DE1751547A1 - Exhaust gas decontamination system for internal combustion engines - Google Patents

Description

DR. ING. ERNST MAIER

PATIlTTAIiWAI ₁ T

8 MUNICH 82

A 21868 ¹ Q 'June I968

EM / Ml / My

Company SUZUKI JIDOSHA KOGYO KABUSHIKI KAISHA ₁ 300, Takatsuka, Kamimura, Hamana-G-un, Shizuoka-Ken / Japan

Exhaust gas decontamination system for combustion engine

The invention relates generally to internal combustion engines. In particular, the invention relates to a device with the help of which flammable hare, hereinafter referred to as waste exhaust gases, which predominantly come from the outlet opening of the cylinder of two-stroke engines and of four-stroke engines in which the valve opening times of the inlet and outlet valves overlap, be ejected, be burned.

With an ordinary two-stroke engine without a predecessor there is a gasoline-air mixture in at least one carburetor generated and sucked into the crankcase when

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the piston is in the area of its top dead center and an inlet opening is opened in the process. This The gasoline-air mixture is referred to below as intake gas (in this description, unless otherwise specified Said, consider a single cylinder arrangement.) The intake gas is pre-compressed as the piston moves downwards emotional. If the piston then approaches its bottom dead center, an outlet opening is opened first, and the exhaust gas generated by the combustion in the cylinder partly passes through the exhaust port as a result the excess energy still contained in it.

* Next, a transfer channel opens, and

the intake gas, which is pre-compressed in the crankcase, enters the cylinder through this transfer duct. This Gas is referred to below as overflow gas. Duroh its inflow into the cylinder pushes the overflow gas the remains of the exhaust gas still contained in the cylinder out of the 'exhaust port. Part of the Overflow gas as a result of the excess energy contained in it from the outlet opening and is thus lost. This part of the overflow gas that is blown out directly from the outlet opening without it being in the cylinder beforehand has been burned is hereinafter referred to as waste exhaust

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■ bezei'dfitiet :. (The term is yours occasionally used Expression Vdrbefbiasegas preferred as the latter leads to confusion with the gas that blows between the piston rings and the cylinder and into the crankcase arrived.) '

With a fast-paced Yier-stroke engine where the inlet valve is already opened before the outlet valve is completely closed, also takes a part ^ of the intake gas the short way from the intake valve directly through the exhaust valve similar to the two-stroke engine, so that it can also be described as waste gas.

As shown in FIG. 1 of the drawing, which is described in more detail below, the exhaust gas produced by the combustion (represented by curve A) at the moment when the outlet opening is opened has a large flow rate M, whereupon the flow rate of exhaust gas decreases to the extent that the energy contained in it decreases. The curve B denotes the unburned gas; increases at the moment the overflow channel is opened, since the waste gas then enters, with the flow rate becoming a maximum shortly before the outlet opening is completely closed again.

The unburned gas contains a large amount of harmful components such as hydrocarbons, carbon monoxide and oxides of nitrogen. To prevent these harmful ones To get exhaust gases directly into the atmosphere, post-combustion systems in the exhaust pipe and air mixing devices are so far been used.

In a secondary incineration plant there is also air is supplied and mixed into the exhaust gas to improve the possibility of combustion, and the mixture is then ignited. The concentration of the flammable components in the exhaust gas is therefore very low, and these are flammable Leftovers cannot be burned without first heating them to a considerably high temperature. the The device therefore becomes complicated and expensive. An afterburning system of this type cannot take effect immediately either as it takes a considerable amount of time to warm up after the engine has been started. The greatest difficulty, however, lies in the high temperature required for post-combustion, which means that other harmful nitrogen oxides as by-products attack.

It is also known to have an air supply device The air is introduced into the exhaust gas to initiate combustion

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- ■ 5-- ■■■. ■■;. ■ ^:

of the unburned exhaust gas components in the exhaust pipe effect as long as the gas is directly behind the outlet from the Cylinder is still hot. However, such a device has the disadvantage that the still cool waste gas leaving the cylinder cannot be ignited and burned.

The invention now assumes that the waste exhaust gas immediately after being blown out of the outlet opening of the cylinder, before it is mixed with the exhaust gases, an im substantially uniform amount from a fuel-air mixture is that even at low temperatures without feeding can be burned by air.

The object of the invention is therefore to create a device with which the content of harmful constituents can be reduced in the exhaust gas of internal combustion engines. .

In particular, the object of the invention is to create a device with which the waste exhaust gas directly after its exit from the outlet opening of the cylinder is intercepted and then ignited and burned, whereby the content of harmful components in the exhaust gas is reduced.

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Briefly, the invention provides an exhaust gas decontamination system for internal combustion engines, which is characterized in that a spark plug is inserted into the exhaust duct directly behind each engine cylinder following the exhaust port and this spark plug is ignited at the moment the exhaust port is opened
is closed during the compression stroke of the cylinder, in which case the waste exhaust gas is ignited and burned.

In an exemplary embodiment according to the invention, a pre-ignition chamber is formed around the spark gap of the spark plug provided in order to facilitate the ignition of the Yerlust exhaust gas therewith.

In a further embodiment according to the invention, a small amount of gas-air mixture is in the
The spark gap of the plug is initiated in order to achieve pre-ignition and, with the help of this initial ignition, then to design the post-ignition and combustion of the waste gas in a particularly favorable manner.

According to a further exemplary embodiment, air is additionally blown in in the area of the spark plug section, thereby improving the combustion of the waste gas and

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the formation of hydrocarbons and carbon monoxides is suppressed.

According to another exemplary embodiment according to the invention, a control device can also be provided that depends on the working conditions of the engine works and the supply of the auxiliary gas in the way controls that its supply is interrupted when it is not required but is resumed, if this is beneficial.

In the invention, a spark plug is used as an additional feature, which is particularly suitable due to its structure and is advantageous to achieve the objects of the invention.

