AT524566A4 - Liquid-cooled internal combustion engine - Google Patents

Abstract

The invention relates to a liquid-cooled internal combustion engine (1), in particular a large engine, comprising a cylinder head (2) having a top-down cooling concept with a head cooling jacket (3) and a cylinder block (4) with a block cooling jacket (5), wherein in the cylinder block (4) at least one cylinder (6) is arranged, with the head cooling jacket (3) comprising a head inlet duct (7) and a head outlet duct (8) and the block cooling jacket (5) comprising a block inlet duct (9) and a block outlet duct (10), with a connecting duct (11 ) is provided between the head cooling jacket (3) and the block cooling jacket (5), wherein a control device (12) is provided in the connecting duct, so that the head cooling jacket (3) and the block cooling jacket (5) are optionally flow-connected.

Description

Liquid-cooled internal combustion engine

The invention relates to a liquid-cooled internal combustion engine, in particular a large engine, comprising a cylinder head having a top-down cooling concept with a head cooling jacket and a cylinder block with a block cooling jacket, at least one cylinder being arranged in the cylinder block, the head cooling jacket having a head inlet duct and a head outlet duct and the block cooling jacket having one Includes block inlet channel and a block outlet channel.

The invention also relates to a method for cooling an internal combustion engine. Liquid-cooled internal combustion engines are known from the prior art.

AT 515 143 B1 and AT 503 182 A?2 each disclose a liquid-cooled internal combustion engine with a cylinder head and a cylinder block, the cylinder head having two partial cooling chambers arranged one above the other, through which the flow occurs according to a so-called top-down cooling concept. The two partial cooling chambers are separated from one another by an intermediate deck and flow-connected to one another in the area of a centrally arranged injector sleeve via at least one transfer channel. The coolant is supplied via an inlet duct in the cylinder block, flows through a cooling chamber in the cylinder block surrounding the cylinder and is fed directly to the upper part of the cooling chamber of the cylinder head via flow transfers in the fire deck and supply ducts. As a result, the cylinder head flows from top to bottom, so to speak, with the coolant first being fed to the upper part of the cooling chamber and after flowing through the upper part of the cooling chamber via the at least one transfer channel into the lower part of the cooling chamber, where the coolant flows radially from the inside via radial cooling channels in the area of the valve bridges is guided to the outside and finally leaves the cylinder head again via the laterally arranged discharge channel.

AT 522 272 A1 also shows a liquid-cooled internal combustion engine in which at least one cooling jacket is provided for the cylinder head and the cylinder block. A flow through the head cooling jacket is through

at least one valve controllable.

The disadvantage of known solutions is that the cooling jacket solutions implemented only react to different load conditions to a limited extent

can be.

This is where the invention comes in. The object of the invention is an internal combustion engine

to be able to cool efficiently under all and changing thermal loads.

This object is achieved according to the invention in that, in an internal combustion engine of the type mentioned at the outset, a connecting channel is provided between the head cooling jacket and the block cooling jacket, with a control device being provided in the connecting channel, so that the head cooling jacket and the block cooling jacket are optionally flow-connected.

An advantage achieved in this way can be seen in particular in the fact that, depending on a cooling requirement, a cooling liquid can flow through the cylinder head and the cylinder block separately from one another or the cooling liquid flows through the cylinder head and the cylinder block in a common circuit. In the internal combustion engine according to the invention, depending on the position of the control device, either two cooling circuits (a cooling circuit in the cylinder head and a cooling circuit in the cylinder block) or a single cooling circuit running over the cylinder head and the cylinder block are formed.

The control device is advantageously designed as an actuator or valve and in particular has two possible positions. In a first position, the control device closes the connecting channel so that no coolant can flow from the head cooling jacket into the block cooling jacket. In a second position, this opens the connecting channel, so that the head cooling jacket and the block cooling jacket are flow-connected. The flow connection between the head cooling jacket and the block cooling jacket is therefore given or not depending on a position of the control device. This is where applicable

existing flow connection within the meaning of the invention.

The cylinder head and the cylinder block are separated from one another in particular by a cylinder head sealing plane. This means that the cylinder head sealing plane is provided between the cylinder head and the cylinder block.

The cylinder head has a top-down cooling concept, i.e. the coolant enters the other part of the head cooling jacket via the head inlet duct at an upper end of the cylinder head, which is furthest away from a fire deck arranged between the cylinder head and the cylinder block. The coolant then flows around the outlet channels, which are thereby cooled. The cooling liquid is then fed into an area of a central component and further into an inner ring section of the head cooling jacket, from there via at least one radial channel in the area of an outlet valve bridge and/or outlet/inlet valve bridge into an outer ring section. The cylinder head is therefore cooled from top to bottom via the head cooling jacket. If the control device is in the first position, that is to say the connecting channel is closed, the cooling liquid exits the cylinder head via the head outlet channel. If, on the other hand, the control device is in the second position, ie the connecting channel is open, the cooling liquid is routed further into the cylinder block. In particular, when the control device is in the open position, none flows

Coolant out of the cylinder head via the head drain channel.

