CN113614352A

CN113614352A - Internal combustion engine

Info

Publication number: CN113614352A
Application number: CN202080024340.1A
Authority: CN
Inventors: A·泽尔克; J·盖尔特; M·布雷顿勃格; T·萨尔穆特; R·格伦德纳
Original assignee: AVL List GmbH
Current assignee: AVL List GmbH
Priority date: 2019-03-27
Filing date: 2020-03-27
Publication date: 2021-11-05
Anticipated expiration: 2040-03-27
Also published as: WO2020191424A1; DE112020001423A5; AT522272B1; AT522272A1; CN113614352B

Abstract

The invention relates to an internal combustion engine and a cooling method associated therewith, wherein a coolant flows first through a first cooling jacket (10) and through a second cooling jacket (20) in the direction of a fire protection plate (5), wherein a coolant flow (K) through the cooling jacket structure is regulated by the position of an adjusting element (8) downstream of the first cooling jacket (10) and/or the second cooling jacket (20).

Description

Internal combustion engine

The invention relates to an internal combustion engine having at least one cylinder, at least one cylinder head and a crankcase, wherein the cylinder head has a cooling jacket structure for fluid cooling and the crankcase has a crankcase cooling jacket for fluid cooling, and wherein the cooling jacket structure of the cylinder head and the crankcase cooling jacket are arranged in at least one coolant circuit and wherein an adjusting element is arranged for controlling the coolant flow downstream (after) in the flow direction of the at least one cooling jacket of the cooling jacket structure of the cylinder head.

One such internal combustion engine is known from EP 2634388 a 1. EP 2634388A shows a control valve for controlling the coolant flow in an engine. The engine has an engine block and a cylinder head. Here, one cooling jacket is provided in each of the cylinder head and the cylinder block. A common control valve for the cooling jackets of the cylinder block and the cylinder head is arranged downstream of the cooling jackets in the flow direction. Cooling of the cylinder block, of the crankcase with a plurality of cylinders and pistons, and of the components with high thermal stress independently of the cooling of the fire protection plate is therefore not easily possible. Furthermore, the complexity is very high by the common control valve, which in turn increases the costs and the structural size. The structural dimensions have a negative effect on the weight, which should be reduced for emission reduction.

In the context of the present invention, a crankcase cooling jacket is also understood to be a cylinder block cooling jacket.

The aim of the invention is to improve the cooling in critical thermal stress regions of an internal combustion engine.

According to the invention, this object is achieved by the internal combustion engine in that: the cylinder head has a first cooling jacket and a second cooling jacket, which is arranged between the first cooling jacket and the flame shield, wherein the first cooling jacket is first flowed through by a coolant flow, and the second cooling jacket is arranged substantially downstream of the first cooling jacket in the flow (coolant flow), so that a Top-Down cooling is achieved (Top-Down-kuhlung).

The second cooling jacket abuts the fire shield. Herein, "top-down cooling" is understood to mean cooling of the cylinder head from a surface facing away from the flame retardant panel, in a direction toward the flame retardant panel. The coolant flows from the upper cooling chamber, i.e. the first cooling chamber, through at least one transfer opening into the lower cooling chamber, which is referred to herein as the "second cooling chamber". Cooling of the fire protection plate and thus of the critical thermally stressed regions of the internal combustion engine is improved by this type of cooling.

The first cooling jacket is connected with its inlet opening in the cylinder head on the pressure side to a coolant pump. The second cooling jacket is connected with its outlet opening in the cylinder head on the suction side to a coolant pump of the coolant circuit.

Improved inflow and cooling of the fire protection plate is achieved by cooling from the top down. Heat from the combustion chamber, which in turn faces away from the second cooling jacket and abuts the fire shield, is carried away by the coolant in the second cooling jacket without further heating the upper region of the cylinder head. Independently thereof, coolant flows through the crankcase. In commercial vehicle engines, the flow through the crankcase cooling jacket (coolant flow) can be kept unregulated. This makes the structure simpler and more cost effective. Nevertheless, a desired, permanently ensured cooling in the region of the cylinder and the piston can be achieved by a continuous flow through the crankcase cooling jacket.

