DE102005037551A1 - Internal combustion engine, has injector injecting fuel into combustion chamber and two ignition mechanisms attached to chamber, where one of mechanisms is arranged in radial outer edge region of chamber - Google Patents

Abstract

The engine has a combustion chamber (12) that is bounded by a cylinder wall (14), and an injector that injects fuel into the chamber. Two ignition mechanisms (36a, 36b) are attached to the chamber, where one of the mechanisms is arranged in a radial outer edge region of the chamber. The mechanisms and the injector are arranged in such a manner that an injected fuel jet is ignited into an area that is away from the injector. An independent claim is also included for a method of operating an internal combustion engine.

Description

The The invention relates to an internal combustion engine according to the preamble of the claim 1. The invention further relates to a method for Operating such an internal combustion engine.

The WO 00/55481 describes an internal combustion engine with a combustion chamber, in which a centrally arranged injector and two asymmetrically arranged ignition devices available. The injector gives a hollow conical injection jet Direction of a piston which limits the combustion chamber from. The both ignition devices are above the lateral surface the injection jet at the injector or in about half way arranged between the injector and the cylinder wall.

task the present invention is to provide an internal combustion engine, who works with gasoline as a fuel and in the case of a knocking Combustion in a wide operating range of the internal combustion engine can be prevented.

These Task is by an internal combustion engine with the characteristics of Claim 1 solved. Advantageous embodiments of the invention can be found in subordinate and referring back to claim 1 Method claims.

Advantages of invention

By the arrangement of the second ignition device at the edge of the combustion chamber, directly next to the cylinder wall, it causes that the fuel is not only during the intake phase, but can also be injected at full load in the compression stroke on its end, usually near the cylinder wall is located, ignited can be. This burns the fuel-air mixture, which in the combustion chamber nearby The cylinder wall forms, off, before an unburned fuel-air mixture (Tail gas) in the knock border zone penetrate directly on the cylinder wall and there uncontrolled inflamed can be. Arrives at the internal combustion engine according to the invention so little or even no unburned fuel to the cylinder wall or in the knock sensitive Combustion zone, as it is burned controlled, before this Zone can reach. As a result, knocking combustion becomes effective prevented.

There in the end region of the fuel jet remote from the injector the fuel-air mixture specifically leaner than near the injector forms when burning, if at all, only a small amount of soot. Since knocking can be effectively prevented, injection start and ignition timing can lie close to each other. this leads to to the additional ones Benefits that not only at higher Load, but also at higher Speeds during the compression phase can be injected. Such an injection while the knocking phase already acts per se as knock protection, as by the short time less self-ignitable mixture can get into the tail gas area. In addition, the fuel enrichment requirement reduced.

By In addition, effective prevention of knocking combustion can a boost pressure can be increased, so that, for example, the Use of a multi-stage compressor (register charging) with two connected in series compressors or turbochargers with different output is conceivable.

On easy way can be achieved advantages mentioned by the second ignition device in one area of the combustion chamber, which removes the maximum from the injector is. To reliably cover different operating modes of the internal combustion engine to be able to should have at least two ignition devices seen from the injector in succession or successively on a common Axis with the injector and preferably at least approximately in the Close at least be arranged an injection jet of the injector. So can at relatively small injection quantity and / or in homogeneous operation of the fuel are ignited by the ignition device rather centrally arranged in the combustion chamber, whereas at a relatively large Injection quantity in layered and / or homogeneous operation at the radially outer edge the ignition chamber arranged ignition device is operated. It can ignite also by a simultaneous or temporally slightly offset Operation of both spark plugs are triggered which leads to an increase in the burning speed.

If, As stated above, the radially outer igniter in the extension of one Axis injector - rather central spark plug is located, the jet pattern of the injector can be designed so that the main amount of injected fuel in the direction of the two ignition devices is hosed. In the extreme case, for example, one is sufficient Mehrlochinjektor only two spaced injection jets, the two ignition devices or their connecting axis "flank" right and left. Or, in other words, the two ignition devices are between the two injection jets in their peripheral areas arranged.

The Invention can also be applied to injectors, the one Similar to jet image a full cone or similar possess a hollow cone. In this application, it is irrelevant whether the injector and the two ignition devices lie on a common axis. The advantages of the invention By the way even achieved when the two ignition devices of a single Injection jet are injected directly.

