FR2837247A1 - Coupling device for linking a combustion engine to a gearbox incorporating integral means for transmission torque measurement based on marking of the angular position of the flywheel and torque transmission means - Google Patents

Abstract

The coupling device (10) for linking a combustion engine to a gearbox comprises an engine flywheel (100) rigidly linked to the crankshaft on which is fixed a large displacement vibration shock absorber (200), a gear shaft (260) driven by the shock absorber and supported on a closing plate of the gearbox housing and means (400) to transmit the torque between clutch and input shafts. Means are provided for marking the angular position of the torque transmission means and the flywheel from which the torque applied to the input shaft can be determined.

Description

previous claims.

  - 1 - t) ISPOSITIVE bE MEASUREMENT bE INPUT TORQUE 1) E GEAR BOX G present invention relates to a device for measuring torque on the input shaft of a gearbox

for motor vehicle.

  More precisely, it relates to a coupling device o between a heat engine and a shift gearbox

under couple.

  This invention finds a preferred, but non-limiting application in a robotized gearbox with pGssage

under couple.

  On vehicles fitted with automatic or robotic gearboxes with torque shifting, knowledge of the gearbox drive torque at the time preceding a gear change is essential to perfect the smoothness of this shift, by making possible very fine steering brakes,

  clutches or couplers stressed during this.

  In fact, the level of torque applied to the wheels during a gear change, which depends on the way in which the clutches or couplers of the gearbox are loaded, varies according to the acceleration level of the vehicle and according to the load level of the vehicle.

engine.

  Many devices are known for determining a torque level. In this connection, IG publication EP 1 065 363 describes a method for controlling the torque produced by each of the - 2 Furthermore, publication WO 0008434 describes a method for measuring the deformation of a torsion bar using two sensors and of this deformation we

deduces the couple applies.

  s Publication US4683746 describes another method for determining the torque at the input of a gearbox, based on the measurement of the angular deformation of the friction-absorbing hub using one or more sensors carried by the tube guide and read on two targets one related to

  o shock-absorbing hub and the other linked to friction.

  This publication poses a certain number of problems, the main ones of which are the following: - the installation of the sensors at the end of the guide tube, making it difficult to assemble the clutch release bearing on the guide tube, as well as the stroke limitation of the clutch stopper and diaphragm, - the installation of the box, with the guide tube and the sensors, on the coupling face of the engine, with the clutch mounted on the flywheel, o - the containment of the sensors and their connections to the computer, and

  - the increase in axial bulk of the box.

  The present, aims to remedy these problems not resolved in the state of the art s bans this goal it proposes to separate the clutch from the flywheel, and to install on the flywheel, between itself and the clutch and not in friction, a shock absorber with great flexibility and very long travel in order to measure the angular deformation of the shock absorber hub and

  deduct the torque at the input of the box.

  In addition, it plans to use the speed and / or ignition sensor of the existing engine to know the speed and the angular position of the flywheel. Wile plans, outside the housing, the installation of a second sensor, of the same type as the first, to know the

angular position of the clutch.

  In accordance with the invention, a target for the second

  o sensor is attached to the clutch.

  The target for the second sensor, in sheet metal, has only one

notch or recess for reading.

  In the absence of torque transmission, the top dead center notch giving the top of the angular position of the flywheel, and the single target notch attached to the clutch giving the top of the angular position of the clutch is diametrically opposed. The absence of torque at the input of the box results in a time lag of the tops coming from the two sensors, and the top pilot is preferably the one given

  by the reading sensor on the steering wheel.

  According to another characteristic of the invention, the passage of a positive torque from the engine to the box increases the time shift between the respective tops of the two sensors, while the passage of a negative torque from the engine to the box decreases the offset in time between the respective tops of the two sensors with respect to the offset observed without passage of torque. The invention also provides means of calculation integrated into the computer of the engine or of the automated gearbox, of translation of the time difference, as a function of the deformation of the shock absorber, therefore of the torque, and of the engine speed, as information. torque usable by the box control unit

of speeds.

  Other characteristics and advantages of the invention

  will appear from the reading of the detailed description which follows for

  the understanding of which we will refer to Figures 1, 2 and

o 3 annexes.

  On volt in figure ['assembly of the clutch device 10. The flywheel 100 is rigidly fixed and in a known manner on vi lebrequ in (not shown) by the screws 101 and comprises a launching ring 102 and a track

s regime capture 103.

