U.S. patent application number 10/124446 was filed with the patent office on 2003-10-16 for position depend tilt and telescoping steering column.
This patent application is currently assigned to DELPHI TECHNOLOGIES, INC.. Invention is credited to Gaeth, Gerald A..
Application Number | 20030192392 10/124446 |
Document ID | / |
Family ID | 28674692 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030192392 |
Kind Code |
A1 |
Gaeth, Gerald A. |
October 16, 2003 |
POSITION DEPEND TILT AND TELESCOPING STEERING COLUMN
Abstract
A steering column assembly moveable along an axis to an extended
and retracted position and having a hand wheel tiltable about a
pivot axis between tilted and untilted positions is provided. A
control mechanism limits the degree of tilting movement of the hand
wheel so that while the steering column assembly is in the extended
position, the steering column is tiltable to the first maximum tilt
angle, and while in the retracted position, the steering column is
tiltable to the second maximum tilt angle. The second maximum tilt
angle is less than the first maximum tilt angle to prevent the
steering column assembly from interfering with any portion of a
vehicle.
Inventors: |
Gaeth, Gerald A.;
(Frankenmuth, MI) |
Correspondence
Address: |
Robert L. Stearns
Reising, Ethington, Barnes, Kisselle,
Learman & McCulloch, P.C.
5291 Colony Drive North
Saginaw
MI
48603
US
|
Assignee: |
DELPHI TECHNOLOGIES, INC.
|
Family ID: |
28674692 |
Appl. No.: |
10/124446 |
Filed: |
April 16, 2002 |
Current U.S.
Class: |
74/493 |
Current CPC
Class: |
B62D 1/181 20130101 |
Class at
Publication: |
74/493 |
International
Class: |
B62D 001/183; B62D
001/18 |
Claims
What is claimed is:
1. A steering column assembly, comprising: a steering column
moveable along an axis having extended and retracted positions
relative to said axis and a hand wheel supported on said steering
column and tiltable about a pivot axis between tilted and untilted
positions; and a control mechanism limiting the degree of tilt of
said hand wheel while in said tilted position between a first
maximum tilt angle and a second maximum tilt angle, said second
maximum tilt angle being less than said first maximum tilt angle
wherein while said steering column is in said extended position,
said steering shaft is moveable to said first maximum tilt angle,
and while in said retracted position said steering shaft is
moveable to said second maximum tilt angle.
2. The steering column as in claim 1 wherein said steering column
has an axial position between and including said extended and
retracted positions and said tilt angle is a function of said axial
position.
3. The steering column as in claim 2 wherein said function is a
linear function.
4. The steering column as in claim 2 wherein said function is a
nonlinear function.
5. The steering column as in claim 1 further comprising a
telescopic sensor to detect an axial position of said steering
shaft between and including said extended and retracted positions;
and a tilt controller communicating with said telescopic sensor to
limit said tilted position of said steering shaft between and
including said first maximum tilt angle and said second maximum
tilt angle.
6. The steering column as in claim 5 wherein said control mechanism
is between and in series with said telescopic sensor and said tilt
controller to receive an input signal from said telescopic sensor
and to send an output signal to said tilt controller to limit said
tilted position of said steering shaft between and including said
first maximum tilt angle and said second maximum tilt angle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to steering column
assemblies, and more particularly to telescoping and tilting
steering column assemblies.
[0003] 2. Related Art
[0004] It is often convenient to a driver of a vehicle to have a
steering column assembly having a hand wheel that can both
telescope inwardly and outwardly, while also being able to tilt
upwardly and downwardly. The tilting and telescoping features of a
steering column assembly allow the driver to adjust the hand wheel
to the desired position while driving the vehicle, while also
allowing the driver to position the hand wheel to a position that
best allows getting in and out of the vehicle. Generally, when
driving a vehicle, the desired "use" position of the hand wheel is
in a telescopically extended position toward the driver, while also
having a certain degree of tilt to provide the most comfortable
position of the hand wheel. However, when the driver is entering or
exiting the vehicle, generally, the most desired "stowed" position
of the hand wheel is fully retracted and fully tilted in an upward
position to provide optimum access.
