A variable speed control system includes a multiple-speed transmission which changes a speed of an engine output in multiple stages based on a change in meshing state of a dog clutch which is caused in association with an operation of a change pedal connected mechanically, a pedal load detection device which detects an operation load of the change pedal, and a control unit which suppresses or shuts off an engine output to the multiple-speed transmission and permits a speed change action of the multiple-speed transmission by the change pedal when a detected pedal load exceeds a pedal load threshold. The variable speed control system further includes an engine revolution speed detection sensor which detects an engine revolution speed. The control unit changes the pedal load threshold according to the engine revolution speed detected. Such variable speed control system can realize a stable speed change action irrespective of running conditions.

The engine control device comprises a basic target torque-deciding part for deciding a basic target torque based on a driving state of a vehicle, a torque reduction amount-deciding part for deciding a torque reduction amount based on a steering wheel operation state, an TCM for deciding a torque-down demand amount, based on a driving state of the vehicle other than the steering wheel operation state, and a final target torque-deciding part for deciding a final target torque, based on the decided basic target torque, the decided torque reduction amount and the decided torque-down demand amount, wherein the final target torque-deciding part is operable, when there is a torque-down demand, to restrict a change in the final target torque corresponding to a change in the torque reduction amount.

A cause identifying device performs: determining that an operation of a transmission with a predetermined high load is a cause of oil temperature of hydraulic oil having been equal to or higher than the predetermined temperature when predetermined conditions that the transmission has operated with the predetermined high load in a target period immediately before the oil temperature of the hydraulic oil has been equal to or higher than the predetermined temperature and a vehicle acceleration in the target period has been equal to or higher than a predetermined acceleration value are satisfied; and determining that occurrence of a predetermined abnormality associated with a gear shifting device is the cause of the oil temperature of the hydraulic oil having been equal to or higher than the predetermined temperature when the predetermined conditions are not satisfied.

A method for shifting a transmission in a machine. The method includes detecting a request for a directional shift of the transmission and determining a ground speed of the machine in response to the request. The method further includes overriding the request if the ground speed is above a ground speed threshold. Further, the method includes preparing the machine for the directional shift by limiting an output speed of a power source of the machine and by issuing a command to a brake unit of the machine to reduce the ground speed of the machine. Furthermore, the method includes validating and raising the request to the transmission to execute the directional shift if the ground speed is below the ground speed threshold.

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

A vehicle includes a transmission having a variator and a sub-transmission mechanism, a controller serving as a shift control unit adapted to, as shift of the transmission, shift the sub-transmission mechanism and the variator so that a through speed ratio becomes a target speed ratio, and an engine serving as a torque increasing portion adapted to increase a torque inputted to the transmission in association with the shift of the transmission. The controller has a torque setting unit adapted to make a magnitude of an inclination larger as an increase amount of the engine rotation speed in association with the shift of the transmission is larger.

A vehicle transmission includes a shaft; speed-changing gears; switching mechanisms; and a shifting mechanism. The shifting mechanism is provided with a double-meshing preventing mechanism configured to switch between a one-way state in which the switching mechanisms are hindered from moving in a downshift direction and allowed to move in an upshift direction and a free state in which the switching mechanisms are allowed to move in both the downshift direction and the upshift direction.

Aspects of the present invention relate to a control module (15) for a vehicle powertrain. The powertrain comprises a transmission (14), an engine (12) and an electric machine (16). The control module (15) is configured to receive an input indicative of a requested upshift and in response to the received signal the control module (15) increases the torque output of the engine (12) prior to the start of the torque phase (20). As the torque output of the engine (12) increases the control module (15) decreases the torque output of the electric machine (16) such that a constant wheel torque is applied to the wheels (18) during the torque phase (20) of the upshift.

A method for carrying out a shifting operation in a sequential manual transmission, in particular a shifting claw transmission, is provided. During the shifting operation, a maximum clutch torque that can be transmitted by a clutch arranged between an engine and a transmission input shaft is automatically reduced without completely disengaging the clutch, and a rider-required drive torque is maintained in a manner which reduces undesired jerking movement of the vehicle due to sudden full clutch actuation.

Aspects of the present invention relate to a control module (15) for a vehicle powertrain. The powertrain comprises a transmission (14), an engine (12) and an electric machine (16). The control module (15) is configured to receive an input indicative of a requested upshift and in response to the received signal the control module (15) increases the torque output of the engine (12) prior to the start of the torque phase (20). As the torque output of the engine (12) increases the control module (15) decreases the torque output of the electric machine (16) such that a constant wheel torque is applied to the wheels (18) during the torque phase (20) of the upshift.