CN115135862A

CN115135862A - Cooling system for internal combustion engine

Info

Publication number: CN115135862A
Application number: CN202180015169.2A
Authority: CN
Inventors: R·伯格; G·布兰多费尔; J·蒂姆; Z·瓦加
Original assignee: AVL List GmbH
Current assignee: AVL List GmbH
Priority date: 2020-02-18
Filing date: 2021-02-18
Publication date: 2022-09-30
Anticipated expiration: 2041-02-18
Also published as: AT523181B1; CN115135862B; DE112021000210A5; WO2021163743A1; AT523181A4

Abstract

The invention relates to a cooling system (100) for an internal combustion engine (20) comprising a cylinder head (21), a cylinder block (22) and a plurality of cylinders (23), wherein at least one head-cooling housing (K) is provided which is arranged in the cylinder head (21) and is fluidically connected to at least one coolant inlet (1) and to at least one head-coolant outlet (10), and wherein in the cylinder block (22) an upper block-cooling housing (11) is arranged adjacent to the cylinder head (21) and a lower block-cooling housing (15) is arranged on a side of the upper block-cooling housing (11) facing away from the cylinder head (21), wherein the upper block-cooling housing (11) is fluidically connected/can be fluidically connected to a first block-coolant outlet (14) and the lower block-cooling housing (15) is fluidically connected/can be connected to a second block-coolant outlet (17), and the lower (15) and/or the upper (11) cylinder cooling housing is/are fluidly connected/connectable to the head cooling housing (K) via at least one fluid connection channel (8a, 16, 29), wherein the head coolant outlet (10), the first cylinder coolant outlet (14) and the second cylinder coolant outlet (17) are each assigned a switchable valve element (25, 26, 27) for controlling a coolant flow through the cooling system (100).

Description

Cooling system for internal combustion engine

The present invention relates to a cooling system for an internal combustion engine having at least one cylinder head, at least one cylinder block and a plurality of cylinders, a method for operating a cooling system, and an internal combustion engine having such a cooling system.

It is known to cool the cylinder block and the cylinder head of an internal combustion engine in different ways by causing coolant to flow through them in different ways. This takes into account the fact that the cylinder block and the cylinder head are subjected to different thermal loads depending on the operating or loading conditions. Heat is transferred to the cylinder head primarily via heat shields (fire shield) or combustion chamber walls and exhaust ports, and specifically to the cylinder block by transferring combustion heat to the cylinder surface near the combustion chamber. By varying the coolant flow, it is possible, for example, to ensure that the cylinder block is not yet cooled during the warm-up phase of the internal combustion engine and thus reaches the operating temperature more quickly. In the prior art, this object is achieved by separating the cooling housing in the cylinder head and the cylinder block and allowing the coolant to flow through in different ways.

For example, a cooling system for an internal combustion engine having a cooling housing through which coolant can flow in a cylinder head and a cooling housing through which coolant can flow in a cylinder block is known from the applicant's AT 514793B 1. Here, the approximate flow direction is a direction from the cylinder head along the cylinder block, and is generally referred to as "cooling from top to bottom". Furthermore, the flow is provided in a transverse direction from the outlet side to the inlet side. This is achieved by means of a manifold or collection chamber from which the coolant flows to the inlet side. The flow through the two cooling shells is controlled by valves. A particular disadvantage of this solution is that the cylinder block is either not cooled at all or is cooled too much so that it cannot manage to solve all operating and load conditions.

EP 2562379 a1 describes a separate coolant circuit for an internal combustion engine, in which a cylinder head water box and an engine block water box are provided. Via the control element, coolant can be supplied to the radiator or the engine block water tank. For this reason, a relatively large number of external lines are required between the cylinder head tank and the block tank, which means that a large amount of coolant is required. Furthermore, here too, it is only possible to switch between cylinder block cooling and airless cylinder block cooling.

It is therefore an object of the present invention to provide a cooling system with improved cooling and heating performance.

The object of the invention is solved by the cooling system according to the invention mentioned at the outset in the following manner: at least one cylinder head cooling housing is arranged in the cylinder head, which is flow-connected to at least one coolant inlet and at least one cylinder head coolant outlet, and an upper cylinder cooling housing is arranged in the cylinder block adjacent to the cylinder head, a lower cylinder cooling housing being arranged on the side of the upper cylinder cooling housing facing away from the cylinder head, wherein the upper cylinder cooling housing is flow-connected or flow-connected to a first cylinder cooling housing outlet, and the lower cylinder cooling housing is flow-connected or flow-connected to a second cylinder cooling housing outlet, and the lower cylinder cooling housing and/or the upper cylinder cooling housing is flow-connected or flow-connected to the cylinder head cooling housing via at least one flow-connection channel, wherein valve elements are assigned to the cylinder head cooling housing outlet, the first cylinder cooling housing outlet and the second cylinder cooling housing outlet, respectively, to control the flow of coolant through the cooling system.

This also enables a simple grading of the coolant output (coolant power). For example, the control of the cooling system can be carried out via a predeterminable (predeterminable) limit temperature of the internal combustion engine or of the coolant. This arrangement enables operation in several different operating modes in a simple manner, which may take into account different operating and load states of the internal combustion engine and the associated thermal conditions.

By providing a dedicated valve element, the cooling housing in the cylinder block can be activated or deactivated as required, while the entire amount of coolant flows through the head-cooling housing in the cylinder head at all times. In this way, sufficient heat dissipation from the high thermal stress region surrounding the exhaust valve on the heat shield can be ensured in every operating range of the internal combustion engine.

In order to sufficiently cool the region of the cylinder block between adjacent cylinders which is subjected to a specific thermal stress, a variant provides for at least one web cooling channel extending in the cylinder block and arranged in the web region between adjacent cylinders, wherein the web cooling channel preferably has a V-shaped profile. Heat can be sufficiently removed from this region and heat damage can be prevented.

In other words, the web guide channel is arranged in a parting plane (parting plane) which is oriented orthogonally to the longitudinal cylinder plane between two adjacent cylinders, the so-called web region. The web guide channel preferably follows a V-shaped profile, i.e. it descends from a starting point close to the cylinder head to a point furthest from the cylinder head and ascends therefrom to an end point which is at approximately the same distance from the cylinder head as the starting point.

