Axially adjustable steering column assembly

Abstract

A steering column assembly includes a steering column extending along a longitudinal axis between a first end and a second end. The steering column includes an outer shroud at the first end, an intermediate shroud telescopically connected with the outer shroud and extending toward the second end, and an inner shroud telescopically connected with the intermediate shroud and further extending toward the second end. The steering column assembly also includes at least one axial adjustment actuator that telescopically moves the intermediate shroud relative to the outer shroud. The at least one axial adjustment actuator includes a first gear rack fixed to the outer shroud and a second gear rack fixed to the inner shroud, at least one gear located between the first and second gear racks, the at least one gear being in toothed engagement with the first and second gear racks and being driven to translate the inner shroud relative to the outer shroud.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Patent Application Serial No. 63 / 272,371, filed October 27, 2021, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments described herein relate to vehicle steering systems, and more particularly to axially extendable and retractable steering columns. BACKGROUND

[0004] Conventional steering columns can be operated manually or electronically adjusted by actuators. Depending on user requirements, the steering column can be adjusted in various directions, including along the axis of the steering column and / or rake direction. Steering columns can be moved axially in several ways. For example, some steering columns telescope by telescoping sheaths or shafts, or can include a sheath or shaft that can slide on a rail and guide system of another component of the steering column.

[0005] Power-type axially adjustable steering columns typically have one actuator and two telescoping sheaths. One sheath is typically pinned at the rake pivot point, and the other sheath can translate with the hand wheel. The actuator can adjust the two sheaths relative to each other to provide the hand wheel telescoping function. Conventional solutions have limitations. Telescoping steering columns increase the amount of space required for the steering column assembly to operate in the underlying structure. As some end-use applications are actually decreasing the available space for the steering column assembly, existing telescoping solutions are becoming a problem. Furthermore, when the telescoping sheaths are moved, a transition period typically occurs when the outer sheath stops moving and the inner sheath starts and / or continues to move. This transition period typically creates undesirable noise. Furthermore, moving both the inner and outer sheaths independently typically results in slow telescoping adjustment.

[0006] In the past, the function of telescoping the steering column was to provide flexibility in hand wheel position and to provide a more comfortable driving position for drivers of different sizes. Recently, there is an opportunity to implement significantly greater telescoping travel, which can also be referred to as stowage travel (i.e., when the hand wheel is not needed). For example, when the vehicle is parked, the hand wheel can be significantly repositioned away from the driver so that he or she can do something other than maneuver the vehicle, such as work on a laptop. Other examples include vehicles with autonomous driving capabilities so that the hand wheel can be stowed when the vehicle is in autonomous driving mode.

[0007] Accordingly, there has been a long-felt need to provide a quiet steering column assembly that provides a wide range of axial adjustment and that provides faster axial adjustment. SUMMARY

[0008] According to one aspect of the disclosure, a steering column assembly includes a steering column extending along a longitudinal axis between a first end and a second end. The steering column includes an outer sheath at the first end, an intermediate sheath telescopically connected with the outer sheath and extending toward the second end, and an inner sheath telescopically connected with the intermediate sheath and further extending toward the second end. The steering column assembly further includes at least one axial adjustment actuator that telescopically moves the intermediate sheath relative to the outer sheath. The at least one axial adjustment actuator includes a first gear rack fixed to the outer sheath and a second gear rack fixed to the inner sheath, at least one gear located between and in toothed engagement with the first and second gear racks, and the at least one gear is driven to translate the inner sheath relative to the outer sheath.

[0009] According to another aspect of the disclosure, an axial adjustment actuator assembly for a steering column having an outer sheath, an intermediate sheath, and an inner sheath is provided. The axial adjustment actuator assembly includes a motor. The axial adjustment actuator assembly further includes a lead screw rotatably driven by the motor. The axial adjustment actuator assembly further includes a nut axially driven along the lead screw during rotation of the lead screw and the nut is connected to the intermediate sheath to axially translate the intermediate sheath at an intermediate sheath speed. The axial adjustment actuator assembly further includes a gear operatively coupled to the nut and engaged with the inner sheath and the outer sheath, wherein the gear translates the inner sheath at an inner sheath speed different than the intermediate sheath speed.

