DE2336600C3 - Device for exhaust gas purification from motor vehicle engines - Google Patents

Description

The invention relates to a device for .ibgas cleaning with an alternator and a Electric ignition system equipped automobile internal combustion engines with a feed device for Additional air and a cleaning device having a thermal reactor and a downstream catalytic converter, a temperature sensor being provided with it in the converter Measuring pulse the additional air supply device at overtemperature by means of an electrical circuit is lockable

Such a device is already known from DE-OS 14 76 486. In this known device a catalyst device is provided within a combustion chamber, in which two thermocouples are arranged. One thermocouple is capable of supplying additional air via a circuit device throttle while the other thermocouple actuates an igniter for the exhaust gas controls within the catalyst device

This known device is disadvantageous in that it only opens up the possibility of being reached when reaching to throttle the supply of additional air at high temperatures in the catalytic converter device. With modern However, exhaust gas purification devices, which are mandatory by many governments in the interest of reducing environmental pollution, are becoming not only viewed as a disadvantage, but also lower temperatures, especially during the Engine starting phase. Undertemperature are dangerous because if one falls below Minimum reaction temperature in the thermal reactor where there is no afterburning of the exhaust gas, which has the consequence that the exhaust gas with its full concentration of pollutants in the catalytic The converter occurs, which results in damage to the same. Therefore, the Internal combustion engine to fear damage to the catalytic converter device because as a result of Undertemperature in the thermal reactor with the entry of exhaust gases too rich in pollutants into the Catalyst device is to be expected

From DE-OS 21 06 608 a safety device for a with an exhaust gas cleaner is provided Internal combustion engine known, in which temperature sensors are provided, the measurement signals via a Computer result in the introduction of additional air into the exhaust gas cleaning device. Furthermore are at this known device fuses or bimetal devices provided with their Help the supply of additional air to the afterburning device is switched off in the event of excess temperature in the exhaust gas. In DE-OS 21 06 608 is also a Mentioned device in which the results of temperature measurements are transmitted to a computer which causes time delays in the ignition device, so that the ignition point is set to later if the determined temperatures make an intervention necessary.

From DE-OS 21 35 206 an exhaust gas afterburning device is known in which the additional air supply is blocked as soon as measurements in the

Afterburner temperatures have been determined to be too high.

The invention is based on the object of providing a device of the type mentioned at the beginning to train that it quickly comes to operating temperature and in a reliable manner in all operating states of the internal combustion engine an operation that does not overburden the exhaust gas purification device is guaranteed

According to the invention, this object is achieved by that also in the thermal reactor a temperature sensor connected to an electronic computer is provided, with the measuring pulse also the ZusatzluftzuführeinrichtuRg can be locked that a first electrical circuit device is provided, the ZUHi completing the additional air supply device in the starting phase of the internal combustion engine by means of an electrical signal supplied by the alternator is formed, and that a responsive to low temperature in the thermal reactor, actuated via the electronic computer second electrical circuit device is provided, which for later setting the Ignition timing of the internal combustion engine is formed

According to a preferred embodiment of the invention it can be provided that a three-way valve operated via the electronic computer or via the first circuit device is provided in the additional air supply device, with the aid of which the supply of additional air into the exhaust pipe can be shut off. _{! 0}

It has also been found to be advantageous that the first electrical circuit device contains an electromagnetic relay arrangement which has a magnetic coil that a first fixed contact is provided that is connected to the electronic computer that a second fixed contact is provided with the Actuating device for the three-way valve is connected and that a movable contact is provided, which is connected to a power source and is designed such that it has the second fixed Contact with the power source for the purpose of actuating the three-way valve connects as soon as the solenoid coil by the electrical output from the alternator of the internal combustion engine during the starting phase Signal is applied

In addition, it can be provided that the second electrical circuit device contains organs for adjusting the ignition point, which comprise an electromagnetic relay, which is triggered by the electronic computer at low temperatures in the thermal Reactor can be acted upon to the ignition point of the To set the internal combustion engine to "Late *" in order to increase the exhaust gas temperature.

