A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
HYDRAULIC DRIVE UNIT OF CONSTRUCTION MACHINE
To secure favorable workability by preventing the abrupt deceleration of a traveling speed irrespective of an engine rotation number, and also preventing an operation of a front working machine from becoming sluggish at a start of a traveling/front complex operation.SOLUTION: A hydraulic drive unit of a construction machine comprises a traveling communication valve 30 in which a first flow passage Oa for introducing oil discharged from a second hydraulic pump P3 to a center bypass passage CB3 of a second valve group V2, and a second flow passage Ob for introducing the oil discharged from the second hydraulic pump P3 to a plurality of front direction changeover valves 7, 10 and 11 of a first valve group V1 are formed. When the traveling communication valve 30 is not in a traveling/front complex operation, the traveling communication valve takes a first position in which the first flow passage Oa is fully opened, and the second flow passage Pb is fully closed, and when the traveling/front complex operation is started, the traveling communication valve takes a second position in which the first flow passage Oa is throttled, and an opening area of the second flow passage Ob is set larger than an opening area of the first flow passage Oa. The second position is changed according to a rotation number of an engine 1, and the opening area of the first flow passage Oa is set small following the lowering of the rotation number of the engine 1.SELECTED DRAWING: Figure 2
【課題】走行・フロント複合動作の開始時に，エンジン回転数に係わらず走行速度の急激な減速を防止し，かつフロント作業機の動作が緩慢にならず，良好な作業性を確保できるようにする。【解決手段】第２油圧ポンプＰ３からの吐出油を第２バルブグループＶ２のセンターバイパス通路ＣＢ３に導く第１流路Ｏａと，第２油圧ポンプＰ３からの吐出油を第１バルブグループＶ１の複数のフロント用の方向切換弁７，１０，１１に導く第２流路Ｏｂとを形成した走行連通弁３０を備え，走行連通弁３０は，走行・フロント複合動作でないときには第１流路Ｏａを全開，第２流路Ｏｂを全閉する第１位置と，走行・フロント複合動作の開始時には第１流路Ｏａを絞り，第２流路Ｏｂの開口面積を第１流路Ｏａの開口面積よりも大きくする第２位置とを有し，第２位置がエンジン１の回転数に応じて変化し，第１流路Ｏａの開口面積をエンジン１の回転数の低下にしたがって小さくする。【選択図】図２
HYDRAULIC DRIVE UNIT OF CONSTRUCTION MACHINE
To secure favorable workability by preventing the abrupt deceleration of a traveling speed irrespective of an engine rotation number, and also preventing an operation of a front working machine from becoming sluggish at a start of a traveling/front complex operation.SOLUTION: A hydraulic drive unit of a construction machine comprises a traveling communication valve 30 in which a first flow passage Oa for introducing oil discharged from a second hydraulic pump P3 to a center bypass passage CB3 of a second valve group V2, and a second flow passage Ob for introducing the oil discharged from the second hydraulic pump P3 to a plurality of front direction changeover valves 7, 10 and 11 of a first valve group V1 are formed. When the traveling communication valve 30 is not in a traveling/front complex operation, the traveling communication valve takes a first position in which the first flow passage Oa is fully opened, and the second flow passage Pb is fully closed, and when the traveling/front complex operation is started, the traveling communication valve takes a second position in which the first flow passage Oa is throttled, and an opening area of the second flow passage Ob is set larger than an opening area of the first flow passage Oa. The second position is changed according to a rotation number of an engine 1, and the opening area of the first flow passage Oa is set small following the lowering of the rotation number of the engine 1.SELECTED DRAWING: Figure 2
【課題】走行・フロント複合動作の開始時に，エンジン回転数に係わらず走行速度の急激な減速を防止し，かつフロント作業機の動作が緩慢にならず，良好な作業性を確保できるようにする。【解決手段】第２油圧ポンプＰ３からの吐出油を第２バルブグループＶ２のセンターバイパス通路ＣＢ３に導く第１流路Ｏａと，第２油圧ポンプＰ３からの吐出油を第１バルブグループＶ１の複数のフロント用の方向切換弁７，１０，１１に導く第２流路Ｏｂとを形成した走行連通弁３０を備え，走行連通弁３０は，走行・フロント複合動作でないときには第１流路Ｏａを全開，第２流路Ｏｂを全閉する第１位置と，走行・フロント複合動作の開始時には第１流路Ｏａを絞り，第２流路Ｏｂの開口面積を第１流路Ｏａの開口面積よりも大きくする第２位置とを有し，第２位置がエンジン１の回転数に応じて変化し，第１流路Ｏａの開口面積をエンジン１の回転数の低下にしたがって小さくする。【選択図】図２
HYDRAULIC DRIVE UNIT OF CONSTRUCTION MACHINE
建設機械の油圧駆動装置
TAKEBAYASHI KEIFUMI (author) / TAKAHASHI KIWAMU (author) / NAKAMURA NATSUKI (author) / OKA DAISUKE (author) / NAKAO YOSHIHIDE (author)
2024-04-09
Patent
Electronic Resource
Japanese