FR2473964A1 - DEVICE FOR CONTROLLING VEHICLE PROPULSION - Google Patents

Abstract

THE INVENTION RELATES TO A VEHICLE PROPULSION CONTROL DEVICE. IT INCLUDES A DEVICE 14 WHICH DETECTS AN EXCESSIVE DIFFERENCE IN ROTATION SPEED OF THE OUTPUT SHAFTS 42, 44 OF THE DIFFERENTIAL 32 AND WHICH, FOR A PREDETERMINED FIXED DURATION, CONTROLS A LOCKING DEVICE 22, 52 OF THE DIFFERENTIAL TO REMOVE AN EXPRESSED PAD. THE INVENTION APPLIES IN PARTICULAR TO VEHICLES WITH TWO DRIVE AXLES.

Description

The present invention relates to the field of control circuits for

  vehicle propulsion devices, and is particularly applicable to vehicles comprising

  a differential mechanism for dividing the torque

  be two output trees. Various mechanisms have been devised in the motor vehicle and transport industry to control

  excessive slippage between the drive wheels of a vehicle.

  These devices are generally used to equalize the rotational speed of two or more output shafts which are themselves driven by a main input or drive shaft. The driven shafts can in practice be considered as output shafts as they are used to drive the wheels of the vehicle, either directly,

  either by an intermediate mechanical coupling. A difference

  The speed difference between these shafts is necessary to allow different rotational speeds of the drive wheels when the vehicle negotiates a turn, encounters bumps or holes on the road or travels over difficult terrain. More generally, the output shafts are coupled by a differential with a main shaft or motor, and the differential is the mechanism that divides

  the torque between the output shafts

  so many different rotational speeds of these trees.

  In the truck industry, it is also advantageous to provide axle tandem propulsion units

  multiple using a differential between the axles accou-

  plant the transmission shaft from the engine with the differentials of each of the two rear drive axles, which will be referred to hereinafter as the front-rear drive axles

and back-to-back.

  Under normal conditions, when the vehicle is

  on good roads or on dry roads, it does not appear

  generally not excessive skating between trees

  output motors and no corrective action is required.

  sary. But during difficult weather conditions, the vehicle can travel on mud or ice, and extreme slippage can occur when one of the wheels loses traction and begins to spin.

24739-34,

  extremely fast, which will be called hereinafter a "skating condition". It has therefore proved advantageous to

  blocking mechanisms or other counter devices -

  to eliminate an excessive difference in rotation speed of the output shaft of the differential.

  Mechanical locking mechanisms for the accou-

  The transmission shaft with a differential output shaft has already been used in the truck industry and examples thereof are given in U.S. Patents Nos. 3,264,901 and 3,390,593. Mechanical locking devices have also been used on axle differentials between tandem-drive road vehicles, as described, for example

  in U.S. Patent No. 2,870,853.

  U.S. Patent No. 3,138,970 discloses

  an electronic control device responsive to a report

  port intended to limit the differences of skating.

  U.S. Patent No. 3,706,351 discloses

  an electromechanical device that uses a separate command

  lective braking to limit the differential speed

between two wheels of a vehicle.

  In general, in a differential mechanism, by blocking two shafts of the group of three shafts comprising the transmission shaft and the two output shafts, the three shafts are blocked and the "differential" function is eliminated. The terms "blocking", "blocking condition" or "blocked condition" generally refer to the

  the condition in which the differential mechanism

  plant the drive shaft with the two output shafts

  tie is rendered inoperative, so that the two output shafts rotate at the same speed and that the torque delivered by the motor is transmitted to the two output shafts as imposed by the external resistance to which each shaft

output is submitted.

  The locking can be done manually by the driver when he detects a slip condition, or it can be done under the effect of an automatic control, as described for example in US Pat. No. 3,138. 970 cited above. Skating control can also

  be assured by means other than the blocking of

  and the braking control device described

  in United States Patent 3,706,351

  has another solution to this problem. Electricity circuits

  therefore, tronics may be provided as control devices for eliminating or at least reducing slippage,

within acceptable limits.

  In general, the electronic control responds to

  input speed signals that are detected and ensures the

  continuous control and control. These devices

  continuous flow can produce repeated cycling of the

  order since the speeds of the

  output tends to become synchronous almost immediately

  after blocking, eliminating the error signal

  before the vehicle is actually out of the state

  skating. The electronic control device con-

  continue to control the output shaft speeds and if

  actually the vehicle is no longer in the initial state of

  at the release of the blocking device, the signal

  error is regenerated and the control of the

  cage is applied again. Oscillations can often

  occur in the propulsion system, at a frequency of

  relatively high frequency between 1 and 3 Hz. These oscillations can harm the vehicle by constraints

  repetitive motor train and can disturb the

  particularly if the control device

  recycling and if the vehicle does not cross the

  part of the road which presents the state of "skating".

  An object of the invention is therefore to eliminate the incon-

  the prior art by means of an apparatus for

  skating control which is not subject to rapid cycling.

  of which, on the contrary, maintains the blocking state

during a predetermined period.

  Another object of the invention is to propose a device

  which is particularly suitable for

  coupling mechanisms of the differential type by

  a fixed and prolonged blocking interval after a

  excessive speed of output. For example, the fixed blocking interval is greater than 20 seconds and it can even reach a few minutes depending on the type of

vehicle and application.

