VEHICLE DEVICE AND PROCEDURES

Abstract

A vehicle (1), comprising: a torque generating machine (4); one or more driven wheels (W D ); a drive train (6) for transmitting torque from the torque generating machine (4) to the one or more driven wheels, the drive train (6) comprising torque transmission means (8); a first decoupling mechanism (11) that is operable 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 open to decouple the torque transmission means (8) from the torque generating machine (4); a second decoupling mechanism (12) that is operable 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 open to decouple the torque transmission means (8) from the one or more driven wheels; and a controller (2) with at least one electronic processor (P) for controlling the operation of the first and second decoupling mechanism (11, 12), wherein at least one electronic processor (P) is configured to: to determine a target operating speed of the torque generating machine (4); to control the working speed of the torque generating machine (4) depending on the determined target operating speed; to close the first decoupling mechanism (11) when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed; and to close the second decoupling mechanism (12) after closing the first decoupling mechanism (11).

Description

TECHNICAL AREA

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

[0002] It is known that disengaging a vehicle's power unit and reducing the operating speed of an internal combustion engine reduces fuel consumption. This strategy is known as vehicle coasting, vehicle gliding, coasting, etc. The operating mode is referred to here as coasting mode.

[0003] An example of a known drive interruption strategy is disclosed in the applicant's earlier British patent application GB1316183 A. A rear-wheel-drive vehicle 1, comprising a drive train 3, is disclosed in Fig. Figure 1 shows the powertrain 3 comprising an internal combustion engine 4, a transmission 5, and a drive train 6. When a coasting mode is activated, the drive train 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 drive train 6 is rotated by a torque applied by drive wheels W. D (the rear wheels in the present arrangement). The dynamic operating states of the respective components when 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-mounted vehicle 1 can also operate in a sliding 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 drive wheels W. D (the front wheels in the present arrangement). The dynamic operating states of the respective components when 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 on 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, represented by a first arrow pointing in the direction of travel (from left to right in Figure 2), include: an engine torque A, dependent on 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, represented by a second arrow pointing in the opposite direction (from right to left in Figure 2), include: an engine torque A, dependent on a driver torque request; and an effective torque B, derived from the road gradient. 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.

[0006] State of the art: EP 1 859 982 A2, DE 11 2009 002 179 T5 and WO 2015 / 099 592 A1.

[0007] 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

[0008] Aspects of the present invention relate to a vehicle that can be selectively operated 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.

[0009] According to another aspect of the present invention, a vehicle is provided which comprises a system described above: a torque generating machine; one or more driven wheels; a working system for transmitting torque from the torque-generating machine to the one or more driven wheels, wherein the drive train comprises a torque transmission means; a first decoupling mechanism that decouples 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 that decouples 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 to decouple the torque transmission means from one or more driven wheels; and A control system 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, resulting in a reduction of powertrain losses. This arrangement is particularly useful when the vehicle is operated in a powertrain decoupling gliding mode, where at least part of the powertrain can be decoupled and the operating speed of the internal combustion engine can be reduced.

[0010] 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.

[0011] At least in certain embodiments, the first decoupling mechanism can accommodate slip in order to absorb a speed difference 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 not accommodate 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.

[0012] 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 input means. The second decoupling mechanism can be operated selectively 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 absorb a speed difference between the second input means and the second output means. The second decoupling mechanism can include one or more friction plates. The second decoupling mechanism can include 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 can, 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 feed the torque transmission means back to the internal combustion engine and to 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] At least one electronic processor can be configured to close the second decoupling mechanism to couple the torque transmission means to one or more driven wheels. At least one electronic processor can be configured to start the torque-generating machine. 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. At least one electronic processor can control the operating speed of the torque-generating machine based on the determined target operating speed. At least one electronic processor can close the first decoupling mechanism when the operating speed of the torque-generating machine is at least substantially equal 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] 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 difference between the first input shaft and the first output shaft when the first decoupling mechanism is closed.

