Vehicle with dual clutch transmission
By pre-operating the shift controller in a dual-clutch transmission, the gear engagement process and the clutch disengagement process overlap, solving the problem of long shifting time in existing technologies and achieving a more efficient shifting process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AUDI AG
- Filing Date
- 2025-11-07
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, dual-clutch transmissions have a relatively long switching time, especially since the gear engagement process only begins after the clutch disengagement process is completed, resulting in a longer overall switching time.
By pre-controlling the switching controller through the evaluation module, the gear engagement process begins before the clutch disengagement process ends, and the gear engagement process and the clutch disengagement process overlap in time. The clutch disengagement process is divided into two stages: transmitting torque and not transmitting torque. The gear engagement process is also divided into two stages: not transmitting torque and transmitting torque. The gear engagement stage without torque begins in advance.
The total switching time is significantly shortened by completing the target gear switching within the overlapping time interval of the clutch disengagement process and gear engagement process, thereby improving switching efficiency.
Smart Images
Figure CN122014847A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a vehicle having a dual-clutch transmission according to the preamble of claim 1 and a method for engaging a target gear in such a dual-clutch transmission according to claim 8. Background Technology
[0002] In this type of dual-clutch transmission, the first sub-transmission can be activated by operating the corresponding first disengagement clutch, and the second sub-transmission can be activated by operating the corresponding second disengagement clutch. Each sub-transmission has at least one synchronizing engagement device through which gears can be engaged. During driving operation, subsequent shifts are automatically performed by an electronic shift controller to shift to the target gear. In this regard, to prepare for subsequent shifts, the shift controller engages the target gear in the passive, i.e., inactive sub-transmission during gear engagement. Before gear engagement, an evaluation module checks whether the disengagement clutch of the passive sub-transmission is engaged. This engagement of the disengagement clutch in the passive sub-transmission occurs under specific circumstances, such as during the determination of the contact point, which defines the position of the disengagement clutch actuator, from which the clutch air gap is exhausted and torque is transmitted through the disengagement clutch.
[0003] In the case of a passively engaged sub-transmission disengagement clutch, the evaluation module manipulates the clutch controller to ensure complete disengagement of the disengagement clutch during the disengagement process, thereby guaranteeing the engagement of the target gear without torque. Therefore, the preparation time for the subsequent shift consists of the disengagement clutch disengagement process and the gear engagement process. In the prior art, the gear engagement process only begins after the disengagement clutch disengagement process has ended. Therefore, in the prior art, the time until the final start of the subsequent shift is correspondingly longer.
[0004] Document DE 10 2006 060 285 A1 discloses a method for minimizing traction interruption during upshifting in an automatic transmission. When an upshift signal is present, the control unit disengages the friction clutch as quickly as possible, then, either in overlapping time, disengages the previously engaged gear as quickly as possible and engages the target gear. After engaging the target gear, the friction clutch is adjusted such that it transmits torque between the drive motor and the input shaft of the automatic transmission within its slip range, while the torque generated by the drive motor is actively influenced.
[0005] Document DE 10 2016 202 286 A1 discloses a method of operating a dual-clutch transmission for a motor vehicle, wherein a first clutch operates in engagement, thereby driving a first transmission branch engaged in the current actual gear, and in a pre-selection phase for switching to a set gear, a set gear is engaged in a second transmission branch, and a clutch hydraulic system is filled in the second clutch, thereby engaging the second clutch. Summary of the Invention
[0006] The purpose of this invention is to provide a vehicle with a dual-clutch transmission that reduces the total switching time compared to the prior art.
[0007] This objective is achieved by the features of claim 1 or 8. Improvements to the invention are disclosed in the dependent claims.
