Energy absorption device

Abstract

A steering column includes a first jacket and a second jacket axially movable relative to the first jacket. The first jacket includes a hole. An energy absorbing device includes a strap body extending between a first end and a second end; and a curved portion located between the first end and the second end. The first end includes a first connector, and the second end includes a second connector selectively connected to the first connector via the hole in the first jacket.

Description

Technical Field

[0001] The following description relates to energy absorbing devices, and more particularly to energy absorbing devices for steering column assemblies. Background Art

[0002] Vehicles (such as cars, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles) include various steering system solutions, such as steer-by-wire and driver interface steering. These steering system solutions typically include a steering column assembly that converts steering input into an output that interacts with a steering linkage to ultimately steer the wheels. The steering column typically includes various safety features, such as air bags for reducing impact forces. In addition, many steering column assemblies are collapsible and include one or more energy absorbing features (such as energy absorbing strips) that allow for a certain amount of compression.

[0003] Some energy-absorbing straps are configured to roll up along their length to absorb energy, and are often referred to as roll straps. Typically, during an impact, the roll strap absorbs energy as the strap deforms, where the kinetic energy can be dissipated through compression of the steering column assembly. Key considerations when designing energy-absorbing straps include load requirements, tuneability, and packaging. The performance of an energy-absorbing strap during a collapse event is traditionally influenced by a number of factors, including material thickness / width, material properties, and / or strap shape or characteristics. While the performance of an energy-absorbing strap can be modified on a vehicle-by-vehicle basis by modifying these properties, packaging requirements often limit the changes that can be made, and meeting specific requirements at specific stages of the collapse cycle can be complex. For example, numerous parts are required to connect the translating upper sheath to the jackscrew nut, requiring multiple assembly steps. The lower sheath also typically requires a large gap to allow the strap to travel, which necessitates additional material to compensate for the loss of stiffness and strength. It is also often necessary to allow space for the tail of the strap to feed out unimpeded, thereby controlling the absorbed load, which further contributes to packaging difficulties.

[0004] Therefore, there remains a need for an operational framework that improves energy absorption characteristics to address packaging, load requirements, and scalability. Summary of the Invention

[0005] The features and technical advantages of the present invention have been summarized in a rather broad manner so that the specific embodiments of the present invention that follow may be better understood. Additional features and advantages of the present invention will be described below, which form the subject matter of the present invention for which protection is sought. It will be understood by those skilled in the art that the disclosed concepts and specific embodiments may be readily used as a basis for modifying or designing other embodiments to achieve the same purposes of the present invention. It will also be appreciated by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the present invention as set forth in the appended claims. This section provides a general overview of the present disclosure, which should not be construed as a complete and comprehensive enumeration of all objects, aspects, features, and advantages associated with the present disclosure.

[0006] One aspect of the present disclosure includes an energy absorbing device. The energy absorbing device includes a strap body extending between a first end and a second end. The strap body has a curved portion located between the first end and the second end. The first end includes a first connector, and the second end includes a second connector that selectively connects to the first connector.

[0007] Another aspect of the present disclosure includes a steering column. The steering column includes a first jacket and a second jacket that is axially movable relative to the first jacket. The first jacket includes an aperture. The energy absorbing device includes a strap body extending between a first end and a second end; and a curved portion located between the first end and the second end. The first end includes a first connector, and the second end includes a second connector that is selectively connected to the first connector via the aperture in the first jacket.

[0008] These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure will be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, according to common practice, the various features of the drawings are not drawn to scale. Instead, the sizes of the various features are arbitrarily expanded or reduced for clarity.

[0010] Figure 1 A vehicle incorporating a steering system according to the principles of the present disclosure is generally shown.

[0011] Figure 2 An energy absorbing device is generally shown including a first arrangement of strap bodies between first and second jackets of an axially adjustable steering column for dissipating kinetic energy.

[0012] Figure 3A The first arrangement of the strap body is generally shown in a connected position.

[0013] Figure 3B A second arrangement of the strap body is generally shown in a connected position.

