Electric steering column device

Abstract

An electrically-driven steering column apparatus includes a steering column rotatably holding a steering shaft and capable of adjusting a position of the steering wheel, and a power transmission mechanism for transmitting to the steering column a rotational driving force of an electric motor as a position adjusting motion driving force, wherein the power transmission mechanism has a joint constructed of a spherical joint element and a cylindrical joint element in which the spherical joint element is slidably fitted, on within a driving force transmission route.

1 . An electrically-driven steering column apparatus comprising: 
 a steering shaft having its rear end to which a steering wheel is attached;    a steering column, for rotatably holding said steering shaft, capable of adjusting a tilt position about a tilt pivot as a fulcrum on the basis of a car-body-side member;    an electric motor for a tilt motion of said steering column; and    a power transmission mechanism for transmitting to said steering column a rotational driving force of said electric motor as a tilt motion driving force for said steering column,    wherein said power transmission mechanism includes a joint constructed of a spherical joint element and a cylindrical joint element in which said spherical joint element is slidably fitted, on within a driving force transmission route from said electric motor to said steering column.    
     
     
         2 . An electrically-driven steering column apparatus comprising: 
 a steering shaft having its rear end to which a steering wheel is attached;    a steering column, for rotatably holding said steering shaft, capable of adjusting a telescopic position on the basis of a car-body-side member;    an electric motor for a telescopic motion of said steering column; and    a power transmission mechanism for transmitting to said steering column a rotational driving force of said electric motor as a telescopic motion driving force for said steering column,    wherein said power transmission mechanism includes a joint constructed of a spherical joint element and a cylindrical joint element in which said spherical joint element is slidably fitted, on within a driving force transmission route from said electric motor to said steering column.    
     
     
         3 . An electrically-driven steering column apparatus according to  claim 1 , wherein a synthetic resin member is interposed between said spherical joint element and said cylindrical joint element.  
     
     
         4 . An electrically-driven steering column apparatus according to  claim 3 , wherein said synthetic resin member is a sleeve fitted in said cylindrical joint element.  
     
     
         5 . An electrically-driven steering column apparatus according to  claim 3 , wherein said synthetic resin member is a slider having a concave spherical surface in which said spherical joint element is fitted.  
     
     
         6 . An electrically-driven steering column apparatus according to  claim 1 , wherein said power transmission mechanism includes: 
 a feed screw mechanism constructed of a feed screw shaft connected to said electric motor and of a plurality of feed nuts screw-engaged onto said feed screw shaft; and    backlash adjusting means for changing an axial distance between said feed nuts in order to make a backlash of said feed screw mechanism adjustable.    
     
     
         7 . An electrically-driven steering column apparatus according to  claim 1 , wherein said power transmission mechanism includes: 
 a feed screw mechanism constructed of a feed screw shaft connected to said electric motor and of a feed nut formed with a slit and screw-engaged onto said feed screw shaft; and    backlash adjusting means for changing a width of the slit in order to make a backlash of said feed screw mechanism adjustable.    
     
     
         8 . An electrically-driven steering column apparatus comprising: 
 a steering shaft having its rear end to which a steering wheel is attached;    a steering column, for rotatably holding said steering shaft, capable of adjusting a position of said steering wheel;    an electric motor for a position adjusting motion of said steering column; and    a power transmission mechanism for transmitting to said steering column a rotational driving force of said electric motor as a position adjusting motion driving force.    
     
     
         9 . An electrically-driven steering column apparatus according to  claim 8 , wherein said power transmission means includes a joint constructed of a spherical joint element and a cylindrical joint element in which said spherical joint element is slidably fitted, on within a driving force transmission route.  
     
     
         10 . An electrically-driven steering column apparatus according to  claim 2 , wherein a synthetic resin member is interposed between said spherical joint element and said cylindrical joint element.  
     
     
         11 . An electrically-driven steering column apparatus according to  claim 10 , wherein said synthetic resin member is a sleeve fitted in said cylindrical joint element.  
     
     
         12 . An electrically-driven steering column apparatus according to  claim 10 , wherein said synthetic resin member is a slider having a concave spherical surface in which said spherical joint element is fitted.  
     
     
         13 . An electrically-driven steering column apparatus according to  claim 2 , wherein said power transmission mechanism includes: 
 a feed screw mechanism constructed of a feed screw shaft connected to said electric motor and of a plurality of feed nuts screw-engaged onto said feed screw shaft; and    backlash adjusting means for changing an axial distance between said feed nuts in order to make a backlash of said feed screw mechanism adjustable.    
     
     
         14 . An electrically-driven steering column apparatus according to  claim 2 , wherein said power transmission mechanism includes: 
 a feed screw mechanism constructed of a feed screw shaft connected to said electric motor and of a feed nut formed with a slit and screw-engaged onto said feed screw shaft; and    backlash adjusting means for changing a width of the slit in order to make a backlash of said feed screw mechanism adjustable.