JP2004103375A - Push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a push-button switch, which is capable of sufficiently ensuring design freedom of contact parts, including a peripheral fixed contact and also capable of making the width dimension of the peripheral fixed contact smaller. <P>SOLUTION: A push-button switch comprises peripheral contacts 2 implanted in a housing 1 by insert-molded, a central fixed contact 3, movable contact plates 4 formed by a metal sheet and having base parts 4a and a tongue piece 4b, a rubber spring 5 which is disposed on the movable contact plates 4 and makes the tongue piece 4b to make contact with the central fixed contact 3, and a stem 6 for pressing the rubber spring 5. In addition, a convex part 4c, having a shape forming a part of a sphere and in contact with the contacts at all times is formed on the base part of the movable contact plate 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a one-point open / close contact type push button that is mounted on various electronic devices and that performs switching by contacting a tongue piece of a movable contact plate whose base always contacts peripheral fixed contacts with a central fixed contact by pressing a rubber spring. About the switch.
[0002]
[Prior art]
As this kind of conventional technology, there is one disclosed in Japanese Patent No. 2833913. In this prior art, a switch case or housing forming an outer shell, a common fixed contact or a peripheral fixed contact having a protrusion disposed around a bottom of the housing, and a center arranged at the center of the bottom of the housing are described. And fixed contacts. The peripheral fixed contact and the central fixed contact are provided on the housing by insert molding.
[0003]
The base is housed in the housing, is made of a thin metal plate, and extends in a cantilever manner through a base that constantly contacts the peripheral fixed contact, and a bent and raised portion from the base, and is disposed so as to be able to contact and separate from the central fixed contact. A movable contact plate having a tongue piece.
[0004]
Further, a dome-shaped spring body, that is, a rubber spring, which is housed in the housing, the leg portion is disposed on the base portion of the movable contact plate, and receives the pressing force to bring the tongue piece into contact with the central fixed contact, A push button or stem for pressing the rubber spring is provided.
[0005]
In this prior art, when a stem is pressed, a rubber spring bends to press a tongue of a movable contact plate, and the tongue contacts a central fixed contact. As a result, the center fixed contact and the peripheral fixed contact are conducted through the movable contact plate, and are closed, that is, turned on.
[0006]
When the pressing force applied to the stem is removed, the rubber spring returns to its original shape, the pressing force applied to the tongue of the movable contact plate is removed, and the tongue is fixed to the center by its own spring force. The contact is separated from the central fixed contact and the peripheral fixed contact, and is opened or turned off.
[0007]
[Problems to be solved by the invention]
In the above-described conventional technology, a convex portion is provided on the peripheral fixed contact, and a stable contact is secured between the peripheral fixed contact and the base of the movable contact plate via the convex portion.
[0008]
However, in the conventional technique described above, in order to prevent the resin from covering the convex portion of the peripheral fixed contact at the time of insert molding, a mold having a concave portion having a shape adapted to the convex portion is used. It is necessary to accommodate the convex portion of the fixed contact and insert-mold the portion of the peripheral fixed contact other than the convex portion in contact with the mold.
[0009]
For this reason, the width dimension of the peripheral fixed contact must be extraly increased by a dimension related to the thickness of the mold that forms the concave portion. That is, in the related art, the width dimension of the peripheral fixed contact becomes large. For this reason, there is a problem that the whole shape is restricted by miniaturization.
[0010]
In addition, the position where the above-mentioned convex portion is provided is limited to a specific position due to the connection of the peripheral fixed contact in the housing. Also, in order to make the contact with the movable contact plate more reliable, if the convex portions of the peripheral fixed contact are to be provided at many places, the shape of the peripheral fixed contact and the mold of the concave portion that fits the convex portion. The shape becomes complicated. Therefore, the number of protrusions provided on the peripheral fixed contact is also limited. As described above, in the related art, the degree of freedom in designing the contact portion including the peripheral fixed contact is limited, and therefore, it is difficult to obtain high-precision switching performance, and a highly reliable switch structure is required. It was difficult.
[0011]
The present invention has been made in view of the above-described conventional technology, and has as its object that the width of the peripheral fixed contact can be set to be small, and the degree of freedom in designing the contact portion including the peripheral fixed contact is largely ensured. It is to provide a push button switch that can be used.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a housing forming an outer shell, a peripheral fixed contact arranged around a bottom of the housing, and a center fixed contact arranged at the center of the bottom of the housing. Have. Further, the base is housed in the housing, is made of a thin metal plate, and extends in a cantilever manner through a base that constantly contacts the peripheral fixed contact, and a bent portion from the base, and can be separated from and connected to the central fixed contact. A movable contact plate having a tongue piece disposed thereon is provided. A rubber spring that is housed in the housing, the leg is placed on the base of the movable contact plate, and receives a pressing force to bring the tongue into contact with the center fixed contact; And a stem for pressing the rubber spring. Further, a protrusion is provided on the base of the movable contact plate so as to contact the peripheral fixed contact.
