OIL SUMP

FIELD OF THE DISCLOSURE

The present invention relates to an oil sump that includes a bottom wall and a lateral outer wall, which in the assembled condition of the oil sump extends upwards from the bottom wall, as seen in the direction of gravity, and an oil storage region, which is arranged in an interior of the oil sump and, when the oil sump is in operation, is filled with oil up to a storage level.

BACKGROUND

Oil sumps of this kind are known from the prior art, serve for receiving a reservoir of an engine oil for an internal combustion engine, and are mounted to an engine block of the internal combustion engine.

Known oil sumps having a base body made from a plastics material are less able to withstand fire and high degrees of heat than oil sumps made from other materials, such as steel sheet or aluminium, a fact resulting from the lower melting point of the plastics material and its lower resistance.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an oil sump of the type mentioned in the introduction that is better able to withstand heat and flame.

According to the invention, this object is achieved in the case of an oil sump having the features of the precharacterising clause of claim 1 in that the oil sump includes an oil cooling region, which is adjacent to the lateral outer wall and is filled with oil to a cool level, and a decoupling device or isolating device for decoupling or isolating the cool level of the oil in the oil cooling region from the storage level of the oil in the oil storage region in a cool condition of the oil sump.

Preferably, a cool level of the oil in the oil cooling region, which is above the storage level of the oil in the oil storage region, is settable by means of the decoupling device.

The concept underlying the present invention is to produce a high level of oil in an oil cooling region of the interior of the oil sump directly adjacent to the lateral outer wall of the oil sump, such that as large as possible a proportion of the lateral outer wall is in contact with oil located in the oil cooling region.

If a high degree of heat or flames act on the oil sump, the lateral outer wall can in fact, in the regions in which it is in contact with oil in the oil cooling region, give off heat to this oil, with the result that the oil has a cooling effect on the lateral outer wall. The material of the lateral outer wall can adopt as a maximum the oil temperature at the inner side of the outer wall, facing the oil cooling region. As a result, the material structure of the lateral outer wall maintains a higher residual stiffness under the action of a high degree of heat and/or in direct contact with flame. This greatly delays or completely prevents collapse or breach of the outer wall.

Where the term “cooling” is used in this description and the attached claims, this does not mean active cooling by the generation of cold but passive cooling by the dissipation of heat from the lateral outer wall of the oil sump.

The present invention is based on the realisation that in particular oil sumps made from a plastics material, for example a polyamide material, fail in the event of a high degree of heat acting on them, for example in the event of an engine fire, specifically at the point at which there is no oil lying against the inner side of the lateral outer wall of the oil sump. In the absence of any cooling there, the surface of the oil sump reaches its melting point, so that the outer wall melts and/or bursts open as a result of the mass of oil in the oil sump. As a result, oil vapours or liquid oil can escape from the oil sump and act as an additional fire accelerant.

EP 1 871 995 B1 discloses an oil sump of which the interior is subdivided into two oil storage regions. In that case, however, both oil storage regions are constantly in fluidic connection with one another, with the result that the oil level is always the same in both storage regions and there is no possibility of decoupling the oil level in the one region from the oil level in the other region. This known oil sump is thus neither intended nor suitable for producing an increased ability to withstand heat and flame by the lateral outer wall of the oil sump as a result of the cool level in an oil cooling region adjacent to the lateral outer wall being decoupled from the storage level of oil in an oil storage region of the oil sump.

Preferably, in the case of the oil sump according to the invention, it is provided for the oil cooling region to extend along the whole of the lateral outer wall of the oil sump.

The oil storage region of the oil sump is preferably completely surrounded by the oil cooling region of the oil sump.

In a preferred embodiment of the invention, it is provided, in the cool condition of the oil sump, for the cool level of the oil in the oil cooling region always to lie above 50%, in particular always above 80%, particularly preferably above 90%, of the height of the lateral outer wall adjacent to the oil cooling region.

This may be achieved in particular in that an upper edge of a separating wall between the oil cooling region and the oil storage region lies above 50%, in particular above 80%, particularly preferably above 90%, of the height of the lateral outer wall that is respectively adjacent to the oil cooling region.

It has proved particularly favourable if, in the cool condition of the oil sump, the cool level of the oil in the oil cooling region lies at the height of a mounting flange of the oil sump by means of which the oil sump is connectable to an engine, or lies by at most the height H of the mounting flange (that is to say, by the amount of its extent in the direction of gravity, in the assembled condition of the oil sump) below a lower edge of the mounting flange.

The decoupling device for decoupling the cool level of the oil in the oil cooling region from the storage level of the oil in the oil storage region may in particular include a separating wall that is arranged between the oil cooling region and the oil storage region.

Preferably, the separating wall extends upwards from the bottom wall of the oil sump, as seen in the direction of gravity.

A separating wall of this kind may take a form that is permanently impermeable to oil.

The separating wall may have an overflow at its upper edge, over which oil can pass from the oil cooling region into the oil storage region.

The separating wall between the oil cooling region and the oil storage region preferably takes the form of a closed ring.

If all that is provided is an oil-impermeable separating wall with an overflow, the oil in the oil cooling region can only circulate with difficulty or not at all, however, since the oil cooling region is laterally closed off from the oil storage region. The oil in the oil cooling region thus only undergoes exchange to a small extent.

In order to achieve greater exchange of the oil in the oil cooling region and the oil storage region, it may be provided for the oil sump to include at least one valve device for temporarily unblocking an oil aperture in the separating wall when the valve device is in an unblocking condition.

The valve device may in particular be arranged on the outer side of the separating wall, facing the oil cooling region, or on the inner side of the separating wall, facing the oil storage region.

The valve device may take a form such that it is movable into the unblocking condition by a control arrangement of the engine or the motor vehicle in which the oil sump is arranged once there has elapsed a predetermined period of time after the engine has been switched off.

As an alternative or in addition thereto, it may also be provided for the valve device to be movable into the unblocking condition in dependence on a temperature of the oil in the oil sump.