Further advantages, features and properties of the invention go from the now following description of embodiments with reference to the figures of the drawing. Show it:

Fig. 1 is a graph in which the flow rates of the burned exhaust gases and the unburned ■ exhaust gas components within the Exhaust gases are reproduced, namely at the exhaust port of a two-stroke engine as a function of the crank angle;

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2 shows the representation of a single-cylinder two-stroke engine, in which the cylinder is cut open;

FIG. 3 shows a representation, comparable to FIG. 2, of a modified embodiment of FIG Invention on a two-stroke engine;

Figures 4a, 4b, and 4c

Schematic representations showing the flow of waste gases at different times of the Show single cylinder two stroke engine during the first phase of the compression stroke;

5 shows a sectional illustration of an exemplary embodiment of the invention in an enlarged illustration;

6 shows a section along line VI-VI in FIG. 5;

Fig. 7 is a graphical representation which is dependent on the throttle valve opening and the engine speed shows the combustion of an exhaust gas decontamination system of known type;

FIG. 8 shows a graphic representation comparable to FIG. 7, but for the exhaust gas detoxification • system according to the invention;

FIG. 9 shows a representation similar to FIG. 2, which shows another Embodiment of the invention reproduces on a two-stroke engine;

FIG. 10 shows a section along the line X-X in FIG. 9;

11 shows a vertical section through the crankcase a two-stroke engine in which the device for discharging an ignition control gas is used;

FIG. 12 shows a section along the line XII-XII in FIG. 11;

13 shows a detail in an enlarged representation of the cylinder of a two-stroke engine with the exhaust port in which the ignition control gas is derived on the cylinder;

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CLAS SAD

Pig. 14 a longitudinal section on an enlarged scale by a control valve which, with the aid of the negative pressure, feeds the ignition control gas controls;

Pig.15 is a side view of the control valve shown in FIG. 14, which is additionally influenced by the throttle valve position;

Pig. 16 looks at a part, partly cut, showing the Pig control valve. 14 shows which is influenced by a centrifugal governor;

Pig. 17 one of the representations after Pig. 7 and 8 comparable illustration showing the condition of the exhaust gas from an engine that is not is equipped with the device according to the invention j

Pig.18 one of the Pig. 17 comparable illustration, in which the numerical values of measurement results are entered, which the hydrocarbon ge ^ stop in the exhaust gas in millionth parts (10) and thus the effectiveness of the invention Show device;

Pig.19 a longitudinal section through one in the invention Device usable spark plug;

Pig.20 the spark plug according to Pig. 19 in bottom view; Pig. 21 the bottom view of a further spark plug;

Pig. 22 a section through the plane XXII-XXII in B ¹ Ig. 19 y

Pig. 23 one of the Pig. 2 comparable illustration a further embodiment of a two-stroke engine according to the invention;

Pig.24 a section according to XXIV-XXIV in Pig.23; and ,

Pig.25 a further embodiment in a representation like Pig. 2, in which a heat shield is provided. ■

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BATH ORIGINAL

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1 shows curves of the exhaust gas of a two-stroke engine obtained from measurement results. Here is the abscissa the representation in degrees of the crank angle and the ordinate according to the flow rate of the gas from the exhaust gas opening divided. The section S shows the crank angle section in which the transfer channel is open while the section E stands for the crank angle section in which the outlet opening is open. Through the curve A and the abscissa is an area that is a measure of the burned gases in the exhaust gas, while the between Curve -B and the abscissa enclosed area a measure of the The proportion of unburned gas components in the exhaust gas is.

In an embodiment according to the invention, shown in Fig. 2, the ¥ orrich> device according to the invention is installed in a two-stroke engine, which has a cylinder 1, a carburetor 2, an inlet port 3, a crankcase 4> a piston 5, a transfer channel 6, a cylinder head 7, an exhaust port 9, an exhaust port 14, which connects to the exhaust port of cylinder 1 and represents the exhaust port, and has an exhaust pipe 15, which is attached to the end of the exhaust port 14.

In addition, the engine has an electrical ignition system, which consists of a battery 10, a first ignition coil 11,

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an ignition distributor with circumferential cam 12 which is coupled to the crankshaft of the engine, a first breaker contact 13 and a first spark plug 8 in Zylinderkopf.7 consists, ^s by which this is geaündet into the cylinder, entered through the overflow gas; the ignition time of the first plug 8 is determined by the first interrupter contact 15.

In this engine, which is constructed in a conventional manner, the device according to the invention is now attached, which consists of a second spark plug 16, which is in the side wall of the outlet port 14 at a point close the outlet opening 9 is used, further from a second breaker contact 17 in the same breaker with the first break contact 13 and a second ignition coil 18, which is actuated by the interruption of the second breaker ■ contact 17 and the ignition voltage to the second spark plug 16 delivers.

Jer from the second interrupter contact 17 determined ignition point the spark plug 16 is placed so that the plug ignites in a moment in which the outlet opening through

the piston is not yet completely closed because in At this moment the flow rate of waste exhaust gas through the exhaust port is a maximum, as indicated by the Pig. .1

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emerges. However, it is desirable that the ignition j

only takes place at the moment when the outlet opening |

It is completely geachloeeen by an ignition in one

at a point in time before the (| exhaust port completely closed l

malfunctions can occur such as premature ignition of the. \

Gas in cylinder 1. - _s

■■■■ - - - ■■ ■!

Tests have shown that the best combustion.

of the exhaust gas loss in an interval of up to 40 ° (measured in degrees of the crankshaft) after complete closing

the outlet opening 9 can be reached and that a further · |

Delaying the ignition of this gas then the combustion y difficult, as it is burned with the other gases I '

mixed, j

■. ■ .. '^; ■■■■ '■■■■. ■ '· ■■■ "■ · ■■ J.- ·

Since the amount of emitted hydrocarbons in the exhaust gas of an internal combustion engine fluctuates somewhat as a result of various influences such as the engine size, the carburetor setting and the load conditions, the proportions of hydrocarbons are approximately in the range between 4000 and 5000 χ 10 ". By applying the invention, the loss exhaust gas If afterburning is carried out, the proportion of emitted hydrocarbons is reduced to between 300 and 500 χ 10 proportions

l. 1 0 9 8 2 9/0 A 0 5 V.

OBIGtNAL INSPECTED 'ί

The gas pressure of the overflowing gas is only low, when the throttle valve is only slightly open, and the amount of gas in the intake gas is only small when idling and when the motor works in so-called braking mode, so that the waste gases already with the est gases in the cylinder mix. Consequently, the gasoline content is also in the Loss exhaust itself is very low, and with this one, The embodiment of the invention shown is difficult to apply the mixture to the spark plug 16 with the aid of an ignition spark ignite.

Measurements given in Figure 7 have shown that no ignition can be achieved (X marks) if the throttle valve opening is less than Is $ 30, and the combustion is unsafe (Dreieok mark), even with throttle openings up to $ 50 when the engine speed is high.

By carefully examining the processes in the waste gas the inside and the outside of the outlet opening could be determined. That the reason for these combustion difficulties lies in the fact that the waste gas is not only is blown out by the energy contained in the overflowing gas, as described above, but that the gas also has a very specific outflow movement.

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V; ; Oi JA --ν OBJGJNAL INSPECTED

leads, as set out in more detail below, and is shown with reference to Fig. 4, within the period of time from the closure of the transfer channel by the piston to to close the outlet opening, and this movement prevents the ignition of the lost exhaust when the suction is tight is low.

