JP2006173084A - Manufacturing method for contact member for push button switch, stamping device, and contact member for push button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce no burrs on a metal layer of a contact member for a push button switch. <P>SOLUTION: In a stamping device 11, a penetrating hole 17 is formed through a die 12 and a punch 13 is vertically movable so as to stamp a sheet 18 placed on the die 12 into the penetrating hole 17. A pressing member 14 has a penetrating hole 19 formed to allow the punch 13 to be vertically movable. A knock-out pin 16 is supported by a compression spring 23 from below. The sheet 18 is placed on the die 12 such that the metal layer 27 is in contact with the die 12. Then, while the sheet 18 is pressed by the pressing member 14 from above, the punch 13 is pushed down to stamp the sheet 18. It is thereby possible to provide the contact member 29 for a push button switch in which the edge portion is formed into the round shape and the metal layer 27 is free from burrs. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manufacturing method of a contact member for a pushbutton switch that is brought into an energized state by contacting an electrode, a punching device used in the manufacturing method, and the contact member.

As such a technique, there is a technique disclosed in Patent Document 1 below. As shown in Patent Document 1, when manufacturing a push button switch, a contact member for a push button switch (hereinafter also referred to as a “contact member”) in which a rubber layer and a metal layer are bonded together is disposed in the mold. It arrange | positions in a recessed part for injection, inject | pours silicone rubber etc. in a metal mold | die, heat-presses and shape | molds. At this time, it is preferable to form the contact member so that the rubber layer is wider than the metal layer so that the injected silicone rubber or the like does not flow into the metal layer side of the contact member. Conventionally, in order to manufacture such a contact member, in the die set, the contact member is arranged and punched so that the metal layer of the contact member is positioned on the punch side.
JP-A 63-96822

  FIG. 15 shows an example of this. As shown in FIG. 15A, the sheet 3 on which the metal layer 1 and the rubber layer 2 are bonded is placed on the die 4 so that the metal layer 1 is on the upper side. A through hole 4 a is formed in the die 4. Then, as shown in FIG. 15 (b), the sheet 3 is punched from the upper side by the punch 6. At this time, since the rubber layer 2 has elasticity, it is compressed and punched out. Therefore, as shown in FIG. 15 (c), in the punched contact member 7, the rubber layer 2 is released from the compression and is wider than the metal layer 1. However, as shown in FIGS. 16 and 17, burrs 8 are generated at the peripheral edge of the metal layer 1 in the contact member 7. This is because, as shown in FIG. 15B, a step is formed so that the metal layer 1 pressed by the punch 6 is recessed with respect to the periphery, and the sheet 3 is punched out. Use of such a contact member with burrs in the metal layer as the contact of the push button switch may cause damage to the substrate facing the metal layer or cause a contact failure of the push button switch. .

  Accordingly, an object of the present invention is to provide a method for manufacturing a contact member for a pushbutton switch in which no burrs are generated on a metal layer, a punching device used in the manufacturing method, and a contact member thereof.

  A contact member manufacturing method for a push button switch according to the present invention is a method for manufacturing a contact member for a push button switch by punching a sheet in which a rubber layer and a metal layer are bonded, and the through hole has a through hole. The sheet is formed by a first step of placing the sheet on the die so that the metal layer of the sheet contacts the surface of the formed die, and a punch in which a concave portion is formed in the direction opposite to the die at the tip portion. In the second step, the sheet portion to be punched is punched while being in contact with a knockout pin supported from below by an elastic member.