[0010] According to yet another aspect of the present disclosure, a steering column assembly includes a steering column extending along a longitudinal axis between a first end and a second end. The steering column includes an outer shroud positioned at the first end, an intermediate shroud telescopically connected with the outer shroud and extending toward the second end, and an inner shroud telescopically connected with the intermediate shroud and further extending toward the second end. The steering column assembly further includes at least one axial adjustment actuator assembly. The at least one axial adjustment actuator assembly includes a motor. The at least one axial adjustment actuator assembly further includes a lead screw rotatably driven by the motor. The at least one axial adjustment actuator assembly further includes a nut axially driven along the lead screw during rotation of the lead screw and connected to the intermediate shroud to axially move the intermediate shroud at an intermediate shroud speed. The at least one axial adjustment actuator assembly further includes an axial speed control component operatively coupled to the nut and engaged with the inner shroud and the outer shroud, wherein the axial speed control component translates the inner shroud at an inner shroud speed different from the intermediate shroud speed.

[0011] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0012] The foregoing and other features and advantages of the present application are believed to be apparent as the application is better understood by reference to the following description taken in conjunction with the accompanying drawings in which:

[0013] Figure 1 A steering system of a vehicle is schematically illustrated in accordance with the principles of the present disclosure;

[0014] Figure 2 is an isometric, partially transparent view of a steering column assembly including a steering column extending along a longitudinal axis;

[0015] Figure 3 is another isometric, partially transparent view of the steering column assembly illustrating the steering column including a pair of telescoping shrouds and an axial adjustment actuator that moves the telescoping shrouds relative to one another along the longitudinal axis;

[0016] Figure 4 is a side view of the steering column in a fully deployed condition;

[0017] Figure 5 is a perspective view of the axial adjustment actuator;

[0018] Figures 6A to 6D sequential illustrations of the steering column assembly being adjusted between a fully deployed condition and a stowed condition; and

[0019] Figures 7A to 7Cis another sequential illustration of a steering column assembly being adjusted between a fully extended condition (as shown) and a stowed condition. Figure 4 is another sequential illustration of a steering column assembly being adjusted between a fully extended condition (as shown) and a stowed condition. DETAILED DESCRIPTION

[0020] Reference will now be made to the drawings wherein various embodiments are shown and described, in a non-limiting manner, Figures 1 to 7C Embodiments of systems, methods, and apparatus for a steering column assembly that allows for tilt and axial movement are shown. Axial movement includes two or more shrouds moving in a telescoping, sliding, or translating manner relative to each other.

[0021] In some embodiments, the vehicle can further include a steering system 40 as generally shown in Figure 1 The steering system 40 can 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 can include an input device 42, such as a steering wheel (steering handle), where a driver can provide steering input mechanically by turning the steering wheel. A steering column assembly 44 extends along an axis from the input device 42 to an output assembly 46. The output assembly 46 can include a pinion shaft assembly, an I-shaft, a universal joint, a steer-by-wire component, or any other feature conventionally located opposite the input device 42. The steering column assembly 44 can include a first portion 48 and a second portion (also referred to herein as a "shroud") that are allowed to move axially relative to each other. The axial movement can include sliding, telescoping, translating, and other axial movement. The steering column assembly 44 can include additional portions that allow for axial movement as well as a carrier that provides tilt and rake movement. An axial adjustment actuator 52 can be located on one or each of the first portion 48, the second portion 50, and any carrier and provides at least one of an extension and a contraction of the steering column assembly 44 along the axis. As will be described in greater detail below, the behavior of the axial adjustment actuator 52 can be controlled via a control system 300.

