JP2004311128A - Push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturizable normally-closed push-button switch having a simple structure. <P>SOLUTION: Circumferential edge parts 4a of a moving contact 4 are mounted above first and second fixed contacts 2 and 3 to electrically connect the fixed contacts 2 and 3 to each other. Insulating projection parts 1b and 1c are formed inside the edge parts 4a of the moving contact 4 and on the inner bottom face of a housing part 1a of a housing 1 in the vicinity of the fixed contact 2 and/or the fixed contact 3. When the swollen part of the moving contact 4 is pressed and reversed, the inside surface of the moving contact 4 contacts the projection parts 1b and 1c to separate the edge parts 4a from the fixed contact 2 and/or the fixed contact 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a push-button switch, and more particularly to a structure of a so-called normally-closed push-button switch in which the contacts are always in a conductive state when not in operation.
[0002]
[Prior art]
The structure of the conventional normally closed type push button switch is to set the operating force at the time of reversal of the movable contact large and apply a high load to the fixed contact in the steady state to ensure electrical contact between the contacts. In addition, there is known a configuration in which a thin plate-shaped return spring for returning a push button to an initial position is combined with a lower surface of a reversible thin plate-shaped movable contact. Thereby, conduction and separation between the fixed contacts by the movable contact can be performed reliably and stably (for example, Patent Document 1).
[0003]
FIG. 12 shows the structure of this conventional push button switch. The switch case 1 has a cavity 10 formed therein, has a contact storage portion 14 in a lower portion thereof, and a pair of fixed contact formation portions 13 are provided to face each other, while a pair of return spring mounting portions 15 are provided. They are formed to face each other. A fixed contact 33 is exposed on one side of the fixed contact forming portion 13, and a projection 16 is formed at the center thereof. A fixed contact 34 is exposed on the other side of the fixed contact forming portion 13. Reference numeral 31 denotes a terminal connected to the fixed contact 33, and reference numeral 32 denotes a terminal connected to the fixed contact.
[0004]
The thin plate-shaped return spring 6 is formed by punching a metal plate having a spring property, such as phosphor bronze, into a rectangular shape, and is slightly curved upward. The thin plate-shaped return spring 6 is deformed and flattened by the pressing force from above, and returns to the original shape when the pressing force is released. That is, an upward urging force is always generated.
[0005]
Similarly, the thin plate-shaped movable contact 4 is formed by punching a metal plate having a spring property such as phosphor bronze into a rectangular shape, and two slits 41 are formed in parallel with the longitudinal direction. In addition, a reversing spring portion 44 is formed between the edge portions 43. One of the short sides of the rectangle is a contact portion 42 of the movable contact 4, and the other of the short sides is a fulcrum piece 46. An opening 47 is provided at the center of the fulcrum side 46 to engage with the projection 16. A downward curved portion 45 is formed on each of the edge portions 43 in a direction orthogonal to the longitudinal direction, and the reversing spring portion 44 is slightly deformed upward.
[0006]
When a pressing force is applied to the reversing spring portion 44, the thin plate-shaped movable contact 4 reverses downward and the contact portion 42 jumps upward and maintains this state. Then, when a pressing force is applied to the inverted spring portion 44 from below in this state, the inverted spring portion 44 is inversely deformed upward and returns. At the center of the thin plate-shaped movable contact 4, there is formed a concave portion 48 having a downwardly projecting portion for pressing the return spring 6 when a pressing force is applied from above.
[0007]
In the pushbutton switch having the above-described configuration, in a steady state, the contact portion 42 is pressed against the fixed contact 34 by a force opposite to the upward elastic force, and the fixed contact 33 and the fixed contact 34 are in a conductive state (normally closed state). Here, when a push button (not shown) is pressed, the reversing spring portion 44 of the thin plate-shaped movable contact 4 is pushed downward, and reversely deforms downward. In this state, the contact portion 42, which is the free end of the thin plate-shaped movable contact 4, jumps up and the contact with the fixed contact 34 is released.
