| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance reliability by calculating the particle size, concn. average value and temporal rate of increase of metal particles in oil on the basis of particle size distribution measured in a time series manner to estimate and diagnose trouble. SOLUTION: When predetermined DC voltage is applied across electrodes 2a, 2b, metal particles in oil are attracted to the cathode 2b in a chain like state to form a bridge between both electrodes 2a, 2b. The potential of the anode 2a lowers by the short-circuit current passed through the bridge but, when attracted metal particles are scattered by resistance heat, the potential of the anode 2a returns to the original potential. That is, pulse voltage is considered to be generated. A signal processing part 30 inputs this pulse voltage signal and holds a peak to output a peak voltage signal to a data processing part 40. The data processing part 40 subjects the peak voltage signal to A/D conversion and identifies not only a particle size from the magnitude of a peak voltage value but also the concn. of particles from the pulse count number corresponding to the particle size to form particle size distribution. A control part 50 diagnoses or estimates the trouble of hydraulic equipment from the particle size distribution.</p> |
