Yanmar 4LHA-HTP Operation Manual page 383

Chapter 3 Fuel Injection Equipment
6. Governing Mechanism
I : Damper spring operation range
II: Partial load spring operation range
S i : Damper spring stroke
S2: Partial load spring stroke
Injection pump speed
Fig. 29 Combination governor characteristics
Governor spring
Yoke
Control lever shaft
S i : Damper spring stroke
S2: Partial load spring stroke
Fig. 30 Control lever shaft assembly
Accelerator variation
Partial load spring
Damper spring
Tension lever
3-1-26
In low speed range I the control sleeve's posi-
tion is controlled by the
flyweights' centrifugal force and the damper
spring force.
(e.g. control sleeve movement from (1) to (2) in
Fig. 29)
In the intermediate-high speed range II (where
the flyweights' centrifugal force exceeds the
damper spring force, but is less than the gov-
ernor spring's set force) the damper spring is
fully compressed, and the partial load spring in
the yoke is compressed an amount equal to
^ S 2 (Fig. 29). AS2 varies according to the bal-
ance of the flyweights' centrifugal force with
each spring's set force (i.e. engine speed and
engine load).
If an uphill slope is negotiated after travelling
on a level road with the control lever position
fixed and the control sleeve positioned at point
(3), because the engine speed decreases, the
control sleeve position will shift in the direction
of point (2) through the action of the partial
load spring and the fuel injection quantity will
be increased.
Conversely, if a downhill slope is negotiated,
the fuel injection quantity will be decreased as
engine speed increases.
Furthermore, if the amount that the accelerator
pedal is depressed is altered, the
sleeve position will move in the direction of the
arrow in Fig. 29.
14LHA Series
balance of the
control