EP2409005B1 - Method and apparatus for oiling rotating or oscillating components - Google Patents

Description

The invention relates to a method for heating a lubrication system of rotating or oscillating components, in particular for an internal combustion engine or a transmission, with at least one Ölsaugrohr, which is arranged in an oil sump and with the oil return bypass bypass line, wherein in the bypass line, a valve is arranged ,

State of the art

The DE 27 53 716 relates to a hot air-emitting heater for powered by an internal combustion engine motor vehicles, acted upon by atmospheric air heat exchanger for heat dissipation of a flowing in a conduit heat transfer medium and also in the line circuit turned on, the exhaust heat of the engine receiving and delivering to the heat carrier heat exchanger. The line circuit for the heat carrier of the heater is at least with the lubricating oil circuit Internal combustion engine in heat-conducting connection. Here, a heat transfer to the lubricating oil in a dry sump is achieved in that heat is discharged through a flowing in a feed line heat transfer to the located in the dry sump tank lubricating oil.

The GB 2 381 576 A discloses an exhaust heat recovery apparatus having a heat exchange conduit and a bypass conduit. In the region of the heat exchanger line, a heat exchanger is arranged. At least one valve device is provided in the heat exchanger line and / or the bypass line in order to influence an exhaust gas flow rate in the heat exchanger line. At least the heat exchanger line has a gradient in an exhaust gas flow direction in the installed position.

The EP 0 885 758 B1 relates to a method for operating a heat exchanger in the exhaust gas stream of an internal combustion engine for motor vehicles, in which the exhaust gas stream is divisible into a main line and into a bypass line. The heat exchanger is arranged in the bypass line. In a warm-up operation, a backflow can be generated in the main line, which causes a back pressure at the exhaust gas outlet of the internal combustion engine. The warm-up operation is divided into two phases, wherein in the first phase, a higher back pressure than in the second phase is generated. A first valve is disposed in the main conduit between the bypass conduit ports, with a second valve disposed in the bypass conduit downstream of the heat exchanger. In the first phase, both valves are closed, wherein in the second phase, the first valve is closed, but the second valve is open.

The EP 0 202 344 describes a tank truck for transporting liquid goods, wherein a medium flowing along the outside of the tank releases heat to the tank contents. The medium is a heat transfer oil and flows through the circuit at least one of the hot exhaust gases of the internal combustion engine of the tank semitrailer traversed Heat exchanger. To reduce a pollutant content of the combustion gases, a catalyst through which the combustion gases flow is arranged in front of the heat exchanger.

The DE 199 08 088 A1 relates to an internal combustion engine, in particular a diesel internal combustion engine, for a vehicle, with a passenger compartment heater, an exhaust pipe, a coolant line forming a cooling circuit with a first pump to which the internal combustion engine is connected, and an exhaust gas heat exchanger for transmitting exhaust gas heat to a heater core , The exhaust gas heat exchanger is effective between the exhaust pipe and a circulation medium line, which forms a circulation circuit to which the heating heat exchanger is connected directly or indirectly.

The DE 199 08 088 A1 but also relates to an internal combustion engine, in particular diesel internal combustion engine, wherein the internal combustion engine is connected to a branching off from the coolant line first bypass, in which a first thermostatic valve is arranged, which largely blocks the first bypass until reaching an average coolant temperature and opens above this coolant temperature , In a parallel to the first bypass extending second bypass, a second thermostatic valve is arranged, which largely blocks the second bypass above the average cooling temperature.

The DE 100 47 810 A1 relates to a heating circuit with an auxiliary heater for motor vehicles with internal combustion engine, which is part of a separate short-circuit, which is switchable by means of a switching device in the heating circuit. As auxiliary heater, an exhaust system of the engine of the motor vehicle is used, from which the exhaust heat is transferred into the heating circuit. The exhaust heat supply is at a heat demand of the interior heating below exhaust gas exhaust heat supply by motorisehe Measures liftable. The DE 100 47 810 A1 but also relates to a method for operating a heating circuit with an auxiliary heater for motor vehicles with internal combustion engine, designed as exhaust gas heat exchanger through which the engine exhaust gas and coolant flow. To increase the heating power of the additional heater, the engine operating parameters can be influenced.

The EP 1 094 214 A2 relates to a heat recovery system having a circulation line in which a heat transfer medium circulates through an engine cooling unit, and an exhaust gas heat exchanger for utilizing the exhaust gases of an engine and a conduit connecting an outlet side of the circulation line to an outlet of the heat exchanger. The exhaust gas heat exchanger is disposed across the circulation passage at a side upstream of the engine cooling unit. The heat transfer medium introduced into the exhaust gas heat exchanger is controlled to a lower temperature sufficient to lower a temperature of the water vapor contained in the exhaust gas stream from which heat is transferred to the heat transfer medium to lower its dew point.

