DE19631236A1 - Gear transmission e.g. for use with motor vehicle IC engine - Google Patents

Abstract

The gear transmission , which uses the principle of a geared -neutral drive has an input shaft 2 and output shaft 3. The input can be coupled to an IC engine via a flywheel and the first stage of the transmission is continuously variable with cone shaped discs 4a,4b and a coupling wheel 6. This connects via a pinion 12 and coupling 11 to a planetary gearing module 13-15. This has an input to a second continuously variable stage 5. Hydraulic cylinders 7,8 provide regulation.

Description

The invention relates to a gear unit with a multi-range structure continuously variable transmission and with further transmissions.

Such gears are in EP 0 210 053, DE 41 13 386, GB 2 045 368 and GB 2 108 599. EP 0 210 053 shows a gear unit a continuously variable transmission, such as a conical pulley belt transmission, wherein the shafts of the conical disk pairs on the input or output side with an input or Output shaft can be connected, the input shaft, such as Input shaft, and the output shaft, such as the output shaft, the gear unit be switched by means of clutches and other gear stages can that each mutually connect with the waves of the cone disc pairs can be produced. It is thus achieved that the usable Translation range of the continuously variable transmission can be driven through multiple times.

GB 2 045 368 and GB 2 108 599 each disclose a transmission unit with a continuously variable transmission, such as conical pulleys  belt transmission or toroidal transmission, the output of the stepless sen transmission with an input of a superposition gear, such as summing gear, is connectable and a second input of the summing gear over a gear stage can be connected to the input of the continuously variable transmission, the output of the summing gear with the gear output shaft connected is.

These clutches can be used for both the gear stage with a fixed ratio on the one input of the summing gear as well as the summing gear can be switched on and off alone. Common to the gears is the one above mentioned EP-Offenlegungsschrift and GB-Offenlegungsschriften that the Transmission range of the continuously variable transmission can be driven through more than once and the range is switched by means of clutches, the gear structure of the EP laid-open specification referred to as an i² gear net and the gear structure of the GB-Offenlegungsschriften as Geared-neutral structures with range switching are known.

The transmission range is switched over for these gear structures che by means of couplings, which can be positive or frictional. The Difficulty with these gears arises from switching the Gear ratios with a fixed gear ratio, so that ideal  be switched by means of a dog clutch at the switchover point can.

The object of the invention is to provide gear units with multi-range structures create which improve behavior in the area change as well have improved comfort.

It was also the task to create a gear unit which by means of a targeted strategy in the control, e.g. B. at Be range switching, a reduced range of components or a simplified te structure.

The invention was also based on the object of creating a method which allows control to ensure comfortable behavior with Be realizing exchange changes.

This can be achieved in that in gear units with gears, which alternately to and from the continuously variable transmissions via at least two disengageable clutches with changeable transmissible torque are connectable, the switching process begins at differential speed and loop fend takes place. With such gear units, the translation range is continuously variable transmission can be used or passed through several times.  

According to the invention, this can also be achieved by the steps loose gearbox with at least two alternately switchable clutches the other transmissions with adjustable, transmissible torque are connectable, the switching process being initiated at differential speed is done and grinding.

It can be particularly advantageous if, in the case of gear units with multib empire structure the translation range of the continuously variable transmission more than can be driven through once by reaching at least two clutches a certain gear ratio of the continuously variable transmission in Power flow of the gear unit can be switched on and off, in which also a The direction of actuation is reversed and after the direction of actuation is reversed closed clutch before or after reaching the switch point starts to close.

The direction of actuation in a continuously variable transmission, especially at a conical pulley belt transmission, gives the direction of control tion, e.g. B. the axial position of the conical washers, which is changed, to vary a gear ratio, d. H. with a conical disk set As a rule, a conical disc is held axially, the second Conical pulley is axially displaceable, the belt means of  stepless gear when shifting its radial circulation area or Contact area changed and thus a changed transmission ratio is set. In this sense, the direction of actuation means a increased gear ratio in the radially inward or radial direction externally operable cone pulley and when the actuation changes direction of reversal of the direction of movement of the displacement the conical disk.

Furthermore, a continuously variable transmission can be used advantageously Superposition gear, like summing gear, with two inputs and one Output in the torque flow can be switched on and off, whereby alternately one input with a downstream gear stage can be switched off and the other input with the output part of the stepless Gearbox is connected and the output part of the via a further coupling Superposition gear, such as summing gear, with the output part of the continuously variable transmission directly or indirectly via at least one fixed transmission tion stage is connectable and at least one clutch before or after Reaching the switchover point begins to close.

Furthermore, it can be advantageous if, in the case of a gear unit with a multit empire structure a continuously variable transmission with a first and a second Wave is arranged in the torque flow and the first and second waves as  The input or output shaft of the continuously variable transmission alternately by means of switches at least two clutches, in particular by means of four clutches are bar and the first and the second shaft by means of gear stages with a Transmission input or transmission output shaft are connectable, one Switching process from the first and second shaft as a drive or Output shaft before or after reaching a changeover point in the event of a difference speed begins and grinds.

Furthermore, it can be particularly advantageous if at least one of the Clutches a friction clutch, such as a friction clutch and / or magnetic powder clutch, in particular all clutches are such clutches.

