VALVE CONTROL SYSTEM HAVING AN ADJUSTABLE CAMSHAFT

Abstract

A valve control system may include an adjustable camshaft that includes an outer shaft and an inner shaft that extends through the outer shaft. The valve control system may further include a phase shifter that comprises a first control element and a second control element that can be rotated relative to the first control element. The outer shaft and the inner shaft may each be connected with a control element. The valve control system may also include a stop coupled with the outer shaft in a torque-proof manner, as well as a counter-stop coupled with the inner shaft in a torque-proof manner. A maximal angle of rotation of the inner shaft in the outer shaft may be determined by the stop bordering on the counter-stop.

Claims

1.-15. (canceled)

16. A valve control system comprising: an adjustable camshaft including an outer shaft and an inner shaft that extends through the outer shaft; a phase shifter including a first control element and a second control element that is rotatable relative to the first control element, wherein the outer and inner shafts are each connected with one of the first or second control elements; a stop coupled with the outer shaft in a torque-proof manner; and a counter-stop coupled with the inner shaft in a torque-proof manner, wherein a maximal angle of rotation of the inner shaft in the outer shaft is determined by the stop bordering on the counter-stop.

17. The valve control system of claim 16 wherein the stop comprises a claw, wherein the counter-stop comprises a recess disposed between projections, wherein the claw of the stop projects into the recess of the counter-stop.

18. The valve control system of claim 17 further comprising: a drive wheel disposed on the outer shaft for rotationally driving the adjustable camshaft, wherein a stop disk; and a stop disk disposed on the drive wheel, the stop disk including the claw of the stop.

19. The valve control system of claim 18 wherein the stop is integrated into the drive wheel.

20. The valve control system of claim 19 wherein the counter-stop is configured in a hub region of the drive wheel on the inner shaft.

21. The valve control system of claim 18 wherein the counter-stop is disposed on the inner shaft and engages with the stop disk.

22. The valve control system of claim 21 wherein the counter-stop is integral with and projects from the inner shaft.

23. The valve control system of claim 16 wherein the stop is configured as a claw extension and is disposed or formed on an end side of the outer shaft, wherein interstices are disposed between claws of the claw extension.

24. The valve control system of claim 23 wherein the counter-stop comprises a journal element that is disposed on an end side of the inner shaft that corresponds to the claw extension, wherein journals of the journal element project radially outward into the interstices of the claw extension.

25. The valve control system of claim 16 wherein the stop includes four claws or four claw extensions, wherein the counter-stop includes four recesses or four interstices.

26. The valve control system of claim 16 wherein the stop and the counter-stop are integrated into the phase shifter.

27. The valve control system of claim 16 wherein the maximal angle of rotation of the inner shaft in the outer shaft is restricted by the stop and the counter-stop, the maximal angle of rotation of the inner shaft in the outer shaft being less than a maximal angle of rotation of the second control element relative to the first control element.

28. The valve control system of claim 16 further comprising adjustable cam elements that are received on the outer shaft so as to rotate, wherein the adjustable cam elements are connected with the inner shaft by bolts that pass through passages in the outer shaft, wherein an angle of rotation of the inner shaft in the outer shaft is restricted by the stop and the counter-stop and is smaller than a maximal angle of rotation of the bolts in the passages.

29. An adjustable camshaft of a valve control system comprising: an outer shaft and an inner shaft that extends through the outer shaft; a stop coupled with the outer shaft in a torque-proof manner; and a counter-stop coupled with the inner shaft in a torque-proof manner, wherein a maximal angle of rotation of the inner shaft in the outer shaft is determined by the stop bordering on the counter-stop.

30. The adjustable camshaft of claim 29 wherein the stop is configured as a claw extension and disposed on or formed onto an end side of the outer shaft, wherein the claw extension includes claws and interstices between the claws.

