Installation for the catalytic afterburning of exhaust gases of a multi-cylinder internal combustion engine

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Drawing sheet — no readable text.

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These and further objects, features, and advantages

INST ALLATION FOR THE CATALYTIC of the present invention will become more apparent AFTERBURNING OF EXHAUST GASES OF A from the following description when taken in connec MULTI-CYLINDER INTERNAL COMBUSTION tion with the accompanying drawing which shows, for ENGINE purposes of illustration only, one embodiment in accor dance with the present invention, and wherein:

The present invention relates to an installation for The single FIGURE is a schematic view of one em the catalytic afterburning of exhaust gases of a multi bodiment of an installation for the catalytic afterburn cylinder internal combustion engine with two exhaust ing of exhaust gases of a multi-cylinder internal con gas lines, of which each includes at least one catalyst. 1) bustion engine according to the present invention. Installations for the catalytic afterburning of exhaust Referring now to the single FIGURE of the drawing, gases of a mutli-cylinder internal combustion engine reference numeral 1 designates in this FIGURE an with two exhaust lines are known, of which each in internal combustion engine arranged in a motor vehicle cludes at least one catalyst, which are acted upon or as driving engine for the vehicle which may be con attacked in common by the exhaust gases after the structed, for example, as opposed cylinder-type engine starting of the internal combustion engine. As a result or as V-engine. The exhaust gas lines 2 coordinated to of the common attack of the catalysts, an undesirably the cylinders on one side are combined into a common long period of time elapses until the catalysts have exhaust line or manifold 3, and the exhaust pipes 4 reached a temperature at which the catalytic afterburn coordinated to the cylinders arranged on the other side ing of the exhaust gases starts fully. It has thereby of the engine are combined into a common exhaust gas proved as particularly disadvantageous that precisely in line or manifold 5. A catalyst 6 is arranged in the ex the first few minutes after the starting of the internal haust gas line 3 and a catalyst 7 is arranged in the ex combustion engine, when the latter is still relatively haust gas line 5. The exhaust gas lines 3 and 5 are cold, the exhaust gases contain a particularly large connected with each other by a connecting line 8 up amount of components harmful to health. 25 stream of the catalysts 6 and 7. Upstream of the cata It is the object of the present invention to provide an lyst 6 and downstream of the connecting line 8, a throt installation for the catalytic afterburning of exhaust tle valve 10 actuated by an adjusting motor 9 of any gases of an internal combustion engine which does not conventional type is arranged in the exhaust gas line 3 exhibit these disadvantages and shortcomings. whereby the adjusting motor 9 is controlled by a ther The problems underlying the present invention are 30 mo-element 11 of any conventional type, such as a solved in that the installation includes devices which heat-sensor, arranged cithier within the area (effective with a cold internal combustion engine, conduct the range) of the internal combustion engine 1 or within entire exhaust gas flow for a predetermined time by the area (effective range) of the catalyst 7. The throttle way of only one of the two catalysts. It is advantageous valve 10, however, may also be arranged in the exhaust that the devices are formed by a connecting line con 35 gas line 3 downstream of the catalyst 6 where it is illus necting the exhaust gas pipes upstream of the catalysts trated in dash and dot lines.

