发明名称 HYDRAULIC CIRCUIT WITH DEVICE FOR DETECTING CONTAMINATION LEVEL OF OPERATING OIL
摘要 <p>Problem: To provide a contamination level determination system for hydraulic oil, which even with light-blocking sensors of simple construction and low price, can improve the sensing accuracy of a contamination level of hydraulic oil contaminated with foreign matter of particle sizes that may cause an operation failure of a hydraulic working machine. Solution: A contamination level determination system for hydraulic oil is provided with a pilot filter 12 arranged in a line of a hydraulic circuit of a hydraulic working machine to remove, from the hydraulic oil, foreign matter of particle sizes that may cause an operation failure of the hydraulic working machine, a first light-blocking sensor 21 for sensing passage of foreign matter on an upstream side of the pilot filter 12, and a second light-blocking sensor 22 for sensing passage of foreign matter on a downstream side of the pilot filter 12. An onboard controller unit 23 functions as a means for determining a frequency of sensing of foreign matter by the first light-blocking sensor 21, a means for determining a frequency of sensing of foreign matter by the second light-blocking sensor 22, and a means for determining a contamination level on the upstream side of the pilot filter 12 on the basis of results of determination by both of these means.</p>
申请公布号 EP2302223(B1) 申请公布日期 2015.06.17
申请号 EP20090770260 申请日期 2009.06.26
申请人 HITACHI CONSTRUCTION MACHINERY CO., LTD 发明人 SATAKE HIDETOSHI
分类号 F15B21/04;E02F9/08;E02F9/22;E02F9/26;G01N21/53 主分类号 F15B21/04
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