In a combustion engine, fuel consumption during a cold NEDC test (starting temperature about 24 ° C) is about 10 to 15% higher than in the same test with an engine oil temperature starting at about 90 ° C, the so-called NEDC -Heißtest. One of the reasons for this is that the lubricating oil has a higher toughness at lower temperatures and that the fuel is condensed on cylinder walls and introduced into the engine oil. In addition, measures are taken to heat the catalyst faster, these are z. As a retardation of the ignition, raising the idle speed and enrichment with Sekundärlufteinblasung. In addition, the majority of the emitted exhaust emissions during the cold start phase of the internal combustion engine, if the catalyst has not yet reached the required operating temperature. At the same time, a Most of the energy supplied unused as exhaust enthalpy dissipated. This is a total of about 30 to 40% of the energy of the fuel supplied.

It is known to improve the warm-up phase of the engine by using exhaust gas heat exchangers which in a complicated manner heat up the engine oil and reduce the oil pressure. On the other hand, it is a problem to protect the engine, in particular the engine oil in this heating from overheating. Therefore, additional high performance oil coolers are used. The known solutions are very complex and only lead to a relatively small reduction in fuel consumption, so that for economic reasons, the practical implementation is usually not realized.

In the JP 2001 323808 A shows an oil lubrication system, in which from an oil suction pipe, which is arranged in an oil sump of a non-insulated oil tank, by means of an oil pump oil can be introduced into a lubrication system. The oil can be heated by means of an oil line and a heat exchanger through an exhaust system. The heated oil can be stored in a thermally insulated intermediate tank and returned by means of a supply line directly under a suction bell of the oil pump in the oil sump.

From the DE 10 2004 031365 A1 a bypass line in an oil / exhaust gas heat exchanger, wherein the heat exchanger for heating oil for lubrication in a warm-up phase by means of exhaust gas is used. The exhaust flow of the heat exchanger can be passed through a multi-way valve through an exhaust bypass to control further heating of the lubricating oil system.

The US 4,393,824 relates to a heating method for lubricating oil, wherein by means of a high-pressure pump and a pressure reducing element, an additional heating of the total amount of lubricating oil can be achieved.

In the JP 2005 299592 A discusses a generic oil lubrication system using heat from an EGR system to increase the viscosity of the lubricating oil. For this purpose, an oil cooler can be bypassed by means of an oil bypass. In any case, all the lubricating oil flows through the oil cooler or bypass and is returned to an oil reservoir. Even the D4 gives no indication of the missing features. A generic oil lubrication system goes out of the JP 60 185011 U ,

The JP 60 185011 U concerns a generic type lubrication system.

From the FR 2 896 531 A1 For example, a method for accelerated heating of a lubrication system of rotating components for an internal combustion engine is known. In this case, an oil suction pipe is arranged in an oil sump, and has a the oil recirculation umführen oil bypass line. A valve is disposed in the oil bypass line, whereby the bypass line and / or at least one of the oil return can be connected to the suction line of an oil pump and the pressure line of a lubrication system. The nature of the installation of the oil bypass line is not chosen to be advantageous in order to allow accelerated heating.

The JP 58 158 126 U considers an oil lubrication system for a turbocharged internal combustion engine in which an oil bypass line may lube-controlled oil pass through a portion of the turbocharger for faster heating.

In the EP 0 123 620 A1 describes a lubricating system with oil bypass line for an internal combustion engine, wherein when an oil minimum pressure is exceeded, an exhaust valve is opened, so that oil flows through the bypass line and bypasses the oil return.

From the DE 10 2007 020 807 A1 a lubrication system with a cylinder head lubricant collection tank is known in which during a warm-up phase returning lubricating oil from the cylinder head in the cylinder head temporarily remains in the lubricant reservoir tank, heated and delayed concentrated in a suction of the oil pump in the oil sump can be returned. For this purpose, both an overflow return special connection is provided, which causes a return of the amount of oil used for the cylinder head lubrication with filled lubricant collection tank, as well as a switching valve that allows concentrated at reservoir already partially concentrated return. The switching valve can be opened as soon as the lubricant has reached the operating temperature, in the warm-up phase it remains closed, so that returning oil from the cylinder head is returned via the overflow line. Furthermore, an oil pressure filling pipe from the oil pump leads directly to the lubricant collecting tank, and is controlled by another switching valve so that the lubricant collecting tank can also be filled directly.

In the JP S59183017 shows a lubrication system in which in a warm-up phase, the entire oil return can be passed through a manifold directly to the Ölsaugrohr an oil pump to avoid mixing with the oil of the oil sump.

task

The invention has for its object to improve an internal combustion engine or a transmission, in particular automatic transmission of the type mentioned with simple means to the extent that the engine oil is performed faster in the cold start phase or in the warm-up phase to operating temperature, so that both a reduced fuel consumption as well as reduced pollutant emissions are achieved, with overheating of the engine oil is to be avoided.

According to the invention the object is achieved in that a oil bypass umführenden oil bypass line is connected to the suction of an oil pump and the pressure line of a lubrication system, wherein the oil bypass line of the internal combustion engine passes through at least one cylinder head, and that falls below a certain limit temperature and exceeding a certain minimum pressure of the lubricating oil in the pressure line the lubricating system, a bypass valve in the oil bypass line is at least partially opened, so that a partial flow of the lubricating oil in a warm-up phase of the lubrication system does not flow through the oil sump until either the minimum pressure or the limit temperature are reached, and that the lubricating oil mass flow through the oil bypass line (23) at least temporarily larger than the lubricating oil mass flow through the oil suction pipe (2).

