ENERGY-ABSORBING ASSEMBLY FOR AN ADJUSTABLE STEERING COLUMN

Abstract

Axially adjustable steering column (45), comprising: a first shell (48) and a second shell (50) axially movable with respect to the first shell (48); wherein the first shell (48) comprises at least one connector opening (114); an energy absorbing assembly (52) comprising a belt body (64A, 64B) connected to the first shell (48), wherein at least one connector (112) extends through the belt body (64A, 64B) and the at least one connector opening (114), wherein the at least one connector opening (114) has an ejection aperture (116) and a retaining slot (118), wherein the connector (112) comprises an upper head (122), a lower head (120) and a connector body (124), wherein the retaining slot (118) is dimensioned to prevent the lower head (120) from passing through it, wherein the connector body (124) is arranged in the retaining slot (118), wherein the first shell (48) extends from an upper end of the steering column (45) and the second shell (50) extends from a lower end of the steering column (45), characterized in that, the retaining slot (118) is oriented toward the lower end with respect to the ejection aperture (116), a ramp (126) extending into the ejection aperture (116) to guide the lower head (120) out of the connector opening (114) when the first shell (48) is compressed relative to the second shell (50) along an axis A.

Description

[0001] The invention relates to an axially adjustable steering column and an energy-absorbing assembly for an axially adjustable steering column.

[0002] The following description relates to energy absorbing devices, in particular to a locking cam and an energy absorbing belt in an adjustable steering column.

[0003] A vehicle, such as a car, truck, sport utility vehicle, crossover, mini-van, personal watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable vehicle, includes various steering systems, such as steer-by-wire and driver interface steering. These steering system schemes typically include a steering column assembly for translating a steering input into an output, which cooperates with a steering linkage to ultimately cause the vehicle's wheels to turn. Regardless of the steering scheme, steering column assemblies include various safety features, such as airbags, to reduce crash forces. Additionally, many steering column assemblies include one or more energy absorption features, such as energy-absorbing belts, that allow some degree of controlled compression.

[0004] Some energy-absorbing belts are designed to unwind along their length to absorb energy and are often referred to as retractable belts. Typically, retractable belts absorb energy during the deformation of the belt during an impact event, with kinetic energy dissipated by compressing the steering column assembly. When designing an energy-absorbing belt, some basic considerations include loading requirements, tunability, and packing. The performance of the energy-absorbing belt during a collapse event has traditionally been influenced by many factors, including material thickness / width, material properties, and / or shapes or parts of the belt.The performance of the energy absorption belt can therefore be modified for a specific vehicle by altering these properties. However, packaging requirements often limit the changes that can be made and can become quite complex when meeting specific requirements during certain phases of the collapse cycle. For example, the lower shroud often also needs to have large gaps to allow belt travel, requiring additional material to compensate for the loss of stiffness and strength. Often, space must also be created to allow one end of the belt to exit freely to control the absorption load, leading to further packaging difficulties.

[0005] Accordingly, there is a continuing need to improve the functionality of energy absorption features to improve packing, loading requirements, and tunability.

[0006] US 2021 / 0 316 779 A1 discloses a steering column according to the preamble of claim 1. US 2016 / 0 244 015 A1 discloses a similar steering column. DE 10 2019 219 112 A1 discloses an energy-absorbing assembly according to the preamble of claim 8. US 9 834 246 B1 discloses a similar assembly.

[0007] It is an object of the invention to provide a steering column and an energy absorbing assembly having improved design, robustness and tunability.

[0008] This object is achieved according to the invention by the features of the independent claims. Advantageous further developments are defined in the subclaims.

[0009] The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, unless otherwise indicated herein, the various aspects of the drawings are not to scale. Rather, the dimensions of the various aspects are arbitrarily expanded or reduced for clarity. Fig. 1 generally illustrates a vehicle having a steering system according to the principles of the present disclosure. Fig. 2 generally represents a steering column having an energy absorbing assembly for dissipating kinetic energy between a first shell and a second shell. Fig. Figure 3 generally represents a disassembled view of the steering column of Fig. 2 with a belt body according to a first arrangement. Fig. Figure 4 generally illustrates an enlarged side view of the energy absorbing device with the belt body according to the first arrangement. Fig. Figure 5 generally illustrates a side view of the energy absorbing device with a belt body according to a second arrangement.

[0010] The following discussion is directed to various embodiments of the disclosure. Although one or more of these embodiments are described in greater detail than others, the disclosed embodiments should not be interpreted or otherwise used as limiting the scope of the disclosure, including the claims. Moreover, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is only exemplary of that embodiment and is not intended to imply that the scope of the disclosure, including the claims, is limited to that embodiment.

