METHOD FOR SUPPRESSING NOISES IN A DUAL CLUTCH TRANSMISSION FOR A MOTOR VEHICLE, AND DUAL CLUTCH TRANSMISSION FOR A MOTOR VEHICLE

Abstract

A method for suppressing noises in a dual clutch transmission, which has two partial transmissions and each partial transmission has at least two synchronizers, for a motor vehicle. A respective shaft of the respective partial transmission is to be synchronized by the respective synchronizer with a respective idler, which is arranged on the respective shaft and is associated with the respective synchronizer, of the respective partial transmission. To suppress noises, one of the synchronizers of one of the partial transmissions is actuated, while the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

Claims

1-10. (canceled)

11. A method for suppressing noises in a dual clutch transmission, which has two partial transmissions and each partial transmission has at least two synchronizers, for a motor vehicle, wherein a respective shaft of the respective partial transmission is to be synchronized by the respective synchronizer with a respective idler, which is arranged on the respective shaft and is associated with the respective synchronizer of the respective partial transmission, wherein to suppress noises, one of the synchronizers of one of the partial transmissions is actuated, while the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

12. The method as claimed in claim 11, wherein the one synchronizer of the one partial transmission is actuated in such a way that a rotationally-fixed connection of the idler, which is associated with the one synchronizer, of the one partial transmission with the shaft of the one partial transmission does not occur.

13. The method as claimed in claim 11, wherein the actuation of the one synchronizer is maintained during a time span.

14. The method as claimed in claim 13, wherein the time span is longer than one second, in particular longer than five seconds, and preferably longer than ten seconds.

15. The method as claimed in claim 13, wherein the actuation of the one synchronizer is ended after the time span, so that a second time span follows the time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler, which is associated with the other synchronizer of the one partial transmission, is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

16. The method as recited in claim 15, wherein the second time span is at least twice as long, in particular at least three times as long as the first time span.

17. The method as claimed in claim 13, wherein the time span is preceded by a further time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

18. The method as claimed in claim 17, wherein the further time span is at least twice as long, in particular at least three times as long as the first time span.

19. The method as claimed in claim 11, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

20. A dual clutch transmission for a motor vehicle, having at least one electronic processing unit, and having two partial transmissions, which each have a shaft, at least two synchronizers, and at least two idlers, which are arranged on the respective shaft and are associated with the respective synchronizers, wherein the respective idler is to be synchronized by the respective associated synchronizer with the respective shaft of the respective partial transmission, wherein the electronic processing unit is designed, in order to suppress noises, to actuate one of the synchronizers of one of the partial transmissions, while the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

21. The method as claimed in claim 12, wherein the actuation of the one synchronizer is maintained during a time span.

22. The method as claimed in claim 14, wherein the actuation of the one synchronizer is ended after the time span, so that a second time span follows the time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler, which is associated with the other synchronizer of the one partial transmission, is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

23. The method as claimed in claim 14, wherein the time span is preceded by a further time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

24. The method as claimed in claim 15, wherein the time span is preceded by a further time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

25. The method as claimed in claim 16, wherein the time span is preceded by a further time span, during which the one synchronizer is unactuated, the one partial transmission is activated, the other partial transmission is deactivated, and the idler which is associated with the other synchronizer of the one partial transmission is connected in a rotationally-fixed manner to the shaft of the one partial transmission.

26. The method as claimed in claim 12, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

27. The method as claimed in claim 13, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

28. The method as claimed in claim 14, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

29. The method as claimed in claim 15, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

30. The method as claimed in claim 16, wherein the actuation of the one synchronizer comprises that the one synchronizer, in particular at least one actuator of the one synchronizer, is activated, so that at least two friction partners of the one synchronizer are brought into mutual friction contact.

Description

[0038] In the figures:

[0039] FIG. 1 partially shows a schematic illustration of a dual clutch transmission according to the invention for a motor vehicle; and

[0040] FIG. 2 shows a diagram to illustrate the method according to the invention for operating the dual clutch transmission and in particular for suppressing noises in the dual clutch transmission.

