DE10202469C1 - Molded part used as an oil sump of a vehicle engine comprises a number of long and short fiber elements embedded in a structure of a metal or a metal alloy of the molded part - Google Patents

Abstract

Molded part comprises a number of long fiber elements (2) embedded in a structure of a metal or a metal alloy of the molded part. The fiber elements are arranged in the structure of the molded part in the form of a flat or spatial lattice (10) or in the form of a skeleton and have a coating corresponding to the composition of the metal or metal alloy of the molded part. An Independent claim is also included for a process for the production of a molded part. Preferred Features: The molded part also has a number of short fiber elements (4a) regularly arranged in the whole structure of the molded part. The molded part is made from aluminum or aluminum alloy. The long and short fiber elements are made from silicon carbide, silicon nitride, silicon carbonitride or aluminum oxide.

Description

The invention relates to a molded component made of cast metal and a method for producing it a molded component made of cast metal, the molded component in particular an oil pan an internal combustion engine.

In particular, oil pans from internal combustion engines for vehicles are often considered thin-walled and one-piece molded metal parts formed below the crankshaft len range of the respective internal combustion engine are arranged and usually one have a deeper oil collection area than the oil reservoir.

With regard to the lowest possible weight and good heat radiation properties is known, such oil pans made of light metal alloys in die casting or to manufacture from wrought alloys in die casting, using as lightweight tall material mostly aluminum is used.

The oil pan is due to the above-mentioned arrangement on the internal combustion engine usually directly facing the road, which is why external influences for example by falling rocks, touching the road or another impact an obstacle can occur, which can cause considerable external loads. If material failure of the oil pan occurs as a result of such an external load, oil can occur leak into the environment, causing u. U. significant environmental damage are caused.

Accordingly, the light metal (aluminum) alloys used should high strength and rigidity properties combined with a high load-bearing capacity and high impact strength.

In addition, pronounced structure-borne noise occurs in internal combustion engines vibrations, which u. a. also be introduced into the oil pan, causing the Oil pan to an essential for the overall noise of the internal combustion engine Sound emitter (sound source) is.  

Simply because of the increasingly strict regulations regarding a Ge Noise emission from internal combustion engines, especially when used in motor vehicles , the light metal (aluminum) alloy used should therefore be low Show noise emission due to structure-borne noise.

In addition, internal combustion engines are particularly temperature fluctuations depending on environmental influences at the place of use of the combustion engine subject to the operating parameters of the internal combustion engine, for example at a cold start of an internal combustion engine of a vehicle in winter. Step next to it in internal combustion engines, regardless of the environmental influences mentioned high temperature gradients.

Therefore, the light metal (aluminum) alloy should also have good temperature changes Have sel properties.

It is also evident that the light alloy is also highly resistant against influences of internal media, d. H. of internal combustion engine media such as Engine oils or coolants, and external media, e.g. H. from environmental media such as Spritz water from road surfaces.

An optimization of conventionally cast oil pans with the named plant substances (aluminum, wrought aluminum alloys) with respect to all of the above However, it is hardly possible to have the required (material) properties, as these Materials (aluminum, wrought aluminum alloys) not all of the required work material properties can combine to the same extent and meet the requirements Exclude some properties. For example, the noise emission with conventionally cast oil pans cannot be reduced further.

From an article by E. Köhler in the magazine ALUMINUM from 1993, issue 7, pages 627 and 628 is a method of producing a composite in the range of Cylinder bores of cylinder crankcases made of aluminum alloys are known, according to the silicon-laden, hollow cylindrical and to produce the final dimensions of the pre-fabricated compacts made of short alumina fibers into the cast shape of the cylinder crankcase in the area of the cylinder bores,  the prefabricated compacts with the application of high pressures during the casting process are infiltrated with melt.

DE 29 40 307 A1 describes a method for producing fiber-reinforced magnesium Alloy composite materials known in which one or more ring and plate mig preformed shaped bodies with a constant density in a casting mold th places are arranged and cast with a magnesium alloy, the Molded body retains its shape. The fibers from which the molded articles are made by, coated with a film of copper, nickel or silver.