It can also be provided that the organs to Adjustment of the ignition point to the tempe- y, temperature of the internal combustion engine have responsive switch, via which a device for adjusting the ignition device in the direction of pre-ignition is actuatable.

An embodiment of the invention is shown in the ho the following is described in more detail with reference to the drawing. The single figure shows a schematic representation of the exhaust gas cleaning device.

The internal combustion engine 1, also referred to below as a motor, has a cylinder 2 with a Combustion chamber 3f. There is also an inlet port 4 with an inlet valve 5 and an outlet or exhaust port 6 with an outlet valve 7 is provided.

For the sake of simplicity, only one cylinder 2 is shown in the drawing. An exhaust manifold 8 is connected to the exhaust gas opening 6. The exhaust manifold 8 is connected to an exhaust line 9 in which a catalytic converter 10 is arranged. The exhaust opening 6 is supplied with additional air via a nozzle 11 from an additional air supply device 12 an additional air supply line 14 with a one-way check valve 15 through which the additional air is guided through the nozzle 11 from the air pump 13 to the exhaust or outlet opening 6.

A thermal reactor is arranged in the exhaust manifold 8, which is generally indicated by the reference number 16 The thermal reactor 16 comprises an inner post-combustion chamber 17, which is of a Inner wall 18 is delimited and has a number of openings 19. The reactor 16 also has an outer post-combustion chamber 20 which is delimited by an outer wall 21 and the inner wall 18 The inner post-combustion chamber 17 is connected to the outer post-combustion chamber 20 through the Openings 19 of the inner wall 18 connected. The exhaust gases coming from the engine 1 are internal Afterburning chamber 17 and pass through the openings 19 into the outer afterburning chamber 20, in which the exhaust gases- for a while remain until they are fed to the actual exhaust pipe 9. The outer post-combustion chamber 20 is not only used to reduce the dwell time of the Exhaust gases in the reactor lengthen, but also help to increase the temperature of the inner post-combustion chamber to uphold to a reasonable extent; however, it can also be omitted if necessary. on in this way, the exhaust gases in the inner and outer afterburning chambers 17 and 20 are intended to be burned up when they are mixed with the additional air are, under such conditions, that the harmful components contained in the exhaust gases, in one reduced or removed to such an extent that the catalytic converter 10 does not destroy or damaged. In other words: the thermal reactor 16 is designed and constructed so that he keeps catalytic converter 10 under the correct and appropriate operating conditions d. H. without Served by the remaining unburned components in the discharged from the thermal reactor 16 Exhaust gases are destroyed. Above all, it should be emphasized that the thermal reactor 16 is a smaller one Can have afterburning capacity than the thermal reactor used earlier and provided as the only afterburning point. In accordance with Experiments carried out by the inventor can improve the afterburning capacity of the thermal Reactor 16 be about 35% to 45% of the thermal reactor previously used. In other words: the volume of the post-combustion 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 the afterburning chamber of the thermal reactor 16 according to the invention about 35% to 90% of the Has total volume of the burner space of the engine.

The invention proposes, as mentioned above, means that overheating and thus destruction or Prevent damage to the thermal reactor 16 and the catalytic converter 10, which is caused by a

causing excessive exothermic reaction under abnormal operating conditions, e.g. B. if the Choke remains inadvertently operated for a long period of time. This will be explained in the following.

