which the movable contact is separated from the upper fixed contact by pressing the stem and the switch is turned off can be considered, but for this purpose, the fixed terminals must be arranged above and below the housing, which complicates the structure and increases the size. There is a problem that leads to high cost and high cost.

Accordingly, the present invention solves the above-mentioned problems, and provides a structure of a normally closed type push button switch which can be reduced in size and cost with a simple structure equivalent to a conventional normally open type switch. The purpose is to.

[0013]

According to a first aspect of the present invention, there is provided a housing having a housing, a fixed contact disposed on an inner bottom surface of the housing, and
A movable contact placed on the fixed contact; and a stem for pressing the movable contact to bring the movable contact into and out of contact with the fixed contact. The movable contact has a bulge whose top bulges upward. A projecting portion, a slit portion provided in parallel with the top portion of the bulging portion interposed therebetween, and a support piece portion provided on both side peripheral portions of the bulging portion through the slit portion; In the extending direction, the both ends of the bulging portion are always in contact with the fixed contact, and the bulging portion of the movable contact is pressed and inverted with the pressing of the stem, so that both ends of the movable contact are The part is separated from the fixed contact.

As a second means, a bent portion which bulges downward is formed in the support piece portion, and the bulge portion of the movable contact is pressed in accordance with the pressing of the stem, and the bent portion is formed. Abuts against the inner bottom surface of the storage section,
The swollen portion of the movable contact is formed to be inverted with the bent portion as a fulcrum.

Further, as a third means, when both ends of the bulging portion of the movable contact are always in contact with the fixed contact, the inner bottom surface of the housing portion and the bent portion of the support piece portion are connected to each other. A gap is formed between them.

As a fourth means, a projecting receiving portion which is in contact with the lower surface of the bent portion is formed on the inner bottom surface of the storage portion below the bent portion of the support piece. And

[0017]

FIG. 1 is a block diagram showing an embodiment of the present invention.
1 to FIG. 5, FIG. 1 is a cross-sectional view when a push button switch is not operated, FIG. 2 is a cross-sectional view showing a state where a stem is pressed, and FIG. 4
Is a partial perspective view showing the contact portion when not pressed, and FIG. 5 is a partial perspective view showing the contact portion in an off state when pressed.

In FIG. 1, a housing 1 is made of an insulating material such as a synthetic resin and is formed in a box shape having a storage portion 1a therein and having an open upper surface. A pair of fixed contacts 2a and 2b made of a conductive metal plate are buried in the bottom surface of the housing portion 1a of the housing 1 in a state where the fixed contacts 2a and 2b face each other and one surface side is exposed. In addition, connection terminals 3a, 3b which are led out from the fixed contacts 2a, 2b and protrude outward are formed on opposite outer surfaces of the housing 1.

Further, a pair of projecting receiving portions 1b are formed on the inner bottom surface of the housing portion 1a and orthogonal to the direction in which the fixed contacts 2a and 2b are arranged. The receiving portion 1b is formed with a difference in height so as to be slightly lower than the position where the fixed contacts 2a and 2b are provided. Alternatively, the receiving portion 1b may be formed to have a higher height by changing the bending shape of the movable contact 4 described later.
A concave guide groove 1c is formed on the inner wall surface of the storage portion 1a at the upper end side of the opening, and an outer peripheral edge of a stem 5 described later is engaged with the guide groove 1c to be guided. It has become.

The movable contact 4 is formed of a conductive metal plate in a substantially disk shape, and has a bulging portion 4a whose top bulges upward at the center. On both sides of the top of the bulging portion 4a, slit portions 4 formed of parallel cutouts are provided.
The movable contact 4 is formed on both sides of the movable contact 4 by providing the slit 4b.

A bent portion 4d bulging downward is formed at the center of the support piece portion 4c, and the lower surface of the bent portion 4d is formed on the inner bottom surface of the storage portion 1a. 1b, the bent portion 4d serves as a fulcrum, and the bulging portion 4a of the movable contact 4 is inverted. By forming the bent portion 4d on the support piece 4c, the bent portion 4d serves as a fulcrum when a stem 5 described later is pressed, thereby generating an operating force and a click feeling (a sense of moderation). Bulging portion 4a is surely inverted.

The receiving portion protrudes upward at a position where the lower surface of the bent portion 4d comes into contact with the inner bottom surface of the housing portion 1a of the housing 1 and becomes a fulcrum when the bulging portion 4a is inverted. 1b, and the fulcrum position at which the bent portion 4d is supported is clear, so that the bulging portion 4a of the movable contact 4 is more reliably inverted.

