DD228585A1 - MIXING COMPRESSION TWO-STROKE INFRARED BRAKING MACHINE - Google Patents

Abstract

The invention relates to a mixture-compressing two-stroke injection internal combustion engine with piston-controlled slits and external ignition, in which the fuel is injected from a point of the cylinder wall opposite the outlet against the cylinder head. In the internal combustion engine according to the invention, the fuel is injected from a Einspritzduese which is located at a thermally low loaded point below the bottom dead center in a laterally offset toward the outlet combustion chamber such that the greater part of the fuel jet to the wall of the combustion chamber, the divided is executed and the upper half screwed to the cylinder head consists of a material with low Waermeleitvermoegen, and the smaller part of the fuel jet is applied for cooling on the edge of the crush zone. Due to the highly thermally stressed combustion chamber wall, the fuel is evaporated and supplied to the ignition source by a rotating swirl flow. The mixture formation takes place almost completely in the combustion chamber of the cylinder head, whereby fuel losses are largely avoided.

Description

Erfindungsbesehreibung

Title of the invention

Mixture-compressing two-stroke injection internal combustion engine

Field of application of the invention

The invention relates to a mixture-compressing two-stroke injection internal combustion engine with piston-controlled slits and spark ignition, wherein the fuel is injected from a point opposite the outlet of the cylinder wall against the cylinder head.

Characteristic of the known technical solutions

It is known from DE-PS 926 455 a Gemischverdichtende two-stroke internal combustion engine with a trained as a turbocharger cylinder head and an obliquely to the cylinder axis in the cylinder wall above the slot zone arranged injection nozzle, wherein the fuel is injected against the cylinder head such that the spray jet into the combustion chamber The fuel is injected before the end of the flushing, but so early that no appreciable part of it can be carried into the preie by the descending flushing flow. Here, the majority of the fuel is distributed by the atomization effect of the spray jet in the cylinder chamber and mixed by the maintained after the completed rinse flow with the charge air.

The invention has the disadvantage that the mixture formation process is initiated during the flushing process. Due to the atomizing effect of the spray jet, most of the fuel is distributed in the cylinder chamber and only a small part of the fuel quantity reaches the inner wall of the combustion chamber. A further disadvantage is that the injection jet runs through the stagnation point of the purge streams, which leads to fuel losses, especially in the case of unstable Rinsing flows in the lower speed range can come.

Due to the central arrangement of the combustion chamber and small squish area only a vortex of low intensity is formed in the combustion chamber. This is not able to completely ablate the sprayed onto the inner wall of the combustion chamber fuel quantity.

It is known from CH-PS 209 724 a two-stroke internal combustion engine with fuel injection, wherein the fuel from a position of the cylinder wall above the exhaust port above the lower piston dead center in an oblique direction from bottom to top against the cylinder head using a purge, in the diametrical purge streams Initially be introduced substantially parallel to the cylinder axis upwards and after the deflection of the cylinder head with energy destruction by clashes and turbulence the old gases push from above to the exhaust port near the lower Kolbentotlage and the fuel in the IPrischluftladevorgang down moving fresh air after the beginning the whirling in order to ensure a good mixture with the fresh air flowing through by a higher than the upper edge of the scavenging ports nozzle in an already free at the beginning of the injection of the waste gases height of the cylinder is injected.

The invention has the disadvantage that the nozzle is arranged in a region with higher thermal load,

 which can lead to coking of the nozzle or to vapor bubble formation within the nozzle and thus to the suspension of the injection.

Object of the invention

The purpose of the invention is to eliminate the disadvantages of the known two-stroke injection internal combustion engine of the type mentioned and to expand its field of application, to further reduce charge cycle losses and the emission of unburned hydrocarbons.

Essence of the invention

The object of the invention is to provide a two-stroke injection internal combustion engine, in which the injection jet can enter the combustion chamber without special influence by the purge flow and the mixture formation takes place in the combustion chamber itself · The injection of the fuel should take place after completion of the pre-purge when the piston is in or after bottom dead center.

In this case, the injection nozzle should be arranged at a relatively cool place of the cylinder. Here, injection nozzles with high exit velocity and long injection length can be used.

