VALVE FOR AN INTERNAL COMBUSTION ENGINE

Abstract

The present disclosure relates to a valve, preferably an exhaust gas or gas exchange valve, having a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge towards the outside which has a crest region. The valve, in order to reduce the mass of the bulge of the valve head, including a laterally outer part section of the edge region that is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

Claims

1. A valve comprising: a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge which has a crest region, wherein in order to reduce the mass of the bulge of the valve head, a laterally outer part section of the edge region is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

2. The valve according to claim 1, wherein the valve is an exhaust gas or gas exchange valve.

3. The valve according to claim 1, wherein the at least one discontinuity includes at least one vertex, inflection point or reversal point.

4. The valve according to claim 1, wherein, in cross section, the at least one discontinuity is arranged on the outside relative to a laterally inner end of the edge region or is arranged on the inside relative to a laterally outer end of the edge region.

5. The valve according to claim 4, wherein the inner lateral end adjoins the crest region or the outer lateral end is the outermost lateral end of the front face.

6. The valve according to claim 1, wherein the outer part section of the edge region has a lower slope in comparison with the inner part section of the edge region, or the outer part section of the edge region has a slope in a range of less than 5.

7. The valve according to claim 1, wherein the outer part section of the edge region is of substantially bulge-free configuration at least in sections or the bulge does not extend as far as a laterally outer end of the valve head.

8. The valve according to claim 1, wherein the bulge of the valve head is formed by way of a spherical, parabolic or frustoconical shaped-out formation, wherein the outer part section of the edge region differs from the spherical, parabolic or frustoconical shaped-out formation.

9. The valve according to claim 1, wherein the bulge of the valve head is arranged centrally and the outer part section of the edge region includes the laterally outermost part of the front face.

10. The valve according to claim 1, wherein the inner part section of the edge region forms a lateral part of the bulge, or the outer part section of the edge region extends laterally next to and outside the bulge.

11. The valve according to claim 1, wherein the outer part section of the edge region or the at least one discontinuity extends annularly in a rotationally symmetrical manner.

12. The valve according to claim 1, wherein the valve is configured as a solid-body valve or a neutral axis of the valve head extends in sections on the load side of an imaginary reference plane, the reference plane running through the effective centre of a valve seat face of the valve head and transversely with respect to a valve stem of the valve.

13. The valve according to claim 12, wherein the neutral axis of the valve head is bulged towards the load side.

14. The valve according to claim 12, wherein the crest region of the neutral axis runs eccentrically relative to the valve stem.

15. The valve according to claim 12, wherein the neutral axis of the valve head extends predominantly on the load side of the reference plane.

16. The valve according to claim 12, wherein the effective centre of the valve seat face of the valve head is defined by way of the centre of the contact area between the valve seat face of the valve head and a valve seat.

17. The valve according to claim 1, wherein the front face of the valve head is of S-shaped configuration at least in sections in cross section.

18. A valve/valve seat combination comprising: a valve including a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge which has a crest region, wherein in order to reduce the mass of the bulge of the valve head, a laterally outer part section of the edge region is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section; and a valve seat for the valve.

19. A motor vehicle, comprising: a valve/valve seat combination, the combination further comprising, a valve including a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge which has a crest region, wherein in order to reduce the mass of the bulge of the valve head, a laterally outer part section of the edge region is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section; and a valve seat for the valve.

20. The motor vehicle of claim 19, wherein the motor vehicle is a commercial vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other advantageous developments of the present disclosure are disclosed in the following description in conjunction with the appended figures, in which:

[0048] FIG. 1 shows a diagrammatic cross-sectional view of a part of two valves in accordance with the prior art,

[0049] FIG. 2 shows a diagrammatic cross-sectional view of a part of a valve in accordance with one embodiment of the present disclosure,

[0050] FIG. 3 shows a diagrammatic cross-sectional view of a part of a valve in accordance with another embodiment of the present disclosure,

[0051] FIG. 4 shows a diagrammatic cross-sectional view of a part of a valve in accordance with yet another embodiment of the present disclosure,

[0052] FIG. 5 shows a diagrammatic cross-sectional view of a part of a valve in accordance with yet another embodiment of the present disclosure,

[0053] FIG. 6 shows a perspective side view of a valve in accordance with one embodiment of the present disclosure, and

[0054] FIG. 7 shows a perspective side view of a valve in accordance with the prior art.

[0055] The embodiments which are shown in the figures are partially consistent, with the result that the same reference numerals are used for similar or substantially identical parts, reference also being made to the description of the other embodiments in order to explain them, in order to avoid repetitions.

