Vehicle equipment and procedures

Abstract

Vehicle (1), comprising the following: a torque generating machine (4); one or more driven wheels (W D ); a drive train (6) for transmitting a torque from the torque generating machine (4) to the one or more driven wheels, wherein the drive train (6) comprises a torque transmission means (8); a first decoupling mechanism (11) that is operational to decouple the torque transmission means (8) from the torque generating machine (4), wherein the first decoupling mechanism (11) is closed to couple the torque transmission means (8) to the torque generating machine (4) and is open to decouple the torque transmission means (8) from the torque generating machine (4); a second decoupling mechanism (12) that is operational to decouple the torque transmission means (8) from the one or more driven wheels, wherein the second decoupling mechanism (12) is closed to couple the torque transmission means (8) to the one or more driven wheels and is open to decouple the torque transmission means (8) from the one or more driven wheels; and a control device (2) with at least one electronic processor (P) for controlling the operation of the first and second decoupling mechanisms (11, 12), wherein the at least one electronic processor (P) is configured to: Closing the first decoupling mechanism (11); Determining a target operating speed of the torque-generating machine (4); After closing the first decoupling mechanism (11), the operating speed of the torque-generating machine (4) is controlled as a function of the determined target operating speed; and The second decoupling mechanism (12) closes when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a vehicle device and a method. In particular, but not exclusively, the vehicle device is capable of selectively coupling and decoupling the vehicle powertrain; and the method relates to the selective coupling and decoupling of the vehicle powertrain. STATE OF THE ART

[0002] It is known to disconnect a vehicle's powertrain and reduce the operating speed of an internal combustion engine to reduce fuel consumption. This strategy is variously known as vehicle coasting, gliding, or idling. This operating mode is referred to here as coasting mode.

[0003] An example of a known powertrain separation strategy is disclosed in the applicant's earlier British patent application GB 1316 183 A. A rear-wheel-drive vehicle 1, comprising a powertrain 3, is disclosed in Fig. Figure 1 shows the powertrain 3, which comprises an internal combustion engine 4, a transmission 5, and a drivetrain 6. When a coasting mode is activated, the drivetrain 6 is decoupled from the internal combustion engine 4. The operating speed of the internal combustion engine 4 can then be reduced, for example, to operate at idle to provide improved fuel efficiency. When the internal combustion engine 4 is decoupled, the drivetrain 6 is rotated by a torque applied by the driven wheels W. D (the rear wheels in the present arrangement). The dynamic operating states of the respective components when the vehicle 1 is operated in a conventional sliding mode are described in Fig. 1 shown.

[0004] A vehicle 1 with a front-wheel drive arrangement is in Fig. Figure 2 shows that the front-wheel-drive vehicle 1 can also be operated in a coasting mode by decoupling the drivetrain 6 from the internal combustion engine 4. When the drivetrain 6 is decoupled, it is rotated by a torque applied by the driven wheels W. D (the front wheels in the present arrangement). The dynamic operating states of the respective components when the vehicle 1 is operated in a conventional sliding mode are described in Fig. 2 shown.

[0005] The relationship between the operating loads on a vehicle 1 traveling down a negative gradient of 2% is in Fig. Figure 3 illustrates the loads, which are expressed as the torque within the drivetrain of vehicle 1. The positive (accelerating) forces acting on vehicle 1 are represented by a first arrow pointing in the direction of travel (from left to right). Fig. 2) comprise: an engine torque A, delivered in response to a driver torque request; and an effective torque B, derived from the road gradient. The sum of the engine torque A and the effective torque B represents a total torque at the wheels of A + B. The negative (decelerating) forces acting on vehicle 1 are represented by a second arrow pointing in the opposite direction (from right to left in Fig. 2) comprise: an aerodynamic torque C; a road loss torque D; an engine loss torque E; a transmission loss torque F; and a drivetrain loss torque G. The total negative torque is -(C+D+E+F+G); and the total positive torque is (A+B). A first difference between the positive torque and the negative torque is calculated as follows: (A+B)-(C+D+E+F+G). When the coasting mode is activated, the vehicle drivetrain 6 is disconnected from the internal combustion engine 4, and the total torque comprises a positive torque, which includes the effective torque B; and a negative torque, which includes the aerodynamic torque C, the road loss torque D, the transmission loss torque F, and the drivetrain loss G. The internal combustion engine 4 is disconnected from the drivetrain 6, so the engine loss torque E is not applied.A second difference between positive and negative torque is calculated as follows: (B)-(C+D+F+G). The internal combustion engine can operate at a lower speed, for example, at idle, or it can be switched off. State of the art is defined in: EP 1 859 982 A2 and WO 2015 / 151320 A1.

[0006] It would be advantageous to expand the range of operating conditions in which the powertrain could be decoupled from the internal combustion engine. The present invention was conceived with this in mind. BRIEF SUMMARY OF THE INVENTION

[0007] Aspects of the present invention relate to a vehicle that is selectively operable to couple and decouple a powertrain; and a method for selectively coupling and decoupled a powertrain of a vehicle, as claimed in the attached claims.

[0008] According to another aspect of the present invention, a vehicle is provided which comprises the following: a torque-generating machine; one or more driven wheels; a drive train for transmitting torque from the torque-generating machine to the one or more driven wheels, the drive train comprising a torque transmission means; a first decoupling mechanism that is operational to decouple the torque transmission means from the internal combustion engine, wherein the first decoupling mechanism is closed to couple the torque transmission means to the internal combustion engine and is open to decouple the torque transmission means from the internal combustion engine; a second decoupling mechanism capable of decoupling the torque transmission means from the one or more driven wheels, wherein the second decoupling mechanism is closed to couple the torque transmission means to the one or more driven wheels, and open to decouple the torque transmission means from one or more driven wheels; and A control device comprising at least one electronic processor for controlling the operation of the first and second decoupling mechanisms. The arrangement of the first and second decoupling mechanisms allows the torque transmission means to be decoupled, thereby reducing powertrain losses. This arrangement is particularly useful when the vehicle is operated in a powertrain isolation mode, where at least part of the powertrain can be decoupled and the operating speed of the internal combustion engine can be reduced.

