Installation Instructions

ManualsBrandsKubota ManualsMiscellaneousB2400

B1700·B2100·B2400

W$M,

11770

1

ENGINE

(5) Slot

(6) Control Groove

(7) Driving

Face

(1)

Pump Element

(2)

Cylinder

(3)

Plunger

(4)

Feed

Hole

III Delivery Valve

The

delivery valve

consists

of

the delivery valve

(1)

and

delivery valve seat

(2).

The

delivery

valve

performs

the

following

functions.

1.

Reverse

flow

preventing function

If the fuel

flow

reverse

from the injection nozzle

side

when

the

plunger

lowers,

the

time

lag

between the next delivery start and

the

nozzle

injection start

increases.

To

avoid this, the delivery

chamber

to

injection pipe interruption

by

delivery

valve

(1)

prevents this

reverse

flow, thus keeping

fuel always filled in the nozzle and pipe.

2.

Suck-back function

After

completing the fuel delivery, the delivery

valve lowers, and

the

relief

plunger

(4) end

contacts

the

delivery valve seat (2). The valve

further lowers until its seat surface

(3)

seats

firmly

the

delivery valve seat. During this time,

the

amount

of

fuel corresponding

to

(A)

is

sucked

back

from inside the injection pipe, the

pressure

inside

the pipe

is

reduced, thus leading

to

an

improved

injection shut

off

and preventing

after

leakage

dribbling.

III

Pump

Element

The

pump element

(1)

is

consist

of

the plunger

(3)

and cylinder

(2).

The

sliding surfaces

are

super-precision machined

to

maintain injection

pressure

at engine

low

speeds.

Since

the driving face

(7)

fits in the control

sleeve,

the

plunger

(3)

is

rotated

by

the

movement

of

the

control rack

to

increase or decrease

of

fuel delivery.

As

described above, the plunger

(3)

is

machined

to

have the slot

(5)

and

the control groove

(6).

A

(3)

Seat Surface

(4)

Relief Plunger

4

0011F042

(1)

Delivery Valve

(2)

Delivery Valve Seat

0011F043

0087F025

III Dumping Valve

1.

At

fuel injection

Since

dumping valve

is

pushed up

to

press

the

spring, fuel

is

pressure-fed

to

injection nozzle the

same

as

without

dumping valve.

2.

At

suck-back

At

suck-back

by

delivery valve after fuel injection

fuel

returns

through

dumping

valve

orifice

Generally

second

injection

is

apt

to

occur

by

reflex

pressure

due

to

reaction

of

sudden

pressure

drop

when changing

into

suck-back by delivery valve

from high

injection

pressure.

As

a result

of

preventing

this

second

injection

perfectly

by

dumping valve and dissolving nozzle clogging,

durability

of

injection nozzle

is

improved.

1-M15