DE10064837A1 - Production of a cylinder crankcase housing of an internal combustion engine of a vehicle comprises a cylinder having a running surface for a piston, and an aluminum bushing with inserted silicon particles - Google Patents

Abstract

Production of a cylinder crankcase housing of an internal combustion engine of a vehicle comprises a cylinder (12) having a running surface for a piston; and an aluminum bushing (14) with inserted silicon particles. The housing is made from an aluminum alloy. A blank for the bushing is produced in a centrifugal casting process or a lost foam process. Preferred Features: The crankcase housing has two or more cylinders with corresponding aluminum bushings. The bushings are sealed under pressure during casting.

Description

The invention relates to a method for producing a cylinder crankcase Internal combustion engine, according to the preamble of claim 1.

Mostly in cylinder crankcases of internal combustion engines aluminum-containing base material are cylinders with in a known manner Appropriate treads for reciprocating piston provided the treads are subjected to high mechanical and thermal loads. It is therefore necessary to design the running surfaces to be particularly wear-resistant. When using That arises from aluminum as the base material for the cylinder crankcase Problem that due to the reduced compared to steel or cast iron Heat resistance of the base material itself is usually not long enough Operating time of the engine guaranteed. That's why it is have been proposed to produce a wear-resistant cylinder tread To cast cast iron bushings with aluminum. Because of the different As a rule, however, there is no melting point of gray cast iron and aluminum cohesive connections, so that not least because of the different Coefficient of thermal expansion of both materials stuck the bushing over the in the case of internal combustion engines, normal operating time is not guaranteed. moreover result from the different specific weights of these materials Casting problems related to positioning and alignment of the bushing the dimensions of the surrounding cylinder crankcase and also with regard to the parallel alignment of the sockets to each other.

For improvement, DE 43 10 698 A1 has already been proposed instead of one Gray cast iron bushing to provide an aluminum bushing. This is made from a blank Fiber composite material produced, the matrix formed from aluminum oxide fibers in their specific weight and with regard to their thermal conductivity in essentially corresponds to the base material of the cylinder crankcase. Further wear-resistant particles in the form of silicon are incorporated into the aluminum oxide fibers  stored. The silicon-containing particles embedded in the unfinished part carry considerably to increase the wear resistance of the tread.

The present invention has for its object the method of simplify and improve the above type, so that aluminum bushings in Cylinder crankcases made of an aluminum alloy inexpensive in large series can be installed.

This object is achieved according to the invention by a method of the above. Kind of with the in Characteristics characterized claim 1 solved. Advantageous embodiments of the Invention are specified in the dependent claims.

For this purpose, it is provided according to the invention that a blank for the aluminum bushing in Centrifugal casting or lost foam process is produced.

This has the advantage that a favorable distribution of the silicon particles is achieved which requires a higher strength.

In a preferred development of the invention, the cylinder crankcase has two or more cylinders with two or more aluminum bushings, all of them Aluminum bushes for a cylinder crankcase made in one piece in the form of glasses become.

The aluminum bushings are expediently subjected to pressure during the casting process compacted, with the casting process first a shape against the direction of gravity filled with material and then the filled form in the direction of gravity up to Curing of the material is pressurized.

For a particularly good connection (positive locking) between the socket and The crankcase is used in the lost foam process before casting the Aluminum bushing a surface facing the cylinder crankcase Socket styrofoam body (later aluminum socket) at least partially with one Adhesive material coated so that styrofoam beads adhere to it created aluminum socket to obtain a clearly defined shape structure.  

In a particularly preferred embodiment of the invention, the Aluminum bush formed a structure.

To produce a particularly wear-resistant tread, one is At least the inner wall of a cylinder-forming surface of the aluminum bushing partially applied a tribologically suitable oxidation layer.

Further features, advantages and advantageous configurations of the invention result from the dependent claims, as well as from the following description of the Invention with reference to the accompanying drawings. This shows in

Fig. 1 a preferred embodiment of a cylinder crankcase according to the invention in sectional view,

Fig. 2, the cylinder crankcase according to FIG. 1 in supervision and

Fig. 3 is an aluminum socket-glasses composite in supervision.

The schematically illustrated in Fig. 1 and 2, preferred embodiment of a cylinder block 10 of aluminum 12 has cast aluminum sockets 14 in respective cylinders. The aluminum bushings 14 are produced as a one-piece or multi-piece bush-spectacle composite 16 , as can be seen from FIG. 3, and are cast into the cylinder crankcase 10 . The socket-spectacle composite 16 results in less susceptibility to mechanical deformation and, at the same time, simplifies manufacture and assembly.

The glasses systems 16 according to the invention are preferably produced from an aluminum alloy with embedded silicon particles in a centrifugal casting or lost foam process. Additional wear resistance is achieved by pressurizing the mold while the cast aluminum material is hardening. The tight fit of the aluminum bushings 14 in the form of the bushing-spectacle composite 16 within the cylinder crankcase 10 also improves significantly.

In the "lost foam process", a styrofoam model of the individual bushes is used first or the entire association of glasses. Then apply glue on the styrofoam model, styrofoam beads adhered to the outer surface.  

Then the styrofoam is gasified using lost foam casting and aluminum replaced. When creating individual sockets, these then become the Glasses bonded together.

Centrifugal casting takes place in a rotating drum. Here too either individual bushings are manufactured which are subsequently connected to each other, or the bandage of glasses is poured immediately. There is a corresponding one Sand core shape or a wax model provided. If necessary, several can be in one form Glasses bandages can be cast at the same time.  

LIST OF REFERENCE NUMBERS

10

cylinder crankcase

12

cylinder

14

aluminum bushing

16

Jacks glasses composite

Claims (7)

1. A method for producing a cylinder crankcase of an internal combustion engine, in particular for a motor vehicle, with at least one cylinder which has a running surface for a working piston, the cylinder crankcase being produced from an aluminum alloy and an aluminum bushing provided with embedded silicon particles being poured into the cylinder, characterized in that that a blank for the aluminum bushing is produced by centrifugal casting or lost foam. 2. The method according to claim 1, characterized in that the Cylinder crankcase two or more cylinders with two or more corresponding Has aluminum bushings, with all aluminum bushings for one Cylinder crankcase are made in one piece glasses. 3. The method according to claim 1 or 2, characterized in that the Aluminum bushings are compressed with pressure during the casting process. 4. The method according to claim 3, characterized in that in the casting process first fill a mold with material against the direction of gravity and then the filled mold is pressurized in the direction of gravity. 5. The method according to at least one of the preceding, characterized in that that in the lost foam process before casting the aluminum bushing surface of the aluminum bush facing the cylinder crankcase is at least partially coated with an adhesive material. 6. The method according to at least one of the preceding, characterized in that that a structure is formed on the surface of the aluminum bushing.   7. The method according to at least one of the preceding, characterized in that that on the surface forming an inner wall of a cylinder Aluminum bushing is at least partially a tribologically suitable one Oxidation layer is applied.