The powertrain device for a vehicle includes an engine and an automatic transmission, the automatic transmission includes a plurality of friction fastening elements for selectively switching motive power transmitting paths, a predetermined friction fastening element among the plurality of friction fastening elements is a travel-start friction fastening element performing slip control in a travel start, and the powertrain device includes, between the engine and the automatic transmission, a motive power connection-disconnection clutch which is released at least in an engine start and is fastened earlier than the travel-start friction fastening element in a travel start of the vehicle.

The powertrain device for a vehicle includes an engine and an automatic transmission, the automatic transmission includes a plurality of friction fastening elements for selectively switching motive power transmitting paths, a predetermined friction fastening element among the plurality of friction fastening elements is a travel-start friction fastening element performing slip control in a travel start, and the powertrain device includes, between the engine and the automatic transmission, a motive power connection-disconnection clutch which is released at least in an engine start and is fastened earlier than the travel-start friction fastening element in a travel start of the vehicle.

A gearshift control apparatus of a vehicle includes: a sensor configured to measure a speed, a brake position sensor (BPS) value, and an accelerator position sensor (APS) value of the vehicle, and a controller configured to, in a gearshift section spaced apart by a preset distance from a speed bump located on a road on which the vehicle travels, (i) calculate a deceleration of the vehicle and a gradient of the road after the speed bump, (ii) determine a correction factor corresponding to the deceleration of the vehicle and the gradient of the road, and (iii) perform a gearshift to a shift stage corresponding to the correction factor and the speed of the vehicle.

A gearshift control apparatus of a vehicle includes: a sensor configured to measure a speed, a brake position sensor (BPS) value, and an accelerator position sensor (APS) value of the vehicle, and a controller configured to, in a gearshift section spaced apart by a preset distance from a speed bump located on a road on which the vehicle travels, (i) calculate a deceleration of the vehicle and a gradient of the road after the speed bump, (ii) determine a correction factor corresponding to the deceleration of the vehicle and the gradient of the road, and (iii) perform a gearshift to a shift stage corresponding to the correction factor and the speed of the vehicle.

A work vehicle includes a power source, a travel device, a power transmission device, and a control device. The power transmission device includes a hydrostatic continuously variable transmission having a relief valve capable of setting a relief pressure, and is configured to transmit power of the power source to the travel device. The control device includes a relief pressure setting unit configured to set the relief pressure of the relief valve in accordance with a target output value of the travel device.

A work vehicle includes a power source, a travel device, a power transmission device, and a control device. The power transmission device includes a hydrostatic continuously variable transmission having a relief valve capable of setting a relief pressure, and is configured to transmit power of the power source to the travel device. The control device includes a relief pressure setting unit configured to set the relief pressure of the relief valve in accordance with a target output value of the travel device.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

A work vehicle includes a vehicle body provided with a travel device; a prime mover provided in the vehicle body; a transmission device capable of speed-changing a driving force from the prime mover and transmitting the driving force to the travel device; a transmission case housing the transmission device and being filled with lubricating oil; and a control device capable of switching between a warm-up operation mode in which a gear of the transmission device is rotated in a state in which transmission of power from the transmission device to the travel device is blocked and a travel operation mode in which the gear is rotated in a state in which the power is transmitted from the transmission device to the travel device.

A gearshift control apparatus of a vehicle includes: a sensor configured to measure a speed, a brake position sensor (BPS) value, and an accelerator position sensor (APS) value of the vehicle, and a controller configured to, in a gearshift section spaced apart by a preset distance from a speed bump located on a road on which the vehicle travels, (i) calculate a deceleration of the vehicle and a gradient of the road after the speed bump, (ii) determine a correction factor corresponding to the deceleration of the vehicle and the gradient of the road, and (iii) perform a gearshift to a shift stage corresponding to the correction factor and the speed of the vehicle.