EP1721072B1 - Cylinder sleeve for an internal combustion engine - Google Patents

Description

The invention relates to a bushing for an internal combustion engine according to the preamble of claim 1.

From the European patent EP 0 837 235 B1 is a bushing made of iron according to the preamble of the main claim is known, which is poured over its lower part in an engine block made of aluminum and in this area over the circumference of the bushing circumferential, in cross-section pliers-shaped engaging portions, the anchoring of the socket in the material of the engine block serve. This avoids that forms in a heating of the bushing and the engine block because of the different expansion coefficients of iron and aluminum, a gap between the bushing and the engine block, which leads to a deterioration of heat dissipation through the engine block, overheating of the liner and thus their damage can lead.

Here, however, only the temperature moderately little loaded, lower bushing area is poured into the engine block. The upper portion of the liner is loaded much higher in temperature, since the combustion takes place here, and since the liners are arranged very close to each other because of their laterally flattened areas. Therefore, this prior art area is surrounded by a gap into which water is introduced to cool this portion of the bushing. This results in a very complex construction, which also offers little strength to the upper portion of the bushing, to which the forces resulting from the ignition pressure of the combustion occurring here take place, and which is surrounded exclusively by a water jacket.

It is therefore an object of the invention to provide a laterally flattened liner, which can be arranged to save space, and which is designed so that they anyway can be completely poured into an engine block, without resulting during engine operation due to lack of heat dissipation temperature problems.

The problem is solved with the features in the characterizing part of the main claim. Advantageous embodiments of the invention are the subject of the dependent claims.

Here, the roughening on the outer surface of the Raugussbuchse provides a very large standing in contact with the material of the engine block outer surface over which the heat of combustion can be well dissipated. In addition, the plurality of elevations with undercuts results in a tight clamping between the bushing and engine block, which prevents the formation of a thermally insulating gap between the bush and engine block with different expansion coefficients due to different materials of bushing and engine block.

Fig. 1

ein aus 4 Raugussbuchsen bestehendes Buchsenpaket zur Verwendung in einem Vierzylindermotor,

Fig. 2

das Raugussbuchsenpaket gemäß Fig. 1 in Draufsicht,

Fig. 3, 4

vergrößerte Querschnitte durch Teile der Buchsenwand mit Ausgestaltungsmöglichkeiten deren Oberflächenrauheit,

Fig_. 5 - 7

Beispiele abgeflachter Raugussbuchsen mit variabler Buchsenwanddicke und konstanter Tiefe der Aufrauung,

Fig. 8

eine Anordnung von 4 Raugussbuchsen mit elliptischer Außenkontur gemäß Fig. 5 zur Verwendung in einem Vierzylindermotor,

Fig. 9 - 11

Ausgestaltungen abgeflachter Raugussbuchsen mit konstanter Buchsenwanddicke und variabler Tiefe der Aufrauung,

Fig. 12

eine Anordnung von 4 Raugussbuchsen mit elliptischer Außenkontur gemäß Fig. 9 zur Verwendung in einem Vierzylindermotor,

Fig. 13 - 15

Beispiele abgeflachter Raugussbuchsen mit variabler Buchsenwanddicke, konstanter Tiefe der Aufrauung und ohne Raugussstrukturen auf den Außenflächen derjenigen Buchsenbereiche, die bei den zu Buchsenpaketen zusammengefassten Raugussbuchsen einander gegenüberliegen und abgeflacht sind,

Fig. 16

zwei über ihre abgeflachten Bereiche zusammengefügte Raugussbuchsen,

Fig. 17

zwei mit Hilfe zweier Brücken zusammengefügte Raugussbuchsen,

Fig. 18

eine Ausgestaltung einer Brücke zum Zusammenfügen von Raugussbuchsen,

Fig. 19

eine weitere Ausgestaltung einer Brücke zum Zusammenfügen von Raugussbuchsen,

Fig. 20-24

Raugussbuchsen mit je einer Abflachung, die in ihrem unteren Bereich eine Stufe aufweist,

Fig. 25

zwei aneinandergefügte Raugussbuchsen mit einem Abstandshalter zwischen den Abflachungen und

Fig. 26

eine vergrößerte Darstellung des Abstandshalters gemäß Fig. 25.

