DE102018206391A1 - Internal combustion engine with oil circuit and method for need-based conditioning of the engine oil of such an internal combustion engine - Google Patents

Abstract

The invention relates to an internal combustion engine with
at least one cylinder head comprising at least one cylinder, each cylinder comprising a combustion chamber formed by a piston crown of a cylinder-associated piston,
at least one cylinder block connected to the at least one cylinder head and serving as an upper crankcase half of a crankcase, which is connected to an oil pan (16) serving as a lower crankcase half of the crankcase, for the purpose of collecting and storing engine oil on the side remote from the cylinder head, and
- A pump (3) for conveying the engine oil via supply line (4) to at least one consumer (5) within an oil circuit (1), wherein a suction line (16 a) of the oil pan (16) to the pump (3) leads to the Pump (3) to supply from the oil pan (16) derived engine oil, each piston is equipped with a spray oil cooling (12), which is at least connectable for the purpose of oil supply via supply line (4) with the pump (3).
It should be provided an internal combustion engine of the type mentioned, which is optimized with respect to the temperature of the engine oil.
This object is achieved by an internal combustion engine, which is characterized in that upstream of the spray oil cooling (12) of the piston, an oil cooler (13) in the oil circuit (1) is arranged.

Description

• - mindestens einem Zylinderkopf umfassend mindestens einen Zylinder, wobei jeder Zylinder einen Brennraum umfasst, der durch einen Kolbenboden eines zylinderzugehörigen Kolbens mit ausgebildet ist,
• - mindestens einem mit dem mindestens einen Zylinderkopf verbundenen und als obere Kurbelgehäusehälfte eines Kurbelgehäuses dienenden Zylinderblock, der mit einer als untere Kurbelgehäusehälfte des Kurbelgehäuses dienenden Ölwanne, die dem Sammeln und Bevorraten von Motoröl dient, auf der dem Zylinderkopf abgewandten Seite verbunden ist, und
• - einer Pumpe zur Förderung des Motoröls via Versorgungsleitung zu mindestens einem Verbraucher innerhalb eines Ölkreislaufs, wobei eine Saugleitung von der Ölwanne zur Pumpe führt, um die Pumpe mit aus der Ölwanne stammendem Motoröl zu versorgen, wobei jeder Kolben mit einer Spritzölkühlung ausgestattet ist, welche zwecks Ölversorgung via Versorgungsleitung mit der Pumpe zumindest verbindbar ist.

The invention relates to an internal combustion engine with

• at least one cylinder head comprising at least one cylinder, each cylinder comprising a combustion chamber formed by a piston crown of a cylinder-associated piston,
• - At least one connected to the at least one cylinder head and serving as the upper crankcase half of a crankcase cylinder block, which is connected to serving as a lower crankcase half of the crankcase oil pan, which serves for the collection and storage of engine oil, on the side facing away from the cylinder head, and
• - A pump for conveying the engine oil via supply line to at least one consumer within an oil circuit, wherein a suction line from the oil pan leads to the pump to supply the pump with originating from the oil pan engine oil, each piston is equipped with a spray oil cooling, which purpose Oil supply via supply line to the pump is at least connectable.

Furthermore, the invention relates to a method for need-based conditioning of the engine oil of such an internal combustion engine.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine relates to diesel engines and gasoline engines, but also to hybrid internal combustion engines, i. Internal combustion engines, which are operated with a hybrid combustion method, and hybrid drives, which comprise at least one further torque source for driving a motor vehicle in addition to the internal combustion engine, for example a drive-connected to the engine or drive connected electric machine, which instead of the internal combustion engine or in addition to Internal combustion engine gives off power.

Internal combustion engines have a cylinder block and at least one cylinder head, which are connected to one another to form the at least one cylinder or combustion chamber. The individual components will be briefly discussed below.

The cylinder block has a corresponding number of cylinder bores for receiving the pistons or the cylinder tubes. The piston of each cylinder of an internal combustion engine is axially movably guided in a cylinder bore or a cylinder tube and defines, together with the cylinder bore or the cylinder tube and the cylinder head, the combustion chamber of a cylinder. The piston head forms a part of the combustion chamber inner wall and seals together with the piston rings the combustion chamber against the cylinder block or the crankcase, so that no combustion gases or combustion air enter the crankcase and no oil enters the combustion chamber.