[0008] This invention relates to a dual-clutch transmission, wherein a first sub-transmission can be activated by operating a corresponding first disengagement clutch, and a second sub-transmission can be activated by operating a corresponding second disengagement clutch. Each sub-transmission has at least one synchronizing engagement device through which a gear can be engaged. During driving operation, a subsequent shift is automatically performed by an electronic shift controller to shift to the target gear. In this regard, to prepare for the subsequent shift, the shift controller causes the target gear to be engaged in the passive, i.e., inactive sub-transmission during gear engagement. Before the gear engagement process, an evaluation module checks whether the disengagement clutch of the passive sub-transmission is engaged. This engagement of the disengagement clutch in the passive sub-transmission occurs in specific situations, such as during the determination of the contact point, which defines the actuator position of the disengagement clutch from which the clutch air gap is exhausted and torque is transmitted through the disengagement clutch.
[0009] With the passive sub-transmission's disengagement clutch engaged, the evaluation module manipulates the clutch controller to ensure complete disengagement of the disengagement clutch during the disengagement process, thereby guaranteeing the target gear's torque engagement. Therefore, the duration for preparing for the subsequent shift consists of the disengagement clutch disengagement process and the gear engagement process.
[0010] According to the characteristic portion of claim 1, in order to shorten the preparation time, the following measures are taken: the evaluation module manipulates the switching controller so that the gear engagement process begins before the clutch disengagement process ends. Therefore, according to the present invention, the clutch disengagement process and the gear engagement process overlap in time over an overlapping time interval, thereby reducing the overall switching time compared to the prior art.
[0011] This invention is based on the understanding that the clutch disengagement process can be divided into a torque-transmitting disengagement stage until the contact point is reached, and a torque-less disengagement stage after the contact point is reached, during which a torque-less clutch air gap is established in the clutch. According to this invention, the evaluation module controls the shift controller such that the gear engagement process begins at least during the torque-less disengagement stage of the clutch disengagement process.
[0012] Alternatively and / or additionally, the present invention is based on the understanding that the gear engagement process can also be divided, that is, divided into a torque-less engagement phase and a torque-transmitting engagement phase, in which a synchronous frictional torque is established in the gear shifting assembly during the torque-transmitting engagement phase. In this context, the evaluation module can manipulate the shifting controller such that the gear engagement process begins before reaching the contact point in the disengagement clutch of the passive sub-transmission. Therefore, the contact point of the disengagement clutch of the second sub-transmission occurs at the moment when the torque-less engagement phase of the gear engagement process has already taken place. The torque-transmitting engagement phase of the gear engagement process begins after reaching the contact point.
[0013] The evaluation module is signal-connected to a clutch sensor device that detects the clamping pressure or related parameters acting in the disengagement clutch of the passive sub-transmission. The evaluation module can determine the contact point of the disengagement clutch based, in particular, the detected clamping pressure and the corresponding torque transmission. The contact point defines the actuator position of the disengagement clutch from which torque is transmitted through the disengagement clutch when the clamping pressure increases, and where a clutch air gap with no torque appears when the clamping pressure decreases.
[0014] Upon successful engagement of the target gear, i.e., after the preparation period has ended, a subsequent shift can be performed. During this shift, the evaluation module manipulates the clutch controller to engage the disengagement clutch of the still-passive sub-transmission. Simultaneously, the clutch controller disengages the disengagement clutch of the active sub-transmission, thereby ending the subsequent shift.
[0015] In one specific embodiment, the vehicle power unit, particularly the internal combustion engine, is alternately connected to a first or second drive shaft via a force output shaft through two disengageable clutches of a dual-clutch transmission, which can switch under load. The first or second sub-transmission can be activated accordingly via these two drive shafts. Fixed gears and floating gears are arranged on the two drive shafts and, particularly, on the driven shaft parallel to their axes, forming gear sets to create gear levels. Within the gear sets, the floating gears can be connected to the corresponding drive shaft by means of a gear shifting element.