Such movability of the valve device into the unblocking condition in dependence on the temperature of the oil that is in contact with the valve device may be achieved in a particularly simple manner in that the valve device includes a bimetallic element.

A bimetallic element of this kind changes its shape in dependence on temperature.

In particular, it may be provided for the bimetallic element to adopt the shape of a substantially planar plate when the oil is at an operating temperature adopted by the oil when the internal combustion engine is in operation, and for the bimetallic element to adopt a curved shape at a lower quiescent temperature adopted by the oil after a relatively long break in operation of the internal combustion engine.

As an alternative thereto, it may also be provided for the bimetallic element to adopt the shape of a substantially planar plate at the quiescent temperature and to adopt a curve shape at the operating temperature.

Preferably, the bimetallic element includes a first layer of a first material and a second layer of a second material, wherein the thermal expansion coefficient of the first material is preferably greater than the thermal expansion coefficient of the second material in the relevant temperature range from the quiescent temperature to the operating temperature.

The first material of the bimetallic element may comprise for example copper, and in particular take the form of pure copper or a copper alloy.

The second material may comprise for example iron and in particular take the form of a steel material, in particular a spring steel material.

The bimetallic element may serve as a valve element that abuts against a valve seating of the valve device in a closed condition of the valve device and hence closes the oil aperture in the separating wall.

In the event of a rise in temperature, the bimetallic element is deformed such that it not longer abuts against the valve seating and hence unblocks the oil aperture in the separating wall so that oil can pass from the oil cooling region into the oil storage region.

As an alternative or in addition thereto, it may also be provided for the bimetallic element to take the form of an actuation element of the valve device that is operatively connected to a valve element of the valve device such that if the oil temperature falls from the operating temperature to the quiescent temperature the bimetallic element actuates a movement of the valve element from the closed condition, in which the valve element abuts against the valve seating of the valve device and closes the oil aperture in the separating wall, into the unblocking condition, in which the valve element is at a spacing from the valve seating and unblocks the oil aperture in the separating wall.

In this case, the valve element may for example take the form of a valve flap that is preferably held pivotally against the valve seating and/or against a valve housing of the valve device.

During operation of an engine that is connected to the oil sump, the valve device is preferably at least at times, in particular always, in a closed condition in which the valve device closes the oil aperture in the separating wall. In this way, during operation of the engine it is possible to set a cool level in the oil cooling region that is higher up than the storage level of the oil in the oil storage region.

Preferably, there is provided at the upper edge of the separating wall between the oil cooling region and the oil storage region an overflow over which oil can pass from the oil cooling region, in particular directly, into the oil storage region.

The oil cooling region preferably has an oil inlet through which oil entering the oil sump from the engine passes, in particular directly, into the oil cooling region.

In a particular embodiment of the invention, it is provided for there to be provided in the oil cooling region a flow directing device that lengthens the flow path of the oil from the oil inlet to an oil outlet of the oil cooling region, through which oil can pass from the oil cooling region into the oil storage region. This prevents oil that enters the oil cooling region from passing directly from the oil inlet to the oil outlet of the oil cooling region and from there escaping into the oil storage region. This would in fact exclude the majority of the oil entering the oil cooling region from a fluid exchange with the oil storage region.

Instead of this, the flow directing device has the effect that the oil entering the oil cooling region moves along the flow path, which preferably encompasses the entire oil cooling region, from the oil inlet to the oil outlet such that successively substantially all the oil received in the oil cooling region passes through the oil outlet and into the oil storage region, and thus substantially the entirety of the oil volume in the oil cooling region is exchanged over time.

The flow directing device may in particular include at least one flow directing element, for example in the form of a flow directing wall, that extends downwards from the oil inlet, as seen in the direction of gravity, into the region below 50%, in particular into the region below 30%, of the height of the lateral outer wall adjacent to the oil cooling region and/or into the region below 50%, in particular into the region below 30%, of the height of the separating wall adjacent to the oil cooling region between the oil cooling region and the oil storage region.

In order to achieve a situation in which a disproportionately large quantity of oil is supplied to the oil cooling region, with the result that the cool level in the oil cooling region can rise rapidly, it may be provided for the oil sump to include an oil return directing device that directs oil entering the oil sump to the oil inlet of the oil cooling region.

The oil return directing device may in particular include a funnel.

The oil return directing device preferably extends into the region that is vertically above the oil outlet of the oil cooling region (in the assembled condition of the oil sump), particularly preferably also into the region vertically above the oil storage region (in the assembled condition of the oil sump).

It is particularly favourable if at least 50%, preferably at least 70%, particularly preferably at least 90%, of the inner surface of the lateral outer wall of the oil sump is adjacent to the oil cooling region of the oil sump, at least when the cool level of the oil in the oil cooling region reaches its highest point in the cool condition of the oil sump.

The highest point of the cool level of the oil in the oil cooling region in this case preferably corresponds to the height of the overflow at the upper edge of the separating wall between the oil cooling region and the oil storage region.

The present invention further relates to a method for preventing an oil sump from failing as a result of the effect of heat.

It is a further object of the present invention to provide a method of this kind that in particular makes an oil sump made from a plastics material better able to withstand heat and flame.

According to the invention, this object is achieved by a method that includes the following:

- filling an oil cooling region of the oil sump, which is adjacent to a lateral outer wall of the oil sump, with oil up to a cool level; and
- decoupling the cool level from a storage level up to which an oil storage region of the oil sump is filled with oil, in a cool condition of the oil sump.

The advantageous effects of the method according to the invention and particular embodiments of the method according to the invention have already been explained above in conjunction with the oil sump according to the invention and with particular embodiments of the oil sump according to the invention, respectively.

The oil sump according to the invention is particularly suitable for performing the method according to the invention for preventing an oil sump from failing as a result of the effect of heat.

The oil sump according to the invention preferably includes a base body that is made in one piece.

The base body preferably comprises a thermoplastic material, for example a polyamide material, in particular polyamide 6.6.