According to the inventive concept, it can be advantageous if a control unit with sensors and / or other electronic units in Signal connection is established and based on the operating point the translation of the continuously variable transmission and the transmissible torque of at least one Coupling the gear unit with a multi-range structure.

In essence, it can be useful if the control unit has a Central computer unit has.  

Furthermore, it can be advantageous if control means for actuation and Control of the adjustment cylinder and / or pressure cylinder of the stepless Gearbox and at least one clutch are available, which hydraulic, mechanically or electromotively operated.

It can also be expedient to design a gear unit in such a way that that a range change of the continuously variable transmission or the gear unit by means of at least one slip-controlled clutch during differential rotation number done.

According to a further inventive idea, it can be advantageous if with a method for controlling or regulating a gear unit Multi-range structure with a continuously variable transmission and other transmissions the transmission range of the continuously variable transmission more than once is mobile and via at least two clutches when a be reached other gear ratio of the continuously variable transmission Gear units in the power flow can be switched on and off, the, after successful reversal of the direction of actuation of the continuously variable transmission, closed close the clutch before or after the switchover point is reached begins.  

The switchover can be performed before or after the switchover point is reached be carried out or carried out. A case distinction is for the difference Train and push operation possible.

In train operation

• 1. When switching to the CVT range in the direction of low overall ratio i _total (with increasing 1 / i _total ), the clutch beginning to close before the switchover point is reached.
• 2. When switching in the direction of smaller 1 / i _total , the clutch starting to close after reaching the switchover point.

In overrun mode

• 3. When switching in the direction of increasing 1 / i _total , the clutch begins to close after reaching the switchover point and
• 4. When shifting in the direction of smaller 1 / i _total , the clutch starting to close before the switch point is reached.

This case distinction can also be formulated in such a way that in the train rich with a smaller reciprocal overall translation (with a smaller one)  Speed ratio ωA / ωE as the synchronization point at which the difference speed in both clutches is O) the range change is initiated.

In the shear range, with a higher reciprocal overall ratio (at a higher speed ratio) than the synchronization point of the range change sel initiated.

According to the method according to the invention, it can be advantageous if a Range change of the continuously variable transmission or the transmission unit by means of at least one slip controlled clutch at differential speed is initiated or takes place.

The slip or the differential speed at which a switching operation or Switching operation takes place or is initiated, is preferably one Value less than 50 1 / min, with a value in the range of 20 1 / min to 2 1 / min is preferred.

The invention further relates to a method for changing the transfer Paths of a multi-range transmission according to the preamble of the An Proverb 12 and a multi-range transmission to carry out the method.  

Generic types are particularly popular for their use in motor vehicles Multi-range gearboxes because of the consumption associated with their use savings potential increasing importance. Examples of such multi-area gearboxes are in Lechner, G .; Nauheimer, H .: Vehicle transmission, springer Verlag 1994, in particular pages 144 to 146.

Theoretically, switching from one transmission path to another at the differential speed 0 the respective open clutch, d. H. at the synchronization point. Corresponding one has tried with simple, form-fitting claw couplings get along, indented or disengaged at differential speed O. will. The switch was unsatisfactory in comfort, so that one tried the transitions with bevelled bevels on one side ge cheaper (freewheel-like) to design, but only in a torque ment support direction of the dog clutches can succeed.

There have also been attempts to use friction clutches and freewheels Control switching operations satisfactorily. In Oetting, H .; Heath Meyer, P .: Stepless transmission for passenger cars, VDI reports 579 is noted that the controls of such clutches are extraordinary is complex.  

The invention is also based on the object of a method according to the The preamble of claim 12, which is structurally simpler Training of the transmission and low control or regulation effort satisfied in shifting comfort. The invention is further based on the object a multi-range transmission for performing the inventive method rens to indicate.

The part of the object of the invention relating to the method is included in the Features of claim 12 solved. Surprisingly, it has turned out asked that a perfect shift comfort can be achieved if one contrary to the prevailing doctrine, the multi-range transmission is not in its neutral point, d. H. at differential speed 0 of the open clutch lung switches, but outside the neutral point. That way takes the control effort, since the exact translation is not recorded must be at which the differential speed is zero, but switching via an area is possible in which there is a low differential speed is. With conventional friction clutches, these differential speeds can Closing the clutch and essentially opening the other friction clutch can be smoothed. Because the differential rotation number is such that when changing the transmission paths between Input shaft and output shaft transmitted tensile or shear torque is supported by closing the clutch, the change takes place  of the transmission path in an extremely comfortable manner without Torque drop or pull or thrust drop or even reversal. Backlashes between gears or torsional elasticity remain Influence.

The sub-claims 13 to 16 are advantageous embodiments of the directed method according to the invention.

The method according to the invention can be used for almost all multi-purpose areas gears are used in which between the individual transmission paths is switched by means of friction clutches. The used continuously variable transmission can be a belt transmission, for example with tapered pulleys, a hydrostatic transmission or even a be multi-speed gearbox, the stages of which via converter or friction clutch lungs are smoothed. Also exist for the further transmission path extensive freedom. It is crucial that the multi-range transmission one Has synchronous point at which the continuously variable transmission with a transmission zung works that lead to a differential speed of zero of each open Coupling or clutches leads.  

Claims 17 and 18 are based on particularly advantageous embodiments a multi-range gearbox directed to carry out the inventions method according to the invention is particularly well suited.

