Abstract: A work vehicle includes a condenser, a fan, a variable mechanism, a fan control unit, an outside air temperature sensor, and a storage unit. The condenser cools a cooling medium used in an air conditioner. The fan cools the condenser. The variable mechanism can change a number of rotations of the fan. The fan control unit controls the variable mechanism. The storage unit stores a plurality of control maps for setting the number of rotations of the fan to respective different numbers of rotations of the fan in accordance with the outside air temperature detected by the outside air temperature sensor. The fan control unit controls the variable mechanism in accordance with one control map selected from the plurality of control maps stored in the storage unit based on an operating state of the air conditioner, to control the number of rotations of the fan.

Abstract: A work vehicle includes a condenser, a fan, a variable mechanism, a fan control unit, an outside air temperature sensor, and a storage unit. The condenser cools a cooling medium used in an air conditioner. The fan cools the condenser. The variable mechanism can change a number of rotations of the fan. The fan control unit controls the variable mechanism. The storage unit stores a plurality of control maps for setting the number of rotations of the fan to respective different numbers of rotations of the fan in accordance with the outside air temperature detected by the outside air temperature sensor. The fan control unit controls the variable mechanism in accordance with one control map selected from the plurality of control maps stored in the storage unit based on an operating state of the air conditioner, to control the number of rotations of the fan.

Abstract: A hydraulic control device of construction machinery is disclosed. The device includes a main merging/diverging valve, operating levers operated to actuate plural actuators, an operating condition judging section, and a pattern collating section. When a load pressure of each actuator is high, a discharge pressure of each discharge oil path is also high, and when a total of the discharge pressures exceeds a predetermined set pressure, the main merging/diverging valve is switched to a diverging position, and when the total of the discharge pressures drops to below the set pressure, the main merging/diverging valve is switched to the merging position.

Abstract: A working machine control device is provided which can surely determine whether working equipment attached to a working machine is in an operation state. The working machine control device is configured to control a vibration generating device that is supplied with pressure oil from a hydraulic pump to generate vibration to operate working equipment attached to a working machine. The working machine control device includes a controller that is configured to obtain frequency characteristic of the pump pressure based on a pump pressure value that is detected by a pressure sensing section, and to determine whether said working equipment is in an operation state or not based on said frequency characteristic.

Abstract: A working machine control device is provided which can surely determine whether working equipment attached to a working machine is in an operation state. The working machine control device is configured to control a vibration generating device that is supplied with pressure oil from a hydraulic pump to generate vibration to operate working equipment attached to a working machine. The working machine control device includes a controller that is configured to obtain frequency characteristic of the pump pressure based on a pump pressure value that is detected by a pressure sensing section, and to determine whether said working equipment is in an operation state or not based on said frequency characteristic.

Abstract: A hydraulic control device of construction machinery having a main merging/diverging valve interposed in a connecting oil path connecting discharge oil paths of first and second hydraulic pumps in a merging position, operating levers for corresponding works operated to actuate plural actuators, an operating condition judging section judging a lever operating condition of each operation lever, a pattern collating section selecting an operating pattern matching an actual operation pattern from set and stored various operation patterns corresponding the operating conditions in a controller. When a load pressure of each actuator is high, a discharge pressure of each discharge oil path is also high, and when a total of the discharge pressures exceeds a predetermined set pressure, the main merging/diverging valve is switched to a diverging position, and when the total of the discharge pressures drops to below the set pressure, the main merging/diverging valve is switched to the merging position.