[0009] The first decoupling mechanism comprises a first torque input means and a first torque output means. The first torque input means is connected to the internal combustion engine. The first torque output means is connected to the torque transmission means. The first decoupling mechanism is selectively operable to transmit torque from the first torque input means to the first torque output means. The first torque input means may include a first input shaft; and the first torque output means may include a first output shaft.

[0010] At least in certain embodiments, the first decoupling mechanism can accommodate slip in order to accommodate a speed differential between the first input means and the first output means. The first decoupling mechanism can comprise one or more friction plates. The first decoupling mechanism can comprise a first multi-plate clutch. In alternative arrangements, the first decoupling mechanism can be configured to accommodate no slip. The first decoupling mechanism can, for example, comprise one or more of the following: a torque converter, a single-plate clutch, a multi-plate clutch, a synchronizer, a hydrostatic clutch, and a magnetic clutch.

[0011] The second decoupling mechanism comprises a second torque input means and a second torque output means. The second torque input means is connected to one or more driven wheels. The second torque output means is connected to the torque transmission means.

[0012] The second decoupling mechanism can be selectively operated to transfer torque from the second torque input means to the second torque output means. The second torque input means can include a second input shaft; and the second torque output means can include a second output shaft.

[0013] At least in certain embodiments, the second decoupling mechanism can accommodate slip to accommodate a speed differential between the second input means and the second output means. The second decoupling mechanism can comprise one or more friction plates. The second decoupling mechanism can comprise one or more of the following: a torque converter, a single-plate clutch, a multi-plate clutch, a synchronizer, a hydrostatic clutch, and a magnetic clutch. In alternative arrangements, the second decoupling mechanism can be an anti-slip mechanism (i.e., a mechanism that does not accommodate slip between the second torque input means and the second torque output means).The second decoupling mechanism may, for example, include a jaw coupling arranged in series with an output of a differential; or a jaw coupling arranged between a ring gear and a differential carrier.

[0014] The first and second decoupling mechanisms can be controlled to re-couple the torque transmission means with the internal combustion engine and the one or more driven wheels.

[0015] The torque transmission device is suitable for transmitting torque to propel the vehicle. The torque transmission device can include a drive shaft. Alternatively or additionally, the torque transmission device can include a differential, a torque transmission gearbox, a transfer case, or a drive mechanism.

[0016] The at least one electronic processor can be configured to close the second decoupling mechanism to couple the torque transmission means to the one or more driven wheels. The at least one electronic processor can be configured to start the torque-generating machine. The at least one electronic processor can be configured to determine a target operating speed of the torque-generating machine. The target operating speed can be determined before, during, or after the second decoupling mechanism closes. The at least one electronic processor can control the operating speed of the torque-generating machine depending on the determined target operating speed.The at least one electronic processor can close the first decoupling mechanism if the operating speed of the torque-generating machine corresponds at least substantially to the determined target operating speed.

[0017] The target operating speed can be determined, at least in essence, to synchronize the speeds of the first input shaft and the first output shaft. The speed of the first output shaft is proportional to the speed of the torque transmission medium. The speed of the torque transmission medium can be measured directly, for example, by a speed sensor. When the second decoupling mechanism is closed, the speed of the torque transmission medium is proportional to the wheel speed. Thus, after the second decoupling mechanism is closed, the speed of the torque transmission medium can be determined based on the wheel speed of one or more driven wheels. The target operating speed can be determined as a function of a wheel speed signal that includes a measured wheel speed of one or more driven wheels.The first input shaft and the first output shaft can be synchronized by adjusting the operating speed of the torque-generating machine to the specified target operating speed.

[0018] The at least one electronic processor can be configured to receive a torque request signal, generated, for example, as a function of an accelerator pedal position signal. The target operating speed can be determined based on this torque request signal. The internal combustion engine can deliver the requested torque when the first decoupling mechanism is closed. In this arrangement, the first decoupling mechanism should provide slip to accommodate any speed differential between the first input shaft and the first output shaft when the first decoupling mechanism is closed.

[0019] The at least one electronic processor can be configured to start the torque-generating machine when the first torque decoupling mechanism is open. The at least one electronic processor can be configured to determine a target operating speed of the torque-generating machine. The target operating speed can be determined, at least substantially, to synchronize the speeds of the first and second input shafts. The target operating speed can be determined as a function of a wheel speed signal, which includes a measured wheel speed of one or more driven wheels. The target operating speed can be determined such that the first and second input shafts rotate at substantially the same speed. The at least one electronic processor can control the operating speed of the torque-generating machine as a function of the determined target operating speed.At least one electronic processor can be configured to close the first decoupling mechanism when the operating speed of the torque-generating machine is at least substantially equal to the specified target operating speed. The second decoupling mechanism can be closed after the first decoupling mechanism has closed. Once the first decoupling mechanism is closed, the second input shaft and the second output shaft rotate at substantially the same speed. In this arrangement, the second decoupling mechanism does not need to accommodate any slippage, since the second input shaft and the second output shaft rotate at substantially the same speed when the second decoupling mechanism is closed.

[0020] The at least one electronic processor can be configured to start the torque-generating machine when the first torque decoupling mechanism is open. The at least one electronic processor can be configured to close the first decoupling mechanism. The at least one electronic processor can determine a target operating speed of the torque-generating machine. After the first decoupling mechanism closes, the at least one electronic processor can control the operating speed of the torque-generating machine depending on the determined target operating speed. The target operating speed can be determined depending on a wheel speed signal, which includes a measured wheel speed of one or more driven wheels. The target operating speed can be determined such that the first and second input shafts rotate at substantially the same speed.The at least one electronic processor can be configured to close the second decoupling mechanism when the operating speed of the torque-generating machine is at least substantially the same as the specified target operating speed. In this arrangement, the second decoupling mechanism does not need to accommodate any slippage, since the second input shaft and the second output shaft rotate at substantially the same speed when the second decoupling mechanism is closed.

