PROCESS FOR MEASURING THE POWER OF A MOTOR VEHICLE ENGINE ON A ROLLER-TYPE STAND, AND MEASURING STAND FOR CARRYING OUT THIS PROCESS

摘要

This method of measuring the power of an automotive vehicle engine on a roller-type testing bench comprises selecting the vehicle velocity and/or the engine speed whereat it is desired to make the measurement; increasing the engine speed during a first acceleration phase up to the selected value, measuring at this value the power available at the wheels, accelerating the engine slightly above the selected value, then disconnecting the drive and engaging the neutral; and allowing the rollers to slow down while they drive the engine transmission by inertia in order to measure, during this second deceleration phase, the power lost in the transmission. An electric signal generator is associated with a testing roller; the period of the signals emitted by the generator is measured as a function of the variation in the rotational speed of the roller by using a quartz clock having a predetermined frequency, whereafter the power is calculated from the measured period and from the moment of inertia of the rollers, and the roller speed is also calculated from the signal period and the roller radius, at predetermined time intervals during the acceleration and deceleration phases.