VALVE ROTATING DEVICE

Abstract

The invention relates to a valve rotating device (24) for a valve (10), preferably an intake valve or exhaust valve, of an internal combustion engine The valve rotating device (24) has a valve restoring spring (22) for preloading the valve (10) toward a closed position of the valve (10) and a Belleville spring (40), which is arranged in operative connection between the valve restoring spring (22) and a support surface (44), which is lubricated with a lubricating fluid. An at least partially, preferably completely, peripherally extending collar portion (46) is arranged on a periphery, preferably inner periphery, of the Belleville spring (40). The collar portion (46) can have a wear-reducing effect and/or can make the valve rotating device (24) easier to install.

Claims

1-15. (canceled)

16. A valve rotating device for an intake or exhaust valve of an internal combustion engine, comprising: a valve return spring for preloading of the valve in a direction towards a closed position of the valve; and a Belville spring, which is arranged in operative connection between the valve return spring and a support surface lubricated by a lubricating fluid, wherein the Belville spring is formed so that on opening of the valve it is compressed into a flattened shape, under the force of the valve return spring, and in a flattened form is supported with sliding friction by the lubricating fluid between the Belville spring and the support surface, to allow a rotation of the valve, wherein an at least partially circumferential collar portion is arranged on a circumference of the Belville spring.

17. The valve rotating device as claimed in claim 16, wherein: the Belville spring in the flattened shape is parallel to the support surface; the at least partially circumferential collar portion is fully circumferential; and/or the circumference of the Belville spring is an inner circumference of the Belville spring.

18. The valve rotating device as claimed in claim 16, wherein the Belville spring comprises an elastically deformable main body portion having a conical and annular disk shape, and: the collar portion is angled in relation to the main body portion; and/or the collar portion extends from the elastic main body.

19. The valve rotating device as claimed in claim 16, wherein: the collar portion confines the Belville spring on its inner circumference; and/or the collar portion is designed to extend substantially parallel to and/or coaxially with a valve axis of the valve and/or a longitudinal axis of a valve body of the valve.

20. The valve rotating device as claimed in claim 16, wherein: the collar portion is arranged for the radial support of the Belville spring.

21. The valve rotating device as claimed in claim 20, wherein: the radial support of the Belville spring is radial in relation to a valve axis of the valve.

22. The valve rotating device as claimed in claim 16, wherein: the collar portion is arranged for flat-spread seating contact against a valve element of the valve.

23. The valve rotating device as claimed in claim 22, wherein: the valve element is a valve guide of the valve.

24. The valve rotating device as claimed in claim 16, wherein: the Belville spring comprises the collar portion.

25. The valve rotating device as claimed in claim 16, wherein: a cylinder head comprises the support surface.

26. The valve rotating device as claimed in claim 16, further comprising: an annular element, wherein the annular element comprises the support surface.

27. The valve rotating device as claimed in claim 26, wherein: the annular element is a further Belville spring or an annular washer.

28. The valve rotating device as claimed in claim 26, wherein: the annular element is arranged in an operative connection between the Belville spring and a cylinder head.

29. The valve rotating device as claimed in claim 26, wherein: the annular element or the Belville spring comprises the collar portion.

30. The valve rotating device as claimed in claim 26, wherein: the annular element comprises the collar portion and the collar portion grips partially around the Belville spring, preferably on the inner circumferential side; or the Belville spring comprises the collar portion and the collar portion grips partially around the annular element, preferably on the inner circumferential side.

31. The valve rotating device as claimed in claim 26, wherein: the annular element comprises the collar portion and the collar portion grips partially around an inner circumferential side of the Belville spring; or the Belville spring comprises the collar portion and the collar portion grips partially around an inner circumferential side of the annular element.

32. The valve rotating device as claimed in claim 26, wherein: the Belville spring and the annular element are held captively together by the collar portion, so that they form a common assembly unit.

