WO2016119768A1

WO2016119768A1 - Internal combustion engine comprising an oil return line having an oil duct

Info

Publication number: WO2016119768A1
Application number: PCT/DE2015/100516
Authority: WO
Inventors: Ralf Siemer
Original assignee: Volkswagen Ag
Priority date: 2015-01-30
Filing date: 2015-12-03
Publication date: 2016-08-04
Also published as: DE102015101410A1; EP3250797A1; EP3250797B1; CN107429583B; CN107429583A

Abstract

The invention relates to an internal combustion engine (1) comprising an oil sump (4) arranged underneath a crank drive (3). The oil sump (4) is filled with oil (8) up to an oil level (7) during operation of the internal combustion engine (1). The oil sump upper part (5) is equipped with multiple through openings (9), each of which is assigned an oil duct (10) for returning the oil (8) to the oil sump (4). In the oil duct (10), a collection point (11) is provided underneath the oil sump upper part (5), into which collection point a section of the oil duct (10) designed as an immersion tube (12) is immersed to below a collection level (13) of the oil volume in the collection point (11). In this way, the oil volume in this collection point (11) seals the free opening of the oil duct (10) during operation and prevents, in particular, an undesired compensation of potential pressure differences between the gas volume within the oil sump (4) and the gas volume within a cylinder crankcase (2), which could otherwise impede the reliable return of the oil (8) due to a gas flow in the opposite direction to the oil flow. For this purpose, the collection point (11) is configured in such a way that the oil level (7) in the oil sump (4) is constantly lower than the collection level (13) of the oil volume in the collection point (11).

Description

description

Internal combustion engine with an oil return having an oil passage

The invention relates to an internal combustion engine with a cylinder crankcase, a

Oil pan, which is filled in operation to an oil level with oil, an oil pan upper part with at least one passage opening and at least one oil channel having, the return of oil, in particular from the oil separation in the oil pan serving oil return is associated.

Such an internal combustion engine is already widely used in practice and therefore already belongs to the prior art due to public prior use.

For example, DE 100 26 113 B4 also describes an internal combustion engine with an oil pan upper part arranged between a crank chamber and an oil pan, which is held between a cylinder crankcase and an adjoining part of an oil pan. An oil channel runs in such a way that the oil returned from the cylinder head is led into the oil sump below the oil level.

During operation of the internal combustion engine, a fine oil mist-containing, so-called blow-by flow is removed from a crankcase by a gas recirculation device and, for example, supplied to the charge air. Blowby means in an internal combustion engine the gas flowing past the piston rings during compression.

With an oil separator is achieved that may still be reflected in the gas flowing through the gas outlet from the cyclone, located oil droplets in the region of the enlarged cross-section gas line section on the surfaces and flow from there under gravity to Ölableitkanal through which the oil either is passed directly to the oil sump of the internal combustion engine or first to the oil outlet and from there, together with the already separated in the cyclone oil to the oil sump of the internal combustion engine. In this way it is achieved that the Ölabscheidegrad is particularly high and that neither oil mist nor occasionally get larger drops of oil in the air intake tract of the internal combustion engine. During operation of the oil separator passes through the gas inlet

Crankcase ventilation gas of an internal combustion engine in the interior of the cyclone and is offset in this in a helical rotary flow, in which the entrained oil droplets due to centrifugal forces are carried to the outside and precipitate on the inner wall of the cyclone. The oil outlet at the lower end of the cyclone leads from the oil collection funnel to the oil sump of the internal combustion engine.

From WO 00/68548 A1 such an oil separator for deoiling of crankcase ventilation gases of an internal combustion engine is known. The oil separator comprises at least one cyclone, one connected to the crankcase of the internal combustion engine

Gas inlet, a gas outlet connected to the air intake tract of the internal combustion engine and an oil outlet connected to the oil sump of the internal combustion engine, wherein the gas outlet protrudes as a dip tube through a top closing the cyclone in the cyclone interior.

