U.S. patent application number 10/214872 was filed with the patent office on 2004-02-12 for vehicle suspension system.
Invention is credited to Brookes, Graham R..
Application Number | 20040026836 10/214872 |
Document ID | / |
Family ID | 31494733 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040026836 |
Kind Code |
A1 |
Brookes, Graham R. |
February 12, 2004 |
Vehicle suspension system
Abstract
A vehicle suspension system has a combination air spring/damper
mounted between spaced first and second components of a vehicle.
The damper has a fluid cylinder attached to the first vehicle
component and a piston rod connected to the second vehicle
component. The air spring has a piston and an end plate with an
intervening flexible bellows forming an air chamber. The air spring
piston is mounted on and surrounds the damper cylinder and the end
plate is secured to the second vehicle component, but at a separate
location from the attachment of the piston rod to distribute the
loading forces at the points of attachment. A flexible sealing
sleeve extends between the piston rod and an end plate opening of
the air spring through which the piston rod extends. A rigid
canister is mounted on the end plate of the air spring and extends
about the flexible bellows and has a sealing skirt at a lower end
which engages the damper cylinder.
Inventors: |
Brookes, Graham R.; (Carmel,
IN) |
Correspondence
Address: |
BRIDGESTONE AMERICAS HOLDINGS, INC.
1200 FIRESTONE PARKWAY
AKRON
OH
44317
US
|
Family ID: |
31494733 |
Appl. No.: |
10/214872 |
Filed: |
August 7, 2002 |
Current U.S.
Class: |
267/64.23 |
Current CPC
Class: |
F16F 9/0463 20130101;
F16F 9/54 20130101; B60G 13/003 20130101; B60G 2202/314 20130101;
B60G 2204/128 20130101; B60G 2204/129 20130101; F16F 9/05 20130101;
B60G 2202/152 20130101 |
Class at
Publication: |
267/64.23 |
International
Class: |
F16F 009/04 |
Claims
1. A vehicle suspension system comprising: first and second spaced
apart vehicle components; a damper having a cylinder and a piston
rod reciprocally mounted therein; a first attachment securing the
cylinder to the first vehicle component and a second attachment
securing the piston rod to a first portion of the second vehicle
component; an air spring including a piston mounted on the damper
cylinder and an end plate attached to a second portion of the
second vehicle component spaced from said piston rod second
attachment to said second vehicle component, and a flexible bellows
sealingly connected to and extending between the piston and the end
plate and forming an air chamber therein for containing a quantity
of air, with the piston rod extending through said air chamber and
through an opening formed in said end plate; and a flexible seal
extending about the end plate opening and piston rod to retain the
air within the air chamber.
2. The vehicle suspension system defined in claim 1 in which the
flexible seal includes an elongated flexible sleeve to provide for
conical movement of the piston rod during movement of the vehicle
components.
3. The vehicle suspension system defined in claim 2 in which the
flexible seal further includes a retaining collar mounted on an
extended end of the piston rod and a clamp ring securing a first
end of the elongated flexible sleeve to said collar.
4. The vehicle system defined in claim 3 in which the end plate
opening is defined by an annular flange; and in which a clamp ring
secures a second end of the elongated flexible sleeve to said
flange.
5. The vehicle system defined in claim 1 in which the second
attachment includes inner and outer of rigid concentric members and
an intervening annular elastomeric bushing and a fastener extending
through an opening in said inner member.
6. The vehicle system defined in claim 1 in which a restraining
canister is mounted concentrically about the air spring piston and
damper rod.
7. The vehicle system defined in claim 6 in which the restraining
canister is secured to the end plate of the air spring and extends
along an outer surface of the flexible bellows and terminates in a
flexible seal which extends about the damper cylinder.
8. The vehicle system defined in claim 7 in which the flexible seal
of the canister includes a flexible brush extending about and in
contact with the damper cylinder.
9. The vehicle system defined in claim 6 in which the canister is a
rigid non-metallic fabric.
10. The vehicle system defined in claim 9 in which the canister
fabric is an elastomeric sheet containing radial reinforcement
cords.
11. The vehicle system defined in claim 6 including a mounting
device for resiliently mounting the canister to the air spring end
plate.
12. The vehicle system defined in claim 1 in which the second
vehicle component is a frame channel having a web wall and at least
one outwardly extending channel leg; in which the channel leg wall
is formed with an opening with the piston rod extending through
said opening; and in which the second attachment secures the piston
rod to the web wall of the frame channel.
13. The vehicle system defined in claim 1 in which the first
attachment is a flexible bushing.
14. A vehicle suspension system comprising: first and second spaced
apart vehicle components; a damper having a cylinder and a piston
rod reciprocally mounted therein; a first attachment securing the
damper cylinder to the first vehicle component and a second
attachment securing the piston rod to the second vehicle component;
an air spring including a piston surrounding the damper cylinder
and an end plate attached to the second vehicle component at a
spaced location from said second attachment, and a flexible bellows
sealingly connected to and extending between the piston and the end
plate and forming an air chamber therein for containing a quantity
of air, with the piston rod extending through said air chamber and
through an opening formed in said end plate; a flexible seal
extending about the end plate opening and piston rod to retain the
air within the air chamber; and a restraining canister mounted
concentrically about the air spring and damper rod.
15. The vehicle suspension system defined in claim 14 in which the
flexible seal includes an elongated flexible sleeve and a retaining
collar mounted on an extended end of the piston rod and a clamp
ring securing a first end of the elongated flexible sleeve to said
collar.
16. The vehicle suspension system defined in claim 15 in which the
restraining canister is secured to the end plate of the air spring
and extends along an outer surface of the flexible bellows and
terminates in a flexible seal which extends about the damper
cylinder.
17. The vehicle suspension system defined in claim 16 in which the
flexible seal of the canister includes a flexible brush extending
about and in contact with the damper cylinder.
18. The vehicle system defined in claim 17 in which the canister is
a rigid non-metallic elastomeric sheet containing radial
reinforcement cords.
19. The vehicle system defined in claim 14 in which the end plate
opening is defined by an annular flange; and in which a clamp ring
secures a second end of the elongated flexible sleeve to said
flange.
20. The vehicle suspension system defined in claim 14 in which the
first vehicle component is a frame channel having a web wall and at
least one outwardly extending channel leg; in which the channel leg
wall is formed with an opening with the piston rod extending
through said opening; and in which the second attachment secures
the piston rod to the web wall of the frame channel.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates to vehicle suspension systems, and in
particular, to a combination air spring and damper in which the
mounting forces are decoupled from each other on one of the vehicle
components to reduce excessive loads on the attachment
locations.
[0003] 2. Background Information
[0004] Numerous suspension systems have been developed which
utilize a combination damper and air spring wherein the damper
cylinder is mounted to one vehicle component such as the wheel
suspension system, with the piston rod of the damper and air spring
end plate being attached to another vehicle component such as the
chassis. However, in these prior suspension systems, the air
spring, and in particular the end plate thereof and the piston rod
of the damper are attached at a common point. Although such
attachments perform satisfactory in many applications, it does
exert an excessive force on a common attachment location which
absorbs both the forces exerted on the air spring as well as the
damper.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention provides a vehicle suspension system
having a combination damper/air spring in which the damper has a
cylinder and a reciprocally mounted piston, with the cylinder being
attached to one component of the vehicle and an extended end of the
piston rod being attached to a second vehicle component. The air
spring surrounds the damper cylinder and the air spring end plate
being attached to the same vehicle component as is the piston rod,
but at a spaced location therefrom in order to distribute the loads
exerted on the damper and air spring to different parts of the
vehicle component.
[0006] The air spring end plate is attached to a leg of the chassis
frame channel and the piston rod extends through a hole in the
chassis leg and is attached to the web wall of the channel spaced
from the end plate attachment.
[0007] Another aspect of the invention is attaching the damper
cylinder and piston rod with a flexible bushing, each consisting of
a pair of concentric rigid cylinders having an intervening annulus
of elastomeric material providing resilient attachments.
[0008] Another feature of the invention is to provide an elongated
seal to enclose the end plate opening through which the piston rod
extends to prevent the escape of air from within the air chamber of
the air spring while permitting conical movement of the piston rod
with respect to its attachment location to compensate for
independent movement of the spaced vehicle components.
[0009] Still another feature of the invention is providing a rigid
canister which extends concentrically about and entraps the
flexible bellows of the air spring therein which can be either
rigidly or fixedly mounted to the end plate of the air spring or
the spaced vehicle component, and which is provided with a flexible
sealing skirt to retard the collection of debris and dirt on the
damper/air spring combination.
[0010] A further advantage of the invention is to mount the
restraining cylinder by a flexible member which allows the canister
to move with the damper/air spring and accommodate larger coning
angles of the damper piston rod.
[0011] A further feature of the invention is to form the
restraining canister of a rigid rubber material containing radial
reinforcement cords, thereby providing a rigid structure unaffected
by the harsh environment which is experienced by the suspension
system.
[0012] Another aspect of the invention is to provide a vehicle
suspension system which by separating the attachment loads,
provides improved damper tuning, ride isolation from the damper
bushing, improved damper bushing durability, and provides an
improved ride to the vehicle by reducing the vibration exerted on
the chassis by the damper/air spring combination.
[0013] The foregoing advantages, construction, and operation of the
present invention will become more readily apparent from the
following description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a side elevational view showing the improved
vehicle suspension system;
[0015] FIG. 2 is an enlarged fragmentary sectional view of FIG. 1;
and
[0016] FIG. 3 is an enlarged fragmentary sectional view of a
modified mounting arrangement for the outer restraining canister of
the suspension system.
[0017] Similar numerals refer to similar parts throughout the
drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 is a side elevational view of the improved vehicle
suspension system which is indicated generally at 1, which includes
a pair of spaced vehicle components indicated generally at 2 and 3,
having an air spring/damper combination 5 mounted therebetween.
Vehicle components 2 and 3 can be various structural parts of a
vehicle and in the preferred embodiment, component 2 is a channel
shaped chassis frame member having a web wall 6 and a pair of
spaced outwardly extending channel legs 7 and 8. Lower component 3
could be various components of the wheel assembly.
[0019] Air spring/damper combination 5 (FIG. 2) includes a damper
indicated generally at 10, having a cylinder 11 containing a fluid
such as oil, in which is reciprocally mounted a piston rod 12. The
lower end of cylinder 11 is connected to vehicle component 3 by an
elastomeric bushing indicated generally at 14. Bushing 14 includes
inner and outer rigid cylinders 15 and 16 respectively, between
which is compressed an annular elastomeric bushing sleeve 17. A
bolt 19 extends through inner cylinder 15 and is secured by a weld,
nut or other attachment means to vehicle component 3. Extended end
20 of piston rod 12 is secured to web wall 6 of vehicle component 2
by a similar bushing assembly having inner and outer rigid metal
cylinders 22 and 23 and an intervening elastomeric bushing sleeve
24, with a bolt 25 extending through inner cylinder 22 for
attachment to web wall 6.
[0020] Air spring/damper combination 5 further includes a usual air
spring 30 which includes a piston 31 which is mounted on and
extends about cylinder 11. One type of mounting would be to form a
central bore 33 in air spring piston 31 through which cylinder 11
is slidably mounted and retained by abutment of the end of cylinder
11 against a stepped shoulder 35 formed in piston 31. A plurality
of O-rings 36 may be mounted between bore forming wall 37 and
cylinder 11 to prevent the flow of air therebetween.
[0021] A usual elastomeric bellows 39 is sealingly clamped at one
open end by a clamp ring 40 against the upper end of piston 31 with
the other open end of bellows 39 being clamped between an annular
flange 43 of an end plate 41 and the upper end of a restraining
cylinder or canister 44 by another clamp ring 40 to form an
internal fluid chamber 32. End plate 41 is formed with an enlarged
central opening 45 defined by an annular upstanding flange 46 with
piston rod 12 extending through opening 45. Flange 46 extends
through a larger opening 47 formed in channel leg 7 of vehicle
component 2.
[0022] In accordance with one of the main features of the
invention, end plate 41 is connected to vehicle component 2 and in
particular to channel leg 7 thereof, so as to be connected to
component 2 at a different location than is the connection of
piston rod 12 with vehicle component 2. This spaced connection
separates the two forces, i.e., the force on the damper from the
force on the air spring. This reduces excessive loads in either
mounting system and hence, reduction in bracket and localized
chassis forces that are experienced when utilizing a common
mounting location. End plate 41 is connected to channel leg 7 by
bolts, welds, or other types of attachments. The diameter of
opening 45 is preferably sufficiently greater than the diameter of
piston rod 12 to permit conical movement of piston rod 12 therein
due to the independent movement of vehicle components 2 and 3,
without rod 12 contacting flange 46.
[0023] In accordance with another feature of the invention, a
flexible seal indicated generally at 50, closes end wall opening 45
to prevent the escape of air contained within internal fluid
chamber 32 into the surrounding atmosphere, and also provides for
conical movement of piston rod 12 with respect to air spring 30.
Seal 50 includes a flexible air impervious sleeve 53 which is
clamped to flange 46 by a clamp ring 54 and to a retaining collar
55 which is mounted on extended end 20 of piston rod 12 by another
clamp ring 57. Collar 55 is attached by welding or a slip-fit
connection to rod end 20 or to outer cylinder 23 of the upper
mounting bushing. A plurality of O-rings 58 may be mounted between
collar 55 and piston rod 12 to provide a fluid tight seal
therewith. Thus, air or other pressurized fluid in chamber 32 is
prevented from escaping through end plate opening 45 to the
surrounding atmosphere while permitting limited conical movement of
rod 12 within opening 45.
[0024] In accordance with still another feature of the invention,
substantially rigid restraining canister 44 surrounds air
spring/damper combination 5. Canister 44 preferably is secured to
end plate 41 and particularly to flange 43, by clamp ring 40 as
shown in FIG. 2. Rigid canister 44 can be formed of a rigid
material such as metal, plastic, or other synthetics or of a
relatively stiff rubber having internal radially extending
reinforcing cords 61, such as shown in FIG. 3. Canister 44
preferably extends to below piston 31 and may have a dust seal 63
mounted on the lower open end 64 of the canister to prevent the
accumulation of dirt and other debris around the air spring/damper
combination. Seal 63 preferably has an inwardly extending rigid
skirt 65 connected to the lower open end of canister 44, with a
flexible brush 66 extending between an open end 68 of the skirt and
cylinder 11. This flexible brush 66 also permits limited conical
movement of cylinder 11 within open end 68 of skirt 65.
[0025] A slightly modified canister mounting arrangement is shown
in FIG. 3 in which canister 44 is resiliently mounted by an
elastomeric sleeve 70 or other type of resilient connection, to
flange 43 of end plate 41 by clamp ring 40. This flexible mounting
provides for additional movement of restraining canister 44 and air
spring/damper combination 5 without damaging any of the protected
components, and preferably will be used when canister 44 is formed
of a relatively rigid and stiff material. The flexible canister
preferably will be clamped directly to end plate 41.
[0026] While embodiments of the invention have been described, the
invention is not limited thereto, but can have other modifications
and arrangements without affecting the concept of the
invention.
[0027] In the foregoing description, certain terms have been used
for brevity, clearness, and understanding. No unnecessary
limitations are to be implied therefrom beyond the requirement of
the prior art because such terms are used for descriptive purposes
and are intended to be broadly construed.
[0028] Moreover, the description and illustration of the invention
is an example and the invention is not limited to the exact details
shown or described.
* * * * *