DE2336600A1 - ELECTRICALLY CONTROLLED EXHAUST GAS PURIFICATION DEVICE FOR COMBUSTION MACHINES - Google Patents

Description

· ρ ₆₈₀₈

Nissan Motor Company, Ltd.

No. 2, Takara-machi, Kanagawa-ku,

Yokohama City, Japan

Electrically controlled exhaust gas cleaning device; for Internal combustion engines

The present invention "relates generally to an exhaust system an internal combustion engine for motor vehicles and im in particular an electronically controlled exhaust gas cleaning system for use in an exhaust system of an internal combustion engine for motor vehicles.

The electronically controlled emission control system to which the present invention is directed is of the class of purification systems that are harmful to the unburned Oxidize or burn components, such as B. hydrocarbon compounds (HC) and carbon monoxide (CO) that are emitted in the engine and through the exhaust system emitted exhaust gases are contained,

A variety of attempts have been made to date to reduce the concentration of unburned hydrocarbon compounds and to reduce carbon monoxides in the exhaust gases. A useful means of achieving this goal is to to equip the exhaust system with a thermal reactor, whereby the exhaust gases, when they flow through, are again

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burns by means of additional air or secondary air, which is introduced into the thermal reactor through exhaust openings in the exhaust system. Another important resource is the use of a catalytic converter, which is also placed on the exhaust system, around the unburned to burn harmful components in the engine exhaust gas through secondary air 'before the engine exhaust gases flow out.

If only the thermal reactor is used with a post-combustion chamber of relatively large capacity in connection- with the exhaust system of the engine, should an extremely high temperature be maintained in the interior of the thermal reactor, such as in the order of 900 ° C to 1000 ⁰ C, so that the unburned and unconsumed harmful constituents in the exhaust gases are brought to such concentrations by burning or oxidizing as is acceptable for reducing environmental pollution. This makes it necessary to use expensive and highly heat-resistant materials in the construction of the thermal reactor. In addition, it must be noted that the effectiveness of the afterburning of the unused hydrocarbon compounds and carbon monoxides in the thermal reactor is closely dependent on the air / fuel ratio of the combustible mixture fed to the engine, i.e. the richer the combustion mixture, the greater it is Effectiveness in the afterburning of the unused and

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unburned components in the thermal reactor. That has poor economy "in fuel consumption result. So only the well-known thermal reactor in connection with the exhaust system of the internal combustion engine used to achieve a reduction in air pollution, Serious problems persist and remain to be resolved.

On the other hand, only the catalytic converter in the exhaust system is used Built into the engine, this catalytic converter works properly when the engine is under normal conditions runs. However, if engine exhaust gases are fed to the catalytic converter, the unburned harmful components, such as Hydrocarbon Compounds (HC) and Carbon Monoxides (CO) Contained in extremely high concentrations, and the unburned harmful ingredients are then added with the additional Air or secondary air supplied from a supply air system is mixed, the catalytic converter is through additional exothermic reaction of the catalyst heated to an exceptionally high temperature, e.g. B. to 1000 ° C, thereby destroying or damaging the catalytic converter. In addition, such overheating attracts that too destruction or damage of the catalytic converter, sometimes the destruction of the built-in parts of the catalytic converter, thereby causing a fire in the motor vehicle. It is well known that they vary

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Concentrations of the non-burned harmful constituents under all different operating conditions of the Engine. That is, the concentrations of the unconsumed or unburned components are among those undesirable Engine operating conditions increase when the engine is under extremely high load, the engine temperature increases suddenly increased, the engine has overheated, the carburetor air jets are narrowed, or a series of misfires occur in the engine. Under these conditions, the relatively expensive catalytic converter would be destroyed or damaged v / earth