The piston serves to transfer the gas forces generated by the combustion to the crankshaft. For this purpose, the piston is articulated by means of a piston pin with a connecting rod, which in turn is rotatably mounted on the crankshaft.

The crankshaft mounted in the crankcase receives the connecting rod forces, which are composed of the gas forces due to the fuel combustion in the combustion chamber and the mass forces due to the non-uniform movement of the engine parts. In this case, the oscillating stroke movement of the piston is transformed into a rotating rotational movement of the crankshaft. The crankshaft transmits the torque to the drive train. A part of the energy transmitted to the crankshaft is generally used to drive auxiliary equipment such as the oil pump and the alternator or serves to drive the camshaft and thus the actuation of the valve train. The camshaft is often stored as an overhead camshaft in the cylinder head.

In general, the upper crankcase half is formed by the cylinder block. The crankcase is usually supplemented by the mounted on the upper crankcase half and serving as an oil pan lower crankcase half. In this case, the upper crankcase half for receiving the oil pan, i. the lower crankcase half, often a flange on. As a rule, a seal is provided in or on the flange surface for sealing the oil sump or the crankcase relative to the environment. The connection is made for example by a screw. The oil pan is used to collect and store the engine oil and is part of the oil circuit. In addition, the oil pan serves as a heat exchanger for lowering the oil temperature when heated to operating temperature internal combustion engine. The oil contained in the oil sump is cooled by means of an air flow passing on the outside of the sump as a result of heat conduction and convection.

For receiving and supporting the crankshaft at least two bearings are provided in the crankcase, which are usually made in two parts and each include a bearing saddle and connectable to the bearing saddle bearing cap. The crankshaft is spaced in the range of crankshaft journals along the crankshaft axis arranged to each other and are usually designed as thickened shaft paragraphs stored. In this case, bearing cap and bearing saddles can be formed as separate components or integrally with the crankcase, ie the crankcase halves. Between the crankshaft and the bearings bearing shells can be arranged as intermediate elements.

When assembled, each bearing saddle is connected to the corresponding bearing cap. In each case a bearing saddle and a bearing cap form - if appropriate in cooperation with bearing shells as intermediate elements - a bore for receiving a crankshaft journal. The bores are usually filled with engine oil, i. Lubricating oil supplied, so that ideally forms between the inner surface of each bore and the associated crankshaft journal with rotating crankshaft - similar to a plain bearing - a viable lubricating film.

To supply the bearings with oil, a pump is provided for the delivery of engine oil to the at least two bearings, wherein the pump supplied via the supply line, a main oil gallery, lead from the channels to the at least two camps, with engine oil. The supply line leads according to the prior art of the pump through the cylinder block to Hauptölgalerie. To form the so-called Hauptölgalerie a main supply channel is often provided, which is aligned along the longitudinal axis of the crankshaft. The main supply channel can be arranged above or below the crankshaft in the crankcase or integrated into the crankshaft.

The pump itself is supplied in the prior art via suction line, which leads from the oil pan to the pump, with originating from the oil pan engine oil and has a sufficiently large flow rate, i. ensure a sufficiently high delivery volume and ensure a sufficiently high oil pressure in the supply system, especially in the main oil gallery. To limit the oil pressure in the system, a bypass line or short circuit line is often provided in the prior art, which branches off downstream of the pump, immediately behind the pump from the supply line, and opens upstream of the pump in the suction line and in which a pressure relief valve is arranged, which automatically opens when a predefinable oil pressure is exceeded.

Optionally, a permanent oil supply of at least two bearings is not required. In particular, if the oil supply of the bearings with another oil supply, for example via Hauptölgalerie, in conjunction, i. interacts, a permanent supply of oil to the bearings may be detrimental to the pressure in the overall system. In this respect, a merely regular but not continuous oil supply of the bearings can be advantageous.

As far as in the context of the present invention, the speech is that a consumer within the oil circuit via supply line with the pump is at least connectable, this is interpreted to the effect that either a permanent connection or a connection, for example by actuation of an actuating element or valve , can be brought about, ie there is no continuous oil supply.