The movable contact 4 is mounted on the fixed contacts 2a and 2b of the storage portion 1a. At this time, both ends of the bulging portion 4a are fixed to the fixed contacts 2a in the extending direction of the slit portion 4b. , 2b are always in contact with each other, and both end portions thereof are contact portions 4e, 4f with the fixed contacts 2a, 2b. As shown in FIG. 1, when the push button switch is not operated, the contact portions are in contact with each other, and the switch is kept on (normally closed).

Further, the movable contact 4 is fixed to the fixed contact 2
a and 2b, a gap G is formed between the lower surface of the bent portion 4d provided on the support piece 4c and the receiving portion 1b of the housing 1. By providing the above, variation in the height dimension between the components can be absorbed, so that contact between the contact portions can be ensured, and the switch can be reliably maintained in the ON state.

The stem 5 is formed of an insulating material such as a synthetic resin into a substantially columnar shape. The stem 5 is provided with an operating portion 5a which is pushed out of the opening of the housing 1 and is operated to be pressed. On the lower surface side of the operating portion 5a, the operating portion 5a is protruded downward and contacts the top of the movable contact 4. Contact and movable contact 4
Is formed to press downwardly. A flange 5c is provided on the outer peripheral edge of the operation portion 5a so as to be engaged with and guided by the guide groove 1c formed on the inner wall surface of the housing 1a of the housing 1 when the stem 5 is pressed. Is formed.

When the stem 5 is pressed, the lower end of the flange 5c abuts against the bottom of the guide groove 1c, whereby further pushing of the stem 5 is restricted. When the stem 5 is returned, the flange 5c is inserted into the housing 1a of the housing 1.
The stem 5 is prevented from protruding outward by being locked to an inner surface of a cover 6 described later, which is fixed to the upper surface of the opening.

The cover 6 is formed in a rectangular shape by a thin metal plate. The cover 6 has the stem 5 in the center.
A through-hole 6a from which the operating portion 5a is projected is provided, and a fixing protrusion (not shown) formed on the upper surface side of the housing 1 (not shown) is inserted through four square corners. An insertion hole is formed.

Next, the operation of the push button switch having the above configuration will be described. In the non-pressing operation state shown in FIG. 1, the movable contact 4 is connected to the contact portions 4 at both ends of the bulging portion 4a as shown in FIG.
e, 4f are in contact with the fixed contacts 2a, 2b, and the switches are on (normally closed)
It has become.

In this state, when the stem 5 is pressed by a finger or the like, the pressing protrusion 5b provided below the operating portion 5a of the stem 5 causes the bulging portion 4 of the movable contact 4 to move.
Pressing the top surface of the top a pushes the bulge 4a downward.

At this time, when the bulging portion 4a of the movable contact 4 is pressed downward, the supporting piece portion 4c formed in a double-supported beam shape on both peripheral edges of the bulging portion 4a follows. The support piece 4 moves downward as shown in FIG.
The lower surface of the bent portion 4d at the center of c contacts the receiving portion 1b projecting from the inner bottom surface of the storage portion 1a.

When the stem 5 is further pressed from this state, the movable contact 4 is biased upward at both ends of a doubly supported beam with the lower surface of the bent portion 4d of the support piece 4c as a fulcrum. As the bulging portion 4a reverses downward, the both end sides largely jump upward.
For this reason, as shown in FIGS. 3 and 5, both ends of the bulging portion 4a also follow and largely jump upward, and the contact portions 4e and 4f provided at both ends are fixed contacts 2a and 2b.
And the switch is turned off.

At the same time, the lower end of the flange 5c formed on the outer peripheral edge of the stem 5 comes into contact with the bottom surface of the guide groove 1c formed in the housing portion 1a, thereby forming a stopper. 5 is restricted.

When the pressing force on the stem 5 is released from this state, the bulging portion 4a of the movable contact 4 is inverted by its own elasticity to return to the initial state, and the urging force at this time causes The stem 5 is pressed upward and returns to the initial position. At this time, as the bulging portion 4a reverses, the support piece portion 4c also follows, so that the contact portions 4 provided at both ends of the movable contact 4 are provided.
e, 4f are inverted downward, return to the initial state, come into contact with the fixed contacts 2a, 2b, and the switch is turned on.

According to the above configuration, the fixed contacts 2a, 2a
The movable contact 4 placed on the upper surface b has a bulge 4a whose top bulges upward, a slit 4b provided in parallel with the top of the bulge 4a, and a slit 4b. Support pieces 4 provided at both peripheral edges of the bulging portion 4a
c, and the contact portions 4e, 4f provided at both ends of the bulging portion 4a are always in contact with the fixed contacts 2a, 2b, and the swelling of the movable contact 4 is caused by the pressing of the stem 5. When the protruding portion 4a is pressed and reversed, the contact portions 4e and 4f of the movable contact 4 are fixed to the fixed contacts 2a,
2b, the fixed contact 2
Since a and 2b can be formed parallel to the same surface of the housing 1, a normally closed type push button switch that can be reduced in size and cost with a simple structure equivalent to a conventional normally open type switch can be provided. Can be provided.