[0021] The at least one electronic processor can be configured to determine the target operating speed of the torque generating machine as a function of the wheel speed signal such that a speed of the torque transmission means is synchronized with a wheel speed represented by the wheel speed signal.

[0022] The vehicle may include a transmission coupled to the torque-generating machine. The transmission is capable of selecting one of several gear ratios. The transmission may be an automatic transmission. The first decoupling mechanism may be integrated into the transmission. Alternatively, the first decoupling mechanism may be located between the internal combustion engine and the transmission; or between the transmission and the torque-transmitting device.

[0023] The torque-generating machine can include an internal combustion engine.

[0024] The control can be configured to activate a drivetrain separation sliding mode by opening the first decoupling mechanism to decouple the torque transmission means from the torque generating machine and by opening the second decoupling mechanism to decouple the torque transmission means from the one or more driven wheels.

[0025] According to a further aspect of the present invention, a method for controlling a first and a second decoupling mechanism for controlling the transmission of torque from a torque-generating machine to one or more driven wheels of a vehicle is provided; wherein the method comprises: Opening the first decoupling mechanism to decouple the torque transmission means from the internal combustion engine; Opening the second decoupling mechanism to decouple the torque transmission means from the one or more driven wheels. The first and second decoupling mechanisms can be opened simultaneously. Alternatively, the first and second decoupling mechanisms can be opened sequentially. The first decoupling mechanism can be opened before the second decoupling mechanism; or the second decoupling mechanism can be opened before the first decoupling mechanism.

[0026] The procedure may include the following: Closing the second decoupling mechanism to couple the torque transmission means to the one or more driven wheels; Determining a target operating speed for the torque-generating machine; Controlling the operating speed of the torque-generating machine as a function of the determined target operating speed; and The first decoupling mechanism closes when the operating speed of the torque-generating machine corresponds at least substantially to the determined target operating speed.

[0027] The target operating speed of the torque-generating machine can be determined after the second decoupling mechanism is closed. The target operating speed of the torque-generating machine can be determined as a function of a wheel speed signal.

[0028] Alternatively or additionally, the procedure can include determining the target operating speed of the torque-generating machine as a function of a torque demand request made by a driver of the vehicle.

[0029] The procedure may include the following: Determining a target operating speed for the torque-generating machine; Controlling the operating speed of the torque-generating machine depending on the determined target operating speed; Closing of the first decoupling mechanism when the operating speed of the torque-generating machine corresponds at least substantially to the determined target operating speed; and Closing the second decoupling mechanism after closing the first decoupling mechanism.

[0030] The procedure may include the following: Closing the first decoupling mechanism; Determining a target operating speed for the torque-generating machine; Controlling the operating speed of the torque-generating machine as a function of the specified target operating speed; and The second decoupling mechanism closes when the operating speed of the torque-generating machine corresponds at least substantially to the determined target operating speed.

[0031] The target operating speed of the torque-generating machine can be determined as a function of a wheel speed signal.

[0032] The first decoupling mechanism can include a first torque input means and a first torque output means. The first decoupling mechanism can include a sliding mechanism to absorb slip between the first torque input means and the first torque output means. For example, the first decoupling mechanism can include one or more friction plates to absorb slip.

[0033] The second decoupling mechanism can include a second torque input means and a second torque output means. The second decoupling mechanism can include an anti-slip mechanism that prevents slippage between the first torque input means and the first torque output means. The second decoupling mechanism can, for example, include a torque converter, a single-plate clutch, a multi-plate clutch, a synchronizer, a hydrostatic clutch, or a magnetic clutch.

[0034] Any control device or devices described herein may appropriately comprise a control unit or a computer device with one or more electronic processors. Accordingly, the system may comprise a single control unit or a single electronic control device, or alternatively, different functions of the control device may be embodied or housed in different control units or devices. As used herein, the term "control device" or "control unit" shall include both a single control unit or device and multiple control units or devices operated together to provide any specified control functionality.To configure a control device, a suitable set of instructions can be provided which, when executed, cause the control unit or computer device to implement the control techniques specified herein. The set of instructions can suitably be embedded in one or more electronic processors. Alternatively, the set of instructions can be provided as software to be executed on the computer device, stored in one or more memories associated with the control device. A first control device can be implemented in software executed on one or more processors. One or more control devices can be implemented in software executed on one or more processors, optionally on the same one or more processors as the first control device. Other suitable arrangements can also be used.

[0035] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives presented in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their individual features, may be considered independently of one another or in any combination. This means that all embodiments and / or features of any embodiment may be combined in any way and / or combination, provided that these features are not incompatible.The applicant reserves the right to amend any originally filed patent claim or to file any new patent claim accordingly, including the right to amend any originally filed patent claim to depend on and / or incorporate any feature of any other patent claim, even if it was not previously claimed in this manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] One or more embodiments of the invention will now be described only in the form of examples with reference to the accompanying figures; these show: Fig. 1 A schematic representation of the main components of a conventional rear-wheel drive vehicle; Fig. 2 a schematic representation of the main components of a conventional front-wheel drive vehicle; Fig. 3 a schematic representation of the forces acting on a vehicle when it is operated in a sliding mode; Fig. 4 a schematic representation of a vehicle configured to operate in a powertrain separation sliding mode according to an embodiment of the present invention; Fig. 5 a schematic representation of the dynamic operating states of the components in the drive train of the in Fig. 4 vehicle shown, when operated in the powertrain disconnect sliding mode; Fig. 6 a schematic representation of the loads on the in Fig. 4 vehicle shown when operated in the powertrain disconnect sliding mode; Fig. 7 a schematic representation of a front-wheel drive vehicle operated in a powertrain separation sliding mode according to an embodiment of the present invention; Fig. 8 a schematic representation of the gearbox and front differential of the in Fig. 7. Vehicle shown with front-wheel drive; and Fig. 9 a schematic representation of a four-wheel drive vehicle capable of operating in a powertrain separation sliding mode according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] A vehicle 1, comprising a control device 2 according to an embodiment of the present invention, is now described with reference to the Fig. 4, Fig. 5 and Fig. 6 described. The control device 2 is selectively configured to activate and deactivate a powertrain separation sliding mode. In the present embodiment, the vehicle 1 is a rear-wheel drive vehicle with driven wheels W D, which are arranged at the rear. It is understood that the invention described herein is not limited to this drive configuration. Furthermore, the invention can be implemented in various types of vehicles.