[0005] One problem encountered by such systems is that the hand
wheel, when moved to a telescopically retracted and upwardly tilted
stowed position, may interfere with the instrument panel which is
undesirable and can cause potential damage to the instrument panel,
and/or hand wheel.
[0006] One solution for preventing the hand wheel from contacting
the instrument panel when in the fully retracted upwardly tilted
stowed position is to limit the freedom of tilting movement and/or
telescoping movement so that the hand wheel does not move far
enough to contact the instrument panel of the hand wheel. However,
this solution has the inherent drawback of limiting the overall
telescoping and tilting adjustability when the hand wheel is in the
extended use position, and thus offering less than optimum
adjustability to the driver.
[0007] A position dependent tilt and telescoping steering column
constructed according to the present invention overcomes or greatly
minimizes the above limitations of prior steering columns.
SUMMARY OF THE INVENTION
[0008] A steering column assembly is constructed to allow for an
otherwise full range of tilting while preventing the steering
column assembly from interfering with any portion of the vehicle
while in a tilted position. The steering column assembly has an
upper steering shaft that is capable of telescoping to an extended
and retracted position, while also being capable of tilting from an
untilted position to a tilted position. While the steering column
assembly is in the extended position, the upper steering shaft can
be tilted to a position, thus forming a first maximum tilt angle
between the untilted position and the tilted position. In addition,
while the steering column assembly is in the retracted position,
the upper steering shaft is moveable to a tilted position to form a
second maximum tilt angle between the untilted position and the
tilted position. The second maximum tilt angle formed while in the
retracted position is less than the first maximum tilt angle formed
while in the extended position, thus preventing the steering column
assembly from interfering with any portion of a vehicle.
[0009] One advantage offered by this invention is that the steering
column assembly, while in an extended position, has a full range of
tiltable movement, however while in a retracted position has a
reduced degree of tiltable movement to prevent interfering of a
hand wheel with an instrument panel or any other portion of the
vehicle.
[0010] Another advantage offered by this invention is that the
degree of tilt of the upper steering shaft throughout the range of
telescopic travel can be provided to best suit the intended
application
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features and advantages of the present
invention will become more readily appreciated when considered in
connection with the following detailed description and appended
drawings, wherein:
[0012] FIG. 1 shows a vehicle having a steering column embodying a
currently preferred embodiment of the present invention;
[0013] FIG. 2 is a schematic view of the steering column assembly
from FIG. 1 showing an extended and retracted position of upper
steering shaft of the steering column assembly;
[0014] FIG. 3 is a schematic view of the steering column assembly
from FIG. 1 showing untilted and tilted positions of the upper
steering shaft of the steering column assembly;
[0015] FIG. 4 is a schematic view of the steering column assembly
from FIG. 1 showing the upper steering shaft in a fully retracted
and fully tilted position; and
[0016] FIG. 5 is a schematic view of the steering column assembly
from FIG. 1 showing the upper steering shaft in a fully extended
and fully tilted position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] As shown generally in FIG. 1, a vehicle 10 having a steering
column assembly 12 embodying a currently preferred construction of
the invention is provided allowing a driver to have a maximum range
of adjustment of a hand wheel 14 of the steering column assembly 12
while driving the vehicle 10, while also having an ability to
adjust the hand wheel 14 to a position for easy entry and exit from
the vehicle 10. As best shown in FIGS. 2 and 3, and upper steering
shaft 16 of the steering column assembly 12 has extended and
retracted positions, and untilted and tilted positions. A wide
variety of combination of these positions are offered by the
invention to provide the driver with the most desirable position of
the hand wheel 14, depending on whether the driver is operating the
vehicle 10, or simply getting in or out of the vehicle 10.
