DE102008001200A1 - Multi-group transmission of a motor vehicle - Google Patents

Abstract

The invention relates to a multi-group transmission of a motor vehicle and a method for operating the same, with at least two arranged in a drive train transmission groups (2, 3, 3 ', 4), are provided in the means for switching an intermediate passage to reduce or avoid traction interruption during gear changes , So that the multi-group transmission is as simple and compact as possible in construction and as simple as possible in the control and comfortable and energy-saving in operation, between a drive motor and a transmission input (5) a two clutches (40, 41) comprehensive double clutch device (7) arranged wherein the one clutch (41) as a starting element for connecting a Arbeitsw3elle (6) of the drive motor with a transmission input shaft (17) and the other clutch (40) as a load switching element for switching an intermediate passage via a connection of the drive shaft (6) of the drive motor with one of the transmission groups (2, 3, 3 ', 4) at least partially passing through the transmission main shaft (30, 30') can be controlled.

Description

The The invention relates to a multi-group transmission of a motor vehicle and a method of operating the same in accordance with Preamble of claim 1 and the preamble of the claim 11th

Multi-group transmission consist of two or more mostly serially arranged gears, through the combination of which a high number of gears is feasible. Increasingly They are considered automated manual transmission, for example, consisting from an input group, a main group and a downstream group, designed. Such transmissions find particular in commercial vehicles Application, as it has a particularly fine grading with, for example 12 or 16 gears offer and have high efficiency. At a lower gear number, configurations are also only from a main group and an input group or a main group and a downstream group possible. They also draw Compared to manual transmissions by a high Ease of use and are compared to automatic transmissions particularly economical in manufacturing and operating costs.

Due to the design are subject to conventional multi-group manual transmission, such as all non-load manual or automated manual transmissions, a traction interruption when changing gear, as always the power flow is interrupted by the drive motor by opening a clutch, to set the gear engaged almost free, in a neutral position Gearbox and drive motor to synchronize to a connection speed and insert the target gear. This creates limitations in terms of mileage due to a loss of speed and optionally an increased fuel consumption. While the traction interruptions in passenger vehicles through losses in the driving dynamics usually only have a disruptive effect, for example in a sports-oriented Driving style, can be on heavy gradients on slopes the Delay driving speed such that an upshift in a desired target passage impossible and unwanted downshifts, Crawl or even additional startup comes.

As a remedy, solutions have already been proposed which reduce or completely avoid these traction interruptions. From the DE 10 2006 024 370 A1 The Applicant is such a multi-group automated transmission with a splitter group as an input gear, a main gear and a range group known as output or secondary gear. The construction of the known multi-group transmission with the input gear and the main gear allows the circuit of a direct gear as an intermediate gear during a gear change. For this purpose, a direct connection of an input shaft of the input gear with a main shaft of the main transmission is temporarily produced by means of a power shift clutch. As a result, the main transmission and the splitter group are fast-free, so that the gear engaged, synchronized the transmission and the target gear can be engaged while the start clutch remains engaged. The power-shift clutch transmits an engine torque to the transmission output, wherein a released dynamic torque is used at a speed reduction between the original gear and target gear to compensate for the traction power largely.

The Power shift clutch can be between the input gearbox and the main gearbox or arranged between the starting clutch and the input gear be. The start clutch and the power shift clutch are in any case separately formed and arranged and each one to actuate associated adjusting device. Possible Traction interruptions by switching the range gearbox between an upper and a lower gear range, for example a switching between the gear ranges "1 to 8" and "9 to 16 ", are not considered in it.

Another multi-group transmission is from the DE 10 2005 046 894 A1 the applicant known. This transmission comprises a main gear and a downstream range group. A drive motor can be connected to the engine-side end of a transmission input shaft via a starting or engine clutch. The transmission input shaft is in turn operatively connected to an output shaft of the transmission via a power shift clutch which is disposed within the range group. At this time, the other end of the transmission input shaft is connected to an input side of the power-shift clutch, and an output shaft of the main transmission is connected to an output side of the power-shift clutch. The range group is designed in planetary construction, wherein the output shaft is connected to a planet carrier and the output side of the power-shift clutch via a sun gear and a planet carrier supported by the planetary gear set is coupled to the output shaft. As a result, a traction interruption can be avoided in a switching operation of the main transmission. In order to avoid a traction interruption even with a range shift of the range group, the output side of the power-shift clutch can also be connected directly to the planet carrier and thus to the output shaft. As a result, switching operations that include a range shift, traction assisted. Also in this multi-group transmission are the starting clutch and the power-shift clutch are formed and arranged separately.

