JP2010225482A - Switch structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch structure requiring no use of a special adhesive and having excellent work efficiency for mounting. <P>SOLUTION: A rod 6 made of resin is integrally held by and fixed to the push button part 31 of a rubber mat 3, and a movable contact part 63 is formed at the tip of the rod 6. Since the movable contact part 63 is formed on the rod 6 made of resin, a special adhesive is not required. Also, man-hours for mounting the rod 6 can be greatly reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a push-type switch used for a small electronic device or the like.

  For example, various push-type switches are provided on a steering wheel of a recent automobile, and various electronic devices can be operated with fingers without releasing the hand from the steering wheel. This push-type switch is a rubber mat having a reverse-bottomed cylindrical push button as described in, for example, JP-A-09-286044, JP-A-2003-123581, and JP-A-2008-016285. Is a basic structure that is mounted on the surface of a printed wiring board.

  In this push type switch, a fixed contact part is formed on the surface of the printed wiring board, a movable contact part is formed on the surface of the push button part facing the printed wiring board, and the push button part is printed via a push rod. By pressing toward the substrate, the movable contact portion and the fixed contact portion are brought into conduction, the pressure is released, and the conduction between the movable contact portion and the fixed contact portion is interrupted by the elastic reaction force of the push button portion.

  For example, as shown in FIG. 6, the conventional push type switch includes a housing 100, a printed wiring board 200, a rubber mat 300 made of silicon rubber, a push rod 400 made of resin, a guide 500 made of resin, and a resin. The cover 600 made of Engagement holes 101 are formed in the left and right side walls of the housing 100, respectively.

  The printed wiring board 200 is formed with a fixed contact portion 201 composed of a pair of adjacent contacts. The rubber mat 300 is formed with an inverted bottomed cylindrical push button portion 301, and a movable contact portion 302 is formed on the surface of the push button portion 301 facing the printed wiring board 200. A through hole 501 is formed in the guide 500, and a push rod 400 is inserted into the through hole 501. A seesaw type switch 601 is swingably held on the cover 600, and a pair of left and right engaging claws 602 protrude downward.

  In order to assemble this push switch, first, the printed wiring board 200 and the rubber mat 300 are laminated on the casing 100 in this order. Next, the push rod 400 inserted through the through hole 501 of the guide 500 is placed on the surface of the rubber mat 300. Finally, the locking claw 602 of the cover 600 is engaged with the engagement hole 101 of the housing 100 to complete the entire operation. Fix it.

  According to this push switch, when one of the right and left sides of the seesaw type switch 601 is pressed with a finger, the push rod 400 on the pressed side is lowered to press the push button portion 301. Then, the movable contact portion 301 moves downward and comes into contact with the fixed contact portion 201, so that the pair of contacts of the fixed contact portion 201 become conductive. When the press of the seesaw type switch 601 is released, the push button portion 301 becomes the original shape due to its own elasticity, and the movable contact portion 301 and the fixed contact portion 201 are separated from each other and the conduction is cut off.

JP 09-286044 A Japanese Patent Laid-Open No. 2003-123581 JP 2008-016285A

  As described above, in the conventional push switch, the movable contact portion is formed on the rubber mat made of silicon rubber. The movable contact portion is made of a conductive metal such as gold. However, there is a problem that a special adhesive is required to firmly bond the silicon rubber and the movable contact portion made of gold or the like.

  Further, the push rod is a small part having a diameter of about 3 mm, and it must be inserted into the through hole of the guide from the lower side and assembled, and improvement in assembling workability is required.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a switch structure excellent in assembly workability without the need to use a special adhesive.

  A feature of the switch structure of the present invention that solves the above problems is a circuit board having a fixed contact portion, and a sheet placed on the surface of the circuit board and away from the circuit board at a position of the flat sheet portion and the fixed contact portion. A rubber mat having a reverse-bottomed cylindrical push button portion projecting from the portion, a resin rod which is integrally held and fixed to the upper bottom portion of the push button portion and protrudes from the rubber mat toward at least the fixed contact portion, and fixed And a movable contact portion formed on the surface of the rod facing the contact portion.

  According to the switch structure of the present invention, the movable contact portion is formed on the surface of the resin rod. Therefore, since the joint strength between the movable contact portion and the rod is high, a special adhesive is not required and the cost can be reduced. In addition, since the rod is integrally held and fixed to the push button portion, there is no problem that the rod falls off during assembly, and the assembly workability is greatly improved. And since the shape of a pushbutton part can be made equivalent to the past, operativity does not change.

It is a disassembled perspective view of the switch structure concerning one Example of this invention. It is sectional drawing of the switch structure concerning one Example of this invention. It is a principal part expanded sectional view of the switch structure concerning one Example of this invention. It is principal part sectional drawing of the metal mold | die used at the time of shaping | molding of a rubber mat in the switch structure which concerns on one Example of this invention. It is sectional drawing of the switch structure concerning the 2nd Example of this invention. It is explanatory sectional drawing which shows the assembly method of the conventional switch structure.

