BRAKE LOCK CIRCUIT
The primary function of the brake lock is to provide a
means for the operator to hold the vehicle while at the
shovel or dump. The brake lock only applies the rear
service brakes. It may also provide a second means to
stop the truck in the event the primary means (brake
valve) malfunctions.
By turning on the dash mounted toggle switch, a sole-
noid valve (14, Figure 2-1) and pressure reducing valve
(13) will apply unmodulated pressure oil at 2000 psi
(13.8 MPa) to fully actuate the rear brakes. A shuttle
valve (11) in the rear brake line provides the inde-
pendence from the brake treadle valve for brake appli-
cation.
WARNING CIRCUIT
The brake warning circuit is equipped with a low brake
pressure warning light (on the overhead display panel)
and an audible alarm (in the cab) to alert the operator
of low brake pressures. Several electrical sensors, a
relay and delay timer are used to detect brake system
problems. (See Figure 2-1 for the following component
references.)
•
Pressure sensor, system supply pressure
Located on the pump pressure sensing manifold.
When system supply pressure drops below 2300
psi (15.8 MPa), the low steering pressure light, low
brake pressure light and buzzer will turn on.
•
Pressure sensor, low brake pressure (20)
Located on the brake manifold. When the accu-
mulator with the lower pressure falls below 1850
psi (12.7 MPa), the low brake pressure light and
buzzer will turn on.
•
Differential pressure switches (8)
Located on the dual controller valve (foot treadle)
and on each dual relay valve. During brake appli-
cation, if the difference in brake apply pressure
between the front and rear circuits is greater than
a preset level, the differential pressure switch lo-
cated on the dual controller valve will turn on the
low brake pressure light and buzzer.
If the difference in brake apply pressure between
the left and right circuits of the front or rear wheel
brakes is greater than a preset level, the differen-
tial pressure switch located on the dual relay valve
at either the front or rear wheels will turn on the
low brake pressure light and buzzer.
The pressure differential switches complete a
path to ground in order to turn on the low brake
pressure light and buzzer. The differential pres-
sure switches provide detection of faults such as
a brake line rupture, poor brake valve tracking,
line blockage, excessive brake displacement or
air trapped in the system.
•
Brake Lock Degradation Switch (23)
Located on the junction block (26) in the hydraulic
components cabinet. When the brake lock switch
is turned on, the brake lock solenoid (14) and
brake warning relay are energized. The brake
warning relay switches the electrical connection
from the differential pressure switch to the brake
lock degradation switch (23). If the brake lock
apply pressure is less than 1000 psi (6.9 MPa), a
path to ground will be completed and the low
brake pressure light and buzzer will turn on.
•
Brake Warning Relay (28)
Located on the RH wall of the hydraulic compo-
nents cabinet. When the brake lock switch is
turned on, the brake warning relay is energized
and switches the electrical connection from any
of the differential pressure switches to the low
brake lock degradation switch. When the brake
lock switch is turned off, the relay is de-energized
and switches the connection from the brake lock
degradation switch to the differential pressure
switches.
•
Brake Warning Delay Timer (27)
Located on the RH wall of the hydraulic compo-
nents cabinet. The delay timer is connected in
series between the low brake pressure light/buzz-
er and the brake warning relay. If any of the
differential pressure switches or the brake lock
degradation switch completes a path to ground,
the delay timer will not complete the circuit for 1.2
seconds. This will allow sufficient time for the
hydraulic brakes to reach the proper pressures
after actuation to avoid false warnings.
J2-4
Brake Circuit
J02027
Содержание 930E-2
Страница 1: ......
Страница 2: ......
Страница 4: ...NOTES ...
Страница 8: ...KOMATSU MODEL 930E Dump Truck A 4 Introduction A00017 03 01 ...
Страница 10: ...NOTES A1 2 Index A01001 2 94 ...
Страница 12: ...930E MAJOR COMPONENTS A2 2 Major Component Description A02055 ...
Страница 35: ...START HERE Walk Around Inspection A03017 General Safety and Operating Instructions A3 21 ...
Страница 46: ...NOTES A3 32 General Safety and Operating Instructions A03017 ...
Страница 78: ...NOTES B1 2 Index B01016 ...
Страница 88: ...NOTES B3 6 Dump Body B03013 03 01 ...
Страница 92: ...NOTES B4 4 Fuel Tank B04015 ...
Страница 94: ...NOTES C1 2 Index C01021 03 01 ...
Страница 118: ...NOTES C5 6 Air Filtration System C05013 5 98 ...
Страница 126: ...NOTES D2 6 24VDC Electric Supply System D02018 ...
Страница 142: ...NOTES D3 16 24VDC System Components D03019 04 01 ...
