GB2406150A - A method of operating a synchromesh gearbox - Google Patents

Abstract

A synchromesh gearbox comprises transmission stages having fixed gear wheels intermeshing with free gear wheels which can be connected to a shaft via clutch sleeves 304a and synchronisation devices. The clutch sleeves 304a are engaged/disengaged by drive means, eg an electric motor 301a, connected to the clutch sleeves by spring and damper mechanisms 302a, 303a. Electric motor 301a is controlled by a control device which engages the clutch sleeves 304a in a speed controlled way up to a synchronisation threshold which is recognized by a counter force effected through locking at the synchronisation threshold and subsequently transition to force control.

Description

2406 1 50 - 1 - Method for operating a motor vehicle The invention relates

to a motor vehicle with a propulsion engine, a torque transfer device with a first activating device, a gearbox with an input shaft and an output shaft and a second activating device wherein the gearbox has a plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a shaft and a freewheel which can be connected to a shaft and a control device wherein the first and the second activating devices can be automatically controlled with initiation through the control device and a method for operating a motor vehicle.

With such motor vehicle transmission stages are engaged in that the freewheel is connected by means of a clutch to the shaft supporting it. The difference in revolutions of the components to be connected to each other should thereby be at least approximately zero. The production of at least approximate equality in the number of revolutions is known as the synchronization process.

With one type of gearbox for example synchronization devices connected to the respective freewheel are used which during a switching process produce at least approximate equality in the number of revolutions between the components to be connected to each other and do not facilitate full engagement of the clutch until the equality in revolutions is produced at least approximately. At the beginning of a switching process the two components to be connected to each other firstly come into contact by means of a friction surface. Assumption then takes place which is dependent upon the engagement force and the friction value. Furthermore the synchronization device can have a locking device so that depending upon this assumption force a further engagement is prevented. If the equality in revolutions is produced to be at least approximate and therefore the assumption force has fallen to at least approximately to zero the locking device opens and the switching process can be ended in that a shape-locking connection is produced between the components to be connected to each other. The engagement position wherein the further engagement is inhibited in the event of insufficient synchronization of revolutions is known as the synchronous position. With another type of gearbox no synchronization device is used.

In this case it is ensured in another way that the shape- locking connection is not produced until there is at least approximate equality in revolutions, for example by means of a corresponding control of the propulsion engine or shaft brakes. Appropriate sensors are used for the purpose of determining the difference in revolutions.

In particular with automated gearboxes wherein a change in transmission stage can take place in an automated way with initiation through the control device wherein activation of the control device can be initiated independently on the basis of a plurality of input values, the control of the synchronous process constitutes a very complex requirement. For example during a sruchronised engagement process at a determined point, the synchronous threshold, at which the clutch sleeve of the clutch comes to a standstill due to the effect of the locking device, a pre- determined force, the synchronous force, should be set at -3 - the moment at which the standstill is reached. This brings with it the fact that the position of the synchronous threshold must be sufficiently accurately known to the control device and / or that a type of synchronous force setting independent which is independent of the exact position of the synchronous threshold must be made available. In order to reach short switching times for an optimum switching it is furthermore decisive how the synchronous force is built up or set in such a way that the influencing parameters are taken into consideration in a sufficiently accurate way.

Switching elasticity in itself has become known through the European patent document EP 579 532 B1. A mechanical auxiliary device is disclosed for engaging the gears of a gearbox which can be switched by means of cables or linkage wherein the switching sequence is transmitted through a switching control shaft which is set into rotation by the cable or the linkage wherein the mechanical connection between the cable or linkage for the purpose of controlling the switching process and the shaft consists of two linked components whose relative displacement is controlled elastically by a spring which thereby takes up energy, that it is compressed during the synchronization phase and which releases the absorbed energy once more after the end of the absorption. The auxiliary device described should overcome certain disadvantages of the conventional gear change switching devices - the synchronization time which is found to be too long or the free path, the considerable transmission force which occurs in the form of synchronization which is too slow and the sensing of switching noise during teeth engagement which is found to be disadvantageous. The mechanical auxiliary device described relates to manual hand switching gearboxes.

In a further patent document EP 695 892 B1 a gearbox switching system is described with at least one actuator means as well as clutch sleeves activated by this wherein the associated connecting mechanism has a spring. With the gear switching system disclosed an inadmissibly high current is prevented with the propulsion means formed as an electric motor if switching cannot be effected immediately. The gear switching system published relates to an automated gearbox.

The switching elasticity described in EP 579 532 B1 assumes the function of an energy collector in that it is compressed at times and then extended again. In this way the clutch sleeve receives an impulse from the spring which is larger than that which could be transferred to it through a fast activation of the gear leaver by the driver. The resulting impulse is thus still dependent upon the activation speed / activation force of the gear lever by the driver wherein precise setting of the required reference force on the clutch sleeve is left to chance.

Also the switching elasticity disclosed in EP 695 892 B1 is compressed during a switching process and then releases the energy stored in it once again. The present switching elasticity facilitates movement of the clutch sleeve corresponding to the synchronization process which is delayed in time in relation to the actuation movement. The switching elasticity protects the electric propulsion engine from overloading but there is no assumption of influence by means of the engagement speed, taking into - 5 - consideration the switching elasticity with regard to the desired reference force.

The system between the clutch sleeve and propulsion means, comprising the connecting mechanism with its kinematic and elastic properties, is very complex particularly with automated gearboxes. With regard to the implementation of synchronized engagement of a transmission stage no sufficiently satisfactory solution has been found up to now which suits the plurality of requirements, particularly in relation to the engagement speed, taking into consideration the characteristics of the elasticity of the mechanism between the propulsion and the clutch sleeve.

It is the object of the present invention to essentially improve the sequence of the synchronous process with a motor vehicle mentioned at the outset in such a way that amongst other things the switching process can be carried out more comfortably, more quickly and causing less wear and tear.

Furthermore there is the object of creating a gearbox as well as a method for operating a gearbox wherein the synchronized change in transmission stage is considerably improved particularly with regard to the build-up of force at the synchronous threshold taking into account the kinematic and elastic properties of the mechanism.

This object is solved according to the invention through a motor vehicle which is mentioned at the outset with a gearbox which has a plurality of characteristics and / or process stages according to the following description with - 6 - figures as well as the claims which particularly in the present combination, but also each respectively in themselves, achieve the desired success.

Thus in order to solve one aspect of the invention with a motor vehicle with a propulsion engine, a torque transmission device with a first activating device, a gearbox with an input shaft and an output shaft and a second activating device wherein the gearbox has sets of wheels forming a plurality of sets of wheels forming transmission stages, each of which is formed by a gearwheel securely connected to a shaft and a freewheel which can be connected to a shaft and a control device wherein the first and the second activating device can be activated in an automated way with initiation through the control device in that in a first operating mode activation is initiated independently by the control device on the basis of a plurality of input values or in a second operating mode activation is initiated through an input of the driver and wherein a connection of a freewheel of at least one transmission stage with the shaft supporting it takes place with a synchronization device by means of an end output element, such as a clutch sleeve, which with the application of a synchronous force during the engagement produces at least approximate equality in revolutions between the elements to be connected and only facilitates full engagement when the synchronization process is completed with at least approximate equality in revolutions. The position of the synchronous threshold of at least one transmission stage is laid down in a storage device assigned to the control device. - 7

In the present case the last element which is moved in order Lo fix a Transmission ratio, i.e. which produces the connection between two force transferring means, e.g. reverse idler gear, pinion block, clutch sleeve, working piston or hydraulic coupling, is described as the end output element.