  According to this pushbutton switch contact member manufacturing method, the sheet is punched into the through-hole by the punch while the metal layer of the sheet is in contact with the surface of the die. At this time, when the tip of the punch presses the rubber layer, the rubber layer part in contact with the tip of the punch is compressed and easily escapes into the space formed in the recess of the punch. Become. Therefore, when the sheet is punched to form the push button switch contact member, the rubber layer portion is released from the compression by the punch and extends laterally. That is, a part of the rubber layer that has swelled and escaped into the space formed in the concave portion of the punch is released from the compression by the punch and returned to the original, so that the rubber layer spreads sideways. As a result, the rubber layer is formed so as to extend more than the metal layer and to extend over substantially the entire circumference of the metal layer. In the second step, first, the metal layer of the sheet is curved and deformed so as to follow a step formed between the surface of the contacting die and the surface of the knockout pin. Thereafter, the sheet is cut along the periphery of the opening of the through hole. Thereby, the part located near the opening part periphery of a through-hole among metal layers will be cut | disconnected in the state curved to the rubber layer side. Accordingly, the peripheral edge of the metal layer on the opposite side of the rubber layer side in the punched push button switch contact member is formed in an R shape over substantially the entire circumference, and no burrs are generated. For this reason, if this contact member for a push button switch is used for a push button switch, there is no possibility that the substrate facing the metal layer is damaged or that a problem such as poor contact occurs. Also, there is no need for polishing work to remove burrs from the metal layer, and the yield is good. In addition, the punched sheet portion is received in the through hole by a knockout pin supported from below by an elastic member. In other words, the surface of the metal layer that is in contact with the knockout pin is received without being subjected to reaction force by the knockout pin while the sheet portion is punched out, so that it is formed without distortion and the occurrence of burrs can be prevented.

  In the second step, the sheet is preferably pressed by a pressing member from the rubber layer side around the area to be punched. Thereby, when punching a sheet | seat with a punch, it can prevent that a sheet | seat slip | deviates with respect to die | dye, and it can manufacture so that the contact member for pushbutton switches may not be distorted.

  The punching device according to the present invention includes a die in which a through hole is formed, a punch in which a concave portion is formed in a direction opposite to the die at the tip, and is configured to be movable into the through hole; And a knockout pin supported from below by an elastic member.

  If such a punching device is used to punch through a sheet in which the rubber layer and the metal layer are bonded, the rubber layer projects from substantially the entire circumference of the metal layer, and a contact member for a pushbutton switch having no burr on the metal layer is manufactured. be able to. That is, the sheet is placed on the die so that the metal layer is in contact with the die, and the sheet is punched into the through hole by punching. At this time, when the tip of the punch presses the rubber layer, the rubber layer part in contact with the tip of the punch is compressed and easily escapes into the space formed in the recess of the punch. Become. Therefore, when the sheet is punched to form the push button switch contact member, the rubber layer portion is released from the compression by the punch and extends laterally. That is, a part of the rubber layer that has swelled and escaped into the space formed in the concave portion of the punch is released from the compression by the punch and returned to the original, so that the rubber layer spreads sideways. Thereby, it is possible to manufacture a contact member for a pushbutton switch that has a rubber layer that is wider than the metal layer and extends over substantially the entire circumference of the metal layer. Further, the metal layer of the sheet is curved and deformed so as to follow a step formed between the surface of the contacting die and the surface of the knockout pin. Thereafter, the sheet is cut along the periphery of the opening of the through hole. Thereby, the portion of the metal layer in the vicinity of the periphery of the opening of the through hole is cut while being curved toward the rubber layer side. Accordingly, the peripheral edge of the metal layer on the opposite side of the rubber layer side in the punched push button switch contact member is formed in an R shape over substantially the entire circumference, and no burrs are generated. For this reason, if this contact member for a push button switch is used for a push button switch, there is no possibility that the substrate facing the metal layer is damaged or that a problem such as poor contact occurs. Further, there is no need for polishing work to remove burrs from the metal layer, and the yield is good. In addition, the punched sheet portion is received in the through hole by a knockout pin supported from below by an elastic member. In other words, the surface of the metal layer that is in contact with the knockout pin is received without being counteracted by the reaction force by the knockout pin while the sheet is punched out. can do. In addition, since the knockout pin is supported from below by the elastic member so as to be positioned in the through hole, the punched contact member for the push button switch receives an impact from the punch and jumps out of the through hole. Can be prevented.

  In this punching device, the tip of the knockout pin that receives the punched sheet is preferably a flat surface. By adopting this configuration, the metal layer is punched out while being restrained by a knockout pin having a flat tip, so that the surface of the metal layer is formed flat and the finish of the contact member for the pushbutton switch is improved.