[0013]
According to the present invention configured as described above, the base of the movable contact plate can be constantly brought into contact with the peripheral fixed contact via the projection provided on the base of the movable contact plate. That is, the base of the movable contact plate and the peripheral fixed contact can be reliably brought into contact.
[0014]
In addition, since the convex portion is provided at the base of the movable contact plate, the peripheral fixed contact can be formed in advance on a surface having no convex portion. Therefore, it is not necessary to form a concave portion for accommodating the convex portion formed on the peripheral fixed contact in the mold, and reduce the width dimension of the peripheral fixed contact by a dimension related to the thickness of the mold forming the concave portion. Can be set.
[0015]
Furthermore, the formation of the convex portion at the base of the movable contact plate can be formed simultaneously with the press working of the thin metal plate at the time of producing the movable contact plate, and the production is simple. Also, a desired number of the projections can be easily formed at a desired position on the base of the movable contact plate facing the peripheral fixed contact, and the design of the contact portion including the peripheral fixed contact can be freely performed. A large degree can be secured.
[0016]
Further, the present invention is characterized in that, in the above invention, the convex portion is set to a shape forming a part of a sphere.
[0017]
According to the present invention configured as described above, the convex portion can always be brought into point contact with the peripheral fixed contact.
[0018]
Further, the present invention is characterized in that, in the above invention, a plurality of the convex portions are provided on the base portion located on the tongue side with respect to the bent and raised portion of the movable contact plate.
[0019]
According to the present invention configured as described above, when the tongue is pressed by the rubber spring so as to contact the central fixed contact, a part of the pressing force is located on the tongue one side with respect to the bent and raised portion of the movable contact plate. And the base portion tends to be pressed against the peripheral fixed contact. As a result, a sufficient contact pressure can be secured between the projection provided on the base portion and the peripheral fixed contact, and the projection can be reliably brought into contact with the peripheral fixed contact.
[0020]
Further, the present invention is characterized in that, in the above invention, an uneven portion is provided on one of the lower surface of the tongue piece facing the central fixed contact and the central fixed contact.
[0021]
In the present invention configured as described above, even if dust enters between the tongue piece and the central fixed contact, the dust is held in the concave portion of the uneven portion, and the tongue piece and the central fixed contact are separated by the convex portion. The contact can be made surely.
[0022]
Further, according to the present invention, in the above invention, the rubber spring has a pressing portion for pressing the tongue piece of the movable contact plate, and a convex portion with which the pressing portion can contact the upper surface of the tongue piece is provided. It is characterized by:
[0023]
According to the present invention configured as described above, the above-mentioned convex portion provided on the upper surface of the tongue piece can prevent sticking between the pressing portion of the rubber spring and the tongue piece accompanying the pressing of the rubber spring. In addition, the above-mentioned convex part which a pressing part can contact can be formed simultaneously with the press working of a thin metal plate at the time of manufacturing a movable contact plate.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a push button switch of the present invention will be described with reference to the drawings.
[0025]
1 to 6 are explanatory views showing an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing the embodiment, FIG. 2 is an enlarged view of a portion A in FIG. 1, and FIG. 3 is an enlarged view of a portion B in FIG. It is. 4 is a plan view showing a movable contact plate provided in the present embodiment, FIG. 5 is an enlarged cross-sectional view taken along line CC of FIG. 4, and FIG. 6 shows a housing provided in the present embodiment and having fixed contacts inserted therein. It is a top view.
[0026]
In this embodiment, as shown in FIG. 1, a housing 1 forming an outer shell, a peripheral fixed contact 2 which is arranged around the bottom of the housing 1 and is a common fixed contact, and a center of the bottom of the housing 1 And a center fixed contact 3 to be arranged. The peripheral fixed contact 2 and the central fixed contact 3 are insert-molded in the housing 1 as shown in FIG. The upper surface of the peripheral fixed contact 2 is formed in advance on a flat surface having no projection.
[0027]
Further, as shown in FIG. 1, it is housed in the housing 1, is made of a thin metal plate, and extends in a cantilever manner through a base portion 4 a that constantly contacts the peripheral fixed contact 2, and a bent and raised portion 4 f from the base portion 4 a. A movable contact plate 4 having a tongue piece 4b which is arranged to be able to contact and separate from the central fixed contact 3 is provided.
