US3461850A

US3461850A - Installation for reducing the noxious exhaust gas emission of internal combustion engines

Info

Publication number: US3461850A
Application number: US664011A
Authority: US
Inventors: Kurt Oblander
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1966-09-02
Filing date: 1967-08-29
Publication date: 1969-08-19
Anticipated expiration: 1986-08-19
Also published as: GB1154813A; DE1576519A1; DE1526519A1

Description

3,461,850 2T GAS EMISSION Aug- 9, 1969 K. OBLANDER INSTALLATION FOR REDUGINGI THE NQXIOUS EXHAU OF INTERNAL COMBUSTION ENGINE Filed Aug. 29, 1967 INVENTOR KURT QBLAENDER BY MfQPW' .NFTORNEYS:

United States Patent Office 3,461,850 Patented Aug. 19, 1969 s Int. Cl. F02m 3%1/00, 39/00 US. Cl. 123-422 15 Claims ABSTRACT OF THE DISCLOSURE An installation for reducing the emission of harmful exhaust gases in internal combustion engines in which the idling air line which supplies combustion air to the cylinders in the idling speed range, by-passing the throttle valve controlled by the gas pedal, extends in direct proximity to the exhaust gas line so as to provide a preheating of the idling air by the exhaust gases. The exhaust gas line and the idling air line may be advantageously combined into a unitary structure in such a manner that additionally a zone is formed opposite the injection nozzles within each individual suction pipe connection which is heated by the exhaust gas line for improving the fuel preparation.

Background of the invention The present invention relates to an installation for the reduction of the harmful exhaust gas emission of internal combustion engines installed primarily in motor vehicles, especially of motor vehicle internal combustion engines within the idling speed range, whereby the combustion air is controlled during normal operation by a throttle valve, and the idling air is supplied to the internal combustion engine in by-passing relationship to this throttle valve.

An installation of the aforementioned type has already been proposed heretofore in the prior art, in which the suction air is conducted through individual suction pipes. free of any throttle valves, between the cylinders and a common intake manifold controlled during normal operation in dependence on a throttle valve. However, a completely different problem underlies this prior art proposal. More particularly, this prior art proposal Was concerned with preventing in the idling speed the harmful influence of air oscillations in the individual suction pipes. In contradistinction thereto, the present invention is concerned with a completely different problem. In order to achieve in the idling speed as small as possible a CO emission in the exhaust gases, it is desirable to adjust the idling speed mixture as lean as possible. However, a limit is imposed to the extent of such lean adjustment by the rotational operation of the engine. This limit can be further displaced in the direction toward a more lean mixture adjustment by a better mixture preparation.

Summary of the invention Such an improved preparation can be achieved according to the present invention with the installations of the type described hereinabove in that the idling air channel extends in direct proximity to the exhaust gas line for the purpose of ehating the idling air. This can be realized by a simple location or displacement of the lines in corresponding mutual proximity. However, the present invention prefers a solution according to which the idling air channel is combined with the exhaust gas line into a unitary casting. It would then be possible that the exhaust gas line surrounds the idling air channel in a casinglike manner. A further construction of the present invention proposes that the pipe-shaped exhaust gas line accommodates in its walls the idling air channel as a further pipe, of course, of considerably smaller diameter.

A fuel preparation is achieved by the arrangement according to the present invention which is superior to the usual atomization of the fuel. This preparation is particularly advantageous since it extends only over the idling speed range and consequently does not influence unfavorably the efficiency and therewith the output in the partial or full load range. This effect can be further improved with internal combustion engines having fuel injection into the suction pipe if, according to a further feature of the present invention, the exhaust gas line serves additionally for the purpose of preheating a limited zone of each suction pipe connection which is disposed opposite the fuel injection nozzle. The fuel jet may then be injected into this limited zone possible at an inclined angle so that the fuel evaporates at least partly. As a result thereof, a still furtheer adjustment in the lean direction is also possible in the patrial load range without significantly reducing the peak output.

As already mentioned hereinabove, internal combustion engines exist for other reasons, whose suction pipe connections lead either individually or in groups from a common intake manifold or pipe to the cylinders. The present invention proposes for this type of internal combustion engines that the exhaust gas line extends directly adjacent the cylinder heads below the suction pipe connections and that the idling air channel extends on the lower side of the exhaust gas line over the entire length of the cylinder block adjacent the same or is combined therewith. This arrangement can be so constructed according to still a further feature of the present invention that the idling air channel is connected at one end to the clean air side of the air filter and after the passage through the exhaust gas line extends approximately parallel to itself along the suction pipe connections and is provided thereat with corresponding aperture for the overflow or passage of the idling air into the suction pipe connections. The configuration and designe of this overflow structure may be made in any manner known to a person skilled in the art. However, it will be particularly appropriate if also for that purpose all channels and lines are combined as unitary casting so that the overflow apertures are constituted by bores in the walls between the idling air channel and the suction pipe connections.

