
13. Oxygen sensor
The oxygen sensor, installed on the exhaust pipe before the three way catalytic reactor, feeds back the mixture density to
the computer by measuring oxygen content in the exhaust gas. Its structure is shown in Fig. 2-378, and its working
principle is shown in Fig. 379.
The sensitive element in the oxygen sensor used to generate
voltage signal is Zirconium oxide (ZrO2), with its surface
coated with catalytic platinum, which is coated again with a
layer of high permeation ceramic for protection of the platinum
electrode. The internal side of the sensitive element of the
oxygen sensor is open to the atmosphere, while the exhaust
gas from the engine passed through the external side. When
the temperature of the sensitive element is over 400°C and
the oxygen contents of the two sides differ greatly, then a
potential will be produced between the two sides. The heating
rod 6 in the oxygen sensor is used to heat the sensitive
element to enable it to operate normally. The oxygen sensor is
connected to 12V power supply for the heater. The internal
side of the sensitive element has a high oxygen content as it
is open to the atmosphere. In the case of thin mixture, the
exhaust gas has a high oxygen content, and the oxygen
contents of the two sides of the sensitive element differ little.
Therefore, the potential produced is also very low (about
0.1V). In the case of dense mixed gas, the exhaust contains
Technical parameters of TEV2 carbon canister control valve
Fig. 378 Schematic Diagram of the oxygen sensor
1. Cable 2. Disk washer 3. Lower insulation bushing 4. Protective sleeve 5.
Angle wire 6. Heating rod 7. Angle gasket 8. Sensor seat 9. Ceramic probe 10.
Protective tube
1. Zirconium oxide ceramic 2. Electrode layer with platinum surface
3.4. Internal and external insulation bushings 5. Exhaust pipe 6.
RRProtective layer of high-permeation ceramic
a. Dense mixed gas (insufficient oxygen)
b. Thin mixed gas (excessive oxygen)
Fig. 379 Sketch of working principle of the oxygen sensor
Atmosphere
Table 34
Output voltage
Fig. 380 Output characteristics of the oxygen sensor (at
600 C exhaust temperature)
1000
mv
800
600
400
200
0.8
0.9
1
1.1
1.2
little oxygen, oxygen densities at the two sides of the sensitive element differ greatly, and the potential produced is also
high (about 0.8V). The output characteristics of the oxygen sensor are shown in Fig. 380. The technical parameters of the
oxygen sensor are shown in Table 35.
Flow
Air tightness
Control frequency
Min. control pulse
Current consumption
Resistance
Operating voltage
Inductance
Operating temperature
2~3m3/h, pressure 200mbar
<2000 cm3/h
30Hz
7ms
0.5A for 13.5V
26Ω
9V~16V
48mH at f=1kHz
-30°C~ +120°C
193
Содержание JL481Q
Страница 1: ......
Страница 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Страница 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Страница 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Страница 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Страница 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Страница 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Страница 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...
Страница 21: ...17 Fig 13 Exterior Feature of JL481Q Engine Power Me N m Torque Pe Kw ge g kwh Fuel Consumption Ratio ...