[0008]
At this time, the reversely deformed reversing spring portion 44 has a thin plate-like return spring 6 which is always urged upward in a pressed state and is pressed upward due to its presence under the lower side. The reversing spring portion 44 is reversibly deformed upward and returns. As a result, the contact portion 42 of the thin plate-shaped movable contact 4 jumps up, and the contact between the contact portion 42 and the fixed contact 34 comes into contact again and returns to the conductive state.
[0009]
[Patent Document 1]
JP-A-10-106386 [0010]
[Problems to be solved by the invention]
However, in the structure of the conventional push button switch described above, the shape of the thin plate-shaped movable contact, which is a reversing spring, is complicated, and two spring members are required in combination with the thin plate-shaped return spring for return. However, there has been a problem that it cannot be simplified, the assembly becomes complicated, and the size cannot be reduced.
[0011]
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems and to provide a normally-closed type push button switch having a simple configuration and capable of being miniaturized.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, as a first means, a housing having a storage portion, first and second fixed contacts disposed on an inner bottom surface of the storage portion, the first and second fixed contacts are provided. A movable contact having a reversible bulging portion disposed on the fixed contact of the first contact. The outer peripheral edge of the movable contact is placed on the first and second fixed contacts and the first and second fixed contacts are placed on the first and second fixed contacts. 2 and a conductive protruding portion is formed on the inner bottom surface of the housing inside the outer peripheral edge of the movable contact and near the first and / or second fixed contact. When the bulging portion of the movable contact is pressed and reversed, the inner surface of the movable contact comes into contact with the protruding portion to separate the outer peripheral edge from the first and / or second fixed contact. It is characterized by doing so.
[0013]
As a second means, the movable contact is formed in a circular dome shape, and the protruding portion is formed by an arc-shaped wall extending along an inner periphery of the circular dome shape of the movable contact. It is characterized by the following.
[0014]
Further, as a third means, the movable contact is formed in a circular dome shape, and the protruding portion is an annular wall provided continuously along an inner periphery of the circular dome shape of the movable contact. It is characterized by having been formed.
[0015]
As a fourth means, the housing is formed of an insulating material, and the protruding portion is formed integrally with the housing.
[0016]
Further, as a fifth means, a third fixed contact is formed between the first and second fixed contacts in the storage portion, and the protruding portion is connected to the first or second fixed contact. When the bulge portion of the movable contact is pressed and reversed, the lower surface of the bulge portion of the movable contact comes into contact with the third fixed contact, and the protruding portion is formed. It is characterized by being electrically connected to one of the first and second fixed contacts that are not formed.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention is shown in FIGS. 1 is a cross-sectional view of the push button switch of the present invention, FIG. 2 is a cross-sectional view at the time of operation of FIG. 1, FIG. 3 is a plan view of the housing, FIG. FIG. 6 is a cross-sectional view of the operation of FIG. 4, FIG. 6 is a plan view of the housing, FIG. 7 is a cross-sectional view of a push button switch according to another embodiment of the present invention, FIG. FIG. 10 is a plan view of the housing, FIG. 10 is a perspective view of the movable contact, and FIG. 11 is a sectional view of the movable contact.
[0018]
1 to 3, the housing 1 is formed of an insulating material such as a synthetic resin into a rectangular box shape having an opening on the upper surface and having a storage portion 1a therein. First and second fixed contacts 2 and 3 made of a conductive metal material are disposed on the inner lower surface of the housing portion 1a of the housing 1 so as to be exposed in the housing portion 1a and face each other. I have. The exposed portions of the first and second fixed contacts 2 and 3 are provided with protruding contact portions 2a and 3a on which an outer peripheral edge 4a of a movable contact 4 described later is placed and abuts. The first and second fixed contacts 2 and 3 are bent and buried in the inner bottom portion of the housing 1, and the other end thereof is led out from a side surface of the housing 1 and is not shown. Connection terminals 2b and 3b connected to the conductive pattern of the circuit board are provided.
