To provide a work machine which is capable of effectively suppressing a pressure loss in a return flow passage and also preventing the occurrence of cavitation.
A revolving super structure 2 comprises a work machine 6, a tank 10, a hydraulic pump 9, a hydraulic control mechanism 20 and the like. The work machine 6 includes a supporting arm 6a, an oscillating arm 6b, and a hydraulic cylinder 62. The inside of a cylinder body 71 of the hydraulic cylinder 62 is partitioned into a rod-side space 74 and a head-side space 75. The hydraulic control mechanism 20 includes an opening/closing control valve 27 which opens/closes a direction control valve 24 or a bypass flow passage 26, and the like. When the direction switching valve 24 is switched to a first direction to return a hydraulic oil from the head-side space 75, the opening/closing control valve 27 is controlled to be opened and when a specific state is detected by a cavitation prevention device 50, the opening/closing control valve 27 is closed.
SAOTOME YOSHIMI
| JP2010185515A | 2010-08-26 | |||
| JP2005291312A | 2005-10-20 | |||
| JPH09151488A | 1997-06-10 | |||
| JP2002089505A | 2002-03-27 | |||
| JPS5988545A | 1984-05-22 |
| US20050229594A1 | 2005-10-20 | |||
| EP2189666A1 | 2010-05-26 |
Hiroshi Takeuchi
Takahisa Shimada
Yuji Takeuchi
Katsumi Imae
Kazunari Ninomiya
Tomoo Harada
Seki Kei
Yasuya Sugiura
Daisuke Kawabe
Masanori Hasegawa
Tsuguya Iwashita
Koji Fukumoto
Ryo Maeda
Mawaki Hachizo
Yukichi Matsunaga
Kenji Kawakita
Shohei Okazawa