DE102007023227B4 - Crankcase for a liquid-cooled internal combustion engine - Google Patents

Abstract

Crankcase (1) for a liquid-cooled internal combustion engine having at least two cylinders (2, 2 ') whose cylinder axes are arranged parallel to each other, wherein between the cylinders (2, 2') a common web (3) is formed and with a coolant channel (4 7) extending at least in sections on at least one side of the cylinders (2, 2 ') substantially transversely to the cylinder axes around the cylinders (2, 2'), wherein the coolant channel (4, 7) in the region of the web (3 ) is formed as a gusset region (5, 5 '), characterized in that in the gusset region (5, 5') a freestanding strut (6, 6 ') extending substantially in the direction of the cylinder axes is arranged, the foot side with the Crankcase (1) is connected.

Description

The invention relates to a crankcase for a liquid-cooled internal combustion engine with the features of the preamble of patent claim 1.

It starts from the German publication DE 102 55 316 A1 in which a crankcase for a liquid-cooled internal combustion engine is described. The internal combustion engine has at least one cylinder bank with cylinders arranged in series, between each of which a web is formed. On each side of the cylinder in each case a coolant channel is formed, wherein the coolant channel in the web region forms a gusset region. On the side opposite the land area of the coolant jacket, a screw pipe for screwing a cylinder head is provided in the crankcase. In order to minimize distortion of the cylinder tube and / or the web during operation of the internal combustion engine and to improve the cooling of the cylinder tube, the cylinder tube has on its outer wall in the coolant jacket in the direction of the cylinder axes aligned stiffening ribs.

With an increase in the specific power of the internal combustion engine can still occur in connection with the cylinder head with the crankcase distortion of the cylinder tube, especially in the gusset region of the coolant channel.

Object of the present invention is to show a measure that reduces distortion of the cylinder tube, and the crankcase in the gusset area and its adjacent areas.

This object is achieved by the feature in the characterizing part of patent claim 1.

In addition, further power and ignition pressure increases, for example, to reduce fuel consumption and emissions, especially in turbocharged diesel engines with approximately unchanged dimensions of the crankcase possible. In addition, package, weight and cost advantages are advantageously associated with this. Furthermore, high financial one-time expenses for a redesign of the crankcase by conformity to existing production facilities are avoided.

According to claim 2, the strut may be integrally formed of the same material and with the crankcase. Advantageously, the strut during casting of the crankcase is simply cast with. This is particularly advantageous in the case of cylinder crankcases in "closed-deck design".

According to claim 3, the strut can also be designed as a separate component which can be inserted into the coolant channel. This has the advantage that even high-strength materials, such as gray cast iron can be used as a strut in the gusset area. This is particularly advantageous in light-metal cylinder crankcases in "open-deck design" advantage.

The embodiments of the strut cross section according to claim 4 are particularly preferred, streamlined design variants.

With the embodiment according to claim 5, a cooling of the thermally highly loaded web can be provided in a simple manner with the inventive design.

Due to the inventive design, it is possible according to claim 6, to place the hole for a cylinder head screw in the crankcase next possible on the coolant jacket, whereby the space can be minimized.

In the following the invention with reference to a particularly preferred embodiment in two figures is explained in more detail.

1 shows a vertical section through a web of an inventively designed crankcase.

2 shows a horizontal section through an inventively designed crankcase.

1 shows a vertical section through a web 3 a inventively designed crankcase 1 , The position of the vertical section in 1 is in 2 shown as section line II. 2 shows a horizontal section through the crankcase 1 , The position of the horizontal section in 2 is in 1 shown as section line II-II. For both figures, the same reference numbers apply to the same elements. The following description refers simultaneously to the 1 and 2 ,

The jetty 3 that of crankcase material between two parallel cylinders 2 . 2 ' is formed, on the one hand has a coolant channel 4 and on the other hand, a second coolant channel 7 on. The coolant channels 4 . 7 extend largely perpendicular to not shown cylinder axes of the cylinder 2 . 2 ' , In the area of the jetty 3 The coolant channels each form a gusset region 5 . 5 ' , recognizable in 2 , In this gusset area 5 . 5 ' is in each case a largely vertical, that is, a strut according to the invention extending substantially in the direction of the cylinder axes 6 . 6 ' arranged. The coolant channels 4 . 7 are cylinder-side of cylinder walls and on the cylinder 2 . 2 ' limited side facing away from crankcase walls. The cylinder walls and the crankcase walls can be made in one or more parts. Adjacent to the gusset area 5 . 5 ' There is a hole in each of the crankcase walls 8th . 8th' , In the present embodiment, a threaded bore, for the screw connection of a cylinder head, not shown, with the crankcase.