[0019]
Further, the housing 1 is provided integrally with the housing 1 at a position between the first and second fixed contacts 2 and 3 in the vicinity of the first and second fixed contacts. A pair of insulating protrusions 1b and 1c are respectively formed. The protrusions 1b and 1c are formed by arc-shaped walls extending along the inner circumference of a movable contact 4 formed in a circular dome shape, which will be described later. The height of the protrusions 1b and 1c is Are formed to be slightly lower than the height of a dome-shaped bulging inner surface of the movable contact 4 described later. The lengths of the arc-shaped walls of the protrusions 1b, 1c are the same as the lengths of the contact portions 2a, 3a protruding from the exposed portions of the first and second fixed contacts 2, 3. It is formed to be slightly longer than that.
[0020]
The movable contact 4 is made of a conductive thin metal plate such as phosphor bronze or stainless steel, and is formed in a circular dome shape having a bulge at the center. , An outer peripheral portion 4a that comes into contact with the contact portions 2a, 3a, an outer peripheral portion 4b that rises conically from the outer peripheral edge 4a, and a reversing portion 4c that has a dome-shaped apex provided at the center of the outer peripheral portion 4b. Is formed. (FIGS. 10 and 11)
[0021]
The stem 5 is made of an insulating synthetic resin or the like and includes a flange-shaped base 5a, a pressing portion 5b protruding above the base 5a, and an operating protrusion 5c protruding below the base 5a. . The stem 5 is accommodated in the accommodating portion 1a of the housing 1, and when the operating protrusion 5c presses the top of the dome-shaped inverting portion 4c of the movable contact 4, the movable contact 4 is inverted and the switch 5 is switched. Is switched.
[0022]
The cover 6 is made of a plate-shaped metal plate, and is attached to the upper surface of the housing 1 so as to cover the opening of the storage section 1a of the housing 1. The stem 5 is prevented from coming off by the upper surface of the base 5a of the stem 5 having a flange shape contacting the inner top surface of the cover 6.
[0023]
Next, the operation of the push button switch having the above configuration will be described. In the initial state shown in FIG. 1, the outer peripheral edge 4a of the movable contact 4 is connected to the contact 2a of the first and second fixed contacts 2, 3. , 3a, and the circuit is in an ON state between the respective fixed contacts.
[0024]
In this state, when the stem 5 is pressed as shown in FIG. 2, the top of the dome-shaped reversal portion 4c of the movable contact is pressed by the operating protrusion 5c, and the movable contact 4 is reversed. At this time, the inner surface of the dome-shaped reversal portion 4c of the movable contact 4 comes into contact with the arc-shaped protrusions 1b and 1c provided in the storage portion 1a, and the outer peripheral edge 4a of the movable contact 4 is The outer peripheral edge 4a is separated from the contact portions 2a and 3a of the first and second fixed contacts 2 and 3 because the outer peripheral edge 4a is rotated about the projecting portions 1b and 1c as a fulcrum. As a result, the first and second fixed contacts 2, 3 are turned off, and the circuit is turned off.
[0025]
As described above, in the above embodiment, the outer peripheral edge 4a of the movable contact 4 is placed on the first and second fixed contacts 2, 3, and the first and second fixed contacts 2, 3 and an insulative protrusion on the inner bottom surface of the housing 1a inside the outer peripheral edge 4a of the movable contact 4 and near the first and second fixed contacts 2, 3. 1b, 1c, when the dome-shaped reversing portion 4c of the movable contact 4 is pressed and reversed, the inner surface of the movable contact 4 comes into contact with the protruding portions 1b, 1c and the outer peripheral edge 4a is formed. Since the first and second fixed contacts 2 and 3 are separated from each other, a normally-closed type with a simple configuration in which only the insulating protrusions 1b and 1c are provided on the inner bottom surface of the storage portion 1a. A push button switch can be configured.
[0026]
Further, the movable contact 4 is formed in a circular dome shape, and the protruding portions 1b and 1c are formed by arc-shaped walls extending along the inner periphery of the circular dome shape of the movable contact 4. Therefore, the directivity at the time of assembling the movable contact 4 is lost, and the assembling is facilitated, and the outer peripheral edge portion 4a can be reliably separated by the protruding portions 1b and 1c.