33. The valve rotating device as claimed in claim 32, wherein: the assembly unit is formed so that it can be fitted both with an orientation in which the Belville spring is arranged on a side of the assembly unit facing the valve return spring, and with an opposed orientation in which the annular element is arranged on the side of the assembly unit facing the valve return spring.

34. The valve rotating device as claimed in claim 16, wherein: the Belville spring is arranged in a recess of a cylinder head that can be or is filled with lubricating fluid, and a further recess of the cylinder head for the collar portion is arranged in the recess.

35. A motor vehicle having a valve rotating device as claimed in claim 16.

Description

[0036] The preferred embodiments and features of the invention hitherto described can be freely combined with one another. Further details and advantages of the invention are described below referring to the drawings attached, of which:

[0037] FIG. 1 shows a half-sectional view of a closed valve having an exemplifying valve rotating device according to the present disclosure;

[0038] FIG. 2 shows a half-sectional view of an opened valve having the exemplifying valve rotating device according to the present disclosure;

[0039] FIG. 3 shows a half-sectional view of a closed valve having a further exemplifying valve rotating device according to the present disclosure; and

[0040] FIG. 4 shows a half-sectional view of a closed valve having a yet another exemplifying valve rotating device according to the present disclosure.

[0041] The embodiments shown in the figures correspond at least partially to one another, so that similar or identical parts are provided with the same reference numerals and are explained also through reference to the description of the other embodiments and figures, in order to avoid repetition.

[0042] FIG. 1 shows a valve 10 in half-section. The valve 10 may suitably be a valve of an internal combustion engine, for example a reciprocating-piston internal combustion engine. The internal combustion engine may be a diesel, petrol and/or gas-fueled internal combustion engine, for example. The valve 10 may preferably serve to connect a fluid passage 12 in a cylinder head 14 of the internal combustion engine and a combustion chamber 16 of the internal combustion engine to one another in the opened state or to separate them from one another in the closed state. For example, the valve 10 may be an intake valve and the fluid passage 12 an air or air/fuel mixture intake port. It is also possible, for example, for the valve 10 to be an exhaust valve and for the fluid passage 12 to be an exhaust port. The internal combustion engine may suitably be contained in a motor vehicle, preferably a commercial vehicle. The valve 10 may take the form, for example, of a poppet valve, as represented.

[0043] The valve 10 comprises a valve body 18, a valve guide 20, a valve return spring 22 and a valve rotating device 24. The valve return spring 22 can be regarded functionally as part of the valve rotating device 24.

[0044] The valve body 18 comprises a valve stem 26 and a combustion chamber-side closing part 28, for example of plate or disk shape. The valve stem 26 and the closing part 28 are connected to one another, preferably integrally in one piece. The valve body 18 is capable of reciprocating movement in the valve guide 20, for example of sleeve-shaped formation, for opening and closing the valve 10. The valve guide 20 may be arranged coaxially with the valve body 18 in the cylinder head 14.

[0045] As is shown in FIG. 1, when the valve 10 is in the closed state the closing part 28 lies forming a seal against a valve seat 30 in the cylinder head 14. The valve 10 forms a seal between the fluid passage 12 and the combustion chamber 16. With the valve 10 in the opened state (see FIG. 2) there is an annular gap between the closing part 28 and the valve seat 30, so that the fluid passage 12 and the combustion chamber 16 have a fluid connection to one another.

[0046] For opening and closing the valve 10, the valve 10 may be actuated, for example, by a suitably mechanical valve gear (not shown). For opening the valve 10 the valve gear may press on a free end 32 of the valve stem 26, in order to lift the closing part 28 from the valve seat 30. For example, the valve gear may comprise a force-transmitting element, for example a rocker arm, cam follower or tappet, for actuating the valve 10 and a camshaft for actuating the force-transmitting element. It is also possible to use other types of valve gears and actuating devices for actuating the valve 10, for example electromagnetic or electromotive devices.

