EP2514934B1 - Lubrication tray for a combustion engine - Google Patents

Description

The invention relates to a lubricant pan for an internal combustion engine with the features of the preamble of patent claim 1.

Drur kgussschmiermittelwannen usually have consistent wall thicknesses. For example, stiffness and acoustic requirements are met with additional ribbing. An example of this measure is from the German patent specification DE 40 14 788 C1 known.

However, ribs mean extra weight and a restriction on the oil flow direction with respect to engine leaning. Each rib also means additional, expensive tooling and often requires additional cooling channels in the tool.

Another way to achieve the acoustic requirements is from the German patent application DE 103 02 191 A1 known. The technical teaching of this disclosure solves the acoustic task in that a plastic-formed wall of a trough-shaped body is partially replaced by a multi-layer component having at least one layer of a metal and at least one layer formed of a plastic material of viscoelastic material. Here, the multilayer part is encapsulated at its edge with the plastic of the oil sump wall.

A disadvantage of this known embodiment is a very complex production of the lubricant pan.

Next is from the German patent application DE 40 09 688 A1 a final part or shielding for motor housing of internal combustion engines, such as oil pans, known, which has at least one of the sound emission of the motor housing significantly involved wall area, which is characterized in that this wall area is flat or slightly curved and at least partially limited by a narrow zone in that the stiffness of the wall material with respect to the rigidity of the wall material outside this zone is reduced by at least 30%, preferably by more than 50%, which leads to a shift of the first self-resonance of the wall area to lower frequencies.

A disadvantage of this configuration is a complicated demolding of the lubricant pan after an injection molding or casting process.

Another measure for improving the acoustics of lubricant troughs is from the German patent application DE 32 32 602 A1 known. In this publication, it is proposed deep-drawn engine parts made of sheet steel, such. As oil pans, cylinder head cover, exhaust manifold, pulleys and the like. To manufacture such that the parts consist of double sheets of different wall thickness and that the individual sheets abut each other over the entire surface.

This known prior art is characterized by a relatively complex production of the lubricant pan.

Based on the known prior art, the present invention seeks to identify a lubricant pan, which is easy to manufacture and meets the acoustic requirements while maintaining rigidity.

This object is solved by the features in the characterizing part of patent claim 1.

Due to the design of the lubricant pan a significant Gewichtsvorteü is achieved while maintaining rigidity, since according to the invention can be dispensed with additional ribs. In addition, the tooling costs are significantly lower, since, for example, no ribbing and / or undercut can be provided on the tool side. Also, no effort for additional cooling of the tools is necessary because no rib areas must be cooled. This leads advantageously to a lower tool tuning requirement and fewer reject parts. Advantageously, caused by the non-ribbed surface of the lubricant pan according to the invention less fire cracks and breakouts on the casting tools, which can be made with a casting tool more lubricant pans and thus the production costs can be reduced. In addition, the shape of the material flow in the casting process is favored.

Advantageous developments of the invention are illustrated in the subclaims.

The size ranges according to claims 2 to 5 are particularly preferred size ranges for a lubricant trough according to the invention.

An embodiment according to claim 6 advantageously reduces the sound radiation of the side walls, whereby the acoustics is further improved.

According to claim 7, the lubricant pan is particularly preferably a casting and manufactured with one of the methods according to claim 8.

Fig. 1

zeigt eine Aufsicht auf eine dreidimensional dargestellte geschnittene erfindungsgemäße Schmiermittelwanne.

Fig. 2

zeigt die Aufsicht auf eine dreidimensional dargestellte erfindungsgemäße Schmiermittelwanne von unten.

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

Fig. 1

shows a plan view of a three-dimensionally illustrated cut lubricant cup according to the invention.

Fig. 2

shows the top view of a three-dimensional illustrated lubricant cup according to the invention from below.

Below, the same reference numerals apply to like components in both figures.

Fig. 1 shows a plan view of a three-dimensional illustrated cut lubricant cup according to the invention 1. A sectional surface of the lubricant pan 1 is shown hatched. The bowl-shaped lubricant pan 1 is shown in the installed position and a numbered with U arrow shows geodetic down. The lubricant pan 1 is provided for an internal combustion engine, not shown, and has a mounting flange 2 for fastening the lubricant pan 1 to a likewise not shown crankcase of the internal combustion engine. At the mounting flange 2 close in the direction of geodetic down side walls 3 at. These lateral walls 3 go geodetically down over a radius in a bottom 4 of Schmiennittelwanne1 1 over. Thus, the lubricant-tight bowl shape of the lubricant pan 1 is formed by the side walls 3 and the bottom 4, the mounting flange 2 is for mounting on the internal combustion engine and the rigidity.