Another oil supply in the above sense is the oil supply to a camshaft, which is usually stored in a two-piece so-called camshaft. The statements already made with regard to the crankshaft bearing apply analogously. The camshaft receiving is usually supplied with engine oil or lubricating oil, to which a supply line is provided, which regularly branches off from the main oil gallery according to the prior art, passes through the cylinder block and extends overhead camshaft into the cylinder head.

Alternatively, a supply line can be provided which leads from the pump directly into the cylinder head, supplies the camshaft intake with engine oil and then - downstream - leads to the main oil gallery.

The crankshaft and the camshaft or associated bearings, i. the recordings are referred to in the context of the present invention as consumers, since they consume or need motor oil to fulfill and maintain their function, i. must be supplied with engine oil.

Further consumers may be, for example, the bearings of a connecting rod or an optional balancing shaft. But consumers in the above sense is also a spray oil cooling, which the piston crown for cooling by means of nozzle from below, i. crankcase side, wetted with engine oil. The spray oil cooling requires or consumes oil, i. the spray oil cooling must be supplied with oil.

A hydraulically operable camshaft phaser or other valve train components, for example, for hydraulic valve clearance, also have a need for engine oil and require an oil supply.

No consumer in the sense of the present invention is one in the supply line arranged oil filter, an optionally provided oil cooler or provided for the promotion of the oil pump. Although these components of the oil circuit are supplied with engine oil. Due to the principle, however, an oil cycle entails the use of these components, which have only tasks, ie functions, which relate to the oil as such, whereas a consumer first makes the oil circulation necessary.

Downstream of the consumers, i. After the oil has been used in the consumers, so-called return lines return the engine oil to the oil sump, closing the oil circuit. The return of the oil is gravity driven. The recycle lines are preferably placed in lower temperature regions or adjacent to any optional liquid cooling of the head or block to prevent overheating of the oil which adversely affects the properties, particularly lubricity, of the oil to be recycled and faster oil aging can cause.

The friction in the bearings to be supplied with oil, for example the crankshaft bearings, which largely depends on the viscosity and thus on the temperature of the oil provided, contributes to the fuel consumption of the internal combustion engine. Basically, efforts are made to minimize fuel consumption. In addition to the improvement of combustion, the reduction of the frictional loss is in the foreground of the efforts.

The majority of known from the prior art concepts for reducing the friction power aims at a rapid heating of the engine oil after a cold start. A rapid heating of the engine oil during the warm-up phase of the internal combustion engine leads to a correspondingly rapid decrease in viscosity and reduces the friction or friction, especially in the oil-supplied bearings.

The higher the oil temperature, the lower the viscosity of the oil and the lower the friction or friction. With regard to the reduction of friction losses in the bearings, the highest possible oil temperature would therefore be desirable.

In this case, the heating of the oil, for example, take place actively by means of a heating device, which is, however, to be regarded as an additional consumer with regard to the use of fuel.

Other concepts involve measures to store the oil heated during operation of the engine for a restart, i. is stored, wherein the high temperature of the oil, for example by means of insulation, to be obtained. With regard to such concepts where engine oil heated during operation is stored in an insulated container and used to lubricate the bearings when the engine is restarted, it must be taken into account that the oil heated during operation can not be kept indefinitely at a high temperature , which is why often a re-heating of the oil during operation of the internal combustion engine has to be done.

Other consumers have different requirements for the oil, especially the oil temperature.

The spray-oil cooling of a piston which sprays the piston crown with motor oil for the purpose of cooling, preferably prefers a cool or cold engine oil, i. an engine oil of the lowest possible temperature in order to extract the largest possible amount of heat the piston.

A hydraulically actuatable camshaft phaser also prefers less warm oil, i. a low-temperature engine oil whose viscosity is not too low. In this way, excessive leakage, which also depends on the viscosity of the hydraulic fluid, can be avoided.

In summary, it can be stated that different consumers have different requirements for the temperature of the oil. As a result, arise in the tempering of the engine oil conflicts.

In view of the above, it is an object of the present invention to provide an internal combustion engine according to the preamble of claim 1, which is optimized in terms of the temperature of the engine oil.

A further sub-task of the invention is to show a method for the need-based conditioning of the engine oil of such an internal combustion engine.

