US 12,221,768 B2
Hydraulic system for working machine
Kohei Nagao, Sakai (JP); and Yuji Fukuda, Sakai (JP)
Assigned to KUBOTA CORPORATION, Osaka (JP)
Filed by KUBOTA CORPORATION, Osaka (JP)
Filed on Jan. 5, 2024, as Appl. No. 18/404,935.
Application 18/404,935 is a continuation of application No. 17/837,255, filed on Jun. 10, 2022, granted, now 11,898,327.
Claims priority of application No. 2021-146278 (JP), filed on Sep. 8, 2021.
Prior Publication US 2024/0151004 A1, May 9, 2024
Int. Cl. E02F 9/22 (2006.01); E02F 9/20 (2006.01); F15B 13/044 (2006.01); F15B 15/20 (2006.01)
CPC E02F 9/2228 (2013.01) [E02F 9/2004 (2013.01); E02F 9/2285 (2013.01); F15B 13/044 (2013.01); F15B 15/20 (2013.01); E02F 9/2292 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A working machine comprising:
a prime mover;
an actuation hydraulic pump to be driven by the prime mover to output hydraulic fluid;
a pilot hydraulic pump to be driven by the prime mover to output pilot fluid;
a first control valve to be actuated by the pilot fluid to control supply of the hydraulic fluid to a first hydraulic actuator to cause the first hydraulic actuator to actuate a first device;
a second control valve to be actuated by the pilot fluid to control supply of the hydraulic fluid to a second hydraulic actuator to cause the second hydraulic actuator to actuate a second device;
an operation device to allow the pilot fluid to be output based on an operation state of the operation device;
a first pilot fluid passage to allow the pilot fluid to be supplied from the operation device to the first control valve;
a second pilot fluid passage to allow the pilot fluid to be supplied from the operation device to the second control valve;
a pressure detector to detect a pilot pressure which is a pressure of the pilot fluid in the first pilot fluid passage;
a blocking switching valve provided in the first pilot fluid passage;
a solenoid valve provided in the second pilot fluid passage; and
a controller configured or programmed to control actuation of the blocking switching valve and the solenoid valve; wherein
the controller is configured or programmed to:
cause the blocking switching valve to unblock the first pilot fluid passage to perform switching to a first operation pattern in which the operation device operates the first device via the first control valve and the first hydraulic actuator; and
cause the blocking switching valve to block the second pilot fluid passage and control the solenoid valve based on the pilot pressure detected by the pressure detector to perform switching to a second operation pattern in which the operation device operates the second device via the second control valve and the second hydraulic actuator.