It may further be provided for the base body of the oil sump to be formed from a glass fibre reinforced plastics material, in particular a glass fibre reinforced polyamide material.

The base body of the oil sump may be manufactured by an injection moulding method, in particular a cascade injection moulding method.

An oil sump having a base body made from a plastics material has the advantage that the oil storage volume can be made larger in a simple manner as a result of laterally added additional chambers.

If these additional chambers are a constituent part of the oil cooling region of the oil sump, this has the advantage that, because of the higher cool level of the oil in the oil cooling region when the engine is in operation, these additional chambers are filled with oil to a high percentage value, preferably completely filled with oil, with the result that the additional oil storage volume provided by the additional chambers is utilised particularly effectively.

Further features and advantages of the invention form the subject matter of the description below and the illustration in the drawings of exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective illustration of an oil sump that includes a front deep region and a rear shallow region, wherein the shallow region extends away from the deep region in an oil sump longitudinal direction of the base body of the oil sump, and wherein there is provided in the interior of the oil sump a separating wall that separates an oil cooling region of the oil sump from an oil storage region of the oil sump, in a view of an upper side of the oil sump that faces the engine block in the assembled condition;

FIG. 2 shows a further perspective illustration of the oil sump from FIG. 1, in a view of an underside of the oil sump, remote from the engine block in the assembled condition of the oil sump;

FIG. 3 shows a plan view of the oil sump from FIGS. 1 and 2, from above;

FIG. 4 shows a side view of the base body of the oil sump from FIGS. 1 to 3, with the direction of view in the direction of the arrow 4 in FIG. 3;

FIG. 5 shows a front view of the oil sump from FIGS. 1 to 4, with the direction of view in the direction of the arrow 5 in FIG. 3;

FIG. 6 shows a view of the oil sump from FIGS. 1 to 5 from behind, with the direction of view in the direction of the arrow 6 in FIG. 3;

FIG. 7 shows a vertical cross section through the oil sump from FIGS. 1 to 6, along the line 7-7 in FIG. 3;

FIG. 8 shows a perspective illustration of a second embodiment of an oil sump that includes a separating wall that separates an oil cooling region from an oil storage region of the oil sump, and includes an oil return directing device that diverts oil entering the oil sump from the engine to an oil inlet of the oil cooling region, in a view of an upper side of the oil sump that faces the engine block in the assembled condition;

FIG. 9 shows a plan view of the oil sump from FIG. 8 from above;

FIG. 10 shows a side view of the oil sump from FIGS. 8 and 9, with the direction of view in the direction of the arrow 10 in FIG. 9;

FIG. 11 shows a front view of the oil sump from FIGS. 8 to 10, with the direction of view in the direction of the arrow 11 in FIG. 9;

FIG. 12 shows a view of the oil sump from FIGS. 8 to 11 from behind, with the direction of view in the direction of the arrow 12 in FIG. 9;

FIG. 13 shows a vertical cross section through the oil sump from FIGS. 8 to 12, along the line 13-13 in FIG. 9;

FIG. 14 shows a vertical section through the oil sump from FIGS. 8 to 13, along the line 14-14 in FIG. 9;

FIG. 15 shows a perspective illustration of a first embodiment of a valve device for temporarily unblocking an oil aperture in a separating wall of an oil sump between an oil cooling region and an oil storage region of the oil sump, wherein the valve device includes a bimetallic element as the valve element for closing the oil aperture and is in a closed condition, in a view of a front side of the valve device;

FIG. 16 shows a perspective illustration of the valve device corresponding to FIG. 15, but without the bimetallic element that closes the oil aperture;

FIG. 17 shows a plan view of a rear side of the bimetallic element, facing the oil aperture;

FIG. 18 shows a further perspective illustration of the valve device from FIGS. 15 to 17, in a view of a rear side of the valve device;

FIG. 19 shows a front view of the valve device from FIGS. 15 to 18;

FIG. 20 shows a front view of the valve device from FIGS. 15 to 19, corresponding to FIG. 19, but without the bimetallic element that closes the oil aperture;

FIG. 21 shows a side view of the valve device from FIGS. 15 to 19, with the direction of view in the direction of the arrow 21 in FIG. 19;

FIG. 22 shows a view of the valve device from FIGS. 15 to 21 from behind, with the direction of view in the direction of the arrow 22 in FIG. 21;

FIG. 23 shows a vertical section through the valve device from FIGS. 15 to 22, along the line 23-23 in FIG. 19;

FIG. 24 shows a perspective illustration of a second embodiment of a valve device for temporarily unblocking an oil aperture in the separating wall between the oil cooling region and the oil storage region of an oil sump, in an unblocking condition of the valve device, wherein the valve device includes a pivotally held valve flap and a bimetallic element for actuating a movement of the valve flap from the unblocking condition into a closed condition, in a view of a front side of the valve device;

FIG. 25 shows a further perspective illustration of the valve device from FIG. 24, in a view of a rear side of the valve device;

FIG. 26 shows a further perspective illustration of the valve device from FIGS. 24 and 25, in a view of the front side of the valve device, but without the valve flap for closing an oil aperture of the valve device;

FIG. 27 shows a perspective illustration of the pivotally held valve flap, the bimetallic element and a spacer element of the valve device from FIGS. 24 to 26;

FIG. 28 shows a front view of the valve device from FIGS. 24 to 27;

FIG. 29 shows a side view of the valve device from FIGS. 24 to 28, with the direction of view in the direction of the arrow 29 in FIG. 28;

FIG. 30 shows a vertical longitudinal section through the valve device from FIGS. 24 to 29, along the line 30-30 in FIG. 28;

FIG. 31 shows a plan view of the valve device from FIGS. 24 to 30 from behind, with the direction of view in the direction of the arrow 31 in FIG. 29; and

FIG. 32 shows a horizontal cross section through the valve device from FIGS. 24 to 31, along the line 32-32 in FIG. 28.

Like or functionally equivalent elements are designated by the same reference numerals in all Figures.

