Impact absorbing type steering column apparatus

Abstract

An impact absorbing type steering column apparatus provided with a collision energy absorbing device for absorbing an energy of a secondary collision of an occupant upon a collision of a vehicle comprises an energy absorption quantity adjusting device for changing a secondary collision energy absorption quantity of the collision energy absorbing device, at least one sensor for detecting a condition of the occupant or the vehicle, and electric control device for controlling a drive of the energy absorption quantity adjusting device on the basis of a result of detection by the sensor.

What is claimed is:  
     
         1 . An impact absorbing type steering column apparatus provided with collision energy absorbing means for absorbing an energy of a secondary collision of an occupant upon a collision of a vehicle, said apparatus comprising: 
 energy absorption quantity adjusting means for changing a secondary collision energy absorption quantity of said collision energy absorbing means;    at least one sensor for detecting a condition of the occupant or the vehicle; and    electric control means for controlling a drive of said energy absorption quantity adjusting means on the basis of a result of detection by said sensor.    
     
     
         2 . An impact absorbing type steering column apparatus according to  claim 1 , further comprising a collapsible column rotatably supporting a steering shaft and getting collapsed with a predetermined collapse load, 
 wherein said collapsible column includes an outer column, an inner column entering said outer column when said collapsible column gets collapsed, and    said collision energy absorbing means has a plurality of metal balls interposed between said outer column and said inner column and forming plastic grooves in at least one of said outer column and said inner column when said collapsible column gets collapsed.    
     
     
         3 . An impact absorbing type steering column apparatus according to  claim 2 , wherein the plurality of metal balls are constructed of a first group of metal balls retained in first metal ball retaining means and a second group of metal balls retaining in second metal ball retaining means, and 
 said energy absorption quantity adjusting means is provided with retaining means rotational driving means for rotating at least one of the first group of metal balls and the second group of metal balls in order to make a part or the whole of angular phases of the metal balls in the first metal ball group with respect to said collapsible column coincident with or different from the metal balls in the second metal ball group.    
     
     
         4 . An impact absorbing type steering column apparatus according to  claim 1 , further comprising: 
 a steering column for rotatably supporting said steering shaft; and    a car body sided bracket, fixed to the car body, for supporting said steering column and allowing said steering column to get released therefrom when an impact load equal to or larger than a predetermined value acts,    wherein said collision energy absorbing means is provided between said steering column and said car body sided bracket, and drawing means causes a plastic deformation of an energy absorbing member composed of a metal plate or a metal wire with a shift of said steering column.    
     
     
         5 . An impact absorbing type steering column apparatus according to  claim 4 , wherein said drawing means is a metal rod or a metal ball, and 
 said energy absorption quantity adjusting means changes at least one of a plastically deformed portion and a plastic deformation quantity of said energy absorbing member by said drawing means.    
     
     
         6 . An impact absorbing type steering column apparatus according to  claim 1 , further comprising: 
 a steering column for rotatably supporting said steering shaft; and    a car body sided bracket, fixed to the car body, for supporting said steering column and allowing said steering column to get released therefrom when an impact load equal to or larger than a predetermined value acts,    wherein said collision energy absorbing means is provided between said steering column and said car body sided bracket, and causes a fracture, or a bending deformation and the fracture of said energy absorbing member composed of the metal plate with a shift of said steering column.    
     
     
         7 . An impact absorbing type steering column apparatus comprising: 
 a collapsible column rotatably supporting a steering shaft and getting collapsed with a predetermined collapse load,    said collapsible column including:    an outer column;    an inner column entering said outer column when said collapsible column gets collapsed; and    a plurality of metal balls interposed between said outer column and said inner column and forming plastic grooves in at least one of said outer column and said inner column in order to absorb a collision energy when said collapsible column gets collapsed,    wherein said steering column apparatus is provided with energy absorption quantity adjusting means for changing an absorption quantity of the collision energy.    
     
     
         8 . An impact absorbing type steering column apparatus according to  claim 7 , wherein the plurality of metal balls are constructed of a first group of metal balls retained in first metal ball retaining means and a second group of metal balls retaining in second metal ball retaining means, and 
 said energy absorption quantity adjusting means is provided with retaining means rotational driving means for rotating at least one of the first group of metal balls and the second group of metal balls in order to make a part or the whole of angular phases of the metal balls in the first metal ball group with respect to said collapsible column coincident with or different from the metal balls in the second metal ball group.    
     
     
         9 . An impact absorbing type steering column apparatus comprising: 
 a steering column for rotatably supporting said steering shaft;    a car body sided bracket, fixed to the car body, for supporting said steering column and allowing said steering column to get released therefrom when an impact load equal to or larger than a predetermined value acts; and    collision energy absorbing means provided between said steering column and said car body sided bracket, for absorbing an energy of a secondary collision of an occupant by causing a plastic deformation of an energy absorbing member composed of a metal plate or a metal wire by use of drawing means with a shift of said steering column,    wherein said steering column apparatus is provided with energy absorption quantity adjusting means for changing an absorption quantity of the collision energy.    
     
     
         10 . An impact absorbing type steering column apparatus according to  claim 9 , wherein said drawing means is a metal rod or a metal ball, and 
 said energy absorption quantity adjusting means changes at least one of a plastically deformed portion and a plastic deformation quantity of said energy absorbing member by said drawing means.    
     
     
         11 . An impact absorbing type steering column apparatus comprising: 
 a steering column for rotatably supporting said steering shaft;    a car body sided bracket, fixed to the car body, for supporting said steering column and allowing said steering column to get released therefrom when an impact load equal to or larger than a predetermined value acts; and    collision energy absorbing means provided between said steering column and said car body sided bracket, for absorbing an energy of a secondary collision of an occupant by causing a fracture, or a bending deformation and the fracture of said energy absorbing member composed of the metal plate with a shift of said steering column,    wherein said steering column apparatus is provided with energy absorption quantity adjusting means for changing an absorption quantity of the collision energy.    
     
     
         12 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein an electromagnetic actuator is a driving source of said energy absorption quantity adjusting means.  
     
     
         13 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein an electric motor is a driving source of said energy absorption quantity adjusting means.  
     
     
         14 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein said energy absorption quantity adjusting means changes an absorption quantity of the secondary collision energy by said energy absorbing means at least three or more stages.  
     
     
         15 . An impact absorbing type steering column apparatus according to any one of claims  1 ,  4 ,  5 ,  9  and  10 , wherein said energy absorption quantity adjusting means changes an absorption quantity of the secondary collision energy by said energy absorbing means in an infinitely variable manner.  
     
     
         16 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein said energy absorption quantity adjusting means changes an absorption quantity of the secondary collision energy by said energy absorbing means in two or more modes, and 
 energy absorption loads are substantially fixed with respect to a progress of a collapse stroke after points of inflections of energy absorption characteristics in the two or more modes.  
 
     
     
         17 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein said energy absorption quantity adjusting means changes an absorption quantity of the secondary collision energy by said energy absorbing means in two or more modes, and 
 energy absorption loads gradually increase with respect to a progress of a collapse stroke after points of inflections of energy absorption characteristics in the two or more modes.  
 
     
     
         18 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein two types of energy absorption characteristics are exhibited, and 
 a large load characteristic has a collapse load that is twice or greater as large as that of a small load characteristic after points of deflections of these two types of energy absorption characteristics.  
 
     
     
         19 . An impact absorbing type steering column apparatus according to any one of claims  1  through  11 , wherein two or more types of energy absorption characteristics are exhibited, and these two or more types of energy absorption characteristics delay a rise timing of absorbing the energy.  
     
     
         20 . An impact absorbing type steering column apparatus comprising: 
 a collapsible column rotatably supporting a steering shaft and getting collapsed with a predetermined collapse load,    said collapsible column including:    an outer column;    an inner column entering said outer column when said collapsible column gets collapsed; and    a plurality of metal balls interposed between said outer column and said inner column and forming plastic grooves in at least one of said outer column and said inner column in order to absorb a collision energy when said collapsible column gets collapsed,    wherein said steering column apparatus is provided with a plurality of metal ball retainers for retaining the metal balls in phases different from each other, and retainer separating means for separating at least of one of said metal ball retainers from said car body sided member in order to reduce the number of plastic grooves formed by the metal balls when said collapsible column gets collapsed.    
     
     
         21 . An impact absorbing type steering column apparatus according to  claim 20 , wherein said retainer separating means is an electrically driven actuator.  
     
     
         22 . An impact absorbing type steering column apparatus according to  claim 21 , wherein said electrically driven actuator separates said metal ball retainer from said car body sided member only when being charged with electricity.  
     
     
         23 . An impact absorbing type steering column apparatus comprising: 
 collision energy absorbing means for absorbing an energy of a secondary collision energy of an occupant upon a collision of a vehicle; and    energy absorption quantity adjusting means for changing an absorption quantity with which said collision energy absorbing means absorbs the secondary collision energy,    wherein an electromagnetic actuator is a driving source of said energy absorption quantity adjusting means, and    a plunger of said electromagnetic actuator is adsorptively held in a predetermined position by a permanent magnet.    
     
     
         24 . An impact absorbing type steering column apparatus according to  claim 23 , wherein said collision energy absorbing means is provided between said steering column and said car body sided bracket and causes a plastic deformation of an energy absorbing member composed of a metal plate or a metal wire by use of drawing means with a shift of said steering column.  
     