[0047] The valve return spring 22 is operatively connected between the valve body 18 and the cylinder head 14. The valve return spring 22 preloads the valve 10 in the direction of the closed state. The valve return spring 22 thereby causes the valve 10 to close when it is no longer held open by the valve gear. The valve return spring 22 may take the form, in particular, of a coil spring. The valve return spring 22 may be arranged coaxially with the valve body 18 and the valve guide 20. The valve return spring 22 may be supported on a valve head 34 of the valve 10. The valve head 34 can be fixed to the valve stem 26 at its free end 32, for example by means of a clamping piece 36. The clamping piece 36, for example, may engage in one or more circumferential grooves on the free end 32 of the valve stem 26. It is also possible for the valve return spring 22 and/or the valve head 34 to be connected to the valve stem 26 in some other way.

[0048] The valve return spring 22 is supported on the cylinder head 14 by means of the valve rotating device 24. The valve rotating device 24 is designed so that it allows the valve return spring 22 or the valve 10 to rotate when the valve 10 opens and closes. The rotary momentum for the rotation can be imparted by the helical shape of the valve return spring 22.

[0049] The valve rotating device 24 is arranged at least partially in a recess 38 in the cylinder head 14. During operation, lubricating fluid, for example oil, collects in the recess 38. For example, the lubricating fluid drips into the recess 38 from a valve gear arranged above it.

[0050] In the embodiment shown the valve rotating device 24 comprises a Belville spring 40 and an annular element 42. It is also possible for the annular element 42 to take the form, for example, of a further Belville spring or an annular washer. The Belville spring 40 and/or the annular element 42 may each be formed, for example, as a sheet-metal part, preferably a formed sheet-metal part.

[0051] The Belville spring 40 is arranged between the valve return spring 22 and the annular element 42. An upper side of the Belville spring 40 is in contact with the valve return spring 22 on an outer circumferential area of the Belville spring 40. An underside of the Belville spring 40 is in contact with the annular element 42 on an inner circumferential area of the Belville spring 40. With the valve 10 in the closed state a line contact suitably results between the Belville spring 40 and the annular element 42.

[0052] The annular element 42 is arranged between the Belville spring 40 and a bottom surface of the recess 38. An upper side of the annular element 42 is in contact with the Belville spring 40 on an inner circumferential area of the annular element 42. An underside of the annular element 42 is in contact with the bottom surface of the recess 38, preferably on an outer circumferential area of the annular element 42.

[0053] The upper side of the annular element 42 forms a support surface 44 for the Belville spring 40. Due to the arrangement of the annular element 42 in the recess 38, the support surface 44 is lubricated by the lubricating fluid in the recess 38. The Belville spring 40 is formed so that on opening of the valve 10 (see FIG. 2) it is elastically deformed due to the increasing spring force of the valve return spring 22 and flattens until it is substantially parallel to the support surface 44. It is also possible for the annular element 42 to be likewise elastically deformed in the process.

[0054] The lubricating fluid is expelled from a diminishing gap between the support surface 44 and the underside of the Belville spring 40. The actuation of the valve 10 occurs so rapidly, however, that a lubricating fluid film remains between the support surface 44 and the underside of the Belville spring 40. The lubricating fluid film makes it possible for the Belville spring 40 to allow a virtually frictionless rotation of the valve return spring 22 through sliding friction due to a so-called displacement contact on the support surface 44. The lubricating fluid film between the underside of the Belville spring 40 and the support surface 44 absorbs the valve spring force. The Belville spring 40 and the annular element 42 are separated from one another by the lubricating fluid film. The friction, particularly in a circumferential direction, approximates to zero. The rotational momentum due to the compression of the valve return spring 22 is capable of rotating the valve 10. This rotation does not vary as a function of specific rotational speeds and does not depend on the dynamics of the valve gear.

