US 11,885,099 B2
Drift-prevention valve device, blade device, and working machine
Shuhei Orimoto, Akashi (JP); Koichi Kiyasu, Akashi (JP); and Hiroshi Maeda, Kako-gun (JP)
Assigned to Caterpillar SARL, Geneva (CH)
Appl. No. 17/286,365
Filed by Caterpillar SARL, Geneva (CH)
PCT Filed Oct. 15, 2019, PCT No. PCT/EP2019/025349
§ 371(c)(1), (2) Date Apr. 16, 2021,
PCT Pub. No. WO2020/078586, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 2018-196058 (JP), filed on Oct. 17, 2018.
Prior Publication US 2021/0372085 A1, Dec. 2, 2021
Int. Cl. E02F 9/22 (2006.01); F15B 11/00 (2006.01); F15B 15/20 (2006.01); E02F 9/08 (2006.01); E02F 3/96 (2006.01); F15B 13/04 (2006.01)
CPC E02F 9/085 (2013.01) [E02F 3/964 (2013.01); E02F 9/2267 (2013.01); E02F 9/2271 (2013.01); E02F 9/2282 (2013.01); E02F 9/2285 (2013.01); F15B 11/003 (2013.01); F15B 13/0401 (2013.01); F15B 15/202 (2013.01); F15B 2211/30515 (2013.01); F15B 2211/3127 (2013.01); F15B 2211/329 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A drift-prevention valve device mounted on a fluid-pressure cylinder configured to actuate an actuated unit by being extended/contracted by supply/discharge of working fluid from a control valve to a first fluid chamber for supporting operation of a machine body by the actuated unit and a second fluid chamber opposed thereto, the drift-prevention valve device comprising:
a nonreturn valve including an accommodation part configured to communicate between the control valve and the first fluid chamber of the fluid-pressure cylinder, a valve element movably accommodated in the accommodation part, and an urging member for urging the valve element in a valve closing direction, configured to allow a flow of working fluid from the control valve to the first fluid chamber of the fluid-pressure cylinder and check the flow of the working fluid in the reverse direction;
a piston accommodation part provided separately from the accommodation part of the non-return valve; and
a power piston movably accommodated in the piston accommodation part, configured to define in the piston accommodation part, a first piston chamber communicating with the second fluid chamber of the fluid-pressure cylinder and a second piston chamber for draining located on the valve element side of the nonreturn valve and communicating with the tank, and further connected to the valve element of the non-return valve, and further connected to the valve element of the non-return valve, and operable by a difference between an urging force of the valve element by the urging member of the nonreturn valve and a second fluid chamber pressure of the fluid-pressure cylinder.