DETAILED DESCRIPTION

[0056] FIG. 1 shows a diagrammatic view of a part of a vaulted valve 1 in accordance with DE 10 2014 013 503 A1 for a petrol or gas engine or a diesel engine which meets the Euro 5 emissions standard, with the result that the valve 1 is loaded with relatively clean, low-soot exhaust gas. For comparison therewith, FIG. 1 likewise diagrammatically shows a valve V which is likewise described in DE 10 2014 013 503 A1.

[0057] In principle, the valve 100 according to the present disclosure can be substantially configured initially like the vaulted valve 1 which can be seen in FIG. 1.

[0058] The valve 1 comprises a valve stem 2 and a valve head 3. The valve head 3 comprises a front face 3.1 which faces a pressure/combustion chamber P (load side) during operation, a rear face 3.2 which faces away from the pressure/combustion chamber P during operation, and an expediently oblique valve seat face 3.3 for seating on a valve seat (seating ring) 5.

[0059] The front face 3.1 is bulged towards the outside, towards the load side P (pressure/combustion chamber) during operation, and the valve 1 is configured as a solid solid-body valve and is therefore configured without cavities, in particular without cooling lines and cooling cavities.

[0060] The neutral axis 4 and therefore the centre line of the valve head 3 is likewise bulged towards the load side P, in particular in such a way that it expediently extends at least predominantly on the load side, that is to say on the load side P during operation, of a notional or imaginary reference plane BE. The reference plane BE runs through the effective centre M of the valve seat face 3.3 of the valve head 3 and transversely with respect to the valve stem 2. The neutral axis 4 identifies as it were the resulting line of action of the valve head 3, whereas the reference plane BE identifies as it were the resulting line of action of the valve seat face 3.3.

[0061] The effective centre M of the valve seat face 3.3 of the valve head 3 is therefore defined by way of the centre of the contact area which results during operation between the valve seat face 3.3 of the valve head 3 and the valve seat 5.

[0062] The neutral axis 4 of the valve head 3 can run at least largely on the load side of the reference plane BE, in particular, by virtue of the fact that the valve 1 is configured as a solid-body valve with an outwardly bulged front face 3.1, with the result that no sliding or only very slight sliding of the valve seat face 3.3 on the valve seat 5 is produced in the case of ignition pressure loading. Since sliding is the main cause for the wear between the valve 1 and the valve seat 5, the wear is reduced or eliminated as a consequence, despite no lubricant or scarcely any lubricant in the form of relatively clean exhaust gas which supplies soot.

[0063] The crest region 3.4 of the front face 3.1 of the valve head 3 is oriented substantially centrally relative to the valve stem 2.

[0064] On account of the valve stem 2, the crest region 4.1 of the neutral axis 4 runs eccentrically relative to the valve stem 2 and in an annularly coaxial manner with respect to the valve stem 2.

[0065] The rear face 3.2 of the valve head 3 is expediently of flatter configuration than the front face 3.1 of the valve head 3. The front face 3.1 and/or the rear face 3.2 can be, for example, of rectilinear or curved configuration.

[0066] The tulip angle of the rear face 3.2 of the valve head 3 is smaller than 20, and is approximately 7 in the embodiment which is shown.

[0067] The valve seat angle of the valve seat face 3.3 is greater than 25, and is approximately 40 in the embodiment which is shown.

[0068] In FIG. 1, moreover, another valve V in accordance with the prior art with a neutral axis F is indicated.

[0069] The comparison between the valve 1 and the valve V shows that the duct-side tulip angle of the valve 1 is smaller (flatter) than in the case of the valve V, and in contrast the front face 3.1 is thickened and bulged, however, with the result that the neutral axis 4 is bulged towards the pressure/combustion chamber P. The shaping of the valve 1 leads to thickening of the valve 1, in particular of the valve head 3 on the side which faces the combustion/pressure chamber P, and thinning on the side which faces away from the combustion/pressure chamber P. The neutral axis F of the valve V in accordance with the prior art runs on the side which faces away from the load side P relative to the reference plane BE, that is to say above the reference plane BE in FIG. 1.

[0070] FIG. 2 shows a diagrammatic cross-sectional view of a part of a valve 100 in accordance with one embodiment of the present disclosure using solid lines, the dotted line in principle showing the course of the edge region of the valve 1 from FIG. 1 for comparison purposes.

[0071] The valve 100 comprises a valve head 3 with a front face 3.1 and a rear face 3.2. The front face 3.1 of the valve head 3 comprises an edge region 10 and a substantially centrally arranged bulge A towards the outside, the bulge A having a crest region 3.4.