Furthermore, from the DE 10 2004 002 283 A1 the applicant a drive device with a transmission known, in which between a drive motor and a starting clutch, a shift brake clutch is arranged. The shift brake clutch is operatively connected via a secondary shaft and a gear set with a transmission output. In a gear change, the shift brake clutch is engaged while the start clutch opens, where supported by a transmitted via the shift brake torque on the transmission output and the drive torque of the drive motor is reduced. About the torque support at the transmission output thus the traction force reduction is reduced. At an upshift, the engine speed can be reduced by the same speed difference resulting from the gear change, which can shorten the shift pause until the end of the gear change and thus the Zugkrafteinbruch time. The manual transmission can be either a conventional manual or automated multi-step transmission as well as a basic transmission with a Nachschaltgruppe. For the shift brake clutch and the secondary shaft and the gear connection to the transmission output a corresponding additional design and cost is required. In addition, sufficient installation space for housing the shift brake clutch and in particular the auxiliary shaft and the additional gear set must be available. The tensile force entry can be effectively reduced, but hardly completely avoided, since the starting clutch must be opened when changing gears in any case.

From the non-prepublished patent application DE 10 2006 060 285.4 Applicant is aware of a method for minimizing traction interruption during upshifts of an automated manual transmission. A reduction of the total traction interruption between the time of occurrence of an upshift request to complete closing of the starting clutch after completion of the gear change is achieved essentially by the fact that the actual gear change, ie opening the start clutch, laying out the inserted original gear and inserting the target gear, without a Switching pause to wait for synchronization of transmission and drive motor speed is performed. Rather, after the fastest possible opening of the clutch, changing the gear ratio and inserting the target gear, the starting clutch so driven in the closing direction that on the one hand initially slipping moment between the drive motor and a transmission input shaft transmits, possibly without causing acceleration shocks, and on the other hand affects the engine torque , In this case, an overspeed of the drive motor, which results from the speed difference of the gears in the upshift, partially converted into drive power, which reduces the traction interruption when looking at the overall switching operation. By means of an existing transmission brake, the transmission input shaft can additionally be braked prematurely, ie overlapping with the opening of the starting clutch and the disengaging of the original gear, whereby the time required for the gear change can be further reduced. Also in this method, the starting clutch for changing gears is opened in any case. In the multi-group transmissions already mentioned, however, a gear change is possible without opening the starting clutch, as described at the outset, as a result of which an even more effective traction assistance can be achieved with a corresponding gear change of such a transmission.

In front In this background, the invention is based on the object Multi-group transmission, which largely traction interruption-free gear changes and to develop a process for its operation, that the multi-group transmission as simple and compact building in the construction and as simple as possible in the Control and comfortable as well as energy saving in operation.

The Solution to this problem arises from the features of independent claims, while advantageous Refinements and developments of the invention the dependent claims are removable.

Of the Invention is based on the finding that an intermediate to Avoidance of traction interruptions during the gear change of a multi-group transmission, with a common coupling device, on the one hand as a starting element serves and on the other hand switches a direct gear, particularly compact building and with a relatively low control effort in the drive train of a Such equipped motor vehicle can be implemented.

Accordingly, the invention is based on a multi-group transmission of a motor vehicle with at least two arranged in a drive train transmission groups, are provided in the means for switching an intermediate passage to reduce or avoid traction interruptions during gear changes. To achieve the object, the invention also provides that between a drive motor and a transmission input a two-clutch double clutch device is arranged, wherein the one clutch as a starting element for connecting a drive shaft the drive motor with a transmission input shaft and the other clutch as a load switching element for switching an intermediate passage via a connection of the drive shaft of the drive motor with a transmission groups at least partially passing through the transmission main shaft is controlled.

The Construction of the double clutch device according to the invention can be beneficial to the compact design of dual clutches as they already are in automated dual-clutch transmissions have proven to be successful. Accordingly, the dual clutch device as a friction clutch with input-side and output-side corresponding Friction partners, for example, as a wet multi-plate clutch formed be, wherein in the double clutch device according to the invention a connected to the drive shaft of the drive motor outer Input part of a first, serving as a load switching element inner Output part and a second, serving as a starting element inner Output part, radially surrounds. The second, facing the transmission input Output part is connected to the transmission input shaft, preferably as an outer hollow shaft is formed. The first, the Drive motor facing output part is connected to the transmission main shaft connected, preferably as a coaxial through the hollow shaft guided inner central shaft is formed.

