DE19955344B4 - Assembly of a fuel injection valve and a module for water injection in a cylinder of an internal combustion engine - Google Patents

Abstract

module from a fuel injection valve (10) and one of them functional independent, annular module (12) for water injection in a cylinder of an internal combustion engine, wherein the module (12) an annular Carrier body (14, 18), with spray holes (16), and wherein the module (12) the fuel injection valve (10) surrounds.

Description

State of technology

The The invention relates to an assembly of a fuel injection valve and one of them functionally independent, annular Module for water injection in a cylinder of an internal combustion engine.

The Injection of water during the combustion phase, especially in direct-injection diesel engines, serves to reduce the nitrogen oxide emissions of the Reduce internal combustion engine. Usually increases the nitrogen oxide output at modern, direct-injection diesel engines that are extremely smoke- and low-particle operation, as an expression of highest combustion quality. the can be counteracted by the injection of a certain amount of water become.

at previously known concepts, the water to be injected directly introduced into the injection valve, so that a bifluide injection is achieved, so the injection of a mixture of fuel and water. But this requires that the injection valve on the increased Flow are designed must, um Disadvantages inadmissible long spraying while to avoid the full load phases. This in turn has negative consequences for mixture formation at low load operating points where no water is injected must become.

From the EP 0 825 341 A1 a fuel injection nozzle is known in which a separate, spatially separated injection valve for injecting water is arranged in the valve block.

From the EP 0 546 985 A1 a fuel injector is known in which an internal nozzle needle for injecting diesel oil and an external, hollow nozzle needle for injecting a gaseous fuel is used.

From the Patent Abstracts of Japan JP 11030164 AA a fuel injection nozzle is known in which a collecting space for an air / water mixture is formed in the interior of the nozzle. The air-water mixture is injected through these same injection ports into the combustion chamber as the fuel, but with a time delay controlled by the fuel nozzle needle.

The The object of the invention is therefore the water injection to allow in a cylinder of an internal combustion engine without that under certain operating conditions, negative effects on the Injection of the fuel result.

Advantages of invention

A Assembly having the features of claim 1 has the advantage that one Water injection completely independent of the fuel injection possible is. The module according to the invention based in principle on the functional separation of the fuel injection on the one hand and water injection on the other. For fuel injection becomes a conventional one Fuel injection valve used with regard to water injection in no way be revised got to. Consequently results in an optimal provision under all operating conditions of the fuel to be injected. Also, at this functional Separate the rest Problems coming from injectors for a bifluid injection are known, do not occur. For example, it eliminates all the problems with the introduction of the injected water into the injection valve are connected, for example, the interruption of the injection valve pending system pressure for the process of introducing the water. Furthermore, no need unfavorable huge Injection hole cross sections are selected, the for Vollastphasen are required, at part load phases, however, to disadvantages to lead. Also, there are no critical lubrication / mixed friction conditions at the injection valve, and it will be undesirable mixing effects avoided by fuel and water. Finally, it prevents a failure the water injection, for example by a deflated water tank or a defect in the water pump, affecting has the fuel metering. The annular module for water injection is arranged in a space-saving manner around the injection valve and allows one symmetrical water introduction into the cylinder. Since the module for Water input independently works from the fuel injection valve, there is a great potential to reduce nitrogen oxide emissions, as the water during a freely selectable, flexible time window can be inserted into the cylinder. After all can that be the valve body the injection valve surrounding water injection module for cooling the body be used.

According to a preferred embodiment of the invention, an annular supply channel for the water to be injected is provided in the carrier body and an annular distribution channel, which is supplied by the supply channel and leads to the spray holes, and a check valve, which prevents a backflow from the spray holes to the supply channel. The check valve, which is preferably formed by an annular membrane which in can abut the distribution channel on an annular sealing seat, minimizes the harmful volume and reduces the formation of vapor bubbles. Furthermore, it ensures a desired system pressure, for example less than 10 bar, in the Absteuerphasen, ie towards the end of the water injection. The restoring force pre-set on the membrane is intensified during the high-pressure phases in the cylinder, which additionally increases the sealing effect in the water injection system.

advantageous Embodiments of the invention will become apparent from the dependent claims.

drawings

The Invention will be described below with reference to a preferred embodiment described in the attached Drawings is shown. In these show:

1 in a schematic, partially sectional view of an assembly according to the invention;

2 on an enlarged scale the section II of 1 ; and

3 on an enlarged scale the section III of 2 ,

description of the embodiment

The assembly according to the invention consists of a fuel injection valve 10 that in a cylinder head 11 an internal combustion engine is arranged. In the area of the front, that of the cylinder head 11 delimited cylinder of the internal combustion engine facing the end of the injector 10 is an annular module 12 arranged for water injection. This module encloses the front end of the fuel injection valve 10 and is in an annular receptacle in the cylinder head 11 received by positive engagement and / or adhesion.

