Yanmar 3JH4E Service Manual page 250

6. Fuel Injection equipment
2) Governor
a) The governor, which is located above the
pump house, consists of a flyweight holder,
governor lever assembly, etc. The flyweight
holder holds four flyweights and governor
sleeve and is supported by the governor
shaft. The drive gear engages with the
flyweight holder gear and speeds up the
drive shaft rotation to rotate the flyweight
holder assembly. The governor lever
assembly is supported by the pivot bolt in
the pump housing and the ball pin located
at the bottom of it is inserted in the control
sleeve which slides on the outside surface
of the plunger.
b) The governor spring located at the top of it
is connected to the tension lever with the
retaining pin and the governor spring end
face is connected to the control lever
through the control lever shaft.
The control lever is linked to the governor
handle through the link to vary the setting
force of the governor spring according to
the inclined angle. A difference between
the setting force of the governor spring and
the centrifugal force of the flyweight
corresponds
movement which increases or decreases
the injection quantity.
3) Timer
There is a built-in timer at the bottom of the
injection pump. A timer spring having a
setting force is installed on the low pressure
side. The fuel pressure in the pump house is
directly applied to the opposite side (high
pressure side). The position of the timer
piston varies according to the relation
between this fuel pressure and timer spring
force and the roller holder is rotated through
the roller holder pin.
When the piston moves in the direction
where the timer spring is shrunk, a lead of
angle takes place (the roller holder moves in
the reverse direction of rotation) to advance
the injection timing. That is, the timer controls
the injection timing according to the fuel oil
pressure in the pump house.
to the control sleeve
Control lever
Control lever shaft
Flyweight
holder gear
Flyweight
holder
Flyweight
Drive gear
Roller
holder
Roller
holder pin
Low
pressure
side
230
Governor sleeve
Retaining pin
Tension
lever
Governor
lever
assembly
Ball pin
Plunger
Control sleeve
010348-00E
High
pressure
side
Timer pin
Timer spring
011208-00E