[0038] As in Fig. As shown in Figure 4, the vehicle 1 comprises a powertrain 3 for generating traction force to propel the vehicle 1. The powertrain 3 comprises an internal combustion engine 4, a transmission 5, and a drive train 6. The internal combustion engine 4 is arranged in a longitudinal (north-south) configuration within the vehicle 1. The transmission 5 is an automated transmission comprising one or more internal friction brakes and one or more multi-plate clutches. The transmission 5 is controlled by a transmission control module (TCM) 7. The drive train 6 is arranged to transmit torque from the internal combustion engine 4 to driven wheels W. Dto transmit. In the present embodiment, the drivetrain 6 is configured to transmit torque to the rear wheels of the vehicle 1. The drivetrain 3 could optionally also include an electric traction motor (not shown) to supply traction force to the driven wheels W. D contain.

[0039] The drive train 6 comprises a torque transmission means for transmitting torque from the internal combustion engine 4 to the driven wheels W D In the present embodiment, the torque transmission means is in the form of a drive shaft 8. The drive shaft 8 is selectively connected to the driven wheels W. DThe vehicle 1 is coupled by a first and a second rear half-shaft 9, 10. The vehicle 1 comprises a first decoupling mechanism 11 and a second decoupling mechanism 12. The first and second decoupling mechanisms 11, 12 are arranged at opposite ends of the drive shaft 8 and can be controlled independently of each other, as described herein. As described herein, the control device 2 is configured to control the operation of the first and second decoupling mechanisms 11, 12.

[0040] The first decoupling mechanism 11 comprises a first input means in the form of a first input shaft; and a first output means in the form of a first output shaft. The internal combustion engine 4 transmits an input torque to the first input shaft; and the first output shaft transmits an output torque to the drive shaft 8. The first decoupling mechanism 11 is selectively operable to couple and decouple the drive shaft 8 from the internal combustion engine 4. The first decoupling mechanism 11 is open to decouple the first input shaft from the first output shaft, thereby decoupling the drive shaft 8 from the internal combustion engine 4. Conversely, the first decoupling mechanism 11 is closed to couple the first input shaft to the first output shaft, thereby coupling the drive shaft 8 to the internal combustion engine 4.The first decoupling mechanism 11 is implemented by controlling the operation of the transmission 5, for example by opening a clutch in the transmission 5 to disconnect the drive shaft 8 from the internal combustion engine 4. In one variant, the first decoupling mechanism 11 can be separate from the transmission 5. For example, the first decoupling mechanism 11 can be located between the drive shaft 8 and the transmission 5; or between the internal combustion engine 4 and the transmission 5.

[0041] The second decoupling mechanism 12 comprises a second input means in the form of a second input shaft; and a second output means in the form of a second output shaft. The drive shaft 8 transmits a torque to the second input shaft; and the second output shaft transmits a torque to the first and second rear half-shafts 9, 10 to drive the driven wheels W. Dto drive. The second output shaft can, for example, transmit torque to a rear differential 13, which is configured to transmit torque to the first and second rear half-shafts 9, 10. When the internal combustion engine 4 is decoupled from the drive shaft 8 (i.e., the first decoupling mechanism 11 is open), the first and second rear half-shafts 9, 10 transmit torque to the second output shaft of the second decoupling mechanism 12. The second decoupling mechanism 12 is operational, disengaging the drive shaft 8 from the driven wheels W. D to decouple. The second decoupling mechanism 12 is closed to couple the second input shaft with the second output shaft, thereby connecting the drive shaft 8 to the driven wheels W. Dis coupled. Conversely, the second decoupling mechanism 12 is open to decouple the second input shaft from the second output shaft, thereby disconnecting the drive shaft 8 from the driven wheels W. D is decoupled. In the present embodiment, the second decoupling mechanism 12 comprises a multi-plate clutch. The multi-plate clutch allows slippage between the second input shaft and the second output shaft to compensate for the different rotational speeds of the drive shaft 8 and the first and second rear half-shafts 9, 10 when the drivetrain disconnect sliding mode is deactivated. In a modified arrangement, the second decoupling mechanism 12 can comprise a first and a second clutch mechanism, which are associated with the first and second rear half-shafts 9, 10, respectively. The first and second clutch mechanisms can, for example, be integrated into the rear differential 13.

