JP2018073467A - Contact member and push button switch member equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a highly reliable contact member at a low cost; and a push button switch member equipped with the contact member.SOLUTION: Provided is a contact member 10 in which a wire net 12, having a plurality of metal wires 22 and 23 woven therein, is exposedly embedded on one of the surfaces of a rubber-like elastic body 11. The wire net 12 is made of the metal wires 22 and 23 extending in a plurality of directions while intersecting each other. The present invention relates to the contact member 10 configured such that at least a surface of the metal wire 22 extending at least in one of the plurality of directions is made of noble metal, and the metal wire 23 extending at least in the direction other than the above-mentioned direction is made of non-noble metal. The present invention also relates to a push button switch member 1 equipped with the contact member 10.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a contact member and a push button switch member including the contact member.

  In a pushbutton switch member, as a contact member that can be elastically connected to and separated from a contact on a circuit board, a metal thin plate or a plated metal plate attached to silicone rubber has been conventionally known. ing. In addition, as other types of contact members, a metal thin plate with a hole, a silicone rubber with a metal mesh attached, and a metal mesh with a metal different from the metal mesh are plated. It is known (see Patent Documents 1 to 4).

  FIG. 8 shows a plan view and cross-sectional views (8A, 8B, 8C, 8D) of conventionally known contact members. The contact member 50 of (8A) has a configuration in which a metal plate 52 such as nickel or SUS is attached to one surface of a disc-shaped silicone rubber 51 as shown in the cross-sectional view along the line P-P. In the contact member 60 of (8B), as shown in the QQ line cross-sectional view, a metal plate 62 such as nickel or SUS is attached to one surface of a disk-shaped silicone rubber 61, and gold or the like is applied to the surface thereof. The plating layer 63 is provided. The contact member 70 of (8C) has a configuration in which a metal net (metal net) 72 such as nickel or SUS is attached to one side of a disc-shaped silicone rubber 71 as shown in the cross-sectional view taken along the line RR. Have. The contact member 80 of (8D) has a configuration in which a wire net 82 plated with gold or the like in advance is attached to one surface of a disk-like silicone rubber 81 as shown in the SS cross-sectional view. The plating layer 83 covers almost the entire surface of the wire mesh 82.

  The contact members 50 and 60 shown in (8A) and (8B) are members having low resistance and excellent conductivity. However, since the surface that contacts the contacts on the circuit board is a flat surface, there is a problem that it is vulnerable to the presence of foreign matter. In order to solve this problem, even if a foreign object is interposed between the contact surfaces 70 and 80 shown in (8C) and (8D), the surfaces that contact the contacts on the circuit board are conventionally used as the metal meshes 72 and 82. A technique of forming an uneven surface that can contact the contact point is employed. It is also known to provide a metal plate with a hole in place of the wire nets 72 and 82.

Japanese Utility Model Publication No. 62-054433 JP 2004-342539 A JP 2012-185556 A JP 2014-240058 A

  However, the following points are required for the above-described conventionally known contact members and members for push button switches provided with them. The first requirement is to reduce the exposure of metals such as nickel and SUS to achieve high corrosion resistance, and to improve the reliability as a contact by preventing the contact member from becoming abnormal during use. The second requirement is to reduce the cost by making no holes in the metal plate by punching or etching, and by reducing the amount of noble metal used.

  An object of the present invention is to satisfy the above requirements, that is, to provide a highly reliable and low cost contact member and a member for a push button switch including the contact member.

  As a result of earnest and development in order to achieve the above object, the present inventor has a configuration in which a part of the wire mesh is embedded in rubber, and one of the two-way metal wires constituting the wire mesh. A contact member was completed in which at least the surface of the metal wire in the direction was formed of a noble metal and the metal wire in the other direction was formed of a metal other than the noble metal. The problem solving means of the present invention is specifically as follows.

  A contact member according to an embodiment for achieving the above object is a contact member embedded so as to expose a wire mesh in which a plurality of metal wires are knitted on one surface of a rubber-like elastic body. The wire mesh is composed of metal wires in a plurality of directions intersecting each other, at least the surface of at least one of the metal wires in the plurality of directions is formed of a noble metal, and the metal wires in directions other than the at least one direction are non-noble metals It is formed by.

