Abstract
A two-part oil pan for an internal combustion engine has a box portion and a pan portion. The pan portion forms a floor of the oil pan and the box portion forms a pan wall of the oil pan. On a peripheral edge having a peripheral first sealing surface on the pan portion and a peripheral second sealing surface on the box portion, the box portion and the pan portion are interconnected in a sealed manner by means of first connection means. The pan portion and the box portion additionally are interconnected by at least one second connection means which is arranged within the edge and additionally at a distance from said edge.
Claims
1.-8. (canceled)
9. A two-part oil pan for an internal combustion engine, comprising: a box section; and a pan section, wherein the pan section forms a base of the oil pan and the box section forms a pan wall of the oil pan, the box section and the pan section are sealingly connected to one another by first connecting means at a peripheral rim with a peripheral first sealing surface on the pan section and a peripheral second sealing surface on the box section, and the pan section and the box section are additionally connected to one another by at least one second connecting means which is arranged within the rim and at a spacing to said rim.
10. The oil pan according to claim 9, wherein the box section has at least one transverse strut which connects two mutually spaced-apart regions of the pan wall to one another, and the pan section and the box section are connected to one another at the transverse strut by the second connecting means.
11. The oil pan according to claim 9, wherein first sealing means are provided on the peripheral sealing surfaces between the box section and the pan section.
12. The oil pan according to claim 11, wherein second sealing means for sealing off the base are provided at the second connecting means.
13. The oil pan according to claim 9, wherein the spacing between the second connecting means and the rim, measured in an orthogonal direction from an inner side of the rim, is at least 20 mm.
14. The oil pan according to claim 9, wherein the spacing between the second connecting means and the rim, measured in an orthogonal direction from an inner side of the rim, is at least 100 mm.
15. The oil pan according to claim 9, wherein the second connecting means is arranged within a radius R about a center of area of the base of the oil pan, wherein the radius R is selected to be less than 400 mm.
16. The oil pan according to claim 9, wherein the second connecting means is arranged within a radius R about a center of area of the base of the oil pan, wherein the radius R is selected to be less than 200 mm.
17. An internal combustion engine comprising an oil pan according to claim 9.
18. A motor vehicle comprising an internal combustion engine according to claim 17.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is an oblique view of a two-part oil pan according to the prior art;
[0030] FIG. 2 is a vertical sectional view through the oil pan as per FIG. 1;
[0031] FIG. 3 is an oblique view from above of a pan section according to an embodiment of the invention;
[0032] FIG. 4 is a vertical sectional view through a two-part oil pan according to an embodiment of the invention;
[0033] FIG. 5 is an oblique view from below of a pan section according to an embodiment of the invention;
[0034] FIG. 6 is an exploded illustration of a two-part oil pan according to an embodiment of the invention; and
[0035] FIG. 7 is a graphical comparison of the measurement results according to the prior art and the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 illustrates a two-part oil pan 1 according to the prior art in an oblique view. The oil pan is composed of an upper box section 2 and a lower pan section 3. The pan section 3 has a base 4, a rim 5 laterally surrounding the base 4, and a first sealing surface 6. The box section 2 forms an encircling pan wall 18 and a second sealing surface 12. Provided in the region of the sealing surface 6 is a multiplicity of bores 7 through which the pan section 3 can be connected by first connecting means 8, which may be in the form of screws, to the box section 2. The base 4 (floor) of the pan section 3 extends substantially in a horizontal plane that is oriented parallel to the X-Y plane of the indicated coordinate system.
[0037] FIG. 2 shows a vertical sectional view of the two-part oil pan 1 as per FIG. 1 with the box section 2 situated at the top, which box section has the pan wall 18 and has an opening 16 which is closed by the pan section 3 situated at the bottom. The base 4 of the pan section 3 is oriented substantially horizontally, and the rim 5 thereof is oriented substantially vertically, that is to say parallel to the illustrated Z direction. The attachment of the pan section 3 to the box section 2 is realized exclusively by first connecting means 8 which are arranged along the peripheral rim 5. A central region of the base 4 of the pan section 3 can thus vibrate relatively freely, similarly to a diaphragm.