Advantageously, the bypass line can pass through a turbocharger.

By returning the lubricating oil directly to the oil pump, the oil in the lubrication system heats up faster. Furthermore, the pressure loss of the lubrication system to be overcome decreases since the oil flowing back through the oil bypass line does not flow through the oil sump. Since the oil of the bypass line is preferably passed through the cylinder block and / or cylinder head, an increased oil volume flow at low temperatures can be achieved in an at least partial opening of the bypass valve, which can be arranged in or on the cylinder head or cylinder block, so that the oil more waste heat can record.

As a result, a reduced friction is achieved in the warm-up phase, since the lubricating oil is led faster to operating temperature and the pressure losses are reduced.

The heating method of the lubricating system according to the invention can be used advantageously both in motor vehicles with automatic transmissions, as well as in motor vehicles with manual transmissions, and serve both for lubrication of the engine as an internal combustion engine and for lubricating the gear unit. In hybrid vehicles, which include both an internal combustion engine and an electric drive unit, the heating method can be used for rapid heating of an electric motor / generator unit, which achieve optimum efficiency only at elevated temperatures, and also lubricate the electromotive moving components. It can be advantageous in these cases Waste heat from the electrical energy storage unit (battery / battery) and / or the inverter heats oil in the bypass line, which in turn heat up the electric motor / generator unit
or lubricate this and a downstream transmission improved. In automatic transmissions, as well as in the internal combustion engine, an oil bypass line can be arranged, which contains a heat exchanger, through which additional heat is introduced into the transmission oil in the heating phase so as to reduce the friction.

The invention can be applied to all types of internal combustion engine driven equipment and vehicles such as cars, trucks, buses, motorcycles, construction machinery, ships, boats, aircraft and mobile and stationary work equipment and devices, power plants such as emergency generators and the like. In particular, in short-term use and with varying workloads, the invention enables optimum lubrication to reduce friction between the moving parts, thus increasing the longevity of the machine, reducing the noise level, achieving higher efficiency, achieving higher power output, delivering lower exhaust emissions, and costs can be saved.

Favorable in the context of the invention, it is when the length of the oil line of the lubrication system from the output of the oil pump to the entry into the oil bypass line at least 80% of the maximum length of the oil line of the lubrication system from the output of the oil pump to the farthest to be lubricated device is. As a result, the lubricating oil flowing through the oil bypass line can heat better. It is particularly advantageous that the lubricating oil mass flow through the oil bypass line is at least temporarily greater than the lubricating oil mass flow through the oil suction pipe and the oil sump. In this case, the total mass flow flowing through the lubricating system is heated faster than without oil bypass line.

It is also expedient if the oil bypass line is arranged in the same housing, in which also at least one of the devices to be lubricated are arranged, so that the back-flowing lubricating oil can additionally heat. It is particularly advantageous if one or several of the oil returns are connected directly to the suction line of an oil pump.

Advantageous in the context of the invention is also, if the oil bypass line consists of a heat insulating material with a thermal conductivity less than 1 W / (m * K) to reduce the heat transfer to the environment during the backflow, especially where the oil bypass line not is guided through the device to be lubricated.

In order to further accelerate the warming up of the oil and to further reduce the pressure loss of the lubricating system, it is favorable if at least one of the lubricating oil return flows arranged downstream of the devices to be lubricated is connected to the oil bypass line, one of the lubricating oil return lines connected to the oil bypass line being part of an exhaust gas turbocharger.

Since at different loads and speeds different lubricating oil pressures are required to ensure adequate lubrication and to avoid damage to the components to be lubricated, it is favorable in the context of the invention, when the bypass valve is closed in the oil bypass line as soon as a predetermined speed or a Speed or torque or force of the components to be lubricated exceeds a predetermined limit.

In an advantageous embodiment of the invention, the lubricating oil flowing through the oil bypass line is heated by a heat exchanger. In order to accelerate the heating of the lubricating oil in addition, it is advantageous if the heat exchanger for heating the lubricating oil is flowed through by the exhaust gas of an internal combustion engine downstream of a catalyst. At this time, the exhaust gas flowing through the heat exchanger flows upstream through a valve. This valve is closed as soon as a specified limit temperature of the Is exhaust gas is achieved to prevent coking of the lubricating oil in the heat exchanger.

In order to reduce the combustion temperature and thus also the nitrogen oxide emissions of the internal combustion engine, flowing through the heat exchanger exhaust flows as exhaust gas recirculation downstream in the sense of the invention through a valve in the intake manifold of an internal combustion engine, wherein the valve is at least partially closed as soon as a predetermined limit temperature of Is exhaust gas is reached or as soon as a predetermined volume flow of the exhaust gas recirculation is achieved. In this case, the exhaust gas is cooled by the heat exchanger, which has a further reduction in the combustion temperature result, so that it can be dispensed with the use of an additional cooler for exhaust gas recirculation.