[0011] A vehicle, such as a passenger car, truck, sport utility vehicle, crossover, minivan, personal watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable vehicle, includes various steering system schemes, such as steer-by-wire and driver interface steering, as described. These steering system schemes typically include a steering column assembly for translating a steering input into an output, which cooperates with a steering linkage to ultimately cause the vehicle's wheels to turn. Regardless of the type of steering scheme, steering column assemblies include various safety features, such as airbags, to reduce crash forces. In addition, many steering column assemblies are designed to collapse and include one or more energy absorption features, such as energy-absorbing belts that allow for some degree of compression.

[0012] First, Fig. 1, a vehicle 20 is generally illustrated in accordance with the principles of the present disclosure. The vehicle 20 may include any suitable vehicle, such as a car, a truck, a sport utility vehicle, a minivan, a crossover, another passenger vehicle, a suitable commercial vehicle, or any other suitable vehicle. While the vehicle 20 may be a wheeled passenger vehicle intended for over-the-road travel, the principles of the present disclosure may also apply to other vehicles, such as aircraft, tractors, boats, or other suitable vehicles. The vehicle 20 may include a propulsion system 30, such as an ignition system, an electronic system, or combinations thereof.

[0013] In some embodiments, the vehicle 20 may further include 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 enables both a driver interface and autonomous steering. The steering system may include an input device 42, such as a steering wheel, wherein a driver can mechanically provide steering input by turning the steering wheel. A steering column assembly 44 may include a steering column 45 extending 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 universal joint, steer-by-wire components, or any other parts typically disposed opposite the input device 42.

[0014] The steering column 45 may include at least two axially adjustable sections, e.g., a first shell 48 and a second shell 50, which are axially adjustable relative to each other. The first shell 48 may be an upper shell and the second shell 50 may be a lower shell, wherein the first shell 48 and the second shell 50 may move axially relative to each other upon impact or other compressive forces. The axial movement may include sliding, telescoping, translational, and other axial movements. The steering column assembly 44 may include additional sections that allow axial movement, as well as brackets that provide tilt and pitch movement. In particular, the steering column assembly 44 may include a powered actuator (not shown) in which the axial adjustments are machine-driven.

[0015] An energy-absorbing assembly 52 may be attached to one or each of the first shell 48, the second shell 50, any brackets, or combinations thereof, and may provide at least one of the functions of variable lift load absorption settings and steering column locking. The energy-absorbing assembly may dissipate kinetic energy between the first shell 48 and the second shell 50.

[0016] A steering gear assembly 54 may be connected 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 steering system, or other types of steering gears associated with autonomous and driver interface steering systems. The steering gear assembly 54 may then be connected to a drive axle 58 via an output shaft 60. The output shaft 60 may include a pitman arm and a sector gear or other conventional components. The output shaft 60 is connected to the steering gear assembly 54 such that rotation of the steering gear input shaft 56 causes a reactive movement of the output shaft 60, causing the drive axle to turn the wheels 61.

[0017] Fig. 2 generally illustrates a steering column 45 having the energy absorbing assembly 52 for dissipating kinetic energy between a first shell 48 and a second shell 50. The first shell 48 and the second shell 50 extend along an axis A. The energy absorbing assembly 52 may be coupled to the first shell 48 (upper shell), the second shell 50 (lower shell), or a combination thereof. In some embodiments, the energy absorbing assembly 52 includes an energy absorbing retractable belt body 64 at least partially coupled to the first shell 48 and extending at least partially between the first shell 48 and the second shell 50.During a collapse event, a force “Fx” may move or collapse the first shell 48 into the second shell 50 along axis A, and the energy absorbing assembly 52 dissipates at least a portion of the kinetic energy of the collapsing first shell 48 and the second shell 50.

[0018] With further reference to Fig. 2, the energy-absorbing assembly 52 may further include an energy-absorbing actuator 66. The energy-absorbing actuator 66 includes a locking cam 68 that moves between a locked position and an unlocked position. In the locked position, the locking cam 68 is pivoted into locked engagement with the belt body 64. In the unlocked position, the locking cam 68 is pivoted to be spaced from the belt body 64. In some embodiments, the second shell 50 includes a window 70 that locates at least a portion of the locking cam 68. The locking cam 68 includes a toothed portion 72, a rear end portion 74, and a body 76 that spaces the toothed portion 72 from the rear end portion 74. The body 76 defines an opening 78 for receiving a pivot pin 80.In some embodiments, the second shell 50 includes an opening 82 for inserting the pivot pin 80 and pivotally connecting the locking cam 68 to the second shell 50. The window 70 may also include a clamping slot 84 extending transversely to the axis A for clamping the first shell 48 and the window 70.

