Lower control arm

Abstract

A lower control arm includes a body including a body portion and an arm extending from the body portion; and a sleeve having a tubular shape. The arm includes an end portion spaced apart from the body portion; a top surface; and a bottom surface opposite the top surface. The sleeve is fixed to the end portion. The sleeve includes a longitudinally extending slit disposed closer to one of the top surface and the bottom surface than a middle portion of the end portion.

Description

Technical Field

[0001] The present invention relates generally to vehicle suspension systems, and more particularly, to a lower control arm for a vehicle suspension system. Background Art

[0002] A vehicle generally includes a suspension system. The suspension system of the vehicle is coupled to the vehicle frame and each wheel assembly. The suspension system absorbs and dampens shock and vibration from the wheel assembly to the vehicle frame. For each wheel assembly, the suspension system may include an upper control arm, a lower control arm, a coil spring, and a shock absorber. The shock absorber extends through the coil spring. One end of the shock absorber and the coil spring may be connected to the lower control arm, and the other end of the shock absorber and the coil spring may be connected to the upper control arm or the vehicle frame.

[0003] The suspension system is arranged so that upward movement of the wheel assembly, such as when a tire hits a bump while the vehicle is in motion, compresses the coil spring and the shock absorber. The coil spring may apply a force that is a function of the difference between the current length of the coil spring and the relaxed length of the coil spring, such as a linear relationship. The shock absorber may apply a force that is a function of the compression or extension speed of the shock absorber. Summary of the invention

[0004] The lower control arm includes a body including a body portion and an arm extending from the body portion; and a sleeve having a tubular shape. The arm includes an end portion spaced apart from the body portion; a top surface; and a bottom surface opposite the top surface. The sleeve is fixed to the end portion. The sleeve includes a longitudinally extending slit disposed closer to one of the top surface and the bottom surface than a middle portion of the end portion.

[0005] The sleeve may be welded to the end.

[0006] The arm may be a first arm, and the body may include a second arm extending from the body portion. The end may be a first end, the top surface may be a first top surface, the bottom surface may be a first bottom surface, and the second arm may include a second end spaced apart from the body portion. The lower control arm may include a second top surface and a second bottom surface, the second top surface and the second bottom surface being spaced apart from each other and fixed relative to the second end; and a second arcuate surface extending from the second top surface to the second bottom surface. The sleeve may be a first sleeve, and the lower control arm may include a second sleeve, the second sleeve having a tubular shape and fixed to the second end. The slit may be a first slit, and the second sleeve may include a second slit extending longitudinally, the second slit being disposed closer to a middle portion of the second end than either of the second top surface and the second bottom surface.

[0007] The first arm may be positioned relative to the second arm in a vehicle forward direction.

[0008] The lower control arm may include a brace extending from a first arm to a second arm.

[0009] The lower control arm may include an upper lip extending from the end to the upper edge; and a lower lip extending from the end to the lower edge. The slit may be spaced apart from the upper lip and the lower lip. The upper lip, the end, and the lower lip may define an arcuate surface extending from the upper edge to the lower edge. The arcuate surface may be shaped to mate with the sleeve.

[0010] The slits may be positioned adjacent to the ends.

[0011] The body may include an upper body and a lower body connected along a seam, and the seam may extend along the body portion and may extend longitudinally along the arm to the end. The seam may extend substantially to the middle of the end.

[0012] The sleeve may comprise two sleeve ends and a sleeve wall having a constant cross section, the sleeve wall extending from one of the sleeve ends to the other of the sleeve ends. The slit may extend from one of the sleeve ends to the other of the sleeve ends. The slit may extend through the sleeve wall. The sleeve wall may have a circular cross section.

[0013] The slits may have a non-linear shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a perspective view of the vehicle.

[0015] Figure 2 is a perspective view of a portion of a vehicle with the body and wheels omitted for illustration purposes.

[0016] Figure 3 is a perspective view of the vehicle's suspension system.

[0017] Figure 4 A perspective view of a portion of a vehicle's frame and suspension system.

[0018] Figure 5 is a perspective view of the lower control arm of the suspension system.

[0019] Figure 6 is a perspective view of a portion of a lower control arm.