Mg. 4a shows the state in which the piston is near its bottom dead center. The inflow movement of the gas a entering through the overflow duct has just ended and the waste gas a is just outside the outlet opening 9 at this moment temporarily in a state of rest. If the piston now moves upwards, as shown in FIG. 4b, the space above the cylinder 1 becomes smaller and the gas enclosed in the cylinder is expressed through the outlet opening. This. Gas is denoted by the reference number a ₂ . At the same time, however, the above-mentioned loss exhaust gas a. pushed outwards.

If the piston is now raised further and the overflow channel 6 is bottomed, the piston reaches finally a position shortly before the closing of the Outlet opening, as shown in FIG. 4o, in which the dtr pressure in the cylinder has risen further and that in the

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Flammable gas contained in the piston is ejected through the narrow gap between the edge of the piston and the edge of the outlet opening 9 in the manner of a sharp gas jet. The direction of this gas jet a * is almost perpendicular from the upper edge of the outlet opening and the gas jet then hits the lower surface of the exhaust gas duct and is thereby swirled. This turbulence also affects _{the waste gas components B 1} and a ₂ , whereby the unburned gas is then mixed with the exhaust gas * _; .

The spark plug 16 must then immediately after Closing the outlet port 9 are ignited to prevent the gasoline-air mixture in the cylinder through a early ignition is also ignited, but in this The gas emerging as a gas jet is ready for a moment the combustible waste gas is mixed with the burnt gases i So the amount of intake gas is only small and thus also the amount of waste gas, the ignition spark is not able to ignite the waste gas with certainty. The area of the throttle valve openings in which no afterburning is possible will, as measurements show have, larger with small amounts of gas.

Ils has also shown that in reality the flow rate of the gas jet a * the largest of the Duroh-

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flow rates of the waste gas in the various positions a .., a _? and a, and that by appropriately feeding this unburned gas a ~ at the right time to the ignition spark of the spark plug 16, without prior mixing, it is possible to obtain complete combustion of this gas even with small gas intake quantities.

The invention is based on this discovery, creating a practically feasible exhaust gas decontamination system is created in the conditions for facilitated ignition of the waste gas through a special training the exhaust opening, so that the combustion of the waste gases, i.e. the detoxification of the exhaust gases, with only small suction quantities, what was previously not achievable is possible.

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An embodiment of the invention is shown in FIGS. 3j, 5 and 6, which has an ignition chamber 2U which is attached directly to the outlet opening 9 on the upper side of the exhaust duct. This ignition chamber 20 has an inlet opening 21 near the upper edge of the outlet opening 9, which is very narrow, and an outlet opening 22 on the back of the flow of the ignition

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plug 16. The spark gap of spark plug 16 is within the ignition chamber 20.

As soon as the outlet opening 9 is completely closed, which corresponds to the position L in FIG. 3 of the crankshaft ignited-.

The device according to the invention described above operates in the following manner. The piston Jf- moves from its top dead center to its bottom dead center, whereby the normal process such as combustion of the sucked in gas, Exhaust and overflow is performed. Shortly before then the outlet opening 9 is completely closed with the renewed stroke of the piston 5, a jet of exhaust gas is lost high speed through the outlet opening, which is now a Slit represents blown out.

Since the inlet opening 21 of the ignition chamber 20 this The opening slot is directly opposite the outlet opening 9, the gas jet exiting through the slot arrives directly into the ignition kaiiimer and is deflected on the floor the chamber 20 swirled. The gas that has entered the ignition chamber 20 in this way fills the latter and arrives also at the same time in the area of the spark gap 23 of the spark plug 16. At this moment, the

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Spark plug 16 produces the spark that causes combustion the up to then unburned gas is introduced. The .Brennfront also migrates through the inlet opening 21 and the outlet opening 22 of the ignition chamber in the remaining part of the outlet channel, where the parts of the at rest Loss exhaust gas can also be burned.

In an experiment carried out with the device according to the invention, a Glow spark plug inserted, and the occurrence or non-occurrence the combustion in the exhaust gas duct was dependent on various values of the throttle valve opening and the engine speed determined. The results of these experiments are shown in FIG. 8, the safe combustion being indicated by a circle Cross indicates that no combustion took place, and a triangle indicates the relationship in which the Afterburn occurred irregularly in some cases, in some cases not.

From Fig. 8 it can be seen that a satisfactory ignition and combustion is achieved even with a throttle valve opening of only 30fo and that an ignition can be achieved even with a throttle valve opening of only 10 ^ when the engine is running with only

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1000 l / min turns, although the combustion in this one Funct "is already unstable. These results clearly show the effectiveness of the device according to the invention in the afterburning "of the waste gas even with small amounts of intake gas; the difference occurs compared to the values shown in FIG. 7 clearly emerge.

The effectiveness in igniting the waste gas in the embodiment just described can by a further embodiment according to the invention, which subsequently is described with reference to FIGS. 9 to 22, can be improved.

In this example of the invention, a small amount is used unburned gasoline-air mixture additionally introduced into the spark gap of the spark plug 16 to help with this gas initiate ignition and combustion, whereby then the resulting burning front is used to subsequently ignite and close the waste gas burn. That way it becomes possible to keep the ignition on initiate a way that is different from that of an electric Spark ignition deviates completely, because a combustion front heats up the lean fuel gas mixture to a certain extent, and also the ignition area is large. In addition, can the waste gas, which spreads irregularly in the exhaust

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gas channel is contained, are intercepted by the flame front of the pilot flame.

Using this embodiment of the invention, the values of hydrocarbon shown in FIG. 18 became salary achieved in millionths of a share. In Fig. 18, the values are shown in brackets which occur when the device according to the invention is not used. The effectiveness can be determined from the measurement results recognize the invention in the exhaust gas detoxification for a wide variety of engine speeds and load conditions.

A special embodiment of the device according to the invention, which is briefly explained in the preceding was, shall now be described in detail with reference to FIGS. 9 to 22 ' be written.

In FIG. 9, a bore 30 for supplying a fuel-air-gas mixture is shown, which is close to. the spark plug 16 is attached and with its outlet opening in the region of the exhaust duct 31, the fuel-air-gas mixture in the spark gap 23 of the spark plug 16 emits. On theirs The inlet end of the bore is connected to a supply line 32.

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copy

ORJGlNAi. INSPECTED

·· That way, a small amount can be unburned

\ Fuel-air mixture (hereinafter referred to as control gas

j draws) are released into the ignition spark gap 23,

'( before ignition, which is then ignited by "the ignition spark

i. is burned. Such combustion is independent and

Ί unaffected by the intake volume and the fuel concentration

] tration of the lost exhaust gas · Sas lost exhaust gas then becomes

j "ignited by the pilot flame of the control gas and

'4 then burns in a kind of secondary combustion

If the amount of suction gas only small and the amount of Verlusta "bgas _t so the Verlustabgaa a meager

et "

res mixture as it mixes with the burned gas. But also in such a particularly lean gas mixture the fuel-air ratio never falls below a certain level

't ' ■

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Limit (about 1/20) of the flammability of gasoline at normal pressure. If such a lean gas mixture becomes effective ignited, so it burns too.

