Patent Publication Number: US-8993906-B2

Title: Vehicle switch

Description:
1. TECHNICAL FIELD 
     The present technical field relates to a vehicle switch mainly mounted on an automobile for detecting, for example, opening/closing of a door. 
     2. BACKGROUND ART 
     In recent years, vehicle switches mounted on door portions of an automobile to detect opening/closing of doors and to control, for example, turning-on of lighting in a vehicle have been developed.  FIG. 6  is a sectional view of a conventional vehicle switch.  FIG. 7  is an exploded perspective view of the conventional vehicle switch. Operation body  2  having operation portion  2 A on the upper part thereof is housed movably up and down in case  1  having a substantially box-like shape with its upper surface opened. Operation body  2  and case  1  are both made of insulating resin. 
     Fixed contact  3  made of metal is attached to the right side surface in  FIG. 6  inside case  1 . A lower end of fixed contact  3  protrudes to the lower part of case  1 . 
     Mounting plate  4  includes opening  4 A, through hole  4 B, mounting portion  4 C, edge portion  4 D, contact portion  4 E, and a plurality of engagement portions  4 F. Mounting plate  4  has an elliptical shape seen from the upper surface, and is made of metal. Mounting plate  4  is provided with opening  4 A on the right side in  FIG. 6 . Mounting plate  4  is provided with flat mounting portion  4 C on the left side thereof. Through hole  4 B is formed in the left part of mounting portion  4 C. Edge portion  4 D is formed on a section that is higher by one step than the outer periphery of mounting portion  4 C. 
     Contact portion  4 E bent downward and extending toward the inside surface of case  1  is formed on a section that faces opening  4 A of mounting plate  4  (that is, on the left inside of opening  4 A). A plurality of engagement portions  4 F are formed on a section of opening  4 A in which contact portion  4 E is not formed. Convex-shaped locking portion  1 A formed on the inner side of case  1  is engaged with contact portion  4 E, and a plurality of convex-shaped locking portions  11 A formed on the outer side of case  1  are engaged with the plurality of engagement portions  4 F. Thus, case  1  is mounted on mounting plate  4 . 
     A central part of U-shaped movable contact  5  is mounted on a lower surface of operation body  2 . Movable contact  5  is brought into elastic contact with contact portion  4 E of mounting plate  4  and fixed contact  3  in a state in which left and right ends of movable contact  5  are slightly flexed. Thus, a switch contact is formed. Movable contact  5  is formed of a metal thin plate. 
     Coil spring  6  is mounted in a slightly contracted state between the inner bottom surface of case  1  and the lower surface of operation body  2 . Spring  6  urges operation body  2  and movable contact  5  upward. 
     Mounting plate  4  is insert-molded on the lower surface of cover  7  made of, for example, rubber. Operation portion  2 A of operation body  2  protrudes upward from an opening on the upper surface of case  1 . Dome portion  7 A in the right part of cover  7  covers operation portion  2 A. Hollow cylindrical portion  7 B is provided in the left part of cover  7 . Thus, vehicle switch  11  is configured. 
     A lower end of fixed contact  3  protruding toward the bottom surface of case  1  is coupled to a room lamp or the like by lead wire (not shown) or the like via an electronic circuit (not shown) of an automobile. Vehicle switch  11  is attached to a chassis (not shown) of a vehicle body by, for example, a screw (not shown) that is allowed to pass through hollow cylindrical portion  7 B and through hole  4 B, and mounting plate  4  is grounded to the chassis. Thus, vehicle switch  11  is mounted on a door portion of a vehicle. 
     In the above-mentioned configuration, when the door of the automobile is opened, operation body  2  is urged upward by spring  6 , and left and right ends of movable contact  5  mounted on operation body  2  are brought into elastic contact with contact portion  4 E and fixed contact  3 , respectively. Thus, contact portion  4 E and fixed contact  3  are electrically connected to each other via movable contact  5 . The electronic circuit of an automobile detects the electric connection, and, for example, turns on the room lamp. 
       FIG. 8  is a sectional view of a conventional vehicle switch during pressing operation. When a door is closed, pressing body  8  attached to the door presses operation portion  2 A via an upper part of dome portion  7 A of cover  7 . Then, dome portion  7 A is elastically deformed, and operation body  2  is shifted downward inside case  1  while it contracts spring  6 . 
     Then, a left end of movable contact  5  mounted on operation body  2  is apart from contact portion  4 E of mounting plate  4  and is brought into elastic contact with a left inside surface of case  1 . Thus, contact portion  4 E and fixed contact  3  are electrically disconnected from each other. The electronic circuit detects the electric disconnection, and, for example, turns off the room lamp. 
