Chevrolet 70 1969 Series, Руководство по ремонту

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ENGINE FUEL SYSTEM 6 M -6
Figure 6—Hydraulic Governor System
(401M and 47BM
Engines) (Typical)
phragm (5) in its outer position and telescopic link
(7) is shortened as lever (8) on throttle shaft (9)
moves and forces link into engagement with dia­
phragm assembly. As engine approaches governed
speed the spinner valve begins to open and hy­
draulic pressure is applied to diaphragm (5) in
slave unit. As pressure moves diaphragm, force
is transmitted through link (7) to the lever (8) on
throttle shaft (9) and throttle plates (10) are moved
1 A c c e l e r a t o r L e v e r
2 Thro ttle Shaft D r i v e r
3 G o v e r n o r T e n s i o n S pring
4 D i a p h r a g m S pring
5 D i a p h r a g m A s s e m b l y
6 H y d ra u lic L i n e C o n n ect io n
( F r o m S p in n e r V alve)
7 T e le s c o p ic L i n k
8 L e v e r
9 Thro ttle Shaft
10 Thro ttle Plates
11 F a st Idle S c r e w
12 T hro ttle D r i v e r A s s e m b l y
T -2 8 7 i
Figure 7—Governor a id Throttle Operation
(401M and 478M Engines) (Typical)
toward closed
engine speed.
If engine
the spring at
off hydraulic
valve closed,
position, thereby governing the
speed falls below governed speed,
spinner valve closes valve and cuts
pressure to governor line. With
line pressure is relieved through
slot in side of spinner vilve. Bleed hole in valve
housing provides correc: pressure regulation at
diaphragm in slave units, Springs (3 and 4) force
diaphragm back to outer position and tension
spring (3) returns throttl 3 plates to open position.
When accelerator pec al is released, the throt­
tle driver assembly (121 engages throttle shaft
driver (2) and moves throttle plates (10) to closed
position.
The internal passage, between governor slave
unit and air horn, insure s clean air in governor
housing as breathing occi rs during diaphragm ac­
tion. Vent also prevents any suction build-up due
to vacuum transmitted through carburetor bodies.
Engine speed at whi^h governor system be­
gins to close throttle pls.tes is controlled by ten­
sion of spinner valve spring.
BENDIX-STROMBERG CARBURETORS
Carburetors described in this section are
used on vehicles equipped with V-6 engines. W W C
type carburetor is used on 401M and 47 8M
engines.
Carburetor is of a down-draft double barrel-
type as shown in figure 8. Each barrel of carbu­
retor has its own idle system, main metering
system, and throttle valve. The idle and main
metering systems are supplemented by the float
system, the accelerating system, and the power
system.
Carburetor is equipped with a manual-type
choke control on all models. The choke lever is
connected to the throttle linkage to provide fast
idle speed position during the choke period on all
models.
Carburetors for all 101M and 478M engines
have a hydraulically operated governor unit which
is built into throttle bocy. Refer to “ Hydraulic
Governor” under “ G O V E R N O R " covered pre­
viously in this group for governor operation.
CHEVROLET SERIES 7 )-8 0 H EAVY DUTY TRUCK SH O P M A N U A L