The invention will be explained with reference to FIGS. 1 to 13.

It shows:

Fig. 1 is a schematic representation of a transmission unit,

Fig. 2 is a schematic comprehensive view of another Getriebeein,

Fig. 3 is a schematic diagram,

Fig. 4 is a functional diagram and

Fig. 5 is a schematic representation.

Fig. 6 is a schematic diagram of a multi-range transmission with two transmission paths,

FIGS. 7 and 8 sketches for explaining the changing of the transmission paths in the transmission shown in FIG. 6,

Fig. 9 shows a modified embodiment of a transmission with power branching,

Fig. 10 is a sketch for explaining the operation of the Getrie bes shown in FIG. 9,

Fig. 11 shows a further embodiment of a transmission with two branches,

Fig. 12 is a sketch for explaining the operation of the gearbox bes of FIG. 11 and

Fig. 13 is a block diagram for explaining the control of the transmission of FIG. 9.

Fig. 1 shows a gear unit which is constructed according to the principle of the geared-neutral transmission, with a transmission input shaft 2 and a transmission output shaft 3. The transmission input shaft 2 can be operatively connected directly or via a torsional vibration damper, such as a dual mass flywheel, to the output shaft of an engine, such as an internal combustion engine. The transmission output shaft 3 is connected to an output shaft which acts via a differential on at least one drive axis, which is not shown in FIG. 1.

Furthermore, the transmission input shaft 2 can also be operatively connected to a starting element, wherein a multi-plate clutch, a friction clutch or a hydrodynamic torque converter can be provided.

The gear unit 1 comprises a continuously variable transmission 1 a having a first conical disc set 4 and a second set of bevel discs 5, wherein a belt means 6 connects the two sets of bevel discs 4 and 5 in Drehmo mentfluß, and the radial position or radial arrangement of the belt 6, such as Chain or thrust link belt that determines the ratio of the continuously variable transmission. The conical disks 4 and 5 are composed of a conical disk 4 a, 5 a, which is connected in a rotationally fixed manner to the input shaft or an output shaft, and an axially displaceable conical disk 4 b, 5 b, the displaceable conical disks 4 b, 5 b by means of the piston-cylinder units 7 , 8 are axially displaceable. The axial displacement of the conical disks 4 b, 5 b and the change in gear ratio thereby generated is controlled by pressurizing the piston-cylinder units 7 , 8 .

The output shaft of the continuously variable transmission 9 is in this game Ausführungsbei with the sun gear 10 of a superposition gear, such as Summierge gear, such as planetary gear, connected. In parallel to the continuously variable transmission, another transmission with a fixed ratio is connected in parallel, a gear 12 being connectable to the input shaft 2 via a clutch 11 and the gear 12 driving the planet carrier 13 of the summing gear via a translation stage. The ring gear 14 of the planetary gear is connected to the output shaft 3 of the gear. The ring gear and the planet carrier can be connected to one another in a rotationally fixed manner via a coupling 15 , so that the planet carrier and ring gear rotate as a fixed block.

The multi-range transmission of FIG. 1 may be when the clutch 11 and the clutch open 15 generate the first operating region for driven shaft 2 with a suitable translation of the continuously variable transmission output speed of the output shaft 3, which is equal to zero, so that the gear ratio, ratio of output speed to input speed is equal to is zero and by varying the variator ratio of the continuously variable transmission, starting a vehicle in the forward or reverse direction is possible, the ratio in one direction or the other having to be changed accordingly, starting from the "neutral ratio" of the continuously variable transmission.

In a further gear ratio range of the gearbox, the clutch 11 is opened and the fixed gear ratio is decoupled from the one input 13 of the summing gear and the clutch 15 is closed, so that the shaft 9 is essentially rigidly coupled to the shaft 3 of the gearbox. The transmission unit can thus be used as a purely continuously variable transmission in a second operating range.

One of the transmission ranges described above is called Geared Neutral Be referred to rich, since the Ab drive shaft can be operated at zero speed and a drive accordingly without clutch actuation with the drive motor running can be kept at a standstill, with the transmission ratio on Approaching or braking in the neutral range. The second Operating area of the multi-area structure serves to translate range of the continuously variable transmission one more time to use a higher To realize gear spread or a more favorable dimensioning.

FIG. 2 also shows a transmission unit with a multi-range structure, a continuously variable transmission being used. The transmission input shaft 50 can be connected by means of a gear stage and the couplings 51 and 52 to the shafts 53 and 54 , these shafts in turn being connectable to the couplings 55 and 56 via gear stages to the output shaft 57 .

The gear stages are represented by the input and output shaft gears 50 a, 57 a and the gears 51 a, 52 a, 55 a and 56 a engaging in these gears. This results in a ratio between the drive and Abtriebswel len 50 , 57 and the clutches 52 , 51 , 55 , 56 and the shafts 54 , 53 , which is fixed by the choice of gears and depending on the clutch actuated.