     Note here that in a state in which the door is closed, in general, pressing body  8  stops at a position in which operation body  2  is separated upward from an upper surface of cover  7  with a predetermined space. Therefore, a tip end of operation portion  2 A of operation body  2  protrudes from the upper end of case  1  by a predetermined length, and a predetermined clearance is given between lower end portion  2 B of operation body  2  and an inner bottom surface of case  1 . 
     That is to say, by opening and closing operations of the door, operation body  2  of vehicle switch  11  mounted on the door portion of the vehicle is pressed and operated, electric connection and disconnection of the switch contact including movable contact  5 , contact portion  4 E and fixed contact  3  are carried out. Then, the electronic circuit of the vehicle detects the electric connection and disconnection, and carries out various controls such as turning on and off of the room lamp. 
     SUMMARY 
     A vehicle switch includes a case having an opening, an operation body, a mounting plate, a cover, a switch contact, and a spacer. The operation body is accommodated in the case, has an operation portion protruding from the opening, and moves in the direction perpendicular to the opening. The mounting plate is mounted on the periphery of the opening of the case. The cover covers the operation body and the mounting plate. The switch contact is housed in the case, and performs electric contact according to movement of the operation body. The spacer is disposed on at least the periphery of the opening on a surface that faces the cover of the mounting plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a vehicle switch in accordance with an embodiment. 
         FIG. 2  is an exploded perspective view of the vehicle switch in accordance with this embodiment. 
         FIG. 3  is a perspective view of a principal part of the vehicle switch in accordance with this embodiment. 
         FIG. 4  is a sectional view of the vehicle switch during pressing operation in accordance with this embodiment. 
         FIG. 5  is a sectional view of the vehicle switch during pressing operation in accordance with this embodiment. 
         FIG. 6  is a sectional view of a conventional vehicle switch. 
         FIG. 7  is an exploded perspective view of the conventional vehicle switch. 
         FIG. 8  is a sectional view of the conventional vehicle switch during pressing operation. 
         FIG. 9  is a sectional view of the conventional vehicle switch during pressing operation. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 9  is a sectional view of a vehicle switch shown in  FIG. 6  during pressing operation. In conventional vehicle switch  11 , when foreign object  10  such as clothes is caught between pressing body  8  and vehicle switch  11  by mistake when a door is closed, operation body  2  is further pressed and shifted more downward than a usual operation position. As a result, lower end portion  2 B of operation body  2  is brought into contact with the inner bottom surface of case  1 , and presses case  1  with relatively large force. Therefore, backlash may be generated in engagement between contact portion  4 E and engagement portions  4 F of mounting plate  4  and locking portion  1 A of case  1 . As a result, when the door is opened and operation body  2  is shifted upward, contact between movable contact  5  and contact portion  4 E or fixed contact  3  may be unstable. 
     Herein, when operation body  2  is made to be short, it is thought that lower end portion  2 B is not easily brought into contact with the inner bottom surface of case  1 . However, when operation body  2  moves up and down, a guide portion on the outside surface of operation body  2  slides on the inside surface of case  1 . Consequently, when operation body  2  becomes short, contact between the guide portion on the outside surface of operation body  2  and the inside surface of case  1  may be unstable, and operation may be difficult to be done 
     Hereinafter, this embodiment is described with reference to  FIGS. 1 to 5 . 
       FIG. 1  is a sectional view of a vehicle switch in accordance with an embodiment.  FIG. 2  is an exploded perspective view of the vehicle switch in accordance with this embodiment.  FIG. 3  is a perspective view of a principal part of the vehicle switch in accordance with this embodiment. 
     Vehicle switch  111  includes case  1  having an opening, operation body  2 , mounting plate  4 , cover  17 , a switch contact, and spacer  9 . Operation body  2  is accommodated in case  1 , has operation portion  2 A protruding from the opening, and moves in the direction perpendicular to the opening. Mounting plate  4  is mounted on the periphery of the opening of case  1 . Cover  17  covers operation body  2  and mounting plate  4 . The switch contact is housed in case  1 , and performs electric contact according to movement of operation body  2 . Spacer  9  is disposed on at least the periphery of the opening on a surface that faces cover  17  of mounting plate  4 . The switch contact includes movable contact  5 , contact portion  4 E, and fixed contact  3 . 
     Operation body  2  is accommodated movably up and down in case  1  having a substantially box-like shape with its upper surface opened. Operation portion  2 A in the upper part of operation body  2  protrudes upward from an opening of case  1 . Fixed contact  3  made of metal such as copper alloy is attached to the right side surface in  FIG. 1  inside case  1 . A lower end of fixed contact  3  protrudes to the lower part of case  1 . Case  1  is made of insulating resin such as polyoxymethylene. Operation body  2  is made of insulating resin such as polybutylene terephthalate. 