Some embodiments of the invention will be described below with reference to the drawings. Show it

Fig. 1

a bushing package consisting of 4 bushings for use in a four-cylinder engine,

Fig. 2

the Raugussbuchsenpaket according to Fig. 1 in plan view,

Fig. 3, 4

enlarged cross-sections through parts of the bushing wall with possibilities of designing their surface roughness,

Fig _. 5 - 7

Examples of flattened Raugussbuchsen with variable socket wall thickness and constant depth of roughening,

Fig. 8

an arrangement of 4 Raugussbuchsen with elliptical outer contour according to Fig. 5 for use in a four-cylinder engine,

Fig. 9 - 11

Embodiments of flattened Raugussbuchsen with constant bushing wall thickness and variable depth of the roughening,

Fig. 12

an arrangement of 4 Raugussbuchsen with elliptical outer contour according to Fig. 9 for use in a four-cylinder engine,

Fig. 13 - 15

Examples of flattened Raugussbuchsen with variable bushing wall thickness, constant depth of roughening and without Raugussstrukturen on the outer surfaces of those bushing areas which face each other and are flattened in the Raugussbuchsen combined into bushing packages,

Fig. 16

two Raugussbuchsen assembled over their flattened areas,

Fig. 17

two Raugussbuchsen, assembled with the help of two bridges,

Fig. 18

an embodiment of a bridge for assembling Raugussbuchsen,

Fig. 19

Another embodiment of a bridge for joining Raugussbuchsen,

Fig. 20-24

Raugussbuchsen with one flattening, which has a step in its lower part,

Fig. 25

two joined Raugussbuchsen with a spacer between the flats and

Fig. 26

an enlarged view of the spacer according to Fig. 25 ,

Fig. 1 shows in perspective and Fig. 2 in top view, one of four Raugussbuchsen 1 to 4 existing bushing package 5. The 4 Raugussbuchsen 1 to 4 have roughened over their entire axial length outer surfaces. Here, the common wall areas 6 to 8 adjacent jacks 1 to 4, a web width x, which corresponds to the other wall thickness of the Raugussbuchsen 1 to 4.

The entire bushing package 5 is made in a single casting process from an aluminum-silicon alloy using the cast-on-casting or lost-foam casting process. Both casting methods are known from the prior art (see DE 199 58 185 A1 to the "lost-foam" casting method) and will not be explained here. In the manufacture of an engine block, the entire bushing package 5 is placed in the mold provided for this purpose and molded with casting material.

The in the 3 and 4 illustrated cross sections 9 and 10 through parts of the wall of the Raugussbuchsen show embodiments of the roughening, wherein the roughening according to section 9 irregularly distributed elevations 11 and the roughening according to cross section 10 regularly distributed elevations 12 has. In both cases, the elevations 10 and 11 are shaped so that they form undercuts 13 and 14, whose function is to anchor the Raugussbuchsen in the surrounding material of the engine block. The height of the elevations 11 and 12 and thus the depth y of the roughening have a value of 0.2 mm to 2 mm.

The in the FIGS. 5 to 15 flattened Raugussbuchsen shown in cross section may consist of cast iron and are then preferably prepared by centrifugal casting. But they can also consist of an aluminum-silicon alloy, which opens up the possibility to produce the Raugussbuchsen in the stand casting process, by centrifugal casting or in the "lost-foam" casting process. Ultimately, it is possible to produce the Raugussbuchsen of a sintered metal. In this case, the bushes can already get their final, one- or two-sided flattened shape as part of the casting process. But it is also possible to flatten the bushes after casting by mechanical processing (milling).

In the manufacture of an engine block made of light metal, such as aluminum, magnesium or an alloy with these metals, there is the opportunity to plug the sockets on quills of the casting tool, to align so that the flattened portions of the bushes face each other, and the Bushings then with the light metal of the engine block to encase. On the other hand, the bushes can be joined together via their flattened areas, that is to say they are welded, soldered or adhesively bonded to one another via their flattened lateral surfaces so that spectacle-shaped arrangements of the bushings result on average. The bushing packages thus obtained are then inserted into the casting tool and encapsulated with the light metal of the engine block.