The first cooling jacket and the second cooling jacket are structurally separated from each other by an intermediate plate and each adjoin the intermediate plate. The first cooling jacket is disposed remotely from the combustion chamber, while the second cooling jacket is disposed proximate to the combustion chamber, separated only by the flame retardant panel.

"arranged substantially in the flow (coolant flow)" is also understood here to mean the case: the flow (coolant flow) is subdivided and not the entire coolant flow flows along the same cooling jacket and flow connections.

In terms of cooling, in particular in the case of a multi-cylinder internal combustion engine connected in series, it is advantageous if a distributor bar is provided, which is connected in flow fashion to the crankcase cooling jacket, and if a collector bar is connected in flow fashion to the cooling jacket structure or at least can be connected in flow fashion thereto downstream of at least one cooling jacket of the cooling jacket structure of the cylinder head.

Preferably, the distribution and collection webs are arranged opposite one another with respect to the longitudinal plane, so that a substantially transverse flow is achieved through the cooling jacket structure in the cylinder head and/or through the crankcase cooling jacket.

Here, a transverse flow is understood to mean a flow which flows through the internal combustion engine predominantly in a transverse plane.

The combination of the cooling from the top down and the cross flow through the internal combustion engine results in a particularly advantageous cooling performance in the case of high-load internal combustion engines.

In a preferred embodiment, it is provided that the actuating element has a minimum flow rate in the closed position, so that, as long as the coolant pump generates a flow speed, a coolant flow through the first and second cooling jackets and the other components of the coolant circuit to be cooled is always possible, independently of the position of the actuating element.

This prevents overheating, since the permanently ensured coolant flow achieves heat transfer by forced convection. This minimum flow can be achieved, for example, by a bypass or an opening in the regulating element. Other solutions are also possible.

In an alternative embodiment, it is provided that the cylinder head has a flow connection from the first cooling jacket to the adjusting element, wherein the adjusting element is arranged downstream of the first cooling jacket in the flow direction, wherein the coolant flow can be controlled by the adjusting element via the flow connection. The advantage thereby results that, for example, in the case of a low temperature load around the second cooling jacket, a part of the coolant flow can already be branched off from the cylinder head downstream of (after) the first cooling jacket. This also enables a warm-up process of the internal combustion engine to be carried out even in the case of a cold start. Furthermore, undesirable heat losses are thereby also reduced. Furthermore, this makes it possible to achieve targeted, precise cooling in dependence on the load. The control of the adjusting element can advantageously be controlled as a function of the rotational speed or the load, and a flexible and powerful cooling which is adapted to the requirements and which minimizes losses can thereby be achieved. Thus, heat loss in the cooling area of the fire protection plate can be reduced mainly.

It is particularly advantageous if the adjusting element is arranged downstream of the second cooling jacket in the flow direction. This ensures that the flow through the cooling jacket takes place without interference up to the adjusting element. By virtue of the inner shape of the cooling jacket, turbulence can thus be generated more easily at locations with a higher thermal load for better cooling. The flow pattern in the cylinder head is largely independent of the corresponding position of the adjusting element.

A particularly advantageous configuration with regard to possible cross flows can also be achieved if the collector strip is arranged in the flow direction between the adjusting element and the second cooling jacket.

In order to be able to better control or regulate the coolant flow as a function of load or as a function of rotational speed, an advantageous embodiment provides that the cylinder head has a flow connection from the first cooling jacket to the auxiliary regulating element, whereby the auxiliary regulating element preferably controls the coolant flow through the first cooling jacket as a function of the coolant flow through the second cooling jacket. This reduces the heat loss that may occur if the cooling effect is too good, by adjusting the cooling in the vicinity of the fire protection plate in accordance with the load.

In terms of weight saving and cost optimization, it is advantageous if the adjustment element and the auxiliary adjustment element are connected, preferably mechanically, and can be adjusted to each other. This also enables simpler control or regulation of the coolant flow.

