Chapter 7 Fuel Supply System
1. Mixture quality not to be influenced by air density
This system atomizes gasoline by using an injector based on pressure atomization, which atomizes fuel mainly by means
of the pressure difference between its interior and exterior.When injection happens at fuel inlet bypath, the high tempera-
ture here can be helpful to atomize fuel. So, mixture quality will not be influenced by air density
2. The influence of air density on air-fuel ratio
Because the injector has no venturi, its injection rate is not determined by vacuum degree within venturi. So it is unlike this
system that the air-fuel ratio of the mixture is inversely proportional to the square root of air density, which exists in carbure-
tor. This feature enables it to provide more accurate correction to the influence of air density on air-fuel ratio than carbure-
tor.
3. Mixture well distributed into multiple cylinders when multiport injection applied
For multiport injection, fuel either enters into cylinders or arrives at inlets. So airflows through intake manifolds contain no
fuel and no fuel film adheres to intake manifold wall. This eliminates the problem of bad mixture distribution into multiple
cylinders when carburetor applied.
4. No additional fuel consumption or deteriorated emission caused by load variation when
multiport injection applied
When multiport injection applied, it is pure air that flows through intake manifold. Therefore there will not be additional fuel
entering from fuel film on cylinder wall into the airflow when the pressure therein drops because the throttle is adjusted to
decrease its flow rate.
5. Improved performance under transition working conditions when multiport injection
applied
Multiport injection eliminates the interference from fuel films on intake manifold walls with control of air-fuel ratio, so the
performance under transition working conditions will be improved.
6. Increased volume efficiency
Firstly, gasoline injection eliminates carburetor and venturi, therefore removing the bottleneck of the inlet passage.
Secondly, the absence of fuel film on intake manifolds eliminates the need to heat the intake pipe with exhausted gas, and
therefore intake and exhaust manifolds can be placed respectively on both sides of the engine to form the so-called "Trans-
verse flow scavenging", improving the charge exchange. As a result, the two points leads to increased volume efficiency
and decreased tendency toward knocking.
7. No risk of mixture generation system freezing up
With a high temperature, the injector for multiport injection system cannot freeze up.
8. Operation of gasoline injection system not to be influenced by the engine placement
For gasoline injection system, its operation will not be influenced by the engine placement because the former has nothing
to do with its gravity.
Section 1 Makeup and Features of Fuel Supply
System for Electronic Fuel Injection Engine
I. Excellent Features of Fuel Supply System
for Electronic Fuel Injection Engine
A
s a control mode, fuel supply system for electronic fuel injection engine is used to electronically control gasoline engine.
It has a lot of excellent features compare with carburetor engine lacks.
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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 ...