An effective decrease of the harmful exhaust gas emissions can be achieved by the present invention in the hot running and idling speed range. Additionally, the arrangement according to the present invention is very simple from a constructive point of view. The adjustment of the idling air can take place in any desired, known manner.

However, a solution is preferred according to the present invention pursuant to which and adjusting screw is arranged in the idling air channel upstream of the section containing apertures leading to the suction pipe connections.

Accordingly, it is an object of the present invention to provide an installation of the type described above which effectively eliminates the emission of harmful exhaust gases in internal combustion engines by extremely simple means.

Another object of the present invention resides in an installation for the reduction of the noxious exhaust gas emissions of internal combustion engines which permits an improved performance, not only by a more lean adjustment of the fuel mixture but additionally by a better fuel preparation.

A further object of the present invention resides in an installation for the reduction of harmful exhaust gas emissions which is superior as regards the fuel preparation than the customary atomization of the fuel.

A still further object of the present invention resides in the provision of an installation for the reduction of the emission of harmful exhaust gases which is so constructed and arranged as to avoid any unfavorable influence with respect to the output in either the partial or full load range.

Still a further object of the present invention resides in an installation for the reduction of the emission of harmful exhaust gases which makes it possible to adjust the fuel mixture still more lean in the partial load range without significantly reducing the peak performance of the engine.

Another object of the present invention resides in an installation of the type described above which is simple in construction, facilitates assembly and disassembly and easy to adjust for proper operation.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention and wherein:

FIGURE 1 is a schematic view of one installation in accordance with the present invention;

FIGURE 2 is a partial cross-sectional view through one embodiment according to the present invention, on an enlarged scale, and showing certain details of the installation of the present invention; and

FIGURE 3 is a plan view on the detail of FIGURE 2.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIGURE 1, reference numeral designates therein a conventional injection-type internal combustion engine to which the combustion air is supplied through individual suction pipe connections 11, combined in a pair-wise manner and leading to a common suction air intake manifold 12. The inlet into this air inlet manifold 12 is controlled by a throttle valve 13 which can be actuated in a conventional manner from the gas pedal 14 simultaneously with the injection pump 15. An air filter 16 is arranged upstream of the throttle valve 13 in a conventional manner. The injection nozzles 17 are supplied with fuel by means of the injection pump which are arranged in the suction pipe connections 11. The exhaust gases enter from the cylinders into the exhaust gas line 18 which leads to the exhaust muffler, etc., of conventional construction (not shown).

An idling air channel 19 branches off from the clean air side of the air filter 16 which extends over the entire length of the cylinder block in direct proximity to the itself in a further section 1912. Apertures are provided in this section 1912 to be described more fully hereinafter with reference to FIGURE 2through which the idling air can pass over into the suction pipe connections 11. A regulating screw 20 is provided upstream of the pipe section 19b by means of which the idling air can be adjusted. Upstream thereof a channel 21 branches off which is intended for the air under hot running operation.

According to FIGURES 2 and 3, the exhaust gas line 18 extends directly adjacent the cylinder heads (not shown in detail) underneath the suction pipe connections 11. Both are combined into a unitary casting so that by a limited zone 23 of the suction pipe connection is heated by the separating wall 22. This zone 23 is disposed opposite the injection nozzle 24 which injects the fuel jet obliquely against this wall 22 within the zone 23. The idling air channel 19 is cast into the wall of the exhaust gas line 18 so that a good preheating is also achieved thereat. The counter-section 19b of the idling air channel is cast into the walls of the suction pipe connections 11 so that, therefore, all the parts are combined into a unitary casting. Exclusively, the reversing section 19a and/or the connecting or end pieces may be inserted as separate pipe pieces. Apertures 26 are provided in the wall 25 between the counter-section 19b and the suction pipe connections 11 through which the idling air passes over into the suction pipe connections 11.

I claim:

1. An installation for reducing harmful exhaust gas emission from fuel-injection type internal combustion engines having fuel-injection nozzle means and exhaust gas line means, particularly for reducing such harmful emission in the idling speed range of motor vehicle engines of this type, in which the combustion air is controlled, during normal operation, by means of a throttle valve, and the idling air is supplied to the internal combustion engine in by-passing relationship to said throttle valve, wherein the improvement comprises preheating means for the idling air including idling air channel means extending in direct proximity to said exhaust gas line means of the engine.