[0014] Figure 3C A third arrangement of strap bodies is generally shown in a connected position.

[0015] Figure 4 The first arrangement of the strap body connected to the first sheath is generally shown.

[0016] Figure 5 A second sheath is generally shown including a window for providing access to the strap body.

[0017] Figure 6A and Figure 6B Various different embodiments of strap actuators for controlling actuation of a strap body are generally shown.

[0018] Figure 7 A strap actuator according to one embodiment is generally shown connected to a second sheath.

[0019] Figure 8 is a flow chart illustrating a method of attaching an energy absorbing device to a steering column. DETAILED DESCRIPTION

[0020] The following discussion is directed to various embodiments of the present disclosure. Although one or more of these embodiments may be described in greater detail than others, the disclosed embodiments should not be interpreted or otherwise used to limit the scope of the present disclosure, including the claims. Furthermore, those skilled in the art will appreciate that the following description has broad application and that the discussion of any embodiment is merely an example of that embodiment and does not limit the scope of the present disclosure, including the claims, to that embodiment.

[0021] As described above, vehicles (such as automobiles, trucks, sport utility vehicles, crossovers, minivans, boats, airplanes, all-terrain vehicles, recreational vehicles, or other suitable vehicles) include various steering system solutions, such as steer-by-wire and driver interface steering. These steering system solutions typically include a steering column assembly for converting steering inputs into outputs that interact with a steering linkage to ultimately steer the wheels of the vehicle. The steering column includes various safety features, such as air bags for reducing impact forces. In addition, many steering column assemblies are collapsible and include one or more energy absorbing features, such as energy absorbing straps, that allow for a certain amount of compression.

[0022] First refer to Figure 1, a vehicle 20 is generally shown according to the principles of the present disclosure. The 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. Although the vehicle 20 may be a passenger vehicle having wheels and used on roads, the principles of the present disclosure may be applied to other vehicles, such as airplanes, tractors, boats, or other suitable vehicles. The vehicle 20 may include a propulsion system 30, such as an ignition system, an electronic system, or a combination thereof.

[0023] 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 allows driver interface and autonomous steering. The steering system may include an input device 42, such as a steering wheel, wherein the driver can mechanically provide steering input by turning the steering wheel. The steering column assembly 44 may include a steering column 45, which 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 universal joint, a wire-controlled steering component, or any other feature that is traditionally located opposite the input device 42.

[0024] The steering column 45 can include at least two axially adjustable parts, for example, a first sleeve 48 and a second sleeve 50 that can be axially adjusted relative to each other. The first sleeve 48 can be an upper sleeve and the second sleeve 50 can be a lower sleeve, wherein the first sleeve 48 and the second sleeve 50 are allowed to move axially relative to each other during an impact or other compressive force. The axial movement can include sliding, telescoping, translation and other axial movements. The steering column assembly 44 can include additional parts that allow axial movement and brackets that provide tilt and pitch movement. More specifically, the steering column assembly 44 can include a powered actuator (not shown) wherein the axial adjustment is machine driven.

[0025] An energy absorbing device 52 may be located on one or each of the first sheath 48 , the second sheath 50 , any brackets, or a combination thereof and provide a variable stroke load absorbing arrangement. The energy absorbing device may dissipate kinetic energy between the first sheath 48 and the second sheath 50 .

[0026] 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, a recirculating ball steering gear, or any other type of steering gear associated with an autonomous driver interface steering system. The steering gear assembly 54 can, in turn, be connected to a drive shaft 58 via an output shaft 60. The output shaft 60 can include a steering rocker arm and a sector gear, or other conventional components. The output shaft 60 is operatively connected to the steering gear assembly 54 such that rotation of the steering gear input shaft 56 results in corresponding movement of the output shaft 60, causing the drive shaft to steer wheels 61.