  The filtering device 200 is fixed to the steering wheel by means of screws 201. It includes a filtering part properly mentioned and a damping part. The filtering part is made up of a watertight toroid-shaped compartment o comprising a first fasque 210 whose circular central opening is provided with a seal 211. Two zones 210a are provided with less deep wind and serve as support and reaction point of the curved springs 230. A second flange 220 completes the toric compartment. Its central circular opening is also provided with a seal 221. In a manner analogous to the flange 210, the flange 220 also has two zones 220a arranged d 180 fulfilling the same function as IQ zone 210a. Zones 210a and 220a are placed opposite. The two circular seals 211 and 221 tighten a circular and planar part 250a of the hub 250, so as to constitute a sealed compartment which can advantageously

  contain a lubricant such as grease.

  s The hub 250 has two external pastes 250b which enter the compartment formed by the two flanges 210 and 220. When the system is at rest, the pastes 250b face the zones 210a and 220a. When the system is under torque, the curved springs 230 are energized between the zones 210a and 220a of the plates 210 and 220 on the one hand and the pastes 250b of the hub 250 on the other hand. This arrangement, with two curved springs 230, makes it possible to reach a relative angle of rotation of the hub 250 relative to the very high plates 210 and 230 (of the order of 90), great flexibility and therefore great performance. in filtering the vibrations of

to rs ion.

  The central part of the hub has grooves 250c driving the clutch shaft 260. in the intermediate radial wind zone made openings 250d, the number o equal to that of the fixing screws 101 of the flywheel 100. These wind openings intended for allow passage of the tool for tightening the screws 101. A certain number of these openings 250d have a non-regular contour comprising a projection 205e. These protuberances are designed to receive the drive steps 271a of one of the elements of the device.

depreciation 270.

  The damping device 270 has the role of calming the oscillations of the filtering system, by being the seat of - 6 dry friction and energy loss. It is made up of a washer in ^ to 271 with in its inner part of the pastes 271a the number equal to that of the projections 250th of the hub. The washer 271 is rotated by the hub, and follows its movements. This washer 271 is sandwiched between two friction elements 272 and 273. The first friction element is in contact with one face of the flywheel and has recesses 272a cooperating with an equal number of pastes 273a of the friction element 273 o ensuring their connection in rotation. The steps 273a penetrate inside the housing 104 provided in the steering wheel. The friction elements are therefore connected in rotation to the flywheel, while the sheet washer 271 is connected to the hub 250. The damping device is kept under pressure by the elastic washer 274, an adjusting element of the system, compressed by the

  hood 275 fixed to the steering wheel by screws or rivet 276.

  The clutch shaft 260 is guided by a bearing 280, itself supported by the plate 290 for closing the clutch compartment. This closure plate is fixed and centered in the clutch housing 300. The seal of the compartment is ensured in the outer part, relative to the clutch housing, by the O-ring 291, and, relative to the shaft. clutch, by the lip seal 292. Finally on the shaft

  the clutch cone 401 of the clutch 400 is fixed.

  2s The clutch 400 consists of the inlet ring 401, the lower ring 402, the intermediate ring 403 and finally the upper ring 404. It is therefore a triple clutch ne, because there are 3 conical friction faces. The cone 401 - 7 has peripherals 401a cooperating with the recesses 403a in equal number of the intermediate ring 403. Similarly, the lower ring 402 has 402a pastes cooperating with the recesses 404a in equal number

s of the upper corner 404.

  The upper ring transmits the entire torque to the hub 500 carried by the primary shaft 510 of the gearbox. For this purpose, the hub has recesses 500a which cooperate with the teeth 404b of the central opening of the upper ring 404. The teeth of the teeth 404b can be parallel to each other and to the axis of rotation of the ring or slightly tilted to neutralize the effect of friction on contact with the hub and increase the efficiency of the system. The hub is linked in rotation to the primary shaft by the splines and

  s is held axially by the stop ring 501.

  In the rest state, the clutch is normally closed, kept in pressure by the cup 502 on which the spring 503 acts. When the clutch is opened, the upper cone 404 is moved away from the intermediate ring 403 by a zo elastic separation system, mounted on the hub, composed of an elastic washer 504, two flat washers 505 and a stop ring 506. When the clutch is closed, the progressive increase in load is ensured by another elastic device composed of an elastic washer 507, a cup 508 and a

s flat washer 509.

