Abstract: A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

Abstract: A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

Abstract: A hydraulic system for a working machine includes an fluid cooler including an input port and an output port, the fluid cooler being configured to cool an operation fluid, an outputting portion to output the operation fluid, a traveling hydraulic device to be activated by the operation fluid, an operating hydraulic device to be activated by the operation fluid, a first output fluid tube connecting the operating hydraulic device to a tank, a second output fluid tube branching from the first output fluid tube and being connected to the input port of the fluid cooler, a third output fluid tube connecting the outputting portion to the output port of the fluid cooler, a fourth output fluid tube connected to the traveling hydraulic device, the fourth output fluid tube being connected to the second output fluid tube, and a first check valve disposed on the fourth output fluid tube.

Abstract: A hydraulic system for a working machine includes an fluid cooler including an input port and an output port, the fluid cooler being configured to cool an operation fluid, an outputting portion to output the operation fluid, a traveling hydraulic device to be activated by the operation fluid, an operating hydraulic device to be activated by the operation fluid, a first output fluid tube connecting the operating hydraulic device to a tank, a second output fluid tube branching from the first output fluid tube and being connected to the input port of the fluid cooler, a third output fluid tube connecting the outputting portion to the output port of the fluid cooler, a fourth output fluid tube connected to the traveling hydraulic device, the fourth output fluid tube being connected to the second output fluid tube, and a first check valve disposed on the fourth output fluid tube.