US2743711A - Diesel compression ignition engines - Google Patents

Description

May I, 1956 v. R. GROSS DIESEL COMPRESSION IGNITION ENGINES Filed April 2, 1952 f I; M MM n WW t /w v a n i 6 United States Patent 2,743,711 DIESEL COMPRESSION IGNITION ENGINES Victor R. Gross, Stuttgart-Unterturkheim, Germany, as-

signor to Daimler-Benz Aktiengesellschaft, Stuttgart- Unterturkheim, Germany Application April 2, 1952, Serial No. 280,009

Claims priority, application Germany April 5, 1951 11 Claims. (Cl. 123 -32) This invention relates to a diesel compression ignition engine having a precombustion chamber, into which the fuel is injected and which is connected to the main combustion chamber by means of an overflow channel.

In diesel engines of this type there frequently occurs the phenomenon commonly referred to as knocking, which, especially while running slowly, will imply palpable inconveniences.

One principal object of the present invention is to eliminate such knocking with means as simple and. eflicient as possible.

According, one feature of this invention substantially consists in using, in the precombustion chamber, insertion members which extend at least beyond the middle axis of and across said precombustion chamber or across the way of the fuel jet and which are preferably constructed as pin-like members.

It has been proved that by these means the knocking phenomenon of the engine may be practically completely eliminated or may be reduced to a degree no longer felt inconvenient. The disposition of pins or bridges, which form the insertion members, thereby olfers the further advantage of particular simplicity, since such pins or bridges may be inserted in simple bores or openings of the precombustion chamber wall and may be provided subsequently in precombustion chambers already existing.

Furthermore, particularly in the case of small engines, a single pin will be sufiicient to give the required result. Also several pins or bridges may be provided, which are disposed in parallel or on difierent levels, preferably crossing one another so as to form a gratelike or trellis-like insertion assembly crossing the direction of the way of the fuel jet.

The accompanying drawings illustrate several embodiments of this invention,

Fig. 1 shows a longitudinal section through a precombustion chamber having such pins or bridges inserted,

Figs. 25 are cross sections illustrative of various ways of disposing the insertion members, Fig. 2 representing a section as taken along the line 22 of Fig. 1,

Fig. 6 is a longitudinal section through a precombustion chamber of dilferent construction, and

Fig. 7 is a cross section as along the line 7-7 of Fig. 6.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts and more particularly to Figures 1 and 2, reference numeral 10 designates the cylinder head which may be of the water-cooled type. A precombustion chamber 12 which is formed by a tube 11 is provided in the cylinder head 10. The precombustion chamber 12 consists of an enlarged part 12a adjacent to the injector nozzle and a channel-like chamber part 12b extending towards the main combustion chamber, which channel-like chamber part is connected to said chamber part 120 by means of a jet like passage. The fuel is injected through the enlarged part 12a in the direction of the channel-like part 12b, whereby such an injection pressure may be used as to make the fuel, such as in starting, suitably enter from across the precombustion chamber directlyinto the main combustion chamber.

Now accordingto this invention there are provided pin- like insertion members 14 or 15, suitably located on or adjacent to the place where said enlarged chamher part 12a passes over into said channel-like chamber part 12b, which insertion members are disposed across the longitudinal axis of the path of the fuel jet and are inserted in bores 16 and 17 of the precombustion chamber wall or tube 11. In the embodiment as illustrated by Figures 1 and 2 three upper pin-like insertion members 14 are disposed at intervals and in parallel above another pin-like insertion member 15 crossing the former. According to the dimensions and the use of the precombustion chamber a different number of insertion pins or bridges may be used. Thus instead of a total number of four pins or bridges more or less of them, eventually only one, may be used.

When using two pins, such as pins 14 and 15,'they may be disposed crosswise as shown in Fig. 3, or in parallel, as illustrated by Fig. 4, extending in the same transversal plane of the precombustion chamber.