[0018] In FIG. 2, a steering column 18 is schematically shown
having the hand wheel 14 connected to an end 20 of the upper
steering shaft 16. The hand wheel 14 and upper steering shaft 16
are shown in both a retracted position with the hand wheel 14 moved
toward a front end 22 of the vehicle 10, and in an extended
position with the hand wheel 14 moved toward a rearward end 24 of
the vehicle 10. A mechanical hard stop 26 is shown in a currently
preferred embodiment of the invention to limit the amount of axial
travel of the upper steering shaft 16, thus limiting how far the
upper steering shaft 16 and hand wheel 14 can extend toward the
rearward end 24 of the vehicle 10.
[0019] The upper steering shaft 16 has an end 28 constructed for
pivotal connection to other mating steering components such as a
lower steering shaft 30, when present. The upper steering shaft 16
has a longitudinal axis 32 corresponding to the untilted and tilted
position such that the axis while in the tilted position, forms a
tilt angle a relative to the axis 32 when in the untilted
position.
[0020] The tilt angle has a vertex 34 generally at the end 28 of
the upper steering shaft 16 where the upper steering shaft 16 is
pivotally connected to the lower steering shaft 30. The
longitudinal axis 32 of the upper steering shaft 16 spans an arc
between the untilted position and the tilted position. As shown in
FIG. 5, the preferred embodiment shows the axis 32 of the upper
steering shaft 16 while in the extended position forming a first
maximum tilt angle, and while in a retracted position, as shown in
FIG. 4, forming a second maximum tilt angle. The second maximum
tilt angle is shown to be less than the first maximum tilt angle,
thus preventing the hand wheel 14 from interfering with an
instrument panel 36 on the vehicle 10 when in the retracted
position.
[0021] A telescopic sensor 38 is provided in the steering column
assembly 12. The telescopic sensor 38 receives an input signal from
the upper steering shaft 16 that provides the telescopic sensor 38
with the axial position of the upper steering shaft 16 relative to
a preprogrammed initialized position. The telescopic sensor 38 then
communicates the axial position of the upper steering shaft 16 to a
central control mechanism, shown here as a control module 42. A
tilt sensor 40 is also provided and senses the tilt position of the
shaft 16 and communicates with the control module 42.
[0022] The control module 42 is preprogrammed with an algorithm
that meets the manufacturer's requirements for telescopic travel of
the upper steering shaft 16 for the vehicle being manufactured. The
algorithm can take on virtually any mathematical formula, thus
allowing the steering column 18 to be programmed to meet a wide
variety of vehicle platforms. Thus, an algorithm can be provided to
allow full telescoping travel of the upper steering shaft 16
between a fully retracted and fully extended position, as shown in
FIG. 2. If full telescoping travel takes place, then the hard stop
26 is responsible for limiting the amount of axial travel of the
upper steering shaft 16 and hand wheel 14. On the other hand, an
algorithm could be provided to limit the telescoping travel of the
upper steering shaft 16 from anywhere between full telescoping
travel and no telescoping travel. An algorithm limiting the amount
of axial travel of the upper steering shaft 16 can be programmed
into the control module 42 thus preventing the upper steering shaft
16 from extending toward the rearward end 24 of the vehicle 10
prior to engagement of the hard stop 26. If an algorithm limiting
full travel of the upper steering shaft 16 is programmed into the
control module 42, the telescoping travel of the upper steering
shaft 16 is then limited by a "soft" stop rather than the hard stop
26.
[0023] Upon determination of the axial position of the upper
steering shaft 16 by the control module 42, the control module 42
communicates with a telescopic controller 44 preferably by way of
an electrical connection between the control module 42 and the
telescopic controller 44. The telescopic controller 44 then
communicates to the upper steering shaft 16 of the steering column
assembly 12 to either allow unrestricted telescoping travel of the
upper steering shaft 16 up to the hard stop 26, or to limit the
telescoping travel of the upper steering shaft 16 to the "soft"
stop.