According to a very advantageous embodiment of the invention the position of the synchronous threshold of at least one transmission stage can be adapted in order to ensure - in spite of the synchronous position varying during operation - sufficiently accurate agreement between actual synchronous position and the synchronous position laid down in the storage device. In a preferred embodiment an adaptation of the synchronous thresholds is carried out if the motor vehicle is at a standstill, the propulsion engine is in operation, a motor vehicle brake is activated and there is a requirement for adaptation of the synchronous threshold position. It is useful if the motor vehicle for the purpose of implementation of the adaptation has been at a standstill since a predetermined time t and the propulsion engine is rotating at least approximately at idling speed. In this way a synchronous threshold adaptation takes place with a low speed difference between the components to be connected through the clutch, the vehicle is secured against movement due to I be moment transferred to the wheels during the adaptation process and the speed of possibly still quickly rotating shafts has been reduced.

In a motor vehicle in whose gearbox transmission stages are engaged through the second activating device which contains the means for selecting and activating the end - 8 - activating elements it is useful for an adaptation of the synchronous threshold position to incorporate the stages: closure of the torque transfer device by means of the first activating device, approaching of a position by means of the second activating device in the direct vicinity of the transmission stage whose synchronous threshold position is to be adapted, starting from a position from which the synchronous threshold will be travelled through with certainty, activation of the end output mechanism so that the end output element is moved in the direction of its end position and determination of a synchronous threshold position on the basis of the checking of the engagement movement of the end output element due to insufficient synchronization. The second activating device has two propulsions wherein one propulsion is for example moved as a selection drive for selecting a clutch sleeve in that a gearbox selector finger is moved in such a way that it can be brought into connection with a gearbox selector fork in order to activate the clutch sleeve which activates the desired transmission stage whose synchronous threshold is to be adapted. For the purpose of carrying out an adaptation process it is useful for the gearbox selector finger to firstly be brought into a position in the direct vicinity of the transmission stage whose synchronous threshold position is to be adapted. Preferably the gearbox selector I finger is brought into connection with the desired gearbox selector fork. A second propulsion of the second activating device serves as a gear change drive for the purpose of moving the gearbox selector finger in such a way that a clutch sleeve with which it is connected by means of a gearbox selector fork is moved so that an engagement or disengagement movement takes place. For the - 9 purpose of adapting the synchronous threshold an engagement movement is carried out starting from a position from which the synchronous threshold is travelled through with certainty, like for example from neutral position to a position which facilitates an adaptation of the synchronous threshold.

In the present case an end output mechanism is understood to be a mechanism which incorporates the end output element wherein a mechanism is used to describe a kinematic chain which consists either of a single element or alternatively of a series of elements wherein the position of each point can be deduced from the position of any other point of the chain. Furthermore within the scope of the present application an end activating element is understood to be an element which is located before the end output element in the kinematic chain, like for example a gearbox selector fork. The end output mechanism typically comprises the clutch sleeve, a clutch, a gearbox selector fork, a gearbox selector finger, kinematics for the movement / force transferring connection of the gearbox selector finger with the selection and switching drive wherein through kinematics a certain transmission is fixed for example through the lever and / or transmission stage formed by a worm with worm gear.

According to a further formation of this preferred embodiment it is useful if an adaptation of the synchronous threshold position furthermore incorporates the stages arithmetic manipulation of the determined synchronous threshold position determined through a calculating device assigned to the control device for the direct use or for the determination of a new synchronous threshold position on the basis of this as well as the old synchronous threshold position.

According to a further particularly preferable formation; of the invention in a motor vehicle wherein the positions of the gear end positions are laid down in a storage device assigned to the control device and these positions are adapted during operation, determination of the synchronous threshold position takes place at least at times on the basis of the adapted end gear positions.

It is useful if after each expiry of a pre-determined time or after a predetermined number of independent adaptation processes the determination of the synchronous threshold position takes place at least once on the basis of the adapted end gear positions. In a preferred embodiment the pre-determined time lies in the region of 40 to 200 hours, in particular in the region 80 to 12 hours or the pre determined number of independent adaptation processes lies t between 15 and 80, in particular between 40 and 60.

In order to solve a further aspect of the object according to a preferred embodiment in a motor vehicle with a i propulsion engine, a torque transfer device with a first activating device, a gearbox with an input shaft and an output shaft and a second activating device wherein the gear box has a plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a shaft and a freewheel which can be connected to a shaft and a control device wherein the first and the second activating device can be activated in an automated way with initiation through the control device in that in a first operating mode an activation of the control device is initiated independently on the basis of a plurality of input values or in a second operating mode activation is initiated through the input of the driver and wherein a connection; of a freewheel of at least one transmission stage with the shaft supporting it takes place by means of an end output element like a clutch sleeve with the synchronization device which with application of a synchronous force during the engagement of produces an at least approximate i equality in revolutions between the elements to be connected, the synchronous force can be modulated: depending upon the driver sportiness, the motor vehicle load, the gearbox oil temperature, the lifting lever position, the propulsion engine moment requirement, the target speed, the differential speed, the gearbox towing moments and / or the status of the synchronization device.

The synchronous force can thus be adapted to a plurality of varying parameters in such a way that also depending: upon these parameters which can change over the duration t of operation and / or can change from switching process to switching process a corresponding adaptation is undertaken so that an optimised course of the synchronization process can take place. i In a motor vehicle with a propulsion engine, a torque transmission device with a first activating device, a gearbox with an input shaft and an output shaft and a second activating device wherein the gearbox has a plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a shaft and a freewheel which can be connected to a shaft and a control device wherein the first and the second activating device can be activated automatically with initiation through the control device in that in a first operating mode an activation of the control device is initiated independently on the basis of a plurality of input values or in a second operating mode activation is initiated through an input of the driver and wherein a connection of a freewheel of at least one transmission stage with the shaft supporting it takes place by means of an end output element, such as clutch sleeve or sliding sleeve, with synchronization device, which upon application of a synchronous force during the engagement produces an at least approximate equality in revolutions between the elements to be connected and only facilitates a complete engagement once the synchronisarion process is complete with at least approximate equality in revolutions, in order to solve a further aspect in a particularly preferable embodiment both the approaching of the synchronous threshold and the synchronization process itself are carried out in a force controlled way. This brings advantages in particular as a pre-determined force is to be set at the synchronous threshold which takes place advantageously by means of force control and thus a transfer between various types of control like for example speed and force control with the disadvantages associated therewith is avoided.

For the purpose of force control of the end output element the counter force opposing it is hereby estimated wherein it is useful if the estimation of the counter force takes place on the basis of the speed of the end activating mechanism taking into consideration the kinetic energy of the end activating mechanism as well as if appropriate its spring rigidity. On the one hand this is the kinetic energy of the clutch sleeve, on the other hand that of the moved components of kinematics and the propulsion.

In taking into consideration the spring rigidity of the end activating mechanism in particular with counter forces above the target threshold of this spring rigidity it is very advantageous to uses its characteristic line directly or indirectly for the purpose of estimation. The end activating mechanism frequently has a spring / damping element for the target setting of the spring rigidity. Its characteristic line is used advantageously if appropriate in complementing the rigidity dependent in itself upon the mechanism.

According to a particularly preferable further formation of this embodiment the estimation of the counter force takes place on the basis of the energy receiving rate by reference to the work carried out by the drive of the end activating mechanism.

For the purpose of solving a further aspect of the object a method is used for approaching the synchronous position of an end output element of a gearbox end activating mechanism for a motor vehicle with a locking synchronized gearbox wherein a synchronous position must be approached as quickly as possible without overshooting. In this connection it is particularly preferable if force control takes place on the basis of the vibration equation using a damping constant which facilitates approaching independently of the precise starting speed of the end output element of the gearbox end activating mechanism and the exact position of the synchronous position and upon which the synchronous force is dependent.