• - mindestens einem Zylinderkopf umfassend mindestens einen Zylinder, wobei jeder Zylinder einen Brennraum umfasst, der durch einen Kolbenboden eines zylinderzugehörigen Kolbens mit ausgebildet ist,
• - mindestens einem mit dem mindestens einen Zylinderkopf verbundenen und als obere Kurbelgehäusehälfte eines Kurbelgehäuses dienenden Zylinderblock, der mit einer als untere Kurbelgehäusehälfte des Kurbelgehäuses dienenden Ölwanne, die dem Sammeln und Bevorraten von Motoröl dient, auf der dem Zylinderkopf abgewandten Seite verbunden ist, und
• - einer Pumpe zur Förderung des Motoröls via Versorgungsleitung zu mindestens einem Verbraucher innerhalb eines Ölkreislaufs, wobei eine Saugleitung von der Ölwanne zur Pumpe führt, um die Pumpe mit aus der Ölwanne stammendem Motoröl zu versorgen, wobei jeder Kolben mit einer Spritzölkühlung ausgestattet ist, welche zwecks Ölversorgung via Versorgungsleitung mit der Pumpe zumindest verbindbar ist,

die dadurch gekennzeichnet ist, dass

• - stromaufwärts der Spritzölkühlung des Kolbens ein Ölkühler im Ölkreislauf angeordnet ist.

The first subtask is solved by an internal combustion engine

• at least one cylinder head comprising at least one cylinder, each cylinder comprising a combustion chamber formed by a piston crown of a cylinder-associated piston,
• - At least one associated with the at least one cylinder head and serving as the upper crankcase half of a crankcase cylinder block, which serves as a lower crankcase half of the crankcase oil pan, the collecting and Stockpiling of engine oil is used, is connected on the side facing away from the cylinder head, and
• - A pump for conveying the engine oil via supply line to at least one consumer within an oil circuit, wherein a suction line from the oil pan leads to the pump to supply the pump with originating from the oil pan engine oil, each piston is equipped with a spray oil cooling, which purpose Oil supply via supply line to the pump is at least connectable,

which is characterized in that

• - An oil cooler in the oil circuit is arranged upstream of the spray oil cooling of the piston.

According to the invention, an oil cooler is provided in the oil circuit with which the engine oil conditionally conditioned upstream of the spray oil cooling of each piston, i. can be tempered or will.

The spray oil cooling, which sprays the piston crown of the piston with engine oil for the purpose of cooling, is supplied according to the invention with a cooled or cooler engine oil, preferably with an engine oil having a temperature T _{oil, piston} ≦ 50 ° C.

The inventive concept in this way supports the spray-oil cooling in order to extract as much heat as possible from the piston. Thus, the temperature of the engine oil is optimized in terms of spray oil cooling.

The cooling of the engine oil using the oil cooler is preferably carried out immediately upstream of the spray oil cooling. Between the spray oil cooling and the oil cooler, preferably no further consumer should be arranged in the oil circuit, in particular no consumer who makes other demands on the oil temperature or prefers or requires a warmer or warm engine oil.

According to the invention, an oil heater and / or a device for thermal conditioning of the engine oil can be arranged elsewhere in the oil circuit, in particular to reheat the oil cooled in the oil cooler after passing through the spray oil cooling, whereby the viscosity of the oil lowered and reduced the friction of other consumers and / or the hydraulic properties of the oil are adjusted.

This also ensures rapid heating of the engine oil and rapid heating of the internal combustion engine, especially after a cold start. The rapid heating of the engine oil during the warm-up phase of the engine provides for a rapid decrease in viscosity and thus for a reduction in friction or friction, especially in the oil-supplied bearings.

Thus, the first sub-task underlying the invention is achieved, namely an internal combustion engine is provided which is optimized with respect to the temperature of the engine oil.

Further advantageous embodiments of the internal combustion engine according to the invention are discussed in connection with the subclaims.

Embodiments of the internal combustion engine may be advantageous in which the supply line of the oil circuit downstream of the pump first passes through the cylinder block before this supply line enters the at least one cylinder head.

The direction of flow of the oil is presently the one most commonly used in internal combustion engines, i. is realized. Namely, the oil is often first routed downstream of the pump to the main oil gallery to supply the bearings of the crankshaft with oil before it flows to a cylinder head.

The oil is heated when passing through the cylinder block, which is why the downstream cylinder-head-side part of the oil circuit is in this case supplied with already preheated in the cylinder block oil.