These Arrangement is particularly advantageous in a multi-group transmission, especially for trucks, buses or special vehicles, applicable, in the three transmission groups with automated transmission control are arranged behind one another in the power flow, wherein the first transmission group as a two-speed splitter gearbox, with the transmission input shaft can be coupled, the second transmission group as a multi-speed, for example, three or four-speed main transmission, and the third transmission group as a downstream two-speed Range gear is formed. This can be the splitter gear and the main gearbox in a space-saving and weight-saving countershaft design with for example two countershafts, and the downstream Range gear in a planetary construction, with for example a inner sun gear, one guided by a planet carrier Planetary gear and an outer ring gear formed be.

The inventive arrangement is particularly space-saving, because the double clutch the function of the starting element and the load switching element united in one assembly. This also makes it possible that both clutches on a common adjusting device adjustable with an actuator, with the help of a single actuator are. The actuator can be considered an electromechanical, hydraulic or pneumatic actuator designed and over a Clutch / gearbox control unit be controlled.

at a simple and energy-saving actuator is the actuator as a sliding sleeve defined on the transmission input shaft formed, which, depending on the position on the transmission input shaft, an adjustment of the starting element associated spring-loaded first deflection lever and / or a load switching element associated spring-loaded second deflection lever causes, so that optionally one or the other of the two clutches or both clutches be brought into an open position or a closed position are.

There the load switching element of the double clutch the drive shaft directly with the transmission main shaft passing through the gearbox connects, corresponds to the intermediate passage at the output of the main gearbox in the ratio i = 1: 1 translated direct gear. If there is no overdrive with a ratio i <1, the intermediate passage thus corresponds to the highest at the same time Gear of the transmission, so that all upshifts in Gears with a ratio i> 1 with the splitter gearbox and the main gearbox traction-assisted can be performed. In principle, traction-assisted are also included Gear changes with gear jumps over two or more Gear steps possible.

additionally however, is an optionally downstream range group too consider. The usual downstream range transmissions in Planetenbauweise is when switching the gear range a traction interruption immanent. In an inventive arrangement the transmission main shaft can on the one hand with the switching devices of the Main gear, such as shift dogs in unsynchronized Main gears or clutches, shift brakes and synchronizers synchronized main gear, be coupled, and on the other hand with its output end with the sun gear of the downstream Range gearbox directly and with a transmission output shaft at the output the range gearbox operatively connected.

Consequently, in this arrangement, although switching operations of the splitter gear and the main transmission by the direct connection between the drive shaft and the transmission main shaft traction assisted. However, since there is only an operative connection between the transmission main shaft and the transmission output shaft, a switching of the range transmission, in which, for example, between a coupling of a ring gear with a fixed housing and a coupling of the ring gear with the planetary gear composites NEN gearbox output shaft is replaced, not zugkraftunterstützt. Therefore, in a gear change in which a Switching of the range gear is provided, the traction assistance reduced in the short term despite intermediate gear shift.

A advantageous extension of traction assistance the range gear can be achieved by making the intermediate gear as a direct gear of all consecutively arranged transmission groups is formed, wherein the transmission main shaft according to the invention directly is connected to the transmission output shaft. At another The arrangement according to the invention can therefore be the main transmission have an additional output shaft, which with the switching devices coupled to the main transmission and at its output end connected to a sun gear of a downstream range transmission is while the transmission main shaft without coupling through the main gear is passed. In this embodiment is the Zugkrafterhaltung by means of intermediate gear also at Gear range switching of the range gearbox without restrictions where. As a further embodiment is basically also a load-reversible design of the range gearbox possible d. H. a range gearbox in which a changing coupling of individual Components of the planetary gear without force flow interruption feasible is.

The The object initially posed is also achieved by a method of operation solved a multi-group transmission. Accordingly, the invention goes Furthermore, from a method for operating a multi-group transmission a motor vehicle, with at least two in a drive train arranged transmission groups, in which at a gear change to Reduction or avoidance of traction interruptions an intermediate course is switched. The invention provides for the solution of the asked Task also, that to carry out a gear change one disposed between a drive motor and a transmission input Double clutch device, in which the one clutch as a starting element and the other clutch is effective as a load switching element, such is controlled, that the load switching element at least partially is closed, that at least partially closed load switching element a direct gear as a counter to a traction interruption during the gear change Intermediate is switched, that in the consequence an inserted Original gear is designed at least approximately load-free, that the rotational speed of the drive motor at least partially closed Power shift element is synchronized to a connection speed of a target gear, and that when reaching the connection speed of the target gear is engaged and the load switching element is opened again.