     Mounting plate  4  includes opening  4 A, through hole  4 B, mounting portion  4 C, edge portion  4 D, contact portion  4 E, and a plurality of engagement portions  4 F. Mounting plate  4  has an elliptical shape seen from the upper surface, and is made of metal such as steel and copper alloy. Mounting plate  4  is provided with opening  4 A on the right side in  FIG. 1 . Mounting plate  4  is provided with flat mounting portion  4 C on the left side. Through hole  4 B is formed in the left part of mounting portion  4 C. Edge portion  4 D is formed on a section that is higher by one step from the outer periphery of mounting portion  4 C. 
     Contact portion  4 E bent downward and extending toward the inside surface of case  1  is formed on a section that faces opening  4 A of mounting plate  4  (that is, on the left inside of opening  4 A). A plurality of engagement portions  4 F are formed on a section of opening  4 A in which contact portion  4 E is not formed. Convex-shaped locking portion  1 A formed on the inner side of case  1  is engaged with contact portion  4 E, and a plurality of convex-shaped locking portions  11 A formed on the outer side of case  1  are engaged with the plurality of engagement portions  4 F. Thus, case  1  is mounted on mounting plate  4 . 
     A central part of U-shaped movable contact  5  is mounted on a lower surface of operation body  2 . Movable contact  5  is brought into elastic contact with contact portion  4 E of mounting plate  4  and fixed contact  3  in a state in which left and right ends of movable contact  5  are slightly flexed. Thus, a switch contact is formed. Movable contact  5  is formed of a metal thin plate of, for example, copper alloy. 
     Coil spring  6  is mounted in a slightly contracted state between the inner bottom surface of case  1  and the lower surface of operation body  2 . Spring  6  urges operation body  2  and movable contact  5  upward. Spring  6  is formed of steel wire, copper alloy wire, or the like. 
     Quadrangular insertion hole  9 A is formed in substantially the middle of flat-shaped spacer  9 . Spacer  9  is placed on mounting portion  4 C and edge portion  4 D of mounting plate  4  such that insertion hole  9 A surrounds the outer periphery of case  1 . Spacer  9  is made of insulating resin such as polypropylene. The thickness of spacer  9  is set such that a clearance is given between lower end portion  2 B of operation body  2  and an inner bottom surface of case  1  when operation body  2  moves downward and an upper end of operation portion  2 A and an upper surface of spacer  9  match with each other in position. 
     Furthermore, positioning part  9 B that protrudes downward from space  9  is engaged with cut-away portion  4 G formed in edge portion  4 D of mounting plate  4 . 
     A plurality of run-through holes  4 H are provided in edge portion  4 D of mounting plate  4  at predetermined intervals. The outer periphery of spacer  9  is provided with hole-shaped recesses or U-shaped cut-away portions  9 C, each of which is formed so as to surround the vicinity of the outer periphery of each of run-through holes  4 H. 
     Spacer  9  and mounting plate  4  are disposed on the lower surface of cover  17 , and spacer  9 , mounting plate  4 , and cover  17  are formed integrally with each other by insert molding. Cover  17  is made of, for example, olefin thermoplastic elastomer having elasticity. 
     Note here that when cover  17  is formed integrally with mounting plate  4  and spacer  9 , as shown in  FIG. 3 , positioning part  9 B of spacer  9  is engaged with cut-away portion  4 G of mounting plate  4 , and cover  17  is insert-molded by injection molding in a state in which spacer  9  is placed on an upper surface of mounting plate  4 . Note here that spacer  9  and mounting plate  4  may be formed integrally by insert molding, and then cover  17  may be integrally formed onto the integrally formed spacer  9  and mounting plate  4 . 
     At this time, resin such as injected elastomer is filled also in a plurality of cut-away portions  9 C of spacer  9 , and run-through holes  4 H in the lower part and the entire outer periphery of the lower surface of mounting plate  4 , so that cover  17  is formed integrally. 
     In this way, cover  17  adheres to mounting plate  4  and spacer  9 . Furthermore, since mounting plate  4  and spacer  9  are coupled to cover  17  via the plurality of cut-away portions  9 C, mounting plate  4  and spacer  9  and cover  17  are not easily displaced or detached from each other, so that they are strongly connected to each other. 
