U.S. patent application number 14/684668 was filed with the patent office on 2016-10-13 for strut and air spring ifs assembly maximizing available steering knuckle wheel cut.
This patent application is currently assigned to Reyco Granning, LLC. The applicant listed for this patent is Reyco Granning, LLC. Invention is credited to John A Hinz.
Application Number | 20160297272 14/684668 |
Document ID | / |
Family ID | 57111264 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160297272 |
Kind Code |
A1 |
Hinz; John A |
October 13, 2016 |
Strut and Air Spring IFS Assembly Maximizing Available Steering
Knuckle Wheel Cut
Abstract
An IFS assembly having a single lower control arm having an
inboard end pivotally secured to a chassis support structure, an
air spring supported by an air spring seat relative to the lower
control arm, a strut having an upper end pivotally secured to the
chassis support structure and a lower end coupled to the lower
control arm outboard end, and a steering knuckle fixed to the strut
lower end, the steering knuckle disposed below the lower air spring
seat and whose rotative movement about the strut axis is unconfined
by proximity between the steering knuckle and the lower air spring
seat, whereby available wheel cut is maximized. Also an IFS module
including right and left side IFS assemblies and adapted for
installation into a vehicle.
Inventors: |
Hinz; John A; (Monticello,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Reyco Granning, LLC |
Mount Vernon |
MO |
US |
|
|
Assignee: |
Reyco Granning, LLC
Mount Vernon
MO
|
Family ID: |
57111264 |
Appl. No.: |
14/684668 |
Filed: |
April 13, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60G 11/28 20130101;
B60G 3/06 20130101; B60G 2200/142 20130101; B62D 7/18 20130101;
B60G 2202/152 20130101; B60G 11/27 20130101; B60G 2200/17
20130101 |
International
Class: |
B60G 11/28 20060101
B60G011/28; B62D 7/18 20060101 B62D007/18 |
Claims
1. An IFS assembly comprising: a single lower control arm having
laterally-spaced inboard and outboard ends, the inboard end adapted
to be pivotally secured to a chassis support structure; a lower air
spring seat supported by the lower control arm, the lower air
spring seat adapted to upwardly support the chassis support
structure relative to the lower control arm through an air spring
engaging the chassis support structure; a strut having upper and
lower ends disposed along a strut axis, the strut upper and lower
ends having relative movement along and about the strut axis, the
strut upper end adapted to be pivotally secured to the chassis
support structure, the strut lower end coupled to the lower control
arm outboard end; and a steering knuckle rotatably and axially
secured to the strut lower end, the steering knuckle disposed below
the lower air spring seat and having rotative movement about the
strut axis that is unconfined by proximity between the steering
knuckle and the lower air spring seat and/or the air spring through
which the lower air spring seat is adapted to support the chassis
support structure, whereby available wheel cut is maximized.
2. The IFS assembly of claim 1, wherein the lower control arm
includes a seat support structure located laterally between the
lower control arm inboard and outboard ends and supporting the
lower air spring seat, the seat support structure projecting
upwardly relative to the lower control arm inboard and outboard
ends.
3. The IFS assembly of claim 2, wherein the seat support structure
includes a rigid strut member extending between the lower air
spring seat and a location on the lower control arm proximate the
lower control arm outboard end.
4. The IFS assembly of claim 3, wherein the rigid strut member has
a longitudinal axis that diverges from the strut axis in an upward
direction from the lower control arm.
5. The IFS assembly of claim 1, wherein the steering knuckle
includes a spindle and caliper mounts, and further comprising a
disk brake assembly including a caliper assembly secured to the
caliper mounts and a rotor rotatably mounted about the spindle and
operatively engageable with the caliper assembly, a portion of the
brake assembly receivable beneath the lower air spring seat during
rotative movement of the steering knuckle about the strut axis.
6. The IFS assembly of claim 1, wherein the strut is adapted to
upwardly support the chassis support structure relative to the
steering knuckle.
7. The IFS assembly of claim 6, wherein the strut comprises: an
upper portion that defines the strut upper end; a lower portion
that defines the strut lower end; a damper housed within the strut
upper and lower portions through which relative motion between the
strut upper and lower ends along the strut axis is dampened; and a
gas spring operably disposed between the strut upper and lower
portions to support the strut upper end away from the strut lower
end along the strut axis, whereby the strut is adapted to upwardly
support the chassis support structure relative to the steering
knuckle.
8. The IFS assembly of claim 7, wherein the gas spring is adapted
to receive gas from and discharge gas to a connected gas reservoir
located externally of the strut and is capable of containing gas at
selectively variable pressures so as to compensate for different
loads between the strut upper and lower ends and/or establish
different nominal axial distances therebetween.