[0022] The steering gear assembly 54 can be connected to the output assembly 46 via a steering gear input shaft 56. The steering gear assembly 54 can be configured as a rack-and-pinion, recirculating ball type steering gear, or any other type of steering gear associated with autonomous and driver interface steering systems. The steering gear assembly 54 can then be connected to a driving axel 58 via an output shaft 60. The output shaft 60 can include pitman arms and sector gears or other conventional components. The output shaft 60 is operably connected to the steering gear assembly 54 such that rotation of the steering gear input shaft 56 causes responsive movement of the output shaft 60 and results in the driving wheel axles turning the wheels 22.

[0023] Referring now to Figure 2 , the steering column assembly 44 is shown in an isometric view. The steering column assembly 44 includes a steering column 62 extending along a longitudinal axis A between a first end 64 and a second end 66. The steering column assembly 44 includes a tilt bracket assembly 68 positioned between the first end 64 and the second end 66. The tilt bracket assembly 68 facilitates tilting movement of the steering column 62 about a pivot axis disposed transverse to the longitudinal axis A.

[0024] With continued reference to Figure 2 , the steering column 62 can be axially adjustable and include a first sheath 48 (may also be referred to herein as an “intermediate sheath”) and a second sheath 50 (may also be referred to herein as an “upper sheath”) that are permitted to move axially relative to one another. The first sheath 48 and the second sheath 50 can be disposed about the longitudinal axis A and are axially movable along the longitudinal axis via an axial adjustment actuator 52. In some embodiments, the axial adjustment actuator 52 is configured to move the first sheath 48 in a first axial direction and to move the second sheath 50 in a second axial direction opposite the first axial direction.

[0025] Referring now to Figure 3Turning column assembly 44 can also include an outer shroud 70 (which can also be referred to herein as a "lower shroud") that can be connected to the tilt bracket assembly 68 and can be axially fixed relative to the vehicle. In other words, outer shroud 70 is grounded to a fixed structure of the vehicle, and first shroud 48 and second shroud 50 are axially adjustable relative to outer shroud 70. Outer shroud 70 can include a bracket channel 72 for positioning first shroud 48 and second shroud 50. In some embodiments, first shroud 48 can define a first cavity 74, and second shroud 50 can define a second cavity 76. In operation, first shroud 48 is sized to be slidably movable within bracket channel 72 of outer shroud 70, second shroud 50 is sized to be slidable within first cavity 74 of first shroud 48, and a portion of steering column 62 is sized to be positioned within second cavity 76. Steering column 62 can be securely engaged with second shroud 50 so as to axially travel with the second shroud during actuation by axial adjustment actuator 52.

[0026] With continued reference to Figure 2 and Figure 3 , axial adjustment actuator 52 can include a gear 78 that is driven to rotate about a fixed pin 80. Gear 78 can be any suitable type of gear, such as a pinion gear, spur gear, etc. A first gear rack 82 can be positioned on second shroud 50, and a second gear rack 84 can be positioned on outer shroud 70. First gear rack 82 and second gear rack 84 can be in meshing engagement with gear 78 on opposite sides of gear 78. Thus, when gear 78 is driven to rotate about fixed pin 80, first gear rack 82 and second gear rack 84 are urged in opposite directions.

[0027] More specifically, the outer sheath 70 can define a pair of outer sidewalls 86 that extend along the open sides of the cradle channel 72. The outer sidewalls 86 can merge at an outer bridge portion 88, and the second rack and pinion 84 can be positioned on an inner surface of the outer bridge portion 88 with the teeth oriented toward the axis A. The second rack and pinion 84 can be connected to the outer bridge portion 88 by a strap 90 formed on the second rack and pinion 84, which is connected to the outer bridge portion 88 by one or more mechanical fasteners 92 and one or more clips 94. It should be appreciated that the second rack and pinion 84 can be coupled to the outer bridge portion 88 in any alternative suitable manner. The second rack and pinion 84 can include one or more flanged ends 96 that overlap the outer bridge portion 88. The first sheath 48 can also define a pair of intermediate sidewalls 98 that fit into the longitudinal space defined by the outer sidewalls 86 and allow relative sliding motion. The pair of intermediate sidewalls 98 can also extend along the open end of the first chamber 74. The first rack and pinion 82 can be attached to an outer surface of the second sheath 50 and positioned in the space between the intermediate sidewalls 98.

