US 12,241,545 B2
Hydraulic control system for transmission
Tomohiro Kanemaki, Tokyo (JP); and Masaki Shiohara, Tokyo (JP)
Assigned to KOMATSU LTD., Tokyo (JP)
Appl. No. 17/784,721
Filed by KOMATSU LTD., Tokyo (JP)
PCT Filed Jan. 18, 2021, PCT No. PCT/JP2021/001504
§ 371(c)(1), (2) Date Jun. 13, 2022,
PCT Pub. No. WO2021/186876, PCT Pub. Date Sep. 23, 2021.
Claims priority of application No. 2020-049909 (JP), filed on Mar. 19, 2020.
Prior Publication US 2023/0025188 A1, Jan. 26, 2023
Int. Cl. F16H 59/46 (2006.01); F16H 59/44 (2006.01); F16H 59/48 (2006.01); F16H 61/02 (2006.01); F16H 61/47 (2010.01)
CPC F16H 59/46 (2013.01) [F16H 59/44 (2013.01); F16H 59/48 (2013.01); F16H 61/0262 (2013.01); F16H 61/47 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A hydraulic control system for a transmission mounted in a work vehicle, the system comprising:
a power source;
a plurality of drive wheels;
a power transmission device configured to be set to a plurality of speed stages and transmit driving power from the power source to the plurality of drive wheels;
a hydraulic pump driven by the power source;
a main valve disposed between the hydraulic pump and the power transmission device and adjusting a main pressure of hydraulic fluid supplied from the hydraulic pump to the power transmission device; and
a controller configured to control the main valve,
the controller being configured to set the main pressure to a pressure value derived by adding a margin pressure to a clutch holding pressure of a speed stage set among the plurality of speed stages based on a load applied to the plurality of drive wheels, the margin pressure being determined based on a load applied to the plurality of drive wheels.