Suspension Systems Prepared by Vaibhav . S. Sutrave

Unitized body Body over frame Types of Vehicle Construction Unitized body Tends to be more tightly structured. Is designed to transmit impact energy throughout the vehicle. Body over frame The body and all major parts are bolted to the frame. Design is used on many pickups and SUVs.

Definitions Spring A component used to absorb shock forces while maintaining vehicle height. Absorbs energy on compression (jounce) and releases energy during extension (rebound). Shock absorber A component used to damp or control motion in a vehicle. Shock absorbers dampen spring oscillations.

Spring Types Coil Air Single-leaf Multileaf Torsion bar

Types of Shock Absorbers Hydraulic Uses hydraulic oil. Gas-charged Uses nitrogen gas as well as oil. Air Uses air chambers to control the height of the shock.

Types of Shock Absorbers

MacPherson Strut Components Spring Shock absorber Upper suspension mount or locator

SLA Suspension Components Wheel spindle assembly (Knuckle) Upper and lower control arm (Suspension arms) Upper and lower ball joints Shock absorber Spring

SLA Suspension Components Wheel spindle assembly (Knuckle) Upper and lower control arm (Suspension arms) Upper and lower ball joints Shock absorber Spring

Typical SLA Suspension

Coil Spring Rear Suspension

Independent Rear Suspension

Multi-Link Rear Suspension

Types of Electronic Suspensions Load-leveling systems Use air shocks in the rear to compensate for vehicle load. Adaptive systems Typically use electronic shocks with variable valving. Fully active systems Use hydraulic actuators as both spring and shock absorber.

Electronic Load-Sensing Shock

Electronic Shocks With Variable Valving

An Active Suspension System

Air springs or shocks Air spring valves Air compressor Typical Electronic Suspension Components Air springs or shocks Air spring valves Air compressor Compressor relay Height sensors Warning lamp Control module On/off switch

Typical Electronic Air Suspension Components

New Advanced Suspension Technology

MAGNETIC SUSPENSION

WORKING The suspension works on magneto- rheological fluid– a synthetic hydrocarbon oil in which microscopically small magnetic particles measuring between three and ten microns are enclosed

When a voltage is applied to a coil – by means of a pulse delivered by a control unit – a magnetic field is created in which the alignment of the particles changes. They position themselves transversely to the direction of flow of the oil, and so inhibit its flow through the piston channels. This alters the characteristic of the damping characteristic much faster than is the case in conventional adaptive dampers.

Summary Four types of springs are used in suspension systems: coil, leaf, torsion bar, and air. Springs take care of two fundamental wheel actions: jounce and rebound. Shock absorbers damp or control motion in a vehicle.

Summary There are two basic adjustable air shock systems: the manual fill type and the automatic or electronic load-leveling type. MacPherson struts provide the damping function of a shock absorber. The unequal length arm or short-long arm (SLA) suspension system is most commonly used on domestic trucks.

Summary Semi-independent suspension is used on many front-wheel drive models. The two basic types of computer suspension systems are adaptive and active. Electronically controlled suspensions can be either simple load-leveling systems, adaptive systems, or fully active systems.