[0041] The exemplary embodiment explained hereinafter is a preferred embodiment of the invention. In the exemplary embodiment, the described components of the embodiments each represent individual features of the invention to be considered independently of one another, which each also refine the invention independently of one another. The disclosure is therefore also to comprise combinations of the features of the embodiment other than those illustrated. Furthermore, the described embodiment can also be supplemented by further ones of the above-described features of the invention.

[0042] In the figures, identical reference signs each refer to functionally-identical elements.

[0043] FIG. 1 partially shows a schematic illustration of a dual clutch transmission 10 for a motor vehicle, in particular for an automobile, for example a passenger vehicle. In its completely produced state, the motor vehicle comprises a drive motor (not shown in the figures), which is designed, for example as an electric motor or as an internal combustion engine, in particular as a reciprocating piston engine. The drive motor has a driven shaft 12 partially recognizable in FIG. 1, which is designed, for example, as a crankshaft. The drive motor can provide at least one torque for driving the motor vehicle via the driven shaft 12. The motor vehicle additionally comprises an output shaft 14 partially recognizable in FIG. 1, onto which the torque provided by the drive motor via the driven shaft 12 can be transmitted via the dual clutch transmission 10. The feature that the drive motor provides or can provide the torque via the driven shaft 12 is to be understood to mean that the driven shaft 12 can provide or provides the torque.

[0044] The dual clutch transmission 10 has a first partial transmission 16 and a second partial transmission 18. The first partial transmission 16 has a first shaft 20, which is, for example an input shaft of the first partial transmission 16. Furthermore, the first partial transmission 16 has a second shaft 22, which is, for example an output shaft of the partial transmission 16. Overall, the dual clutch transmission 10 has, for example, seven forward gears for effectuating forward travel of the motor vehicle and at least or precisely one reverse gear for effectuating reverse travel. The forward gears and the reverse gears are gears, so that the dual clutch transmission 10 has a total of at least or precisely eight gears. In this case, the partial transmission 16 has four first ones of the gears, while the partial transmission 18 has four second ones of the gears. In other words, the respective partial transmission 16 or 18 forms four of the eight gears of the dual clutch transmission 10. A first of the gears is identified with G1 in FIG. 1, wherein a second of the gears is identified with G2 in FIG. 1. The gears G1 and G2 are formed by the partial transmission 16. It is apparent from FIG. 1 that the gear G1 and thus the partial transmission 16 has gearwheels 24 and 26, which mesh with one another or are engaged with one another via respective gear teeth. The gearwheels 24 and 26 are also referred to as wheels. The gearwheel 24 is a fixed wheel, which is permanently connected in a rotationally-fixed manner to the shaft 20. In contrast, however, the gearwheel 26 is an idler, which is rotatably arranged on the shaft 22 and therefore, in particular when the gearwheel 26 is not connected in a rotationally-fixed manner to the shaft 22, can be rotated in relation to the shaft 22 or rotates in relation to the shaft 22.

[0045] The gear G2 and thus the partial transmission 16 has gearwheels 28 and 30, which mesh with one another via respective gear teeth. The gearwheel 28 is a fixed wheel, since it is permanently connected in a rotationally-fixed manner to the shaft 20. However, the gearwheel 30 is an idler, since it is rotatably arranged on the shaft 22. The gearwheels 28 and 30 are wheels of the gear G2.

[0046] A shifting device 32 is associated with the gearwheel 26, by means of which the gearwheel 26 can be connected in a rotationally-fixed manner to the shaft 22. The shifting device 32 comprises a synchronizer 34, by means of which the gearwheel 26 can be synchronized with the shaft 22. The synchronizer 34 and thus the shifting device 32 comprises, for example, a shifting collar 36, also referred to as a sliding collar, which can be displaced in the axial direction of the shaft 22 and thus of the gearwheel 26 in relation to the gearwheel 26 and in relation to the shaft 22 between at least one coupling position and at least one decoupling position. For this purpose, the synchronizer 34 and thus the shifting device 32 comprise an actuator 38, by means of which the shifting collar 36 can be displaced.

