US 11,898,328 B2
Work vehicle and control method for work vehicle
Shogo Miyazaki, Tokyo (JP); and Akira Takeno, Tokyo (JP)
Assigned to Komatsu Ltd., Tokyo (JP)
Appl. No. 17/617,081
Filed by Komatsu Ltd., Tokyo (JP)
PCT Filed Jun. 12, 2020, PCT No. PCT/JP2020/023273
§ 371(c)(1), (2) Date Dec. 7, 2021,
PCT Pub. No. WO2020/255892, PCT Pub. Date Dec. 24, 2020.
Claims priority of application No. 2019-114082 (JP), filed on Jun. 19, 2019.
Prior Publication US 2022/0235536 A1, Jul. 28, 2022
Int. Cl. F16H 47/04 (2006.01); E02F 9/22 (2006.01)
CPC E02F 9/2253 (2013.01) [E02F 9/2235 (2013.01); E02F 9/2292 (2013.01); F16H 47/04 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A work vehicle comprising:
an input shaft that is connected to an engine;
an output shaft that is connected to a traveling device;
a power transmission device that includes a hydraulic transmission mechanism including a first hydraulic pump motor and a second hydraulic pump motor and transmitting power input to the input shaft to the output shaft via a clutch mechanism, the first hydraulic pump motor functioning as one of a hydraulic pump and a hydraulic motor and the second hydraulic pump motor functioning as the other of the hydraulic pump and the hydraulic motor; and
a control device,
wherein the control device includes:
a clutch control unit that outputs a clutch command for engaging a specified clutch among a plurality of clutches of the clutch mechanism based on a speed ratio indicating a ratio between a rotation speed of the input shaft and a rotation speed of the output shaft;
a storage unit that stores correlation data indicating a relationship between the speed ratio and a capacity of the first hydraulic pump motor and a capacity of the second hydraulic pump motor; and
a power control unit that outputs a capacity command for changing at least one of the capacity of the first hydraulic pump motor and the capacity of the second hydraulic pump motor based on the speed ratio and the correlation data, and
the correlation data is set so that both the capacity of the first hydraulic pump motor and the capacity of the second hydraulic pump motor are changed with a change in the speed ratio in a predetermined speed ratio range between a first speed ratio and a second speed ratio higher than the first speed ratio.