Spring damper assembly for adjustable steering column

Abstract

A steering column having an energy absorbing assembly. The steering column includes a first jacket and a second jacket that is axially movable relative to the first jacket. The second jacket includes a window. The energy absorbing assembly includes a locking cam positioned within the window and connected to the second jacket; and a strap body connected to the first jacket. The locking cam includes a toothed portion that selectively engages the strap body. The energy absorbing assembly includes at least one of a buffer or a cam spring positioned between the locking cam and an edge of the window.

Description

Technical Field

[0001] The following description relates to energy absorbing devices, and more particularly to a damper and a cam spring for a locking cam in an adjustable steering column. 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 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 a certain amount of controlled compression.

[0003] Some energy-absorbing straps are configured to roll up along their length to absorb energy and are often referred to as roll-up straps. Typically, in the event of an impact, the roll-up strap absorbs energy as the strap deforms, where the kinetic energy can be dissipated through compression of the steering column assembly. These energy-absorbing straps include a series of teeth that mesh with a strap actuator. The strap actuator typically includes a locking cam or other device that can move between engagement and disengagement with the series of teeth. The energy-absorbing strap is typically located in a long channel extending through the lower jacket and retained therein by a complex series of non-integral reinforcement brackets and guides. The strap actuator is then connected to one of the reinforcement brackets, and the locking cam is biased by a small, complex linear cam spring. The long channel in the lower jacket allows the strap to travel, which requires additional material to compensate for the loss of stiffness and strength. It is also often necessary to leave space for the tail of the strap to be fed out unimpeded to control the absorbed load, which further creates 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 assembly comprising a locking cam including a toothed portion, a bumper having at least one ring, and a pivot pin connected to the locking cam and extending through the at least one ring.

[0007] Another aspect of the present disclosure includes an energy absorbing assembly comprising: a locking cam including a tail portion and a toothed portion; a cam spring operatively connected to the locking cam; and a pivot pin connected to the locking cam, the locking cam being biased in a pivot direction by the cam spring.

[0008] Another aspect of the present disclosure includes a steering column having an energy absorbing assembly. The steering column includes a first jacket and a second jacket that is axially movable relative to the first jacket. The second jacket includes a window. An energy absorbing device includes a locking cam positioned in the window and connected to the second jacket, and a strap body connected to the first jacket. The locking cam includes a toothed portion that selectively engages the strap body. The energy absorbing device includes at least one of a cam spring or a buffer positioned between the locking cam and an edge of the window.

[0009] These and other aspects of the present disclosure are disclosed in the following detailed description of the specific embodiments, the appended claims, and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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.

[0011] Figure 1 A vehicle with a steering system according to the principles of the present disclosure is generally shown.

[0012] Figure 2 A steering column is generally shown with an energy absorbing assembly for dissipating kinetic energy between a first jacket and a second jacket.

[0013] Figure 3 Overall, it shows Figure 2 Exploded view of the steering column in the .

[0014] Figure 4 An enlarged side view of the energy absorbing device is generally shown.

[0015] Figure 5 An enlarged top view of an energy-absorbing device located in a steering column is generally shown.

[0016] Figure 6 A side view of the energy absorbing device is generally shown in a hard stop position.

[0017] Figure 7A The locking cam of the energy absorbing device is generally shown in a locked position.

[0018] Figure 7B The locking cam of the energy absorbing device is generally shown in an unlocked position.

[0019] Figure 8A The locking cam of the energy absorbing device is generally shown to which the bumper is connected.

[0020] Figure 8B The energy absorbing device is generally shown with the buffer disconnected from its locking cam. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The steering column 45 may include at least two axially adjustable portions, for example, a first sleeve 48 and a second sleeve 50 that are axially adjustable relative to each other. The first sleeve 48 may be an upper sleeve and the second sleeve 50 may be a lower sleeve, wherein the first sleeve 48 and the second sleeve 50 are permitted to move axially relative to each other during an impact or other compressive force. The axial movement may include sliding, telescoping, translating, and other axial motions. The steering column assembly 44 may include additional portions that allow axial motion and brackets that provide rake and tilt motions. More specifically, the steering column assembly 44 may include a powered actuator (not shown) wherein the axial adjustment is machine driven.

[0026] The energy absorbing assembly 52 may be located on one or each of the first jacket 48 , the second jacket 50 , any bracket, or a combination thereof and may provide at least one of a variable travel load absorbing arrangement and a steering column locking function. The energy absorbing assembly may dissipate kinetic energy between the first jacket 48 and the second jacket 50 .

[0027] 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 then 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.

[0028] Figure 2 A steering column 45 is generally shown with an energy absorbing assembly 52 for dissipating kinetic energy between a first jacket 48 and a second jacket 50. The first jacket 48 and the second jacket 50 extend along an axis A. The energy absorbing assembly 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 assembly (energy absorbing device) 52 includes an energy absorbing roll-up strap body 64 that is at least partially coupled to the first jacket 48 and extends at least partially between the first jacket 48 and the second jacket 50. During a collapse event, a force "Fx" can cause the first jacket 48 to move or collapse into the second jacket 50 along the axis A, and the energy absorbing assembly 52 dissipates at least some of the kinetic energy of the collapsing first jacket 48 and the second jacket 50.