2. An installation according to claim 1, wherein the idling air channel means is combined with the exhaust gas line means in a common structural unit.

3. An installation according to claim 2, wherein said common structural unit is a unitary casting.

4. An installation according to claim 3, wherein suction pipe connecting means leading to the engine cylinder are provided, and wherein said exhaust gas line means additionally serves for the preheating of a predetermined zone of the suction pipe connecting means, said zone being disposed substantially opposite the fuel injection nozzle means.

5. An installation for reducing the harmful exhaust gas emission in internal combustion engines having exhaust gas line means, especially in the idling speed range of motor-vehicle internal combustion engines, in which the combustion air is controlled during normal operation by a throttle valve, and the idling air is supplied to the internal combustion engine in by-passing relationship to this throttle valve, wherein the improvement comprises preheating means for the idling air including idling air channel means extending in direct proximity to the exhaust gas line means of the engine, said idling air channel means being combined with said exhaust gas line means in a unitary casting, further including suction pipe connecting means leading to the engine cylinder and fuel injection nozzle means extending into said suction pipe connecting means, said exhaust gas line means additionally serving for the preheating of a predetermined zone of said suction pipe connecting means, which zone is disposed substantially opposite said fuel injection nozzle, wherein the internal combustion engine includes a common intake manifold, said suction pipe connecting means connecting said intake manifold with the engin cylinders, said exhaust gas line means extending directly adjacent the cylinder head underneath the suction pipe connecting means, and the idling air channel means extending along the lower side of the exhaust gas line means over the entire length of the cylinder block.

6. An installation according to claim 5, wherein the idling air channel means is operatively connected at one end to the clean air side of an air filter means and after passing through the exhaust gas line means, is provided with a reversing section and a counter section extending back upon itself substantially parallel to itself along the suction pipe connecting means, said counter section being provided with aperture means for the passage of the idling air into the suction pipe connecting means.

7. An installation according to claim 6, further comprising adjusting means arranged in the idling air channel means upstream of said counter section.

8. An installation according to claim 1, wherein suction pipe connecting means leading to the engine cylinder are provided, and wherein said exhaust gas line means additionally serves for the preheating of a predetermined zone of the suction pipe connecting means, said zone being disposed substantially opposite said fuel injection nozzle means.

9. An installation according to claim 8, wherein the internal combustion engine includes a common intake manifold, suction pipe connecting means connecting said intake manifold with the engine cylinders, said exhaust gas line means extending directly adjacent the cylinder heads underneath the suction pipe connecting means, and the idling air channel means extending along the lower side of the exhaust gas line means over the entire length of the cylinder block.

10. An installation according to claim 1, wherein the idling air channel means is operatively connected at one end to the clean air side of an air filter means and after passing through the exhaust gas line means, is provided with a reversing section and a counter section extending back upon itself substantially parallel to itself along the suction pipe connecting means, said counter section being provided with aperture means for the passage of the idling air into the suction pipe connecting means.

11. An installation according to claim 10, further comprising adjusting means arranged in the idling air channel means upstream of said counter section.

12. An installation for reducing the harmful exhaust gas emission in internal combustion engines having exhaust gas line means, especially in the idling speed range of motor-vehicle internal combustion engines, in which the combustion air is controlled during normal operation by a throttle valve, and the idling air is supplied to the internal combustion engine in by-passing relationship to this throttle valve, wherein the improvement comprises preheating means for the idling air including idling air channel means extending in direct proximity to the exhaust gas line means of the engine, wherein the internal combustion engine includes a common intake manifold, suction pipe connecting means connecting said intake manifold with the engine cylinders, said exhaust gas line means extending directly adjacent the cylinder heads underneath the suction pipe connecting means, and the idling air channel means extending along the lower side of the exhaust gas line means over the entire length of the cylinder block.

13. An installation according to claim 12, wherein the idling air channel means is operatively connected at one end to the clean air side of an air filter means and after passing through the exhaust gas line means, is provided with a reversing section and counter section extending back upon itself substantially parallel to itself along the suction pipe connecting means, said counter section being provided with aperture means for the passage of the idling air into the suction pipe connecting means.

14. An installation according to claim 13, further comprising adjusting means arranged in the idling air channel means upstream of said counter section.

15. An installation according to claim 10, wherein the idling air channel means including its counter section is combined with the exhaust gas line means in a common structural unit.

References Cited UNITED STATES PATENTS 2,102,476 12/1937 Mennesson.

2,252,972 8/ 1941 Grevas.

3,145,699 8/1964 High 123-133 3,211,139 10/1965 Weber 123119 AL LAWRENCE SMITH, Primary Examiner US. Cl. X.R,