In order to ensure cooling continuously, in one embodiment it is provided that, independently of the position of the actuating element and/or the auxiliary actuating element, a minimum coolant flow through the second cooling jacket is present, wherein for this purpose the closed position of the actuating element has a minimum flow, while the auxiliary actuating element in the fully open position has a flow which is lower than the total coolant flow through the inlet.

With regard to cooling of the crankcase, it is advantageous that the coolant can flow through the crankcase cooling jacket independently of the coolant flow through the cooling jacket,

in order to facilitate the actuation of the setting element, the setting element is preferably connected to an actuator which serves as a drive for the setting of the setting element and is controlled thereby.

In respect of cost and weight and maintenance simplicity, it is also advantageous if the auxiliary adjusting element and the adjusting element are connected to a common actuator for control.

The object set forth is also achieved by a method for cooling an internal combustion engine as described above, wherein the coolant first flows through the first cooling jacket and through the second cooling jacket in the direction of the fire protection plate, wherein the coolant flow through the cooling jacket is regulated downstream of the second cooling jacket by the position of the adjusting element.

Advantageously, the auxiliary adjustment element regulates the coolant flow through the first cooling jacket.

In order to ensure continuous cooling of the critical thermally stressed component region, it is advantageously provided in one embodiment that the coolant flow through the second cooling jacket always has a volume flow greater than 0 during operation of the internal combustion engine.

In one variant, it is provided that the actuating element and/or the auxiliary actuating element is/are controlled as a function of the load of the internal combustion engine. The coolant flow (coolant flow) can thereby be adjusted based on the amount of heat generated, according to the required coolant amount. This makes it possible to avoid excessive heat losses and to achieve targeted cooling as a function of the load. Heat losses can be reduced here, mainly in the vicinity of the fire protection plate.

For the same reason, it is advantageous to control the adjusting element and/or the auxiliary adjusting element as a function of the engine speed.

In a cylinder head with two Cooling chambers arranged above one another, "Top-Down Cooling (Top-Down-Cooling)" is a Cooling concept in which coolant flows from an upper Cooling chamber through a transfer opening (transfer opening) into a lower Cooling chamber, wherein a coolant inlet is arranged in the region of the upper Cooling chamber and a coolant outlet is arranged in the region of the lower Cooling chamber.

The region of high thermal stress of the fire protection plate is, for example, a valve bridge (valve bridge) of the fire protection plate between two exhaust valves (exhaust valves) of the gas exchange valve or between an inlet valve (inlet valve) and an exhaust valve of the gas exchange valve.

The cooling of the cylinder head is carried out as follows: by the coolant flowing into the first cooling jacket of the cylinder head, at least a portion of the coolant flows from the first cooling jacket into the second cooling jacket through at least one transfer opening (transfer opening), and the coolant leaves the cylinder head after flowing through the second cooling jacket. Where it flows through the adjustment member.

In a first embodiment, all the coolant flows from the first cooling jacket into the second cooling jacket.

In a second embodiment, depending on the position of the auxiliary adjusting element, a partial quantity of coolant is guided out of the first cooling jacket. Another portion of the coolant flows from the first cooling jacket, into the second cooling jacket, and from the second cooling jacket out of the cylinder head to the adjustment member.

The invention is further explained below with reference to the non-limiting figures. Shown in the attached drawings:

fig. 1 shows a schematic sketch of a first embodiment of an internal combustion engine according to the invention in a section along a transverse plane;

fig. 2 shows, analogously to fig. 1, an internal combustion engine according to the invention in a second embodiment;

fig. 3 shows a schematic illustration of a coolant circuit of an internal combustion engine according to the invention in a third embodiment;

fig. 4 shows a schematic representation similar to fig. 1 of an internal combustion engine according to the invention in a third embodiment;

fig. 5 shows, in a schematic diagram similar to fig. 1, an internal combustion engine according to the invention in a fourth embodiment in a first position;

FIG. 6 shows, in a schematic diagram similar to FIG. 1, an internal combustion engine of a fourth embodiment in a second position;

fig. 1 and 2 show an internal combustion engine having a cylinder head 1 and a crankcase 2. It may be designed for one or more cylinders 3.

