Volvo Truck Corporation

Volvo Lastvagnar Ab

Fredrik Karpenman

Magnus Blanckenfiell

Anders Hedman

Erik Lauri

Klas Bergström

Henrik Ryberg

Fredrik Sjöqvist

Marcus Persson

Behrooz Razaznejad

Samuel Jakobsson

Jenny Lepa

Oskar Lygner

Sami Aho

An automated mechanical transmission for a vehicle includes a main gearbox assembly comprising a main shaft and being adapted to be shiftable between at least one engaged state and a neutral state; a split gearbox assembly comprising an input shaft and being adapted to be shiftable between a first engaged state, a second engaged state and a neutral state; a countershaft; a crawler gearbox assembly comprising a crawler gear engagement member which is adapted to selectively engage and disengage a crawler gear defining a torque path from the input shaft to the main gearbox assembly via the countershaft; a gearbox brake; and transmission control unit. The transmission is configured to be settable in an AMT neutral state defined by the main gearbox assembly being in the neutral state. When the transmission control unit obtains a request to engage the crawler gear from the AMT neutral state, the transmission control unit is configured to apply the gearbox brake so that a rotational speed of the countershaft is reduced to a first predetermined rotational speed which is higher than a zero rotational speed; and when the first predetermined rotational speed is reached, release the gearbox brake, set the split gearbox assembly to the neutral state and engage the crawler gear by the crawler gear engagement member.

Automated mechanical transmission for a vehicle

A transmission includes a plurality of pneumatic actuators for gear shifting, wherein the pneumatic actuators are arranged to discharge compressed air via a common ventilation system including at least one ventilation opening arranged in a housing arrangement of the transmission. A method for controlling ventilation of the transmission includes determining that a predetermined flushing condition is fulfilled and, in response thereto, initiating a flushing action in which at least two of the pneumatic actuators are controlled to discharge compressed air simultaneously or substantially simultaneously to the common ventilation system so as to force air through the at least one ventilation opening.

Method for controlling ventilation of a transmission

A system for controlling a clutch in a heavy vehicle including an internal combustion engine and an automated mechanical transmission, where the engine is running, the clutch is engaged and the transmission is in neutral, including an electronic control unit adapted to receive a request to shut down the engine, to disengage the clutch of the transmission, and to shut down the engine, where the electronic control unit is adapted to reengage the clutch when the rotation of the engine and the rotation of the transmission input shaft is zero, and to actively slow down rotation of the transmission input shaft by the use of a brake device if the stop time for the transmission input shaft exceeds a predefined time interval. The advantage of the invention is that vibrations and noise are reduced during shut down of the engine.

Method and system for disengaging a clutch during engine shutdown and vehicle comprising such a system

The present disclosure relates to a method for defining a clutch slipping point position (X) of a clutch in a gearbox comprising an input shaft arranged to be braked by a braking means. The method includes determining if the clutch is dragging when the clutch is fully disengaged. The method includes when it is determined that the clutch is dragging, applying the braking means with a predetermined brake torque (T) and so that the input shaft is not rotating; and thereafter: moving the clutch from the fully disengaged position towards an engaged position; determining when the input shaft starts to rotate with a predetermined rotation value indicative of a rotational speed of the input shaft; registering a clutch position (X) in which the clutch is positioned when the predetermined rotation value is reached; using a clutch transfer characteristics of the clutch, T, and Xto define the clutch slipping point position (X).

Method for defining a clutch slipping point position

The present invention relates to a method for controlling a clutch arrangement () of a vehicle transmission () arranged within a gearbox housing () of a vehicle, the clutch arrangement being connected to a pneumatically controlled actuator arrangement () for controllably arrange the clutch arrangement between a closed position and an open position, wherein the vehicle transmission further comprises at least one rotatable transmission component (&#x2033;) configured to assume an engaged state, a disengaged state and an at least partially engaged state. By means of the method, the rotatable transmission component is arranged to be positioned in the at least partially engaged state for increasing the heat within the gearbox housing.

Method for controlling a clutch arrangement

A method for controlling a multi-clutch transmission of a vehicle includes activating the central synchronizer to the first active state, such that the speed of a first member of a tooth clutch, attempting to engage the tooth clutch to be engaged, and if the tooth clutch to be engaged is determined not to be fully engaged a predetermined period of time after an initiation of an engagement, the following steps are performed: activating the central synchronizer to the second active state such that the speeds of the two members of the tooth clutch to be engaged are slightly unsynchronized, and engaging the tooth clutch to be engaged.

