De Dion suspension characteristics: Camber change on bumps, none on rebound
Ford Ranger EV Data
Ranger
EV discussion group (EVCN)
EVA
specs
Specifications
Vehicle Size:
Overall Length (in.): 187.8
Overall Width (in.): 69.4
Overall Height (in.): 65.6
Wheel Base (in.): 112
Curb Weight (lbs.): PbA - 4,936/NiMH - 4,196
Payload (lbs.): PbA - 650 lbs./NiMH - 1,250 lbs.
Number of Occupants: 3 passengers
Battery/Motor:
Voltage: 312
Motor Type: 3 Phase AC
Horsepower: 90 hp
Power: 67 kW
Energy Capacity: PbA - 23 kWh, 60 Ah
...............................NiMH - 26 kWh
Battery Modules: PbA - 39 @ 8V
.............................. NiMH - 25
Vehicle Systems:
Recharging Specifications: Conductive Charging - 240v/30 amp
Transmission: Automatic
Suspension: Front - A Arms/ Rear - Leaf Spring (de
Dion tube)
Steering: Electro-Hydraulic Power
Air Bags: Driver and passenger side (passenger side can be defeated)
Tires: Low-Rolling Resistance
Brake Assist: Front - Disc, Rear - Disc Regenerative
Anti-Lock Braking System (ABS): 4-Wheel
Air Conditioning/Heater: Standard
Audio System: AM/FM Cassette
Performance:
Range: PbA - 50 miles
............. Ni-MH 65-85 miles
Acceleration: 0 - 50 mph in 12.5 seconds
Maximum Speed: 75 mph governed.
A de Dion tube is an automobile suspension technology. It is a sophisticated form of non-independent suspension and is a considerable improvement over the alternative swing axle and Hotchkiss drive types. A de Dion suspension uses universal joints at both the wheel hubs and differential, and uses a solid tubular beam to hold the opposite wheels in parallel. Unlike an anti-roll bar, a de Dion tube is not directly connected to the chassis nor is it intended to flex. In suspension geometry it is close to the trailing beam suspension most recently seen on the front wheel drive Chrysler "K-cars", but without the torsional flexibility of that suspension.
The benefits of a de Dion suspension include:
Reduced unsprung weight compared to the Hotchkiss drive since the differential is connected to the chassis. Unlike a fully independent suspension there are no camber changes on suspension unloading (or rebound). Fixing the camber of both wheels at zero degrees assists in obtaining good traction from wide tires and also tends to reduce wheel hop under high power operations compared to an independent suspension.
There are costs, however:
The de Dion tube adds unsprung weights compared to a fully independent suspension. If coil springs are used then a lateral location link (usually either a Panhard rod or Watts linkage), plus additional torque links on each side (five link suspension) or a combination of lower trailing links and an upper transverse wishbone are required. None of these additional links are required if steel leaf springs are used. Sympathetic camber changes on opposite wheels are seen on single-wheel suspension compression. This is not important for operation on improved surfaces but is more critical for rough road or off road use. Compared to a fully independent rear suspension the ability to refine the dynamic response of the vehicle is somewhat limited. De Dion tubes are generally considered exotic and are rarely used. The original Mazda Cosmo, Alfa Romeo GTV6, and Rover P6 are examples of production vehicles using this suspension.
A recent production vehicle using this suspension using an aluminum tube with leaf springs was the Ford Ranger EV. The earliest production used carbon fiber leaf springs which required the use of a transverse locating linkage of the Watts type. Subsequent production used steel leaf springs which were sufficiently rigid to perform the transverse location function. Rather than only a differential, an integrated drive component consisting of an AC electrical motor, 3:1 reduction, and differential action was mounted to the chassies.
De Dion suspension characteristics: Camber change on bumps, none on rebound
 |
Click for |