[0047] Correspondingly, a shifting device 40 is provided in the gearwheel 30, by means of which the gearwheel 30 can be connected in a rotationally-fixed manner to the shaft 22. The shifting device 40 comprises a synchronizer 42, by means of which the gearwheel 30 can be synchronized with the shaft 22. The synchronizer 42 and thus the shifting device 40 comprise a shifting collar 44, also referred to as a sliding collar, which can be displaced in the axial direction of the shaft 22 and thus of the gearwheel 30 in relation to the shaft 22 and in relation to the gearwheel 30 between at least one coupling position and at least one decoupling position.

[0048] For this purpose, the synchronizer 42 and the shifting device 40 comprise an actuator 47, by means of which the shifting collar 44, also referred to as a sliding collar, can be displaced. In the respective decoupling position, the respective gearwheel 26 or 30 is decoupled from the shaft 22, so that the gearwheel 26 or 30 can rotate in relation to the shaft 22 or so that torque cannot be transmitted between the gearwheel 26 or 30 and the shaft 22. However, in the respective coupling position, the respective gearwheel 26 or 30 is connected in a rotationally-fixed manner, in particular in a formfitting manner, to the shaft 22, in particular via the respective synchronizer 34 or 42, so that torques can be transmitted between the shaft 22 and the gearwheel 26 or 30, in particular via the shifting device 32 or 40.

[0049] A third of the gears is identified by G3 in FIG. 1, and a fourth of the gears is identified by G3 in FIG. 1. The gears G3 and G4 are components of the partial transmission 18 or are formed by the partial transmission 18. The gear G3 and thus the partial transmission 18 comprise gearwheels 46 and 48, which mesh with one another via respective gear teeth. Moreover, the partial transmission 18 comprises a shaft 50, which is designed, for example as an input shaft of the partial transmission 18. Furthermore, the partial transmission 18 comprises a shaft 52, which is designed, for example as an output shaft of the partial transmission 18. The gearwheel 46 is a fixed wheel, which is permanently connected in a rotationally-fixed manner to the shaft 50. In contrast, the gearwheel 48 is an idler, which is rotatably arranged on the shaft 52. The gearwheels 46 and 48 are wheels of the gear G3.

[0050] The gear G4 and thus the partial transmission 18 furthermore comprise gearwheels 54 and 56, which mesh with one another via respective gear teeth and are wheels of the gear G4. The gearwheel 54 is a fixed wheel, which is permanently connected in a rotationally-fixed manner to the shaft 50. In contrast, the gearwheel 56 is an idler, which is arranged, in particular mounted, rotatably on the shaft 52.

[0051] A shifting device 58 is associated with the gearwheel 48, by means of which the gearwheel 48 can be connected in a rotationally-fixed manner to the shaft 52. The shifting device 58 comprises a synchronizer 60, by means of which the gearwheel 48 can be synchronized with the shaft 52. The synchronizer 60 and thus the shifting device 58 comprise a shifting collar 62, which can be displaced in the axial direction of the shaft 52 and thus of the gearwheel 48 in relation to the gearwheel 48 and in relation to the shaft 52 between at least one coupling position and at least one decoupling position. For this purpose, the synchronizer 60 and thus the shifting device 58 comprise an actuator 64, by means of which the shifting collar 62 can be displaced.

[0052] Accordingly, a shifting device 66 is associated with the gearwheel 56, by means of which the gearwheel 56 can be connected in a rotationally-fixed manner to the shaft 52. For this purpose, the shifting device 66 comprises a synchronizer 68, by means of which the gearwheel 56 can be synchronized with the shaft 52. The synchronizer 68 and thus the shifting device 66 comprise a shifting collar 70, which can be displaced in the axial direction of the shaft 52 and thus of the gearwheel 56 in relation to the shaft 52 and in relation to the gearwheel 56 between at least one coupling position and at least one decoupling position. For this purpose, the synchronizer 68 and the shifting device 66 comprise an actuator 72, by means of which the shifting collar 70 can be displaced. The respective actuator 38, 46, 64, or 72 is, for example, electrically and/or pneumatically and/or hydraulically operable or actuatable.

