Principle of straight line walking circuit of Doosan 225-9 excavator
When the excavator falls into the pit or works in other special conditions, the excavator is required to move the working device (the arm, the bucket, the bucket, and turn) by the side of the excavator, so as to realize the self rescue or other functions of the excavator.
When walking normally, the front and rear pumps supply oil to the left and right tracks respectively.
When walking in a normal line, push the walking foot valve, give the straight line signal (no other action), then move the valve core to the right, cut off the central oil path. The pressure oil of the pump 1 (front pump) reaches the left walking motor through the straight walking valve and the left walking valve; the pressure oil of the pump 2 (rear pump) reaches the right walking motor through the right walking valve and realizes normal. Walk.
When there are other actions in a straight line, the hydraulic oil is redistributed through a straight running valve. At this point, pump 2 supplies oil to 2 walking motors, and pump 1 supplies oil to other actions.
When the signals of walking and other movements are given at the same time, each valve core in the multi-channel valve receives different signals, the way of opening the valve core is different, the direction of the oil path on the edge of the movement; the front pump (pump 1) - the linear walking valve (the valve core left shift) - the related action valve core. The rear pump has 2 oil roads, the one is the pump 2- straight walking valve left walking valve left line Walk the motor; pump 2- right walk valve - right walking motor.
Priority loop of Dou Shan 225-9 excavator
In parallel circuit, 2 actions must be carried out at the same time, the load of the 2 action must be the same, otherwise the load will not move. In order to improve the working efficiency of the excavator, at the same time, the 2 actions are required at the same time, but the lifting of the arm and the load of the revolving are high, so the lifting and turning of the arm should be guaranteed first.
When the boom is combined with the bucket rod, to increase the load of the boom and ensure that the boom can be raised, throttling is carried out at the front end of the multi position valve.
When the boom performs priority on the bucket shaft oil circuit, the handle action gives each signal to open the corresponding spool.
