A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
WORK MACHINE INCLUDING CONTRACTIVE AND EXPANSIVE ARM
To suppress excessive force from being applied to a contractive and expansive arm when excavating sediment in a hole bottom and the like with an elongated contractive and expansive arm.SOLUTION: A work machine comprises: a boom; a contractive and expansive arm; a clamshell bucket; an arm cylinder 25; a bucket opening/closing cylinder 26; hydraulic pumps 31, 32; a pilot pump 33; a control valve 35 for opening/closing a bucket; an operation device 37 for opening/closing a bucket having a pilot valve 37a outputting pilot pressure p2 to a pressure receiving portion at a bucket closing operation side of the control valve; a variable relief valve 1 lowering a relief pressure of a bottom side oil chamber of the arm cylinder 25 from first set pressure to second set pressure; and an expansive sensor S detecting elongation of the contractive and expansive arm to a length longer than a set length. When the contractive and expansive arm is elongated to a length longer than the set length and closing operation of the clamshell bucket is carried out, the relief pressure of the bottom side oil chamber of the arm cylinder by the variable relief valve is changed from the first set pressure to the second set pressure.SELECTED DRAWING: Figure 4
【課題】伸縮アームを伸ばして穴底等の土砂を掘削する際に伸縮アームに過度な応力がかかることを抑制する。【解決手段】ブーム、伸縮アーム、クラムシェルバケット、アームシリンダ２５、バケット開閉シリンダ２６、油圧ポンプ３１，３２、パイロットポンプ３３、バケット開閉用のコントロール弁３５、コントロール弁のバケット閉じ動作側の受圧部にパイロット圧ｐ２を出力するパイロット弁３７ａを持つバケット開閉用操作装置３７、アームシリンダ２５のボトム側油室のリリーフ圧を第１設定圧力から第２設定圧力に低下させる可変リリーフ弁１、及び伸縮アームが設定長さ以上に伸長したことを検出する伸長センサＳを備えた作業機械において、伸縮アームが設定長さ以上に伸長してクラムシェルバケットの閉じ操作がされた場合に、可変リリーフ弁によるアームシリンダのボトム側油室のリリーフ圧を第１設定圧力から第２設定圧力に切り換えるように構成する。【選択図】 図４
WORK MACHINE INCLUDING CONTRACTIVE AND EXPANSIVE ARM
To suppress excessive force from being applied to a contractive and expansive arm when excavating sediment in a hole bottom and the like with an elongated contractive and expansive arm.SOLUTION: A work machine comprises: a boom; a contractive and expansive arm; a clamshell bucket; an arm cylinder 25; a bucket opening/closing cylinder 26; hydraulic pumps 31, 32; a pilot pump 33; a control valve 35 for opening/closing a bucket; an operation device 37 for opening/closing a bucket having a pilot valve 37a outputting pilot pressure p2 to a pressure receiving portion at a bucket closing operation side of the control valve; a variable relief valve 1 lowering a relief pressure of a bottom side oil chamber of the arm cylinder 25 from first set pressure to second set pressure; and an expansive sensor S detecting elongation of the contractive and expansive arm to a length longer than a set length. When the contractive and expansive arm is elongated to a length longer than the set length and closing operation of the clamshell bucket is carried out, the relief pressure of the bottom side oil chamber of the arm cylinder by the variable relief valve is changed from the first set pressure to the second set pressure.SELECTED DRAWING: Figure 4
【課題】伸縮アームを伸ばして穴底等の土砂を掘削する際に伸縮アームに過度な応力がかかることを抑制する。【解決手段】ブーム、伸縮アーム、クラムシェルバケット、アームシリンダ２５、バケット開閉シリンダ２６、油圧ポンプ３１，３２、パイロットポンプ３３、バケット開閉用のコントロール弁３５、コントロール弁のバケット閉じ動作側の受圧部にパイロット圧ｐ２を出力するパイロット弁３７ａを持つバケット開閉用操作装置３７、アームシリンダ２５のボトム側油室のリリーフ圧を第１設定圧力から第２設定圧力に低下させる可変リリーフ弁１、及び伸縮アームが設定長さ以上に伸長したことを検出する伸長センサＳを備えた作業機械において、伸縮アームが設定長さ以上に伸長してクラムシェルバケットの閉じ操作がされた場合に、可変リリーフ弁によるアームシリンダのボトム側油室のリリーフ圧を第１設定圧力から第２設定圧力に切り換えるように構成する。【選択図】 図４
WORK MACHINE INCLUDING CONTRACTIVE AND EXPANSIVE ARM
伸縮アームを有する作業機械
SHIMODA KASUMI (author) / ITO MINORU (author) / TANAKA SHINYA (author)
2019-09-19
Patent
Electronic Resource
Japanese
IPC:
E02F
Baggern
,
DREDGING
Crack Damage and Treatment of Low House on Expansive-Contractive Red Clay 1.52
| British Library Conference Proceedings | 1993
Foundations in poor soils including expansive clays
| TIBKAT | 1978