US 12,110,651 B2
Work machine and method for controling work machine
Shota Yamawaki, Tokyo (JP); and Shogo Miyazaki, Tokyo (JP)
Assigned to KOMATSU LTD., Tokyo (JP)
Appl. No. 17/426,399
Filed by KOMATSU LTD., Tokyo (JP)
PCT Filed Mar. 18, 2020, PCT No. PCT/JP2020/012075
§ 371(c)(1), (2) Date Jul. 28, 2021,
PCT Pub. No. WO2020/203315, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 2019-067317 (JP), filed on Mar. 29, 2019.
Prior Publication US 2022/0106763 A1, Apr. 7, 2022
Int. Cl. E02F 3/28 (2006.01); E02F 3/42 (2006.01); E02F 3/43 (2006.01); E02F 9/22 (2006.01); E02F 9/08 (2006.01); E02F 9/20 (2006.01)
CPC E02F 3/431 (2013.01) [E02F 3/283 (2013.01); E02F 3/422 (2013.01); E02F 9/2203 (2013.01); E02F 9/2228 (2013.01); E02F 9/2271 (2013.01); E02F 9/0841 (2013.01); E02F 9/2004 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A work machine comprising:
a boom;
a work tool configured to drive with respect to the boom;
a cylinder configured to drive the work tool;
a sub-link attached to the boom, the sub-link being configured to transmit driving force of the cylinder to the work tool;
an operating lever configured to operate the work tool;
a sensor configured to detect a stroke of the cylinder; and
a controller including a processor, the controller being configured to control the cylinder based on an operating amount of the operating lever and limit a flow rate of hydraulic fluid supplied to the cylinder based on a posture of the sub-link with respect to the boom,
the controller being further configured to
calculate a first flow rate limit amount based on a difference between the posture of the sub-link and a limit posture of the sub-link, the limit posture corresponding to a mechanism limit of the sub-link that is different from an end position of the cylinder,
calculate a second flow rate limit amount based on a difference between the stroke and the end position of the cylinder,
determine a larger of the first flow rate limit amount and the second flow rate limit amount,
set the larger of the first flow rate limit amount and the second flow rate limit amount as a flow rate limit amount, and
control the flow rate of the hydraulic fluid supplied to the cylinder such that the flow rate does not exceed a difference between a maximum flow rate and the flow rate limit amount.