[0016] The gear shifting element in a dual-clutch transmission can preferably be implemented as a synchronously engaging device that can be axially displaced on one or both sides. This synchronously engaging device has a sleeve that can be axially displaced within a shifting displacement by a shift fork. The shift fork can be displaced within an adjusting displacement by, for example, a hydraulically operated servo actuator. The internal teeth of the sleeve are supported on corresponding external teeth of a sleeve carrier arranged on the drive shaft in a manner that prevents relative rotation. The sleeve can be moved by the shift fork to a shifting position in which the internal teeth of the sleeve engage both with the external teeth of the sleeve carrier and with the external teeth of the floating gear clutch. Attached Figure Description
[0017] The embodiments are described below with reference to the accompanying drawings. Wherein:
[0018] Figure 1 The transmission structure of the powertrain of a vehicle with a built-in dual-clutch transmission is shown.
[0019] Figure 2 A graph is shown to illustrate the time history of the preparation for a subsequent switchover according to a comparative example not covered by this invention.
[0020] Figure 3 It shows the corresponding Figure 2 A schematic diagram illustrating the timeline of the preparation process for a subsequent switchover according to the present invention. Detailed Implementation
[0021] exist Figure 1 The diagram illustrates the transmission structure of a motor vehicle's powertrain, which primarily comprises an internal combustion engine 1 and a dual-clutch transmission. The dual-clutch transmission has a first drive shaft 7 and a second drive shaft 9. They are coaxially arranged and can be alternately connected to the force output shaft 10 of the internal combustion engine 1 via two hydraulically operated, load-switching disengagement clutches K1 and K2 to transmit torque. Figure 1 In this configuration, the first drive shaft 7 is implemented as a solid shaft, which extends coaxially within the second drive shaft 9, which is implemented as a hollow shaft. A driven shaft 13 is arranged parallel to the axes of the two drive shafts 7 and 9. This driven shaft acts on the input shaft 19 of the axle differential 21 via a gear stage 15 having spur gears. Flange shafts 23 extend from the axle differential 21 to wheels (not shown) on both sides.
[0022] The first sub-transmission I and the second sub-transmission II of the dual-clutch transmission can be activated respectively via the first drive shaft 7 and the second drive shaft 9. Viewed axially, the first sub-transmission I is arranged away from the clutch, while the second sub-transmission II is arranged closer to the clutch. Fixed gears and floating gears are arranged in multiple gear pairs / gear planes on the two drive shafts 7 and 9 and on the driven shaft 13. These form a gear set with six forward gear stages G1 to G6 and one reverse gear stage R. In the figure, the floating gears for all gear stages are located on the driven side of the driven shaft 13. The floating gears can be switched by gear shifting elements S1 to S4, which are also located on the driven shaft 13.
[0023] Each gear shifting element S1 to S4 is implemented as a synchronous engagement device with a sliding sleeve 24, which can be axially displaced to both sides by an adjustment displacement Δs via a shift fork 25 shown. The sliding sleeve 24 sits on a corresponding external toothed portion of a sliding sleeve carrier 27 (not shown) arranged on the driven shaft 13 in a manner that prevents relative rotation. Figure 1 In this configuration, each sliding sleeve 24 is positioned in a non-operating position. The sliding sleeve 24 can be moved from the non-operating position to a shifting position to engage one of the gears G1 to G6 or R. In the shifting position, the internal teeth of the sliding sleeve engage with the sliding sleeve carrier 27 on one hand and with the external teeth of the clutch body 29 of the floating gear on the other.
[0024] exist Figure 1 In this configuration, each shift fork 25 is operatively connected, for example, to a hydraulically operated servo drive 26, which can be controlled by a shift controller 31. When operatively operated, the shift fork 25 is axially displaced by an adjustment displacement Δs, or axially displaced by an adjustment displacement Δs, so that the associated shift sleeve 24 engages or disengages with the floating gear.
[0025] exist Figure 1 In this system, the switching controller 31 and the clutch controller 35 can be controlled by the evaluation module 30. The evaluation module 30 is signal-connected to a sensor device, which detects the clamping pressure or related parameters acting in the disengagement clutches K1 and K2. Based on the detected clamping pressure and the associated transmittable clutch torque, the evaluation module 30 determines the contact point KP of the disengagement clutches K1 and K2.