[0035]

As described above, the push button switch according to the present invention comprises a housing having a housing, a fixed contact provided on the inner bottom surface of the housing, and a movable contact mounted on the fixed contact. And a stem that presses the movable contact to move the movable contact into and out of contact with the fixed contact. The movable contact has a bulged portion whose top bulges upward, and the top of the bulged portion is sandwiched therebetween. A slit portion provided in parallel and a support piece portion provided on both peripheral edges of the bulging portion through this slit portion are formed, and both ends of the bulging portion are fixed contacts in the extending direction of the slit portion. The fixed contact is placed on the same surface of the housing because the contact portion is always in contact and the bulge portion of the movable contact is pressed and inverted with the pressing of the stem, so that both ends of the movable contact are separated from the fixed contact. Because it can be formed in parallel to In normally open type of switch and the equivalent of a simple structure of years, miniaturization, it is possible to provide a normally closed type of push-button switch that cost reduction can be achieved.

Further, a bent portion which swells downward is formed on the support piece, and the swelling portion of the movable contact is pressed with the pressing of the stem, and the bent portion comes into contact with the inner bottom surface of the storage portion. Thus, since the bulging portion of the movable contact is formed to be inverted with the bent portion as a fulcrum, by forming the bent portion on the support piece, the bent portion becomes a fulcrum when the stem is pressed, and the operating force and the like are increased. A click feeling (a sense of moderation) can be generated, and the bulging portion of the movable contact can be reliably reversed.

When both ends of the bulging portion of the movable contact are constantly in contact with the fixed contact, a gap G is formed between the inner bottom surface of the storage portion and the bent portion of the support piece. Therefore, by providing the gap G, the variation in the height dimension between the components can be absorbed, so that the contact between the contact portions can be ensured, and the switch can be reliably maintained in the ON state. be able to.

Further, since a protruding receiving portion which is in contact with the lower surface of the bent portion is formed on the inner bottom surface of the storage portion below the bent portion of the support piece portion, a fulcrum position at which the bent portion is supported is provided. It becomes clear and the bulging portion of the movable contact can be more reliably reversed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a non-operating state of a push button switch according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the stem of the push button switch of the present invention is pressed.

FIG. 3 is a cross-sectional view showing a state where a contact is turned off when the stem is pressed similarly according to the present invention.

FIG. 4 is a partial perspective view showing a contact portion of the present invention when the stem is not pressed.

FIG. 5 is a partial perspective view showing the contact portion of the present invention in a state where the contact portion is turned off when the stem is pressed.

FIG. 6 is a sectional view showing a conventional push button switch.

FIG. 7 is a partial sectional view showing a state where a stem of a conventional push button switch is pressed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 1a Storage part 1b Receiving part 1c Guide groove part 2a, 2b Fixed contact 3a, 3b Connection terminal 4 Movable contact 4a Swelling part 4b Slit part 4c Support piece part 4d Bending part 4e, 4f Contact part 5 Stem 5a Operating part 5b Press Projection 5c Flange 6 Cover 6a Through-hole G Gap

Claims (4)

[Claims] 1. A housing having a storage portion, a fixed contact disposed on an inner bottom surface of the storage portion, a movable contact placed on the fixed contact, and a movable contact formed by pressing the movable contact. And a stem for bringing the fixed contact into and out of contact with the fixed contact.The movable contact has a bulge having a top bulging upward, a slit provided in parallel with the top of the bulge, and Forming support pieces provided on both peripheral edges of the bulging portion via a slit portion, and constantly contacting both ends of the bulging portion with the fixed contact in the extending direction of the slit portion, A push button switch, wherein a bulge portion of the movable contact is pressed and inverted with the pressing of the stem, so that both ends of the movable contact are separated from the fixed contact. 2. A bent portion that bulges downward is formed in the support piece portion, and a bulge portion of the movable contact is pressed with the pressing of the stem, and the bent portion is formed inside the storage portion. 2. The push-button switch according to claim 1, wherein the bulge portion of the movable contact is inverted by using the bent portion as a fulcrum by contacting the bottom surface. 3. A gap between the inner bottom surface of the housing and the bent portion of the support piece when both ends of the bulging portion of the movable contact are always in contact with the fixed contact. 3. The push button switch according to claim 2, wherein the push button switch is formed. 4. A receiving portion formed on the inner bottom surface of said storage portion at a position below said bent portion of said support piece portion and in contact with a lower surface of said bent portion. Or the push button switch according to 3.