JP2024099085A - Dome-shaped contact member and push button switch member including same - Google Patents

Abstract

[Problem] To achieve both an increase in volume and a large change in load when the switch is turned on, and to achieve a clearer clicking sensation. [Solution] The present invention relates to a dome-shaped contact member 20 that can be switched on by contacting a part of it with the contact on a substrate from above, the dome-shaped contact member 20 comprising a dome portion 22 that can be elastically deformed by pressing from the part and then releasing the pressing, and an extension portion 21 that extends radially outward from the dome portion 22, the dome portion 22 comprising a through hole 23 at its top as a part thereof that penetrates the dome portion 22 in the thickness direction, the opening area of the through hole 23 being 1.1% to 3.5% of the area of the dome portion 22, and a push button switch member 30 comprising the dome-shaped contact member 20. [Selected Figure] Figure 1

Description

The present invention relates to a dome-shaped contact member and a push button switch member equipped with the same.

Conventionally, a dome-shaped contact member that can make and break contact with a contact on a board has been used to turn a switch on and off (see, for example, Patent Document 1). Conventionally known dome-shaped contact members are generally placed above a contact on a board, such as a circuit board. The dome-shaped contact member has the function of pressing the dome portion constituting the dome-shaped contact member against the contact to turn the switch on, and releasing the pressure to release the contact between the dome portion and the contact to turn the switch off.

JP 2013-191418 A

Prior to the present invention, the inventors of the present application developed a push button switch component that integrates a dome-shaped contact member with a pressing member that presses the dome portion of the dome-shaped contact member from above. The push button switch component will be described below.

Figure 6 shows a push button switch member developed prior to the present invention and the various components that make up the push button switch member.

The push button switch member 130 developed prior to the present invention comprises a dome-shaped contact member 120 and a pressing member 110 fixed to the dome-shaped contact member 120. The pressing member 110 comprises a foot 111 having a rectangular parallelepiped outer shape with an annular space inside, a thin-walled elastic deformation portion 112 connected to the foot 111, and an outward protrusion 113 connected to the elastic deformation portion 112. The pressing member 110 comprises a concave space 114 extending inward from the inside of the foot 111, and an inward protrusion 115 protruding from the inner bottom surface of the space 114 to the opening side of the foot 111. The pressing member 110 also comprises a recess 116 on the bottom surface of the foot 111 for fixing the dome-shaped contact member 120.

The dome-shaped contact member 120 comprises a dome-shaped dome portion 122, an extension portion 121 extending radially outward from the dome portion 122, and two arm portions 126 located further outward from the extension portion 121. The shape of the dome portion 122 is approximately circular in a plan view. The shape of the extension portion 121 is approximately rectangular in a plan view. The two arm portions 126 are connected to the extension portion 121 and are provided at both ends of the extension direction of one diameter of the dome portion 122. In addition, the four corners of the extension portion 121 are provided with protruding contacts 127 that can come into contact with outer contacts on a board.

The pushbutton switch member 130 is a member in which the vicinity of the tip of the arm portion 126 is fixed to the recess 116, and the dome-shaped contact member 120 and the pressing member 110 are integrated. When the outer protrusion 113 is pressed toward the board in a state in which a board having an outer contact and an inner contact located directly below the top of the dome portion 122 on the inside of the outer contact is placed on the foot portion 111 side of the pushbutton switch member 130, the dome-shaped contact member 120 is pressed toward the board by the inner protrusion 115. This action causes the protruding contact 127 to come into contact with the outer contact on the board. Next, the dome portion 122 deforms, and its top is recessed and comes into contact with the inner contact on the board. As a result, the outer contact and the inner contact are electrically connected via the dome-shaped contact member 120, and the switch is turned on. When the pressure from the outer protrusion 113 is released, the inner protrusion 115 moves away from the dome portion 122. This causes the dome portion 122 to return to the shape it had before it was pressed. As a result, the outer contact and the inner contact are electrically disconnected, and the switch is turned off.

There is a demand for the addition of a further function to the push button switch member 130 having the above-mentioned configuration and function. This is to increase the volume when the switch is turned on, to make the clicking sensation even clearer. However, the increase in volume cannot come at the expense of the change in load at the time of the click.

The present invention was made to satisfy the above requirements, and aims to provide both an increase in volume and a large change in load when the switch is turned on, resulting in a clearer clicking sensation.

