FLOW GUIDING DEVICE, CYLINDER HEAD ASSEMBLY, AND INTERNAL COMBUSTION ENGINE

Abstract

A flow guiding device for an internal combustion engine includes a main body substantially in the shape of a surface shell of a truncated cone and/or a cylinder and a plurality of orifices in the main body. The main body is adapted to be mounted between a cylinder head body and an ignition assembly of the internal combustion engine, and wherein the orifices are adapted to guide a cooling medium between an outside volume and an inside volume of the truncated cone or cylinder.

Claims

1. A system, comprising: a flow guiding device for an internal combustion engine, comprising: a main body substantially in the shape of a surface shell of a truncated cone and/or a cylinder; and a plurality of orifices in the main body, wherein the main body is adapted to be mounted between a cylinder head body and an ignition assembly of the internal combustion engine, and wherein the plurality of orifices are adapted to guide a cooling medium between an outside volume and an inside volume of the truncated cone and/or the cylinder.

2. The system of claim 1, comprising a cylinder head assembly for the internal combustion engine including the cylinder head body, the ignition assembly, and a cooling cavity for cooling the cylinder head body and the ignition assembly, the cooling cavity including bridge cavities for cooling a fire deck of the cylinder head body, the bridge cavities leading from a peripheral part of the cylinder head body between inlet openings and exhaust openings in the cylinder head body to a central part of the cylinder head body, the cooling cavity furthermore comprising: a central cavity in the central part of the cylinder head body, wherein the central cavity at least partly surrounds the ignition assembly and is in fluid communication with the bridge cavities, and axial channels disposed around the ignition assembly, wherein the axial channels are essentially parallel to a longitudinal axis of the ignition assembly, wherein the axial channels are in fluid communication with the bridge cavities and the central cavity.

3. The system of claim 2, wherein the cylinder head assembly further comprises a pump configured to convey the cooling medium from the central cavity and/or the axial channels to the bridge cavities, wherein the plurality of orifices are disposed at transitions between the bridge cavities and the central cavity and/or between the bridge cavities and the axial channels, and the plurality of orifices have a smaller cross-sectional area than the bridge cavities, such that a flow velocity of the cooling medium towards the peripheral part of the cylinder head body is increased at least in a region of the bridge cavities due to the passing of the cooling medium through the plurality of orifices and such that a direction of the cooling medium flow has a component towards the fire deck of the cylinder head body.

4. The system of claim 2, wherein the cylinder head assembly further comprises a pump configured to convey the cooling medium from the bridge cavities through the central cavity to the axial channels, wherein the plurality of orifices are disposed at transitions between the bridge cavities and the central cavity and/or between the bridge cavities and the axial channels, and the plurality of orifices have a smaller cross-sectional area than the bridge cavities, such that a flow velocity of the cooling medium towards the central part of the cylinder head is increased at least in a region of the bridge cavities due to the passing of the cooling medium through the plurality of orifices.

5. The system of claim 1, wherein the flow guiding device: is embodied as at least one separate component part, and/or is mounted between the cylinder head body and the ignition assembly, and/or at least partially surrounds the ignition assembly, and/or is arranged on an end of the ignition assembly closest to the fire deck.

6. The system of claim 1, wherein the plurality of orifices comprise first orifices adjacent to intake openings in the cylinder head body and second orifices adjacent to exhaust openings in the cylinder head body, wherein the first orifices have a smaller cross-sectional area than the second orifices.

7. The system of claim 2, wherein the central cavity and/or the axial channels are delimited in part by the ignition assembly and in part by the cylinder head body.

8. The system of claim 1, wherein: the plurality of orifices comprise four orifices, and/or the plurality of orifices are in the shape of rounded oblong holes, and/or circular holes, and/or cut-outs at an end of the main body closest to the fire deck, and/or the plurality of orifices are evenly distributed circumferentially around the truncated cone and/or the cylinder head and/or the ignition assembly.

9. The system of claim 2, comprising the internal combustion engine having at least one of the cylinder head assembly with the flow guiding device.

10. (canceled)

11. (canceled)

12. A system, comprising: a cooling guide portion of a cylinder head assembly of an internal combustion engine, wherein the cooling guide portion comprises a plurality of orifices disposed in a central part of a cylinder head body having a cooling cavity, wherein the cooling cavity includes bridge cavities for cooling a fire deck of the cylinder head body, wherein the bridge cavities extend from a peripheral part of the cylinder head body between inlet openings and exhaust openings in the cylinder head body to the central part of the cylinder head body, wherein the plurality of orifices are configured to increase a flow velocity of a cooling medium at least in a region of the bridge cavities.

13. The system of claim 12, wherein a flow of the cooling medium through the plurality of orifices is configured to direct the cooling medium towards the peripheral part of the cylinder head body.

14. The system of claim 13, wherein a flow direction of the cooling medium is at least partially towards the fire deck of the cylinder head body.

