DE102011122280A1 - Combustion engine, has coolant duct branched from coolant distributor, and locking unit attached to coolant duct and releasing fluid connection through coolant duct only when reaching or exceeding minimum pressure by coolant pressure - Google Patents

Abstract

The invention relates to an internal combustion engine (1) with a coolant distributor (18) which receives pressurized coolant with a coolant pressure adjustable to at least two different values, and with at least one coolant line branching from the coolant distributor (18) and leading to a coolant consumer (16) ( 17). It is provided that the coolant line (17) is associated with a fluid connection through the coolant line (17) only when reaching or exceeding a minimum pressure by the coolant pressure releasing blocking means (19). The invention further relates to a method for operating an internal combustion engine (1).

Description

The invention relates to an internal combustion engine with a coolant distributor, which receives pressurized coolant with a coolant pressure which can be set to at least two different values, and with at least one coolant line branching off from the coolant distributor and leading to a coolant consumer. The invention further relates to a method for operating an internal combustion engine.

Internal combustion engines of the type mentioned are known from the prior art. They usually have a coolant circuit, at least consisting of a conveyor, in particular a coolant pump, and the coolant distributor. The coolant circuit serves to supply the at least one coolant consumer with coolant. For this purpose, the coolant is conveyed by the conveyor in the direction of the coolant distributor. From this, the coolant then passes through the coolant line to the coolant consumer. It must be ensured that the refrigerant is supplied to the coolant consumer with a sufficiently large flow rate to ensure proper operation of the coolant consumer. The present in the coolant distributor coolant is thus pressurized, for example by the conveying action of the conveyor. In this case, the coolant pressure, which the coolant has in the coolant distributor, can be set to at least two different values, in particular a normal operating pressure, which is reached during normal operation of the internal combustion engine, and a static pressure, which is present when the internal combustion engine is switched off. Instead of the static pressure, an idling pressure, which is set in an idling operation of the internal combustion engine, in particular at an idling speed, can be defined. Under the coolant consumer is to understand at this point a device which is cooled by the coolant. The coolant consumer consumes the coolant so far not in the literal sense, so it can be collected after cooling of the coolant consumer and re-supplied to the coolant consumers.

As already stated above, the coolant serves to cool the coolant consumer or at least a portion of the coolant consumer. In known from the prior art internal combustion engine, the coolant consumer is acted upon regardless of the operating condition of the internal combustion engine with a uniform flow rate of the coolant, so even at low load of the engine. Under light conditions, however, it may not be necessary to cool the coolant consumer. The conveyor must thus provide an unnecessarily high throughput of the coolant at low load of the internal combustion engine.

It is therefore an object of the invention to propose an internal combustion engine, which does not have the aforementioned disadvantage, but in particular allows a reduction in the throughput of the coolant distributor supplied coolant.

This is inventively achieved with an internal combustion engine with the features of claim 1. It is provided that the coolant line is assigned a fluid connection through the coolant line only when reaching or exceeding a minimum pressure by the coolant pressure releasing blocking means. Due to the coolant line, the coolant consumer is connected to the coolant distributor. Accordingly, coolant can pass from the coolant distributor to the coolant consumer only when the fluid connection through the coolant line is released. In order to be able to reduce the coolant throughput with which the coolant is supplied to the coolant distributor by the delivery device, it is provided to obstruct the coolant line when the minimum pressure falls below the coolant pressure, ie to interrupt the fluid connection through the coolant line. The minimum pressure can be specified in principle arbitrary. For example, it is determined by the properties of the blocking agent. However, it can also be provided that the minimum pressure is set variably and the locking means is adjusted accordingly. The latter is particularly the case when the blocking means is designed as a switching valve or has a valve element to which the minimum pressure is adjustable, for example by changing an elasticity of the valve element or a spring force with which the valve element is acted upon.