  Furthermore, it is preferable that the tip of the knockout pin is substantially on the same plane as the surface on which the sheet is placed in the die. Since the metal layer of the sheet is suppressed while being in contact with the tip of the knockout pin from when the sheet is punched out, the finish of the contact member for the push button switch is improved. Further, since the knockout pin is supported from below by the elastic member, the pushbutton switch contact member formed by punching the sheet is returned to the original position in the sheet by the knockout pin after being punched. It is. Therefore, after that, since the contact member for the push button switch can be taken out by moving the sheet, for example, the manufacturing efficiency is good. That is, since the punched contact member for the push button switch is returned to the original position of the sheet, the trouble of collecting the punched contact member for the push button switch can be saved.

  In this punching device, it is preferable that the tip of the knockout pin for receiving the punched sheet is formed in a concave shape or a convex shape, and a flat surface portion is formed on the upper surface periphery of the tip of the knockout pin. By employ | adopting this structure, the shape of the center part of a metal layer can be made into a convex shape or a concave shape. Thereby, the foreign material resistance of the contact member for pushbutton switches can be improved.

  Furthermore, it is preferable to further include a pressing member for pressing the sheet placed on the die around the area to be punched. When the sheet is punched out, the sheet can be prevented from being displaced with respect to the die, and the push button switch contact member can be manufactured without being distorted.

  Further, the contact member for a push button switch according to the present invention is a contact member for a push button switch in which a rubber layer and a metal layer are bonded, and the rubber layer projects from substantially the entire circumference of the metal layer. The peripheral edge of the metal layer on the opposite side is formed in an R shape over substantially the entire circumference by punching.

  According to this pushbutton switch contact member, the peripheral edge of the metal layer is formed in an R shape over substantially the entire circumference. For this reason, if this contact member for a push button switch is used for a push button switch, damage such as damage to the substrate or the like due to contact of the metal layer can be suppressed, and there is no possibility of causing problems such as poor contact. Further, there is no need for polishing work for removing burrs on the metal layer, and the yield is good.

  In the contact member for the pushbutton switch, the shape of the central portion of the metal layer is a convex shape that swells on the opposite side of the rubber layer or a concave shape that is depressed on the rubber layer side. The shape is preferably a planar shape. By adopting this configuration, the foreign matter resistance of the push button switch contact member can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the contact member for pushbutton switches which a burr | flash does not produce in a metal layer, the punching apparatus used for the manufacturing method, and the contact member can be provided.

  Hereinafter, preferred embodiments of a contact member manufacturing method for a pushbutton switch, a punching device used in the manufacturing method, and a contact member manufactured by the punching device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional view of a punching device 11 in the present embodiment. As shown in FIG. 1, the punching device 11 includes a die 12, a punch 13, a pressing member 14, and a knockout pin 16.

  The die 12 has a flat plate shape and is disposed horizontally. A cylindrical through hole (die hole) 17 is formed in the die 12. The inner diameter of the through hole 17 is φ2.82 mm (dimensional tolerance: +0.005 to +0.008 mm). The punch 13 has a cylindrical shape and is movable in the vertical direction. As the punch 13 moves downward, the sheet 18 that is a punching object placed on the die 12 is punched into the through hole 17. The outer diameter of the punch 13 is φ2.82 mm (dimensional tolerance: −0 to +0.005 mm).

  The pressing member 14 has a flat plate shape. The holding member 14 is formed with a through hole 19 for the punch 13 to move in the vertical direction. A cylindrical protrusion 21 is formed on the periphery of the lower opening of the through hole 19. The protruding portion 21 protrudes 0.2 mm toward the lower side. The pressing member 14 comes into contact with the die 12 by a protruding portion (not shown) at the peripheral edge thereof. The thickness from the surface from which the protruding portion 21 protrudes to the lower surface of the protruding portion is 0.5 to 1.0 mm. This thickness needs to be set larger than the thickness of the sheet 18. By designing in this way, when the protruding portion of the pressing member 14 is in contact with the upper surface of the die 12, the tip of the protruding portion 21 and the upper surface of the die 12 can be separated by 0.3 to 0.8 mm. .