The operation of a transmission shown in Fig. 2 can be explained in that the clutches 51 , 52 and 55 , 56 are alternately engaged or disengaged, so that diametrically opposite clutches are engaged according to this scheme and the other two Clutches are disengaged. Starting with a closed clutch 52 and an open clutch 51 , the drive-side torque is transmitted from the drive shaft 50 via the clutch 52 to the variator 58 , the two conical disks 59 being connected to the conical disks 61 in the power flow via a belt means 60 . At the same time, the clutch 55 is opened and the clutch 56 is closed, so that a torque is transmitted from the shaft 53 via the conical disks and the belt means 60 to the pair of conical disks 61 and from there via the shaft 54 and the clutch 56 to the output shaft 57 .

In a second operating area, the clutches 52 and 56 are open and the clutches 51 and 55 are closed, so that the torque flow takes place from the drive shaft 50 via the clutch 51 to the conical disk pair 61 and from there via the belt means to the conical disk pair 59 and via the Coupling 55 on the output shaft 57 . Because of this arrangement, the gear ratio of the variator can be used several times by means of the gear ratios of the driven shafts 53 and 54 . The engagement of the clutches, which are preferably provided as frictional clutches, should take place at differential speed, so that a sliding shifting process takes place. This ensures a comfortable gear shift.

FIG. 3 shows a control unit 100 with various inputs 101 to 103 for connection with sensors. These sensors signal or detect the respective operating state of the system, such as vehicles, such sensors identifying, for example, the engine speed, the transmission input speed, the vehicle speed, the throttle valve position of the engine, the load lever position or other state variables. Furthermore, a gear is assigned to the gear selector lever 105 , which detects the gear or gear selected and forwards it via the signal line 106 to the input 104 of the control unit 100 .

The control unit 100 controls the transmission ratio of the continuously variable transmission 110 , such as a conical pulley belt transmission or a toroidal transmission, whereby a pressurization of the pressure cylinders, such as pressure and adjusting cylinders, 113 and 114, is controlled, the translation being set with the axial displacement of at least one pulley of each pulley set. Furthermore, the control unit 100 controls the clutches 111 to 112 , so that the engagement state or the torque that can be transmitted by these clutches is specifically varied and determined.

The clutches 111 to 112 are shown schematically and depending on the embodiment, a different number of clutches can be shown with the clutches 111 to 112 . In the exemplary embodiment of FIG. 1, two clutches 11 and 15 are shown, which are opened or closed when the range is switched or are controlled in a targeted manner when crawling. In Fig. 2 are shown 52 as well as 55 and 56, four clutches 51, which are controlled, opened or closed at a range change.

When changing ranges of gear units with multi-range structures the connection and disconnection strategies of the corresponding couplings such as be carried out by automatic gears when changing gears. When changing gears In the case of stepped automatic machines, speed jumps in the range from 1.2 to 1.6 performed, which must be synchronized by means of couplings. The present invention is based on the above-mentioned transmission units with multi-area structures such as a change of area cause that is switched at differential speeds, d. H. not on syn is switched chronopoint and the differential speeds are very small, d. H.,  that the ratio of the speeds when switching from the speed before and after switching in the range up to 1.1 and special up to 1.05 or up to 1.01. Each shift can be done without changing the output Moments take place, d. that is, range switching toward larger or smaller translation without interrupting the tractive force.

The differential speed at which the range change is started can result from the resolution of the speed signals and a dead time at Determination of the speed signals and a lead value result, which takes the dynamics of the system into account as a function of time. Thus at the dynamics of the system, especially the behavior ten in the area of the control dead time is taken into account, thus a control can take place at a differential speed.

This control method can be used with the Geared-Neutral-Ge in the changeover range as well as in the so-called i² gearboxes at Area changes are carried out.

When changing ranges it is important that the torque curve on the output side remains homogeneous and the power loss at the coupling is not too great. This can be achieved if the area change is just before or after the synchronization point is carried out. The output torque curve remains  homogeneous, also taking into account the existing elasticities in the Gear structure when an optimal differential speed and torque is controlled.

Fig. 4 shows the course of the speed ratio between the output speed of the gear unit to the input speed of the gear unit as a function of the variator ratio n _var , wherein the variator ratio can be changed in the range from n _varmin to n _varmax . In a first operating range, the ratio ω output to ω drive is minimal at the maximum variator ratio, as shown in the ratio Ω₁. With a decreasing variator ratio n _var , the ratio increases up to the value Ω₂. The curve 200 represents this situation of the speed ratio as a function of the variator ratio. Before the minimal variator ratio, an example of an i² transmission according to FIG. 2 is a change or changeover the waves of the conical pulley sets started, so that for a speed ratio Ω₂ again an increasing speed ratio takes place with increasing variator ratio.

The switchover can now ideally take place at the specified variator ratio Ω₃ or, as in the transmission according to the invention, at differential speed, as represented by line 201 . The switchover point Ω₂ thus occurs before the specified variator ratio Ω₃. Accordingly, the schematic representation of FIG. 4 can be applied not only to a so-called i² transmission, but also to so-called geared-neutral transmissions or other multi-range structure transmissions.