[0029] Continue to refer to Figure 2 , the energy absorbing assembly 52 may also 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 hinged into locking engagement with the strap body 64. In the unlocked position, the locking cam 68 is hinged so that it is spaced apart from the strap body 64. In some embodiments, the second sheath 50 includes a window 70 that positions at least a portion of the locking cam 68. Now referring to Figure 2 and Figure 3 The locking cam 68 includes a toothed portion 72, a tail portion 74, and a body 76 separating the toothed portion 72 from the tail portion 74. The body 76 defines an opening 78 for receiving a pivot pin 80. In some embodiments, the second sheath 50 includes a hole 82 for inserting the pivot pin 80 and pivotally connecting the locking cam 68 to the second sheath 50. The window 70 may also include a clamping groove 84 transverse to the axis A for clamping the first sheath 48 and the window 70.

[0030] Now refer to Figure 3 and Figure 4The energy absorbing roll-up strap body 64 may include a first end 86 and a second end 88 ( ) separated from the first end 86 by an intermediate portion 90. Figure 6 The first end 86 may be located on the outer surface of the first sheath 48, and the second end may be located on the inner surface of the first sheath 48 ( Figure 6 ). The middle portion 90 includes a curved portion 92. The curved portion 92 can help the strip body 64 "roll up" during a collapse event when the first end 86 or the second end 88 moves in the direction of the force "Fx". The middle portion 90 can include an initial collapse or rolling area 94 located between the curved portion 92 and a first flat portion 96. The first flat portion 96 extends from the first end 86 to the middle portion 90. The initial rolling area 94 represents the starting location for rolling up or deformation, at which the "rolling up" or deformation of the strip body 64 begins during a collapse event. The second flat portion 98 ( Figure 6 ) extends between the middle portion 90 and the second end 88.

[0031] The first flat portion 96 includes a series of teeth 100 extending therefrom. A pair of side walls 102 can extend along the first flat portion 96 on opposite sides of the teeth 100. Each side wall 102 can extend between a lower stop tab 104 and an upper stop tab 106. In use, the lower stop tab 104 can contact a portion of the energy absorbing actuator 66 and produce a hard stop in a first direction, and the upper stop tab 106 can contact a portion of the energy absorbing actuator 66 and produce a hard stop in a second direction. More specifically, the locking cam 68 includes a bumper 108. The bumper 108 includes a pair of rings 110 spaced apart from a bridging portion 112. The locking cam 68 includes a bumper groove 114 for retaining the bridging portion 112, the rings 110 are positioned on opposing surfaces of the locking cam 68, and the pivot pin 80 extends through each ring 110. The rings 110 are sized and spaced to contact the lower and upper stop tabs 104, 106 in the hard stop position. The second sheath 50 may also define a channel 111 sized to guide the lower and upper stop tabs 104, 106 in a direction along the axis A.

[0032] Reference Figure 4The energy absorbing actuator 66 includes a cam spring 116. The cam spring 116 includes a spring portion 120 and a housing 122. The spring portion 120 can be configured as a flat spring and includes a first leg 124 that abuts the rear surface of the locking cam 68 and extends between a first clip 126 and a bend 128. The spring portion 120 also includes a second leg 130 that extends from a second clip 132 to a bend 128. The second leg 130 abuts the inner surface of the window 70 and includes a spring retaining tab 134 that extends into a groove 136 of the second sheath 50. The first leg 124 and the second leg 130 are separated by the bend 128. The second clip 132 extends from the second leg 130 at a lateral angle to the outer surface of the second sheath 50. The first clamping portion 126 extends from the first leg portion 124 at a lateral angle over the exterior of the second sheath 50 and the second clamping portion 132 .

[0033] Figure 5 An enlarged top view of the energy absorbing device 52 positioned generally within the steering column 45 is shown. As shown, the toothed portion 72 is sized to fit between the sidewalls 102 and selectively engage the series of teeth 100 on the first flat portion 96. A ring 110 of a bumper 108 extends from the locking cam 68 into the opposing travel paths of the lower and upper stop tabs 104, 106. The bumper 108 may be formed of a resilient material so that contact therewith is relatively quiet. Figure 6 The energy absorbing device 52 is generally shown in a side view in a hard stop position, with the ring 110 engaged with the upper stop tab 106. As shown, the lower stop tab 104 and the upper stop tab 106 each include a bumper interface 138 that is rounded to interface with the rounded ring 110. The first sheath 48 may have a notch 144 at the end thereof that is sized to accommodate the width of the curved portion 92.

