Figure 3-13 shows the control block diagram of the Kobelco excavator outrigger confluence system.
1. When performing the arm outstretching operation, the pilot switches the arm spool and confluence spool twice, and at the same time, it is input to the low pressure sensor (SE-8).
2. 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 PI cut-off proportional valve (PSV-D), as shown in FIGS. 3-14.
3. The PI cut proportional valve outputs the proportional valve 2 times pressure corresponding to the command current of the electromechanical controller to switch the PI cut spool. 4. Due to the switching of the arm spool and PI cut spool, the negative pressure control pressure changes. The pressure is input to PI, P2 side negative pressure sensor (SE.26, SE-27) and back pressure sensor (SE-280PI, P2 side negative pressure sensor and back pressure sensor output voltage is input to the electromechanical controller, internally The negative pressure control signal is processed and output to the PI pump proportional valve (PSV-PI) and P2 spring proportional valve CPSV-P2), as shown in Figure 3-15.
5. The PI pump proportional valve and P2 pump proportional valve output the secondary pressure of the proportional valve corresponding to the command current from the electromechanical controller, causing the displacement of the PI pump and P2 pump to change.
6. Switch the small arm spool through the pure hydraulic command (pilot 2 times pressure), and switch off the PI spool through the current hydraulic command (proportional valve 2 times pressure). In this way, the discharge oil of the PI pump is merged into the discharge oil of the P2 pump.
