A method for automatically warming up a clutch actuator for a clutch of a transmission in a vehicle, wherein the clutch actuator is operable by use of pressurized fluid and configured to actuate the clutch from an engaged to a disengaged state, and/or vice versa, the method including: identifying if a temperature is below a predetermined temperature value and if the clutch actuator is leaking, and if it is identified that the temperature is below the predetermined temperature value and that the clutch actuator is leaking; then repeatedly pressurizing the clutch actuator by use of the pressurized fluid until a state is reached indicative of the clutch actuator being functional, or until a maximum run out state is reached indicative of a faulty clutch actuator.

In a method for controlling a clutch actuator for an automated manual transmission, when a driver's operation signal is input for operation of the clutch actuator, the hydraulic pressure of a hydraulic chamber of the clutch actuator forms pressure equilibrium with the atmospheric pressure through a pressure equilibrium control by standing by at a control-standby state before an actual stroke position of the clutch actuator enters a hydraulic pressure generation range from a hydraulic pressure release range. When the actual stroke position of the clutch actuator enters the hydraulic pressure generation range from the hydraulic pressure release range, the clutch actuator is moved to the predetermined stroke position by a predetermined operation speed, and then controlled to follow the driver's operation signal.

A method for determining the engaged gear in a manual gearbox of a vehicle comprising a number of gears is described, wherein the vehicle comprises an engine, the manual gearbox, and at least one clutch. The method comprises the following steps: determination of the revolution rate of the engine as a function of time; differentiating the determined revolution rate of the engine against time; determination of the speed of the vehicle; and determination of the engaged gear based on characteristic curves of the revolution rate of the engine as a function of time for a number of the gears in the case of a fixed rate of engagement of the clutch, the revolution rate of the engine, the differential of the revolution rate of the engine against time and the speed of the vehicle.

A method of operating a vehicle drivetrain for rocking the vehicle free. The drivetrain has a transmission with an input and an output that can be coupled by a clutch. The input and output are connected to a drive aggregate and a drive output, respectively. The clutch is actuated based on driver actuation of an accelerator and a rotational speed of the drive output such that following accelerator actuation, when its actuation decreases, the clutch disengages with a first opening gradient. Then, based on a calculated point in time at which drive aggregate torque upon the clutch corresponds to torque on the clutch from the drive output, the clutch disengages with a second, smaller opening gradient. And depending on a rotational speed of the drive output relative to a limit value, the clutch either initiates or terminates engagement with a first closing gradient.

This vehicle transmission system includes a transmission (21) in which a gear is shifted by an operation of a driver of a vehicle (1), a clutch device (26) that is disposed in a motion transfer path between the transmission (21) and an engine (13) of the vehicle (1), and is disconnected and connected by an action of a clutch actuator (50), and a clutch control unit (61) that is configured to control disconnection and connection of the clutch device (26) by the clutch actuator (50). In a case where the vehicle (1) is started with a gear position of the transmission (21) located at or above a gear that is set in advance, and a vehicle speed (V) is less than or no higher than a set value (v2) that is set in advance, the clutch control unit (61) transitions to clutch capacity-limiting control in which a clutch capacity is reduced below that during normal clutch control.

An automatic transmission device for a vehicle driven by transmitting a torque of an engine to driving wheels includes a clutch provided in a torque transmission system extending from the engine to the driving wheels, a transmission located between the clutch and the driving wheels in the torque transmission system, and a transmission controller. The transmission controller is configured or programmed to perform a torque feedback-control to bring the clutch into a sliding state in response to issue of a shift command and feedback-control a transmission torque to a target torque, disengage the clutch after the torque feedback-control, change a shift stage of the transmission according to the shift command after disengaging the clutch, and engage the clutch after changing the shift stage.

The present invention relates to a saddle-ride type vehicle comprising a clutch assembly (4), interposed between an engine (2) and a gearbox (3), which includes a clutch device (11) in turn comprising two clutch elements (one integral with the shaft of the engine and the other with the input shaft of the gearbox) and return means (12) that keep these elements (11A, 11B) in contact in a closure condition of the clutch. According to the invention, the clutch assembly (4) further comprises an operating device (21) of the clutch device that causes detachment of the elements (11A, 11B) of the clutch device up to an opening condition of the clutch assembly. This latter further comprises a control device (6) to limit the torque peaks during gear change. This device comprises an actuation means (5) that, during gear change, exerts a predetermined force (S) in contrast to the force exerted by said return means (12) of the clutch assembly, wherein said predetermined force (S) is less than the force (F) generated by the return means (12) so as to cause a mutual slip of the elements (11A, 11B) of the clutch device (11) without said opening condition being reached. The operating device (21) is of hydraulic type and comprises a primary pump (22) operated by means of a control lever (23), wherein this primary pump (22) is hydraulically connected, through a primary hydraulic circuit (16), to a primary piston (24) acting on at least one of the elements (11A, 11B) of the clutch device (11) in opposition to the return means (12) so that, following an action on the control lever (23), the primary piston (24) exerts an action the elements (11A, 11B) determining the opening condition. According to the invention, the control device (6) comprises a secondary piston (25) connected to the primary piston (24), wherein the actuation means (5) exerts, directly or indirectly, the predetermined force (S) on the secondary piston (25), said predetermined force (S) being transferred to the primary piston (24) in opposition to the force (F) of the return means (12).

A method of operating a vehicle drivetrain for rocking the vehicle free. The drivetrain has a transmission with an input and an output that can be coupled by a clutch. The input and output are connected to a drive aggregate and a drive output, respectively. The clutch is actuated based on driver actuation of an accelerator and a rotational speed of the drive output such that following accelerator actuation, when its actuation decreases, the clutch disengages with a first opening gradient. Then, based on a calculated point in time at which drive aggregate torque upon the clutch corresponds to torque on the clutch from the drive output, the clutch disengages with a second, smaller opening gradient. And depending on a rotational speed of the drive output relative to a limit value, the clutch either initiates or terminates engagement with a first closing gradient.

A system, method and apparatus are disclosed for a clutch assembly for an automated manual transmission. The clutch assembly includes a dual power path. One power path connects a prime mover to the automated manual transmission via a wet clutch, and a second power path connects one of the prime mover and the automated manual transmission to a grounded connection for synchronizing the speed thereof for a gear change.

A gear-position learning device for an automatic clutch transmission includes a transmission configured to be shifted by an operation of a driver of a vehicle, a clutch device disposed in a transmission path between the transmission and an engine and configured to be connected and disconnected by actuation of a clutch actuator, a controller configured to control connection and disconnection of the clutch device performed by the clutch actuator, a shift drum configured to rotate according to a shift operation that the driver performs on a shift operator and switch the shift stage of the transmission, and a rotational position defining mechanism configured to define a rotational position of the shift drum, wherein the controller has a learning mode for learning a rotation angle of the shift drum and is configured to control connection and disconnection of the clutch device during the learning mode such that the shift drum is at a rotational position determined by the rotational position defining mechanism.