In order to solve the above problem, an exhaust gas purification system has heretofore been proposed in which both the thermal reactor as well as the catalytic converter used in combination in an exhaust system of an engine in order to take advantage of both systems. According to this system, the engine exhaust gases are fed to the exhaust system are supplied, first afterburned when they pass through the thermal reactor, which is connected to the exhaust system is connected and the flow downstream to the Exhaust openings is arranged. The exhaust gases flowing into the thermal reactor are initially grounded with additional air mixed with the exhaust gas openings from an additional air supply system is supplied to aid in the afterburning of the exhaust gases. The exhaust gases then pass through the catalytic media Converter that flows in relation to the thermal reactor

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is arranged downstream in order to remove the remaining unburned components in the exhaust gases to be further burned. So the engine exhaust will be in two consecutive steps so that the exhaust gases do not reach an extremely high temperature in the thermal Reactor must be brought and the catalytic converter relatively lean or pre-cleaned exhaust gases supplied will. The toxic components contained in the engine exhaust gases can thus be reduced to concentrations that which are much lower than those achieved using an arrangement, each independently only from the thermal reactor or the. see kafcalyti Converter exists.

But even if such a system is installed in the engine's exhaust system, which includes both the thermal reactor and the contains catalytic converter, it occasionally occurs when the thermal reactor and the catalytic converter parts of the system, destruction or damage due to overheating caused by unburned harmful components relatively high concentration is caused, e.g. B ,, if the choke is accidentally closed for a long period of time remains or if the vehicle operator is forced to shut down the engine despite a series of misfires that result in a major one Number of cylinders of the engine occur to continue driving. In this case the following is to be determined: if the the harmful components that have not been burned extremely high

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Concentrations containing exhaust gases, the relative temperatures have to be fed to the thermal reactor under certain operating conditions of the engine, or if unburned gases are fed to the thermal reactor, while a series of misfires occur in the engine, the temperature of the thermal reactor drops below its Initial reaction temperature, so that the thermal reactor is no longer operational. The result is that one large amount of unconsumed and unburned exhaust gases is fed to the catalytic converter, so that the catalytic converter through the excess exothermic! Reaction would be destroyed or damaged.

The well-known exhaust gas cleaning system, both the thermal Reactor as well as the kafcalytischen converter contains is inadequate, and serious problems awaiting solution, so that an imperative need for an improved one Exhaust gas cleaning system is available,

According to the invention there is an improved electronically controlled Exhaust gas purification system proposed in which the exhaust system of the engine contains not only a catalytic converter, but also a thermal auxiliary reactor, its Capacity is smaller than that of the thermal reactor previously used. The thermal reactor is downstream after the exhaust openings of the exhaust system and upstream arranged with respect to the catalytic converter.

⁺ containing A '> gae $ 409809/0848 ~ ⁷ ""

233660Q

The engine exhaust, the unused harmful components contained and supplied to the exhaust system, become such when passing through the thermal reactor Concentrations post-burned as they are from the catalytic Converters can be processed, d. i.e., to such an extent that the catalytic converter does not destroy or is damaged by the exothermic reaction caused by the remaining un-farmed harmful constituents in caused by the exhaust gases emitted from the thermal reactor. The exhaust gases are then the catalytic Converters supplied, wherein they are further burned to remove the remaining unburned components in the exhaust gases to remove. The engine exhaust is so that way post-burned in two successive steps in such a way that the catalytic converter is not only reliable works, but is also not destroyed or damaged by the remaining unburned harmful constituents relatively low concentrations. In the exhaust gas cleaning system according to the invention, it is possible to increase the effectiveness of the overall afterburning of the system. '

The electronically controlled exhaust gas cleaning system according to the invention also contains electronic controls for the thermal reactor and the catalytic converter protect against destruction or damage due to overheating caused by the non-burned harmful

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components of relatively high concentration in the exhaust gases caused, the exhaust gases being emitted from the engine during abnormal operating conditions, e.g. B. the Choke is unintentionally closed for long periods of time or when the driver is forced to drive a motor vehicle drive even though misfires are occurring in a number of cylinders in the engine. The electronic controls control an air supply system by throttling or Shutting off the flow of additional air passing through the thermal reactor and the catalytic converter under such abnormal operating conditions. As a result, the thermal remain. Reactor and the catalytic converter except Operation so that they get through the unburned harmful ingredients relatively high concentration in the exhaust gases are not overheated. With these electronic controls the inflow of secondary air or supply air is shut off or throttled when the temperature of the thermal reactor rises above a critical fourth, in this case above 850 ° G, at which the thermal reactor would be destroyed or damaged, and / or if the temperature of the catalytic converter rises above a critical value, in this case above 750 ° C, at which the catalytic converter would be destroyed or damaged. The secondary air continues to be throttled or shut off during the starting process.