Advantageously, the web cooling channel is designed as part of the upper block cooling housing and connects the outlet side portion of the upper block cooling housing to the inlet side portion of the upper block cooling housing. This makes it possible to achieve a flow through the internal combustion engine, in particular the cylinder block, in the transverse direction. The gas flow mainly flows along the wall towards the combustion chamber, thereby better cooling the combustion chamber.

In order to be able to cool the combustion chamber region in the vicinity of the heat shield or the cylinder head gasket, which is subject to particularly high thermal loads, in a targeted manner, the upper cylinder cooling housing in the region of the cylinder edge is advantageously at least partially annular. The cylinder edge area is the following area in the cylinder block: this region adjoins the cylinder bore or a cylinder liner arranged therein, as viewed in the radial direction from the cylinder axis. The cylinder edge region extends from the cylinder or cylinder bore to approximately 1.50 times the cylinder diameter or cylinder bore diameter, preferably at most 1.35 times the diameter. The cooling space created in this way is also referred to herein as ring cooling, since a substantially annular arrangement results. The height of the upper block-cooling housing is preferably 10 to 30% of the cylinder bore as viewed in the axial direction of the cylinder. In other words, the upper block-cooling housing extends into the cylinder block from the upper side of the cylinder block facing the cylinder head, as viewed in the axial direction of the cylinder, with a height of between 10% and 30% of the cylinder bore.

In order to achieve an advantageous cooling process, in a variant a first valve element is provided at the head coolant outlet of the head cooling housing, which can be switched at least between an open first valve position, a closed second valve position, preferably between an open first valve position, a closed second valve position and a throttled third valve position.

In order to be able to react more flexibly to cooling requirements, in a further embodiment variant a second valve element is provided at the first cylinder coolant outlet of the upper cylinder cooling housing, which second valve element can be switched at least between a closed first valve position and an open second valve position.

Further flexibility is provided if a third valve element is provided at the second cylinder coolant outlet of the lower cylinder coolant housing, which third valve element is switchable between at least a closed first valve position and a second open valve position.

By combining valve elements in three different valve positions, different switching positions can be achieved for different operating modes of the cooling system. This allows the cooling system to be adapted to various load and operating conditions of the combustion engine.

In order to improve the flow conditions and to be able to cool the regions subjected to high thermal loads in a targeted manner, the upper cylinder cooling housing extends between an intake side and an exhaust side of the internal combustion engine, and at least one throttle section is provided at least one transition between the intake side and the exhaust side. A throttle section is understood here to mean a region in which the cross section or flow cross section of the cooling housing is reduced compared to the cross section of an adjoining region upstream and/or downstream.

Conveniently, there is one throttle section provided on one end face of the cylinder block, preferably between the cylinder and the end face, and on the side of the cylinder block opposite the end face, preferably between the cylinder and the side (portion) of the cylinder block opposite the end face, respectively. In one variant, the opening cross section of the upper cylinder cooling housing in the throttle section is reduced to 15% or less of the cross section upstream and/or downstream of the throttle section.

In a particularly advantageous embodiment, a continuous cast wall is provided between the upper and lower cylinder cooling housings. In other words, the upper block-cooling housing and the lower block-cooling housing are completely separated from each other by the casting wall within the cylinder block. This facilitates manufacturing and may prevent leakage and uncontrolled coolant transfer in the cylinder block.

This arrangement enables cooling of the most critical channels of the internal combustion engine. In particular the cast wall opens up new ways of manufacturing such an internal combustion engine and simplifies production, since the manufacturing steps (insertion and joining of separate elements of the cooling housing) can be eliminated. Furthermore, an optimal separation of the flow conditions in the upper and lower cooling shells can be ensured.

In a variant of the cooling system, the head-cooling housing is arranged mainly on the exhaust gas side of the internal combustion engine, wherein the coolant inlet opens into a distribution manifold extending along the exhaust gas side, which distribution manifold is arranged in the cylinder head and is flow-connected to a main cooling housing of the head-cooling housing, which main cooling housing also extends along the exhaust gas side, and from which the coolant leaves the cylinder head again via a head-coolant outlet, wherein the distribution manifold is further away from the cylinder block than the main cooling housing. In other words, the coolant flows into a distribution manifold in the cylinder head and from there into the main cooling housing in the direction of the cylinder block and from there at least partially, depending on the operating mode of the cooling system, out of the cylinder head via the head coolant outlet. This results in what is known as "top-down cooling", i.e. the coolant is supplied completely to the cylinder head and flows from there to the regions which are subjected to a specific thermal load, for example the combustion chamber head cover or the heat shield plate (fire shield), the exhaust valve including the valve bridge (valve bridge) or web and optionally the cylinder block. Not only good flow conditions can be achieved, but also packaging advantages can be achieved if the coolant inlet is provided on the cylinder head or one end of the engine, since ducts can be chosen to save space.

In a further variant, an exhaust manifold is arranged along the exhaust side of the internal combustion engine between a main cooling housing of the head cooling housing and the head coolant outlet, which exhaust manifold is flow-connected to the main cooling housing and the head cooling housing, wherein the main cooling housing preferably has at least one cooling web extending in a valve web between the exhaust valves and which cooling web is connected to the exhaust manifold via a cooling hole.

Advantages in cooling, particularly with respect to cross-flow (cross-flow) between the exhaust side and the intake side, may be realized if the upper cylinder cooling housing is connected to the first cylinder coolant outlet via an intake manifold that extends along the intake side. Preferably, an intake manifold is provided in the cylinder head and provides a corresponding connection from the upper block cooling housing to the intake manifold.

It is advantageous, in particular for packaging reasons, if the distribution manifold and/or the exhaust manifold and/or the intake manifold are provided in the cylinder head.

The exhaust manifold, the intake manifold and the distribution manifold may extend substantially the entire length of the cylinder head and the cylinder block, respectively. This makes it possible to achieve distribution of the coolant and the coolant flow over the entire length of the cylinder head and the cylinder block.