From DE 41 04 680 A1 is a die-cast, be made of a magnesium alloy standing piston of an internal combustion engine, in which a preformed body is cast from ceramic short fibers, the short fibers parallel to one Level and are statistically randomly oriented within this level.

JP 62074033 A describes a method for producing a composite material a metal matrix and reinforcing fibers are known, with the reinforcing fibers first a coherent, firmly connected and porous molded body provides, regardless of the metal matrix heated and fully after heating constantly immersed in a bath made of the molten metal matrix.

It is an object of the invention to provide a molded component made of cast metal, in particular one To create an oil pan of an internal combustion engine, which is the same with minimized weight reasonably high strength and rigidity properties as well as a good tempera resistance to door changes.

This object is achieved according to the invention by a molded component made of cast metal, ins in particular an oil pan of an internal combustion engine, each with the combination of features cations of claims 1, 2 and 3.

Due to the incorporation of fiber elements into the structure of the metal or the me Alloy of the molded component is the strength and rigidity properties compared to conventional molded components, especially oil pans, while maintaining of a high level in terms of material ductility. The ange  The low component weight that is striven for is not significantly reinforced by this chamfer reinforcement changes. In addition, the resistance to temperature changes and fatigue behavior positively influenced under thermal change.

If the molded component has a large number of short fiber elements, the short fiber elements in the structure of the metal or metal alloy randomly ori are arranged in such a way that they cause such a disorder in the structure of the metal alloy tion or the structure of the metal, in particular coated and high-strength short fibers an improved resistance to internal and external media.

The molded component has a plurality of long fiber elements, the long ones Fiber elements in the structure of the molded component depending on the direction and according to a flä arranged or spatial lattice or skeleton-like, it has the following formed component high strength and stiffness values. This affects in particular advantageous in designing the molded component as a light metal oil pan.

The molded component is advantageously made of a light metal material, in particular Aluminum, or a light metal alloy, in particular an aluminum alloy, educated. Accordingly, the component weight can be reduced further.

It is also advantageous if the molded component by means of die casting or die casting is producible, which means that the die casting or die casting process already in use drive can be used to manufacture the molded component according to the invention NEN. As a result, the molded component can be produced inexpensively.

Is a surface of the fiber elements at least partially coated u. U. un desired reactions between a fiber material and the metal or the metal Alloy of the molded component avoided during the metal casting process. Farther the internal interfaces become inherent due to the coating of the fiber elements ver between the fiber elements and the metal or metal alloy repaired.

A composition of the coating of the surface of the fiber elements can also a composition of the metal or the metal alloy of the molded component  correspond. The fiber elements can also be made of a high-strength material, in particular silicon carbide, silicon nitride, silicon carbonitride or aluminum oxide be educated.

Is in such a molded component with a variety of short fiber elements in Ge add at least one metal foam body to the metal or metal alloy arranged as a sandwich insert, is a sound emission of the molded component, in particular when the molded component is designed as a light metal oil pan, can be further reduced. The Metal foam body has a higher melting point than the metal or Metal alloy of the molded component.

If the molded component has both short fiber elements and long fiber elements in the Structure on, with short, coated fiber elements disordered and long, coated tete fiber elements depending on the direction skeletal in the structure of the metal or Me tall alloy of the molded component are arranged, these effect fiber elements a particularly reduced sound emission due to media, air and structure-borne noise.

It is another object of the invention to provide a method for producing a Molded component made of cast metal, in particular an oil pan of an internal combustion engine, to create, which in a simple and inexpensive way influencing Properties of the formed molded component allows.

This further object is achieved according to the invention by a method for producing a Molded component made of cast metal, in particular an oil pan of an internal combustion engine, solved with the features of claims 10, 11 and 12.

The process for producing a molded component from metal casting with composite Me tall or metal alloy materials enables inexpensive and efficient loading use of known die casting and die casting processes with special consideration supply of fiber components as a composite component in metal or in metal yaw. Accordingly, the strength and rigidity properties as well temperature change fatigue properties and resistance to spreading structure-borne noise and aggressive media influences in a simple way be, whereby a low component weight is obtained.  