[0020] Figure 7 is a perspective view of the bushing for the lower control arm.

[0021] Figure 8 is a side view of a portion of a lower control arm.

[0022] Fig. 9 is a bottom view of the vehicle. DETAILED DESCRIPTION

[0023] The lower control arm 56 described herein can reduce the energy entering the passenger compartment 38 of the vehicle 30 from a frontal collision and / or the intrusion of the frontal collision into the passenger compartment 38. Reducing the intrusion and / or energy entering the passenger compartment 38 during a collision can reduce injuries to occupants in the passenger compartment. The lower control arm 56 can be disengaged during a frontal collision; therefore, less energy is transferred rearwardly via the lower control arm 56, and more of the front end of the vehicle 30 effectively acts as a crumple zone, thereby absorbing more energy from the collision.

[0024] refer to Figure 1 , Figure 2 and Fig. 9 , the vehicle 30 may include a body 32 and a frame 34. The vehicle 30 may be a unibody structure, in which the frame 34 and the body 32 are a single component. The vehicle 30 may alternatively be a body-on-frame split structure, in which the frame 34 supports the body 32, which is a separate component from the frame 34. The frame 34 and the body 32 may be formed of any suitable material, such as steel, aluminum, etc. The frame 34 may include two frame rails 36 extending longitudinally relative to the vehicle 30. The vehicle 30 includes a passenger compartment 38 within the frame 34, and the passenger compartment 38 is as shown in Fig. 9 The bottom plate 40 is shown from below.

[0025] The vehicle 30 includes four wheel assemblies 42. Each wheel assembly 42 includes a wheel 44; a tire 46 extending circumferentially around the wheel 44; a rotor 48 to which the wheel 44 is attached (e.g., bolted); and a knuckle 50. The knuckle 50 extends generally vertically from the center of the rotor 48. The rotor 48 is rotatably coupled to the knuckle 50. The rotor 48, the wheel 44, and the tire 46 can rotate together relative to the knuckle 50.

[0026] refer to Figures 2 to 4 , the vehicle 30 includes a suspension system 52. The suspension system 52 is coupled to the frame 34 and the wheel assembly 42. The suspension system 52 absorbs and dampens shock and vibration from the wheel assembly 42 to the frame 34. For each wheel assembly 42, the suspension system 52 includes an upper control arm 54, a lower control arm 56, a coil spring 58, and a shock absorber 60. The coil spring 58 has a spiral shape. The shock absorber 60 extends through the center of the spiral shape of the coil spring 58. One end of the shock absorber 60 and the coil spring 58 may be connected to the lower control arm 56, and the other end of the shock absorber 60 and the coil spring 58 may be connected to the upper control arm 54 or the frame 34.

[0027] The suspension system 52 is arranged so that upward movement of the wheel assembly 42, such as when the tire 46 hits a bump while the vehicle 30 is in motion, compresses the coil spring 58 and the shock absorber 60. The coil spring 58 may apply a force that is a function of the difference between the current length of the coil spring 58 and the relaxed length of the coil spring 58, such as a linear relationship. The shock absorber 60 may apply a force that is a function of the compression or extension speed of the shock absorber 60.

[0028] The upper control arm 54 extends from the frame 34 to the steering knuckle 50. The upper control arm 54 can be rotatably attached to the frame 34 and rotatably attached to the steering knuckle 50. The upper control arm 54 can have a wishbone shape, and the upper control arm 54 can extend from the UCA steering knuckle connection 62 to two UCA frame connections 64. The UCA steering knuckle connection 62 can connect the steering knuckle 50 and the upper control arm 54. The UCA steering knuckle connection 62 can have multiple degrees of freedom, such as a ball joint with three rotational degrees of freedom. The UCA frame connections 64 can each have a single rotational degree of freedom around a common axis A. The axis A can extend in a general vehicle forward direction.

[0029] refer to Figures 2 to 5 , a lower control arm 56 may be disposed below the upper control arm 54. The lower control arm 56 extends from the frame 34, such as the frame rail 36, to the steering knuckle 50. The lower control arm 56 may be rotatably attached to the frame 34 and rotatably attached to the steering knuckle 50. The lower control arm 56 may be rotatably connected to the frame 34 at an axis B and have a single rotational degree of freedom about the axis B. The axis B may extend in a generally vehicle forward direction, and the axis B may be parallel to the axis A. The lower control arm 56 may be rotatably connected to the steering knuckle 50 via an LCA knuckle connection 66, which may have multiple degrees of freedom, such as a ball joint having three rotational degrees of freedom.