The Double clutch thus allows a gear change in one automated multi-group transmission without the starting element inevitably has to be disengaged. Rather, that supports Load switching element preferably in the slip operation, the engine torque the drive motor during a Zughoch- or Zugrückschaltung at the transmission output, so that the main gear and the splitter gear of the multi-group transmission load-free and thus switchable while the engine speed of the drive motor the preselected target gear is adjusted. The switching elements of the main gear and the splitter gear can contribute to the production of the target translation Reaching the target gear speed, and then the load switching element, d. H. the intermediate clutch, fully open again become. Individual steps of the gear change can also overlap be performed.

By the momentum support at the output via the intermediate passage is the loss of speed of the vehicle during a train circuit largely reduced. In addition, shortened the switching time. Thus, the overall performance is increased. Since the drive train during the gear change by the Intermediate remains biased, also reduce vibrations. In addition, switching shocks are largely avoided.

This increases ride comfort and reduces wear on the claimed components in the drive train.

There the traction support basically at all Upshifts is available the deceleration for the synchronization of the rotating masses Gear changes take place via the intermediate passage. An optionally provided gear brake can thus be saved or eliminated, which is additionally cost-effective and space-saving as well as saving weight. Since the double clutch with a relative simple and energy-saving actuator technology is actuated, is the multi-group transmission according to the invention with Intermediate circuit thus also special cost operational.

to Clarification of the invention, the description is a drawing attached with two embodiments. in this shows

1 a transmission diagram of a multi-group transmission of a motor vehicle with a double clutch device for switching an intermediate gear,

2 the transmission scheme according to 1 with an associated torque flow with switched intermediate passage,

3 A second embodiment of a multi-group transmission with the double clutch device for switching an intermediate gear,

4 in the left half of the picture the double clutch on a larger scale in a first shift position in neutral position, and in the right half on a smaller scale the transmission scheme of 3 .

5 in the left half of the picture, the dual clutch in a second shift position while driving in a drive, and in the right half of the diagram, the transmission scheme with an associated torque flow,

6 in the left half of the picture, the double clutch in a third shift position while driving in the drive with additionally engaged intermediate gear, and in the right half of the picture the transmission diagram with an associated torque flow, and

7 in the left half of the picture, the dual clutch in a fourth shift position when driving in the intermediate gear without a drive, and in the right half of the picture the transmission diagram with an associated torque flow.

The 1 shows as a two-countershaft transmission 1 trained multi-group transmission with two parallel, rotatably mounted countershafts 8th . 9 and three successively arranged transmission groups 2 . 3 and 4 as it may be installed for example in the drive train of a truck. Such a transmission is inherently from the series ZF-AS Tronic and the aforementioned DE 10 2006 024 370 A1 the applicant known.

The first, at a transmission entrance 5 arranged transmission group 2 is designed as a two-speed splitter gear. The second transmission group 3 forms a three-speed main gearbox. As the third transmission group 4 is arranged downstream of a two-speed range transmission.

The splitter gear 2 has two gear constants i _k1 , i _k2 , each one on the first countershaft 8th and on the second countershaft 9 rotatably mounted fixed gear 10 . 12 respectively. 13 . 15 have, which with a loose wheel 11 respectively. 14 comb. For switching the gear constants i _k1 , i _k2 is a switching device 16 , advantageously with synchronization, arranged over which the idler gears 11 respectively. 14 optionally non-rotatably with a transmission input shaft 17 are connectable.

The main gearbox 3 has three forward gears i ₁ , i ₂ and i ₃ and one reverse gear i _R. The first gear and the second gear each include two fixed wheels 18 . 20 respectively. 21 . 23 and a loose wheel 19 respectively. 22 , The 3rd gear is in common with the second gear constant i _{k2 of} the splitter _gearbox 2 realized. The reverse gear includes two fixed wheels 24 and 28 , a central idler wheel 26 and two rotatably mounted intermediate wheels 25 and 27 , on the one hand with the respective fixed wheel 24 respectively. 28 and on the other hand with the central idler gear 26 comb. To shift the 1st gear and the reverse gear is a switching device 29 provided with shift dogs, via which the associated idler gears 19 respectively. 26 Optionally non-rotatable with a transmission mainshaft 30 are connectable. Another switching device 31 with shift dogs is arranged to shift the 2nd gear and 3rd gear. This switching device 31 optionally connects the associated idler gears 14 respectively. 22 rotatably with the transmission main shaft 30 ,

The range gearbox 4 is designed as a planetary gear. Therein is a planetary gear set 32 from a planet carrier 33 guided. The planet wheels 32 comb on the one hand with a central sun gear 34 and on the other hand with an outer ring gear 35 , The sun wheel 34 is with the transmission main shaft 30 connected at the end remote from the drive motor end. The planet carrier 33 is with a transmission output shaft 36 connected. For switching the range gearbox 4 is a switching device 37 , advantageously with synchronization, arranged. This switching device 37 optionally connects the ring gear 35 with a fixed housing 38 or with the planet carrier 33 or with the transmission output shaft 36 ,

