FLUID PRESSURE CIRCUIT OF WORKING MACHINE - New Caterpillar Mitsubishi Corporation

Title:

FLUID PRESSURE CIRCUIT OF WORKING MACHINE

Document Type and Number:

Japanese Patent JP3833163

Kind Code:

B2

Abstract:

PROBLEM TO BE SOLVED: To provide a fluid pressure circuit of a working machine, which disables a plurality of pilot operations depending on the details of work through the use of a single changeover valve, and which can adapt to restrictions on a space, associated with the downsizing of the working machine.
SOLUTION: An electromagnetic changeover valve 83 for locking is provided in a common pilot primary-pressure passage 76 which is guided from a pilot pump 74 to respective pilot valves 72 and 73 for controlling a bucket cylinder and a swing cylinder. The switching operation of the valve 83 is performed by a mode selection switch 87 at the switching of work from excavating work to a shovel and crane work, so that pilot primary pressure can be released from inside the passage 76. This prevents the occurrence of pilot secondary pressure which is output from the respective pilot valves 72 and 73 so as to pilot-operate corresponding spools 66 and 67 of a control valve 63, respectively.

Inventors:

Osuda Kosen

Application Number:

JP2002305013A

Publication Date:

October 11, 2006

Filing Date:

October 18, 2002

Export Citation:

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