• Fig. 5: Dargestellt ist eine Buchse 15 mit im Querschnitt elliptischer Außenform, variabler Dicke der Buchsenwand 19 und konstanter Tiefe der Aufrauung 20.
• 
  Fig. 6: Dargestellt ist eine Buchse 16 mit variabler Dicke der Buchsenwand 19', mit konstanter Tiefe der Aufrauung 20 und mit einer Außenform, die im Querschnitt aus vier näherungsweise gleich großen, kreisbogenförmigen Segmenten 21 bis 24 besteht, wobei die einander gegenüberliegenden Segmente 21 und 22 dickere Bereiche der Buchsenwand 19' und die einander gegenüberliegenden Segmente 23 und 24 dünnere Bereiche der Buchsenwand 19', d.h., deren abgeflachte Bereiche nach außen begrenzen.
  Fig. 7: Dargestellt ist eine Buchse 17 mit variabler Dicke der Buchsenwand 19", mit konstanter Tiefe der Aufrauung 20 und mit einer Außenform, die sich im Querschnitt aus zwei einander gegenüberliegenden kreisbogenförmigen Segmenten 25 und 26 und zwei einander gegenüberliegenden, ebenen Segmenten 27 und 28 zusammensetzt. Hierbei werden die einander gegenüberliegenden abgeflachten Bereiche der Buchse 17 von den Segmenten 27 und 28 nach außen begrenzt.
  Fig. 8 zeigt eine Möglichkeit, die Raugussbuchsen 15 mit elliptischer Außenkontur auf platzsparende Weise nebeneinander anzuordnen, sodass sich ein für einen Vierzylindermotor geeignetes Buchsenpaket 18 ergibt. Hierbei begrenzen die Nebenachsenbereiche der elliptischen Kontur die abgeflachten Bereiche der Buchsen 15, welche abgeflachten Bereiche bei der Anordnung der Buchsen 15 zu einem Buchsenpaket 18 auf Abstand einander gegenüberliegen.
  Fig. 9: Dargestellt ist eine Buchse 29 mit konstanter Dicke der Buchsenwand 32, mit variabler Tiefe der Aufrauung 33 und mit einer im Querschnitt elliptischen Außenkontur, die der Außenform der Buchse 15 gemäß Fig. 5 gleicht.
  Fig. 10: Dargestellt ist eine Buchse 30 mit konstanter Dicke der Buchsenwand 32, mit variabler Tiefe der Aufrauung 33' und mit einer im Querschnitt aus kreisbogenförmigen Segmenten bestehenden Außenkontur, die der Außenform der Buchse 16 gemäß Fig. 6 gleicht.
  Fig. 11: Dargestellt ist eine Buchse 31 mit konstanter Dicke der Buchsenwand 32, mit variabler Tiefe der Aufrauung 33" und mit einer im Querschnitt aus zwei kreisbogenförmigen Segmenten und zwei ebenen Segmenten, die jeweils einander gegenüberliegen, gebildeten Außenkontur, die der Außenform der in Fig. 7 dargestellten Buchse 17 gleicht. Hergestellt werden die in den Fig. 9 bis 11 dargestellten Raugussbuchsen 29 bis 31 im Schleudergussverfahren, wobei die Variation der Tiefe der Aufrauungen 33, 33' und 33" durch eine entsprechende Einstellung der Verfahrensparameter erreichbar ist.
• Fig. 12 zeigt eine Anordnung von 4 der in Fig. 9 gezeigten Raugussbuchsen 29 zu einem Buchsenpaket 34 ähnlich dem in Fig. 8 dargestellten Buchsenpaket 18 zur Verwendung in einem Vierzylindermotor. Die Raugussbuchsen der gezeigten Art können hierbei auf einen Abstand z von 0,5 mm bis 0,05 mm nebeneinander angeordnet werden.
• Fig. 13: Dargestellt ist eine Buchse 35 mit variabler Buchsenwanddicke, konstanter Tiefe der Aufrauung und einer elliptischen Außenkontur, die der Außenkontur der in Fig. 5 dargestellten Buchse 15 gleicht. Die einander gegenüberliegenden, abgeflachten Buchsenbereiche 38 und 39 weisen hierbei keine Raugussstrukturen auf.
• Fig. 14: Dargestellt ist eine Buchse 36 mit variabler Buchsenwanddicke, konstanter Tiefe der Aufrauung und einer im Querschnitt aus mehreren kreisbogenförmigen Segmenten bestehenden Außenkontur, die der Außenform der in Fig. 6 dargestellten Buchse 16 gleicht. Die einander gegenüberliegenden, abgeflachten Buchsenbereiche 40 und 41 weisen keine Raugussstrukturen auf.
• Fig. 15: Dargestellt ist eine Buchse 37 mit variabler Buchsenwanddicke, konstanter Tiefe der Aufrauung und einer Außenkontur, die im Querschnitt aus zwei kreisbogenförmigen und zwei ebenen Segmenten besteht, und die der Außenform der in Fig. 7 dargestellten Buchse 17 gleicht. Hierbei kann, wenn die Buchse das erste oder das letzte Element eines in einer Reihe angeordneten Buchsenpaketes ist, ein ebenes Segment 43 der Außenkontur mit einer Raugussstruktur versehen sein und das dem gegenüberliegende Segment 42 ohne Raugussstruktur ausgebildet sein. Hierbei können diejenigen Segmente 38 bis 42 der Außenkonturen der Raugussbuchsen 35 bis 37, die keine Raugussstrukturen aufweisen, bereits im Rahmen der Gießvorganges hergestellt werden. Möglich ist aber auch, die gesamte Mantelfläche der Buchse mit einer Raugussstruktur zu versehen und im Anschluss daran die Raugussstrukturen der abzuflachenden Buchsenbereiche wegzufräsen.

