GB2110300A - Fuel injection system for a compression ignition engine - Google Patents
Fuel injection system for a compression ignition engine Download PDFInfo
- Publication number
- GB2110300A GB2110300A GB08231660A GB8231660A GB2110300A GB 2110300 A GB2110300 A GB 2110300A GB 08231660 A GB08231660 A GB 08231660A GB 8231660 A GB8231660 A GB 8231660A GB 2110300 A GB2110300 A GB 2110300A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fuel
- accumulator
- nozzle
- pump
- inlet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
- F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
A high pressure fuel pump supplies fuel through a pipeline to an injection nozzle and in or adjacent the nozzle is an accumulator connected to the inlet of the nozzle. The pipeline is connected to the accumulator by a non-return valve which allows fuel flow to the accumulator but prevents flow in the reverse direction. Any secondary injection of fuel due to pressure waves in the accumulator occurs very quickly after the main delivery of fuel so that the displacement of fuel to the engine is effectively continuous.
Description
SPECIFICATION
Fuel system for compression ignition engine
This invention relates to a fuel system for a compression ignition engine of the kind comprising a pump for supplying liquid fuel at a high pressure, an injection nozzle through which fuel is directed into a combustion space of the engine, a pipeline connecting the outlet of the pump with the inlet of the injection nozzle and the nozzle including a resiliently loaded valve member which is moved to the open position by the fuel under pressure delivered by the pump.
Such systems are well known in the art and in general are designed so that secondary injection of fuel from the nozzle into the combustion chamber following the main delivery of fuel, is avoided. Secondary injection of fuel can occur due to a pressure wave in the column of fuel contained in the pipeline and which upon closure of the valve in the nozzle following delivery of fuel, travels back towards the pump and is reflected back towards the nozzle. Every effort is made in most systems of this type to prevent secondary injection of fuel to the reflected pressure wave since in most cases, the fuel is not properly burnt in the combustion chamber of the engine and therefore leads to smoke in the exhaust of the engine.
There are some engines where it is desirable to
prolong the period of fuel delivery without
reducing to any significant extent, the rate of fuel delivery and it is desirable to be able to use
standard equipment. Such an engine for example
is one which is designed to operate on a low quality fuel which is supplied to a combustion chamber of the engine through a separate
injection system and which also requires the
injection of some high quality fuel to ensure
ignition and satisfactory burning of the low quality fuel. The low quality fuel which may for example
be a heavy oil, will in general be injected into the combustion chamber over a period considered in terms of degrees of crankshaft rotation, which is
longer than the accepted period when high quality fuel is being delivered.It is however desirable that the injection of the high quality fuel should
continue for as long as possible during the
delivery of the low quality fuel. Whilst a system for delivering the high quality fuel at the desired
rate could be designed it would be a "special"
system which might not have much application to
other types of engine. As a result the system
would be expensive. It is therefore an object of the present invention to provide a system of the
kind specified in which the period of fuel delivery
is extended using secondary injection.
According to the invention a system of the kind specified comprises an accumulator disposed at or adjacent the injection nozzle, the inlet of the injection nozzle communicating with the accumulator, an inlet to the accumulator said inlet being connected to the outlet of the pump through said pipeline and a non-return valve in said accumulator inlet, said non-return valve being arranged to allow fuel flow into said accumulator from the pump but to prevent fuel flow in the opposite direction.
In the accompanying drawings: Figure 1 is a diagrammatic view of a conventional fuel system; and
Figure 2 shows the modification in accordance with the invention, to the fuel system shown in
Figure 1.
The fuel system comprises a high pressure
injection pump which is indicated at 10 and which has an outlet connected by way of a
pipeline 11, to a fuel injection nozzle generally
indicated at 12. The fuel injection nozzle is of the
conventional inwardly opening type well known in
the art and including a valve member which is
biased to the closed position by a spring. The
injection pump 10 is driven in timed relationship
with the associated engine and it may be of the
rotary distributor type or of the type known in the
art as an "in-line" pump. It includes a pumping
plunger and an outlet which is controlled by a
delivery valve which may be of the unloading
type.
In operation, fuel is delivered by the injection
pump and the pressure wave generated at the
start of fuel delivery travels along the pipeline 11
to effect opening of the spring loaded valve
contained within the nozzle. The flow of fuel
through an orifice of the nozzle occurs until the
delivery of fuel by the injection pump terminates.
When the flow of fuel terminates the valve
member in the nozzle closes quickly since it is
biased by a strong spring and the effect of this is
that a pressure wave is generated in the nozzle
which travels back along the pipeline to the pump 1 0. The effect of the unloading delivery valve is to
allow a predetermined quantity of fuel to escape
from the pipeline 11 before the delivery valve
closes. in this manner the residual pressure in the
pipeline 11 is reduced and this helps the valve
member in the nozzle to close quickly.The
pressure wave in the column of fuel in the pipeline
11 and which is generated by closure of the valve
member of the nozzle is reflected back along the
pipeline owing to the fact that the delivery valve is
closed and the pressure wave may be sufficient to
cause momentary opening of the valve member of
the nozzle so that so-called secondary injection of
fuel occurs. Every effort is made in conventional
fuel systems to minimise the risik of secondary
injection since it can lead to poor combustion of
the fuel which is delivered to the engine. The
unloading delivery valve does help to reduce
secondary injection.Moreover, because of the
fact that the pressure wave has to travel twice the
length of the pipeline, there is an interval between
the termination of the main flow of fuel through
the injection nozzle and the commencement if it
takes place, of the secondary injection of fuel.
