Patent Publication Number: US-2022212712-A1

Title: Steering column adjustment assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims the benefits of priority to U.S. Provisional Patent Application Ser. No. 63/134,437, filed Jan. 6, 2021, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to a steering assembly and, more particularly, to an adjustment assembly for an axially adjustable steering column. 
     BACKGROUND 
     A vehicle, such as a car, truck, sport utility vehicle, crossover, mini-van, marine craft, aircraft, all-terrain vehicle, recreational vehicle, or other suitable vehicles, include various steering system schemes, for example, steer-by-wire and driver interface steering. These steering system schemes typically include a steering column for providing a steering input to an output that interacts with a steering linkage to ultimately cause the vehicle road wheels (or other intermediary elements) to turn the vehicle. Some steering columns can be movably retracted from an operational position that is close to a driver to a stowed position when manual steering control is not needed. For example, stowable steering columns that can retract deep into vehicle instrument panels can provide more space for a parked driver or for a person sitting in the driver&#39;s seat during autonomous driving. 
     The distance between the operational and stowed positions of the steering column can be about 150 mm. This distance is significantly greater than the telescopic range of adjustment (e.g., about 50 mm) that is available with conventional steering columns for driver comfort. Therefore, reference to a stowed position is distinguishable from axial adjustment over a range of different manual steering positions that simply accommodate different sized drivers. As autonomous functionality continues to be widely adopted, the automotive market is looking for faster actuators to stow and redeploy steering columns. These faster actuators are generally designed to move at speeds two or three times faster than the previous generation of actuators. To accomplish this speed, the actuator includes a motor that is larger and more powerful than those traditionally used. However, this performance increase does not come without concerns. 
     The additional requirements in motor performance increase the potential for damaging the motor and interrelated parts when the actuator is suddenly stopped at a physical limit, e.g. a retraction or extension limit. In addition, the motor shaft can be damaged when the travel is impeded during motion between its physical limits. While position sensors and motor control have preemptively reduced some risks of damage, risks are still present. 
     Certain protection features have been incorporated to reduce damage to the motor. Many of these protection features are mechanical, e.g. shear pins, slip clutches, belts, and tolerance rings that all provide protection from excessive torque. Many of these protection features, such as shear pins, for example, require intervention to reset, which is not desirable in an automotive application. In addition, many of these protection features include a sacrificial element like a belt or fuse (shear pin) that requires replacement once activated, which is also not desirable in the automotive industry. 
     Accordingly, there is a continuing desire to develop protection features that automatically reset. 
     SUMMARY 
     According to one aspect of the disclosure, an axially adjustable steering column includes a steering column component axially adjustable along a longitudinal axis of the axially adjustable steering column. The steering column also includes a driven assembly operatively coupled to the steering column component. The steering column further includes a driving assembly. The steering column yet further includes a connection assembly that includes a connection gear having a first set of teeth operatively connected to the driving assembly, the connection gear having a set of gear clutch teeth. The connection assembly also includes a clutch member operatively connected to the driven assembly, the driven assembly moving along an axis in response to actuation from the driving assembly and causes the provided axially adjustable steering column to be adjusted along the axis, the clutch member having a set of clutch member teeth. The clutch member teeth are engaged with the gear clutch teeth in a connected state to transmit torque from the driving assembly to the driven assembly. The clutch member teeth and the gear clutch teeth are disengaged in an overload state, wherein the clutch member teeth are permitted to rotate relative to the gear clutch teeth in the overload state such that the provided driving assembly does not actuate the provided driven assembly. 
     According to another aspect of the disclosure, an axial adjustment assembly for an axially adjustable steering column includes a driving assembly. The axial adjustment assembly also includes a driven assembly operatively coupled to a steering column component. The axial adjustment assembly further includes a connection assembly operatively connecting the driving assembly to the driven assembly to transmit a driving actuation force provided by the driving assembly to the driven assembly to axially adjust the steering column component. The connection assembly includes a connection gear driven by the driving assembly and having a set of gear clutch teeth. The connection assembly also includes a clutch member operatively coupled to the driven assembly and having a set of clutch member teeth, wherein the set of gear clutch teeth and the set of clutch member teeth are engaged in a connected state, wherein the set of gear clutch teeth and the set of clutch member teeth are disengaged in a disconnected state. 
     These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims, and the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to-scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. 
         FIG. 1  schematically illustrates a steering system according to the principles of the present disclosure. 
         FIG. 2  schematically illustrates a steering column assembly according to the principles of the present disclosure. 
         FIG. 3  is a perspective, disassembled view of an adjustment assembly according to the principles of the present disclosure. 