[0028] The first rack and pinion 82 can include two sequences of axially aligned rack teeth 100 along its longitudinal edges, separated by flat portions 102. The intermediate sidewalls 98 can extend to an intermediate bridge portion 104 that defines an inward protrusion 106 that extends along the axis between the rack teeth 100. It should be appreciated that the intermediate sidewalls 98 can be guided by the outer sidewalls 88, and the rack teeth 100 can be guided on opposite sides of the inward protrusion 106 to limit unwanted rotation between the components. Additionally, the first sheath 48 can include a channel 105, and the second sheath 50 can include a guide pin 107 that extends therefrom (see FIG. 6), which travels along the channel 105 during axial adjustment, during extension and retraction of the column assembly 44, to further limit unwanted rotation between the components. In some embodiments, the intermediate sidewalls 98 can include openings 99 for receiving opposite ends of the securing pin 80. Figure 2

[0029] In some embodiments, one or both of the first rack and pinion 82 and the second rack and pinion 84 can be further configured as energy-absorbing strips. Thus, upon receipt of a compressive force, the rack 78 can become rotationally locked, and one or both of the first rack and pinion 82 (e.g., the strap 90) and the second rack and pinion 84 are deformed by elongation or the like.

[0030] Reference is now made to Figure 4 and Figure 5 ​The gear 78 can include a pair of gears 78 positioned on opposite sides of the driven nut 108. The driven nut 108 can include a fixed pin 80 (e.g., a pair of pins) extending from opposite sides thereof, and can further include a bore 110 oriented substantially coaxially with the axis A. A lead screw 112 can extend between a floating end 114 and a fixed end 116 and through the bore 110 in the driven nut 108. In some embodiments, the floating end 114 is positioned between the medial side walls 98 and the fixed end 116 is positioned in a power unit 118 of the axial adjustment actuator 52. The power unit 118 can include a motor that rotates the lead screw 112. As shown in Figure 4 FIG. 8, the lead screw 112 can be configured as a lead screw and define helically arranged teeth that intermesh with helically arranged teeth in the bore 110 in the driven nut 108. The motor can rotate the lead screw 112 directly or can rotate the lead screw 112 through a gear arrangement (not shown). In operation, the power unit 118 rotates the lead screw 112, causing the driven nut 108 to move along the axis relative to the axis A, the axial travel of the driven nut 108 causing rotation of the gear 78 with the first gear rack 82 positioned on one side of the gear 78 and being pushed in one axial direction by the intermeshing teeth, and the second gear rack 84 positioned on the opposite side of the gear 78 and being pushed in the opposite axial direction by the intermeshing teeth.

[0031] Figures 6A to 6D A steering column assembly 44 is shown being adjusted between a fully deployed state Figure 6A and a stowed state Figure 6D . More specifically, Figure 6A the steering column assembly 44 is shown in a fully deployed state, Figure 6B the steering column assembly 44 is shown in a first retracted position, Figure 6C the steering column assembly 44 is shown in a second retracted position that is further retracted than the first retracted position, and Figure 6D the steering column assembly 44 is shown in a stowed or fully retracted position.

[0032] Figures 7A to 7C is another sequential illustration of a steering column assembly 44 being adjusted between a fully deployed state (as shown in Figure 4 ) and a stowed state Figure 7C . Figure 7B the steering column assembly 44 is shown in a first retracted position, Figure 7C the steering column assembly 44 is shown in a second retracted position that is further retracted than the first retracted position.