.; The ignition effect of an ignition spark, however, is such

r ~ ~~ dad, although, in an extremely small area, by ätnr

l _} the ignition spark occurs, an ignition occurs

. is, the resulting ·? flame cools down again before

; they IU a flame grows η can that from lioh aelbat

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progresses. Consequently «there is no flame front and the Ignition of the entire volume of gas almost always becomes impossible.

In contrast to this, a pilot flame »as it is generated in the manner specified in accordance with the invention, such a high preheating, so that the flame front goes ahead and the gas is sure to burn. In addition, if the amount of intake gas is low and the amount of lost gas is low, the lost gas is mostly the same as the burned gas Exhaust gas is strongly mixed and does not appear as a lean gas, as considered theoretically. There is therefore hardly any Possibility of igniting the waste gas with a small ignition spark, whereas with a pilot flame the result the flame front a combustion can be achieved.

there is also no need to carry out the combustion at high temperatures, using oxides of nitrogen It is consequently a feature of the device according to the invention that the exhaust gas from an internal combustion engine are hardly detoxified without & ate the portion of stiok • toffoxyden is growing.

Am example of results obtained by feeding Burning the · Steuergaae * were achieved »whereby the

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br #: imung./der loss emissions is carried out as secondary combustion, is in the Pig. 18 reproduced. It is from this it can be seen that even in the area of low suction quantities (this is the section below the dashed line Line;) the proportion of hydrocarbons is significantly reduced is-tv in comparison to the hydrocarbon content in Klam-, set values, which are the values for unburned waste gas represent.

- -Bas control gas passing through line 32 and the bore 30 is supplied, for example, by a pumping device 41 are promoted as. it is shown in Figures 9 and 10. This pumping device 4-1 has a pump chamber 33. as well as a diaphragm piston 34 »which passes through the pump chamber, and a piston rod 35» which is equipped with a .. End is connected to the center of the diaphragm piston and its central area via a connecting lever 37 connection with a small crank 36 has. The piston 35 can on this Way are driven to a reciprocating movement with a small stroke, whereby the diaphragm piston 34 also performs a reciprocating motion. The pump chamber 33 then performs the well-known pumping processes of suction and Blowing through.

., pie pump chamber is still with a suction valve 38 and a discharge valve 39 connected to the suction line

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40 or the delivery line 41a are connected, which latter is connected to the supply line 32. The suction line 40 leads to a branch 48 of the engine intake line. However, the suction line 40 can also be small lead separate carburetor.

The small crank 36 is seated on a shaft 42, which via a gear train 43 »44 and further gears 45 and 46 is connected to the shaft of the ignition distributor. The translation of the gears is selected so that the pump 41 turns on with one revolution of the engine crankshaft 47 performs a reciprocating work cycle. Is there the timing of this movement so placed that the delivery stroke of the pump, which is shown in FIG. 9 by the crank angle M-M is shown, the ignition instant K of the spark plug 16 includes.

In this way, a small amount of control gas is fed into the ignition spark gap 23 of the spark plug 16 initiated with each work cycle before the actual ignition.

Another embodiment of the invention in which a control gas is supplied is shown in FIGS

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shown using a particular method. The device has a pressure chamber 50 with an inlet opening 51, with which it is connected to the crankcase 52 is and also has an outlet opening 53 'to which an outlet line 54 is connected, which is connected to the supply line 32 (see Fig. 9) is connected. To open and close inlet 51 and outlet 53, rotary valves 55, and 56 are provided, which are arranged coaxially with one another and are driven via a gear 57 and a shaft 58. The gear 57 is in turn from the crankshaft of the engine via a gear 59a, which is seated on the crankshaft, and a dual gear 59 driven so that the rotary valve 55 and 56 rotate at the same speed like the crankshaft.

The period of time during which the inlet 51 during a Revolution of the rotary valve 55 is open, corresponds to the time span in which the piston from top dead center to slides down until the moment when the overflow channel 6 is opened (this corresponds to a crank angle W-W in fig. 11). The length of time during which the outlet opening 53 is opened by the rotary valve 56, corresponds about the crank angle Ma-Ma of the engine crankshaft, which also includes the ignition point K of the auxiliary plug 16.

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The effect is as follows: The sucked in gas, which is located in the crankcase 52, is therein when it is lowered of the piston is compressed, and a portion of this compressed gas then passes through the inlet port 51 in the pressure chamber 50. Before the overflow channel 60 is opened, the inlet 51 is closed so that the compressed gas remains trapped in the pressure chamber 50. Then, before the spark plug 16 is ignited the outlet opening 53 is opened, so that the compressed gas via the supply line 54 as control gas through the bore 30 can get into the spark gap 23 of the spark plug 16. *

In a modified embodiment, the Rotary valve 56 of the outlet opening 53 omitted, and the timing for the delivery of the compressed control gas, which should fall within the crankshaft angle range Ma-Ma, is determined by suitable dimensioning, e.g. the volume of the pressure chamber and the inner diameter and length of the supply line 54 controlled.

Another implementation example for the possibility the supply of the control gas is shown in FIG. 13, where a bore 61 for discharging the control gas is in the cylinder wall of the two-stroke engine is attached. The hole

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ends at a small distance above the outlet opening 9 on the inner surface of the cylinder. The outlet opening of the bore 61 is arranged so that it allows control gas to enter the spark gap of the spark plug ^ l6, as follows after being described in more detail.

y / ird the piston 5 is raised and thus the fuel-air-mixture compressed in the cylinder, especially if the outlet opening is already small and completely closed in it = is, the pressure in the cylinder rises and compressed gas is forced through the bore 61. Here but this through-hole 61 is also worn by the upper edge of the piston 5, only a very large one gets there small amount of control gas into the bore. This amount of gas is then fed to the ignition spark gap 23 and ignited by the spark plug. While it seems logical that the ignition of the spark plug 16 should take place at the moment in which the inlet opening of the through hole 61 is closed, it is already ignited when the bore 61 is still open, namely as soon as the outlet opening 9 is completely closed, namely at the front of the Ibgases, causing the combustion to take the form of a Flanime continues moving down the jet of the burnt gas adapts. By suitable choice of length and diameter

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of the bore 61, taking into account the speed of propagation of the combustion front, it is possible to set the ignition point at the point in time that is most favorable for the combustion of the waste gas without fear must that the combustion front gets into the engine cylinder.

