Land vehicles – Wheeled – Running gear
Reexamination Certificate
2001-05-15
2004-04-27
Dickson, Paul N. (Department: 3619)
Land vehicles
Wheeled
Running gear
C074S492000, C188S380000
Reexamination Certificate
active
06726248
ABSTRACT:
This application claims the benefits of Japanese Application Nos. 2000-143646, 2000-255886, 2000-266950, 2000-307709 and 2001-085183 which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an impact absorbing type steering column apparatus, and more particularly to a technology capable of making a collapse load variable.
2. Related Background Art
If an automobile collides with other automobile or a structure etc, a driver might suffer a secondary collision with a steering wheel by its inertia. The automobiles manufactured over the recent years broadly take an impact absorbing type steering shaft and an impact absorbing type steering column apparatus for the purpose of preventing the driver from being injured in that case. The impact absorbing type steering column apparatus is structured such that the steering column gets separated with the steering shaft when the driver suffers the secondary collision, and normally gets collapsed simultaneously with the steering shaft, and a collision energy is absorbed on that occasion.
What has hitherto been known as an collision energy absorbing system is a mesh system for causing a compression buckling deformation of a mesh member formed in a part of the steering column. As disclosed in Japanese Patent Application Post-Exam Publication No. 46-35527, however, there has been widely adopted a ball system in which metal balls are interposed between an outer column and an inner column and act to form plastic grooves in an inner peripheral surface of the outer column and in an outer peripheral surface of the inner column when collapsed.
Further, a drawing type system disclosed in Japanese Patent Application Laid-Open No. 7-329796 has also been taken over the recent years. A drawing type collision energy absorbing mechanism takes such a configuration that one side end of an energy absorbing member composed of, e.g., a band-like steel plate is fixed to a car body sided bracket, and a drawing member such as a steel rod etc fitted in a buckling portion formed in the energy absorbing member is provided on the side of the steering column and causes a drawing deformation of the energy absorbing member when the steering column shifts forward.
Moreover, a tear-up system disclosed in Japanese Utility Model Publication No. 5-68776 has partly been adopted. The tear-up type collision energy absorbing mechanism takes such a configuration that a central portion of the energy absorbing member composed of, e.g., a band-like steel plate is fixed to the car body sided bracket, two side portions of the energy absorbing member are fixed to the steering column in a way that bends it in a U-shape, and the energy absorbing member is torn up while being deformed by bending when the steering column shifts forward.
By the way, in each of the impact absorbing type steering column apparatuses described above, the steering column becomes collapsed when a predetermined collapse load acts, however, this collapse load is normally set based on a kinetic energy generated when a driver having a standard weight secondarily collides with the steering wheel. If the driver is a small-sized women and when a car speed is low, however, as a matter of course, the kinetic energy thereof decreases, and the energy absorption quantity can not be adjusted corresponding to a driver's physique, a car speed etc.
SUMMARY OF THE INVENTION
It is a primary object of the present invention, which was devised to under such circumstances, to provide an impact absorbing type steering column apparatus capable of making a collapse load variable and adjusting an energy absorption quantity upon a secondary collision corresponding to a driver's physique, a car speed etc.
To accomplish the above object, according to a first aspect of the present invention, an impact absorbing type steering column apparatus provided with collision energy absorbing mechanism for absorbing an energy of a secondary collision of an occupant upon a collision of a vehicle, comprises an energy absorption quantity adjusting member for changing a secondary collision energy absorption quantity of the collision energy absorbing mechanism, at least one sensor for detecting a condition of the occupant or the vehicle, and an electric control unit for controlling a drive of the energy absorption quantity adjusting member on the basis of a result of detection by the sensor.
According to the first aspect of the invention, for example, if a weight of the driver is heavy and when a car speed is high the control unit controls a drive of the energy absorption quantity adjusting member, thereby increasing the collapse load with which the collision energy absorbing mechanism operates. While on the other hand, if the weight of the driver is light and when the car speed is low, the control unit decreases the collapse load with which the collision energy absorbing mechanism operates. The collapsible column thus properly gets collapsed.
According to a second aspect of the present invention, the impact absorbing type steering column apparatus according to the first aspect of the invention may comprise a collapsible column rotatably supporting a steering shaft and getting collapsed with a predetermined collapse load, wherein the collapsible column includes an outer column, an inner column entering the outer column when the collapsible column gets collapsed, and the collision energy absorbing mechanism has a plurality of metal balls interposed between the outer column and the inner column and forming plastic grooves in at least one of the outer column and the inner column when the collapsible column gets collapsed.
According to the second aspect of the invention, for instance, the electric control unit, if the weight of the driver is heavy, increases the collapse load by setting larger the number of plastic grooves formed by the metal balls. By contrast, the electric control unit, if the weight of the driver is light, decreases the collapse load by setting smaller the number of plastic grooves. The collapsible column thus properly gets collapsed.
According to a third aspect of the present invention, in the impact absorbing type steering column apparatus according to the second aspect of the invention, the plurality of metal balls may be 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 the energy absorption quantity adjusting member may be provided with a retaining member rotational driving mechanism 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 the collapsible column coincident with or different from the metal balls in the second metal ball group.
According to the third aspect of the invention, for example, the electric control unit having detected the weight of the driver etc outputs a drive command to the retaining member rotational driving mechanism in order to rotate the first metal ball retaining member or the second metal ball retaining member.
According to a fourth aspect of the present invention, the impact absorbing type steering column apparatus according to the first aspect of the invention may further comprise a steering column for rotatably supporting the steering shaft, and a car body sided bracket, fixed to the car body, for supporting the steering column and allowing the steering column to get released therefrom when an impact load equal to or larger than a predetermined value acts, wherein the collision energy absorbing mechanism may be provided between the steering column and the car body sided bracket, and a drawing member may cause a plastic deformation of an energy absorbing member composed of a metal plate or a metal wire with a shift of the steering column.
According to the fourth aspect of the invention, for instance, the electric control unit, if th
Nomura Tetsuo
Satou Kenji
Dickson Paul N.
Ilan Ruth
Miles & Stockbridge P.C.
NSK Ltd.
LandOfFree
Impact absorbing type steering column apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Impact absorbing type steering column apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Impact absorbing type steering column apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3192766