DE2034930A1 - Carburetors for internal combustion engines - Google Patents

Description

Dr. F. Zumstein son. - Dr. E. Assmann

Pr, R.Koei) ig! I'.i? R.; Ii · - Di '"\'. · Ν? .. η. I-biabauar

Or. F. r.:!.'.-a; “i:i JL.n.

Potentünwälla

8 Munich 2, Dräuhausstraße 4 / III

3331-70

SOGIETE -HTDUSTItIELIE DE BREVETS ET D ¹ ETUDES SIBE Carburettors for internal combustion engines.

The invention relates to the carburetor for

Internal combustion engines with means to limit pollution, the atmospheric air through the engine exhaust gases, and in particular, if not exclusively, such for Internal combustion engines for automobiles.

As is well known, the oxides of nitrogen are the

The main pollutants contained in the exhaust gases of internal combustion engines, and in order to reduce the nitrogen oxide content of the exhaust gases, it has already been proposed to recirculate some of them back into the fresh gases arriving in the engine's inlet pipe, this recirculation having the effect of reducing the combustion stone temperature in to lower the combustion chambers of the engine and thereby reduce the nitrogen oxide content of the A _U3 puff gases.

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This solution is effective, but has

the disadvantage of a certain reduction in the power of the engine, so that it would obviously be expedient to use this solution to be used only if the operating conditions of the engine result in a substantial formation of nitrogen oxides, «O that for all other operating conditions does not affect the performance of the engine or at least affects it less than under the first mentioned operating conditions »

Huη are the only operating conditions of the engine, for which a return of exhaust gases into the inlet line is essential, the operation with Partial load, while such a return is at low speed and is practically unnecessary at full load.

The invention is now a

Carburettor for internal combustion engines, which has a recirculation ■ of exhaust gases into the inlet pipe only at part load of the Motors reserved.

The carburetor according to the invention for internal combustion engines with a return line, which the exhaust line of the engine connects to the main inlet line of the carburetor containing a main throttle element, is characterized in that that it has a passage cross-section in the return line which is regulated by a closure member which, on the one hand, is under the action of return means that seek to bring it into its closed position, and on the other hand, there is a pneumatic device working with negative pressure, which opens the closure member can generate when the pressure prevailing in the working chamber of this pneumatic device falls below a certain value falls, whereby this working chamber · with -the main inlet ■ of the carburetor via at least one pressure extraction opening in connection which stands along the wall of this pipe near it of the main throttle element is attached in such a position that it is upstream of the main throttle element, when this is closed or slightly opened, while it is downstream of the throttle member from a "partial opening of the same on, which is the lower threshold of the Working the engine with part load corresponds to "" for which one

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Recirculation of exhaust gases is to be made.

With this carburetor you actually get the result you want.

If the main throttle element is closed or slightly opened (slow running of the engine), the pressure extraction opening or openings are located upstream from the throttle element and are exposed to atmospheric pressure, so that the closing element regulating the amount of exhaust gases returned is then closed, since its means of return are predominant over the pneumatic vacuum device.

When the throttle device has an opening degree

reached, for which one of the pressure extraction openings (if two such openings are present) downstream and the other is upstream of the throttle member, a transition state is reached in which the resulting negative pressure in the pneumatic negative pressure device The device is somewhat predominant over the return means of the closure member in the return line so that it then opens easily.

When the throttle body has its' opening stroke

continues and the pressure release port or ports immediately lying downwards from it (partial load of the engine), the resulting negative pressure is considerably greater, and the pneumatic negative pressure device generates a clear one opening of the closure member in the return line.

When finally the throttle organ

approaches the position of its largest opening (the engine is working at full load), the one prevailing in the inlet line becomes The negative pressure is considerably smaller, and the locking means of the locking link the return line will again be predominant and cause the closure of the same.

