Iveco Daily. Manual — part 176
88071
Figure 268
Each pumping assembly comprises:
- a plunger (5) operated by a three-lobed element (2)
floating on the shaft of the pump (6). Since the element
(2) floats on a misaligned portion of the shaft (6), during
shaft rotation, it does not turn with it but is only shifted
1. Cylinder — 2. Three-lobed element — 3. Plate intake valve — 4. Ball delivery valve — 5. Plunger — 6. Pump shaft —
7. Low-pressure fuel inlet — 8. Fuel ducts to supply pumping elements.
in a circular movement on a wider radius, with the result
of working the three pumping elements alternately:
- a plate intake valve (3);
- a ball delivery valve (4).
Sec. B - B
Sec. C - C
600
F1C ENGINE
D
AILY
Base - May 2004
High-pressure pump internal structure
88072
Figure 269
The pumping element (3) is arranged on the cam on the pump
shaft. In the suction phase, the pumping element is supplied
through the supply duct (5). The amount of fuel to send to the
pumping element is determined by the pressure regulator (7).
The pressure regulator, on the basis of the PWM command
1. Outlet for delivery to rail — 2. Delivery valve to rail — 3. Pumping element — 4. Pump shaft — 5. Pumping element supply
duct — 6. Pressure regulator supply duct — 7. Pressure regulator.
Working principle
Figure 270
received from the control unit, chokes the flow of fuel to the
pumping element. During the compression phase of the
pumping element, the fuel, on reaching such a pressure as to
open the delivery valve to the common rail (2), supplies it
through the outlet (1).
A
B
C
B--B
Sec. D - D
Sec. B - B
F1C ENGINE
601
D
AILY
Base - May 2004
88073
Figure 271
Figure 271 shows the low-pressure fuel routing in the pump;
it highlights the main supply duct of the pumping elements (4),
the supply ducts of the pumping elements (1-3-6), the ducts
used to lubricate the pump (2), the pressure regulator (5), the
5-bar relief valve (8) and the fuel outlet.
The pump shaft is lubricated by the fuel through the delivery
and return ducts (2).
1, 3, 6 Pumping element inlet — 2. Pump lubrication ducts — 4. Main pumping element supply duct — 5. Pressure regulator —
7. Regulator outlet duct — 8. Relief valve 5 bar — 9. Fuel outlet from regulator inlet.
Sec. C - C (Figure 270)
The pressure regulator (5) determines the amount of fuel with
which to supply the pumping elements; excess fuel flows out
through the duct (9).
The 5-bar relief valve, besides acting as a manifold for the fuel
outlets, has the function of keeping the pressure constant at
5 bars at the regulator inlet.
72598
602
F1C ENGINE
D
AILY
Base - May 2004
72600
Figure 272
The figure shows the high-pressure fuel flow through the
outlet ducts of the pumping elements.
1, 2 Fuel outlet ducts — 3. Fuel outlet from the pump with coupling for high-pressure pipe for the common rail.
Sec. A - A (Figure 270)
72601
F1C ENGINE
603
D
AILY
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