  The knockout pin 16 is supported from below by a compression spring (elastic member) 23 disposed on the base 22. That is, the knockout pin 16 is supported so as to be urged toward the punch 13 by the compression spring 23. The knockout pin 16 includes a cylindrical portion 16a and a stopper portion 16b. The cylindrical portion 16 a is positioned in the through hole 17 provided in the die 2. The cylindrical portion 16a supports the sheet portion punched out by the punch 13 from below. The outer diameter of the cylindrical portion 16a is φ2.82 mm (dimensional tolerance: −0.005 to +0 mm). The height of the cylindrical portion 16a is the same as the thickness of the die 12, and the upper surface of the cylindrical portion 16a is a plane. Therefore, when the knockout pin 16 moves to the upper limit, the upper surface of the cylindrical portion 16a and the upper surface of the die 12 are located on the same plane. The stopper portion 16b is formed on the lower side of the cylindrical portion 16a and has a disk shape having a diameter larger than the diameter of the cylindrical portion 16a and the through hole 17. That is, the stopper portion 16b plays a role of restricting the upward movement of the knockout pin 16 by bringing its upper surface into contact with the lower surface of the die 12.

  The sheet 18 is an object to be punched (work), and is formed by bonding an elastic rubber layer 26 made of silicone rubber and a metal layer 27 by adhesion.

  FIG. 2 is a sectional view of the punch 13. As shown in FIG. 2, a concave portion 13 a that is recessed in the direction opposite to the die 12 and a flat surface portion 13 b are formed at the tip of the cylindrical punch 13. The recess 13a is formed in a conical shape having an apex angle of 60 degrees. The flat portion 13 b is formed on the periphery of the tip surface of the punch 13. The width t of the flat portion 13b is 0.1 mm (dimensional tolerance: −0.05 to +0 mm). When the sheet is pressed using the punch 13 having such a tip portion, the rubber layer portion pressed by the flat portion 13b escapes into the space formed by the concave portion 13a and swells.

  Next, a method of manufacturing a pushbutton switch contact member using the punching device 11 described above will be described.

  First, as shown in FIG. 1, the sheet 18 is placed on the die 12 so that the metal layer 27 contacts the die 12. Next, as shown in FIG. 3, the sheet 18 is pressed from above by the pressing member 14 so that the sheet 18 does not shift on the die 12. Thereby, the cylindrical protrusion 21 comes into contact with the periphery of the region where the sheet 18 is punched.

  Next, the punch 13 located in the through hole 19 is pushed down. As a result, the rubber layer 26 is pressed by the flat portion 13 b of the punch 13. As a result, the portion of the rubber layer 26 in contact with the flat portion 13b of the punch 13 is compressed, escapes into the space formed in the concave portion 13a of the punch 13, and slightly bulges.

  Further, when the punch 13 is pushed down, as shown in a region A of FIG. 4, the surface of the metal layer 27 to be punched is in contact with the surface of the knockout pin 16 and in the vicinity of the periphery of the opening of the through hole 17 of the die 12. The metal layer 27 is curved and deformed toward the rubber layer 26 along a step formed between the upper surface of the die 12 and the upper surface of the knockout pin 16.

  Further, when the punch 13 is pushed down, as shown in FIG. 5, the sheet 18 is cut into a circular shape along the periphery of the opening of the through hole 17 of the die 12 and punched out.

  While the punch 13 punches the sheet 18, the metal layer 27 is received by the upper surface of the knockout pin 16 supported from below by the compression spring 23, and the upper surface of the knockout pin 16 is formed in a plane. ing. Therefore, the surface of the metal layer 27 that is in contact with the knockout pin 16 is stably formed on a flat surface, and the generation of burrs is prevented and the finish is good. Further, since the knockout pin 16 is supported from below by the compression spring 23 so that at least a part of the columnar portion 16 a is located in the through hole 17, the punched sheet portion is caused by the impact from the punch 13. There is no jump out of the die 12.