From the combination of gear groups 2 . 3 and 4 of the illustrated transmission scheme result in a total of 2 × 3 × 2 = 12 gears. The power flow of the transmission 1 Branches after a shift sequence, in which, starting with the 1st gear in the main transmission 3 , initially alternating the splitter gearbox 2 and the main gearbox 3 2 × 3 = 6 gears of a lower gear range "1. Gear to 6th gear "to be switched. When the sixth gear is reached, the gearbox shifts 4 around, and it's going to be the main gearbox again 3 and the splitter gear 2 alternately switched through, so that in turn 2 × 3 = 6 gears, but now in an upper gear range "7. Gear to 12th gear ", to be switched. Because the upstream splitter gear 2 also the reverse gear ratio i _{R is} aufschaltbar, there are also two reverse gears available.

Between a drive shaft 6 a non-illustrated drive motor and the transmission input 5 is a double clutch device according to the invention 7 arranged ( 4 .). This double clutch device 7 has an outer cylindrical input part 39 with driving friction disc ben 56 . 64 on that with the drive shaft 6 rotatably connected. The entrance part 39 surrounds two inner output parts 40 . 41 with driven friction discs 55 . 63 ,

The first, the drive shaft 6 facing output part 40 is formed as a load switching element for switching an intermediate passage. This power switch element 40 is with the through the gear 1 guided transmission main shaft 30 rotatably connected.

The second, the transmission input 5 facing output part 41 is designed as a starting element. This starting element 41 is with the with the switching device 16 of the splitter gear 2 Coupling transmission input shaft 17 rotatably connected. The transmission input shaft 17 is formed as a hollow shaft through which the transmission main shaft 30 passed through.

2 illustrates the torque flow (dashed lines) of the intermediate gear of the transmission 1 , The load switching element 40 the double clutch 7 is closed, leaving the drive shaft 6 directly with the transmission main shaft 30 is frictionally connected. The starting element 41 on the other hand is open, so that only the load switching element 40 transmits a drive torque. The transmitted torque runs over the range gearbox 4 to the transmission output shaft 36 from where it is transmitted to the non-illustrated driven vehicle wheels. The moment flux of the intermediate passage corresponds to a direct ratio of the splitter gearbox 2 and the main gearbox 3 with an additional downstream transmission of the range gearbox 4 ,

The 3 shows another two-countershaft transmission 1' in which a main transmission 3 ' in addition an output shaft 42 having. The output shaft 42 is formed as a hollow shaft on which the switching devices 29 ' . 31 ' of the main gearbox 3 ' are arranged. To shift the first gear and the reverse gear are the associated idler gears 19 respectively. 26 optionally non-rotatable with the output shaft 42 rotatably connected. To the circuit of the 2nd gear and the 3rd gear are accordingly the loose wheels 14 respectively. 22 optionally non-rotatable with the output shaft 42 rotatably coupled. The output shaft 42 is in turn at her pointing away from the drive motor end with the sun gear 34 of the range gearbox 4 connected. The transmission main shaft 30 ' is central to the output shaft 42 and the range gearbox 4 performed and directly with the transmission output shaft 36 connected. Otherwise, the gear is 1' identical to the previously described gearbox 1 , A corresponding moment flow of the intermediate passage is in the right half of 7 clarified. The torque flow of the intermediate gear corresponds to a direct ratio of the overall transmission 1' ,

The 4 to 7 show the double clutch device 7 with an adjusting device according to the invention 43 for their operation. In these figures, in each case a switching position of the adjusting device in the left half of the picture 43 and in the right half of the picture an associated torque flow of the gearbox 1' in the embodiment with fully performed transmission mainshaft 30 ' shown.

First, the adjusting device 43 described. The adjusting device 43 has a trained as a sliding sleeve actuator 44 on which is on the transmission input shaft 17 is mounted axially displaceable. The sliding sleeve 44 is by means of an actuator not further explained 45 displaceable in defined axial positions. Furthermore, the starting element 41 a bellcrank 47 assigned to a support point 53 a holder 49 is supported. The lever 47 is on the one hand by a designed as a compression spring spring means 48 applied, which is between the lever 47 and the holder 49 supported, and on the other hand with one end to the one leg 65 a right-angled, axially displaceable connecting part 51 in a suspension point 54 suspended. This thigh 65 is parallel to the transmission input shaft 17 aligned and carries a friction disk 52 , The other thigh 66 of the connecting part 51 is perpendicular to the transmission input shaft 17 aligned and is from the sliding sleeve 44 in the direction of the transmission input 5 acted upon.