  Another object of the invention is to propose a mechanism

  blocking mechanism whose operating time is blocked

  extended after its order, and specifically intended

  to a tandem propulsion vehicle with differences

between axles.

  Yet another object of the invention is to provide a fault indicator circuit for a slip control apparatus for inhibiting control.

  if an actual blocking condition is not detected

  after a given period. The use of the circuit

  the trouble of checking the operation of the app-

  similar mechanical blocking and detection functions.

  Yet another object of the invention is to provide an automatic test skating control circuit for

  vehicles, automatically controlling the proper func-

  when the vehicle is turned on.

  Another object of the invention is to propose

  a slip control blocking device which inhibits

  be any blocking control during braking of the vehicle

cule.

  The invention therefore relates to an apparatus for a

  hicle which includes a main shaft of transmission and

  the first and second output shafts intended to transmit

  be a driving torque to the wheels of the vehicle. The device

  carries a device that detects the relative speed of rotation

  between the first and second shafts to detect a slippage condition, and a control device responsive to the detection device for eliminating an excessive speed difference between the shafts.

  exit. In one embodiment, the communication device

  mande acts on a differential mechanism to block

  in rotation two groups of trees at the control of the dis-

  positive detection. The control device works

  for a predetermined time after being actuated.

  The invention is particularly applicable to vehicles with

  tandem propulsion including a differential between

  sieux, with a device such as a fork and a stirrup

  intended to slide a clutch collar which

  rust the main input shaft of the differential between axles with one of the output shafts of this differential,

  or to lock the two output shafts together.

  Other features and advantages of the invention

  will appear in the following description.

  In the attached drawings, given solely as examples

in no way limiting:

  Figure 1 is a schematic diagram illustrating the principle

  of the electronic control circuit according to the invention,

  FIG. 2 is a view from above of a tractor and

  truck driver comprising a differential between axles according to the invention,

  FIG. 3 is a view on a larger scale of a

  of the differential between axles of Figure 1,

  FIG. 4 is a simplified diagram of a mode of realization

  control circuit according to the invention, and

  Figures 5A and 5B are detail diagrams of the

cooked from Figure 4.

  FIG. 1 is therefore a simplified diagram of a skid control circuit according to the invention. The control device, generally designated 10, is connected to receive electrical signals from two sensors, not shown, which detect the rotational speed of two propulsion output shafts. In general, a sensor can be positioned to detect rotational speed

  of the input or transmission shaft, at the entrance to the

  and a second sensor can be positioned to

  detect the rotational speed of an output shaft of the

  tial. The sensors themselves may be of the current type

  for example, magnetic sensors that deliver an im-

  output pulse at the passage of each tooth of a pinion or a rotor fixed on the shaft. The frequency of the incoming signals is then proportional to the speed of rotation of the shaft. The detected signals W1 and W2 are applied on input lines 11 and 12 to a differential circuit

  14 which measures the difference between the two frequencies.

  differential cook 14 may consist of a comparator which compares the difference between the absolute values of the two

  input signals, if they are proportional to the frequency

  respectively, with a reference value. The reference value can itself be produced by the addition

  of the two input signals and its multiplication by a variable

  their reference (0.05 in this case) and which is suitable for the type of comparator used. The differential circuit 14 thus delivers an output signal on the line 15 in the case

  simply o the difference in rotation speed of the ar-

  is greater than a predetermined allowable slip value. Some slippage is obviously acceptable because of the normal operating conditions of the vehicle, for example when driving in bends and on uneven terrain, as well as to accept different radii

pneumatic tires.

  The output signal on line 15 may be considered as an error signal or a difference signal DIFE indicating an excessive difference in rotational speed

  trees. The DIFF signal is applied to two delays

  Tl represented in 16 and T3 represented in 18. The time

  Tl feeder delivers an output pulse after a nominal start delay of the order of 0.25 to 0.5 second

  and it is intended to reduce to a minimum a false

  presence of a beginning of wheel slip. After this

  delay-start Tl, the output signal of the time

  the riser 16 is applied to the forcing input S of a circuit

  rocker 19 type RS which then delivers a pulse

  at its output Q. The output pulse is applied by a line 20 to a power amplifier 21 which

  energizes a control device or an electromagnet 22.

  The controller 22 is used to operate a device that eliminates the slip state detected by the input signals of the sensors. An electromagnet used as a control device 22 can shift a clutch collar and thereby place a differential mechanism in a "locked state". This application will be described in more detail later. The controller 22 may also be used in combination with a selective brake control device of the kind described in US Pat. No. 3,706,351, or in a four-wheel drive vehicle of the type described in US Pat. the patent of

  United States of America No. 3,557,634 to engage a clutch

  ge and transmit the engine torque to the front axle of the vehicle. The control signal from the power amplifier 21 is also applied to a timer T2 designated 23. The timer T2 is the timer

  basic cycle and establishes a time interval

  determined, for example of the order of 30 to 60 seconds,

  where the control device 22 remains actuated. At the end of this predetermined interval, the timer T2 delivers an output signal to an OR gate 24 which delivers

  an output signal at the terminal R of the rocker circuit 19.