A further aspect for solving the obect takes place by means of control in such a way that the production of a reference engagement force on the clutch sleeve takes place on the basis of the engagement speed and the elasticity in the region of the mechanism. The elasticity is thereby used in a targeted way in order to convert the kinetic energy of the actuator into potential energy during the run-up to the synchronous threshold.

According to a particularly preferred embodiment of a gearbox which between the clutch sleeve and freewheel has - synchronous devices which are suitable during an engagement process for locking a full engagement with the formation of a shape-locking connection at the synchronous threshold for so long until at least approximate equality of revolutions is reached wherein through the engagement movement locking at the synchronous threshold kinetic energy is stored in the form of potential energy in the elasticity, at the time of the checking of the engagement movement the energy stored in the elasticity is at least approximate to the reference force.

Within the scope of the present invention terms such as reference engagement force or synchronous force - respectively describe the force on an activating device such as gearbox selector finger for the activation of the -cl-utch-sl-eeve In a preferred embodiment of the invention the approaching speed of the synchronous threshold is selected dependent upon the characteristics of the elasticity in such a way that at the time of checking having been carried out of - the engagement movement the energy stored in the elasticity corresponds at least approximately to the reference force. At this time approximately the entire kinetic energy is stored as location energy in the elasticity so that according to the speed minimum there is an energy maximum in the elasticity. In this embodiment a precise setting of the reference / synchronous force advantageously takes place at the synchronous threshold through a corresponding modulation of the approaching speed to the synchronous threshold.

In another useful embodiment depending upon the approach speed to the synchronous threshold an elasticity is selected with characteristics so that at the time of checking of the engagement movement having been completed the energy stored in the elasticity corresponds at least approximately to the reference force. In this embodiment with a predetermined approach speed to the synchronous threshold through the selection of a corresponding elasticity the desired reference force at the synchronous threshold is reached.

In the preferred embodiment the target threshold of the elasticity lies clearly below the forces arising during the synchronization process. In this way during each synchronized switching process the force build-up takes place at the synchronous threshold including elasticity and its characteristic line.

Depending upon the reference force at the synchronous threshold it is preferable if the elasticity reacts in the case of a synchronous force in the region of 50 - 450 N. in the region of 200 - 600 N or in the region of 400 1000 N. In a particularly preferable embodiment the target threshold lies in the region of 150 - 350 N. Furthermore for the purpose of solving the object a method is proposed for operating a gearbox for a motor vehicle which has a plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a shaft and a freewheel intermeshing with the gearwheel which can be connected to the other shaft. The gearbox has clutch sleeves which are suitable for producing a connection between the freewheel of a transmission stage and the shaft supporting it, propulsion means which are suitable for effecting an engagement or disengagement movement of the clutch sleeve, a mechanism for connecting the propulsion means to the clutch sleeves, synchronous devices working between the clutch sleeve and the freewheel which are suitable for producing during an engagement process a synchronous moment on the basis of an engagement force and locking a further engagement beyond this synchronous threshold for so long until at least approximate equality of revolutions is reached, an elasticity in the region of the mechanism which is suitable for storing kinetic energy in the form of potential energy and vice versa emitting potential energy in the form of kinetic energy once more as well as a control device for controlling the propulsion means wherein the fixing of a transmission ratio comprises the stages: engagement of the clutch sleeve in a speed controlled way as far as the synchronous threshold, recognition of a counter force effected by the locking at the synchronous threshold, then transition to the force control wherein through the locking of the engagement movement at the synchronous threshold energy is stored in the elasticity which is then used decisively for the purpose of producing the reference force at the synchronous threshold.

The application of this method is preferable in a gearbox which is characterized by the features of at least one of the claims of the claims 1 - 7.

The embodiments of the invention are explained in greater detail below by reference to figures. The drawings show: Figure 1 schematically and by way of example a motor vehicle with a torque transfer device which can be activated in an automated way and a gearbox which can be activated in an automated way, - Figures 2, 2a schematically and by way of example a clutch, Figure 3 schematically and by way of example a diagram relating to the initialization pre-conditions for a synchronous threshold adaptation, Figure 3a schematically and by way of example a propulsion and clutch sleeve with a connecting mechanism, Figure 4a a diagram for the dependence of the synchronous force for example upon the load lever position, Figure 4b a diagram relating to an example offset of the synchronous force depending upon the gearbox temperature, Figure 4c by way of example the formation of a synchronization reference force from synchronous force according to characterization field and a force offset, Figure 4d by way of example a characteristic line of switching elasticity incorporated by the mechanism and the course of the force / path during a switching process, Figure 5a a flowchart for controlling the propulsion for the activation of the clutch sleeve, Figure 5b different paths for reaching the reference position of the clutch sleeve during reference work of the propulsion in the speed / work diagram, Figure 5c a favourable path in the speed / work diagram, Figure 6 a flowchart for controlling the propulsion for the activation of the clutch sleeve. Figure 1 shows schematically and by way of example a motor vehicle 1 with

a torque transfer device 4 and a gearbox 6.

In the present case the torque transfer device 4 is in arranged in the flux between the propulsion engine 2 and the gearbox 6. Between the propulsion engine 2 and the torque transfer device 4 it is useful for a divided gyrating mass to be arranged whose partial masses can be rotated against each other with the intermediate connection of a spring / damper device wherein in particular the vibration properties in technical terms of the drive train are considerably improved. The invention is preferably combined with a damping device for taking up or compensating for rotation impacts or a device for compensating for damping vibrations, as is described in particular in the publications DE OS 34 18 671, DE OS 34 11 092, DE OS 34 11 239, DE OS 36 30 398, DE OS 36 28 774 and DE OS 37 21 712 of the applicant. The motor vehicle 1 is driven by a propulsion engine 2 which in the present case is represented as an internal combustion engine such as a petrol engine or diesel engine. In another embodiment the propulsion can also take place by means of hybrid propulsion, an electric motor or a hydraulic motor. In the embodiment shown the torque transfer device 4 is a friction clutch by means of which the propulsion engine 2 can be separated from the gearbox 6 particularly for the starting or implementation of switching processes. Through an increasing engagement / disengagement of the clutch more or less moment is transferred. In this connection a contact plate and a pressure plate are displaced axially relatively against each other and take an intermediately arranged friction disc with them to a greater or lesser extent. The torque transfer device 4 formed as a clutch is advantageously self-adjusting, i.e. the wear and tear of the friction linings is compensated for in such a way that a constant low disengagement force is guaranteed. The invention is preferably combined with a friction clutch as is described in particular in the applications DE OS 42 39 291, DE OS 42 39 289 and DE OS 43 06 505 of the applicant.

By means of a shaft 8 the wheels 12 of the motor vehicle 1 are driven by means of a differential 10. Speed sensors 60, 61 are assigned to the driven wheels 12 wherein if appropriate even only one speed sensor 60 or 61 is provided with each speed sensor 60, 61 producing a signal corresponding to the speed of the wheels 12. Additionally or alternatively a sensor 52 is provided at another position In the drive train, for example on the shaft 8, for the purpose of determining the gearbox output speed.

The gearbox input speed can be determined by means of a further sensor or also, as in the present embodiment, be determined from the propulsion engine speed. For example the transmission ratio set in the gearbox can thus be ascertained. Activation of the friction clutch 4 which can advantageously be carried out in a pressed, in another embodiment also pulled, manner takes place in the present case by means of an activating device 46 such as the clutch actuator. For the purpose of activating the gearbox 6 an activating device with two actuators 48 and 50 is provided wherein one of the actuators carries out a selection activation and the other a switching activation.

