Robin America DY30 Service Manual page 33

3.
Variation in quantity of fuel
to
be injected
The quantity
of
fuel injected vanes according to the condition of the engine, i. e. high speed or low speed operation and
loaded or unloaded operation. (See Figs. 55 and 56.)
The plunger lead is engraved on the surface of plunger in an inclined curve. By rotating the plunger, the distance between
the upper part of the plunger and the suction port is varied. (Variation in effective stroke)
Rotation
of
the plunger is made by the control rack. When this control rack is shifted to left and/or right, the geared pinion
rotates, which is connected to the plunger by means of the control sleeve. In other words, the plunger turns as much amount
as the rack rotates. Accordingly, the effective stroke varies coincident with the position where the rack is set.
1) Relation between the plunger and the barrel
EFFECTIVE STROKE
PLUNGER BARREL
I N T A K E E X H A U S T
PORT
INJECTION INJECTION INJECTION INJECTION
STARTS. ENDS. STARTS. ENDS.
M A X . D E L I V E R Y
H A L F D E L I V E R Y N O D E L I V E R Y
Fig. 55
2) Relation between the plunger and the rack
CONTROL SLEEVE
M A X . D E L I V E R Y HALF D E L I V E R Y
N O D E L I V E R Y
Fig. 56
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30
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