In order to ensure the oil return from the oil separator in the oil sump in all mounting positions and all dynamic conditions, it is necessary to realize a complex design or routing of the oil return below the oil level in the sump.

Due to the gas pressure occurring in the oil passage during operation of the internal combustion engine, it may happen that the oil does not flow to the oil sump arranged at the lowest level of the oil system, but collects at other points in the oil system. The cause of this may be, for example, fast cornering, whereby the oil is pressed to the outside and thereby additionally a gas pressure is built up in the oil passage, which counteracts the unimpeded outflow of the oil.

Against this background, the invention has the object, an internal combustion engine of the type mentioned in such a way that in particular driving dynamics caused pressure fluctuations in the oil line system does not lead to a deterioration of the oil flow in the oil channel.

This object is achieved with an internal combustion engine according to the features of

The subclaims relate to particularly expedient developments of the invention.

According to the invention, therefore, an internal combustion engine is provided, in which the oil channel has a collection point, which receives a free passage of the oil passage occluding oil volume during operation, wherein the collection point is arranged such that an oil level of the oil pan in the direction of gravity below the collection level, ie geodesically deeper than the collection level of the oil volume is in the collection point. Thus, by the oil channel is partially designed as a collection point or is connected to such a collection point in which collects an oil volume that does not flow into the oil pan even with strong driving dynamics and which closes the free passage of the oil channel, is also the gas exchange between the sections in

Flow direction before and behind the collection point prevented. In the episode will be

Pressure fluctuations, for example, caused by a sloshing in the sump oil volume or due to gas pressure differences in the crank mechanism, no longer transferred to the oil line system, but by the oil volume in the

Collection point local limited. Thus, a reliable oil return is always guaranteed even under unfavorable operating conditions. Essential for the invention is a geodetically above the oil inlet, in particular above a floor level of the collection point arranged oil drain, the collecting point receives a line of the oil channel occluding oil volume, the collection level is above the oil level of the oil pan.

A particularly advantageous embodiment of the invention is also achieved in that the collection point has a bent pipe section with an oil inlet and an oil drain, which include between them a pipe bend section in a geodetically lower position. By the oil feed and the oil drain according to the principle of

communicating tubes connected and always remain filled with oil, the volume of oil present in the collection closes the oil channel gas-tight. In practice, therefore, under the influence of air pressure fluctuations only the relative oil level of the oil supply to the oil flow is changed, but without it can lead to an undesirable passage of gases.

According to the invention, the oil channel could have a pipe bend between two horizontally extending regions which reaches a lower region. On the other hand, it is particularly practical if, in the case of a vertical or at least substantially from top to bottom region of the oil channel, the collection point is bent in an S-shape

Having pipe section which is integrally connected to the oil inlet and the oil drain, so that the course of the oil channel can be easily integrated into a vertical arrangement according to the principle of a siphon.

Another, also particularly promising embodiment of the invention is also achieved in that the collection point has an oil collection container equipped with a collection level defining oil drain, and that the oil passage as a dip tube has executed portion which lies with its opening below the collection level, that is immersed in the oil volume. As a result, in a simple manner, a reliable gas-tight final collection point area is created on the principle of a bottle closure in any operating situation, wherein the overcoming of the oil in operation

Height difference, if necessary, by the immersion depth of the dip tube in the

Olsammelbehälter set and can be easily adapted to different internal combustion engines. The Olsammelbehälter may be equipped in an open design with an overflow, or in a closed design with at least one outlet opening as an oil drain, which may optionally be closed.

In addition, according to a particularly practical variant of the invention, a plurality of oil passages, each with at least one dip tube, can lead into a common oil collection container and submerge into the collecting volume. As a result, the space required and the design effort to realize the invention are reduced. In addition, at the same time, the oil volume which is required in the collection point and, for example, can not be completely removed even when changing the oil, is reduced to a minimum compared with several separate collection points.