DETAILED DESCRIPTION OF THE INVENTION

An oil sump that is illustrated as a whole in FIGS. 1 to 8 and is designated 100 includes a trough-shaped base body 102 that includes a deep front region 104 and a shallow rear region 106, wherein the shallow region 106 extends away from the deep region 104 in an oil sump longitudinal direction 108 of the oil sump 100 and the base body 102.

The shallow region 106 of the base body 102 has mutually opposite side walls 110, which extend in the longitudinal direction 108 and are connected to one another by a rear wall 112 at a rear end of the base body 102, remote from the deep region 104, and a bottom 114 that connects the two side walls 110 to one another.

In the installed condition of the oil sump 100, the bottom 114 of the shallow region 106 of the base body 102 is oriented to be almost horizontal, with a slight inclination towards the deep region 104 of the base body 102 of the oil sump 100.

The deep front region 104 of the base body 102 of the oil sump 100 includes a bottom 116, a front wall 118 that is remote from the shallow region 106 of the oil sump 100, a rear wall 120 that connects the bottom 116 of the deep region 104 to the bottom 114 of the shallow region 106, and two side walls 122 that connect the front wall 118 to the rear wall 120 and extend substantially parallel to the oil sump longitudinal direction 108.

Around the upper edge of the deep region 104 and the upper edge of the shallow region 106 of the base body 102 of the oil sump 100 there runs a mounting flange 124, which serves for assembly of the base body 102 of the oil sump 100 (by way of a gasket, not illustrated) to the engine block of an internal combustion engine (not illustrated).

The mounting flange 124 has a plurality of receptacles 126 that are at a spacing from one another in the peripheral direction of the mounting flange 124, for mounting screws (not illustrated) by means of which the oil sump 100 is fastenable to the engine block.

In order to stiffen the base body 102 of the oil sump 100 and to protect it from the effects of impact from outside the oil sump 100, in particular from stone chippings, the oil sump 100 may be provided with a ribbing 128.

The ribbing 128 may include in particular transverse ribs 130 that are arranged on the outside of the base body 102 and extend, starting from the mounting flange 124, downwards as seen in the direction of gravity 132, over a side wall 110 of the shallow region 106 or over a side wall 122 of the deep region 104 of the oil sump 100, in an oil sump transverse direction 134 that is oriented perpendicular to the oil sump longitudinal direction 108 and perpendicular to the direction of gravity 132, over the bottom 114 of the shallow region 106 or over the bottom 116 of the deep region 104, and then upwards again, as seen in the direction of gravity 132, over a further side wall 110 of the shallow region 106 that is opposite the first side wall 110, or over a further side wall 122 of the deep region 104 of the oil sump 100, to the mounting flange 124.

The transverse ribs 130 are preferably at a spacing from one another in the oil sump longitudinal direction 108, in particular being substantially equidistant.

Further, the ribbing 128 may include longitudinal ribs 136 that are arranged on the outside of the base body 102 of the oil sump 100 and extend, starting from the mounting flange 124, downwards as seen in the direction of gravity 132, over the front wall 118 of the deep region 104 of the oil sump 100, over the bottom 116 of the deep region 104 of the oil sump 100 in the oil sump longitudinal direction 108, along the rear wall 120 of the deep region 104 from the bottom 116 of the deep region 104 to the bottom 114 of the shallow region 106, over the bottom 114 of the shallow region 106 in the oil sump longitudinal direction 108, and over the rear wall 112 of the shallow region 106 of the oil sump 100, upwards as seen in the direction of gravity 132, to the mounting flange 124.

The longitudinal ribs 136 are preferably at a spacing from one another in the oil sump transverse direction 134, in particular being substantially equidistant.

The front wall 118, the side walls 122 of the deep region 104, the side walls 110 of the shallow region 106 and the rear wall 112 of the shallow region 106 of the oil sump 100 together form a lateral outer wall 138 of the oil sump 100 that is preferably in the form of a closed ring, encloses an interior 140 of the oil sump 100 and, in the assembled condition of the oil sump 100, extends upwards as seen in the direction of gravity 132, from the bottom wall 142 of the oil sump 100, which is formed by the bottom 116 of the deep region 104, the rear wall 120 of the deep region 104, and the bottom 114 of the shallow region 106.

Arranged in the interior 140 of the oil sump 100 is a separating wall 144 which, like the lateral outer wall 138, in the assembled condition of the oil sump 100 extends upwards from the bottom wall 142 of the oil sump 100, as seen in the direction of gravity 132, preferably approximately as far as the height of the lower edge of the mounting flange 124 (see sectional illustration in FIG. 7).

This separating wall 144 preferably runs substantially parallel to the lateral outer wall 138, which surrounds it, and is preferably likewise substantially in the form of a closed ring.

The separating wall 144 separates a region of the interior 140 of the oil sump 100 that lies within the separating wall 144, which is designated the oil storage region 146 below, from a region of the interior 140 of the oil sump 100 that lies between the separating wall 144 and the lateral outer wall 138 of the oil sump 100, which is designated the oil cooling region 148 below.

The oil cooling region 148 may be subdivided, by transverse walls 150 that extend in the oil sump transverse direction 134 from the separating wall 144 to the lateral outer wall 138 and are preferably arranged in the region of transition between the shallow region 106 and the deep region 104 of the oil sump 100, into a front oil cooling region 148a and a rear oil cooling region 148b.

For the purpose of increasing its mechanical stiffness, the separating wall 144 may be provided with ribs 152 that, in the assembled condition of the oil sump 100, preferably extend from the bottom wall 142 upwards, as seen in the direction of gravity 132, to the upper edge 154 of the separating wall 144.

As seen in the peripheral direction of the separating wall 144, these ribs 152 are preferably at a spacing from one another, in particular being substantially equidistant.

The mounting flange 124 of the oil sump 100 surrounds an oil entry face 156 of the oil sump 100 that is preferably oriented to be substantially horizontal in the assembled condition of the oil sump 100, and through which oil, in liquid form and/or in the form of oil mist, coming from the engine block of the internal combustion engine connected to the oil sump 100 enters the interior 140 of the oil sump 100.

