16. Injection System
16.1
General description
This chapter deals with the high pressure side of the fuel system
including injection pump, high pressure pipe and injection valve.
The injection pumps are one-cylinder pumps with built-in roller
tappets. The element is pressure lubricated and the drain fuel is
led to a pipe system with atmospheric pressure outside the pump.
The injection pumps can be provided with an individual emer-
gency stop cylinder coupled to an electro-pneumatic overspeed
protecting system.
The high pressure line consists of a high pressure pipe and a
high pressure connection piece, screwed sideways into the nozzle
holder.
The injection valve consists of a nozzle holder and a multiorifice
nozzle.
16.2
Injection pump
16.2.1 Function
The injection pump pressurizes fuel to the injection nozzle. It has
a regulating mechanism for increasing or decreasing the fuel feed
quantity according to the engine load and speed. The pumps are
governed by the governor.
The plunger, pushed up by the camshaft via the roller tappet
and pulled back by the spring acting on the roller tappet, recip-
rocate in the element on a predetermined stroke to feed fuel under
pressure.
The plunger also controls the injected amount by adjusting the
helix edge position relative to the discharge port. The plunger has
an obliquely cut groove (lead) on its side. When the plunger is at
the lowest position or bottom dead centre, fuel flows through the
inlet port into the element bore. Rotation of the camshaft moves
the plunger up. When the top edge of the plunger step is lined up
with the ports, application of pressure to fuel begins. As the
plunger moves up further, and the helix of the plunger meets with
the ports, the high pressure fuel flows through the lead to the
ports and the pressure feed of fuel is completed.
The plunger stroke during which the fuel is fed under pressure
is called the effective stroke.
According to the engine load, the amount of fuel injected is
increased or reduced by turning the plunger a certain angle to
change the helix position where the ports are closed on the up
stroke and hence increasing or reducing the effective stroke. The
22-9601
Injection System
16
L’Orange
16-1
Содержание Vasa R22
Страница 14: ...Appendix B Welding Precautions 200147 00 4...
Страница 42: ...02 Fuel Lubricating Oil Cooling Water 22 9601 02 22 VASA 22...
Страница 60: ...03 Start Stop and Operation 22 9632 03 12 VASA 22...
Страница 72: ...04 Maintenance Schedule 22 9845 III 04 12 MD HF...
Страница 92: ...06 II Adjustments Clearances and Wear limits 22 9601 06 6 VASA 22...
Страница 116: ...08 Operating Troubles Emergency Operation 22 9601 08 8 VASA 22...
Страница 143: ...Diagram for 8V22 balancing system 1 2 3 4 Fig 11 7 2211539545 22 9601 Crank Mechanism 11 VASA 22 11 17...
Страница 144: ...11 Crank Mechanism 22 9601 11 18 VASA 22...
Страница 156: ...12 Cylinder Head with Valves 22 9601 12 12 VASA 22...
Страница 164: ...13 Camshaft Driving Gear 22 9601 13 8 VASA 22...
Страница 172: ...14 Valve Mechanism and Camshaft 22 9601 14 8 VASA 22...
Страница 183: ...22 200520 Turbocharging and Air Cooling 15 VTR Turbocharger 15 11...
Страница 189: ...15 III Turbocharging and Air Cooling 22 8604 15 6 VTR 161 251 Turbochargers...
Страница 209: ...17 Fuel system 22 9601 17 8 VASA 22...
Страница 229: ...18 Lubricating Oil System 22 9601 18 20 VASA 22...
Страница 247: ...19 Cooling Water System 22 9601 19 18 VASA 22...
Страница 261: ...21 Starting Air System 22 9601 21 10 VASA 22...