In the present embodiment, the inventively designed crankcase 1 a so-called "closed deck" crankcase, ie the coolant channels 4 . 7 are largely closed in the direction of the cylinder head, not shown, except for small, not shown openings. Because of this, the struts are 6 . 6 ' preferably in one piece and of the same material with the crankcase 1 cast. For reasons of weight, an aluminum alloy is preferably used. For bleeding the further coolant channel 7 , This has a vent hole 9 in the direction of the cylinder head.

In a further, not shown embodiment, the invention can also be used in an "open deck" crankcase. In this case, the coolant channel 4 . 7 open towards the cylinder head. The completion of the coolant channel 4 . 7 takes place to the cylinder head by means of a cylinder head gasket, not shown. Preferably, the strut 6 . 6 ' then as a separate, in the coolant channel 4 . 7 usable component executed. In this case, the strut 6 . 6 ' also be made of a different material than the crankcase, preferably a high-strength material such as gray cast iron.

In the present embodiment, the strut 6 . 6 ' spaced substantially equidistant from the cylinder walls, but may also have an elliptical or round cross-section in other embodiments. These are particularly streamlined shapes.

In a further, not shown embodiment, the coolant channels 4 . 7 also through a hole in the bridge 3 be fluidly connected to each other to realize a particularly good web cooling.

Due to the very rigid embodiment of the invention, it is possible to spatially very close to the gusset area 5 . 5 ' in the crankcase wall a hole 8th . 8th' to provide for a cylinder head screw.

The inventive design is a particularly stiff crankcase 1 achieved, with deformations are minimized by the tightening torques when screwing a cylinder head. In addition, further power and Zünddrucksteigerungen for consumption and emission reduction are possible, especially in turbocharged diesel engines or gasoline engines, with virtually unchanged dimensions of the crankcase 1 , This is associated with package, weight and cost advantages. Next are high financial one-off expenses, such as a redesign of the crankcase 1 avoided by conformity to existing production facilities.

LIST OF REFERENCE NUMBERS

1

crankcase

2, 2 '

cylinder

3

web

4

Coolant channel

5, 5 '

interstitial region

6, 6 '

strut

7

second coolant channel

8, 8 '

drilling

9

vent hole

Claims (6)

Crankcase ( 1 ) for a liquid-cooled internal combustion engine having at least two cylinders ( 2 . 2 ' ), whose cylinder axes are arranged parallel to each other, wherein between the cylinders ( 2 . 2 ' ) a common footbridge ( 3 ) is formed and with a coolant channel ( 4 . 7 ), which at least partially on at least one side of the cylinder ( 2 . 2 ' ) substantially transverse to the cylinder axes around the cylinder ( 2 . 2 ' ), wherein the coolant channel ( 4 . 7 ) in the area of the bridge ( 3 ) as a gusset area ( 5 . 5 ' ), characterized in that in the gusset region ( 5 . 5 ' ) a freestanding strut extending substantially in the direction of the cylinder axes (US Pat. 6 . 6 ' ) is arranged, the foot side with the crankcase ( 1 ) connected is. Crankcase according to claim 1, characterized in that the strut ( 6 . 6 ' ) in one piece and with the same material as the crankcase ( 1 ). Crankcase according to claim 1, characterized in that the strut ( 6 . 6 ' ) is a separate component which can be inserted into the coolant channel. Crankcase according to one of claims 1 to 3, wherein the cylinders are formed by cylinder walls, characterized in that the strut ( 6 . 6 ' ) is formed substantially cylindrical or equidistant to the cylinder walls. Crankcase according to one of the claims 1 to 4, wherein on the opposite side of the coolant channel of the cylinder, a second coolant channel is provided, characterized in that the coolant channel ( 4 ) and the second coolant channel ( 7 ) via at least one bore in the web ( 3 ) are fluidly connected to each other. Crankcase according to one of the claims 1 to 5, wherein the coolant channel is formed by the cylinder walls and at least one crankcase wall, characterized in that adjacent to the gusset area (FIG. 5 . 5 ' ) in the crankcase wall a hole ( 8th . 8th' ) is provided for a cylinder head screw.

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