The module 12 has a carrier body, which consists of an outer ring 14 that exists with spray holes 16 is provided for the injected water, and an inner ring 18 which divides the interior of the outer ring so that an annular feed channel 20 and a likewise annular distribution channel 22 are formed. The feed channel 20 stands over supply openings 24 placed in the outer wall of the outer ring 14 are formed, with a supply line 26 for the water to be injected in the cylinder head 11 is trained. In the supply line 26 is a spring-loaded ball check valve 28 immediately before the module for water injection. The feed channel 20 and the distribution channel 22 stand together through overflow openings 30 in conjunction, in the inner ring 18 are formed.

On the side facing away from the cylinder of the module is a lid 32 provided the outer ring 14 completes and thereby the inner ring 18 supported. To improve the seal is between the lid 32 and the inner ring 18 another O-ring 34 arranged.

Between the outer ring 14 and the inner ring 18 is an annular membrane 36 arranged, which forms a check valve, which is a return flow from the spray holes 16 to the feed channel 20 prevented. The membrane 36 considered in a radial section has an L-shaped cross section, wherein one of the legs between the inner ring 18 and the outer ring 14 is clamped. The other leg acts with an annular sealing seat 38 together, on the inner ring 18 is trained. The membrane is biased so that they are at the sealing seat 38 is applied with a certain bias, so that an overflow of the injected water from the distribution channel 22 in the spray holes 16 only above a certain system pressure is possible, preferably in the order of 10 bar.

With the module described can be injected into the cylinder of an internal combustion engine in a simple manner by the system pressure is suitably controlled on the inlet side. Particularly advantageous results can be achieved if the injection holes 16 the module so with the spray holes of the fuel injection valve 10 are aligned so that their predetermined spray paths intersect (see 2 ).

According to a development, not shown, the module can be made of a silicon nitride-based ceramic composite material. The advantage here is that smallest spray hole geometries can be realized already in the sintering process. It would then no longer be necessary to provide a check valve inside the module; the check valve 28 in the supply line 26 would be enough.

10

Fuel injection valve

11

cylinder head

12

module

14

outer ring

16

spiracle

18

inner ring

20

supply channel

22

distribution channel

 24

Treatment opening

26

supply line

28

check valve

30

overflow

32

cover

34

seal

36

membrane

38

sealing seat

Claims (10)

Assembly from a fuel injection valve ( 10 ) and a functionally independent, annular module ( 12 ) for injecting water into a cylinder of an internal combustion engine, wherein the module ( 12 ) an annular carrier body ( 14 . 18 ) provided with spray holes ( 16 ), and wherein the module ( 12 ) the fuel injection valve ( 10 ) surrounds. An assembly according to claim 1, characterized in that in the carrier body ( 14 . 18 ) an annular feed channel ( 20 ) is provided for the water to be injected and an annular distribution channel ( 22 ) coming from the feed channel ( 20 ) and to the spray holes ( 16 ) and that a check valve ( 36 . 38 ), which is a return flow from the spray holes ( 16 ) to the feed channel ( 20 ) prevented. An assembly according to claim 2, characterized in that the check valve by an annular membrane ( 36 ) formed in the distribution channel ( 22 ) on an annular sealing seat ( 38 ) may be present. Assembly according to one of the preceding claims, characterized in that the carrier body has an outer ring ( 14 ), which with the spray holes ( 16 ), and an inner ring ( 18 ), with the sealing seat ( 38 ), and that the membrane ( 36 ) between the inner ring ( 18 ) and the outer ring ( 14 ) is clamped. Assembly according to one of the preceding claims, characterized in that a cover ( 32 ) is provided, which the carrier body ( 14 . 18 ) completes. Assembly according to one of the preceding claims, characterized in that the injection holes of the fuel injection valve ( 10 ) and the spray holes ( 16 ) of the module ( 12 ) are aligned so that the spray paths predetermined by them intersect. Assembly according to one of the preceding claims, characterized in that the module ( 12 ) non-positively in a cylinder head ( 11 ) is recorded. Assembly according to one of the preceding claims, characterized in that the module ( 12 ) positively in a cylinder head ( 11 ) is recorded. An assembly according to claim 7 or 8, characterized in that in the cylinder head ( 11 ) a supply line ( 26 ) for the module ( 12 ) is provided and that in the supply line ( 26 ) a check valve ( 28 ) is arranged. An assembly according to claim 9, characterized in that the check valve ( 28 ) has a spring-loaded valve ball.