[0027]
Further, since the housing 1 is formed of an insulating material and the protruding portions 1b and 1c are formed integrally with the housing 1, a normally closed type can be achieved with a simple configuration without increasing the number of parts. It has become.
[0028]
In the above embodiment, the arc-shaped projections 1b and 1c provided on the housing 1 are formed one by one in the vicinity of the first and second fixed contacts 2 and 3, respectively. However, separately from this, the protruding portions 1b and 1c may be formed by annular walls that are continuous along the inner periphery of the circular dome-shaped inverted portion 4c of the movable contact 4. In this case, the annular protruding portion comes into contact with the entire circumference of the inner surface of the inverted portion 4c of the movable contact 4, so that the circular dome-shaped inverted portion 4c of the movable contact 4 is pressed. When the inversion is performed, a stable inversion operation can be obtained.
[0029]
FIGS. 4 to 6 show one of the pair of protrusions 1b and 1c provided on the housing 1 in which the protrusion 1c provided near the second fixed contact 3 on one side is deleted and the other is used. This shows a modification in which only the protruding portion 1b provided near the first fixed contact 2 on the side is formed.
[0030]
As an operation in this case, in the initial state shown in FIG. 4, the outer peripheral edge portion 4a of the movable contact 4 is in contact with the contact portions 2a, 3a of the first and second fixed contacts 2, 3. The conductive state is established between the fixed contacts, and the circuit is turned on.
[0031]
In this state, when the stem 5 is pressed as shown in FIG. 5, the top of the dome-shaped reversal portion 4c of the movable contact is pressed by the operating projection 5c, and the movable contact 4 is reversed. At this time, the inner surface of the dome-shaped reversal portion 4c of the movable contact 4 comes into contact with the arc-shaped projection 1b provided on the housing portion 1a, and the movable contact 4 located on the projection 1b side Is raised upward with the protrusion 1b as a fulcrum, so that one end of the outer peripheral edge 4a is separated from the contact portion 2a of the first fixed contact 2. As a result, the first and second fixed contacts 2, 3 are turned off, and the circuit is turned off.
[0032]
In this case, the arc-shaped protruding portion 1b formed on the housing 1 is not provided near the first fixed contact 2 but is provided near the second fixed contact 3 on the opposite side. It may be provided. Also in this case, an operation state similar to the above configuration can be obtained. In the configuration of the above-described modification, the same effect as that of the above-described embodiment is obtained.
[0033]
FIGS. 7 to 9 show the configuration of another embodiment of the present invention. In this case, the difference from the above embodiment is that a third fixed contact is provided at the center of the inner bottom surface of the housing portion 1a of the housing 1. Is formed. That is, in the present embodiment, the circuit configuration of the switch is different from the configuration of the above-described embodiment, and the switch has a two-contact (double-headed) type configuration in which the circuit can be switched when the switch operates. Note that the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0034]
In the drawing, first and second fixed contacts 8 and 9 made of a conductive metal material are disposed on the inner bottom surface of a storage portion 7a of a housing 7 so as to be exposed in the storage portion 7a and opposed to each other. ing. The exposed portions of the first and second fixed contacts 8 and 9 are provided with protruding contact portions 8a and 9a on which the outer peripheral edge 4a of the movable contact 4 is placed and abuts. Further, a third fixed contact 10 similarly made of a conductive metal material is disposed at an intermediate position between the first and second fixed contacts 8 and 9. At the center of the third fixed contact 10, there is provided a protruding contact portion 10a with which the inner surface of the top of the dome-shaped inverted portion 4c of the movable contact 4 abuts.
[0035]
The first, second, and third fixed contacts 8, 9, and 10 are bent and buried in the inner bottom of the housing 7, and the other end of the first, second, and third fixed contacts 8, 9, and 10 extends outward from the side surface of the housing 7. Connection terminals 8b, 9b, and 10b are provided, which are led out and connected to conductive patterns on an external circuit board (not shown).