[0028]
In the housing 1 above the movable contact plate 4, there is provided a rubber spring 5 for receiving the pressing force and bringing the tongue piece 4 b into contact with the central fixed contact 3. The leg 5a of the rubber spring 5 is mounted on the base 4a of the movable contact plate 4. At the center of the rubber spring 5, a pressing portion 5b for pressing the tongue piece 4b of the movable contact plate 4 to make contact with the central fixed contact 3 is provided.
[0029]
Further, a stem 6 movably mounted on the housing 1 and operating to press the rubber spring 5 is provided.
[0030]
In particular, in the present embodiment, as shown in FIG. 2 in which part A of FIG. 1 is enlarged, a convex portion that contacts the peripheral fixed contact 2, for example, a part of a sphere, is formed on the lower surface of the base 4 a of the movable contact plate 4. A convex portion 4c having a shape is provided. The projection 4c is always in point contact with the peripheral fixed contact 2.
[0031]
As shown in FIG. 4, a plurality of, for example, four, protrusions 4c are provided on the base 4a located on the tongue piece 4b side with respect to the bent and raised portion 4f of the movable contact plate 4. Two of these four projections 4c are located, for example, on an imaginary line passing substantially through the center of the movable contact plate 4 in the lateral direction, and the other two are located near the tip of the tongue piece 4b. Let me do it. All or a part of these projections 4c are always in point contact with the peripheral fixed contact 2.
[0032]
Also, as shown in FIGS. 3, 4 and 5 in which the portion B of FIG. 1 is enlarged, the lower surface of the tongue piece 4b of the movable contact plate 4 has, for example, the same shape as the convex portion 4c of the base 4a. Three projections 4d are provided. These projections 4d are positioned, for example, at equal intervals so as to surround the center of the tongue piece 4b. All or some of these projections 4d can be point-contacted to the central fixed contact 3.
[0033]
With the provision of the three convex portions 4d described above, an uneven portion is formed on the lower surface of the tongue piece 4b of the movable contact plate 4 facing the central fixed contact 3. That is, the projections of the projections and depressions are three projections 4d, and the depressions of the projections and depressions are spaces including the lower surface of the tongue piece 4b formed around the projection 4d.
[0034]
Further, on the upper surface of the tongue piece 4b of the movable contact plate 4 opposed to the pressing portion 5b of the rubber spring 5, as shown in FIGS. 3 and 4, a convex portion 4e with which the pressing portion 5b can contact is provided. The projection 4e provided on the upper surface of the tongue 4b is also set to have the same shape as the projection 4d provided on the lower surface of the tongue 4b, for example, and is located at the center of the tongue 4b.
[0035]
In the present embodiment configured as described above, the base 4a of the movable contact plate 4 is always in contact with the peripheral fixed contact 2 by the elasticity of the leg 5a of the rubber spring 5 housed in the housing 1 so as to be regulated by the stem 6. It is pressed. That is, all or some of the four protrusions 4c provided on the lower surface of the base 4a are held so as to always make point contact with the peripheral fixed contact 2.
[0036]
When the stem 6 is pressed from this state, the rubber spring 5 bends, and the pressing portion 5b presses the tongue 4b via the convex portion 4e provided on the upper surface of the tongue 4b of the movable contact plate 4. All or some of the three protrusions 4d provided on the lower surface of the tongue piece 4b make point contact with the central fixed contact. As a result, the central fixed contact 3 and the peripheral fixed contact 2 conduct through the movable contact plate 4 and are closed, that is, turned on.
[0037]
When the pressing force applied to the stem 6 is removed from the above state, the rubber spring 5 returns to the original shape, and the pressing force applied to the tongue 4b of the movable contact plate 4 is removed. As a result, the tongue piece 4b, that is, the protrusion 4d of the tongue piece 4b is separated from the central fixed contact 3 by the spring force of the tongue piece 4b, and the gap between the central fixed contact 3 and the peripheral fixed contact 2 is cut off. That is, it is turned off.
[0038]
In the present embodiment configured as described above, as described above, the convex portion 4c provided on the lower surface of the base 4a of the movable contact plate 4 can always be brought into point contact with the peripheral fixed contact 2. That is, the base portion 4a of the movable contact plate 4 and the peripheral fixed contact 2 can be reliably contacted.
[0039]
Further, when the tongue piece 4b is pressed by the rubber spring 5 so as to come into contact with the central fixed contact 3, a part of the pressing force is positioned on the tongue piece 4b side with respect to the bent and raised portion 4f of the movable contact plate 4. The base portion 4 a is transmitted to the peripheral fixed contact 2. In the present embodiment, since the four convex portions 4c are provided so as to be located at the base portion 4a pressed against the peripheral fixed contact 2 at this time, even when the tongue piece 4b is pressed, the convex portions 4c are provided. Can be reliably brought into contact with the peripheral fixed contact 2.
