Robin America DY30 Service Manual page 40

2.
Operation
1) Starting
When the speed control lever is set on the side of high speed, the governor spring is pulled via the control
link.
The
governor levers 1 and 2 are pulled by the tension of the governor spring. The control rack
of
injection pump is pushed
toward "fuel increase." The governor lever 1 has an oblong hole, and the governor lever 2 moves to the extent of this
oblong hole by means of the start spring tension. The control rack of injection pump is pushed toward the maximum
of "fuel increase." This movement within the extent of oblong hole is called "revolution playing angle," for which we
will explain later.
2) After starting and during operation
When engine starts up, centrifugal force acts on the flyweight and it pushes the governor sleeve. The governor yoke,
governor shaft, and governor lever 2 are assembled in one piece, and accordingly the motion of the governor sleeve
pushes the control rack of the injection pump toward "fuel decrease.'' The governor lever again moves to the extent
of the oblong hole. Thereafter, the governor lever 1 and the governor lever 2 move simultaneously and are balanced at
the specified revolution. Suppose that a load is put suddenly on, the fuel supply is as it is at that instance, accordingly
the fuel supply is insufficient against the load. As a resut, engine revolution decreases, which means that the centrifugal
force on the flyweight decreases. Then the governor lever 2 moves to the position where it balances the tension of the
governor spring. The control rack of injection pump is pushed toward "fuel increase" and engine revolution revives.
3) Stopping
The governor plays a role exactly reverse to that of starting. When the speed control lever is set at the position
of
"Stop," it pushes the control rack of injection pump toward "No Injection" and the engine stops.
3. "Revolution Playing Angle"
This mechanism is to supply more fuel than the maximum supply for normal high speed operation. This mechanism is devel-
oped for the purpose of improving starting ability.
Required amount of fuel supply is set by the governor lever 1. The governor lever 1 has an oblong hole, to which pins of the
governor lever 2 is fitted. As the start spring is pulling the governor lever 2, it moves toward the arrow mark A. Then the
control rack of the injection pump is pushed to "Maximum supply." The angle the governor lever
2
moves within the extent
of oblong hole is called 'Revolution Playing Angle ."
At the time of starting, the governor does not function as yet and the governor lever
2
functions.However, during operation,
the governor functions and accordingly the governor lever
2
moves toward the arrow mark
B
within the extent of oblong
hole. The governor levers 1 and 2 incroporate each other and pushes the control rack
of
the injection pump.
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