The following in the FIGS. 5 to 7 . 9 to 11 and 13 to 15 illustrated design possibilities of Raugussbuchsen are conceivable:

• Fig. 5 A bush 15 with an elliptical outer shape, variable thickness of the bushing wall 19 and a constant depth of the roughening 20 is shown.
• 
  Fig. 6 FIG. 4 illustrates a variable thickness bushing 16 of the bushing wall 19 ', having a constant depth of roughening 20 and having an outer shape that is four cross-sectionally approximately circular arcuate segments 21 to 24, with the opposed segments 21 and 22 being thicker Portions of the bushing wall 19 'and the opposing segments 23 and 24 thinner portions of the bushing wall 19', ie, limit their flattened areas to the outside.
  Fig. 7 FIG. 4 illustrates a variable thickness bushing 17 of bushing wall 19 ", with a constant depth of roughening 20 and an outer shape which is composed in cross section of two opposing circular arcuate segments 25 and 26 and two opposite planar segments 27 and 28. Here, the opposing flattened portions of the bushing 17 are bounded by the segments 27 and 28 to the outside.
  Fig. 8 shows a way to arrange the Raugussbuchsen 15 elliptical outer contour in a space-saving manner next to each other, so that there is a suitable for a four-cylinder engine bushing package 18. In this case, the minor axis regions of the elliptical contour limit the flattened regions of the bushings 15, which flattened regions lie opposite each other in the arrangement of the bushes 15 to form a bushing package 18.
  Fig. 9 FIG. 2 shows a bushing 29 of constant thickness of the bushing wall 32, with variable depth of the roughening 33 and with an elliptical outer contour in the cross-section corresponding to the outer shape of the bush 15 according to FIG Fig. 5 like.
  Fig. 10 FIG. 1 shows a bushing 30 with a constant thickness of the bushing wall 32, with a variable depth of the roughening 33 'and with an outer contour consisting of circular-arc-shaped segments in cross-section corresponding to the outer shape of the bushing 16 Fig. 6 like.
  Fig. 11 FIG. 1 shows a bushing 31 of constant thickness, the bushing wall 32, with variable depth of the roughening 33 "and with an outer contour formed in cross-section from two arcuate segments and two planar segments, which face each other, corresponding to the outer shape of the in Fig. 7 illustrated socket 17 is similar. The are made in the Fig. 9 to 11 shown Raugussbuchsen 29 to 31 by centrifugal casting, the variation of the depth of the roughening 33, 33 'and 33 "can be achieved by a corresponding adjustment of the process parameters.
• Fig. 12 FIG. 4 shows an arrangement of FIG. 4 of FIG Fig. 9 shown Raugussbuchsen 29 to a socket package 34 similar to the in Fig. 8 shown bushing package 18 for use in a four-cylinder engine. The Raugussbuchsen the type shown here can be arranged side by side to a distance z of 0.5 mm to 0.05 mm.
• Fig. 13 : Shown is a bushing 35 with variable bushing wall thickness, constant depth of roughening and an elliptical outer contour corresponding to the outer contour of the in Fig. 5 illustrated socket 15 is similar. The mutually opposite, flattened bushing areas 38 and 39 in this case have no Raugussstrukturen.
• Fig. 14 FIG. 3 shows a bushing 36 with variable bushing wall thickness, constant depth of the roughening and an outer contour consisting of a plurality of arcuate segments in cross-section, corresponding to the outer shape of the in Fig. 6 represented socket 16 is similar. The opposing, flattened sleeve portions 40 and 41 have no Raugussstrukturen.
• Fig. 15 FIG. 3 shows a bushing 37 with variable bushing wall thickness, constant depth of roughening and an outer contour, which in cross section consists of two arcuate and two planar segments, and which corresponds to the outer shape of the in Fig. 7 illustrated socket 17 is similar. Here, if the bushing is the first or the last element of a bushing package arranged in a row, a flat segment 43 of the outer contour may be provided with a Raugussstruktur and the opposite segment 42 may be formed without Raugussstruktur. In this case, those segments 38 to 42 of the outer contours of the Raugussbuchsen 35 to 37, which have no Raugussstrukturen, already be prepared in the context of the casting process. But it is also possible to provide the entire lateral surface of the sleeve with a Raugussstruktur and subsequently milled away the Raugussstrukturen the flattened bushing areas.