  Next, as shown in FIG. 6, when punching of the sheet 18 by the punch 13 is completed, the punch 13 and the pressing member 14 are moved upward and separated from the sheet 18. At this time, the compressed compression spring 23 pushes up the knockout pin 16 by its restoring force until the stopper portion 16b of the knockout pin 16 contacts the lower surface of the die 12. Along with this, the punched sheet portion fits in the original position of the sheet.

  Next, as shown in FIG. 7, the sheet 18 is moved and the sheet portion punched out by the punch 13 is pushed downward from above by the pushing member 28 for pushing out the push button switch contact member from the sheet. Thereby, as shown in FIG. 8, the punched sheet portion is pushed out from the sheet 18 as the push button switch contact member 29.

  Thus, the push-button switch contact member 29 can be efficiently manufactured by returning the punched sheet portion to the original position of the sheet and then extruding it from the sheet in a subsequent process. That is, the trouble of picking up the contact member for the push button switch punched out by the punch 13 and jumping out from the through hole of the die can be saved.

  FIG. 9A is a cross-sectional view of the push button switch contact member 29, and FIG. 9B is a plan view of the push button switch contact member 29. 9A is a cross-sectional view taken along line AA of the pushbutton switch contact member 29 shown in FIG. 9B. As shown in the region A of FIG. 4 described above, the metal layer 27 near the periphery of the opening of the through hole 17 of the die 12 is curved toward the rubber layer 26 when punched. Accordingly, the peripheral edge 31 of the metal layer 27 in the pushbutton switch contact member 29 is formed in an R shape over substantially the entire circumference, and no burrs are generated. Therefore, when such a push button switch contact member 29 is used for a push button switch, it is possible to prevent the substrate or the like facing the metal layer 27 from being damaged and damaged, and there is no possibility of causing problems such as poor contact. . Further, there is no need for polishing work for removing burrs from the metal layer 27, and the yield is good.

  Further, as shown in FIG. 9, the diameter of the rubber layer 26 of the push button switch contact member 29 is larger than the diameter of the metal layer 27. Thereby, when the contact member 29 is disposed in the contact member disposing recess in the push button switch molding die, it is possible to prevent the metal layer 27 from being deformed by contacting the die.

  Furthermore, when the pushbutton switch is molded with a mold, the thermal expansion of the rubber layer 26 makes it possible to fill the gap between the pushbutton switch contact member 29 and the contact member placement recess. As a result, it is possible to prevent a situation where the resin injected into the mold flows into the metal layer 27 side, and a situation where the position of the contact member 29 shifts due to the pressure of the resin injected into the mold. Can also be prevented.

  FIG. 10 is data obtained by linearly measuring the shape of the metal layer 27 of the contact member 29 for a pushbutton switch actually manufactured using an optical non-contact type surface roughness measuring device. As shown in FIG. 10, the peripheral portion 31 of the metal layer 27 was formed in an R shape over substantially the entire circumference of the metal layer 27, and it was confirmed that no burrs were generated. In addition, although the radius of R part in the peripheral part 31 of the metal layer 27 changed with positions, since the burr | flash did not generate | occur | produce in the peripheral part 31, practicality is fully recognized.

  Further, as shown in FIG. 3 described above, when the flat portion 13b of the punch 13 presses the rubber layer 26, the portion of the rubber layer 26 that is in contact with the flat portion 13b of the punch 13 is compressed by the flat portion 13b. Then, it escapes into the space formed in the recess 13a of the punch 13 and bulges slightly. Therefore, when the sheet 18 is punched and the push button switch contact member 29 is formed, the rubber layer 26 portion is released from the compression by the punch 13 and extends laterally. That is, a part of the rubber layer 26 that has swelled into the space formed in the concave portion of the punch 13 is released from the compression by the punch 13 and returned to the original, so that the rubber layer 26 spreads sideways. become. As a result, the rubber layer 26 is formed so as to extend more than the metal layer 27 and to extend over substantially the entire circumference of the metal layer.

  By adjusting the thickness of the protruding portion at the peripheral edge of the pressing member 14 or the downward projecting distance of the projecting portion 21, it escapes into the space formed in the concave portion 13a of the punch 13 during punching and expands. The amount of the rubber layer 26 to be protruded can be adjusted, and the protruding distance of the push button switch contact member 29 to the side of the rubber layer 26 can be adjusted.