It is expedient for the purposes of the invention if the exhaust gas flowing parallel to the heat exchanger of the internal combustion engine flows through another valve and that this valve is at least partially closed at times to increase the exhaust gas flow and thus the heat transfer in the heat exchanger.

In a further advantageous embodiment of the invention, a further heat exchanger and a further valve is arranged downstream of the oil pump for cooling, wherein this valve is at least partially opened when a predetermined limit value for the lubricating oil temperature is exceeded or not reached. In one embodiment, the heat exchanger is flowed through by a cooling medium, such as ambient air or cooling liquid, in order to cool the lubricating oil. In another embodiment, this heat exchanger is flowed through by the exhaust gas of the internal combustion engine in order to heat the lubricating oil and reduce the friction. It is advantageous if a further valve is arranged in the lubricating oil line parallel to the heat exchanger and the valve. This valve is at least partially closed when a predetermined limit for the lubricating oil temperature exceeded or fallen short of. It is expedient in this case also if this heat exchanger is arranged in the circuit for cabin heating or in the circuit for heating or cooling of an electric battery.

For controlling oil pressure and oil temperature, it is favorable in the context of the invention, when a control unit controls the opening cross section of the various valves, and if sensors for detecting the lubricating oil pressure, the lubricating oil temperature, the exhaust gas temperature, the rotational speed, the load and / or the coolant temperature with the Control unit are connected.

In an advantageous embodiment of the invention, the lubrication system, the exhaust pipe and the intake manifold are part of an internal combustion engine.

Favorable for the purposes of the invention is also when at least a part of the lubrication system is arranged in a transmission which is connected to the internal combustion engine and the internal combustion engine and the transmission are part of a motor vehicle. It is particularly advantageous if the exhaust gas heat exchanger is designed to be double-flow, so that the transmission oil and the engine oil can be heated simultaneously in parallel and the exhaust gas heat exchanger is connected to the exhaust pipe by a heat-insulating material which has a heat conductivity less than 1 W / (m * K) aufweißt.

The sealing of the valves in the exhaust pipe has a particularly important meaning, since a high density on the one hand improves the effectiveness of the heating and on the other hand in the closed position avoids that the oil heats up unintentionally, for example, at high engine loads and speeds. This can then be dispensed with the use of an additional oil cooler. This makes it advantageous in the sense of the invention, when the valves are integrally formed in the exhaust pipe as a three-way valve and that these valves as Double-acting poppet valve are executed, wherein the plate has two sealing surfaces. Of which a sealing surface at the outermost end of the valve is arranged, as in an outlet valve in the cylinder head of an internal combustion engine. The second sealing surface is arranged on the opposite side of the valve disk, from which the valve stem leads away from the actuator. In the active state, the outermost end of the valve closes the exhaust gas bypass and in the passive state, the inner sealing surface of the plate closes the line to the heat exchanger.

embodiment

Further advantageous embodiments are disclosed in the subclaims and the following description of the figures.

Fig. 1

ein Schaltbild einer ersten Ausführung der Erfindung in einer Verbrennungskraftmaschine;

Fig. 2

ein Schaltbild einer zweiten Ausführung der Erfindung in einer Verbrennungskraftmaschine;

Fig. 3

ein Schaltbild einer weiteren Ausführungsform der Erfindung in einem kalten Zustand;

Fig. 4

ein Schaltbild der Ausführungsform der Fig. 3 in einem warmen Zustand;

Fig. 5

ein Schaltbild einer Ausführungsform der Erfindung in einem Automatikgetriebe;

Show it:

Fig. 1

a circuit diagram of a first embodiment of the invention in an internal combustion engine;

Fig. 2

a circuit diagram of a second embodiment of the invention in an internal combustion engine;

Fig. 3

a circuit diagram of another embodiment of the invention in a cold state;

Fig. 4

a circuit diagram of the embodiment of the Fig. 3 in a warm state;

Fig. 5

a circuit diagram of an embodiment of the invention in an automatic transmission;

In the different figures, the same parts are always provided with the same reference numerals, so that they are usually described only once.

Fig. 1 shows an internal combustion engine 30 in a schematic diagram. The internal combustion engine 30 has an exhaust pipe 14, in which a catalyst 10 is arranged. In the illustrated embodiment, the internal combustion engine 30 is shown as a four-cylinder engine, the four cylinder manifolds open into a common exhaust pipe 14.

Viewed in the exhaust gas flow direction of the exhaust gas, a heat exchanger 8 is arranged in the exhaust gas line 14 behind the catalytic converter 10, and a turbocharger 24 is arranged in front of the catalytic converter. The internal combustion engine 30 has a lubricating oil system 16. The lubricating oil system has an oil sump 1, an oil receiving line 2, an oil pump 3, devices to be lubricated 31 of a cylinder head 12 and a cylinder block 15 and a turbocharger 24, an oil pan 5, and an oil pressure relief valve 4.

The lubricating oil system 16 is also assigned a bypass valve 17. The bypass valve 17 controls the flow of the engine oil through the lubricating oil bypass 23, so that the temperature and the pressure of the engine oil can be set to optimum values. Furthermore, the lubricating oil system 16 has a plurality of oil returns 19.