31. The adjustable camshaft of claim 30 wherein the counter-stop comprises a journal element disposed on an end side of the inner shaft corresponding to the claw extension, wherein journals of the journal element project radially outward into the interstices of the claw extension.

Description

PREFERRED EXEMPLARY EMBODIMENT OF THE INVENTION

[0022] Further measures that improve the invention will be presented in greater detail below, together with the description of a preferred exemplary embodiment of the invention, using the figures. These show:

[0023] FIG. 1 a cross-sectional view through a valve control system having an adjustable camshaft and a phase shifter,

[0024] FIG. 2 a view of the detail Z according to FIG. 1, in an enlarged representation,

[0025] FIG. 3 a representation of the section H-H according to FIG. 1,

[0026] FIG. 4 a perspective view of the inner shaft with a stop disk,

[0027] FIG. 5 a perspective view of the inner shaft without a stop disk,

[0028] FIG. 6 a perspective view of the stop disk,

[0029] FIG. 7 a cross-sectional perspective view of an adjustable camshaft having a stop and a counter-stop, according to a further variant, and

[0030] FIG. 8 a perspective view of the variant according to FIG. 7 of the stop and the counter-stop, in a non-sectional representation.

[0031] FIG. 1 shows, in a cross-sectional view, a valve control system 1 having an adjustable camshaft 10 and having a phase shifter 13. The adjustable camshaft 10 has an outer shaft 11 and an inner shaft 12, and the inner shaft 12 extends through the tubular outer shaft 11. On the outside, on the outer shaft 11, cam elements 25 are accommodated so as to rotate, and connected with the inner shaft 12 in torque-proof manner, using bolts 26, and when the inner shaft 12 is rotated in the outer shaft 11, the cam elements 25 rotate on the outside of the outer shaft 11, with the inner shaft 12.

[0032] The phase shifter 13, which is merely represented schematically, serves to produce the rotation of the inner shaft 12 in the outer shaft 11. In order to produce the rotation of the inner shaft 12 in the outer shaft 11, the phase shifter 13 has a first control element 14 and a second control element 15, and the control elements 14 and 15 can be configured as a stator and as a rotor, and can be acted on hydraulically, as known from DE 10 2008 005 292 A1.

[0033] Bordering on the phase shifter 13, a drive wheel 20 is connected with the outer shaft 11, by way of which wheel the camshaft 10 can be put into rotation. The adjustment of the angle of rotation of the inner shaft 12 in the outer shaft 11 takes place during operation of the camshaft 10, and, according to the exemplary embodiment shown, a stop disk 21, on which a stop 16 is configured, which can be brought into an active connection with a counter-stop 17 on the outer shaft 12, serves to restrict the angle of rotation of the inner shaft 12 in the outer shaft 1. First, Detail Z shown in the subsequent FIG. 2 will be described in greater detail.

[0034] FIG. 2 shows Detail Z of the adjustable camshaft 10 with the outer shaft 11 and with the inner shaft 12 that extends through the outer shaft 11 and a drive wheel 20 is shown, which is connected with the outer shaft 11. Not shown is a phase shifter, in deviation from FIG. 1.

[0035] On a flat side of the drive wheel 20, a stop disk 21 is disposed by way of screw elements 30, and the stop disk 21 has stops 16, which project axially into the hub of the drive wheel 20, in the form of claws 18, out of the plane of the stop disk 21. In this regard, the claws 18 are situated above the outside of the inner shaft 12 and can enter into interaction with counter-stops, as will be explained in greater detail in connection with the subsequent FIG. 3, which represents a section along the section line H-H according to FIG. 1.