  When set to "0", the Q output of the tilting circuit 19 passes

  at the low level, which releases the control device 22.

  The setting of the tilt circuit 19 can also be

  re after timer T3, or security timer

  the delay, because the output of the circuit 18 is also applied to an input of the OR gate 24. The

  T3 safety timer is set for a longer time.

  less than the interval T1 and less than the interval T2. The

  function of the safety timer is to release the dis-

  positive control 22 in the case where the patient condition

  swimming was not eliminated after the time interval T3.

  For example, the interval T2 can be set to 30 seconds and the interval T3 to 15 seconds. If the DIFF signal on line 15 is still present at the end of the period of seconds, the safety timer T3 returns the tilt circuit 19 to "O", thus freeing the controller 22. The operation of the safety timer

  based on the assumption that the pre-skating condition

  detected, must have been removed after the

  time T3, so that the DIFF signal on the line should no longer be present. If this DIFF signal is still

  present, there is reason to assume that a malfunction is

  This has occurred, for example, a sensor fault or a fault in the locking mechanism. In either case, it is desirable to release the controller and give the driver an indication of the malfunction. The time interval T3 can be set to any value in the range defined by T1 and T2. For example, the time interval T2 can be set

  at 30.5 seconds with timer T3 at 30.0 seconds.

  This situation opens a very narrow window for the

  T3 porator (30.0 to 30.5 seconds) and the latter can be used to eliminate the detection of parasitic DIFF signals due to strong vibrations of the gears or others. Figures 2 to 5B illustrate an embodiment of the invention applying to a differential between axles of a four-wheel drive vehicle. Figure 2 is a

  plan view of a cabin 20 and a truck carrier 22.

  The carrier 22 is supported by a tandem engine rear axle, comprising a front-rear axle 24 and an axle

rear-26

  The torque developed by the vehicle engine is trans-

  put by the transmission shaft 30 to a differential 32 between axles supported in a housing 31 and which divides the torque between the front differential 34 and the rear differential 36. The transmission shaft 30 t coupled with the input 38 of the differential between the axle by a universal joint 40. The axle differential 32 divides the developed torque at the inlet 38 between a first output shaft 42 and a second output shaft 44. As shown in FIG. output 42 is driven directly by the left differential gear 32 and the shaft

  output 44 is driven by a series of reduced gears

  45-47 which in turn are driven by the right side pinion of the differential 32. The output shaft 34 is

  turn in turn a pinion that drives the crown den-

  the front-rear differential 34. The output shaft 42 is coupled by a universal joint 48 with a shaft of

  transmission 50 which, in turn, leads to the crown of

  36 rear-rear differential.

  A collar 52 is coupled by splines with

  the output shaft 42. The collar 52 can move axially

  on the shaft 42 by means of a fork, not shown, and which can be moved to the left, seen in FIG. 3, in engagement with the teeth 54 provided on the hub of the reduction gear 45. When the collar 52

  meshes with the teeth 54, the pinion 45 and the spindle

  42 are locked mechanically with each other and rotate with the same speed. Differential 32 can no longer change equal speed division until

  the collar 52 is clear of the teeth 54.

  An example of a tandem axle assembly including an axle differential and a locking mechanism is disclosed in US Patent 2,870,853 and in the publication of Rockwell SFHD, STHD, SUHD

  Parts Book ", No. SP-76-46-1 published by Rockwell International

Corporation, Troy, Michigan.

  The housing 31 of the differential supports two sensors 56

  and 58. The sensor 58 responds to the rotation of the teeth of the

  gnon 45 and thus detects the rotational speed of the output shaft 42. The sensor 56 responds to the rotation of the rotor

  toothed 60 supported by the differential housing 32 and detected

  Thus the speed of rotation of the main shaft 30. The sensors 56 and 58 deliver output signals on the lines 62 and 64 to the control device 66 located on the housing 31 of the interstage differential 32. A

  detection of a difference in speed, in response to

  On the input lines 62 and 64, the control device 66 outputs an output signal on line 68.

  to the solenoid pneumatic valve 70 which functions

  is used in the usual manner to move the collar 52 and lock the differential 32. At the establishment of the blocking condition, the control device 66 delivers

  a signal to the indicator light 72 visible by the driver

the vehicle.

  The control device 66 is powered by the circuit

  braking system and includes a device for inhibiting

  locking mechanism when the vehicle brakes are operated. FIG. 2 shows a storage battery designated 74, connected to a brake lamp contact 76, closed by the operation of the throttle valve 78. The interconnection between the control devices 66 and the brake lamp circuit enables also to detect an open line condition. In this case, the open brake circuit is detected by the control device

  66 which inhibits the operation of the locking device

lage.