Furthermore, the electronic control elements contain

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according to the invention organs for controlling the ignition time to the electronic Controlling a pre-ignition and a retarded ignition mechanism, each of which forms a distributor. It is well known that the thermal reactor fails during operation, when the temperature of the thermal reactor reaches the initial reaction temperature under certain engine operating conditions falls off, so that a large part of the unconsumed and unburned harmful components enter the catalytic converter are supplied, which leads to its destruction or damage. To solve this problem, the Ignition timing control elements in such a way that they actuate the retard mechanism when the temperature of the thermal Reactor drops to the initial reaction temperature in order to heat the exhaust gases given off by the engine, so that the exhaust gases heated in this way are fed to the thermal reactor, the temperature of which is then above the initial reaction temperature increases and the thermal reactor works again. The ignition timing controls still contain Switch organs in relation to, the motor temperature, the Operate the pre-ignition mechanism while the engine is warming up.

If a number of cylinders of the engine misfires, so that the temperature of the thermal reactor drops to the initial reaction temperature due to the unburned gases emitted by the engine when the ignition spark is delayed to heat the unburned gases that are introduced into the thermal reactor, the unburned gases heated in this way also suddenly

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burned in the thermal reactor by means of air flowing through the misfired cylinder is thickened, even if-the supply air is flowing into the thermal reactor is obstructed, so that the thermal reactor would be destroyed or damaged. To eliminate this problem, "operate the electronic controls of the present Invention of the spark delay mechanism when the Temperature amount of the thermal reactor reaches or exceeds a threshold value even if the temperature of the thermal reactor to the initial reaction temperature drops, but then actuates the spark delay mechanism when the temperature of the thermal reactor falls below a predetermined value lower than that of the reaction color temperature.

According to the invention is an electronically controlled exhaust gas cleaning system to the. Use in conjunction with an internal combustion engine for a motor vehicle provided with at least one Combustion chamber, an exhaust system through which the exhaust gases given off by the engine flow, the exhaust system an exhaust port opening to the combustion chamber, an exhaust manifold and one connected to the exhaust manifold Has exhaust pipe, furthermore an air supply system, that consists of an air pump and a second air supply line with a one-way check valve for supplying the supply air from the air pump to the exhaust opening through a nozzle, a generator driven by the engine, a

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divider, which has an inflammatory disease and a late sin chartism contains, and a catalytic converter arranged in the exhaust line, the electronic The controlled exhaust gas cleaning system comprises the following parts: a thermal auxiliary reactor, which is arranged in the exhaust manifold is and seen in the direction of flow before the catalytic Converter is arranged to initially use the niclifc post-incineration of burnt or unused harmful components contained in the exhaust gases, mud. to such an extent that the rest were not burned harmful ingredients that are present in the exhaust gases passed through the thermal reactor, can be processed by the catalytic converter, and electronically controlled elements for electronically controlling the secondary air or supply air supply ssys-fcees, ™ To prevent the secondary air from being introduced into the exhaust port to be grounded under at least one of the following conditions, namely that at least one of the temperatures of the thermal reactor and the catalytic converter iiT at? a critical value at which the thermal heaktcs? ■ and the catalytic converter are destroyed, and the other condition that the engine is started, d. H. left on will.

Further features, details and advantages of the invention result from the following description based on the

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Drawing. Show:

1 shows a schematic overall overview of a preferred one Execution form of an electronically controlled exhaust gas purification igungssystems according to the invention and

Fig. 2 is a schematic overall overview of another Embodiment of an electronically controlled exhaust gas cleaning system according to the invention.

