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31 - 6
Section E
Hydraulics
9803/6400
Section E
31 - 6
Issue 1
Control Valve JS200/JS240
Operation
(continued)
Combined Operations
1. Travel Combination Operations (Refer to Fig. 1, 13).
When travelling forward or backward (including spin turn) any spool other than the travel spool is selected or when operating
the excavator, when the travel spool (left, right travel) spool is selected, the signal passage and tank passage are cut off at that
spool signal land and the signal passage pressure rises to the relief set pressure.
The pressure of P
t
, P
f
ports rises and when the signal passage pressure rises, the pressure of the signal passage (f) connects
to the straight travel spool recess (Fig. 1). It passes through the straight travel spool passage (p), (o) cavity pressure rises and
the spool selects to the left as shown. (Travel forward state).
Whilst the boom is lifting (boom II selected), when the travel spool is selected the pressure passing through the (i) (j) passage
rises, so the shuttle (Q) resists the spring force and moves to the right as shown (Fig. 13).
For this reason, passage x y is connected and the P
4
port oil flows from the outer piping through P
3
port and is released to the
tank passage. The straight travel spool is then selected so the straight travel state is achieved.
(Fig. 1,13)
In this straight travel state, the oil delivered from P
R
port activates the 4-spool traction motor, passes through passage d F and
activates the 5-spool traction motor. (Fig. 13)
In this way, the left and right traction motors are activated so straight travel can be maintained while simultaneous actions with
other services are carried out.
Also, the oil delivered to the P
L
port is delivered to the 5-spool side from the 5-spool side parallel passage B. Part of the oil
pushes open the load check (R) and is led from passage C G c to the 4-spool parallel passage b, activating other services. (Fig.
13)
2. Boom Lowering Stroke Regulation (Refer Fig. 7).
Puts pressure on the Ps port of the boom section and activates the piston, moving the boom I spool back a little as shown.
When the spool is pushed back, the spool neutral passage a is opened and delivers oil to other spool sections.
3. Slew Priority Circuit (Refer to Fig. 2).
When operating the dipper and slew simultaneously, when the dipper load is light, the flow of oil for the slew section upstream is
obtained by means of the constrictions (v), so slew priority is maintained.
Relief Valve (Refer to Fig. 3, 5, 8, 9, 11)
.
P
L
port is connected to the load check (n) and passage E and P
R
port is connected to load check (m) and passage e. Both are
connected to the relief valve which prevents the maximum pressure of the 4-spool and 5-spool pump from exceeding the set
pressure. (Fig. 8) (=main relief valve).
The relief valve has a booster function so that when pressure is put on P
1
port, the set pressure of the high pressure side can
be changed.
Also, there is a relief valve on each ram port of the boom I (Fig. 3,5), bucket I (Fig. 11), dipper I (Fig. 9, 5-spool sectional
diagram J-J) and prevents the actuator pressure from becoming abnormally high due to outside forces. (=overload relief valve)
When the ram pressure becomes negative, the relief valve also functions to absorb oil from the tank and prevent cavitation.
(Combination port relief valve).
Summary of Contents for JS 200 Series
Page 57: ...9 1 Section 3 Routine Maintenance 9803 6400 Section 3 9 1 Issue 2 Component Location Diagram...
Page 113: ......
Page 137: ...5 3 Section C Electrics 9803 6400 Section C 5 3 Issue 2 Pump Control FLOW CHART...
Page 201: ...10 7 Section C Electrics 9803 6400 Section C 10 7 Issue 1 CAPs II Diagnostic system K C...
Page 215: ...Section E Section E Hydraulics 9803 6400 Issue 2 3 2 3 2 Schematics...
Page 217: ...Section E Section E 9803 6400 Issue 2 3 3 3 3 Hydraulics Schematics...
Page 218: ...3 5 Section E Hydraulics 9803 6400 Section E 3 5 Issue 1 Schematics Shuttle Block JS200 JS240...
Page 232: ...10 1 Section E Hydraulics 9803 6400 Section E 10 1 Issue 1 Hydraulic Pump JS200 JS240...
Page 233: ...10 2 Section E Hydraulics 9803 6400 Section E 10 2 Issue 1 Hydraulic Pump JS200 JS240...
Page 234: ...10 3 Section E Hydraulics 9803 6400 Section E 10 3 Issue 1 Hydraulic Pump JS200 JS240...
Page 263: ...30 2 Section E Hydraulics 9803 6400 Section E 30 2 Issue 1 Control Valve JS200 JS240...
Page 264: ...30 3 Section E Hydraulics 9803 6400 Section E 30 3 Issue 1 Control Valve JS200 JS240...
Page 265: ...30 4 Section E Hydraulics 9803 6400 Section E 30 4 Issue 1 Control Valve JS200 JS240...
Page 266: ...30 5 Section E Hydraulics 9803 6400 Section E 30 5 Issue 1 Control Valve JS200 JS240...
Page 267: ...30 6 Section E Hydraulics 9803 6400 Section E 30 6 Issue 1 Control Valve JS200 JS240...
Page 268: ...30 7 Section E Hydraulics 9803 6400 Section E 30 7 Issue 1 Control Valve JS200 JS240...
Page 327: ...51 12 Section E Hydraulics 9803 6400 Section E 51 12 Issue 1 Solenoid Valve 8 spool...
Page 328: ...55 1 Schematic Section E Hydraulics 9803 6400 Section E 55 1 Issue 1 Shuttle Valve...
Page 330: ...55 3 Schematic Section E Hydraulics 9803 6400 Section E 55 3 Issue 1 Cushion Valves...
Page 481: ...7 15 Section F Transmission 9803 6400 Section F 7 15 Issue 2 Motor...
Page 482: ...7 16 Section F Transmission 9803 6400 Section F 7 16 Issue 1 Motor...