According to the invention, a floor thickness d decreases from a geometric floor center 5 (shown in FIG Fig. 2 ) in the direction of the walls 3 to continuously, wherein an inner radius R _i at the transition from the bottom 4 to the walls 3 is greater than a corresponding outer radius R _a . The area of the geometric center of the ground 5 is shown as a crossing point However, the center of the floor 5 can be up to 30% of the total floor area in terms of area in which the punctiform geometric floor center 5 lies.

Preferably, the bottom thickness d in the region of the bottom center 5 has a wall thickness of at least 2 mm and at the transition to the radius 3 has a wall thickness of not more than 10 mm. With respect to the radius of the transition from the bottom 4 to the walls 3 preferably has an outer radius R _a of at least 3 mm and the corresponding inner radius R _i of this has preferably the double outer radius R _a and at least 6 mm.

In a further particularly preferred embodiment, the walls 3 have a geometry corresponding to the bottom 4. This means that an in Fig. 1 constant ground thickness d continuously increases from a geometric wall center in the direction of the bottom 4 or the mounting flange 2 or a connecting the wall 3, wherein an inner radius R _i at the transition from the walls to the bottom 4 and at the transition to the mounting flange 2 is greater than a corresponding outer radius R _a .

The lubricant trough 1 is preferably a cast part, wherein the lubricant trough 1 can be produced as a die cast part or a sand casting or an injection molded part. _

Fig. 2 shows a plan view of an underside of a three-dimensionally illustrated inventive lubricant pan 1. As from Fig. 2 can be seen, the base 4, starting from the region of its geometric center 5 an increasing wall thickness in the direction of the walls 3, which is marked by individual rings shown by dashed lines. In a table shown above the lubricant trough 1, a ground thickness d belonging to a ring is in each case by way of example applied, starting at 2.3 mm for the geometric center 5 of the base 4, up to a thickness of 4.1 mm in the area of the outer radius R _a , A U-numbered arrow in turn marks the direction of geodesic below.

In this particularly preferred embodiment, the wall thickness of the bottom 4 changes starting from the production-related, supplier-specific minimum wall thickness of 2.3 mm, even 2 mm are still displayed in the antinode (bottom center), towards the corners continuously to 3 to 3.5 mm. The range of the radius itself is, as shown in the table, about 4.1 mm. The same design can also be applied to the walls 3, but is in Fig. 2 not shown. The Eckenausrundungen have the inversion for this version, in the vertex, the wall thickness is greater (inner radius R _i is about twice as large as the outer radius R _a ).

The inventive design of the lubricant pan 1 brings a significant weight advantage, since it can be dispensed with additional ribs while maintaining rigidity. The tool costs are lower. The material flow is favored during casting, there is no additional effort required for additional cooling of the tool. This leads advantageously to a lower tool tuning requirement and less rejects. Preferably, casting methods such as die casting, sand casting or injection molding are used for the production.

An optimum for the lubricant pan 1 according to the invention is achieved when the continuous wall thickness increase, as in Fig. 2 shown diagonally (to the corners). With a not shown, kontinugerichen wall thickness increase normal to the walls, the stiffness is increased again, but also at the same time the weight of the lubricant pan. 1

In a further embodiment, the radii R _i and R _{a can} also be represented as bevels, ie the radii assume the value "infinite".

LIST OF REFERENCE NUMBERS

1.

lubricant sump

Second

mounting flange

Third

wall

4th

ground

5th

bottom center

U

geodesic below

d

bottom thickness

R _i

inner radius

R _a

outer radius

Claims (8)

1. A lubricant sump (1) for an internal combustion engine having an assembly flange (2) for fastening the lubricant sump (1) to an engine crank case, where side walls (3) of the lubricant sump (1) are disposed and, when in the installed position, merge geodetically downwards (U) over a radius in a bottom (4),
   characterised in that the thickness (d) of the bottom continuously increases from a geometrical centre (5) towards the walls (3), wherein an inner radius (R_i) at the transition from the bottom (4) to the walls (3) is greater than or equal to a corresponding outer radius (R_a).
2. A lubricant sump according to claim 1,
   characterised in that the wall thickness (d) at the centre (5) of the bottom is at least 2 mm.
3. A lubricant sump according to claim 1 or claim 2,
   characterised in that the thickness (d) at the transition to the radius is up to 10 mm.
4. A lubricant sump according to any of claims 1 to 3,
   characterised in that an outer radius (R_a) is at least 3 mm.
5. A lubricant sump according to any of claims 1 to 4,
   characterised in that an inner radius (R_i) is preferably twice the outer radius and at least 6 mm.
6. A lubricant sump according to any of claims 1 to 5,
   characterised in that the walls (3) correspond in shape to the bottom (4).
7. A lubricant sump according to any of claims 1 to 6,
   characterised in that the sump (1) is a casting.
8. A lubricant sump according to claim 7,
   characterised in that the sump (1) is a pressure die casting or a sand casting or an injection moulding.

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