To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.

To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.

A shift control device for a vehicle includes: an engine; a shift mechanism disposed between the engine and driving wheels; a shift control section configured to control a transmission gear ratio of the shift mechanism; and a fuel cut control section configured to stop a fuel supply to the engine, at least when an accelerator pedal is in a release state, and when an engine speed is equal to or greater than a predetermined rotation speed, the shift control section being configured to perform a minimum rotation speed restriction control to control the transmission gear ratio of the shift mechanism so that the minimum rotation speed of the engine is equal to or greater than the predetermined rotation speed regardless of a vehicle front condition and an accelerator operation condition.

A shift control device for a vehicle includes: an engine; a shift mechanism disposed between the engine and driving wheels; a shift control section configured to control a transmission gear ratio of the shift mechanism; and a fuel cut control section configured to stop a fuel supply to the engine, at least when an accelerator pedal is in a release state, and when an engine speed is equal to or greater than a predetermined rotation speed, the shift control section being configured to perform a minimum rotation speed restriction control to control the transmission gear ratio of the shift mechanism so that the minimum rotation speed of the engine is equal to or greater than the predetermined rotation speed regardless of a vehicle front condition and an accelerator operation condition.

A vehicle control system and a method for a vehicle running on a low friction road inhibit repetitive gear shifts of a transmission of the vehicle. The vehicle control system of the vehicle includes: one or more sensors for sensing an engine speed of the vehicle, an engine oil temperature, a position of an accelerator pedal, a lateral acceleration of the vehicle, a rotational angle of a steering wheel, or whether a low friction road running mode switch is turned on or off; and a controller for receiving sensor data from the sensors. In particular, the controller determines whether the vehicle satisfies an entry condition for performing a repetitive shift prevention control based on the sensor data, and controls a gear shift of the transmission and an engine torque to inhibit the repetitive gear shifts of the vehicle when the downshift occurs when the vehicle has satisfied the entry condition.

A method for operating a powertrain, having at least one drive motor and at least one gearbox, of a motor vehicle which can be driven by the drive motor, via the gearbox, in which heat is transferred from the drive motor to the gearbox in a targeted manner, as a result of which the gearbox is heated in a targeted manner The heat is transferred from the drive motor to the gearbox in a targeted manner on the basis of predictive data which include at least one future state of the motor vehicle.

A control system for a hydrostatic drive system can include a hydraulic charge pump circuit having a hydraulic load and a tank. The hydraulic charge pump can be in fluid communication with the hydraulic charge pump circuit. A bypass line can extend to the tank from a junction between the hydraulic charge pump and the hydraulic load. A charge bypass valve can be disposed to control flow through the bypass line. The control system can include a control device configured to determine one or more operational parameters for the power machine and control the charge bypass valve to allow flow through the bypass line, from the hydraulic charge pump to the tank, based on the determined operational parameters during a starting operation.

A quickshifter-equipped vehicle control unit includes an engine speed calculator configured to calculate an engine speed and a shift controller configured to operate in a quick shift mode and in a normal shift mode. The quick shift mode is a mode in which upon detection of the shift operation, the shift controller adjusts an output of an engine while keeping a main clutch in an engaged state, and the normal shift mode is a mode in which upon detection of the shift operation, the shift controller controls a clutch actuator to bring the main clutch into a disengaged state. The shift controller selects the quick shift mode when the engine speed is higher than a predetermined rotational speed threshold, and selects the normal shift mode when the engine speed is lower than the rotational speed threshold.

An engine lubrication system including: an oil pump configured to be driven by an engine; an oil jet mechanism configured to inject oil pressure-fed by the oil pump to a piston; and circuitry configured to set a target hydraulic pressure of the oil injected from the oil jet mechanism according to an operation state of the engine; determine a hydraulic pressure state of the oil injected from the oil jet mechanism; and change a gear stage of the automatic transmission to a lower gear stage in a case that a predetermined condition between the determined hydraulic pressure state and the target hydraulic pressure is satisfied.

An engine lubrication system including: an oil pump configured to be driven by an engine; an oil jet mechanism configured to inject oil pressure-fed by the oil pump to a piston; and circuitry configured to set a target hydraulic pressure of the oil injected from the oil jet mechanism according to an operation state of the engine; determine a hydraulic pressure state of the oil injected from the oil jet mechanism; and change a gear stage of the automatic transmission to a lower gear stage in a case that a predetermined condition between the determined hydraulic pressure state and the target hydraulic pressure is satisfied.