In a further modification of the invention, a recess is formed in the upper edge of the outlet opening to produce a pilot flame, and the upper adjoining part of the Aualaßkanals is instead of a special one Through-hole 61 is used for supplying the control gas, the ignition spark gap 23 of the spark plug 16 in this Recess is used in such a way that the unburned fuel-air mixture is blown through this recess into the ignition spark gap.

You test results in which the waste gases were burned without the aid of a control gas are recorded in FIG. 17, from which it can be seen that ignition and combustion are certain to proceed when the throttle opening is large enough «In In FIG. 17, an area is indicated by circles in which the combustion is proceeding satisfactorily, dwr The area marked with a triangle shows the unsafe

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Combustion and at the measuring points marked with crosses no combustion took place.

It is now pointless to supply control gas in the area in which the combustion is taking place anyway, since this is the case only means additional fuel consumption and the temperature in the exhaust line is unnecessarily raised will. So becomes the area where combustion is unsafe and the area where no combustion at all takes place out of itself, determined and created a device with which the control gas is supplied in a controlled manner is, so that control gas is supplied only during these working areas, it is possible to such Avoid wasting fuel and an exhaust gas decontamination system to create that works effectively with a high degree of efficiency and over the entire working area. One such a control device can be realized in the following manner.

A first embodiment is shown in FIG. 14; the control device is placed on the outside of the intake pipe 31 of the engine and has a vacuum chamber 62, with which it connects to the suction line 31 via a channel 63 is connected, which has a narrowed Abaohnitt-

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shows. A membrane 64 spans the chamber 62 and forms a partition wall between the interior of the device and the aforesaid The vacuum chamber 62 and a chamber 65 on the rear side of the membrane, which connect with the outside air, are divided Has.

In the vacuum chamber 62, a screw cap spring 66 is inserted, which serves to reset the diaphragm 64. An adjusting spring 67 is inserted into the chamber 65 on the rear side of the membrane, one end of which touches the rear side of the membrane and can be adjusted by an adjusting screw 68. The membrane 64 is connected in its middle section to the plunger of a valve 69 which is inserted _{into a passage S 1.} The valve is normally closed in that it is pressed against the valve seat 70 due to the force of the return spring 66, whereby the passage S _{1 is} closed.

The Durohtrittsweg S ₁ corresponds to the connection 48 on the intake line 40 of the pump device shown in Fig. 9 (the Durohtrittawtg'S-, in the case by the dashed lines in Fig. 14 drawn channel S is shown _1a), and also corresponds to the outlet conduit 54 in Figs. 11 and 12 and the through-hole 61 in Fig. 13

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That is, the valve 69 is somewhere in the Path of the control gas supplied to the supply hole 30 (or 61) is inserted.

Although a negative pressure is generated in the intake line in every operating state of the engine, it is the negative pressure is particularly strong when the opening width of the throttle valve is only small, and it becomes weaker when the engine speed increases. The negative pressure in the chamber 62 is depending on the suction conditions of the The engine is influenced, with a pressure connection to the intake pipe via the narrowed channel 63.

If the negative pressure exceeds a certain limit value, which can be set by the adjusting spring 67, then the membrane 64 is bent to the negative pressure side and thus opens the valve 69. That is the negative pressure Particularly strong in the intake path of the engine, the feed line for the control gas is open, and control gas is supplied in the manner described.

The conditions under which the passage S. is open correspond to the area below curve I in lig. 17 · This curve can be placed in such a way that

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the operating points at which the combustion is inherently unsafe are below this curve I. The area in which there is unsafe combustion and the area in which the exhaust gases do not burn at all are cleared through Determines small intake quantities of the engine, but since the intake quantity of the engine and the negative pressure in the intake line are dependent on one another, the supply of the control gas can be dependent on the negative pressure in the intake line and their interruption to avoid unnecessary fuel consumption to avoid being carried out in the manner described.

The membrane 64 and the valve 69 are mechanically connected directly to one another in the above example, it can but also think that the membrane operates an electrical switch, which then opens or closes an electromagnetic valve.

The supply of the control gas to the spark plug 16 can also be effected as a function of the degree of opening of the throttle valve, as is shown in the example according to FIG. 15. In the device shown, the passage So (S ₀₀ ) ^m ^ the passage S _{1 just described}

£ Ca I

(S ₁ J comparable, and this passage is through

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a valve 72, which is pressed onto its valve seat by a spring 73, is opened or closed. To open the valve 72, the spring force of the spring 73 can be overcome by a greater force of a further spring 75 which presses on the tappet of the valve 72 with the aid of an intermediate member 74 on which a lever 76 acts. If the lever 76 is rotated in the direction of the arrow, the intermediate member 74- is lifted off the valve stem, so that the valve 72 closes _{the passage S 2 as a result of the force of the spring 73.}

The operating end of the lever arm of the lever 76 can be pivoted by an eye 80 on a control member 77, which is connected to the throttle valve 79 on the carburetor 78 of the Motor is in connection, with the control member 77 for example with the (not shown) accelerator pedal or gas suction in connection and corresponding to the opening width · the Throttle valve 79 is adjusted. If the control element 77 is moved in the direction of the arrow, the throttle valve opening width becomes enlarged. In the direction of movement in which the throttle valve opening is enlarged, the Pressure of the lever 76 on the valve after.

Between the cam 80 in its lowest position with the throttle valve closed and the lever 76, in which

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rather this pushes the valve tappet in completely a little margin a left. If the throttle valve is then opened slowly and this opening reaches a certain value, the cam 80 touches the drive end of the lever 76. If the throttle valve is then opened further, the lever is pivoted in the direction of the arrow, whereby the valve 72 slowly closes the passage Sp and thus interrupts the supply of control gas.

The setting value of the throttle opening, below

whose passage channel S2 is open so that control

* gas hindu kick, is made by suitable choice of leeway a between the driven end of the lever and the driver cam 80 is determined. This results in a border line » which is shown in FIG. 17 as a dashed line II. This boundary line can be placed almost exactly between the areas in which, on the one hand, reliable ignition without control gas and, on the other hand, unsafe ignition or no ignition takes place. Here, too, one can be actuated as a function of the throttle valve position Switch may be provided which then actuates an electromagnetic valve instead of the mechanical device shown in FIG.

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Another simple example of controlling the supply of the control gas is shown in FIG. This arrangement has a passage channel S ,, a control slide 81, a "spring 82, which the control slide 81 pushes into its closed position, an adjusting lever 83 for pressing down the control slide into its open position against the force of the spring 82, one spring 84 to generate the counterforce on the lever 83, a second Lever arm 85 and other related parts. The elements listed largely correspond to the parts that are shown in FIG.