[0019] Now, with reference to the Fig. 3 and Fig. 4, the energy-absorbing retractable belt body 64A is illustrated according to a first arrangement. The belt body 64A may include a first end 86A and a second end 88A spaced from the first end 86A by an intermediate portion 90A. The first end 86A may be disposed on an outer surface of the first shell 48, and the second end 88A may be disposed on an inner surface of the first shell 48 ( Fig. 4). The intermediate section 90A includes a curved section 92A. The curved section 92A can facilitate the "unrolling" of the belt body 64A during a collapse event because the first end 86A is held stationary and the second end 88A moves in the direction of the force 'Fx' ( Fig. 2). The intermediate section 90A may include an initial collapse or unroll region 94A disposed between the first segment 96A and a second segment 98A. The first segment 96A may extend from the first end 86A to the intermediate section 90A. The initial unroll region 94 represents the point of initiation of unrolling or deformation of the belt body 64 during a collapse event. The second segment 98A may extend between the intermediate section 90A and the second end 88A.

[0020] The first segment 96A includes a series of teeth 100A extending therefrom. A pair of sidewalls 102A may extend along the first portion 96A on opposite sides of the teeth 100A. Each sidewall 102A may extend between a lower stop tab 104A and an upper stop tab 106A. In use, the lower stop tab 104A may contact a portion of the energy-absorbing actuator 66 (e.g., the pivot pin 80) and create a hard stop in a first direction, and the upper stop tab 106A may contact a portion of the energy-absorbing actuator 66 and create a hard stop in a second direction.

[0021] With further reference to Fig. 3 and Fig. 4, the first segment 96A may include at least one upper aperture 108A (e.g., a pair of upper apertures 108A). The pair of upper apertures 108A may be spaced apart by the teeth 100A. In some embodiments, the second segment 98A may include at least one lower aperture 110A aligned with at least one of the upper apertures 108A. A connector 112 may be disposed through each of the upper apertures 108A. In some embodiments, the connectors 112 may include rivets, and during assembly, a rivet may be driven through at least one of the upper apertures 108A and at least one of the lower apertures 110A before a rivet backing (not shown) is deformed between the at least one upper aperture 108A and the at least one lower aperture 110A. The locking cam 68 moves between a locked and an unlocked position. In the locked position ( Fig. 4) The locking cam 68 is pivoted into locked engagement with the teeth 100A on the belt body 64A. In the unlocked position, the locking cam 68 is pivoted so that it is spaced from the teeth 100A on the belt body 64A.

[0022] The first shell 48 may include at least one connector opening 114 (e.g., a pair of connector openings 114). Each connector opening 114 may include an ejection aperture 116 and a retention slot 118. The retention slot 118 may be disposed on the first shell 48 and extend toward the second shell 50, and the ejection aperture 116 may be congruent with and extend from the retention slot 118 (e.g., toward an end of the first shell 48 opposite the second shell 50). During assembly, a connector 112 may be inserted through the belt body 64A and into each of the connector openings 114 (e.g., the retention slot 118). As shown in Fig. 4, the connectors 112 include a lower head 120 and an upper head 122 spaced from the lower head 120 by a connector body 124 having a smaller cross-section than the lower head 120 and the upper head 122. When inserted into the retention slot 118A, the connector body 124 is locked against radial and orbital movement with respect to the axis A and is locked against axial movement along the axis A toward the second shell 50.

[0023] The first shell 48 may further include a ramp 126 extending into each of the ejection apertures 116. Each ramp 126 may be integrally connected to the shell 48 (e.g., stamped or otherwise formed therefrom) and may include a half-shell shape ( Fig. 3). In other arrangements, each ramp 126 may be planar or differently shaped. During use, the ramp 126 may guide the lower head 120 out of the connector opening 114 when the first shell 48 is compressed relative to the second shell 50 along the axis A. In some embodiments, a first segment 96A may extend along the axis A from the intermediate portion 90A a first distance, and a second segment 98A may extend from the intermediate portion 90A a second distance that is less than the first. In some embodiments, a second end 88A may terminate before the upper aperture 108A. In some embodiments, the second end 88A may extend the same distance as the first end 86A and include a second lower aperture (not shown).

