EP2616650B1 - Coolant circuit for an internal combustion engine - Google Patents

Description

Coolant circuit for an internal combustion engine, in particular designed as a two-circuit cooling coolant circuit for internal combustion engines with at least two parallel cylinder banks, preferably in V or W design.

Such coolant circuits are used in internal combustion engine construction for motor vehicles for cooling assemblies of the internal combustion engine, in particular of cylinder heads and cylinder crankcases, at a different temperature level.

Coolant circuits for internal combustion engines with a cylinder crankcase having opposite cylinder banks, that is designed as a so-called "V-engine" are among others from the DE 103 18 744 A1 or the DE 10 2006 044 680 A1 known. However, there is always a fluidic connection between the coolant jacket of the cylinder crankcase and the coolant jacket in the overlying cylinder heads, so that no separate flow at different temperature levels is possible.

Such a dual-circuit cooling, as is known from the DE 198 03 885 A1 or the JP 600 199 12 A shows, in which the cylinder crankcase and the cylinder head are internally fluidically separated from each other and involved in parallel to each other subcircuits of the coolant circuit are so far mainly used in inline engines with a single cylinder bank.

The DE 100 21 525 A1 However, shows a cooling circuit for a multi-cylinder V-engine with a, a cylinder head housing and a cylinder block surrounding cooling jacket, which is supplied via a pump with coolant, at least one cylinder cooling jacket and at least one cylinder head cooling chamber provided with a connection for the supply of the cooling liquid are and wherein the flow through the cylinder head housing and cylinder block with coolant takes place in parallel.

The disadvantage, however, is that a blockage of the outflow of the cylinder cooling jacket, for faster heating of the therein cooling liquid, while cooling liquid flow through the cylinder head cooling chamber, an undesirable cooling liquid movement in the cylinder cooling jacket by cross flows to result, which slows the heating of the cylinder block.

The generic US 5,497,734 A and JP 10 184358 A each show a coolant circuit for an internal combustion engine, comprising a cylinder crankcase with at least two cylinder banks, and associated cylinder heads, wherein the cylinder crankcase and the cylinder heads can be acted upon by parallel running partial circuits of the coolant circuit of a coolant pump with coolant, wherein a first control valve with at least two synchronously switchable first connections and a second connection in a cylinder crankcase partial circuit is arranged and wherein the first terminals are connected in pairs with each one of the cylinder banks in fluid communication. The disadvantage is that the control valves shown for combining the coolant from the cylinder banks constructed consuming and difficult to control synchronously. The object of the present invention is therefore to provide a coolant circuit for an internal combustion engine having a plurality of cylinder banks. This object is solved by the features of patent claim 1.

Coolant circuit for an internal combustion engine, comprising a cylinder crankcase with at least two cylinder banks, and associated cylinder heads, wherein the cylinder crankcase and the cylinder heads can be acted upon by separate and parallel partial circuits of the coolant circuit of a coolant pump with coolant, wherein a first control valve with at least two synchronously switchable first Terminals and a second port in a cylinder crankcase subcircuit is arranged, wherein the first ports are each connected in fluid communication with one of the cylinder banks and wherein the first control valve is designed as a rotatable about a rotation ball valve, wherein the first terminals radially and the second terminal axially arranged thereon.