Referring particularly to FIG. 1, there is shown a first embodiment of an electronically controlled exhaust gas cleaning system according to the invention and an exhaust system of an internal combustion engine controlled thereby, the internal combustion engine being generally designated by the reference numeral 1. The engine 1 comprises a cylinder 2 containing the combustion chamber 3, an inlet opening M having an inlet valve 5 ^{a nd} an outlet or exhaust port 6 with an outlet valve 7 · In the drawing, only one cylinder 2 is shown for reasons of simplification. Reference numeral 8 denotes an exhaust manifold connected to the exhaust port 6. The exhaust manifold 8 is also connected to the exhaust line 9 in which the catalytic converter 10 is arranged. The exhaust gas opening 6 is acted upon by additional or secondary air through a nozzle 11 from a secondary air supply system, which is designated quite generally by the reference number 12. The second or supply air supply; uügnsysteni 12 includes

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- 13 - ■, ■ ■ ·

an air pump 13 driven by the engine 1, and an air supply line 14 with a one-way check valve 15 »that the supply air through the nozzle 11 of the air pump 13 is guided to the exhaust or outlet opening 6 will.

In the exhaust manifold 8, a thermal auxiliary sreaktor is according to the invention arranged, quite generally by the reference number

16 is designated and with respect to the flow according to

the outlet opening 6 is arranged. The thermal reactor includes an internal post-combustion chamber 17, which is of a Inner wall 18 is limited, which has a number of openings 19 having. Furthermore, the reactor 16 has an outer afterburning chamber 20, which is through an outer wall 21 and the Inner wall 18 is limited. The inner post-combustion chamber

17 is connected to the outer top combustion chamber 20 through openings 19 of the inner wall 18 connected. The ones from. The exhaust gases emitted from the engine 1 are grounded through the exhaust manifold 8 of the Combustion chamber 17 supplied and pass through the openings 19 in the outer post-combustion chamber 20, in which the Exhaust gases remain for a while until they are fed to the exhaust pipe 9. The outer post-combustion chamber 20 serves not only to lengthen the residence time of the exhaust gases in the chamber 20, but also to reduce the temperature of the thermal Hold up reactor 16 to a reasonable extent; however, it can also be omitted if necessary.

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In this way, the exhaust gases in the inner and outer Naclwerbrannfc skammer 17 and 20, if they are mixed with the supply air under such conditions that sufficient combustible components are contained in the exhaust gases and the exhaust gases are overheated so that the not burned and unused harmful components contained in the exhaust gases are reduced or removed to such an extent that the catalytic converter 10 is not destroyed or damaged. In other words: the thermal reactor 16 according to the invention is designed and constructed in such a way that it keeps the catalytic converter 10 under the correct and suitable operating conditions without this being caused by the remaining unburned components in the thus post-burned and released from the thermal reactor 16 Exhaust is destroyed. In particular, it should be emphasized that the thermal reactor 16 according to the present invention can have a smaller afterburning capacity than the thermal reactor previously used. In accordance with experiments carried out by the inventor, the post-combustion capacity of the thermal reactor 16 can be about 35% to 4-5% of the thermal reactor previously used. In other words, the volume of the afterburning chamber of the thermal reactor previously used had to be 100% to 200 % of the total volume of the combustion chamber of the internal combustion engine, while the volume of the afterburning chamber of the thermal reactor 16 according to the invention was about 35 % to 90% of the total volume of the combustion chamber of the engine having.

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As noted above, the present invention proposes means before that overheating and thus destruction or damage of the thermal reactor 16 and the catalytic Prevent converter 10 from being caused by an excess exothermic reaction under such abnormal operating conditions caused "when the choke is inadvertently left closed for an extended period of time. This will now be fully discussed below.