Embodiments of the internal combustion engine may also be advantageous in which the supply line of the oil circuit downstream of the pump first passes through the at least one cylinder head before this supply line enters the cylinder block.

Under certain conditions, it may be advantageous for the fastest possible heating of the oil when the supply line of the oil circuit first passes through the cylinder head, i. the oil circuit is designed in this way. Particularly at very low outside temperatures, the circumstance that the cylinder head warms up more quickly as a result of the combustion processes taking place in the cylinders, supports a rapid heating of the oil. This effect is even more noticeable when further optional technical features are realized, such as the integration of the manifold in the cylinder head. Such and further embodiments which support the heating in the cylinder head are to be considered.

Advantageous embodiments of the internal combustion engine, in which a filter is provided in the supply line, preferably downstream of the pump and upstream of the first provided in the oil circuit consumer.

The filter is intended to retain particles, in particular solids particles originating from the abrasion, in order to protect the components downstream of the oil circuit, in particular the consumers, from being damaged.

Also advantageous embodiments of the internal combustion engine, in which a further heat exchanger is provided in the oil circuit, for example, to prevent overheating of the oil, which adversely affect the properties, in particular the lubricity of the oil and can cause a faster aging of the oil. Advantageous are heat exchangers that can be used as oil cooler, but also as a heater for the oil.

Naturally, cooling of the engine oil in the warm-up phase of the internal combustion engine counteracts the goal of reducing the friction by heating the oil as quickly as possible, which is why the oil cooler should only be activated when needed and as a rule not during the warm-up phase. In individual cases, however, if the coolant heats up faster during the warm-up phase than the engine oil, it may be useful to use the oil cooler against its actual function for heating the oil.

Embodiments of the internal combustion engine in which the oil cooler is arranged downstream of the pump are advantageous, with no further consumer being arranged in the oil circuit between the spray oil cooling and the oil cooler, in particular no consumer requiring hot or warmer oil.

Embodiments of the internal combustion engine in which an actuating element is arranged in the oil circuit between the spray oil cooling and the oil cooler are advantageous. The actuator may alternatively be arranged upstream of the oil cooler.

By transferring the control element in the closed position, the spray oil cooling can be separated from the rest of the oil circuit. This takes into account the fact that a spray oil cooling does not require a permanent supply of oil. In this respect, a merely realizable, but not continuous oil supply is sufficient.

Embodiments of the internal combustion engine in which the oil cooler is a low-temperature oil cooler are advantageous.

According to the present embodiment, the oil cooler is a low-temperature oil cooler that can cool the engine oil to temperatures T _oil ≦ 50 ° C and T _oil ≦ 40 ° C or less. The oil cooler can extract the heat from the oil by means of air cooling or liquid cooling.

The latter requires the use of a coolant driven oil cooler which extracts heat from the oil using a coolant such as water. The inclusion of such an oil cooler in the liquid cooling of the internal combustion engine is not expedient because the coolant of the engine cooling of a heated in-service internal combustion engine regularly reaches temperatures T _coolant ≥ 90 ° C and thus unsuitable for use in a low-temperature oil cooler.

For supplying the oil cooler, therefore, coolant of a low-temperature coolant circuit of the internal combustion engine would have to be used or branched off and fed to the oil cooler.

Embodiments of the internal combustion engine in which a crankshaft is rotatably mounted in at least two bearings are advantageous, wherein the crankshaft is articulated to the piston of each cylinder, so that the piston oscillates along a piston longitudinal axis when the crankshaft revolves about an axis of rotation, the piston longitudinal axis is perpendicular to the axis of rotation.

In this context, embodiments of the internal combustion engine in which the at least two bearings of the crankshaft are at least connectable to the pump for the purpose of supplying oil via the supply line are advantageous.

Embodiments of the internal combustion engine in which an oil heater in the oil circuit is arranged upstream of the at least two bearings of the crankshaft are advantageous.

As already explained, the highest possible oil temperature should be aimed at reducing friction losses in the bearings. With increasing oil temperature, the viscosity of the oil decreases and the friction or friction in the bearings is reduced.