[0019] At least one electronic processor can be configured to start the torque-generating machine when the first torque decoupling mechanism is open. 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. 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 the same as the specified target operating speed. The second decoupling mechanism can close 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 account for 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] At least one electronic processor can be configured to start the torque-generating machine when the first torque decoupling mechanism is open. At least one electronic processor can be configured to close the first decoupling mechanism. At least one electronic processor can determine a target operating speed of the torque-generating machine. After the first decoupling mechanism closes, at least one electronic processor can control the operating speed of the torque-generating machine based on the determined target operating speed. The target operating speed can be determined based 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.At least one electronic processor can be designed 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 account for 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] 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 may be used to select one of several gear ratios. The transmission may be automatic. 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-generating machine.

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

[0024] The control can be configured to activate a drivetrain decoupling sliding mode by opening the first decoupling mechanism to decouple the torque transmission means from the torque generating machine and 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; the method consists of: 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 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 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 specified 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 triggered 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 specified 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 first 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 comprise a first torque input means and a first torque output means. The first decoupling mechanism can include a slip 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. This second decoupling mechanism can include an anti-slip mechanism that prevents slippage between the first torque input means and the first torque output means. For example, the second decoupling mechanism can include a torque converter, a single-plate clutch, a multi-plate clutch, a synchronizer, a hydrostatic clutch, or a magnetic clutch.

[0034] Any control devices described herein may appropriately comprise a control unit or a computer device with one or more electronic processors. Accordingly, the system comprises 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 operating together to provide any specified control functionality. To configure a control device, a suitable set of instructions may 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 unit. A first control unit can be implemented in software running on one or more processors. One or more control units can be implemented in software running on one or more processors, optionally on the same one or more processors as the first control unit. 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 in any 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 drawings; the following applies: Fig. Figure 1 shows a schematic representation of the main components of a conventional rear-wheel drive vehicle; Fig. Figure 2 shows a schematic representation of the main components of a conventional front-wheel drive vehicle; Fig. Figure 3 shows a schematic representation of the forces acting on a vehicle when operating in a sliding mode; Fig. Figure 4 shows a schematic representation of a vehicle configured to operate in a powertrain decoupling sliding mode according to an embodiment of the present invention; Fig. Figure 5 shows a schematic representation of the dynamic operating states of the components in the vehicle's drive position. Fig. 4, when it enters the aforementioned powertrain decoupling gliding mode; Fig. Figure 6 is a schematic representation of the loads on the vehicle, which are in Fig. 4 are shown when it is operated in the aforementioned powertrain decoupling gliding mode; Fig. Figure 7 shows a schematic representation of a front-wheel drive vehicle when operating in a drivetrain decoupling sliding mode in accordance with an embodiment of the present invention; Fig. Figure 8 shows a schematic representation of the gearbox and front differential of the vehicle in Fig. 7. Vehicle shown with front-wheel drive; and Fig. Figure 9 shows a schematic representation of an all-wheel drive vehicle that can be operated in a drivetrain decoupling sliding mode according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] A vehicle 1 with a control system 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 unit 2 is selectively configured to activate and deactivate a powertrain decoupling sliding mode. In the present embodiment, the vehicle 1 is a rear-wheel-drive automobile with driven wheels W Dwhich are located at the rear. It is understood that the invention described here 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 includes 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 with one or more internal friction brakes and one or more multi-plate clutches.

[0039] The transmission 5 is controlled by a transmission control module (TCM) 7. The drivetrain 6 is arranged to transmit torque from the internal combustion engine 4 to the 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 include.

[0040] 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 has 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 the first and second rear half-shafts 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 located at opposite ends of the drive shaft 8 and can be controlled independently of each other, as described herein. As described herein, the controller 2 is configured to control the operation of the first and second decoupling mechanisms 11, 12.

[0041] 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 can be selectively actuated 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 and thereby 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 arranged between the drive shaft 8 and the transmission 5, or between the internal combustion engine 4 and the transmission 5.