  The release maneuver consists in releasing the rings from the pressure exerted by the spring 503. The cup 502 is moved away from the ring 404 by the action of a fork (not L: -8 shown) controlled by the device. appropriate actuation. The actual measuring device comprises tracking means 700, 710 arranged on either side of the vibration damper 200. It consists of a first sensor 700 carried by the clutch housing 300 and placed opposite of the track 103 cut in the flywheel 100, and of a second sensor 701 also carried by the clutch housing 300 and placed opposite the sheet track 711 carried by the inlet cone

  401 of the clutch 400 and comprising a single recess 711 a.

  In the figure, the wind sensors positioned opposite to

  facilitate the description, when in reality their orientation

angular may be different.

  s The determination of the input torque of the gearbox is based on a measurement of the time difference between two tops given by these two sensors reading the two separate tracks. For the sensor 700, the top considered is that of the top dead center given by the particular notch size in the steering wheel, and for the sensor 710

  where only one top is given per revolution by the single recess 711a.

  Preferably, an angular offset of 180 is chosen between the two tops in the absence of torque (state of rest), in order to obtain maximum precision of the measurement. When an engine torque is transmitted from the steering wheel to the clutch, that is to say in: pulling situation, the springs of the shock absorber are compressed, and this results in an angular delay of the clutch compared to its angular orientation resting. For a given speed, the passage of an engine torque from the steering wheel to the clutch (pulling situation), therefore results in an increase in offset between the

so two tops.

  Conversely, during the transmission of a negative torque from the engine and the flywheel to the clutch (c <retro situation >>) the shock absorber springs are compressed in the other see, which results in a angular advance of the clutch with respect to its angular orientation at rest. For a given speed, the passage of a negative torque from the steering wheel to the clutch, therefore reduces the offset of the two tops

in time.

  In accordance with the invention, the means of cal cu associated with the coupling device proposes wind capable of translating these time differences (which depend on the one hand on the speed of rotation and on the other hand on the compression of the springs and done of the couple) in torque information transmitted, and to provide this

  information to the gearbox computer.

Claims (8)

  1. Coupling device (10) between a heat engine and a gearbox with change of ratios under torque characterized in that it comprises a flywheel (100) rigidly connected to the crankshaft on which is fixed a torsional vibration damper a large clearance (200), a clutch shaft (260) driven by the vibration damper and supported by a closure plate (290) of the clutch compartment, means suitable for transmitting the torque (400) between the 'clutch shaft (260) and the input shaft (510) of the gearbox, and locating means (700, 710? of the relative angular position of the coupling means (400) and the flywheel (100) making it possible to deduce, by knowing the torsional stiffness of the vibration damper, the torque applied to the input shaft of the gearbox.   2. Coupling device according to claim 1, characterized in that the tracking means (700, 710) are arranged on the side and   on the other side of the vibration damper (200).   3. Coupling device according to claim 1 or 2, characterized in that the locating means comprise a first engine ignition sensor (700) giving the engine speed information and a reference reference- switch to neutral position high at   passage of the target (103) of the flywheel (100).   - 11 4. coupling device according to claim 1, 2 or 3, characterized in that the tracking means comprise a second sensor (710) associated with a target   (711) linked to the inlet cone (401) of the clutch (400).   5. Coupling device according to claim 4 characterized in that the target (711) has only one notch (711a) giving only one top per round.   6. Coupling device according to one of claims   previous characterized in that the top dead center notch of the target (103) and the notch (711a) of the target (711) are diametrically opposed when the damper is not constrained. 7. coupling device according to claim 5 or 6 characterized in that the passage of a positive torque from the motor to the box increases the time offset between the respective tops of the two sensors (700, 710) by   relative to the offset observed without passage of torque.   8. Coupling device according to claim 5 or 6 characterized in that the passage of a negative torque from the motor to the gearbox reduces the offset in time between the respective tops of the two sensors (700, 710), by   relative to the offset observed without passage of torque. - 12   9. Scion coupling device one of the claims   previous characterized in that a calculator associates deduces the level of torque in input of ends of the angular deformation of the shock absorber, in function of so   stiffness and engine rotation speed.   10. coupling device according to claim 9, characterized in that the torque level information at the end of the ends