Yanmar 4LHA-HTP Operation Manual page 435

Chapter 3 Fuel Injection Equipment
1. Fuel Supply System
F u r t h e r m o r e , the angleich spring is gradually com-
pressed as t h e engine speed rises. This is because
the increased governor weight thrust load exceeds
the angleich load before high speed control is ef-
fected. W h e n the governor lever and the bottom of
the tension lever come into contact (end of angleich
stroke), t h e
amount, a n d the rack reaches the rated position
( R E ) .
Control lever position
Rated speed setting
Full load stopper
Tension lever
Angleich spring assembly
Governor lever
(
injection volume is reduced by that
Increase Decrease
Angleich stroke
Cam speed
Injection volume
(6) Necessity of torque spring and function
Engines used in construction machinery are sub-
jected to sudden loads which cause a decrease in
speed and sometimes result in stopping of the
engine. A torque spring is provided to move the
control rack for a higher injection volume when
engine speed falls. T h e higher torque can withstand
overloads and prevent the engine from stopping.
The governor c o n t r o l lever is f i x e d at point G in
the diagram on the right, the continuous rated
output position. If the engine is loaded, the tension
lever encompasses t h e torque spring, the control
rack comes away f r o m full load stopper, and this
fluctuates between G and H according to engine
load.
If the load on the engine exceeds the continuous
rated output, the speed falls and the governor
spring tension exceeds the governor weight thrust
load to overcome the torque spring set load. The
tension lever then gradually causes the control rack
to increase the injection volume. T h e torque rise
stroke ends when the control rack reaches F'.
Control lever
rated speed position
Torque spring
Torque rise stroke
3-2-13
with angleich spring
V
Engine speed-
4LHA Series
Injection volume
Increase Decreas<