Usually, the coolant pressure, which is present in the coolant distributor, depending on the operating condition of the internal combustion engine, wherein the coolant pressure is the higher, the higher the voltage applied to the internal combustion engine load. In particular, if the coolant is supplied to the coolant consumer exclusively for purposes of cooling, therefore, at low load and correspondingly low coolant pressure, the fluid connection can be interrupted by the coolant line to the coolant consumer, without any impairment of the operation of the internal combustion engine is to be expected. At high load of the internal combustion engine, however, a sufficient cooling of the coolant consumer should be ensured, so that at high load and correspondingly high coolant pressure, the coolant line through the Locking means is released. Accordingly, the coolant can pass through the coolant line to the coolant consumer.

For example, a lubricant can be used as a coolant. The coolant circuit in this case is a lubricant circuit, the coolant line is a lubricant line, the coolant pump is a lubricant pump, the coolant consumer is a lubricant consumer and the coolant pressure is a lubricant pressure. In addition or as an alternative, it may of course be provided in this case that the coolant consumer uses the coolant for lubrication purposes, in particular if he has mutually movable parts.

A further development of the invention provides that the blocking means has a valve element which is displaceable for releasing the fluid connection and / or elastically deformable. The valve member cooperates with a valve seat to interrupt or release the fluid connection. If the valve element is in contact with the valve seat, then the fluid connection is interrupted, but if the valve element is displaced away from the valve seat, the fluid connection is at least partially released. The valve seat, for example, also be associated with the blocking means, so that the blocking means is an integral unit of valve element and valve seat and can also be installed as a unit. Alternatively, however, the valve seat can also be associated, for example, with another region of the internal combustion engine, in particular formed by a wall of a recess in which the blocking means or the valve element is arranged.

The valve element is either displaceable or deformable. The valve element is urged by a restoring force in the direction of the valve seat, so that the fluid connection is interrupted as long as the coolant pressure is less than the minimum pressure. If, on the other hand, the coolant pressure reaches or exceeds the minimum pressure, the force exerted by the coolant with the coolant pressure on the valve element is greater than the restoring force of the valve element. Consequently, the valve element is either displaced or deformed to release the fluid connection. The restoring force can be, for example, a spring force exerted by a spring element on the valve element. Alternatively, the valve element is at least partially elastic, so that the restoring force is a force of elasticity, which is effected by the valve element itself. To release the fluid connection, it is usually sufficient if only a portion of the valve element is displaceable or deformable. However, it can also be provided a displacement of the valve element as a whole. The valve element consists for example of an elastomer.

A further development of the invention provides that the blocking means has a support element for the valve element. Such an embodiment is particularly useful if the valve element is deformable. In this case, the support member serves as a holder for the valve element, which also holds this securely when it deforms to release the fluid connection, in particular elastically deformed is. The support element is for example made of metal or plastic.

A development of the invention provides that the valve element, the support element in the circumferential direction at least partially, in particular completely encompasses. For example, the support element is cylindrical or hollow cylindrical. The valve element now surrounds the support element in the circumferential direction, so that it can be supported in the circumferential direction inwardly at this. Accordingly, the valve element can not be deformed elastically or only slightly in this direction. In this way, a proper function of the locking means can be ensured. For example, the coolant line is at least partially in the support element, for which purpose this is hollow cylinder-like design as stated above. The valve element now surrounds the support element in the circumferential direction preferably completely, so it rests against the outside of a lateral surface of the support element. In addition, it at least temporarily covers at least one of the end faces in order to be able to interrupt the fluid connection guided through the support element when the coolant pressure is less than the minimum pressure. If the minimum pressure exceeds or reaches the coolant pressure, the valve element or its region arranged on the end face of the support element at least partially releases the fluid connection through the coolant line or the support element. For this purpose, the area for example has a preferably integrally formed fluid flap, which opens as soon as the coolant pressure reaches or exceeds the minimum pressure.

A development of the invention provides that the valve element is arranged in a recess assigned to the coolant line, wherein the recess is present in particular as a stepped bore representing an opening of the coolant line. The recess is assigned to the coolant line such that the valve element can be arranged to completely interrupt the fluid connection through the coolant line. For example, the recess forms a region of the coolant line, in particular its mouth in the coolant distributor. Especially preferred the recess is formed as a stepped bore, wherein a section facing the coolant distributor is larger in diameter than a section facing away from the coolant distributor. In the larger diameter portion, the blocking means or at least the valve element is provided. The stepped bore represents so far the mouth of the coolant line in the coolant distributor; the larger diameter portion of the stepped bore thus opens directly into the coolant distributor.