The coolant also flows from top to bottom in the cylinder block. The coolant is conducted from the outlet side to the inlet side, in particular flowing around an upper area of the cylinder liner facing the fire deck, and is conducted to the block discharge channel arranged on the outlet side of the cylinder block while flowing around a lower area of the cylinder liner facing away from the fire deck. If the control device is in the first position, ie the connecting channel is closed, the coolant enters the cylinder block via the block inlet channel. There is no fluid communication between the cylinder block and the cylinder head. If, on the other hand, the control device is in the second position, that is to say the connecting channel is open, the coolant is conducted from the cylinder head via the connecting channel into the cylinder block. In particular, no coolant is conducted from the block inlet channel into the block cooling jacket when the control device opens the connecting channel to the cylinder head,

so that the cylinder head and the cylinder block are fluidly connected.

Basically, a temperature of the cooling liquid increases from top to bottom when cooling the cylinder head and the cylinder block. Consequently it is

Favorable if, with a low or normal thermal load on the internal combustion engine, the coolant is conducted via the connecting channel from the cylinder head into the cylinder block. On the other hand, when the internal combustion engine is exposed to high thermal loads, two separate cooling circuits flow through the cylinder head and the cylinder block. A temperature of the cooling liquid is higher at the end of the cylinder head than the cooling liquid which is above the

Block inlet channel enters the block cooling jacket.

It is favorable if the connecting channel branches off from the head cooling jacket upstream of the head outlet channel and enters the block cooling jacket downstream of the block inlet channel. This ensures that all of the coolant gets from the cylinder head into the cylinder block, around the cylinder block as well

to cool sufficiently.

It is advantageous if a second control device is provided in the head cooling jacket upstream of the head outlet channel. As a result, a desired coolant flow direction and coolant flow rate can be realized even better. In principle, it is sufficient if only the control device is provided in the connecting duct, since the arrangement and design of the head cooling jacket is sufficient to direct the entire amount of cooling into the cylinder block. However, in order to prevent a small amount of cooling liquid from entering the head drainage channel when the control device is in an open position, it makes sense to also provide a second control device for the head drainage channel. This control device can also be brought into an open position and a closed position, the second control device being open when cooling liquid is in the head drain channel and closed when cooling liquid is in the connecting channel

shall flow.

It is expedient if a third control device is provided in the block cooling jacket downstream of the block inlet channel. The third control device allows an even better control and distribution of the coolant. This can be provided in addition to or as an alternative to the second control device and prevents the ingress of cooling liquid from the block inlet channel into the block cooling jacket when it is in a closed position. In this case, in particular, the control device in

Connection channel open. In an open position, on the other hand, cooling liquid can flow from the block inlet channel into the block cooling jacket.

It is advantageous if at least one busbar is provided. The manifold is provided and arranged to feed the block cooling jacket and the head cooling jacket with coolant, the head inlet channel and/or the block inlet channel being able to be supplied with coolant via the at least one manifold. It can be advantageous if a common header, arranged in particular in the cylinder block, is provided for the head cooling jacket and the block cooling jacket, it also being advantageous if there are two headers, one for the head cooling jacket and one for the block cooling jacket. If two busbars are provided, they can either do both

in the cylinder block or one in the cylinder head and one cylinder block.

It is particularly favorable if all the inlet and outlet channels and, in particular, also the collector bar are arranged on the same side of the longitudinal plane of the engine in order to achieve the most compact possible design of the internal combustion engine.

The head cooling jacket favorably comprises a first head part cooling jacket and a second head part cooling jacket, the first head part cooling jacket and the second head part cooling jacket being flow-connected to one another at least in the area of a central component via at least one transfer channel. The first head part cooling jacket is flow-connected to the head inlet channel and the second head part cooling jacket is flow-connected to the connecting channel and the head outlet channel. The first header cooling jacket is spaced from a fire deck and the second header cooling jacket is adjacent to the fire deck, with the first and second header cooling jackets being separated from each other by an intermediate deck. The transition channel is arranged in the steerage.