In this device, however, the drive lever arm 85 is opposed to a driver 91 which is attached to an actuating rod 89 is attached, in a direction indicated by an arrow by a driving claw 88 at least a centrifugal weight 87, which is thrown outward by centrifugal action, is displaceable. That Centrifugal weight 87 is attached to a lever which is articulated on the shaft 86, which is at a certain relative speed rotates at the speed of the crankshaft. The drive lever end 85 is normally the driver 91 opposite, where there is a gap b between these two. By means of a return spring, the actuation

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- 36 - rod 89 pushed back against the direction of the arrow.

As the rotational speed of the shaft 86 increases, the centrifugal force, which acts on the centrifugal weights 87, wakes up, causing the driving claw on the centrifugal lever 67 the rod 89 in the direction of the arrow, aleo against the force the spring 90 moves. The driver 91 then touches the adjusting lever arm 85. As the speed increases further of the shaft 86, the rod 89 is displaced further in the direction of the arrow, whereby the lever 85 the pressing-down element 83 lifts off the slide piston 81. The spool 81 then follows the force of the spring 82 and closes the passage S-z, whereby the supply of the control gas is interrupted.

The limit speed of the shaft 86 at which the interruption occurs in the described arrangement, can be changed by various influencing factors, including setting the gap b. An example of the boundary line is shown in FIG. 17 by the Line III drawn in dash-dotted lines is shown (vertical line). The device just described differs completely from the two examples previously described, but this control device is simple

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and convenient to use and depends on the engine speed, which is of influence on various characteristics of the engine, and it is also very important in its application effective.

If z. B. drives a motor vehicle at high speed and the throttle valve is only slightly open, so it can happen that the exhaust gas is not detoxified if no control gas is supplied. One such condition only occurs when the motor is braked, So what happens when the vehicle is descending a steep slope at high speed. on the other hand but it does not often happen that the engine sioh rotates at a low speed and the throttle valve is wide open, a control gas would then be necessary. Ba so little fuel is wasted.

The most frequently occurring work ebeieL cn is illustrated in Fig. 17 which are conditioned by the traveling resistance of the vehicle by the curves IV (two dots and dash.) Limited. It can be seen from these curves that the area in which the fuel-air mixture is unnecessarily wasted and that in which exhaust gas purification is not carried out can be kept to a minimum and that they are

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simple control device effective and economical the Infeed of the Steuergaaes causes.

With this principle, too, a combination of an electrical switch and an electromagnetic valve can optionally be used, in which case the switch is operated by the centrifugal device. On this occasion, the installation effort can nooh be reduced in that the centrifugal device used anyway is used for the centrifugal device Pre-control of the ignition point for the ignition distributor is also used.

In the invention, a spark plug is also used 16 of very special construction which will be described in more detail below, the loss of the exhaust gas in the off _(puffleitung the aid of the control gas naohverbrennt as was ready described above.

In the case of several, in the Pig. 19 to 22 of the embodiment of the candle 16 is an ignition anode 92 with an elongated tip and a cathode 93 t which surrounds the anode 92 and has a recessed edge 94, with the rim near the tip of the anode 92

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surrounds this coaxially and thus forms the ignition spark gap 23. In this way, the cathode 93 encloses an annular chamber 95. Like the known spark plugs, this plug also has an external thread 96 for screwing in and a hexagon 97 on her body. A plurality of holes 98 leading into the annular chamber 95 are provided in the wall of the cathode, whose axes are set at an angle to the diameter lines are.

The spark plug 16 is with its thread 96 in a Threaded bore 99 provided in the upper wall of the outlet channel, as shown in FIG. 13 shows. This hole also has an annular groove 100 which is at the same height as the holes 98 when the Spark plug 16 is inserted, and the bores 30 and 61 open into this annular groove. 61 supplied control gas spreads in the annular groove 100 and passes through the holes 98 into the annular chamber 95, with a certain inclination to the diameter lines. A vortex then arises in the annular chamber, and the control gas flows through in the form of this vortex the ignition spark gap leaves the annular chamber and enters the outlet channel. That way, a small one too Amount of control gas is not dispersed, but actually fed into the ignition spark gap. So there is no ignition

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delay on, and at the same time ee is possible, only one use very small amount of control gas.

Since, in addition, the spark plug with its ignition spark gap 23 is attached in a flasehenhale-shaped constriction of the outlet channel, the interior of the chamber 95 prevails a slight negative pressure, and in addition, the chamber is not influenced by the turbulent gas flow in the outlet channel itself. The control gas can therefore be supplied during the exhaust stroke of the engine without disadvantages as a result appear. The spark plug 16 just described, however, has the further effect that the waste gas is more easily captured if no control gas is supplied to the ignition spark gap. It has to do with the fact that that Loss exhaust gas is present in the outlet channel immediately after the outlet opening has been completely closed, and there in In the annular chamber 95 of the spark plug 16 there is a slight negative pressure as a result of the exhaust gas stream that previously flowed past it, this negative pressure has the effect that some loss exhaust gas is sucked into the chamber when it is again Adjusts pressure equilibrium. So Ee is currently during the right moment in the spark gap and in their surroundings loss exhaust gas present.

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In the modification shown in FIG of the spark plug, several cutouts 101 are made on the lower edge 94 of the cathode 93, whereby the annular gap of the ignition spark gap 23 is divided. Such an interruption or division of the annular gap is advantageous because it facilitates spark formation, also makes the correction of any eccentricity of the anode easier and easier in addition, the cooling.

Another embodiment of the invention is shown in FIGS. Here is going to be a full To achieve combustion of the fuel contained in the exhaust gas, air is additionally supplied to the waste gas. That Loss exhaust gas is indeed a fuel-air mixture and ignites itself and burns, even if ea is expelled, the oxygen required to burn this gas at normal Pressure is necessary, but does not have to be sufficient in every case, since the ratio of fuel to air is usually is on the order of 1:15 in order to achieve properties that are favorable for normal engine operation, e.g. for the propagation speed of the plasma front. During such combustion, the waste exhaust gas releases the hydrocarbon If the content is reduced, the carbon monoxide content increases.

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In addition, some of the waste gas that has already mixed with the burned gases only burns imperfect or not at all. However, if air is additionally supplied, the oxygen content is sufficient and the formation of hydrocarbons and carbon monoxide is reduced, so that the cleaning of the exhaust gas is further improved.

As stated earlier, the exhaust gas is lost caught, ignited and burned in the very short time during which it is still unmixed in the exhaust duct is. So if air is simply fed in, it only leads to the loss of gas being lost with this air, and ignition then becomes impossible. In the invention, the air is now supplied without the loss of exhaust gas is split, so that a complete combustion of the waste gas a is possible.

