US 11,739,502 B2
Work machine
Kento Kumagai, Ami-machi (JP); Shinya Imura, Toride (JP); Yasutaka Tsuruga, Ryugasaki (JP); Takaaki Chiba, Kasumigaura (JP); Hiroaki Amano, Tsukuba (JP); Shinji Nishikawa, Kasumigaura (JP); Akihiro Narazaki, Tsukuba (JP); Genroku Sugiyama, Tsuchiura (JP); and Shinjiro Yamamoto, Ami-machi (JP)
Assigned to Hitachi Construction Machinery Co., Ltd., Tokyo (JP)
Appl. No. 17/641,038
Filed by Hitachi Construction Machinery Co., Ltd., Tokyo (JP)
PCT Filed Mar. 18, 2021, PCT No. PCT/JP2021/011253
§ 371(c)(1), (2) Date Mar. 7, 2022,
PCT Pub. No. WO2021/200244, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-060813 (JP), filed on Mar. 30, 2020.
Prior Publication US 2022/0333348 A1, Oct. 20, 2022
Int. Cl. E02F 9/22 (2006.01); F15B 11/024 (2006.01); E02F 9/20 (2006.01); F15B 13/02 (2006.01)
CPC E02F 9/2217 (2013.01) [E02F 9/2004 (2013.01); E02F 9/2228 (2013.01); E02F 9/2235 (2013.01); F15B 11/024 (2013.01); F15B 13/02 (2013.01); E02F 9/2282 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01); E02F 9/2296 (2013.01); F15B 2211/3058 (2013.01); F15B 2211/35 (2013.01); F15B 2211/40576 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A work machine comprising:
a machine body;
a work device mounted on the machine body;
an actuator that drives the machine body or the work device;
a hydraulic working fluid tank;
a hydraulic pump that sucks a hydraulic working fluid from the hydraulic working fluid tank and supplies the hydraulic working fluid to the actuator;
a flow rate control valve that is connected in parallel to a delivery line of the hydraulic pump and controls a flow of a hydraulic fluid to be supplied from the hydraulic pump to the actuator;
an operation lever that gives an instruction for an operation of the actuator; and
a controller that controls the flow rate control valve according to an input amount of the operation lever, wherein
the work machine includes
a regeneration valve that allows a hydraulic working fluid to flow from a meter-out side to a meter-in side of the flow rate control valve, and
a selector valve that is provided on a tank line connecting the flow rate control valve and the hydraulic working fluid tank to each other and opens or interrupts the tank line, and
the controller is configured to
calculate a target actuator flow rate that is a target flow rate for the actuator, on the basis of the input amount of the operation lever,
calculate a regeneration flow rate that is a flow rate of a hydraulic fluid passing through the regeneration valve, on the basis of the input amount of the operation lever and the target actuator flow rate,
subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate,
calculate a target flow rate control valve opening amount on the basis of the target actuator flow rate,
calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate,
control the selector valve on the basis of the input amount of the operation lever,
control the flow rate control valve according to the target flow rate control valve opening amount, and
control the hydraulic pump according to the target pump flow rate.