[0036] FIG. 3 shows a cross-section along the section line H-H through the drive wheel 20 according to FIG. 1, wherein the section line is configured in such a manner that the claws 18 also lie in the section plane, to form the stop 16 of the stop disk 21. The cross-sectional view makes it clear that counter-stops in the form of projections 27 are configured on the inner shaft 12, which projections project away radially outward from the inner shaft 12 and form the counter-stop 17. In this regard, the projections 27 extend into recesses 19, which are configured between the claws 18 of the stop disk 21. If the inner shaft 12 is now rotated in the outer shaft 11, the projections 27 make contact with the claws 18 in the circumference direction, so that the rotation of the inner shaft 12 in the outer shaft 11 is restricted.

[0037] The exemplary embodiment according to FIGS. 1 to 3 shows a stop disk 21 having four claws 18, so that four recesses 19 are formed between the claws 18. Projections 27 extend into each of the recesses 19, so that four projections 27 are configured on the inner shaft 12.

[0038] FIG. 4, in a perspective view, shows the stop disk 21 in place above the inner shaft 12, without the drive wheel 20 for accommodation of the stop disk 21 with the outer shaft 11 being shown. From the reduced view, it is evident that the projections 27 extend into the recesses 19 between the claws 18, and thereby, analogously, the claws 18 of the stop disk 21 extend into interstices between the projections 27. As the result of the interaction of the claws 18 with the projections 27 that becomes possible, the angle of rotation of the inner shaft 12 relative to the stop disk 21 is restricted.

[0039] FIG. 5, without the stop disk 21 according to FIG. 4, shows the inner shaft 12 with the projections 27, between which the recesses 19 are situated, thereby forming the counter-stop 17. The view shows four projections 27, which are configured in one piece with the inner shaft 12, and, for example, the inner shaft 12 can be prepared by working it with a lathe, and the recesses 19 are subsequently produced by means of intermittent milling work.

[0040] FIG. 6, finally, shows a perspective view of the stop disk 21 with the claws 18 that project away axially, and the stop 16 is formed by the claws 18, which stop can interact accordingly with the counter-stop 17 according to FIG. 5.

[0041] FIGS. 7 and 8, in a sectional (FIG. 7) and a non-sectional (FIG. 8) perspective view, show a further embodiment variant for forming the stop 16 and the counter-stop 17, which are disposed on the end side of the adjustable camshaft 10 having the outer shaft 11 and the inner shaft 12. The stop 16 is configured on the end side of the outer shaft 11, in the form of a claw extension 22, and interstices 28 are formed by the claw extension 22. The end of the outer shaft 11 is therefore configured approximately in crown shape, and two interstices 28 are configured, for example. The counter-stop 17 is formed by a journal element 23, which is disposed on the end side of the inner shaft 12, corresponding to the claw extension 22. The journal element 23 has two journals 24 disposed diametrically opposite one another at 180, which journals project radially outward into the interstices 28 of the claw extension 22. When the inner shaft 12 is rotated in the outer shaft 11, the journals 24 make contact with the edges of the interstices 28, thereby restricting the angle of rotation by the corresponding desired amount. The journal element 23 is affixed to the end side of the inner shaft 12 by way of a screw element 29, and thereby structured as an individual part.

[0042] The invention is not restricted, in its embodiment, to the preferred exemplary embodiments indicated above. Instead, a number of variants are conceivable, which make use of the solution presented even in fundamentally different types of embodiments. All the characteristics and/or advantages, including design details and spatial arrangement, which are evident from the claims, the specification or the drawings, can be essential to the invention both in themselves and in the most varied combinations.

REFERENCE SYMBOL LIST

[0043] 1 valve control system [0044] 10 adjustable camshaft [0045] 11 outer shaft [0046] 12 inner shaft [0047] 13 phase shifter [0048] 14 first control element [0049] 15 second control element [0050] 16 stop [0051] 17 counter-stop [0052] 18 claw [0053] 19 recess [0054] 20 drive wheel [0055] 21 stop disk [0056] 22 claw extension [0057] 23 journal element [0058] 24 journal [0059] 25 cam element [0060] 26 bolt [0061] 27 projection [0062] 28 interstice [0063] 29 screw element [0064] 30 screw element