[0027] Figure 2 An energy absorbing device 52 is shown. The energy absorbing device 52 can be connected to the first jacket 48 (upper jacket), the second jacket 50 (lower jacket), or a combination thereof. In some embodiments, the energy absorbing device 52 includes an energy absorbing roll-up strap body 64 that is at least partially coupled between the first jacket 48 and the second jacket 50. During a collapse event, a force "Fx" can cause the first jacket 48 or the second jacket 50 to move or collapse along the axis A, and the energy absorbing device 52 dissipates at least a portion of the kinetic energy of the collapsing first jacket 48 and the second jacket 50.

[0028] Continue to refer to Figure 2In some embodiments, the energy-absorbing roll-up strap body 64 can include a first end 66 and a second end 68 separated from the first end 66 by a middle portion 70. The middle portion 70 includes a curved portion 72 having a radius "R." The curved portion 72 can facilitate "rolling up" of the strap body 64 during a collapse event when the second end 68 moves in the direction of the force "Fx" and the first end 66 remains secured to the second jacket 50 via a series of teeth 80. The middle portion 70 can include an initial collapse or roll-up region 74 located between the curved portion 72 and a first flat portion 76, extending from the first flat portion 76 and the second flat portion 78. The initial collapse region 74 encapsulates the strap body 64 to one end of the first jacket 48 and provides a location for initiating roll-up or deformation, at which "rolling up" or deformation of a portion of the strap body 64 begins during a collapse event. The second flat portion 78 can extend between the middle portion 70 and the second end 68. The first flat portion 76 can define the series of teeth 80 extending therefrom toward the first end 66. The teeth 80 can be located in rows on opposite edges of the first flat portion 76. Each row of teeth 80 can include an end tooth closest to the first end 66 that is larger than the other teeth 80 to limit travel (e.g., to act as a hard stop). The strap body 64 defines a thickness "T". In some embodiments, the first end 66 defines a first connector and the second end 68 defines a second connector. For example, the first end 66 defines an opening 82 that includes a spring finger 84 that protrudes into the opening 82, and the second end 68 includes a tail portion 86 that is angled toward the opening 82.

[0029] As in Figure 3A and 3B As best shown in FIG. 6 , the spring finger 84 contacts the tail portion 86, retaining the tail portion 86 in the opening 82. The tail portion 86 can extend from the second end 68 at an angle toward the spring finger 84 to provide additional retention. In some embodiments, the tail portion 86 can include a serration 88 having at least one wedge surface 90 angled toward the spring finger 84 to prevent the tail portion 92 from disengaging from the opening 82. In some embodiments, the serration 88 can include at least one cam surface 92 on the opposite side of the wedge surface 90 that contacts the spring finger 84 and allows it to ratchet into secure engagement with the at least one wedge surface 90. Multiple serrations 88 can be spaced apart to compensate for various tolerances, thereby allowing for multiple configurations for different sheath sizes and configurations. The wedge surface 90 can extend from the tail portion 86 at a different angle than the cam surface 92. Thus, the spring fingers 84 can form a non-reverse-drivable ("no-reverse") connection with the tail portion 92 to prevent unintended disassembly. Figure 3A and Figure 3B In the arrangement of the absorption device 52 shown, there is no need for additional brackets or fasteners for assembly (eg, it is self-retaining). Figure 3C An alternative arrangement is shown in which the first end 66 defines a first connector and the second end 68 defines a second connector. For example, the first connector may include a first hole 71 and the second connector may include a second hole 73. After the first and second connectors are aligned, a fastener 75 may be positioned in the first hole 71, the second hole 73, and the first sheath 48.

[0030] Figures 3A to 3C The energy absorbing device 52 shown can be configured to be applied only within the collapsed distance of the first jacket 48, and the strap body 64 need not be fed into any void or cavity in the steering column. In addition, it should be understood that the tail portion 86 can be located at the first end 66 ( Figure 3A ) or the second end 68 ( Figure 3B ) on the opposite ends 66, 68, and the opening 82 and the spring finger 84 can be located on the opposite ends 66, 68.