In Pig. 1, the reference number 22 denotes a by, the engine driven generator that generates an electrical signal Sg that is fed to an electrical switch, which contains an electromagnetic relay, which is indicated generally by the reference numeral 23. The relay 23 consists of a coil · 24, which is generated by the generator 22 originating signal Sg is applied, a first stationary contact 25, a second stationary contact 26 and a movable contact 27 which is connected via an ignition switch 28 to an electrical power source, e.g. B. with a battery 29 which is arranged on the vehicle floor. The relay 23 is of the type in which the movable contact 27 normally connected to the second fixed contact 26 is as shown in the drawing. Reference numeral 30 denotes a temperature sensor on the outer wall of the thermal reactor 16 is arranged, us the temperature of the thermal reactor 16 to sense, the temperature sensor an electrical signal St ^ analogous to the temperature of the thermal reactor is generated, while the reference

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number 31 denotes another temperature sensor that was used on catalytic converter 10 is arranged to the temperature of the catalytic converter 10 to feel and one of the Temperature of the catalytic converter to generate analog electrical signal Stp. The signals analogous to the temperatures St. and Stp are fed to an electronic co-processor circuit 32, which generates an electrical actuation signal S ,, when the temperature of the thermal reactor 16 is above a critical value increases, in the present case over 850 ° G, at which the thermal reactor 16 destroyed or damaged and / or if the temperature of the catalytic converter rises above the critical value, in this case above 750 ° C, at which the catalytic converter 10 destroyed or would be damaged.

On the other hand, contains the supply air system a three-way valve 33 to the supply air in a supply air supply line 14 back to air pump I3 through a bypass 34 lead to the flow of the supply air, which is the thermal Reactor 16 is fed through the nozzle 11, shut off. The three-way valve 34 is operated by a coil 35 whose one end is connected to both the second fixed contact 26 of the relay 23 and the electronic computer elements 32 while the other end of the coil 35 is grounded.

During operation, when the ignition switch 28 is closed and the I.Io'to3? is under Änfangsbotriebsbedioguagen, will the generator 22 is not energized to the extent that the elec-

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tric signal Sg, which comes from him, the coil 24 is not sufficiently applied. The movable contact 27 then remains connected to the second fixed contact 26 and the coil 35 is accordingly acted upon by the battery 29, so that the Three-way valve 33 is actuated to prevent the flow of the air flowing from the air pump 13 to the outlet opening 6 through the nozzle 11 Shut off the supply air. The reason for the throttling or Abder flow of the secondary air during the starting process of the The engine is that when the engine 1 has to start despite overheating and the catalytic converter 10 is then ready for operation is, the catalytic converter would respond immediately to the unburned gases when supply air flows in, causing such exo thermal eeaction would be caused that the catalytic Converter 10 would be destroyed.

On the other hand, when the engine changes from the cranking to the warm-up operating conditions, the generator 22 is energized to such an extent that the electrical signal Sg is then applied to the coil 24, the movable contact 27 is separated from the second fixed contact 26, whereby the. Coil 35 is no longer acted upon by the battery 29. The supply air is therefore conveyed through the nozzle 11 from the air blower 13 to the outlet opening 6. The computer electronic circuit is then connected to the battery 29 via the first fixed contact 25, which communicates with the movable contact 27. When the temperature of the thermal reactor 16

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in this pall above 850 ° C, as mentioned above, is generated the electronic computer circuit 32 the electrical Operating signal S. applied to the coil 35 so that the three-way valve 33 is operated. The secondary air is then prevented from flowing into the thermal reactor 16. as As a result, the temperature of the thermal reactor 16 falls below 8 ^ 0 ° G, so that the thermal reactor 16 is not destroyed or damaged. Similarly, the computer electronic circuit 32 generates when the temperature of the catalytic converter 10 in the present case 750 ° G exceeds, as described above, the electrical operating signal S ^, which acts on the coil 33, so that the Three-way valve 34- is operated.

Reference is now made to FIG. 2, in which another Embodiment of the electronically controlled exhaust gas cleaning system is shown, which contains a Zündzeitvers te llorgan, which is adapted to the heat of the exhaust gases given off by the engine 1 when the temperature of the thermal reactor below its initial reaction temperature under certain operating conditions falls.

