DE102006010470A1 - Turbocharger with convection cooling - Google Patents

Abstract

The engine (15) has a turbocharger (1) attached at a turbocharger supply system and at a turbocharger-return system for discharging coolant warmed in the turbocharger to a coolant circuit. The supply system between a water pump-outlet connection and a radiator-supply system is deviated from a cooling water circuit. The turbocharger-return system is opened in the area of a cooling water circuit provided between a radiator-return system and a water pump-inlet connection, where a water level of a compensation tank (9) is higher than the supply system and the turbocharger-return system.

Description

The The invention relates to an internal combustion engine with a turbocharger, with a cooling water circuit and with a surge tank for the cooling water circuit.

Such an internal combustion engine is in the US 4,561,387 shown. In this internal combustion engine is disadvantageous that damage to the turbocharger may occur if the proposed there solenoid valve between reservoir and turbocharger malfunctions.

The US 4 107 927 shows an internal combustion engine with a turbocharger, which is included in the cooling water circuit of the internal combustion engine. Design requirements are opposed to a realization of this concept in modern internal combustion engines.

The JP 2 045 617 shows a device in which after switching off the ignition of an internal combustion engine, this is operated for a certain time at idle until the turbocharger has been sufficiently cooled. This requires sensors and electronics.

The JP 5 9224 414 shows an internal combustion engine having an additional separate cooling circuit including radiator for cooling the turbocharger and cylinder head. The engine block of the internal combustion engine is cooled in a primary cooling circuit.

The DE 2 825 945 shows an internal combustion engine in which the turbocharger is supplied with the motor running with a pressure generated by the water pump with coolant. After switching off the engine, the cooling water circuit stops, which can lead to overheating of the turbocharger.

A The problem underlying the invention is immediate after stopping the engine sufficient cooling of the Ensure turbocharger. If this is not ensured, then can Damage result, as described in more detail in the prior art.

The Invention is thus based on the task of an internal combustion engine to provide, in which the turbocharger is always sufficiently cooled.

These The object is solved by the subject matter of the independent patent claims. advantageous Further developments emerge from the dependent claims.

The The invention provides a turbocharger whose turbocharger supply between the water pump outlet and the radiator inlet from the cooling water circuit branches. This will ensure that the turbocharger is under pressure standing cooling water is supplied. This is a good cooling of the turbocharger in the normal Operation of the internal combustion engine guaranteed.

Of the Turbocharger return ends doing so in an area of the cooling water circuit between the radiator return and the water pump inlet port into the cooling water circuit. Thereby the turbocharger is pressurized by the water pump is produced. This results in an improved flow through the Turbocharger with cooling water.

to Improvement of cooling the turbocharger with the engine off, when the water pump no cooling water promotes, is the turbocharger return over a Degassing line with the expansion tank in conjunction. It lies the water level of the partially filled with air expansion tank geodetically higher than the turbocharger return. This embodiment ensures that a flow in Gear comes, which cools the turbocharger, even if the water pump promotes no coolant. This is attributed to a convection effect. Of Furthermore, the steam generated in the turbocharger water space is discharged to the expansion tank.

Without this vent tube would become fill the turbocharger water space with steam and the cooling would be interrupted become. Due to the inventive design Ensures that the turbocharger in case of afterheating at shut off engine safely cooled becomes. The cooling effect is similar the operation of a coffee machine, in which a water vapor-water mixture due to a warming is led upwards. The counterpressure acting at the lower level, which enables the upfeed, is according to the invention formed by the pending at the turbocharger feed water volume.

The Invention leaves also be implemented by the fact that the turbocharger flow over a Degassing line with the Ausgleichsbehäl ter is in communication. Then the water level of the expansion tank must be higher than the turbocharger flow. That when turning off the internal combustion engine in the turbocharger in Water space resulting gas in the form of water vapor is then over the Degassing vent into the expansion tank while the Water content is attributed to that region of the cooling water circuit, the communicates with the turbocharger feed.

deviant that would be it also possible the Turbocharger feed with a hose to connect to the radiator return, where the turbocharger return connected to the expansion tank with a hose. As well Is it possible, the turbocharger feed with a hose to the cooling water circuit to connect in the combustion engine, the turbocharger return connected to the expansion tank with a hose.