It is expedient if the block cooling jacket comprises a first block part cooling jacket and a second block part cooling jacket, the first block part cooling jacket and the second block part cooling jacket being flow-connected via a further transfer channel. The first block cooling jacket faces the fire deck and the second block cooling jacket part is arranged on a side facing away from the fire deck. The connecting channel and the block inlet channel open into the first part of the block cooling jacket, the block outlet channel to the

second block part cooling jacket connects. For optimal and uniform cooling of the cylinder liner, it is advantageous if the two block part cooling jackets are arranged one above the other in relation to the cylinder axis, the first block part cooling jacket being arranged between the second block part cooling jacket and the cylinder head sealing plane. It is advantageous if the first block part cooling jacket and/or the second block part cooling jacket surrounds the cylinder liner at least predominantly, preferably completely. The further flow transition and connecting channel are preferably arranged on different sides of the longitudinal plane of the motor. This enables a flow around the cylinder liner transverse to the longitudinal plane of the engine. It can be provided in particular that the further flow transition is arranged on the inlet side.

The internal combustion engine can be self-igniting or spark-igniting, preferably with an active or passive prechamber - i.e. with a so-called PCSI

Cylinder head (PCSI=pre-chamber spark ignition) - be trained.

According to one embodiment of the invention, the cylinder head is designed as a single cylinder head. In principle, however, there is an application of the invention

nothing in the way of multi-cylinder heads.

Further features, advantages and effects result from the exemplary embodiment presented below. In the figures to which reference is made

will show:

1 shows a schematic representation of an internal combustion engine according to the invention;

and FIG. 2 shows a section through part of an internal combustion engine according to the invention.

1 shows a schematic representation of an internal combustion engine according to the invention with a cylinder head 2 and a cylinder block 4 which are separated from one another by a cylinder head sealing plane 18 . This is a single-cylinder internal combustion engine. However, the internal combustion engine according to the invention can also have two, three, four or more cylinders 6 .

Fig. 2 shows a section through part of an inventive

Internal combustion engine 1 shown. The internal combustion engine 1 has a cylinder head 2

- For example, a single cylinder head - and a cylinder block 5, which are connected to each other in the area of a fire deck 19 of the cylinder head 2.

A cylinder head sealing plane between cylinder head 2 and cylinder block 5 is designated by reference numeral 18 . The intake side 21 and the exhaust side 22 of the internal combustion engine 1 are arranged on different sides of a longitudinal engine plane 20 spanned by the crankshaft (not shown) and the cylinder axis ZA.

The example designed as a single cylinder head cylinder head 2 has two intake valves 23 and two exhaust valves 24, with intake ports 25 on the intake valves 23 and outlet ports 26 on the exhaust valves 24 with a

Combustion chamber 27 are flow-connected.

In Fig. 1, the cooling chambers and flow paths of the coolant in the cylinder head 2 and in the cylinder block 1 are partially shown schematically. A so-called top-down cooling concept is used. In the context of the present disclosure, such a concept is understood in particular to mean that a coolant flow is guided in the cylinder head 2 in the direction of the cylinder block 5 or the fire deck 19 . In other words, coolant in a direction along the cylinder axis ZA from a fire deck 19 and the

Out of the cylinder block 3 remote area to the fire deck 19 or to the cylinder block 5, whereby in particular a high cooling effect on the fire deck 19, which is subjected to high thermal loads, can be achieved.

The cylinder head 2 has a head cooling jacket 3 with a head inlet channel 7 and a head outlet channel 8 . The cylinder block 3 has a block cooling jacket 5 with a block inlet channel 9 and a block outlet channel 10 . A connecting channel 11 is also provided between the head cooling jacket 3 and the block cooling jacket 5 , a control device 12 being arranged in the connecting channel 11 . The control device 12 can be switched to two positions in order to realize two positions of the coolant flow. Depending on the load and/or temperature, a single water circuit through the cylinder head 2 and the cylinder block 5 or two separate water circuits for the cylinder head 2 and for the cylinder block are implemented. This achieves a targeted and better temperature control. To make the flow even better needs-based

To be able to control and regulate, the head flow channel 8 has a second

Control device 13 and the block feed channel 9 has a third control device 14 .

The cylinder head 2 having the top-down cooling concept has in detail a head cooling jacket 3 with an upper first head part cooling chamber 31 and a lower second head part cooling chamber 32 which are separated from one another by an intermediate deck 26 . The upper first head-part cooling chamber 31 is therefore further away from the cylinder block 5 than the lower, second head-part cooling chamber 32, viewed in a direction along the cylinder axis ZA are flow-connected in the tween deck 18. The term central is to be understood here in particular with regard to the cylinder axis 8 so that a central component 19 is arranged as close as possible to or in the cylinder axis 8 . The component 19 can be formed by a pre-chamber ignition unit—particularly in the case of a diesel internal combustion engine, by a fuel injection device or—in the case of an Otto internal combustion engine.

As is usual with cylinder heads 2 with top-down cooling concepts, coolant flows through the cylinder head 2 from above—ie an area remote from the fire deck 4 of the cylinder head 2 downward—ie an area close to the fire deck 4 . The coolant is fed to the upper first head part cooling chamber 31, flows through the first head part cooling chamber 31 while cooling the outlet channels 24 and reaches the transfer channel 16 arranged near the cylinder axis 8 in the area of the central component 15 into the fire deck 19

adjoining lower second head part cooling space 32.