[0031] Now refer to Figure 4 In some embodiments, the roll-up strap body 64 can be directly connected to the first sheath 48, which can be an upper inner sheath. The first sheath 48 can extend between a lower end 94 that is inserted into the second sheath 50 and an upper end 96 opposite the lower end 94. The lower end 94 can include a notch 98 that has a wedge shape and is sized to be inserted into the curved portion 72, and a hole 100 spaced between the lower end 94 and the upper end 96 for receiving the tail portion 86. The wedge-shaped notch 98 limits left-right movement while establishing the position of the strap body 64 along the axis A. Therefore, the roll-up strap body 64 can be connected only to the first sheath 48 without any fasteners. During assembly, the mandrel 102 with the back support 104 can be brought into the first sheath 48 until the tail portion 86 protrudes through the hole 100 and the curved portion 72 is located in the notch 98, after which the tail portion 86 can be inserted into the opening 82 and contacted with the spring fingers 84, where the tail portion can be engaged and locked. In some embodiments, the hole 100 defines a wedge shape, and the tail portion 86 defines a wedge shape. Therefore, when the tail portion 86 is inserted into the hole 100 and engaged or otherwise secured thereto, the tail portion 86 cinch into the hole 100 via the intersection of the wedge surfaces, and the curved portion 70 is seated in the notch 98. As the curved portion 70 is seated in the notch 98, the curved portion 70 is secured within the wedge shape of the notch 98. The wedge shape of the notch 98, the tail portion 86, and the hole 100 provide constraints and / or accommodate various tolerances.

[0032] Now refer to Figure 5 , the second sheath 50 is shown as a lower outer sheath that fits over the first sheath 48. In some embodiments, the second sheath 50 defines a window 106 that provides access to the strap body 64 and, more specifically, the teeth 80 formed thereon. The window 106 can be sized to expose only a small length of the strap body 64 and the width of the strap body to improve the strength of the second sheath 50. The second sheath 50 can also include a strap channel 108 raised from its outer surface to provide space for the strap body 64. The second sheath 50 can also include one or more protrusions 110 that extend around the window 106 for attachment to a strap actuator 112. The strap actuator 112 may include a series of teeth 114 that selectively engage the teeth 80 on the strap body 64 to lock the position of the steering column assembly 44 until the force Fx overcomes the connection between the tail portion 86 and the spring finger 84 (which causes the strap body 64 to "roll up" and dissipate the force Fx).

[0033] Figure 6A and Figure 6B Various embodiments of the strap actuator 112 are shown. Figure 6A , the strap actuator 112 may include a gear 116A defining helical teeth 114 driven by a motor 119. The operation of the motor 119 may be via a control system (not shown). Figure 6B In FIG. 1 , gear 116B comprises a sprocket configuration driven by a helical worm gear. Gears 116A and 116B may have other configurations and transmit force to teeth 80 on the strap body 64.

[0034] Figure 7 An embodiment is shown in which the gear 116 includes a helical structure. The gear 116 can be configured to rotate in response to travel of the first sheath 48, or can otherwise be driven by a motor 119 in response to a steering column actuator 120 that moves the first sheath 48 along the axis A relative to the second sheath 50.

[0035] Figure 8A flow chart of a method 200 for assembling and controlling a steering column assembly is shown. At step 202, method 200 includes providing at least one sheath configured to move axially relative to another portion. At step 204, method 200 includes providing a notch at one end of the sheath and a hole spaced apart from the end. At step 206, method 200 includes providing an energy absorbing device comprising a first end and a second end separated by a curved portion. At step 208, method 200 includes inserting one end of the energy absorbing device into a chamber defined by the sheath. For example, step 208 may include, at step 210, using a mandrel with a back support portion that compresses the curved portion. At step 212, method 200 includes aligning the first end and the second end of the energy absorbing device with the hole. Step 212 may further include, at step 214, positioning the curved portion into the notch. At step 216, the method includes connecting the first end and the second end of the energy absorbing device. For example, step 216 may include placing the tail portion of the energy absorbing strap described herein through the hole of the jacket into the opening of the energy absorbing strap described herein at step 218. Step 218 may include engaging the serrations on the tail portion with spring fingers in the opening at step 220.

