Non-machined integrated forming under sheet for a vehicle steering system

Abstract

The invention relates to a non-machined integrally formed lower jacket for a vehicle steering system. A steering column assembly according to the present disclosure includes a lower jacket formed of steel, wherein the lower jacket is unmachined. The steering column assembly also includes an upper jacket disposed within the lower jacket and adjustable in a retractable manner relative to the lower jacket.

Description

Non-machined integrally formed lower sleeve for vehicle steering systems

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 713,404, filed October 29, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The following description relates to a vehicle steering system, and more specifically to a non-machined, one-piece molded lower sleeve. Background Technology

[0004] Vehicles (such as cars, trucks, SUVs, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles) may include a variety of steering system types. Steer-by-wire and driver-interface steering are examples of available steering system types. These steering system schemes typically include a steering column assembly for translating steering inputs into outputs that interact with steering linkages to ultimately cause the vehicle's wheels to turn.

[0005] In electrically adjustable (i.e., telescopic and tilt) steering column assemblies, a die-cast and machined lower sleeve is utilized. The machining of the lower sleeve is necessary, primarily due to the draft angle required during casting. Some machining is performed to meet higher dimensional accuracy requirements for sleeve features. Specific machining interfaces include upper sleeve positioning features such as deep holes, tilt mechanism pivot axes, lower bearing housings, and column pivot axes. The aforementioned machining increases the cost of the original casting. Summary of the Invention

[0006] According to one aspect of this disclosure, a steering column assembly includes a lower sleeve formed of steel, wherein the lower sleeve is unmachined. The steering column assembly also includes an upper sleeve disposed within the lower sleeve and adjustable in a telescopic manner relative to the lower sleeve.

[0007] According to another aspect of this disclosure, a steering column assembly includes a lower sleeve formed of steel, wherein the lower sleeve is unmachined and is a single, integrally formed component, not composed of welded parts. The steering column assembly also includes an upper sleeve disposed within the lower sleeve and adjustable in a telescopic manner relative to the lower sleeve. The steering column assembly further includes a telescopic actuator mechanism. The steering column assembly also includes a tilt actuator adjustment mechanism.

[0008] To this end, this disclosure provides a steering column assembly including: a lower sleeve formed of steel, wherein the lower sleeve is unmachined; and an upper sleeve disposed within the lower sleeve and adjustable in a telescopic manner relative to the lower sleeve.

[0009] In one embodiment, the steering column assembly further includes an electrically adjustable mechanism for adjusting at least one of the upper and lower sheaths.

[0010] In one embodiment, the electrically adjustable mechanism includes a telescopic actuator mechanism.

[0011] In one embodiment, the steering column assembly further includes a tilt actuator adjustment mechanism.

[0012] In one embodiment, the lower sheath is a single integrally formed component, which is not composed of welded components.

[0013] In one embodiment, the steering column assembly further includes an energy-absorbing device operatively coupled to the upper sheath to absorb energy during contraction deformation.

[0014] In one embodiment, the lower sheath includes at least one molded upper sheath support pad as part of the single integrally molded component.

[0015] In one embodiment, the lower sheath includes at least one shaped lower pivot lug as part of the single integrally formed component.

[0016] In one embodiment, the lower sheath includes at least one molded lower bearing housing as part of the single integrally molded component.

[0017] In one embodiment, the lower sheath includes at least one punched tilting mechanism pivot feature as part of the single integrally formed component.

[0018] In one embodiment, the lower sheath includes at least one assembly anti-misalignment lug as part of the single integrally formed component.

[0019] In one embodiment, the lower sheath includes at least one actuator twist-lock attachment port as part of the single integrally formed component.

[0020] In one embodiment, the lower sheath includes at least one zipper-interlocking seam as part of the single integrally formed component.

[0021] In one embodiment, the lower sheath includes at least one support leg as part of the single integrally formed component.

[0022] This disclosure also provides a steering column assembly, comprising: a lower sleeve formed of steel, wherein the lower sleeve is unmachined, wherein the lower sleeve is a single integrally formed component not composed of welded parts; an upper sleeve disposed within the lower sleeve and adjustable in a telescopic manner relative to the lower sleeve; a telescopic actuator mechanism; and a tilt actuator adjustment mechanism.

[0023] These and other aspects of this disclosure are disclosed in the following detailed description of embodiments, the appended claims and the accompanying drawings. Attached Figure Description

[0024] This disclosure is best understood in conjunction with the accompanying drawings, based on the following description. It should be emphasized that, in accordance with conventional practice, the various features in the drawings are not necessarily drawn to scale. Instead, for clarity, the dimensions of the various features may be arbitrarily enlarged or reduced.