         FIG. 4  is a perspective, disassembled view of a connection assembly according to the principles of the present disclosure. 
         FIG. 5  is a perspective, partial cross-sectional view of the connection assembly according to the principles of the present disclosure. 
         FIG. 6  is a side, elevational, partial cross-sectional view of the connection assembly according to another aspect of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion is directed to various embodiments of the disclosure. Although one or more of these embodiments may be discussed in greater detail relative to other embodiments, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment. 
     As described, a vehicle, such as a car, truck, sport utility vehicle, crossover, mini-van, marine craft, aircraft, all-terrain vehicle, recreational vehicle, or other suitable vehicles, include various steering system schemes, for example, steer-by-wire and driver interface steering. These steering system schemes typically include a steering column for providing steering input to an output that interacts with a steering linkage to ultimately cause the vehicle wheels (or other elements) to turn the vehicle. Some steering columns can be movably retracted from an operational position that is close to a driver to a stowed position when manual steering control is not needed. For example, stowable steering columns that can retract deep into vehicle instrument panels can provide more space for a parked driver or for a person sitting in the driver&#39;s seat during autonomous driving. 
     The distance between the operational and stowed positions of the steering column can be about 150 mm. This distance is significantly greater than the telescopic range of adjustment (e.g., about 50 mm) that is available with conventional steering columns for driver comfort. Therefore, reference to a stowed position is distinguishable from axial adjustment over a range of different manual steering positions that simply accommodate different sized drivers. As autonomous functionality continues to be widely adopted, the automotive market is looking for faster actuators to stow and redeploy steering columns. These faster actuators are generally designed to move at speeds two or three times faster than the previous generation of actuators. To accomplish this speed, the actuator includes a motor that is larger and more powerful than those traditionally used. However, this performance increase does not come without concerns. 
     Accordingly, systems and methods, such as those described herein, configured to provide a resettable protection feature, may be desirable. In some embodiments, the assembly described herein may be configured to provide a protection feature to a retractable steering column. 
       FIG. 1  generally illustrates a vehicle according to the principles of the present disclosure. As noted above, the embodiments disclosed herein may be utilized in any suitable vehicle, such as a car, a truck, a sport utility vehicle, a mini-van, a crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. The principles of the present disclosure may apply to other vehicles, such as planes, boats, trains, drones, or other suitable vehicles. 
     The vehicle includes a steering system  40 . The steering system  40  may be configured as a driver interface steering system, an autonomous driving system, or a system that allows for both driver interface and autonomous steering. The steering system  40  may include an input device  42 , such as a steering wheel, wherein a driver may mechanically provide a steering input by turning the steering wheel. An airbag device  43  may be located on or near the input device  42 . A steering column  44  extends along an axis from the input device  42  to an output assembly  46 . The output assembly  46  may include a pinion shaft assembly, an I-shaft, a cardan joint, steer-by-wire components or any other features conventionally located opposite the input device  42 . The steering column  44  may include a first portion  48  and a second portion  50  that are permitted to move axially with respect to one another. The first portion  48  and second portion  50  may be configured as jackets, shafts, brackets, rails, or other members that permit axial movement therebetween. The axial movement may include sliding, telescopic, translating, and other axial movements. The steering column  44  may include additional features that permit axial movement and brackets that provide rake and tilt movement. 
     The steering column  44  is moveable between a range of positions from an extended position to a retracted position e.g., stowed position. In the extended position, the end of the first portion  48  having the input device  42  attached thereto is moved axially away from the second portion  50  so that the input device  42  is located near an operator of the vehicle. In the retracted position, the end of the first portion  48  having the input device  42  attached thereto is moved axially towards the second portion  50  so that the input device  42  is located away from an operator of the vehicle. In some embodiments, the retracted position may correspond to stowing the input device  42  (i.e., stowed position). For example, it may be beneficial to place the input device  42  in a stowed position during autonomous driving. In some embodiments, the retracted position can be on the order of about 150 mm away from the extended position, such as at least 100 mm, or at least about 125 mm away from the extended position. 
     A steering gear assembly  54  may connect to the output assembly  46  via a steering gear input shaft  56 . The steering gear assembly  54  may be configured as a rack-and-pinion, a recirculating ball-type steering gear, or any other types of steering gears associated with autonomous and driver-interface steering systems. The steering gear assembly  54  may then connect to a driving axle  58  via an output shaft  60 . The output shaft  60  may include a pitman arm and sector gear or other traditional components. The output shaft  60  is operably connected to the steering gear assembly  54  such that a rotation of the steering gear input shaft  56  causes a responsive movement of the output shaft  60  and causes the drive axle to turn the wheels  22 . 
