3. SWING PRIORITY SYSTEM R/G R/G Ps Ps Pm1 Pm2 T1,T2 Pm2 T1,T2 Pm1 P2 P1 P2 P1 Rs CK1 Pn2 Pn1 D B A C DR P BC COMP.
NRV2 NRV1 S/Motor DB Pk C5 A5 B5 Pc5 Pd5 D5 OPTION-B BUCKET CK2 Pb5 Pa5 SRG ARG SH C4 D4 B4 (RG) SGo Dr PG Pd4 DR3 Pc4 1 REGENERATIION CUT BREAKER Pa4 Pb4 Au Dr(R7) 0 Pc4 0 ARM OPTION-A Pc4 2 Pb3 GB GA DR2 Pc3 Pa2 1 BOOM UP ARM OUT Pd4 1 B(CW) Mu A(CCW) C2 D2 V3 Pb2 1 B2 A2 DR1 Pd2 Pc2 SWING BOOM P02 Pa2 Pb2 0 0 Pc1 D1 C1 Patt B1 A1 Pb1 Pa1 P01 DR0 Pd1 TRAVEL (LEFT) TRAVEL (RIGHT) Ptr STRAIGHT TRAVEL T1 P2 P1 Pu MRV SWING ARM BUCKET BOOM TRAVEL Psv (2) (4) (3) (1) SH (3) (1) (2) (4) Pd1 Pc1 Pb1 Pa1 (1) (2) (3) (4) A1 A2 a4 A B D E G F H J Pd2 Pc2 Pc4 0 Pa2 0 Pb2 0 T P Pd4 0 Pa5 Pb5 Dr#,dr#,R# a2 a1 Pm1 (Pump) Pm2 (Pump) Pk (T/Joint) Pi1 (Fl,MCV) Pi2 (Fr,MCV) Pm1 Pm2 A1 A2 A1 A2 ACC P3 P4 PG(S/Motor) Po1(MCV) M T T P2 P1 19 Dr B1 B3 A3 a3 T(dr2) D21073HS04 When carrying out the combined operation of swing and arm of the leftcontrol valve, the swing speed can be lowered than operating speed of arm.
Pc3 pressure from the swing shuttle block change the swing priority spool and decreases the oil flow rate to the next section to make the swing operation most preferential. This is called the swing priority system. For details, refer to page 2-44. 3-8