The heat exchanger 8, at least upstream of the exhaust stream, an exhaust valve or exhaust gas recirculation valve 20, 21, 41, advantageously an EGR control valve upstream, which regulates the exhaust gas flow through the heat exchanger 8 and thus indirectly controls the oil temperature. The heat exchanger 8 is integrated in the lubricating oil system 16, so that the oil is heated in a warm-up phase of the internal combustion engine 30 by means of the exhaust heat. As an alternative to a heat exchanger 8, it is possible to use one or more electrical heating elements, in particular heating rods, which likewise fulfill the purpose of heating the oil within the bypass line. In particular, when used in an automatic transmission, it makes sense to use an exhaust / oil heat exchanger for heating the oil in the bypass line.

In the illustrated embodiment, an exhaust valve 13 is additionally arranged in the exhaust pipe 14 parallel to the heat exchanger 8, which controls the exhaust gas flow through the heat exchanger 8 bypassing exhaust gas bypass 38.

In the lubricating oil system 16 downstream of the oil pump 3, a valve 29 and a heat exchanger 26 with a supply line 27 and a discharge line 28 is arranged for controlling the oil temperature and the oil pressure. In a further oil bypass bypassing the heat exchanger 26, a valve 25 for regulating the oil pressure and the oil temperature is further arranged. The heat exchanger 26 can serve as an oil cooler for heating a cabin interior of a vehicle.

For regulating oil pressure and oil temperature, a control unit 18 is connected to the valves 13, 17, 20, 21, 25, 29 and 41, and at least with sensors for detecting the lubricating oil pressure 32, the lubricating oil temperature 33, the exhaust gas temperature 34, the rotational speed 35, the load 36 and the coolant temperature 37 connected.

In the intake system 6 of the internal combustion engine 30, a throttle valve 7 is arranged, which is connected to a turbocharger 24 which opens downstream into an intake manifold 9. To reduce the combustion temperature, the intake manifold is connected to the exhaust gas recirculation exhaust pipe 14 via an exhaust gas recirculation valve 21, which may be configured as an EGR control valve, the connection being located downstream of the heat exchanger 8. In this case, the heat exchanger 8 may be an EGR heat exchanger. In this way harmful nitric oxide emissions are reduced

By the in Fig. 1 advantageous embodiment, the engine oil is heated faster 30 in a warm-up phase of the internal combustion engine. Parallel to the heat exchanger 8 is controlled via the second exhaust valve 13 exhaust bypass 38 is guided so that overheating of the engine oil is avoided in the heat exchanger. The heat exchanger 8 is preferred sufficiently dimensioned in the counterflow principle, so that the engine oil is heated as quickly as possible, the exhaust gas is cooled down as much as possible.

Fig. 2 shows an advantageous embodiment of the invention. In contrast to Fig. 1 the exhaust outlet of the heat exchanger 8 is connected only to the intake manifold 9, so that the exhaust valve 13 and the exhaust gas recirculation valve 20 are not required.

In this advantageous embodiment of the invention, the heat exchanger has a dual function. On the one hand, the heat exchanger 8 heats up the engine oil during the warm-up phase due to the exhaust gas temperature in order to avoid high combustion temperatures. On the other hand, the heat exchanger 8 acts as a cooler of the exhaust gas recirculation 22 by the exhaust gas recirculated into the intake manifold 9 is cooled by the lubricating oil. This can be dispensed with an additional cooler for exhaust gas recirculation and additional valves to control the exhaust gas flow rate.

Fig. 3 shows an embodiment of an oil lubricating device in a cold state, eg shortly after starting a motor vehicle.
The main oil flow through the bypass valve 17 is shown in bold. The oil flows from the cylinder head 12 into the turbocharger 24. From the turbocharger 24, a bypass line leads to the opened bypass valve 17 through which the oil continues to flow and is combined with the oil return line 19 from the turbocharger. From there, the oil continues to flow through the heat exchanger 8 in which it is heated by the hot exhaust gas. Thereafter, the oil is returned through the oil pan where the return line 23 is connected to the Ölansaugrohr 2, so that the heated oil can be sucked directly further from the oil pump 3.
The flow of the exhaust gas through the heat exchanger 8 is also shown in bold. The hot exhaust gas flows from the catalyst 10 into the exhaust pipe 14 and thence through the opened exhaust gas recirculation valve 21 into the heat exchanger 8 where it heats the cold oil the exhaust gas cools down. From there, the cold exhaust gas flows through the exhaust gas recirculation line 22 back into the intake manifold. 9

As soon as a certain limit value for the oil pressure is reached, the oil bypass valve 17 is completely or at least partially closed, so that the oil pressure in the internal combustion engine 30 can rise again.
The oil bypass valve 17 is completely or at least partially closed when exceeding a maximum oil temperature, while then the exhaust gas recirculation valve 21 is closed or alternatively the in Fig. 4 shown EGR bypass flap 39, opened.