9. An IFS assembly comprising: a chassis support structure; a
single lower control arm having laterally-spaced inboard and
outboard ends, the inboard end pivotally secured to the chassis
support structure; a lower air spring seat supported by the lower
control arm; an air spring supported by the lower air spring seat
and engaging the chassis support structure, the chassis support
structure upwardly supported by the air spring relative to the
lower air spring seat; a strut having upper and lower ends disposed
along a strut axis, the strut upper and lower ends having relative
movement along and about the strut axis, the strut upper end
pivotally secured to the chassis support structure, the strut lower
end coupled to the lower control arm outboard end; and a steering
knuckle rotatably and axially secured to the strut lower end, the
steering knuckle disposed below the lower air spring seat and
having rotative movement about the strut axis that is unconfined by
proximity between the steering knuckle and the lower air spring
seat, whereby available wheel cut is maximized.
10. The IFS assembly of claim 9, wherein the lower control arm
includes a seat support structure located laterally between the
lower control arm inboard and outboard ends and supporting the
lower air spring seat, the seat support structure projecting
upwardly relative to the lower control arm inboard and outboard
ends.
11. The IFS assembly of claim 10, wherein the seat support
structure includes a rigid strut member extending between the lower
air spring seat and a location on the lower control arm proximate
the lower control arm outboard end.
12. The IFS assembly of claim 11, wherein the rigid strut member
has a longitudinal axis that diverges from the strut axis in an
upward direction from the lower control arm.
13. The IFS assembly of claim 9, wherein the steering knuckle
includes a spindle and caliper mounts, and further comprising a
disk brake assembly including a caliper assembly secured to the
caliper mounts and a rotor rotatably mounted about the spindle and
operatively engageable with the caliper assembly, a portion of the
brake assembly receivable beneath the lower air spring seat during
rotative movement of the steering knuckle about the strut axis.
14. The IFS assembly of claim 9, wherein the chassis support
structure is upwardly supported by the strut relative to the
steering knuckle.
15. The IFS assembly of claim 14, wherein the strut comprises: an
upper portion that defines the strut upper end; a lower portion
that defines the strut lower end; a damper housed within the strut
upper and lower portions through which relative motion between the
strut upper and lower ends along the strut axis is dampened; and a
gas spring operably disposed between the strut upper and lower
portions to support the strut upper end away from the strut lower
end along the strut axis, whereby the chassis support structure is
upwardly supported by the strut relative to the steering
knuckle.
16. The IFS assembly of claim 15, wherein the gas spring is adapted
to receive gas from and discharge gas to a connected gas reservoir
located externally of the strut and is capable of containing gas at
selectively variable pressures so as to compensate for different
loads supported by the strut and/or establish different ride
heights.
17. The IFS assembly of claim 9, wherein the air spring is in
engagement with the chassis support structure at a first location
and the strut upper end is pivotally secured to the chassis support
structure at a second location laterally outboard of the first
location.
18. The IFS assembly of claim 17, wherein the first location is
below the second location.
19. The IFS assembly of claim 9, wherein the chassis support
structure comprises a torque tube assembly including an elongate
torque tube fixed at longitudinally spaced first and second
locations along the torque tube and an upper strut mount having
laterally-spaced inboard and outboard ends, the upper strut mount
inboard end affixed to the torque tube between the first and second
locations, the strut upper end pivotally secured to the upper strut
mount outboard end.
20. The IFS assembly of claim 19, wherein the strut upper end
includes a compliance bushing and surrounding ring structure, and
the upper strut mount includes a pair of superposed flanges having
apertures between which the ring structure and compliance bushing
are disposed, and further comprising an elongate member extending
through the flange apertures and the compliance bushing, thereby
defining a clevis joint through which the strut upper end is
pivotally secured to the chassis support structure.
Description
BACKGROUND
[0001] The present disclosure relates to vehicle suspension
systems, particularly independent front suspension ("IFS")
assemblies.
[0002] IFS assemblies employing struts, which are capable of
supporting a side load and typically provide damping capabilities,
are well known. It is also known to provide an IFS assembly
including struts that provide upward support axially therealong,
and such suspensions typically employ a single lower control arm.
Moreover, it is known to employ air springs with such struts. For
example, MacPherson type strut IFS assemblies wherein an air spring
is located above and generally in line with the strut are disclosed
by U.S. Pat. Nos. 4,206,907; 4,655,438; 4,974,872; and 6,382,602.