(1) In order to achieve the above object, a dome-shaped contact member according to one embodiment is a dome-shaped contact member that can be switched on by contacting a part of the dome-shaped contact member with a contact on a substrate from above the contact,
a dome portion that is elastically deformable by being pressed from the portion and by being released from the pressing force;
an extension portion extending radially outwardly of the dome portion;
Equipped with
The dome portion includes a through hole penetrating in a thickness direction of the dome portion at a top portion as the part,
The opening area of the through hole is 1.1% to 3.5% of the area of the dome portion.
(2) In the dome-shaped contact member according to another embodiment, the extension portion may preferably include an arm portion for fixing the dome-shaped contact member to a fixing member.
(3) In order to achieve the above object, a member for a push button switch according to one embodiment includes:
The dome-shaped contact member;
a pressing member that is fixed to the dome-shaped contact member from a protruding side of the dome portion and is elastically deformable in a direction pressing the dome portion and in an opposite direction;
Equipped with.
(4) In order to achieve the above object, a member for a push button switch according to one embodiment comprises:
The dome-shaped contact member;
a pressing member that covers the dome-shaped contact member from the protruding side of the dome portion and is fixed to the dome-shaped contact member via the arm portion, the pressing member being elastically deformable in a direction pressing the dome portion and in an opposite direction;
Equipped with.

The present invention achieves both an increase in volume and a large change in load when the switch is turned on, providing a clearer clicking sensation.

FIG. 1 shows a dome-shaped contact member according to an embodiment of the present invention and a push button switch member having the dome-shaped contact member as a constituent element. FIG. 2 shows the positional relationship between the push button switch member and the substrate. FIG. 3 shows modified examples (3A to 3C) of the pressing member. FIG. 4 shows modified examples (4A to 4D) of the dome-shaped contact member. FIG. 5 shows graphs of the results of a sound volume measurement test (5A) and a load-displacement measurement test (5B) for a push button switch member. FIG. 6 shows a push button switch member developed prior to the present invention and each of the components constituting the push button switch member.

The following describes an embodiment of the present invention with reference to the drawings. Note that the embodiment described below does not limit the invention according to each claim in the claims. Furthermore, not all of the elements and combinations thereof described in the embodiment are necessarily essential to the solution of the present invention.

Figure 1 shows a dome-shaped contact member according to an embodiment of the present invention and a push button switch member that includes the dome-shaped contact member as a component. Figure 2 shows the positional relationship between the push button switch member and the substrate.

A push button switch member 30 according to an embodiment of the present invention includes a dome-shaped contact member 20 and a pressing member 10 as an example of a fixing member fixed to the dome-shaped contact member 20. The pressing member 10 is provided on the dome-shaped contact member 20 so as to cover the outside of the dome-shaped contact member 20. The pressing member 10 includes a foot 11 having a rectangular parallelepiped outer shape with an annular space inside, a thin-walled elastic deformation portion 12 connected to the foot 11, and an outward protrusion 13 connected to the elastic deformation portion 12. The elastic deformation portion 12 is formed so as to cover the annular space of the foot 11. In this embodiment, the elastic deformation portion 12 has a hemispherical dome shape. The outward protrusion 13 is a substantially cylindrical member that protrudes from the outer top surface of the elastic deformation portion 12. The pressing member 10 has a concave space 14 extending inward from the inside of the foot 11, and an inward protrusion 15 that protrudes from the inner bottom surface of the space 14 toward the opening side of the foot 11. The pressing member 10 also has a recess 16 on the bottom surface of the foot 11 for fixing the dome-shaped contact member 20.

In this embodiment, the pressing member 10 is entirely made of a rubber-like elastic material. However, the pressing member 10 may be made of at least the elastically deforming portion 12 of a rubber-like elastic material, and any other components than the elastically deforming portion 12 may be made of a material other than a rubber-like elastic material, such as a synthetic resin, metal, or ceramics. Examples of suitable rubber-like elastic materials include thermosetting elastomers such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR) or styrene butadiene rubber (SBR), thermoplastic elastomers such as urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, and fluorine-based elastomers, or composites of the above. Of these exemplary rubber-like elastic materials, silicone rubber is particularly preferred.