[0030] refer to Figure 5 , the lower control arm 56 can have a body 68 having a wishbone shape. The body 68 includes a body portion 70; a first arm 72, which extends from the body portion 70; and a second arm 74, which extends from the body portion 70. (The adjectives "first" and "second" are used as identifiers throughout this document and are not intended to indicate importance or order.) The body portion 70 includes a base 76 to which the shock absorber 60 and the coil spring 58 can be attached. The body portion 70 includes the LCA steering knuckle connection 66. The first arm 72 can be arranged in a vehicle forward direction relative to the second arm 74. A strut 78 extends from the first arm 72 and extends to the second arm 74. The strut 78 can be parallel to the axis B.

[0031] The first arm 72 includes a first top surface 80, a first forward-facing surface 82, a first bottom surface 84, and a first rearward-facing surface 86. The second arm 74 includes a second top surface 88, a second forward-facing surface 90, a second bottom surface 92, and a second rearward-facing surface 94. For each of the first arm 72 and the second arm 74, the top surface 80, 88 is connected to the forward-facing surface 82, 90, which is connected to the bottom surface 84, 92, which is connected to the rearward-facing surface 86, 94, which is connected to the top surface 80, 88. The top surface 80, 88 faces in a generally vehicle upward direction. The bottom surface 84, 92 faces in a generally vehicle downward direction. The forward-facing surface 82, 90 faces in a generally vehicle forward direction. The rearward-facing surface 86, 94 faces in a generally vehicle rearward direction. The top surface 80, 88 is opposite the bottom surface 84, 92. The forward facing surfaces 82 , 90 are opposite the rearward facing surfaces 86 , 94 .

[0032] refer to Figure 5 and Figure 6 , the first arm 72 includes a first end 96 spaced from the main body portion 70, and the first arm 72 extends from the main body portion 70 to the first end 96. A first upper lip 98 extends from the first end 96 to a first upper edge 100, and a first lower lip 102 extends from the first end 96 to a first lower edge 104. The first upper edge 100 and the first lower edge 104 are spaced from each other and fixed relative to the first end 96. The second arm 74 includes a second end 106 spaced from the main body portion 70, and the second arm 74 extends from the main body portion 70 to the second end 106. A second upper lip 108 extends from the second end 106 to a second upper edge 110, and a second lower lip 112 extends from the second end 106 to a second lower edge 114. The second upper edge 110 and the second lower edge 114 are spaced from each other and fixed relative to the second end 106. The upper and lower lips 98, 102, 108, 112 may be curved panels having a constant thickness. The upper lips 98 , 108 may extend upward and away from the body 68 , and the lower lips 102 , 112 may extend downward and away from the body 68 .

[0033] refer to Figure 5 , Figure 6 and Figure 8, a first arcuate surface 116 extends from the first upper edge 100 to the first lower edge 104. The first arcuate surface 116 can be defined by the first upper lip 98, the first end 96, and the first lower lip 102. The second arcuate surface 118 extends from the second upper edge 110 to the second lower edge 114. The second arcuate surface 118 can be defined by the second upper lip 108, the second end 106, and the second lower lip 112. The arcuate surface can have a partial circular shape. The first arcuate surface 116 and the second arcuate surface 118 can each be curved at a constant radial distance from the axis B.

[0034] refer to Figure 5 , the body 68 of the lower control arm 56 includes an upper body 120 and a lower body 122 connected along a seam 124. The seam 124 can divide the body 68 so that the upper body 120 and the lower body 122 can be formed by stamping, such as by having each of the upper body 120 and the lower body 122 have no overhanging or undercut sections in one direction. The seam 124 extends along the body portion 70, that is, longitudinally from the body portion 70 on the first forward surface 82 and on the first rearward surface 86 along the first arm 72 to the first end 96, and longitudinally from the body portion 70 on the second forward surface 90 and on the second rearward surface 94 along the second arm 74 to the second end 106. As measured in a direction perpendicular to the seam 124, the seam 124 can extend substantially to a middle portion 126 of the first end 96 and substantially to a middle portion 128 of the second end 106.