  The present invention is not limited to the embodiment described above.

  For example, the shape of the recess 13a at the tip of the punch 13 is not limited to a conical shape, and may be a truncated cone shape or a dome shape. In this case, the depth of the recess 13a is preferably about 1 to 3 times the thickness of the rubber layer 26.

  Further, the shape of the push button switch contact member 29 formed by punching the sheet 18 is not limited to a circle, and may be an ellipse or a polygon. In this case, the cross-sectional shape of the punch 13, the cross-sectional shape of the through-hole 19 in the pressing member 14, the cross-sectional shape of the through-hole 17 in the die 12, the cross-sectional shape of the knockout pin 16, etc. What is necessary is just to match a shape.

  Further, the dimensions of the push button switch contact member 29 are not limited to the dimensions of the above-described embodiment. The outer diameter of the punch 13, the inner diameter of the through hole 19 in the pressing member 14, the inner diameter of the through hole 17 in the die 12, the outer diameter of the knockout pin 16 and the like are appropriately set in accordance with the dimensions of the contact member 29 for the push button switch. Can be changed.

  The sheet 18 has a two-layer structure in which a rubber layer 26 of silicone rubber and a metal layer 27 are bonded together, but the structure of the sheet 18 is not limited to this. For example, the number of rubber layers bonded to the metal layer 27 may be multiple layers such as two layers or three layers. This is because if the punching apparatus according to the present invention can be used to place the metal layer 27 side of the sheet 18 on the die 12 and punch the sheet, the peripheral edge of the metal layer 27 can be formed in an R shape. This is because the object of the present invention can be achieved.

  In addition, a large number of small holes may be formed in the metal layer 27. Thereby, the rigidity of the metal layer 27 can be reduced, and the workability of the pushbutton switch contact member can be improved.

  In the above-described embodiment, the shape of the top end of the knockout pin 16 is a plane, but is not limited thereto. For example, the concave shape in which the upper tip surface is depressed downward or the convex shape in which the upper tip surface is swollen upward may be used. However, when the shape of the upper tip of the knockout pin 16 is a concave shape or a convex shape, it is preferable to form a flat portion on the upper surface periphery of the tip of the knockout pin 16. Hereinafter, the reason why it is preferable to form the plane portion will be described.

  (1) First, when the entire upper tip is recessed without forming a flat portion on the upper surface periphery of the tip of the knockout pin 16 (concave shape), the metal layer 27 of the contact member 29 for the pushbutton switch that has been punched out This is because the end portion of the metal layer 27 may protrude outside the end portion of the rubber layer 26, and in this case, the metal layer 27 comes into contact with the mold and is deformed.

  (2) Further, when the entire upper tip is inflated without forming a flat portion at the upper peripheral edge of the tip of the knockout pin 16 (convex shape), the metal layer 27 of the push button switch contact member 29 that has been punched This is because the end portion faces the counter substrate, and in this case, the counter substrate may be damaged.

  (3) Further, when the entire top end is depressed or swelled without forming a flat surface at the periphery of the top surface of the knockout pin 16 (a concave or convex shape), a punched contact member for a pushbutton switch The side surface of the rubber layer 26 is depressed toward the center of the rubber layer 26. In this case, the effect of preventing the resin injected into the mold from flowing into the metal layer 27 (seal effect) is obtained. It is because it will reduce.

  11 and 12 are views of the knockout pin 16 as viewed from the side. A flat surface portion is formed on the periphery of the upper surface of the tip of the knockout pin 16 shown in FIGS. The knockout pin 16 shown in FIG. 11 is formed in a concave shape in which the central portion of the upper tip is recessed downward. The upper tip has a flat portion 16c formed at the periphery of the upper surface of the tip and a recess 16d formed at the center of the upper surface of the tip. The knockout pin 16 shown in FIG. 12 is formed in a convex shape in which the central portion of the upper tip swells upward. The upper tip has a flat portion 16c formed at the periphery of the upper surface of the tip and a bulging portion 16e formed at the center of the upper surface of the tip.

