JP6854585B2 - Push switch - Google Patents

Description

The present invention relates to a push switch.

Push switches are known as button switches used in mobile communication devices such as mobile phones, portable and in-vehicle audio devices, digital camera VTRs, and the like.

FIG. 6 is a vertical cross-sectional view of the pressing switch 100 described in Patent Document 1. The pressing switch 100 has a case 101, a contact 102, an elastic body 103, and a stem 104. The case 101 has a first opening 105 in which a central electrode and a side electrode are integrally molded on the inner bottom surface, and a plurality of second openings 106 around the first opening 105. On the side electrode in the first opening 105, a thin metal contactor 102 having a tongue piece extending toward the center inside the annulus is placed. On the annulus of the contact 102, an elastic body 103 having a substantially conical shape, which is made of an elastic insulating material such as rubber and has an opening downward, is placed. On top of that, a planar top surface that covers the first opening 105 and the second opening 106, and a plurality of sliding protrusions 107 that project substantially vertically from the top surface and are inserted into the second opening 106. The stem 104 having the above is incorporated in the case 101. When the top surface of the stem 104 is pressed, the elastic body 103 is deformed, the top of the elastic body 103 presses the tongue piece of the contactor 102, and the contactor 102 comes into contact with the center electrode, so that the center electrode and the side electrode are formed. Is electrically conductive, and the pressing switch 100 is turned on.

Since a switch using a rubber spring such as the pressing switch 100 has low durability and a short product life, a push switch using a metal spring to improve the durability and the product life is also known. However, in a push switch that uses a metal spring as a movable contact, a metallic bending sound (click sound) and a contact sound between the movable contact and the fixed contact on the board are generated due to the pressing operation, and these sounds are generated. It can get in the way. Therefore, in order to reduce these sounds, for example, in Patent Document 2, in Patent Document 2, for example, in a key switch module including a substrate, a fixed contact formed on the substrate, and a key switch formed of a dome spring covering the fixed contact, the module is fixed. It has been proposed that a sound absorbing member made of anisotropic conductive rubber is arranged so as to cover the contacts.

Further, in Patent Document 3, the tact plate is formed of the first and second tact plates, and the first tact plate is elastically deformed in two stages by pressing the key top to form the tact plate at the center of the first tact plate. The convex part is brought into contact with the second tact plate by the first stage deformation to connect between the first and second terminals, and the central part of the second tact plate is brought into contact with the contact part of the third terminal by the second stage deformation. A two-stage operation push switch for connecting the first, second, and third terminals is described. In such a switch in which two springs (tact plates) are arranged one above the other, the lower spring acts as a buffer against the upper spring, so that the click sound of the upper spring itself and the springs and the lower spring and the terminal on the board ( Collision noise with the contacts) is somewhat reduced.

Japanese Unexamined Patent Publication No. 2011-108429 Japanese Unexamined Patent Publication No. 2011-040320 Japanese Unexamined Patent Publication No. 2004-031171

Push switches that use conductive rubber as sound absorbing members have concerns about the reliability of conductive rubber in terms of life and conductivity, and because it is difficult to bond, the manufacturing process becomes complicated, and the thickness of the entire switch increases, resulting in miniaturization. There are problems such as difficulty. Further, when conductive rubber is used, since the rubber body comes under the metal spring, the feeling (switch feeling) for the operator is affected, and there is a problem that the characteristics tend to vary among products.

In addition, in a two-stage switch using two metal springs, since the springs are made of metal, there is no change in the sound produced at the time of collision, and the fulcrum of the upper spring is also made of metal, so vibration is easily transmitted. Sound is easy to make in this respect as well. Further, since the lower spring itself, which serves as a buffer, also has switch characteristics such as a click feeling and a stroke, extra sound is generated in this respect as well.

Therefore, an object of the present invention is to provide a push switch that suppresses the generation of sound associated with the operation while ensuring a good feel and durability for the operator.

It has a substrate with a plurality of fixed contacts formed on the upper surface and a convex curved shape that is placed above the substrate and reverses when pressed by the operator, and the operating load is applied when the curved shape begins to reverse. A first metal member having a click characteristic in which an operating load takes a minimum value when the curved shape finishes reversing while taking a maximum value, and a first metal placed on a substrate below the first metal member. A second metal member having a convex curved shape that deforms by being pressed through the member to generate conduction between a plurality of fixed contacts and does not have a click characteristic, and a first and second metal member. A push switch having a cushioning member disposed between the metal members of the above is provided.