In order to advantageously influence the flow conditions and to simplify the production of the cylinder head and the cylinder block and the supply and discharge of the coolant as much as possible, it is provided in a variant of the cooling system that at least a coolant inlet and/or at least a head coolant outlet and/or at least a first block coolant outlet and/or at least a second block coolant outlet are provided in the cylinder head.

The object of the invention is further solved by the method mentioned at the outset for operating a cooling system according to the invention, namely by changing the valve elements between at least three switching positions, wherein each valve element is in each case in an open first valve position or a closed second valve position or a throttled third valve position, the cooling system being operated at least in a first operating mode, in which coolant flows only through the head cooling housing, or in a second operating mode, in which coolant flows through the head cooling housing and the upper cylinder cooling housing, or in a third operating mode, in which coolant flows through the head cooling housing, the upper cylinder cooling housing and the lower cylinder cooling housing. In this context, throttle position refers to a position of the valve in which the flow cross section is reduced compared to the open position, but a flow of coolant is still possible.

The different operating modes allow cooling to be adapted as optimally as possible to the operating and load conditions of the internal combustion engine. The first operating mode is preferably used when the internal combustion engine is cold, in which on the one hand the generated heat has to be dissipated from the cylinder head, but on the other hand the cooling of the cylinder block is reduced as much as possible to allow rapid heating. The second operating mode is preferably used to achieve a normal operating state of the internal combustion engine, while the third operating mode is used at high loads or when the internal combustion engine is strongly warmed up.

In the above-described operating mode, it is advantageously provided that,

in a first switching position for the first operating mode, the first valve element is brought into the open first valve position, and the second and third valve elements are in the closed second valve position;

in a second switching position for the second operating mode, the first valve element is preferably brought into a third throttled valve position, the second valve element is brought into an open first valve position, and the third valve element is in a closed second valve position, and

in a third switching position for the third operating mode, the first valve element is brought into the closed second valve position, and the second and third valve elements are in the open first valve position.

In a first operating mode, in a first switching position, which is preferably set when the internal combustion engine and/or the coolant are cold, the first valve is open and the second and third valves are closed.

Advantageously, in the third operating mode, in a third switching position, which is preferably set when the internal combustion engine and/or the coolant are hot, the first valve is closed, the second valve is open and the third valve is open.

In order to be able to react more effectively to flow conditions, it is advantageously provided that in the first operating mode, the delivery valve is closed in the first switching position.

The same effect can be achieved if in the second operating mode and/or the third operating mode the delivery valve is open in the second/third switching position.

In all switching positions and in all operating modes, the entire coolant flow cools the housing through the cylinder. A first valve element disposed downstream of the cylinder cooling housing that allows coolant to flow out through the cylinder coolant outlet in an open first valve position; at the same time, the second valve element downstream of the upper block cooling housing and the third valve element downstream of the lower block cooling housing are blocked (blocked) and prevented from flowing out in the cylinder block. All the coolant is thus fed directly to the return line (return line) of the cooling system.

If the first valve element is moved to the throttled third position and at the same time the second valve element is moved to the open first valve position, a partial flow of coolant is guided into the upper cylinder cooling housing of the cylinder block. The third valve element is held in the closed second valve position. After flowing through the upper block cooling housing, the coolant exits the engine partially through the head coolant outlet and partially through the first block coolant outlet.

In the third switching position, the first valve element is in the closed second valve position and is completely closed. The second and third valve elements are in the open first valve position and are fully open. A portion of the flow of coolant exits the internal combustion engine through the first block coolant outlet after flowing through the upper block coolant housing, and a remaining portion of the flow of coolant exits the internal combustion engine through the second block coolant outlet after flowing through the lower block coolant housing.

The object of the invention is also solved by the initially mentioned internal combustion engine. Advantageously, the cylinder head and/or the cylinder block are made of cast aluminium. The described cooling system or method enables the cooling in the internal combustion engine to be controlled in a targeted manner and the heat to be dissipated so efficiently that the use of cast aluminum can be prolonged in the manufacture of the internal combustion engine. As a result, the weight of the internal combustion engine can be reduced, thereby reducing fuel consumption and emissions. The cylinder head and/or the cylinder block can also advantageously be cast in another light metal and/or designed with alloying additions.

The invention is explained in more detail below with reference to non-limiting exemplary embodiments shown in the drawings, in which:

fig. 1 shows a cooling housing of a cooling system according to the invention in a first oblique view;

FIG. 2 shows the cooling housing in a second oblique view;

fig. 3 shows the cooling housing in a side view from the outlet side;

FIG. 4 shows the cooling housing in a top view;

FIG. 5 shows the cooling housing in a side view from one end face;

FIG. 6 shows a cross-sectional view of the cooling housing along line VI-VI in FIG. 4;

FIG. 7 shows a cross-sectional view of the cooling housing along line VII-VII in FIG. 4;

FIG. 8 shows a cross-sectional view of the cooling housing along line VIII-VIII in FIG. 4;

FIG. 9 shows an oblique view of the cooling housing with coolant flowing through the cooling housing in the first switch position;

FIG. 10 shows another oblique view of the cooling housing with coolant flowing through the cooling housing in the first switching position;

FIG. 11 shows an oblique view illustrating coolant flowing through the cooling housing in a second switch position;

FIG. 12 shows another oblique view of the cooling housing with coolant flowing through the cooling housing in the second switch position;

FIG. 13 shows an oblique view illustrating coolant flowing through the cooling housing in a third switch position;

FIG. 14 shows another oblique view of coolant flowing through the cooling housing in the third switch position;

FIG. 15 shows a top view of an internal combustion engine according to the present invention;

FIG. 16 shows a cross-sectional view of the internal combustion engine along line XVI-XVI in FIG. 15;

FIG. 17 illustrates a cross-sectional view of the internal combustion engine along line XVII-XVII in FIG. 15;

FIG. 18 shows a cross-sectional view of the internal combustion engine along line XVIII-XVIII of FIG. 15;

fig. 19 shows a cylinder block of an internal combustion engine according to the present invention in a plan view;

FIG. 20 shows a cross-sectional view of the internal combustion engine along line XX-XX in FIG. 17;

FIG. 21 shows a cross-sectional view of the internal combustion engine along line XXI-XXI in FIG. 20;

FIG. 22 shows a cross-sectional view of the internal combustion engine along line XXII-XXII in FIG. 17; and

fig. 23 shows a cross-sectional view of the internal combustion engine along line XXIII-XXIII in fig. 17.