Of these patents, the '907 and '602 patents also disclose varying
the air spring pressure for load and ride height adjustment
purposes.
[0003] Further examples of MacPherson type strut IFS assemblies in
which coil springs and leaf springs are located between a single
lower control arm and the vehicle chassis are disclosed by U.S.
Pat. Nos. 2,018,653; 2,842,230; 2,967,066; 3,333,653; 3,926,454;
and 4,653,772.
[0004] It is also known to provide MacPherson type strut IFS
assemblies wherein the steering knuckle includes an arm portion
extending below and transferring the load to the strut, as
disclose, for example, in U.S. Pat. No. 5,192,100.
[0005] It is desirable to reduce loading of both struts and air
springs in an IFS assembly, to maximize the available wheel cut of
an IFS assembly, to simplify vehicle suspension installations by
OEM manufacturers, provide variable load-carrying and right height
capabilities, and provide other advancements in areas of IFS
technologies and configurations.
SUMMARY
[0006] The present disclosure beneficially provides such
advancements.
[0007] According to a first aspect, the present disclosure provides
an IFS assembly including a single lower control arm having
laterally-spaced inboard and outboard ends, the inboard end adapted
to be pivotally secured to a chassis support structure. A lower air
spring seat is supported by the lower control arm, the lower air
spring seat adapted to upwardly support the chassis support
structure relative to the lower control arm through an air spring
engaging the chassis support structure. The IFS assembly includes a
strut having upper and lower ends disposed along a strut axis, the
strut upper and lower ends having relative movement along and about
the strut axis. The strut upper end is adapted to be pivotally
secured to the chassis support structure and the strut lower end is
coupled to the lower control arm outboard end. A steering knuckle
is rotatably and axially secured to the strut lower end, the
steering knuckle disposed below the lower air spring seat and has
rotative movement about the strut axis that is unconfined by
proximity between the steering knuckle and the lower air spring
seat and/or the air spring through which the lower air spring seat
is adapted to support the chassis support structure. Consequently,
available wheel cut is maximized.
[0008] According to a second aspect, the present disclosure
provides an IFS assembly including a chassis support structure and
a single lower control arm having laterally-spaced inboard and
outboard ends, the inboard end pivotally secured to the chassis
support structure. A lower air spring seat is supported by the
lower control arm, and an air spring is supported by the lower air
spring seat and engages the chassis support structure. The chassis
support structure is upwardly supported by the air spring relative
to the lower air spring seat. The IFS assembly includes a strut
having upper and lower ends disposed along a strut axis, the strut
upper and lower ends having relative movement along and about the
strut axis. The strut upper end is pivotally secured to the chassis
support structure, and the strut lower end is coupled to the lower
control arm outboard end. A steering knuckle is rotatably and
axially secured to the strut lower end and is disposed below the
lower air spring seat. The steering knuckle has rotative movement
about the strut axis that is unconfined by proximity between the
steering knuckle and the lower air spring seat. Consequently,
available wheel cut is maximized.
[0009] According to a third aspect, the present disclosure provides
an IFS assembly including a single lower control arm defining
laterally-spaced inboard and outboard ends, the inboard end adapted
to be pivotally secured to a chassis support structure. The IFS
assembly includes a strut having upper and lower ends disposed
along a strut axis, the strut upper and lower ends having relative
movement along and about the strut axis. The strut upper end is
adapted to be pivotally secured to the chassis support structure.
The IFS assembly includes a steering knuckle including a strut
supporting portion affixed to and supporting the strut lower end,
and a load arm extending below and secured to the lower control
arm. The outboard end of the lower control arm is disposed between
the load arm and the strut lower end, and the lower control arm is
upwardly supported by the load arm.
[0010] According to a fourth aspect, the present disclosure
provides an IFS assembly including a chassis support structure and
a single lower control arm defining laterally-spaced inboard and
outboard ends, the inboard end pivotally secured to the chassis
support structure. The IFS assembly includes a strut having upper
and lower ends disposed along a strut axis, the strut upper and
lower ends having relative movement along and about the strut axis.
The strut upper end is pivotally secured to the chassis support
structure. The IFS assembly includes a steering knuckle including a
strut supporting portion affixed to and supporting the strut lower
end, and a load arm extending below and secured to the lower
control arm. The outboard end of the lower control arm is disposed
between the load arm and the strut lower end, and the lower control
arm is upwardly supported by the load arm.
