INTERNAL COMBUSTION ENGINE HAVING AT LEAST ONE CYLINDER

Abstract

Various embodiments of the present disclosure are directed to an internal combustion engine cylinder head. In one example embodiment, the cylinder head includes a combustion chamber, a fire deck, an intermediate deck remote from a combustion chamber, a central receptacle that receives an injection or ignition device, at least one valve bridge, at least two adjacent gas exchange valves, a top-down cooling system, at least one first transfer opening, and at least one second transfer opening. The top-down cooling system including a first sub-cooling chamber and a second sub-cooling chamber. The at least one first transfer opening positioned between the first sub-cooling chamber and the second sub-cooling chamber. The at least one second transfer opening positioned between the first sub-cooling chamber and the second sub-cooling chamber is arranged in the region in the region of the at least one valve bridge between the at least two adjacent gas exchange valves.

Claims

1. Cylinder head for an internal combustion engine having at least one cylinder, the cylinder head comprising: a combustion chamber; a fire deck; an intermediate deck remote from a combustion chamber; a central receptacle configured and arranged to receive an injection or ignition device; at least one valve bridge; at least two adjacent gas exchange valves; a top-down cooling system having a first sub-cooling chamber which adjoins the intermediate deck and is remote from the combustion chamber, and a second sub-cooling chamber which adjoins the fire deck and is in close proximity to the combustion chamber; wherein the intermediate deck is arranged between the first sub-cooling chamber and the second sub-cooling chamber; and at least one first transfer opening is arranged between the first sub-cooling chamber and the second sub-cooling chamber in the region of the central receptacle; and at least one second transfer opening between the first sub-cooling chamber and the second sub-cooling chamber is arranged in the region of the at least one valve bridge between the at least two adjacent gas exchange valves.

2. The cylinder head of claim 1, wherein the first sub-cooling chamber is arranged above the second sub-cooling chamber and coolant within the first sub-cooling chamber is configured and arranged to flow via the first transfer opening and the at least one second transfer opening in the region between the at least two adjacent gas exchange valves into the second sub-cooling chamber.

3. The cylinder head of claim 1, wherein the first transfer opening is formed with an especially continuous taper in the direction of the second sub-cooling chamber.

4. The cylinder head of claim 1, wherein the at least one second transfer opening is inclined in the direction of a flow direction of the coolant in the valve bridges, wherein the inclination of the at least one second transfer opening deviates from a cylinder axis by about 0° to about 45°.

5. The cylinder head of claim 1, further including a hot spot of the fire deck; and wherein the at least one second transfer opening is arranged above the hot spot.

6. The cylinder head of claim 1, wherein the at least one second transfer opening is parallel to a cylinder axis.

7. The cylinder head of claim 1, wherein the distance (a) between the at least one second transfer opening and a cylinder axis is 15% to 40% of the diameter of the cylinder.

8. The cylinder head of claim 1, wherein the at least one valve bridge includes at least two valve bridges, wherein the at least one second transfer opening includes a first and a second second transfer opening; and wherein the first second transfer opening is arranged in the region of a first valve bridge of the at least two valve bridges and at least a second second transfer opening is arranged in the region of a second valve bridge of the at least two valve bridges.

9. The cylinder head of claim 8, wherein the at least one valve bridge includes at least three valve bridges, the at least one second transfer opening is arranged in each case in the region of a first valve bridge, a second valve bridge and a third valve bridge of the at least three valve bridges.

10. The cylinder head of claim 8, wherein the at least one second transfer opening includes at least two second transfer openings equidistant from a cylinder axis.

11. The cylinder head of claim 10, wherein the at least one second transfer opening further includes a third second transfer opening, wherein centers of the at least three second transfer openings lie on a circular line around the cylinder axis, the diameter of the circular line is 30% to 80%, of the diameter of the cylinder.

12. The cylinder head of claim 1, wherein the at least one valve bridge includes at least two valve bridges, characterized in that the distance (a) between the at least one second transfer opening and a cylinder axis is less than the distance between a valve axis of at least one adjacent gas exchange valve of the at least two adjacent gas exchange valves and a cylinder axis.

13. Method for cooling a cylinder head according to claim 1, wherein coolant flows into the first sub-cooling chamber of the cylinder head, at least part of the coolant flows from the first sub-cooling chamber into the second sub-cooling chamber via the at least one first transfer opening in the region of the central receptacle for an injection or ignition device, and wherein the coolant exits the cylinder head after flowing through the second sub-cooling chamber, characterized in that at least a further part of the coolant flows from the first sub-cooling chamber via the at least one second transfer opening in the region of the at least one valve bridge between two adjacent gas exchange valves into the second sub-cooling chamber.

14. The cylinder head of claim 1, wherein the first transfer opening is annular, and the central receptacle is concentric with a cylinder axis of the at least one cylinder

15. The cylinder head of claim 4, wherein the inclination of the at least one second transfer opening deviates from the cylinder axis by 15° to 30°

16. The cylinder head of claim 5, wherein the second transfer opening is directed towards the hot spot.

17. The cylinder head of claim 7, wherein the distance between the at least one second transfer opening and the cylinder axis is 20-25% of the cylinder diameter.