A development of the invention provides that the valve element - seen in cross section - is clamped between a wall of the recess and the support member. The cross section is to be interpreted such that a longitudinal direction of the valve element or the blocking means - parallel to which the cross section is present - is defined by the main flow direction of the coolant. As already stated above, the valve element can surround the support element in the circumferential direction at least in certain areas. In this case, the valve element is arranged in cross-section between the wall of the recess and the support element. In particular, when the valve element is elastically deformable, a clamping effect on the valve element is achieved by this arrangement, so that it is held stationary. It is provided, for example, that the inner dimensions of the recess, in which the valve element is present, seen in cross-section are smaller than the outer dimensions of the valve element. Additionally or alternatively, it may also be provided that the inner dimensions of the valve element in its relaxed state are smaller than the outer dimensions of the support element. Upon introduction of the support element into the valve element or the valve element into the recess, the valve element is correspondingly elastically deformed, whereby the clamping effect for holding the valve element is achieved. Among the dimensions of the valve element, the recess and the support member is to be understood at this point in particular their diameter; Accordingly, the elements mentioned - seen in longitudinal section - circular.

A development of the invention provides that on the support element and / or on a wall of the recess there is a valve seat, which cooperates with the valve element for interrupting or releasing the fluid connection. As already stated above, the valve seat is necessary to achieve the interruption of the fluid connection. For this purpose, the valve element of the blocking means cooperates with the valve seat. The valve seat is now, for example, on the support element or on the wall of the recess in which the valve element is arranged before. The valve element thus acts, for example, either together with the support element or the wall of the recess.

A development of the invention provides that the coolant distributor is a lubricant leading portion of a bearing of a shaft, in particular a camshaft, the internal combustion engine and the coolant line is present in a bearing bush of the bearing for branching of the lubricant leading area. The bearing point of the shaft or the lubricant leading area is supplied to the extent under the coolant pressure standing coolant in the form of lubricant. For this purpose, the region of the bearing is fluidly connected, for example, to the lubricant circuit or its delivery device. He is supplied to the extent the lubricant with a certain throughput. To supply the coolant consumer with coolant via the coolant line, the latter now branches off from the region of the bearing point leading away from the lubricant. For this purpose, it is arranged for example in the bearing bush of the bearing or engages through this leading in the direction of the lubricant area. Accordingly, coolant or lubricant can pass from the bearing point through the coolant line to the coolant consumer as soon as the blocking means releases the fluid connection through the coolant line. This is the case when the lubricant pressure present in the bearing point of the shaft-that is, the coolant pressure-reaches or exceeds the minimum pressure. The shaft may be, for example, the camshaft or one of the camshafts of the internal combustion engine.

A development of the invention provides that the coolant consumer is a valve cooling. The valve cooling is used to cool at least one valve with the aid of the coolant. For example, the coolant is applied as a spray or film to at least a portion of the valve. The region of the valve is, in particular, a valve stem end facing the camshaft of the internal combustion engine and / or a valve stem seal which at least partially surrounds the valve stem or the valve stem end. In such an embodiment, it is particularly advantageous if the above-described lubricant leading portion of the bearing is used as a coolant distributor. In this way, extremely short distances between a Kühlmittelausbringvorrichtung the valve cooling and the at least one valve of the internal combustion engine are achieved. The Kühlmittelausbringvorrichtung is connected to the coolant distributor on the opposite side of the coolant line to this and serves to discharge the coolant in the direction of the valve. The Kühlmittelausbringvorrichtung is designed for this purpose, for example, as a nozzle element, by means of which a jet or a spray of the coolant can be generated.