Страница 146: ...FIGURE 2 1 PROPULSION SYSTEM DIAGRAM E2 2 Electrical Propulsion System Components E02014 3 01 ...
Страница 191: ...FIGURE 2 3 ELECTRICAL CABINET FRONT VIEW E02014 3 01 Electrical Propulsion System Components E2 47 ...
Страница 192: ...FIGURE 2 4 ELECTRICAL CABINET TOP VIEW E2 48 Electrical Propulsion System Components E02014 3 01 ...
Страница 193: ...FIGURE 2 5 ELECTRICAL CABINET REAR FLOOR VIEW E02014 3 01 Electrical Propulsion System Components E2 49 ...
Страница 196: ...NOTES E2 52 Electrical Propulsion System Components E02014 3 01 ...
Страница 240: ...NOTES E3 44 AC Drive System Electrical Checkout Procedure 3 01 E03015 Release 17 Software ...
Страница 242: ...NOTES G1 2 Index G01017 ...
Страница 250: ...NOTES G2 8 Tires and Rims G02015 ...
Страница 274: ...NOTES H1 2 Index H01013 04 01 ...
Страница 282: ...NOTES H2 8 Front Suspensions H02013 2 01 ...
Страница 288: ...NOTES H3 6 Rear Suspensions H03013 ...
Страница 334: ...NOTES J3 32 Brake Circuit Component Service J03019 1 99 ...
Страница 378: ...NOTES L2 8 Hydraulic System L02028 ...
Страница 401: ...FIGURE 4 5 FLOW AMPLIFIER VALVE L04031 Steering Circuit L4 7 ...
Страница 403: ...FIGURE 4 6 FLOW AMPLIFIER NO STEER L04031 Steering Circuit L4 9 ...
Страница 405: ...FIGURE 4 7 FLOW AMPLIFIER LEFT STEER L04031 Steering Circuit L4 11 ...
Страница 407: ...FIGURE 4 8 FLOW AMPLIFIER RIGHT STEER L04031 Steering Circuit L4 13 ...
Страница 409: ...FIGURE 4 9 FLOW AMPLIFIER NO STEER EXTERNAL SHOCK LOAD L04031 Steering Circuit L4 15 ...
Страница 414: ...NOTES L4 20 Steering Circuit L04031 ...
Страница 422: ...NOTES L5 8 Steering Control Unit L05021 ...
Страница 429: ...L06021 Steering Circuit Component Repair L6 7 ...
Страница 450: ...NOTES L6 28 Steering Circuit Component Repair L06021 ...
Страница 466: ...NOTES L7 16 Hoist Circuit L07023 ...
Страница 492: ...NOTES L9 6 Hydraulic System Filters L09008 ...
Страница 504: ...NOTES L10 12 Hydraulic Check out Procedure L10012 ...
Страница 508: ...NOTES M1 2 Index M01034 03 01 ...
Страница 518: ...NOTES M2 3 10 Ansul Checkfire Electric Detection and Actuation System M02003 ...
Страница 524: ...NOTES M5 4 Wiggins Quick Fill Fuel System M05002 10 96 ...
Страница 532: ...NOTES M8 8 Special Tools M08012 9 99 ...
Страница 560: ...NOTES M9 28 Air Conditioning System M09010 6 97 for HFC 134a Refrigerant ...
Страница 575: ...ALTERNATOR PARTS Refer to previous page for Parts List M13003 04 01 Niehoff Alternator Overhaul Manual M13 5 ...
Страница 618: ...M20 20 Payload Meter II M20007 10 00 ...
Страница 619: ...M20007 10 00 Payload Meter II M20 21 ...
Страница 627: ...M20007 10 00 Payload Meter II M20 29 ...
Страница 634: ...NOTES N1 2 Index N01020 03 01 ...
Страница 654: ...NOTES N3 6 Cab Components N03011 7 98 ...
Страница 660: ...NOTES N4 6 Operator Comfort N04020 ...
Страница 686: ...NOTES N5 26 Operator Cab Controls N05044 ...
Страница 688: ...NOTES P1 2 Index P01024 ...
Страница 691: ...P02034 Lubrication and Service P2 3 ...
Страница 722: ......
Страница 723: ......
Страница 724: ......
Страница 725: ......
Страница 726: ......
Страница 727: ......
Страница 728: ......
Страница 729: ......
Страница 730: ......
Страница 731: ......
Страница 732: ......
Страница 733: ......
Страница 734: ......
Страница 735: ......
Страница 736: ......
Страница 737: ...NOTES R1 2 930E Schematics R01048 with Cummins QSK60 Series Engine ...
Страница 738: ......
Страница 739: ......