Fig. 1 to 14 show various aspects of a cooling system 100 according to the invention, while fig. 15 to 23 show an internal combustion engine 20 with such a cooling system 100. Herein, the internal combustion engine 20 has a cylinder head 21, a cylinder block 22 adjacent to the cylinder head, and a plurality of cylinders 23 formed substantially in the cylinder block 22 and closed on one side by the cylinder head 21. In the exemplary embodiment shown, the internal combustion engine 20 has four cylinders 23, of which one is arranged as an outer cylinder on the end face S of the internal combustion engine 20 and one is arranged as an outer cylinder on the side (portion) S' of the internal combustion engine 20 facing away from the end face. Two central cylinders are disposed therebetween. In the cylinder block 22, the central cylinders are separated from one another and from the outer cylinders, respectively, by cylinder webs 28 (see, for example, fig. 19 and 22 or 16, which show a sectional view through the internal combustion engine 20 in the region of the cylinder webs 28).

The cylinder head 21 and the cylinder block 22 are connected by a cylinder head bolt, not shown; the recess provided for this purpose is marked in the figure with reference numeral 6.

Between the cylinder head 21 and the cylinder block 22 is a parting (separating) plane T (see, for example, fig. 16 to 18) in which, for example, a cylinder head gasket (not shown) is disposed. The longitudinal axis L (see, for example, fig. 4, 19 or 23) of the internal combustion engine 20 or of the cylinder head 21 and of the cylinder block 22 extends substantially parallel to the parting plane T and orthogonal to the cylinder axis 23a (see, for example, fig. 17 and 22); the longitudinal plane LL is spanned by the longitudinal axis L and the cylinder axis 23a (the longitudinal axis L and the cylinder axis 23a sandwich the longitudinal plane LL). For example, in fig. 22, the longitudinal plane LL lies in the plate plane, whereas in fig. 19, the longitudinal plane LL extends through a longitudinal axis L perpendicular to the plate plane.

Fig. 1 shows an oblique view of a cooling system 100 with a cylinder head cooling housing K, an upper cylinder block cooling housing 11 and a lower cylinder block cooling housing 15. The head-cooling housing K is located in the cylinder head 21 (see, for example, fig. 16), while the block-cooling

housings

11, 15 are located in the cylinder block 22.

The upper block-cooling housing 11 is designed next to the cylinder head 21 or parting plane T, while the lower block-cooling housing 15 is arranged on the side of the upper block-cooling housing 11 facing away from the cylinder head 21 or the head-cooling housing K.

The cylinder head cooling housing K is flow connected or can be flow connected to at least one coolant inlet 1, a cylinder head coolant outlet 10, an upper cylinder block cooling housing 11 and a lower cylinder block cooling housing 15. At least the

flow connection channels

8a, 16, 29 are provided for connection to the

cylinder cooling housings

11, 15. The upper block cooling housing 11 is fluidly connected or fluidly connectable to a first block coolant outlet 14 and the lower block cooling housing 15 is fluidly connected or fluidly connectable to a second block coolant outlet 17.

Coolant is fed from a water pump, not shown in detail, via a coolant inlet 1 to the head-cooling housing K. The coolant may be water, glycol, oil, mixtures thereof, or other additives.

The coolant inlet 1 is located on one end surface S of the cylinder head 21. Downstream of the coolant inlet 1, a distribution manifold 2 is provided extending along the outlet side a of the internal combustion engine 20. The distribution manifold 2 extends substantially parallel to the longitudinal plane LL (see for example fig. 4) or to the parting plane T. For each cylinder 23, a supply line 3 leads from the distribution manifold 2 to the main cooling housing 4. The supply line 3 extends in each case substantially at right angles to the longitudinal axis L. The flow cross-section of the distribution manifold 2 decreases away from the coolant inlet 1 to ensure that the supply line 3 is supplied with coolant uniformly over the entire length of the cylinder head 21.

The main cooling housing 4 extends substantially over the exhaust port 4a extending from the cylinder 23, which places a certain thermal load on the cylinder head 21. Fig. 1 shows only the recess provided in the cooling housing 100, and fig. 18 and 21 each show the outlet passage 4 a. Valve webs 7 (see, for example, fig. 15 or 17, which show a section through the internal combustion engine 20 in the region of the valve webs 7) extending between the exhaust ports 4a, which extend substantially in planes (valve web planes 70; see, for example, fig. 4, 15 and 20, in which the valve web planes 7 are each shown by way of example at the cylinder block 23) which are orthogonal to the longitudinal axis L through the cylinder axes 23, the valve webs 7 being supplied with coolant by means of cooling webs 7a extending in the valve webs 7, wherein one such cooling web 7a is provided for each cylinder 23. The cooling web 7a also surrounds a receiving region of a spray nozzle or spark plug, which is designated by reference numeral 5.

Fig. 17 and 22 show such a receiving region 5, without the nozzle being shown. In other words, between the two exhaust ports 4a, the cooling web 7a is connected to the receiving region 5 for the injection nozzle and extends to the main cooling housing 4 in the cylinder head 21.

Between the exhaust valves (exhaust valves) or ports 4a, starting from the cooling web 7a, a head-cooling (drilled) hole 8 is also provided in the valve web plane 70 for each cylinder 23, which hole extends away from the respective cylinder axis 23 towards the exhaust side a and is designed substantially parallel to the parting plane T between the cylinder head 21 and the cylinder block 22.

Via the head cooling bores 8, a flow connection is formed with the exhaust manifold 9. As with the distribution manifold 2, the exhaust manifold 9 extends along the exhaust side a of the internal combustion engine 20 and is substantially parallel to the longitudinal plane LL or to the parting plane T and is flow-connected to a head-coolant outlet 10, which is provided on the cylinder head 21 or on an end face S of the internal combustion engine 20.

The exhaust manifold 9 is disposed closer to the cylinder block 22 or the parting plane T between the cylinder head 21 and the cylinder block 22 than the manifold 2 and the main cooling housing 4. In other words, the manifold 9 is located between the main cooling housing 4 and the parting (separating) plane T that separates the cylinder head 21 and the cylinder block 22 of the internal combustion engine 20.

