89
it from the seat in lower casing 15. The compressed air from V
2
outlet arrives at Z
2
outlet and further to the actuating mechanisms of the service brake second circuit.
Coincidentally with the increase of the pressure at Z
2
outlet, the pressure un-
der pistons 14 and 23 increases, and the force, that acts on piston 23 from the top, is
equalized as a result. As a consequence of it, the pressure that corresponds to the
force on the brake valve lever is also established at Z
2
outlet. Thus, the action of the
follower is performed in the lower unit of the brake valve.
If the upper unit of the brake valve fails, the lower unit will be controlled me-
chanically via stud 7 and the lifter of small piston 14, keeping completely its ability
to operate.
If the lower unit of the brake valve fails, the upper unit operates as described
above.
Care of the double
-
unit brake valve lies in its regular examination, cleaning it
from mud, checking for tightness.
Care should be taken to the condition of the brake valve protective rubber
hood and its tight contact with the casing, because mud getting onto the valve lifter
and friction surfaces can cause failure of the brake valve.
The tightness of the brake valve is checked with the help of soap emulsion in
two states, when the brake is engaged, and when it is released. Air leakage through
the brake valve outlet to atmosphere, when the brake is released, shows non-
tightness of the inlet valve of one of the brake valve units and if the air leakage
Fig. 70. Brake Valve:
1-lever; 2-thrust screw; 3- pro-
tecting hood; 4 - roller; 5 - lever
body; 6 - valve lifter; 7 - stud; 8 -
valve head; 9 - flange; 10, 12, 16, 21
- springs; 11 - upper casing; 13,
18 - supporting rings; 14 - small
piston; 15 - lower casing; 17 -
lower
-
unit valve; 19, 22, 27 -
packing rings; 20 - atmosphere
outlet valve; 23 - big piston; 24 -
upper
-
unit valve; 25 - upper fol-
lower piston; 26 - elastic element;
Z
1
- outlet to air booster of front
axle brake circuit; Z
2
- outlet to air
booster of intermediate and rear
axle brake circuit; V
1
and V
2
-
outlets to air bottles; a - hole
Содержание 4320-10
Страница 1: ...URAL 4320 10 URAL 4320 31 TRUCKS AND THEIR MODIFICATIONS ...
Страница 180: ...179 Fig 119 Truck Lubrication Diagram ...