Farther Is it possible, the turbocharger feed with a hose to the water cycle to connect in the combustion engine, during the Turbocharger return with a hose to the thermostat housing or to the suction side of Water pump is connected. This embodiment can also be used with a electric auxiliary pump in the flow tube of the turbocharger be configured.

These deviating from the invention embodiments have not proven. In some of these embodiments, the water flow through the Turbocharger due to too low differential pressure between the radiator outlet and the expansion tank too low. When the engine is stopped, the cooling of the turbocharger is weak, because hoses due to requirements of a constructive nature and the degassing situation unfavorable have to be relocated. When the expansion tank with in the cooling circuit the turbocharger is involved, there must be elaborate additional measures be taken to a foaming to avoid. Such additional measures to lead again to increase the flow resistance in the expansion tank, what the cooling of the turbocharger worsened when the engine is stopped. When the turbocharger forcibly acted upon by the water pump of the cooling circuit with is, then there is indeed a high water flow and a good cooling with the engine running. However, the cooling with the engine is so bad, that often Turbocharger damage to adjust. A designated Additional pump is expensive and prone to failure and should therefore be avoided.

The Invention goes with a clever combination of measures another way, resulting in reliable cooling of the turbocharger both during operation of the internal combustion engine as well as after stopping the engine Internal combustion engine results. Inadmissible temperatures are avoided, as well an undesirable oil coking in the bearings of the turbocharger and thus increased wear. With the Invention can the requirements for the boundary conditions for the operation of a turbocharger fulfilled in a simple way so that any damage be attributed to the turbocharger on causes can, related to the production of the turbocharger. The invention is omitted on additional moving parts such as a Nachhitzepumpe, continue are overpressures in the cooling system avoided, leading to a water vapor outlet and possibly too a cooling water loss to lead can.

In a development of the invention, the turbocharger flow is on one extending in the region of an engine block of the internal combustion engine Coolant channel or even to a coolant channel running in the engine block itself connected. This regularly results in a reliable flow through the Turbocharger with coolant, which is pumped through such channels at high pressure to get a good one cooling of the engine block.

deviant of which the turbocharger flow can also be attached to an engine block thermostat housing is connected. This represents a simple construction and final assembly safe.

Especially In a confined space, the turbocharger return can continue in one the coolant circuit connected Heizradiator return lead. In certain embodiments thus a good loading of the turbocharger after stopping the engine ensures, if the turbocharger over its turbocharger return with cooling water is supplied from the heating system.

It has been proven to provide the turbocharger return here between a point at which the Heizradiator return flows into a Heizradiator, and a point at which the Heizradiator return flows in a thermostat to the Heizradiator return ( 37 ) is connected, especially in the event that the thermostat is arranged in the water pump inlet.

Of the Turbocharger return But also in a further connected to the coolant circuit Water pump return or in a further to the coolant circuit connected oil cooler supply lead. Depending on the installation space this may be necessary to small dimensions of the cooling system to obtain.

It should be sought to divert the degassing as possible in the area of the highest point of the connecting line between turbo charger return and coolant circuit of the connecting line. This ensures that air bubbles easily separate from the coolant without, for example, the convection flow is obstructed by the air bubbles. Depending on the design of the cooling system, it may be necessary that the degassing in the region of the highest point of the connecting line between the turbocharger return line and coolant circuit or between turbocharger flow and coolant circuit branches off from this connection line.

The Invention can also be applied to internal combustion engines, in which the flow through the turbocharger is limited with throttles, especially if the Turbocharger connected near the output port of the water pump is. Then it may be necessary be the line to the turbocharger flow, the line from the turbocharger return and the degassing line, each with a throttle for adjusting the flow resistance for the coolant to provide the flow through the other components of the cooling system with coolant sure.

