| 摘要 |
A main control valve for a hydraulic excavator and a hydraulic excavator having the same. The hydraulic excavator main control valve comprises: a straight travel valve unit (1), a rotary unit (2), a dozer blade unit (3), a boom 2/hammer unit (5), an arm 1 unit (6), a travel left unit (7), an oil inlet unit, a travel right unit (8), a boom 1 unit (9), a bucket unit (10), an arm 2 unit (11), and an oil return passage (T2). The main control valve for hydraulic excavator is oil supplied by three pumps (P1, P2, P3) comprising a first pump (P1), a second pump (P2), and a third pump (P3). The first pump (P1) and the second pump (P2) are two variable pumps having the same displacement, and the third pump is standalone. The three pumps (P1, P2, P3) are under total power control, and the rated pressure of the third pump (P3) is less than the rated pressure of the first pump (P1) and that of the second pump (P2). The main control valve for hydraulic excavator further comprises a level-mode oil supply circuit, though which the first pump (P1), the second pump (P2) and third pump (P3) supply oil confluently to the arm cylinder of the hydraulic excavator. The main control valve for hydraulic excavator makes single-movements more rapid, and oil flow distribution is done appropriately during composite-movements. The valve also has the advantages of high work efficiency when in a level position and energy-saving when excavating. |
