FR2528769A1 - Drive motor with inertial flywheel for wheeled vehicle - uses tachometers, torque meters and processor to operate servo controls to use flywheel energy as motive force - Google Patents

Abstract

A thermal engine is connected through two clutches and gearbox to drive wheels. A flywheel of carbon or glass fibre is connected to a shaft between the two clutches and also to a reduction gear and speed controller. The same shaft is connected to a dynamo and starter assembly powered from an electrical power source through a controllable switch. Brakes acting on discs on the wheels are operated from a pedal while speed control is obtained from an accelerator pedal. The clutches and speed controllers and the brakes are controlled from a processor through servo controllers. Tachometers and torque meters provide inputs for the processor which determines whether the flywheel or the motor will provide motive power and if braking energy can recharge the flywheel inertia.

Description

The present invention relates to a power train, provided with a

  combustion engine and flywheel,

for a wheeled vehicle.

  It is known that energy used for transport accounts for about 25% of the needs of a modern country and that this energy currently comes almost exclusively from oil. In this use, individual motor transport and public transport and trucks represent respectively 50% and 20%, so the total energy spent on transport is around 15 to 20%

  total energy expenditure of a country.

  Given the available limits of possible energy resources and the increasing cost of these resources, it has become essential to actively seek ways to reduce fuel consumption.

  motor vehicle engines.

  -Among the means envisaged for this purpose, it has already been thought to associate an inertial flywheel with a powertrain of a vehicle, in order to recover a part of

  the kinetic energy of the latter at the moment of braking.

  In the known powertrains of this type, the flywheel is connected, by means of clutches, on the one hand to the engine and on the other hand to a continuously variable transmission coupled to the drive wheels of the engine. vehicle Thus, the engine provides energy to the steering wheel that activates the vehicle through the transmission Energy recovery is obtained-by accelerating the steering wheel as the vehicle slows down It is seen that in a device of this type , the steering wheel can not be used

than energy recovery.

  Furthermore, other devices are known in which the steering wheel, initially driven by an auxiliary electric motor, is also intended to restart the engine after each stop thereof, which is cut at each stop circulation, so to save fuel and reduce pollution and noise Such a device limits the role of the steering wheel to two functions, namely energy recovery and engine launch and has the disadvantage of requiring an auxiliary electric motor In addition, it is difficult to power the equipment of the vehicle to

  the stop, since then the engine is cut.

  The present invention relates to an inertial flywheel power unit in which the latter can perform a plurality of functions and in particular initially start the engine, after being itself launched, either electrically or crank; momentarily add additional power to the engine to safely ensure high speed overruns; slow down the vehicle; restart the engine and the vehicle whenever necessary, so that the engine can be shut down at each deceleration or stoppage of traffic; continuously train accessory equipment

  even during the engine shutdowns.

  For these purposes, according to the invention, the power unit for a wheeled vehicle whose driving is obtained at least in part by action on an acceleration member and on a brake member, the power train comprising a heat engine of which the output shaft is connected to the driving wheels of the vehicle by a continuous speed variator, two clutches in series arranged between said heat engine and said continuous speed variator, and a flywheel whose shaft is connected to the shaft the output of the engine between the two clutches, is remarkable in that it comprises another continuous speed controller disposed on the flywheel shaft; a tachometer and a torque meter disposed on the output shaft of the engine between it and the clutches; a tachometer and a torque meter disposed on the flywheel shaft between it and this other continuous speed variator; tachometers arranged at the input and output of the continuous speed drive placed between the clutches and the driving wheels; transducers capable of transforming the displacements of said acceleration member and of said brake member into electrical signals representative of said displacements and a computer receiving as information the signals coming from the different tachometers, torque meters and transducers and controlling the operation of the heat engine,

  clutches and two continuous speed drives.

  It can thus be seen that, thanks to such a structure, the computer can, depending on the data it receives, firstly connect the engine or the steering wheel to the driving wheels by controlling the clutches, and secondly transmit the energy from the engine and / or the steering wheel to the drive wheels of the vehicle, or the drive wheels to the engine and / or the steering wheel by control of the reports

  opening said continuous speed drives.

  It is therefore easy to see that such a structure allows a

  optimal adaptation of the motor group configuration

  propellant according to the invention to the recovery of energy and

  the restitution of energy previously stored.