The in the Fig. 7 . 11 and 15 Sockets 17, 31 and 37, whose outer contours have the flat segments 27, 28, 42 and 43, can be joined together by gluing, soldering or welding over these segments, resulting in spectacle-like bushing structures in cross-section. This has the advantage that in the manufacture of engine blocks several bushings can be placed simultaneously in the casting machine, whereby the production of the engine blocks is accelerated and cheapened. According to Fig. 16 In this case, each an adhesive or solder layer 44 is applied to the opposite, flattened portions of the jacks before the jacks are combined.

Another way to connect jacks together before pouring into an engine block is in Fig. 17 shown. Used here are bridges 45 and 46 which are glued or soldered to adjacent areas of the end faces 47 and 48 and 49 and 50 of the sockets 51 and 52 and connect the jacks 51 and 52 thereby.

According to Fig. 18 For example, the bridges 45, 46 may be in the shape of round discs. According to Fig. 19 can be given to the bridges 45 ', 46' but also the shape of rectangular slices. The bridges are made of light metal or a light metal alloy.

When sockets are mounted on sleeves before casting, the gap between the sockets can not be arbitrarily narrow so that the light metal of the engine block flows through the gap between the sockets, fills the space between the sockets, and after cooling, makes a firm connection between the sockets creates. If bushings are flattened on opposite jacket areas, it is necessary for this purpose to ensure that the bushings always assume a clearly defined rotational position when mounted on the sleeves, so that the gap between the flattened areas of the bushings retains its maximum width and not is reduced by partially twisted sockets or completely closed. This is achieved by the fact that the opposing flattenings of the bushing lateral surfaces in their lower, the crankshaft facing areas 53, 53 ', which in the Fig. 20 . 23 and 24 in side view and in the FIGS. 21 and 22 are shown in plan view. The steps 53, 53 'likewise have flattened regions 54, 54' ( Fig. 20 . 23, 24 ), which must be aligned parallel to each other when pushing the bushings on quills, so that the sockets fit on the sleeves, and thus ensure that the jacks always take a clearly defined rotational position to each other. In addition, the bushes can be joined to one another via the flattened regions 54, 54 'of the steps 53, 53', ie, glued together, or soldered.