The suspension point 54 of the reversing lever 47 is designed such that the lever 47 with a pivoting movement around the support point 53 the connecting part 51 in the axial direction entrains, wherein the lever 47 also around the suspension point 54 pivoted.

The starting element 41 carries a drivable friction disc 55 that between the at the connecting part 51 arranged friction disc 52 and the at the clutch input part 39 arranged driving friction disc 56 circulates.

In analogous manner to the load switching element 40 a bellcrank 50 assigned to a support point 58 a holder 57 rotatably supported. The lever 50 is at one end in a suspension point 60 on a linearly sprung, axially displaceable straight connecting part 59 attached, which is a friction disc 61 having. At the other end of the bellcrank 50 is, opposite, a spring means 62 arranged, located between the lever 50 and a clutch housing 46 supported. The load switching element 40 carries a drivable friction disc 63 that between the at the connecting part 59 arranged friction disc 61 and the at the clutch input part 39 arranged driving friction disc 64 circulates.

In the closed state of the load switching element 40 or of the starting element 41 are the corresponding friction discs 61 . 63 . 64 respectively. 52 . 55 . 56 pressed against each other. Depending on the travel and contact pressure friction can be established or slip generated. The sliding sleeve 44 exerts on actuation of the dual clutch device 7 depending on their axial position on one of the two lever 47 . 50 and / or the vertical leg 66 of the connecting part 51 a restoring force, where they, depending on Beaufschlagungs position and Beaufschlagungs direction, via a collar the one lever 47 pushes away, the other lever 50 or the connecting part 51 however, engages behind.

Without an influence of the sliding sleeve 44 or of the actuator 45 is the starting element 41 closed by spring force. The starting element 41 is therefore of the "normally closed type". By contrast, the load switching element 40 opened by spring force, ie from the "normally open type" ( 5 ). Accordingly, the actuator becomes 45 activated to change this initial state, wherein the spring means 48 . 62 and the sliding sleeve 44 alternately the lever 47 . 50 actuate.

The operation of the actuator 43 will be in the 4 to 7 illustrated by four possible switching positions.

4 shows the dual clutch device 7 in its neutral position, ie both the starting element 41 as well as the load switching element 40 are opened. To do this, place the sliding sleeve 44 by a corresponding displacement in the direction of the drive motor against the action of the spring 48 the bellcrank 47 of the starting element 41 around, leaving the connecting part 51 in the direction of the transmission input 5 is moved and the friction disc 55 of the starting element 41 from the driving friction disc 56 solves. The load switching element 40 is opened by spring force, with the associated compression spring 62 the bellcrank 50 pivoted so that the connecting part 59 in the direction of the transmission input 5 is reset, and the load switching element 40 from the driving friction disc 64 is solved.

5 shows a shift position in normal driving with an engaged drive, for example, the 7th gear, with closed starting element 41 and open power switch element 40 , This switching position corresponds to the already mentioned starting position of the dual clutch device 7 without the action of the sliding sleeve 44 , In this case, the load switching element 40 still open by spring force. The sliding sleeve 44 is in the direction of the transmission input 5 pushed back so far that now the spring 48 of the starting element 41 the bellcrank 47 of the starting element 41 flips so that the connecting part 51 shifted towards the drive motor, causing the friction disc 52 of the connecting part 51 the starting element 41 or its friction disc 55 against the driving friction disc 56 presses and thus the frictional engagement of the starting element 41 is made. In the right half of the picture, the torque flow of the engaged 7th gear is in the transmission 1' shown highlighted by dashed lines. This branches over the input _constant i _{k1 of} the splitter gearbox 2 i, the 1st gear i, of the main gearbox 3 and the upper gear group of the range gearbox 4 to the transmission output shaft 36 ,

6 shows a switching position while driving with inlaid driving gear and additionally engaged intermediate gear. This corresponds to a snapshot at the beginning of a gear change. Here is the starting element 41 still closed by spring force. The load switching element 40 is engaged by means of the actuator, wherein the sliding sleeve 44 just in the direction of the transmission input 5 shifted is that the bellcrank 50 is pivoted against the spring force, so that the connecting part 59 is adjusted in the direction of the drive motor and the associated friction disc 61 the friction disc 63 of the load switching element 40 against the driving friction disc 64 pressed. About the closed or partially closed load switching element 40 is the drive shaft 6 of the drive motor with the transmission main shaft 30 ' and thus with the transmission output shaft 36 directly coupled, so the direct gear switched.