Fig. 4 shows the system in a simplified version in the warm state. The bypass valve 17 is completely or at least partially closed, so that only a very small volume of oil flow through the heat exchanger 8 flows. The majority of the lubricating oil - shown in bold here - then flows through the bearings 31, eg crankshaft main bearings, connecting rod bearings, camshaft bearings, piston injectors, camshaft adjuster, camshaft plunger, etc. either through return lines 19 or directly back into the oil pan 1. The exhaust gas recirculation valve 21 can either be closed or be open. If the exhaust gas recirculation valve 21 is open, it is advantageous if the exhaust gas is guided back into the exhaust gas recirculation line 22 and the intake manifold 9 via a further EGR bypass flap 39.

Fig. 5 The exhaust gas flows from an internal combustion engine (not shown) through a catalytic converter 10 into a 3-way valve 41. In the cold state, the exhaust gas flows through a heat exchanger 8 and heats the transmission oil passing through a bypass valve 17 is released. In the warm state, the exhaust gas does not flow through the heat exchanger 8 but through the bypass 38 and the bypass valve 17 is completely or at least partially closed.

With increasing oil pressure, the volume flow of the oil pump 3 decreases more or less linear, this occurs especially at low oil temperatures. With decreasing volume flow, however, the heat transfer coefficient between oil and cylinder head 12 or cylinder block 15 decreases so that the oil can absorb only a small amount of heat from the cylinder head 12 or cylinder block 15. At very high pressures, a pressure relief valve 4 opens. This reduces the oil volume flow flowing through the cylinder head 12 and block 15, so that the mechanical pumping power of the oil pump 3 is reduced. This reduces the heat transfer coefficient between oil and metal of the cylinder block 15 or head 12.

An increase in the heat transfer coefficient at low temperatures can be achieved by an embodiment of the invention in that the volume flow through the cylinder block 15 and in particular through the cylinder head 12 is increased at low temperatures. This is achieved by at least partial opening of the (bypass) valve 17, for example as a function of temperature, pressure, engine speed and / or load. Supporting this is also conceivable, the volume flow rate of the oil pump 3 to increase mechanically or by a manual transmission or increase by moving conveyor wheels.

Furthermore, it is supportive conceivable to flow through the oil gallery in the cylinder head 12 in series instead of parallel, ie in countercurrent principle of the oil. For this purpose, it may be advantageous first to let the oil flow flow through a main gallery of a cylinder head 12, then to flow back in the opposite direction at the outlet-side end by means of a valve through a further main gallery of a cylinder head 12, so that the flow path of the oil through the cylinder head 12 is increased becomes. The valve may also be arranged on the other side of the bypass line 23 in the oil pan.

The oil contained in the oil passages of an internal combustion engine 30 is only a fraction, usually only 10% of the total volume of oil. In the warm-up phase, the entire oil volume is uniformly heated in known methods. Core idea of the invention is a targeted rapid heating of the lubricating oil located in the oil passages, this being achieved by connecting the oil passage of the cylinder heads 12 by means of a bypass line 23 with the suction side of the oil pump, wherein at the end of the bypass line 23, a negative pressure is applied to the Do not let oil flow back into the sump 1 but back into the oil channel. Thus, in the warm-up phase of the engine, only a small portion of the total oil to be rapidly heated is used for lubrication.

The generation of a negative pressure at the end of the bypass line 23 can be achieved by direct connection of the bypass line 23 with the suction side of the oil pump 3 and with a direct connection to the oil suction pipe 2. For this purpose, the bypass line 23 can be at least partially integrated in a plastic oil pan with integrated oil suction 2, which leads to improved insulation and less heat loss. Furthermore, the mouth of the bypass line 23 can be positioned in the oil sump 1 in close proximity to the opening of the Ölsaugrohres 2, so that the opening of the bypass line end in the direction of the opening of the Ölansaugrohres 2 shows and forms an angle of 0 to 45 °, which is also facilitates installation and the option of retrofitting later.

It is conceivable to improve the heat transfer of the oil in the cylinder head, the use of ribbed bodies in the oil galleries, for example by a rough surface design of the oil passages in the cylinder block 15 or head 12 - in particular by incorporation of a thread - whereby a reduction in the flowable amount of oil is achieved.

In addition, additional active heat sources may be introduced into the bypass line 23, eg electrical heating rods or heating elements, preferably, one or more PTC heating rods, EGR oil cooler (exhaust gas recirculation cooler), full flow oil cooler or the like may be arranged to quickly heat the oil in the oil passages in the warm-up phase.

Furthermore, it is additionally conceivable to direct the exhaust pipe 14 directly through or adjacent to the oil sump 1 or into the bypass line 23 via a further valve, at least in the warm-up phase, whereby an increase in the heat transfer is made possible by a multiple, and optionally dispenses with a heat exchanger 8 can be.

Furthermore, a motor control in the warm-up phase at least a small part of the heat exchanger 8 to control the heating of the oil in the bypass line 23, and after some time shut off the oil flow through the bypass line 23 to prevent coking in the exhaust gas heat exchanger 8 , Control variables for the control can be the higher the required oil pressure as a function of speed and load, and the desired oil temperature as a lower priority.