The head cooling (drilled) holes 8 extend from the outside of the cylinder head 21 on the exhaust side a to the cooling web 7 a. In this case, the connection between the exhaust manifold 9 and the periphery of the cylinder head 21, which is made during production of the head cooling hole 8, is closed by a plug (not shown) for normal operation.

Starting from the receiving region 5, the cooling web 7a is shaped in a direction parallel to the parting plane T around the exhaust port 4a, in particular in the region of the valve seat which is subject to a specific thermal stress, and extends until it extends in the region of the cylinder web 28 through the plane of the cylinder web 28 in a direction orthogonal to the longitudinal axis L (cylinder web plane 280; see, for example, fig. 4, 15 and 22, in each case one cylinder 23 being exemplarily depicted with a cylinder web plane 280). There, a connection is formed between the cooling webs 7a of the adjacent cylinders 23 on the one hand and the main cooling housing 4 on the other hand. Furthermore, a first flow connecting channel 8a is provided in the vicinity of the cylinder web 28 to connect the cooling web 7a to the exhaust manifold 9 and, on the other hand, to establish a connection from the head cooling housing K to the upper block cooling housing 11, which will be explained in more detail below. Similar to the head cooling hole 8, the first flow connection passage 8a extends away from the corresponding cylinder axis 23 toward the outlet side a, but is designed to be inclined with respect to the parting plane T. In other words, the end of the first flow connection channel 8a closer to the longitudinal plane LL is further away from the parting plane T than the end of the first flow connection channel closer to the exhaust side a.

The head-cooling housing K thus comprises a main cooling housing 4, a cooling web 7a and a head-cooling hole 8 and is connected by flow to a coolant inlet 1 via a manifold 2 or to a head-coolant outlet 10 via an exhaust manifold 9. The flow connections to the head cooling housing 11 and the lower block cooling housing 15 are described further below.

As described above, the cylinder block 22 adjoining the cylinder head 21 at the parting plane T has the upper block-cooling housing 11 and the lower block-cooling housing 15.

The upper block-cooling housing 11 is disposed immediately adjacent to the parting plane T and extends from the parting plane T into the cylinder block 22 in a direction parallel to the cylinder axis 23 a. The upper block cooling housing 11 is designed to open towards the cylinder head 22 and sealing against the cylinder head 21 is achieved, for example, by means of a cylinder head gasket (gasket), not shown in more detail.

The upper block cooling housing 11 is designed essentially as a ring cooling system, so that it at least partially surrounds the cylinder 23 in the region of the cylinder edge. In this context, the cylinder edge region is to be understood as the following region in the cylinder block 22: viewed in the radial direction from the cylinder axis 23a, this region adjoins the cylinder 23, i.e. the cylinder bore or the cylinder liner arranged therein. The cylinder rim region 23 extends from the cylinder or cylinder bore to about 1.50 times the cylinder diameter or cylinder bore diameter B (see, e.g., fig. 19), preferably at most 1.35 times the diameter. The outer cylinder 23 is enclosed at an angle of approximately 300 °, i.e. from the end face S or a side S' facing away from the end face, to the cylinder web 28. The intermediate cylinders 23 are surrounded on the inlet E and outlet a side by cylinder webs 28, which cylinder webs 28 are bounded on both sides by an angle of approximately 120 ° between the cylinders 23.

In the direction along the cylinder axis 23a, the upper block-cooling housing 11 has a height H1 between 10% and 30% of the bore diameter B of the cylinder 23. This means that the area of the cylinder block 22, specifically, adjacent to the combustion chambers of the cylinders 23 is efficiently cooled.

In the region of the longitudinal plane LL, on the end face S and on the side S' facing away from the end face, at least one throttle section D is provided in the upper cylinder cooling housing 11 at the transition between the outlet side a and the inlet side E to influence the flow for optimum cooling effect. In particular, the top view in fig. 4 shows the throttle sections D, which reduce the flow cross section between the outlet side a and the inlet side E in the upper cylinder cooling housing 11. The opening cross section Q of the upper cylinder cooling housing 11 is reduced to approximately 15% in the region of the throttle section D, corresponding to a throttle of 85%. In other words, in the throttle section D, the cross section of the upper block-cooling housing 11 is reduced to 15% of the opening cross section Q upstream and downstream of the throttle section D.

The upper cylinder block cooling housing 11 is supplied with coolant through a flow connection with the cylinder head cooling housing K. For this purpose, on the one hand, the first flow connection channels 8a already described above are provided, which supply coolant from the side of the cooling web 7a into the upper block cooling housing 11. The second flow connecting passage 29 (see fig. 6, 17, and 18) feeds coolant from the exhaust manifold 9 to the upper block cooling housing 11. Therefore, the upper block-cooling housing 11 is supplied with coolant from the head-cooling housing K via the first flow connecting passage 8a and the second flow connecting passage 29 on the exhaust side of the internal combustion engine 20.

In addition to the described ring-like cooling fed from the head-cooling housing K, the upper cylinder-cooling housing 11 has web-cooling channels 12 which are provided for cooling the cylinder webs 28 between adjacent cylinders 23. In the exemplary embodiment shown, the web cooling channels 12 are V-shaped and formed by two (drilled) holes extending obliquely from the parting plane T in the cylinder web 28. The bore is formed by a cylinder web 28. The holes leave on the inlet E and outlet side, respectively, and are inclined downwards in the direction of the longitudinal plane LL, so that their distance from the parting plane T increases as they approach the longitudinal plane LL. The intersection of the two holes represents the deepest point of the web cooling channel 12; the depth H2 (see fig. 16) of intersection of the two bores, i.e. the distance to the parting plane T, is between 35% and 50% of the bore diameter B of the cylinder bore of the cylinder 23.

Thus, the web cooling passage 12 connects the outlet side portion of the upper block cooling shell 11 to the inlet side portion. This means that the throttle section D is arranged in the upper block cooling housing 11 on the side of the outlet a and the inlet E in the region of the end face S and the side (portion) S' facing away from the end face, and the web cooling channel 12 with a substantially V-shaped profile is arranged in the region of the cylinder web 28 between adjacent cylinders 23.

