Patent Application
20160031281
This disclosure relates to air suspensions and, more specifically, air reservoirs for air suspensions.
Some vehicles utilize air suspensions having air springs or pneumatic springs to provide relative motion between the chassis of the vehicle and the wheels. Generally, air suspensions utilize air in lieu of conventional, mechanical springs and other suspension components.
An air suspension system, such as those usable with a vehicle, is provided. The air suspension system includes a rigid frame member defining a fixed volume, which is unsealed. An air reservoir is disposed within the fixed volume and variably occupies the fixed volume.
The air reservoir includes a flexible bladder expandable between an unfilled volume, a first filled volume, and a second filled volume larger than the first filled volume. The first filled volume and the second filled volume at least partially expand into the fixed volume of the rigid frame member. A fill port is formed in one end of the flexible bladder and provides access to the expandable volume.
The air reservoir also includes a feed tube disposed through the fill port into the expandable volume and in airflow communication with the expandable volume. At least one air spring is in airflow communication with the air reservoir.
The above features and advantages, and other features and advantages, of the present subject matter are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the disclosed structures, methods, or both.
Referring to the drawings, like reference numbers correspond to like or similar components wherever possible throughout the several figures.
A compressor assembly 4 supplies pressurized air to a plurality of air springs 6 through one or more valves in a valve assembly 8. As shown in
The air springs 6 receive pressurized air from the air reservoir 16, and possibly directly from the compressor assembly 4, to adjust the height of the vehicle 2 relative to the road surface by adjusting the air suspension system 10. The compressor assembly 4 and the valve assembly 8 may be operated by a control system (not shown), and the air springs 6 may return pressurized air to the air reservoir 16.
Referring also to
The rigid frame member 12 shown in
The rigid frame member 12 may be, for example and without limitation: a structural element of a body-on-frame chassis, a body-frame-integral chassis, or a chamber within a body panel. In many configurations, the rigid frame member 12 is a load-bearing or supporting member of the vehicle 2. Regardless of the primary function of the rigid frame member 12, it is an otherwise-structural element that defines the fixed volume 14 in which the air reservoir 16 is at least partially disposed. The fixed volume 14 is unsealed, such that it could not act as a reservoir for the air spring system 10.
While the systems may be described with respect to automotive or vehicular applications, those skilled in the art will recognize broader applicability. Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” et cetera, are used descriptively of the figures, and do not represent limitations. Any numerical designations, such as “first” or “second” are illustrative only and are not intended to be limiting.
Features shown in one figure may be combined with, substituted for, or modified by, features shown in any of the figures. Unless stated otherwise, no features, elements, or limitations are mutually exclusive of any other features, elements, or limitations. Any specific configurations shown in the figures are illustrative only and the specific configurations shown are not limiting of the claims or the description.
Referring to
In the air suspension system 10 shown, a flexible bladder 20 is disposed within the fixed volume 14 of the rigid frame member 12. The rigid frame member 12 and the flexible bladder 20 are show sectioned to illustrate the remaining components of the air reservoir 16. The rigid frame member 12 shown may be only a portion of the chassis or frame section into which the air reservoir 16 is disposed.
The flexible bladder 20 defines an expandable volume that is expandable between at least a first filled volume 22A and a second filled volume 22B from an unfilled volume 22C. The first filled volume 22A is illustrated in
The second filled volume 22B may be at least two times larger than the first filled volume 22A and at least ten times larger than the unfilled volume 22C. As the flexible bladder 20 expands from the unfilled volume 22C to the first filled volume 22A and to the second filled volume 22B, the flexible bladder 20 progressively occupies more of the otherwise unusable void within the rigid frame member 12.
Note that the relative sizes of the components shown in the figures are schematic and illustrative, but may not match the actual relative dimensions of the rigid frame member 12 or the flexible bladder 20 used in the air reservoir 16. All of the volumetric states shown in
A fill port 24 is formed in one end of the flexible bladder 20. The fill port 24 provides access to the expandable volume, and the flexible bladder 20 may be oriented such that the fill port 24 is substantially adjacent to the access hole 18 of the rigid frame member 12.
A feed tube 26 is disposed through the fill port 24 into the expandable volume. The feed tube 26 is in airflow communication with the expandable volume, such that air may be removed from, or added to, the flexible bladder 20 via the feed tube 26. At least a portion of the feed tube 26 is hollow, and one or more flow holes 28 or ports may be formed in the feed tube 26.
The feed tube 26 has a fill end 30 formed on one end thereof and a push end 32 formed opposite the fill end 30. The fill end 30 is substantially sealed to the fill port 24 of the flexile bladder 20. The push end 32 is disposed within the expandable volume. The flow holes 28 are illustrated as defined in the push end 32 but may be disposed along additional portions of the feed tube 26.
During assembly of the air suspension system 10, the air reservoir 16 may be installed or inserted into the fixed volume 14 of the rigid frame member 12 while the flexible bladder 20 is at the unfilled volume 22C (as illustrated in
In some configurations of the air reservoir 16, the push end 32 of the feed tube 26 may be attached to the flexible bladder 20 opposite the fill port 24, which may assist in inserting the flexible bladder 20 into the fixed volume 14. An air fitting 34 and a mounting plate 36 may assist in assembly of the air reservoir 16 to the rigid frame member 12 and communication with the remainder of the air suspension system 10. The flexible bladder 20 may be crimped or clamped to the feed tube 26 or may be held and sealed to the feed tube 26 as part of the air fitting 34 or mounting plate 36.
As shown in
The flexible bladder 20 may be held to the feed tube 26 for installation into the fixed volume 14 of the rigid frame member 12. As illustrated in
The sacrificial bands 40 may be formed from, for example and without limitation: plastic, rubber, thin metal straps, or other materials configured to break as the flexible bladder 20 expands. The sacrificial bands 40 may also include joints or other localized areas designed to facilitate breaking of the sacrificial bands 40 as the flexible bladder 20 expands.
After the sacrificial bands 40 break, the flexible bladder 20 expands to the first filled volume 22A and then to the second filled volume 22B, which is substantially restrained by the rigid frame member 12 and constrained within a portion of the fixed volume 14. The flexible bladder 20 shown in
The flexible bladder 20 may be formed from various materials, including, for example and without limitation, fiber-reinforced rubber. Reinforcement fibers may include, for example and without limitation: aramid, glass, or polyester. The flexible bladder 20 may be formed from non-corroding materials to limit corrosion between the rigid frame member 12 and the air reservoir 16, including galvanic or other electrochemical corrosion that may occur between metals. The flexible bladder 20 is an alternative to rigid, fixed-volume tanks, such as those formed from steel, aluminum, or other metals.
The feed tube 26 may be formed from, for example and without limitation: steel, aluminum, stiff rubber, or plastic. The feed tube 26 may be substantially rigid or may be flexible, in order to ease installation when the fixed volume 14 has limited space or odd angles relative to the access hole 18 or other access areas or points. Note that
The flexible bladder 20 will conform to the shape of the fixed volume 14 within the rigid frame member 12 when inflated, such as the more-complex shape illustrated in
Therefore, the rigid frame member 12 may provide some structural support for the air reservoir 16, without affecting the load-bearing or structural functionality of the rigid frame member 12 within the vehicle 2. Furthermore, the flexible bladder 20 is capable of contouring to the shape of the fixed volume with the rigid frame member 12. Contrarily, metal tanks used as air reservoirs provide substantially all of the force countering the interior pressure and are unable to alter shape or contour within structural members.
In some configurations of the air reservoir 16, the fixed volume 14 of the rigid frame member 12 may greatly exceed the size of the first filled volume 22A or the second filled volume 22B, such that the flexible bladder 20 may have little contact with any walls of the rigid frame member 12 other than portions adjacent the access hole 18. In other configurations of the air reservoir 16, the fixed volume 14 of the rigid frame member 12 may be substantially filled by the flexible bladder 20 as it reaches the second filled volume 22B, such that all available space is used and the flexible bladder 20 is closely contoured to the shape of the fixed volume 14. Note however, that the flexible bladder 20 is sealed and the rigid frame member 12 is unsealed, such that the fixed volume 14 could not be used as an air reservoir on its own, without the flexible bladder 20.
The flexible bladder 20 and feed tube 26 allow the air reservoir 16 to be packaged largely within otherwise unusable space. Rigid metallic tanks are generally attached to the underside of vehicles and occupy volumetric space usable for other vehicle components. However, the air reservoir 16 may occupy the otherwise unusable space within the rigid frame member 12.
The rigid frame member 12 may provide some protection from road debris or objects that could puncture the flexible bladder 20. Therefore, the air reservoir 16 uses the rigid frame member 12 to structurally support the flexible bladder 20 and also to protect the flexible bladder 20.
Referring now to
The air reservoir 116 has a flexible bladder 120 disposed within the fixed volume 114. The air reservoir 116 has an end-mounted configuration such that the rigid frame member 112 does not require an access hole and the flexible bladder 120 may be mounted by insertion or installation through an open end 118 of the rigid frame member 112. The air reservoir 116 may be disposed loosely within the fixed volume 114 or may attached to the open end 118 with a cap or bracket 121, as illustrated.
The flexible bladder 120 defines an expandable volume 122 and a feed tube 126 extends into the expandable volume 122. The feed tube 126 may be substantially straight (as shown in
Referring now to
The air reservoir 216 has a flexible bladder 220 disposed within the fixed volume 214. The flexible bladder 220 defines an expandable volume 222 between a fill port 224 and an end plug 225. A feed tube 226 extends through the fill port 224 into the expandable volume 222 and has flow holes 128 to provide airflow communication with the expandable volume 222. The fill port 224 also includes plug structure.
As illustrated in
As used herein, the term substantially refers to quantities, values, dimensions, or alignments that are within manufacturing variance or tolerance ranges of being exact. Substantially equal dimensions, for example, may be planned as ideally equal but normal manufacturing tolerances may cause the resulting dimensions to vary by 10-20% for different pieces. Substantially aligned, for example, refers components that are intended to be truly aligned but may be slightly offset when assembled under real world manufacturing conditions.
The detailed description and the drawings or figures are supportive and descriptive of the subject matter discussed herein. While some of the best modes and other embodiments for have been described in detail, various alternative designs, configurations, and embodiments exist.
