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Title:
APPARATUS FOR DIAGNOSING FAILURE OF HYDRAULIC PUMP FOR WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/1998/006946
Kind Code:
A1
Abstract:
An apparatus for diagnosing failure of hydraulic pumps for a work machine, which apparatus is inexpensive and capable of surely specifying a faulty hydraulic pump or pumps. Pressure sensors (61-64) are provided on lines (30, 40) leading to a tank (T) from locations leaving center bypasses of flow control valves (21, 231-234, 451-454, 26) connected to hydraulic pumps (1-6), and respective solenoid directional control valves (51-56) are provided on input circuits of respective regulators (11-16) to permit, when excited, pressure from a pilot pump (7) to be introduced into the regulators (11-16). When a switch (80) commands judgement with all the flow control valves in neutral positions, a signal from a processing device (70) energizes one of the solenoid directional control valves to cause a corresponding hydraulic pump to discharge a fluid at a maximum flow rate. A detected value from an associated pressure sensor at this time is converted into a flow rate and stored, and this sequence is carried out with respect to the respective hydraulic pumps. On the basis of flow rates obtained from every judgement, failure of a specified hydraulic pump or pumps is diagnosed.

Inventors:
TANAKA YASUO (JP)
OCHIAI MASAMI (JP)
YAGYU TAKASHI (JP)
HASHIMOTO AKIRA (JP)
FURUNO YOSHINORI (JP)
WATANABE YUTAKA (JP)
SUGIYAMA YUKIHIKO (JP)
Application Number:
PCT/JP1997/002771
Publication Date:
February 19, 1998
Filing Date:
August 07, 1997
Export Citation:
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Assignee:
HITACHI CONSTRUCTION MACHINERY (JP)
TANAKA YASUO (JP)
OCHIAI MASAMI (JP)
YAGYU TAKASHI (JP)
HASHIMOTO AKIRA (JP)
FURUNO YOSHINORI (JP)
WATANABE YUTAKA (JP)
SUGIYAMA YUKIHIKO (JP)
International Classes:
E02F9/22; E02F9/26; F04B49/06; F04B51/00; F15B20/00; (IPC1-7): F04B51/00; F15B20/00
Foreign References:
JPS5983812A1984-05-15
JPS6220681A1987-01-29
Attorney, Agent or Firm:
Take, Kenjiro (6-13 Nishishinbashi 1-chom, Minato-ku Tokyo 105, JP)
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