Kobelco excavator arm retracting and confluence system control frame, when the forearm retracting and confluence operation is performed, the pilot pressure switches the small spool and the forearm converging spool and the forearm T2 spool twice, and at the same time, it is input to the low pressure pressure sensor 0 The output voltage of the low pressure pressure sensor is input to the electromechanical controller, and the pilot signal is processed internally, and the command current corresponding to the input voltage is output to the cut-off proportional valve.
0PI cuts off the proportional valve to output the secondary pressure of the proportional valve corresponding to the command current of the electromechanical controller. Switching PI cuts off 0 to switch between the forearm spool and the PI cut-off spool. The negative pressure controls the pressure change, and this pressure is input to the PI , P2 toilet negative pressure sensor (SE.26, s02 and back pressure sensor.
0PI, P2 side negative pressure sensor and back pressure sensor output voltage is input to the electromechanical controller, internal negative pressure control signal processing, output to the P1 pump proportional valve (PSV-PI) and P2 pump proportional valve.
The 0PI pump proportional valve and the P2 pump proportional valve output the secondary pressure of the proportional valve corresponding to the command current of the electromechanical controller, so that the discharge volume of the PI pump and P2 pump changes.
0 Through pure hydraulic command (pilot 2 times pressure) to switch the Xiaoying spool and the forearm converging spool and forearm spool, through the electric current hydraulic command (proportional valve 2 times pressure) to switch the PI cut-off spool, in this way, the PI pump The discharge oil is merged into the discharge oil of the storage pump. @In addition, there is a large amount of oil in the large cavity of the forearm hydraulic cylinder, and a spool for adding fruit will produce back pressure. Therefore, use the forearm spool and the small arm spool. The arm T2 spool returns the oil return on the side of the human chamber to the tank circuit.