The illustrated 12-speed transmission scheme 1' may for example have a gradation, in which the 10th gear is the direct gear and thus the intermediate gear and two overdrives are provided. In the force flow diagram, in addition to the torque flow of the drive gear, which is located above the transmission 1' Branches, in addition, the torque flow of the direct gear, the rectilinear the gearbox 1' interspersed, highlighted by dashed lines.

7 finally shows a switching position when driving in the intermediate passage or direct gear with the starting element open 41 , The load switching element 40 So it is still closed. To open the starting element 41 is the sliding sleeve 44 one compared to 6 larger travel in the direction of the transmission input 5 moved so that the sliding sleeve 44 now the connecting part 51 or its legs 66 engages behind and in the direction of transmission input 5 against the force of the spring 48 entrains, which in turn the friction disc 55 of the starting element 41 from the driving friction disc 56 solves. In the force flow diagram, accordingly, only the torque flow of the direct gear is rectilinear, the gearbox 1' interspersed, present.

The gear 1 . 1' with the double clutch device 7 allows the implementation of a method according to the invention, in which a transition is switched to a transition to the Zugkrafterhaltung an intermediate gear. At the in 1 illustrated transmission scheme 1 the intermediate gear is designed as a direct gear plus range gear ratio. On the other hand, in the case of 3 illustrated transmission scheme 1' the intermediate passage designed as a direct gear including range gearbox.

If a gear change, for example an upshift, is signaled to a driver request or according to a shift strategy while driving, then the intermediate gear is engaged by engagement of the load shift element acting as an intermediate clutch 40 switched on, causing the main gearbox 3 respectively. 3 ' and the splitter gear 2 load-free and thus switchable without the starting element 41 is disengaged. The now switchable main gearbox 3 respectively. 3 ' is then switched to its neutral position.

The intermediate clutch 40 is driven during the switching operation for the realization of a slip operation, so that they subsequently the torque of the drive motor via the operative connection of the transmission output shaft 36 is supported to the roadway, wherein the engine speed is lowered to a synchronous speed of a target gear. The released during the speed reduction torque is thus used to compensate for the tensile force intrusion during the neutral position. As soon as the synchronous speed is reached, the target gear becomes the main gearbox 3 respectively. 3 ' and, if necessary, the splinter group 2 connected via an intermediate neutral position in the new or previous, the shift sequence or the selected gear jump corresponding gear constant. Subsequently, the intermediate clutch 40 reopened and the traction assisted gear change completed.

1, 1'

Two-countershaft transmission

2

split transmission

3, 3 '

main gearbox

4

range transmission

5

transmission input

6

drive shaft

7

Dual clutch assembly

8th

Countershaft

9

Countershaft

10

fixed gear

11

Losrad

12

fixed gear

13

fixed gear

14

Losrad

15

fixed gear

16

switching device

17

Transmission input shaft

18

fixed gear

19

Losrad

20

fixed gear

21

fixed gear

22

Losrad

23

fixed gear

24

fixed gear

25

idler

26

Losrad

27

idler

28

fixed gear

29 29 '

switching device

30 30 '

Transmission main shaft

31 31 '

switching device

32

planetary gear

33

planet carrier

34

sun

35

ring gear

36

Gearbox output shaft

37

switching device

38

casing

39

Clutch input part

40

Load switching element

41

starting element

42

output shaft

43

setting device

44

actuator

45

actuator

46

clutch housing

47

Umlenkhebel

48

spring means

49

bracket

50

Umlenkhebel

51

connecting part

52

friction

53

support point

54

suspension point

55

friction

56

friction

57

bracket

58

support point

59

connecting part

60

suspension point

61

friction

62

spring means

63

friction

64

friction

65

leg

66

leg

i _k1

Splitter gear-gear constant

i _k2

Splitter gear-gear constant

i ₁

Main transmission gear

i ₂

Main transmission gear

i ₃

Main transmission gear

i _R

Main gear reverse

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102006024370 A1 [0004, 0034]
• - DE 102005046894 A1 [0006]
• DE 102004002283 A1 [0007]
• - DE 102006060285 [0008]

Claims (12)