The invention further relates to a method for operating an internal combustion engine, in particular according to the preceding embodiments, wherein the internal combustion engine has a coolant distributor which receives pressurized coolant with a coolant pressure adjustable to at least two different values and at least one branching off from the coolant distributor and leading to a coolant consumer Has coolant line. It is provided that a fluid connection is released through the coolant line only when reaching or exceeding a minimum pressure by the coolant pressure. For this purpose, for example, the blocking means described above is associated with the coolant line. The internal combustion engine can be developed according to the above explanations. It is particularly advantageous if the coolant is subjected to a coolant pressure which is set as a function of an operating state of the internal combustion engine. For example, at low load of the internal combustion engine, a first, lower coolant pressure and at a higher load a second, higher coolant pressure. The minimum pressure is now preferably greater than the first, lower coolant pressure and, for example, corresponds to the second coolant pressure. However, it can also lie between the first and the second coolant pressure. Accordingly, the fluid connection through the coolant line is only released when the coolant pressure reaches or exceeds the first coolant pressure.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings, without any limitation of the invention. Showing:

1 a schematic representation of a portion of an internal combustion engine having a lubricant serving as a coolant distributor area of a bearing point of a camshaft of the internal combustion engine and with a leading to a coolant consumer coolant line, which is associated with a blocking means,

2 a detailed sectional view of a portion of the internal combustion engine, in which the camshaft and a coolant supply are shown in the lubricant leading portion of the bearing,

3 a longitudinal section through a portion of the internal combustion engine, in which the locking means is shown in a first embodiment,

4 a detail sectional view of the from 3 known blocking means in a first state,

5 a detail sectional view of the from 3 known blocking means in a second state,

6 a longitudinal section through a portion of the internal combustion engine, in which the locking means is shown in a second embodiment,

7 the locking means according to the second embodiment in the first state, and

8th the locking means according to the second embodiment in the second state.

The 1 shows a schematic representation of a portion of an internal combustion engine 1 which is a camshaft 2 and a depository 3 the camshaft has. The depository 3 is from a two-part bearing block 4 formed, the two halves by means of at least one screw 5 attached to each other. The internal combustion engine 1 also has at least one valve 6 that made a valve disk 7 and a valve stem 8th consists. The valve stem 8th is through a housing 9 which also includes the bearing block 4 training, up to a drag lever 10 the internal combustion engine 1 guided, by means of which the valve 6 from the camshaft 2 is periodically actuated. For this purpose, the camshaft 2 in the area of the rocker arm 10 at least one cam 11 on. A not shown here implementation of the valve stem 8th through the housing 9 is by means of a valve stem cover 12 sealed, so no coolant through the passage to the valve plate 7 can get.

Because in the operation of the internal combustion engine 1 , especially at high load, the valve 6 is exposed to a high temperature load, is a valve cooling 13 provided by means of which coolant to at least a portion of the valve 6 can be applied. The coolant is, for example, by a Kühlmittelausbringvorrichtung 14 , In particular a nozzle element, for example as a spray, in the direction of the valve stem cover 12 applied. This is by the arrow 15 indicated. The valve cooling 13 represents in this respect a coolant consumer 16 dar. The coolant consumer 16 is through a coolant line 17 Coolant from a coolant distributor 18 fed. As a coolant distributor 18 serves in this embodiment, a lubricant leading portion of the bearing 3 , Accordingly, the lubricant present in the latter is used as the coolant. From the coolant distributor 18 branches the coolant line 17 from. The coolant line 17 is a blocking agent 19 associated with which a fluid connection through the coolant line 17 only when a minimum pressure is reached or exceeded by that in the coolant distributor 18 present coolant pressure releases and otherwise interrupts. The coolant distributor 18 is for example by a lubricant supply 20 , which in particular a pressure line 21 includes, supplied under the coolant pressure standing coolant or lubricant. The coolant can be pressurized, for example, by means of a conveyor, not shown here.