The clutch actuator 46 and / or the gearbox actuators 48, are designed as electric direct current motors wherein it can also be very useful in another embodiment, especially if large activating forces are required, to provide a hydraulic system for activation. The control of the clutch 4 and the gearbox 6 takes place through a control device 44 which usefully forms a construction unit with the clutch actuator 46 wherein it can also be advantageous in another embodiment to arrange this in another position in the motor vehicle. The activation of the clutch 4 and the gearbox 6 can take place in an automated way through the control device 44 in an automated mode of operation or in a manual mode of operation through driver input by means of a transmission selector device 60 such as a gear lever wherein the input is recorded by means of a sensor 61. In the automated mode of operation transmission changes are carried out by corresponding control of the actuators 46, 48 and 50 according to characteristic lines which are laid down in a storage device assigned to the control device 44. A plurality of driving programs fixed by at least one characteristic line also exist, between which the driver can choose, such as a sporty driving program, in which the propulsion engine 2 is operated in a performance optimised way, an economy program, in which the propulsion engine 2 is driven in a consumption optimised way, or a winter program, in which the motor vehicle 1 is operated in a driving safety optimised way. Furthermore in the embodiment described characteristic lines can be adjusted in an adaptive way for example to the driver behaviour and / or to other secondary conditions such as carriageway friction, outside temperature, etc. A control device 18 controls the propulsion engine 2 by influencing the supply of mixture or composition wherein as a substitute a throttle valve 22 is shown in the figure, whose opening angle is recorded by means of an angle indicator 20 and whose signal is available to the control device 18. With other embodiments of the propulsion engine regulation, in the case of an internal combustion engine, a corresponding signal is made available to the control device 18, by reference to which the mixture composition and / or the volume supplied can be determined. It is useful if the signal of an existing lambda probe is also used.

Furthermore in the present embodiment a signal of a load lever 14, whose position is recorded by means of a sensor 16, activated by the driver, a signal relating to the engine speed, produced by a speed sensor 28 which is assigned to the engine output shaft, a signal of a suction pipe pressure sensor 26 and a signal of a cooling water temperature sensor 24 are available to the control device 18. The control devices 18 and 44 can be formed in constructively and / or functionally separated sub regions. It is then useful for them to be connected to each other for example by means of a CAN bus 54 or another electrical connection for the purpose of data exchange.

However it can also be advantageous to bring the regions of the control devices together, particularly since an assignment of the functions is not always clearly possible and co-operation is necessary. In particular during certain phases of the transmission change the control device 44 can control the propulsion engine 2 with regard to the speed and / or the moment. Both the clutch actuator 46 and the gearbox actuators 48 and 50 produce signals, from which the actuator position can at least be deduced, which are available to the control device 44.. The determination of position takes place in the present case within the actuator wherein an incremental indicator is used which determines the actuator position in relation to a reference point. In another embodiment, however, it can also be useful for the indicator to be arranged outside of the actuator and / or to provide an absolute position determination by means of a potentiometer. A determination of the actuator position is of great significance with regard to the clutch actuator particularly since the gripping point of the clutch 4 can be assigned to a determined engagement path and therefore to an actuator position. The gripping point of the clutch 4 when starting up and during operation is advantageously re determined repeatedly, particularly depending upon parameters such as clutch wear and tear, clutch temperature, etc. Determination of the gearbox actuator position is important within regard to the determination of the transmission ratio which has been set. Furthermore signals of speed sensors 62 and 63 of the wheels 65 and 66 which are not driven are available to the control device 44. In order to determine a vehicle speed it can be a good idea to use the average value of the speed sensors 62 and 63 / 60 and 61 in order to compensate for speed differences for example during travelling around bends. By means of the speed signals the vehicle speed can be ascertained and over and above that slippage recognition can also be carried out. In the figure output connections of the control devices are shown as lines drawn through.

Input connections are shown as broken lines. The connection of the sensors 61, 62 and 63 to the control device is only indicated.

Figure 2 shows schematically and by way of example a synchronized clutch of a gearbox for connecting a freewheel 201 to the synchronous bodies 203 connected in a rotationally secure way to the shaft. The representation A thereby shows the clutch sleeve 202 in neutral position wherein in representation B the pre-synchronisation and in representation C the main synchronization are shown. The clutch sleeve 202 is activated by means of a gearbox selector fork 211 and is connected to the synchronous body 203 in a rotationally secure, but axially displaceable, way together with the synchronous ring 204 which with pressure members 206 and compression springs 205 corresponding to these forms the synchronization device.

During the pre-synchronisation phase B the clutch sleeve 202 it displaced with pre-synchronisation force FAV in t.he direction of the freewheel 201. Dependent upon the friction on the tapered friction surface R between the synchronous ring 204 and the freewheel 201 a pre synchronisation moment TRV is built up wherein the i synchronous ring 204 rotates until impacting of the pressure members 206 against the side edge of the pressure member recesses 210 in locking output position. In the locking output position an orientation of the toothed inclined areas of the switching toothing of the clutch sleeve 209 and the switching toothing of the freewheel 208 axially in front of each other in region D takes place through the axial movement of the clutch sleeve 202. In the onward course the pre-synchronisation force FAV depending upon the ramp like arrangement in the region pressure member / coupling sleeve effects contrary to the spring force FD of the compression spring 205 tilting of the pressure members 206 wherein a further axial displacement of the clutch sleeve 202 becomes possible and the transition to the main synchronization phase C, in which the toothed inclined areas of the switching toothing 209 of the clutch sleeve and the switching toothing 208 of the freewheel come into contact with each other. In the present case this position is described as the synchronous position. Subsequently the axial synchronous force FA is applied by means of the toothed inclined areas and the friction moment OR is produced at the tapering friction surface between the synchronous ring 204 and the synchronous cone of the freewheel 201 wherein the speed synchronization between the freewheel 201 and coupling sleeve 202 is effected.

In another embodiment the synchronous device can also be connected to the loose wheel. Ever another arrangement of the synchronous device can be useful in another embodiment. If appropriate the position referred to in the present case as the synchronous position is then another one but in principle this does not change anything in the conversion of the inventive idea behind the present application.

Figure 2a shows schematically and by way of example a clutch of a gearbox for connecting a freewheel 205a to the shaft 201a supporting it. In this embodiment a coupling sleeve 203a is supported by a connecting element 202a connected in an axial and rotationally secure way to the shaft 201a, on which it is arranged in an axially displaceable but rotationally secure way. A synchronization device 204a is connected to the freewheel 205a.

In a starting position 200a the two components 202a and 205a of the clutch which are to be connected to each other are still separate. The clutch sleeve 203a is in a fully disengaged position A'. If the clutch sleeve 203 is displaced in the direction of the arrow a position 210a is reached, in which the synchronization device 204a with a conical friction surface comes into connection with a corresponding surface of the clutch sleeve 203a. Dependent upon the friction and the engagement force effective in the direction of the arrow the freewheel 205a is increasingly taken along wherein an assumption moment is produced which can trigger a locking device arranged for example on the clutch sleeve 203a which is not represented and this prevents a further engagement of the clutch sleeve 203a. This position is referred to as the synchronous position or synchronous threshold. If the freewheel 205a has reached at least approximately the speed of the clutch sleeve 203a and therefore the assumption moment has fallen at least approximately to zero, the locking device opens and the clutch sleeve 203a can go further from position B' into position C'. In the fully engaged position 220a a shape- locking connection is produced in the peripheral direction between the clutch sleeve 203a and the freewheel 205a in such a way that the freewheel 205a is connected to the shaft 201 by means of the clutch sleeve 203a and the element 202a.