In a further development of the method for producing a molded component, at least least a metal foam body in a mold before pouring the melt of the Metal or metal alloy inserted and a variety of short fiber elements in a melt of metal or metal alloy before casting metal randomly stored (suspended), the metal foam body has a higher melting temperature has than the metal or metal alloy.

A complex of randomly oriented short fiber elements and especially ske long fiber elements with a lattice-like orientation result in a far-reaching reduction the noise emission from media, air and structure-borne noise.

Further preferred exemplary embodiments of the method according to the invention are shown in the further dependent claims of the procedural claim.

The present invention will hereinafter be described by way of preferred embodiments play in connection with the accompanying drawing, wherein

Fig. 1 illustrates an embodiment of the method for producing a mold component.

From Fig. 1, a two-part die casting mold with a first die casting mold 1 with an inner profile of a molded component and a further die casting mold 3 with an outer profile of the molded component is shown schematically. As can be seen from Fig. 1, when the die-cast molds 1 , 3 are assembled, a cavity 6 is formed , which is essentially modeled on the shape of the molded component to be produced.

The between the two die-casting molds 1 , 3 when the same is formed is formed in the embodiment 6 shown in FIG. 1 of the die-casting mold for casting an oil pan for an internal combustion engine made of a ductile aluminum alloy 4 .

The essential design requirements for the die casting mold, in particular with regard to the expected shrinkage behavior of the cast molded part, correspond to the known rules of casting technology (die casting technology), which is why, for reasons of simplification, a detailed description of the design criteria of the cavity 6 is omitted below.

The aluminum alloy 4 is poured or injected into the cavity 6 of the light metal die 1 , 3 by means of the feed 7 . For the sake of simplicity, only one feed line of the feed 7 is shown in FIG. 1, without the method or the device for carrying out this method for producing a molded component from metal casting being restricted to this. Rather, depending on the desired shape of the molded component, which essentially corresponds to the cavity in the light metal die 1 , 3 , several or even a plurality of supply lines to the feed 7 can be provided to ensure a continuous material flow and to ensure that the material is equally available in all areas of the cavity 6 in the necessary amount.

The casting material, that is to say the aluminum alloy 4 in the present case , is fed to the feed 7 and thus to the light metal die 1 , 3 from the die casting cylinder 5 , as indicated by the arrow 8 . Again, the exemplary embodiment shown of the device for carrying out the method for producing a molded component, in the present case a light metal oil pan, is not limited to a die-cast cylinder 5 . Rather, depending on the amount of melt to be poured in the light metal material or the light metal alloy and depending on the number of supply lines required, the required amount of die-cast cylinders 5 can be used.

The production and provision of the melt of the aluminum alloy 4 is carried out using known devices and methods and is accordingly not shown in more detail in FIG. 1.

According to the exemplary embodiment of the method for producing a molded component, in particular the oil pan of the internal combustion engine, shown in FIG. 1, high-strength fiber elements ( 2 , 4 a) are embedded in a structure of the molded component.

For this purpose, a plurality of elongated fiber elements 2 (hereinafter referred to as "long" fiber elements or "long fibers") are inserted into the light metal die 1 , 3 before pouring the melt 4 of the light metal alloy.

The long fiber elements 2 are inserted, as shown schematically in FIG . The illustrated in Fig. 1, from single, long, high-strength fiber elements produced skeleton 10 of the present Langfa coated fibers 2 is formed in a lattice shape. The long fiber elements 2 have a circular cross-section 2 a in the embodiment shown. The longitudinal extent of the long fiber elements 2 is indicated by the lines 2 b.

In the embodiment shown, the skeleton 10 is regularly present in the entire body of the oil pan. However, the present method is not limited to this embodiment. B. the fiber reinforcement can be limited to areas of the molded component, in this case the oil pan.

The "long" fiber elements can generally be considered metallic or non-metallic assembled objects in an endless form with an aligned distribution that assembling to large-area or compact structures with different enables technological processes, in particular as long fiber skeleton or sand soft insert, are described.

In this preferred embodiment of the method for producing a molded component is a sufficiently ductile aluminum alloy without further composites additives, ie without "short" fiber elements 4a as will be explained in more detail below, skeletal in the "long" with surface-coated high strength fiber elements from specified alloy die-casting mold 1 , 3 poured.

