Damping system for steering wheel

Abstract

A damping system includes: a fixed member; an airbag device including a back holder and disposed on a rear side of the fixed member; an elastic member mounted in a mounting hole of the back holder; and a horn switch mechanism including a support member supported on the fixed member on a front side of the back holder, and a slider disposed between the support member and the elastic member. The airbag device functions as a damper mass of a dynamic damper, and the elastic member functions as a spring thereof. The horn switch mechanism includes an extended portion extending forwards. An engaged portion is formed at a circumferential edge portion of the mounting hole to extend rearwards. The elastic member includes an engaging portion opened in a front surface thereof. The elastic member is sandwiched by the engaged portion fitted in the engaging portion and the extended portion.

What is claimed is: 
     
       1. A damping system for a steering wheel, comprising:
 a fixed member fixed to a steering shaft extending in a front-rear direction; 
 an airbag device which comprises a back holder provided at a front portion thereof and which is disposed on a rear side of the fixed member; 
 an elastic member mounted in a mounting hole formed in the back holder so as to penetrate therethrough in a front-to-rear direction; and 
 a horn switch mechanism comprising:
 a support member supported on the fixed member at a position on a front side of the back holder; and 
 a slider disposed between the support member and the elastic member so as to activate a horn unit by a forward movement of the slider associated with a pressing operation of the airbag device, 
 
 wherein said damping system allows the airbag device to function as a damper mass of a dynamic damper, and allows the elastic member to function as a spring of the dynamic damper, 
 wherein the horn switch mechanism further comprises an extended portion extending forwards, 
 wherein the back holder comprises an engaged portion extending rearwards and formed at a circumferential edge portion of the mounting hole, 
 wherein the elastic member comprises an engaging portion comprising a recess portion opened in a front surface of the elastic member, 
 wherein the elastic member is sandwiched by the engaged portion fitted in the engaging portion and the extended portion in the front-rear direction, and 
 wherein the elastic member is formed, as a whole, of an elastic materiel of rubber or elastomer. 
 
     
     
       2. The damping system for a steering wheel according to  claim 1 ,
 wherein the elastic member comprises a groove portion which is opened in at least one of the front surface and a rear surface of the elastic member. 
 
     
     
       3. The damping system for a steering wheel according to  claim 2 ,
 wherein the groove portion is formed between the engaging portion and the slider. 
 
     
     
       4. A damping system for a steering wheel comprising:
 an airbag device that includes a pad portion having a surface and a back holder forming a bag accommodation space between the pad portion and the back holder;   a plurality of pins each having a front end portion, a rear end portion, a shaft portion extending in a front-rear direction, and a collar portion provided at the rear end portion, wherein a diameter of the collar portion is set to be larger than a diameter of the shaft portion;   a plurality of elastic members, each of which is formed, as a whole, of an elastic material of rubber or elastomer and is located between the back holder and an outer periphery of a corresponding one of the pins;   a plurality of sliders, each of which moves forward associated with a pressing operation of the airbag device and is located between the outer periphery of a corresponding one of the pins and the corresponding elastic member; and   a plurality of biasing members, each of which applies a biasing force to urge the airbag device away from the steering wheel and is located around the outer periphery of a corresponding one of the pins, wherein   each pin is mounted on the steering wheel at the front end portion using a snap-in fitting structure and supports the airbag device at the rear end portion,   each pin includes a locking groove formed at the front end portion,   the steering wheel includes a plurality of through holes, each of which passes through the steering wheel in the front-rear direction,   a plurality of clips are held on the steering wheel corresponding to the through holes,   the snap-in fitting structure includes the locking groove of each pin and one of the clips that is engaged with the locking groove,   the back holder includes a plurality of mounting portions and a plurality of mounting holes, wherein each mounting hole passes through a corresponding one of the mounting portions in the front-rear direction,   the shaft portion of each pin and the corresponding slider are inserted into a corresponding one of the mounting holes,   the back holder includes a plurality of engaged portions, each of the engaged portions extends rearward from a circumferential edge portion of a corresponding one of the mounting holes,   each elastic member contacts a corresponding one of the sliders and a corresponding one of the engaged portions and suppresses vibrations transmitted between the back holder and the corresponding pin,   the damping system allows the airbag device to function as a damper mass of a dynamic damper and allows the elastic members to function as a spring of the dynamic damper, and   each elastic member includes a portion, which is disposed between the corresponding slider and the corresponding engaged portion and contacts the engaged portion, and an inner surface of an insertion hole contacting the corresponding slider, wherein the portion of the elastic member extends in a radial direction of the corresponding mounting hole, and is located rearward of the corresponding mounting portion.    
     
     
       5. The damping system for a steering wheel according to claim 4, wherein a resin member is located between the front end portion of each pin and an inner periphery of a corresponding one of the through holes.  
     
     
       6. The damping system for a steering wheel according to claim 5, wherein
 the steering wheel has a frame portion that includes a fixed member,   the through holes are provided in the fixed member, and   each pin is directly mounted on the fixed member using the snap-in fitting structure.    
     
     
       7. The damping system for a steering wheel according to claim 4, wherein the engaged portions are integrally formed with the back holder.  
     
     
       8. The damping system for a steering wheel according to claim 4, wherein
 each elastic member includes a front surface, a rear surface, a front groove portion that is opened in the front surface, and a rear groove portion that is opened in the rear surface, and   the portion of each elastic member includes a part of the elastic member between a bottom surface of the front groove portion and a bottom surface of the rear groove portion.    
     