Figure 3 shows schematically and by way of example a diagram relating to the initialization pre-conditions for a synchronous threshold adaptation. In this embodiment it is checked in step 301 whether the vehicle is at a standstill. It can usefully also be required that the vehicle has been at a standstill for a pre-determined time t in order to ensure that quickly rotating shafts have reduced their rotation speed. If this is not the case no synchronous threshold adaptation is carried out (see block 307); otherwise it is ascertained furthermore in step 302 whether a motor vehicle brake is activated in order to ensure that the vehicle is not set into motion due to the limited moment transferred to the wheels which is necessary for the adaptation. If the motor vehicle brake is not activated no synchronous threshold adaptation is carried out (see block 307); otherwise it is furthermore checked in step 303 whether the propulsion engine is idling wherein a speed difference on the synchronous device which is too high is avoided. Only if this is the case is there a transition to step 304; otherwise no synchronous threshold adaptation is carried out. In step 304 it is ascertained whether a transmission stage has been engaged. Only if this is the case is there continuation with the next step 305; otherwise there is a branching off to block 307. Only if an adaptation is necessary is it furthermore checked in step 306 whethe another higher prioritised adaptation is present which makes it necessary co go to step 307. If there is no higher prioritized adaptation the synchronous threshold adaptation is carried out in step 308. If another higher prioritised adaptation or other function is to be carried out which would collide with the implementation of the synchronous threshold adaptation, the synchronous threshold adaptation is put back for so long until this other adaptation or function has ended and is only then carried out.

The criteria described for initialising a synchronous threshold adaptation are by way of example. In other embodiments therefore the criteria can be checked in another sequence. In particular it can be a good idea to pose so the beginning the question of whether an adaptation is necessary or whether there is another higher prioritized adaptation or function. It can also be useful to bypass one or several criteria, i.e. in spite of the branching to step 307 provided according to the figure to continue the course in the direction of implementation of the adaptation in step 308. This is indicated in the figure through the connections shown in broken lines. In other embodiments it can furthermore be advantageous to make the initialization of the adaptation of the synchronous thresholds dependent upon other or further criteria.

For the purpose of implementing the adaptation of the synchronous threshold in a preferred embodiment the starting clutch 4 is closed wherein it is sufficient to close the clutch so far that at least a clutch moment is transferred which is large enough to allow the locking device connected to the clutch sleeve to become effective.

In a next step in the selection direction the gear is scarfed up whose synchronous threshold is to be adapted, for example the selector drive 48 is activated in such a way that a selector finger comes into connection with the selector fork belonging to the transmission stage in question or at least moves into the vicinity of the selector fork concerned. In this step the middle of the selector path is preferably started up as a starting position as all positions can then be easily reached. In modified embodiments, however, it can also be very advantageous to start in another position in the switching path in question, namely a position in the selector path directly in front of the switching path of the gear, whose synchronous threshold is to be adapted. Starting from this position preferably neutral position - from which the synchronous threshold can be travelled through with certainty the clutch sleeve is now moved in the direction of the end position of the transmission stage whose synchronous position is to be adapted wherein the travailing speed is very slow in comparison with a normal switching process. The travel in the direction of the end position usefully takes place in a speed regulated way with a defined speed, controlled by means of angle acceleration with a defined acceleration, moment controlled with a defined force, control by means of the angle position of the propulsion with a defined path either iteratively or with stochastic path provision, by means of voltage control of the propulsion or by means of power control of the propulsion. It can also be advantageous to use a combination of the said types of control.

With a running motor 2 - preferably at idling speed - and closed clutch a differential speed thus results between the gear input shaft and the gear output shaft. As shown and described with Figure 2 through the assumption moment on the synchronization device a checking of the engagement movement takes place. This position of the clutch sleeve can firstly be fixed as a synchronous position. The value of the clutch sleeve position ascertained can be used as a crude value or as a value manipulated with corrective values. The value to be used is advantageously calculated from this newly ascertained value and the old value.

A detection of the movement checking of the clutch sleeve 203 usefully takes place through observation of the clutch sleeve path, the clutch sleeve speed, the clutch sleeve acceleration wherein this information is advantageously measured off in the region of the end output mechanism or in the region of a mechanism which activates this. An indicator integrated into the propulsion, such as an incremental path indicator, is advantageously used.

According to a further embodiment the movement checking is carried out in the region close to the clutch sleeve - in particular in front oF a possibly existing switching elasticity - wherein distortion through elasticities and / or clearances is avoided. In another embodiment the detection of the movement checking of the clutch sleeve 203 takes place by means of force measurement in the region of the kinetic stretch between the clutch sleeve and the propulsion. In a furthe- advantageous embodiment the movement checking of the clutch sleeve 203 is ascertained by means of the power taken up by the propulsion.

The determination of the synchronous position takes place in the preferred embodiment by means of the angle position, the speed of the angle acceleration of the propulsion engine wherein it is useful if an incremental path indicator integrated into the drive is used. In another advantageous embodiment the position determination takes place by means of the propulsion engine voltage or the propulsion engine power. Determination by means of the angle speed and / or the transferred moment of one or several gearbox shafts is also used in a further advantageous embodiment. According to a further useful embodiment the checking of the clutch sleeve movement is ascertained by means of a combination of the steps just described.

For the arithmetic manipulation of the ascertained synchronous position through a calculating device an algorithm is used in the preferred embodiment which carries out a multiplicative and / or additive correction of the ascertained synchronous position. In another embodiment it is useful for a corrective algorithm to be used which is based upon another mathematical law such as power, logarithm, differential and / or integral wherein a combination with a type of correction of the algorithm can also be advantageous in the preferred embodiment. The development of the preferred correction algorithm takes place on the basis of experimental values, trials, calculations by means of modelling of the kinematic transmission stretch, simulations, measurements and / or analysis of the construction drawings.

If in the preferred embodiment the new synchronous threshold is formed by the newly ascertained synchronous threshold and the old one, an example calculation rule could look as follows: SyncThreshold. new = (x. SyncThreshold. old + Sync. Threshold. ascertained) /10 0, Wherein the factor x is preferably very large, e.g. between 80 and 100, and the factor y is preferably very small, e.g. between O and 20.

In the preferred embodiment an adaptation of the synchronous thresholds is carried out under the above- described conditions. However, if the driver accelerates, e.g. during the adaptation during a stop at traffic lights, the motor vehicle is to accelerate as soon as possible. In this case therefore the desired gear must be engaged immediately, as soon as the idling switch and / or the vehicle brake is no longer activated. Particularly preferable is an embodiment wherein the desired transmission stage in the case described is set within 600 ms, in particular within 300 to 400 ms.

The embodiments of the invention described can in particular also be used during sensing of the synchronous positions of the transmission stages with prototype or series motor vehicle within the scope of a routine of bringing the same into operation.

Depending upon the already described method of functioning of the synchronization device the synchronization moment is dependent upon the friction value of the synchronization device, the synchronous force Fsc according to the engagement force and the friction radius Rsc of a ringshaped synchronisation device, wherein the following can be assumed approximately for the synchronization moment Msc MSYI]C = if. FSYI]C Rfric The amount of the synchronization moment has direct influence upon the switching comfort as a high synchronization moment can cause interfering noises and vibrations in the drive train. There can be influence through the synchronous force Fsc.

According to the preferred embodiment of the invention a modulation of the synchronous force Fsc is provided in that as far as possible no noise or vibrations occur in the drive train and the switching process therefore takes place in a more comfortable way. The modulation of the synchronous force Fsc can take place depending upon one or several parameters, as described below, wherein for example in Figure 4a a dependence upon the load lever position and in Figure 4b the formation of an offset dependent upon the gearbox oil temperature are shown. In Figure 4c the formation of a synchronization reference force from synchronous force according to characterization

field and a force offset is represented.

In the case of dependence upon the load lever position, as shown in Figure 4a, the synchronous force FSC in the preferred embodiment is increased with increasing load lever position wherein the increase takes place for each transmission stage according to an individual characteristic line. The synchronous force Fsc is preferably increased starting from a certain value with load lever position zero corresponding to no accelerator activation to approximately double value with switching with full-open throttle. With switching under kickdown conditions the synchronous force Fs,,nC is increased still further. For a smaller vehicle with an engine in the region 1 to 1.8 l capacity for example a modulation of the synchronous force FS5,IIC from 120-310 Nm, in particular from 190-250 Nm, to 420-650 Nm, in particular to 490-560 Nm, is advantageous. With larger motor vehicles the synchronous force FSYI1C is modulated in an accordingly adapted way. In the embodiment shown no modulation of the synchronous force FSYI1C takes place for reverse gear. The exact course of the characteristic lines is oriented according to which synchronous force Franc is the most favourable for each transmission stage with a certain load lever position wherein this can for example be ascertained by arithmetic or through trials. In this way an optimum switching process with regard to the synchronous force Fs:,nC depending upon the load lever position for each transmission stage is possible. It is advantageous if the courses of the characteristic lines are essentially linear wherein it can also be useful in another embodiment if the characteristic lines of regions of the characteristic lines have a course which corresponds to or is similar to a non-linear function such as sinusoidal function, tangent function, e function, log function or parabolic function. In order to simplify the control it can also be advantageous in a further embodiment to use a single characteristic line for c'l transmission stages or to use at le: st one characteristic line repeatedly.

In Figure 4b the course of an offset dependent upon a parameter is shown in the example of the gearbox oil temperature. In the example a certain synchronous force offset is given for a gearbox oil temperature below 20 C which in the region -20 C to iO C is reduced in a linear way to zero in such a way that above a gearbox oil temperature of 10 C there is no longer any offset. The course of the offset over the temperature is of course dependent upon the course of the viscosity of the gearbox oil over the temperature wherein in the present embodiment the use of a common multi-region gearbox oil was used as a basis. Through the offset the synchronous force is adapted to the viscosity of the gearbox oil, an increased force loss at temperature-related lower viscosity is compensated for, in such a way that usefully a corresponding course of the synchronous force offset is provided if another oil is used. In the preferred embodiment the course is linear wherein it car also be useful in another embodiment if the course at least in sub-regions corresponds to or is similar to a function such as sinusoidal, tangent, e-, log or parabolic function.

As shown in Figure 4c, in the preferred embodiment the synchronous reference force is determined from a synchronous force taken from a characterization field like that shown in Figure 4a and an offset formed according to an offset function as shown in Figure 4b. For the purpose of forming the synchronous reference force it is also useful in further advantageous embodiments of the invention to modulate the synchronous force alternatively or additionally on the basis of other parameters and / or to form another or further offset values on the basis of other parameters.

In an advantageous embodiment of the invention the synchronous force synchronous force Fsc is moduiared on the basis of a driver characteristic value. This driver characteristic value can for example characterize the type of driver wherein with a division from 1 to 100 1 stands for a very consumption oriented driver and 100 for a very performance oriented driver. The driver type can be determined e.g. through observation of the load lever activation, the activation of the brake and / or in the manual mode of operation the switching frequency. In the preferred embodiment the synchronous force Fsc is all the higher with higher values for drivertypes wherein in the characterization field the dependence of the synchronous force upon the driver type is preferably at least approximately linear. In another embodiment a non- linear dependence of the synchronous force at least in sub- regions is preferred corresponding to or similar to a function such as sinusoidal, tangent, e-, log or parabolic function.

According to an advantageous further embodiment of the invention the synchronous force synchronous force Fsc is modulated on the basis of a mountaineering characteristic value. This mountaineering characteristic value can for example characterize the degree of the carriageway gradient wherein in a division from 1 to 100 1 stands for a level carriageway / in another embodiment for a very large slope and 100 stands for a very large gradient. The mountaineering characteristic value can be determined e.g. on the basis of the load lever activation, the activation of the brake, in the manual mode of operation the switching frequency and / or one or several wheel revolutions. In the preferred embodiment the synchronous force Fsc is all the higher with higher values for the mountaineering characteristic value wherein in the characteristic field the dependence of the synchronous force upon the mountaineering characteristic value is preferably at least approximately linear. In another embodiment a nonlinear dependence of the synchronous force is preferred at least in subregions according to a function such as sinusoidal, tangent, e-, log, or parabolic function accordingly or similarly.

Furthermore a modulation of the synchronous force FBC in further advantageous embodiments of the invention can take place on the basis of a moment requirement upon the propulsion engine wherein a high moment requirement h.rings about an increase of the synchronous force, on the basis of the target speed of the new transmission stage in a transmission stage change wherein in accordance with a high target speed the synchronous force is increased, on the basis of the speed difference to be overcome during the synchronization, wherein a high speed difference brings about a higher synchronous force, on the basis of the friction behaviour of the synchronization device wherein a low friction value of the synchronization device brings about an increased synchronous force and / or on the basis of the reduced moment of inertia upon the synchronization device depending upon the target gear wherein a large reduced moment of inertia gives rise to an increase in the synchronous force.

It is furthermore very advantageous if in the course of the synchronous process the synchronous force is modulated, especially if towards the end of che synchronous process the synchronous force is reduced wherein amongst other things the comfort of the switching process is improved. The end of the synchronous process can for example be detected on the basis of the speed difference between the shafts to be synchronized which is then low wherein the speed difference can be measured directly or can be determined within the control device by means of a mathematical model.

A further inventive idea relates to the starting of the synchronous position. Both the starting of the synchronous position and the synchronous force build-up are carried out in a force controlled way. In this way a fast synchronous force build-up can take place which is independent of an imprecise synchronous position deposited in the storage device assigned to the control device 17, -14 wherein the entire control of the switching act vation in relation to the dispersal of the synchronous position becomes more robust. It is attempted to control the propulsion exactly at the time at which the clutch sleeve 202 comes to a standstill at the synchronous threshold C during an engagement movement in such a way that then precisely the desired synchronous force FA is produced, which takes place in a preferred embodiment on the basis of the work carried out by the propulsion using a work / force characteristic line. The synchronous force is pre- determined here on the basis of the energy receiving rate as a function of the mechanical work performed by the drive.

In Figure 3a a drive 301 a and a clutch sleeve 304a with a connected mechanism 305a which has elasticity 302a and a damper 303a are represented schematically and by way of example. The aim is to bring the clutch sleeve 3G4a into synchronous position as soon as possible and to set precisely the desired synchronous force there as soon as possible. The propulsion takes place thereby starting from the propulsion engine with intermediate switching of a mechanism which has the elasticity 302a and the damper 303a wherein the elasticity on the one hand consists of construction- dependent parts of the kinematic stretch and on the other hand of a specially provided spring device which provides the main part of the overall elasticity.

This spring device is formed in a preferred embodiment by two elements which can be rotated against each other, to which compression springs are intermediately switched, against whose resistance the two elements rotate against each other. The resistance force / spring force increases with increasing angle of rotation wherein the increase over the entire area of rotation usefully has different climbs. An example course is shown in Figure 4d. For the purpose of producing this course several compression springs with different characteristic lines are provided in sequential and / or parallel switching. In another embodiment, however, it can also be useful if the characteristic line has the same climb over the entire area of movement.

According to a further inventive idea an elastomer synthetic material whose elasticity characteristic line is set as desired by a corresponding material selection and / or processing, for example addition of substances influencing the elasticity or use of manufacturing or handling methods influencing the elasticity. It is advantageous in this case too if the elastomer synthetic material has climbs of the characteristic line changing over the area of requirement. In another embodiment, however, it is preferable if the characteristic line has the same climb over the entire area of movement.