[0035] refer to Figures 5 to 8 , the lower control arm 56 includes a first sleeve 130 and a second sleeve 132. The first sleeve 130 and the second sleeve 132 have a tubular shape. The sleeves each include two sleeve ends 134 and a sleeve wall 136 extending from one of the sleeve ends 134 to the other of the sleeve ends 134. The sleeve wall 136 may have a circular cross-section with a constant wall thickness, and the cross-section may be constant from one of the sleeve ends 134 to the other of the sleeve ends 134. The circular cross-section of the sleeve wall 136 may define an axis B.

[0036] refer to Figure 6 and Figure 8, a first sleeve 130 is fixed to the first end 96, and a second sleeve 132 is fixed to the second end 106. The first arcuate surface 116 is shaped to mate with a sleeve wall 136 of the first sleeve 130, and the second arcuate surface 118 is shaped to mate with a sleeve wall 136 of the second sleeve 132. More specifically, the constant radial distance from the axis B to the first arcuate surface 116 can be substantially equal to the outer radius of the first sleeve 130, and the constant radial distance from the axis B to the second arcuate surface 118 can be substantially equal to the outer radius of the second sleeve 132. The first sleeve 130 is fixed to, for example, welded to, the first arcuate surface 116, and the second sleeve 132 is fixed to, for example, welded to, the second arcuate surface 118.

[0037] refer to Figures 6 to 8 , the first sleeve 130 includes a first slit 138 extending longitudinally from one of the sleeve ends 134 of the first sleeve 130 to the other of the sleeve ends 134, and the second sleeve 132 includes a second slit 140 extending from one of the sleeve ends 134 of the second sleeve 132 to the other of the sleeve ends 134. For the purposes of this disclosure, "longitudinal" with respect to the tubular shape means parallel to the axial direction of the tubular shape, i.e., perpendicular to the cross-section of the tubular shape. The slits 138, 140 may have a non-linear shape, such as following a path having a plurality of bends or angles, in which case the direction of each of the slits 138, 140 is the direction of the straight line having the smallest average distance between the first slit 138 or the second slit 140 and the straight line. The non-linear shape of the slots 138 , 140 may facilitate alignment of the sleeves 130 , 132 during installation simply by fitting properly, with no offset between portions of the sleeves 130 , 132 on one side of the slots 138 , 140 and portions of the sleeves 130 , 132 on the other side of the slots 138 , 140 .

[0038] refer to Figure 8 , the first slit 138 is spaced apart from the first upper edge 100 and the first lower edge 104. The first slit 138 can be disposed adjacent to the first end 96 of the first arm 72, and the first slit 138 can be spaced apart from the first upper lip 98 and the first lower lip 102. The first slit 138 is disposed closer to one of the first top surface 80 and the first bottom surface 84 than the middle portion 126 of the first end 96. In other words, as Figure 8 As shown, the shortest distance X from the first top surface 80 to the first slit 138 is less than the shortest distance Y from the first slit 138 to the middle portion 126 of the first end portion 96. The first slit 138 can be disposed along the first arcuate surface 116 closer to one of the first upper lip 98 and the first lower lip 102 than to the middle portion 126 of the first end portion 96. In other words, Figure 8 As shown, the shortest circumferential distance Z from the first upper lip 98 to the first slit 138 is less than the shortest circumferential distance W from the first slit 138 to the middle 126 of the first end 96. Alternatively or additionally, the first slit 138 can be disposed substantially 60° about the axis B relative to the middle 126 of the first end 96.

[0039] refer to Figure 5 , the second slit 140 is spaced apart from the second upper edge 110 and the second lower edge 114. The second slit 140 can be disposed adjacent to the second end 106 of the second arm 74, and the second slit 140 can be spaced apart from the second upper lip 108 and the second lower lip 112. The second slit 140 can be disposed closer to the middle 128 of the second end 106 than to either of the second top surface 88 and the second bottom surface 92. The second slit 140 can be disposed along the second arcuate surface 118 closer to the middle 128 of the second end 106 than to either of the second upper lip 108 and the second lower lip 112.

