US 12,276,086 B2
Hydraulic system for working machine
Yuji Fukuda, Osaka (JP)
Assigned to KUBOTA CORPORATION, Osaka (JP)
Filed by KUBOTA CORPORATION, Osaka (JP)
Filed on Oct. 12, 2021, as Appl. No. 17/499,365.
Claims priority of application No. 2020-172796 (JP), filed on Oct. 13, 2020.
Prior Publication US 2022/0112687 A1, Apr. 14, 2022
Int. Cl. E02F 9/22 (2006.01); F15B 11/024 (2006.01)
CPC E02F 9/2217 (2013.01) [F15B 11/024 (2013.01); E02F 9/2282 (2013.01); F15B 2211/3116 (2013.01); F15B 2211/3133 (2013.01); F15B 2211/40507 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A hydraulic system for a working machine, comprising:
a hydraulic actuator configured to be operated by operation fluid;
a first control valve connected to the hydraulic actuator;
a second control valve disposed downstream of the first control valve;
a communication fluid line for fluid communication between the hydraulic actuator and the control valve; and
a discharge fluid line to discharge the operation fluid from the first control valve,
wherein the first control valve comprises:
a first input port, a first communication port, a second communication port, an output port, and a discharge port;
a first supply path from the first input port to the second communication port to guide the operation fluid toward the hydraulic actuator;
a regeneration path from the first communication port to the first supply path to guide the operation fluid having been returned to the first control valve from the hydraulic actuator, to the first supply path and not to the discharge fluid line through the discharge port; and
a branched path that branches from the regeneration path and supplies the operation fluid to the second control valve and not to the discharge fluid line, and
wherein the discharge port is disconnected or isolated from the regeneration path and the branched path, to prevent fluid communication from the regeneration path and the branched path to the discharge port, and
wherein the branched path has a first throttle.