  The minimum components of the switch structure of the present invention are a circuit board, a rubber mat, and a rod. As in the conventional case, a housing that accommodates the whole may be used, and when it is disposed on a handle or the like, it can be assembled to the handle body. Further, the push button portion of the rubber mat may be exposed and the surface thereof may be used as a switch, or a cover for holding the switch as in the conventional case may be provided.

  A general printed wiring board can be used as the circuit board. A fixed contact portion made of a conductive metal is formed on the surface.

  The rubber mat has insulating properties, sealing properties, and elasticity, and it is desirable to use silicon rubber from the viewpoint of durability. This rubber mat has a flat sheet portion and an inverted bottomed cylindrical push button portion protruding from the sheet portion. The push button portion has an upper bottom portion, and a resin rod is integrally held and fixed to the upper bottom portion.

  In order to hold and fix the rod to the upper bottom part of the push button part, it is possible to hold and fix the formed push button part and the rod together by fitting or the like. It is desirable that the rubber mat is integrally held and fixed by inserting and integrally forming the rubber mat. In this way, when a rubber mat having a plurality of push button portions is molded, the rod can be integrated with each push button portion at the same time, so that the assembly workability is remarkably improved.

  In order to further increase the bonding strength between the upper bottom of the push button portion and the rod, it is desirable to increase the bonding area. In order to do this, there are methods of knurling the surface of the rod, forming irregularities, and forming a flange portion.

  A movable contact portion is formed on the surface of the rod facing the fixed contact portion. The movable contact portion is made of a conductive metal such as gold and may be joined to a metal plate, but it is preferable to form the movable contact portion into a thin film by plating. For example, a Ni plating layer can be formed by electroless plating, and then a gold plating layer can be formed by electrolytic plating. Since the rod is made of resin, it is possible to form a plating film with high bonding strength without using a special adhesive.

  Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1 is an exploded perspective view of the switch structure according to the present embodiment, and FIG. 2 is a sectional view thereof. This switch structure is disposed on a steering wheel of an automobile, and includes a housing 1, a printed wiring board 2, a rubber mat 3, a guide 4, a cover 5, a rod 6, and a seesaw type switch 7. , Is composed of.

  The box-shaped housing 1 is made of PP, and engagement holes 10 are formed on the left and right side walls, respectively. In the housing 1, a printed wiring board 2, a rubber mat 3, and a guide 4 are stacked and disposed in this order, and a cover 5 is fixed to the housing 1 so as to cover an upper opening of the housing 1.

  Printed wiring is formed on the surface of the printed wiring board 2 facing the rubber mat 3, and fixed contact portions 20 each consisting of a pair of contacts are formed at six positions.

  The rubber mat 3 is made of silicon rubber and includes a flat sheet portion 30 and an inverted bottomed cylindrical push button portion 31 protruding from the sheet portion 30 in a direction away from the printed wiring board 2. The overall shape of the rubber mat 3 is formed in the same size as the printed wiring board 2. The push button portion 31 is formed at a position facing the fixed contact portion 20, and the PP rod 6 is integrally held and fixed to the push button portion 31.

  As shown in FIG. 3 in an enlarged manner, the push button portion 31 includes a thick upper base 32 and a skirt portion 33 that connects the upper base 32 and the seat portion 30. Is held fixed.

  As shown in an enlarged view in FIG. 3, the rod 6 includes a cylindrical large-diameter portion 60, a cylindrical rod portion 61 that extends coaxially from the center of the large-diameter portion 60, and the large-diameter portion 60 and the rod portion 61. It consists of a disc-shaped flange portion 62 formed coaxially, and a movable contact portion 63 made of a gold plating layer is formed on the tip surface of the large diameter portion 60. The distal end portion of the large diameter portion 60 and the distal end portion of the rod portion 61 protrude to both sides of the upper bottom portion 32, and the central portion having the flange portion 62 is embedded in the upper bottom portion 32.

  This rubber mat 3 was manufactured as follows. First, the rod 6 is formed by injection molding, and the movable contact portion 63 is formed at the tip of the large diameter portion 60 by electroless Ni plating and electrolytic gold plating. As shown in FIG. 4, the rod 6 having the movable contact portion 63 is inserted into a molding die composed of an upper die 70 and a lower die 71, and liquid silicone rubber is injected into the cavity 72 and cured to form the rubber mat 3. Form. As a result, the rod 6 is integrally held and fixed to the push button portion 31 and is prevented from falling off the push button portion 31 due to the shape effect of the flange portion 62.

  The PP guide 4 is formed in a substantially inverted box shape having an outer peripheral shape that is slightly larger than the printed wiring board 2 and the rubber mat 3, and ribs 40 are formed therein. The rubber mat 3 and the printed wiring board 2 are fixed by the peripheral edge and the tip of the rib 40 contacting the sheet portion 30 of the rubber mat 3. Further, three pairs of through holes 41 through which the rod portion 61 of the rod 6 is inserted are formed on the upper bottom of the guide 4 to guide the rod portion 61 so as to move up and down stably.

  The PP cover 5 is formed in a substantially plate shape having a size covering the opening of the housing 1, and three rectangular mounting holes 50 are formed therethrough. Brackets 51 are formed in the vicinity of the mounting holes 50, respectively. The seesaw type switch 7 is swingably held in the mounting hole 50 via a bracket 51 and a metal rod 52, respectively.