[0040] The first slit 138 and the second slit 140 may therefore have different rotational alignments relative to the middle portions 126, 128 of the arms 72, 74. During a collision, the first sleeve 130 may be separated from the frame 34 more easily, i.e., at a lower force, than the second sleeve 132 is separated from the frame 34. The first slit 138 is designed to separate at a first threshold force, and the second slit 140 is designed to separate at a second threshold force. The second threshold force may be higher than the force experienced in any test scenario; in other words, the second sleeve 132 is designed not to separate under a standard test protocol. The first threshold force is less than the second threshold force. The first threshold force is associated with a frontal collision with the vehicle 30. Specifically, the thickness of the first sleeve 130, the material type of the first sleeve 130, the location of the first slit 138, the welding of the first sleeve 130 to the first curved surface 116, etc. are designed to allow the frame 34 to separate at the first threshold force.

[0041] refer to Fig. 9In the event of a collision with the front end of the vehicle 30, the first crumple zone 142 of the vehicle 30 may be deformed due to compression in the forward direction of the vehicle. The first crumple zone 142 extends from the most forward end of the vehicle 30 to the first end 96 of the lower control arm 54. The force of the collision may then cause the first sleeve 130 to disengage from the frame 34; specifically, the weld between the first slit 138 and the first upper edge 100 may crack, and / or the first upper lip 98 may crack, and the first sleeve 130 may be deformed due to the opening at the first slit 138. Since the first slit 138 is located closer to the first top surface 80 or the first bottom surface 84 than the middle portion 126 of the first end portion 96, such as 60° relative to the middle portion 126 of the first end portion 96 about the axis B, the force of the collision may be able to cause the first sleeve to disengage. Once the first sleeve 130 is disengaged, the second crumple zone 144 may be deformed due to compression in the vehicle forward direction, and if the second crumple zone 144 is fully deformed, the third crumple zone 146 may be deformed in the vehicle forward direction. The second crumple zone 144 extends from the first end 96 of the lower control arm 54 to the second end 106 of the lower control arm 54, and the third crumple zone 146 extends from the second end 106 of the lower control arm 54 to the floor 40 of the passenger compartment 38. The disengagement of the first end 96 of the lower control arm 54 can allow the second crumple zone 144 to absorb more energy from the collision. The disengagement of the first end 96 can therefore reduce the force transmitted to the passenger compartment 38 by the collision. In addition, during a lower speed collision where the possibility of intrusion into the passenger compartment 38 is minimal, the first sleeve 130 can remain attached to the frame 34.

[0042] The present disclosure has been described in an illustrative manner, and it should be understood that the terms that have been used are intended to have the nature of words of description rather than limitation. "Substantially" as used herein means that the size, duration, shape or other adjective may vary slightly from what is described due to physical defects, power outages, mechanical processing or other manufacturing changes, etc. In view of the above teachings, many modifications and variations of the present disclosure are possible, and the present disclosure can be practiced in other ways than specifically described.

[0043] According to the present invention, a lower control arm is provided, which has: a body, the body including a body part and an arm extending from the body part, the arm including an end part, the end part being spaced apart from the body part; a top surface; and a bottom surface, the bottom surface being opposite to the top surface; and a sleeve, the sleeve having a tubular shape and being fixed to the end part, the sleeve including a longitudinally extending slit, the slit being arranged to be closer to one of the top surface and the bottom surface than to the middle of the end part.

[0044] According to one embodiment, the sleeve is welded to the end portion.

[0045] According to one embodiment, the arm is a first arm and the body includes a second arm extending from the body portion.

[0046] According to one embodiment, the end is a first end, the top surface is a first top surface, the bottom surface is a first bottom surface, and the second arm includes a second end spaced apart from the main body portion, the lower control arm further comprising: a second top surface and a second bottom surface, the second top surface and the second bottom surface being spaced apart from each other and fixed relative to the second end; and a second arcuate surface, the second arcuate surface extending from the second top surface to the second bottom surface.

[0047] According to one embodiment, the sleeve is a first sleeve and the lower control arm further comprises a second sleeve having a tubular shape and fixed to the second end.