[0072] The edge region 10 is expediently delimited in cross section by way of a laterally inner end E1 and a laterally outer end E2. The inner end E1 adjoins the crest region 3.4, it being possible for the outer end E2 to be the outermost lateral end of the front face 3.1 or the valve head 3.

[0073] The edge region 10 extends in an annular manner around the bulge A of the valve head 3, and is arranged here partially laterally next to and outside the bulge A and partially on the bulge A. The bulge A itself can be of substantially spherical, parabolic or frustoconical shape at least in sections.

[0074] One feature of the valve 100 is that a laterally outer part section of the edge region 10 is of flatter configuration in comparison with a laterally inner part section of the edge region 10, and the edge region 10 comprises a plurality of discontinuities P1 to P4 in cross section, in order to reduce the mass of the bulge A, in particular the mass of the bulge base. As a result, the front face 3.1 can expediently be shaped in a substantially S-shaped manner in cross section.

[0075] In the case of the embodiment which is shown in FIG. 2, the outer part section of the edge region 10 is configured without a bulge, with the result that the outer part section has a slope of substantially 0 and, as a consequence, the outer part section of the edge region 10 has a smaller slope in comparison with the inner part section of the edge region 10. Within the context of the present disclosure, however, the outer part section can also have slopes in a range of preferably approximately 5.

[0076] In contrast to the vaulted valve 1, the bulge A of the valve 100 does not extend as far as the laterally outer end E2, with the result that at least the outer part section of the edge region 10 differs from the spherical, parabolic or frustoconical bulge A.

[0077] The plurality of discontinuities P1 to P4 in cross section can expediently be formed by way of at least one vertex, inflection point or reversal point, or a combination thereof.

[0078] FIGS. 3 to 5 show diagrammatic cross-sectional views of a part of a valve 100 in accordance with other embodiments of the present disclosure.

[0079] Here, FIG. 3 shows, in particular, an edge region 10 with part sections which run in a linear manner in cross section and one discontinuity P1.

[0080] Here, FIG. 4 shows, in particular, an edge region 10 with part sections which run in a curved manner in cross section and two discontinuities P1 and P2.

[0081] Here, FIG. 5 shows, in particular, an edge region 10 with part sections which run in a curved manner in cross section and one discontinuity P1.

[0082] FIG. 6 shows a perspective side view of a valve 100 in accordance with one embodiment of the present disclosure, FIG. 7 showing a perspective side view of the vaulted valve 1.

[0083] In the case of the vaulted valve 1 which can be seen in FIG. 7 and can be configured in accordance with DE 10 2014 013 503 A1 as has already been mentioned above, it is possible that the edge region of the valve head 3, in particular the bulge base, is not loaded or is at least not loaded substantially during operation, for example by way of a compression spring force and/or valve spring force.

[0084] In the case of the valve 100 which can be seen in FIG. 6, the outer part section of the edge region 10 is therefore of flatter configuration in comparison with the inner part section of the edge region 10, in order to reduce the mass of the bulge A of the valve head 3, the edge region 10 comprising at least one discontinuity P1 to P4 in cross section, in order, as a result, to remove the mass which is not loaded or is loaded only insubstantially during operation.

[0085] Despite an identical minimum wall thickness of the valve head in comparison with the vaulted valve 1, this can make it possible that the maximum stress of the valve head 3 of the valve 100 and the maximum stress of the valve head 3 of the vaulted valve 1 remain substantially identical, for example with a maximum stress X of, for example, approximately from 136 to 137 Mpa.

[0086] The present disclosure is not restricted to the above-described preferred embodiments. Rather, a multiplicity of variants and modifications are possible which likewise utilize the concept of the present disclosure and therefore fall within the scope of protection.

LIST OF REFERENCE SIGNS

[0087] 1 Valve in accordance with the prior art [0088] 2 Valve stem [0089] 3 Valve head [0090] 3.1 Front face of the valve head [0091] 3.2 Rear face of the valve head [0092] 3.3 Valve seat face [0093] 3.4 Crest region of the front face of the valve head [0094] 4 Neutral axis [0095] 4.1 Crest region of the neutral axis [0096] 5 Valve seat [0097] Tulip angle of the rear face of the valve head [0098] Valve seat angle of the valve seat face of the valve head [0099] P Load side, in particular combustion chamber side and/or pressure chamber side [0100] BE Reference plane [0101] M Effective centre of the valve seat face [0102] V Valve in accordance with the prior art [0103] F Neutral axis of the valve head of the valve V [0104] 100 Valve [0105] 10 Edge region [0106] P1 Discontinuity [0107] P2 Discontinuity [0108] P3 Discontinuity [0109] P4 Discontinuity [0110] A Bulge [0111] E1 Laterally inner end [0112] E2 Laterally outer end