[0055] In the embodiment shown in FIGS. 1 and 2 the Belville spring 40 comprises an elastically deformable main body portion 48 and a circumferential collar portion 46. The main body portion 48 has a conical and annular disk shape. The collar portion 46 is arranged on the main body portion 48 on the inner circumferential side. The collar portion 46 extends from the main body portion 48 at an angle to the main body portion 48.

[0056] The collar portion 46 is capable of allowing a flat-spread seating contact of the Belville spring 40 against an outer surface of the valve guide 20. It can therefore serve to prevent the Belville spring 40 cutting successively, for example abradingly, into the valve guide 20 during its rotation, and in so doing causing wear both to the valve guide 20 and to the Belville spring 40. The collar portion 46 therefore serves to support the Belville spring 40 in a radial direction relative to a longitudinal axis A of the valve 10. The collar portion 46 may have a height, for example, in the single or two-digit millimeter range.

[0057] It is also possible, for example, for the annular element rather than the Belville spring to comprise the collar portion, for the purpose of preventing the Belville spring and/or the annular element cutting into the valve guide.

[0058] FIG. 3 shows a further exemplary embodiment of the valve rotating device 24. Here the collar portion 46 of the Belville spring 40 is arranged so that it grips around the annular element 42 on the inner circumferential side. In particular, the collar portion 46 of the Belville spring 40 together with the main body portion 48 forms an annular recess, in which the annular element 42 is partially received. The annular element 42 can thereby be purposely held captive by the Belville spring 40 when assembling the valve rotating device 24. The annular element 42 and the Belville spring 40 may thus form a common assembly unit that is easy to fit.

[0059] It is possible in this exemplary embodiment, too, for the annular element rather than the Belville spring to comprise the collar portion. The collar portion may grip partially around the Belville spring, so that the Belville spring and the annular element are held captively together.

[0060] The assembly unit formed by the Belville spring 40 and the annular element 42 may have the further advantage that it can be fitted on both sides. This means that the assembly unit comprising the Belville spring 40 and the annular element 42 can be fitted both with an orientation in which the Belville spring 40 is in contact with the valve return spring 22, and with an orientation in which the annular element 42 is in contact with the valve return spring 22. This suitably serves to further improve the ease of fitting, since incorrect assembly is precluded.

[0061] It is possible for a further recess 50 for the collar portion 46 to be formed in the recess 38, as represented in FIG. 3. The further recess 50 is capable of partially receiving the collar portion 46 when the valve 10 is opened.

[0062] FIG. 4 shows a further exemplary embodiment of the valve rotating device 24. Here the valve rotating device 24 comprises only the Belville spring 40. The support surface 44 for the Belville spring 40 is formed by a bottom surface of the recess 38.

[0063] The invention is not limited to the preferred exemplary embodiments described above, a number of variants and modifications instead being possible, which likewise make use of the idea of the invention and therefore come into the scope of the patent. In particular, the invention also claims protection for the subject matter and the features of the dependent claims independently of the claims referred to. In particular, the features of the independent claim 1 are disclosed independently of one another. In addition, the features of the dependent claims are also disclosed independently of all features of the independent claim 1 and, for example, independently of the features relating to the presence and/or the configuration of the valve return spring, the Belville spring and/or the collar portion of the independent claim 1. All ranges specified herein are disclosed on the understanding that virtually all values falling within the respective range are disclosed individually, for example also as respective preferred narrower outer limits of the respective range.

LIST OF REFERENCE NUMERALS

[0064] A valve axis [0065] 10 valve [0066] 12 fluid passage [0067] 14 cylinder head [0068] 16 combustion chamber [0069] 18 valve body [0070] 20 valve guide [0071] 22 valve return spring [0072] 24 valve rotating device [0073] 26 valve stem [0074] 28 closing part [0075] 30 valve seat [0076] 32 free end [0077] 34 valve head [0078] 36 clamping piece [0079] 38 recess [0080] 40 Belville spring [0081] 42 annular element [0082] 44 support surface [0083] 46 collar portion [0084] 48 main body portion [0085] 50 further recess