By arranging a first control valve with at least two synchronously switchable first connections and a second connection in the cylinder crankcase subcircuit, a coolant flow in the cylinder crankcase subcircuit can also be set in internal combustion engines with a plurality of cylinder banks lying opposite each other, independently of the coolant flow in the cylinder head subcircuit become. The cylinder crankcase generally has a single coolant jacket, which surrounds the two cylinder banks, so that a coolant exchange between the cylinder banks is in principle possible at any time. The cylinder crankcase subcircuit and the cylinder head subcircuit run in sections parallel within the coolant circuit. The synchronous switchability of the paired with the cylinder banks fluidly connected first Ports prevent unwanted cross-flow of the coolant in the cylinder crankcase between the cylinder banks, regardless of the coolant flow in the cylinder head partial circuit. If the first connections of the first control valve are closed synchronously, for example, then a coolant flow in the parallel cylinder head partial circuit can not stimulate any cross-flow of the coolant between the cylinder banks. The cylinder crankcase can thereby heat up faster. This operating principle can be applied analogously for internal combustion engines in V or W construction or boxer engines. Due to the design as a ball valve with radial first ports and axial second port, a first control valve can be provided particularly favorable. The ball valve consists of a housing with rotatably mounted therein Querschnittsverstellglied. The cross-section adjustment is formed as a spherical hollow body, with an axial opening in the region of the axis of rotation of the Querschnittsverstellglieds and two, preferably symmetrically opposed, radial openings in a radial peripheral region of the Querschnittsverstellglieds. The axial opening is in almost every rotational position of the Querschnittsverstellglieds in almost complete coverage with the second port. The radial openings can be continuously overlapped in synchronism with the first terminals. The overlap of each first terminal with the complementary radial opening in each switching position is the same size. The rotary actuation of the cross section adjustment member is preferably carried out via an electric drive or a pressure cell with electropneumatic pressure transducer.

In a preferred embodiment, the amount of coolant to be supplied to the first control valve is to be distributed uniformly in all switching positions of the first control valve to all first connections. This ensures that the same amount of coolant flows through all the cylinder banks or that the coolant flow through the cylinder banks can be prevented at the same time. Thus, unwanted cross flows between the cylinder banks are avoided in each switching position of the first control valve.

In a preferred embodiment, the cylinder banks are each acted upon by a separate cylinder crankcase flow parallel with coolant.

In a preferred embodiment, the first control valve is disposed downstream of the cylinder crankcase, wherein the second port is fluidly connected to a cylinder crankcase return. The first control valve is acted upon by the first ports with coolant from the cylinder banks. The coolant is discharged via the second connection in a cylinder crankcase return, depending on the switching position of the control valve.

In a preferred embodiment, the first control valve is arranged upstream of the cylinder crankcase, wherein the second connection is fluidly connected to a common cylinder crankcase flow. The first control valve is acted upon via the second connection with coolant from a common cylinder crankcase flow. Depending on the switching position of the control valve, the coolant is distributed via the first connections to the parallel cylinder crankcase heaters associated with the cylinder banks. From the cylinder banks, the coolant is discharged via a cylinder crankcase return.

In a preferred embodiment, the coolant can be circulated by the coolant pump at least temporarily between a main heat exchanger and the cylinder heads and / or the cylinder crankcase. The coolant flow between said components can be temporarily prevented by valves or a coolant pump which can be switched on and off, as a result of which a controlled temperature control of the components is possible independently of one another.

In a preferred embodiment, each cylinder head has its own cylinder head lead and own cylinder head return, with the cylinder crankcase headers and the cylinder head headers being fed from a common flow section downstream of the coolant pump.

In a preferred embodiment, the cylinder crankcase return is merge at a junction with the cylinder head recirculations to a common return section.

In a preferred embodiment, the common return section leads to the main heat exchanger and the common flow section goes from the main heat exchanger.

The division of the cylinder head headers and the cylinder crankcase headers from the common flow section downstream of the main heat exchanger allows the lowest possible use of tubing and the use of a single main heat exchanger and a single coolant pump for all subcircuits. The same applies analogously for the merger of the cylinder crankcase return and the cylinder head returns to a common return section upstream of the main heat exchanger.

