Yanmar 4JH2E Service Manual page 109

Chapter 3 Fuel Injection Equipment
13. Fuel Injection Pump Outline
----------------------------------------------------------~4JH2-UTE
13. Fuel Injection Pump Outline(4JH2-UTE)
Flyweight
Drive shaft
Feed pump
Roller holder
Cam disk//
Timer
Fig. 1 VE type injection pump construction
With the PE type (in-line type) injection pump.
the number of pump elements (plunger
assemblies) must be the same as the number
of engine cylinders. However. with the VE type
(distributor type) injection pump. the number of
plungers has no relationship to the number of
engine cylinders. and there is only one plunger.
This single plunger reciprocates while rotating.
and fuel oil is injected into each cylinder
through the injection pipes in accordance with
the engine's firing order.
As well as this. the governor. timer. feed pump
etc. installed on the outside of the PE type in-
jection pump are equipped within the VE type
injection pump.
3-44
Full-load adjusting screw
Governor lever
Magnet valve
Distributor head
Plunger
Delivery valve
In comparison with the PE type, the VE type
injection pump has less than half the number
of component parts, and was developed in
order to satisfy the need for a small. light-
weight and high-speed injection pump.
In response to operator requirements, it was
possible to design a pump with acceleration
close to that of gasoline vehicles.
A VE type injection pump for direct injection
system engines has recently been developed.
and is expected to be adopted in a wide range
of fields. including construction machinery,
medium-sized trucks etc.
Printed in Japan
AOAI029-9109SP