In the drawing, the reference numeral 22 denotes an alternator driven by the engine 1 which generates an electrical signal which is fed to an electrical circuit device which includes an electromagnetic relay, which is generally indicated by the reference numeral 23. The relay 23 consists of a solenoid 24, which is acted upon by the signal coming from the alternator 22, a first stationary contact 25, a second stationary contact 26 and a movable contact 27 which is connected to an electrical power source 29 via an ignition switch 28 connected, e.g. B. with a battery which is arranged on the vehicle floor. The relay 23 is of the type in which the movable contact 27 is normally connected to the second fixed contact 26 as shown in the drawing. The reference number 30 denotes a temperature sensor which is arranged on the outer wall 21 of the thermal reactor 16 in order to sense the temperature of the thermal reactor 16, the temperature sensor generating an electrical signal Sri analogous to the temperature of the 2i thermal reactor, while the reference number 31 another temperature sensor referred to, which is arranged in the catalytic converter 10 to sense and to control the temperature of the catalytic converter 10 to generate a J "temperature of the catalytic converter analog electrical signal Sk. the temperatures analog signals St \ and S ^ are supplied to an electronic calculator 36 , which generates an electrical actuation signal Si when the temperature of the thermal reactor 16 rises above a critical value, in the present case above 850 ⁰ C, at which the thermal reactor 16 would be destroyed or damaged, and / or when the temperature of the catalytic converter above the critical value increases, i n in which the catalytic converter would be destroyed or damaged 10 this * o case about 75O ⁰ C.

On the other hand, the additional air supply device 12 contains a three-way valve 33 to the additional air also back to the air pump 13 through a bypass 34 to ■ * ■> lead and shut off the flow of additional air to the thermal reactor 16 or to the nozzle 11. That Three-way valve 33 is operated by a spool 35, one end of which is fixed to both the second Contact 26 of the Pelais 33 as well as with the computer 36 so is connected, while the other end of the coil 35 is grounded

During operation, when the ignition switch 28 is closed and the engine is under start-up conditions is the alternator 22 is not energized to the extent that the electrical signal coming from her If the magnetic coil 24 is sufficiently applied, the movable contact 27 then remains with the second Fixed contact 26 connected and the coil 35 is accordingly acted upon by the battery 29, so that the three-way valve 33 is operated to reduce the flow from the air pump 13 to the outlet opening 6 through the nozzle 11 to shut off additional flowing air. The reason for throttling or shutting off the flow of additional air during the engine starting operation is that when the engine 1 is to be started in a warm state, i.e. H. the catalytic converter 10 is already ready for operation, the catalytic converter immediately reacts to the unburned exhaust gases would respond when additional air flows in, causing such an excessive exothermic reaction would cause the catalytic converter IC to be destroyed.

On the other hand, when the engine has come from the cranking condition to the normal operating condition, the alternator 22 is energized to such an extent that its electrical signal is sufficiently applied to the solenoid 24. The movable contact 27 is separated primarily from the second fixed contact 26, as a result of which the coil 35 is no longer acted upon by the battery 29. The additional air is therefore conveyed by the air blower 13 through the nozzle 11 to the outlet opening 6. The electron computer 36 is then connected to the battery 29 via the first fixed contact 25, which is connected to the movable contact 27. If the Temperatui of the thermal reactor 16 in this case above 850 ⁰ C, as mentioned above, decreases, the computer 36 generates, among other things; electrical operating signal Si that the coil 3! applied so that the three-way valve 33 is actuated. The additional air is then prevented from flowing into the thermal reactor 16. As a result of this, the temperature of the thermal reactor 16 drops below 85O ⁰ C, so that the thermal reactor 16 is not overloaded. In the same way, generates dei electronic computer 36, when the temperature exceeds dei katalytivhen converter 10 in the present case 75O ⁰ C, as described above, the electrically operating signal Si applied to the coil 35, daf way. the three-way valve 33 is actuated.

The electronically controlled Aiigasreinigungsvorrich device also contains an ignition timing device, by means of which the temperature of the exhaust gas emitted by the engine 1 « is increased when the temperature of the thermal reactor 16 falls below the initial reaction temperature