In a preferred embodiment, a second control valve between the main heat exchanger and the coolant pump is arranged in the common flow section, in addition to a branch of the common return section, bypassing the main heat exchanger, opens. Due to the branch, the main heat exchanger, if appropriate, the second control valve, if necessary, be bypassed. In this so-called bypass mode, a coolant flow in the cylinder heads, and in dependence on the first control valve in the cylinder crankcase, possible without the heated coolant in the main heat exchanger is cooled. This allows a particularly rapid and uniform heating of the internal combustion engine at an elevated temperature level. Alternatively, upon reaching a certain minimum temperature, the second control valve may direct the coolant through the main heat exchanger by closing the branch. As a second control valve in this case is preferably a continuously controllable control valve and more preferably a map thermostat, which can be energized when needed for map change.

The coolant circuit described does not extend exclusively to the examples set forth; in particular, further heat exchangers can be added as desired in further sub-circuits. In addition, the connection of a known ventilation system is provided with a surge tank to the coolant circuit.

Further details and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the drawings.

• Fig. 1 eine schematische Darstellung einer ersten Ausführungsform eines erfindungsgemäßen Kühlmittelkreislaufs;
• Fig. 2 eine schematische Darstellung einer zweiten Ausführungsform eines erfindungsgemäßen Kühlmittelkreislaufs;
• Fig. 3 eine Schnittansicht eines als Kugelventil ausgebildeten ersten Stellventils.

Show:

• Fig. 1 a schematic representation of a first embodiment of a coolant circuit according to the invention;
• Fig. 2 a schematic representation of a second embodiment of a coolant circuit according to the invention;
• Fig. 3 a sectional view of a ball valve designed as a first control valve.

According to Fig. 1 has a coolant circuit 1 for an internal combustion engine 2, a main heat exchanger 8 for heat exchange between him flowing around The internal combustion engine 2 consists essentially of a cylinder crankcase 3, which contains the displacements of the working cylinder in two parallel and mutually opposite cylinder banks 3a and is penetrated by a single coolant jacket, as well as, the cylinder banks 3a associated, cylinder heads 4, which accommodate essentially gas exchange devices for the working cylinder and are also penetrated by a coolant jacket. The coolant jackets of the cylinder heads 4 and the cylinder crankcase 3 are not internally fluidically connected, but involved in separate and parallel to each other subcircuits 5 and 6 of the coolant circuit 1. For this purpose, each cylinder head 4, and each cylinder bank 3a of the cylinder crankcase 3 via its own flow connection 6a and 5a, which are acted upon by a cooling medium pump 7 having common flow section 14 with coolant. For this purpose, the common flow section 14 branches at a branch point 12, at which the coolant is distributed to the two sides of the V-shaped internal combustion engine 2, on. Further downstream takes place a further division between the cylinder head 4 or cylinder bank 3a. The coolant from the cylinder banks 3a flows via a respective first port 9a to a first control valve 10. The first control valve 10 is as a in Fig. 3 formed closer ball valve that switches the first terminals 9a so synchronous that the first control valve 10 to be supplied coolant quantity is distributed uniformly in each switching position on the two first terminals 9a. In particular, the first control valve 10 can completely separate the two first connections 9a from a cylinder crankcase return 5b connected to a second connection 9b of the first control valve 10. The cylinder heads 4, however, have their own cylinder head returns 6b, which are merged at a junction 13 with the cylinder crankcase return 5b to a common return section 15. The common return section 15 extends to the input side of the main heat exchanger 8, while the common flow section 14 from the output side of the main heat exchanger 8 springs. The common flow section 14 contains, in addition to the central coolant pump 7, a second control valve 11 arranged upstream of the coolant pump 7, which is additionally contacted by a branch 16 branching off from the common return section 15, bypassing the main heat exchanger 8. The second control valve 11 is designed as an energizable map thermostat, which closes the branch 16 in response to variable by means of energization Kühlmitteltemperaturschwellwerten and passes the coolant through the main heat exchanger 8. Otherwise, the coolant is passed via the branch 16 on the main heat exchanger 8 to the coolant pump 7. From one of the cylinder heads 4, a heating circuit 17 with a heating heat exchanger 18 located therein for heating ambient air for a vehicle interior, which opens upstream of the coolant pump 7 and downstream of the second control valve 11 again in the common flow section 14.