Ideally, the width of the gap 55 is 1 mm to 3.5 mm for a Raugussbuchse with a wall thickness 56 of 2.5 mm and a depth 57 of the roughening of 1.5 mm. The web width 60 is 5.5 mm for bushes with a cylinder diameter 58 of 82 mm. Achievable here is a cylinder spacing 59 of 87.5 mm.

In Fig. 23 is in side view and in Fig. 24 to see well in plan view formed in the sleeve outer surface flattening 61, which has no roughening in contrast to the other sleeve outer surface.

Another solution to the problem of keeping the flats of the Raugussbuchsen at a distance, and to ensure that the sockets are arranged in a clearly defined rotational position to each other, is according to FIGS. 25 and 26 in a spacer 62 arranged between the flattened regions 63 and 64. This has the further advantage that space is available for the cooling bores to be introduced into the engine block between the flattened regions 63 and 64 of the bushings held at a distance from one another.

According to an embodiment of the Raugussbuchsen not shown in the figures, opposing areas of the outer surfaces of juxtaposed bushings may be concave.

LIST OF REFERENCE NUMBERS

x

web width

y

Depth of roughening

z

Distance between two Raugussbuchsen

1 to 4

rough-cast sleeve

5

sleeve package

6 to 8

wall area

9, 10

cross-section

11, 12

survey

13.14

undercut

15 to 17

Bushing, bushing

18

sleeve package

19, 19 ', 19 "

wall socket

20

roughening

21 to 24

Segment of the outer shape of the socket 16

25 to 28

Segment of the outer shape of the bush 17

29 to 31

Bushing, bushing

32

wall socket

33, 33 ', 33 "

roughening

34

sleeve package

35 to 37

Bushing, bushing

38, 39

flattened portion of the bush 35

40, 41

flattened portion of the bush 36

42, 43

Segment of the outer contour of the bush 37

44

Adhesive or solder layer

45, 45 ', 46, 46'

bridge

47 to 50

front

51, 52

Bushing, bushing

53, 53 '

step

54, 54 '

flattened area of level 53

55

gap width

56

wall thickness

57

Depth of roughening

58

Cylinder diameter

60

web width

61

flattening

62

spacer

63, 64

flattened area

Claims (9)

1. Cylinder sleeve (29) for an internal combustion engine, the outer surface of which comprises at least one flat region (54, 54', 61) that extends along the entire axial length thereof, and comprises, at least in the lower region thereof facing the crankcase, at least one engaging section having at least one projection comprising an undercut,
   characterised in that
   the cylinder sleeve is embodied as a rough cast sleeve whose outer surface comprises a rough zone (33) that extends along the entire axial length thereof and consists of a plurality of elevations (11, 12) with undercuts (13, 14),
   the cylinder sleeve comprises an outer contour that is elliptical in cross-section, and
   the outer shape of the cylinder sleeve is formed at constant wall thickness (32) by a depth of the rough zone (33) varying over the circumference.
2. Cylinder sleeve according to claim 1, characterised in that the height of the elevations (11, 12) is 0.2 mm to 2 mm.
3. Cylinder sleeve according to one of the preceding claims, characterised in that the at least one flat region is provided on the underside thereof facing the crankcase, with a step (53) having a radially outer flat region (54).
4. Cylinder sleeve according to one of the preceding claims, characterised in that said cylinder sleeve consists of cast-iron and is produced by the centrifugal casting method.
5. Cylinder sleeve according to claim 1 to 4, characterised in that said cylinder sleeve consists of an aluminium-silicon alloy.
6. Cylinder sleeve according to claim 5, characterised in that the cylinder sleeve is produced by the static casting method.
7. Cylinder sleeve according to claim 5, characterised in that the cylinder sleeve is produced by the centrifugal casting method.
8. Cylinder sleeve according to claim 5, characterised in that the cylinder sleeve is produced by the lost-foam casting method.
9. Cylinder sleeve according to claim 1 to 3, characterised in that the cylinder sleeve consists of sintered metal.

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