An electronic computer circuit 36, as shown in FIG. 2, operates in essentially the same manner as the electronic computer circuit 32 except that the electronic computer circuit 36 continues to _{generate a different electrical operating signal S 0} when the temperature of the thermal reactor 16 increases the initial reaction temperature drops, in the present case 650 ° C. Reference number 37 denotes a

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A distributor which contains an early ignition device 38 and a retarded ignition device 39. The pre-ignition device 38 has an interrupter camshaft 40, a fixed, grounded contact 41, and a movable contact 42 carried by a movable contact arm 43. The movable contact arm 43 is connected to the primary coil 44a of the ignition coil and also to a capacitor 45, one end of which is grounded. The backbite device 39 likewise includes a breaker camshaft 46, a fixed, grounded contact 47, and a movable contact 48 "carried by the contact arm 49. The movable contact arm is connected to a capacitor 50, one end of which is grounded. This movable contact arm 49 is also connected to the primary spulensei te 44a of the ignition coil 44 through an electromagnetic relay 51st the relay assembly 51 comprises two fixed contacts 52 and 53 / wherein the contact with the primary coil side 44a of the ignition coil 44 is connected, while the contact 53 ^w ith the Spätzundungsvorrichtung 39 is in connection, furthermore a movable contact 5 ^ and a coil 55 »which, when energized, closes the relay arrangement 51» The coil is grounded at one end and the other end is via a switch 56 responsible for the motor temperature connected to the electronic computer circuit 36. The motor switch 56 can h Convenient design and contains in the illustrated embodiment, two fixed contacts 57 and 53 and a movable contact 59. The contact 57 is

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connected to the coil 55 of the relay assembly 51 while contact 58 with computer electronic circuit 36 in FIG Connection. The movable contact 59 is arranged to close the fixed contacts 57 and 58 when the z. B. by the temperature of the coolant in the water cooling, not shown, which is provided on the engine body, determined motor temperature is low.

If the temperature of the thermal reactor drops below the reaction start temperature during operation, it is generated the electronic computer circuit 36 provides the electrical operating signal Sp, that of the relay arrangement 51 via the switch 56 is supplied, so that the coil 55 is then acted upon is, whereby the contacts 52 and 53 are connected to each other will. In this way, the retarded ignition device 39 is actuated and, accordingly, the ignition spark is delayed, so that the Exhaust gases emitted by the engine are heated and fed to the thermal reactor 16, whereby its temperature is above the initial reaction temperature rises and the thermal reactor 16 is made ready for operation again.

It should be pointed out here that, as mentioned above, the electronic computer circuit 36 _{does not generate the electrical operating signal S 2} when "the amount of the temperature increase of the thermal reactor 16 exceeds a threshold value, even if the temperature of the thermal reactor on the initial reaction temperature

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falls, ie 650 G, but it then generates the electrical operating signal S ₂ when the temperature of the thermal reactor 16 falls below a predetermined value, in the present case below 450 ° C, which is lower than 650 ° C.

After the principles of the present invention above
has been described in connection with special exemplary embodiments, does not need to be pointed out and
it goes without saying that this description is only
has been given, for example, and cannot be regarded as a limitation on the subject matter of the invention.

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Claims (6)

