Patent Application
20070241527
The subject invention relates to a vehicle suspension that utilizes a unique pogo rod and bracket configuration to replace standard torque rods for controlling suspension and axle travel.
Vehicle suspension systems are used to absorb road load inputs and other vibrations to provide a smooth and comfortable ride. Vehicle suspension systems include various components that couple an axle member to a vehicle frame or sub-frame. A typical suspension system includes upper and lower torque rods that extend between each end of the axle member and the vehicle frame. Each end of the torque rod is connected to an associated vehicle or axle bracket with a bushing mount. This requires complicated bracket assemblies and multiple fastening elements, which is undesirable.
Vehicle suspension systems also often include a stabilizer bar that is used to increase roll rigidity and improve steering stability. Typically, the stabilizer bar is connected to lower control arms, which are mounted to a wheel component, such as a knuckle. To further improve suspension characteristics, a transverse torque rod is often used to connect one axle end to the vehicle frame at an opposite axle end. Again, these connection interfaces for the stabilizer bar and transverse torque rods require complicated bracket configurations.
Further, these bushing and bracket type connection interfaces have limited degrees of relative movement. Suspension systems are needed that more effectively absorb road load inputs and vibrations without adding additional hardware, which overcomplicates the system. Thus, there is a need for a simplified suspension connection interface between an axle and a vehicle frame that provides a more comfortable vehicle ride.
A vehicle suspension system utilizes a resilient rod and bracket configuration to replace standard torque rods. Resilient rods are used to couple an axle member to a vehicle member. The axle member includes an axle bracket and the vehicle member includes a vehicle bracket. Upper and lower resilient rods are coupled to the axle and vehicle brackets at each axle end.
The resilient rods are pogo rods that utilize a pair of resilient grommets at each rod end that are compressed against a bracket flange by a pair of rigid cups to provide a resilient mount interface. This resilient mount interface at each rod end allows relative movement between the axle and vehicle brackets and each rod end in up to ten degrees of freedom.
The vehicle brackets and axle brackets are simplified as each bracket has to have only one opening for each rod end. Thus, the axle bracket only has two (2) openings, one for the upper resilient rod and one for the lower resilient rod. Correspondingly, the vehicle bracket only has two (2) openings, one each for the upper and lower resilient rods.
The pogo rods can be used to replace standard torque rods in all locations within a vehicle suspension, including a transverse torque rod. Further, the pogo rods can be used to replace linkage traditionally used for connecting a stabilizer bar between the axle member and the vehicle member. Further, the pogo rods are easily incorporated into suspensions for I beam or tubular front or rear axles.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
In the example shown, each of the first 20 and second 22 axle ends includes an upper pogo rod 30a and a lower pogo rod 30b (indicated by dashed lines). The suspension system 16 could also include a transverse pogo rod 32 that extends from an axle bracket 34 at one axle end to a vehicle bracket 36 mounted to the vehicle frame 18 at an opposite axle end.
One end of the suspension system 16 is shown in greater detail in
In this example, the axle 10 comprises a non-drive axle having an I-beam configuration as shown. The axle mount portion 42 of the axle bracket 24 is mounted to an upper surface of the axle 10. The vehicle mount portion 38 of the vehicle bracket 26 is mounted to the vehicle frame 18, which could comprise a longitudinally extending channel beam, for example. The upper 30a and lower 30b pogo rods extend generally parallel to each other between the flange portions 40, 44 of the vehicle 26 and axle 24 brackets. Another pogo connection 31 extends between the vehicle frame 18 and lower pogo rod 30b as shown.
The pogo rod 30 is shown in greater detail in
Preferably, the first 54 and second 56 rods ends are threaded such that the first 62 and second 64 rigid cups are threadably attached to the rod body 52. The first 62 and second 64 rigid cups are preferably formed from a steel material, however, other rigid materials could also be used. Jam nuts 66 could optionally be used to further secure and hold the first 62 and second 64 rigid cups in place.
As shown in
The combination of the first 58 and second 60 elastomeric components, and the first 62 and second 64 rigid cups cooperate with the bracket flange 68 to allow relative movement in up to ten degrees of freedom. Thus, the rod body 52 can rotate, twist, and move axially relative to the vehicle 26 and axle 24 brackets.
Further, the vehicle 26 and axle 24 brackets are significantly simplified compared to traditional torque rod mounts. One example of this simplified bracket configuration is shown in greater detail in
The axle bracket 24 includes a first flat portion 76 that mounts to the axle 10 and a second flat portion 78 that receives the upper 30a and lower 30b pogo rods. The first 76 and second 78 flat portions are preferably orientated in the shape of a T.
For both second flat portions 72, 78, only two (2) openings 80 are required to be formed in the respective vehicle 26 and axle 24 bracket, as shown in
Another example configuration is shown in
By welding the axle bracket 84 to the tubular axle 82, traditionally used U-bolt attachments are eliminated, which results in weight and cost savings. Further, no re-torque is required, which reduces maintenance.
Another example of a five (5) pogo rod configuration, similar to that of
The fifth pogo rod could be eliminated by orientating either of the upper 30a and lower 30b pogo rods at each end of the axle 10 in a V-shaped configuration. The upper pogo rods 30a would form an upper V-shape, and the lower pogo rods 30b would form a lower V-shape. Apexes of the upper and lower V-shapes would be positioned at the axle 10.
Pogo rods 30 can also be used for a linkage assembly for the stabilizer bar 48 as shown in
The stabilizer bar 48 is also connected to the axle 10 as shown
As shown in
Another suspension embodiment is shown in
The subject invention provides a suspension system that is lighter and more cost effective than traditional trailing arm front air suspensions. Pogo rods are used as a linkage control to replace traditional torque rods. This significantly reduces system cost and the associated brackets are drastically simplified with regard to design and fastener requirements.
A standard five (5) pogo rod configuration provides two upper trailing arms, two lower trailing arms, and a transverse arm. As discussed above, the transverse arm could be removed by mounting the upper trailing arms in a first V, and mounting the lower trailing arms in a second V, to absorb transverse loads in addition to fore-and-aft loadings. Sway is controlled by using smaller pogo rods as the linkage for the stabilizer bar.
The bracket designs at both the vehicle frame and axle are simplified as only one hole is required for attaching each pogo rod end. The hole has the same size for all attachments. This eliminates bosses and fasteners traditionally needed to attach a typical straddle mount torque rod.
The subject invention can be used for many different axles including an I-beam front axle, a tubular box section front axle, or any truck or trailer rear axle such as a tag axle, pusher axle, drive axle, etc. Further, by having the upper and lower pogo rods parallel to each other, brake dive, i.e. steering effect, issues are reduced. These issues can be a problem for a leaf spring or traditional trailing arm suspension.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