  Figure 4 is a simplified diagram illustrating the

  of the control device 66. The input signals from the sensors 56 and 58 are applied to

  input lines 62 and 64 to circuits 80 and 82 con-

  signal trainers. The shaping circuits 80 and 82

  converts sinusoidal input signals into

  rectangular lines that are applied to lines 84

  and 86 to trip circuits 88 and 90. The circuits

  Trigger 88 and 90 are ordered alternately

  oscillator 92 so that a pulse is applied to an output line 94 or an output line 96. The lines 94 and 96 are connected to the inputs of an

  OR gate 98 whose output is connected to a counter-de-

  counter 100 by a line 102. The signal on line 102 indicates the pulse frequency of one or the other of

  sensors, and the frequency of the pulses is directly

  proportional to the speed of rotation of the shafts 30 and 42, measured by the sensors 56 and 58. The oscillator 92 delivers

  also a signal on line 104 to the counter-

  up counter 100 so that the signal on the line 102 can be correlated according to whether it comes from the circuit of

  trigger 88 or trip circuit 90. A cir-

  cooked trigger is used to advance the

  up-down counter 100 while the other trigger circuit

  order the countdown. Signals on the line

  104, from the oscillator 92, allow the function

  counter 100 in the counting or defrost mode.

  counting according to the particular sensor whose signals are counted. For example, the up-down counter 100

  is set to the binary value "4". The content of the counter-

  down counter 100 indicates that a sensor, for example the captor

  56 has received more signals per unit of time than the other sensor, for example the sensor 58. The contents of the up-down counter 100 indicate the opposite condition. The counting and counting range is established by

  an oscillator 110 and a generator 112 of e-

  Sampling. In general, the duration of the range may

  be of the order of 200 milliseconds. The meter-decompo-

  100 is initially set up with the binary value

  re "4". If a count "0'2 is reached in the sampling range, a DIFF output signal is applied

  on line 114, at the output of up-down counter 100.

  Similarly, if a binary digit "8" is

  dyed in the sampling range of the meter-de-

* counter 100, a DIFF signal is applied on the line 114.

  The output signal DIFF is applied to a floating circuit

  their blocking 116 and an entry of a NAND gate 118.

  The DIFF signal sets the blocking switch circuit 116 to "1" so that it outputs a signal at its output Q to a driver 120 on the line 122. The output of the driver 120 is applied to a driver. electromagnet 71 which actuates the collar 52 of the interstitial differential to block it. The driving circuit 122 also gives a visual indication to the driver by lighting a

indication lamp 72.

  The blocking switch circuit 116 is reset to "0" on receipt of the quiescent pulse of the counter 124, at the passage of a predetermined time set in the counter 124 and demerged upon the transmission of the DIFF signal. . The meter is thus allowed to operate and it starts to

  count upon receipt of an authorization signal for

  from the toggle circuit 116 on a line 123.

  The quiescent signal from the counter 124 is applied to the flip-flop circuit 116 by a line 128.

  signal of rest on line 128 appears 435 se-

  condes after the transmission of the DIFF signal on line 114 of the described embodiment. Of course, the control circuit can be modified to establish fixed time intervals or different durations, preferably greater than about 20 seconds in other embodiments. A second output signal of the counter 124 is applied on a line 130 to the second input of the NAND gate 118. This second output corresponds to that of the disturbance timer T3 of FIG.

  also, the counting authorization signal on the

  gne 126 is used to provide the boot reference

  counter allowing the counter 124.

  The output signal of the NAND gate 118 is used to set a failover circuit 136 to "1" provided that the DIFF signal is present on the line 114 at the same time as the output of the counter 124 outputs a signal on the line 130. This condition effectively imposes that the signal DIFF is present at the instant T3, according to FIG. 1. When passing to "1" of the flip-flop circuit 136, a signal is applied on a line 138 to a driver circuit 140 which

  in turn, excites a disturbance indicator 144. A

  The output signal of the flip-flop circuit 136 on the line 125 to the counter-counter 100 also serves to stop or inhibit the control device, so that no other

  operation of the driver circuit 120 is possible.

  Figures 5A and 5B are diagrams of the details of the

  Fig. 4. The signal shaping circuits and 82 are identical and only one will be described. The

  shaper circuit 80 therefore comprises a voltage comparator

  180, a Zener diode D1 and filter circuits consisting of resistors and capacitors R1, C15

  and R2, C16 and C4. Resistors R5 and R9 form a division

  voltage and provide a reference voltage to an input of the voltage comparator 180 whose other input receives the signal from the sensors. Current sensors can be used, for example magnetic reluctance type

  variable, producing a sinusoidal signal at the input of the

  80. The output signal of the comparator 180 is a rectangular signal and is applied to a circuit

  controlled trigger 88. To facilitate the description,

  it will be assumed that the output signal of the voltage comparator 180 is applied directly to the input of the circuit.

  firing 88 and three NAND gates (elements 380,382 and 384) interposed as will be explained by

  the following. Trigger circuit 88 has a cir-

  190 type D rocker switch which passes to 1 "Z at the receiver.

  the output signal of the comparator 180 and which delivers

  at its output a high level signal. The Q output of the circuit

  cooker rocker 90 is connected to an input of an AND gate

  192 with four inputs whose three other inputs receive

  wind a counter output signal that will be explained later. Trigger circuit 88 further includes a driver circuit 194 buffer and inverter that attacks

  a NAND gate 196. The exit of the NAND gate 196 de-

  delivers a positive impulse of about 20 microseconds which

  is applied to the output line 94 of the circuit

  88. A similar impulse of 20 microseconds

  is applied to the output line 96 of the circuit de-

  90. Lines 94 and 96 are connected to a portal

  OR 99 constituted by a NOR gate 200 connected to an inverter 202. The output signal of the OR gate 99 is

  applied to the up-down counter 100 which may for example be

  a prepositioned binary type counter.