[0034] Figure 7AThe locking cam 68 is generally shown in the locked position. As shown, the tail portion 74 can be biased by the cam spring 116 in the pivoting direction toward the locked position. The first clamping portion 126 can extend to a clamping portion bend 146 so that the edges on the end of the first clamping portion 126 do not wear and scratch the outer surface of the second sheath 50. The housing portion 120 can be generally U-shaped and include a pair of wings 147 that extend around opposite sides of the first leg 124 and opposite sides of the second leg 130 to center the cam spring 116 on the end of the locking cam 68 facing the direction of the axis A. Each wing 147 can extend to a pin interface surface 148. Each pin interface surface 148 can be inserted into an annular groove 150 ( Figure 3 ). Each interface surface 148 can be rounded to match the contour of the annular groove 150. Each interface surface 148 can extend upward from the central axis of the pivot pin 80 and at least partially surround its upper surface. The cam spring 116 can thus bias the pivot pin 90 and the locking cam 68 in a first pivot direction (e.g., toward the locked position). Figure 7B The locking cam 68 is generally shown in an unlocked position, wherein the cam spring 116 (shown without the housing portion 120) is compressed by moving the first leg 124 toward the second leg 126 (e.g., by actuating the tail portion 74). More specifically, the first leg 124 is articulated relative to the bend 128, and the upper portion of the first leg 124 moves toward the second leg 130. During this movement of the locking cam 68 in the pivoting direction, the first clamping portion 126 moves from a first angle to a second angle that is closer to parallel to the axis A than the first angle. In the unlocked position, the first guard 48 can move along the axis A relative to the second guard 50.

[0035] Figure 8A The locking cam 68 with the bumper 108 connected thereto is generally shown separated from the other features of the energy absorbing device 52 . Figure 8B The locking cam 68 is generally shown separated from the other features of the energy absorbing device 52, with the bumper 108 disengaged therefrom. Figure 8B As best shown in FIG, the bumper slot 114 can be defined by a pair of prongs 152, and at least one of the prongs 152 can include a hook 154 that extends into the bumper slot 114. The bridge portion 112 can include at least one rib 156 for latching onto the at least one hook 154 to form a snap-fit engagement therewith. The bridge portion 112 can include a first profile 158 that mates with the bumper slot 114 and a second profile 160 that extends outwardly beyond the prongs 152.

[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 assembly for a steering column, comprising: a locking cam including a toothed portion; a buffer having at least one ring; as well as a pivot pin connected to the locking cam and extending through the at least one ring; Wherein, the locking cam includes a buffer groove, and the buffer includes a bridging portion extending into the buffer groove.

2. The energy absorbing assembly according to claim 1, wherein: The at least one ring includes a pair of rings located on opposite sides of the locking cam.

3. The energy absorbing assembly according to claim 1, wherein: The buffer groove is defined by at least one prong having a hook portion.

4. The energy absorbing assembly according to claim 3, wherein: The bridge portion includes at least one rib in locking engagement with the hook portion.

5. An energy absorbing assembly for a steering column, comprising: a locking cam comprising a tail portion and a toothed portion; a cam spring operatively connected to the tail portion; as well as a pivot pin connected to the locking cam, and the locking cam is biased in a pivoting direction by the cam spring; The cam spring includes: a first leg portion extending along the tail portion; and a second leg portion separated from the first leg portion by a bent portion; The first leg portion extends from the first clamping portion to the bent portion, and the first clamping portion extends from the first leg portion at a transverse angle thereto so as to contact a sheath provided on the steering column.

6. The energy absorbing assembly of claim 5, wherein: The second leg extends from the second clamping portion to the bent portion, and the second clamping portion extends from the second leg at a transverse angle thereto.

7. The energy absorbing assembly of claim 6, wherein: The cam spring includes a retaining tab connected to a provided sheath.

8. The energy absorbing assembly of claim 5, wherein: The first clamping portion includes a clamping portion bent portion for separating an edge of a distal end of the first clamping portion from the provided sheath.

9. The energy absorbing assembly of claim 5, wherein: The cam spring includes a housing extending to at least one pin interface surface.

10. The energy absorbing assembly of claim 9, wherein: The pivot pin includes at least one slot, and the at least one pin interface surface extends into the at least one slot.

11. The energy absorbing assembly of claim 9, wherein: The at least one pin interface surface comprises a pair of interface surfaces, and the at least one groove comprises a pair of grooves.

12. A steering column comprising: a first sheath and a second sheath, wherein the second sheath is axially movable relative to the first sheath; The second sheath includes a window; an energy absorbing device comprising: a locking cam located in the window and connected to the second sheath; and a strap body connected to the first sheath; The locking cam includes a toothed portion that selectively engages the strap body; and at least one of a cam spring or a buffer, wherein the cam spring is positioned between the locking cam and an edge of the window; wherein the strap body includes a lower stop tab and an upper stop tab, and wherein the energy absorbing device includes a bumper that contacts the lower stop tab and the upper stop tab; Wherein, the buffer includes a pair of rings located on opposite surfaces of the locking cam, and a pivot pin is connected to the locking cam and extends through the pair of rings.

13. The steering column according to claim 12, wherein: The bumper includes a bridge portion separating the rings, and the locking cam includes a bumper groove in which the bridge portion is located.

14. The steering column according to claim 12, wherein: The energy absorbing device includes a cam spring, and the cam spring includes a first leg extending along the locking cam; and a second leg spaced apart from the first leg by a bend and extending along an edge of the window.

15. The steering column according to claim 14, wherein The cam spring includes a pair of spring retention tabs, and the second sheath includes a slot connected to the retention tabs.

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