The cylinder block 5 has an upper first block part cooling jacket 51 and a lower second block part cooling jacket 52 around the cylinder liner 28, which can be dry or wet. The first block part cooling jacket 51 is arranged between the second block part cooling jacket 52 and the cylinder head sealing plane 18 . In their arrangement on the cylinder liner 28, the first block part cooling jacket 51 and the second block part cooling jacket 52 are separated from one another. In other words, a first block part cooling jacket 51 and second block part cooling jacket 52 are provided on the cylinder liner 28 along the

Cylinder liner 28 are separated from each other, the second

Block part cooling jacket 51 is arranged on a side facing away from the fire deck 19 of the first block part cooling jacket 51 .

The first block part cooling jacket 51 is connected to the second block part cooling jacket 52 via a further transfer channel 17 . The other transition channel 17 runs offset from the cylinder liner 28 in the cylinder block 5.

The liquid coolant is supplied to the internal combustion engine 1 via the head inlet channel 7 to the head cooling jacket 3 of the cylinder head 2 . The coolant flows through the head cooling jacket 3 from top to bottom and thereby cools the cylinder head 2. The head cooling jacket 3 can be flow-connected to the block cooling jacket 5 via a connecting channel 11 and a control device 12 arranged therein. This is the case when the control device 12 is in an open position: the cooling liquid is conducted via the connecting channel 11 into the block cooling jacket 5, flows through it from top to bottom and leaves the block cooling jacket 5 via a block discharge channel 10. If the control device 12 is in a second position, the connecting channel 11 is closed. The coolant leaves the head cooling jacket 3 via a block outlet channel 8 . The block cooling jacket 5 is supplied via a block inlet channel 9 with cooling liquid, which exits again via the block outlet channel 10 after the cylinder block 4 has been cooled.

Since the head cooling jacket 3 has a first head part cooling jacket 31 and a second head part cooling jacket 32 and the block cooling jacket 5 has a first block part cooling jacket 51 and a second block part cooling jacket 52, both the cylinder head 2 and the cylinder block 4 have at least several — for example four — transverse to the engine longitudinal plane 20 Out trains S1, S2, S3, S4, wherein the two trains S1, S2 in the cylinder head 2 and the trains S3, S4 in the cylinder block 5 intersect the longitudinal plane 20 of the engine. A pass here denotes a substantially continuous heat transfer surface between two 180° detours of the flow path through the head 3 and block cooling rooms 5.

In this way, efficient cooling of thermally critical areas both in the cylinder head 2 and in the cylinder block 4 is achieved.

Claims (7)

patent claims 1. Liquid-cooled internal combustion engine (1), in particular a large engine, comprising a cylinder head (2) having a top-down cooling concept with a head cooling jacket (3) and a cylinder block (4) with a block cooling jacket (5), wherein in the cylinder block (4) there is at least one Cylinder (6) is arranged, wherein the head cooling jacket (3) comprises a head inlet duct (7) and a head outlet duct (8) and the block cooling jacket (5) comprises a block inlet duct (9) and a block outlet duct (10), characterized in that a connecting duct ( 11) is provided between the head cooling jacket (3) and the block cooling jacket (5), wherein a control device (12) is provided in the connecting channel, so that the head cooling jacket (3) and the block cooling jacket (5) if necessary are flow connected. 2. Internal combustion engine (1) according to claim 1, characterized in that the connecting channel (11) branches off from the head cooling jacket (3) upstream of the head outlet channel (8) and enters the block cooling jacket (5) downstream of the block inlet channel (9). 3. Internal combustion engine (1) according to claim 1 or 2, characterized in that a second control device (13) is provided in the head cooling jacket (3) upstream of the head outlet channel (8). 4. Internal combustion engine (1) according to any one of claims 1 to 3, characterized in that in the block cooling jacket (5) downstream of the block inlet channel (9) a third control device (14) is provided. 5. Internal combustion engine (1) according to any one of claims 1 to 4, characterized characterized in that at least one busbar is provided. 6. internal combustion engine (1) according to any one of claims 1 to 5; characterized in that the head cooling jacket (3) comprises a first head part cooling jacket (31) and a second head part cooling jacket (32), the first head part cooling jacket (31) and the second head part cooling jacket (32) being connected to one another at least in the area of a central component (15) via at least a transfer channel (16) are flow connected. 7. Internal combustion engine (1) according to any one of claims 1 to 6, characterized in that the block cooling jacket (5) comprises a first block part cooling jacket (51) and a second block part cooling jacket (52), wherein the first block part cooling jacket (51) and the second block part cooling jacket ( 52) are flow-connected via a further transfer channel (17).