By arranging an oil heater upstream of the bearings, the oil made available to the bearings is specifically conditioned or tempered as required. The oil, which is supplied via oil cooler of the spray oil cooling, should preferably not upstream of the oil cooler, go through the oil heater. Then, in a first step, heat would be introduced into the oil using the oil heater, which would then have to be withdrawn from the heated oil again in the oil cooler in a second step.

The oil heater can also be used for rapid heating of the engine oil and rapid heating of the engine after a cold start.

It should also be taken into account that the cooled oil is regularly collected in the sump after passing through the spray oil cooling, where it mixes with the oil already in the oil sump, thereby reducing the average oil temperature in the oil circuit. However, a lower oil temperature is not advantageous for each consumer arranged in the oil circuit, which is why the use of oil heating can be advantageous. The heating of the oil, for example, can be done actively by means of a heater.

Advantageous embodiments of the internal combustion engine, in which the pump for the purpose of oil supply via supply line with a camshaft receptacle is at least connectable.

Advantageous embodiments of the internal combustion engine, in which the pump for the purpose of oil supply via supply line with a camshaft adjuster is at least connectable.

In connection with the two preceding embodiments, reference is made to the statements already made.

In this connection, embodiments of the internal combustion engine in which a device for thermally conditioning the engine oil in the oil circuit is arranged upstream of the camshaft receptacle and / or of the camshaft adjuster are advantageous.

The device for thermally conditioning the engine oil is preferably a heat exchanger that can both introduce heat into the oil and extract heat from the oil.

Using such a device, the requirements of a hydraulically actuable phaser on the oil or the oil temperature can be met. For example, the oil should not be too fluid to avoid excessive leakage.

The second sub-task underlying the invention, namely to disclose a method for conditioning the engine oil of an internal combustion engine of the type described above, is achieved by a method characterized in that the engine oil is cooled using the oil cooler upstream of the spray oil cooling to the piston to extract more heat.

The comments made in connection with the internal combustion engine according to the invention also apply to the inventive method. Reference is therefore made to the description of the internal combustion engine according to the invention and the different embodiments.

Advantageous embodiments of the method in which the engine oil is cooled using the oil cooler to a temperature T _{oil, piston} ≤ 40 ° C.

Particularly advantageous embodiments of the method in which the engine oil is cooled using the oil cooler to a temperature T _{oil, piston} ≤ 30 ° C.

For conditioning of the engine oil of an internal combustion engine according to need, in which an oil heater and / or a device for thermal conditioning of the engine oil is provided in the oil circuit, process variants may be advantageous, which are characterized in that the engine oil after passing through the spray oil cooling using the oil heating and / / or the device is heated.

• 1 schematisch den Ölkreislauf einer ersten Ausführungsform der Brennkraftmaschine, und
• 2 schematisch den Ölkreislauf einer zweiten Ausführungsform der Brennkraftmaschine.

In the following the invention with reference to two embodiments of the internal combustion engine according to the 1 and 2 described in more detail. Hereby shows:

• 1 schematically the oil circuit of a first embodiment of the internal combustion engine, and
• 2 schematically the oil circuit of a second embodiment of the internal combustion engine.

1 shows schematically the oil circuit 1 a first embodiment of the internal combustion engine.

For pumping engine oil through the oil circuit 1 is a pump 3 provided, wherein a suction line 16a from an oil pan 16 , which serves to collect and store the engine oil, to the pump 3 leads to the pump 3 with out of the oil pan 16 supply engine oil.

The pump 3 Promotes the oil via supply line 4 to those in the oil circuit 1 intended consumers 5 , The oil first flows through a downstream of the pump 3 arranged filters 6 and one downstream of the filter 6 disposed heat exchangers 7 , which is usually disabled during the warm-up phase.

Downstream opens the supply line 4 in the main oil gallery 8th , from the channels 8a to the four main camps 5 . 9b the crankshaft and the three crankshaft-side connecting rod bearings 5 . 9a lead to oil them.

From the main oil gallery arranged in the cylinder block 8th leads the supply line 4 to the cylinder head and other consumers 5 namely the four intake side camshaft bearings 5 . 10a and the four exhaust side camshaft bearings 5 . 11a the respective camshaft holder 10 . 11 , The valve train 2 is present variable, ie adjustable.

These are hydraulically actuated camshaft adjuster 10b . 11b provided by operating control valves 10d . 11d with the oil circuit 1 or oil in the camshaft shots 10 . 11 are connectable. check valves 10c . 11c prevent a flow of oil in both directions.