On the inlet side, the upper block cooling housing 11 is flow connected to an intake manifold 13 and via the intake manifold to a first block coolant outlet 14. In this case, the intake manifold 13 is provided in the cylinder head 21 and is connected to the upper block-cooling housing 11 in the cylinder block 22 via the transfer passage 30. In an exemplary embodiment, not shown, the manifold 13 is disposed in the cylinder block 22.

The intake manifold 13 is provided along the inlet side E. The first block coolant outlet 14 is provided on the end surface S of the internal combustion engine 20.

The lower block-cooling housing 15 is arranged to extend around the cylinder 23 in a similar manner to the upper block-cooling housing 11. The area of the cylinder web 28 is left free. Here, in the exemplary embodiment shown, the lower cylinder cooling housing 15 has no connection between the outlet side a and the inlet side E. The lower cylinder cooling shell 15 is of corrugated design at its lower end facing away from the parting plane T. The lower block cooling housing 15 has a maximum extension in the direction parallel to the cylinder axis 23a in the region of the cylinder web 28 and on the end face S or the side (portion) S' facing away from the end face.

The lower block-cooling housing 15 is also supplied with coolant from a head-cooling housing K located in the cylinder head 21. For this purpose, a third flow connection 16 is provided, which adjoins the exhaust manifold 9 and is connected to the lower block-cooling housing 15 via a parting plane T in the region of a side S' which faces away from the end face in the region of the longitudinal plane LL.

The lower block cooling housing 15 has a second block coolant outlet 17 provided at the end surface S of the internal combustion engine 20. The coolant entering the lower block-cooling housing 15 via the third flow connection passage 16 flows completely through it in the direction along the longitudinal axis L and then flows out again at the end face S of the internal combustion engine 20. In the exemplary embodiment shown, the second block coolant outlet 17 is provided on the cylinder head 21 and is connected to the lower block cooling housing 15 via a lift channel (standpipe channel) 24. In a variation not shown, the second cylinder coolant outlet 17 may also be provided on the cylinder block 22.

Fig. 6 to 8 show cross-sectional views along the lines VI-VI, VII-VII and VIII-VIII in fig. 4, showing intersecting surfaces through the cooling housing.

The upper block-cooling housing 11 and the lower block-cooling housing 15 are completely separated from each other in the cylinder block 22 by a horizontal and/or curved casting wall G. Thus, in contrast to prior art solutions, no inserts need to be provided to ensure the separation of the

cylinder cooling housings

11, 15. During the manufacturing process, this cast wall G is formed by insert core pieces for forming the lower cylinder cooling housing 15 and for forming the upper cylinder cooling housing 11. The core member for manufacturing the internal combustion engine by casting and the hole formed in the subsequent step have substantially the same shape as the cooling housing shown in fig. 1 to 14.

Valve elements

25, 26, 27 are associated with the

coolant outlets

10, 14, 17, respectively, in order to be able to set different operating (running) modes of the cooling system 100. The

valve elements

25, 26, 27 are schematically shown in fig. 1, 9, 11 and 13 and are positioned after the

coolant outlets

10, 14, 17. In a practical embodiment, the

valve elements

25, 26, 27 may be designed as thermostatic valves and be positioned directly at the

coolant outlets

10, 14, 17 or remote from them via pipes. The illustration in the figure is used to explain this function.

A first valve element 25 is assigned to the head coolant outlet 10, a second valve element 26 is assigned to the first block coolant outlet 14, and a third valve element 27 is assigned to the second block coolant outlet 17. The

valve elements

25, 26, 27 are each switchable between at least an open first valve position and a closed second valve position. At least the first valve element 25 can also be switched into a throttled third valve position in which the flow cross section between the fully closed and the fully open valve element is releasable. In an exemplary embodiment, which is not described further below, the second valve element and/or the third valve element can also be switched in a throttled third valve position.

Fig. 9 to 14 show the coolant flow through the cooling system 100 in three switching positions of the

valve elements

25, 26, 27, each switching position corresponding to an operating mode. The flow direction of the coolant is here indicated by arrows, but the flow paths are only partially shown for the sake of clarity.

All of the coolant enters the head-cooling housing K via the coolant inlet 1. The coolant is fed through the distribution manifold 2 via the exhaust port 4a into the main cooling housing 4 and via the supply line 3 to the area to be cooled.

The flow through the cylinder head cooling housing K is always independent of the switch position.

Fig. 9 and 10 show the flow conditions in the first mode of operation. In the associated first switching position, the first valve element 25 is in the open first valve position and the second 26 and third 27 valve elements are in the closed second valve position. The first valve element 25 is thus fully open.

The coolant is conveyed by a coolant pump, not shown, via a coolant inlet 1 into the distribution manifold 2 and along the outlet side a from the end face S towards the side (portion) S' of the internal combustion engine 20 facing away from the end face. Via the supply line 3, the coolant flows into a main cooling housing 4 of a head cooling housing 4 located above the exhaust port. Via the cooling webs 7a between the outlet valves and the head-cooling housing parts arranged between adjacent cylinders 23, the coolant flows in the direction of the longitudinal plane LL and cools the receiving region 5 and the valve seat region of the outlet valves (this process is shown only for the outer cylinder 23 at the end face S, but takes place in this way for all cylinders 23). The coolant flows via the head coolant bore 8 and the first flow connection channel 8a to the exhaust manifold 9 and from there out of the cylinder head 21 via the head coolant outlet 10 at the end face S. As shown in fig. 9 and 10, the entire coolant volume exits the cooling system 100 through the head coolant outlet 10. The coolant thus flows in the distribution manifold 2 along the longitudinal axis L from the end face S to the side face S 'facing away from the end face and in the exhaust manifold 9 from the side face S' facing away from the end face to the end face and flows from the outlet side a towards the inlet side E through the supply line 3, the main cooling housing 4, the cooling web 7a, the head cooling holes 8 and the first flow connecting channel 8a and returns to the outlet side a transversely through the cylinder head 21. Since the distribution manifold 2 is arranged further away from the parting plane T than the head cooling bores 8 or the exhaust manifold 9, this results in what is known as a "top-down" flow through the cylinder head 21 in the direction of the combustion chamber and the heat shield (flame shield) which is subject to high thermal loads.