[0042] The control device 2 comprises at least one electronic processor P configured to execute a set of computer instructions stored on a non-volatile, computer-readable medium. The control device 2 monitors one or more vehicle dynamic conditions, such as vehicle acceleration and / or speed; and one or more vehicle operating parameters, such as an output torque from the internal combustion engine 4. The control device 2 is configured to identify a vehicle sliding possibility when the measured dynamic condition(s) differs from a desired vehicle dynamic condition for the current vehicle operating parameter(s). The control device 2 can also check to identify a positive torque request indicating a driver intention to maintain the current dynamic vehicle conditions.If these conditions are met, the control device 2 outputs an activation signal S. ACT a COM signal is sent to a vehicle communication network to activate a powertrain separation sliding mode. This depends on the activation signal S. ACTThe first decoupling mechanism 11 is opened to decouple the drive shaft 8 from the internal combustion engine 4; and the second decoupling mechanism 12 is opened to decouple the drive shaft 8 from the first and second rear half-shafts 9, 10. A powertrain control module (PCM) is also operated to reduce the torque requirement of the internal combustion engine 4. The internal combustion engine 4 can be operated at idle during the powertrain separation gliding mode or can be shut down by preventing the combustion cycle. Opening both the first and second decoupling mechanisms 11, 12 reduces the rotational speed of the drive shaft 8, and it can come to rest depending on the duration of the powertrain separation gliding mode. Since the powertrain 6 is not connected to the driven wheels W DWhen the second decoupling mechanism 12 is open, the total losses acting on the vehicle 1 can be reduced. At least in certain embodiments, this allows the activation of the powertrain separation sliding mode over a wider range of operating conditions.

[0043] With reference to Fig. 4 is the at least one processor P configured to receive a wheel speed signal S WH , a combustion engine speed signal S ICE and a torque request signal S TQ to receive the wheel speed signal S WH is generated by at least one wheel speed sensor 14, which is connected to the driven wheels W D assigned to vehicle 1. The combustion engine speed signal S ICE is generated by a crankshaft speed sensor 15. The torque request signal S TQThe torque request signal S is generated depending on a pedal position sensor 16, which is assigned to an accelerator pedal 17. TQ This includes a torque request signal generated by the driver of vehicle 1 when the accelerator pedal 17 is depressed. Alternatively or additionally, the torque request signal can be generated by a cruise control system, for example to adjust a target vehicle speed.

[0044] The transmission control module (TCM) 7 detects the activation signal S ACT , which is output to the COM communication network. Depending on this activation signal S ACTThe transmission control module 7 controls the operation of the internal clutches in the transmission 5 to decouple the drive shaft 8 from the transmission 5. The second decoupling mechanism 12 is also open to disconnect the drive shaft 8 from the first and second rear half-shafts 9, 10. The drive shaft 8 is thereby disconnected from the internal combustion engine 4 and the driven wheels W. D separated. The first and second decoupling mechanisms 11, 12 can be opened simultaneously or sequentially to activate the powertrain separation sliding mode. The internal combustion engine 4 is shut down by preventing the combustion cycle. As in Fig. As shown in Figure 5, when the first and second decoupling mechanisms 11, 12 are open, the drive shaft 8 comes to rest. The operating speed of the internal combustion engine 4 can be reduced, for example, to an idle speed. It is understood that the first and second rear half-shafts 9, 10 continue to rotate, since the rotation of the driven wheels W D transmits an input torque.

[0045] The operating loads acting on vehicle 1 when the powertrain separation sliding mode has been activated are in Fig. Figure 6 shows this schematically. The first arrow 19 (pointing from left to right) represents the positive forces acting on the vehicle 1. The same rate of deceleration can be achieved by activating the drivetrain disconnect sliding mode according to one aspect of the present invention. The effective torque B is provided due to the negative gradient on which the vehicle 1 travels. The positive contribution of the engine torque A is removed because the transmission 5 selects neutral and the internal combustion engine 4 is decelerated to idle speed or stopped. The second arrow 20 (pointing from right to left) represents the negative (i.e., decelerating) forces. The negative contributions of the engine loss torque E and the transmission loss torque F are eliminated. The drivetrain loss torque G is at least partially eliminated because the drive shaft 8 is decoupled from the internal combustion engine 4 and the driven wheel W.The total positive torque is provided by the effective torque B, and the total negative torque includes the aerodynamic torque C and the road loss torque D, i.e., -(C+D). A second difference between the positive and negative torques is calculated as follows: (B)-(C+D). Removing the drivetrain loss torque G increases the range of operating conditions in which the drivetrain disconnect mode can be usefully activated, for example, to allow activation at smaller gradients.

[0046] The control unit 2 monitors the dynamic vehicle conditions and vehicle operating parameters to determine when the drivetrain separation mode is no longer appropriate (i.e., when the effective torque B is no longer sufficient to compensate for the aerodynamic torque C and the road loss torque D). The control unit 2 then deactivates the drivetrain separation sliding mode. The control unit 2 implements a first control strategy to engage the drive shaft 8 with the driven wheels W. D and to couple with the internal combustion engine 4. In particular, the control device 2 closes the second decoupling mechanism 12 to connect the drive shaft 8 through the first and second rear half-shafts 9, 10 to the driven wheels W. D to couple. The drive shaft 8 is decoupled during the drivetrain separation sliding mode and has a lower rotational speed than the driven wheels W. DThe rotational speed of the drive shaft 8 can indeed be zero (0) during the drivetrain disconnect sliding mode. The multi-plate clutch arrangement of the second decoupling mechanism 12 allows slippage between the second input shaft and the second output shaft. The second decoupling mechanism 12 closes, and the rotational speed of the drive shaft 8 increases proportionally to the rotational speed of the first and second rear half-shafts 9, 10, which are connected to the driven wheels W. DThe control unit 2 initiates an engine start procedure, for example by activating a starter motor (not shown) to restart the internal combustion engine 4. The engine start procedure can be performed simultaneously with the closing of the second decoupling mechanism 12. After the second decoupling mechanism 12 is closed, the control unit 2 determines the rotational speed of the drive shaft 8. The rotational speed of the drive shaft 8 could be measured directly, for example using a dedicated speed sensor. In the present embodiment, however, the rotational speed of the drive shaft 8 is determined as a function of the measured wheel speed (as indicated by the wheel speed signal SWH), which is proportional to the rotational speed of the drive shaft 8.The control device 2 then determines a target operating speed for the internal combustion engine 4, at least substantially, such that it corresponds to the speed via the first decoupling mechanism 11. The control device 2 outputs an engine speed request signal depending on the determined target operating speed. As soon as the operating speed of the internal combustion engine 4 corresponds at least substantially to the target operating speed, the control device 2 outputs a control signal to close the first decoupling mechanism 11. The drive train 6 is thereby reconnected to the internal combustion engine 4 and the driven wheels W. D coupled.

