Vehicle Suspension Is The Mechanism Engineering Essay Example

spring are connected by a ball articulation, which is built into the terminal of the suspension arm. Additionally, the rubber mount is molded at the other terminal. This design allows the suspension parts to work freely, making it the most common type of suspension in the market today. However, this system requires a more solid body or sub frame construction. Additionally, even slight changes in wheel path can cause scouring during the bounce of one wheel. Furthermore, precise alignment of the steering geometry is crucial and requires more attention (Crankshaft).

Dependent suspension

This system typically connects two wheels that are parallel to each other on the same rigid, straight, and vertical axle. Because all mechanical linkages work together, any motion of one wheel can affect the motion of the other wheel when the vehicle encounters road shocks or abnormalities. Due to its durability, this system is commonly used in heavy trucks, SUVs, and rear-wheel-drive cars.

Semi independent suspensions: This system uses a cross member to connect the two tracking weaponries. Despite the strong connection between the cross member and the tracking weaponries, the cross member will twist with each upward and downward motion of the wheels. This twisting action provides semi independent motion and stabilizes the vehicle. The suspension aims to reduce body displacement and improve vehicle stability.

The suspension system consists of a shock absorber and spring, which do not add energy to the system but instead receive energy from other sources like the engine. This energy affects the motion of the vehicle body and limits it close to its equilibrium (Genta & Morello, 2009, p.358).

Examples of passive and active suspension:

• Passive suspension system
• Active suspension
  

system

SUSPENSION Components:
Coil springs: These heavy-duty steel wires support the weight of the vehicle and absorb energy from road shocks or vibrations between the road and the vehicle body.

Springs are typically positioned between control mechanisms and the human body or around the McPherson strut. They come in various forms such as conelike or coiling lesions, with constant or uneven rates, variable pitch spacing, and different wire thicknesses. Coil springs can be customized and used in various configurations within the suspension system (Ciulla, 2002).

Muffling members

When a vehicle encounters road shocks, the spring absorbs the energy and deflects, causing a bouncing motion that affects the car's handling and comfort. To prevent this, muffling members, also known as shock absorbers, are installed. These members are designed to store this oscillation energy and allow the spring to return to its original state.

There are multiple types of shock absorbers available today, including hydraulic, lever type, and telescopic direct moving type (Hillier, 1991, p. 364).

Leaf spring:

This particular spring is primarily utilized in heavy and commercial vehicles.

The suspension system consists of toughened steel or composite material leaves or bases that are connected to the vehicle frame and axle using U bolts. These metal plates rest against the leaf springs and ensure that the springs remain level against the axle, preventing shaking when driving with a heavy load. The U bolt also provides flexibility when encountering road shocks and vibrations.

The foliage spring form allows for flexibility and shock absorption. This type of spring is highly reliable and strong for transporting heavy loads. It also helps distribute the weight evenly across the entire structure, unlike the spiral spring which only transfers the weight to

a single point (Spring-makers-resource.net).

Torsion bar:

These metal bars function as springs and can be twisted along their axis. Their main purpose is to withstand the twisting force applied to the vehicle as it moves. Once the force is countered, the bar usually returns to its original state.

This text describes the function of the tortuosity saloon and the anti axial rotation bar in a vehicle's suspension system. The tortuosity saloon opposes the forces generated by the vehicle's motion, but it lacks in providing a progressive spring rate when the saloon diameter changes. On the other hand, the anti axial rotation bar is fitted underneath the front and rear of the vehicle and is connected to the lower control arm. It works with daze absorbers/struts to enhance stability, body roll, and cornering grip. When the wheels move at different angles, the anti sway saloon helps maintain balance and stability during harsh movements or sways of the vehicle.

The correct anti-roll bars can assist in reducing over or understeer. When fitted tightly, they provide a bumpy ride and transfer force directly to the other wheel, making the vehicle safer from rolling (Turnfast.com, 2008).

Air spring:

The air spring is designed to provide a vibration-free and smooth drive with a constant preset frame height. It also reduces spring oscillation, ensuring that maneuvering control is not compromised.