       FIG. 2  provides an enlarged schematic view of the steering column  44 . The steering column  44  may include a steering shaft  62  located along the first portion  48  and the second portion  50 . In some embodiments, the steering shaft  62  may be located within the first portion  48  and the second portion  50 . The steering shaft  62  may also include more than one portion that permits axial adjustability. An adjustment assembly  52  may be located on the first portion  48 , the second portion  50 , the steering shaft  62 , any brackets, or combinations thereof to provide steering column adjustment overload protection. 
     With reference now to  FIG. 3 , a disassembled view of the adjustment assembly  52  is illustrated. The adjustment assembly  52  includes a driving assembly  64 , a driven assembly  66 , and a connection assembly  68 . The driving assembly  64  may include a motor  70  that drives the driven assembly  66  resulting in the steering column  44  assembly moving between the retracted and extended positions. The connection assembly  68  connects the driving assembly  64  to the driven assembly  66  in a connected state and disconnects the driving assembly  64  from the driven assembly  66  in a disconnected state (which may be referred to as an overload state). The connection assembly  68  includes a clutch member  72  ( FIG. 4 ) that causes the connection assembly  68  to be actuated between the connected state and the disconnected state. The connection assembly  68  may further include at least one spring element  74  ( FIG. 4 ) that biases the connection assembly  68  in the connected state. In operation, when the steering column assembly  44  is moved to a physical limit, or impeded during movement, the biasing force of the spring element  74  is overcome such that the driving assembly  64  and the driven assembly  66  are operably disconnected and the driving assembly  64  can continue to operate without transferring damaging force to the driven assembly  66 . 
     With continued reference to  FIG. 3 , the driven member  66  may include a lead screw  76  and a jack screw nut  78 . The lead screw  76  extends along an axis A between a first end  80  located near the connection assembly  68  and a second end  82  located near the jack screw nut  78 . The second end  82  may define exterior teeth and the jack screw nut  78  may include an internal surface defining internal teeth meshed with the exterior teeth, wherein rotation of the lead screw  76  from the driving assembly  64  causes the jack screw nut  78  to travel along the axis A. The jack screw nut  78  may be operably connected to one of the first portion  48  and the second portion  50  of the steering column assembly  44  and the lead screw  76  may be operably connected to the other of the first portion and the second portion  50 . In some embodiments, one of the lead screw  76  and the jack screw nut  78  connects to one of the first portion  48  and the second portion  50  while the other of the lead screw  76  and the jack screw nut  78  connects to another portion of the steering column assembly  44  or nearby vehicle components. As such, travel of the lead screw nut  78  further causes the steering column assembly  44  to move between the extended and retracted positions. 
     In some embodiments, the lead screw  76  may be connected or otherwise integral with the steering shaft  62 . The driven member  66  may further include a pair of travel stops  84 , such as travel stop rings, that limit the travel distance of the jack screw nut  78  with respect to the lead screw  76 . A pair of retaining clips  86  may be attached to the lead screw  76  on or near the respective ends  80 ,  82 . In some embodiments, the lead screw  76  may be located in a lead screw housing  88  and a pair of bearing elements  90  may be located on opposite ends of the lead screw housing  88  along the axis A. As best illustrated in  FIG. 5 , the bearing elements  90  may be configured as ball and track bearings with an inner track  92  operably connected to the lead screw  76  and an outer track  94  operably connected to the lead screw housing  88 . With reference now back to  FIG. 3 , at least one bearing retainer ring  96  may be located next to, and axially retain, at least one of the bearing elements  90 . The lead screw housing  88  may include connection tabs  98  and a pair of fasteners  100  for connecting the lead screw housing  88  to a connection assembly housing  102 . The connection assembly housing  102  may locate and protect certain features of the driving assembly  64 , the driven assembly  66 , the connection assembly  68 , or combinations thereof. The connection assembly housing  102  further includes a driving assembly connection surface  104 . The lead screw housing  88  may be located at a substantially transverse angle to the driving assembly connection surface  104 . In some embodiments, the driving assembly connection surface  104  may be oriented along—or parallel to—an axis B that is substantially perpendicular to the axis A, or less in other embodiments, such as 70° or less, 50° or less, or 30° or less. Additional fasteners  100  may connect the connection assembly housing  102  to the driving assembly  64 . 
     With continued reference to  FIG. 3 , the driving assembly  64  may further be connected to include a controller (not shown) through an electrical connector  106  for instructing certain operations of the driving assembly  64 , e.g. to cause the steering column assembly  44  to extend or retract. The driving assembly  64  may further include a driving gear  108  that is caused to rotate, for example, by the motor  70 . The driving gear  108  may be at least partially supported via a plug  110  and a cushion element  112  that further provide delashing functionality. 
     A disassembled view of the connection assembly  68  is illustrated in  FIG. 4 . The connection assembly includes the clutch member  72 , the at least one spring element  74 , and a connection gear  114 . In some embodiments, components of the connection assembly  68  extend along the axis A. The clutch member  72  comprises a body portion  116  and a flanged portion  118  extending radially outwardly from the body portion  116 . The clutch member  72  further includes an inner wall  120  defining a series of teeth for locating the first end  80  of the lead screw  76 , which may include teeth intermeshed with the teeth defined by the inner wall  120 , such that the lead screw  76  and the clutch member  72  conjointly rotate. The flanged portion  118  may further include a first set of connection teeth  122  (which may be referred to herein as a first interface portion or clutch member teeth) for connection to the connection gear  114 . More particularly, the connection gear  114  may include a second set of connection teeth  124  (which may be referred to herein as a second interface portion or gear clutch teeth) intermeshed or otherwise rotationally connected with the first set of connection teeth  122  when the driving assembly  64  is in the connected state and allowed to slide out of meshed engagement from the first set of connection teeth  122  when the driving assembly  64  is in the disconnected state. 
     With continued reference to  FIG. 4 , the connection gear  114  may further include driven teeth  126  intermeshed with the driving gear  108 . As such, the driving gear  108  may cause the connection gear  114  to rotate and, in response, cause the second set of connection teeth  124  to drive the first set of connection teeth  122  and cause the lead screw  76  to also rotate and thus the jack screw nut  78  to travel along the axis A, when in the connected state. The connection gear  114  further includes an inner wall  128  for locating the body portion  116  of the clutch member  72 . The at least one spring element  74  may include at least one washer spring located about the body portion  116  of the clutch member  72  opposite the flanged portion  118 . The at least one spring element  74  may be retained between a pair of retainers  130 , such as thrust washers, and the retainers  130  may be secured to the clutch member  72  via a clip  132 . More particularly, the body portion  116  may include a clip retaining aperture  134  for securing the clip  132  and sandwiching the at least one spring element  74  and the retainers  130  between the clip  132  and the connection gear  114 . The at least one spring element  74  therefore biases the second set of connection teeth  124  into engagement with the first set of connection teeth  122  in the connected state. 
     An assembled view of the connection assembly  68  is illustrated in  FIG. 5 . In operation, the spring elements  74  are compressed between the clip  132  and the connection gear  114  to bias the second set of connection teeth  124  into engagement with the first set of connection teeth  122  in the connected state. The connection gear  114  is driven by the motor  70  and the torque is transmitted to the clutch member  72 . If the clutch member  72  cannot rotate, for example, during an overload event, the connection gear  114  can continue to rotate by sliding the first set of connection teeth  122  and the second set of connection teeth  124  past each other and further compressing the at least one spring element  74 . Therefore, the connection gear  114  is permitted to rotate in its position relative to the clutch member  72  and may be limited to axial movement at the height of the first set of connection teeth  122  and the second set of connection teeth  124 . The first set of connection teeth  122  and the second set of connection teeth  124  are symmetric such that the direction of rotation of the connection gear  114  will not affect the overload functionality. The symmetry may be varied if the application requires differing operational torques in the design. In some embodiments, the clutch member  72 , the connection gear  114 , or combinations thereof may be formed of polymeric materials (e.g., plastic, polymer, etc.) to reduce noise. 
       FIG. 6  schematically illustrates a connection assembly  268  in accordance with another embodiment of the disclosure. Unless otherwise illustrated, the connection assembly  268  may share components and features of those described in reference to the connection assembly  68  described in connection with  FIGS. 2-5 . However, the spring element  274  may alternatively include any number of springs, such as compression springs, air springs, dampers, or combinations thereof. In addition, the clutch element  272  may include a variety of interfacing surface(s) with the connection gear  214 . For example, non-toothed cam surfaces that conjointly rotate under a threshold pressure, but respectively rotate under a pressure above threshold. Similarly, the clutch member  272  may include any number of clutch arrangements, such as clutch packs that include a plurality of friction clutch plates. 
     The above discussion is meant to be illustrative of the principles and various embodiments of the present disclosure. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. 
     The word “example” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word “example” is intended to present concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from context, “X includes A or B” is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then “X includes A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Moreover, use of the term “an implementation” or “one implementation” throughout is not intended to mean the same embodiment or implementation unless described as such. 
     The above-described embodiments, implementations, and aspects have been described in order to allow easy understanding of the present disclosure and do not limit the present disclosure. On the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation to encompass all such modifications and equivalent structure as is permitted under the law.