The Invention is also in a motor vehicle with such an internal combustion engine realized.

The Invention is based on embodiments illustrated in the drawing.

1 shows a schematic representation of a cooled according to the invention the turbocharger,

2 shows a schematic representation of a coolant circuit of an internal combustion engine, on which the invention is realized,

3 shows a schematic representation of a coolant circuit of another internal combustion engine, on which the invention is realized.

1 shows a schematic representation of the cooling of a turbocharger 1 a not shown in this view internal combustion engine with a cooling circuit, also not shown.

The turbocharger 1 has a turbocharger flow 2 and via a turbocharger return 3 , Here is a flow line 4 connected between a water pump outlet port and a radiator flow to the coolant circuit of the internal combustion engine. To the turbocharger return 3 is an output line 5 connected to a tee 6 leads. One of the other two connections of the tee 6 is with a return line 7 connected in an area of the coolant circuit between the radiator return and the water pump input port to the internal combustion engine. The remaining connection of the tee 6 is with a degassing line 8th connected to a surge tank 9 leads, above a water level 10 in the expansion tank 9 , At the bottom of the expansion tank 9 is a compensation line 11 connected, which leads to the coolant circuit of the internal combustion engine.

As you can see in this view, the water level is 10 above the turbocharger 1 ,

During normal operation of the internal combustion engine, the turbocharger 1 supplied with pressurized water, via the supply line 4 and via the return line 7 , If the engine is turned off, then form due to the high temperatures of the turbocharger 1 Gas bubbles inside the turbocharger 1 , This is in 1 by drawn gas bubbles in the output line 5 and in the turbocharger 1 illustrated. Due to the gas bubbles that will be inside the turbocharger 1 , in the supply line 4 and in the output line 5 conveyed coolant upwards, into the area of the T-piece 6 that is advantageously at a relatively high point of output line 5 and return line 7 is arranged. At the tee 6 the gas bubbles separate from the coolant, because they escape through the degassing line 8th in the expansion tank 9 , There, the water vapor contained in the gas bubbles condenses and the condensed coolant is returned to the cooling circuit. Likewise, with the gas bubbles mitbefördertes coolant in the expansion tank 9 and thus returned to the cooling circuit of the internal combustion engine.

2 shows a schematic representation of the cooling system of an internal combustion engine 15 where the in 1 described turbocharger is provided. The internal combustion engine 15 is here as a V-engine with a first row of cylinders 16 and with a second row of cylinders 17 educated. A water pump 18 with a water pump inlet connection 20 , with a first water pump outlet 21 for the first row of cylinders 16 and with a second water pump output port 22 for the second row of cylinders 17 ,

The coolant flow in the internal combustion engine 1 that by the water pump 18 is generated is illustrated with directional arrows.

The coolant outlets of the first cylinder bank 16 and the second cylinder bank 17 be in a jetty 23 merged. From there, the cooling water flow enters a Radia tor supply line 24 out and into a radiator forerun 25 a radiator 26 one. In the radiator 26 is a radiator return 27 provided, via a radiator return line 28 with a thermostat 29 connected is. From the thermostat 29 leads a water pump line 30 to the water pump 18 back. A short circuit line 31 connects the thermostat 29 with the jetty 23 ,

By this arrangement, the coolant circuit of the internal combustion engine 15 specified.

At the start of the internal combustion engine 15 when cold, the thermostat closes 29 the connection between radiator return line 28 and thermostats 29 , At the same time, the connection between the short-circuit line 31 and the thermostat 29 open. Coolant then circulates from the water pump 18 in the first row of cylinders 16 , in the second row of cylinders 17 and in the jetty 23 , From there, the coolant enters the short circuit line 31 , to the thermostat 29 and from there via the water pump line 30 back to the water pump 18 guided.

