Volvo Truck Corporation

Volvo Lastvagnar Ab

Magnus Blanckenfiell

Fredrik Karpenman

Anders Eriksson

Marcus Steen

Klas Bergström

Anders Lindgren

Marcus Persson

Per-Olof Källen

Ödül Bilen

Jenny Lepa

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

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.

Method for automatically warming up a clutch actuator

In a method for estimating the quality of an urea based reagent in terms of urea concentration, the reagent is injected upstream of a SCR catalyst in an exhaust aftertreatment system. A demanded NOx conversion rate is set substantially lower than a currently estimated maximum NOx conversion rate of the SCR catalyst. An actual NOx conversion rate is monitored for a certain time period. The urea concentration of the reagent is estimated based on comparing the monitored actual NOx conversion and the demanded NOx conversion during the time period. A corresponding system is also disclosed.

Method and system for estimating reagent quality

An engine driven vehicle includes at least one engine, and control devices that are arranged to control a transmission that is driven by the engine. The control devices are arranged to receive at least two sets of data, each set including at least one of a first signal that includes information about the gradient of the surface on which the vehicle is being driven sent from a first sensor, and at least one second signal that includes information about the vehicle's speed sent from a second sensor, and at least one third signal that includes information about the vehicle's acceleration. The control devices are also arranged to calculate at least one of two different resistance to travel constants kand k, in response to the first, second and third signals, and to control the transmission in response to at least one of the constants kand k.

Growing community of inventors

Hisings Kärra, Sweden

Magnus Blanckenfiell