2.Technology principle 920 922 924.pptx

descripcion 920/922

1. Technology principle 920-922-924

2. 2 1 Positive Control Advanced Diagram of principle Pilot pressure principle (SD) Power regulation (LR) Oil distribution principle Hydraulic principle diagram Summary 2

3. Positive Control 3 Principle : The pump flow rate is proportional to the pilot pressure of the controls and adjusted with an electronic logic. Electronic logic Regulator Pump Primary valve Distributor Master User Sensor Actuation SD Signal

4. Travel Diagram of principle 4 OUTPUT 4/20mA LEFT RIGHT R L Boom up Boom down Bucket opening Bucket closing Stick out Stick in Left swing Right swing Front R travel Rear R travel Front L travel Rear L travel Y51 Y52 P1 P2 MASTER Y415: Straight travel Y419: Sum stick Y418: Cut 2 Y421: Stick regeneration Y417: Cut 1 Y420: Sum boom Y450: Stick by-pass SD SD B170 B171 B167 B168 B162 B161 B165 B164 B163 10 bars <P< 25 bars Distributor block Pilot pressure INPUT

5. Pilot pressure principle (SD) 5 R TRAVEL SERVO Y51 Y52 10 bar = Qmin 25.5 bar = Qmax SERVO SERVO L R L R ELECTRONIC mA mA 0 bar = 4 mA 27 bar = 18,4 mA SD1 SD2 450 mA = Qmin 940 mA = Qmax 6 bar = ROD OPENING 30 bar = MAX PILOT PRESSURE IN THE "POSITIVE CONTROL" SYSTEM, THE PILOT SIGNAL HAS A DIRECT INFLUENCE ON THE PUMP REGULATION. THIS WILL ONLY GIVE THE OIL CORRESPONDING TO THE ROD OPENING. ALL THE PILOT SIGNALS ARE MANAGED BY THE ELECTRONICS. THE MACHINE REACTS EXACTLY AS THE OPERATOR WISHES. BUT THE ELECTRONICS BECOME ESSENTIAL TO THE OPERATION OF THE EXCAVATOR. ENGINE REG REG P1 P2 B171 P

6. Power regulation (LR) 6 R TRAVEL SERVO Y51 Y52 0 bar = Pmax 30 bar = Pmin SERVO SERVO L R L R B171 ELECTRONIC THE POWER CONTROL ACTS ON THE PUMP FLOW ACCORDING TO THE LOAD OF THE HEAT ENGINE. THE CONTROL PARAMETER IS THE ENGINE SYSTEM. mA 220 mA = 3 bar 970 mA = 30 bar P SD2 SD1 LR Y50 SYSTEM INSTRUCTIONS ACTUAL SYSTEM ENGINE REG REG P1 P2

7. Oil distribution principle 7 SERVO L R SERVO L R SERVO Secondary circuit in parallel Primary circuit in series REGENERATION / BY-PASS STICK CUT 1 STICK SWING TRAVEL R TRAVEL L BOOM BUCKET PRIORITY SLIDE CUT 2 OPTION SUM BOOM SUM STICK ENGINE REG REG P1 P2

8. Hydraulic principle diagram 8 P CUT 1 STICK SWING TRAVEL R TRAVEL L BOOM BUCKET TRAVEL SPOOL CUT 2 OPTION SUM BOOM SUM STICK B161 Y51 Y52 450 mA = Qmin 940 mA = Qmax 10 bar = Qmin 25.5 bar = Qmax SERVO L R B168 B164 B165 B163 B167 B162 SERVO P B159 B160 SERVO L R A179 MASTER CAN 1 EXAMPLE: BOOM UP P P P P P P SERVO B170 P SD1 SD2 LR SERVO Y50 P 750mA REGENERATION BY-PASS STICK ENGINE REG REG P1 Y51 P2 B171 P Y415 TRAVEL // Y419 SUM STICK Y418 CUT 2 Y421 STICK REGEN Y417 CUT 1 Y420 SUM BOOM Y450 STICK BY-PASS A178