Method, computer program when run on a computer, computer readable medium and control unit for controlling a multi-clutch transmission

A method is provided for controlling a drivetrain of a vehicle, wherein the drive train includes a combustion engine in drive connection with a dual clutch transmission, wherein the dual clutch transmission is provided with a normally closed input clutch, a normally open input clutch, wherein the normally closed input clutch connecting the combustion engine with a first input shaft and the normally open input clutch connecting the combustion engine with a second input shaft and the first input shaft is in operative connection with a connection sleeve, wherein the connection sleeve can be arranged in an engaged and a disengaged position, whereby in the engaged position the connection sleeve enables an operative connection between the first input shaft to a gearwheel and in the disengaged position gearwheel is disconnected from the first input shaft and the connection sleeve is in a disengaged position when the drivetrain is turned off, wherein the method is automatically initiated at start of the drivetrain, and including the steps of; starting the combustion engine, controlling the normally open and the normally closed input clutch to an engaged or semi engaged state such that both the first and the second input shaft reaches a predetermined synchronized speed, and thereafter opening the normally closed input clutch, and when the countershaft sleeve reaches an essentially synchronous speed with the gearwheel engaging the connection sleeve.

Method for controlling a drivetrain of a vehicle

A method of controlling a vehicle presenting a plurality of wheels, an engine and a clutch for selectively connecting the engine to a number of the wheels includes receiving a torque control signal indicative of a demanded output torque of the engine, and observing a value of a first vehicle operation parameter being the vehicle speed or a parameter which is indicative of the vehicle speed, controlling the clutch so as to be engaged if the received torque control signal indicates that the demanded engine torque is minimal or below a first threshold value and the observed first vehicle operation parameter value is above a second threshold value,subsequently to the step of controlling the clutch so as to be engaged, performing a test disengagement of the clutch, including at least partly disengaging the clutch,observing a behavior, in response to the test disengagement, of a second vehicle operation parameter, andbased at least partly on the observation of the behavior of the second vehicle operation parameter, determining whether to control the clutch so as to be re-engaged or disengaged.

Method of controlling a vehicle

A method is provided for preselecting a gear in a multi-clutch transmission of a vehicle upon exiting free-wheeling state, wherein the multi-clutch transmission being operated in a free-wheeling state having a gear of a first set of gears preselected and a first friction clutch being disengaged; the method including the steps of: A) upon determining that at least one predetermined condition for exiting free-wheeling state is met; increasing the rotational speed of the prime mover towards a rotational synchronization speed of the preselected gear; the second friction clutch being in a closed state such that the rotational speed of the input shaft of the second friction clutch increases with the increasing rotational speed of the prime mover; B) disengaging the second friction clutch; C) engaging, at a suitable time point, at least one tooth clutch of the second subset of the tooth clutches corresponding to a gear of the second set of gears such that the gear of the second set of gears becomes preselected.

Method for preselecting a gear in a multi-clutch transmission of a vehicle upon exiting free-wheeling state

A method is provided for controlling an actuator of a vehicle transmission, the actuator being connected to an engaging sleeve, the engaging sleeve being axially displaceable between a gear wheel disengaging position and a gear wheel engaging position of the vehicle transmission for executing a transmission gear shift. The method includes actuating the actuator during a first predetermined time period for initiating a translational movement of the engaging sleeve front the gear wheel disengaging position towards the gear wheel engaging position, wherein the first predetermined time period is smaller than a total time period for the engaging sleeve to reach the gear wheel engaging position, determining, during a second predetermined time period initiated after the duration of the first predetermined time period, if the engaging sleeve has reached the gear wheel engaging position, and actuating the actuator during a third predetermined time period if it was determined that the engaging sleeve failed to reach the gear wheel engaging position during the second predetermined time period. A corresponding computer, computer readable medium, control unit, and vehicle transmission are also provided.

Method for controlling an actuator of a vehicle transmission

A method for operating a semi-automatic or automatic mechanical transmission of a heavy truck when driving at idle speed is provided. The method includes supplying fuel to the engine of the heavy truck at a rate that facilitates engine-idle operation. In another step, the method engages the automatic or semi-automatic transmission in a gear higher than the starting gear of the transmission and permits the truck to operate at a first substantially uniform driving velocity under engine-idle power. Depending upon traffic and environmental requirements which require a higher speed, the driver upshifts the semi-automatic or automatic transmission by depressing a control device for manual gear selection arranged on a gear shift lever of the truck and then drives the truck at a second substantially uniform driving velocity under engine-idle power. The second substantially uniform driving velocity is greater than the first substantially uniform driving velocity.

Growing community of inventors

Västra Frölunda, Sweden

Fredrik Karpenman