[0024] The first shell 48 may also include a terminal end that engages the curved portion 92. In particular, the terminal end may be oriented toward the second shell 50 and form a notch 128 sized to accommodate a width of the curved portion 92. As shown in Fig. 4, the second segment 98A of the belt body 64A may define a curved portion 130A extending toward the first segment 96A. The curved portion 130A may be at least partially disposed between first and second ramps 126 spaced apart along the axis A.

[0025] In Fig.5, the belt body 64B is illustrated according to a second arrangement. The belt body 64B may have all of the same aspects, constructions, and materials as described in the first arrangement. However, the belt body 64B may include a modified connection to the first shell 48. In particular, the belt body 64B may include a single upper aperture 108B. The upper aperture 108B may be located proximate a first end 64B. A connector 112 (e.g., a rivet) may extend through the upper aperture 108B and into a connector opening 114, as previously described. In some embodiments, a first segment 96B may extend along axis A from the intermediate portion 90B a first distance, and a second segment 98B may extend from the intermediate portion 90B a second distance that is less than the first.In some embodiments, a second end 88B may terminate before the upper aperture 108B.

Claims

[1] Axially adjustable steering column (45), comprising: a first shell (48) and a second shell (50) axially movable with respect to the first shell (48); wherein the first shell (48) comprises at least one connector opening (114); an energy absorbing assembly (52) comprising a belt body (64A, 64B) connected to the first shell (48), wherein at least one connector (112) extends through the belt body (64A, 64B) and the at least one connector opening (114), wherein the at least one connector opening (114) has an ejection aperture (116) and a retaining slot (118), wherein the connector (112) comprises an upper head (122), a lower head (120) and a connector body (124), wherein the retaining slot (118) is dimensioned to prevent the lower head (120) from passing through it, wherein the connector body (124) is arranged in the retaining slot (118), wherein the first shell (48) extends from an upper end of the steering column (45) and the second shell (50) extends from a lower end of the steering column (45), characterized by , that, the retaining slot (118) is oriented toward the lower end with respect to the ejection aperture (116), a ramp (126) extending into the ejection aperture (116) to guide the lower head (120) out of the connector opening (114) when the first shell (48) is compressed relative to the second shell (50) along an axis A. [2] The steering column (45) of claim 1, wherein the ramp (126) extends from an outer surface of the first shell (48) and into the ejection aperture (116) toward the retaining slot (118). [3] Steering column (45) according to claim 2, wherein the ramp (126) is half-shell-shaped. [4] Steering column (45) according to claim 1, wherein the at least one connector (112) comprises a rivet. [5] The steering column (45) of claim 1, wherein the at least one connector opening (114) comprises a pair of connector openings (114) with ejection apertures (116) and the at least one connector (112) comprises a pair of connectors (112). [6] The steering column (45) of claim 1, wherein the second shell (50) includes a window (70) and the energy absorbing assembly (52) includes a locking cam (68) at least partially disposed within the window (70) and connected to the second shell (50). [7] Steering column (45) according to claim 6, wherein the locking cam (68) comprises a toothed portion (72) for selective engagement with the belt body (64). [8] Energy absorbing assembly (52) for an axially adjustable steering column (45), the energy absorbing assembly (52) comprising: a belt body (64) extending between a first end (86A) configured to be disposed on an outer side of a first shell (48) and a second end (88A) configured to be disposed on an inner side of the first shell (48); a curved portion (92) disposed between the first end (86A) and the second end (88A); wherein a first segment (96A, 96B) extends between the curved portion (92) and the first end (86A) and a second segment (98A, 98B) extends between the curved portion (92) and the second end (88A); wherein the first segment (96A, 96B) comprises at least one upper aperture (108A, 108B) for receiving a connector (112) to connect the first segment (96A, 96B) to the outside of the first shell (48), characterized by , that the connector (112) is disposed in the upper aperture (108A, 108B) and is configured to be ejected from an opening (78) having a ramp (126) in the first shell (48) to release the connection therewith. [9] The energy absorbing assembly (52) of claim 8, wherein the second segment (98A, 98B) includes a lower aperture (110A) for receiving a rivet backing prior to deformation thereof. [10] The energy absorbing assembly (52) of claim 8, wherein the first segment (96A, 96B) defines a plurality of teeth (100A). [11] The energy absorbing assembly (52) of claim 10, wherein the at least one upper aperture (108A, 108B) comprises a pair of upper apertures (108A, 108B), each upper aperture (108A, 108B) being disposed on an opposite side of the teeth (100A). [12] The energy absorbing assembly (52) of claim 8, wherein the second segment (98A, 98B) includes a bent portion (130A) extending toward the first segment (96A, 96B).

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