According to Fig. 2 a coolant circuit 1 for an internal combustion engine 2 has a main heat exchanger 8 for heat exchange between the surrounding air flowing around it and the coolant flowing through it from the coolant circuit 1, and a coolant pump 7 for generating a coolant circulation in the coolant circuit 1. The internal combustion engine 2 consists essentially of a cylinder crankcase 3, which contains the displacements of the working cylinder in two parallel and opposite cylinder banks 3a and is penetrated by a single coolant jacket, and the cylinder banks 3a associated, cylinder heads 4, which accommodate essentially devices for gas exchange for the working cylinder and also from a coolant jacket are interspersed. The coolant jackets of the cylinder heads 4 and the cylinder crankcase 3 are not internally fluidically connected, but in separate and mutually parallel partial circuits 5 and 6 of the Integrated coolant circuit 1. For this purpose, each cylinder head 4, and each cylinder bank 3a of the cylinder crankcase 3 via its own flow connection 6a and 5a, which are acted upon by a cooling medium pump 7 having common flow section 14 with coolant. For this purpose, the common flow section 14 branches at a branch point 12, at which the coolant is distributed to the cylinder heads 4 or the cylinder banks 3, on. A common cylinder crankcase flow 5c opens to a second port 9b of a, in Fig. 3 The first control valve 10 distributes the coolant via synchronously switchable first ports 9a to the parallel cylinder crankcase advances 5a, which lead to the cylinder banks 3a. The first control valve 10 synchronously switches the first ports 9a such that the coolant amount to be supplied to the first control valve 10 is uniformly distributed in each shift position to the first two ports 9a. In particular, the first control valve 10 can completely separate the two first connections 9a from the common cylinder crankcase flow 5c. The cylinder heads 4, however, have their own cylinder head returns 6b, which are merged at a junction 13 with the cylinder crankcase return 5b to a common return section 15. The common return section 15 extends to the input side of the main heat exchanger 8, while the common flow section 14 from the output side of the main heat exchanger 8 springs. The common flow section 14 contains, in addition to the central coolant pump 7, a second control valve 11 arranged upstream of the coolant pump 7, which is additionally contacted by a branch 16 branching off from the common return section 15, bypassing the main heat exchanger 8. The second control valve 11 is designed as an energizable map thermostat, which closes the branch 16 in response to variable by means of energization Kühlmitteltemperaturschwellwerten and passes the coolant through the main heat exchanger 8. Otherwise, the coolant is passed via the branch 16 on the main heat exchanger 8 to the coolant pump 7. From one of the cylinder heads 4, a heating circuit 17 with a heating heat exchanger 18 located therein for heating ambient air for a vehicle interior, which opens upstream of the coolant pump 7 and downstream of the second control valve 11 again in the common flow section 14.

According to Fig. 3 has a ball valve 10 for a coolant circuit of an internal combustion engine, a housing 10 b, in which a Querschnittsverstellglied 10 a is rotatably mounted about a rotation axis A. The housing 10b has an axial second terminal 9b and two radially opposite first radial terminals 9a. The cross-section adjustment member 10a is formed as a spherical hollow body with corresponding openings 10d and 10e. The axial opening 10e is independent of the current position of the Querschnittsverstellglieds 10a always approximately congruent with the second terminal 9b. The radial openings 10d are distributed symmetrically over the radial circumference of the Querschnittsverstellglieds, so that the first terminals 9a occupy the same coverage with the complementary radial openings 10d in each rotational position of the Querschnittsverstellglieds 10a. In the position shown, the first terminals 9a are fully opened. If the Querschnittsverstellglied 10 a rotated at an angle of 90 ° about the axis of rotation A, the first terminals 9 a are closed. In addition to these two edge positions, all possible intermediate positions are conceivable. For this purpose, to actuate the Querschnittsverstellglieds 10a, for example, a non-illustrated pressure cell attack with electropneumatic pressure transducer. To prevent leakage, the gap between the cross-section adjustment member 10a and the housing 10b is sealed by seals 10c.