The dome-shaped contact member 20 according to the embodiment of the present invention includes a dome portion 22 having a dome shape, a through hole 23 penetrating from the top of the dome portion 22 in the thickness direction of the dome portion 22, an extension portion 21 extending radially outward from the dome portion 22, and two arm portions 26 located further outward from the extension portion 21. The shape of the dome portion 22 is approximately circular in a plan view. The shape of the extension portion 21 is approximately rectangular in a plan view. The two arm portions 26 are connected to the extension portion 21 and are provided at both ends of the extension direction of one diameter of the dome portion 22. The vicinity of the tip of each arm portion 26 in the length direction is fixed to the recess 16 of the pressing member 10. The portions of each arm portion 26 of the dome-shaped contact member 20 other than the vicinity of the tip are not fixed to the pressing member 10. Therefore, when the outer protrusion 13 of the pressing member 10 is pressed, the dome-shaped contact member 20 pressed by the inner protrusion 15 can be deformed in the pressing direction with the vicinity of the tip of each arm portion 26 as a fulcrum. In addition, the four corners of the extension portion 21 are provided with protruding contacts 27 that can come into contact with outer contacts 41 on the substrate 40. The outer contacts 41 are an example of contacts on the substrate 40.

The through hole 23 is provided at the top of the dome portion 22 of the dome-shaped contact member 20 as part of the dome portion 22, penetrating the dome portion 22 in the thickness direction. The through hole 23 comes into contact with the inner contact 42 on the substrate 40 when the dome portion 22 is deformed. The inner contact 42 is an example of a contact on the substrate 40.

The material of the dome-shaped contact member 20 is not particularly limited as long as it enables the switch operation, but conductive materials such as nickel silver, stainless steel, copper, aluminum, and silver are preferable. The dome-shaped contact member 20 is preferably plated with a precious metal (e.g., gold plating). The dome-shaped contact member 20 may be made of a material with poor conductivity such as synthetic resin, and the concave side of the dome portion 22 and one side of the dome-shaped contact member 20 connected to the concave side may be coated with a highly conductive metal or conductive polymer. Furthermore, the dome-shaped contact member 20 may be made of a material with poor conductivity such as synthetic resin, and the entire outer surface of the dome-shaped contact member 20 may be coated with a highly conductive metal or conductive polymer.

The push button switch member 30 is a member in which the dome-shaped contact member 20 and the pressing member 10 are integrated by fixing the vicinity of the tip of the arm portion 26 to the recess 16. The substrate 40 has an outer contact 41 and an inner contact 42 located on the inside of the outer contact 41 and directly below the top of the dome portion 22. The outer contact 41 is, for example, a ring-shaped or polygonal frame-shaped contact in a plan view, and is provided on the substrate 40 at a position where it can contact the protruding contact 27 of the dome-shaped contact member 20 by pressing from the outer protrusion 13. The inner contact 42 is, for example, a dot-shaped, ring-shaped or polygonal frame-shaped contact, and is provided on the substrate 40 at a position where it can contact the periphery of the through hole 23 at the top of the dome portion 22 by pressing from the outer protrusion 13. The inner contact 42 has an area large enough to allow the peripheral portion of the through hole 23 to come into contact. When the outer protrusion 13 is pressed toward the substrate 40 with a gap between them and the foot 11 of the push button switch member 30, the dome-shaped contact member 20 is pressed toward the substrate 40 by the inner protrusion 15. This action causes the protruding contact 27 to contact the outer contact 41 on the substrate 40. Then, when the top of the dome portion 22 cannot withstand the pressure, it suddenly dents. This causes the top of the dome portion 22 to contact the inner contact 42 on the substrate 40. As a result, the outer contact 41 and the inner contact 42 are electrically connected through the dome-shaped contact member 20, and the switch is turned on. In addition, the dome portion 22 generates a sound together with a sudden drop in load when it deforms. This sudden drop in load and sound give the operator who operates the switch a clicking sensation that the switch has been operated reliably. On the other hand, when the pressure from the outward protrusion 13 is released, the elastic deformation portion 12 recovers to its original shape before the pressure, and the inward protrusion 15 separates from the dome portion 22. This causes the dome portion 22 to return to its shape before the pressure. As a result, the outer contact 41 and the inner contact 42 are electrically disconnected, and the switch is turned off. Note that the on and off states of the switch described above may be reversed. That is, the switch may be turned off when the outer contact 41 and the inner contact 42 are in contact with each other, and the switch may be turned on when the outer contact 41 and the inner contact 42 are not in contact with each other.