When the coolant heats up, the thermostat closes 29 the connection between the short circuit line 31 and the thermostat 29 , at the same time the connection between the radiator return line 28 and the thermostat 29 open. The coolant then flows from the web cable 23 in the radiator feed line 24 and into the radiator forerun 25 , It gets in the radiator 26 cooled and takes its way over the radiator return 27 and the radiator return line 28 to the thermostat 29 , From there it is via the water pump line 30 back to the water pump 18 promoted.

To the cooling circuit described above, several additional units are connected, such as an oil cooler 32 , a heating radiator 33 , the equalization tank 9 and the turbocharger 1 , This is the oil cooler 32 via an oil cooler supply line 34 with coolant from the radiator supply line 24 provided. That in the oil cooler 32 heated coolant is via an oil cooler drain line 35 into the radiator return line 28 recycled.

The heating radiator 33 is supplied with coolant that at one point of the bridge line 23 is taken. From there it is via a Heizradradiator supply 36 to the radiator radiator 33 guided. The in the radiator radiator 33 Cooled coolant is passed through a heating radiator return line 37 to the thermostat 29 recycled. From the heating radiator return line 37 branches a compensation line 38 to the bottom of the expansion tank 9 from. Furthermore, the return line 7 from the tee 6 to the heating radiator return line 37 connected.

A vent line 39 extends between the bridge line 23 and the expansion tank 9 , where the the expansion tank 9 facing the end of the vent line 39 in one above the water level 10 opening gas pipeline 40 and in one below the water level 10 opening coolant line 41 forks.

The supply line 4 to the turbocharger 1 is at a coolant outlet 42 second row of cylinders 17 connected to the coolant circuit. With a properly sized flow throttle 43 becomes the flow resistance of the flow line 4 adjusted so that the turbocharger 1 during normal operation of the internal combustion engine 15 is sufficiently supplied with coolant.

With a degassing throttle 44 in the degassing line 8th is set their flow resistance. The degassing throttle has 44 during operation of the internal combustion engine 15 the task of excessive coolant flow from the turbocharger return 3 to the expansion tank 9 counteract. With the internal combustion engine stopped 15 when there are gas bubbles in the turbocharger 1 form, causes the degassing 44 that, above all, water vapor in the expansion tank 9 escapes and not so much coolant.

In an embodiment not shown here, the design can 2 be essentially taken over. In from the in 2 As shown, the return line 7 not on the heating radiator return line 37 connected but at the thermostat 29 , at the water pump line 30 or right next to the water pump 18 , The supply line 4 can also at the jetty 23 or on the radiator feed line 24 be connected. The flow throttle 43 and the degassing throttle 44 can also be designed as variably adjustable throttles.

In another example, not shown here, in which a thermostat is not connected to the motor input, as in 2 but rather at the engine outlet, can the return line 7 on the radiator return line 28 be connected.

With the above variants it is guaranteed that the turbocharger 1 it is always flowed through with coolant, it does not matter which lines the thermostat 29 just opens or locks.

In another embodiment, not shown here are in the in 2 shown representation of the points on de nen the return line 7 and the heating radiator return line 37 in the compensation line 38 lead, as close as possible to each other. As a result, at high engine speeds, a backflow in the line 38 reduced or completely avoided.

3 shows a schematic representation of another internal combustion engine 45 , the in-line four-cylinder with a single row of cylinders 46 is executed. Parts with the same function are in 3 denoted by the same reference numerals as in 1 and in 2 , but they are provided with an apostrophe.

When starting the internal combustion engine 45 in cold condition is the thermostat 29 ' closed. The coolant therefore circulates from the water pump 18 ' into the cylinder bank 46 , from there into the Heizradradiator supply line 36 ' , through the heating radiator 33 ' , back to the heating radiator return line 37 ' , from there into the oil cooler 32 ' and back into the water pump input port 20 ' , Coolant flows from the thermostat 29 ' to the tee 6 ' and from there via the supply line 4 ' to the turbocharger 1' , The coolant in the turbocharger 1' is via the output line 5 ' into the radiator return line 28 sucked, due to the action of the water pump 18 ' passing over the oil cooler 32 ' with the radiator return line 28 ' communicates.