Multi-group transmission of a motor vehicle, with at least two transmission groups arranged in a drive train (US Pat. 2 . 3 . 3 ' . 4 ), in which means are provided for switching an intermediate gear to reduce or avoid traction interruptions during gear changes, characterized in that between a drive motor and a transmission input ( 5 ) a two clutches ( 40 . 41 ) comprehensive double coupling device ( 7 ), wherein the one clutch ( 41 ) as a starting element for connecting a drive shaft ( 6 ) of the drive motor with a transmission input shaft ( 17 ) and the other clutch ( 40 ) as a load switching element for switching an intermediate passage via a connection of the drive shaft (FIG. 6 ) of the drive motor with one of the transmission groups ( 2 . 3 . 3 ' . 4 ) at least partially penetrating transmission main shaft ( 30 . 30 ' ) is controllable. Multi-group transmission according to claim 1, characterized in that both clutches ( 40 . 41 ) via a common regulatory body ( 43 ) with an actuating element ( 44 ) by means of a single actuator ( 45 ) are adjustable. Multi-group transmission according to claim 2, characterized in that the actuating element ( 44 ) as one on the transmission input shaft ( 17 ) defined sliding sliding sleeve is formed, which, depending on the position on the transmission input shaft ( 17 ), an adjustment of the starting element ( 41 ) associated spring-loaded first deflection lever ( 47 ) and / or a load switching element ( 40 ) associated spring-loaded second deflection lever ( 50 ), so that either one or the other of the two clutches ( 40 . 41 ) or both couplings ( 40 . 41 ) can be brought into an open position or a closed position. Multi-group transmission according to one of claims 1 to 3, characterized in that the double clutch device ( 7 ) as a friction clutch with corresponding friction partners ( 52 . 55 . 56 ; 61 . 63 . 64 ) is formed, in which a with the drive shaft ( 6 ) of the drive motor connected outer input part ( 39 ) a first, serving as a load switching element inner output part ( 40 ), and a second, serving as a starting element inner output part ( 41 ), wherein the first output part ( 40 ) with the transmission main shaft ( 30 . 30 ' ) and the second output part ( 41 ) with the transmission input shaft ( 17 ) connected is. Multi-group transmission according to one of claims 1 to 4, characterized in that the transmission input shaft ( 17 ) as an outer hollow shaft and the transmission main shaft ( 30 . 30 ' ) as one through the transmission main shaft ( 30 . 30 ' ) coaxially guided inner central shaft is formed. Multi-group transmission according to one of claims 1 to 5, characterized in that three transmission groups ( 2 . 3 . 3 ' . 4 ) are arranged one behind the other in the power flow, wherein the first transmission group ( 2 ) as a two-speed splitter gearbox with the transmission input shaft ( 17 ), the second transmission group ( 3 . 3 ' ) as a multi-speed main transmission, and the third transmission group ( 4 ) is formed as a downstream two-speed range transmission. Multi-group transmission according to claim 6, characterized in that the splitter transmission ( 2 ) and the main transmission ( 3 . 3 ' ) are formed in a Vorgelegebau way, and that the downstream range transmission ( 4 ) is formed in a planetary construction. Multi-group transmission according to one of claims 1 to 7, characterized in that the intermediate passage as a direct gear of the splitter gear ( 2 ) and the main transmission ( 3 ), wherein the transmission main shaft ( 30 ) with at least one switching device ( 29 . 31 ) of the main transmission ( 3 ) is coupled, and with its output end with a sun gear ( 34 ) of a downstream range transmission ( 4 ) directly and with a transmission output shaft ( 36 ) via the range gear ( 4 ) is operatively connected. Multi-group transmission according to one of claims 1 to 7, characterized in that the intermediate passage as a direct gear of all successively arranged transmission groups ( 2 . 3 ' . 4 ), wherein the transmission main shaft ( 30 ' ) directly to the transmission output shaft ( 36 ) and that the main transmission ( 3 ' ) an output shaft ( 42 ) having at least one switching device ( 29 ' . 31 ' ) of the main transmission ( 3 ' ) and at its output end with a sun gear ( 34 ) of a downstream range transmission ( 4 ) connected is. Multi-group transmission according to one of the claims 1 to 9, characterized in that a lastumschaltbares range gear is provided as a rear-group. Method for operating a multi-group transmission of a motor vehicle, having at least two transmission groups arranged in a drive train (US Pat. 2 . 3 . 3 ' . 4 ), in which an intermediate gear is switched during a gear change to reduce or avoid traction interruptions, characterized in that for carrying out a gear change between a drive motor and a transmission input ( 5 ) arranged double clutch device ( 7 ), at the one clutch ( 41 ) as a starting element and the other coupling ( 40 ) is operated as a load switching element, is driven such that the load switching element ( 40 ) is at least partially closed, that at least partially closed load switching element ( 40 ) a direct gear as a traction interruption during gear change counteracting intermediate passage is switched, that in the consequence an inserted original gear is designed at least approximately load-free that the rotational speed of the drive motor at least partially closed load switching element ( 40 ) is synchronized to a connection speed of a target gear, and that when reaching the connection speed of the target gear is engaged and the load switching element ( 40 ) is opened again. A method according to claim 11, characterized in that the load switching element ( 40 ) is at least temporarily driven to perform a slip operation in a gear change.