List of reference numbers:

A

axis of rotation

1

Coolant circuit

2

Internal combustion engine

3

cylinder crankcase

3a

cylinder bank

4

cylinder head

5

Cylinder crankcase partial circuit

5a

Cylinder crankcase lead

5b

Cylinder crankcase return

5c

common cylinder crankcase flow

6

Cylinder head sub-circuit

6a

Cylinder head forward

6b

Cylinder Head return

7

Coolant pump

8th

Main heat exchanger

9a

first connection

9b

second connection

10

first control valve

10a

cross section adjustment

10b

casing

10c

poetry

10d

radial opening

10e

axial opening

11

second control valve

12

branching point

13

junction

14

common forerun section

15

common return section

16

junction

17

heating circuit

18

Heater core

Claims (10)

1. Coolant circuit (1) for an internal combustion engine (2), which has a cylinder crankcase (3) having at least two cylinder banks (3a), and associated cylinder heads (4), wherein the cylinder crankcase (3) and the cylinder heads (4) can be supplied with coolant by a coolant pump (7) by means of separate sub-circuits (5, 6) of the coolant circuit (1) extending parallel to each other, wherein a first control valve (10) having at least two synchronously switchable first connections (9a) and a second connection (9b) is arranged in a cylinder crankcase sub-circuit (5) and wherein the first connections (9a) each have a flow connection with one of the cylinder banks (3a) in pairs, characterised in that the first control valve (10) is configured as ball valve rotatable about an axis of rotation (A), wherein the first connections (9a) are arranged radially thereon and the second connection (9b) is arranged axially thereon.
2. Coolant circuit for an internal combustion engine according to claim 1, characterised in that the quantity of coolant to be fed to the first control valve (10) in each switch position of the first control valve (10) is to be distributed evenly over all the first connections (9a).
3. Coolant circuit for an internal combustion engine according to claim 1 or 2, characterised in that each of the cylinder banks (3a) can be supplied with coolant in parallel via its own cylinder crankcase feed (5a).
4. Coolant circuit for an internal combustion engine according to any one of claims 1 to 3, characterised in that the first control valve (10) is arranged downstream of the cylinder crankcase (3), wherein the second connection (9b) has a flow connection with a cylinder crankcase return (5b).
5. Coolant circuit for an internal combustion engine according to any one of claims 1 to 3, characterised in that the first control valve (10) is arranged upstream of the cylinder crankcase (3), wherein the second connection (9b) has a flow connection with a shared cylinder crankcase feed (5c).
6. Coolant circuit for an internal combustion engine according to any one of claims 1 to 5, characterised in that the coolant can be circulated by the coolant pump (7) at least at times between a main heat exchanger (8) and the cylinder heads (4) and/or the cylinder crankcase (3).
7. Coolant circuit for an internal combustion engine according to any one of claims 1 to 6, characterised in that each cylinder head (4) has its own cylinder head feed (6a) and its own cylinder head return (6b), wherein the cylinder crankcase feeds (5a) and the cylinder head feeds (6a) are fed from a shared feed section (14) downstream of the coolant pump (7).
8. Coolant circuit for an internal combustion engine according to claim 7, characterised in that the cylinder crankcase return (5b) can be merged with the cylinder head returns (6b) at a connection point (13), to form a shared return section (15).
9. Coolant circuit for an internal combustion engine according to claim 8, characterised in that the shared return section (15) leads to the main heat exchanger (8) and the shared feed section (14) leaves the main heat exchanger (8).
10. Coolant circuit for an internal combustion engine according to any one of claims 7 to 9, characterised in that in the shared feed section (14) there is arranged between main heat exchanger (8) and coolant pump (7) a second control valve (11), into which additionally a branch (16) of the shared return section (15) leads, bypassing the main heat exchanger (8).

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