DE202014003535U1 - Fuel rail for an internal combustion engine - Google Patents

Abstract

A fuel rail (170) for internal combustion engines (110) storing high pressure fuel comprising: - a common rail conduit (500) in fluid communication with a fuel pump (180) and fixedly connected to the engine , - a cover (560) which seals one end (501, 502) of the common rail, wherein a diaphragm (570) is fixedly connected to the cover and disposed in the piping of the fuel rail.

Description

TECHNICAL AREA

The present invention relates to a fuel rail for an internal combustion engine, which is particularly suitable for spark ignition or gasoline engines. The fuel rail includes an inner membrane for reducing the pressure waves in the strip. However, the invention is suitable for any fuel injection system, regardless of the injection pressure, and for all types of internal combustion engines.

BACKGROUND

As is known, in the field of internal combustion engines, Gasoline Direct Injection (GDI) is a variant of the fuel injection used in modern two-stroke and four-stroke gasoline engines. The gasoline is pressurized and injected via a common rail fuel line directly into the combustion chamber of each cylinder, as opposed to the conventional multipoint fuel injection that takes place in the intake port. For some applications, gasoline direct injection allows for stratified fuel combustion (Ultramagermix combustion) for improved fuel efficiency and reduced low load emissions. Direct injection gasoline (GDI) engines have a number of features that could not be achieved with intake port injection engines: avoidance of a fuel wall film in the manifold, improved accuracy of the air / fuel ratio during the dynamics, less Throttle losses in gas exchange by stratified and homogeneous lean operation, higher heat efficiency by charge stratification, increased compression ratio, which reduces fuel consumption and CO ₂ emissions, lower heat losses, rapid heating of the catalyst by injection during the gas expansion phase, increase in power and volumetric efficiency due to Intercooling, better cold start and better ride comfort.

As is also known, there is a problem of high pressure injection systems in the behavior of the transient hydraulic signal during injections, and particularly in the pressure wave variations. In simplified terms, this phenomenon can be described as follows: When an injection starts, there is a sudden pressure drop in the nozzle distribution chamber, creating a pressure wave (p - Δp) in the manifold in the injector and the injection pipe to the common Ledge moved backwards. After reaching the bar, a pressure wave (p + Δp) is reflected by the injection line, the injection channel to the distribution chamber of the nozzle forward. The same effect occurs when the injection ends: A pressure wave (p + Δp) moves from the nozzle to the strip and is then reflected (p - Δp). In conclusion, it can be said that the individual injections in the same injection nozzle and also from injection nozzle to injection nozzle take place under different pressure conditions. Of course, pressure wave fluctuations are also produced by the volumetric fuel pump, which by definition works by pumping the fuel at a predetermined frequency.

It should be noted that the pressure wave variations not only affect the quality of the injection, but also increase the mechanical stress on the components of the fuel injection.

Therefore, there is a need for a fuel rail whose structure eliminates the above-mentioned deficiencies.

A goal of an embodiment of the invention is to provide a fuel rail for internal combustion engines, the structure of which is adapted to reduce the pressure wave fluctuations in the strip when fuel injection occurs.

These objects are achieved by a fuel rail and an internal combustion engine having the features described in the independent claims.

The dependent claims define preferred and / or particularly advantageous aspects.

SUMMARY

• – eine Common-Rail-Leitung, die in Fluidverbindung mit einer Kraftstoffpumpe steht und mit dem Motor fest verbunden ist,
• – eine Abdeckung, die ein Ende der Common-Rail-Leitung abdichtet,

wobei eine Membran mit der Abdeckung fest verbunden ist und in der Rohrleitung der Kraftstoffleiste angeordnet ist.One embodiment of the disclosure provides a fuel rail for internal combustion engines in which high pressure fuel is stored; full:

• A common-rail conduit in fluid communication with a fuel pump and fixedly connected to the engine,
• A cover which seals one end of the common rail line,

wherein a membrane is fixedly connected to the cover and disposed in the pipeline of the fuel rail.

An advantage of this embodiment is that thanks to this new design of the fuel rail, the pressure wave fluctuations can be minimized, which is favorable to the control of the fuel injection and the lifetime of the Components of the fuel injection effects. The present solution also requires no additional parts, nor does it affect the envelope of the fuel injection system.

According to another embodiment, the membrane is made of a metallic material.

The choice of a metallic material ensures a corresponding resistance to the pressure in the strip, which can reach a value up to 2000 kPa.

According to a further embodiment, the membrane is laser-welded to the cover.

This type of manufacture makes it possible to firmly connect the membrane to the cover and to create a group which can subsequently be installed, for example by being pressed into the common rail line.

According to another embodiment, the membrane is fixedly connected to an annular cylindrical portion of the cover.

An advantage of this embodiment is that the cover, which has a closed circular portion and an annular cylindrical portion, and the diaphragm define a closed cavity which can accommodate the stresses to which the diaphragm is subjected due to the pressure wave variations.

According to another embodiment, the number of covers and the membranes is exactly two.

According to a further embodiment, the two membranes have a different shape and / or are made of different materials.