When the coolant is heated, the thermostat opens 29 , then the way over the radiator feed line 24 ' to the radiator 26 ' Approved. At the flow through the turbocharger 1' nothing changes.

When parking the internal combustion engine 45 is the flow through the turbocharger 1' from the turbocharger supply 2 ' to the turbola der-Rücklauf 3 ' completed. Inside the turbocharger 1' Gas bubbles form over the turbocharger flow 2 ' to the tee 6 ' and from there via the degassing line 8th' to the top of the surge tank 9 ' escape.

The escaping gas bubbles / coolant mixture is passed through the outlet line 5 ' replenished coolant replaced.

In this design, the flow direction of the turbocharger 1' in the normal operating condition of the internal combustion engine 45 reversed to the flow of coolant with the internal combustion engine stopped, when gas bubbles inside the turbocharger 1' form. For this purpose, the opening for the turbocharger flow 2 ' arranged at a geodetically higher altitude than that for the turbocharger return 3 ' , The water level 10 ' then lies at a higher altitude than the turbocharger return 3 ' , As a result, a supply and a supply of coolant to the turbocharger 1' ensured when there is coolant in it due to a gas bubble formation in the expansion tank 9 ' emptied.

Unlike in the embodiment according to 1 and 2 Also, a continuous convection flow does not occur when there are gas bubbles inside the turbocharger 1' form. Not only because of it, but also because of the flow throttle 43 ' limited flow through the turbocharger 1' this version is suitable for turbochargers, which are subject to limited thermal load. For this embodiment has advantages in terms of compactness in the arrangement of the components provided for the coolant circuit. A particularly space-saving design is hereby made possible.

In another, not shown here, but particularly space-saving embodiment, the output line 5 ' at the turbocharger return 3 ' not to the radiator return line 28 ' but connected to the Heizradradiator return line 37 ' , At the flow through the turbocharger 1' nothing changes. The coolant in the turbocharger 1' is via the output line 5 ' in the Heizradradiator return line 37 ' sucked, due to the action of the water pump 18 ' passing over the oil cooler 32 ' with the radiator radiator return line 37 ' communicates.

1

turbocharger

2

Turbocharger Forward

3

Turbocharger return

4

supply line

5

output line

6

Tee

7

Return line

8th

degassing

9

surge tank

10

water level

11

compensation line

15

internal combustion engine

16

First Cylinder row, cylinder block

17

Second Cylinder row, cylinder block

18

water pump

20

Water pump input port

21

first Water pump output port

22

second Water pump output port

23

quill

24

Radiator supply line

25

Radiator Lead

26

radiator

27

Radiator return

28

Radiator return pipe

29

thermostat

30

Water pump line

31

Short-circuit line

32

oil cooler

33

Heating radiator

34

Oil cooler inlet pipe

35

Oil cooler drain line

36

Heating radiator supply line

37

Heating radiator return pipe

38

compensation line

39

vent line

40

gas pipe

41

Coolant line

42

Coolant outlet

43

supply flow restrictor

44

Entgasungsdrossel

45

internal combustion engine

46

cylinder bank

Claims (12)