In the construction as represented by Fig. 5 it is assumed that the pins or bridges are disposed in three superposed levels one above the other, the top level being formed by a transversal pin or member 14, the second level by two pins 18 disposed in parallel and at an angle relative to pin 14, the third level being formed by another pair of pins 19 disposed likewise at an angle to the pins of the two other ranges.

In the embodiments as illustrated by Figures 6 and 7 the pins 14, 15 and 14" are equally disposed in three superposed levels, the pins 14' and 14!" extending in parallel. Said pins are inserted in that case in cross bores of an insertion member 11 which lines the channel-like chamber part 121), while each of the pins 14' and 14" engage in recesses of pin 15.

Instead of a cylindrical shape the pins or bridges may be constructed with any other cross section, e. g. a square one. However the cylindrical construction of the insertion pins will, as a rule, present particular advantages as to the manufacture.

This invention is not restricted to the embodiments as illustrated, but is appropriate for all types of diesel (compression ignition) engines, being however especially important for such vehicle diesel engines as are working within a broad range of different numbers of revolutions as well as of output.

What I claim is:

1. A diesel internal combustion engine of the injection type comprising a main combustion chamber, a precombustion chamber having an enlarged and a reduced cross sectional portion, an injection nozzle opening into said enlarged cross sectional portion, and several pinlike insertion members extending across said precombustion chamber, said insertion members being located exclusively in a region intermediate said enlarged and reduced portions thereby leaving a free enlarged portion of said precombustion chamber having an axial length of at least about half the axial distance from said injection nozzle to said main combustion chamber.

2. A diesel engine according to claim 1, in which the insertion members are disposed side by side like a grate.

3. A diesel engine according to claim 1, in which the insertion members are disposed crosswise with respect to each other.

4. A diesel engine according to claim 1, in which the insertion members are disposed crosswise on different levels.

'5. A diesel-injection internal combustion engine cornprising a main combustion chamber, a prechamber connected with the main combustion chamber, a sleeve-like insert member at least partially forming the prechamber wall and providing a communicating passage between said prech'arnber and said main combustion chamber, transverse bores in the insert member within the region of transition from said prechamber into said communicating passage, cylindrical pin-shaped insertion members'incording to claim 5, wherein said insertion members are disposed crosswise on different levels.

8. A diesel-injection internal combustion engine ac cording to claim 5, wherein said insertion members are disposed crosswise and are in contact with each other.

9. A diesel internal combustion engine of the injection type comprising a main combustion chamber, a precombustion chamber having an enlarged and a reduced crosssectional portion, an injection nozzle opening into said enlarged cross-sectional portion, and at least one pinlilte insertion member extending across said precombustion chamber, said insertion members being located exclusively in a region intermediate said enlarged and reduced portions thereby leaving a free enlarged portion of said precombustion chamber having an axial length of at least about half the axial distance from said injection nozzle to said main combustion chamber.

10. A diesel internal combustion engine of the injection type comprising a main combustion chamber, a precombustion chamber having an enlarged and a reduced cross-sectional portion, an injection nozzle opening into said enlarged cross-sectional portion, and at least one pinlike insertion member extending across said precombustion chamber, said insertion member being located in a region intermediate said enlarged and reduced portions thereby leaving a free enlarged portion of said precombustion chamber having an axial length of at least about half of the axial distance from said injection nozzle to said main combustion chamber and providing for impingement of the injected fuel jet on said insertion member only after traversing said axial length.

11. A diesel-injection internal combustion engine according to claim 9, in which the pin-like insertion member is of cylindrical form, in combination with a sleevesha'ped insert member forming at least in part the wall of the prechamber and having a transversely-extending bore in which the pin-like insert member is inserted.

References Cited in the file of this patent UNITED STATES PATENTS 1,329,797 Raabe Feb. 3, 1920 FOREIGN PATENTS 384,496 Great Britain Dec. 8, 1932

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