Preferably, the oil passage is arranged concentrically to a Olsammelbehälter the collection point. In this case, according to a particularly practical embodiment of the invention, the efficiency can be further increased by arranging several collection points in cascade such that the oil drain of a first collection point leads into an oil supply of a second collection point, whereby the collection points can be flowed through in a series arrangement. The oil feed of a second collection point lies in the direction of gravity below an oil drain of a first collection point.

In another, also particularly practical variant of the invention, a plurality of Olsammelbehälter are arranged concentrically to each other. By this design can be realized in a particularly space-saving multiple overcoming of a height difference for a further improved gas-tight closure. The space required for this purpose is therefore

comparatively low.

The collection point could be arranged outside the internal combustion engine and connected to it by suitable lines. In contrast, an embodiment is particularly simple in which the collection point is arranged inside the cylinder crankcase, in particular within the space defined by the oil sump. In addition, it is particularly useful if the effective oil column as geodesic

Height difference between the oil inlet and the oil drain is at least 100 mm.

In addition, according to the principle of hydraulic press by different cross-sectional areas of the oil supply to the oil drain at a comparatively low force on one side a large force on the other side can be achieved. The cross-sectional ratio can be adapted to the conditions actually occurring by an appropriate design of the cable cross-sections easily.

The invention allows numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and will be described below. This shows in each case in a schematic representation in

1 shows a cross section through an internal combustion engine with a cylinder crankcase and an oil return, which is associated with a collecting point exhibiting oil channel.

2 shows a cross section through an oil pan upper part and a lower part of the oil pan

Internal combustion engine with two collection points;

3 shows a perspective view of the oil pan bottom part shown in FIG. 2 with the two collection points;

Fig. 4 is a perspective view of the oil pan base with an oil planer and

a collection point with two immersion tubes connected to a structural unit;

5 shows a variant of a collection point with an S-shaped bent pipe section.

Fig. 6 shows a further variant of a collection point with a coaxial to the oil inlet

Oil drain;

FIG. 7 shows a simplified variant of the collection point shown in FIG. 4 with two dip tubes opening into the same oil collection container; FIG.

Fig. 8 shows a variant of a collection point with two concentric oil collecting containers. FIG. 1 shows, in a very simplified schematic representation, a cross section through an internal combustion engine 1 with a cylinder crankcase 2 and one below a cylinder crankcase 2

Crankshaft 3 arranged oil pan 4. The oil pan 4 comprises an adapted to the rotational circle of the crank mechanism 3 Olwannenoberteil 5 and a lower pan part 6, which is filled during operation of the internal combustion engine 1 to an oil level 7 with oil 8. The

Olwannenoberteil 5 is equipped with a plurality of passage openings 9, each of which an oil passage 10 is assigned to return the oil 8 in the oil pan 4, for better clarity, only one example of a possible arrangement is shown. In the oil passage 10 is provided below the oil pan upper part 5 as an oil retaining cup

Collection point 11 is provided, in which a running as a dip tube 12 portion of the oil passage 10 to below a collecting level 13 of the oil volume in the collection point 1 1 dips. As a result, closes the oil volume in this collection point 1 1 in operation, the free passage of the oil passage 10 and in particular prevents undesirable compensation of possible pressure differences between the gas volume within the sump 4 and the gas volume within the cylinder crankcase 2, which otherwise by a flow of oil directed counter to the gas flow reliable Repatriation of the oil 8 could complicate. In this case, the collection point 11 is designed such that the oil level 7 in the oil pan 4 in the direction of gravity is always lower than the collection level 13 of the oil volume in the collection point 11. Upon reaching an upper edge 14 of the oil collecting cup 25 executed collection point 11 can Overflow oil 8 freely. Shown only by dashed lines is an embodiment in which the oil collecting container 25 is circumferentially enclosed by a further oil reservoir 25 ', so as to increase the efficiency of the

Oil channel closure continues to improve. As a result, the oil 8 flows out of the first

Oil collecting 25 first in the other oil reservoir 25 'and only then in the oil pan. 4

Figure 2 shows a Olwannenoberteil 5 and an oil pan bottom part 6 of the internal combustion engine 1 with two collection points 1 1 in a sectional side view. As can be seen, the oil passes through an oil passage opening 9 of a respective collecting point 11

Oil return into the associated oil reservoir 25. In this case, the oil reservoir 25 each have different collection levels 13, from which flows over from the oil and flows into the oil pan 4, in which the oil collects to an oil level 7.