Furthermore, it is conceivable to exploit the difference in height potential between the cylinder head 12 and the oil suction line 2 for improving the oil flow behavior in the bypass line 23, or to make this height potential structurally as large as possible.

In addition, the use of thermal insulation of the bypass line 23 and / or the EGR bypass (exhaust gas recirculation) upstream of the valve 17 by using a ceramic tube is advantageously conceivable to limit the temperature of the exhaust gas heat exchanger 8 and the exhaust gas recirculation valve 21 when the exhaust gas recirculation valve 21 is closed.

Preferably, an oil pan with line in front of the oil suction 2 in an oil pan, not shown, of the oil sump 1 are integrated to absorb the oil that exits from the bearings in the head and crankshaft while it is also warmed up, and feed directly to the oil pump, without the oil sump heat. The valve 17 may in this case also be integrated in the oil sump after merging the bypass line 23 and the line of the oil sump, wherein a check valve must be present in the line of the oil sump, so that the oil does not flow from the bypass line 23 back into the oil sump can.

Advantageously, a combination of oil pan with spray nozzles, which are arranged in the connecting rod for cooling the piston to increase the flow rate of the oil flow, wherein the spray nozzles are not turned off in the cold start.

The exhaust gas flow for heating the oil in the bypass line 23 can in principle be diverted as desired from the normal exhaust gas flow. Particularly advantageously, the exhaust gas before a turbocharger by means of a conventional EGR valve (exhaust gas recirculation valve) are diverted at a large distance from the turbocharger, the high mass flow of the exhaust gas can be achieved in a small size and independent of the EGR calibration. Thus, a warm-up of the oil can be achieved without affecting the combustion temperature and thus also the exhaust gas. As part of the use of exhaust gas recirculation, it may be advantageous if the EGR cooler assembly has a vertical gas guide with an angle up to 40 degrees to the vertical, so that condensation water can be discharged into an exhaust.

If the internal combustion engine 30 has no turbocharger or no exhaust gas recirculation, an additional flap in the main exhaust gas flow can produce a pressure difference and thus conduct an increased volume flow through the heat exchanger 8.

The invention is not limited to the illustrated embodiments. It is conceivable that the heat exchanger 26 is connected to the exhaust pipe 14 in order to effect a faster heating of the lubricating oil. The arrangement of the valves may vary, the valves may be arranged upstream and downstream of the various heat exchangers and vice versa. The invention may be used to lubricate engine parts, transmission parts or other moving components of a vehicle.

Claims (16)