  Oscillator 92 may consist of a sampling oscillator 210 connected to a four-bit binary counter 212. The counter 212 delivers an exit code on lines 214a, b, c and d. The output lines 214ac deliver binary codes identified respectively by

  A, B and C. The codes A, B, C establish conditions for

  code of the AND gate 192 of the trigger circuit 88. Similarly, the condition codes A, B, C produce

  inputs of the corresponding AND gate of the circuit de-

  90. The different codes ensure that only one of the trigger circuits 88 and 90 is triggered at a given time. The oscillator 210 can operate for example at 40 KHz and the sampling frequency provided by the four-bit counter to each of the triggering circuits 88 and 90 is of the order of 5 KHz. The sampling time is chosen large enough so that even the fastest possible sensor is in the

range from 0 to 1 KHz.

  The four-bit counter 212 outputs an output on the

  line 104 to the count control input and

  counting of the up-down counter 100. Therefore, this last

  deny one way or the other depending on the state of the control input on line 104 that continually passes from one state to another in synchronism with

  the control of the tripping circuits 88 and 90.

  Figure 5A also shows the oscillator 110 and the

  generator 112 of sampling range. Ltoscilla-

  110 provides a pulse of 13.3 milli-

  seconds at its output terminal. This pulse is applied to the generator 112 by the line 220. The generator 112 may consist of a divider circuit arranged to divide by

  sixteen incoming signals, thus delivering a signal of

  with a nominal duration of 200 milliseconds on a line 222 attacking an input of the NAND gate 224. The other

  entry of the NAND gate 224 is conditioned by the

  output signal of the NAND gate 226. The output signal of the NAND gate 224 is applied to the up-down counter and places it in the binary state four every 200 milliseconds. Therefore, the counter 100 has a range for receiving rate pulses on the line 102 for a period of 200 milliseconds before being returned to the four binary value. During this 200 millisecond range, up-down counter 100 can count down to zero or counter up to eight, depending on the pulse frequency difference of

  input lines 62 and 64 of the sensors. If a binai count

  When e8 is reached, an output pulse is delivered on a line 230 by the counter 100 to an input of the AND gate 232. If the zero count is reached, the output of the up-down counter 100 is applied on a line 234 by

  an inverter 236 to the second input of the AND gate 232.

  The output of the latter is connected to the NOR gate

  238 which delivers the output signal DIFF on the line 114.

  This signal is high or "1" when the output of the counter-counter 100 reaches the binary count eight

  or the zero binary count, indicating a noticeable difference

  speed of rotation of the two trees measured. The signal

  DIFF at high level on line 114 is applied to the cir-

  beating rocker 116 by an inverter 240. The cir-

  The tilting furnace 116 consists of two NAND gates 242 and 244 cross-connected, the output of the NAND gate 242

  being connected to the driver and inverter circuit 246. The output

  This portion of the latter is applied on a line 122 to the driver circuit 120 which comprises transistors 150, 152 and 154. An electromagnet 71 is powered by the circuit

  120 and the indicator 72 indicating the blocking

cage.

  The output signal of the NAND gate 242 is also applied to the counter authorization terminal of the counter 124. The counter can be set for a predetermined period or a fixed interval of 7, 27 or 435 seconds and after the expiration. during this period, it delivers a clock signal on the lines 128 and 130. The counter 124 is set for a fixed interval of 435 seconds in the described embodiment. Line 128 contains a circuit 255 with a time constant RC which introduces a delay of approximately

  half a second. The signal on line 128 goes to

  high at the end of the predetermined interval, for example

  full 435 seconds during which the blocking condition

  is maintained. During this predetermined interval, the

  The blocking state is maintained regardless of the value of the DIFF signal on the line 114 because the flip-flop circuit 116 remains blocked until it is reset to "0" by the delayed-interval signal on the line 128. effect, the delay signal on line 128, delayed

  half a second by the delay circuit 255, is applied

  at an entrance to the NAND gate 256 whose exit

  attack an entry in the NAND gate 242. The second one

  The gate of the NAND gate 256 receives a clock signal through line 126 from oscillator 110. The NAND gate 256 is used to avoid any speed condition of the gate.

  operation of the blocking rocker circuit 116.

  part of the NAND gate 256 goes down to the

  simultaneous clock pulse of line 126 and the delayed signal of line 198. The low level signal at the output of the NAND gate 256 passes to the level

  up the NAND gate 242 which forces the cir-

  cooked attack and inverter 246, thereby stopping the electro-

  magnet 71 and the indicator 72. Simultaneously, the high level signal at the output of the NAND gate 242 returns to

rest the counter 124.

  The delay signal on line 130 is the same

  signal than that of line 128, but without being delayed.