An advantage of these embodiments is that it is possible through the membranes of different shape and / or of different materials to optimize two different pulse frequencies.

According to another embodiment, the two covers have a different length of their annular cylindrical portion.

Moreover, in this embodiment, since the closed cavity between the two pairs of cover and membrane has a different volume, it is possible to optimize two different pulse frequencies.

According to another embodiment, the membrane is biased by an external valve.

An advantage of this embodiment is that the external valve can be regulated accordingly, depending on the dynamic characteristics of the fuel injection system, to find the correct adjustment of the diaphragm.

Another embodiment of the disclosure provides an internal combustion engine provided with a fuel rail according to any one of the preceding embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Now, the various embodiments will be described by way of example with reference to the accompanying drawings, in which:

1 shows a drive system;

2 is a sectional view of an internal combustion engine, the drive system of 1 belongs;

3 a view of a fuel rail for the internal combustion engine of 2 is;

4 the pressure wave damping diaphragm in the fuel rail of 3 shows.

DETAILED DESCRIPTION OF THE DRAWINGS

Some embodiments may include a motor vehicle drive system 100 include that in 1 and 2 is shown and includes: an internal combustion engine (VKM) 110 with an engine block 120 , the at least one cylinder 125 with a piston 140 defined to be coupled to a crankshaft 145 rotates. A cylinder head 130 works with the piston 140 together to a combustion chamber 150 define.

A fuel-air mixture (not shown) is in the combustion chamber 150 is arranged and ignited, which leads to hot, expansive exhaust gases, which is a reciprocating motion of the piston 140 cause. The fuel is passed through at least one fuel injector 160 provided, and the air is passed through at least one suction port 210 provided. The fuel becomes the fuel injector at high pressure 160 transported, starting from a fuel rail 170 in fluid communication with a high pressure fuel pump 180 which increases the pressure of the fuel coming from a fuel source 190 receives.

Each of the cylinders 125 has at least two valves 215 passing through a camshaft 135 be actuated, which is timed with the crankshaft 145 rotates. The valves 215 selectively allow the admission of air into the combustion chamber 150 starting from the opening 210 and alternatively, the exit of exhaust gases through an opening 220 , In some examples, a phaser may 155 the timing between the camshaft 135 and the crankshaft 145 vary selectively.

The air can pass through an intake manifold 200 to the air intake opening (s) 210 to get promoted. An air intake line 205 can transfer air from the surrounding atmosphere to the intake manifold 200 to lead. In other embodiments, a throttle 330 be provided to the air flow in the manifold 200 to regulate. In other embodiments, a blower air system such. As a turbocharger 230 be provided, which is a compressor 240 that has a turbine 250 is rotatably connected. The rotation of the compressor 240 increases the pressure and the temperature of the air in the pipe 205 and in the manifold 200 , One in the lead 205 arranged intercooler 260 can lower the temperature of the air. The turbine 250 Rotates by exhaust gases from an exhaust manifold 225 receives the exhaust gases from the exhaust ports 220 and passes through a series of wings before expanding through the turbine 250 he follows. The exhaust gases exit the turbine 250 out and get into an exhaust system 270 directed. This example shows a variable turbine geometry (VTG) with a VTG actuator 290 , which is arranged to move the wings to change the flow of exhaust gas through the turbine. In other embodiments, the turbocharger 230 a fixed geometry turbine with an overflow valve 290 be.

The exhaust system 270 can be an exhaust pipe 275 comprising one or more exhaust aftertreatment devices 280 includes. The aftertreatment devices may be any device designed to alter the composition of the exhaust gases. Some examples of aftertreatment devices 280 include, but are not limited to (two- and three-way) replacement catalysts, oxidation catalysts, NOx storage catalysts, hydrocarbon adsorbers. Other embodiments may include an exhaust gas recirculation (EGR) system. 300 include that between the exhaust manifold 225 and the intake manifold 200 is arranged. The EGR system 300 can be an EGR cooler 310 include the temperature of the exhaust gases in the EGR system 300 to lower. An EGR valve 320 regulates the exhaust flow in the EGR system 300 ,

The drive system 100 Furthermore, an electronic control unit (ECU) 450 comprising communicating with one or more sensors and / or devices connected to the VKM 110 are connected.

In accordance with one embodiment of the present invention, a new fuel rail is provided to reduce the effects of pressure wave fluctuations during fuel injection. According to 3 becomes the above goal through a fuel rail 170 achieved in the high pressure fuel for internal combustion engines 110 is stored and typically a common rail line 500 which may have a tubular shape and in fluid communication with the fuel pump 180 stands, comes from the high-pressure fuel. The common rail line is firmly connected to the engine. Typically, the common rail line is on the cylinder head 130 fastened, by a corresponding number of brackets 510 , which are welded to the common rail line and connected by bolts to the cylinder head. Other types of mechanical fastening are possible. Starting from the common rail line extends a plurality of injection lines 520 , respectively, the fuel from the common bar to an injector 160 transport. The injectors are by means of suitable brackets 530 constantly connected to the injection lines. Alternatively, the injectors may be attached directly to the common rail line. Depending on the architecture of the engine, the fuel rail may be a pressure regulating valve 540 and / or a pressure sensor 550 include.