In one in the Pig. An embodiment of the invention shown in FIG. 23 leads an air supply bore 110 with its outlet opening into the exhaust gas duct 31 directly adjoining the outlet opening 9. About 20 cnr are fed through this feed duct in compliance with the following conditions. The first condition is that the

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Air as early as possible, preferably at the same time as the Ignition of the spark plug 16 is supplied. The second condition is that the air supply be intermittent for everyone Exhaust emission of the machine takes place. This means that once during one revolution of the crankshaft in a two-stroke engine and air must be supplied once during two revolutions of the crankshaft of a four-stroke engine, where the air supply is within the crank angle range W-W in Pig. 23 takes place.

In this way, the air is supplied during or shortly after the ignition of the waste exhaust gas. If the air is added during the combustion and the oxidation, the chemical reaction is supported, but even if the air is added after the combustion has already taken place, the hydrocarbons and carbon monoxide still react because of the heat generated during the combustion the oxygen in the air and oxidizing. The waste exhaust gas is completely converted in this way into non-disturbing water and carbon dioxide, or the hydrocarbons and carbon monoxide, which are in the remaining part of the combustion gas, can be oxidized to a certain extent.

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Since it is prevented that the additional air within the Period of time is supplied in which the waste gas from the Outlet port emerges, so that is the time span of the opening of the transfer channel until the outlet opening is closed and igniting the spark plug 16, so there is the disadvantage that the waste gas permeated by the air will not, so that the effect of the exhaust gas decontamination system, in which the waste exhaust gas is ignited and burned by the spark plug, not adversely affected thereby will.

The air supply can be effected by a pump such as that shown in Fig. 24. This pump is mainly a diaphragm pump with a pump chamber 111, in which a diaphragm piston 112 is arranged and over a piston rod 113 is actuated. The pump also contains an inlet valve 116 and a discharge valve 117. The inlet valve 116 is in contact with the outside air while the dispensing valve 117 is connected to an air supply line 118, which supplies the air in the manner described the channel 110 conducts.

The piston rod is connected via a connecting rod 115 113 connected to a small crank 114, one of which

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dreliung causes the piston rod 113 to move back and forth. The diaphragm piston 112 thus executes to and fro movements and also pumps by enlarging and reducing the pump chamber volume.

The small crank 114 is connected via gears 119 to 122 to the shaft 29 of the ignition distributor, which in turn is connected to the crankshaft 47 via gears 123 and 124, as FIG. 23 shows. The diaphragm pump 112 is thus driven by the crankshaft of the engine in such a way that the diaphragm piston 112 executes a reciprocating movement during one revolution of the crankshaft, so that a dose of additional air is supplied through the supply duct 110 during each revolution of the crankshaft .

At the other end of the piston rod 113 'to the diaphragm piston 112 alao opposite, a further diaphragm piston 125 is fixed, which is located within a pump chamber 126 which acts in a manner similar to the pump chamber 111. Also, an inlet valve 127, which with the intake pipe 128 (see Pig. 23) of the engine is in connection, and a discharge valve 129, from which a line 130 leads to the 3teuergaszuführbohrung 30 (or 61). The fuel-air mixture delivered by this pump

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is, the control gas supply bore 30 is used as control gas once per revolution of the crankshaft of the engine (or 61) fed.

Also, the back sides of the diaphragm piston 112, and 125 can also pump chambers be formed 111a and 126a having inlet and outlet valves and serve as a pump other purposes, as is possible, these pumping chambers 111, 111a, 126, to combine 126a, thereby supplying air and To make control gas so that they are in phase with each other or in antiphase with respect to the crankshaft rotation.

In practical designs, the pumping sections are either in phase or in opposite phase, but can go through suitable selection of the inner diameter and the length of the air supply line 118 and the supply line 130 for the Control gas (and, if necessary, installation of special intermediate chambers 131 and 132) the timing of the supply of air and control gas are selected so that at the outlet opening

. · or in the spark gap of the spark plug in Fig. 23 Ranges M-M given in degrees of the crankshaft and W-W incurred.

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So if the air supply pump is designed as a double pump, so it is possible to provide a pump for the control gas at the same time, so that the afterburning is certain the loss of exhaust gas is brought about with the help of a control gas without the need for an additional, special pump,

In the described examples of the invention for two-stroke engines, the waste gas is burned in the exhaust duct. As a result, part of the engine cylinder is heated directly, and the cylinder temperature is thereby further increased, if no special countermeasures are taken. An increase in the cylinder temperature can, however, lead to Defects and disadvantages such as special thermal expansion of the moving parts, thermal deformation of individual parts and Tear off the oil film on the cylinder wall. At a

Four-stroke engine there is a risk of overheating of the valves and valve seats. In another embodiment According to the invention, a heat shield is therefore provided in the exhaust duct so that the heat of combustion of the waste gas is lost is no longer transmitted to the engine cylinder.

Such an example is shown in FIG. In this the inner surface of the outlet channel 31 is hollowed out in the radial direction with the exception of the areas at the ends

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- 4β -

and a hollow cylinder or funnel 141 into the channel made of a thermally poorly conductive metal, the inner surface of which then represents the inner wall of the exhaust gas duct.

The cavity 140 between the cylinder or funnel 141 and the hollowed-out nozzle wall can either remain empty or with a heat-insulating material such as about asbestos can be filled. The exhaust pipe 145 is then connected to the end of the exhaust duct 31 in a known manner Muffler (not shown) connected.

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Claims (12)