[0025] Figure 1 schematically illustrates a vehicle with a steering system.

[0026] Figure 2 is an exploded perspective view of the steering column assembly.

[0027] Figure 3 is a perspective view of the non-machined lower sheath.

[0028] Figure 4 is a front view of the end of the non-machined lower sheath. Detailed Implementation

[0029] Various embodiments of this disclosure will be discussed below. Although one or more of these embodiments may be described in more detail than others, the disclosed embodiments should not be construed as or otherwise used to limit the scope of this disclosure (including the claims). Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is merely illustrative of that embodiment and is not intended to imply that the scope of this disclosure (including the claims) is limited to that embodiment.

[0030] As described, vehicles (such as cars, trucks, SUVs, crossovers, minivans, boats, aircraft, all-terrain vehicles, motorhomes, or other suitable vehicles) include a variety of steering systems (e.g., steer-by-wire and driver-interface steering). These steering systems typically include a steering column assembly for converting steering inputs into outputs that interact with steering linkages to ultimately cause the vehicle's wheels to turn.

[0031] Referring first to Figure 1, a vehicle 20 is generally illustrated according to the principles of this disclosure. Vehicle 20 may include any suitable vehicle, such as a car, truck, sport utility vehicle, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. While vehicle 20 may be a wheeled passenger vehicle intended for use on roads, the principles of this disclosure can be applied to other vehicles, such as airplanes, tractors, boats, or other suitable vehicles. Vehicle 20 may include a propulsion system 30, such as an ignition system, electronic systems, or combinations thereof.

[0032] In some embodiments, the vehicle 20 may also include a steering system 40. The steering system 40 may be configured as a driver-interface steering system, an automatic driving system, or a system that allows both driver-interface and automatic steering. The steering system may include an input device 42 (such as a steering wheel) through which the driver mechanically provides steering input by turning the steering wheel. The steering column assembly 44 may include a steering column 45 extending along a longitudinal axis A 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, a steer-by-wire component, or any other feature conventionally positioned relative to the input device 42.

[0033] The steering column 45 may include at least two axially adjustable portions, such as an upper sleeve 48 and a lower sleeve 50 capable of axial adjustment relative to each other. The relative axial movement is described herein as telescoping movement, wherein the upper sleeve 48 telescops within the lower sleeve 50 over a range of axial dimensions from an extended column position to a retracted column position. The steering column assembly 44 may include additional portions providing rake and / or yaw movement.

[0034] Energy absorption device 52 is connected to upper sheath 48 to provide load absorption. During a collapse event, forces can cause upper sheath 48 to move or collapse along the longitudinal axis A of steering column 45, and energy absorption device 52 dissipates at least some of the kinetic energy of upper sheath (first sheath) 48 and lower sheath (second sheath) 50 during the collapse event.

[0035] The steering gear assembly 54 can be connected to the output assembly 46 via the steering gear input shaft 56. The steering gear assembly 54 can be configured as a rack and pinion type, a recirculating ball type steering gear, or any other type of steering gear associated with an automatic and driver-interface steering system. The steering gear assembly 54 can then be connected to the drive shaft 58 via the output shaft 60. The output shaft 60 is operatively connected to the steering gear assembly 54 such that rotation of the steering gear input shaft 56 causes a responsive movement of the output shaft 60 and causes the drive wheel axle to rotate the wheel 61.

[0036] Figure 2 shows an exploded view of the steering column assembly 44. In this view, the first sleeve 48 is shown removed from the second sleeve 50. During assembly, the first sleeve 48 is the upper sleeve that telescopically engages within the second sleeve 50, which is the lower sleeve. The steering shaft assembly 80 extends within both sleeves 48 and 50, with its first end 82 extending outward from the upper sleeve 48 to connect to the steering input device 42. The second end 84 of the steering shaft assembly 80 extends out of the lower sleeve 50 and is supported by the lower bearing assembly 86. The lower sleeve 50 is operatively coupled to a mounting bracket 90 for mounting the steering column assembly 44 to a vehicle structure.

[0037] A pair of actuator assemblies contribute to the electric adjustment of the steering column assembly 44, specifically the telescopic drive assembly 100 and the tilt actuator assembly 110.

[0038] The telescopic drive assembly 100 is a power actuator that actuates the telescopic movement of the upper sheath 48 relative to the lower sheath 50. The telescopic drive assembly 100 includes an electric actuator 102 (such as an electric motor) that drives the rotational movement of a threaded rod 104. A gearbox 106 facilitates the transmission of power from the output shaft (not shown) of the electric actuator 102 to the threaded rod 104. Rotation of the threaded rod 104 causes translation of a telescopic drive nut 108 threaded to the outer surface of the threaded rod 104. The translation of the telescopic drive nut 108 is generally parallel to the longitudinal axis of the steering column 45.