According to FIG. 5, in the drive train between a drive unit 401 and drive wheels 402 of a motor vehicle on a connected to the drive means 401 shaft 403, a torsional damper 404, a Continuously Variable Control bare frictional clutch K1, here a lamellar or friction clutch, as a speed transducer and the primary side of a serving as a torque converter, continuously variable transmission 405 , here a Umschlingungsge gear, arranged as a torque converter. The secondary side of the transmission 405 drives the central wheel of a planetary gear 407 , here a planetary gear, via a shaft 406 , the hollow ring of which is connected to the drive wheels 402 via a shaft 408 , a spur gear 409 and a differential gear 410 . The web of the epicyclic gear 407 is connected via a spur gear 411 to the driven side of the clutch K1. The Umtriebge gear 407 can be bypassed by means of a second continuously controllable slipping clutch K2, which is connected on the one hand to the spur gear 411 and the epicyclic gear of the epicyclic gear 407 and on the other hand to the hollow ring of the epicyclic gear 407 . With this arrangement, it is possible for the continuously variable transmission 405 to operate both for zero control (geared-neutral operation) with the clutch K1 and clutch K2 open in the driving ranges "forward", "reverse" and "neutral" as well as with the clutch open Clutch K1 and closed clutch K2 to be used in normal operations.

With the drive device 401 , the setpoint generator 412 for a Regelein direction 413 is connected, which in turn is connected to the drive train.

The setpoint generator 412 is a desired on the output side torque M _a , which may have a fixed or changing value, depending on the driver, for example depending on the accelerator position, supplied as a selection signal and the drive device 401 as a control signal. The specification of the desired output torque M _a as a function of time t is schematically represented by a functional unit 414 . Furthermore, the setpoint generator 412 receives signals from the drive device 401 therein which correspond to the input speed n _e and the input torque M _{e of} the drive train. In addition, the driver can use a selector lever (not shown) on the setpoint generator 412 to set a standing, parking or neutral range P (park) and N (neutral) as well as a reverse and a forward driving range. The setpoint generator 412 contains a memory in which previously empirically determined pairs of values of speed differences Δn between the input and output sides of the clutch K1 and of clutch torques M _K1 , which are to be transmitted by the clutch K1, as a function of the respective variables M _a , n _e and M _e are assigned to one another and stored in such a way that their product Δn × M _{K1 is} always approximately zero but not equal to zero. Furthermore, the memory for a desired output torque M _a , the low creep torque M _Kr with an amount B that lies between zero and, for example, fifty Newton meters (Nm), a speed difference or slip speed Δn associated with this amount between the input and output sides of the Clutch K1 in the amount of A, which is between zero and, for example, fifty revolutions per minute, each for the reverse driving range and the forward driving range, the slip speed having a negative value A in the reverse driving range and a positive value A in the forward driving range. For desired output torques M _a that are greater than the creeping torque M _Kr , that is to say driving torques M _F , the desired torque M₈ is stored with proportional values C × M _a for the forward and reverse driving range (with C = const.). In contrast, the moments M _Kr and M _F and the speed difference Δn are zero in the stationary, park or neutral ranges P, N.

The setpoint generator 412 then supplies the control device 413 with a setpoint signal which corresponds to a speed difference Δn retrieved from the memory in accordance with the input signals M _a , n _e and M _e , and with a setpoint signal for the pressure p _K1 , which also is called up from the memory of the setpoint generator 412 in accordance with its input signals M _a , n _e and M _e and determines the pressure with which the two clutch halves of the clutch K1 are pressed together in order to set the desired torque M _{K1 of} the clutch K1 to be transmitted.

A the speed n₁ on the primary side of the belt converter 405 measuring speed sensor 415 and the speed n₂ on the secondary side of the belt converter 405 measuring speed sensor 416 lead the control device 413 to the measured speeds n₁ and n₂ accordingly corresponding to the actual value signal in the control device 413 the setpoint signal for the speed difference Δn is compared. Depending on the comparison result, the wrap converter 405 is then supplied with a control signal for the pressure p 1 on the primary side and a control signal for the pressure p 2 on the secondary side of the wrap converter 405 . These control signals then adjust the primary and secondary pressure cylinders of the belt converter 405 by compressing the respective pair of discs, the position of the belt means and thus the gear ratio i = n₁ / n₂ of the belt converter 405 so that the respective input signals of the setpoint generator 412 assigned assigned speed difference on the clutch K1 results. Likewise, a pressure sensor (not shown) on the clutch K1 measures the actual value p _{K1 of} the pressure with which the clutch halves of the clutch K1 are pressed together and supplies this actual value to the control device 413 . The regulating device 413 then compares the actual value with the pressure setpoint p _K1 supplied to it by the setpoint generator 412 and regulates a difference between the setpoint and actual value so that a control signal corresponding to the setpoint is generated at the pressure signal output for the pressure p _{K1 of} the clutch K1 and the Coupling K1 compresses accordingly. With clutch K2 open, the gear ratio i corresponds to a forward _{gear ratio} i _vw for a positive setpoint of the speed difference Δn (see the diagram entered in the control device 413 ) and a reverse gear _ratio i _rw for a negative setpoint for the speed difference _Δn , on the other hand for the stationary , Park or neutral range at the setpoint zero for the speed difference Δn a speed ratio i _Q for the geared-neutral point at which the output speed n _{a is} equal to zero.

In this way it is ensured that the losses in the clutch K1 are very small over the entire operating range, since the product determining these losses Δn × M _K1 over the entire operating range is approximately zero, ie very small but not equal to zero.

Furthermore, since a very low output torque B, corresponding to one Creep torque at a very low slip speed A and the like Gear ratio i for low output speed, can be ensured the vibration occurring at a standstill with previous translation regulations  against the vehicle because the moment in the drive train is then depends only on the moment of clutch K1.