  In the contact member according to another embodiment, the wire mesh may further expose metal wires in a plurality of directions from the rubber-like elastic body.

  In the contact member according to another embodiment, the wire mesh is further formed by knitting two-way metal wires, embedded in a rubber-like elastic body so that the two-way metal wires are both exposed, In terms of the number exposed from the elastic body, at least the number of unidirectional metal wires whose surface is formed of a noble metal may be larger than the number of other direction metal wires formed of a non-noble metal.

  In the contact member according to another embodiment, the wire mesh is formed by knitting metal wires in two directions, and is embedded in a rubber-like elastic body so that the metal wires in two directions are exposed together. The height at which the metal wire is exposed from the elastic body may be smaller than the diameter of the exposed metal wire.

  In the contact member according to another embodiment, one or a plurality of protrusions may be provided on the surface of the rubber-like elastic body opposite to the wire mesh.

  In the contact member according to another embodiment, the surface of the protrusion may be a curved surface.

  The member for pushbutton switches which concerns on one embodiment for achieving the said objective is provided with the contact member in any one of the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, a highly reliable and low-cost contact member and a pushbutton switch member provided with the same can be provided.

FIG. 1 is a longitudinal sectional view showing a state in which a pushbutton switch member according to an embodiment of the present invention is arranged on a circuit board. 2 shows a wire mesh used for a contact member connected to the pushbutton switch member of FIG. 1, (2A) is a plan view of the wire mesh, (2B) is a cross-sectional view taken along line AA of (2A), Each is shown. 3 shows a first embodiment of a contact member connected to the pushbutton switch member of FIG. 1, wherein (3A) is a surface of the contact member facing the substrate side contact, and (3B) is a view of (3A). BB line sectional drawing is shown, respectively. FIG. 4 shows a cross-sectional view (4A) of only one direction of metal wire constituting the wire mesh of FIG. 3, and a cross-sectional view (4B) of only the other metal wire, respectively. FIG. 5 shows a second embodiment of the contact member connected to the pushbutton switch member of FIG. 1, wherein (5A) shows the surface of the contact member facing the substrate side contact, and (5B) shows the surface of (5A). CC sectional view is shown, respectively. FIG. 6 shows a third embodiment of the contact member connected to the pushbutton switch member of FIG. 1, (6A) shows the surface of the contact member opposite to the wire mesh, and (6B) shows the D- of (6A). D line sectional drawing is shown, respectively. FIG. 7 shows a flow of an example of a suitable manufacturing method of the contact member according to each embodiment of the present invention. FIG. 8 shows a plan view and cross-sectional views (8A, 8B, 8C, 8D) of conventionally known contact members.

  Next, preferred embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and all the elements and combinations thereof described in the embodiments are essential to the solution means of the present invention. Not necessarily.

<1. Pushbutton Switch Member>
FIG. 1 is a longitudinal sectional view showing a state in which a pushbutton switch member according to an embodiment of the present invention is arranged on a circuit board.

  As shown in FIG. 1, the pushbutton switch member 1 is disposed on the circuit board 2 and elastically reciprocates in the direction of the circuit board 2 (downward in FIG. 1) and in the opposite direction (upward in FIG. 1). It is a movable member. The push button switch member 1 preferably has a substantially rectangular parallelepiped or substantially cylindrical key top 3, a dome portion 4 connected in a skirt shape on the radially outer side of the key top 3, and the radially outer side of the dome portion 4. And a flange portion 5 fixed to the circuit board 2. The key top 3 includes a downward projecting portion 6 projecting in the direction of the circuit board 2 on the lower surface facing the circuit board 2. The circuit board 2 includes a plurality of board-side contacts 7 and 8 that are not in contact with each other at a position facing the downward projecting portion 6. On the other hand, the downward projecting portion 6 connects a contact member 10 having a portion made of a conductive material at a position where it can be connected to the substrate side contacts 7 and 8 at the tip thereof.