Internal combustion engine ( 15 ; 45 ) with a turbocharger ( 1 ; 1' ), with a coolant circuit and with an expansion tank ( 9 ; 9 ' ) for the coolant circuit, the coolant circuit having the following features: - a water pump ( 18 ; 18 ' ) with a water pump inlet connection ( 20 . 20 ' ) and with an output terminal ( 22 . 23 ; 22 ' ) for circulating the coolant, wherein the water pump output port ( 22 . 23 ; 22 ' ) during operation of the water pump ( 18 ; 18 ' ) has a higher pressure level than the water pump input port ( 20 . 20 ' ), - a radiator ( 26 ; 26 ' ) for cooling the coolant, wherein the radiator ( 26 ; 26 ' ) via a radiator flow ( 25 ; 25 ' ) for the supply of warmer coolant and via a radiator return ( 27 ; 27 ' ) for removal in the radiator ( 26 ; 26 ' ) cooled coolant is enclosed in the coolant circuit, wherein the turbocharger ( 1 ; 1' ) via a turbocharger flow ( 2 ; 2 ' ) for the supply of cooler coolant and via a turbocharger return ( 3 ; 3 ' ) for removal in the turbocharger ( 1 ; 1' ) heated coolant is connected to the coolant circuit, wherein the turbocharger flow ( 2 ; 2 ' ) between the water pump outlet port ( 21 ; 22 ; 21 ' ) and the radiator forerunner ( 25 ; 25 ' ) branches off from the coolant circuit and wherein the turbocharger return ( 3 ; 3 ' ) in a region of the coolant circuit between the radiator return ( 27 ; 27 ' ) and the water pump inlet port ( 20 ; 20 ' ) opens into the coolant circuit and wherein the turbocharger return ( 3 ; 3 ' ) or the turbulence of the Vorlauf ( 2 ; 2 ' ) via a degassing line ( 8th ; 8th' ) with the expansion tank ( 9 ; 9 ' ) and the water level ( 10 ; 10 ' ) of the expansion tank ( 9 ; 9 ' ) is higher than the turbocharger return ( 3 ; 3 ' ) or the turbocharger flow ( 2 ; 2 ' ). Internal combustion engine according to claim 1, characterized in that the turbocharger supply ( 2 ; 2 ' ) to one in the area of an engine block ( 16 . 17 ; 16 ' ) of the internal combustion engine ( 15 ; 45 ) extending coolant channel is connected. Internal combustion engine according to claim 2, characterized in that the turbocharger supply ( 2 ' ) to one on the engine block ( 16 ' ) mounted thermostat housing ( 29 ' ) connected. Internal combustion engine according to claim 2, characterized in that the turbocharger supply ( 2 ) to one in the engine block ( 17 ) extending coolant channel is connected. Internal combustion engine according to one of the preceding claims, characterized in that the turbocharger return ( 3 ; 3 ' ) in a further connected to the coolant circuit Heizradiator return ( 37 ; 37 ' ) opens. Internal combustion engine according to claim 5, characterized in that the turbocharger return ( 3 ) between a point at which the Heizradiator return ( 37 ) in a Heizradiator ( 33 ) and a point where the heating radiator return ( 37 ) in a thermostat ( 29 ), to the Heizradiator return ( 37 ) connected. Internal combustion engine according to one of the preceding claims, characterized characterized in that the turbocharger return in egg nen continue to the coolant circuit connected water pump return empties. Internal combustion engine according to one of the preceding claims, characterized in that the turbocharger return ( 3 ' ) in a further connected to the coolant circuit oil cooler feed ( 28 ' ) opens. Internal combustion engine according to one of the preceding claims, characterized in that the degassing line ( 8th ) in the region of the highest point of the connecting line between turbocharger return ( 3 ) and coolant circuit branches off the connection line. Internal combustion engine according to one of claims 1 to 8, characterized in that the degassing line ( 8th' ) in the region of the highest point of the connecting line between turbocharger return ( 3 ' ) and coolant circuit or between turbocharger flow ( 2 ' ) and coolant circuit branches off the connection line. Internal combustion engine according to one of the preceding claims, characterized in that the line to the turbocharger flow, the line from the turbocharger return and / or the degassing line, each with a throttle ( 43 . 44 ; 43 ' . 44 ' ) is provided for adjusting the flow resistance for the cooling liquid. Motor vehicle with an internal combustion engine after a of the preceding claims.