[0026] The evaluation module 30 stores a switching strategy to perform a subsequent shift to the target gear without traction interruption, in which the shift is performed from the current gear of one sub-transmission (or, alternatively, from an inactive position) to the target gear of another sub-transmission.
[0027] The core of this invention is to shorten the total switching time in subsequent self-executed shifts. This is achieved by engaging the target gear earlier than in existing technologies.
[0028] To better understand this invention, please refer to the following: Figure 2 Comparative examples described that are not covered by this invention. Figure 2 The diagram illustrates the timeline of preparation for a subsequent shift (i.e., shifting to the target gear) performed during driving operation, wherein, for example, the current gear is the third gear G3 in sub-transmission I, and the target gear is the fourth gear G4 in sub-transmission II.
[0029] Therefore, the evaluation module 30 first manipulates the clutch controller 35 so that during the gear engagement process t Z The gear shifting element S1 (shown as a dashed line in the figure) is moved from its inactive position to its shifting position, thereby engaging the target gear G4 in the still passive second sub-transmission II. Then, the evaluation module 30 manipulates the clutch controller 35 and the shifting controller 31 to disengage the current sub-transmission I and the current gear G3.
[0030] However, during the gear engagement process t Z Before proceeding, evaluation module 30 checks whether the disengaged clutch K2 of the still passive sub-transmission II is engaged. Figure 2 In the diagram, the disengagement clutch K2 engages at time t=0. With this engagement of the disengagement clutch K2 in the passive sub-transmission II, the evaluation module 30 manipulates the clutch controller 35 to ensure proper disengagement during the disengagement process t... K The clutch K2 (shown by the solid line in the diagram) is fully disengaged, thus ensuring that the target gear G4 is engaged without torque. Therefore, Figure 2 The chart shows the duration t used to prepare for the subsequent switch. V The disengagement process of the clutch t K and the gear engagement process t Z composition. Figure 2 In the diagram, only when the disengagement clutch K2 is fully disengaged, i.e., during the disengagement process t... K The gear shifting process only begins at the point where the entire process is complete. Z Therefore, in Figure 2 In the middle, the preparation for the subsequent shift (i.e., shifting to the fourth gear G4) occupies a correspondingly long preparation time t. V .
[0031] Unlike Figure 2 ,exist Figure 3 The diagram shows the time history during the preparation of the subsequent switchover according to the present invention, which is based on the understanding that: the clutch disengagement process tK It can be divided into: the initial separation stage of the transmitted torque t K1 This continues until the contact point KP is reached; and the subsequent torqueless separation phase t K2 It begins at the contact point KP. During the torque-less separation phase t... K2 In this process, a torqueless clutch air gap is established in the disengagement clutch K2. The contact point KP defines the actuator position of the disengagement clutch as follows: from this actuator position, torque is transmitted through the disengagement clutch K2 when the clamping pressure increases, and from this position, a torqueless clutch air gap appears when the clamping pressure decreases.
[0032] Gear engagement process t Z It can be divided into the following four stages: the first engagement stage without torque t Z1 In the first engagement stage, the gear shifting element S1 exhausts the mechanical movement clearance, that is, no adjustment movement of the gear shifting element S1 is performed; in the second engagement stage t, there is no torque. Z2 In the second engagement stage, the gear shifting element S1 moves from its inactive position until it touches the still locked synchronizer ring (i.e., reaches the synchronization point); the third engagement stage t transmits torque. Z3 In the third engagement stage, the gear shifting element S1 stops until the input shaft is synchronized to the synchronous speed by the frictional torque of the synchronizing component; and in the fourth engagement stage t, the torque is transmitted. Z4 In this fourth engagement stage, the synchronizing ring rotates until the locking action is released and the gear adjuster allows the sliding sleeve to move further into the teeth, that is, until it moves into its switching position, thereby engaging the target gear G4.