     
         25 . An impact absorbing type steering column apparatus according to  claim 23 , wherein said drawing means is a metal rod or a metal ball, and 
 said energy absorption quantity adjusting means changes at least one of a plastically deformed portion and a plastic deformation quantity of said energy absorbing member by said drawing means.    
     
     
         26 . An electric power steering apparatus including an impact absorbing steering column apparatus provided with a collision energy absorbing device which absorbs energy of a secondary collision of an occupant upon a collision of a vehicle, said impact absorbing steering column apparatus comprising: 
 an energy absorption quantity adjusting device which changes a secondary collision energy absorption quantity of said collision energy absorbing device;    at least one sensor which detects a condition of the occupant or the vehicle; and    an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor.    
     
     
         27 . An electric power steering apparatus including an impact absorbing steering column apparatus provided with a collision energy absorbing device which absorbs energy of a secondary collision of an occupant upon a collision of a vehicle, said impact absorbing steering column apparatus comprising: 
 an energy absorption quantity adjusting device which changes a secondary collision energy absorption quantity of said collision en rgy absorbing device;    at least one sensor which detects a condition of the occupant or the vehicle; and    an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor;    wherein said energy absorption quantity adjusting device is operative to change the absorption quantity of the secondary collision energy by said energy absorbing device among two or more stages, and    wherein energy absorption loads are substantially fixed with respect to progress of a collapse stroke after points of inflection of energy absorbing characteristics in said two or more stages.    
     
     
         28 . An electric power steering apparatus including an impact absorbing steering column apparatus provided with a collision energy absorbing device which absorbs energy of a secondary collision of an occupant upon a collision of a vehicle, said impact absorbing steering column apparatus comprising: 
 an energy absorption quantity adjusting device which changes a secondary collision energy absorption quantity of said collision energy absorbing device;    at least one sensor which detects a condition of the occupant or the vehicle; and    an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor;    wherein said energy absorption quantity adjusting device is operative to change the absorption quantity of the secondary collision energy by said energy absorbing device among two or more stages, and    wherein energy absorption loads are gradually increased with respect to progress of a collapse stroke after points of inflection of energy absorbing characteristics in said two or more stages.    
     
     
         29 . An electric power steering apparatus according to  claim 28 , 
 wherein two energy absorption characteristics are exhibited, and    a large load characteristic has a collapse load that is at least twice as large as that of a small load characteristic after points of inflection of the two energy absorption characteristics.    
     
     
         30 . An electric power steering apparatus including an impact absorbing steering column apparatus provided with a collision energy absorbing device which absorbs energy of a secondary collision of an occupant upon a collision of a vehicle, said impact absorbing steering column apparatus comprising: 
 an energy absorption quantity adjusting device which changes a secondary collision energy absorption quantity of said collision energy absorbing device;    at least one sensor which detects a condition of the occupant or the vehicle; and    an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor;    wherein said impact absorbing steering column apparatus has a plurality of energy absorption characteristics; and    said energy absorption characteristics delay a rise timing of absorbing the energy.    
     
     
         31 . An electric power steering apparatus, comprising: 
 a collapsible column rotatably supporting a steering shaft and being collapsible with a predetermined collapse load,    said collapsible column including:    an upper column;    a lower column in which the upper column is partially fitted and into which the upper column is displaced when said collapsible column is collapsed,    a collision energy absorbing device provided between the upper column and the lower column to absorb energy of a secondary collision of an occupant upon a collision of a vehicle,    at least one sensor which detects a condition of the occupant or the vehicle,    an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor;    wherein said apparatus has a plurality of energy absorption characteristics; and    an electric power assisting unit is fixedly provided to said lower column.    
     
     
         32 . An electric power steering apparatus according to  claim 31 , 
 wherein said energy absorption quantity adjusting device is operative to change the absorption quantity of the secondary collision energy by said energy absorbing device among two or more stages, and    energy absorption loads are substantially fixed with respect to progress of a collapse stroke after points of inflection of energy absorbing characteristics in said two or more stages.    
     
     
         33 . An electric power steering apparatus according to  claim 31 , 
 wherein said energy absorption quantity adjusting device is operative to change the absorption quantity of the secondary collision energy by said energy absorbing device among two or more stages, and    energy absorption loads are gradually increased with respect to progress of a collapse stroke after points of inflection of energy absorbing characteristics in said two or more stages.    
     
     
         34 . An electric power steering apparatus according to  claim 31 , 
 wherein two energy absorption characteristics are exhibited, and    a large load characteristic has a collapse load that is at least twice as large as that of a small load characteristic after points of inflection of the two energy absorption characteristics.    
     
     
         35 . An electric power steering apparatus according to  claim 31 , further comprising: 
 an electric control device which controls a drive of said energy absorption quantity adjusting device based on a result of detection by said sensor;    wherein said apparatus has a plurality of energy absorption characteristics; and    an electric power assisting unit is fixedly provided to said lower column.