  In addition, because the control of the engine is performed by means of the computer and not directly by the bodies actuated by the driver of the vehicle, it can be seen that the driving of the vehicle can be optimized with regard to the consumption of fuel. fuel

  To perfect this effect, it is indispensable

  It is conceivable that the powertrain package includes a manually operated gear selector, available to the driver of the vehicle, mounted between the continuous speed variator.

  associated with the engine and the drive wheels.

  To start the engine, when the flywheel is stopped, we can provide a dynamo starter may be driven by at least one source of electrical energy and / or a crank Thus, the dynamo starter and / or the crank can rotate the steering wheel, after which, when the speed of said steering wheel is sufficient,

  can start the engine by connecting it to the steering wheel.

  The steering wheel allows, in the event of slowing down of the vehicle, to store energy which is used, in addition to slowing down the vehicle, to restart the engine whenever it is necessary, to drive permanently accessory equipment and / or to temporarily bring a

  additional power to the engine.

  Thanks to the steering wheel, it is therefore possible to cut the engine at each stop of the vehicle, or downhill, since said engine can be restarted at any time by

the steering wheel.

  In the case where it is expected to use the steering wheel energy to provide additional temporary power to the engine, for example in case of overtaking another vehicle, it is advantageous to associate a compressor to the device. supplying the engine with air and fuel, so that said compressor can provide this additional power in the case where the steering wheel can not do so, due to the storage of insufficient energy.

  heard, the compressor is then controlled by the computer.

  The brakes of the vehicle are advantageously controlled via the computer, according to the indications

  given by the transducer associated with the brake member.

  However, it is further provided, for safety, a direct actuation of the brakes through said body. Preferably, the computer comprises a memory of several values of rotation speed of the steering wheel and at each instant it compares the actual rotation speed of the steering wheel to these values stored in memory and the result of the comparison is used by said computer to determine the type of operation, it imposes on the powertrain Moreover, the calculator takes into account, to determine said type of operation? because the

  vehicle is stationary or on the contrary is driving.

  Preferably, the flywheel is made of a low specific mass material, but of high mechanical strength, such as composite materials based on glass fibers, carbon, KEVLAR (registered trademark), etc.

  can be locked in an enclosure under low pressure.

  In the event of an accident, the kinetic energy of the steering wheel can be quickly transformed into heat by automatic injection

of liquid in said enclosure.

  Thanks to the invention, we obtain a light recovery system, easy to achieve, quiet, safe and high efficiency tests on a vehicle equipped with such a system and used for 1/3 of the time in town, 1/3 on road at km / h and 1/3 on highway at 120 km / h showed that fuel consumption was at least 25% lower

  for the same vehicle, not equipped with the power unit

  In addition, thanks to the stopping of the engine at each stop of the vehicle, the pollution of the atmosphere and the noise decrease. The power of the engine can be chosen relatively low, because the instantaneous a large amount of energy from the steering wheel provides the acceleration supplement needed to overtake

  safely other vehicles on the road.

  The figures of the annexed drawing will make clear how

the invention can be realized.

  Figure 1 shows the block diagram of a system according to the invention. Figure 2a at 2 o'clock illustrate different modes of operation

of the system according to the invention.

  Figure 3 shows a diagram of the use of the system in

  energy recovery during a slowdown of the vehicle.

  Figure 4 shows a diagram of the use of the system in

  energy recovery for acceleration of the vehicle.

  The power unit according to the invention, whose block diagram is given in FIG. 1, comprises a heat engine 1 whose output shaft 1 'is connected by two clutches 2 and 3, a variable speed drive 4, a selector 5 and a mechanical member 6, such as a bridge, to driving wheels 7 Furthermore, it comprises a flywheel 8 rotating about its axis 8 ', which is connected via a gearbox 10 and a speed variator 11, at the motor shaft line 1, between the

clutches 2 and 3.

  The steering wheel shaft line 8 is further connected to a dynamometer.

  starter 12 may be powered by an electrical source 13, a crank 14 and equipment 15, such as pumps A controllable switch 9 is

  disposed between the power source 13 and the dynamo starter 12.

2528769.

