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Patent Searching and Data


Title:
WORKING MACHINE
Document Type and Number:
WIPO Patent Application WO/2018/179183
Kind Code:
A1
Abstract:
This working machine is provided with: a hydraulic cylinder 20 which drives a working implement 3; a control valve 22 which switches a discharge pipeline of a hydraulic pump 21 to be connected to a bottom oil chamber or a rod oil chamber of the hydraulic cylinder 20, or to a tank; a pilot pump 23 which outputs pilot pressure to drive the control valve 22; an engine 24 which drives the hydraulic pump 21 and the pilot pump 23; and an accumulator 26 which accumulates returned hydraulic oil from the hydraulic cylinder 20. The working machine is also provided with a bypass pipeline 41 which bypasses the control valve 22 and connects the bottom oil chamber of the hydraulic cylinder 20 to the discharge pipeline 21a of the hydraulic pump 21, and in which the accumulator 26 is installed, a controlling valve 27 for pressure accumulation, provided between the bottom oil chamber of the hydraulic cylinder 20 and the accumulator 26, a controlling valve 28 for release, provided between the accumulator 26 and the discharge pipeline 21a, and a hydraulic system controller 30 which opens the controlling valve 28 for release if an engine rotational speed N is less than a set value Ns.

Inventors:
OGAWA Yuichi (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
HIJIKATA Seiji (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
HOSHINO Masatoshi (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
TAKAHASHI Kiwamu (Hitachi Construction Machinery Tierra Co. Ltd., 1-2, Sasagaoka, Minakuchicho, Koka-sh, Shiga 61, 〒5280061, JP)
ISHIKAWA Kouji (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
Application Number:
JP2017/013074
Publication Date:
October 04, 2018
Filing Date:
March 29, 2017
Export Citation:
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Assignee:
HITACHI CONSTRUCTION MACHINERY CO., LTD. (16-1, Higashiueno 2-chome Taito-k, Tokyo 15, 〒1100015, JP)
International Classes:
F15B21/14; E02F9/22
Foreign References:
JP2009275771A2009-11-26
JP2012013203A2012-01-19
Attorney, Agent or Firm:
KAICHI IP (3-16, Nihonbashi-muromachi 4-chome Chuo-k, Tokyo 22, 〒1030022, JP)
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