Yanmar 4LHA-HTP Operation Manual page 391

Chapter 3 Fuel Injection Equipment
6. Governing Mechanism
Partial load operation
Flyweight
Fig. 40 Operation of governor equipped with negative torque control device: partial load operation
In the speed range exceeding idling operation,
and the range where the control lever is posi-
tioned between the idling position and the
maximunn speed position, the starting spring
and start-idling spring are already fully com-
pressed, and the torque control lever and the
tension lever (which are in contact at points A
and B through the torque control lever pushrod
and stopper pin), and the starting lever, move
together as one (Fig. 40).
Therefore, during partial load operation the
damper spring and the partial load spring are
acted upon by (and oppose) the flyweights'
centrifugal force.
If the speed increases during partial load opera-
tion in accordance with a change in the control
lever position (i.e. the control, sleeve position)
after the accelerator pedal is depressed, the
Partial load spring
Control lever shaft
_ —^M4jpivot)-
==
1 " r f C ^ - - S t o p p e r p i n ^
h :
i
Starting lever
Torque control lever
Control sleeve
Damper spring
J
Start-idling spring
^
n
Point B
I . J :
M 2 _
(pivot)
d b
consequent increase in the flyweights' centrif-
ugal force moves the governor sleeve to the
right, thereby pushing the torque control lever
to the right. Then, as the torque control lever,
the starting lever and the tension lever behave
as one component, movement of the governor
sleeve by the flyweights' centrifugal force
compresses the damper spring and the partial
load spring, and pivots the starting lever
around fvte. Thus, the control sleeve is moved
to the left to decrease the fuel injection quanti-
ty. As a result of this, the speed is decreased
to maintain a suitable engine speed, and an in-
jection quantity corresponding to the engine
load etc. is obtained at the point where the
flyweights' centrifugal force is balanced with
the combined forces of the damper and partial
load springs.
3-1-34
i 4LHA Series
Tension lever
Starting spring
Point A
Pushrod