FR2530203A1 - CIRCUIT FOR PROVIDING AND PROVIDING AN INFORMATION SIGNAL FOR CHANGING THE REPORT OF A GEARBOX IN A MOTOR VEHICLE - Google Patents

Abstract

CIRCUIT FOR DEVELOPING AND PROVIDING AN INFORMATION SIGNAL TO CHANGE THE RATIO OF A GEARBOX IN A MOTOR VEHICLE. BASED ON THE MEASURED CHARACTERISTICS: VEHICLE SPEED, ENGINE ROTATION SPEED, INJECTION TIME, COOLING WATER TEMPERATURE AND ENGAGED SPEED, AN UNFAVORABLE AREA OF OPERATION AS REGARDS CONSUMPTION, IS DETERMINED BY AN APPLIANCE 5 IN A DIAGRAM INJECTION TIME-ROTATION SPEED. WHEN THE ENGINE OPERATING POINT IS IN THIS AREA, A SIGNAL WILL APPEAR THAT THE UPPER GEAR MUST BE ENGAGED. THE GEAR CHANGE CHARACTERISTIC IS CHOSEN SO THAT FOR EACH GEAR AND EACH LINEAR SPEED, SUFFICIENT ACCELERATION POWER IS STILL RETAINED.

Description

Circuit for developing and providing a signal for

  to change the ratio of a gearbox in

a motor vehicle.

  The present invention relates to a circuit for developing and providing an optical or audible information signal for changing the ratio of a gearbox in a motor vehicle which informs the driver that he must pass on a higher gear

  in order to use the motor within a range of

  more economical, the signal being developed according to the measured data, vehicle speed, engine rotation speed n, additional load (injection time ti) and cooling water temperature

  e, supplied to a control device.

  Such gearshift signage

  As is known from DE-A-20 29 634,

  positive indicators of fuel consumption, the

  the driver has information on how he can save fuel For this, in the case of known gearshift signaling, the engine speed and the load are displayed on a vehicle indicator. two hands on two scales The driver must then try to position, by operating the accelerator and / or shifting to a higher gear, the point of intersection of the two needles so that it falls in a low consumption zone fuel consumption on the specific fuel consumption curves visible on the indicator Because the driver of the vehicle must therefore constantly observe the load indicator and the speed indicator (or tachometer) and must, by changing its way to drive, adjust their angular position relative to a consumption

  favorable fuel, it acts at the same time as

  This can be done in the case of fixed installations, but it is very difficult in a vehicle that moves in

  This activity would divert too much

  the driver's attention.

  Starting from this state of affairs, the object of the invention is to develop a circuit providing an indication of gearshift that gives the driver of a vehicle clear information that is easy to process on his way of driving, without this is to the detriment of

  his attention to traffic.

  This goal is achieved through the invention by the

  depending on the temperature O and the ratio used

  a motor operating range is determined

  unfavorable for consumption, delimited by a

  a characteristic representing the injection time as a function of the rotational speed of the engine and in that a signal of passage to the higher ratio is delivered when the operating point of the engine is in this range The operating range of the adverse engine screws -a-vis

  of fuel consumption is determined by a provision

  It triggers, as a result, a signa-

  optical or acoustic indication on an indicating device, to inform the driver of the vehicle that he must leave the non-economic operating range by shifting to a higher ratio The circuit according to the invention makes it possible to operate economically a motor vehicle engine without divert the driver's attention from the traffic. The invention will be explained in more detail by means of a nonlimiting example of embodiment described below and shown in the accompanying drawings in which: FIG. 1 represents the circuit according to the invention; FIG. 2 is a flowchart for implementing

calculation operations.

  A transmitter 1 of the number of revolutions N of the engine,

  a transmitter 2 of the speed v of the vehicle, a trans-

  3 of the injection time ti and a transmitter 4 of the cooling water temperature e are connected to a control device 5 whose flow chart is shown in FIG. 2 and which controls an indicator 6 A first comparator stage 7 of the control device checks whether the measured injection time ti is less than a minimum injection time that can be prescribed ti min. If this is the case, there is engine braking or disengagement and the indication circuit of passage at upper ratio is not switched on, ie the indicator switches to the off position If, on the other hand, ti is greater than tmin, the measured characteristic quantities are transferred to a calculation stage 8 which forms the quotient of the speed of rotation of the engine by the speed v and multiplies it by a factor 2 x; K = n / v 2 x The exponent is about 4 or 5, depending on the type of gearbox and the transmitters 1 and 2 used. The multiplication by the factor 2 X is necessary, to increase by calculation the ratios of gear ratios which are for example 2.35; 2.90; 3.20, so as to obtain, before the comma, values distinguished by integers. The initial value K of the calculation stage 8 is then transmitted to a chain of comparator stages 9, 10, 11, 12 The stage comparator 9 checks if K is greater than K 1, K 1 being for example equal to 110, and if so, there is a false signal, because there is no ratio corresponding to a value of If K is also lower than K 1, the signal arrives in the comparator stage 10 for K greater than K 2, K 2 being for example equal to 95 If this condition is fulfilled, this expresses the fact that it is for the moment the first report that must be engaged on the box 22; (this report) G 1 is transmitted at the same time

  that the temperature at a memory 14 for n G = f (G, 0).