  The delay signal on line 130 is applied

  at the NAND gate 118 and thence to the switch circuit of

  storage 136 constituted by two NAND gates 260 and 262 connected in a cross. The NAND gate 260 also receives

  a signal from line 124 from a braking circuit

  swimming 270 which will be described later. The exit of the

  NAND gate 260 issues an FS signal or signal of

  which is normally at a low level when it is

  inoperative and which goes to the high level or "1" for one

  of disturbance in which the circuit is stopped. For example

  if the DIFF signal on line 114 is still present, at the high level or in the "1" state, at the moment when the signal of

  delay is produced on line 130, one half

  second before the delayed signal on line 128, the output of the NAND gate 260 goes low, producing an OFS signal. At the same time, the output of the NAND gate 262 goes low so that the FS signal goes to

low level or "0".

  The FS signal from the NAND gate 260 is

  only at an input of the NAND gate 226 (Figure 5A). In turn, the gate 226 sends a signal to the NAND gate 224 which continuously positions the up-down counter 100 and therefore inhibits the operation of the control circuit. The signal from gate 262 produces a low level on line 138 to the driver and inverter 274. The output of the driver and inverter circuit

: 473964

  274 controls the driving circuit 140 which consists of transistors 276, 278 and 280, similar to the driving circuit 220. A trouble indicator 144 is excited when the

  device works in the trouble mode.

  An additional characteristic appearing in FIGS. 5A and 5B is the incorporation of the braking circuit 270 in the apparatus of FIG. 4. The braking circuit 270 detects a braking condition and an open circuit condition that can result for example from a burned filament or disconnected wire. Line 290 is connected to the brake circuit with the vehicle battery and the

  brake lamps. When braking is applied, latency

  the line 290 is normally of the order of 13.6 volts. The braking circuit 270 comprises resistors R25, R36, R26, a capacitor C21 and diodes. In addition, the voltage comparators 292 and 294 are provided as well as an inverter 296, AND gates 298 and 300 and a NAND gate 302. The resistors R7, R49 and R8 constitute a voltage divider which drives an input of the comparator voltage 294 whose other input is connected to the line 290 by the resistor R25. If the brake contact is activated,

  the voltage comparator 294 goes high to its output.

  on the line 304 which attacks the inverter 296 and makes it go low. The inverter 296 is connected to the NOR gate 306 which forces the output on the line 114 by the NOR gate 238 to the "" state or the low level. Thus,

  keeping the DIFF signal low during the closing

  braking contact, the blocking circuit can not be activated. Inhibiting the locking during braking is desirable in order to avoid a locking of the differential between axles, resulting from a non-synchronous rotation of the wheels

during braking.

  The braking circuit 270 furthermore makes it possible to detect an open brake circuit by the voltage comparator 292 which is kept low in the case of an open braking circuit and which normally receives a voltage between one-third and two-thirds of the current. regulated voltage, resulting from the bias circuit of the resistors R36,

2A73964

  R25 and R26. In a braking system condition

  green, the logic output of the voltage comparator 292 and the voltage comparator 294 is applied to the NAND gate 298 which drives the NAND gate 202, in turn controlling the AND gate 300. An output signal on the line 264 is generated at an input of the NAND gate 260 of the fault switch circuit 136, setting it to state "1" to produce a high level or state fault signal.

  "1". The signal FS continuously positions the counter

  up-counter 100 by the NAND gate 226, as already described, prohibiting any further production of the DIFF signal

on line 114.

  Although a closed brake or a closed brake contact and an open or floating condition of the stop lamp circuit prohibits operation of the electromagnet drive circuit 120, the open circuit condition controls the fault switch circuit. 136 which remains commanded until a manual rest, while

  the tight brake condition temporarily inhibits the production of

  DIFF signal on the line 114 by the NOR gate 238. In the latter case, when the brake lamps are off, the control circuit becomes effective for

  excite the electromagnet drive circuit 120.

  Another characteristic of the circuits of FIGS. 5A, B lies in a circuit 330 for automatic control at the

  energizing comprising NAND gates 332,334

  The automatic control circuit further comprises a capacitor C10, a resistor R27 and a NAND gate 342 (FIG. 5A). The voltage regulator shown in FIG. 5A delivers a regulated output voltage V

  about 6 volts. During the start-up period, the impulse

  The 6 volt output produces a power-up PUP signal held for about two seconds by a time constant RC established by a resistor R7 and a capacitor C10. The power-up signal assures an "O" state at the output of the NAND gate 342, which signal is applied to the NAND gate 332 by line 344. This signal provides a means of controlling the circuits during a staging sequence. energized by producing TEST and TEST signals

  simulating a sensor input, and producing

  Simulated tages using NAND gates 380 and 382. An encoded signal D is also produced by the four-bit bit counter 212 and is applied to an input of the NAND gate 380. Therefore, after the contact closure of vehicle ignition and when the voltage regulator is stabilized, pulses are produced at the

  exit of the NAND gate 384, attacking the

  their 190 to produce simulated counts that are sampled by the sampling oscillator 210 and the binary counter 212. But the trigger circuit receives no simulated counting and therefore, a DIFF signal is produced on the line 114. This signal DIFF is applied to the NAND gate 340 with the TEST signal which returns to "O" the automatic test flip-flop circuit 330 (by the signal P1fR RPST) as well as the flip-flop circuit.