By a corresponding embodiment of the combustion chamber or a suction can be achieved that the cylinder charge, so in the combustion chamber existing fuel-air mixture, one swirling Movement component has. The cylinder charge thus rotates the cylinder axis. The outside ignition allows in this combination a combustion control such that this spiral advances towards the center of the combustion chamber. By the on the cylinder charge acting centrifugal force becomes hot and specifically lighter Fuel gas in the combustion chamber center and thus pulled away from the cylinder walls. The increase caused thereby the burning speed improves the efficiency of the internal combustion engine. This may alternatively or additionally can also be achieved through the use of more than two ignition devices, at the radially outer edge the combustion chamber evenly distributed are arranged.

drawings

following become particularly preferred embodiments the present invention with reference to the accompanying Drawing closer explained. In the drawing show:

1 a partial section through a cylinder of a first embodiment of an internal combustion engine;

2 a combustion chamber side view of a cylinder head portion of the internal combustion engine of 1 ;

3 a representation similar 2 an alternative embodiment; and

4 a representation similar 1 another alternative embodiment.

description the embodiments

In 1 is a cylinder of an internal combustion engine with a total of 10 (the internal combustion engine comprises a plurality of identical cylinders, only one of which is shown here). It includes a combustion chamber 12 from a cylinder wall 14 a cylinder head 16 , and a piston 18 is limited.

As synonymous with 2 it can be seen, lead to the combustion chamber 12 in the present embodiment, two inlet channels 20a and 20b in the cylinder head 16 available. In 1 is only the inlet channel 20a visible, noticeable. Likewise, there are two outlet channels 22a and 22b present, of which in 1 only the outlet channel 22a is visible. In another embodiment, not shown, only one inlet and one outlet channel is present. To the combustion chamber 12 There are inlet valves 24a and 24b and exhaust valves 26a and 26b intended. Near the central axis of the combustion chamber 12 is in the cylinder head 16 in the present embodiment, a Zweilochinjektor 28 arranged the fuel at high pressure directly into the combustion chamber 12 can inject (in an embodiment, not shown, an injector is provided with more than two spray holes). Appropriate injection jets carry in 2 the reference numerals 30a and 30b , Between the two injection jets 30a and 30b is a free space 32 present, whose central axis in 2 With 34 is designated.

On the injector 28 outgoing axis 34 lie in the in 2 view shown two ignition devices 36a and 36b , While one ignition device 36a in the middle of the combustion chamber 12 and relatively close to the injector 28 is arranged, the ignition device 36b at the radially outer edge 38 of the combustion chamber 12 in the immediate vicinity of the cylinder wall 14 in that area of the combustion chamber 12 arranged by the injector 28 maximum is removed. One recognizes in 2 in that the radially outer ignition device 36b in a so-called "gusset area" between the two exhaust valves 26a and 26b is arranged. The gusset area is in 2 with the reference number 40 marked and represented by a crosshatch.

During operation of the internal combustion engine at full load, the injector injects 28 the fuel by means of the two injection jets 30a and 30b during the compression phase (and / or during the intake phase) into the combustion chamber 12 one. By controlling the ignition device 36b become the two injection jets 30a and 30b in their from the injector 28 remote end areas 42a and 42b inflamed. In this way, this will be in the area of the cylinder wall 14 existing fuel-air mixture burned before unburned fuel-air mixture in the knock-end edge area directly on the cylinder wall 14 can penetrate. This effectively prevents uncontrolled knocking combustion.

In this case, the two ignition devices 36a and 36b operated independently of each other. Thus, it is possible, for example, with relatively small injection quantity and / or in a homogeneous operation of the internal combustion engine, the fuel-air mixture only by the ignition device 36a while the fuel is ignited by the igniter at a relatively large injection rate, such as at full load 36b is ignited. It is also possible that the two ignition devices 36a and 36b at the same time or, during the same work cycle, be operated in quick succession.

The arrangement of the ignition device 36b in the gusset area 40 has several advantages: On the one hand, this area is very sensitive to heat because of its high thermal load, so that knocking is most likely to occur there. On the other hand this area becomes 40 through the appropriately directed injection jets 30a and 30b Although cooled, due to the heat in this area 40 However, the injected fuel is better and faster processed, as it evaporates faster. An optional double injection (distribution of the injection in the intake and compression phase) can thus achieve a particularly significant cooling effect. Eventually, so will the spark plugs 36a and 36b spared.