Referring to FIG. 6, a range-change transmission to a driven by a motor not dargestell th e input shaft and an output shaft for a drive of a working machine, or for example a vehicle. At a first branch node 503 , the transmission path from the input wave e to the output wave a is divided into two paths. A first path contains a friction clutch K1, which is followed by a transmission stage 505 , to which a differential gear 507 connects, the output of which is connected to the output shaft a via a second branching node 509 .

The second transmission path contains a continuously variable transmission CVT, which is designed, for example, as a belt transmission with two disks of variable diameter. The output of the continuously variable transmission CVT is connected via a node 511 to a support member of the differential gear 507 and via a second friction clutch K2 to the second branching node 509 .

The transmission ratio determined by the differential gear 507 is such that the output shaft a rotates at N times the speed of the shaft coming from the transmission stage 505 when the node 511 is stationary.

The structure of such a transmission is known per se. The synchronization point corresponds to the ratio of the continuously variable transmission CVT at which the Speed ratios are such that both clutches K1 and K2 ge can be closed, d. H. work without differential speed.

The function of the transmission according to FIG. 6 and the switching between the clutches K1 and K2 are explained with reference to FIGS. 7 and 8.

In FIG. 8, the abscissa represents the speed ratio ν _G = ω _a / ω _e of the entire transmission and the ordinate represents the speed ratio of _CVT ω = _Wa / ω _e of the CVT ν applied. Mean
ν _G the speed ratio of the entire transmission,
ν _CVT the speed ratio of the CVT transmission,
ω _a the speed of the output shaft a,
ω _{e is} the speed of the input shaft e and
ω _{Wa is} the speed of the output shaft of the CVT continuously variable transmission.

In the range of low overall speed ratios, the clutch K1 is closed and the clutch K2 is opened, with the relative speed Δω _K2 / ω _e in the lower left half of FIG. 7. the clutch K2 is specified. This relative speed decreases with decreasing speed ratio of the continuously variable transmission bes CVT and becomes zero at the speed ratio 0.45, the synchronization point of the transmission. At speed ratios ν _G greater than 0.45, clutch K2 is closed and clutch K1 is open, the relative speed at clutch K1 being indicated in the lower right half of FIG. 7.

The switching of the transmission according to FIG. 6 takes place as follows:
In the traction range (input shaft e drives output shaft a), when the gear ratio is reduced, ie when shifting up, the system switches before the synchronization point is reached, ie before the differential number of clutch K2 decreases to 0. If the clutch K2 is closed in this state and the clutch K1 is opened, there is a positive output torque due to the differential speed in the clutch K2, which delays the drive motor, not shown, until the clutch K2 no longer slips. A positive drive torque (train) before and after changing the transmission paths of the transmission or its range switchover is homogeneously supplemented by a positive drive torque by delaying the motor masses affected by inertia during the change of range.

Conversely, the clutch K2 closes in the thrust area and that Only open clutch K1 after passing through the synchronization point, so that the now required acceleration of the engine masses the thrust torque homogeneously supplemented.

Fig. 8 shows the corresponding control strategy when increasing the gear ratio (downshift). In the train area, the change from clutch K2 to clutch K1 only takes place when a positive differential speed has built up in clutch K1. In contrast to conventional automatic stepping machines, this allows a range change, which in turn results in a positive output torque during the range change due to the deceleration of the motor. Conversely, in the thrust area, there is already a change before the synchronization point, so that a homogeneous output torque curve also results here during the area change.

With the described control strategy or the procedure for changing the Transmission paths are made with a simple structure of the multi-range transmission or its couplings an extremely comfortable area change achieved.  

Fig. 9 shows schematically an embodiment of a multi-range transmission known per se, which is particularly well suited for carrying out the described range change method. The continuously variable transmission CVT is here as a belt transmission with two conical pulleys 51 and 52 , the effective diameter of which determines the transmission ratio or speed ratio of the continuously variable transmission. The differential gear 507 is designed as a planetary gear, the ring gear 513 is rotatably connected to the output shaft a, the planet gear 515 meshes with the gear ratio 505 and the sun gear 517 is rotatably connected to the output shaft of the continuously variable transmission CVT. The first clutch K1 connects the input shaft e to the transmission stage; the second clutch K2 connects the planet gear carrier 515 to the ring gear 513 .

The function of the transmission according to FIG. 9 is explained with reference to FIG. 10. The total speed ratio ν _G is plotted on the abscissa as the quotient of the speed ω _{a of} the output shaft a and the speed ω _{e of} the input shaft e. The ordinate shows the speed ratio ν _{CVT of} the continuously variable transmission CVT as the ratio of the diameter of its pulleys of the S₁ / S₂.

In power-split operation, in which the transmission stage 505 and the differential gear 507 are effective in addition to the continuously variable transmission, the clutch K1 is closed and the clutch K2 is opened; in direct operation, in which clutch K2 is closed and clutch K1 is open, only the continuously variable transmission CVT is effective.

The switchover strategy between clutches K1 and K2 is the same as explained with reference to the previous exemplary embodiment according to FIGS. 6 to 8.

As can be seen, the speed ratio of the transmission according to FIG. 9 can be changed into the negative, so that it is only possible to switch between forward and reverse rotation of the output shaft with the aid of the continuously variable transmission CVT.