[0036]
In addition, the housing 7 is provided integrally with the housing 7 at a position between the first fixed contact 8 and the third fixed contact 10 near the first fixed contact 8 in the storage portion 7a of the housing 7. Is formed with an insulating protrusion 7b. The projecting portion 7b is formed of an arc-shaped wall extending along the inner periphery of the movable contact 4 formed in a circular dome shape, and the height of the projecting portion 7b is the same as that of the movable contact 4. 4 is formed so as to be slightly lower than the height of the dome-shaped bulging inner surface. The length of the arc-shaped wall of the protrusion 7b is formed to be slightly longer than the length of the contact portion 8a protruding from the exposed portion of the first fixed contact 8. ing.
[0037]
Next, the operation of the push button switch having the above configuration will be described. In the initial state shown in FIG. 7, the outer peripheral edge 4a of the movable contact 4 is connected to the contact portion 8a of the first and second fixed contacts 8,9. , 9a, and the fixed contacts are in a conductive state, and the circuit is on.
[0038]
In this state, when the stem 5 is pressed as shown in FIG. 8, the top of the dome-shaped reversal portion 4c of the movable contact 4 is pressed by the operating projection 5c, and the movable contact 4 is reversed. At this time, the inner surface of the dome-shaped reversal portion 4c of the movable contact 4 comes into contact with the arc-shaped protrusion 7b provided in the storage portion 7a, and the outer peripheral edge 4a of the movable contact 4 is Since the projection 7b is lifted upward with the fulcrum as a fulcrum, one end of the outer peripheral edge 4a is separated from the contact portion 8a of the first fixed contact 8. As a result, the first and second fixed contacts 8, 9 are turned off.
[0039]
At this time, when the movable contact 4 is inverted, the inner surface of the top of the dome-shaped inverted portion 4c of the movable contact 4 comes into contact with the protruding contact portion 10a of the third fixed contact 10. Then, the second fixed contact 9 and the third fixed contact 10 are brought into conduction through the movable contact 4, and the circuit is switched.
[0040]
As described above, according to the other embodiment described above, the third fixed contact 10 is formed between the first and second fixed contacts 8 and 9 of the storage portion 7a of the housing 7 and By forming the protruding portion 7b near the first fixed contact 8, when the dome-shaped reversing portion 4c of the movable contact 4 is pressed and reversed, the outer peripheral edge 4a of the movable contact 4 is The contact portion 8a of the first fixed contact 8 separates, and the inner surface of the top of the reversing portion 4c of the movable contact 4 comes into contact with the contact portion 10a of the third fixed contact 10 to form the second fixed contact. Since the contact 9 is made conductive, a two-contact (double-headed) push button switch that can switch the circuit when the switch is operated can be easily configured.
[0041]
【The invention's effect】
As described above, the push button switch according to the present invention includes a housing having a storage portion, first and second fixed contacts disposed on the inner bottom surface of the storage portion, and a first and a second fixed contact on the first and second fixed contacts. And a movable contact having a reversible bulging portion, the outer peripheral portion of the movable contact being placed on the first and second fixed contacts, and conducting between the first and second fixed contacts. At the same time, an insulating protrusion is formed on the inner bottom surface of the storage portion inside the outer peripheral edge of the movable contact and near the first and / or second fixed contact, and the bulging portion of the movable contact is pressed. At the time of reversing, the inner surface of the movable contact comes into contact with the protruding portion to separate the outer peripheral portion from the first and / or second fixed contact. A normally closed pushbutton switch can be configured with a simple configuration just by providing Can the configuration of the pitch easily, the entire switch can be downsized.
[0042]
In addition, the movable contact is formed in a circular dome shape, and the protruding portion is formed by an arc-shaped wall extending along the inner periphery of the circular dome shape of the movable contact, so that the movable contact is incorporated when the movable contact is assembled. Directivity is lost, assembly is facilitated, and the outer peripheral edge can be reliably separated by the arc-shaped wall.