18. The cylinder head of claim 9, wherein the at least one valve bridge includes at least four valve bridges, and a fourth valve bridge of the at least four valve bridges is arranged in the region of the at least one second transfer opening.

19. The cylinder head of claim 11, wherein the at least three second transfer openings lie on a circular line around the cylinder axis, the diameter of the circular line is 35%-50% of the cylinder diameter.

Description

[0024] The invention is explained in more detail below with reference to the non-limiting figures, wherein:

[0025] FIG. 1 shows a cylinder head according to the invention in a section according to line I-I in FIG. 3,

[0026] FIG. 2 shows detail II from FIG. 1,

[0027] FIG. 3 shows the cylinder head in a section according to line III-III in FIG. 1, and

[0028] FIG. 4 shows a detail of a cylinder head according to a further embodiment.

[0029] FIGS. 1 to 3 show a cylinder head 1 designed for one or more cylinders 16. FIGS. 1 to 3 each show the cylinder head 1 with one cylinder 16.

[0030] The cylinder head 1, which is designed with a top-down cooling system, has an upper first sub-cooling chamber 2, i.e. remote from the combustion chamber, and a lower second sub-cooling chamber 3, i.e. close to the combustion chamber, wherein the first sub-cooling chamber 2 is separated from the second sub-cooling chamber 3 by an intermediate deck 4. The second sub-cooling chamber 3 adjoins the fire deck 5 forming a combustion chamber ceiling. The combustion chamber adjoining the fire deck 5 is indicated by reference sign 17.

[0031] A number of valve openings 6a, 6b, 6c, 6d for gas exchange valves 7a, 7b, 7c, 7d opening into the combustion chamber 17 are arranged in the fire deck 5 for each cylinder 16. The gas exchange valves 7a, 7b, 7c, 7d form inlet valves for supplying air or an air-fuel mixture to the combustion chamber and outlet valves for discharging exhaust gases from the combustion chamber 17. Valve bridges 8a, 8b, 8c, 8d are arranged between the valve openings 6a, 6b; 6b, 6c; 6c, 6d; 6d, 6a of adjacent gas exchange valves 7a, 7b, 7c, 7d.

[0032] In the region of the cylinder axis 16a, the cylinder head 1 has a central receptacle 10, formed for example by an inserted sleeve, for a central element, for example a spark plug or an injection device. The central receptacle 10 is formed concentrically to the cylinder axis 16a, for example. In the region of the central receptacle 10, at least one first transfer opening 11 is arranged between the first sub-cooling chamber 2 and the second sub-cooling chamber 3, which in the embodiment example is formed by an annular gap between the intermediate deck 4 and the receptacle 10.

[0033] In addition to the first transfer opening 11, a second transfer opening 12a, 12b, 12c, 12d is arranged in the region of at least one, preferably each, valve bridge 8a, 8b, 8c, 8d at a distance from the cylinder axis 16a of the cylinder 16. The second transfer openings 12a, 12b, 12c, 12d are formed parallel to the cylinder axis 16a. The centers 13a, 13b, 13c, 13d of the second transfer openings 12a, 12b, 12c, 12d are arranged on a circular line 14 around the cylinder axis 16a, the diameter d of which is between 30% to 80%, for example 50%, of the diameter D of the cylinder 16. The distance a between the center 13a, 13b, 13c, 13d of at least one second transfer opening 12a, 12b, 12c, 12d and the cylinder axis 16a is smaller in the exemplary embodiment than the distance A between a valve axis 9a, 9b, 9c, 9d of an adjacent gas exchange valve 7a, 7b, 7c, 7d and the cylinder axis 16a. In other words, the centers 13a, 13b, 13c, 13d of the second transfer openings 12a, 12b, 12c, 12d are arranged closer to the cylinder axis 16a in the exemplary embodiment than the valve axes 9a, 9b, 9c, 9d of the nearest gas exchange valves 7a, 7b, 7c, 7d.

[0034] As can be clearly seen from FIG. 2, at least one second transfer opening 12a, 12b, 12c, 12d is directed towards a hot spot 15 of the nearest valve bridge 8a, 8b, 8c, 8d of the fire deck 5. The separate second transfer openings 12a, 12b, 12c, 12d thus enable a targeted inflow and thus improved cooling in the desired area.

[0035] As indicated by the arrows S in FIGS. 1 and 2, the liquid coolant flows from the first sub-cooling chamber 2 via the first transfer opening 11 and the second transfer openings 12a, 12b, 12c, 12d into the second sub-cooling chamber 3, and flows radially outward along the valve bridges 8a, 8b, 8c, 8d of the fire deck 5, absorbing and dissipating heat from hot spots 15 of thermally highly stressed areas.

[0036] Due to the arrangement of the second transfer openings 12a, 12b, 12c, 12d, which can be individually designed for the particular case, very high turbulence can be generated in the desired areas and cooling can thus be improved.

[0037] A further advantage is that flows S through the second transfer openings 12a, 12b, 12c, 12d are less sensitive to manufacturing tolerances than flows S through the first transfer opening 11.

[0038] FIG. 4 shows a detail of a further cylinder head 1 according to the invention, in which the transfer opening 11 is formed with a taper in the direction of the second sub-cooling chamber 3, allowing coolant to flow in the direction of the element. In a sectional view, the tapering transfer opening 11 consequently represents a conical annular gap.