[0047] The control strategy described above for terminating the drivetrain disconnect sliding mode requires that the second decoupling mechanism 12 allow slip between the second input shaft and the second output shaft to accommodate the different rotational speeds of the drive shaft 8 and the first and second rear half-shafts 9, 10 when the drivetrain disconnect sliding mode is deactivated. In the present embodiment, the second decoupling mechanism 12 comprises a multi-plate clutch to allow slip. A first variant, which does not require the second decoupling mechanism 12 to provide slip, is now described. In the first variant, the second decoupling mechanism 12 may, for example, comprise a dog clutch arranged in series with a differential output; or a dog clutch arranged between a ring gear and a differential carrier.The control device 2 is configured to activate the powertrain separation sliding mode by opening the first and second decoupling mechanisms 11, 12 to decouple the drive shaft 8. The first and second decoupling mechanisms 11, 12 can be opened simultaneously or sequentially to decouple the drive shaft 8. Alternative control strategies implemented for the first variant to deactivate the powertrain separation sliding mode are now described. In another variant, when the internal combustion engine 3 is stopped and comes to rest during the powertrain separation sliding mode, the first decoupling mechanism 11 can be closed simultaneously with or before the restart of the internal combustion engine 3. This control strategy would allow the drive shaft 8 to be coupled to the internal combustion engine 3 when their rotational speeds are similar, possibly both at zero.

[0048] A second control strategy for deactivating the powertrain separation sliding mode is now described. The control device 2 determines, based on the measured wheel speed of the driven wheels W, the D a target operating speed for the internal combustion engine 4. In particular, the target operating speed is determined such that the input speed of the first decoupling mechanism 11 is essentially the same as the input speed of the second decoupling mechanism 12 (which is proportional to the wheel speed of the driven wheels W). D(is). When the operating speed of the internal combustion engine 4 matches the target operating speed, the first decoupling mechanism 11 is closed. The first decoupling mechanism 11 accepts slip, allowing the speed of the drive shaft 8 to increase progressively to match the input speed of the first decoupling mechanism 11. By controlling the operating speed of the internal combustion engine 4, the speed of the drive shaft 8 can be adjusted, at least substantially, to match the output speed of the second decoupling mechanism 12. Once the speed has been adjusted, the second decoupling mechanism 12 closes to reconnect the drive shaft 8 to the driven wheels W via the first and second rear half-shafts 9, 10. Dto couple. By controlling the operating speed of the combustion engine 4 to synchronize the speed of the drive shaft 8 with the output speed of the second decoupling mechanism 12, an anti-slip coupling mechanism can be used.

[0049] A third control strategy for deactivating the powertrain separation sliding mode is now described. The internal combustion engine 4 is restarted. The first decoupling mechanism 11 is closed to couple the drive shaft 8 to the internal combustion engine 4. The first decoupling mechanism 11 engages slip, allowing the rotational speed of the drive shaft 8 to increase progressively to match the input speed of the first decoupling mechanism 11. The control device 2 then determines, based on the measured wheel speed of the driven wheels W Da target operating speed for the internal combustion engine 4. The target operating speed is determined such that the input speed of the first decoupling mechanism 11 is essentially the same as the input speed of the second decoupling mechanism 12 (which is proportional to the wheel speed of the driven wheels W). D (is). When the operating speed of the internal combustion engine 4 matches the target operating speed, the second decoupling mechanism 12 is closed to reconnect the drive shaft 8 via the first and second rear half-shafts 9, 10 to the driven wheels W. Dto couple. By controlling the operating speed of the internal combustion engine 4, the speed of the drive shaft 8 can be adapted, at least substantially, to the input speed of the second decoupling mechanism 12. It is understood that controlling the operating speed of the internal combustion engine 4 to synchronize the speed of the drive shaft 8 with the input speed of the second decoupling mechanism 12 enables the use of an anti-slip coupling mechanism.

[0050] The second and third control strategies are both applicable to the variant of the second decoupling mechanism 12 described above, which does not allow any slippage between the second input wave and the second output wave. However, it is understood that the second control strategy could also be applied to arrangements where the second decoupling mechanism 12 allows slippage.

[0051] The vehicle 1 in the above embodiment has a rear-wheel drive arrangement. The invention described herein is equally applicable to a vehicle 1 with a front-wheel drive arrangement. A further embodiment of the present invention, implemented in a vehicle 1 with a front-wheel drive arrangement, is now described with reference to the Fig. 7 and Fig. 8 described. The same reference symbols are used for the same components in the description of this arrangement.

[0052] As in Fig. As shown in Figure 7, the vehicle 1 comprises a powertrain 3 for generating traction force to propel the vehicle 1. The powertrain 3 comprises an internal combustion engine 4, a transmission 5, and a drivetrain 6. The internal combustion engine 4 is arranged in a transverse (east-west) configuration within the vehicle 1. The transmission 5 is an automated transmission comprising one or more internal friction brakes and one or more multi-plate clutches. The drivetrain 6 is arranged to transmit torque from the internal combustion engine 4 to driven wheels W. D to transmit. In the present embodiment, the drive train 6 is configured to transmit torque to the front wheels of the vehicle 1.

[0053] The drive train 6 comprises a torque transmission means for transmitting torque from the internal combustion engine 4 to the driven wheels W D With reference to Fig. The torque transmission means 8 comprises a front differential 21, which is connected to the transmission 5. In particular, the front axle differential 21 comprises an input ring gear 22 that meshes with an output ring gear 23 of the transmission 5. The front differential 21 comprises a first and a second output shaft 24, 25, which are coupled to corresponding first and second front half-shafts 26, 27. In operation, the first and second front half-shafts 26, 27 transmit torque to the driven wheels W. D of the vehicle 1.

