公开(公告)号：EP1452743A4

公开(公告)日：2009-10-21

申请号：EP02802708

申请日：2002-11-01

申请人： HITACHI CONSTRUCTION MACHINERY

发明人： NAKAMURA TSUYOSHI ,  TOYOOKA TSUKASA ,  ISHIKAWA KOJI ,  NISHIMURA MASAO

IPC分类号： E02F9/22 ,  F15B11/00 ,  F15B11/02 ,  F15B11/16

CPC分类号： F15B11/167 ,  E02F9/2075 ,  E02F9/2225 ,  E02F9/2239 ,  E02F9/2267 ,  E02F9/2271 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/165 ,  F15B2211/20553 ,  F15B2211/20584 ,  F15B2211/265 ,  F15B2211/30505 ,  F15B2211/3059 ,  F15B2211/3116 ,  F15B2211/31576 ,  F15B2211/329 ,  F15B2211/50554 ,  F15B2211/575 ,  F15B2211/61 ,  F15B2211/7142

摘要： To permit smooth performance of both of an operation requiring a high pressure and an operation desired to produce a pressure at a suppressed level, a shuttle block 50 positioned between pilot operating units 35-37 and flow control valves 5-15 and pump regulators 28a,28b is arranged in association with shuttle valves 61-63,65-75, which select maximum pressures of groups of operation signal pressures produced by the pilot operating units 35-37, respectively, and at least one of the plural groups of operation signals, and is constructed to include hydraulic selector valves 81,82 and a boom-lowering, hydraulic selector valve 83. The hydraulic selector valves 81,82 are operated based on the maximum pressures to produce control signal pressures from a pressure of a pilot pump 2. The boom-lowering, hydraulic selector valve 83 is operated based on an operation signal pressure Dd relating to a single boom-lowering operation among the operation signal pressures produced by the pilot operating units 35-37 to produce aboom-lowering, control signal pressure from the pressure of the pilot pump 2.

公开(公告)号：EP1178157A4

公开(公告)日：2008-05-07

申请号：EP00900432

申请日：2000-01-18

申请人： HITACHI CONSTRUCTION MACHINERY

发明人： TOYOOKA TSUKASA ,  HIRATA TOICHI ,  SUGIYAMA GENROKU ,  ISHIKAWA KOUJI ,  NISHIMURA MASAO ,  NAKAMURA TSUYOSHI

IPC分类号： E02F9/20 ,  E02F9/22 ,  F15B11/00 ,  F15B11/17

CPC分类号： E02F9/2267 ,  E02F9/2239 ,  E02F9/2242 ,  E02F9/2271 ,  E02F9/2292

摘要： A hydraulic driving device of civil engineering and construction machinery, comprising hydraulic pumps (1, 2), a switching valve group (15a) which is connected to the pump (1) and includes a bypass stop valve (7), a switching valve group (15b) which is connected to the pump (2) and includes a preliminary directional control valve (11), a communication pipe line (13) establishing communication of the upstream-most side of the switching valve group (15a) with the supply pipe line (11a) of the preliminary directional control valve (11), a merge switching valve (14) allowing the communication pipe line (13) to communicate or shut off, an interlocked operation means switching the merge switching valve (14) to open position and the bypass stop valve (7) to closed position in conjuction with the switching operation of the preliminary directional control valve (11), and a selective switching valve (28) switching between the states where the switching operation of the merge switching valve (14) is enabled and disabled by the interlocked operation means, wherein the switching valve groups (15a, 15b), communication pipe line (13), and merge switching valve (14) are installed in a housing (15) so that a change in the maximum value of the operating speed of an actuator controlled by the preliminary directional control valve can be achieved.