Opposing spring rebound tension suspension system - BRYANT PETER E.
Jounce and Rebound. • Jounce is the upward movement or compression of suspension components. • Rebound is the downward movement or. As the control arm travels through jounce and rebound, the rubber portion of the bushing will twist and stretch. This action transfers energy into the bushing and. The tire's ability to develop cornering force, in relation to its vertical load, . Modern tires can develop a friction coefficient as high as , which means .. A small camber change during jounce and rebound is characteristic of the strut design.
During suspension movement, the torsion bar will twist, providing spring action. Air Springs The air spring is another type of spring that is becoming more popular on passenger cars, light trucks, and heavy trucks. The air spring is a rubber cylinder filled with compressed air. A piston attached to the lower control arm moves up and down with the lower control arm.
This causes the compressed air to provide spring action. If the vehicle load changes, a valve at the top of the airbag opens to add or release air from the air spring. An onboard compressor supplies air. Tires as Springs An often-overlooked spring is the tire. Tires are air springs that support the total weight of the vehicle.
The air spring action of the tire is very important to the ride quality and safe handling of the vehicle. As a matter of fact, tires may be viewed as the number-one ride control component.
Tire size, construction, compound and inflation are very important to the ride quality of the vehicle. Radial ply tires have ply cords, which run across the centerline of the tread and around the tire. The two sets of belts are at right angles. Some belts are made of steel wire; others are made of polyester or other substances. Today, radial tires come as original equipment on most passenger cars and light trucks. Bias ply tires use cords that run at an angle across the centerline of the tire tread.
The alternate ply cords cross at opposite angles. Bias belted tires are the same as bias ply, with the addition of layers of cords - or belts - circling the tire beneath the tread. Both of these types of tires will most likely be found on older model vehicles. The air pressure determines the spring rate of the tire. An over inflated tire will have a higher spring rate and will produce excessive road shock.
Over inflated tires will transmit road shock rather than reduce it. Over or under inflation also affects handling and tire wear. When adjusting tire pressure, always refer to the vehicle manufacturer's specifications, not the specification on the side of the tire. The air pressure specified by the vehicle manufacturer will provide safe operation and best overall ride quality of the vehicle.
What is claimed is:
The tire pressure stamped on the side is the maximum pressure a tire is designed to hold at a specific load. Strut Mount Design Strut mounts are vehicle specific, and there are numerous designs in use today on both front and rear suspension systems.
- Meaning of "jounce" in the English dictionary
The three most common designs are inner plate, center sleeve, and spacer bushing. The inner plate is designed so the strut piston rod cannot push through the upper or lower surface plate if the rubber core fails.
This design generally does not require washers. Due to the fact that the upper and lower service plates mostly cover the rubber portion of the mount, it is difficult to see if the inner rubber bushing has failed.What does rebound relationship mean?
However, these components wear over time and with a thorough inspection a proper recommendation can be made. The bearing is located on the bottom of the strut mount and is not serviceable. Defective bearing will require replacement of the entire strut mount. This design provides increased side to side stability.
The strut stem extends through the center sleeve.
JOUNCE - Definition and synonyms of jounce in the English dictionary
Upper and lower retainer washers prevent the strut rod from pushing through the strut mount. The bearing is a separate component from the strut mount. If inspection reveals cracks or tears in the rubber bushing, replacement is required. If the bearing is found to be defective it can be replaced separately.
The operation is similar to the style we just discussed except the bearing is pressed in the strut mount. The bearings, washer, and the upper plate retain the strut rod. If the rubber bushing is cracked, torn, or the bearing is binding or seized, the strut mount requires replacement.
Anti-Sway Bars Another important component of a suspension system is the anti-sway bar. This device is used along with shock absorbers to provide additional stability. The anti-sway bar is simply a metal rod connected to both of the lower control arms. When the suspension at one wheel moves up and down the anti-sway bar transfers the movement to the other wheel. In this way the sway bar creates a more level ride and reduces vehicle sway or lean during cornering.