The 2 shows a detailed representation of a portion of the internal combustion engine 1 , wherein in particular the lubricant supply 20 is recognizable. The coolant supply 20 comprises, as already stated above, the pressure line 21 , From this branches a supply line 22 through which the coolant in the direction of the arrow 23 and the arrow 24 to the depository 3 the camshaft 2 is guided. The supply line 22 Can partially over the screw connections 5 be guided. Also recognizable is the blocking agent 19 which, for example, in the coolant line 17 (only partially recognizable here) is arranged.

The 3 shows a longitudinal section through a portion of the internal combustion engine 1 (relative to a longitudinal axis 25 the camshaft 2 ). Visible here is that two valves 6 present on both sides of the bearing 3 are arranged. Every valve 6 has a valve cooling 13 , which respectively via the coolant line 17 leading to the lubricant area of the bearing 3 , so the coolant distributor 18 , are connected. Both coolant lines 17 so join together in the coolant distributor 18 one. You are the blocking agent 19 assigned in a recess 26 present, via which the coolant lines 17 in the lubricant leading area of the bearing 3 open out. The blocking agent 19 So it serves as a common blocking agent for the two coolant lines 17 , Alternatively, however, could also for any coolant line 17 a separate, blocking agent 19 available. In principle, any blocking agent 19 So any number of coolant lines 17 be assigned fluidically. The blocking agent 19 has a valve element 27 and a support element 28 on. The support element 28 is designed as a hollow cylinder, so that by its interior a fluid connection between the bearing 3 and the coolant lines 17 can be produced. In the illustration shown here it can be seen that the valve element 27 the support element 28 in the circumferential direction - relative to one, for example, perpendicular to the longitudinal axis 25 standing longitudinal axis of the valve element 27 or the support element 27 - At least partially, preferably completely, embraces. Here is the valve element 27 at least partially elastically deformable to the fluid connection through the coolant lines 17 to be able to share. The support element 28 in this respect serves to the valve element 27 in the recess 26 to fix. For this purpose, it urges the valve element 27 in the radial direction outward against a wall 29 the recess 26 ,

This is in the 4 and 5 shown in detail. The 4 shows the valve element 27 according to the in the 3 illustrated embodiment in a first state in which the fluid connection through the coolant lines 17 is interrupted. It becomes clear that the valve element 27 Crushed ribs on its outer circumference 30 which, after insertion of the valve element 27 into the recess 26 with the wall 29 come into contact or crushing contact, so that the valve element 27 clamped in the recess 26 is held. As already stated above, the support element serves 28 in addition, the valve element 27 To keep dimensionally stable in the radial direction and corresponding to the crush ribs 30 in the radial direction with respect to the wall 29 to keep. It now becomes clear that the valve element 27 the support element 28 on at least one of its end faces, namely the coolant distributor 18 facing end face, overlaps. Alternatively, this can of course also on the coolant distributor 18 facing away from the case.

On the the coolant distributor 18 remote end face here is only a partial overlapping of the support element 28 provided so that a rear grip connection between the valve element 27 and support element 28 is present, which slipping out of the support element 28 from the valve element 27 prevented. The support element 28 is for example as a ring, in particular as a metal ring, for example as a steel ring before. The valve element 27 consists at least partially, preferably completely, of an elastomer. The valve element 27 has on its the support element 28 completely overlapping side at least one fluid flap or a wing 31 , which according to the 5 is elastically deformable such that it on reaching or exceeding the minimum pressure by the coolant pressure in the coolant distributor 18 a flow cross section 32 of the valve element 27 releases. The 4 In this respect shows a first state in which the fluid connection is interrupted and the 5 a second state in which the coolant is released.

The 6 shows a longitudinal section of the internal combustion engine 1 , wherein the blocking agent 19 in a second embodiment. Basically, the structure of the internal combustion engine is similar 1 already described, so that reference is made in this regard to the above statements. The blocking agent 19 consists of the valve element as already described 27 and the support element 28 and is in the recess 26 arranged. However, it is now envisaged that the wing or wings 31 of the valve element 27 with one of the support element 28 trained valve seat 33 for releasing or blocking the fluid connection through the coolant lines 17 interact.