  The outer diameter of each knockout pin 16 is φ2.82 mm, similar to the knockout pin 16 in the above-described embodiment. The width of the flat portion of each knockout pin 16 is 0.5 mm. Furthermore, the hollow part 16d and the bulging part 16e are formed of a part of a spherical surface having a radius of 8.3 mm, and the depth of the hollow part 16d with respect to the flat part 16c and the height of the bulging part 16e with respect to the flat part 16c are respectively. 0.05 mm.

  13 is a cross-sectional view of the pushbutton switch contact member 29 punched using the knockout pin 16 shown in FIG. 11, and FIG. 14 is a pushbutton switch punched using the knockout pin 16 shown in FIG. FIG.

  A rubber layer 26 protrudes from substantially the entire circumference of the metal layer 27 of each push button switch contact member 29. The diameter of the rubber layer 26 is φ2.82 mm, and the diameter of the metal layer 27 is smaller than the diameter of the rubber layer 26. The peripheral portion of the metal layer 27 on the side opposite to the rubber layer 26 of each push button switch contact member 29 is formed in an R shape over substantially the entire circumference.

  The shape of the central portion of the metal layer 27 of the pushbutton switch contact member 29 shown in FIG. 13 is a convex shape that swells on the opposite side to the rubber layer 26, and the height 27h of this bulge is 0.02 mm.

  The shape of the central portion of the metal layer 27 of the pushbutton switch contact member 29 shown in FIG. 14 is a concave shape recessed to the rubber layer 26 side, and the depth 27d of this recess is 0.02 mm. The shape from the peripheral part to the center part of the metal layer 27 of the contact member 29 for each push button switch is a planar shape.

  As shown in FIG. 13, when the central portion of the metal layer 27 of the pushbutton switch contact member 29 is formed in a convex shape, when the metal layer 27 comes into contact with the opposing substrate of the pushbutton switch, The contact surface on the counter substrate gradually spreads from the center portion of the metal layer 27 toward the outer peripheral portion. Therefore, for example, when a foreign substance exists on the counter substrate, the foreign substance can be gradually moved from the central part toward the outer peripheral part according to the spread of the contact surface of the metal layer 27.

  As shown in FIG. 14, when the central portion of the metal layer 27 of the contact member 29 has a concave shape, when the metal layer 27 comes into contact with the counter substrate of the pushbutton switch, The contact surface of the metal layer 27 gradually spreads from the outer periphery of the metal layer 27 toward the center. Therefore, for example, when a foreign substance exists on the counter substrate, the foreign substance can be gradually moved from the outer peripheral part toward the central part in accordance with the spread of the contact surface of the metal layer 27.

  In this way, by changing the metal layer 27 of the push button switch contact member 29 to be punched into a convex shape or a concave shape, the foreign matter resistance of the push button switch contact member 29 can be improved.

  Here, in order to improve the foreign matter resistance, some push button switch contact members have a plurality of small holes provided on the surface thereof. By further deforming such a contact member into a convex shape or a concave shape, the moved foreign matter can be easily taken into the hole. Therefore, in this case, the foreign matter resistance can be further improved.

  The contact member for the pushbutton switch may be excessively deformed by the contracted resin when it is thermoformed as a part of the pushbutton switch with a mold. In such a case, by using the punching device according to the present invention, by deforming the contact member into a convex shape or a concave shape in advance according to the amount of deformation, excessive deformation at the time of heat forming can be offset. It is possible to improve the finished condition of the contact member for the push button switch after molding.