[0048] According to one embodiment, the slit is a first slit, and the second sleeve includes a longitudinally extending second slit disposed closer to a middle portion of the second end portion than to either of the second top surface and the second bottom surface.

[0049] According to one embodiment, the first arm is disposed relative to the second arm in a vehicle forward direction.

[0050] According to one embodiment, the above invention is further characterized by an upper lip extending from the end to the upper edge and a lower lip extending from the end to the lower edge.

[0051] According to one embodiment, the slit is spaced apart from the upper lip and the lower lip.

[0052] According to one embodiment, the upper lip, the end portion and the lower lip define an arcuate surface extending from the upper edge to the lower edge.

[0053] According to one embodiment, the arcuate surface is shaped to mate with the sleeve.

[0054] According to one embodiment, the slit is arranged next to the end.

[0055] According to one embodiment, the body comprises an upper body and a lower body connected along a seam extending along the body portion and longitudinally along the arm to the end.

[0056] According to one embodiment, the seam extends substantially to the middle of the end portion.

[0057] According to one embodiment, the sleeve comprises two sleeve ends and a sleeve wall with a constant cross-section, which extends from one of the sleeve ends to the other of the sleeve ends.

[0058] According to one embodiment, the slit extends from one of the sleeve ends to the other of the sleeve ends.

[0059] According to one embodiment, the slit extends through the sleeve wall.

[0060] According to one embodiment, the sleeve wall has a circular cross-section.

[0061] According to one embodiment, the cross section of the sleeve wall defines an axis and the slit is arranged around said axis at substantially 60° relative to the middle of the end portion.

[0062] According to one embodiment, the slit has a non-linear shape.

Claims

1. A lower control arm, comprising: a body including a body portion and an arm extending from the body portion, the arm including an end portion, the end portion being spaced apart from the body portion; top surface; and a bottom surface, the bottom surface being opposite to the top surface; as well as A sleeve having a tubular shape and fixed to the end portion, the sleeve including a longitudinally extending slit disposed closer to one of the top surface and the bottom surface than a middle portion of the end portion.

2. The lower control arm of claim 1 wherein the sleeve is welded to the end portion.

3. The lower control arm of claim 1, wherein the arm is a first arm and the body includes a second arm extending from the body portion.

4. The lower control arm of claim 3, wherein the end is a first end, the top surface is a first top surface, the bottom surface is a first bottom surface, and the second arm includes a second end spaced apart from the body portion, the lower control arm further comprising: a second top surface and a second bottom surface, the second top surface and the second bottom surface being spaced apart from each other and fixed relative to the second end; and a second arcuate surface extending from the second top surface to the second bottom surface. 5 . The lower control arm of claim 4 , wherein the sleeve is a first sleeve, the lower control arm further comprising a second sleeve having a tubular shape and fixed to the second end.

6. The lower control arm of claim 5, wherein the slit is a first slit, and the second sleeve includes a longitudinally extending second slit disposed closer to a middle portion of the second end portion than to either of the second top surface and the second bottom surface.

7. The lower control arm of claim 3, wherein the first arm is disposed relative to the second arm in a vehicle forward direction.

8. The lower control arm of claim 1, further comprising an upper lip extending from the end to an upper edge; and a lower lip extending from the end to a lower edge.

9. The lower control arm of claim 8, wherein the upper lip, the end portion, and the lower lip define an arcuate surface extending from the upper edge to the lower edge.

10. The lower control arm of claim 1, wherein the slot is positioned adjacent the end portion.

11. The lower control arm of claim 1 wherein the body includes an upper body and a lower body connected along a seam, the seam extending along the body portion and extending longitudinally along the arm to the end.

12. The lower control arm of claim 1, wherein the slot has a non-linear shape.

13. The lower control arm of any one of claims 1 to 12, wherein the sleeve includes two sleeve ends and a sleeve wall having a constant cross-section, the sleeve wall extending from one of the sleeve ends to the other of the sleeve ends.

14. The lower control arm of claim 13, wherein the sleeve wall has a circular cross-section.

15. The lower control arm of claim 14 wherein said cross section of said sleeve wall defines an axis and said slot is disposed substantially 60° about said axis relative to said middle of said end portion.

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