The air spring system serves as both a mechanical foliage type spring and can be used in conjunction with them. It minimizes the shock and vibration that is transmitted to the human body, cargo, and driver while transporting. Furthermore, an adjustable height control valve enables convenient adaptation according to the load and road conditions. The system also incorporates

other important elements like a pressure regulator, air lines, and air springs.

The system's main drawback is its instability in preventing suspension oscillation, but this can be resolved by using a shock absorber (Bennet, 2007, p. 268).

Shrubs:

These components act as the connection between the vehicle, springs, levers, and shock absorbers. They function as the pivot point for vehicle motion and prevent direct contact between the body and suspension links. Their soft design enables them to maintain alignment settings that aid in control and allow for equal rotation. Shrubs are typically installed in areas where there is metal to metal contact.

However, the main drawback is that it wears out over time and needs to be replaced, which can be expensive and difficult depending on the type of shrubs or where they need to be fitted (Autolign).

Ball joints:

The primary function of ball joints is to allow the suspension to move at any angle or rotate the yoke, which is typically the interface between a control arm and a metacarpophalangeal joint in a vehicle suspension. It serves as the pivot point between the suspension and the Sur, improving performance (TRW Automotive, 2010). Control arms: These usually connect the body of a vehicle to its suspension.


COMMON SUSPENSION SYSTEM TYPES:



Dragging arm:

This is typically connected at the front of the body, allowing the rear to move up and down. Two of these form a dual dragging arm system and generally function in the same way as dual wishbones.

The suspension system mentioned is situated alongside the human body and runs parallel to it, without any friction. However, it necessitates a large amount of space beneath the vehicle (Longhurst, 2010).
McPherson states that:
This type of

suspension is an improvement on the dual wishbone system. Instead of having a higher transverse link, it features a pivot point on the wheel house panel. This pivot point holds the end of the piston road and spiral spring, causing all forces to concentrate at this point and resulting in bending stress in the piston road. To prevent damage from this stress to the shock absorber's elastic camber and camber exchanges, the rod diameter in the shock absorber must be increased by at least 18mm from 11mm. Typically, all components of this system are combined into one assembly; however, its drawback is that it occupies a significant amount of space beneath the car (Reimpell, Stoll & Betzler, 2001, p. 10).

Double wishing bone: The double wishing bone is a system that uses two triangulated wishing bones and a path route to steer the wheel. The lower wishing bone provides vertical support. This system has a sporty design with a wide through loading breadth and low height, which improves gesture thrust, transmission of forces, road-holding, and camber control. However, planning this system can be complex and expensive (Volkswagen Canada, 2010).

Multilink suspension: The multilink suspension is based on the dual wishing bone design but includes more than three lateral arms and multiple longitudinal arms with varying lengths and angles that deviate from their natural directions.

The suspension systems in cars typically consist of connected weaponries that are equipped with spherical articulation or bushing at each end. These components prevent flexing and allow the suspension to function in tensile and compression forces. The pivots in this suspension are designed to enable the spindle to rotate for steering and

adjustment of suspension geometry by providing torsion in all suspension arms. Different car manufacturers have different designs for their suspension systems. The main advantage of this system is that it allows the vehicle to flex more, resulting in better handling due to the presence of multiple links. However, a drawback is that it is more expensive to design and manufacture due to its complexity (Raiciu, 2009).

Transverse leaf spring:

This system, used in the past, combines a leaf spring with independent dual wishing bone. The leaf spring is connected at each end of the lower wishing bone and is placed across the vehicle. A subframe in the middle of the vehicle connects to the center of the spring, while shock absorbers are mounted on each side of the lower wishing bones (Longhurst, 2010).

Solid-axle: leaf spring

This type of suspension provides a simple method for positioning and mounting the hub and wheel units.

The combination of spiral or leaf springs can create an efficient non-independent suspension system. This system transmits force through the final thrust unit and axles to the wheels, causing the axle to act as a live axle and rotate. When the vehicle accelerates, it generates torsion reaction that makes the axle spin in the opposite direction of wheel rotation. Similarly, during braking, a similar twisting effect can cause wheel rotation.

The distortion of the foliage spring can lead to blocking with the suspension gesture, according to the CDX Online eTextbook.