  The output value thereof arrives in a comparator stage 15 for N greater than n G If the answer is

  yes, a memory 16 or a corresponding computing stage

  the value of the function ti G = f (n G, n) is attacked, its output value being transmitted to a comparator stage 17 satisfying whether ti 4 ti G If the two conditions n o n G ti ti ti G are satisfied, a command is sent to the indicator 6 for

  trigger the start signal of the upper gear.

  If in the comparator stage 10 the upper K condition

  K 2 is not fulfilled, the comparator stage 11, verifying K greater than K 3, is put into service. If, for example, K 3 is chosen at the value 60 and the result of the comparison is positive, then there is again a false signal, which means an intermediate value between the first and the second ratio, which does not exist in the box. A value K corresponding to the second ratio can only be controlled with the comparator stage 12 verifying that K is greater than K 4, with a value of K 4 of, for example 40 If this condition is fulfilled, the memory n G = f (n G, 9) receives the information the second gear is engaged As previously described, after the travel of the elements 15, 16, 17, the indication of passage to the higher gear is triggered, or, when the

  answer is no in comparators 15 and 17, this indi-

  Likewise, if the gear ratio is not engaged, the third and fourth gear ratios, for example in a gearbox, are tested in corresponding comparator stages; if the result is positive, information is transmitted to the memory 14 on the gear engaged If none of the reports 1 to 4

  recognized, the indication goes to the negative

  intermediate of the comparator stage 13.

  The injection time diagram ti as a function of the speed of rotation of the motor n, used for the circuit

  comprises an upper curve 18 and a characteristic 19.

  The upper curve 18 corresponds to a full load curve. The characteristic 19, which comprises a vertical branch parallel to the ordinate axis and a branch increasing with the speed of rotation, separates the higher economic consumption area from the unfavorable domain 21. point of view of consumption Values

  of the function are denoted by ti G, n G, the injection time

  corresponding to the angular point of the two branches by tieck * The shape of the characteristic 19 is chosen so as to have, after passage to each higher gear and for any speed, a sufficient reserve of acceleration, so that after being the report, fuel savings can be achieved without limiting the driving

  individual dependent on the traffic.

  To indicate the shift to higher gear, a

  arrow illuminates in the driver's field of vision.

  This mark may be a transparent mark on the windshield of the vehicle, self-illuminating or illuminating while being

  illuminated by a separate light source.

  To avoid, in extreme cases, light changes

  Permanent re signals of the signal to the upper gear

  6, the signal is produced only after a time of re-

  In addition, by extension of the characteristic 19, a strip having an inner line 19 'and an outer line 19' is obtained.

  hysteresis of change of ratio When passing the

  unfavorable head 21 to the favorable area 20, it is the outer line 19 "which becomes the demarcation line, and the inner line 19 'during the passage in opposite direction.

Claims (1)

CLAIMS 1 Circuit for developing and providing an information signal which indicates to the driver of an automotive vehicle, optically or acoustically, that he must use the engine in a more economical operating range * by engaging a ratio, the signal being developed according to the measured characteristics: vehicle speed v, engine rotation speed n, additional load (injection time t i) and cooling water temperature 9, transmitted to a control device, characterized in that depending on the temperature G and the engaged ratio, an operating range (21) of the unfavorable engine for consumption is determined, which is delimited by a characteristic (19) representing the time of injection as a function of the rotational speed of the engine, and in that it is transmitted a signal of passage to the higher ratio, when the point of engine operation is in this area operating (21). Circuit arrangement according to Claim 1, characterized in that the transmitters (1 or 2) of the rotational speed of the motor and the speed of the vehicle are connected to the control device (5), which forms the quotient of the two characteristics and if necessary, by comparison with predetermined limit values corresponding to the gear ratios, a higher-pass signal is produced. Circuit according to Claim 2, characterized in that, for the gear engaged in each case, the limit value of the rotational speed is calculated or taken from a memory, an injection time limit value for a speed of The increasing rotation is calculated or taken from a memory and by comparison of the rotational speed and the measured injection times with the corresponding limit values, it is determined whether the operating point of the motor is within the range (20). ) favorable to consumption; 4. Circuit according to any one of claims 1 to 3, characterized in that once the limit values have been reached, it is only after a given delay time that the indication of engagement of a higher ratio is given. Circuit according to any one of claims 1 to 4, characterized in that the characteristic (19) is in the form of a strip comprising an inner line (19 ') and an outer line (19 "), and what is the outer line (19 ") which constitutes the dividing line when moving from the unfavorable zone for consumption (21) to the favorable zone for consumption (20), and the inner line (19 ') ) when moving from the favorable zone for consumption (20) to the unfavorable zone for consumption (21). 6 circuit according to any one of claims 1 to 5, characterized in that the appearance of the characteristic (19) may vary during operation according to the speed engaged in each case. 7 circuit according to any one of claims 1 to 6, characterized in that the characteristic (19) comprises a branch rising vertically and a branch increasing with the rotational speed, and in that it is shaped so that following a signal of passage to the upper gear, the acceleration reserve of the vehicle is at least equal to that which existed before. 8 Circuit according to any one of claims 1 to 7, characterized in that, when disengaged, the signaling ceases and in that this state is detected because, for a number of predeterminable calculation operations no valid gear ratio is recognized. Circuit according to any one of the claims   1 to 8, characterized in that the activation signaling   the upper gear consists of a transparent light mark on the windshield of the motor vehicle, self-luminescent or becoming illuminated while being illuminated by a separate light source.