Patent EP-0127494-A1 (EP)
Inventor: DRUTER YVES
IPC: B60R16/02
Filed: 1984-04-19
Abstract: 1. A device for assisting the economical operation of a vehicle having a diesel motor in which the flow of the injection pump is controlled by a regulating valve, comprising three permanent digital measuring means for measuring the load of the motor (1 to 22, PS), the motor operating conditions (RM) and the forward speed of the vehicle (VA) respectively, a dead memory (M) containing experimentally determined value tables, a microprocessor (P) and a control device (C) arranged and programmed to calculate, from the three digital measurements and the value tables, the true values resulting from measurement or calculation of the motor operating conditions, the engaged speed-ratio and the specific or hourly consumption respectively, and the theoretical value of the speed-ratio which would give minimal consumption of fuel, and a device (AF) for displaying said true and/or theoretical values, characterised in that the digital measuring device for measuring the motor load is a device for measuring the position (PS) of the regulating valve and comprises a permanent magnet (13) integral with the end of the rod (6) normally ensuring the transmission of drive between the blade (4) of the normal mechanical regulator of the injection pump and the lever (7) of the regulating valve of said pump, and an induction coil constituted by a winding (14) with a fixed magnetic core (15) located in the field of the magnet (13), said induction coil being inserted in an oscillatory circuit (18 to 22) or relaxation circuit for translating the angular position of the opening of the regulating valve (8) into a variable frequency, and a counter (T) which transforms said variable frequency into a digital signal, and in that said device for assisting the operation contains an economically functioning contact (23) actuable by the user and that its control device (C) is programmed to control the microprocessor (P) in such a way that in a first phase of operation it measures the motor operating conditions (RM) and the forward speed (VA), calculates from this the quotient to determine the engaged speed-ratio and displays on the display device (AF) at least the motor operating conditions and the engaged speed-ratio, and that, in a second phase which follows the first phase and after having checked that the motor operating conditions (RM) are stable, it measures the position of the regulating valve (PS), calculates, according to the tables, the hourly consumption and possibly the specific consumption calculating the quotient of this latter amount with power, and displays at least one of these two consumption values, whilst, in a third phase which follows the preceding one, if the economically functioning control switch is closed, it extracts from the value tables, as a function of the position of the regulating valve (PS) already determined, the torque and the consumption, determines the power by calculating the product of the torque and the motor operating conditions (RM), determines the theoretical motor operating conditions which would give the minimum consumption for the same calculated power, calculates the speed-ratio to engage by choosing from the possible speed ratios that which is closest to the theoretical ratio, adjusting as a result the calculation of the theoretical motor operating conditions to correspond to the same forward speed (VA), and displays the theoretical ratio and motor operating conditions thus determined.