[0033] according to Figure 3 The diagram illustrates this understanding, which is applied as follows: In preparation for a subsequent shift (i.e., shifting to the target gear G4), the evaluation module 30 manipulates the shift controller 31 to induce a torque-free engagement phase t. Z1 The disengagement of the second sub-transmission clutch K2 begins before its contact point KP. Therefore, once the disengagement clutch K2 is engaged during the disengagement process t... K By the time the gear shifting element S1 reaches contact point KP, at least the torqueless engagement phase t has been completed. Z1 Or the second engagement stage t without torque Z2 After reaching the contact point KP (and during the clutch disengagement process t), K (Previously), gear engagement process t Z The third stage of torque transmission t Z3 And the subsequent fourth engagement stage t of the torque transmission Z4This process begins immediately, during which the gear shifting element S1 shifts to its shifting position. (Compared to...) Figure 2 The gear shifting process t is performed earlier in time. Z The clutch disengagement process t K and the gear engagement process t Z The overlap occurs within the overlapping time interval Δt. Therefore, compared to existing technologies ( Figure 2 The preparation time t for the subsequent shift to the target gear. V Significantly shortened.
[0034] After the target gear G4 is engaged, that is, during the preparation duration t V After completion, a subsequent switch is performed, in which the evaluation module 30 manipulates the clutch controller 31 to engage the still passive disengagement clutch K2 of the sub-transmission II, that is, to disengage the still active disengagement clutch K1 of the sub-transmission I, thereby ending the subsequent switch.
[0035] List of reference numerals
[0036] 1. Internal Combustion Engine
[0037] 7 First drive shaft
[0038] 9 Second drive shaft
[0039] 10 Force Output Shaft
[0040] 13 Driven Shaft
[0041] 15 Spur Gear Stage
[0042] 19 Input shafts
[0043] 21. Axle differential
[0044] 23 Flange Shaft
[0045] 24 Switching Set
[0046] 25. Shift fork
[0047] 26 servo drives
[0048] 27. Switch carrier
[0049] 29 Floating Gear Clutch
[0050] 30 Evaluation Modules
[0051] 31 Switching Controller
[0052] 35 Clutch Controller
[0053] 37 Sensor Device
[0054] G1 to G6 forward gears
[0055] R (Reverse)
[0056] K1 and K2 disengagement clutches
[0057] S1 to S4 gear shifting element
[0058] KP contact point
[0059] Δs Adjustment displacement
[0060] t K Clutch disengagement process
[0061] t K1 Separation stage of torque transmission
[0062] t K2 Separation phase without torque
[0063] t Z Gear engagement process
[0064] t Z1 t Z2 Momentless engagement phase
[0065] t Z3 t Z4 The engagement stage of torque transmission
[0066] Δt Overlapping time interval
[0067] t V Preparation duration
Claims
1. A vehicle having a dual-clutch transmission, wherein a first sub-transmission (I) of the dual-clutch transmission can be activated by operating a corresponding first disengagement clutch (K1), and a second sub-transmission (II) can be activated by operating a corresponding second disengagement clutch (K2), each sub-transmission (I, II) having at least one gear shifting element (S1 to S4), particularly a synchronizing engagement device, by which a gear can be engaged, wherein, The switching controller (31) can perform a subsequent switching, during which the target gear (G4) can be switched while driving. The switching controller (31) prepares for the subsequent switching during the gear engagement process (t). Z In the passive, i.e., inactive sub-transmission (II), the target gear (G4) is engaged. The switching controller (31) has an evaluation module (30) that evaluates the gear engagement process (t) Z Before checking whether the release clutch (K2) of the passive sub-transmission (II) is engaged, if the release clutch (K2) of the passive sub-transmission (II) is engaged, the evaluation module (30) manipulates the clutch controller (35) so that during the release clutch disengagement process (t) K In this process, the disengagement clutch (K2) is fully disengaged, thereby ensuring that the target gear (G4) is engaged without torque, which prepares for the duration (t) of the subsequent shift. V This includes the clutch disengagement process (t) K ) and the gear engagement process (t Z ), Its features are, In order to shorten the preparation time (t) V The evaluation module (30) controls the shift controller (31) to make the gear engagement process (t) Z During the clutch disengagement process (t) K The disengagement process begins before the clutch ends, thus separating the clutch from the clutch (t). K ) and the gear engagement process (t K They overlap in time over an overlapping time interval (Δt).