According to the invention the object is achieved in that the injection nozzle is disposed below the bottom dead center with respect to the outlet, wherein the injection channel is adapted to the cone shape of the injection jet and ends with its upper edge in height of the upper edge of the outlet channel, the injection jet with a high exit velocity and slender Spray cone below the stagnation point of the purge streams in the direction of the arranged in the cylinder head over the exhaust port combustion chamber, the injection jet passes through the purge stream only once, runs and the injection jet with its main part on the lying in the exhaust direction combustion chamber side and the smaller part of the injection

Beam impinges on the ending approximately in the center of the cylinder pinch surface and thereby cools. The applied fuel is removed by the rotating swirl flow or evaporates on the hot wall of the combustion chamber and is carried to the ignition source. The combustion chamber, which is formed spherical or cylindrical, is designed to be split, wherein the main part of the combustion chamber of a material with a low thermal conductivity, preferably ceramic, consists, and bolted to the cylinder head. The Geraischbildung done in this arrangement almost completely in the combustion chamber, whereby the fuel losses are minimized by the change of charge. The ignition source, preferably a glow plug, is arranged opposite the point of impact of the fuel in the upper combustion chamber part.

embodiment

The invention will be explained in more detail with reference to an embodiment.

FIG. 1 shows the two-stroke injection internal combustion engine according to the invention with an injection nozzle arranged below the bottom dead center, with inlet and outlet channels and with a laterally offset combustion chamber arranged in the cylinder head. This combustion chamber is designed so that the upper combustion chamber half, the a, us a ceramic material and in the outlet side facing away from the ignition source (spark plug) is arranged, screwed to the cylinder head and thus interchangeable. The injection of the fuel takes place from bottom to top in the combustion chamber, wherein the largest part of the fuel jet is applied to the combustion chamber wall, is evaporated by the highly thermally loaded combustion chamber wall and fed by the rotating swirl flow of the spark plug. The smaller part of the fuel jet is sprayed onto the edge of the pinch zone and thus serves for cooling. The mixture formation is almost complete

in the cylinder head combustion chamber. The injection nozzle is arranged at a thermally low loaded point of the cylinder.

The injection takes place at bottom dead center, wherein the injection jet underflows the stagnation point and traverses the purge stream only after its deflection on the cylinder head. Through the injection, which takes place at bottom dead center, the injection jet hits the purge stream at a time when it has only a lower intensity and the main part of the purge stream is already moving in the direction of the outlet. As a result, charge transfer losses can be largely avoided.

Claims (4)

claim 1 »A mixture-compressing two-stroke internal combustion engine with piston controlled slits and spark ignition in which the fuel is injected from a point of the cylinder wall opposite the outlet against the cylinder head using a purge in which diametral purge streams are initially directed upwards almost parallel to the cylinder wall and after the diversion on the cylinder head, expel the exhaust gases from above to the outlet slot near bottom dead center, characterized in that the injection nozzle is disposed below the bottom dead center with respect to the outlet, wherein the injection channel is adapted to the cone shape of the injection jet and ends with its upper edge equal to the upper edge of the outlet channel, and the injection jet with a high exit velocity and slender spray cone below the stagnation point in the direction of Cylinder head arranged above the outlet combustion chamber, wherein the injection jet impinges with its main part on the lying in the outlet direction of the combustion chamber side and the smaller part of the injection jet to the approximately center in the cylinder squish and is removed by the rotating swirl flow, 2 · mixture-compressing two-stroke-injection internal combustion engine according to claim 1, mm Q mm characterized in that the combustion chamber, which is formed spherical or cylindrical, is designed to be split, wherein the main part of the combustion chamber consists of a material with a low thermal conductivity, preferably of ceramic and is screwed to the cylinder head. 3. mixture-compressing two-stroke-injection internal combustion engine according to claim 1 and 2, characterized in that the mixture formation takes place almost completely in the combustion chamber. 4. Mixture-compressing Z-wide-stroke injection internal combustion engine according to claim 1 to 3 » characterized in that the ignition source is arranged opposite the impact point of the spray jet in the upper part of the combustion chamber. For this Λ page drawing