The oil mist entering the oil sump 100 when the internal combustion engine is in operation is primarily precipitated onto the inner side of the lateral outer wall 138, and runs down into the oil cooling region 148 of the interior 140 of the oil sump 100.

Further, the oil return ducts (not illustrated) of the engine block are preferably arranged on the engine block such that the oil escaping from these oil return ducts passes through the outer region 156a of the oil entry face 156 of the oil sump 100—wherein, in the assembled condition of the oil sump 100 the outer region 156a lies vertically above the oil cooling region 148 (see FIG. 7)—and directly into the oil cooling region 148 of the interior 140 of the oil sump 100.

As a result of this inflow of oil returning from the internal combustion engine to the oil sump 100, when the internal combustion engine and the oil sump 100 are in operation the oil level in the oil cooling region 148 rises rapidly until it reaches the upper edge 154 of the separating wall 144, which forms an overflow 158 over which excess oil from the oil cooling region 148 runs over into the oil storage region 146.

For this reason, in a cool condition of the oil sump the oil cooling region 148 of the oil sump 100 is always filled with oil up to a cool level 160 that is at the height of the overflow 158 or just below the overflow 158.

By contrast, when the oil sump 100 and the internal combustion engine are in operation, oil is drawn off by suction from the oil storage region 146 of the interior 140 of the oil sump 100 by an oil suction pipe (not illustrated), in order to supply this oil to the internal combustion engine.

For this reason, during operation of the oil sump 100 the oil storage region 146 is filled with oil up to a (variable) storage level 162, with the storage level 162 always lower than the cool level 160.

Because the separating wall 144 between the oil storage region 146 and the oil cooling region 148 is oil-impermeable in form, the separating wall 144 forms a decoupling device 164 that prevents the oil level in the oil storage region 146 and in the oil cooling region 148 from levelling out and thus decouples the cool level 160 of the oil in the oil cooling region 148 from the storage level 162 of the oil in the oil storage region 146.

In particular, the effect of the decoupling device 164 is that when the oil sump 100 and the internal combustion engine are in operation, the cool level 160 of the oil cooling region 148, at least in the deep region 104 of the oil sump 100, is always above 50%, preferably above 90%, of the height of the portion of the lateral outer wall 138 that is respectively adjacent to the oil cooling region 148.

Particularly preferably, the cool level 160 of the oil cooling region 148 lies at the height of the mounting flange 124 of the oil sump 100 or only just below it, preferably at most by the height H of the mounting flange 124 (see FIG. 7), below a lower edge of the mounting flange 124 as seen in the direction of gravity 132.

The effect of this is that in the oil sump 100 the cool level 160 of the oil in the oil cooling region 148, which is adjacent to the lateral outer wall 138 of the oil sump 100, is always so high that the majority of the lateral outer wall 138 is in contact on its inner side with oil in the oil cooling region 148. As a result, in particular in the event of flames and/or heat acting from the outside of the oil sump 100, the portion of the lateral outer wall 138 that is in contact with oil is cooled by the oil in the oil cooling region 148, such that the material of the lateral outer wall 138 adopts the oil temperature as a maximum.

As a result, the structure of the lateral outer wall 138 maintains a higher residual stiffness even under the action of high temperatures and/or in direct contact with flame, as a result of which collapse or breach of the lateral outer wall 138 is greatly delayed or even completely prevented.

The separating wall 144 of the decoupling device 164 is preferably formed in one piece with the base body 102 of the oil sump 100.

The base body 102—including the separating wall 144—is preferably formed from a thermoplastic material, for example a polyamide material, in particular polyamide 6.6.

It is further preferably provided for the base body 102—including the separating wall 144—to be formed from a glass fibre reinforced plastics material, in particular a glass fibre reinforced polyamide material.

The base body 102 may be manufactured by an injection moulding method, in particular a cascade injection moulding method.

As can best be seen from FIG. 7, it may be provided for the separating wall 144 to taper from the bottom wall 142 towards its upper edge 154.

In the first embodiment, illustrated in FIGS. 1 to 7, of an oil sump 100 having an oil cooling region 148 that is separated off from an oil storage region 146 in the interior 140 of the oil sump 100 by a separating wall 144, there is only a small amount of exchange between the oil in the oil cooling region 148 and the oil in the oil storage region 146, because only the oil just entering the oil cooling region 148 through the oil entry face 156 of the oil sump 100 can pass into the oil storage region 146 by way of the overflow 158, so the oil within the oil cooling region 148 is circulated to only a very small extent or not at all, and thus there is hardly any exchange with the oil in the oil storage region 146.

A second embodiment, illustrated in FIGS. 8 to 14, of an oil sump 100 differs from the first embodiment illustrated in FIGS. 1 to 7 in particular in that there is provided in the oil cooling region 148 a flow directing device 166, which lengthens the flow path of the oil from an oil inlet 168 in the oil cooling region 148, through which oil entering the oil sump 100 from the internal combustion engine passes into the oil cooling region 148, to an oil outlet 170 of the oil cooling region 148 through which oil can pass from the oil cooling region 148 into the oil storage region 146.

This flow directing device 166 includes a flow directing element 172, for example in the form of a flow directing wall 174 that extends downwards, as seen in the direction of gravity 132, from the oil inlet 168 above the cool level 160 into the oil reservoir in the oil cooling region 148 and into the region that is below 50%, in particular into the region that is below 30%, of the height of the lateral outer wall 138 adjacent to the oil cooling region 148.

As can best be seen from FIG. 13, the flow directing wall 174 thus subdivides the oil cooling region 148 into an inlet region 176 facing the lateral outer wall 138 of the oil sump 100 and an outlet region 178 facing the separating wall 144, wherein the outlet region 178 is fluidically connected to the inlet region 176 by an oil aperture 180 that extends from the bottom wall 142, upwards as seen in the direction of gravity 132, to a lower edge 182 of the flow directing wall 174.