[0043]
Further, the movable contact is formed in a circular dome shape, and the protruding portion is formed by an annular wall provided continuously along the inner circumference of the circular dome shape of the movable contact. Abuts over the entire circumference of the inner surface of the movable contact, so that when the bulging portion of the movable contact is pressed and reversed, a stable reversing operation can be obtained.
[0044]
In addition, since the housing is formed of an insulating material and the protruding portion is formed integrally with the housing, a normally closed type can be achieved with a simple configuration without increasing the number of parts, so that cost reduction can be achieved.
[0045]
In the housing, a third fixed contact is formed between the first and second fixed contacts, and a protruding portion is formed only on one of the first and second fixed contacts, and the movable portion is movable. When the bulging portion of the contact is pressed and reversed, the lower surface of the bulging portion of the movable contact comes into contact with the third fixed contact, and the first or second fixed contact having no protrusion is formed. Since conduction is established with either one of the switches, a two-contact (double-headed) type push button switch that can switch circuits when the switch is operated can be easily configured.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a push-button switch according to an embodiment of the present invention.
FIG. 2 is a sectional view showing a state at the time of operation of FIG. 1 of the present invention.
FIG. 3 is a plan view showing a housing of the present invention.
FIG. 4 is a sectional view showing a push button switch according to a modification of the present invention.
5 is a cross-sectional view showing a state at the time of operation of FIG. 4 of the present invention.
FIG. 6 is a plan view showing a housing of the present invention;
FIG. 7 is a sectional view showing a push-button switch according to another embodiment of the present invention.
8 is a cross-sectional view showing a state at the time of operation of FIG. 7 of the present invention.
FIG. 9 is a plan view showing a housing of the present invention.
FIG. 10 is a perspective view showing a movable contact of the present invention.
FIG. 11 is a sectional view showing a movable contact of the present invention.
FIG. 12 is an exploded perspective view showing a conventional push button switch.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 housing 1a housing portions 1b, 1c projecting portion 2 first fixed contact 2a contact portion 2b connection terminal 3 second fixed contact 3a contact portion 3b connection terminal 4 movable contact 4a outer peripheral edge 4b outer peripheral portion 4c inversion portion (bulging portion) Part)
5 Stem 5a Base 5b Pressing part 5c Working protrusion 6 Cover 7 Housing 7a Storage part 7b Projection 8 First fixed contact 8a Contact part 8b Connection terminal 9 Second fixed terminal 9a Contact part 9b Connection terminal 10 Third fixing Terminal 10a Contact part 10b Connection terminal

Claims (5)

A housing having a housing, first and second fixed contacts arranged on the inner bottom surface of the housing, and a reversible bulge arranged on the first and second fixed contacts; And a movable contact, wherein an outer peripheral edge of the movable contact is placed on the first and second fixed contacts to conduct between the first and second fixed contacts, and an outer peripheral edge of the movable contact is provided. Forming an insulative protrusion on the inner bottom surface of the housing portion inside the portion and near the first and / or second fixed contact, when the bulging portion of the movable contact is pressed and inverted. Wherein the inner surface of the movable contact is in contact with the protruding portion to separate the outer peripheral edge from the first and / or second fixed contact. The movable contact is formed in a circular dome shape, and the protrusion is formed by an arc-shaped wall extending along an inner periphery of the circular dome shape of the movable contact. Pushbutton switch as described. The movable contact is formed in a circular dome shape, and the protruding portion is formed by an annular wall provided continuously along an inner periphery of the circular dome shape of the movable contact. Item 2. The push button switch according to Item 1. 2. The push button switch according to claim 1, wherein said housing is formed of an insulating material, and said projecting portion is formed integrally with said housing. A third fixed contact is formed between the first and second fixed contacts in the storage portion, and the protruding portion is formed only on one of the first and second fixed contacts. When the bulging portion of the movable contact is pressed and reversed, the lower surface of the bulging portion of the movable contact comes into contact with the third fixed contact, and the first or the first or the non-protruding portion is not formed. 2. The push button switch according to claim 1, wherein the switch is electrically connected to one of the second fixed contacts.

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