2. The vehicle according to claim 1, characterized in that, Clutch disengagement process (t) K The process is divided into: the separation phase of the initial transmitted torque up to the point of contact (KP) (t). K1 ) and the subsequent momentless separation phase after reaching the contact point (KP) (t K2 During the torqueless separation phase, a torqueless clutch air gap is established in the disengaged clutch (K2). In particular, the evaluation module (30) controls the shift controller (31) to make the gear engagement process (t Z At least during the clutch disengagement process (t) K The separation phase of the torqueless phase (t) K2 It begins in the middle.
3. The vehicle according to claim 1 or 2, characterized in that, Gear engagement process (t) Z ) is divided into at least one hook-up phase without moment (t) Z1 t Z2 ) and at least one torque transmission engagement stage (t Z3 t Z4 During the engagement phase of the torque transmission, a synchronous frictional torque is established in the gear shifting assembly, especially the evaluation module (30) controls the shifting controller (31) to achieve a torque-free engagement phase (t). Z1 t Z2 The engagement begins before reaching the contact point (KP) of the disengagement clutch (K2) of the second sub-transmission (II), thus the contact point (KP) of the disengagement clutch (K2) of the second sub-transmission (II) is engaged during the gear shift process (t). Z The inert phase of the hook-up (t) Z1 t Z2 The moment that has occurred occurs, and the gear engagement process begins after reaching the contact point (KP). Z The torque transmission stage of the hook-up process (t) Z3 t Z4 ).
4. The vehicle according to any one of the preceding claims, characterized in that, The evaluation module (30) is signal-connected to a sensor device (37) that detects the clamping pressure or related parameters acting in the release clutch (K2) of the passive sub-transmission (II). The evaluation module (30) determines the contact point (KP) of the release clutch (K2) based on the detected clamping pressure and the corresponding transmittable clutch torque. Alternatively, in a dry clutch system, the evaluation module (30) has a displacement measurement system to determine the contact point (KP).
5. The vehicle according to any one of the preceding claims, characterized in that, After the target gear is engaged, i.e. after the preparation duration (tV) ends, a subsequent switch can be performed. In the subsequent switch, the evaluation module (30) manipulates the clutch controller (31) to engage the disengagement clutch (K2) of the still passive sub-transmission (II), and in this case, disengagement clutch (K1) of the still active sub-transmission (I) is disengaged, thereby ending the subsequent switch.
6. The vehicle according to any one of the preceding claims, characterized in that, The release clutch (K2) of the passive sub-transmission (II) engages under certain conditions—for example, in the process of determining the contact point (KP)—which defines the actuator position of the release clutch (K2) from which torque is transmitted through the release clutch (K2) when the clamping pressure increases, and when a clutch air gap without torque occurs when the clamping pressure decreases.
7. The vehicle according to any one of the preceding claims, characterized in that, The vehicle power unit (1), particularly the internal combustion engine, drives the first drive shaft (7) or the second drive shaft (9) alternately via the force output shaft (10) through two disengageable clutches (K1, K2) of the dual-clutch transmission that can switch under load. This allows the first sub-transmission (I) or the second sub-transmission (II) to be activated by means of these two drive shafts (7, 9). Fixed gears and floating gears are arranged on these two drive shafts (7, 9) and on the driven shaft (13) that is parallel to the axis of the drive shafts. The fixed gears and floating gears are combined into gear sets to form forward gear stages (G1 to G6). In the gear sets, the floating gears can be connected to the corresponding drive shafts (7, 9, 13) by means of gear shifting elements (S1 to S4).
8. A method for engaging a target gear (G4) in a dual-clutch transmission of a vehicle according to any one of the preceding claims.