FIG. 3 additionally shows the oil pan bottom 6 shown in FIG. 2 with the two collection points 11. As can be seen, the two collection points 11 are connected to form a structural unit and can be fixed in the lower part of the oil pan 6 without problems. To recognize the respective dip tube 12 of the two integrated into the oil pan bottom 6 oil reservoir 25 of the collection points 1 1, which is associated with the corresponding Oldurchlassöffnung 9 of the oil return shown in Figure 2 of the upper pan.

A further variant of a collection point 24 can be seen in Figure 4, in which two separate dip tubes 12 are connected to form a structural unit. Here, a first exchange tube 12 'serves as a coarse oil discharge of an old passage opening 9 in an oil planer 29. The further dip tube 12 "serves for the fine oil return of a collection channel (not further shown.) Both dip tubes 12', 12" open into an oil collection container 25, the respective oil volumes being separated by a

Partition 30 are separated. When the maximum collection level 13 is exceeded, the oil flows into the oil pan 4 or into the adjacent collection area.

FIG. 5 shows a variant of a collection point 15 with an S-shaped curve of the oil channel 10, wherein the oil volume is collected in a pipe bend section 16 arranged in a geodetically lower position, that of an oil inlet 17 and a oil inlet 17 running parallel to it Oil drain 18 is included and so always remains filled with oil according to the principle of communicating pipes, thus making the passage of gases at least difficult. The pipe bend portion 16 is integrally connected to the oil inlet 17 and the oil drain 18, but can also be designed separable or replaceable.

In contrast, a further variant of a collection point 19 is shown in Figure 6, in which the oil inlet 17 to the oil drain 18 is not only parallel, but also along a common axis 20 coaxial. In the region of a cross-sectional widening 21 of the oil channel 10, two flow guide elements 22, 23 are arranged such that, similar to the S-shaped pipe bend section 16 shown in FIG. 5, a flow deflection of the oil occurs, with the second flow guide element 23 simultaneously overflowing the oil Achieving a maximum collection level allows. The first flow guide 22 dips into the collecting volume. Due to the coaxial arrangement, this variant can be used without problems even if the structural conditions of the structure are essentially unchanged

Internal combustion engine 1 realized or even with existing internal combustion engine. 1

be retrofitted.

In Figure 7 a simplified embodiment of the collection point shown in Figure 4 24 is shown with two independent dip tubes 12, which open into the same oil reservoir 25, wherein a respective, designed as an oil inlet 17 opening in a

Submersible tube section below a collecting level 13 in the collection point 24 is located. Of course, in this variant, similar to the dashed line in FIG. 1, the oil collecting container 25 can be surrounded by a further oil collecting container 25 'on the circumference.

be included.

In Figure 8, finally, a variant is shown, in the two concentric

Oil collecting 25, 25 'each form a collection point 26 and are arranged concentrically with each other so that the oil drain 18 of the first oil collecting tank 25 cascade into an oil inlet of the second oil collecting container 25' leads. For this purpose, the upper edge 14 of the inner oil collecting container 25 is higher than the edge 14 'of the inner oil collecting container 25 enclosing outer oil collection container 25'. The oil feed 17 is embodied here by way of example as a pipe bend section 16, so that the supplied oil is first collected in the pipe bend section 16. During operation, the oil flows over the upper edge 14 of the inner oil collecting container 25 and passes through an annular gap 27 between the inner oil collecting container 25 and the outer oil collecting container 25 'to an inlet opening 28 arranged in a region near the bottom of the outer oil collecting container 25' Intake port 28, indicated by an arrow, flows the oil into the outer oil reservoir 25 'and, when the edge 14' of the outer oil reservoir 25 'is reached, it can freely overflow, whereby the oil passes into the oil sump 4 shown in FIG. The cascading arrangement of the oil reservoirs 25, 25 'in the concentric design is achieved by the additional overcoming of the geodetic height difference between the edge 14 of the inner oil reservoir 25 and the