  When the key top 3 is not pressed from above, the contact member 10 and the substrate side contacts 7 and 8 are kept in a non-contact state. When the pressure is applied from above the key top 3 and the pressure exceeds a certain threshold value, the dome portion 4 is suddenly deformed (buckled), and the contact member 10 contacts the substrate side contacts 7 and 8. By this contact, an energization path is formed from the substrate-side contact 7 to the substrate-side contact 8 through the contact member 10, so that the switch is turned ON (or OFF). When the pressure on the key top 3 is released, the dome portion 4 returns to its original shape by its own elastic force, so that the key top 3 rises. As a result, the contact member 10 is separated from the substrate side contacts 7 and 8.

  In this embodiment, the push button switch member 1 is a member integrally formed of a rubber material. However, the push button switch member 1 is not a member integrally formed of a rubber material, and may be formed of any material as long as at least the dome portion 4 is formed of a rubber material. The rubber material constituting the pushbutton switch member 1 is thermosetting 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). It is preferable to use thermoplastic elastomers such as urethane, ester, styrene, olefin, butadiene, and fluorine, or composites thereof. Among the candidate materials, silicone rubber is particularly preferable.

<2. Contact Member>
2.1 First Embodiment FIG. 2 shows a wire mesh used for a contact member connected to the pushbutton switch member of FIG. 1, (2A) is a plan view of the wire mesh, and (2B) is an A of (2A). -A line sectional drawing is shown, respectively. 3 shows a first embodiment of a contact member connected to the pushbutton switch member of FIG. 1, wherein (3A) is a surface of the contact member facing the substrate side contact, and (3B) is a view of (3A). BB line sectional drawing is shown, respectively.

  FIG. 2 shows a large metal mesh 9 having a larger area than the metal mesh 12 used in the contact member 10 of FIG. As will be described later, the contact member 10 is produced by pasting a large metal mesh 9 on a rubber sheet and vulcanizing it, and then punching it to a desired size. The large size metal mesh 9 is a material for producing a large number of so-called metal meshes 12.

  The large-sized metal mesh 9 is composed of two-way metal wires 22 and 23 that intersect each other, and at least the surface of one of the two metal wires 22 is formed of a noble metal. The large metal mesh 9 may be made of metal wires in three or more directions. In that case, at least the surface of the metal wire in at least one of the three or more directions is formed of a noble metal, and the metal wires in the remaining directions are formed of a non-noble metal. Since it is sufficient that at least the surface of the metal wire 22 is made of a noble metal, for example, a nickel coat layer is formed on the surface of a metal wire made of a non-noble metal (for example, copper), and the nickel coat layer is formed on the nickel coat layer. A coating layer of a noble metal such as gold may be formed. 2 and the plan view after FIG. 2 show an example in which the metal wire 22 is formed only from the noble metal, and the metal wire 22 formed only from the noble metal is shown in black. On the other hand, in FIG. 2 and the plan views after FIG. 2, the metal wire 23 formed of a metal other than the noble metal is shown in gray. At least the surface of the metal wire 22 has a noble metal, that is, gold (Au), platinum (Pt), silver (Ag), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru) or osmium ( Os). The metal wire 23 is made of a conductive metal other than the noble metal, and is preferably made of any one of nickel (Ni), copper (Cu), tungsten (W), stainless steel (SUS), or any alloy thereof. As an example, it is more preferable that a nickel plating layer is formed on a copper or copper core. In this way, at least the surface of one of the metal wires 22 and 23 (in this embodiment, the metal wire 22) is made of a noble metal, and the other metal wire (in this embodiment, the metal wire 23). By using non-noble metal without using noble metal, high reliability as a contact can be realized and the contact member 10 can be configured at low cost.

