Zero delivery drain
(17) Zero delivery drain
The zero delivery drain (17) has a function of
preventing fuel flow to the pressurizing part when no
fuel is being delivered.
Though the suction control valve is set to no flow, a
small amount of fuel flows to the pressurizing part.
The zero delivery drain is provided to prevent this and
this small amount of fuel is returned through the zero
delivery drain and returned to the fuel tank.
Note, other than no delivery, fuel is delivered to the
pressurizing part based on the amount of throttle and
very little flows to the zero delivery drain.
Overflow valve
(18) Ball
(19) Valve body
(20) Spring
(21) Port
(22) Valve piston
[G] While closed
[H] While opened
When the pressure of fuel delivered from the feed
pump rises above a prescribed amount, the overflow
valve has a function of returning fuel to the tank.
When fuel pressure increases and exceeds the force of
the spring, the valve piston is pushed.
Here, the fuel passes through the port (21) provided in
the valve body and returns to the fuel tank.
Therefore, the pressure in the suction control valve is
stabilized and fuel flow is accurately adjusted.
3.10.4 Specification of supply pump
Pump type
Bosch PF49
Engine model
Rail pressure reference values
At idling
At rated speed (No
load)
D1803-CR-E4
25 to 30 MPa
260 to 300 kgf/cm
2
3700 to 4300 psi
55 to 60 MPa
560 to 610 kgf/cm
2
8000 to 8700 psi
D1803-CR-TE4
75 to 80 MPa
765 to 815 kgf/cm
2
10900 to 11600 psi
D1803-CR-TIE4
100 to 110 MPa
1020 to
1120 kgf/cm
2
14500 to 15900 psi
V2403-CR-E4
V2403-CR-TE4
60 to 65 MPa
620 to 660 kgf/cm
2
8700 to 9400 psi
V2403-CR-TIE4
95 to 115 MPa
970 to 1170 kgf/cm
2
14000 to 16600 psi
V2403-CR-TE4BG
70 to 75 MPa
720 to 760 kgf/cm
2
10200 to 10800 psi
3.11 Injection pipe
3.11.1 Outline of injection pipe
Injection pipes connect the supply pump and rail as
well as the rail and injectors.
3.11.2 Structure of injection pipe
The injection pipes between the rail and injectors are
designed with equal length.
(1) Injection pipe
MECHANISM
3. Fuel system
4. ENGINE
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4
4-23
KiSC issued 12, 2018 A
Содержание D1803-CR-E4
Страница 17: ...1 SAFETY KiSC issued 12 2018 A ...
Страница 24: ...2 GENERAL KiSC issued 12 2018 A ...
Страница 67: ...3 MAINTENANCE KiSC issued 12 2018 A ...
Страница 100: ...4 ENGINE KiSC issued 12 2018 A ...