     
       9. The damping system for a steering wheel according to claim 4, wherein a front surface is provided on the elastic member, and a part of the front surface abuts the corresponding mounting portion which is spaced apart from the corresponding slider by the elastic member.  
     
     
       10. A damping system for a steering wheel comprising:
 an airbag device that includes a pad portion having a surface and a back holder forming a bag accommodation space between the pad portion and the back holder;   a plurality of pins each having a front end portion, a rear end portion, a shaft portion extending in a front-rear direction, and a collar portion provided at the rear end portion, wherein a diameter of the collar portion is set to be larger than a diameter of the shaft portion;   a plurality of elastic members, each of which is formed, as a whole, of an elastic material of rubber or elastomer and is located between the back holder and an outer periphery of a corresponding one of the pins;   a plurality of sliders, each of which moves forward associated with a pressing operation of the airbag device and is located between the outer periphery of a corresponding one of the pins and the corresponding elastic member; and   a plurality of biasing members, each of which applies a biasing force to urge the airbag device away from the steering wheel and is located around the outer periphery of a corresponding one of the pins, wherein   each pin is mounted on the steering wheel at the front end portion using a snap-in fitting structure and supports the airbag device at the rear end portion,   each pin includes a locking groove formed at the front end portion,   the steering wheel includes a plurality of through holes, each of which passes through the steering wheel in the front-rear direction,   a plurality of clips are held on the steering wheel corresponding to the through holes,   the snap-in fitting structure includes the locking groove of each pin and one of the clips that is engaged with the locking groove,   the back holder includes a plurality of mounting portions and a plurality of mounting holes, wherein each mounting hole passes through a corresponding one of the mounting portions in the front-rear direction,   the shaft portion of each pin and the corresponding slider are inserted into a corresponding one of the mounting holes,   the back holder includes a plurality of engaged portions, each of which extends rearward from a circumferential edge portion of a corresponding one of the mounting holes,   each elastic member contacts a corresponding one of the sliders and a corresponding one of the engaged portions and suppresses vibrations transmitted between the back holder and the corresponding pin,   the damping system allows the airbag device to function as a damper mass of a dynamic damper and allows the elastic members to function as a spring of the dynamic damper, and   each elastic member includes a portion, which is disposed between the corresponding slider and the corresponding engaged portion and contacts the engaged portion, and an inner surface of an insertion hole contacting the corresponding slider, wherein   the portion of the elastic member extends in a radial direction of the corresponding mounting hole, and   the insertion hole extends forward of a rear surface of the corresponding mounting portion.    
     
     
       11. The damping system for a steering wheel according to claim 10, wherein the engaged portions are integrally formed with the back holder.  
     
     
       12. A damping system for a steering wheel comprising:
 an airbag device that includes a pad portion having a surface and a back holder forming a bag accommodation space between the pad portion and the back holder;   a plurality of pins each having a front end portion, a rear end portion, a shaft portion extending in a front-rear direction, and a collar portion provided at the rear end portion, wherein a diameter of the collar portion is set to be larger than a diameter of the shaft portion;   a plurality of elastic members, each of which is formed, as a whole, of an elastic material of rubber or elastomer and is located between the back holder and an outer periphery of a corresponding one of the pins;   a plurality of sliders, each of which moves forward associated with a pressing operation of the airbag device and is located between the outer periphery of a corresponding one of the pins and the corresponding elastic member; and   a plurality of biasing members, each of which applies a biasing force to urge the airbag device away from the steering wheel and is located around the outer periphery of a corresponding one of the pins, wherein   each pin is mounted on the steering wheel at the front end portion using a snap-in fitting structure and supports the airbag device at the rear end portion,   each pin includes a locking groove formed at the front end portion,   the steering wheel includes a plurality of through holes, each of which passes through the steering wheel in the front-rear direction,   a plurality of clips are held on the steering wheel corresponding to the through holes,   the snap-in fitting structure includes the locking groove of each pin and one of the clips that is engaged with the locking groove,   the back holder includes a plurality of mounting portions and a plurality of mounting holes, wherein each mounting hole passes through a corresponding one of the mounting portions in the front-rear direction,   the shaft portion of each pin and the corresponding slider are inserted into a corresponding one of the mounting holes,   each elastic member is located on an outer side of a corresponding one of the sliders and suppresses vibrations transmitted between the back holder and the corresponding pin,   the damping system allows the airbag device to function as a damper mass of a dynamic damper and allows the elastic members to function as a spring of the dynamic damper, and   each elastic member includes a portion, which is disposed between the corresponding mounting portion and the corresponding slider in a radial direction of the corresponding mounting hole, and an inner surface of an insertion hole contacting the corresponding slider, wherein the portion of the elastic member extends in the radial direction and is located rearward of the corresponding mounting portion, wherein   a front surface is provided on the elastic member, and a part of the front surface abuts the corresponding mounting portion which is spaced apart from the corresponding slider by the elastic member.    
     
     
       13. The damping system for a steering wheel according to claim 12, wherein
 each elastic member further includes a rear surface, a front groove portion that is opened in the front surface, and a rear groove portion that is opened in the rear surface, and   the portion of each elastic member includes a part of the elastic member between a bottom surface of the front groove portion and a bottom surface of the rear groove portion.