Patent Application
20230256785
This invention pertains to sway bar systems, and a method of controlling their operation. Specifically, this invention relates to use of a hydraulic cylinder allowing control of the displacement of a sway bar on a vehicle, and to use of one electronic control unit to regulate flow of fluid within said hydraulic cylinder.
Sway bar, anti-sway bar, roll bar or anti-roll bar systems for vehicles typically function by forcibly maintaining both right and left sides of said vehicle leveled. In detail, a sway bar is coupled to a vehicle frame, each right and left end of said sway bar are respectively connected to vehicle's right and left wheel axle thanks to sway bar links. Said sway bar acts like a torsion spring helping vehicle's suspension to maintain vehicle leveled.
Heretofore, the general approach for adjusting the response characteristics of this sway bar system has been to modify the length of said sway bar links. More specifically, this has been accomplished by replacing said sway bar links by adjustable hydraulic dampers, controlled manually or electronically.
Past manually or electronically controlled sway bar damper links utilize a manual or electronic control device, such as valves piloted by solenoids, located on each said sway bar damper links. By controlling said valves, a fluid path is opened allowing fluid to flow between a damper link cylinder and its own fluid reserve, resulting in a change of damping characteristics of said sway bar links, and so of the entire vehicle's sway bar system.
In more common sway bar systems, response characteristic adjustment works in a way that sway bar links are disconnected from vehicle's wheel axle sides, allowing right and left vehicle's sides to travel independently and without the resistance of the vehicle sway bar torsion spring characteristic.
Examples of such electronically controlled sway bar damper links are described and shown in US Patent US 2019/0100071 A1, and depict a sway bar system composed of at least one electronically controlled damper links, each electronically controlled damper links comprising its own fluid reserve cylinder, and its own electronic valve.
In the event of using two damper links on each side of the vehicle and independently controlling each sway bar links through its own electronic control system, such design would significantly rise the production cost of said sway bar system, in addition of increasing the total amount of electric energy required to use said sway bar system.
In any event, such sway bar system includes sway bar links that do not use a mix of fluid and gas in their main damper cylinder, and to function properly need their own fluid reserve comprising a fluid chamber, a gas chamber, and an internal floating piston, which would significantly rise the production cost of said sway bar system, and create a difficulty in adapting such system to any vehicle, as freeing enough room to mount such design around a vehicle wheel area can be hard to achieve.
Finally, such design does not describe a way to hydraulically control its system while not electronically controlled. By doing so, said sway bar system constantly relies on electronic inputs in order to function properly, which would also increase the total amount of electric energy required to use said sway bar system, and more importantly, in the event of an electric failure, such sway bar system would not be usable anymore, and the safety of the vehicle and users would be compromised.
To achieve optimum electronic control of a vehicle's sway bar system response characteristic, it would be advantageous to develop innovative devices allowing efficient and compact valve control.
This invention pertains to sway bar systems, and a method of controlling their operation. Specifically, the present invention relates to provide a way of adjusting the response characteristics of a sway bar system by changing the structure of the typical sway bar links and regulating the modified structure by utilizing an electronically adjustable sway bar link. Said electronically adjustable sway bar link comprises a twin tube cylinder filled with mixed incompressible fluid and pressurized gas and forms a determined volume in order to host pressurized gas higher than fluid flow regulation functions, permitting a directional control valve to always remain fully submerged in incompressible fluid and to modify the fluid path between each tube of said twin tube cylinder, allowing closed or opened fluid flow operation, determined by a controlling device receiving an electronic input and piloting said directional control valve.
This invention allows high performance and simple adjustability of a vehicle's sway bar response characteristics by lowering amount of parts, cost, electric energy consumption, and vehicle's clearance required for installation.
A clear understanding of the electronically adjustable sway bar link summarized above may be add by examining the figures below. The figures display and reference the assembly, which are not necessarily drawn to scale. Accordingly:
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. Furthermore, the term “sway bar” refers to an anti-sway bar, a roll-bar, an anti-roll bar, a stabilizer bar or any similar system, while “hydraulic cylinders” refers to any damper cylinder, such as a shock or similar devices. An “eyelet” refers to the mounting of the hydraulic cylinders shaft to a chassis mounting point.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one having ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In describing the invention, it will be understood that several techniques and steps are disclosed. Each of these has individual benefit and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps in an unnecessary fashion. Nevertheless, the specification and claims should be read with the understanding that such combinations are entirely within the scope of the invention and the claims.
An electronically adjustable sway bar link and its use is discussed herein. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details.
The present disclosure is to be considered as an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated by the figures or description below.
The present invention will now be described by referencing the appended figures representing preferred embodiments.
Once said electronically adjustable sway bar link (16) is assembled, it forms a determined volume (9) at the upper end of said twin tube cylinder as depicted on
When in operation, the directional control valve (11) of the electronically adjustable sway bar link (16) depicted in
When in operation, the directional control valve (11) of the electronically adjustable sway bar link (16) depicted in
When said controlling device (14A) receives an electronic input, said controlling device (14A) sets the directional control valve (11) to its said open flow configuration (12A) which allows fluid to flow in any direction from said outer tube (1) to said inner tube (3). As said shaft (5) needs to travel through said twin tube cylinder inner tube (3), said open flow configuration (12A) allows fluid to flow from below said piston (7) in said inner tube (3), through said directional control valve (11), across said outer tube (1), through said flow regulation holes (4A), and finally back in said inner tube (3) below said piston (7), thus allowing said shaft (5) to travel through said inner tube (3) and collapsing electronically adjustable sway bar link (16).
When in operation, the controlling device (14A) receives an electronic input generated by an external electronic control unit (22). Said input is determined manually by vehicle's user through a human interface connected to said external electronic control unit (22), or automatically by an algorithm programmed into said external electronic control unit (22), and calculated with transmitted inputs from vehicle sensors such as speed, roll angle, roll angle rate, lateral acceleration, and steering angle.
Said directional control valve (11) is piloted by said controlling device (14A) received electronic inputs generated by said external electronic control unit (22), and regulates fluid flow between said outer tube and said inner tube in order to change the damping characteristic of the electronically adjustable sway bar link (16).
The operation of controlling device (14A) increases or decreases the response characteristics of the vehicle's sway bar (21).
This electronically adjustable sway bar link is designed to fit any on-road or off-road vehicle, such as automobiles, trucks, recreational vehicles, utility vehicles.
This electronically adjustable sway bar link is designed to work with any style of sway bar systems. This design offers an efficient and compact way of electronically controlling the response characteristics of a vehicle's sway bar, as it is all contained within one outer tube, rather than controlling each sway bar link with its own fluid reserve.
It also provides efficient performance, as sway bar links mounted in such way where pressurized gas remain in the upper end of the damper cylinder, keeps the fluid flow regulation functions always submerge in incompressible fluid.
Electric energy savings is another great advantage of the present electronically controlled adjustment system for sway bars, as specific hydraulic connections allow this system to function safely without using electric energy when not in operation.
Finally, the production cost of such system is lowered as less parts are required for the final assembly, which also allows an easier adaptation on any vehicle as less room around vehicle wheel axles is required for proper mounting.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/309,503, filed Feb. 11, 2022. The entire contents of Application Ser. No. 63/309,503 are hereby incorporated by reference herein.