If necessary, hydraulically switchable plungers are used as the cam follower elements, via the oil circuit 1 can also be supplied with oil (not shown). A connection or disconnection of the plunger is effected by varying the oil pressure with which the plunger are acted upon. Increasing or decreasing the oil pressure activates or deactivates the plungers.

To the oil pressure in the supply line 4 of the oil circuit 1 To vary, is to promote the oil, a vane pump 3a used in which serving as a stator in a hollow cylinder rotates a cylinder serving as a rotor. The eccentricity of the axis of rotation of the rotor is variable, whereby the flow rate of the pump 3 . 3a is changeable. An increased flow rate leads to an increased oil pressure at the pump outlet.

An adjustment of the eccentricity is carried out using an electrically controllable pump valve 17 , which in addition to a permanently open pressure line 18a another oil pressure line 18b to the vane pump 3a free or blocked and operated by means of motor control. The oil or oil pressure surface is actuated by operating the valve 17 increases or decreases, so that the spring force counteracts a larger or smaller force resulting from the oil pressure and the eccentricity varies.

There are return lines (not shown) provided, the engine oil gravity driven back into the oil pan 16 conduct.

Each piston of the three cylinders is with a spray oil cooling 5 . 12 equipped, which sprays the piston crown with oil for cooling from the bottom, ie crankcase side. The spray oil cooling 5 . 12 are via supply line 4 with the pump 3 connectable to be supplied with oil. By transferring the control element 12a in the open position, this connection is made.

Upstream of spray oil cooling 5 . 12 the piston is an oil cooler 13 in the oil circuit 1 arranged between the actuator 12a and the main oil gallery 8th from which the supply line 4 branches off and to the spray oil cooling 5 . 12 leads.

The oil cooler 13 is a low temperature oil cooler 13a which can cool the oil to low temperatures T _oil ≤ 40 ° C or less.

By transferring the control element 12a in the closed position, the spray oil cooling 5 . 12 from the rest of the oil circuit 1 be separated. This has advantages, as a spray oil cooling 5 . 12 no permanent oil supply required.

2 shows schematically the oil circuit 1 a second embodiment of the internal combustion engine. It should only the differences to the in 1 Otherwise, reference will be made to FIG 1 , The same reference numerals have been used for the same components.

Unlike the in 1 illustrated embodiment is in the in 2 illustrated oil circuit 1 an oil heater 19 upstream of the main camp 5 . 9b The crankshaft arranged the oil before entering the bearings 5 . 9b should heat to reduce the bearing friction. The heat exchanger 7 of the 1 eliminated.

In addition, upstream of the camshaft adjuster 10b . 11b a device 14 provided for the thermal conditioning of the engine oil.

The presentation of the 2 should illustrate only the fundamental principle, namely that additional heat exchanger 14 . 19 can be provided. The oil, which is the oil cooler 13 should be fed, preferably on the oil heater 19 and the device 14 be passed, so as not to introduce unnecessary heat in the oil, the oil in the cooler 13 would have to be withdrawn again (not shown).

In an analogous manner, it is usually more advantageous, the oil, which is the device 14 is fed to the oil heater 19 To avoid unnecessary heat transfer to the oil in the device 14 would have to be withdrawn again (not shown).

LIST OF REFERENCE NUMBERS

1

Oil circuit

2

valve train

3

pump

3a

Vane pump

4

supply line

5

consumer

6

filter

7

heat exchangers

8th

Main oil gallery

8a

channel

9a

crankshaft-side connecting rod bearing

9b

Crankshaft bearing, main bearing

10

camshaft mount

10a

Bearing of the camshaft holder

10b

Phaser

10c

check valve

10d

control valve

11

camshaft mount

11a

Bearing of the camshaft holder

11b

Phaser

11c

check valve

11d

control valve

12

Oil-spray cooling

12a

actuator

13

oil cooler

13a

Low temperature oil cooler

14

Device for the thermal conditioning of engine oil

16

oil pan

16a

suction

17

pump valve

18a

pressure line

18b

pressure line

19

Heating oil

T _{oil, piston}

Temperature of the engine oil of the spray oil cooling

Claims (17)