[0039] The tilting actuator assembly 110 is used to perform pivoting adjustments of the lower sheath 50. The energy absorption device 52 is operatively coupled to the upper sheath 48 to absorb energy during contraction deformation.

[0040] Referring now to Figures 3 and 4, the lower sheath 50 is a rolled steel sheath, and is formed without machining. The lower sheath 50 is a single, integrally formed component, which is not composed of welded parts to form the lower sheath 50. The lower sheath 50 includes several features formed thereon. For example, the steel sheath is provided with a formed upper sheath support pad 120, a formed lower pivot lug 122, a formed lower bearing seat 124, a punched tilting mechanism pivot feature 126, an assembly anti-misalignment lug 128, an actuator twist lock attachment hole, a zipper interlocking seam 130 for the steel wrapping layer, and a support leg 132 (Figure 3).

[0041] Existing electrically adjustable steering column lower sleeves are not made of steel and typically require machining to add specific functional features. The embodiments disclosed herein involve rolling a steel lower sleeve that requires no machining after forming. By avoiding welding or other joining processes, the disclosed embodiments advantageously reduce the cost and assembly complexity of the entire steering system while realizing the benefits of a steel sleeve.

[0042] In the embodiments disclosed herein, the lower sheath 50 is formed with a steel stamping that "encloses" the lower sheath. When combined with a backlash elimination mechanism, this helps to avoid any machining inside the sheath 50, thereby effectively eliminating any gaps between the upper sheath 48 and the lower sheath 50. The lower sheath 50 has contact pads stamped into its inner surface. The smaller contact area helps to minimize friction between the sheaths 48 and 50.

[0043] Furthermore, as described in detail above, multiple features are provided and formed in the lower sheath 50 without the need for multiple stamping and / or welding operations. All required design features are punched / stamped from a single sheet of steel, eliminating the need for welding additional stamped parts. The rigidity of the workpiece is enhanced by the zipper-interlocking seam.

[0044] Although the invention has been described in detail with reference to only a limited number of embodiments, it is readily understood that the invention is not limited to these disclosed embodiments. Rather, the invention can be modified to include any number of variations, alterations, substitutions, or equivalent arrangements not previously described but commensurate with the spirit and scope of the invention. Furthermore, while various embodiments of the invention have been described, it should be understood that aspects of the invention may include only some of the described embodiments. Moreover, any feature, element, component, or advantage of any embodiment can be used in any other embodiment. Therefore, the invention should not be considered as limited to the foregoing description.

Claims

1. A steering column assembly, comprising: A lower sheath, which is formed of steel, wherein the lower sheath is unmachined; and an upper sheath, which is disposed within the lower sheath and is adjustable in a telescopic manner relative to the lower sheath.

2. The steering column assembly according to claim 1, further comprising an electric adjustment mechanism for adjusting at least one of the upper sleeve and the lower sleeve.

3. The steering column assembly according to claim 2, wherein, The electric adjustment mechanism includes a telescopic actuator mechanism.

4. The steering column assembly according to claim 2 further includes a tilt actuator adjustment mechanism.

5. The steering column assembly according to claim 1, wherein, The lower sheath is a single, integrally formed component, which is not composed of welded parts.

6. The steering column assembly of claim 1 further includes an energy absorption device operatively coupled to the upper sheath to absorb energy during contraction deformation.

7. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one molded upper sheath support pad as part of the single integrally molded component.

8. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one shaped lower pivot lug as part of the single integrally formed component.

9. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one molded lower bearing housing as part of the single integral molded component.

10. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one punched tilting mechanism pivot feature as part of the single integrally formed component.

11. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one assembled anti-misalignment lug as part of the single integrally molded component.

12. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one actuator twist-lock attachment port as part of the single integrally formed component.

13. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one zipper-interlocking seam as part of the single integrally molded component.

14. The steering column assembly according to claim 5, wherein, The lower sheath includes at least one support leg as part of the single integrally molded component.

15. A steering column assembly, comprising: A lower sheath, formed of steel, wherein the lower sheath is unmachined, wherein the lower sheath is a single, integrally formed component not composed of welded parts; an upper sheath disposed within the lower sheath and adjustable in a telescopic manner relative to the lower sheath; a telescopic actuator mechanism; and a tilt actuator adjustment mechanism.

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