As a result of the presence of the flow directing wall 174, it is thus possible for the oil passing through the oil inlet 168 and into the oil cooling region 148 not to pass directly to the oil outlet 170 and from there over the overflow 158 and into the oil storage region 146; rather, by the principle of communicating vessels, the oil that has passed most recently through the oil inlet 168 and into the inlet region 176 of the oil cooling region 148 pushes the oil that is located at the cool level 160, at the oil outlet 170 of the outlet region 178, over the overflow 158 and into the oil storage region 146, whereupon the oil flowing out into the oil storage region 146 is replaced by oil rising out of the region of the oil aperture 180 at the lower end of the oil cooling region 148.

Thus, in accordance with this siphoning principle, the oil entering the oil cooling region 148 through the oil inlet 168 is gradually conveyed first downwards through the inlet region 176 and then back up through the outlet region 178, such that the entire volume of oil passes successively from the oil cooling region 148 to the oil outlet 170 and over the overflow 158 into the oil storage region 146, as a result of which a constant exchange of oil is ensured in the oil cooling region 148, with a cool level 160 of the oil in the oil cooling region 148 that is higher than the storage level 162 in the oil storage region 146 constantly being maintained.

In this second embodiment, the oil sump 100 further includes an oil return directing device 184 that diverts oil entering the oil sump 100 from the engine towards the oil inlet 168 of the inlet region 176 of the oil cooling region 148.

This oil return directing device 184 includes in particular an oil return directing wall 186 that extends from an upper edge of the flow directing wall 174 of the flow directing device 166, inclined at an angle a to the direction of gravity 132 in the assembled condition of the oil sump 100, into the region vertically above the oil outlet 170 of the outlet region 178 of the oil cooling region 148 and preferably also extends into the region vertically above the oil storage region 146 of the oil sump 100.

Preferably, the oil return directing device 184 completely covers the oil outlet 170 of the oil cooling region 148.

In the assembled condition of the oil sump 100, the angle of inclination α to the direction of gravity 132 here is preferably more than 45° and/or less than 80°.

The upper side of the oil return directing wall 186 that is remote from the separating wall 144 in this case acts as an oil return directing face 188, which keeps oil coming from the internal combustion engine away from the oil outlet 170 of the oil cooling region 148 and from part of the oil storage region 146, and directs it towards the oil inlet 168 of the oil cooling region 148.

The effect of this is that more oil passes through the oil inlet 168 and into the oil cooling region 148 than through the oil outlet 170, so a preferential direction of flow through the oil cooling region 148 is established from the oil inlet 168 to the oil outlet 170.

As can best be seen from FIGS. 8, 9 and 14, the flow directing device 166 includes transverse webs 190, which are oriented transversely, preferably substantially perpendicular, to the flow directing wall 174 and, in the assembled condition of the oil sump 100, extend through the oil cooling region 148 from the separating wall 144 to the lateral outer wall 138.

In this arrangement, an outer edge 192 of each transverse web 190 is preferably implemented in a guide profile 194 oriented substantially in the direction of gravity 132 on the inner side of the lateral outer wall 138, while an inner edge 196 of each transverse web 190 is preferably implemented in a guide profile 198 that runs substantially in the direction of gravity 132 over the outer side of the separating wall 144 that faces the lateral outer wall 138.

The flow directing device 166 and the oil return directing device 184 are preferably made in one piece with one another and may be manufactured separately from the base body 102 of the oil sump 100.

The flow directing device 166 and the oil return directing device 184 may thus in particular together form an oil directing device 200.

The oil directing device 200 is preferably formed from a thermoplastic material, for example a polyamide material, in particular polyamide 6.6.

Further, it is preferably provided for the oil directing device 200 to be formed from a glass fibre reinforced plastics material, in particular a glass fibre reinforced polyamide material.

The oil directing device 200 may be manufactured by an injection moulding method, in particular a cascade injection moulding method.

The oil directing device 200 may in particular be formed from the same material as the base body 102 of the oil sump 100.

After manufacture, the oil directing device 200 may be pushed into the guide profiles 194 and 198 of the lateral outer wall 138 and the separating wall 144 respectively by means of its transverse webs 190.

The oil directing device 200 may be detachably held on the base body 102 of the oil sump 100, for example by a press fit or by positive locking, in particular by latching.

The fact that the oil directing device 200 is detachably fastened to the base body 102 of the oil sump 100 has the advantage that the oil directing device 200 may be removed from the base body 102 for the purpose of cleaning or maintenance.

As an alternative thereto, however, it is also possible to fix the oil directing device 200 non-detachably in the condition in which it is pushed into the base body 102, for example by adhesion and/or welding.

Otherwise, the second embodiment of an oil sump 100 that is illustrated in FIGS. 8 to 14, corresponds, as regards its structure, functioning and manufacture, to the first embodiment illustrated in FIGS. 1 to 7, so in this respect reference is made to the description thereof above.

Another way of achieving oil exchange between the oil cooling region 148 and the oil storage region 146 while simultaneously maintaining a cool level 160 of the oil in the oil cooling region 148 that lies above the storage level 162 of the oil in the oil storage region 146 consists in including in the oil sump 100 a valve device 202 for temporarily unblocking an oil aperture in the separating wall 144 when the valve device 202 is in an unblocking condition.

A first exemplary embodiment of a valve device 202 of this kind is illustrated in FIGS. 15 to 23.

This valve device 202 includes a mount 204 that is fastenable on a portion of the separating wall 144 that has an oil aperture (not illustrated).

The mount 204 carries a valve seating 206, with an oil passage duct 208 extending through the mount 204 and the valve seating 206.

For the purpose of closing the oil passage duct 208, in a closed condition of the valve device 202 there serves a valve element 210 which, in this embodiment, includes a bimetallic element 212.

The bimetallic element 212 includes a first layer 213a of a first material, which is remote from the valve seating 206, and a second layer 213b of a second material, which faces the valve element 210.

Preferably, the first material has a greater thermal expansion coefficient than the second material in the temperature range extending from the quiescent temperature of the oil, during long breaks in operation of the internal combustion engine, and the operating temperature of the oil, when the internal combustion engine is in prolonged operation.

The first material and/or the second material is preferably a metallic material.

For example, a material containing copper, for example pure copper or a copper alloy, may be used as the first material.

For example, a material containing iron, in particular a steel material, for example a spring steel material, in particular the material 1.4310 or material 1.4301 according to DIN EN 10151, may be used as the second material.

FIG. 17 shows a plan view of the inner side 214 of the valve element 210, which faces the valve seating 206.

This inner side 214 may be provided with a sealing face 216, which is preferably in the form of a closed ring, of an elastomer material, for example AEM (ethylene acrylate rubber), which in the closed condition of the valve device 202 surrounds the outlet opening of the oil passage duct 208.

As an alternative thereto, it may also be provided for the inner side 214 of the valve element 210 to be provided substantially over its entire surface with a coating of an elastomer material, for example AEM.

In the closed condition of the valve device 202, the sealing element 216 preferably abuts against a sealing bead 218 that is arranged on the valve seating 206 and surrounds the outlet opening of the oil passage duct 208 in the form of a closed ring.

The sealing bead 218 may be formed for example from a polyamide material.

The sealing bead 218 may in particular be made in one piece with the valve seating 206.

The valve seating 206 may in particular be made in one piece with the mount 204 of the valve device 202.

Instead of a sealing bead 218 on the valve seating 206, it may also be provided for a sealing lip, for example made from an elastomer material, to be arranged on the inner side 214 of the valve element 210.

In order to fasten the valve element 210 on the valve seating 206, it may for example be provided for the valve seating 206 to have one or more holding elements 220, for example in the form of holding pegs 222, that are configured to be brought into engagement with one or more holding elements 224 corresponding thereto on the valve element 210, for example in the form of holding openings 226.

In particular, it may be provided for the holding elements 224 of the valve element 210 and the holding elements 220 of the valve seating 206 to be connected to one another by force locking, by positive locking and/or by substance-to-substance bond.

For example, it may be provided for the holding elements 224 of the valve element 210 and the holding elements 220 of the valve seating 206 to be connected to one another by heat staking or by screwing them to one another. The valve device 202 is placed on a region of the separating wall 144 having the oil aperture by means of the abutment face 228 of the mount 204, which is remote from the valve element 210, and is fastened to the separating wall 144, preferably by substance-to-substance bond, in particular by adhesion or welding.

The valve device 202 may be arranged on the inner side of the separating wall 144, facing the oil storage region 146. This has the advantage that there is more working space available in the oil storage region 146 of the oil sump 100 for the purpose of fastening the valve device 202 to the separating wall 144, for example for welding the valve device 202 to the separating wall 144, and this facilitates assembly of the valve device 202.

However, the valve device 202 may also be arranged on the outer side of the separating wall 144, facing the oil cooling region 148. This has the advantage that the hydrostatic pressure in the oil cooling region 148, which is higher because of the higher cool level 160 of the oil in the oil cooling region 148, biases the valve element 210 against the valve seating 206 in the closed condition and thus promotes closing of the valve device 202.

The bimetallic element 212 of the valve device 202 preferably takes a form such that at a high oil temperature, as occurs when the internal combustion engine is in prolonged operation, the valve element 210 adopts the shape of a substantially planar plate, which abuts against the sealing bead 218 of the valve seating 206 in substantially fluid-tight manner by means of the sealing element 216.

This blocks the fluid connection between the oil cooling region 148 and the oil storage region 146 through the oil passage duct 208 of the valve device 202, such that in the oil cooling region 148 the desired high cool level 160 is established during operation of the internal combustion engine, and this high cool level 160 ensures sufficient cooling of the lateral outer wall 138 in the event of the oil sump 100 being acted upon by heat and/or flames.

When the oil temperature falls after the internal combustion engine has been at a standstill for a certain period, the layer 213a of the first material contracts to a greater extent than the second layer 213b of the second material, with the result that the valve element 210 curves concavely—as seen in a plan view of the front side 230 of the valve element, remote from the valve seating 206—and thus moves away from the valve seating 206.

As a result, the valve device 202 moves from the closed condition to the unblocking condition in which the valve device 202 unblocks the oil aperture in the separating wall 144, such that oil can flow out of the oil cooling region 148 and into the oil storage region 146 in order to enable an oil exchange between the oil cooling region 148 and the oil storage region 146 and thus sufficient oil circulation.

When the internal combustion engine is started again, a certain warm-up time is required until the oil temperature has risen enough to convert the bimetallic element 212 back into the substantially planar shape in which it closes the oil passage duct 208. Once the valve device 202 has moved back into the closed condition from the unblocking condition by the increase in the oil temperature, the cool level 160 in the oil cooling region 148 is decoupled from the storage level 162 in the oil storage region 146 and can rise again to the height of the overflow 158 in order to ensure protection from heat and flames over the entire height of the lateral outer wall 138.

The valve device 202 thus provides a temperature-controlled valve that moves into the closed condition at high oil temperatures and into the unblocking condition at low oil temperatures.

If, as described above, the oil cooling region 148 is subdivided into a front oil cooling region 148a and a rear oil cooling region 148b by transverse walls 150, then for each of these oil cooling region 148a, 148b at least one valve device 202 is respectively required.

Preferably, for each oil cooling region 148a, 148b or where appropriate for the single oil cooling region 148 there are respectively provided two valve devices 202 that are preferably arranged on different sides of the vertical longitudinal centre plane of the oil sump 100 that runs parallel to the oil sump longitudinal direction 108 and (in the assembled condition of the oil sump 100) parallel to the direction of gravity 132.

A valve device 202 of this kind is preferably used in the first embodiment of the oil sump 100, illustrated in FIGS. 1 to 7, but may in principle also be used in the second embodiment of the oil sump 100, illustrated in FIGS. 8 to 14.