The solid-axle system uses spiral springs and replaces leaf springs. It is lighter and has less unsprung weight, providing a comfortable drive. However, it cannot keep the axle in line. This system is mainly used in rear-wheel drive vehicles.

It typically includes one or more control arms and two lower control arms that manage side motion and axle movement. If only one upper arm is used, a track saloon may be necessary to connect the vehicle from one end to the other. Rubber bushings can be utilized to reduce vibration as the suspension travels over road abnormalities.

According to Monroe engineering driven safety (2008), the use of two upper arms eliminates the need for the rear suspension path. This is a variation of the rear foliage spring suspension commonly found in the rear-solid axle spiral spring suspension diagram.

Beam axle:
The beam axle suspension connects the front two wheels using a solid axle, ensuring that there is no camber loss from body roll as the wheels remain perpendicular to the road. It is a simple and strong construction, making it suitable for carrying heavy loads. However, it has drawbacks such as bulkiness and taking up a lot of space. Additionally, it is a dependent suspension where force from one wheel can affect the other wheel, resulting in an uncomfortable drive and reduced vehicle stability during cornering (Lowry, 2004).

Hydropneumatic suspension:
Originally invented by Citroen, this type of suspension system utilizes hydraulics and air pressure.

The system compresses a gas rather than a fluid. The hydraulic fluid typically provides leveling and damping while the gas acts as a spring. Occasionally, an engine-driven pump can drive this system, pressurizing the hydraulic system and aiding in leveling at various heights, helping with lifting and stopping body roll. Fully powered braking system and power steering may also be provided.

The hydrolastic displacers are present in both the rear and front units. These displacers are connected

using a small connecting pipe, and each displacer includes a rubber spring. The pipes, rubber, and fluid in this system function as a damping system. The rubber springs ensure that the car remains level and free from any tilting movements. It achieves this without limiting the full range of motion of the suspension, resulting in a comfortable drive.

The drawbacks of the dynamic suspension system used in the Audi A4 include the high cost of repair or replacement and the need for a highly skilled individual to handle it (Marsh, 2001).

Dynamic suspension

This Audi A4 feature utilizes aluminum materials to minimize unsprung weight. It shifts the function to the front and the grip to the rear, with the front axle being moved 154 millimeters forward. To optimize axle-load distribution, the car battery has been relocated to the trunk.

By placing an additional derived function at the back, the weight distribution is improved, resulting in better balance and handling. These vehicles are more responsive and require less effort to steer and position, leading to better handling and a lower risk of tipping over while cornering.

ELECTRONIC AND ACTIVE SUSPENSIONS

These suspensions are computer-operated and gather information from various sensors, such as the vehicle's turning speed, wheel rotation speed, pitch, roll, and height. A basic system only maintains the vehicle's height, while a four-wheel height adjustment system can increase ground clearance off-road and reduce aerodynamic drag, improving fuel efficiency. Electronically controlled suspension systems are typically more expensive and are commonly found in high-performance and luxury cars. Active suspension systems are the latest advancements, utilizing microprocessing technology.

This paragraph discusses the variation of the opening size of

a restrictor valve in a hydraulic suspension or shock absorber, which changes the effective spring rate and is controlled by inputs such as lateral force, load, acceleration, or driver preference for vehicle velocity. The text also introduces the concept of a future suspension called Active Electromagnetic, which combines a passive spring with a brushless tubular permanent magnet actuator. This system improves safety and stability during cornering and braking by providing pitch and active roll. It can also reduce road shocks by utilizing measurements and specifications of the actuator. Additionally, the text mentions the INTEGRATED KINETIC TM H2 CES SYSTEM, an integrated reactive system that controls damping and reduces high roll and articulation stiffness.

The performance of the vehicle is improved with the tire burden optimization. This improvement is achieved by replacing four double-acting hydraulic cylinders with two integrated CES damper valves on antiroll bars and shock absorbers. Additionally, an automatic pressure maintenance unit (APMU) and a pair of collectors with valves and interconnected hydraulic lines are utilized. The flow of the hydraulic system is regulated by the two CES valves in each corner, which results in enhanced performance and handling. Furthermore, the CES damper valves are electronically controlled by intelligent control algorithms to allow for wheel movements and body control (Tenneco).