[0042] 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 the torque to the second input shaft; and the second output shaft transmits 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 (e.g., 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 serves to disconnect 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 decoupling sliding mode is deactivated. In a modified arrangement, the second decoupling mechanism 12 can comprise a first and a second clutch mechanism, each 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.

[0043] The control unit 2 comprises at least one electronic processor P configured to execute a set of computational instructions stored on a non-transient, computer-readable medium. The control unit 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 unit 2 is configured to identify a vehicle gliding opportunity when the measured dynamic condition(s) differs from a desired vehicle dynamic condition for the current vehicle operating parameter(s). The control unit 2 can also check to identify a positive torque request, indicating a driver intention to maintain the current dynamic vehicle conditions. When these conditions are met, the control unit 2 outputs an activation signal S.ACT a COM signal is sent to a vehicle communication network to activate a powertrain decoupling gliding mode. This depends on the activation signal S. ACTThe first decoupling mechanism 11 opens to decouple the drive shaft 8 from the internal combustion engine 4; and the second decoupling mechanism 12 opens to decouple the drive shaft 8 from the first and second rear half-shafts 9, 10. A powertrain control module (PCM) also operates to reduce the torque demand of the internal combustion engine 4. The internal combustion engine 4 can operate at idle during the powertrain decoupling glide 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 decoupling glide 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 powertrain decoupling sliding mode to be activated over a wider range of operating conditions.

[0044] With reference to Fig. 4 at least one electronic processor P is configured to process a wheel speed signal S WH , an internal 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 speed control system, for example to adapt to a target vehicle speed.

[0045] The transmission control module (TCM) 7 detects the activation signal S ACT which is communicated 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. DThe first and second decoupling mechanisms 11, 12 can be opened simultaneously or sequentially to activate the drivetrain decoupling sliding mode. The internal combustion engine 4 is shut down by locking the combustion cycle. 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, as the rotation of the driven wheels W D transmits an input torque.

[0046] The operating loads acting on vehicle 1 when the powertrain decoupling gliding mode has been activated are in Fig. Figure 6 shows a schematic representation. The first arrow 19 (pointing from left to right) represents the positive forces acting on the vehicle 1. The same deceleration can be achieved by activating the drivetrain decoupling 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 slowed down to idle speed or stopped. The second arrow 20 (pointing from right to left) represents the negative (e.g., 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 entire positive torque is provided by the effective torque B, and the entire negative torque comprises the aerodynamic torque C and the road loss torque D, e.g., -(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 decoupling glide mode can be advantageously activated, for example, to allow activation on smaller gradients.

[0047] Control 2 monitors the vehicle's dynamic conditions and operating parameters to determine when the powertrain decoupling gliding mode is no longer appropriate (e.g., when the effective torque B is no longer sufficient to compensate for the aerodynamic torque C and the road loss torque D). Control 2 then deactivates the powertrain decoupling gliding mode. Control 2 implements an initial 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 unit 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 decoupling sliding mode and has a lower rotational speed than the driven wheels W. DIn fact, the rotational speed of the drive shaft 8 can be zero (0) during the drivetrain decoupling sliding mode. The multi-disc 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 engages, 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. Dare connected. The controller 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 controller 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 unit 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 unit 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 unit 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.

[0048] The control strategy described above for terminating the drivetrain decoupling sliding mode requires that the second decoupling mechanism 12 allow slippage 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 decoupling sliding mode is deactivated. In the present embodiment, the second decoupling mechanism 12 comprises a multi-plate clutch to allow slippage. A first variant, which does not require the second decoupling mechanism 12 to provide slippage, 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.Control 2 is configured to activate the powertrain decoupling glide 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 to decouple the drive shaft 8 or sequentially. Alternative control strategies implemented for the first variant to deactivate the powertrain decoupling glide mode are now described. In another variant, if the internal combustion engine 3 is stopped and comes to rest during the powertrain decoupling glide 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 the rotational speeds are similar or possibly both zero.