The cylinder head 1 is conceived with a top-down cooling system, with an upper, i.e. remote from the combustion chamber, first cooling jacket 10 and a lower, i.e. close to the combustion chamber, second cooling jacket 20, wherein the first cooling jacket 10 and the second cooling jacket 20 are separated from each other by an intermediate plate 4. The second cooling jacket 20 adjoins the fire protection plate 5 forming a combustion chamber plate. The combustion chamber adjacent the fire shield 5 is indicated by reference numeral 6.

The piston 7 delimits a combustion chamber 6 adjacent to the cylinder 3 and the fire protection plate 5. The piston is movably arranged in a cylinder 3, which is moved back and forth by combustion of the gas mixture brought into the combustion chamber by the gas exchange valve and its discharge.

Downstream of the second cooling jacket 20, a control element 8 is arranged, which controls the coolant flow K as a function of the load and/or as a function of the rotational speed. The adjusting element 8 can be constructed very simply and can adjust the flow rate.

The adjusting element 8 can be driven and controlled by an actuator 9, as shown in the present embodiment.

In the crankcase 2 there is a crankcase cooling jacket 30, which also has a flow S of coolant flowing through it. The flow S of the coolant flows to the outside through two flow connections indicated by arrows S.

As indicated by the arrows K in fig. 1 and 2, the liquid coolant flows out of the first cooling jacket 10, through one or more transfer openings (transfer openings) into the second cooling jacket 20 and flows along the fire protection plate 5 to the outside, wherein heat is absorbed and removed from the hot location in the high-heat-load region.

By the load-dependent control of the actuating element 8, the cooling performance and thus the cooling are increased in a targeted manner in the case of high loads of the internal combustion engine and correspondingly large heat increases.

Fig. 2 shows a second embodiment of the internal combustion engine according to the invention. The two embodiments are essentially identical here, and only the differences between the two embodiments will be discussed. Functionally identical components are provided with the same reference numerals.

In the second embodiment, the auxiliary adjusting element 11 is arranged downstream of the first cooling jacket 10 in the flow direction. When the auxiliary adjusting element 11 is open or partially open, the coolant flow K partially flows out of the cylinder head 1. The part of the coolant flow K remaining in the cylinder head 1 continues to flow into the second cooling jacket 20 and from there to the adjusting element 8.

In this embodiment, the adjusting element 8 and the auxiliary adjusting element 11 are mechanically connected. In alternative embodiments, they can also be connected in other types and ways.

In this embodiment, the two

actuating elements

8 and 11 have a common actuator 9. In an alternative embodiment, it is provided that both have their own actuators and that the

actuating elements

8, 11 are connected, for example, in a signal-conducting manner.

If the actuator 9 now actuates the adjusting

elements

8 and 11 by increasing the load, the coolant flow (flow) K through the second cooling jacket 20 increases. The

actuating elements

8 and 11, on the other hand, serve to reduce the coolant flow K through the second cooling jacket 20 in the event of a load reduction.

Fig. 3 shows a coolant circuit 40 of a third embodiment of the internal combustion engine according to the invention. In fig. 3, a plurality of cylinders 3 are arranged in series along a longitudinal plane epsilon. In the coolant circuit 40, with respect to the longitudinal plane epsilon, a distribution bar 41 is provided at one side of the cylinder 3. Opposite thereto, a collecting bar 42 is arranged adjacent to the cylinder 3 on the other side of the longitudinal plane epsilon. In the coolant circuit, it first flows through the distribution bar 41. This distributes the total volume flow G to the individual passages or regions of the crankcase cooling jacket 30 as a flow S through the crankcase 2 or through the cylinder block.

Furthermore, the coolant circuit 40 passes through the first cooling jacket 10, from there through the second cooling jacket 20 and further into the collector bar 42.