Internal combustion engine with - at least one cylinder head comprising at least one cylinder, each cylinder comprising a combustion chamber, which is formed by a piston head of a cylinder-associated piston, - at least one connected to the at least one cylinder head and serving as the upper crankcase half of a crankcase cylinder block, which with a as the lower crankcase half of the crankcase serving oil pan (16), which is used for collecting and storing of engine oil, on the side facing away from the cylinder head is connected, and - a pump (3) for conveying the engine oil via supply line (4) to at least one consumer ( 5) within an oil circuit (1), wherein a suction line (16 a) of the oil pan (16) leads to the pump (3) to supply the pump (3) from the oil pan (16) derived engine oil, each piston with a spray oil cooling (12) is equipped, which for the purpose of oil supply via supply line (4) m it is at least connectable to the pump (3), characterized in that - upstream of the spray oil cooling (12) of the piston, an oil cooler (13) in the oil circuit (1) is arranged. Internal combustion engine after Claim 1 , characterized in that the supply line (4) of the oil circuit (1) downstream of the pump (3) first passes through the cylinder block before the supply line (4) enters the at least one cylinder head. Internal combustion engine after Claim 1 , characterized in that the supply line (4) of the oil circuit (1) downstream of the pump (3) first passes through the at least one cylinder head before the supply line (4) enters the cylinder block. Internal combustion engine according to one of the preceding claims, characterized in that a filter (6) in the supply line (4) is provided, preferably downstream of the pump (3) and upstream of the first in the oil circuit (1) provided consumer (5). Internal combustion engine according to one of the preceding claims, characterized in that the oil cooler (13) downstream of the pump (3) is arranged, wherein between the spray oil cooling (12) and the oil cooler (13) no further consumer (5) in the oil circuit (1) is. Internal combustion engine according to one of the preceding claims, characterized in that between the spray oil cooling (12) and the oil cooler (13) an adjusting element (12a) in the oil circuit (1) is arranged. Internal combustion engine according to one of the preceding claims, characterized in that the oil cooler (13) is a low-temperature oil cooler (13a). Internal combustion engine according to one of the preceding claims, characterized in that in the crankcase, a crankshaft is rotatably mounted in at least two bearings (9b), wherein the crankshaft is pivotally connected to the piston of each cylinder, so that the piston along an axis of rotation rotating crankshaft along a Piston longitudinal axis oscillates, wherein the piston longitudinal axis is perpendicular to the axis of rotation. Internal combustion engine after Claim 8 , characterized in that the at least two bearings (9b) of the crankshaft for the purpose of oil supply via supply line (4) with the pump (3) are at least connectable. Internal combustion engine after Claim 9 , characterized in that upstream of the at least two bearings (9b) of the crankshaft, an oil heater (19) in the oil circuit (1) is arranged. Internal combustion engine according to one of the preceding claims, characterized in that the pump (3) for the purpose of oil supply via the supply line (4) with a camshaft receptacle (10, 11) is at least connectable. Internal combustion engine according to one of the preceding claims, characterized in that the pump (3) for the purpose of oil supply via the supply line (4) with a camshaft adjuster (10b, 11b) is at least connectable. Internal combustion engine after Claim 11 or 12 , characterized in that upstream of the camshaft receiving means (10, 11) and / or the camshaft adjuster (10b, 11b) a device (14) for the thermal conditioning of the engine oil in the oil circuit (1) is arranged. Method for conditioning the engine oil according to requirements of an internal combustion engine according to one of the preceding claims, characterized in that the engine oil is cooled using the oil cooler (13) upstream of the spray oil cooling (12) in order to extract more heat from the piston. Method according to Claim 14 , characterized in that the engine oil is cooled using the oil cooler (13) to a temperature T _{oil, piston} ≤ 40 ° C. Method according to Claim 14 or 15 Characterized in that the engine oil by using the oil cooler (13) ≤ 30 ° C is cooled to a temperature T _{oil, piston.} Method according to one of Claims 14 to 16 for conditional conditioning of the engine oil of an internal combustion engine, in which an oil heater (19) and / or a device (14) for thermal conditioning of the engine oil in the oil circuit (1) is provided, characterized in that the engine oil after passing through the spray oil cooling (12) below Use of the oil heater (19) and / or the device (14) is heated.

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