The through hole 23 increases the volume of the sound (=sound volume) generated when the dome portion 22 is deformed as described above. The volume of the sound when the dome portion 22 is deformed tends to increase in proportion to the opening area of the through hole 23. Also, the amount of load change when the dome portion 22 is depressed decreases in inverse proportion to the opening area of the through hole 23. Therefore, in order to achieve both increased sound volume and large changes in load in the push button switch member 30, the ratio of the opening area of the through hole 23 to the area of the dome portion 22 is important.

The opening area of the through hole 23 is preferably 1.1% to 3.5% of the area of the dome portion 22, and more preferably 1.6% to 2.9%.

Figure 3 shows modified examples of the pressing member (3A to 3C). Also, Figure 4 shows modified examples of the dome-shaped contact member (4A to 4D). Note that in these modified examples, parts that are common to the above-mentioned embodiment are given the same reference numerals and their description will be omitted.

The shape of the elastic deformation portion 12 in the pressing member 10 does not necessarily have to be a hemispherical dome shape as shown in FIG. 1. For example, a pressing member 10a may be used in which the shape of the elastic deformation portion 12a is an approximately truncated cone shape as shown in FIG. 3A. A pressing member 10b may be used in which the shape of the elastic deformation portion 12b is an approximately prism shape as shown in FIG. 3B. Furthermore, a pressing member 10c may be used in which the shape of the elastic deformation portion 12c is an approximately truncated pyramid shape as shown in FIG. 3C, and the outward protrusion portion 13c is an approximately rectangular parallelepiped shape.

The shape of the through hole 23 in the dome-shaped contact member 20 does not necessarily have to be circular as shown in FIG. 1 in plan view. For example, a dome-shaped contact member 20a in which the shape of the through hole 23a is a square as shown in FIG. 4A may be used. A dome-shaped contact member 20b in which the shape of the through hole 23b is a triangle as shown in FIG. 4B may be used. A dome-shaped contact member 20c in which the shape of the through hole 23c is an ellipse as shown in FIG. 4C may be used. Furthermore, a dome-shaped contact member 20d in which the shape of the through hole 23d is a star shape as shown in FIG. 4D may be used.

Other Embodiments
In the above-described embodiment, the dome-shaped contact member 20 is adhered to the pressing member 10, but the present invention is not limited to this. For example, the dome-shaped contact member 20 may be fixed to the substrate 40 side, not to the pressing member 10. In this case, the substrate 40 serves as a fixing member.

Next, examples of the present invention will be described in comparison with comparative examples. Note that the present invention is not limited to the following examples.

1. Raw material (1) Dome-shaped contact member A dome-shaped contact member was formed using conductive material SUS 303. The dimensions of the dome-shaped contact member were as follows: diameter of the opening surface of the recess side of the dome was 6.2 mm, the length of the extension was 7 mm square, the thickness of the extension was 0.1 mm, and the length from one end of the arm to the other end was 5.3 mm.
(2) Pressing member The pressing member was molded using as a raw material a silicone rubber compound (product number HG-060-U) manufactured by Shin-Etsu Chemical Co., Ltd. The dimensions of the pressing member were as follows: height from the foot of the pressing member to the tip of the outward protrusion was 6 mm, diameter of the outward protrusion was 6 mm, diameter of the elastic deformation portion was 13 mm, and one side of the foot was 20 mm.

2. Manufacturing of a member for a push button switch The molded dome-shaped contact member was fixed to the recess of the pressing member via the arm portion using an adhesive to manufacture a member for a push button switch.

3. Examples and Comparative Examples (Example 1)
A push button switch member having a through hole diameter of 0.3 mm and a ratio of the opening area of the through hole to the total area of the dome portion (hereinafter referred to as the hole area ratio) of 0.6% was manufactured using the above manufacturing method and subjected to the following tests.
Example 2
The same as in Example 1 was used except that the hole diameter was 0.5 mm and the hole area ratio was 1.0%.
Example 3
The same as in Example 1 was used except that the hole diameter was 0.8 mm and the hole area ratio was 1.6%.
Example 4
The same as in Example 1 was used except that the hole diameter was 1.0 mm and the hole area ratio was 1.9%.
Example 5
The same as in Example 1 was used except that the hole diameter was 1.5 mm and the hole area ratio was 2.9%.
Example 6
The same as in Example 1 was used except that the hole diameter was 2.0 mm and the hole area ratio was 3.6%.
(Example 7)
The same as in Example 1 was used except that the hole diameter was 2.5 mm and the hole area ratio was 4.4%.
Comparative Example
A push button switch member having no through hole and a hole diameter of 0.0 mm was used as a comparative example, which was manufactured by the above manufacturing method and subjected to the following tests.