A second exemplary embodiment, illustrated in FIGS. 24 to 32, of a valve device 202 differs from the first embodiment illustrated in FIGS. 15 to 23, in particular in that the bimetallic element 212 in the second embodiment does not serve as a valve element but as an actuation element 232 for actuating movement of the valve element 210 from the closed condition into the unblocking condition.

This exemplary embodiment of a valve device 202 also includes a mount 204 that is configured to abut against the separating wall 144 by means of an abutment face 228 and to be fastened thereto.

Here, in this embodiment of the valve device 202, it is preferably provided for the valve device 202 to be arranged on the outer side of the separating wall 144, facing the oil cooling region 148.

The valve device 202 further includes a valve seating 206 having a sealing face 234 which—in the assembled condition of the oil sump 100—is inclined in relation to the direction of gravity 132. The angle of inclination β of the sealing face 234 in relation to the direction of gravity 132 is preferably more than 10° and/or less than 20° (see FIG. 30).

An oil passage duct 208 extends through the mount 204 and the valve seating 206.

In this embodiment, the valve element 210 which, in the closed condition of the valve device 202, closes the oil passage duct 208 takes the form of a valve flap 236 that is held pivotally about a pivot axis 242—which, in the assembled condition of the oil sump 100, is preferably oriented substantially horizontally—by means of two pivot pins 238, each in a respective pivot pin receptacle 240 of the valve seating 206.

The pivot pin receptacles 240 of the valve seating 206 are closable by means of a valve housing cover 244 (illustrated separately, for example in FIG. 27) in order to retain the pivot pins 238 of the valve flap 236 in the pivot pin receptacles 240.

The valve housing cover 244 is configured to be fastened to the valve seating 206 by substance-to-substance bond, positive locking and/or force locking once the pivot pins 238 have been introduced into the respectively associated pivot pin receptacle 240.

For example, it may be provided for the valve housing cover 244 to be latchable to the valve seating 206.

On its inner side 214 facing the valve seating 206, the valve element 210 has a sealing bead 246 that is in the form of a closed ring and, in the closed condition of the valve device 202, surrounds the exit opening of the oil passage duct 208 and abuts against the sealing face 234 in substantially fluid-tight manner.

The sealing bead 246 is preferably formed from an elastomer material, for example AEM (ethylene acrylate rubber).

The sealing bead 246 may in particular be cast onto or moulded onto a base element 248 of the valve element 210 that is formed for example from a polyamide material.

For a casting-on or moulding-on procedure of this kind, the base element 248 may in particular have an entry opening 250 and one or more exit openings 252 for the elastomer material to be cast or moulded into (see in particular FIG. 28), wherein the exit openings 252 are connected to the entry opening 250 preferably through cavities in the base element 248.

Further, in this embodiment the valve element 210 includes a spacer element 254, for example in the form of a spacer pin 256 that extends from the inner side 214 of the valve element 210 in the direction of the bimetallic element 212, which is fastened to the mount 204 of the valve device 202 and passes across the entry opening of the oil passage duct 208 (see FIG. 31).

The bimetallic element 212 is preferably connected by one or more holding elements 224, for example in the form of holding openings 226, to one or more respectively associated holding elements 220 of the mount 204, for example in the form of holding pegs 222, for example by substance-to-substance bond, force locking and/or positive locking.

The bimetallic element 212 has a first layer 213a made from the first material, with the greater thermal expansion coefficient, which is remote from the valve element 210, and a second layer made from the second material, with the smaller thermal expansion coefficient, which faces the valve element 210.

The bimetallic element 212 takes a form such that, in the unblocking condition of the valve device 202, which is illustrated in particular in FIG. 30, at the low quiescent temperature of the oil, it takes the form of a substantially planar strip.

The valve element 210 abuts against the bimetallic element 212 by means of the spacer element 254, and is deflected by the bimetallic element 212 out of the closed condition and into the unblocking condition illustrated in FIG. 30, in which the valve element 210 unblocks the exit opening of the oil passage duct 208 such that oil can pass out of the oil cooling region 148 and into the oil storage region 146.

When the valve device 202 is in this unblocking condition, the cool level 160 of the oil in the oil cooling region 148 is thus at the same height as the storage level 162 of the oil in the oil storage region 146.

When, after the internal combustion engine has been started, the oil temperature rises, the bimetallic element 212 changes to a concave shape (as seen from the valve element 210), with the result that the bimetallic element moves away from the exit opening of the oil passage duct 208.

Because of the action of gravity on the valve element 210, which is held pivotally about the horizontal pivot axis 242, the valve element 210 follows this movement of the bimetallic element 212, wherein the spacer element 254 remains in contact with the bimetallic element 212 until the sealing bead 256 of the valve element 210 abuts in substantially fluid-tight manner against the sealing face 234 of the valve seating 206.

Consequently, the valve device 202 moves into the closed condition in which the oil aperture in the separating wall 144 is blocked, such that the cool level 160 of the oil in the oil cooling region 148 is decoupled from the storage level 162 of the oil in the oil storage region 146 and rises as far as the overflow 158 as a result of the inflow of oil from the internal combustion engine, with the result that protection against flames is provided over the entire height of the lateral outer wall 138.

If the internal combustion engine is switched off for a relatively long period the oil cools down again, as a result of which the bimetallic element 212 returns to its planar shape and, by way of the spacer element 254, moves the valve element 210 back into the unblocking condition illustrated in FIG. 30, in which once again an oil exchange is possible between the oil cooling region 148 and the oil storage region 146 through the oil passage duct 208 of the valve device 202.

Otherwise, the second embodiment of the valve device 202 that is illustrated in FIGS. 24 to 32 corresponds, as regards its structure, functioning and manufacture, to the first embodiment illustrated in FIGS. 15 to 23, so in this respect reference is made to the description thereof above.

	Number	Date	Country
Parent	PCT/EP2018/055556	Mar 2018	US
Child	16569022		US

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