In the embodiment shown, the collector bar 42 is connected to the cooling channel of a retarder (reduction gear) 43. The coolant is led further from the damper (reduction gear) 43 through the EGR cooler 44. From there, the coolant reaches partly the vehicle cooler 45 and partly the thermostat 46. Coolant is also directed from the vehicle cooler 45 to the thermostat 46. From there, it reaches the coolant pump 47 again, which in turn leads into the distribution bar 41.

EGR refers here to exhaust gas recirculation. The hot exhaust gases are cooled with coolant by means of an EGR cooler 44. The thermostat 46 adjusts the temperature of the coolant circuit 40.

In an alternative embodiment, it is possible for the collector bar 42 to be in flow connection with other components of the vehicle.

In this embodiment, the first cooling jacket 10 has a flow connection to a collector bar 42 in which the adjusting element 8 is arranged. The adjusting element 8 is thus arranged downstream of the cooling jacket structure of the cylinder head 1. Depending on the position of the actuating element 8, a partial volume flow T flows via this flow connection to the collector bar 42.

In the flow connection between the thermostat 46 and the collecting bar 41, an oil cooler 48 is arranged in parallel with the coolant pump 47. Here, the coolant is taken between the coolant pump 47 and the collection bar 41 and fed back between the thermostat 46 and the coolant pump 47 before flowing through the coolant pump 47.

Alternatively or also in another embodiment, the coolant is fed back from the oil cooler 48 between the EGR cooler 44 and the vehicle radiator 45, as indicated by the dashed arrow in fig. 3.

The oil cooler 48 is not adjusted in the embodiment shown.

Furthermore, the connection for the cooling air compressor 49 branches off from the distribution strip 41 and is again led upstream of the coolant pump 47.

Fig. 4 shows a schematic diagram of an internal combustion engine of a third embodiment. Here it can be seen that the coolant flows from the distribution bar 41 into the crankcase cooling jacket 30 along arrow G. From there, the coolant flows along the arrow S into the first cooling jacket 10, which in turn is the upper cooling jacket. In the case of an open adjusting element 8, a portion of the coolant flows along the arrow K to the collector bar 42. The adjusting element 8 is actuated by an actuator 9. The coolant remaining in the first cooling jacket 10 flows further through the openings in the intermediate plate 4 to the lower, second cooling jacket 20 and from there to the collector bar 42.

Fig. 5 and 6 show a fourth embodiment of the internal combustion engine. In fig. 5, the first position of the adjusting element 8 is shown, while in fig. 6, the adjusting element 8 is shown in its second position. The flow through the cylinder head 1 and the crankcase 2 proceeds similarly to the third embodiment. In contrast to the third embodiment, however, the collector bar 42 is arranged downstream of the second cooling jacket 20 in the flow direction, and a flow connection to the adjusting element 8 is provided from the collector bar 42. The adjustment element 8 now adjusts the coolant flow out of the second cooling jacket 20. Furthermore, the first cooling jacket 10 is also directly in flow connection with the adjusting element 8.

In the first position shown in fig. 5, no coolant flows along the flow connection from the first cooling jacket 10 to the setting element 8.

In the second position, as shown in fig. 6, a portion of the coolant flow K flows along the flow connection from the first cooling jacket 10 to the adjusting element 8. The temperature in the cylinder head 1 is thus flexibly adjusted by the position of the adjusting element 8.

The control of the adjusting element 8 can be effected in dependence on the rotational speed or in dependence on the load.

Claims

1. An internal combustion engine having at least one cylinder (3), at least one cylinder head (1) and a crankcase (2), wherein the cylinder head (1) has a cooling jacket structure for fluid cooling and the crankcase (2) has a crankcase cooling jacket (30) for fluid cooling, and the cooling jacket structure and the crankcase cooling jacket (30) of the cylinder head (1) are arranged in at least one coolant circuit (40), and an adjusting element (8) is arranged for controlling a coolant flow (K) downstream of at least one cooling jacket (10; 20) of the cooling jacket structure of the cylinder head (1) in a flow direction, characterized in that the cooling jacket structure has a first cooling jacket (10) and a second cooling jacket (20) arranged between the first cooling jacket (10) and a fire shield (5), wherein the first cooling jacket (10) is first flowed through by the coolant flow (K) and the second cooling jacket (20) is arranged substantially in the flow downstream of the first cooling jacket (10), so that a top-down cooling is achieved.