[0038] FIG. 3 illustrates a pan section 3 for an oil pan according to an embodiment of the invention in an oblique view from above. The pan section 3 has an encircling (peripheral) rim 5 with a first sealing surface 6, with a multiplicity of first connecting means 8 being arranged along the rim 5. Additionally, the pan section 3 also has two second connecting means 9, which are each arranged with a spacing A to the rim 5. Here, the spacing A to the rim 5 is measured, as illustrated, in an orthogonal direction with respect to the inwardly directed surface of the rim 5. By means of the arrangement of the two second connecting means 9, the vibration characteristics of the base 4 (floor) can be positively influenced in that, in the installed state, the natural frequency of the base 4 is considerably increased by the additional second connecting means 9.
[0039] FIG. 4 shows a vertical sectional view through the oil pan 1 with the section passing through the two second connecting means 9. The oil pan 1 is formed by the box section 2 and the pan section 3, which are connected to one another by the first connecting means 8 and additionally by the second connecting means 9. It is possible to see the base 4 formed by the pan section 3, the rim 5 and the pan wall 18 formed by the box section 2. To form the second connecting means 9, the box section 2 has two screw bosses 10 into which screws 11 can be screwed through the bores 7. The second connecting means 9 or the screw bosses 10 are arranged on a transverse strut 17 which connects mutually spaced-apart regions 19 of the pan wall 18 to one another. The transverse strut 17 stiffens the oil pan 1. A first sealing means 13 (not illustrated in any more detail) which closes off the oil pan 1 in oil-tight fashion is arranged between the first sealing surface 6 of the pan section 3 and a second sealing surface 12 of the box section 2. Additionally, second sealing means 14 are provided at the second connecting means 9 in order to also close off these regions in oil-tight fashion to the outside.
[0040] FIG. 5 shows a pan section 3 in an oblique view from below, with the first connecting means 8 and the second connecting means 9 being visible. It is possible to clearly see here that the second connecting means 9 should be arranged so as to be spaced apart as far as possible (by the greatest possible distance) from the rim 5.
[0041] FIG. 6 shows the oil pan 1 in an oblique view, wherein the box section 2 has been illustrated as having been separated from the pan section 3 in a vertical direction, that is to say in the Z direction. The pan section 3 forms the base 4 with the rim 5, and the box section 2 forms the pan wall 18 with the opening 16, which is closed off by the base 4 or by the pan section 3.
[0042] The box section 2 has a flange surface 15 on which a crankcase (not illustrated) of an internal combustion engine can be flange-mounted. It is also possible to clearly see one of the provided screw bosses 10 that are provided for receiving the screws 11 and for forming second connecting means 9. By means of the additional attachment of the pan section 3 to the box section 2 by the second connecting means 9, the acoustic characteristics of the oil pan 1 are positively influenced. Aside from the improvement in acoustics, the present invention also offers further advantages. For example, the oil pan 1 can be significantly stiffened by the additional second connecting means 9. The oil pan 1 thus deforms to a considerably lesser extent under load, and depending on the application can also be dimensioned to be smaller and thus more lightweight. Furthermore, a weight saving can be realized because fewer sound insulation measures are necessary on the vehicle. Furthermore, the number of first connecting means 8 required in the region of the rim 5 can be reduced, because a proportion of the forces is transmitted via the second connecting means 9.
[0043] FIG. 7 finally shows, on the basis of a graph, the measured improvements in the acoustic characteristics imparted by the invention in relation to oil pans without second connecting means. Here, the respectively measured frequency in hertz is plotted on the horizontal axis, and the sound power in watts is plotted on the vertical axis. The vertical axis furthermore rises logarithmically. The bar plotted in each case on the left at each frequency shows the measured values of a pan section 3 designed according to the prior art. Adjacently to the right thereof are the respective measured values of a pan section 3 designed according to the present invention. It can be clearly seen here that the sound power levels of the pan section designed according to the invention with second connecting means are considerably lower than the sound power levels of a pan section designed according to the prior art.
[0044] List of reference designations [0045] 1) Oil pan [0046] 2) Box section [0047] 3) Pan section [0048] 4) Base (floor) [0049] 5) Rim (edge) [0050] 6) First sealing surface [0051] 7) Bores [0052] 8) First connecting means [0053] 9) Second connecting means [0054] 10) Screw boss [0055] 11) Screw [0056] 12) Second sealing surface [0057] 13) First sealing means [0058] 14) Second sealing means [0059] 15) Flange surface [0060] 16) Opening [0061] 17) Transverse strut [0062] 18) Pan wall [0063] 19) Spaced-apart regions [0064] A) Spacing
