Abstract: It is made possible to prevent damage to hydraulic parts of a work machine due to a decrease in performance of a hydraulic fluid even when the hydraulic fluid of a hydraulic system is changed and the hydraulic fluid becomes a mixed oil in which a mineral oil and a biodegradable oil are mixed with each other. For this purpose, a 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 the mineral oil or the biodegradable oil or the mixed oil of the mineral oil and the biodegradable oil, and abnormality determination values for respective kinds of the hydraulic fluid. A controller checks whether the oil change history information includes oil change information for which oil kind determination has not been made.

Abstract: A computer for a manufacturer includes: a storage device storing amount-of-change determination values specified for respective amount-of-change indexes indicative of tendencies of temporal changes in pieces of sensor data A, B, and C, about a plurality of oil properties including a viscosity, a density, and a dielectric constant of oil; an abnormality determining section determining abnormality of the oil on the basis of the pieces of sensor data A, B, and C about the plurality of oil properties and abnormality determination values SAh, SAl, SBh, and SCh prescribed for the respective pieces of sensor data A, B, and C about the plurality of oil properties; a cause identifying section identifying, when the abnormality determining section determines the oil to be abnormal, the cause of the abnormality on the basis of the type of the oil property determined to be abnormal and the amount-of-change determination value of the oil property.

Abstract: It is made possible to prevent damage to hydraulic parts of a work machine due to a decrease in performance of a hydraulic fluid even when the hydraulic fluid of a hydraulic system is changed and the hydraulic fluid becomes a mixed oil in which a mineral oil and a biodegradable oil are mixed with each other. For this purpose, a 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 the mineral oil or the biodegradable oil or the mixed oil of the mineral oil and the biodegradable oil, and abnormality determination values for respective kinds of the hydraulic fluid. A controller checks whether the oil change history information includes oil change information for which oil kind determination has not been made.

Abstract: A computer for a manufacturer includes: a storage device storing amount-of-change determination values specified for respective amount-of-change indexes indicative of tendencies of temporal changes in pieces of sensor data A, B, and C, about a plurality of oil properties including a viscosity, a density, and a dielectric constant of oil; an abnormality determining section determining abnormality of the oil on the basis of the pieces of sensor data A, B, and C about the plurality of oil properties and abnormality determination values SAh, SAI, SBh, and SCh prescribed for the respective pieces of sensor data A, B, and C about the plurality of oil properties; a cause identifying section identifying, when the abnormality determining section determines the oil to be abnormal, the cause of the abnormality on the basis of the type of the oil property determined to be abnormal and the amount-of-change determination value of the oil property.

Abstract: A diagnostic system for a work machine includes a data storage device (210) in which sensor information (A) input from a sensor (101A) that senses an oil property of oil used for operation of the work machine and an abnormality degree determination value defined for each kind of the sensor information (A) are stored, and an arithmetic processing device (104) that executes first processing of discriminating the degree of abnormality level of the oil based on the sensor information (A) and the abnormality degree determination value, second processing of determining whether or not necessity to carry out oil analysis involving oil extraction exists based on the degree of abnormality level of the oil discriminated in the first processing, and third processing of outputting information indicating that the oil analysis is necessary to other terminal if it is determined that the oil analysis is necessary in the second processing.

Abstract: A diagnostic system for a work machine includes a data storage device (210) in which sensor information (A) input from a sensor (101A) that senses an oil property of oil used for operation of the work machine and an abnormality degree determination value defined for each kind of the sensor information (A) are stored, and an arithmetic processing device (104) that executes first processing of discriminating the degree of abnormality level of the oil based on the sensor information (A) and the abnormality degree determination value, second processing of determining whether or not necessity to carry out oil analysis involving oil extraction exists based on the degree of abnormality level of the oil discriminated in the first processing, and third processing of outputting information indicating that the oil analysis is necessary to other terminal if it is determined that the oil analysis is necessary in the second processing.