15. The system of claim 12, wherein the plurality of orifices is configured to direct the cooling medium towards the central part of the cylinder head body.

16. The system of claim 12, wherein each of the plurality of orifices has a smaller cross-sectional area than the bridge cavities.

17. The system of claim 12, wherein the cooling cavity comprises: a central cavity in the central part of the cylinder head body, wherein the central cavity at least partly surrounds an ignition assembly and is in fluid communication with the bridge cavities; and/or axial channels disposed around the ignition assembly, wherein the axial channels are parallel to a longitudinal axis of the ignition assembly, and the axial channels are in fluid communication with the bridge cavities.

18. The system of claim 12, comprising the cylinder head assembly, the internal combustion engine, or a combination thereof.

19. The system of claim 12, comprising a flow guiding device having the cooling guide portion, wherein the flow guiding device comprises: a main body; the plurality of orifices in the main body, wherein the main body is adapted to be mounted between the cylinder head body and an ignition assembly of the internal combustion engine, and wherein the plurality of orifices are adapted to guide the cooling medium between an outside volume and an inside volume of the main body.

20. A method, comprising: guiding a cooling medium via a cooling guide portion of a cylinder head assembly of an internal combustion engine, wherein the cooling guide portion comprises a plurality of orifices disposed in a central part of a cylinder head body having a cooling cavity, wherein the cooling cavity includes bridge cavities for cooling a fire deck of the cylinder head body, wherein the bridge cavities extend from a peripheral part of the cylinder head body between inlet openings and exhaust openings in the cylinder head body to the central part of the cylinder head body; and increasing a flow velocity of the cooling medium at least in a region of the bridge cavities via the plurality of orifices.

21. The method of claim 20, comprising directing the cooling medium towards the peripheral part of the cylinder head body via a flow of the cooling medium through the plurality of orifices.

22. The method of claim 20, comprising directing the cooling medium towards the central part of the cylinder head body via a flow of the cooling medium through the plurality of orifices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Further details and advantages of certain embodiments of the invention are apparent from the figures and the accompanying description of the figures. The figures show:

[0095] FIG. 1 is an embodiment of a flow guiding device according to the certain embodiments of invention;

[0096] FIG. 2 is an embodiment of a flow guiding device according to certain embodiments of the invention fitted onto an ignition assembly;

[0097] FIG. 3a is an embodiment of the internal combustion engine according to certain embodiments of the invention, in particular the flow guiding device fitted onto the ignition assembly together with a cooling cavity in a cylinder head;

[0098] FIG. 3b is the depiction of FIG. 3a together with some further structure of the cylinder head assembly according to certain embodiments of the invention;

[0099] FIGS. 4a to 4c illustrate three examples of embodiments of flow guiding devices according to the certain embodiments of invention;

[0100] FIGS. 5a, 5b illustrate a cylinder head assembly according to the prior art and a cylinder head assembly according to certain embodiments of the invention; and

[0101] FIG. 6 is a schematic cross-sectional view of the cylinder head assembly according to the certain embodiments of invention.

DETAILED DESCRIPTION

[0102] FIG. 1 shows a flow guiding device 1 according to certain embodiments of the invention in a side view. As can be seen, the flow guiding device 1 is roughly of the shape of a truncated cone.

[0103] The flow guiding device 1 comprises a main body 2 and orifices 3 disposed on the truncated cone shape. The orifices 3 of the flow guiding device 1 depicted in FIG. 1 constitute different examples of how the orifices 3 can be embodied regarding size and shape (e.g. rounded oblong holes). Further examples and a visualisation of their effects can be found in FIGS. 4a to 4c.

[0104] The way an example of a flow guiding device 1 according to certain embodiments of the invention is arranged on the ignition assembly 5 is depicted in FIG. 2. The flow guiding device 1 is placed on the ignition assembly 5 roughly concentrically with a longitudinal axis X of the same.

[0105] FIG. 3a shows how the flow guiding device 1 fitted on the ignition assembly 5 is situated in relation to a cooling cavity 7 in a cylinder head body 4.

[0106] The cooling cavity 7 comprises a peripheral part, which transitions into the bridge cavities 8, which lead to the central cavity 11 and/or axial channels 12 (see FIG. 3b). The bridge cavities 8 are disposed between intake and exhaust openings (not depicted) in the cylinder head body 4.

[0107] In this particular example, there are orifices 3, 3.1 and 3.2 of various shapes and sizes on the flow guiding device 1. Additionally, visualisations of the flow profile created by the orifices 3 are drawn. As is for example apparent, a slightly offset orifice 3.1 pushes the flow profile closer to the lower part of the bridge cavity 8 (closer to the fire deck 9, see FIG. 3b) in comparison to the orifice 3.1.