[0049] A second control strategy for deactivating the powertrain decoupling sliding mode is now described. Control 2 determines W based on the measured wheel speed of the driven wheels. 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 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 connect. By controlling the operating speed of the internal 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.

[0050] A third control strategy for deactivating the powertrain decoupling 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 unit 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 (that of the wheel speed of the driven wheels W). D (is proportional). 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 connect. 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.

[0051] 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.

[0052] The vehicle 1 in the above embodiment has a rear-wheel drive arrangement. The invention described here 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, will now be described with regard to the Fig. 7 and Fig. 8 described. The same reference numerals are used for the same components in the description of this arrangement.

[0053] As in Fig. As shown in Figure 7, the vehicle 1 comprises a drive system 3 for generating traction force to propel the vehicle 1. The drive system 3 includes an internal combustion engine 4, a transmission 5, and a drive train 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 with one or more internal friction brakes and one or more multi-plate clutches. The drive train 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.

[0054] 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. Figure 8 of the torque transmission means includes a front axle differential 21, which is driven by the transmission 5. In particular, the front axle differential 21 has an input gear 22 that meshes with an output gear 23 of the transmission 5. The front differential 21 comprises the first and second output shafts 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.

[0055] 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 decoupling 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 controller 2 is configured to control the operation of the first and second decoupling mechanisms 11, 12.

[0056] 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 with the gearbox 5.

[0057] 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 with 11a. Alternatively, the first decoupling mechanism 11 can be built 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 gear 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 the 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.

[0058] The front axle differential 21 transmits the torque to the first and second front half-shafts 26, 27 to drive the driven wheels W Dto drive. The second decoupling mechanism 12 is selectively actuated 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 first and second output decoupling mechanisms 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 serves to decouple the transmission 5 and the front axle differential 21 from the driven wheels W. Dto decouple. The second decoupling mechanism 12 in this embodiment is operable 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.

[0059] The controller 2 in this further embodiment is configured to implement the first control strategy described herein. When the drivetrain decoupling 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 controller 2 may be configured to implement the second and third control strategies described herein to deactivate the drivetrain decoupling sliding mode.

[0060] 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.

[0061] In a further modified arrangement, the second decoupling mechanism 12 can be associated with the input gear ring 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 gear ring 22. Conversely, the second decoupling mechanism 12c is closed to couple the input gear ring 22.

[0062] At least some of the features described herein with reference to the front axle differential 21 can be incorporated into the rear differential 13, which was 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.

[0063] Vehicle 1 can include one or more electric drive motors. Vehicle 1 can be, for example, a mild hybrid electric vehicle (MHEV) or a plug-in hybrid electric vehicle (PHEV). The electric drive motor(s) can be, for example, integrated into the transmission 5 or the powertrain 6. The electric drive motor(s) could, for example, be coupled to the transmission input shaft 28, the transmission intermediate shaft, or the transmission output shaft.

[0064] Aspects of the invention described herein could also be incorporated into an all-wheel drive vehicle with front and rear driven wheels. D A vehicle 1 with all-wheel drive and 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 driveshaft 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 driveshaft 31 from the transfer case 30. The second decoupling mechanism 12 comprises first and second output decoupling mechanisms 12a, 12b, which are associated with the first and second front half-shafts 26, 27, respectively. When the vehicle 1 operates in a drivetrain decoupling sliding mode, the first decoupling mechanism 11 opens to disconnect the transfer case 30 from the front driveshaft 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 disconnected when the drivetrain decoupling sliding mode is activated. It is understood that additional decoupling mechanisms are used to disconnect the drive shaft 8 from the rear driven wheels W. D For example, these can be used with reference to the in Fig. 5 shown vehicle 1 with rear-wheel drive mechanisms described in the in Fig. The all-wheel drive function of vehicle 1, as shown in Figure 9, can be implemented. The all-wheel drive function of vehicle 1 can be permanently engaged. Alternatively, the all-wheel drive function of vehicle 1 can be selectively all-wheel drive, for example, operating in two-wheel drive under normal operating conditions. The activation of the drivetrain decoupling sliding mode can be controlled depending on whether vehicle 1 is operating in all-wheel drive or two-wheel drive mode.