  A contact member 10 shown in FIG. 3 includes a substantially disc-shaped rubber-like elastic body 11 and a wire mesh 12. The metal mesh 12 has a form in which metal wires 22 and 23 are knitted on one surface of the rubber-like elastic body 11. The metal wire 22 and the metal wire 23 may have the same diameter or different diameters. More preferably, the diameter of the metal wire 22 made of noble metal is larger than the diameter of the metal wire 23 made of a non-noble metal. By making the diameter of the metal wire 22 larger than the diameter of the metal wire 23, the allowable current can be increased, or the contact area with the substrate side contacts 7 and 8 can be expected to increase, and contact stability can be achieved. The metal mesh 12 is embedded in the rubber-like elastic body 11 so that a part thereof is exposed from the rubber-like elastic body 11. The metal mesh 12 is a part of a large metal mesh 9 composed of two-way metal wires 22 and 23 intersecting each other as shown in FIG. As a suitable wire mesh 12, a wire mesh of plain weave, twill weave or plain tatami weave can be exemplified. In the present application, “intersection” is interpreted to include not only a positional relationship that intersects at a right angle but also a relationship that intersects at an angle other than a right angle.

  In the case of plain weaving, it is desirable that the tension of one metal wire (also referred to as “lattice” here) 22 and the tension of the other metal wire (also referred to as “meridian” here) 23 are substantially the same. . When the latitude line 22 is a non-noble metal wire coated with a very thin noble metal coat layer such as gold, the diameter of the latitude line 22 after the noble metal noble metal coat and the non-noble metal meridian 23 The diameter should be almost the same. On the other hand, when the latitude line 22 is a metal wire provided with a coating layer of a noble metal such as gold that is much thicker than the previous example, the diameter of the latitude line 22 after the noble metal coating such as gold and the meridian made of non-noble metal If the diameter of the line 23 is substantially the same, the latitude line 22 having a thick coat layer of noble metal such as gold has a lower tension than the meridian line 23. For this reason, it is preferable to make the diameter of the latitude line 22 and the diameter of the meridian 23 substantially the same before the coating of the noble metal such as gold. As a result, the diameter of the latitude line 22 on which a coating layer of a noble metal such as gold is formed is larger than the diameter of the meridian 23.

  In the case of flat tatami weave, the wire mesh 12 is established by making a difference in the tension between the latitude line 22 and the meridian line 23. In this embodiment, the latitude line 22 of at least a noble metal such as gold is made lower in tension than the meridian 23, and the latitude line 22 reliably contacts the substrate side contacts 7, 8 when pressed against the substrate side contacts 7, 8. It is preferable to do so. If the latitude line 22 has a thin coating layer of noble metal such as gold, the diameter of the latitude line 22 after the coating of noble metal such as gold is the same as or smaller than the diameter of the meridian 23, A tension difference with the meridian 23 can be realized. On the other hand, when a thick coat layer of noble metal such as gold is formed on the latitude line 22, in order to realize a tension difference between the latitude line 22 and the meridian 23, the diameter of the latitude line 22 at the stage before coating of the noble metal such as gold is set to If the diameter is equal to or smaller than the diameter of the meridian 23, the diameter of the latitude line 22 after the noble metal coating such as gold can be made larger than the diameter of the meridian 23. This is because a coat layer of noble metal such as gold hardly contributes to an increase in the tension of the latitude line 22, and the tension is determined solely by the thickness of the latitude line 22 before coating. In the following, the expressions “metal line 22” and “metal line 23” are used instead of the expressions “lattice line 22” and “meridian line 23”.

  As shown in FIG. 3, the metal mesh 12 according to the first embodiment exposes both the metal wires 22 and 23 from the rubber-like elastic body 11. When the wire mesh 12 is embedded in the rubber-like elastic body 11 from this state, the adhesive force between the wire mesh 12 and the rubber-like elastic body 11 becomes stronger. However, since the areas of the metal wires 22 and 23 exposed from the rubber-like elastic body 11 are reduced, the function as an electrical contact is further lowered. Conversely, when the wire mesh 12 is exposed upward from the rubber-like elastic body 11 from the state of FIG. 3, the adhesive force between the wire mesh 12 and the rubber-like elastic body 11 becomes weaker. However, since the area | region of the metal wires 22 and 23 exposed from the rubber-like elastic body 11 increases, the function as an electrical contact becomes higher.