Since the second and

third valve elements

26, 27 are in the closed second switching position, no coolant flows from the head-cooling housing K into the block-cooling housing, since the outflow of the upper and lower block-cooling

housings

11, 15 is blocked, with the result that the coolant flows only through the head-cooling housing K in the cylinder head 21. All coolant reaches the head coolant outlet 10 of the cylinder head 21 from the head cooling housing K via the manifold 9.

The first switching position for the first operating mode is used in particular when the internal combustion engine 20 and/or the coolant are cold.

In a second switching position for the second operating mode, the upper cylinder cooling housing 11 is switched to a second switching position according to fig. 11 and 12. For this purpose, the first valve element 25 is in the throttled third valve position, the second valve element 26 is switched to the open first valve position and the third valve element 27 is in the closed second valve position.

As a result, the head coolant outlet 10 from the cylinder head 21 is throttled, and the first block coolant outlet 14 from the intake manifold 13 of the upper block-cooling housing 11 is fully opened. The coolant flows into the upper block-cooling housing 11 through the first flow connection passage 8a and the second flow connection passage 29, and flows from the exhaust side a to the intake side E through the cylinder block 22 through the throttle section D and the web cooling passage 12.

Due to the throttled third switching position of the first valve element 25, the coolant therefore no longer flows completely through the head cooling housing K, but partially through the upper block cooling housing 11.

This second switching position is associated with the second operating mode when the internal combustion engine 20 and/or the coolant are hot.

The full cooling effect of the cooling system 100 is produced at the third switching position of the third operating mode. Here, as shown in fig. 13 and 14, the head-cooling housing K, the upper block-cooling housing 11, and the lower block-cooling housing 15 are activated (operated). For this purpose, the first valve element 25 at the head cooling housing outlet 10 is brought into the closed second valve position, and at the end face S the second valve element 26 at the first block cooling housing outlet 14 and the third valve element 27 at the second block cooling housing are in the open first valve position and are therefore fully open.

The coolant flows from the head-cooling housing K into the upper block-cooling housing in the manner described above and enters the lower block-cooling housing 15 through the third flow connection channel 16 on the side S' of the internal combustion engine 20 facing away from the end face S. In the lower cylinder cooling housing 15, the coolant flows through the cylinder 22 in the longitudinal direction from the side S' facing away from the end face to the end face S, where it reaches the second cylinder coolant outlet 17 via the lifting channel (riser channel) 24. .

In the third switching position described, a flow reversal occurs in the exhaust manifold 9 in the cylinder head 21 (see fig. 13). The coolant no longer leaves the cylinder head 21 via the first head coolant outlet 10, for example to a thermal management module, which is not shown in greater detail, but flows in the exhaust manifold 9 from the end face S in the longitudinal direction to the side S' facing away from the end face to the third flow connection channel 16, where the coolant is conducted from the cylinder head 21 into the lower block-cooling housing 15 of the cylinder block 22. In this mode of operation, the coolant flow exits through the first and second

block coolant outlets

14, 17, depending on the arrangement of the

block coolant outlets

14, 17 on the cylinder head 21 or cylinder block 22 as shown.

The third switching position is assigned to the third operating mode when the internal combustion engine 20 and/or the coolant are hot. In the third operating mode, the internal combustion engine 20 is completely cooled. The following applies to all switching positions: the entire coolant flows through the head-cooling housing K of the cylinder head 21, optionally depending on the temperature of the coolant, through the switching positions of the

valve elements

25, 26, 27, a part of the coolant entering the head-cooling housing K flows through the upper cylinder-cooling housing 11 in the cylinder block 22, and/or a part of the coolant entering the head-cooling housing K flows through the lower cylinder-cooling housing 15 in the cylinder block 22.

Fig. 15 to 23 show an internal combustion engine 20 according to the invention. This has a cylinder head 21 and a cylinder block 22 for each of a plurality of cylinders 23, and a cooling system 100 for use with a liquid coolant. The coolant may be formed, for example, as water, water with additives, or any other suitable coolant. A head-cooling casing K is provided in the cylinder head 21 for cooling a thermal critical area in the cylinder head 21. The cylinder block 22 has an upper block-cooling housing 11 and a lower block-cooling housing 15 that are fluidly connected to the head-cooling housing K. The head-cooling housing K is flow-connected to the coolant inlet 1 and the head-cooling outlet 10 of the cylinder head 21.

In addition to the upper and lower cylinder-cooling

housings

11, 15 and the head-cooling housing K in the cylinder block 22, the cooling system comprises, for example, a coolant pump, not shown in greater detail, a first valve element 25, designed for example as a thermostatic valve, a second valve element 26, designed for example as a thermostatic valve, and a third valve element 27, designed for example as a thermostatic valve, a radiator, not shown in greater detail, an internal heater, not shown in greater detail, an expansion tank, not shown in greater detail, and an oil cooler, not shown in greater detail.

The cooling system 100 has an exhaust manifold 9 and an intake manifold 13 extending in the longitudinal direction of the cylinder block 22 or the cylinder head 21, wherein the intake manifold 13 may be provided in the cylinder block 22 or in the cylinder head 21. In the illustrated embodiment, the intake manifold 13 is provided in the cylinder head 21.

In this case, the longitudinal direction of the internal combustion engine 20 refers to a direction parallel to the crankshaft axis, in which case the longitudinal direction is oriented along the longitudinal axis L (see fig. 23). The transverse direction of the internal combustion engine 20 is understood to be the direction oriented generally orthogonal to the crankshaft or longitudinal axis L and orthogonal to the cylinder axis 23 a.

