US 12,135,046 B2
Hydraulic machine
Minheuk Kang, Gyeongsangnam-do (KR); and Manseuk Jeon, Gyeongsangnam-do (KR)
Assigned to VOLVO CONSTRUCTION EQUIPMENT AB, Eskilstuna (SE)
Appl. No. 17/926,800
Filed by Volvo Construction Equipment AB, Eskilstuna (SE)
PCT Filed May 22, 2020, PCT No. PCT/KR2020/006675
§ 371(c)(1), (2) Date Nov. 21, 2022,
PCT Pub. No. WO2021/235574, PCT Pub. Date Nov. 25, 2021.
Prior Publication US 2023/0193931 A1, Jun. 22, 2023
Int. Cl. F15B 13/02 (2006.01); F15B 11/044 (2006.01); F15B 11/16 (2006.01)
CPC F15B 13/027 (2013.01) [F15B 11/044 (2013.01); F15B 11/161 (2013.01); F15B 2211/30505 (2013.01); F15B 2211/3116 (2013.01); F15B 2211/323 (2013.01); F15B 2211/329 (2013.01); F15B 2211/353 (2013.01); F15B 2211/40515 (2013.01); F15B 2211/45 (2013.01); F15B 2211/555 (2013.01); F15B 2211/6316 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A hydraulic machine comprising:
at least one actuator, the at least one actuator comprising a first actuator and a second actuator;
a tank;
a directional control valve disposed between the at least one actuator and the tank; and
an adjustable return check valve disposed between the directional control valve and the tank, the adjustable return check valve adjusted to provide a low back pressure when the first actuator operates and a high back pressure when the second actuator operates, wherein the adjustable return check valve comprises:
a valve block having a path defined therein;
a poppet opening or closing the path;
a guide configured to apply force to the poppet via a spring in a direction of closing the path; and
a piston, wherein when the piston pushes the guide toward the poppet, the guide applies a greater amount of force to the poppet, so that the adjustable return check valve provides the high back pressure.