[0033] It should be appreciated that some arrangements of the steering column assembly 44 can include two or more actuators and / or three or more sheaths. These designs can increase the stow capability of a given packaging space compared to conventional steering columns. The steering column assembly 44 can increase the stow capability by having a shorter lead screw 112 compared to conventional telescoping mechanisms, which can be achieved for any vehicle. Additionally, the axial expansion of the steering column assembly 44 can also be increased due to the actuation causing both the first portion 48 and the second portion 50 to move in unison. In some embodiments, the teeth on the first rack gear 82 are sized differently than the rack teeth 100 on the second rack gear 84 such that actuation causes the first portion 48 to move at a first speed and the second portion 50 to move at a second speed that is different than the first speed. In some embodiments, the first speed is slower than the second speed. For example, actuation by the axial adjustment actuator 52 can cause the second sheath 50 to translate at about twice the speed of the first sheath 48. However, the relative tooth profiles of the first rack gear 82 and the second rack gear 84 can be tailored to achieve any desired relative speed ratio. Because the first portion 48 and the second portion 50 are both moved simultaneously rather than in separate steps, the steering column assembly 44 eliminates the transition period and associated noise. Additionally, because the teeth on the first rack gear 82 and the rack teeth 100 on the second rack gear 84 are always intermeshed, axial translation is locked unless actuated otherwise.

[0034] Although the axial adjustment actuator 52 is illustrated as being operatively coupled to the outer sheath 70 in the description herein and in the drawings, it should be appreciated that the axial adjustment actuator 52 can be mounted to a carrier or emulator housing (not shown) that is attached to the outer sheath 70. Thus, the axial adjustment actuator 52 can be mounted to an emulator housing, directly to the outer sheath 70, or indirectly to the outer sheath 70.

[0035] While the application has been described in detail herein in reference to only a limited number of embodiments, it should be understood that the application is not limited to these disclosures but rather encompasses any and all alternatives, modifications, variations, changes, and equivalents, which fall within the spirit and scope of the present application. Further, although various embodiments of the application have been described herein in terms of a number of embodiments, those skilled in the art will recognize that embodiments of the present application can be practiced with only some or all of the described features and functions, and equivalents thereof. Thus, the present application should not be limited to the embodiments described herein, but can be practiced with any number of variations as would be known to one skilled in the art.

Claims

1. A steering column assembly, comprising: A steering column that extends along a longitudinal axis between a first end and a second end; The steering column includes an outer sheath located at the first end, an intermediate sheath that is telescopically connected to the outer sheath and extends toward the second end, and an inner sheath that is telescopically connected to the intermediate sheath and further extends toward the second end. At least one axial adjustment actuator causes the intermediate sheath to move telescopically relative to the outer sheath; and The at least one axial adjustment actuator includes a first gear rack fixed to the outer sheath and a second gear rack fixed to the inner sheath, at least one gear is located between the first gear rack and the second gear rack, and the at least one gear engages with the first gear rack and the second gear rack in a tooth meshing manner, and the at least one gear is driven to cause the inner sheath to translate relative to the outer sheath. The axial adjustment actuator includes: motor; A lead screw, which can be driven in a rotary manner by the motor; A nut that is axially driven along the lead screw during rotation of the lead screw; The at least one gear is operatively coupled to the nut; the nut includes a pair of pins extending from opposite sides of the nut, each of the pair of pins being connected to the intermediate sheath.

2. The steering column assembly according to claim 1, wherein, The size of the multiple teeth on the second gear rack is designed such that the inner sheath translates at an inner sheath speed different from the speed of the intermediate sheath during translation.

3. The steering column assembly according to claim 2, wherein, The inner sheath moves faster than the middle sheath.

4. The steering column assembly according to claim 2, wherein, The speed of the inner sheath is twice the speed of the intermediate sheath.

5. The steering column assembly according to claim 1, wherein, The at least one gear includes a pair of gears, each of which is connected to the nut via a corresponding pin of the pair of pins.

