Bosch DCI 700 Original Instructions Manual page 12

en | 12 | DCI 700
458922-52_Pal
 20: Adapter cable 1 687 465 895
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3.9 Functional description
---Separator--- 3.9.1 Test
The DCI 700 contains all components, e.g. a high-pres‐
sure pump and a high-pressure rail for pressure genera‐
tion, test oil tank, flow meter, actuation circuit boards,
computer unit and a HMI needed to test common rail
injectors.
Both solenoid valve-controlled and piezo-controlled in‐
jectors can be tested.
Injectors are tested when the protective door is closed.
The safety switch on the protective door immediately
interrupts the test process and decreases the test oil
pressure completely if the protective door is opened.
The "DCI" software is installed on the computer unit
and is used to test common rail injectors. The "DCI"
software includes a database (license-dependent) with
test sequences for injectors. Each test sequence in‐
cludes different test steps (leak test, EM, VL, LL, ...)
with actuation profiles that must be completed in suc‐
cession during the injector test.
After the test, the results can be displayed in a test
protocol and printed out.
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3.9.2 Test oil supply
As soon as the injector test is started, the drive motor
of the DCI 700 starts and operates the high-pressure
pump at a rotational speed that depends on the test
step. Simultaneously, the fuel pump starts and delivers
test oil from the test oil tank to the high-pressure pump
through the test oil filter.
The high-pressure pump draws test oil into the high-
pressure chamber, pressurizes the test oil and directs it
further to the high-pressure rail via high-pressure hose
assemblies. A portion of the test oil that does not need
to be supplied to the injectors is returned to the test oil
tank. The cooler test oil flows through the injected fuel
quantity block, cooling the injected fuel quantity from
the injector.
A pressure control valve that opens or closes depend‐
ing on the amount of test oil is used to regulate the
pressure in the high-pressure rail. A bypass through
which the test oil can flow opens when needed. The
test oil flows to the heat exchanger through hose as‐
semblies, where it is cooled before flowing back to the
test oil tank.
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3.9.3 Flow measuring
Once the injector test has started, the actuation elec‐
tronics actuate the injectors using a defined control
progression that depends on the test step and injector.
The injectors start to inject.
The test oil injected by the injector (injected fuel quan‐
tity) is collected in the injection chamber and flows into
the measurement channel at the "Injection" test con‐
nection through a hose assembly. At the same time, the
test oil flows out of the injector return (return quantity)
into the measurement channel at the "Return" test con‐
nection through a hose assembly. One measurement
channel for the injected fuel quantity and one measure‐
ment channel for the return quantity are provided for
each injector.
The test oil flows through an inlet filter where it is fil‐
tered immediately downstream from the test connec‐
tion. The pressure drop across the inlet filter is moni‐
tored. If a fouled inlet filter is detected, the user Is noti‐
fied by a message from the "DCI" software that the the
test oil filter in the inlet filter must be changed.
After passing through the inlet filter, the filtered test oil
flows to the flow meter through channels in the meas‐
urement block. The test oil flows through the flow me‐
ter and the flow meter measures the amount of test oil.
The values determined for the amount are displayed by
the "DCI" software. The test of oil is directed back to
the test oil tank through the heat exchanger after the
measurement.
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3.9.4 Test oil conditioning
As soon as the DCI 700 is switched on, the test oil
heater in the test oil tank starts and heats the test oil.
The heater control then brings the test oil to the re‐
quired test oil temperature of 40 °C.
To protect against overheating, a minimum amount of
test oil must be kept in the test oil tank. The amount
that is monitored by a float switch in the test oil tank. If
the amount of test oil drops, the float switch detects
this and the "DCI" software informs the user by means
of a message. In addition, a thermal switch and heater
fuse are installed in the test oil tank as a safety ele‐
ment; in the event of a fault, they are actuated in suc‐
cession.
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3.9.5 Test oil cooling
The injected and hot test oil is mixed with the cooler
test oil from the high-pressure pump and the test oil
tank in a distributor. The mixed test oil flows through a
heat exchanger, which transfers the heat to the ambi‐
ent air. A fan on the heat exchanger assists the cooling
process.
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4. Operation
4.1 --- Switch on DCI 700
 All protective devices e.g. protective covers and safe‐
ty-related devices e.g. extraction devices are present
and functional.
 Test equipment is correctly set up and connected.
Robert Bosch GmbH