  In order to increase the adhesion between the metal mesh 12 and the rubber-like elastic body 11 and to exhibit a high function as an electrical contact of the metal mesh 12, both the metal wires 22 and 23 are exposed from the rubber-like elastic body 11, and It is preferable that the metal wire 22 is exposed in a wider area in plan view than the metal wire 23. The wire mesh 12 is preferably attached directly to the rubber-like elastic body 11 without interposing an adhesive layer on the rubber-like elastic body 11 or the like. By not interposing the adhesive layer or the like, the risk that the wire mesh 12 is peeled off from the rubber-like elastic body 11 can be further reduced, so that the quality of the pushbutton switch member 1 can be further improved. Further, the cost of the push button switch member 1 can be reduced by omitting the step of forming the adhesive layer.

  Further, as another viewpoint of increasing the adhesive force between the wire mesh 12 and the rubber-like elastic body 11 and exhibiting a high function as an electrical contact of the wire mesh 12, the metal wire 22 protruding from the rubber-like elastic body 11 can be used. A ratio between the number of vertices and the number of vertices of the metal wire 23 can be given. 100 (%) × P1 / P2 where P1 is the number of vertices of one of the metal lines 22 and 23 (the one is more preferable for the metal line 23) and P2 is the other number of vertices. Is preferably 10% to 90%, more preferably 20% to 70%, and still more preferably 30% to 50%. When 100 (%) × P1 / P2 is in such a range, the adhesion force is secured by increasing the adhesion area and the fitting effect between the rubber-like elastic body 11 and the metal wires 22 and 23, and the board-side contact 7 , 8 can be ensured by increasing the number of metal wires 22 and 23 in contact with each other.

  FIG. 4 shows a cross-sectional view (4A) of only one direction of metal wire constituting the wire mesh of FIG. 3, and a cross-sectional view (4B) of only the other metal wire, respectively. Therefore, in (4A), the metal wire 23 intertwined with the metal wire 22 is not drawn. Similarly, in (4B), the metal wire 22 intertwined with the metal wire 23 is not drawn. Further, only in FIG. 4, the X direction, the Y direction, and the Z direction are shown because the length directions of the metal line 22 and the metal line 23 need to be clearly shown.

  In place of, or in addition to, the exposed areas of the metal wires 22 and 23 and the number of exposed vertices of the metal wires 22 and 23 as described above, the following exposed heights of the metal wires 22 and 23 are as follows: Thus, it is possible to achieve harmony between the function of increasing the adhesive force between the metal mesh 12 and the rubber-like elastic body 11 and the function of exhibiting high performance as an electrical contact of the metal mesh 12. As shown in FIG. 4, in this embodiment, the height (L1) at which the metal wire 22 is exposed on the rubber-like elastic body 11 is the height at which the metal wire 23 is exposed on the rubber-like elastic body 11 ( L2) is the same or larger (L2 ≦ L1). L1 is preferably 5% or more and 80% or less of the diameter (D22) of the metal wire 22, and more preferably 20% or more and 60% or less. L2 is preferably larger than 0% and not more than 50% of the diameter (D23) of the metal wire 23, and more preferably not less than 3% and not more than 30%. L2 may be 0% of the diameter (D23) of the metal wire 23, that is, the state in which the metal wire 23 is not exposed from the rubber-like elastic body 11.

2.2 Second Embodiment FIG. 5 shows a second embodiment of a contact member connected to the pushbutton switch member of FIG. 1, and (5A) shows a surface of the contact member facing the substrate side contact. 5B) is a sectional view taken along line CC of (5A), respectively.

  In the contact member 10a according to the second embodiment, the same components as those of the contact member 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted instead of the description in the first embodiment. .

  In the contact member 10a according to the second embodiment, the depth in which the wire mesh 12 is embedded in the rubber-like elastic body 11 is deeper than that in the first embodiment. In this embodiment, only the metal wire 22 (metal wire made of a noble metal) forming the wire mesh 12 is exposed from the rubber-like elastic body 11. The metal wire 23 is completely embedded in the rubber-like elastic body 11. Structures and materials other than this point are common to the first embodiment. Only the metal wire 23 may be exposed from the rubber-like elastic body 11. In such a state, the adhesive force between the wire mesh 12 and the rubber-like elastic body 11 is higher than in the state of the first embodiment.