The electronic computer 36 outputs a further electrical cal operating signal S2 when the temperature de; thermal reactor 16 drops to the initial reaction temperature, in the present case 650 ° C. Di <reference number 37 denotes the ignition distributor, which contains an early ignition device 38 and an etching device 39. The pre-ignition device 38 has an interrupter camshaft 40, a fixed, geerde th contact 41 and a movable contact 42, which is carried by a movable contact arm 43 other end is grounded. The retard 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 49 is connected to a capacitor 50, one end of which is grounded. Diesel movable contact arm 49 is also connected to the primary coil side 44a of the ignition coil 4A via an electromagnetic relay 51. The relay arrangement 51 comprises two fixed contacts 52 and 53, the contact 52 being connected to the primary coil column 44a of the ignition coil 44, while the contact 5- is connected to the retarding device 39 and a movable one is provided. Contact 54 and a coil 55 which, when energized, closes the relay arrangement 51 The coil 55 is: at one end grounded and the other end is via a switch which is responsive to the engine temperature! 56 connected to the computer 36. The motor switch 56 may be of conventional design and includes FIG

illustrated embodiment, two fixed contacts 57 and 58 and a movable contact 59. The Contact 57 is connected to coil 55 of relay arrangement 51, while contact 58 is connected to electronic computer 36. The movable one Κα / * akt 59 is arranged around the fixed contacts 57 and then to close 58 when the z. B. by the temperature of the coolant in the not shown Water cooling, which is provided on the engine body, determined engine temperature is low.

If the temperature of the thermal reactor falls below the initial reaction temperature during operation

temperature drops, the electronic computer 36 generates the electrical operating signal & that of the relay arrangement 51 is supplied via the switch 56, so that the coil 55 is then acted upon, whereby the contacts 52 and 53 are connected to each other. In this way, the retarder 39 is actuated and accordingly, the ignition timing is adjusted to "late" so that the exhaust gases emitted by the engine are hotter than that thermal reactor 16 are fed, whereby its temperature rises above the initial reaction temperature and the thermal reactor 16 again becomes operational.

1 sheet of drawings

Claims (5)

Patent claims: 1. Device for exhaust gas purification with an alternator and an electrical ignition system equipped automobile internal combustion engines with a supply device for additional air and a a thermal reactor and a downstream catalytic converter having cleaning device, wherein a temperature sensor in the Converter is provided, with whose measuring pulse the additional air supply device at upper temperature can be locked by means of an electrical circuit, characterized in that also im thermal reactor (16) is a temperature sensor (30) connected to an electronic computer (36) is provided, with the measuring pulse of which the additional air supply device (12) can also be locked, that a £ TSte electrical circuit device (23 to 27) is provided to complete the Additional air supply device is designed in the starting phase of the internal combustion engine by means of an electrical signal supplied by the alternator (22), and that a signal is set to sub-temperature im thermal reactor responsive, actuated via the electronic computer, second electrical Circuit device (39,51,59) is provided which is designed for later setting the ignition timing of the internal combustion engine 2. Device according to claim 1, characterized in that in the additional air supply device (12) one that can be actuated via the electronic computer (36) or via the first circuit device (23 to 27) Three-way valve (33) is provided .1, with the help of desüen the supply of additional air into the exhaust gas path (6, 9) can be shut off 3. Apparatus according to claim 1 or 2, characterized in that the first electrical circuit device (23 to 27) is an electromagnetic Contains relay arrangement (23) which has a magnetic coil (24) that a first fixed contact (25) is provided, which is connected to the electronic computer (36) is connected that a second fixed contact (26) is provided with the actuating device (Coil 35) for the three-way valve (33) is connected, and that a movable contact (27) is provided is, which is connected to a power source (29) and is designed such that it the second fixed contact (26) with the power source for the purpose of actuating the three-way valve (33) connects as soon as the magnetic coil is triggered by the electrical signal emitted by the alternator (22) of the internal combustion engine during the starting phase is applied. 4. Device according to one of claims 1 to 3, characterized in that the second electrical Circuit device (29, 51, 52) contains organs (38, 39) for adjusting the ignition point, which an electromagnetic relay (51), which can be acted upon by the electronic computer (36) if the temperature in the thermal reactor (16) is too low is to set the ignition point of the internal combustion engine to "late" in order to increase the exhaust gas temperature to deliver. 5. Device according to one of claims 1 to 4, characterized in that the organs (38,39) for adjusting the ignition timing M have a switch (56) responsive to the temperature of the internal combustion engine, via which a device for adjusting the ignition device in the direction of Advance ignition is actuatable