CPC E02F 9/2228 (2013.01) [E02F 9/2242 (2013.01); E02F 9/2253 (2013.01); E02F 9/2267 (2013.01); E02F 9/2285 (2013.01); F15B 13/02 (2013.01); F15B 21/0427 (2019.01); E02F 9/2292 (2013.01); E02F 9/2296 (2013.01); F15B 2211/20576 (2013.01)] | 12 Claims |
1. A hydraulic system of a working machine, comprising:
a hydraulic pump to output a hydraulic fluid;
at least one proportional valve to deliver the hydraulic fluid output from the hydraulic pump to a supply target;
a valve body that includes the proportional valve;
a heat-up fluid passage that is provided in the valve body and into which the hydraulic fluid output from the hydraulic pump flows;
at least one switching valve switchable between an open position in which the hydraulic fluid having passed through the heat-up fluid passage is supplied therethrough to a hydraulic device and a closed position in which the hydraulic fluid having passed through the heat-up fluid passage is not supplied therethrough to the hydraulic device and the hydraulic fluid from the hydraulic device is allowed to flow therethrough to be returned;
a controller configured or programmed to operate the switching valve and the proportional valve; and
a return circuit through which the hydraulic fluid having flown into the heat-up fluid passage is returned as a result of at least one of the switching valve and the proportional valve being operated by the controller.
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