[0053] In the respective decoupling position of the respective shifting collar 62 or 70, the respective gearwheel 48 or 56 is decoupled from the shaft 52, so that torques cannot be transmitted between the respective gearwheel 48 or 56 and the shaft 52. In the respective coupling position of the shifting collar 62 or 70, however, the gearwheel 48 or 56 is connected in a rotationally-fixed manner via the shifting collar 62 or 70, in particular connected in a formfitting, rotationally-fixed manner, to the shaft 52, so that torques can be transmitted between the gearwheel 48 or 56 and the shaft 52, in particular via the respective synchronizer 60 or 68.

[0054] It is apparent from FIG. 1 that the gearwheel 26 is associated with the synchronizer 34 or vice versa. The gearwheel 30 is associated with the synchronizer 42 or vice versa. The gearwheel 48 is associated with the synchronizer 60 or vice versa, and the gearwheel 56 is associated with the synchronizer 68 or vice versa.

[0055] The dual clutch transmission 10 additionally also comprises an electronic processing unit 74, referred to as a control unit, which is coupled for signaling to the actuators 38, 46, 64, and 72, for example. The processing unit 74 can thus activate the actuators 38, 46, 64, and 72. By way of such an activation of the respective actuator 38, 46, 64, or 72, the electronic processing unit 74 can effectuate a displacement of the respective shifting collar 36, 44, 62, or 70 via the respective actuator 38, 46, 64, and 72. In particular, the electronic processing unit 74 can actuate the respective synchronizer 34, 42, 60, or 68 by activating the actuator 38, 46, 64, or 72. A or the actuation of the respective synchronizer 34, 42, 60, or 68 is to be understood to mean that at least two friction partners 76 and 78 of the respective synchronizer 34, 42, 60, or 68 are brought, in particular moved, into mutual contact, in particular into mutual friction contact. The friction partner 76 is co-rotatable here, for example with the respective shaft 22 or 52, wherein the respective friction partner 76 is preferably connected in a rotationally-fixed manner to the shaft 22 or 52. For example, the friction partner 76 is formed by the respective shifting collar 36, 44, 62, or 70 or is at least co-rotatable with the respective shifting collar 36, 44, 62, or 70.

[0056] The friction partner 78 is, for example co-rotatable with the respective idler. In particular, the respective friction partner 78 can be connected in a rotationally-fixed manner to the respective idler. The respective idler is at least or exclusively coupled frictionally, i.e. by friction with the shaft 22 or 52, due to the friction contact between the friction partners 76 and 78, wherein the friction contact is effectuated or set by actuating the respective synchronizer 34, 42, 60, or 68.

[0057] In the context of an engagement of the initially designed respective gear G1, G2, G3, or G4, due to the friction contact of a friction resulting therefrom between the friction partners 76 and 78, the respective idler can be synchronized with the respective shaft 22 or 52.

[0058] As is moreover apparent from FIG. 1, a first clutch 80 of the dual clutch transmission 10 is associated with the partial transmission 16, and a second clutch 82 of the dual clutch transmission 10 is associated with the partial transmission 18. The respective clutch 80 or 82 can be opened and closed. It is preferably provided that the clutch 82 is open while the clutch 80 is closed. While the clutch 82 is closed, the clutch 80 is preferably open. If the clutch 80 is closed while the clutch 82 is open, the partial transmission 16 is thus activated or active, while the partial transmission 18 is deactivated or passive. If the clutch 82 is closed while the clutch 80 is open, the partial transmission 18 is thus activated or active while the partial transmission 16 is deactivated or passive.

[0059] To now avoid undesired noises and thus be able to implement particularly advantageous noise behavior of the dual clutch transmission 10, in particular during its operation, in a particularly simple and cost-effective manner, a method for suppressing noises in the dual clutch transmission 10 is carried out. For example, to suppress noises in the dual clutch transmission 10, the synchronizer 42 of the partial transmission 16 is actuated while the partial transmission 16 is active, the partial transmission 18 is deactivated, and the gearwheel 26 is connected in a rotationally-fixed manner to the shaft 22.