A calibrated device is preferably used between the pneumatic device and the pressure extraction openings Passage provided to prevent the possible transmission of pulsations to the pneumatic device or at least to weaken "

. Furthermore, the closure member can expediently regulate the amount of exhaust gases that are recirculated

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designed so that it also forms a scraper for the opening, the passage cross-section of which is controlled by it will.

The invention is hereinafter referred to explained by way of example on the drawing, the single illustration of which is a schematic axial section of an inventive Carburetor for internal combustion engines is.

The carburetor shown has a

Main inlet line 1, which is provided with a main throttle element 2 and with the exhaust line ^ 3 of the engine through a Return line 4 is connected.

In the return line 4 is a nozzle

5 is provided, the passage cross section 5a through a closure member 6 is regulated, which on the one hand under the action of a spring 7, which it in its closed position seeks to bring, and on the other hand is under the action of a pneumatic device 8 working with negative pressure, which causes the closure member 6 to open when the pressure in its working chamber 8a falls below a certain level Value falls.

The working chamber 8a of the pneumatic

Vacuum device 8 is available through a line 9 to the Main inlet pipe 1 communicates via two openings, e.g. 10a and 10b, which are along the V / and the pipe in the vicinity of the main throttle element 3 2 are arranged in such a position that they flow s upwards from the main throttle element 2 when this is closed (position shown in the drawing) or slightly open while it is downstream of the Throttle body from a partial opening to lie, which is the lower threshold value of working the engine with part load is equivalent to.

The pneumatic vacuum device

contains a membrane 11, which divides a chamber into two sections, which through one with the outside space through one Opening 13 communicating housing 12 and a seal Lid 14 is formed so that the working chamber 8a of the pneumatic Device 8 is limited by the membrane 11 and the cover 14 ″, to which the line 9 is connected.

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The membrane 11 is supported with her

middle zone on a rigid reinforcement part 15 from to which a rod 16 is attached, the lower end of which has the Closing member 6 forms.

This lower end has a frustoconical section 6a which forms a valve and can completely close the passage cross section 5a. This truncated cone part is stepped by smaller ones . Sections extended, which a free passage cross-section let exist if the closure member is raised a little. These stepped sections run into a sharp one Edge, which forms a scraper for the wall of the "passage cross-section 5a. ·

Finally, a calibrated nozzle 17 is expediently provided in the line 9, which allows to prevent or attenuate the transmission of any pulsations occurring in the main inlet line 1 »

The above carburetor with recirculation from Exhaust gases works exactly in the manner described above.

BADORiGINAL.

103845/0937 '

Claims (3)

- 6 - 3331-70 Claims ί 1 »K / carburettor for internal combustion engines with one the exhaust line of the Kotors with the one main throttle body containing main inlet line of the carburetor connecting return line, characterized in that the return line (4) one. Passage Lsquersclinitt (5a) has, v / which is regulated by a closure member (6)., which, on the one hand, is affected by return means (7), which seek to bring it into its closed position, and on the other hand, there is a pneumatic device (8) operating with negative pressure, which opens the closure member (6) causes when the pressure prevailing in its working chamber (8a) falls below a certain value, this working chamber (8a) in connection with the main inlet line (1) of the carburetor via at least one pressure extraction opening (10a, 10b) stands, which along the wall of the line at the level of the main throttle organ (2) Assume such positions that, this opening or openings (10a, 10b) upstream of. the main throttle organ (2) when closed or weakly open, lie downstream of the restrictor from a partial opening of the same, which is the lower threshold value de3 operating state of the engine with partial load corresponds to which exhaust gases are to be recirculated. 2.) Carburetor according to claim 1, characterized in that it is between the pneumatic device (8) and the pressure extraction openings assigned to it. (10a, 10b) a calibrated passage (17, which the possible transmission of pulsations to the pneumatic device prevents or at least weakens. . 3.) Carburetor according to claim 1 or 2, characterized in that the closure member (6) is designed is that it is also used as a scraper for the wall of the passage cross-section (5a) regulated by the closure member works. 109845/0997