[0054] According to the other embodiments described herein, the vehicle 1 comprises a first decoupling mechanism 11 and a second decoupling mechanism 12. The first and second decoupling mechanisms 11, 12 can be selectively opened to decouple the front differential 21 from the drivetrain 6 when the vehicle 1 is operated in a drivetrain separation sliding mode. The first and second decoupling mechanisms 11, 12 can be controlled independently of each other. For example, the first and second decoupling mechanisms 11, 12 can be opened simultaneously or sequentially. As described herein, the control device 2 is configured to control the operation of the first and second decoupling mechanisms 11, 12.

[0055] The gearbox 5 transmits an input torque to the input ring gear 22; and the differential transmits an output torque to the front half-shafts 26, 27. The first decoupling mechanism 11 is selectively operable to couple and decouple the front differential 21 from the gearbox 5.

[0056] The first decoupling mechanism 11 is installed in the transmission 5. The first decoupling mechanism 11 can be associated with a transmission input shaft 28 that is connected to the internal combustion engine 4. This arrangement of the first decoupling mechanism is shown in Fig. 8 designated by reference numeral 11a. Alternatively, the first decoupling mechanism 11 can be integrated into the transmission 5, for example by selecting neutral or opening a transmission clutch, as indicated by reference numeral 11b in Fig. 8. In another alternative, the first decoupling mechanism 11 can be installed in the gearbox 5 upstream of a gearbox that drives an intermediate shaft 29 inside the gearbox 5, as indicated by reference numeral 11c in Fig. 8. Alternatively, the first decoupling mechanism 11 can be installed in the intermediate shaft of the gearbox 5, as indicated by reference numeral 11d in Fig. 8 is specified. These variations of the first decoupling mechanism 11 can be incorporated into the other embodiments described herein.

[0057] The front axle differential 21 transmits torque to the first and second front half-shafts 26, 27 to the driven wheels W Dto drive. The second decoupling mechanism 12 is selectively operable to couple and decouple the first and second output shafts 24, 25 with the respective first and second front half-shafts 26, 27. The second decoupling mechanism 12 in the present embodiment comprises a first and a second output decoupling mechanism 12a, 12b, which can be opened to decouple the first and second output shafts 24, 25 from the first and second front half-shafts 26, 27. The second decoupling mechanism 12 is operable to disconnect the transmission 5 and the front differential 21 from the driven wheels W. Dto decouple. The second decoupling mechanism 12 in this embodiment is operational to separate both sides of the front differential 21. The first and second output decoupling mechanisms 12a, 12b can be operated together or independently of each other. The first and second output decoupling mechanisms 12a, 12b in the present embodiment are integrated into the front differential 21. However, it is understood that the first and second output decoupling mechanisms 12a, 12b can be separate from the front differential 21, which is arranged, for example, between the front differential 21 and the first and second front half-shafts 26, 27.

[0058] The control unit 2 in this further embodiment is configured to implement the first control strategy described herein. When the drivetrain separation sliding mode is activated, the first and second decoupling mechanisms 11, 12 are open such that the front differential 21 and the transmission 5 are decoupled from the drivetrain 6. In further embodiments, the second decoupling mechanism 12 may include one or more anti-slip mechanisms. The control unit 2 may be configured to implement the second and third control strategies described herein to deactivate the drivetrain separation sliding mode.

[0059] In certain modified arrangements, the second decoupling mechanism 12 can provide one-sided isolation. The second decoupling mechanism 12 can include a single output decoupling mechanism (either the first output decoupling mechanism 12a or the second output decoupling mechanism 12b) that can be opened to decouple the front differential 21. In this arrangement, the front differential 21 can rotate when the output decoupling mechanism 12 is open.

[0060] In another modified arrangement, the second decoupling mechanism 12 can be associated with the input ring gear 22 of the front differential 21. This arrangement of the second decoupling mechanism is shown in Fig. 8 is designated with the reference symbol 12c. The second decoupling mechanism 12c is open to decouple the input ring gear 22. Conversely, the second decoupling mechanism 12c is closed to couple the input ring gear 22.

[0061] At least some of the features described herein with reference to the front differential 21 can be incorporated into the rear differential 13, which is described with reference to the rear-wheel drive embodiments of the present invention. For example, the second decoupling mechanism 12 described with reference to the front differential 21 can be incorporated into the rear differential 13 to allow the first and second rear half-shafts 9, 10 to be selectively coupled and decoupled.

[0062] Vehicle 1 can include one or more electric traction motors. Vehicle 1 can be, for example, a mild hybrid electric vehicle (MHEV) or a plug-in hybrid electric vehicle (PHEV). The electric traction motor(s) can be, for example, integrated into the transmission 5 or the powertrain 6. The electric traction motor(s) could, for example, be coupled to the transmission input shaft 28, the transmission intermediate shaft, or the transmission output shaft.