1. A method for heating a lubricating system (16) for rotating or oscillating components, for an internal combustion engine (30) having at least one oil suction pipe (2) which is arranged in an oil sump (1) and having an oil bypass line (23) which bypasses the oil returns (19), a valve (17) being arranged in the oil bypass line (23),
   the bypass line (23) being connected to the suction line of an oil pump (3) and the length of the oil line of the lubricating system (16) from the outlet of the oil pump (3) to the inlet into the oil bypass line (23) preferably amounting to at least 80% of the maximum length of the oil line of the lubricating system (16) from the outlet of the oil pump (3) to the most distant device (31) to be lubricated,
   characterised in that
   the bypass line (23) extends through at least one cylinder head (12) and, in the event of the temperature falling below a specific limit temperature and the pressure of the lubricating oil in the pressure line of the lubricating system (16) exceeding a specific minimum pressure, the bypass valve (17) is at least partially opened, such that in a warming-up phase of the lubricating system (16) at least a sub-stream of the lubricating oil does not flow through the oil sump (1) until either the minimum pressure or the limit temperature is achieved, and in that the lubricating oil mass flow rate through the oil bypass line (23) is at least temporarily greater than the lubricating oil mass flow rate through the oil suction pipe (2).
2. A method according to claim 1,
   characterised in that
   the bypass line (23) extends through a turbocharger (24).
3. A method according to claim 1 or 2,
   characterised in that
   the bypass valve (17) is closed as soon as a specified rotational speed or speed or torque or force of the components to be lubricated exceeds a specified limit value and/or in that, below a specified rotational speed or speed or torque or force, the delivery capacity of the oil pump (3) is raised in particular during the warming-up phase in order to generate an increased pump volumetric flow rate within the oil line.
4. A method according to one of the preceding claims,
   characterised in that
   the lubricating oil flowing through the oil bypass line (23) and/or at least one of the oil returns (19) is heated by a heat exchanger (8).
5. A method according to claim 4,
   characterised in that
   the exhaust gas from an internal combustion engine (30) is passed through the heat exchanger (8) to heat the lubricating oil, and in that the exhaust gas flowing through the heat exchanger (8) flows upstream through an exhaust gas valve/exhaust gas recirculation valve (20, 21, 41), and in that the exhaust gas valve/exhaust gas recirculation valve (20, 21, 41) is closed as soon as a specified limit temperature of the exhaust gas or the lubricating oil is reached, and/or in that at least some of the exhaust gas is passed via a controllable valve directly over or beside the oil sump (1), into or through an oil pan (5) or into the bypass line (23) in order to increase heat transfer.
6. A method according to claim 4 or 5,
   characterised in that
   the exhaust gas flowing through the heat exchanger (8) flows through an exhaust gas recirculation valve (21) and is connected downstream as exhaust gas recirculation (22) to the intake manifold (9) of an internal combustion engine (30), and in that the exhaust gas recirculation valve (21) is at least partially closed as soon as a specified limit temperature of the exhaust gas is reached or a specified volumetric flow rate of the exhaust gas recirculation is reached.
7. A method according to one of claims 4 to 6,
   characterised in that
   the exhaust gas from the internal combustion engine (30) flowing parallel to the heat exchanger (8) flows through an exhaust gas valve (13) and in that the second exhaust gas valve (13) is temporarily at least partially closed in order to increase exhaust gas flow and thus also heat transfer in the heat exchanger (8).
8. A method according to one of the preceding claims,
   characterised in that
   a heat exchanger (26) and a valve (29) for cooling are arranged downstream of the oil pump (3), and in that the valve (29) is at least partially opened if the lubricating oil temperature exceeds or falls below a specified limit value or the coolant inlet temperature (27) or coolant outlet temperature (28) falls below a specified limit value, a valve (25) preferably being arranged in the lubricating oil line parallel to the heat exchanger (26) and valve (29), and in that the valve (25) is at least partially closed if the lubricating oil temperature exceeds or falls below a specified limit value.
9. An apparatus for heating a lubricating system (16) for rotating or oscillating components for an internal combustion engine (30) for carrying out a method according to one of claims 1 to 8, having at least one oil suction pipe (2) which is arranged in an oil sump (1) and having an oil bypass line (23) which bypasses the oil return (19), a bypass valve (17) being arranged in the oil bypass line (23), and
   the oil bypass line (23) being connected to the suction line of an oil pump (3) and the pressure line of a lubricating system (16),
   characterised in that
   the oil bypass line (23) extends through at least one cylinder head (12);
   and at least one sensor for detecting the lubricating oil pressure (32) and the lubricating oil temperature (33) is provided,
   such that at least in a warming-up phase of the lubricating system (16) at least a sub-stream of the lubricating oil does not flow through the oil sump (1) until either a limit oil pressure or a limit oil temperature is reached, and in that the lubricating oil mass flow rate through the oil bypass line (23) is at least temporarily greater than the lubricating oil mass flow rate through the oil suction pipe (2).
10. An apparatus according to claim 9,
    characterised in that
    the oil bypass line extends through a turbocharger (24).
11. An apparatus according to claim 9 or 10,
    characterised in that
    the length of the oil line of the lubricant system (16) from the outlet of the oil pump (3) to the inlet into the oil bypass line (23) amounts to at least 80% of the maximum length of the oil line of the lubricating system (16) from the outlet of the oil pump (3) to the most distant device (31) to be lubricated.
12. An apparatus according to one of claims 9 to 11,
    characterised in that
    the oil bypass line (23) and/or at least one of the oil returns (19) is connected to a heat exchanger (8) and the heat exchanger (8) for heating the lubricating oil is arranged downstream of the catalytic converter (10) in the exhaust gas system of an internal combustion engine (30), and in that an exhaust gas valve/exhaust gas recirculation valve (20, 41) is arranged upstream of the heat exchanger (8), which valve modifies throughflow as a function of at least the oil temperature or exhaust gas temperature, an exhaust gas recirculation valve (21) preferably being arranged downstream of the heat exchanger (8) and the first exhaust gas recirculation valve (21) being connected downstream to the intake manifold (9) of an internal combustion engine.
13. An apparatus according to claim 12,
    characterised in that
    an exhaust gas valve (13) is arranged parallel to the heat exchanger (8) in an exhaust gas bypass line (38) which bypasses the heat exchanger (8) in order at least temporarily to increase exhaust gas flow and thus also heat transfer in the heat exchanger (8).
14. An apparatus according to one of claims 12 or 13,
    characterised in that
    the heat exchanger (8) is arranged within an exhaust gas line (14) and is connected to this exhaust gas line (14) by a thermally insulating material which has a coefficient of thermal conductivity of less than 1 W/(m*K), and in that the heat exchanger (8) is of two-part construction and connected to the lubricating system of an internal combustion engine (30) and/or the lubricating system of a transmission, and in that both the internal combustion engine (30) and the transmission are part of a motor vehicle.
15. An apparatus according to one of claims 9 to 14,
    characterised in that
    the oil bypass line (23) is arranged in the same housing (15) in which at least one of the devices (31) to be lubricated is also arranged, a further part of the oil bypass line (23) being integrated in one piece in the oil pan (5), the end of the oil bypass line (23) preferably being arranged in the immediate vicinity of the opening of the oil suction line (2) and pointing towards the opening of the oil suction line (2), the two ends in particular adopting an angle of 0° to 45° to one another.
16. An apparatus according to one of claims 9 to 15,
    characterised in that
    at least one of the coolant lines (27) and (28) is connected to a heat exchanger (26) for passenger compartment heating and/or to a heat exchanger for a battery heating and cooling system.

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