2.3 Third Embodiment FIG. 6 shows a third embodiment of the contact member connected to the pushbutton switch member of FIG. 1, (6A) shows the surface of the contact member opposite to the wire mesh, (6B) (6A) is a sectional view taken along line DD of (6A), respectively.

  In the contact member 10b according to the third embodiment, components that are the same as those of the contact members 10 and 10a according to the above-described embodiments are denoted by the same reference numerals, and the descriptions thereof are replaced with the descriptions in the above-described embodiments. Omitted.

  The contact member 10b according to the third embodiment is common to the contact member 10 according to the first embodiment, except that a plurality of protrusions 40 are provided on the surface of the rubber-like elastic body 11 opposite to the wire mesh 12. In this embodiment, the protrusion 40 preferably has a curved surface. The protrusion 40 has a function of preventing the surface of the contact member 10b opposite to the wire mesh 12 from sticking to another contact member 10b. If the protruding portion 40 is not provided, the surface of the contact member 10b opposite to the wire mesh 12 sticks to either the wire mesh 12 side of another contact member 10b or the opposite surface thereof, and the two contact members 10b, 10b may not be easily separated. As a result, there is a risk that the push button switch member 1 is commercialized in a state where the two contact members 10b and 10b overlap. Thereafter, when one of the two contact members 10b, 10b comes off, there is a problem that the stroke (distance when the key top 3 is pushed in) is increased by the thickness of the one contact member 10b. Since the protrusion part 40 has a function which prevents said sticking, the possibility that the said malfunction will arise is reduced.

  Further, since the surface state of the surface on which the protruding portion 40 is formed and the surface on which the metal mesh 12 is formed can be differentiated, when the contact member 10b is disposed inside the molding die, the original laminated surface is mistakenly formed. The risk of placement with the opposite side up can also be reduced.

  The formation of the protruding portion 40 increases the reliability of the pushbutton switch member 1 including the contact member 10b, and contributes to cost reduction for the following reason. As another method for preventing the contact members 10b from sticking to each other, a method of reducing the adhesiveness by irradiating the surface on which the protruding portion 40 is formed with ultraviolet rays is also conceivable. However, if the process of ultraviolet irradiation is included in the manufacturing process, the cost of the contact member 10b is reduced. When the mold is formed, the formation of the projecting portion 40 leads to cost reduction as compared with the case where an ultraviolet irradiation process is performed.

  When the diameter of the contact member 10b is 3 mm, the number of protrusions 40 is 3 to 20, preferably 4 to 15, and particularly preferably 6 to 12. The shape of the protrusion 40 is preferably a substantially hemispherical shape. The protrusion 40 may have a shape in which a part of the plurality lacks a part of a complete body, but at least three of the protrusions 40 are preferably a complete body. Further, it is desirable that the protruding portions 40 are regularly arranged on one whole surface of the rubber-like elastic body 11 so as to be spaced apart at a constant interval. For example, a square arrangement or a staggered arrangement is suitable as the arrangement form of the protrusions 40. When the protrusions 40 are regularly arranged, it is easy to bond horizontally when bonding to the lower protrusion 6.

  The diameter range of the bottom area of the protrusion 40 is preferably φ0.1 mm to 2.0 mm, more preferably φ0.2 mm to 1.0 mm, and further preferably φ0.4 mm to 0.6 mm. Moreover, the height of the protrusion part 40 becomes like this. Preferably it is 0.01 mm-1.0 mm, More preferably, it is 0.03 mm-0.50 mm, More preferably, it is 0.05 mm-0.15 mm. If the protrusion part 40 is made into the range of said magnitude | size, sticking of the contact members 10b can be reduced more.

<3. Contact Member Manufacturing Method>
Next, an example of a manufacturing process of the above-described various contact members 10, 10a, 10b (hereinafter referred to as “10 etc.”) will be described.

  FIG. 7 shows a flow of an example of a suitable manufacturing method of the contact member according to each embodiment of the present invention.