and by a throttle valve arranged upstream or down If the cold internal combustion engine 1 is started, stream of one of the catalysts in one of the exhaust gas then the engine runs at first with a rich fuel mixture lines, which is actuated in dependence of an adjusting which has a high proportion of harmful components. motor controlled by a thermo-element. The throttle 40 Due to the still relatively low temperature of the inter valve closes the one exhaust gas line with a cold inter nal combustion engine and for the catalyst 7, the throt nal combustion engine and opens again the exhaust gas tle valve 10 is pivoted, controlled by the thermo-cle line after a predetermined time, for example, in depen ment 11 by means of the adjusting motor 9 into a posi dence on the temperature of the catalyst acted upon by 45 tion in which it closes the exhaust gas line 3 so that the all of the exhaust gases or of the internal combustion exhaust gases in the exhaust gas line 3 are conducted engine. also into the exhaust gas line 5 by way of the connect The advantages achieved with the present invention ing line 8. Due to the fact that the catalyst 7 is acted consist in particular in that an installation for the cata upon with the entire exhaust gas flow of the internal lytic afterburning of exhaust gases of an internal com combustion engine, the catalyst 7 is heated up very bustion engine is created in a simple manner, by means SO rapidly to a temperature at which it becomes fully ef of which the exhaust gases are purified within the short fective. The throttle valve 10 is pivoted into the illus est period of time after the starting of the internal com trated position in dependence on the temperature of bustion engine, already with a still relatively cold inter the internal combustion engine 1 or of the catalyst 7 nal combustion engine because, as a result of the attack after a predetermined time so that the exhaust gases of of only one catalyst with all of the exhaust gases of the 55 the exhaust gas line 3 then act upon the catalyst 6. By internal combustion engine, this catalyst reaches its reason of the very high exhaust gas temperatures which operating temperature very rapidly. If the second cata exist already at this moment and of the warmed-up lyst is interconnected, then the second catalyst reaches exhaust gas lines, the catalyst 6 is heated up in a very its operating temperature also within the shortest per short period of time to a temperature at which it is also iod of time by reason of the already very high exhaust 6) becomes fully effective. The non-purified exhaust gases gas temperature and of the already heated-up exhaust which are discharged during this relatively short warm gas pipes. Prior to the interconnection of the second up phase, additionally exhibit a lesser proportion of catalyst, the warm-up enrichment of the fuel mixture harmful components than the exhaust gases with a cold can be increasingly reduced by reason of the warming internal combustion engine since the warm-up enrich up internal combustion engine so that after the second 65 ment of the fuel mixture is reduced with increasing catalyst is connected in, the exhaust of harmful materi temperature of the internal combustion engine. als is very slight in the warm-up phase of the second While I have shown and described only one embodi Catalyst. ment in accordance with the present invention, it is

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understood that the same is not limited thereto but is adjusting motor controlled by a heat-responsive ele Susceptible of numerous changes and modifications as inct.

known to those skilled in the art, and therefore do not 4. An installation according to claim 3, characterized wish to be limited to the details shown and described in that the throttle valve means is arranged upstream of herein but intend to cover all such changes and modifi said other catalyst means. cations as are encompassed by the scope of the ap 5. An installation according to claim 3, characterized pended claims. in that the throttle valvc means is arranged downstream claim: of the other catalyst means.

1. An installation for the catalytic afterburning of () 6. An installation according to claim 2, characterized exhaust gases of a multi-cylinder internal combustion in that the throttle valvc means closes the one exhaust engine having two cylinder rows with two exhaust gas gas line with a cold internal combustion engine and lines, each of which includes at least one catalyst after a predetermined time again opens the same. means, coordinated to each cylinder row and commu 7. An installation according to claim 6, characterized nicating with each other only downstream of the cylin 5 in that the throttle valve means opens the exhaust gas der rows, characterized by tcmperature-responsive line in dependence on the temperature of the catalyst means operable during engine start-up to conduct sub stantially the entire cxhaust gas flow from the internal means

acted upon by all of the exhaust gases.

installation according to claim 6, characterized combustion engine during warmup for a predetermined in that the throttle valve means opens the exhaust gas time by way of only one of thc two catalyst means and 2) line in dependence on the temperature of the internal then after a short period of time to conduct the exhaust gas flow from each row of cylinders by way of its associ combustion engine.

9. An installation according to claim 6, characterized ated gas line and catalyst means. in that the temperature-responsive means includes an 2. An installation according to claim 1, characterized adjusting in that the communication between the exhaust gas ment. motor controlled by a heat-responsive ele lines is effected by a connecting line upstream of thc catalyst means, and said temperature-responsive means 10. An installation according to claim 9, character including a throttle valve arranged in one of the ex ized in that the throttle valve means is arranged up haust gas lines in the flow path of the other catalyst stream of said other catalyst means. means and means for actuating the throttle valve 1. An installation according to claim 9, character S. ized in that the throttle valve means is arranged down 3. An installation according to claim 2, characterized stream of the other catalyst

means.

in that the temperature-responsive means includes an