An alternative embodiment of a cylinder 10 an internal combustion engine shows 3 , Here, as below, such elements and regions that are functionally equivalent to previously described elements and regions bear the same reference numerals and are not explained again in detail.

In the internal combustion engine, to the in 3 shown cylinder 10 is heard by a corresponding configuration of the inlet channels 20a and 20b the cylinder charge present in the combustion chamber, that is to say the fuel-air mixture present there, is provided with a swirl, that is to say a component of movement about the in 3 perpendicular to the plane of the cylinder axis. In addition, the cylinder includes 10 the in 3 shown internal combustion engine in addition to the already from the 1 and 2 known ignition devices 36a and 36b additional ignition devices 36c . 36d and 36e passing over the cylinder wall 14 of the cylinder 10 in their immediate vicinity, ie at the radially outer edge 38 of the combustion chamber 12 , are arranged. Both measures can the burning speed of the fuel-air mixture in the combustion chamber 12 be accelerated. In addition to heterogeneous and homogeneous fuel-air mixtures can be ignited so quickly that knocking is prevented even at full load. It is understood that even at the in 3 shown embodiment, two injection jets in the direction of each ignition device 36a to 36d could be injected so that they the respective ignition device 36a to 36d flank (in total eight injection jets).

Another alternative embodiment is in 4 shown. In this only a partial beam 30a at its far end 42a ignited, but not one from the injector 28 In the opposite direction emitted injection jet 30b , It is also possible to use an injector 18 , which emits a full-cone or hollow cone-shaped injection jet.

Claims (11)

Internal combustion engine, with at least one of a cylinder wall ( 14 ) limited combustion chamber ( 12 ), with at least one injector ( 28 ), the fuel in the combustion chamber ( 12 ), and with at least two of the combustion chamber ( 12 ) associated ignition devices ( 36 ), characterized in that at least one ignition device ( 36b ; 36b . 36c . 36d . 36e ) in a radially outer edge region ( 38 ) of the combustion chamber ( 12 ) is arranged. Internal combustion engine according to claim 1, characterized in that at least one ignition device ( 36b ; 36b . 36c . 36d . 36e ) and the injector ( 28 ) are arranged to one another such that at least in an operating state of the internal combustion engine, an injected fuel jet ( 30a ) at his from the injector ( 28 ) remote area ( 42a ) is ignited. Internal combustion engine according to one of claims 1 or 2, characterized in that the ignition device ( 36b ; 36b . 36c . 36d . 36e ) in one area ( 38 ) disposed of the injector ( 28 ) is maximally removed. Internal combustion engine according to one of the preceding claims, characterized in that the two ignition devices ( 36a . 36b ) and the injector ( 28 ) at least approximately on a common axis ( 34 ) and the ignition devices ( 36a . 36b ) at least in the vicinity of at least one injection jet ( 30a . 30b ) lie. Internal combustion engine according to claim 4, characterized in that the injector ( 28 ) is formed such that it has at least two injection jets ( 30a . 30b ) and that the two ignition devices ( 36a . 36b ) between the two injection jets ( 30a . 30b ) are arranged in the edge regions. Internal combustion engine according to one of the preceding claims, characterized in that an ignition device ( 36a ) at least approximately in the middle of the combustion chamber ( 12 ) is arranged. Internal combustion engine according to one of the preceding claims, that several ignition devices ( 36b . 36c . 36d . 36e ) at the radially outer edge ( 38 ) of the combustion chamber ( 12 ), preferably evenly distributed, are arranged. Internal combustion engine according to one of the preceding claims, characterized in that the combustion chamber ( 12 ) and / or at least one inlet channel ( 20 ) are / is designed such that in the combustion chamber ( 12 ) located fuel-air mixture having a swirl-shaped component of movement. Internal combustion engine according to one of the preceding Claims, characterized in that it is a multi-stage compressor device includes. Method for operating an internal combustion engine according to one of the preceding claims, characterized in that the at least two ignition devices ( 36a . 36b ) are operated independently of each other. A method according to claim 10, characterized in that at relatively small injection quantity and / or in homogeneous operation, the fuel at least by a center rather in the combustion chamber ( 12 ) arranged ignition device ( 36a ), and that the fuel at relatively high injection quantity at least by the at least one at the radially outer edge ( 38 ) of the combustion chamber ( 12 ) arranged ignition device ( 36b ) is operated.