6. The steering column assembly according to claim 1, wherein, The at least one gear is a pinion.

7. The steering column assembly according to claim 1, wherein, The at least one gear is a spur gear.

8. The steering column assembly according to claim 1, wherein, The intermediate sheath is provided with a channel, and the inner sheath includes a guide pin that travels along the channel during axial adjustment of the steering column assembly.

9. An axial adjustment actuator assembly for a steering column, the steering column having an outer sheath, an intermediate sheath, and an inner sheath, the axial adjustment actuator assembly comprising: motor; A lead screw, which can be driven in a rotary manner by the motor; A nut, which is axially driven along the lead screw during the rotation of the lead screw, and the nut is connected to the intermediate sleeve so that the intermediate sleeve translates axially at the intermediate sleeve speed; as well as A gear, which is operatively connected to the nut and engages with the inner sleeve and the outer sleeve, wherein the gear causes the inner sleeve to translate at an inner sleeve speed different from the speed of the intermediate sleeve. The nut includes a pair of pins extending from opposite sides of the nut, each of the pair of pins being connected to the intermediate sheath.

10. The axial adjustment actuator assembly according to claim 9, wherein, The gear engages with a first gear rack fixed to the outer sheath and a second gear rack fixed to the inner sheath. The gear engages with the first gear rack and the second gear rack in a tooth-meshing manner, and the gear is driven to cause the inner sheath to translate relative to the outer sheath.

11. The axial adjustment actuator assembly according to claim 9, wherein, The inner sheath moves faster than the middle sheath.

12. The axial adjustment actuator assembly according to claim 9, wherein, The speed of the inner sheath is twice the speed of the intermediate sheath.

13. The axial adjustment actuator assembly according to claim 9, wherein, The gear is a first gear, and the axial adjustment actuator assembly includes a second gear. Each of the first gear and the second gear is connected to the nut via a corresponding pin of the pair of pins.

14. The axial adjustment actuator assembly according to claim 9, wherein, The gear in question is a pinion.

15. The axial adjustment actuator assembly according to claim 9, wherein, The gear in question is a spur gear.

16. The axial adjustment actuator assembly according to claim 9, wherein, The intermediate sheath is provided with a channel, and the inner sheath includes a guide pin that travels along the channel during axial adjustment.

17. A steering column assembly, comprising: A steering column that extends along a longitudinal axis between a first end and a second end; The steering column includes an outer sheath located at the first end, an intermediate sheath that is telescopically connected to the outer sheath and extends toward the second end, and an inner sheath that is telescopically connected to the intermediate sheath and further extends toward the second end. as well as At least one axial adjustment actuator assembly, comprising: motor; A lead screw, which can be driven in a rotary manner by the motor; A nut, which is axially driven along the lead screw during rotation of the lead screw, is connected to the intermediate sleeve to cause the intermediate sleeve to translate axially at an intermediate sleeve velocity; and An axial speed control component is operatively connected to the nut and engages with the inner sleeve and the outer sleeve, wherein the axial speed control component causes the inner sleeve to translate at an inner sleeve speed different from the speed of the intermediate sleeve. The nut includes a pair of pins extending from opposite sides of the nut, each of the pair of pins being connected to the intermediate sheath.

18. The steering column assembly of claim 17, wherein, The axial speed control component is a pinion gear, which engages with a first gear rack fixed to the outer sheath and a second gear rack fixed to the inner sheath.

19. The steering column assembly of claim 17, wherein, The axial speed control component is a spur gear, and the axial speed control component engages with a first gear rack fixed to the outer sheath and a second gear rack fixed to the inner sheath.

20. The steering column assembly of claim 17, wherein, The inner sheath moves faster than the middle sheath.

21. The steering column assembly of claim 17, wherein, The intermediate sheath is provided with a channel, and the inner sheath includes a guide pin that travels along the channel during axial adjustment of the steering column assembly.

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