Title:
HYDRAULIC CIRCUIT OF EARTH DRILL
Document Type and Number:
Japanese Patent JP3193552
Kind Code:
B2
Abstract:
PURPOSE: To provide a hydraulic circuit of an earth drill which allows a boom winch and an auxiliary winch to be driven with different pumps during attached work of the earth drill in terms of the earth drill where a crane is used as a base machine and a main winch is driven with a first hydraulic pump and the boom winch and the auxiliary winch are driven with a second hydraulic pump.
CONSTITUTION: A boom winch control direction change over valve 40 is installed to even a discharge pipeline 26 of a first hydraulic pump 23 for a main winch drive as well. A hydraulic motor 6a of a boom winch 6 is connected to each of the secondary pipelines of each direction change over valve 40 in the lateral part of the first hydraulic pump 23 and a direction change over valve 27 in the lateral part of a second hydraulic pump 24 by way of change over valves 41 and 42. A secondary circuit of a pilot valve 35 of the boom winch 6 is changed over and connected to a pilot unit of the direction change over valves 40 and 27 by way of change over valves. During earth drill attached work, the boom winch 6 is driven with the first hydraulic pump 23.
Inventors:
Akio Kiue
Application Number:
JP34041893A
Publication Date:
July 30, 2001
Filing Date:
December 08, 1993
Export Citation:
Assignee:
Hitachi Construction Machinery Co., Ltd.
International Classes:
E21B11/00; E21B15/00; (IPC1-7): E21B11/00; E21B15/00
Domestic Patent References:
| JP5915184A | ||||
| JP547092U |
Attorney, Agent or Firm:
Katsuichi Wakata