Claims

1. A cooling system (100) for an internal combustion engine (20) comprising at least one cylinder head (21), at least one cylinder block (22) and a plurality of cylinders (23), characterized in that at least one head-cooling housing (K) is provided which is arranged in the cylinder head (21) and is fluidly connected to at least one coolant inlet (1) and at least one head-coolant outlet (10), and an upper block-cooling housing (11) is arranged in the cylinder block (22) adjacent to the cylinder head (21), while a lower block-cooling housing (15) is arranged on the side of the upper block-cooling housing (11) facing away from the cylinder head (21), wherein the upper block-cooling housing (11) is or can be fluidly connected to a first block-coolant outlet (14), and the lower block-cooling housing (15) is or can be fluidly connected to a second block-coolant outlet (14) 17) And the lower block cooling housing (15) and/or the upper block cooling housing (11) is or can be fluidly connected to the head cooling housing (K) via at least one flow connection channel (8a, 16, 29), wherein a switchable valve element (25, 26, 27) is associated with each of the head coolant outlet (10), the first block coolant outlet (14) and the second block coolant outlet (17) for controlling a coolant flow through the cooling system (100).

2. The cooling system (100) according to claim 1, wherein at least one web cooling channel (12) is provided which extends in the cylinder block (22), which is provided in a cylinder web (28) between adjacent cylinders (23), wherein the web cooling channel (12) is preferably designed with a V-shaped profile.

3. The cooling system (100) according to claim 2, wherein the web cooling channel (12) is designed as part of the upper cylinder cooling housing (11) and connects an outlet side portion of the upper cylinder cooling housing (11) to an inlet side portion of the upper cylinder cooling housing (11).

4. The cooling system (100) as claimed in any of claims 1 to 3, characterized in that the upper block-cooling housing (11) at least partially surrounds the cylinder (23) annularly in a cylinder edge region, wherein the upper block-cooling housing (11) preferably has a height (H1) of between 10% and 30% of a bore diameter (D) of the cylinder (23), viewed in an axial direction of the cylinder (23).

5. Cooling system (100) according to one of the claims 1 to 4, characterized in that a first valve element (25) is provided at the head coolant outlet (10) of the head cooling housing (K), which first valve element is switchable at least between an open first valve position, a closed second valve position, preferably between an open first valve position, a closed second valve position and a throttled third valve position.

6. A cooling system (100) according to any of the claims 1-5, characterized in that a second valve element (26) is arranged at the first cylinder coolant outlet (14) of the upper cylinder cooling housing (11), which second valve element is switchable between at least a closed first valve position and an open second valve position.

7. The cooling system (100) according to any one of the claims 1 to 6, characterized in that a third valve element (27) is provided at the second cylinder coolant outlet (17) of the lower cylinder cooling housing (15), which third valve element is switchable between at least a closed first valve position and an open second valve position.

8. The cooling system (100) according to any one of claims 1 to 7, characterized in that the upper block cooling housing (11) extends between an inlet (E) and an outlet (A) side, and at least one throttling section (D) is provided at least one transition between the inlet (E) and the outlet (A) side.

9. The cooling system (100) as claimed in claim 8, characterized in that a throttle section (D) is provided in each case on an end face (S) of the cylinder block (22), preferably between the cylinder (23) and the end face (S), and on a side (S ') of the cylinder block (22) facing away from the end face (S), preferably between the cylinder (23) and a side (S') of the cylinder block (22) facing away from the end face (S).

10. The cooling system (100) according to claim 8 or 9, characterized in that in the throttling section (D) the opening cross section (Q) of the upper block cooling housing (11) is reduced to 15% or less of the upstream and/or downstream cross section of the throttling section (D).

11. The cooling system (100) according to any one of claims 1 to 10, wherein a continuous cast wall (G) is provided between the upper block cooling housing (11) and the lower block cooling housing (15).

12. The cooling system (100) according to any one of claims 1 to 11, characterised in that the head-cooling housing (K) is arranged mainly on an outlet side (a), wherein the coolant inlet (1) opens into a distribution manifold (2) which extends along the outlet side (a) and is arranged in the cylinder head (21) and is flow-connected to a main cooling housing (4) of the head-cooling housing (K) which also extends along the outlet side (a) and from which coolant leaves the cylinder head (21) again via the head-coolant outlet (10), wherein the distribution manifold (2) is further away from the cylinder block (22) than the main cooling housing (4).

13. The cooling system (100) according to any of the claims 1 to 12, characterized in that an exhaust manifold (9) is arranged along the outlet side (a) of the internal combustion engine (20) between the main cooling housing (4) and the head coolant outlet (10) of the head cooling housing (K), which exhaust manifold is flow-connected to the main cooling housing (4) and the head coolant outlet (10), wherein the main cooling housing (4) preferably has at least one cooling web (7a) extending in a valve web (7) between the outlet valves, which cooling web is connected to the exhaust manifold (9) via a head cooling hole (8).

14. A cooling system according to any one of claims 1-13, characterised in that the upper cylinder cooling housing (11) is connected to the first cylinder coolant outlet (14) via an inlet manifold (13) extending along the inlet side (E).

15. A cooling system according to any one of claims 1-14, characterised in that at least the coolant inlet (1) and/or at least the head coolant outlet (10) and/or at least the first block coolant outlet (14) and/or at least the second block coolant outlet (17) are provided in the cylinder head (21).

16. A method for operating a cooling system (100) according to one of claims 1 to 15, characterized in that, by changing the valve elements (25, 26, 27) between at least three switching positions, wherein each valve element (25, 26, 27) is in each case in an open first valve position or a closed second valve position or a throttled third valve position, the cooling system (100) is operated at least in a first or second or third operating mode, in which the coolant flows only through the head-cooling housing (K), and in which the coolant flows through the head-cooling housing (K) and the upper cylinder-cooling housing (11), in the third operating mode, coolant flows through the head cooling housing (K), the upper block cooling housing (11) and the lower block cooling housing (15).

17. The method of claim 16,

in a first switching position for the first operating mode, the first valve element (25) is brought into the open first valve position, and the second valve element (26) and the third valve element (27) are in the closed second valve position;

in a second switching position for the second operating mode, the first valve element (25) is preferably brought into a third valve position of the throttle, the second valve element (26) is brought into the open first valve position, and the third valve element (27) is in the closed second valve position, and

in a third switching position for the third operating mode, the first valve element (25) is brought into the closed second valve position, and the second valve element (26) and the third valve element (27) are in the open first valve position.

18. An internal combustion engine (20) comprising a cooling system (100) according to any one of claims 1 to 15.

19. Internal combustion engine (20) according to claim 18, characterized in that the cylinder head (21) and/or the cylinder block (22) are designed as cast aluminium.