2. An internal combustion engine according to claim 1, characterized in that a distribution strip (41) is provided, which is in flow connection with the crankcase cooling jacket (30) in the flow direction and downstream of at least one of the cooling jackets (10; 20) of the cooling jacket structure of the cylinder head (1) in the flow direction, a collector strip (42) is in flow connection or at least can be in flow connection with the cooling jacket structure.

3. An internal combustion engine according to claim 1 or 2, characterized in that the adjusting element (8) is arranged downstream of the second cooling jacket (20) in the flow direction.

4. An internal combustion engine according to claim 3, characterized in that the collector bar (42) is arranged in the flow direction between the adjusting element (8) and the second cooling jacket (20).

5. An internal combustion engine according to any one of claims 1 to 4, characterized in that the adjusting element (8) has a minimum flow in the closed position, so that, independently of the position of the adjusting element (8), a coolant flow (K) can always arrive through the second cooling jacket (20), preferably through the first cooling jacket (10) and the second cooling jacket (20).

6. An internal combustion engine according to any one of claims 1 to 5, characterized in that the cylinder head (1) has a flow connection from the first cooling jacket (10) to the adjusting element (8), wherein the adjusting element (8) is arranged downstream of the first cooling jacket (10) in the flow direction, wherein the coolant flow (K) is controllable by the adjusting element (8) by means of the flow connection.

7. An internal combustion engine according to any one of claims 1 to 6, characterized in that the cylinder head (1) has a flow connection from the first cooling jacket (10) to an auxiliary adjustment element (11), wherein the coolant flow (K) is controllable by the auxiliary adjustment element (11) by means of the flow connection.

8. An internal combustion engine according to claim 7, characterized in that the adjustment element (8) and the auxiliary adjustment element (11) are connected, preferably mechanically connected, and are adjustable in relation to each other.

9. Internal combustion engine according to claim 7 or 8, characterized in that, independently of the position of the adjusting element (8) and/or the auxiliary adjusting element (11), there is a minimum coolant flow through the second cooling jacket (20), wherein for this purpose the closed position of the adjusting element (8) has a minimum flow and preferably the auxiliary adjusting element (11) has a flow in the fully open position which is smaller than the total coolant flow (K) of the inlet.

10. An internal combustion engine according to any one of claims 1 to 9, characterized in that the crankcase cooling jacket (30) is flowable by a coolant, independently of the coolant flow (K) through the cooling jacket structure.

11. An internal combustion engine according to any one of claims 1 to 10, characterized in that the adjusting element (8) is connected with an actuator (9) which serves as a drive for the adjustment of the adjusting element (8).

12. An internal combustion engine according to claim 11, characterized in that the auxiliary adjusting element (11) and the adjusting element (8) are connected to a common actuator (9) for control.

13. A method for cooling an internal combustion engine according to any one of claims 1 to 12, characterized in that a coolant flows first through the first cooling jacket (10) and through the second cooling jacket (20) in the direction of the fire plate (5), wherein the coolant flow (K) through the cooling jacket structure is regulated by the position of the adjusting element (8) downstream of the first cooling jacket (10) and/or the second cooling jacket (20).

14. Method according to claim 13, characterized in that the auxiliary adjustment element (11) regulates the coolant flow (K) through the first cooling jacket (10).

15. The method as claimed in any of claims 13 to 14, characterized in that the adjusting element (8) and/or the auxiliary adjusting element (11) are controlled as a function of the load of the internal combustion engine.

16. The method as claimed in claim 13, 14 or 15, characterized in that the coolant flow (K) through the second cooling jacket (20) always has a volume flow greater than 0 when the internal combustion engine is running.

17. The method as claimed in one of claims 13 to 16, characterized in that the adjusting element (8) and/or the auxiliary adjusting element (11) is controlled as a function of the rotational speed of the internal combustion engine.