[0063] Aspects of the invention described herein could also be incorporated into a four-wheel drive vehicle with front and rear driven wheels W D A vehicle 1 with four-wheel drive and comprising first and second decoupling mechanisms 11, 12 according to an embodiment of the present invention is in Fig. Figure 9 shows that the vehicle 1 comprises a transfer case 30 which is drive-connected to the transmission 5. A front drive shaft 31 connects the transfer case 30 to the first and second front half-shafts 26, 27. The first decoupling mechanism 11 is integrated into the transfer case 30 and serves to disconnect the front drive shaft 31 from the transfer case 30. The second decoupling mechanism 12 comprises a first and a second output decoupling mechanism 12a, 12b, which are associated with the first and second front half-shafts 26, 27, respectively. When the vehicle 1 is operated in a drivetrain separation sliding mode, the first decoupling mechanism 11 opens to disconnect the transfer case 30 from the front drive shaft 31. and the first and second output decoupling mechanisms 12a, 12b are opened to disconnect the first and second front half-shafts 26, 27 from the front drive shaft 31.The front drive shaft 31 can thus be separated from the internal combustion engine 3 and the front driven wheels W. D They will be separated when the drivetrain separation sliding mode is activated. It is understood that additional decoupling mechanisms are used to separate the drive shaft 8 from the rear driven wheels W. D They may be provided for. For example, the mechanisms described herein with reference to the one in Fig. The five vehicles shown, 1 with rear-wheel drive, are described in which vehicle 1 with four-wheel drive is implemented, which is in Fig.Figure 9 shows that the four-wheel drive function of vehicle 1 can be permanently engaged. Alternatively, the four-wheel drive function of vehicle 1 can be selectively a four-wheel drive, for example, operating in two-wheel drive under normal operating conditions. The activation of the drivetrain separation sliding mode can be controlled depending on whether vehicle 1 is operating in four-wheel drive or two-wheel drive.

[0064] It is understood that various changes and modifications can be made to the embodiments described herein without deviating from the scope of the present invention.

Claims

[1] Vehicle (1) comprising the following: a torque generating machine (4); one or more driven wheels (W D ); a drive train (6) for transmitting a torque from the torque generating machine (4) to the one or more driven wheels, wherein the drive train (6) comprises a torque transmission means (8); a first decoupling mechanism (11) that is operational to decouple the torque transmission means (8) from the torque generating machine (4), wherein the first decoupling mechanism (11) is closed to couple the torque transmission means (8) to the torque generating machine (4) and is open to decouple the torque transmission means (8) from the torque generating machine (4); a second decoupling mechanism (12) that is operational to decouple the torque transmission means (8) from the one or more driven wheels, wherein the second decoupling mechanism (12) is closed to couple the torque transmission means (8) to the one or more driven wheels and is open to decouple the torque transmission means (8) from the one or more driven wheels; and a control device (2) with at least one electronic processor (P) for controlling the operation of the first and second decoupling mechanisms (11, 12), wherein the at least one electronic processor (P) is configured to: Closing the first decoupling mechanism (11); Determining a target operating speed of the torque-generating machine (4); After closing the first decoupling mechanism (11), the operating speed of the torque-generating machine (4) is controlled as a function of the determined target operating speed; and The second decoupling mechanism (12) closes when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed. [2] Vehicle (1) according to claim 1, wherein the first decoupling mechanism (11) comprises a first torque input means and a first torque output means, wherein the first decoupling mechanism (11) accommodates a slip between the first torque input means and the first torque output means. [3] Vehicle (1) according to claim 1 or 2, wherein the at least one electronic processor (P) is configured to determine the target operating speed of the torque generating machine (4) as a function of a wheel speed signal. [4] Vehicle (1) according to one of the preceding claims, wherein the second decoupling mechanism (12) comprises a second torque input means and a second torque output means, wherein the second decoupling mechanism (12) is an anti-slip mechanism. [5] Vehicle (1) according to claim 4, wherein the second decoupling mechanism (12) comprises one or more of the following sets: a torque converter, a single-disc clutch, a multi-disc clutch, a synchronizing device, a hydrostatic clutch and a magnetic clutch. [6] Vehicle (1) according to one of the preceding claims, comprising a transmission (5) coupled to the torque generating machine (4), wherein the first decoupling mechanism (11) is incorporated into the transmission (5). [7] Vehicle (1) according to any one of claims 1 to 5, comprising a transmission (5) coupled to the torque generating machine (4), wherein the first decoupling mechanism (11) is arranged between the torque generating machine (4) and the transmission (5); or between the transmission (5) and the torque transmission means (8). [8] Vehicle (1) according to any of the preceding claims, wherein the first decoupling mechanism (11) comprises one or more of the following sets: a torque converter, a single-disc clutch, a multi-plate clutch, a synchronizing device, a hydrostatic clutch and a magnetic clutch. [9] Vehicle (1) according to one of the preceding claims, wherein the torque generating machine (4) comprises an internal combustion engine (4). [10] Vehicle (1) according to one of the preceding claims, wherein the control device is configured to activate a powertrain separation sliding mode by opening the first decoupling mechanism (11) to decouple the torque transmission means (8) from the torque generating machine (4) and opening the second decoupling mechanism (12) to decouple the torque transmission means (8) from the one or more driven wheels. [11] Method for controlling a first and a second decoupling mechanism (11, 12) for controlling the transmission of a torque from a torque generating machine (4) to one or more driven wheels of a vehicle (1); wherein the method comprises: Opening the first decoupling mechanism (11) to decouple the torque transmission means from the torque generating machine (4); Opening the second decoupling mechanism (12) to decouple the torque transmission means (8) from the one or more driven wheels; Closing the first decoupling mechanism (11); Determining a target operating speed of the torque-generating machine (4); after closing the first decoupling mechanism (11), controlling the operating speed of the torque-generating machine (4) depending on the determined target operating speed; and The second decoupling mechanism (12) closes when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed. [12] Method according to claim 11 comprising determining the target operating speed of the torque generating machine (4) as a function of a wheel speed signal. [13] Method according to claim 11 or 12, wherein the second decoupling mechanism (12) comprises a second torque input means and a second torque output means; wherein the method comprises at least substantially adjusting the rotational speed of the second torque input means and the second torque output means and then closing the second decoupling mechanism (12). [14] Method according to any one of claims 11 to 13, comprising activating a drive train separation sliding mode by opening the first decoupling mechanism (11) to decouple the torque transmission means (8) from the torque generating machine (4), and opening the second decoupling mechanism (12) to decouple the torque transmission means (8) from the one or more driven wheels. [15] Control device comprising at least one processor (P) configured to implement the method described in any one of claims 11 to 14.

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