Fig. 11 shows a further embodiment of a suitable for the use of the inventive method, known per se gearbox. It is a so-called i² transmission, in which the spread of the continuously variable transmission CVT can be used both in one direction and in the other.

The input shaft E of the transmission shown in FIG. 11 is wetting stage via a first transla and a clutch K1 with a pulley S1 of the continuously variable transmission CVT and, via a third translation stage and a third clutch K3 to the second pulley S2. The first pulley S1 is connected via a clutch K2 and a second gear stage to the output shaft a. Likewise, the second belt pulley S2 is connected to the output shaft a via a clutch K4 and a fourth transmission stage.

According to FIG. 12 _, the clutches K1 and K4 are closed in the work area with a smaller overall ratio ω _e / ω _a and in the area with a larger overall ratio the clutches K2 and K3. The individual gear ratios are selected so that the gear ratios shown and in the translation 502 of the continuously variable transmission CVT the synchronization point results in which all clutches can be closed without differential speed. The same strategy as explained above applies to switching the clutches K1 and K4 to K2 and K3 and vice versa. Again, it is possible with the invention, by using simple friction clutches K1 to K4, to switch comfortably from one area to the other without any freewheels or claw clutches.

The method according to the invention as well as those operating under its use Multi-range gearboxes are suitable for diverse applications in which it with a simple construction to an even switchover arrives between the transmission paths. All types of drives can do this be, for example, for lathes, centrifuges, machine tools, etc.  

The method according to the invention and the method under are particularly suitable Use of this method working multi-range gearbox for motor vehicles witness.

FIG. 13 shows such an application example using the transmission according to FIG. 9.

The output shaft of the transmission a is connected to the driven wheels 521 of a vehicle via an axle differential 519 .

The input shaft e is connected via a dual-mass flywheel 523 to an internal combustion engine 525 , which is controlled by an accelerator pedal 527 .

The ring gear 13 works with a lockup clutch KL to stop the vehicle.

A programmable electronic control unit 529 are the input variables (dashed lines), the speed wa of the output shaft a, the torque M _{D of} the internal combustion engine, the speed N of the internal combustion engine 525 , which corresponds to the speed of the input shaft e, and the speed of the output shaft ω _a of the continuously variable transmission CVT. From these values, the electronic control unit 529 calculates values for controlling the translation of the continuously variable transmission CVT and for controlling the clutch K1 and K2 in accordance with a program stored in it, in accordance with the switching strategy between the two transmission paths of the transmission described with reference to FIGS. 7 and 8.

The control of the continuously variable transmission CVT and the clutches K1 and K2 can advantageously, as known per se, electronically-hydraulically take place, the actuating forces being applied hydraulically and the The size of the forces is determined electrically / electronically. The hydraulic parts can also be replaced by electric servomotors.

In the example shown, the input variables in the electronic control unit 529 are used to calculate whether the transmission is in overrun or in pulling operation, in order to thereby activate the corresponding shift program according to FIGS. 7 and 8. It goes without saying that a sensor can be provided in the drive train which directly determines whether there is a pulling or pushing operation. The respective differential speed at which the respective clutch is shifted and / or the shift speed can depend on the magnitude of the pulling or pushing torque.

The control unit 529 can be combined with an electronic engine control unit, so that the entire drive train control is integrated in one unit.

A method of changing the transmission paths of a multi-area gearbox with an input shaft (e), an output shaft (a) and two by means of at least one friction clutch (K1, K2) switchable over transmission paths between the input and output shaft, which transm pathways contain a continuously variable transmission (CVT) arranged in this way is that the differential speed of the respective open clutch at a certain th ratio of the continuously variable transmission O is characterized by that switching between the transmission paths at a difference speed of the clutch to be closed (K1 or K2), the Differential speed is such that a by closing the clutch transmitted between the input shaft (e) and the output shaft (a) Tension or shear torque is supported.

The invention further relates to the applications DE 19530929, DE 19530930, DE 19530931, DE 19530932, DE 19530933, DE 19530852, DE 19536747, DE 19536863, DE 19536864 and DE 19536865, their content expressly belongs to the disclosure content of the present application.  

The claims submitted with the application are drafted strikes without prejudice for obtaining further patent protection. The The applicant reserves the right to do so, so far only in the description and / or to claim disclosed features.

Relationships used in subclaims point to the others Training the subject of the main claim by the features of respective subclaim; they are not a waiver of education development of an independent, objective protection for the characteristics of the to understand related subclaims.

However, the subjects of these subclaims also form independent ones Inventions that are one of the items of the previous sub have independent design.

The invention is also not based on the embodiment (s) of the Be limited writing. Rather, numerous Ab are within the scope of the invention Changes and modifications possible, especially such variants, Elements and combinations and / or materials, for example, by Combination or modification of individual in connection with that in the general description and embodiments as well as the claims described features and elements contained in the drawings  ten or process steps are inventive and can be combined Characteristics of a new item or new procedural steps or process step sequences, also in so far as they are manufacturing, testing and Concern working procedures.