  Tachometers 16, 17 and 18 are mounted on the shaft line of the motor 1, respectively between the latter and the clutch 2, between the clutch 3 and the variable speed drive 4 and at the output of the latter. a torque meter 19 is mounted on the shaft 2 of the motor 1. Similarly, a tachometer 20 and a torque meter 21 are provided

on the shaft 8 'of the steering wheel 8.

  The assembly also comprises brakes 22 acting for example on discs 23 integral in rotation with the wheels 7, and an accelerator pedal 24 and a brake pedal 25, respectively associated with translators or

transmitters 26 and 27.

  The clutches 2 and 3, the variable speed drives 4 and 11 and the brakes 22 are respectively controlled via servocontrols 28, 29, 30, 31 and 32, the brakes 22 also being able to be controlled by a park brake device.

33 usable in parking.

  Furthermore, the motor 1, the selector 5, the switch 9, the tachometers 16, 17, 18, 20, the torque meters 19 and 21, the transmitters 26 and 27, the servo-controls 28, 29, 30, 31 and 32, and the parking brake device 33 are connected to a computer 34 by control and / or data transmission links represented by lines provided with

arrows.

  For safety purposes a direct additional connection is provided between the transmitter 27 and the servo-control 32 of the brakes 22. Usually, the speed selector 5 comprises at least one forward position, a neutral position and a position of In addition, the electrical source 13 may be an on-board battery, a power distribution network of a garage for example,

and / or a solar generator.

  The operation of the propulsion unit according to the invention is explained below with the aid of the diagrams of FIGS. 2a to 2h, on which, for each operating configuration, only the necessary members are shown. In the drawings, V is the speed of the vehicle (not shown) driven by the power train, Q the actual rotational speed of the flywheel 8 and Cr the torque at the wheel 7. In addition, it has been assumed that in the calculator 34 were stored a plurality of set values for the speed Q of the steering wheel, namely a first minimum value Q ml (for example equal to 3000 rpm), a second minimum value Q m 2 (for example equal to 5000 t / min), greater than the first, a city setpoint value Q v (for example equal to 10000 rpm), a QR road reference value (for example equal to 15 000 rpm) and a maximum value QM (for example equal to 21,000 rpm) The computer 34 is programmed to use the QR route setpoint instead of the QV city setpoint only when the vehicle speed V (supplied for example to the computer 34 by the tachometer 18 and the selector 5) exceeds a speed threshold Vs (for example equal at 60 km / h) during a time displayed in memory (for example equal to

2 minutes).

  When the vehicle is stationary (V = O and Cr = O) the clutches 2 and 3 are open If it is desired to start the engine 1, while the rotation speed Q of the steering wheel is lower than the first minimum value ml, the switch 9 is deliberately closed, for example in the usual manner with the aid of a contact key inserted and turned in a locking lock of the direction of the vehicle (not shown). The computer 34 then imposes the configuration of 2 for which the electrical source 13 actuates the dynamodemarreur 12 which drives the flywheel 8 in rotation As a result, the speed of rotation

the steering wheel 8 increases.

  As soon as this speed Q reaches the first minimum value Qml the computer 34 is warned by the tachometer 20 and it opens the switch 9 and closes the clutch 2 via the servo-control 28 At this moment (see FIG. 2 b), the energy stored in the flywheel 8 is used to rotate the motor 1, through the variable speed drive 11 and the clutch, to the start of said motor This start is reported to the computer 34 by the tachometer 16 The clutch 2 remains closed but now it is the engine 1, which rotates the flywheel 8, whose speed of rotation Q is increased (see Figure 2 c). If the vehicle remains stationary, the computer 34 opens the clutch 2, as soon as the speed of rotation of the steering wheel 8 reaches the city setpoint XV As soon as the speed? By decreasing from this value, the value of the clutch 2 is closed again so that the speed of the steering wheel 8 is increased by the motor 1 to the value? V If, at the instant when the switch 9 is closed to drive the wheel 8 with the source 13 (Figure 2a), the speed n of said wheel is still greater than? the calculator 34 immediately opens the switch 9, while closing the clutch 2, to go into the configuration of FIG. 2b. As soon as the motor 1 is started, either the configuration of FIG. the speed Q is less than QV 'or the clutch 2 is open to reduce the speed S to the value QV if the vehicle

remains at rest.