The known form of fuel system shown in Figure
1 is modified as shown in Figure 2, by the provision of an accumulator 13 connected to the inlet of the nozzle. The pipeline 11 is connected to the accumulator by way of a non-return valve 14 which is arranged to permit flow of fuel from the pipeline 11 into the accumulator but to prevent flow of fuel in the opposite direction. The valve 14 will close as soon as delivery of fuel by the pump 10 ceases. When the valve member of the injection nozzle closes the pressure wave which is generated is reflected by the closed non-return valve 14 and the reflected wave will open the valve member of the fuel injection nozzle almost immediately it has closed. The accumulator 13 stores a volume of fuel which is delivered during the secondary injection of fuel. Thus whilst the valve member iru ehe fuel injection nozzle does close following the cessation of delivery of fuel by the pump, it is opened very quickly to allow the secondary injection of fuel, and the delivery of fuel to the engine in the two stages, can be said to be continuous.
The accumulator 13 is shown in Figure 2 to be exterior of the fuel of the fuel injection nozzle. It may however be incorporated in the design of the nozzle as also may the non-return valve.
Claims (2)
1. A fuel system for a compression ignition engine comprising a pump for supplying liquid fuel at a high pressure, an injection nozzle through which fuel is directed into a combustion space of the engine and a pipeline connecting the outlet of the pump with the inlet of the injection nozzle, the nozzle including a resiliently loaded valve member which is moved to the open position by the fuel under pressure delivered by the pump, an accumulator disposed at or adjacent the nozzle, the inlet of the injection nozzle communicating with the accumulator, an inlet to the accumulator said inlet being connected to the outlet of the pump through said pipeline and a non-return valve in said accumulator inlet, said non-return valve being arranged to allow flow of fuel into said accumulator from the pump but to prevent fuel flow in the opposite direction.
2. A fuel system for a compression ignition engine comprising the combination and arrangement of parts substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings as modified by
Figure 2 thereof.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08231660A GB2110300A (en) | 1981-11-27 | 1982-11-05 | Fuel injection system for a compression ignition engine |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8135833 | 1981-11-27 | ||
GB08231660A GB2110300A (en) | 1981-11-27 | 1982-11-05 | Fuel injection system for a compression ignition engine |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2110300A true GB2110300A (en) | 1983-06-15 |
Family
ID=26281397
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08231660A Withdrawn GB2110300A (en) | 1981-11-27 | 1982-11-05 | Fuel injection system for a compression ignition engine |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2110300A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0174261A1 (en) * | 1984-08-14 | 1986-03-12 | Ail Corporation | Fuel delivery control system |
GB2341637A (en) * | 1998-09-15 | 2000-03-22 | Daimler Chrysler Ag | Fuel injection system for a diesel i.c. engine, with solenoid injectors each having an accumulator |
-
1982
- 1982-11-05 GB GB08231660A patent/GB2110300A/en not_active Withdrawn
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0174261A1 (en) * | 1984-08-14 | 1986-03-12 | Ail Corporation | Fuel delivery control system |
GB2341637A (en) * | 1998-09-15 | 2000-03-22 | Daimler Chrysler Ag | Fuel injection system for a diesel i.c. engine, with solenoid injectors each having an accumulator |
GB2341637B (en) * | 1998-09-15 | 2000-08-16 | Daimler Chrysler Ag | Fuel injection system for a diesel internal combustion engine |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4590904A (en) | Fuel injection apparatus | |
KR930010661B1 (en) | Pressure valve | |
US5566660A (en) | Fuel injection rate shaping apparatus for a unit fuel injector | |
US4372272A (en) | Fuel delivery system with feed and drain line damping | |
US4864990A (en) | Injection system for a dual-fuel engine | |
US4475515A (en) | Fuel systems for compression ignition engines | |
FR2393164A1 (en) | ELECTROMAGNETIC FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINES | |
US6568927B1 (en) | Piston pump for high-pressure fuel generation | |
AU8735198A (en) | Device for injecting fuel into a diesel engine | |
JPS61286573A (en) | Fuel injector for engine | |
JPH04292568A (en) | Injection device for use in air compressor internal combustion engin | |
ES8501061A1 (en) | Fuel injection system | |
GB2110300A (en) | Fuel injection system for a compression ignition engine | |
ES482909A1 (en) | Fuel injection pump with positive displacement delivery valve having two port areas opened according to fuel flow rate | |
GB2227056A (en) | I.c.engine fuel injection pump and injector | |
US4709680A (en) | Device for controlling fuel injection apparatus in diesel engines | |
ES8700727A1 (en) | Liquid fuel pumping apparatus | |
ES8308615A1 (en) | Fuel injector for internal combustion engine | |
EP0255350A2 (en) | High pressure fuel injection system | |
US5462030A (en) | Encapsulated adjustable rate shaping device for a fuel injection system | |
JPS59113252A (en) | Fuel injection pump device | |
GB2114236A (en) | Fuel injection system | |
JPH0256511B2 (en) | ||
ES2007194A6 (en) | Fuel injection system. | |
JPH0114417B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |