Main bearing cap for internal combustion engines

1. A bearing cap for a main bearing in an internal combustion engine, the cap being composed partially of an aluminum alloy and partially of an iron alloy forming a core in the aluminum material: the core having lateral portions with bores for mounting bolts and a central portion between the lateral portions, the central portion terminating at a distance from a supporting surface for a bearing shell, the supporting surface being the outer limiting surface of an aluminum alloy layer outside the iron core, wherein said iron alloy core having in its central portion at least two channels spaced from each other on each side of the center of the central portion, said channels being filled with an aluminum alloy forming a coherent mass with the aluminum layer.

2. The bearing cap of claim 1 , wherein said central portion of the core is essentially U-shaped with a thickness decreasing from the center towards the lateral portions.

3. The bearing cap of claim 1 , wherein opposite sides of said central portion of the core is provided with pockets to increase the mechanical grip between the core and the aluminum alloy.

4. The bearing cap of claim 1 , wherein said aluminum alloy layer is a semi-circular layer of substantially uniform thickness outside the iron alloy core.

5. The bearing cap of claim 1 , wherein the bearing cap is one of several bearing caps composing a main bearing bridge.

6. A main bearing bridge for an internal combustion engine, comprising:

a plurality of main bearing caps, each cap made partially of an aluminum alloy and partially of an iron alloy forming a core in the aluminum material said core having lateral portions with bores for mounting bolts and a central portion between said lateral portion, said central portion terminating at a distance from a supporting surface for a bearing shell, said supporting surface being the outer limiting surface of an aluminum alloy layer outside the core, said core having in its central portion at least two channels spaced from each other on each side of the center of said central portion, said channels being filled with an aluminum alloy forming a coherent mass with said aluminum layer.

7. The bearing bridge according to claim 6 , wherein said central portion of said core is essentially U-shaped with a thickness decreasing from the center towards said lateral portions.

8. The bearing bridge according to claim 6 , wherein opposite sides of said central portion of said core is provided with pockets to increase the mechanical grip between said core and said aluminum alloy.

9. The bearing bridge according to claim 6 , wherein said aluminum alloy layer is a semi-circular layer of substantially uniform thickness outside said core.