  The engine having been started in the manner described above, the driver chooses his direction of travel thanks to the selector 5, and, with the parking brake 33 released, he presses the pedal 24 to accelerate. By means of the transmitter 26, the calculator 34 records the bias on said accelerator pedal 24 and closes the clutch 3 by

  via the servo control 29.

  The computer 34 then adjusts all the parameters of the power train, and in particular the parameters of the engine 1 and the ratio of the variable speed drive 4 (via the servocontrol 30), depending on the

requested power.

  As long as the vehicle is traveling (V 0) without decelerating (Cr> 0) and the rotation speed Q of the flywheel 8 is less than or equal to the set value f V or 2 R which is to apply at this time, the calculator 34 does take to

  the power train the configuration shown schematically

  2d, for which the motor 1 drives both the wheels 7, through the clutches 2 and 3 and the variable speed drive 4, and the flywheel 8, through the clutch.

2 and the drive controller 11.

  On the other hand, when the speed f 2 becomes greater than the corresponding QV or QR setpoint value (but lower than the maximum value q M), the clutch 2 is opened and the steering wheel 8 drives the wheels 7 via the variator. 11, the clutch 3 and the variable speed drive 4 (Figure 2 e) From this configuration, when the speed of the steering wheel 8 returns by decreasing the set value QV or VR, the clutch 2 is closed from again so that the whole resumes the configuration of the figure

  2 d, until the steering wheel has returned to sufficient speed.

  When a large power demand, for example in case of overtaking another vehicle, which results in the full throttle of the accelerator pedal 24, the computer 34 can control the powertrain according to two operating modes depending on the value of the rotation speed P of the flywheel 8, at the time of this power demand If the speed Q is greater than the second minimum value Q 2 'the motor 1 and the flywheel 8 provide simultaneously On the other hand, if the speed Q of the flywheel 8 is less than Q m 2 and / or if the energy demand is of long duration, the calculator 34 immediately orders the energy to the wheels 7, according to the diagram of FIG. a supercharging device of the compressor motor 36 capable of providing a surplus of power capable of responding to the load on the

pedal 24.

  When the driver releases the pressure on the accelerator pedal 24 to slow down his vehicle, the computer 34 adjusts accordingly the power supply of the motor 1 (configuration of Figures 2d and 2f) and / or the variable speed drives 4 and it (configuration of Figure 2 e, in particular) without necessarily

change the configuration of the moment.

  Such a change occurs however as soon as the brake pedal 25 is actuated It can take several forms if the rotation speed Q of the flywheel 8 is lower than the maximum speed QM, the clutch 2 is open, the engine 1 is possibly cut, and the braking is obtained by acting on the two variable speed drives 4 and he which accelerate the flywheel 8 according to the pressure on the brake 25 (configuration of Figure 2 g); if the rotation speed Q of the flywheel 8 is equal to the maximum speed QM 'and / or if the braking is of long duration, the clutch 2 is closed and braking is obtained by acting on the two variable speed drives 4 and 1 h which, on the one hand, accelerate the steering wheel 8 and on the other hand, allow to use the engine brake; if one or the other of these braking with recovery is not effective enough (for example the deceleration they generate is less than a set deceleration corresponding to the depression of the pedal 25), the computer 34 actuates the brakes 22 via the brake booster 32 Such a braking action may vary with the

vehicle speed.

  After a stoppage of circulation and stop of the engine, restarting it can take place in two different ways: if the speed of rotation S? the steering wheel 8 is greater than the set value? v or QR 'said flywheel 8 starts the vehicle by engaging the clutch 3 according to the diagram of Figure 2 e, then when the speed Q reaches decreasing this value of -set, the flywheel 8 restart the engine 1 by engaging of the clutch 2,

according to the diagram of figure 2 b.

  if the rotation speed 2 is less than or equal to the setpoint value Q V or q R 'the steering wheel 8 restarts the engine 1 according to the diagram of FIG. 2b, then the engine accelerates the vehicle

  and the steering wheel 8 according to the diagram of FIG. 2 d.

  At the initial launch of the powertrain assembly according to the invention, if the electric source 13 is deficient and if the energy of the steering wheel 8 is insufficient, the flywheel 8 is launched by means of the crank 14, the clutches 2 and 3 being then As soon as the flywheel 8 is launched, the process then proceeds according to the diagram of FIG. 2 b (launch of the engine 1) and that of the

  figure 2 d (acceleration to vehicle and steering wheel).