It is sectional drawing which shows one Embodiment of the punching apparatus which concerns on this invention. It is sectional drawing of the punch used for the punching apparatus of FIG. It is sectional drawing which shows a mode that a sheet | seat is punched by the punching apparatus of FIG. It is an expanded sectional view which shows a mode that a sheet | seat is punched by the punching apparatus of FIG. It is sectional drawing which shows a mode that a sheet | seat is punched by the punching apparatus of FIG. It is sectional drawing which shows a mode that a sheet | seat is punched by the punching apparatus of FIG. 1, and a punch is separated. It is sectional drawing which shows a mode that the sheet | seat part punched out from the sheet | seat is extruded. It is sectional drawing which shows a mode that the sheet | seat part punched out from the sheet | seat is extruded. FIG. 9A shows a push-button switch contact member manufactured by punching a sheet, FIG. 9A is a sectional view of the push-button switch contact member, and FIG. 9B is a plan view of the push-button switch contact member. FIG. 4 is an external shape measured by an optical non-contact type surface roughness measuring device for a metal layer in a push button switch contact member manufactured by the push button switch contact member manufacturing method according to the present invention. It is the figure which looked at the knockout pin in which the plane part was formed in the upper surface periphery of the front end from the side. It is the figure which looked at the knockout pin in which the plane part was formed in the upper surface periphery of the front end from the side. It is sectional drawing of the contact member for pushbutton switches stamped using the knockout pin shown in FIG. It is sectional drawing of the contact member for pushbutton switches punched using the knockout pin shown in FIG. FIG. 15A is a cross-sectional view of a punching device showing a state of manufacturing a push-button switch contact member by a conventional push-button switch contact member manufacturing method, and FIG. 15A shows a state in which a sheet is placed on a die. (B) shows a state of punching a sheet by punching, and FIG. 15 (b) is a cross-sectional view showing a state of punching a sheet. It is sectional drawing of the contact member for pushbutton switches manufactured by the conventional contact member manufacturing method for pushbutton switches. It is the external shape measured by the optical system non-contact type surface roughness measuring apparatus of the metal layer in the contact member for pushbutton switches manufactured by the conventional manufacturing method of the contact member for pushbutton switches.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Die, 13 ... Punch, 13a ... Recess, 14 ... Pressing member, 16 ... Knockout pin, 17 ... Through-hole, 18 ... Sheet (work), 23 ... Compression spring (elastic member), 26 ... Rubber layer, 27 ... Metal layer, 29... Push-button switch contact member, 31.

Claims (9)

In the contact member manufacturing method for a push button switch, in which the contact member for the push button switch is manufactured by punching a sheet on which the rubber layer and the metal layer are bonded,
A first step of placing the sheet on the die such that the metal layer of the sheet is in contact with the surface of the die in which a through hole is formed;
Including a second step in which the sheet is punched into the through-hole by a punch having a recess formed in a direction opposite to the die at the tip portion;
In the second step, the sheet part to be punched is punched while being in contact with a knockout pin supported from below by an elastic member.   2. The method for manufacturing a contact member for a pushbutton switch according to claim 1, wherein, in the second step, the sheet is pressed by a pressing member from the rubber layer side around a region to be punched out. A die formed with a through hole;
A punch having a recess formed in a direction opposite to the die at the tip, and configured to be movable into the through hole;
A knockout pin positioned in the through hole and supported from below by an elastic member;
A punching device comprising:   4. The punching device according to claim 3, wherein a tip of the knockout pin that receives the punched sheet is a flat surface.   The punching device according to claim 4, wherein a tip of the knockout pin is substantially flush with a surface of the die on which the sheet is placed. The tip of the knockout pin that receives the sheet to be punched is formed in a concave shape or a convex shape,
The punching device according to claim 3, wherein a flat portion is formed on a peripheral edge of the upper surface of the tip of the knockout pin.   The punching device according to any one of claims 3 to 6, further comprising a pressing member for pressing a sheet placed on the die around a region to be punched. A contact member for a pushbutton switch in which a rubber layer and a metal layer are bonded together,
The rubber layer projects from substantially the entire circumference of the metal layer,
A contact member for a pushbutton switch, wherein a peripheral portion of the metal layer on the side opposite to the rubber layer is formed in an R shape over substantially the entire circumference by punching. The shape of the central portion of the metal layer is a convex shape that swells on the opposite side of the rubber layer or a concave shape that is depressed on the rubber layer side,
The contact member for a pushbutton switch according to claim 8, wherein a shape from a peripheral portion of the metal layer to the central portion is a planar shape.

Images