Kobelco excavator arm recovery control frame for cavitation prevention system.
1. When the arm recovery operation is performed, the pilot pressure switches the arm spool twice, and at the same time, it is input to the low pressure pressure sensor.
The engine speed command output by the throttle potentiometer is input to the electromechanical controller.
The output voltage of the low pressure pressure sensor is input to the electromechanical controller, and the pilot signal processing is performed internally, and the command current corresponding to the input voltage is output to the forearm variable regeneration proportional valve (PSV-A).
In addition, the command current corresponding to the input voltage from the throttle potentiometer is output to the forearm variable regenerative proportional valve
The forearm variable regeneration proportional valve outputs the secondary pressure of the proportional valve corresponding to the command current from the electromechanical controller, and switches the forearm variable regeneration spool.
2. P2 side negative pressure sensor (SE-27) and back pressure sensor Qiao E. 28) The output voltage is input to the electromechanical controller, and the negative pressure control signal is processed internally, and the command current corresponding to the input voltage is output to the P2 pump proportional state (PSV-P2)
3. The P2 pump proportional valve outputs the secondary pressure of the proportional valve corresponding to the command current from the electromechanical controller, and the discharge volume of the P2 pump changes.
The forearm variable regeneration valve acenaphthene is controlled by the directional stroke corresponding to the number of engine rotations, and the engine speed is reduced by changing the regeneration rate
4. Cavitation will not occur when the discharge volume of the P2 pump is reduced. In addition, when the arm recovery operation is performed, the excitation signal from the electromechanical integrated controller to the rotary parking brake solenoid valve (SV-I) is cut off , The rotating stop brake is released. Note: 0 and 0 are processed by the pilot signal in the electromechanical controller, and the signal is selected by the high bit. Output to the forearm variable regeneration proportional valve.
