US 11,987,955 B2
Work machine management system
Akira Kurasako, Tsuchiura (JP); Hideki Akita, Tsuchiura (JP); and Hidekazu Motoki, Kashiwa (JP)
Assigned to Hitachi Construction Machinery Co., Ltd., Tokyo (JP)
Appl. No. 17/633,458
Filed by Hitachi Construction Machinery Co., Ltd., Tokyo (JP)
PCT Filed Apr. 15, 2020, PCT No. PCT/JP2020/016623
§ 371(c)(1), (2) Date Feb. 7, 2022,
PCT Pub. No. WO2021/044660, PCT Pub. Date Mar. 11, 2021.
Claims priority of application No. 2019-160201 (JP), filed on Sep. 3, 2019.
Prior Publication US 2022/0282455 A1, Sep. 8, 2022
Int. Cl. E02F 9/22 (2006.01); E02F 9/26 (2006.01)
CPC E02F 9/2235 (2013.01) [E02F 9/26 (2013.01); E02F 9/2271 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A work machine management system comprising:
a work machine including a hydraulic system that drives a plurality of actuators by a hydraulic fluid and an oil sensor that detects a plurality of oil properties including a density and a permittivity of the hydraulic fluid;
a storage device that stores respective abnormality determination values of the plurality of oil properties; and
a controller that diagnoses an abnormality in the hydraulic fluid by comparing respective values of the plurality of oil properties detected by the oil sensor with the respective abnormality determination values of the plurality of oil properties, the abnormality determination values being stored in the storage device, wherein
the storage device stores,
in advance, oil change history information of the hydraulic fluid, oil kind determination values for determining whether the hydraulic fluid is either a mineral oil or a biodegradable oil or a mixed oil of the mineral oil and the biodegradable oil, the oil kind determination values being set by at least one of a density and a permittivity of the hydraulic fluid, and abnormality determination values for respective kinds of the hydraulic fluid as the abnormality determination values, and
the controller is configured to
check whether the oil change history information stored in the storage device includes oil change information for which oil kind determination has not been made,
determine a kind of the hydraulic fluid on a basis of the value of at least one of the plurality of oil properties detected by the oil sensor and the oil kind determination values stored in the storage device when there is oil change information for which oil kind determination has not been made, and
determine the abnormality in the hydraulic fluid by using abnormality determination values of the hydraulic fluid corresponding to a result of determination of the kind of the hydraulic fluid, among the abnormality determination values for the respective kinds of the hydraulic fluid.