[0065] It should be noted that various changes and modifications can be made to the invention described herein without deviating from the scope of the present application.

Claims

[1] A vehicle (1) comprising: a torque generating machine (4); one or more driven wheels (W D ); a drive train (6) for transmitting torque from the torque generating machine (4) to the one or more driven wheels, the drive train (6) comprising torque transmission means (8); a first decoupling mechanism (11) that is operable 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 open to decouple the torque transmission means (8) from the torque generating machine (4); a second decoupling mechanism (12) that is operable 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 open to decouple the torque transmission means (8) from the one or more driven wheels; and a controller (2) with at least one electronic processor (P) for controlling the operation of the first and second decoupling mechanism (11, 12), wherein at least one electronic processor (P) is configured to: to determine a target operating speed of the torque generating machine (4); to control the working speed of the torque generating machine (4) depending on the determined target operating speed; to close the first decoupling mechanism (11) when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed; and to close the second decoupling mechanism (12) after closing the first decoupling mechanism (11). [2] Vehicle (1) according to claim 1, wherein the first decoupling mechanism (11) comprises the first torque input means and the first torque output means, wherein the first decoupling mechanism (11) accommodates slip between the first torque input means and the first torque output means. [3] A vehicle (1) according to claim 1 or claim 2, wherein at least one electronic processor (P) is configured to determine the operating speed of the torque generating machine (4) as a function of a wheel speed signal. [4] A vehicle (1) according to one of the preceding claims, wherein the second decoupling mechanism (12) comprises the second torque input means and the second torque output means, wherein the second decoupling mechanism (12) is a slip-resistant mechanism. [5] A 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 synchronizer, a hydrostatic clutch and a magnetic clutch. [6] A vehicle (1) according to one of the preceding claims comprises a transmission (5) coupled to the torque generating machine (4), wherein the first decoupling mechanism (11) is incorporated into the transmission (5). [7] A 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 device (8). [8] A 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-disc clutch, a synchronizer, a hydrostatic clutch and a magnetic clutch. [9] A vehicle (1) according to any of the preceding claims, wherein the torque generating machine (4) comprises an internal combustion engine (4). [10] A vehicle (1) according to any of the preceding claims, wherein the control is configured to activate a disconnect sliding mode of the drive train by opening the first decoupling mechanism (11) to disconnect the torque transmission means (8) from the torque generating machine (4) and opening the second decoupling mechanism (12) to disconnect the torque transmission means (8) from the one or more driven wheels. [11] A method for controlling the first and second decoupling mechanism (11, 12) and the transmission of torque from a torque-generating machine (4) to one or more driven wheels of a vehicle (1); the method comprising: Opening the first decoupling mechanism (11) to decouple the torque transmission means (8) 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; Determining a target operating speed of the torque-generating machine (4); Controlling the working speed of the torque-generating machine (4) as a function of the determined target working speed; Closing of the first decoupling mechanism (11) when the operating speed of the torque-generating machine (4) corresponds at least substantially to the determined target operating speed; and Closing the second decoupling mechanism (12) after closing the first decoupling mechanism (11). [12] A method according to claim 11, wherein the target operating speed of the torque generating machine (4) is determined as a function of a wheel speed signal. [13] A method according to claim 11 or claim 12, wherein the second decoupling mechanism (12) comprises the second torque input means and the second torque output means; wherein the method at least substantially comprises 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] A method according to any one of claims 11 to 13, comprising the activation of a drive train decoupling sliding mode to decouple the torque transmission means (8) from the torque generating machine (4) by opening the first decoupling mechanism (11) and to decouple the torque transmission means (8) from one or more driven wheels by opening the second decoupling mechanism (12). [15] A controller comprising at least one processor (P) configured to implement the method described in claims 11 to 14.

Images