  disturbance 136. Trouble indicator 144 is, however,

  less excited for about two seconds, ie

  the period during which the start signal is

  feels. When the PiWR RST signal goes to 'O', the indicator of

  disturbance is no longer supplied unless a malfunction

  is detected in the circuit. The output signal of the NAND gate 342 also serves as a power supply idle and is used with the PUP signal by the NAND gates 210, 242, 332 and 300 to reset the counters and associated flip-flop circuits. with these doors NAND. So the power up sequence

  initialise the device and give an indica-

  positive indication that the disturbance indicator and

  electronic circuit board components work properly. Integrated circuits that can be used in the circuits of FIGS. 5A and 5B are given as examples in the following table: Reference Numbers

82, 180, 292, 294

196, 210

192

, 112, 212

202, 236, 336, 33,

240, 246, 274, 29 <

110

242, 260, 340

118, 224, 226, 24J

256, 262, 302, 33

334, 380, 382, 381

200, 238, 306

232, 298, 300

Part Numbers

LM 2901

CD 4013

CD 4093

CD 4082

CD 4007

F 4029

CD 4049

LM 555

CD 4023

CD 4011

CD 4040

CD 4001oo

CD 4081

  2, Representative values of the circuit elements of FIGS. 5A and 5B are given by way of example in the following table: Element R1 R2 R3a R3b R4 R5 R6 R7 R8 R9 R10 R11 R12

R13

  R14.a R14B Ri 4 R15 R16 K K K value 1, 5K K

4,7KI-

  4.7K 1.5K 27K KKK sb K 1.5K Element R22 R23 R25 R26 R27 R28 R29 R31 R32 R34 R35 R3 6 R39 R40 R41 R42 R43 Value 1.8K K 68K 7.5K 8.2K 4.7K 1K 8 2K 4.7K Element R17 R18 R19 R20a R20b R21 a: R2 lb R62 C1 C2 C3 c4 cZr C5 c6

C7

C8 Clo Cll C12

C13

C14

C15-C21

C22 C50

C51

c60 D1 D4 D6 D7 D8 D9 D10 D11

D12

  D13 D14 D15 D16 K value, K 5K 6.2 OpF 0, OpF pF 1 OpF 'pF 0.01F 0.047 lOpF

O, 0111P

  0, 00 lyI 1 OPF 0, O0 lF 0.001 0, lpF 2.2 F lOOOpF 1lN5221

1N5221

1N4001

1N4734A

1N5395

1N4736

1N4755

1N4004

1N4002

1N4755

1N4oo004 MZo4746

1N4001

  E element R44 R49 R50 R51 R52 R60 R61 D20 D21 L1 Value 1K 4.71 3K 3K K K

MZP4746

1 N5395

  2.2pM It is clear that many modifications can be made to the described embodiment and

  illustrated without departing from the scope or spirit of the invention.

Claims (23)