- 49 PATENT CLAIMS 1. Exhaust gas decontamination system for combustion engines with at least a cylinder with a closable outlet opening, which is followed by an exhaust duct, into which some fuel-air-gas mixture before the outlet opening is completely closed escapes as waste gas, characterized in that a spark plug (16) is provided which, with its ignition spark gap (25) is attached immediately after the outlet opening (9), and an ignition circuit (12,13,18) is provided which ignites the candle (16) immediately after the outlet opening (9) is closed, so that the waste gas ignited and burned. 2. Exhaust gas decontamination system for two-stroke engines with at least a piston and cylinder, the outlet opening of which has an upper edge, the outlet opening from the Piston is completely closed during the upstroke at the moment when the piston sweeps over the edge, and an outlet channel adjoins the outlet opening, characterized in that one in the outlet channel (H) The ignition chamber (20) is inserted directly next to the outlet opening (9), which adjoins the edge of the outlet opening (9) with a narrow inlet opening (21), 109829/0405 that a spark plug (16) is arranged in such a way that the ignition spark gap (25) protrudes into the ignition chamber (20), and that an ignition circuit (12,13,18) is provided which the candle (16) ignites immediately after the outlet opening (9) is completely closed. 3. Exhaust gas decontamination system for internal combustion engines with at least one cylinder whose closable outlet opening f is directly connected to an outlet channel, in which before it is completely closed, some fuel-air mixture is blown in, which escapes as waste exhaust gas, characterized in that immediately 'subsequently a spark plug (16) with its ignition spark gap (23) is inserted into the outlet opening O), an ignition circuit (12,13,18) the candle ignites immediately after the outlet opening (9) has been completely closed and a control gas supply device (32, 41, 48) is provided for supplying a keel, n amount of fuel-air mixture as control gas directly in the ignition spark gap (23) of the candle (16), where it is ignited and burned and thus forms a pilot flame to burn off the loss. 4. exhaust gas decontamination system according to claim 3 »characterized in that the control gas supply device is a 109829/0405 Outlet opening (30) near the ignition spark gap (23) of the plug (16) and one depending on a main barrel part of the engine moving pump (41), the fuel-air mixture from the intake duct (71) of the engine or from a special carburetor and the mixture as control gas in the control gas supply channel (30) gives away. 5. Exhaust gas decontamination system for two-stroke internal combustion engines with a crankcase, in the fuel-air mixture sucked in and then compressed, with at least one cylinder with a closable outlet opening which is immediately followed by an outlet channel into which some fuel-air mixture is blown, which as Loss exhaust gas escapes before the outlet opening is completely closed, characterized by a spark plug (16), whose ignition spark gap (23) protrudes into the outlet channel (14) immediately adjacent to the outlet opening (9), one Ignition circuit (12, 13 »18) for igniting the spark plug (16) immediately after closing the outlet opening (9) and a control gas supply device (61; 30,32,41,48) for supplying a small amount of fuel-air mixture as control gas directly into the ignition spark gap (23) »which is in it is ignited ^ and serves as a pilot flame for the subsequent combustion of the waste gas. 109829/0405 6. Exhaust gas decontamination system for a two-stroke heater with at least one piston, an associated cylinder with a closable outlet opening to which immediately followed by an outlet channel into which some fuel-air mixture is blown and as waste gas escapes before the outlet opening is completely closed, characterized by a spark plug (16) with an ignition spark gap (23) »which immediately adjoins the Outlet opening (9) is inserted into the exhaust gas duct (14), an ignition circuit (12,13,18) for igniting the spark plug immediately after the outlet opening (9) is completely closed, and a control gas supply duct (61) whose outlet close to the ignition spark gap, and its entry on the cylinder inner wall immediately above the Outlet opening (9) opens, which control gas supply channel (61) a small amount during the compression stroke of the piston (5) Amount of fuel-air mixture as a control gas from the cylinder (1) into the ignition spark gap (23), where it is ignited and, as an ignition flame, causes the subsequent combustion of the waste gas. 7. Exhaust gas decontamination system according to claim 3 »characterized in that the control gas supply device has a supply channel, the outlet of which is near the ignition spark gap (23), an exhaust gas device for the delivery of a 109829/0406 Fuel-air mixture as a control gas for the inlet opening of this channel and a control device between this delivery device and the channel, which, depending on the negative pressure in the intake pipe of the engine, only allows a small amount of control gas to be released into the channel if the strength of the negative pressure is a certain one Dimension exceeds (Fig. H). 8. Exhaust gas decontamination system according to claim 3 »daduroh marked, that the control gas supply device has a supply channel with an outlet opening in the vicinity of the ignition spark stray (23) »a dispensing device for dispensing a fuel-air mixture as a control gas into the inlet opening of the feed channel and a control device between of the dispensing device and the feed channel, which depending on the degree of opening of the throttle valve dee Engine carburetor only allows a small amount of control gas to pass into the control gas supply channel when the throttle valve is opened falls below a certain degree of opening (Fig. 15). 9. Exhaust gas decontamination system according to claim 3 »thereby gekennzeiohnet, that the Steuergaazuführeinrichtung has a feed channel, the outlet opening in the immediate Is arranged near the ignition spark gap (23), an output 109823/0406 device is provided which emits a fuel-air mixture as a control gas into the duct inlet opening, and a control device is arranged between the dispenser and the channel, which depending on the speed of a main running part of the engine a small amount Then releases control gas into the feed channel when the engine speed falls below a certain value (Fig. 16). 10. Exhaust gas decontamination system according to any one of claims 3 to 9, characterized in that the spark plug (16) has a pin-shaped central anode (92) and a flat-shaped one Has cathode (93) surrounding the anode (92) and a forms ring-shaped ignition spark gap (23) between anode (92) and cathode (94), the small amount of control gas in the ignition spark gap (23) is guided through the hollow interior (95) of the plug (16). 11. Exhaust gas decontamination system for an internal combustion engine with at least one cylinder, a closable outlet opening, which is directly connected to an outlet channel, into which some fuel-air mixture is blown and escapes as waste gas before the outlet opening is completely closed during the compression stroke of the piston is, characterized in that a spark plug (16) with 109829/0405 its ignition spark gap (23) protrudes into the exhaust gas duct (31) immediately following the outlet opening (9), an ignition circuit is provided, which opens the candle (16) immediately after the outlet opening has been completely closed (9) ignites and thus ignites the waste gas and burns, and an air supply device in the immediate vicinity the ignition of the spark plug (16) promotes air in the exhaust duct (31) to improve the complete combustion of the Loss of exhaust gas. 12. Exhaust gas detoxification system for internal combustion engines with at least one cylinder at the closable outlet opening immediately followed by an outlet channel, characterized by a spark plug (16), its ignition spark gap (23) protrudes into the outlet channel (31) immediately behind the outlet opening (9), to a control gas supply channel (30), the outlet of which opens near the ignition spark gap, a double pump with a first and a second diaphragm pump, which is driven depending on the engine and an ignition circuit for igniting the plug (16) during each stroke of the engine after the exhaust port (9) is closed, the first diaphragm pump (125) using a small amount of fuel-air mixture as a control gas through the control gas supply channel (30) into the spark gap (23) promotes immediately before the ignition of the ignition spark 109829/04 05 and the second diaphragm pump (112) conveys air via the air supply channel (110) after the candle (16) has ignited. 13 · Exhaust gas decontamination system for an internal combustion engine with at least one cylinder with a closable outlet opening, which is immediately followed by an outlet channel, which is formed by a tubular structure (RO) and into which some fuel-air mixture is blown, which escapes as waste exhaust before the Outlet opening is completely closed, characterized by a combustion device for initiating the combustion of the loss exhaust gas in the channel (31) and a Heat shield in the tubular structure (UO), which allows the transfer of heat from the exhaust duct (31) to the cylinder (1) prevents U * exhaust gas decontamination system according to claim 13, characterized in that the heat shield is formed by that there is a recess (142) on the inner wall of the tubular structure (UO) with the exception of the ends and a second tube (U1) is inserted into the tubular structure, so that the second tube (141) and the tubular outlet nozzle (UO) an insulating cavity (142) exists. 108829/0405 Blank page