[0108] Orifice 3.1 is also larger in cross-sectional area than orifice 3.1, which allows for a greater flow of cooling medium in this area. This can for example be beneficial if there are exhaust openings adjacent to the orifice 3.1, which are in need of greater cooling performance in the vicinity compared to the vicinity of intake openings (due to the combustion heat to which the exhaust openings are subjected).

[0109] Further cooling cavities 3 can be present, which are formed as cut-outs from the main body 2 of the flow guiding device 1, such that the orifices 3 are realised by the main body 2 together with a wall of the bridge cavities 8. Such orifices 3 can be used for bringing the flow of cooling medium even closer to the fire deck 9 (see also FIGS. 4b and 4c).

[0110] FIG. 3b shows the internal combustion engine in the area of the cylinder head assembly 10 according to certain embodiments of the invention. The ignition assembly 5 is arranged centrally inside an opening of the cylinder head body 4.

[0111] In this embodiment, the ignition assembly 5 abuts the fire deck 9 of the cylinder head body 4.

[0112] The axial channels 12 are parallel to the longitudinal axis X and are depicted symbolically.

[0113] A pump P is present which pumps cooling medium through the cooling cavities 7 and in particular the bridge cavities 8, to a central cavity 11 (not depicted as hidden behind the flow guiding device 1) and/or axial channels 12 and back to the pump P. Different other cooling cavities or the like can be disposed between the pump P and the mentioned objects. In particular, the cooling cavity 7 can be integrated into a water jacket of the cylinder head body 4.

[0114] Viewing FIG. 3b and FIG. 3a makes it clear that the flow guiding device 1 is arranged with its narrower end closer to the fire deck 9 and the main combustion chamber in the depiction below the fire deck 9.

[0115] The central axis of the main combustion chamber coincides with the longitudinal axis X of the ignition assembly 2 in this embodiment. In some other embodiments of the invention, however, the longitudinal axis X of the ignition assembly 5 can have ain most cases relatively smalloffset compared to the central axis of the main combustion chamber 9.

[0116] FIGS. 4a to 4c show different examples of flow guiding devices 1 with different shapes and embodiments of the orifices 3. The orifices 3 can be chosen such that the cooling medium flows through the bridge cavities 8 as desired (symbolised by arrows).

[0117] Several different shapes of the orifices 3 can be used as depicted in FIGS. 4a to 4c. The orifices 3 can be holes in the main body 2 of the flow guiding device 1. However, the orifices 3 can also be realised as cut-outs in the main body 2, while some side wall of the bridge cavity 8 serves as the rest of the boundary of the orifice 3.

[0118] Persons skilled in the art can choose the exact shape of the orifice 3 needed for the specific cooling needs at hand. As already noted, for example, bigger orifices 3 can be chosen for bridge cavities 3 adjacent to exhaust openings of the cylinder head body 4, and smaller orifices 3 can be used for bridge cavities 8 adjacent to intake openings in the cylinder head body 4.

[0119] FIG. 5a shows a cylinder head body according to the prior art without a flow guiding device 1 in the cooling cavity 7.

[0120] Comparing the flow visualisation of the cooling medium flow in FIGS. 5a and 5b shows the higher flow velocity of the cooling medium flow in the vicinity of the fire deck 9 close to the ignition assembly 5. This result is achieved with the flow guiding device 1 according to certain embodiments of the invention. The orifices 3 cause the higher flow velocity in the mentioned area.

[0121] Furthermore, the cooling medium flow in the embodiment according to the invention in FIG. 5b is directed from the distal end of the ignition assembly 5 towards the fire deck 9, i.e., inverted or upside down compared to the embodiment according to the prior art.

[0122] This helps to increase the effect of the flow guiding device 1 with its orifices 3 as the quicker flow is impinging directly on the backside (the upper side in FIG. 5b) of the fire deck 9.

[0123] However, the advantage of increased flow velocity can to a lesser extent than visible in FIG. 5b also be achieved when the direction of the cooling medium flow is from the fire deck 9 towards the distal end of the ignition assembly 2.

[0124] FIG. 6 shows a purely schematic cross-sectional view of the cylinder head assembly 10. The bore of the cylinder which the cylinder head assembly 4 covers is indicated by the larger circle. The cylinder head body 4 in this embodiment comprises two intake openings 14 and two exhaust openings 15. Between the intake openings 14 and exhaust openings 15, the bridge cavities 8 lead to the central cavity 11, which is disposed around the ignition assembly 5 (not depicted in FIG. 6).

[0125] The flow guiding device 1 (also not depicted in FIG. 6) is arranged such that the orifices 3 are present at the interfaces 13 between the bridge cavities 8 and the central cavity 11. In other embodiments, the interfaces 13 could lead directly into the axial channels 12.

[0126] As mentioned in connection with FIGS. 3a, 3b as well as FIGS. 4a to 4c, the orifices 3 can be adapted, e.g., depending on the proximity of the specific orifice 3 to the exhaust openings 15, which receive some of the highest thermal loadings in the cylinder head.