  1 - Device for controlling the propulsion of a vehicle   comprising a main drive shaft (30) and first and second output shafts (32, 44) for applying a driving torque to the vehicle wheels, and a main drive shaft coupling device (32) with said first drive shafts (32, 44); first and second output shaft, device (10) characterized in that it comprises a device (14) for detecting the relative speed of rotation of said first and second output shafts and a control device (22) responsive to said device detection when it detects a skating condition, and comprising a device for eliminating said   slipping condition, said operating control device   during a predetermined time after it has been triggered.   2 - Device according to claim 1, characterized in that said coupling device (32) of said main drive shaft (30) with said first and second output shafts (44) is a differential (32), said control device ( 22) locking together the rotation two shafts of the group comprising said main drive shaft and said first and second output trees.   3 - Device according to claim 1, characterized in that said first output shaft (42) is normally   driven by said main drive shaft (30), said device   eliminating said slip condition including the clutch coupling (52) of said main drive shaft with said second output shaft.   4 - Device according to claim 1, characterized in that said wheels of the vehicle are provided with brakes, said device (22) for eliminating said slip condition selectively controlling the application of said brakes. - Device according to claim 1, characterized in that said vehicle is a tandem propulsion vehicle   comprising a front-rear axle (34) and a rear axle-   rearward (36) for driving said wheels of the vehicle and a differential (32) between axle to divide the torque between said front-rear axle and said rear-rear axle, the input of said differential (32) being coupled with said motor shaft (30) and its outputs being coupled   with said first and second output shafts (42, 44).   6 - Device according to claim 5, characterized   in that said control device (10) delivers a   control signal upon detection of a patient condition.   to operate the device (22) for eliminating   said slip condition, said device comprising in   in addition to a safety timer (T3) operating at an in-   stant set before the end of said predetermined time to interrupt the operation of said controller if said control signal is still present at said fixed time. 7 - Device according to claim 6, characterized in that said durability timer (T3) operates for a short period.   8 - Device according to claim 7, characterized   in that said fixed duration is not more than one half   nute. 9 - Apparatus according to claim 6, characterized   in that said fixed duration ends at the same time as said predetermined duration.   Device according to claim 1 or 6, characterized   characterized in that said vehicle comprises a brake, said disc   positive device further comprising a device responsive to   applying said brake of the vehicle by producing a braking signal and a device (66) connected to receive said   braking signal to inhibit the operation of said disc   positive control, so that said communication device   (10) is ineffective to eliminate the condition of   the application of the vehicle brake.   11 - Device according to claim 10, characterized   in that said vehicle comprises a lamp circuit   braking lamps and brake lamps operating on the   cation of said brake, said device (66) responsive to the   application of said vehicle brake comprising a device   connected to said brake lamp circuit.   12 - Device according to claim 1 or 6, Z L73964   characterized in that it comprises a device (66) connected to the brake lamp circuit for detecting a condition   circuit, and a device for inhibiting the function   said control device (10) to detect said open circuit condition so that the   operation of the control device (10) or interrupts   detection of an open circuit condition in the said brake lamp circuit.   13 - Device according to claim 12, characterized   in that it further comprises a self-test circuit   which controls the operation of that device   control in response to starting said vehicle.   14 - Device according to claim 1, characterized   se in that it includes an automatic test circuit which   responds to the start of said vehicle by stopping the control device.   Device according to claim 1, characterized   in that said detection device comprises two cap-   tors (56, 58) each positioned against a rotating shaft   respective and producing signals whose frequency is   the rotational speed of the respective shaft, said control device (10) comprising a circuit for   gate (98) receiving said signals from each of said   said gate circuit driving the signals from   each of said sensors, a device (100) for   said signals from said gate circuit and   a difference signal when a difference is detected.   predetermined counting of said counting device,   a timer connected to receive said power signal   and produce a control signal during said   predetermined duration and an attack device (120)   said control signal to eliminate said condition. skating.   16 - Device according to claim 16, characterized   in that said counting device consists of a counter-counter (100) which counts in response to the signals   of one of said sensors and which counts in response to the sig-   other of said sensors, said gate circuit (99) 2 -73964   alternately driving the signals of said sensors to said counting device.   17 - Device according to claim 16, characterized   in that said up-down counter (100) can be set in advance, said control device (10) further comprising a device (112) for bringing to rest   said up-down counter at fixed intervals.   18 - Device according to claim 17, characterized   in that said fixed count is prepared-tied   with said countdown, said up-down counter (100) pro-   setting said difference signal to exceed one   either of said prepared counts.   19 - Device according to claim 18, characterized   characterized in that it comprises a differential (32) coupling said main drive shaft (30) with said first and   second output shafts (42, 44), said   (22) locking together in rotation any two   in the group comprising said main drive shaft   and said first and second output shafts.   20 - Device according to claim 19, characterized   in that said vehicle comprises a coupling collar   plement (52) and an associated set of fork and caliper for rotationally locking said main shaft   with one of said output shafts, said device for   that (120) comprising an electromagnet (22) for actuating said collar.   21 - Device according to claim 1j, characterized   in that it further includes a timer of   (T3) which produces a security signal if the said   difference is present at a fixed moment before the ex-   said predetermined duration, said selection signal   being applied to said counting device for   fishing for any other production of said difference signal.   22 - Device according to claim 15 or 21, characterized in that said vehicle comprises brakes,   said device further comprising a circuit (66) responsive to   applying the said brakes by inhibiting the trans-   sending said difference signal to said timer. 24.73964   23 - Device according to claim li or 21, characterized in that said vehicle comprises a brake lamp circuit, said device further comprising a device (66) connected to said brake lamp circuit and for detecting an open circuit condition , thus prohibiting the production of said difference signal.   24 - Method for improving the correction of the   kept in a vehicle comprising a main drive shaft   cipal (30) and first and second output shafts (42, 44) for applying a driving torque to the wheels of said vehicle and a device (32) for coupling said main drive shaft with said first and second shafts   output, characterized in that it consists essentially of   to detect (14) a slip condition between   two shafts of the group comprising said main drive shaft   pal and said first and second output shafts, with   rusting (52) said coupling device (32) to eliminate said slip condition and to maintain said lock condition for a predetermined time (T3). - Method according to claim 24, characterized in that said vehicle is a tandem-propelled vehicle comprising a front-rear axle (34) and an axle   rear-end (36) for driving said wheels of the vehicle   and an inter-axle differential (32) for dividing the torque between said front-rear axle and said rear-to-rear axle, said inter-axle differential having an input coupled to said main drive shaft (30) and outputs coupled with said first axle and the second output shaft (42, 44), said method further comprising inhibiting the locking of said coupling device (52) if said slip condition is detected before the   end of said predetermined period (T3).   The method of claim 24 or 25, wherein said vehicle comprises brakes, said method further comprising detecting (66) the application of the vehicle brakes and inhibiting the locking of said coupling device (32) in response to the application of said brakes of the vehicle.   27 - Process according to claim 24 or 25, in   said vehicle comprises a brake lamp circuit   said method further comprising detecting (66) an open circuit condition of said brake lamp circuit and stopping the application of said method in response to said opening condition of said brake circuit. brake lamp.   28 - Method for improving the correction of pa-   in a vehicle comprising a main drive shaft   pal (30) and first and second output shafts (42, 44)   intended to apply a driving torque to the wheels of said vehicle   and a coupling device (32) of said main drive shaft with said first and second output shaft, characterized in that it essentially consists in detecting (14) a slip condition between two shafts of the group comprising said main drive shaft and said   first and second output trees, and to activate a   (22) to eliminate said slip condition of   continuously for a predetermined period of time (T3j) independently   the condition between these two trees.