  A shaft portion 70 having a center hole is formed at the center of the back surface of the seesaw type switch 7, and the seesaw type switch 7 is swingably held by being pivotally connected to the bracket 51 by a metal rod 52. Further, protrusions 71 are formed on both sides of the shaft portion 70, respectively.

  Further, a locking claw 53 extending toward the housing 1 is formed from the left and right side walls of the cover 5, and the locking claw 53 engages with the engagement hole 10 of the housing 1, whereby the cover 5 is secured to the housing 1. It is fixed to. In this state, the tips of the pair of protrusions 71 are in contact with the tips of the rod portion 61 of the rod 6. Further, a rib (not shown) is formed on the surface of the cover 5 facing the guide 4, and the rib abuts against the surface of the guide 4 to restrict the lifting of the guide 4, and the rubber mat 3 and the printed wiring board 2 by the guide 4 are controlled. Is secured and sealability is secured.

  In order to assemble the switch structure of this embodiment, the printed wiring board 2, the rubber mat 3 on which the plurality of rods 6 are held and fixed, and the guide 4 are laminated in this order in the housing 1, and the seesaw type switch 7 is provided. It is only necessary to press the held cover 5 toward the housing 1 to engage the locking claw 53 with the engagement hole 10. Therefore, the assembly can be performed very easily, and the assembly workability is greatly improved.

  In the switch structure of the present embodiment configured as described above, when one of the seesaw type switches 7 is pushed with a finger, the seesaw type switch 7 swings and one protrusion 71 moves the rod portion 61 downward. Press. Then, the rod 6 presses the push button portion 31 downward, and the skirt portion 31 is elastically deformed so that the upper bottom portion 32 is lowered together with the rod 6. As a result, the movable contact portion 63 and the fixed contact portion 20 come into contact with each other and a part of the wiring of the printed wiring board 2 is conducted.

  When the pressing by the finger is released, the skirt portion 31 returns to its original shape due to its own elasticity, and the rod 6 ascends together with the upper bottom portion 32, whereby the conduction between the movable contact portion 63 and the fixed contact portion 20 is released.

  FIG. 5 shows a cross-sectional view of the switch structure according to the present embodiment. This switch structure has the same configuration as that of the first embodiment except that the fixing structure of the rod 6 and the push button portion 31 is different, and accordingly the guide 4 is not used. A description will be given.

  The rod 6 is integrally held and fixed to the push button portion 31 of the rubber mat 3 by insert molding. The rod 6 includes a large-diameter portion 60 similar to that of the first embodiment, a shaft portion 64 extending in the axial direction from the large-diameter portion 60 and having a smaller diameter than the large-diameter portion 60, and a flange portion 65 formed at the tip of the shaft portion 64. It consists of. A part of the large-diameter portion 60, the entire shaft portion 64, and the entire flange portion 65 are embedded in the upper bottom portion 32 of the push button portion 31. The tip of the large-diameter portion 60 protrudes from the push button portion 31 toward the fixed contact portion 20 of the printed wiring board 2, and a movable contact portion 63 is formed on the tip surface.

  The cover 5 holds the seesaw type switch 7 so as to be swingable, and is fixed to the housing 1. In this state, the protrusion 71 of the seesaw type switch 7 is in contact with the surface of the upper bottom portion 32 of the push button portion 31. Further, ribs 54 are formed to protrude from the cover 5, and the rubber mat 3 and the printed wiring board 2 are fixed by the tips of the ribs 54 coming into contact with the sheet portion 30 of the rubber mat 3.

  According to the switch structure of the present embodiment, since no guide is used, the number of parts can be reduced compared to the first embodiment, and the assembly workability is further improved. Further, since only the silicon rubber layer is exposed on the surface of the rubber mat 3, the sealing property is high and the reliability is further improved.

  The switch structure of the present invention can be used not only for a switch provided on a steering wheel but also for a button switch of a game controller, a key of a keyboard, and the like.

1: Housing 2: Printed wiring board (circuit board)
3: Rubber mat 4: Guide 5: Cover 6: Rod 7: Seesaw type switch
20: Fixed contact
30: Seat part
31: Push button
63: Movable contact

Claims (3)

A circuit board having a fixed contact portion;
A rubber mat placed on the surface of the circuit board and having a flat sheet portion and an inverted bottomed cylindrical push button portion protruding from the sheet portion in a direction away from the circuit board at the position of the fixed contact portion;
A resin rod integrally held and fixed to the upper bottom portion of the push button portion and protruding from the rubber mat toward at least the fixed contact portion;
And a movable contact portion formed on the surface of the rod facing the fixed contact portion.   The switch structure according to claim 1, wherein the rod is integrated with the rubber mat by insert molding when the rubber mat is molded.   3. The switch structure according to claim 1, wherein the rod has a guide that protrudes to both sides in the thickness direction of the upper bottom of the push button portion and holds an end portion on the opposite side to the movable contact portion so as to be able to protrude and retract. .

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