     Operation portion  2 A of operation body  2  protrudes upward from the opening on the upper surface of case  1 . Dome portion  17 A in the right part of cover  17  covers operation portion  2 A. In the left part of cover  17 , hollow cylindrical portion  17 B whose upper end surface is on substantially the same plane as the surface of the periphery of the dome portion  17 A is provided. Thus, vehicle switch  111  is configured. A lower end of fixed contact  3  protruding toward the right bottom surface of case  1  is coupled to a room lamp or the like by lead wire (not shown) or the like via an electronic circuit (not shown) of an automobile. Vehicle switch  111  is attached to a chassis (not shown) of a vehicle body by, for example, a screw (not shown) that is allowed to pass through hollow cylindrical portion  17 B and through hole  4 B, and mounting plate  4  is grounded to the chassis. Thus, vehicle switch  111  is mounted on the door portion of the vehicle. 
     In the above-mentioned configuration, when the door of the automobile is opened, operation body  2  is urged upward by spring  6 , and left and right ends of movable contact  5  mounted on operation body  2  are brought into elastic contact with contact portion  4 E and fixed contact  3 , respectively. Therefore, contact portion  4 E and fixed contact  3  are electrically connected to each other via movable contact  5 . The electronic circuit of an automobile detects the electric connection, and, for example, turns on the room lamp. 
       FIG. 4  is a sectional view of vehicle switch  111  shown in  FIG. 1  during pressing operation. When the door is closed, pressing body  8  attached to the door presses operation portion  2 A via an upper part of dome portion  17 A of cover  17 . Then, dome portion  17 A is elastically deformed, and operation body  2  is shifted downward inside case  1  while it contracts spring  6 . 
     Then, a left end of movable contact  5  mounted on operation body  2  is apart from contact portion  4 E of mounting plate  4  and is brought into elastic contact with a left inside surface of case  1 , and contact portion  4 E and fixed contact  3  are electrically disconnected from each other. The electronic circuit detects the electric disconnection, and, for example, turns off a room lamp. 
     That is to say, by opening/closing operation of the door, operation body  2  of vehicle switch  111  mounted on the door portion of the vehicle is pressed and operated, and operation body  2  moves up and down. Thus, electric connection and disconnection of the switch contact including movable contact  5 , contact portion  4 E and fixed contact  3  are performed. Then, the electronic circuit of the vehicle detects the electric connection and disconnection, and controls turning on and off of a room lamp. 
     In a state in which the door is closed, pressing body  8  stops at a position in which operation body  2  is separated upward from an upper surface of cover  17  on the periphery of dome portion  17 A with a predetermined space. A tip end of operation portion  2 A of operation body  2  protrudes from an opening of the upper end of case  1  by a predetermined length. Then, a predetermined clearance is kept between lower end portion  2 B and the inner bottom surface of case  1 . 
     Furthermore, as shown in the sectional view of  FIG. 5 , when for example, foreign object  10  such as clothes is caught between pressing body  8  and vehicle switch  111  by mistake when a door is closed, a tip end of operation portion  2 A is pressed down to the vicinity of the upper surface of spacer  9  via dome portion  17 A. However, with spacer  9 , the tip end of operation portion  2 A is not pressed down from spacer  9 . 
     Therefore, even if pressing body  8  presses operation body  2  excessively via foreign object  10  or dome portion  17 A, lower end portion  2 B of operation body  2  is not brought into contact with the inner bottom surface of case  1 . Consequently, reliable operations are possible. 
     That is to say, when the door is closed, in general, since pressing body  8  allows operation body  2  to shift downward to a predetermined position, a switch contact becomes in an electrically non-contact state. Then, when a door is closed in a state in which foreign object  10  such as clothes is caught by mistake, pressing body  8 , foreign object  10 , or the like, stops on the upper surface of spacer  9  via dome portion  17 A. Therefore, operation body  2  is not pressed further downward. As a result, since lower end portion  2 B of operation body  2  is not brought into contact with the inner bottom surface of case  1 , backlash does not easily occur in engagement between contact portion  4 E and engagement portion  4 F of mounting plate  4  and locking portion  1 A of case  1 . 
     In this way, according to this embodiment, by disposing spacer  9  having a predetermined thickness on the upper surface of mounting plate  4  in the vicinity of the outer periphery of operation body  2 , the tip end of operation portion  2 A of operation body  2  stops on the upper surface of spacer  9 . Consequently, shift of operation body  2  downward is regulated, and operation body  2  is not pressed downward from the predetermined position. As a result, reliable operation of vehicle switch  111  is achieved. 
     A vehicle switch according to this embodiment has an advantageous effect that reliable operation can be carried out, and is useful mainly for detecting, for example, opening/closing operation of a door in an automobile.