[0040]
Further, even if dust enters between the lower surface of the tongue piece 4b of the movable contact plate 4 and the central fixed contact 3, such dust will remain in the space around the three protrusions 4d provided on the lower surface of the tongue piece 4b. Held in pieces. That is, even when dust enters, the tongue piece 4b and the center fixed contact 3 can be reliably brought into contact with each other by the projection 4d.
[0041]
As described above, in the present embodiment, the base 4a of the movable contact plate 4 and the peripheral fixed contact 2 can be always and reliably brought into contact with each other by the convex portion 4c provided on the lower surface of the base 4a of the movable contact plate 4. Further, the tongue piece 4b and the center fixed contact 3 can be reliably brought into contact with each other by the convex portion 4d provided on the lower surface of the tongue piece 4b.
[0042]
Further, in the present embodiment, since the protrusion 4c is provided on the base 4a of the movable contact plate 4, the upper surface of the peripheral fixed contact 2 can be formed in advance as a flat surface having no protrusion as described above. Therefore, when insert molding the peripheral fixed contact 2 and the central fixed contact 3 into the housing 1, it is not necessary to form a concave portion for accommodating the convex portion formed on the peripheral fixed contact 2 in the mold, and the concave portion is formed. The width dimension of the peripheral fixed contact 2 can be reduced by a dimension related to the thickness of the die to be formed. This makes it possible to reduce the size of the overall shape.
[0043]
Further, in the present embodiment, the convex portion 4c on the base 4a of the movable contact plate 4 can be formed simultaneously with the pressing of a thin metal plate when the movable contact plate 4 having the base 4a and the tongue piece 4b is manufactured. Easy to make. In addition, a desired number of protrusions 4c can be easily formed at desired positions of the base 4a of the movable contact plate 4. Thereby, a large degree of freedom in designing the contact portion including the peripheral fixed contact 2 can be ensured. For this reason, as described above, highly accurate switching performance can be ensured, and a highly reliable switch structure can be obtained.
[0044]
Further, in the present embodiment, the protrusion 4e provided on the upper surface of the tongue piece 4b can prevent the pressing portion 5b of the rubber spring 5 from sticking to the tongue piece 4b due to the pressing of the rubber spring 5, and the reliability can be improved. Contributes to securing a highly switchable structure. It is to be noted that both the convex portion 4e provided on the upper surface of the tongue piece 4b and the convex portion 4d provided on the lower surface of the tongue piece 4b are simultaneously formed at the time of pressing the thin metal plate when manufacturing the movable contact plate 4. It can be easily formed.
[0045]
In addition, as described above, since the convex portion 4e is provided on the upper surface of the tongue piece 4b, when the rubber spring 5 is pressed, the center of the pressing portion 5b of the rubber spring 5 and the convex portion When the position does not coincide with the position 4e, the pressing portion 5b is inclined, and a part of the pressing portion 5b tends to be strongly pressed by the tongue piece 4b. Therefore, the convex portion 4d at a position close to the position where a part of the pressing portion 5b is strongly pressed by the tongue piece 4b comes into contact with the central fixed contact 3 with a large contact pressure. As a result, the corresponding convex portion 4d can be brought into point contact with the central fixed contact 3 with a strong force, and the tongue piece 4b and the central fixed contact 3 can be more reliably brought into contact with each other, ensuring high-precision switching performance. To contribute.
[0046]
Further, in the present embodiment, as described above, the three convex portions 4d provided on the lower surface of the tongue piece 4b form an uneven portion on the lower surface of the tongue piece 4b. This can prevent poor contact due to dust between them and contribute to ensuring high-precision switching performance.
[0047]
In the above-described embodiment, three projections 4d are provided on the lower surface of the tongue piece 4b of the movable contact plate 4 to form the unevenness on the lower surface of the tongue piece 4b. Instead of being provided on the lower surface of 4b, it may be provided on the upper surface of the central fixed contact 3. Even with such a configuration, dust entering between the tongue piece 4b and the central fixed contact 3 can be held in the concave portion of the uneven portion, and the tongue piece 4b and the central portion can be held by the convex portion of the uneven portion. The fixed contact 3 can be reliably brought into contact.