  The dynamo-starter 12, for example of the type known commercially under the name of DYNASTAR, as well as the hydraulic pump 15 and any other accessory devices are constantly driven by the steering wheel during a stoppage of long-term traffic (the engine having been cut), when the speed Q of the steering wheel 8 goes down to the value úml, the engine 1 is automatically restarted (according to the diagram of Figure 2 b) until the steering wheel 8 takes a speed equal to the setpoint speed 2 V

(set in town).

  To obtain the various effects described above, it is essential that the computer 34 applies at each instant, via the servocontrols 30 and 31, the correct opening ratios a and e to the two dimmers

1 speed S 30 and 31.

  If wb and W 5 are the instantaneous speeds measured by the tachometers 17 and 18 (and transmitted to the computer), the opening ratio a of the variator 4 must be equal to wb ws. Similarly, if ú V is the instantaneous speed measured by the tachometer 20, the opening ratio 6 of the variator 11 must be equal

at B = N V.

  wb It will be noticed that if the ratio of the gearbox 10 is equal to K, we have QV

V K

  Preferably, the drives 4 and 11 are of the belt type

  trapezoidal and variable gauge pulleys.

  The steering wheel 8 being usable for two purposes, namely the slowing down of the vehicle and the additional acceleration of overtaking, the maximum kinetic energy E stored in the steering wheel must include the energy e M = 1 MV 2 of the mass vehicle M launched at the maximum reference speed VM, plus a complementary quantity called setpoint, always available to ensure overtaking maneuvers

with the desired security.

  Advantageously, it is possible for E = 2 e M. to result in, with the choices specified above, a dimensioning of the flywheel 8 limited to that of a wheel of

  relief with regard to its mass and its size.

  Recovery is achieved by accelerating the steering wheel as the vehicle slows down and vice versa for restitution. At transmission efficiencies, we can write (with I = moment of inertia of the flywheel 8): the energy transfer E = 1 MV 2 = 1 I 2

2 2

d E M Vd V = _c S

  -the power put in play '= MV -_ = -s Q -

  dt dt -t acceleration obtained from V -Cv Q dt MV In Figures 3 and 4 schematically illustrated

  case of recovery and restitution, respectively.

  In these figures, we have drawn two rectangular axes X'OX and Y'OY dividing the plane into four quadrants.

  first quadrant delimited by the OX and OY half-axes

  gular, the curve M represents the variation of the kinetic energy of the vehicle (carried on the half-axis OY) as a function of the speed V of said vehicle (carried on the half axis OX) In the second quadrant delimited by the rectangular axes OX and OY 'are represented by the overall range D a of variation of the opening ratio a of the variator 4, the speeds W and Wb being respectively carried on the axes OX and OY' in the third quadrant delimited by the rectangular half axes OX 'and OY', there is shown the overall range D of variation of the opening ratio S of the variator 11, the speeds Q and wb being respectively carried on the axes OX 'and OY' Finally, in the fourth quadrant delimited by the rectangular half-axes OX 'and OY, the curve N representing the variation of the kinetic energy of the flywheel 8 (carried on the half-axis OY) as a function of the rotational speed 2 of said

  steering wheel (carried on the half axis OX ').

  As a hypothesis (not mandatory), we start with the diagram of FIG. 3, illustrating the energy recovery, of an initial situation for which, on the one hand, the vehicle rolls initially to its maximum reference speed VM , that is to say that then its kinetic energy is equal to E

e M -

  (point Ao of the layer M), and secondly the steering wheel rotates at a set speed ç O corresponding to a kinetic energy of setpoint e 0, stored in said steering wheel (point B of the curve N) In this initial situation , the opening ratios a and 6 of the dimmers 4 and 11

  present respectively the values ao and SO.

  If the driver of the vehicle presses on the brake pedal, the speed of the vehicle passes from the value VM to a lower value V 1, the point A moving to come to Ai corresponding to a kinetic energy lower than e M Simultaneously, the ratio has passed from the value at 0 to a value greater than 1 corresponding to a decrease of ws and an increase of Wb, whereas the ratio has gone from the value SO to a value greater than 61 corresponding to an increase of wb and 52 following, the point BO moves in B 1 on the curve (N), for which the energy e 1 stored in the flywheel 8 is greater than the set value e Thus, as a function of the pressure exerted on the brake, the calculator 34 manages the revving of the steering wheel 8, using for the opening ratios of optimal values Cv information from the torque meter

  21 is used in feedback feedback.