[0024] The control module 42 not only communicates with the
telescopic controller 44, but also with a tilt controller 46
preferably by way of an electrical connection between the control
module 42 and the tilt controller 46. An algorithm preprogrammed
into the control module 42 not only facilitates the telescopic
travel of the upper steering shaft 16, but also the tilting
movement of the upper steering shaft 16. Depending on the
mathematical formula of the algorithm the control module 42 uses
the linear position of the upper steering shaft 16 to determine the
degree of tilting movement of the upper steering shaft 16, and thus
the hand wheel 14. Upon processing the algorithm within the control
module 42, the control module 42 communicates information to the
tilt controller 46, which communicates with the upper steering
shaft 16. The tilt controller 46 facilitates movement of the upper
steering shaft 16 between the untilted and tilted positions,
depending on the algorithm preprogrammed into the control module
42. An algorithm can be programmed in the control module 42 to
allow full tilting movement between the untilted and tilted
positions, or can be programmed to restrict the amount of tilting
movement to a range anywhere therebetween, including no tilting
movement at all. Preferably, the algorithm provides for a varying
degree of tilting movement along the telescoping travel of the
upper steering shaft 16.
[0025] The full degree of tilting movement of the upper steering
shaft 16 is limited by a tilting hard stop 48. If however, an
algorithm is programmed to limit the degree of tilting movement,
then the tilting movement is limited by a "soft" stop. In one
presently preferred embodiment of the invention, an algorithm
having a mathematical formula of: tiltup limit=f(telescopic
position)=((Xmm+(22.5 mm)).div.4.5)+5, where X=telescopic position.
Thus, this algorithm provides for telescopic and tilting movement
as charted below.
1 X = TELE(mm) TILT (deg.degree.) -20.0 5.5 -15.0 6.6 -10.0 7.7
-5.0 8.8 0.0 10.0 5.0 11.1 10.0 12.2 15.0 13.3 20.0 14.4 25.0
15.5
[0026] The algorithm above is only one presently preferred
algorithm for a specific vehicle platform, and should not be viewed
as the sole embodiment. As mentioned, virtually any mathematical
formula can be used to create an algorithm as best suited for the
vehicle platform. The algorithm above provides for a tilt angle
that is a function of the telescopic position of the upper steering
shaft 16, where the function is a linear function. It should be
understood that the functional relationship between the telescopic
position and the tilt angle could just as easily take on a function
that is nonlinear. The table above shows that when the upper
steering shaft 16 of the steering column assembly 12 is in a fully
retracted telescopic position, at X=-20.0 mm, the degree of tilt
.alpha. of the upper steering shaft 16 between the untilted and
tilted positions is 5.5.degree.. As the telescopic position of the
upper steering shaft 16 extends towards a fully extended position,
the degree of the tilt angle .alpha. increases.
[0027] As best shown in FIGS. 4 and 5, the fully retracted and
fully extended positions, respectively, provide for a different
degree of tilt of the upper steering shaft 16. FIG. 4, showing the
upper steering shaft 16 in a fully retracted position, provides for
a tilt angle .alpha. between the untilted and tilted positions of
5.5.degree.. In this position, it is a "soft" stop provided by the
algorithm that limits the degree of tilt of the upper steering
shaft 16, and not the hard stop 48. On the other hand, FIG. 5 shows
the upper steering shaft 16 in a fully extended position providing
for a tilt angle .alpha. of 15.degree. between the untilted and
tilted positions, and shows the hard stop 48 as limiting the amount
of tilt of the upper steering shaft 16.
[0028] The steering column assembly 12 having a maximum tilt angle
that can change relative to the telescoping or axial position of
the upper steering shaft 16 provides greater flexibility in the
ability to design the instrument panel 36. The tilting movement of
the hand wheel 14 can be better controlled to prevent interference
of the steering column 18 and hand wheel 14 with the instrument
panel 36.
[0029] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described. The invention is defined by the claims.
* * * * *