Inlet opening 28 of the outer oil collecting container 25 'achieved a significant increase in efficiency and effective protection even large occurring during driving pressure differences, which also only a small space is required.

LIST OF REFERENCE NUMBERS

Internal combustion engine 21 Cross-sectional widening Cylinder crankcase 22 Flow guide Crank drive 23 Flow guide Oil sump 24 Collection point

Upper sump section 25 Oil sump lower sump lower 26 Collection point

Oil level 27 Annular gap

Oil 28 inlet opening

Passage opening 29 Oil planer

Oil duct 30 Partition wall collection point

dip tube

Overflow level

edge

Collection point pipe bend section

oil supply

oil drain

collection

axis

Claims

claims

1. internal combustion engine (1) with a cylinder crankcase (2), an oil pan (4), which is filled in operation up to an oil level (7) with oil (8), a sump upper part (5) with at least one passage opening (9), and with at least one oil return (10) having an oil passage (10) for returning oil (8) into the oil sump (4), characterized in that the oil passage (10) has a collection point (1 1, 15, 19, 24, 26), in the operation of the internal combustion engine (1) accommodating a free passage of the oil passage (10) closes oil volume, wherein the collection point (1 1, 15, 19, 24, 26) is arranged such that the oil level (7) of the oil pan (4 ) in the direction of gravity below a collection level (13) of the oil volume in the collection point (11, 15, 19, 24, 26).

2. Internal combustion engine (1) according to claim 1, characterized in that the

Collection point (15, 26) has a bent pipe section with an oil inlet (17) and an oil drain (18), which include between them a pipe bend portion (16) in a geodetically lower lying position.

3. Internal combustion engine (1) according to claims 1 or 2, characterized in that the collecting point (15) has an S-shaped pipe bend portion (16) which is integrally connected to the oil inlet (17) and the oil drain (18).

4. Internal combustion engine (1) according to at least one of the preceding claims, characterized in that the collecting point (11, 24) with a collecting level (13) defining oil drain (18) equipped oil collecting container (25), and that the oil passage (10 ) has a section designed as a dip tube (12).

5. internal combustion engine (1) according to at least one of the preceding claims, characterized in that a plurality of oil passages (10), each with at least one dip tube (12) into a common oil collecting container (25).

6. Internal combustion engine (1) according to at least one of the preceding claims, characterized in that the oil passage (10) is arranged concentrically to a Olsammelbehälter (25) of the collection point (1 1, 24).

7. Internal combustion engine (1) according to at least one of the preceding claims, characterized in that a plurality of collection points and / or a plurality Olsammelbehälter (25, 25 ') are arranged such that the oil drain (18) of a first collection point and / or a first oil collection container ( 25) into an oil inlet (17) of a second collection point and / or a second oil collection container (25 ') leads.

8. Internal combustion engine (1) according to at least one of the preceding claims, characterized in that a plurality of Olsammelbehälter (25, 25 ') are arranged concentrically with each other.

9. internal combustion engine (1) according to at least one of the preceding claims, characterized in that the collecting point (11, 15, 19, 24, 26) within the

Cylinder crankcase (2), in particular within the of the oil pan (4) limited space is arranged.

10. Internal combustion engine (1) according to at least one of the preceding claims, characterized in that the effective oil column as geodetic height difference between the oil inlet (17) and the oil drain (18) is at least 100 mm.