Claims (18)

1. Multi-range structure gear unit with a stepless gear be, such as conical pulley belt transmission or To roid gearbox, whose transmission range can be driven through more than once is and with other gears that the continuously variable transmission via we at least two alternately switchable clutches with changeable one adjustable transmissible torque can be switched, the switching process is initiated at differential speed and takes place grinding. 2. Gear unit with a multi-range structure, with a stepless gear be, such as conical pulley belt transmission or To roid gearbox, whose transmission range can be driven through more than once is by at least two clutches when a certain one is reached Gear ratio of the continuously variable transmission in the power flow Gear unit can be switched on and off, which also includes an actuator Direction reversal takes place and that after successful actuation  Reverse clutch closed before or after reaching Um switching point begins to close. 3. Gear unit according to one of claims 1 or 2, in which the stepless gear a superposition gear, like summing gear, with two inputs and one output in the torque flow net can be switched on and off, with alternating one input downstream gear stage can be switched on and off and the other Input is connected to the output part of the continuously variable transmission and via a further coupling the output part of the superposition ge drive, like summing gear, with the output part of the stepless Connect the gearbox directly or indirectly via a fixed gear ratio is bar and at least one clutch before or after reaching the order switching point begins to close. 4. Gear unit with a multi-range structure, in particular according to one of the Claims 1 to 3, in which a continuously variable transmission with a first and a second shaft is arranged in the torque flow, and the first and second shaft as the input or output shaft of the continuously variable transmission mutually by means of at least two couplings, in particular by means of four clutches, are switchable and the first and the second shaft with by means of gear stages with a gear input or gear  gear shaft are connectable, characterized in that a formwork tion of the first shaft as the input or output shaft and the two th shaft as input or output shaft before or after reaching one Switchover point begins at differential speed and takes place grinding. 5. Gear unit in particular according to one of the preceding claims che, characterized in that the couplings friction clutch lungs, such as friction clutches and / or magnetic powder clutches, are. 6. Gear unit with a multi-range structure, in particular according to one of the preceding claims, characterized in that a tax unit with sensors and / or other electronic units in Signalver is binding and based on the operating point the translation of the stu feneless gear and the transmissible torque of at least one drives clutch. 7. Gear unit according to claim 6, characterized in that the Control unit has a central computer unit. 8. Gear unit according to one of the preceding claims, characterized characterized in that control means for actuating and controlling the  Adjusting cylinder and / or pressure cylinder of the continuously variable transmission and the at least one clutch are present, which hydraulic, me can be operated mechanically and / or electrically. 9. Gear unit in particular according to one of the preceding claims che, characterized in that a range change of the stepless Gearbox by means of at least one slip-controlled clutch at differential speed. 10. Method for controlling or regulating a gear unit with multiple empire structure, with a continuously variable transmission and other transmissions, the gear ratio range of the continuously variable transmission is more than one can be driven through and via at least two clutches when reached a certain transmission ratio of the continuously variable transmission other gear units can be switched on and off in the power flow, whereby after the direction of actuation of the continuously variable transmission has been reversed closed clutch before or after reaching the switch point Closing begins. 11. The method in particular according to one of the preceding claims, characterized in that a range change of the stepless Ge  driven by means of at least one slip-controlled clutch Differential speed is initiated or takes place. 12. Procedure for changing the transmission paths of a multi-area gearbox with an input shaft (e), an output shaft (a) and two by means of at least one friction clutch (K1, K2) switchable over transmission paths between the input and output shaft, which Transmission paths include a continuously variable transmission (CVT) that does so is arranged that the differential speed of the respective open clutch with a certain ratio of the continuously variable transmission OP is there characterized in that the switch between the transfers paths at a differential speed of the clutch to be closed (K1 or K2) takes place, the differential speed being such that by closing the clutch between the input shaft (s) and the Output shaft (a) transmitted tensile or shear torque supported becomes. 13. The method according to claim 12, characterized in that at one Reduction of the ratio of the multi-range transmission in its train area of the open clutch before the differential speed O ge is reached is closed.   14. The method according to claim 12 or 13, characterized in that at a reduction in the translation of the multi-range transmission in the Thrust range the open clutch after passing through the difference speed 0 is closed. 15. The method according to any one of claims 12 to 14, characterized in net that with an increase in the translation of the multi-range transmission bes in the pull area the open clutch after passing through the dif reference speed O is closed. 16. The method according to any one of claims 12 to 15, characterized in net that with an increase in the translation of the multi-range transmission bes in the thrust area the open clutch before reaching the Diffe limit speed 0 is closed. 17. Multi-range transmission for performing the method according to one of claims 12 to 16, characterized in that a first transmission path between the input shaft (e) and the output shaft (a) contains a first clutch (K1) and a differential gear ( 5 , 7 ) That a second transmission path between the input shaft and the output shaft from the continuously variable transmission (CVT), whose output shaft is rotatably connected to a support member of the differential gear ( 5 , 7 ), and a second clutch (K2) between the output shaft and the output shaft contains, the first clutch (K1) being closed and the second clutch (K2) open in a first working range of the transmission with large gear ratios and the first clutch (K1) open in a second area with smaller gear ratios and the second clutch ( K2) is closed. 18. Multi-range transmission according to claim 17, characterized in that the differential gear is a planetary gear, the sun gear ( 17 ) is connected to the output shaft of the continuously variable transmission (CVT), the planet gear carrier ( 15 ) via the first clutch (K1) with the input shaft e is connected and the ring gear ( 13 ) with the output shaft (a) and via the second clutch (K2) is connected to the planet carrier.