Claims (1. ^ Electronically controlled discharge cleaning device for internal combustion engines for motor vehicles with at least one combustion chamber, an exhaust system through which the from Engine emitted exhaust gases flow through, the exhaust system having a passage opening towards the combustion chamber has, an exhaust manifold and an exhaust pipe connected to this exhaust manifold, a supply air supply system that has an air blower and a supply air supply line with a one-way check valve to remove the supply air from Feed the air blower to the exhaust or outlet opening through a nozzle, furthermore one driven by the engine Generator, a distributor that has a spray igniter and a retarder device and one in the Exhaust pipe arranged catalytic converter, thereby marked eichnet that the electronically controlled Exhaust gas cleaning device comprises the following parts: a thermal auxiliary reactor (16), which is located in the exhaust manifold (8) is arranged with respect to the flow above the catalytic converter (10) for the first post-combustion unburned harmful components contained in the exhaust gases to such an extent that the remaining unburned harmful components in the exhaust gases passed through the thermal reactor (16) are acceptable for the catalytic converter (10) and electronic controls for electronic control of the secondary air supply system in order to prevent the secondary or supply air from entering the exhaust gas opening (6) is supplied under at least one of the following conditions, namely once that at least one of the both temperatures of the thermal reactor (16) and the catalytic converter (10) above a critical value lie, in which the thermal reactor (16) and the catalytic 409809/0848 tables converter (10) were destroyed, and the others that the engine (1) is under starting conditions. 2. Exhaust gas cleaning device according to claim 1, characterized by the arrangement of an electrical power source (29) * for the electronic control elements, a first temperature sensor element (3.0) ,, which is arranged on the thermal reactor (16) to the temperature of the thermal reactor (16) and to generate an electrical signal (St ,,) analogous to the temperature of the thermal reactor (16), a second temperature sensor device (31) which is arranged on the catalytic converter (10) in order to determine the temperature of the catalytic converter (10) and .ein the temperature of the catalytic converter (10) _{to generate an analog signal (St 2} ), an electronic computer circuit (32, 36) which is connected to the power source (29) and is fed by it and to at least one of the electrical, responds to the temperature of the thermal reactor (16) analog and the temperature of the catalytic converter (10) analog signals to a first electrical operation bssignal (S.) to generate when at least one of the temperatures of the thermal reactor (16) and the catalytic converter (10) rises above the critical value, a three-way valve (33) which is provided in the two air supply line (14) to the To prevent secondary air in the secondary air supply line (14-) from flowing into the exhaust gas openings (6) and to guide the secondary air back to the air blower (13), electrical actuating devices (35) for actuating the three-way valve (33), if these electrical actuating devices ( 35) are acted upon by the first electrical switch, which separates the electronic computer circuit (32, 36) from the power source (29) and connects the electrical actuating devices (35) to the power source (29) in order to switch the three-way A098OS / 08 actuate valve (33) with the aid of the power source (29), when the engine (1) stents under starting conditions. 3. exhaust gas cleaning device according to any one of the preceding claims, characterized in that the electrical changeover switch contains an electromagnetic relay arrangement (23) which has a magnetic coil (24), that a first fixed contact (25) is provided which is connected to the electronic computer circuit (32, 36) is that a second fixed contact (26) is provided which is connected to the actuating device (35) is, and that a movable contact (27) is provided which is connected to the power source (29) and such is designed that it can connect the second fixed contact (26) to the power source (29) to the three-way valve (33) to be actuated when the solenoid (24) by the electrical, from the generator (22) during the Starting operation output signal is applied. 4. Exhaust gas cleaning device according to claim 2, characterized in that the electronic Computerkr.eis (32, 36) of the electronic control device 'furthermore a second electrical operating signal (Sp) generated when the reactor temperature drops to the initial reaction temperature. 5. An exhaust gas purification device according to claim 4, characterized in that the electronic control devices further contain ignition timing control elements (38, 39) which comprise an electromagnetic relay (5Ό _{which is acted upon by the second electrical operating signal (S 2} ) to the ignition delay device of the distributor Press to raise the temperature of the exhaust gases. 409809/0848 6. exhaust gas cleaning device according to claim 5 »characterized characterized in that the ignition control elements (38, 39) continue to respond to the temperature of the engine (1) Responsive switch (56) included to switch the 2 pre-ignition device (38) during the warm-up of the To operate the motor (1). 7 · Exhaust gas cleaning device according to claim 6, characterized characterized in that the computer electrical circuit (32, 36) cut-off elements for switching off the second contains electrical operating signal to actuate the retarder device (39)? if at the temperature rise of the thermal reactor (16) a threshold is exceeded to prevent until the temperature of the thermal Eeaktors (16) falls below a predetermined value which is lower than that Initial reaction temperature. 409809/0848