4 shows the exact structure of an end section 502 the common rail line. Of course, these ends have to 501 . 502 the common rail line to be sealed properly, so that leakage of fuel from the common rail line is prevented. The seal is made by means of a cover 560 achieved. Usually, the cover is made of steel or other suitable metallic material, with a corresponding engagement depth into the common rail 500 is pressed. The cover comprises a closed circular section 561 and an annular cylindrical portion 562 , where the two parts, as shown in 4 can be seen defining a volume V.

In order to achieve the object, according to an embodiment of the present invention, a membrane 570 with the cover 560 firmly connected, wherein the membrane in particular on the annular cylindrical portion 562 the cover is attached. In this way, the volume V becomes a closed cavity. The Pressure wave fluctuations can thus be absorbed by the tension of the diaphragm which, depending on the amplitude and direction of the pressure wave, either compresses or increases the volume V, thereby minimizing the pressure fluctuations in the common rail. The fact that the membrane is firmly connected to the cover (and not screwed for example in the common rail line) means that no additional parts are present, since the membrane can be attached to the cover before the cover on the Bar is pressed. The membrane may be made of a metallic material and fixed to the cover by laser welding.

Due to the fact that each end of the common rail line through a cover 560 can be sealed, two membranes 570 be used, each of them is firmly connected to an end cover. These two membranes could have different shapes and / or be made of different materials to optimize two different pulse frequencies. The corresponding volumes V may also be different by the length of the annular cylindrical section 562 the coverage is changed, thereby fulfilling the same purpose of optimizing two different pulse frequencies.

According to an alternative embodiment, the membrane 570 be biased by an external valve, which can be regulated according to the dynamic characteristics of the fuel injection system according to find the right adjustment of the membrane.

In summary, thanks to this new design of the fuel rail, the pressure wave fluctuations can be minimized, which has a favorable effect on the control of the fuel injection and the lifetime of the components of the fuel injection. Moreover, the present solution does not require additional parts nor does it affect the envelope of the fuel injection system.

In the foregoing summary and detailed description, at least one exemplary embodiment has been presented; however, it should be noted that there are a large number of modification options. It should also be noted that the exemplary embodiment or exemplary embodiments are only examples and are not intended to limit the scope, applicability, or construction in any way whatsoever. Rather, the foregoing summary and detailed description will provide those skilled in the art with a practical guide to implementing at least one example embodiment, it being understood that various changes may be made in the functions and arrangements of the elements described with reference to an exemplary embodiment without departing from the spirit of the invention Scope of protection as defined in the appended claims and their legal equivalents.

LIST OF REFERENCE NUMBERS

100

drive system

110

Internal combustion engine

120

block

125

cylinder

130

cylinder head

135

camshaft

140

piston

145

crankshaft

150

combustion chamber

155

Phaser

160

fuel Injector

165

Fuel injection system

170

Fuel rail

180

Fuel pump

190

Fuel source

200

intake manifold

205

air intake

210

suction

215

valves

220

opening

225

exhaust manifold

230

turbocharger

240

compressor

245

turbocharger shaft

250

turbine

260

Intercooler

270

exhaust system

275

exhaust pipe

280

aftertreatment devices

290

VTG actuator

300

Exhaust gas recirculation system

310

EGR cooler

320

AGR valve

330

throttle

360

spark

450

ECU

500

Common rail line

501

first end of the common rail line

502

second end of the common rail line

510

Brackets of the common rail

520

Fuel injection lines

530

Brackets of the fuel injectors

540

Pressure regulating valve

550

pressure sensor

560

cover

570

membrane

Claims (9)

Fuel rail ( 170 ) for internal combustion engines ( 110 ) stored in the high-pressure fuel, comprising: - a common-rail line ( 500 ) in fluid communication with a fuel pump ( 180 ) and is firmly connected to the engine, - a cover ( 560 ), which is an end ( 501 . 502 ) seals the common rail line, wherein a membrane ( 570 ) Is firmly connected to the cover and is arranged in the pipeline of Krafstoffleiste. Fuel rail according to claim 1, wherein the membrane ( 570 ) is made of a metallic material. Fuel rail according to claim 2, wherein the membrane ( 570 ) laser welded to the cover ( 560 ). Fuel rail according to one of the preceding claims, wherein the membrane ( 570 ) with an annular cylindrical portion ( 562 ) is firmly connected to the cover. Fuel rail according to one of the preceding claims, wherein the number of covers ( 560 ) and the membranes ( 570 ) is exactly two. Fuel rail according to claim 5, wherein the two membranes ( 570 ) have a different shape and / or are made of different materials. Fuel rail according to claim 5 or 6, wherein the two covers ( 560 ) a different length of its annular cylindrical portion ( 562 ) exhibit. Fuel rail according to one of the preceding claims, wherein the membrane ( 570 ) is biased by an external valve. Internal combustion engine ( 110 ) with a fuel rail ( 170 ) is provided according to one of the preceding claims.

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