In the above push switch, the cushioning member is preferably a waterproof sheet for sealing a plurality of fixed contacts and a second metal member with the substrate.
It is preferable that the push switch further has a fixing member in which the peripheral edge portion of the first metal member is fixed and an opening in which the first metal member is exposed is formed on the upper surface.

According to the above-mentioned push switch, it is possible to suppress the generation of sound due to the operation while ensuring a good feel and durability for the operator.

It is a perspective view of the push switch 1. It is an exploded perspective view of the push switch 1. It is a bottom view of the push switch 1. FIG. 5 is a sectional view taken along line IV-IV of the push switch 1. It is a vertical sectional view of another push switch 1A. It is a vertical sectional view of the pressing switch 100.

Hereinafter, the push switch will be described in detail with reference to the attached drawings. However, it should be understood that the present invention is not limited to the drawings or embodiments described below.

1 to 4 are a perspective view, an exploded perspective view, a bottom view, and a sectional view taken along line IV-IV of the push switch 1, respectively. The push switch 1 is a tact switch that can be used in electric appliances such as mobile phones, and is for improving the feeling when the operator applies an operating load to the conductive portion (contact portion) 2 which is the main body of the switch. It is composed of the push feeling unit 3 of. The push switch 1 is provided with a cushioning member between the internal metal spring and the fixed contact to separate the conductive portion 2 and the push feeling portion 3, thereby ensuring a good feel and durability for the operator. However, it is a silent switch that reduces the generation of sound that accompanies operation.

As shown in FIG. 2, the conductive portion 2 has a substrate 10, a conductive spring 20, an adhesive sheet 30, and a waterproof sheet 40.

A central contact 12 and an outer contact 14 are formed on the upper surface of the substrate 10 as an example of a plurality of fixed contacts. The central contact 12 is, for example, a conductor having a circular upper surface, and is arranged at the center of the upper surface of the substrate 10. The outer contact 14 is two conductors having a rectangular upper surface, and is arranged at the center of the upper surface of the substrate 10 so as to sandwich the central contact 12.

As shown in FIG. 3, electrodes 13a, 13b, 15a, 15b for connecting the push switch 1 to an external device are formed on the back surface of the substrate 10. The electrodes 13a and 13b are electrically connected to the central contact 12 via through electrodes and back surface wiring (not shown). The electrodes 15a and 15b are electrically connected to the outer contact 14 via through electrodes and back surface wiring (not shown). Further, an insulating sheet material formed of an insulating synthetic resin is arranged on the back surface of the substrate 10.

The conductive spring 20 is an example of a second metal member, and is made of, for example, stainless steel. The conductive spring 20 has a convex curved (arch) shape, both ends of which are in contact with and fixed to each of the two outer contacts 14, and are placed on the substrate 10 so as to straddle the central contact 12. .. The conduction spring 20 is arranged below the push feeling spring 60, and is deformed by applying an operating load via the push feeling spring 60 to conduct conduction between the central contact 12 and the outer contact 14. Give rise. Further, the conductive spring 20 returns to its original shape when the operating load is removed. The conductive spring 20 is a non-click spring that does not give a click feeling to the operator.

The adhesive sheet 30 is for fixing the conductive spring 20 and the waterproof sheet 40 on the substrate 10 and has a size suitable for the substrate 10. A rectangular opening 31 is formed in the central portion of the adhesive sheet 30, and the central contact 12 is located therein. Both ends of the conductive spring 20 are fixed by the adhesive sheet 30 on the outer contact 14.

The waterproof sheet 40 is a sheet for sealing the central contact 12, the outer contact 14, and the conductive spring 20 with the substrate 10, has the same size as the substrate 10, and is attached on the adhesive sheet 30. ing. The waterproof sheet 40 is arranged between the conduction spring 20 and the push feeling spring 60, and functions as a cushioning member that reduces the sound generated by the conduction spring 20 and the push feeling spring 60. Since the conductive portion 2 is sealed by the waterproof sheet 40, the push switch 1 has a waterproof and dustproof structure. Since the conductive portion 2 has the same basic structure as a push switch that has been mass-produced conventionally, it is highly reliable in terms of life and conduction.

Further, as shown in FIG. 2, the push feeling portion 3 arranged on the conductive portion 2 has an adhesive sheet 50, a push feeling spring 60, and a cover sheet 70.

The adhesive sheet 50 is for fixing the push feeling portion 3 on the waterproof sheet 40, is arranged on the waterproof sheet 40, and fixes the cover sheet 70 on the waterproof sheet 40. The adhesive sheet 50 has a size suitable for the substrate 10, and a substantially circular opening 51 is formed in the center thereof.

The push feeling spring 60 is an example of the first metal member, and is arranged above the substrate 10 on the waterproof sheet 40. As shown in FIGS. 2 and 4, the push feeling spring 60 has a convex curved (dome) shape and is arranged in the opening 51 of the adhesive sheet 50. When the pressing spring 60 is pressed under an operating load, the dome-shaped curvature is deformed so as to be crushed, and at least a part of the dome shape is inverted to press the lower conductive spring 20. As a result, the central contact 12 and the outer contact 14 become conductive, and the push switch 1 is turned on. Further, the push feeling spring 60 returns to the original dome shape when the operating load is removed. As a result, the force for pressing the conductive spring 20 is lost, and the central contact 12 and the outer contact 14 are not conductive, so that the push switch 1 is turned off. The push feeling spring 60 may be deformed in a concave shape only at the central portion thereof, or may be deformed in a concave shape as a whole.

The cover sheet 70 is an example of a fixing member, and is attached to the upper side of the adhesive sheet 50 to fix the peripheral edge portion of the push feeling spring 60 so that the push feeling spring 60 does not pop out upward. To do. A circular opening 71 smaller than the opening 51 of the adhesive sheet 50 is formed in the central portion of the cover sheet 70. The central portion of the upper surface of the push feeling spring 60 is exposed through the opening 71. As shown in FIG. 4, in the push switch 1, since the cover sheet 70 is in contact with the upper surface of the push feeling spring 60 at the edge of the opening 71, the push feeling portion 3 has a dustproof structure.

In the push switch 1, when the push feeling spring 60 is clicked, the conduction spring 20 is pressed to generate continuity. At that time, since the waterproof sheet 40 and the conductive spring 20 between the push feeling spring 60 and the substrate 10 serve as a buffer, the speed at which the dome-shaped metal spring directly hits the fixed contact of the substrate 10 is compared with the case where the dome-shaped metal spring directly hits the fixed contact of the substrate 10. (Impact) is suppressed. Further, a sound is generated when the conductive spring 20 hits the central contact 12, but since the conductive spring 20 is covered with the waterproof sheet 40, the sound is not reverberated and the volume is reduced. Further, in the push switch 1, the conductive portion 2 and the push feeling portion 3 are separated, and the push feeling spring 60 is arranged on the soft waterproof sheet 40. Therefore, the collision noise and vibration generated by the push feeling spring 60 are generated. , It is absorbed by the waterproof sheet 40 and the like, and it becomes difficult to transmit to the outside. For these reasons, in the push switch 1, the sound generated when the internal metal spring is pressed and clicked (reversed) and the contact sound generated when the metal spring comes into contact with the fixed contact for conduction are reduced.

Further, in the push switch 1, since the conductive portion 2 and the push feeling portion 3 are separated and the lower conductive portion 2 has a waterproof and dustproof structure, the upper push feeling portion 3 has an opening in the cover sheet 70. 71 can be provided. In general, if the cushioning material is sandwiched between them, the feeling of pushing may be deteriorated for the operator, and if the entire surface of the spring 60 for feeling of pushing is covered with a sheet, the sheet may be stretched and the spring for feeling of pushing may be deteriorated. There is a risk of hindering the feeling of pressing 60. However, in the push switch 1, the upper surface of the push feeling spring 60 is opened by the opening 71 of the cover sheet 70, and the suppression of the push feeling spring 60 by the cover sheet 70 is reduced, so that a good click feeling is obtained. It is possible to give a feeling of pushing and to secure a feeling of pushing. As a result, the push switch 1 has an advantage that the switch feeling can be easily adjusted and the stroke can be easily extended.

The push switch 1 is a one-stage switch, but is provided with two springs, a conduction spring 20 and a push feeling spring 60. The continuity spring 20 is for continuity, the push feeling spring 60 is for push feeling, and so on. The purpose is divided. Therefore, the push feeling spring 60 needs a click feeling (click characteristic), but it is preferable that the conduction spring 20 does not have a click feeling. That is, with respect to the push feeling spring 60, it is necessary that the operating load takes a maximum value when the curved shape starts to reverse and the operating load takes a minimum value when the curved shape finishes turning. Regarding 20, it is preferable that there is no maximum value and minimum value of such an operating load. Further, it is preferable that the conductive spring 20 has a low operating load and a small repulsive force when pushed. Otherwise, even if the push feeling spring 60 gives a push feeling, the conduction spring 20 may not be deformed and continuity may not occur, and the operator feels like a two-stage switch. , There is an inconvenience.

Generally, the click rate is used as an index indicating the good feeling when the push switch is pressed. The click rate is the maximum value of the operating load when the curvature of the movable member begins to reverse when an operating load is applied to the convex movable member (metal member) that constitutes the push switch, and the operating load is further calculated from that value. In addition, it is the ratio to the amount of decrease in the operating load until the curvature of the movable member is completely reversed. The higher the click rate of the push switch, the more favorable the operator feel (click feeling) when the pressing operation is performed.

In the push switch 1, it is preferable that the click rate of the push feeling spring 60 is as high as possible and the click rate of the conductive spring 20 is as low as possible. For example, the click rate of the push feeling spring 60 is preferably 30 to 40%, and the click rate of the conductive spring 20 is preferably 1 to 5%.

The opening 71 of the cover sheet 70 does not have to be circular, and the opening may be, for example, a clover type. Depending on the shape of the opening, the operator may not be able to directly press the upper surface of the push feeling spring 60, but if the cover sheet 70 has an opening, the entire surface of the cover sheet 70 is covered. A better pressing feeling can be obtained than in the case.

FIG. 5 is a cross-sectional view of another push switch 1A. The push switch 1A has a cushioning material 80 such as plastic arranged only on the upper part of the conductive spring 20 instead of the adhesive sheet 30 and the waterproof sheet 40 in the push switch 1, and the entire upper surface of the cover sheet 70 is a waterproof sheet. It differs from the push switch 1 only in that it is covered with 90. Even in the push switch 1A, the conduction spring 20 and the push feeling spring 60 do not come into direct contact with each other, and the inside of the switch is covered with the substrate 10 and the uppermost waterproof sheet 90. Is obtained.

For waterproofing and dustproofing, a tarpaulin 40, 90 covers the entire space between the conductive portion 2 and the pressing portion 3 or the entire upper portion of the pressing portion 3, as in the push switches 1 and 1A. Is good. However, in applications where waterproofing and dustproofing are not essential, the waterproofing sheets 40 and 90 may not be provided, and the cushioning material 80 may be simply sandwiched on the conductive spring 20.

1,1A Push switch 2 Conductive part 3 Push feeling part 10 Board 12 Central contact 14 Outer contact 20 Conductive spring 30 Adhesive sheet 40 Waterproof sheet 50 Adhesive sheet 60 Push feeling spring 70 Cover sheet

Claims (2)

A substrate with multiple fixed contacts formed on the top surface,
It has a convex curved shape that is arranged above the substrate and reverses when pressed by the operator, and when the curved shape begins to reverse, the operating load reaches a maximum value and the curved shape reverses. The first metal member, which has a click characteristic in which the operating load takes a minimum value when finished,
Below the first metal member , the first metal member is placed on the substrate so that its end is in contact with the substrate when the first metal member is not pressed, and is pressed via the first metal member. A second metal member having a convex curved shape that deforms to cause conduction between the plurality of fixed contacts and does not have the click characteristic, and the second metal member.
A cushioning member arranged between the first and second metal members, and
It has a fixing member that fixes the peripheral edge portion of the first metal member and has an opening formed on the upper surface from which the first metal member is exposed.
A push switch characterized in that the click rate of the first metal member is larger than the click rate of the second metal member. The push switch according to claim 1, wherein the cushioning member is a waterproof sheet for sealing the plurality of fixed contacts and the second metal member with the substrate.

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