Factors Affecting Driving Force Characteristics of 4WD Vehicles on a 4WD Chassis Dynamometer 2009-01-1350
Recent studies have reported that the control of the latest chassis dynamometer for four-wheel-drive vehicles (4WD-CHDY) applied to exhaust emission and fuel economy tests have been improved. However, there are only a few evaluations of work at the wheel (wheel-work) of a vehicle. Furthermore, there are few studies on the effect on wheel-work from facility conditions in laboratory such as cooling fans and vehicle restraint devices.
Tests were performed to investigate factors affecting the driving force characteristics of 4WD vehicles by the total work at the four wheels and ratio of wheel-work at the front wheel to the rear wheel on 4WD-CHDY using two types of vehicles and three laboratories.
A comparison of the three laboratories reveals that the difference of tire-loss affects the difference of wheel-work. Furthermore, a comparison between actual roads and 4WD-CHDY indicates that the wheel-work differs in some cases.
Therefore, we conducted a test to investigate the factors affecting tire-loss. We evaluated the effect of conditions of the cooling fan and vehicle restraints and found that the cooling fan condition affected tire temperature, which in turn affected the resultant wheel-work. Moreover, we found that the increase of the vertical tire load by additional restriction and restraint tension do not affect wheel-work.