[0060] The respective synchronizer 34, 42, 60, or 68 is designed, for example, as a friction cone synchronizer, via which the respective gear G1, G2, G3, or G4, also referred to as a gear step, is shiftable, i.e. can be shifted.

[0061] Since the gearwheel 26 is connected in a rotationally-fixed manner to the shaft 22 via the synchronizer 34 and thus via the shifting device 32, in the present case the gear G1 is a currently shifted or engaged travel gear, wherein, for example, all other shifting elements of the partial transmission 16 are in their neutral position or are not actuated, so that, for example, all other idlers of the partial transmission 16 are not connected in a rotationally-fixed manner to the shaft 22 or so that all other gears of the partial transmission 16 are disengaged or deactivated.

[0062] In the passive partial transmission 18, either no gear is shifted or, in particular precisely, one of the gears of the partial transmission 18 is preselected. In the exemplary embodiment illustrated in FIG. 1, the shifting collar 62 is in its decoupling position while the shifting collar 70 is in its coupling position. The gearwheel 56 is thus connected in a rotationally-fixed manner to the shaft 52, so that the gear G4 is preselected. However, the clutch 82 is open, so that the partial transmission 18 is deactivated. All other shifting elements are in their neutral position or are not shifted, for example, so that, for example, all other gears are disengaged or all other idlers of the partial transmission 18 are not connected in a rotationally-fixed manner to the shaft 52.

[0063] In particular, the synchronizer 42 is actuated in such a way that a rotationally-fixed connection of the gearwheel 30 to the shaft 22 does not occur. A, in particular exclusive, frictional coupling of the gearwheel 30 to the shaft 22 does occur due to the actuation of the synchronizer 42, however a relative rotation is permitted between the shaft 22 and the gearwheel 30, so that a rotationally-fixed coupling of the gearwheel 30 to the shaft 22 does not occur. A torque definable with respect to time and in its level can be generated by the actuation of the synchronizer 42, which is transmitted, for example, via the described friction contact between the friction partners 76 and 78 of the synchronizer 42 between the shaft 22 and the gearwheel 30. Undesired free oscillation of at least one or more regions of the dual clutch transmission 10 can thus be avoided, for example. The dual clutch transmission 10 can thus be designed with particularly low friction. At the same time, advantageous noise behavior can be implemented, since a noise-generating free oscillation or noise-generating oscillations can be actively suppressed by the active actuation of the synchronizer 42. In particular, optimized bearings and/or seals and/or an optimized clutch drag torque can be used in order to keep the internal friction of the dual clutch transmission 10 particularly low.

[0064] FIG. 2 shows a diagram to illustrate the method. A curve 84 plotted in the diagram illustrates the actuation of the synchronizer 42. It is apparent from FIG. 2 that the actuation of the synchronizer 42 is maintained during a first time span t1. After the time span t1, the actuation of the synchronizer 42 is ended, so that a second time span t2 follows the first time span t1. During the time span t2, the synchronizer 42 is unactuated, the partial transmission 16 is activated, the partial transmission 18 is deactivated, the gearwheel 26 is connected in a rotationally-fixed manner to the shaft 22, and the gearwheel 30 is decoupled from the shaft 22 or all idlers of the partial transmission 16 with the exception of the gearwheel 26 are decoupled from the shaft 22, so that they are not connected in a rotationally-fixed manner to the shaft 22.

[0065] Furthermore, it is apparent from FIG. 2 that the first time span t1 is preceded by a further, third time span t3, during which the synchronizer 42 is unactuated, the partial transmission 16 is activated, the partial transmission 18 is deactivated, and the gearwheel 26 is connected in a rotationally-fixed manner to the shaft 22 and the gearwheel 30 is decoupled from the shaft 22. The actuation of the synchronizer 42 thus only takes place temporarily and otherwise does not occur, whereby a particularly efficiency-favorable and thus energy-efficient operation can be ensured.