[0036] Although the present invention has been described in detail in conjunction with only a limited number of embodiments, it will be readily understood that the present invention is not limited to these disclosed embodiments. Rather, the present invention may be modified to include any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described but commensurate with the concept and scope of the present invention. Additionally, although various embodiments of the present invention have been described, it will be understood that aspects of the present invention may include only some of the described embodiments. Furthermore, any features, elements, components, or advantages of any one embodiment may be used in any other embodiment. Therefore, the present invention should not be construed as being limited by the foregoing description.

Claims

1. An energy absorbing device for a steering column, comprising: a strip body extending between a first end and a second end; a curved portion located between the first end and the second end; as well as The first end includes a first connector, and the second end includes a second connector selectively connected to the first connector, wherein the first connector includes a tail portion, wherein the tail portion comprises at least one sawtooth portion snap-fitted to the second connector, Wherein, the second connector includes a spring finger portion selectively engaged with the at least one serrated portion.

2. The energy absorbing device according to claim 1, wherein: The at least one serration includes a plurality of serrations providing a variety of tolerances.

3. The energy absorbing device according to claim 1, wherein: The at least one serration includes a cam surface for engaging the spring finger and a wedge surface for capturing the spring finger.

4. The energy absorbing device according to claim 3, wherein: The cam surface extends at a first angle and the wedge surface extends at a second angle different from the first angle.

5. The energy absorbing device according to claim 1, wherein: The second connector further includes an opening for receiving the tail portion, and the spring finger extends into the opening.

6. The energy absorbing device according to claim 1, wherein: At least a portion of the strap body defines at least one row of teeth.

7. The energy absorbing device according to claim 6, wherein: The at least one row of teeth includes a plurality of teeth of a first size and at least one tooth of a second size, the at least one tooth of the second size being larger than the plurality of teeth of the first size.

8. The energy absorbing device according to claim 7, wherein: The plurality of teeth of the first size are located between the curved portion and the at least one tooth of the second size.

9. The energy absorbing device according to claim 1, wherein: The first connector includes a first hole and the second connector includes a second hole, and a fastener extends through the first hole and the second hole to connect the first end to the second end.

10. The energy absorbing device according to claim 1, wherein: The first connector includes a first hole and the second connector includes a second hole, and a fastener extends through the first and second holes and the hole in the first jacket of the steering column to connect the first end to the second end.

11. A steering column comprising: a first sheath and a second sheath, wherein the second sheath is axially movable relative to the first sheath; The first sheath includes an aperture; An energy absorbing device comprising a strap body extending between a first end and a second end; a curved portion located between the first end and the second end; and The first end includes a first connector and the second end includes a second connector that is selectively connected to the first connector through the hole in the first sheath, wherein the first connector includes a tail portion, wherein the tail portion comprises at least one sawtooth portion snap-fitted to the second connector, Wherein, the second connector includes a spring finger portion selectively engaged with the at least one serrated portion.

12. The steering column according to claim 11, wherein The first sheath includes a notch on a distal end thereof, the notch being wedge-shaped, and the bent portion being located within the notch.

13. The steering column according to claim 12, wherein: The first sheath defines a wedge-shaped aperture spaced from the slot.

14. The steering column according to claim 13, wherein: The tail portion defines a wedge shape for forming a wedge-shaped interface between the tail portion and the aperture in the first sheath.

15. The steering column according to claim 14, wherein The second connector includes an opening with the spring finger, which snaps into the at least one serration and draws the curved portion into the notch.

16. The steering column according to claim 11, wherein The first connector includes a first hole and the second connector includes a second hole, and a fastener extends through the first and second holes and the hole in the first jacket to connect the first end to the second end.

17. The steering column according to claim 11, wherein The second sheath includes a strap channel protruding from an outer surface thereof to provide space for the strap body.

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