According to another preferred embodiment of the method for the manufacture of a lung shape component are infiltrated into the melt 4 of the respective light-metal alloy die-cast "short" and high-strength fiber elements 4a. In Fig. 1, the infiltration with the so-called short fibers 4 a is indicated by the points in the light alloy 4 .

Such "short" fiber elements can generally be metallic or non-metallic Objects with a finite length-thickness ratio that deviates from the spherical shape random distribution in the order of a few micrometers to millimeters be written.  

Silicon carbides, silicon nitrides and silicon can be used, in particular, as high-strength short fibers carbonitrides or aluminum oxides are used.

A coating advantageously corresponds to the composition of the same the light alloy used.

The two exemplary embodiments of the method described above can each be used separately or together. Accordingly, a melt 4 infiltrated with short fibers 4 a can finally be used to produce the oil pan without a long fiber skeleton 10 being provided in the die casting mold 1 , 3 . Likewise, a melt 4 of the light metal alloy without infiltrated short fibers 4 a can be used for casting the oil pan, a skeleton 10 made of long fibers 2 having been inserted into the die casting mold 1 , 3 . According to a further preferred exemplary embodiment, the two exemplary embodiments of the method are combined with one another, ie before the melt 4 is poured in, a skeleton 10 made of long fibers 2 is inserted into the die 1 , 3 , 4 short fibers 4 a being infiltrated in the melt used for the subsequent casting process ( sus pendulum).

Due to the short fibers 4 a infiltrated in the melt 4 a, a marked increase in strength is achieved, in particular due to the random distribution of the fiber particles 4 a. In addition to this increase in strength, the toughness of the die casting-related light metal matrix is retained due to grain refinement of the structure. The term "grain refinement" is defined here as a reduction in the grain size, the spatial representation of a multi-crystal distribution in metals and their alloys denoting the single crystal, which is in the order of a few micrometers to millimeters, materially known as "grain". If the grain size decreases, for example by adding alloy elements or second phases or defined heat treatments in a metal structure, this is referred to as grain refinement. In contrast, when grain growth begins, this state of a metallic structure defines itself as grain coarsening.

The inner interfaces generated due to the randomly distributed fiber particles 4 a also cause an attributable reduction in the sound emission of the base material.

The directionally introduced long fiber components 2 , which preferably have a comparable chemical composition to the short fibers 4 a, cause a further attenuation of the sound emission, the combination with the short fiber particles 4 a being a particularly noteworthy increase in strength, toughness, resistance to fatigue and media influences and a significant reduction in noise emissions.

According to a further likewise preferred exemplary embodiment, instead of forming a lattice (skeleton 10 ) from long fibers 2, a sandwich insert is used in the molded component, consisting of at least one metal foam body. The metal tall foam body has a higher melting temperature than the light metal alloy used and is preferably coated with an at least thin layer of the alloy material.

A light metal oil pan, which was cast from a melt with infiltrated short fibers 4 a and has at least one coated sandwich insert, which consists of a metal foam body made of a higher melting light metal alloy compared to the material of the oil pan, brings about a significant reduction in the sound emission of the oil pan.

It should be noted that the fiber reinforcement of light alloys for oil sump a desired low level in the manufacturing process of die casting or die casting Component weight not changed significantly. Compared to conventionally made oil troughs, the strength and rigidity properties are increased with retention a high level of material ductility. In the same way, the temperature resistance to changes and fatigue behavior under thermal changes positively influenced. Coated, stored in the light alloy and high-strength short fibers result in improved resistance to internal and external re media. In the complex with skeleton-like coated long fibers and their orderly alignment is a reduction of sound emissions through media, air  and structure-borne noise to be expected. The coating of fiber components improves the internal interface properties between short and long fibers and the Leichtme tallmatrix.