  First, a compound such as silicone rubber is weighed and masticated (S101). At the same time, the cross-linking agent is weighed (S102). The measured cross-linking agent is kneaded into the compound after mastication (S103). One or more crosslinking agents may be used. Further, the coloring material is weighed (S104), and the coloring material is kneaded into the compound that has undergone S103 (S105). In addition, a coloring material contains a pigment and / or dye, for example.

  Further, the filler is weighed (S201), the auxiliary is weighed (S202), and the silane coupling agent is weighed (S203), and the weighed filler, auxiliary and silane coupling agent are mixed (S204). The mixture is kneaded with the compound that has undergone S107 (S301). Note that the filler, auxiliary agent and silane coupling agent are not essential, and at least one of them may not be added. Subsequently, the compound having undergone S301 is formed into a sheet shape and cut into an appropriate size (S302).

  Next, a plurality of metal wires 22 and a plurality of metal wires 23 are prepared, and the wire mesh 12 is produced (S400). Next, the wire mesh 12 is bonded to the sheet molded body and cut (S401). Subsequently, the sheet molded body with the metal mesh 12 bonded is placed in a mold and molded. In the molding, the mold is heated to perform primary vulcanization of the sheet molded body in the mold (S402). Next, the mold is opened, and the molded product taken out from the mold is heated to perform secondary vulcanization (S403). Finally, the contact member 10 is completed by punching into a diameter of about 3 mm (S404).

<4. Other Embodiments>
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be implemented in various modified forms.

  For example, the wire mesh 12 may be a contact formed by knitting a metal wire by any method as long as the wire mesh 12 includes metal wires 22 and 23 in a plurality of directions intersecting each other. Further, instead of the steps S402 to S403 in the flow of FIG. 7, the following steps may be performed. For example, following S401, a part of the wire mesh 12 is embedded in the sheet molded body by a laminating process using a pinch roll (S402a). Then, it puts into a hot air dryer, performs primary vulcanization in a non-pressurized state (S402b), peels off the protective film (single-sided release treatment PET) (S402c), and performs secondary vulcanization (S402b). S403a). Thereafter, like the flow of FIG. 7, the contact member 10 and the like are completed by punching into a diameter of about 3 mm (S404). The protrusion 40 is a substantially hemispherical member and preferably has a curved surface. However, the protrusion 40 is not limited to such a member. For example, the protrusion 40 has a substantially rectangular parallelepiped protrusion. Department may be sufficient. Further, the shape of the protrusion 40 may be a conical shape.

  The present invention can be used for a device including a push button switch.

DESCRIPTION OF SYMBOLS 1 ... Member for pushbutton switches 10, 10a, 10b ... Contact member, 11 ... Rubber-like elastic body, 12 ... Metal mesh, 22, 23 ... Metal wire, 40 ... Projection part .

Claims (7)

A contact member embedded on one surface of a rubber-like elastic body so as to expose a wire mesh in which a plurality of metal wires are knitted,
The wire mesh is composed of the metal wires in a plurality of directions intersecting each other, at least a surface of the metal wire in at least one direction of the plurality of directions is formed of a noble metal, and the metal in a direction other than the at least one direction. A contact member in which the wire is formed of a non-noble metal.   The contact member according to claim 1, wherein the metal mesh exposes the metal wires in the plurality of directions from the rubber-like elastic body. The wire mesh is configured by knitting the metal wire in two directions,
Embedded in the rubber-like elastic body so that the metal wires in the two directions are exposed together,
In the number of points exposed from the rubber-like elastic body, the metal wire in one direction at least the surface of which is formed of noble metal is more than the metal wire in the other direction formed of non-noble metal. The contact member according to claim 2, wherein the contact member is large. The wire mesh is configured by knitting the metal wire in two directions,
Embedded in the rubber-like elastic body so that the metal wires in the two directions are exposed together,
The contact member according to claim 2 or 3, wherein a height at which the metal wire is exposed from the rubber-like elastic body is smaller than a diameter of the exposed metal wire.   The contact member according to any one of claims 1 to 4, further comprising one or a plurality of protrusions on a surface of the rubber-like elastic body opposite to the wire mesh.   The contact member according to claim 5, wherein a surface of the protruding portion is a curved surface.   The member for pushbutton switches provided with the contact member of any one of Claims 1-6.