Bushings Bushings are used in many locations on the vehicle suspension system. Most bushings are made with natural rubber. However, in some cases, urethane compounds may be used. Bushings made of natural rubber offer high tensile tear strength and excellent stability at low temperatures. Natural rubber is an elastomeric material. Elastomeric refers to the natural elastic nature of rubber to allow movement of the bushing in a twisting plane.
Movement is controlled by the design of the rubber element. Natural rubber requires no lubrication, isolates minor vibration, reduces transmitted road shock, operates noise free, and offers a large degree of bushing compliance.
Bushing compliance permits movement without binding. Natural rubber resists permanent deflections, is water resistant and very durable. In addition, natural rubber offers high load carrying capabilities. As with all suspension system components, control arm bushings are dynamic components, meaning that they operate while the vehicle is in motion.
Control arms act as locators because they hold the position of the suspension in relation to the chassis. They are attached to the vehicle frame with rubber elastomeric bushings. During suspension travel, the control arm bushings provide a pivot point for the control arm. They also maintain the lateral and vertical location of the control arm pivot points, maintain dynamic wheel alignment, reduce transmitted noise, road shock, and vibration, while providing resistance to suspension movement.
During suspension travel the rubber portion of the bushing must twist to allow control arm movement. Control arm bushings that are in good condition act as a spring; that is, the rubber will spring back to the position from which it started.
This twisting action of the rubber will provide resistance to suspension movement. As previously stated, control arm bushings are dynamic suspension components. As the control arm travels through jounce and rebound, the rubber portion of the bushing will twist and stretch. All existing coil springs, load leaf springs, air springs, torsion bars or rubber blocks suspensions have no provision for control of the rebound forces of inertia and gravity negative suspension loads.
Particularly, those rebound loads occurring at the inside wheel during hard cornering or if a wheel drops into a pot-hole. These devices help somewhat the vehicle resist roll but only as it relates to the body lean, because they are fixed to the sprung mass and leaning with the body. Thus, they actually reduce the load on the unloaded side of the vehicle.
They use the body as a structure to support the torsion bar of the anti sway system transferring wheel jounce motion across to the opposite side. The disclosure herein will obviate the need for anti-sway bars saving the cost of providing and installing them. Shock absorbers only dampen the bouncing movement of the vehicle wheels and suspension caused by the reaction to road surface, cornering and braking. Thus, the rate of sway may be affected to a minor degree.
Meanwhile the springs on the side of the vehicle, following the inside of the turn, unload extending toward their free position using the axle as a location for inducing lift of the sprung weight on that side resulting in increased body roll. The Roll Center axis is a function of the particular vehicle's suspension geometry. Roll or sway is increased if the vehicle center of gravity is raised as in a SUV, four-wheel drive vehicle or truck. A sudden turn opposite the direction of vehicle travel can cause momentum to continue the sway of the vehicle forcing its center of gravity to move laterally past its maximum upright position, and so the vehicle continues on rolling and overturns.
The techniques disclosed in the various embodiments of ' are in the nature of an overload spring that engages and changes the spring constant at the extremes of wheel travel. There is no spring in ' connected to specifically resist rebound forces due to diverging motion of the sprung weight to unsprung weight.
The graph in ' showing wheel travel verses spring forces verifies these conclusions. In addition to many disclosures in ' of prior paired spring configurations there is a specific explanation in column 5, lines 1 through 5 as follows: At best the structures for multiple springs shown in these patents have differing spring rates to give an allegedly more comfortable ride.
An opposing spring suspension can have little effect on the ride stiffness but stabilizes cornering and evasive maneuvering sway by helping the vehicle to resist roll while maintaining the general ride quality.
The added spring communicates roll resistance to the vehicle axle at its top center section. Force is concurrently applied at the ends of the stabilizing spring to the leaf spring of the vehicle by shackles.
Adjustment of the device is achieved by use of a plurality of mounting apertures for the shackles located at varying distances from the center of the stabilizing spring thereby allowing for adjustment by the user for desired performance characteristics. Further force adjustment is achieved with one or a combination of an optional axle spacer located at the center section of the stabilizing spring to communicate with the axle.
This stabilizer system does not employ opposing spring technology. The center of gravity of the unsprung mass relative to the center of gravity of the sprung mass is affected during the cornering maneuvers.