  In FIG. 4, illustrating the restitution of energy, it is assumed that initially the energy situation of the steering wheel 8 is represented by the point B (stored kinetic energy = e 0, a = S and = 2>), while the vehicle is in A 3 (speed VO <VM, energy

kinetic = e 3, a = a 3).

  When the driver of the vehicle presses on the accelerator 24, for example to overtake another vehicle, the speed increases from VO to VV point A 3 passing A 4 corresponding to a higher kinetic energy for the vehicle, while point B In B 4 corresponding to a lower kinetic energy for the flywheel 8 Simultaneously, the ratio has gone from the initial value to O to a value less than 4 corresponding to a decrease of wb and an increase of ws, while the ratio3 passes from the initial value to O to a value less than 4

  corresponding to a decrease of 52 and Wb.

  Depending on the pressure exerted on the accelerator 24 at the end of the stroke, the computer 34 manages the speed V of the vehicle using opening ratios a

and 8 optimal.

  The Cv information of the torque meter 21, changed sign, is

  used in servo feedback.

Claims (9)

  1. Power train for a wheeled vehicle, the driving of which is obtained at least in part by action on an accelerating member (24) and on a brake member (25), this power unit comprising a heat engine (1) , whose output shaft (1 ') is connected to the drive wheels (7) of said vehicle by a continuous speed variator (4) associated with said motor (1), two clutches (2) and (3) in series arranged between said heat engine (1) and said continuous speed variator (4), and an inertia flywheel (8) whose shaft (8 ') is connected to the output shaft (1') of the heat engine (1) between the two clutches (2) and (3), characterized in that it comprises another continuous speed variator (11) disposed on the shaft (8 ') of the flywheel (8); a tachometer (16) and a torque meter (19) disposed on the output shaft (1 ') of the heat engine (1) between the latter and the clutches (2) and (3); a tachometer (20) and a torque meter (21) disposed on the shaft (8 ') of the flywheel (8) between it and this other continuous speed variator (11); tachometers (17) and (18) disposed at the input and output of the continuous speed drive (4) between the clutches (2) and (3) and the drive wheels (7); transducers (26) and (27) capable of transforming the displacements of said acceleration member (24) and said brake member (25) into electrical signals representative of said displacements and a computer (34) receiving as information the signals from the different tachometers (16,17,18,20), torque meters (19,21) and transducers (26,27) and controlling the operation of the heat engine (1), the clutches (2 and 3) and the two continuous drives of speed (4 and 11).   2. power train according to claim 1, characterized in that it comprises a gear selector (5) manually controlled, mounted between the continuous speed controller (4) associated with the engine (1) and said drive wheels (7).   3. Power train according to any one of claims 1 or 2,   characterized in that a compressor (36) controlled by said computer 34, is provided for the engine power supply thermal (1) in air and fuel.   4. Power train according to any one of claims 1 to 3,   1 O characterized in that the brakes (22) of the vehicle are   controlled via the calculator (34).   5. Power train according to any one of Claims 1 to 4,   characterized in that it comprises a dynamodemarreur (12) capable of being driven by at least one energy source   electric motor (13) and to drive said flywheel (8) in rotation.   6. Power train according to any one of Claims 1 to 5,   characterized in that it comprises a manual crank   (14) capable of driving said flywheel (8) in rotation.   7 Power train according to any one of Claims 1 to 6,   characterized in that the computer (34) has in memory several rotational speed values of the steering wheel and, at each instant, it compares the actual rotational speed of the steering wheel (8) to these values stored in memory, and that the result of the comparison is used by said calculator (34) to determine the type of   operation it imposes on said motor-propulsion unit.   8. An assembly according to any one of claims 1 to   7, characterized in that the calculator (34) takes into account, in determining the type of operation of the power train, that the vehicle is stationary or on the contrary, it rolls.   9 Power train according to any one of Claims 1 to 8,   characterized in that the flywheel is made of a low specific mass material but of high mechanical strength,   such as composite materials based on resistant fibers.