The fixing of the target threshold of the elasticity takes place in the preferred embodiment through a pre-tensioned incorporation of the elastic elements wherein this pre- tensioning lies according to the desired target threshold in the region of 50-450 N. in the region of 200-600 N or in the region of 400-1000 N. In a particularly preferred embodiment the pre-tension lies in the region of 150-350 N. According to a further advantageous embodiment it is provided that the elasticity is distributed, i.e several individual elasticities are provided which in their overall effect achieve the desired effect. Also the use of elasticities which are loaded and work in axial direction is provided in a further embodiment. With the present gearbox the elasticities are arranged within the mechanism between the drive and the clutch sleeve wherein in this connection the actual drive element, for example the anchor shaft of a propulsion engine, is referred to as the propulsion. In terms of construction an elasticity is preferably integrated within a case which encloses the drive and a subsequent gearbox stage.

The damper of the mechanism is represented with 303a wherein the damping can be based upon construction dependent friction or upon another additional, possibly adjustable, damping element. In the embodiment shown it is preferable if for purpose of controlling the drive 301a of the clutch sleeve 304a through the control device 18, 44 of Figure 1 in an engagement process the clutch sleeve 304a is driven up co the synchronous threshold in a speed controlled way, then with counter force recognised through the locking of the further engagement movement through the mechanism described with Figure 2 a transition to force control takes place and the force at this point in time corresponds, on the basis of the energy stored in the elasticity 302a, at least approximately to the reference force at the synchronous position. Precise agreement between elasticity 302a on the one hand and the engagement speed to the synchronous position on the other hand is decisive here.

The starting of the synchronous position takes place in a speed controlled way. The speed is regulated to a determined value using the characteristics of elasticity of the mechanism 305a connecting the drive 301a and the clutch sleeve 304a depending upon the required synchronous reference force. In a preferred embodiment the starting speed to the synchronous threshold lies in the region of 25-200 mm/s according to a required synchronous reference force of 250- 1000 N. With a three-fold increase in the required synchronous reference force the starting speed to the synchronous threshold increases about five-fold when using an elasticity with a characteristic line as shown and described in Figure 4 with 401a.

During the speed controlled starting to the synchronous position a force limit is already overlying, whose level is firstly kept low in order to compensate for the friction present in the mechanism which is, however, then raised above a certain engagement speed in order to prevent the turning back of the drive when the counter force is quickly increasing. It is preferable to increase the level of the force limit from an engagement speed of 3 - 40 mm/s, in particular from 5 - 25 mm/s. For the purpose of compensating for the friction with low engagement speed by means of overlying force limitation it is useful to regulate the force dependent upon the friction causing values like for example the gearbox oil temperature in such a way that the required engagement speed is always adhered to. With high friction high compensation takes place. With friction which is becoming lower the compensation is also reduced.

The transition to force control takes place at the synchronous position at which the engagement movement of the clutch sleeve is hindered, the elasticity is loaded up with a change of the kinetic energy into potential energy and thus a force is built up which corresponds at least approximately to the desired synchronous force.

Compensation of the friction in the activating mechanism takes place through the propulsion force continuing to work in the drive. When an electric motor is used for the drive the recognition of the movement checking takes place on the basis of the increasing energy requirement of the engine and / or the speed reduction.

In the further course the force is limited to / set at the value of the required synchronous force wherein only a relatively Small change continues to be necessary as already the force brought about tY rough the elasticity corresponds at least approximately to the desired synchronous force. In the preferred embodiment this lies in the field of 100 - 1000 N wherein a synchronization only takes place as a rule in the region of 200 - 600 Nm and only, if a particularly fast synchronisation is required, synchronous forces up to approximately 1000 N are admitted.

During the transition to force control when an electric motor is used for the propulsion of the clutch sleeve 304a the voltage and the speed of the propulsion engine are used for the determination of the reference force wherein the actually effective friction within the force limitation phase is exactly compensated for. The preferred method offers according to a further inventive idea the possibility of using uniform switching elasticity for various transmission stages and / or gearbox and constructing the synchronous force by means of a corresponding control of the starting speed to the synchronous threshold.

In the present embodiment through the fact that the elasticity 302a is incorporated in a targeted way into the entire synchronized engagement process amongst other things a decisive time advantage is achieved. In connection with the switching elasticity 302a reference is made to the German applications DE 197 34 023 Al and DE 197 13 423 Al of the applicant, whose publication also belongs expressly to the publication content of the present application. Within the scope of the preferred control of the synchronized engagement process it is also particularly useful if in a storage device assigned to the control device L8, 44 the most precise position of the synchronous threshold possible is stored and this value is updated at regular intervals.

Figure 4d shows in diagram 401a by way of example a characteristic line of a switching elasticity surrounded by the mechanism 305a wherein the deflection with a certain force is represented. After running through the clearances Sp present in the mechanism a disengagement force F corresponding to a deflection is introduced which follows a characteristic line a as far as point 1, then a characteristic line b as far as point 2 with a clearly lower climb and then as far as the end of the deflection region a characteristic line c with an in turn clearly larger climb. The target threshold of the elasticity, i.e. the force wherein a noticeable deflection takes place lies below the forces in the upper region of the part A of the characteristic line arising during a synchronized engagement process. In the present embodiment a switching elasticity is preferred, for whose deflection around approximately 3.5 mm a force of approximately 1300 N is necessary.

According to a further inventive idea it is proposed in association with the gearbox of the present motor vehicle to provide an electric engine whose rotor is for example connected to a freely rotating gyrating mass, which can advantageously be isolated by means of at least one clutch from the propulsion unit such as an internal combustion engine and from the output shaft for the purpose of centrifugal use, or forms this in such a way that by means of the arrangements hybrid drives are possible. The gearbox facilitates according to this embodiment an extensive use of the electric engine for example as a starting unit for the internal combustion engine, power generator, part drive, full drive and as a unit for the conversion of kinetic energy into electric energy- or into kinetic rotation energy using the rotor as a gyrating mass during delaying processes of the motor vehicle when the internal combustion engine is uncoupled (recuperation).

For this purpose the instantaneous value of the mechanical work is calculated continuously by the control device 18, 44, approximately continuously in another embodiment usefully also discreetly. This takes place in the preferred embodiment by means of a routine as is shown in Figure 5a. In a first process, see query in step 502, the calculating process is initialized and the reference work is calculated, step 507. In further processes, query in section 502, the current actuator work is calculated in step 503. Subsequently it is ascertained in step 504 whether the present clutch sleeve position lies sufficiently close to the point in time - at the synchronous threshold. If this is the case the exit conditions - reference force equals synchronous force - are set in step 505 and the routine is left; otherwise in a next step 506 the calculation of the reference force on the basis of the current position with regard to the deflecting curve in the speed / work diagram 510 shown in Figure 5c takes place taking into consideration the force / work characteristic line which is advantageously determined through trials. In another embodiment it is useful for it to be calculated by reference to the elastic characteristic line of the mechanism. With each calculating stage starting from the present position - point in the speed / work diagram 510 in Figure 5c - the reference force is determined for the next stage in such a way that the desired deflecting curve 511 is followed as well as possible.

Figure 5b shows a speed / work diagram in which various paths for reaching the reference position (synchronous position) with application of the reference force in accordance with the reference work Aref are represented. The boundaries of the fields are shown in the figure in points. Above it is determined by the maximum power and the maximum voltage of the drive. Very slow paths such as path a are unfavourable due to the time required for the synchronous force build-up wherein the field has a lower boundary. It is endeavoured during engagement to follow a fast path such as path c. The course of a favourable path is represented in diagram 510 in Figure 5c.