[0048]
Further, in the above-described embodiment, the width of the peripheral fixed contact 2 can be set small by not providing the convex portion on the peripheral fixed contact 2, so that the overall shape can be reduced in size. However, when the overall shape is made equal to the conventional one, the width of the peripheral fixed contact 2 can be set smaller, so that the center fixed contact 3 can be set larger than the conventional one. With such a configuration, a large contact area between the tongue piece 4b of the movable contact plate 4 and the center fixed contact 3 can be ensured, and the tongue piece 4b and the center fixed contact 3 can be more reliably brought into contact. Can be.
[0049]
【The invention's effect】
As described above, according to the present invention, the convex portion for contacting the peripheral fixed contact is provided at the base of the movable contact plate, so that the width dimension of the peripheral fixed contact can be set to be small. Can be realized.
[0050]
In addition, the convex portion can be formed at the same time as the production of the movable contact plate, so that the production is simple and the degree of freedom in designing the contact portion including the peripheral fixed contact can be largely ensured. As a result, the contact between the movable contact plate and the peripheral fixed contact can be reliably performed, the switching performance with high accuracy can be ensured, and a switch structure with higher reliability than before can be provided.
[0051]
In the present invention, the above-mentioned convex portion is set in a shape that forms a part of a sphere. As a result, the convex portion is always in point contact with the peripheral fixed contact, and the base of the movable contact plate and the peripheral fixed contact are surely brought into contact with each other, which contributes to ensuring high-precision switching performance.
[0052]
Further, in the present invention, a plurality of the convex portions are provided on a base portion located on one side of the tongue with respect to the bent and raised portion of the movable contact plate. As a result, even when the rubber spring is pressed, a sufficient contact pressure of the convex portion with respect to the peripheral fixed contact can be obtained, which contributes to ensuring high-precision switching performance.
[0053]
In the present invention, an uneven portion is provided on one of the lower surface of the tongue piece facing the central fixed contact and the central fixed contact. With this, even if dust enters between the tongue and the central fixed contact, the dust is retained in the concave portion of the uneven portion, and the tongue and the central fixed contact are reliably secured by the convex portion of the uneven portion. Can be contacted. That is, contact failure due to dust between the tongue piece and the center fixed contact can be prevented, which contributes to ensuring highly accurate switching performance.
[0054]
Further, according to the present invention, the rubber spring has a pressing portion for pressing the tongue piece of the movable contact plate, and a convex portion on the upper surface of the tongue piece that the pressing portion can contact. The protrusion prevents sticking between the pressing portion of the rubber spring and the tongue piece, and contributes to securing a highly reliable switch structure.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one embodiment of a push button switch of the present invention.
FIG. 2 is an enlarged view of a portion A in FIG.
FIG. 3 is an enlarged view of a portion B in FIG. 1;
FIG. 4 is a plan view showing a movable contact plate provided in the embodiment shown in FIG. 1;
FIG. 5 is an enlarged cross-sectional view taken along the line CC of FIG. 4;
FIG. 6 is a plan view showing a housing provided in the embodiment shown in FIG. 1 and having fixed contacts inserted therein.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Peripheral fixed contact 3 Center fixed contact 4 Movable contact plate 4a Base 4b Tongue piece 4c Convex 4d Convex 4e Convex 4f Bend-up section 5 Rubber spring 5a Leg 5b Press section 6 Stem

Claims (5)

A housing forming an outer shell, a peripheral fixed contact disposed around a bottom of the housing, and a central fixed contact disposed at the center of the bottom of the housing;
A base that is housed in the housing, is made of a thin metal plate, and extends in a cantilever manner through a base that constantly contacts the peripheral fixed contact, and a bent and raised portion from the base, and is disposed so as to be able to contact and separate from the central fixed contact. A movable contact plate having a tongue piece,
A rubber spring that is housed in the housing, the leg is placed on the base of the movable contact plate, and receives a pressing force to contact the tongue piece with the central fixed contact, and is movably mounted on the housing. And a stem that presses the rubber spring.
A push button switch, wherein a convex portion for contacting the peripheral fixed contact is provided on the base of the movable contact plate. In the invention according to claim 1,
A push button switch, wherein the convex portion is set in a shape forming a part of a sphere. In the invention according to claim 1,
A push button switch, wherein a plurality of the convex portions are provided on a portion of the base portion located on the tongue side with respect to the bent and raised portion of the movable contact plate. In the invention according to claim 1,
A push button switch, wherein an uneven portion is provided on one of a lower surface of the tongue piece facing the central fixed contact and the central fixed contact. In the invention according to claim 1,
A push button switch, wherein the rubber spring has a pressing portion for pressing the tongue piece of the movable contact plate, and a convex portion with which the pressing portion can contact is provided on an upper surface of the tongue piece.

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