[0011] According to a fifth aspect, the present disclosure provides
an IFS assembly including a single lower control arm defining
laterally-spaced inboard and outboard ends, the inboard end adapted
to be pivotally secured to a chassis support structure, and a
steering knuckle secured to the lower control arm outboard end. The
IFS assembly includes a strut having upper and lower ends disposed
along a strut axis, the strut upper and lower ends having relative
movement along and about the strut axis. The strut lower end is
fixed relative to the steering knuckle, and the strut upper end
provided with a clevis ring structure adapted to surround a bushing
extending therethrough. The strut upper end is adapted to be
pivotally secured to the chassis support structure through the
clevis ring structure and the bushing about a generally horizontal
first axis.
[0012] According to a sixth aspect, the present disclosure provides
an IFS assembly including a chassis support structure and a single
lower control arm defining laterally-spaced inboard and outboard
ends, the inboard end pivotally secured to the chassis support
structure. A steering knuckle is secured to the lower control arm
outboard end. The IFS assembly includes a bushing and a strut
having upper and lower ends disposed along a strut axis, the strut
upper and lower ends having relative movement along and about the
strut axis. The strut lower end is fixed relative to the steering
knuckle, and the strut upper end provided with a clevis ring
structure. The bushing extends through and is surrounded by the
clevis ring structure, and the strut upper end is pivotally secured
to the chassis support structure through the clevis ring structure
and the bushing about a generally horizontal first axis.
[0013] According to a seventh aspect, the present disclosure
provides an IFS assembly including a single lower control arm
having laterally-spaced inboard and outboard ends, the inboard end
adapted to be pivotally secured to a chassis support structure, and
a steering knuckle secured to the lower control arm outboard end.
The IFS assembly includes a strut having upper and lower ends
disposed along a strut axis, the strut upper and lower ends having
relative movement along and about the strut axis. The strut lower
end is fixed relative to the steering knuckle. A torque tube
assembly includes an elongate torque tube extending between first
and second joints at which the torque tube is adapted to be rigidly
fixed relative to the chassis support structure, and an upper strut
mount having laterally-spaced first and second ends. The first end
is rigidly affixed to the torque tube between the first and second
joints. The strut upper end is adapted to be pivotally secured to
the second end.
[0014] According to an eighth aspect, the present disclosure
provides an IFS assembly including a chassis support structure
having a first portion and a torque tube assembly, and a single
lower control arm having laterally-spaced inboard and outboard
ends. The inboard end is pivotally secured to the chassis support
structure first portion, and a steering knuckle is secured to the
lower control arm outboard end. The IFS assembly includes a strut
having upper and lower ends disposed along a strut axis, the strut
upper and lower ends having relative movement along and about the
strut axis. The strut lower end is fixed relative to the steering
knuckle. The torque tube assembly includes an elongate torque tube
extending between first and second joints at which the torque tube
is rigidly fixed relative to the chassis support structure first
portion, and an upper strut mount having laterally-spaced first and
second ends. The first end is rigidly affixed to the torque tube
between the first and second joints, and the strut upper end is
pivotally secured to the second end.
[0015] According to a ninth aspect, the present disclosure provides
an IFS module adapted for installation into a vehicle. The IFS
module includes a chassis support structure having laterally
opposite right and left sides, and adapted for attachment to the
vehicle frame. The IFS module includes a pair of left and right
side single lower control arms, each lower control arm defining
laterally-spaced inboard and outboard ends, and each inboard end is
pivotally secured to the chassis support structure. The IFS module
includes a pair of left and right side struts, each strut having
upper and lower ends disposed along a respective strut axis, the
upper and lower ends of each strut having relative movement along
and about the respective strut axis. The strut upper ends are
pivotally secured to the chassis support structure. The IFS module
also includes a pair of left and right side steering knuckles, each
steering knuckle fixed relative to the respective strut lower end
and secured to the respective lower control arm outboard end.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The various objects, features and attendant advantages of
the present invention will become fully appreciated as the same
becomes better understood when considered in conjunction with the
accompanying drawings, wherein like reference characters designate
the same, similar or corresponding parts throughout the several
views:
[0017] FIG. 1 is a rear, upper perspective view of an IFS module
incorporating right and left side IFS assemblies according to an
embodiment of the present disclosure;
[0018] FIG. 2 is a top plan view of the IFS module of FIG. 1;
[0019] FIG. 3 is a rear elevation of the IFS module of FIG. 1;
[0020] FIG. 4 is a bottom plan view of the IFS module of FIG.
1;
[0021] FIG. 5 is right side elevation of the IFS module of FIG.
1;
[0022] FIG. 6 is a partially sectioned view of the IFS module of
FIG. 5 along line 6-6;
[0023] FIG. 7 is a partially exploded, front, upper perspective
view of the IFS module of FIG. 1;
[0024] FIG. 8 is a front, upper perspective view of the IFS module
of FIG. 1;
[0025] FIG. 9 is a longitudinal sectional view of a first
embodiment strut used in an IFS assembly according to the present
disclosure; and
[0026] FIG. 10 is a longitudinal sectional view of a second
embodiment strut used in an IFS assembly according to the present
disclosure.
DETAILED DESCRIPTION
[0027] The invention is adaptable to various modifications and
alternative forms, and the specific embodiments thereof shown by
way of example in the drawings are herein described in detail. The
exemplary embodiments of the present disclosure are chosen and
described so that others skilled in the art may appreciate and
understand the principles and practices of the present disclosure.
It should be understood, however, that the drawings and detailed
description are not intended to limit the invention to the
particular forms disclosed, but on the contrary, the intention is
to cover all modifications, equivalents and alternatives falling
within the spirit and scope of the present invention as defined by
the appended claims.
[0028] FIGS. 1-8 depict an embodiment of IFS module 20 which is a
free standing assemblage adapted for installation into a vehicle.
IFS module 20 may be affixed to vehicle frame 22 shown in dashed
lines in FIG. 1, for example. IFS module 20 includes chassis
support structure 24 having right side 26 and left side 28 sharing
substantially rigid chassis support structure first portion 29 to
which is attached, or which forms a part of, right side IFS
assembly 30 and left side IFS assembly 32. Alternatively, chassis
support structure 24 or first portion 29 thereof may form an
integral part of the vehicle to which right and left side IFS
assemblies 30, 32 are installed directly, rather than through an
IFS module such as IFS module 20. Chassis support structure 24 may
be a stamped sheet metal and/or metal beam weldment formed of
suitably rigid material. Chassis support structure right and left
sides 26, 28 as shown are substantially mirror images of each
other. In other words, chassis support structure 24 is
substantially symmetrical about its lateral center, which coincides
with the lateral center of the vehicle. Likewise, right and left
side IFS assemblies 30, 32 as shown are substantially mirror images
of each other. Unless indicated otherwise, structural and
functional descriptions herein which specify neither chassis
support structure right or left side 26, 28, nor right or left side
IFS assembly 30, 32, or components thereof, should be construed to
relate to the chassis support structure, IFS assembly and
components of either side. Moreover, corresponding elements between
the right and left sides have a common reference numeral and in the
accompanying Figures, the element of only the right or left side
element may be indicated.
[0029] In the depicted embodiment, each IFS assembly 30, 32
includes lower control arm 34, strut 36 which extends generally
vertically along its strut axis 37, steering knuckle 38, and torque
tube assembly 40. As shown, torque tube assembly 40 is an
integrated part of the respective chassis support structure right
or left side 26, 28, but may be a separate component affixed
thereto. Torque tube assembly 40 is formed of an elongate torque
tube 42 that extends fore and aft along generally horizontal axis
43, and laterally extending upper strut mount 44. Relative to
chassis support structure first portion 29, torque tube 42 is
secured at fixed forward joint 63 and aft joint 64 spaced along
torque tube axis 43. As 63, 64 may be welds. Upper strut mount 44
has inboard end 45 affixed, as by welds, to torque tube 42 at a
location between joints 63, 64, and outboard end 46 which extends
laterally outward from inboard end 45 in a generally horizontal
plane.
[0030] Strut upper end 48 and strut lower end 50 are disposed along
strut axis 37, and have relative movement along and about strut
axis 37. Strut upper end 48 is provided with steel clevis ring
structure 52 that surrounds hushing 54. In the depicted embodiment,
bushing 54 is a compliance bushing formed of elastomeric material
such as vulcanized rubber surrounding and bonded to cylindrical
steel sleeve 55 and/or the interior surface of clevis ring
structure 52. Sleeve 55 is concentric with clevis ring structure
52, and compliance bushing 54 may be a component part of strut 36.
Strut upper end 48 is pivotally secured to upper strut mount
outboard end 46 with bolt 56 and nut 57. Bolt 56 extends along axis
58 through upper strut mount outboard end 46 and bushing sleeve 55.
In the depicted embodiment, upper strut mount 44 is defined by an
inverted U-shaped channel having spaced parallel forward flange 60
and aft flange 62 provided at outboard end 46 with apertures
aligned along axis 58. Upper strut mount 44, strut upper end 48,
and elongate bolt 56 thus define a clevis joint. The interior of
bushing sleeve 55 is closely fitted about bolt 56 to resist
rotation of strut upper end 48 with strut lower end 50, though a
degree of compliance is obtained through elastic deformation of
compliance bushing 54, generally in a plane perpendicular to strut
axis 37. Strut upper end 48 also has a nominal position relative to
chassis support structure 24 in which the axes of bolt 56, bushing
sleeve 55 and clevis ring structure 52 are coincident with axis 58,
and strut axis 37 is substantially perpendicular to axis 58. In the
nominal position, elastically deformable compliance bushing 54 is
substantially undeformed. Deviation from the nominal position is
the result of the compliance facilitated by elastic deformation of
bushing 54. Deviation from the nominal position is typically caused
by angular displacement of clevis ring structure 52 about strut
axis 37 due to frictionally induced torque imparted on strut upper
end 48 by strut lower end 50, at the onset of or during rotative
movement of steering knuckle 38 about strut axis 37. In some
embodiments, deviation from the nominal position may also be caused
by strut 36 experiencing a bending moment in fore or aft directions
generally parallel with axis 58.
[0031] Strut lower end 50 is fixed at two locations along strut
axis 37 to strut supporting portion 66 of steering knuckle 38.
Strut supporting portion 66 includes encircling clamp 65 which
surrounds strut lower end 50 received therethrough, and boss 67 and
mating bracket 68 located below encircling clamp 65. Each of boss
67 and bracket 68 is configured with a semi-cylindrical inner
surface that engages the outer cylindrical surface of strut lower
end 50. The semi-cylindrical inner surfaces of boss 67 and bracket
68 are provided with circumferentially extending, radially inwardly
projecting ridges 70 that are received in cooperating
circumferential groove 71 (FIGS. 9 and 10) provided in the
cylindrical outer surface of strut lower end 50. Ridges 70 and
groove 71 axially align strut lower end 50 relative to steering
knuckle 38 and secure them against relative movement along strut
axis 37. Frictional engagement between the cylindrical outer
surface of strut lower end 50 and the interfacing cylindrical
surfaces of encircling clamp 65, and the clamp defined by boss 67
and bracket 68, rotatably and axially fix strut lower end 50 to
steering knuckle strut supporting portion 66. Bolts 72 hold bracket
68 and boss 67 together against strut lower end 50; bolt 72 and nut
73 hold encircling clamp 65 tightly closed upon strut lower end
50.
[0032] Certain embodiments of IFS module 20 are provided with
components that may be included in IFS assembly 30, 32 as
individually installed in a vehicle, or which may be installed
subsequent to installation of the IFS assemblies 30, 32. Steering
knuckle 38 includes caliper assembly mounts 74 and spindle 76, to
which caliper assembly 78 and rotor 80 of disk brake assembly 82
are respectively attached. Rotor 80 as shown is provided with
central wheel mounting flange 81 provided with wheel mounting lugs
83 for attachment of the vehicle wheels (not shown). A portion of
rotor 80 is disposed within caliper assembly 78 in a manner
well-known to those having ordinary skill in the art, whereby
caliper assembly 78 and rotor 80 are operatively engageable. As
discussed herein below, IFS assembly 30, 32 maximizes the available
wheel cut, i.e., the angle in either direction about strut axis 37
that a vehicle front wheel can be turned.
[0033] As perhaps best seen in FIGS. 4 and 6, steering knuckle 38
is provided with load arm 84 that extends laterally inwardly and
below lower control arm 34, to which load arm is secured. Steering
knuckle 38 also has elongate turning arm 86 which, in the depicted
embodiment, extends rearwardly and laterally inwardly from load arm
84 to turning arm terminal end 88. Lower control arm 34 has
laterally-spaced inboard and outboard ends 90, 92. Lower control
arm inboard end 90 is pivotally secured to chassis support
structure first portion 29 at a pair of locations that are spaced
fore and aft. These pivotal attachments are about generally
horizontal and parallel forward and aft axes 94, 96 that extend
fore and aft, the attachments being made with bolts 98 and nuts
100, as perhaps best seen in FIG. 4.
[0034] Lower control arm outboard end 92 is rotatably secured to,
and is upwardly supported by, steering knuckle load arm 84 through
interconnecting ball joint 102. Steering knuckle 38 thus places a
compressive force onto ball joint 102 and lower control arm 34.
Strut axis 97 extends through ball joint 102. Referring to FIGS. 6
and 7, lower control arm outboard end 92 has top surface 104
disposed above ball joint 102 and is superposed by strut axial end
106 defined by strut lower end 50. As noted above, strut lower end
50 is axially supported by steering knuckle strut supporting
portion 66, and so strut axial end 106 is in spaced superposition
with top surface 104. Thus, lower control arm outboard end 92 is
sandwiched between strut 36 and steering knuckle load arm 84 along
strut axis 37.
[0035] IFS module 20 includes steering box 108 having housing 109
secured to chassis support structure first portion 29 at a
laterally central position between right and left side lower
control arm inboard ends 90. Steering box 108 has rotatable input
shaft 110 extending rearwardly from housing 109, the rearward end
of input shaft 110 adapted to be rotatably connected to a steering
shaft (not shown). Steering box 108 also has rotatable output shaft
112 downwardly extending through an aperture in chassis support
structure first portion 29 at the lateral center of chassis support
structure 24. Rotatable input and output shafts 110, 112 are
operably coupled within housing 109 for corresponding rotation.
Pitman arm 114 is rotatably secured to steering box output shaft
112 and converts angular movement of output shaft 112 to linear
movement of a pair of elongate right and left side tie rods 116
each individually secured at one end to pitman arm 114 via an
interconnecting tie rod end 118, as perhaps best seen in FIG. 4.
Each tie rod 116 is secured at its opposite end to a turning arm
terminal end 88 via an interconnecting tie rod end 118. Pitman arm
114, tie rods 116 and tie rod ends 118 thus form steering linkage
between steering box 108 and turning arms 86, through which
coordinated rotative movements of right and left side steering
knuckles 38 about their respective strut axes 37 is accomplished,
these rotative movements induced by rotation steering box input
shaft 110 through steering box output shaft 112 and the steering
linkage.
[0036] IFS module 20 and the IFS assemblies 30, 32 include a pair
of right and left side air springs 120 operably disposed between
the respective chassis support structure right or left side 26, 28
and the respective right or left side lower control arm 34. Each
air spring 120 engages chassis support structure 24 at a respective
right or left side location 122 at which the air spring is retained
to chassis support structure 24 with threaded fastener 124. Chassis
support structure 24 and air springs 120 are upwardly supported
relative to lower control arms 34, and thus by steering knuckle
load arms 84.
[0037] Air spring 120 is supported by lower air spring seat 126,
which is supported by seat support structure 128 of lower control
arm 34. Seat support structure 128 is located laterally between
lower control arm inboard and outboard ends 90, 92, and projects
upwardly relative thereto. Seat support structure 128 includes
rigid strut member 130 which extends along longitudinal axis 132
between lower air spring seat 126 and a location on lower control
arm 34 proximate its outboard end 92, as perhaps best seen in FIGS.
1 and 3. Steering knuckle 38 is disposed below lower air spring
seat 126 and air spring 120, and rigid strut member longitudinal
axis 132 diverges from strut axis 37 in an upward direction from
lower control arm 34. Lower air spring seat 126, air spring 120,
and rigid strut member 130 are thus located well out of the path of
rotative movement of steering knuckle 38 and disk brake assembly 82
carried thereby, whereby rotative movement of steering knuckle 38
about strut axis 37 is unconfined by proximity between steering
knuckle 38 and lower air spring seat 126 and/or air spring 120 is
unconfined by proximity therebetween and available wheel cut is
maximized. Moreover, a portion of disk brake assembly 82 carried by
steering knuckle 38 is receivable beneath lower air spring seat 126
during rotative movement of steering knuckle 38 about strut axis
37.
[0038] FIG. 9 shows the internal structure and further details of
strut 36, and FIG. 10 shows the internal structure and details of
alternative embodiment strut 36a, which may be substituted for
strut 36. Except for distinctions between strut 36 and strut 36a
discussed below and revealed by a comparison between FIGS. 9 and
10, reference herein and in FIGS. 1-8 to strut 36 shall be
understood to apply to and encompass strut 36a. Additionally, it is
to be understood that the horizontal orientation of struts 36, 36a
depicted in FIGS. 9 and 10 is merely to provide a larger view than
obtainable by depicting them in a substantially vertical
orientation, and does not alter the context used heretofore with
respect to descriptors such as "upper" and "lower"; "above" and
"below"; "top" and "bottom"; "vertical" and "horizontal"; and the
like.
