Title:
CONTROL DEVICE FOR HYDRAULIC EXCAVATION WORK MACHINE
Document Type and Number:
Japanese Patent JP3739509
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a control device having a high level of safety for a hydraulic excavation work machine, capable of preventing the the uncontrollable state of a hydraulic actuator, even upon the occurrence of the seizure of a control solenoid valve laid in a pipeline.
SOLUTION: Regarding control solenoid proportional valves 13a to 13c arranged within a pilot oil feed pipeline for feeding pilot pressure to a direction selector valve 2b for controlling an arm cylinder 3b, and a direction selector valve 2d for controlling an offset cylinder 3d, a switch 10a to open and close the solenoid proportional valve 13b, for example, is pressed for the opening operation thereof and, then, released to output an off-signal for closing the valve 13b. In this case, when a pressure detector 11 in the pilot oil feed pipeline communicated to the outlet of the solenoid proportional valve 13b detects pilot pressure higher than the prescribed value, an off-signal is outputted for closing a shutoff solenoid selector valve 14, and pilot pressure to a right offset pilot pipeline T4 is interrupted, thereby returning the spool of a flow control valve 2d to a neutral position.
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Inventors:
Toshiaki Nishida
Hiroyuki Adachi
Kazuhiro Shibamori
Junichi Hosono
Hiroyuki Adachi
Kazuhiro Shibamori
Junichi Hosono
Application Number:
JP2379397A
Publication Date:
January 25, 2006
Filing Date:
February 06, 1997
Export Citation:
Assignee:
Hitachi Construction Machinery Co., Ltd.
International Classes:
E02F9/22; F15B20/00; E02F9/20; (IPC1-7): F15B20/00; E02F9/22
Domestic Patent References:
| JP625606U | ||||
| JP5040976A | ||||
| JP719207A | ||||
| JP640417U | ||||
| JP4213631A |
Attorney, Agent or Firm:
Kenjiro Take