Claims (16)

1. Molded component made of cast metal, in particular an oil pan of an internal combustion engine, with a plurality of long fiber elements ( 2 ) embedded in a structure of a metal or a metal alloy of the molded component ( 2 ), characterized in that the long fiber elements ( 2 ) in the structure of the Depending on the direction, the molded component is arranged in a lattice-like manner according to a flat or spatial grid ( 10 ) or at least partially and is at least partially provided with a coating which corresponds to a composition of the metal or the metal alloy of the molded component. 2. Molded component made of cast metal, in particular an oil pan of an internal combustion engine, with a large number of short fiber elements ( 4 a) embedded in a structure of a metal or a metal alloy of the molded component, characterized in that the short fiber elements ( 4 a) in entire structure of the molded component are arranged randomly oriented. 3. Molded component made of cast metal, in particular an oil pan of an internal combustion engine, with a large number of short and a plurality of long, each in a Ge insert of a metal or a metal alloy of the molded component incorporated fiber elements ( 2 , 4 a), in the structure the molded component the short fiber elements ( 4 a) randomly distributed and the long fiber elements ( 2 ) are arranged depending on the direction. 4. Molded component according to at least one of claims 1 to 3, characterized characterized in that the molded component made of a light metal material, especially aluminum, or a light metal alloy, especially one Aluminum alloy, is formed.   5. Molded component according to at least one of claims 1 to 4, characterized records that the molded component can be produced by die casting or die casting is. 6. Molded component according to at least one of claims 2 to 5, characterized in that a surface of the fiber elements ( 2 , 4 a) is at least partially coated. 7. Molded component according to claim 6, characterized in that a composition of a coating of the surface of the fiber elements ( 2 , 4 a) speaks to a composition of the metal or the metal alloy of the molded component ent. 8. Molded component according to at least one of claims 1 to 7, characterized in that the fiber elements ( 2 , 4 a) made of a high-strength material, in particular special silicon carbide (SiC), silicon nitride (SiN), silicon carbonitride (SiCN) or aluminum oxide (Al ₂ O ₃ ), are formed. 9. molded component according to at least one of claims 2 and 4 to 8, characterized net by at least one arranged in the molded component as a sandwich insert Metal foam body, the metal foam body having a higher melt point as the metal or the metal alloy of the molded component. 10. A method for producing a molded component made of cast metal, in particular an oil pan of an internal combustion engine, a plurality of short fiber elements ( 4 a) being partially embedded in a structure of a metal or a metal alloy of the molded component, characterized in that the short fiber element elements ( 4 a) are infiltrated in a melt of the metal or metal alloy prior to metal casting. 11. A method for producing a molded component from cast metal, in particular an oil pan of an internal combustion engine, a plurality of long fiber elements ( 2 ) being embedded in a structure of a metal or a metal alloy of the molded component, characterized in that the long fiber elements ( 2 ) individually oriented in a casting mold before pouring the melt ( 4 ) of the metal or the metal alloy, the long fiber elements ( 2 ) according to a flat or spatial grid ( 10 ) or skeletally inserted into the casting mold , 12. A method for producing a molded component from cast metal, in particular an oil pan of an internal combustion engine, a plurality of short fiber elements ( 4 a) and a plurality of long fiber elements ( 2 ) being embedded in a structure of a metal or a metal alloy of the molded component , wherein the short fiber elements ( 4 a) in a melt of the metal or metal alloy infiltrates before the metal casting and / or the long fiber elements are oriented individually into a mold before pouring the melt ( 4 ) of the metal or metal alloy be inserted. 13. A method for producing a molded component according to one of claims 10 to 12, characterized in that the long and / or short fiber elements ( 2 , 4 a) are at least partially surface-coated and / or are formed from a high strength material. 14. A method for producing a molded component according to at least one of the claims che 10 to 13, characterized in that the molded component from one Light metal, especially aluminum, or a light metal alloy, in particular special aluminum alloy, is designed as a light metal casting. 15. A method for producing a molded component according to at least one of the claims che 10 to 14, characterized in that the molded component in one print casting process or a press casting process, in particular from a ductile Aluminum alloy is manufactured. 16. A method for producing a molded component according to at least one of the claims che 10 and 13 to 15, characterized by at least one metal foam body, the at least one metal foam body in a mold in front of the Pouring the melt of the metal or the metal alloy is inserted, and wherein the metal foam body has a higher melting temperature than the metal or the metal alloy.