This is based on the 7 and 8th illustrated, wherein the valve element 27 in the 7 in the first state and in the 8th is in the second state. It becomes clear that the valve element 27 or the wing (s) 31 such on the valve seat 33 abut that the fluid connection through the coolant lines 17 is interrupted. Reaches the coolant pressure in the coolant distributor 18 the minimum pressure or exceeds this, then the valve element 27 or its wings 31 deformed so elastically that the wings 31 from the valve seat 33 lift off and thus the flow cross section 33 release. The valve element 27 is in the embodiment shown here in the support element 28 attached so that it can not get out of this. For example, fasteners not shown here are provided for this purpose. It becomes clear that here the support element 28 not as described above of the valve element 27 is encompassed, but that it is directly with the wall 29 is in touching contact and, for example, by clamping action with this clamping in the recess 26 is held.

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2

camshaft

3

depository

4

bearing block

5

screw

6

Valve

7

valve disc

8th

valve stem

9

casing

10

cam follower

11

cam

12

Valve stem cover

13

valve cooling

14

Kühlmittelausbringvorrichtung

15

arrow

16

Coolant consumers

17

Coolant line

18

Coolant distributor

19

blocking means

20

lubricant feed

21

pressure line

22

supply line

23

arrow

24

arrow

25

longitudinal axis

26

recess

27

valve element

28

support element

29

wall

30

crush ribs

31

wing

32

Flow area

33

valve seat

Claims (10)

Internal combustion engine ( 1 ) with a coolant distributor ( 18 ) receiving pressurized refrigerant having a coolant pressure adjustable to at least two different values, and at least one of the coolant manifold (10). 18 ) and to a coolant consumer ( 16 ) leading coolant line ( 17 ), characterized in that the coolant line ( 17 ) a fluid connection through the coolant line ( 17 ) only when reaching or exceeding a minimum pressure by the coolant pressure releasing blocking agent ( 19 ) assigned. Internal combustion engine according to claim 1, characterized in that the blocking means ( 19 ) for releasing the fluid connection displaceable and / or elastically deformable valve element ( 27 ) having. Internal combustion engine according to one of the preceding claims, characterized in that the blocking means ( 19 ) a support element ( 28 ) for the valve element ( 27 ) having. Internal combustion engine according to one of the preceding claims, characterized in that the valve element ( 27 ) the support element ( 28 ) in the circumferential direction at least partially, in particular completely, surrounds. Internal combustion engine according to one of the preceding claims, characterized in that the valve element ( 27 ) in one of the coolant line ( 17 ) associated recess ( 26 ) is arranged, wherein the recess ( 26 ) in particular as a mouth of the coolant line ( 27 ) is present stepped bore. Internal combustion engine according to one of the preceding claims, characterized in that the valve element ( 27 ) - seen in cross-section - between a wall ( 29 ) of the recess ( 26 ) and the support element ( 28 ) is held clamped. Internal combustion engine according to one of the preceding claims, characterized in that on the support element ( 28 ) and / or on a wall the recess ( 26 ) a valve seat ( 33 ) present with the valve element ( 27 ) cooperates to interrupt or release the fluid connection. Internal combustion engine according to one of the preceding claims, characterized in that the coolant distributor ( 18 ) a lubricant leading area of a storage site ( 3 ) of a wave ( 2 ), in particular a camshaft ( 2 ), the internal combustion engine ( 1 ) and the coolant line ( 17 ) in a bearing bush of the depository ( 3 ) is present for branching off the lubricant leading portion. Internal combustion engine according to one of the preceding claims, characterized in that the coolant consumer ( 16 ) a valve cooling ( 13 ). Method for operating an internal combustion engine ( 1 ), in particular according to one or more of the preceding claims, wherein the internal combustion engine ( 1 ) via a coolant distributor ( 18 ) receiving pressurized coolant having a coolant pressure adjustable to at least two different values, and at least one of the coolant manifold (10). 18 ) and to a coolant consumer ( 16 ) leading coolant line ( 17 ), characterized in that a fluid connection through the coolant line ( 17 ) is released only when reaching or exceeding a minimum pressure by the coolant pressure.

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