In a further embodiment of the invention a control of the setting of the desired synchronous force (synchronous reference force) takes place without using information concerning the position of the synchronous threshold. The synchronization process itself and usefully also the starting of the synchronous position are carried out in a force controlled way wherein it can also be useful in another embodiment to start the synchronous position in a speed controlled way. For the purpose of force control the force opposing the drive is continuously estimated, approximately continuously in another embodiment, usefully also discreetly. In this connection through the control a calculation takes place taking into consideration the rigidity of the kinematic stretch between the drive and the clutch sleeve and the kinetic energy of the propulsion wherein a very fast and precise setting of the synchronous reference force is achieved without overshooting. In particular a situation is avoided wherein the drive force must then be corrected when the synchronous position is reached in order to compensate for a false starting speed.

As shown in Figure 6 according to a preferred embodiment the force opposing the drive is estimated through the observation of the drive speed (see step 601) and this counter force is used for the force preindication.

According to the verification in step 602 and the branch with step 604 the calculation of the reference force is carried out for so long until either the desired synchronous force Fgync according to the equation | Fsync - F | Fbounary is set sufficiently - as far as Fbounary - wherein Fi corresponds to the estimated counter force or the drive speed |vi| falls below a value vbOunary. When one of these criteria is achieved the starting conditions in step 603 are set in that the reference force Firef for the next stage is set equal to the desired synchronous force FsYnc A further preferred embodiment of the invention facilitates the starting of the synchronous position using artificial damping in the propulsion in that the driving of the synchronous position and the synchronous force build-up are carried on starting from the position referred to as A in Figure 2 wherein for the pre indication of the reference drive force Firef of the drive the equation Firef = FmaX - kvi is used. FmaX is calculated as FmaX = Fsync / + Foffset wherein Fsync refers to the desired synchronous force on the clutch sleeve, the drive degree of effect, vi the starting speed and Foffset k parameters.

Also in this embodiment the desired synchronous force is set quickly and without overshooting wherein in particular the selection of the parameter k which can also be referred to as a damping constant is essentially influential and a corresponding setting of this parameter must take place according to the other values.

With gearboxes whose transmission stages are switched by means of switching clutches it is necessary to deposit positions like for example of the gear end positions or the synchronous thresholds in a storage device assigned to the control device in order to ensure a friction free course of the switching processes. On the basis of operation dependent changes in the region of kinematics between the clutch sleeve and the propulsion, like for example wear and tear, deviations can result between the positions deposited in the storage device and the actual positions which is why it is necessary to newly adapt positions. An adaptation takes place preferably repeatedly during operation. Between certain positions there is a connection, i.e. a displacement due to operation dependent changes has an effect upon these positions in the same way or there is at least a proportional connection.

According to an embodiment of the invention at least at times a connection is produced between positions so that the adaptation can also use a position for the correction of another position. For example the adaptation of the gear end positions can be connected to the adaptation of the synchronous threshold position in that with a completed adaptation of a gear end position also the associated -ynchronous threshold position is correspondingly corrected. It is useful if this coupling of the positions is not permanent but instead only effective at times. For example the positions for an adaptation after the expiry of a certain time can be connected to each other. In this connection time periods in the region of 40 to 200 hours, in particular 80 to 100 hours, are useful. In another embodiment, however, it can also be opportune to produce the connection more often, for example at intervals of several hours or even several times per hour. In another embodiment the coupling is dependent upon the number of completed gear end position adaptations. A coupling takes place usefully after a pre- determined number of gear end position adaptations, for example after 15 to 80, in particular after 40 to 60 gear end position adaptations. Also a connection of positions for a common adaptation on the basis of other events, for example the motor vehicle start or during standstill, e.g. at traffic lights, can be useful.

In a further embodiment In a gearbox wherein the positions of the gear end positions are laid down in a storage device assigned to the control device and these gear end positions are adapted during the operation.

According to a further inventive idea it is proposed that in association with the gearbox of the present motor vehicle an electric motor should be provided whose rotor is connected for example with a freely rotating gyrating mass which can advantageously be isolated by means of at least one coupling from a drive unit such as an internal combustion engine and from the output shaft for the purpose of centrifugal use, or forms this in such a way that by means of these arrangements hybrid;ropulsions are possible. According to this embodiment the gearbox facilitates an extensive use of the electric motor for example as a starter unit for The internal combustion engine, power generator, part drive, full drive and a unit for the conversion of kinetic energy into electric energy or into kinetic rotation energy using the rotor as a gyrating mass during rotating processes of the motor vehicle when the internal combustion engine is uncoupled (recuperation).

The embodiments are not to be understood as a limitation of the invention. Within the scope of the invention, as defined by the claims, numerous changes and modifications are possible, particularly such variants, elements and combinations and/or materials which can be derived through combination or changing of individual features/elements or procedural steps described in connection with those in the general description and embodiments as well as the claims and in the drawings.

Claims (3)

1. Claims 1. Method for operating a gearbox for a motor vehicle which has a

   plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a main shaft and a free gearwheel intermeshing with the gear wheel which can be connected to a secondary shaft, the gearbox also comprising clutch sleeves for producing a connection between the free gearwheel of a transmission stage and the secondary shaft, drive means for effecting an engagement or disengagement of the clutch sleeves, a mechanism for connecting the drive means to the clutch sleeves, synchronization devices between the clutch sleeve and the free gearwheel for producing a synchronization torque during an engagement process on the basis of an engagement force in a frictional way and for locking a further engagement beyond this synchronization threshold until at least approximate equality in revolutions is achieved, an elasticity in the region of the mechanism which is suitable for storing kinetic energy in the form of potential energy and vice versa for emitting potential energy in the form of kinetic energy and a control device for controlling the propulsion means, wherein the selection of a transmission ratio comprises the steps - engagement of a clutch sleeve in a speed controlled way up to the synchronization threshold, - recognition of a counter force effected through the locking at the synchronization threshold, and subsequently transition to force control.
2. 2. A method as claimed in Claim 1, wherein energy is stored in the elasticity through the locking of the clutch engagement movement at the synchronization threshold.
3. 3. Method as claimed in Claim 1 or Claim 2, wherein movement of the clutch sleeve is controlled in dependence on force, the control makes use of a damping constant which facilitates starting of force control independently of the exact starting speed of the clutch sleeve and the exact position at which force control takes over from speed control.

   3. Method as claimed in Claim 1 or Claim 2, wherein for starting the synchronization position of an output element of a gearbox end activation mechanism for a motor vehicle with a locking synchronized gearbox, the synchronous position is started as soon as possible without overshooting, wherein force control takes place on the basis of the vibration equation using a damping constant which facilitates starting independently of the exact starting speed of the end output element of the gearbox end activation mechanism and the exact position of the synchronization position and upon which the synchronization force is dependent. so

   Claims 1. Method for operating a gearbox for a motor vehicle which has a plurality of sets of wheels forming transmission stages, each of which are formed by a gearwheel securely connected to a main shaft and a free gearwheel intermeshing with the gear wheel which can be engaged with a secondary shaft, the gearbox also comprising clutch sleeves for producing engagement between the free gearwheel of a transmission stage and the secondary shaft, drive means for effecting an engagement or disengagement of the clutch sleeves, a mechanism for connecting the drive means to the clutch sleeves, frictional synchronization devices between respective clutch sleeves and free gearwheels for producing a synchronization torque during an engagement process and for preventing further engagement beyond this synchronization threshold until at least approximate equality in revolutions is achieved, elastic means for storing kinetic energy in the form of potential energy and for emitting potential energy in the form of kinetic energy and a control device for controlling the drive means, wherein the selection of a transmission ratio comprises the steps - moving a clutch sleeve up to the synchronization threshold while controlling the speed of movement of the sleeve, - monitoring a counter force resisting movement of the clutch sleeve, and - on recognizing a counter force representing locking at the synchronization threshold, controlling further 3 movement of the clutch sleeve in dependence on the force needed to move the sleeve.

   2. A method as claimed in Claim 1, wherein energy is stored in the elastic means through the locking of the clutch engagement movement at the synchronization threshold.