[0039] Referring to FIG. 9, strut upper end 48 is defined by
cylindrical strut upper portion 134 and strut lower end 50 is
defined by cylindrical strut lower portion 136. Strut upper and
lower portions 134, 136 are telescopically engaged along strut axis
37, and respectively form a strut rod and a strut body. Strut lower
portion 136 is sealably closed at its free end by end cap 138 that
defines above-mentioned strut axial end 106. Above-mentioned clevis
ring structure 52 is sealably fixed to the free end of strut upper
portion 134. Concentrically disposed within strut upper portion 134
is cylindrical damper body 140, within which is slidably disposed
annular damper valve 142, Damper valve 142 is affixed to one end of
elongate damper rod 144 that extends therethrough. The opposite end
of damper rod 144 is secured to plate 145 sealably fixed to the
interior wall of strut lower portion 136 and relative to end cap
138. One end of cylindrical damper body 140 is sealably affixed to
strut upper end 48; the opposite end of damper body 140 is affixed
to sliding bearing member 146. The cylindrical space between the
superposing cylindrical surfaces of strut upper portion 134 and
strut lower portion 136 located above sliding bearing member 146 is
vented to atmosphere. Sliding bearing member 146 is slidably
disposed within cylindrical lower portion 136, and surrounds and
moves axially along valve rod 144. Sealably surrounding valve rod
144 at the end of damper body 140 affixed to sliding bearing member
146, and located below the lower side of damper valve 142 is
annular seal 147. Above the upper side of damper valve 142 is
disk-shaped floating piston 148, slidably sealed to the inner
diameter of damper body 140. First oil chamber 150 is defined
between damper valve 142 and floating piston 148, and second oil
chamber 152 is defined between damper valve 142 and annular seal
147, thereby defining internal monotube damper assembly 153 having
controlled oil flow across damper valve 142 between first and
second oil chambers 150, 152 along the path defined by arrow 154.
Damper 153 is thus housed within strut upper and lower portions
134, 136 and dampens relative motion between strut upper and lower
ends 48, 50 along strut axis 37.
[0040] Also housed within strut upper and lower portions 134, 146
is gas spring 156, which may utilize high pressure nitrogen as the
working fluid. Gas spring 156 includes first gas chamber 158
located in damper body 140 between clevis ring structure 52 and
floating piston 148, and second gas chamber 160 located in strut
lower portion 136 and sliding bearing member 146 annular seal 147
and plate 145. The pressurized nitrogen gas within gas spring 156
provides the biasing force that urges strut upper and lower ends
48, 50 apart along strut axis 37, and thus allows struts 39 to
upwardly support chassis support structure 24 relative to steering
knuckles 38. Additionally, the high pressure nitrogen gas within
gas spring, which acts on the upper side of floating piston 148,
prevents cavitation in the hydraulic oil of damper 153. First gas
chamber 158 is provided with a circumferentially arranged plurality
of orifices 162 through the cylindrical wall of damper body 140
proximate the axial end thereof. First and second gas chambers are
in fluid communication along a path indicated by arrow 164, which
extends through orifices 162, along the outer cylindrical surface
of damper body 140, and about damper rod 144 within sliding bearing
member 146. Above the axial end of cylindrical damper body 140, in
clevis ring structure 52, strut upper end 48 is provided with gas
port 166 adapted for connection with gas reservoir 168 externally
of strut 36. IFS module 20 includes right and left side gas
reservoirs 168 respectively mounted to chassis support structure
right and left sides 26, 28. Each gas spring 156 is adapted to
receive gas from and discharge gas to its connected gas reservoir
168, and is capable of containing gas at selectively variable
pressures so as to compensate for different loads between the strut
upper and lower ends 48, 50 and/or establish different nominal
axial distances therebetween, thereby enabling changes to vehicle
ride height and providing vehicle kneeling capabilities.
[0041] Referring now to FIG. 10, strut 36a is substantially
identical to strut 36 except for providing circular wall 170
sealably fixed within cylindrical damper body 140 just below
orifices 162, and sealed, third gas chamber 172 within damper body
140 between wall 170 and floating piston 148. Third gas chamber 172
provides damper 153 with a sealed nitrogen charge which bears on
the upper side of floating piston 148.
[0042] Forces imparted by the pressurized nitrogen in gas spring
156 urge strut upper and lower ends 48, 50 apart, and struts 36,
36a therefore upwardly support chassis support structure 24. Struts
36, 36a act in parallel with air springs 120 to upwardly support
chassis support structure 24 and other portions of a vehicle's
sprung weight relative to different portions of steering knuckles
38. Air springs 120 may thus be smaller than prior air springs
operably disposed in series connection with struts or other
springs, and positioned so as not to constrain rotative movement of
the steering knuckles, maximizing available wheel cut.
[0043] While exemplary embodiments have been disclosed hereinabove,
the present invention is not limited thereto. Instead, this
application is intended to cover any variations, uses, or
adaptations of the present disclosure using its general
principles.
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