Figure 5 shows graphs of the results of a volume measurement test (5A) and a load-displacement measurement test (5B) for a pushbutton switch component.

4. Sound volume measurement test In order to evaluate the effect of the through-hole size on the switch sound volume, the push button switch members of the above examples and comparative examples were pressed from above, and the generated sound volume was measured using a precision sound level meter LA-5111 manufactured by Ono Sokki Co., Ltd. The measurement was performed five times, and the average value was calculated. Figure 5A shows a graph showing the relationship between the hole diameter of the through-hole and the average switch sound volume.

5. Load-displacement measurement test In order to evaluate the effect of the size of the through hole on the load change at the time of clicking, the push button switch members of the above examples and comparative examples were pressed from above using a measuring device GT-FL500 manufactured by Aiko Engineering Co., Ltd., and the load and displacement (stroke) at the time of pressing were measured. FIG. 5B shows the load-displacement curve of the push button switch member at the time of pressing. The evaluation of the test was performed using the value of the load at the peak time described above. The larger the load at the peak time, the larger the load change due to the deformation of the dome part. Taking this tendency into consideration, in each example, the percentage of the peak load when the peak load of the comparative example is set to 100% was calculated and used for evaluation.

6. Evaluation Each test was evaluated in three stages. Specifically, A was the best (pass), C was the worst (fail), and B was intermediate between A and C (fail). In the evaluation of the switch sound volume, A was rated for 51 dB or more, B was rated for 49 dB or more and less than 51 dB, and C was rated for less than 49 dB. In the evaluation of the load, A was rated for 80% or more of the comparative example without a through hole, B was rated for 65% or more and less than 80%, and C was rated for less than 65%.

As is clear from Table 1, the switch sound increased compared to the comparative example as the hole area ratio of the through-hole increased. On the other hand, the rate of change in load decreased as the hole area ratio of the through-hole increased. Push button switch components that were rated A, which are good in both respects, are in the range enclosed in a thick frame in Table 1, and had a through-hole hole area ratio of 1.6% to 2.9%. It is believed that these push button switch components achieve both a louder switch sound and a large change in load, providing a clear clicking sensation.

The present invention can be used for push button switches for use in various devices equipped with push keys, such as automobiles, in-vehicle electronic devices, portable communication devices, personal computers, cameras, home audio devices, and household electrical appliances.

10: pressing member (an example of a fixing member), 11: foot portion, 12: elastic deformation portion, 13: outward protrusion portion, 14: space, 15: inward protrusion portion, 16: recess, 20: dome-shaped contact member, 21: extension portion, 22: dome portion, 23: through hole, 26: arm portion, 27: protruding contact, 30: member for push button switch, 40: substrate (an example of a fixing member), 41: outer contact (an example of a contact), 42: inner contact (an example of a contact).

Claims (4)

A dome-shaped contact member capable of turning on a switch by bringing a part of the contact into contact with a contact on a substrate from above,
a dome portion that is elastically deformable by being pressed from the portion and by being released from the pressing force;
an extension portion extending radially outwardly of the dome portion;
Equipped with
The dome portion includes a through hole penetrating in a thickness direction of the dome portion at a top portion as the part,
A dome-shaped contact member, wherein an opening area of the through hole is 1.1% to 3.5% of an area of the dome portion. The dome-shaped contact member according to claim 1, characterized in that the extension portion is provided with an arm portion for fixing the dome-shaped contact member to a fixed member. The dome-shaped contact member according to claim 1 ;
a pressing member that is fixed to the dome-shaped contact member from a protruding side of the dome portion and is elastically deformable in a direction pressing the dome portion and in an opposite direction;
A push button switch member comprising: The dome-shaped contact member according to claim 2 ;
a pressing member that covers the dome-shaped contact member from the protruding side of the dome portion and is fixed to the dome-shaped contact member via the arm portion, the pressing member being elastically deformable in a direction pressing the dome portion and in an opposite direction;
A push button switch member comprising: