METHOD FOR PRODUCING A CAMSHAFT ASSEMBLY

Abstract

A method for producing a ready-for-use camshaft for controlling valves of an internal combustion engine may be directed towards camshafts that include a carrier shaft on which an end component, for example, a drive wheel, a phase adjuster, or a part of a phase adjuster, is arranged and cam elements that are attached in a positionally fixed manner to the carrier shaft. In some examples, the method comprises providing a carrier shaft and an end component, joining the end component to the carrier shaft, grinding at least the carrier shaft to form cam seats so as to establish readiness for use, introducing a surface profile into a first cam seat, providing a cam element with ready-for-use characteristics, seating the cam element on the cam seat with the surface profile, and repeating certain steps for additional cam elements.

Claims

1.-9. (canceled)

10. A method for producing a ready-for-use camshaft for controlling valves of an internal combustion engine, the method comprising: joining an end component to a carrier shaft; grinding the carrier shaft to form cam seats so as to establish readiness for use; introducing a surface profile into a first cam seat; seating a first cam element with ready-for-use characteristics on the first cam seat with the surface profile such that the first cam element is attached in a positionally fixed manner to the carrier shaft; and repeating the introducing and seating steps for a second cam seat and a second cam element.

11. The method of claim 10 wherein the end component is a drive wheel, a phase adjuster, or a part of a phase adjuster.

12. The method of claim 10 wherein the grinding comprises machining of the end component so as to establish readiness for use.

13. The method of claim 10 wherein the grinding comprises grinding machining of the end component so as to establish readiness for use.

14. The method of claim 10 wherein the grinding comprises machining of the cam seats and finish machining of bearing points formed on the carrier shaft between or adjacent to the cam seats.

15. The method of claim 10 wherein the grinding of the carrier shaft to establish readiness for use is performed on a grinding installation, wherein at least the introducing the surface profile and the seating of the first cam element are performed on a cam seating installation.

16. The method of claim 10 further comprising clamping the end component by way of a tailstock positioned at a side of the carrier shaft opposite the end component for the introducing the surface profile into the first cam seat and for the seating of the first cam element on the first cam seat.

17. The method of claim 16 further comprising guiding the first and second cam elements over the tailstock such that the tailstock remains positioned on the carrier shaft as the first and second cam elements are seated on the carrier shaft.

18. The method of claim 10 further comprising: at least one of grinding the first and second cam elements, respectively, to final dimensions before seating the first and second cam elements on the carrier shaft, or subjecting the first and second cam elements, respectively, to surface finish machining before seating the first and second cam elements on the carrier shaft; and orienting the first and second cam elements rotationally so as to correspond, respectively, to orientations of the first and second cam seats on the carrier shaft before seating the first and second cam elements on the carrier shaft.

19. The method of claim 10 further comprising coating the first and second cam elements before seating the first and second cam elements on the carrier shaft.

20. The method of claim 10 further comprising grinding bores in the first and second cam elements that have diameters that are larger, respectively, than diameters of the first and second cam seats.

21. The method of claim 10 wherein a roller-burnishing tool is used to introduce the surface profile into the first cam seat.

22. The method of claim 10 wherein seating the first cam element on the first cam seat comprises pressing the first cam element onto the first cam seat.

23. A method for producing a ready-for-use camshaft for controlling valves of an internal combustion engine, the method comprising: joining an end component to a carrier shaft; grinding the carrier shaft to form a first cam seat; introducing a surface profile into the first cam seat; and seating a first cam element on the first cam seat such that the first cam element is fixed to the carrier shaft.

24. The method of claim 23 further comprising repeating the grinding, introducing, and seating steps for a second cam seat and a second cam element.

25. The method of claim 24 wherein the grinding comprises machining the first cam seat and finish machining bearing points formed on the carrier shaft between the first cam seat and a second cam seat or adjacent to the first cam seat.

26. The method of claim 24 wherein the grinding of the carrier shaft is performed on a grinding installation, wherein at least the introducing the surface profile and the seating of the first cam element are performed on a cam seating installation.

27. The method of claim 24 further comprising clamping the end component by way of a tailstock positioned at a side of the carrier shaft opposite the end component for introducing the surface profile into the first cam seat and for seating the first cam element on the first cam seat.

28. The method of claim 24 further comprising guiding the first cam element and a second cam element over the tailstock such that the tailstock remains positioned on the carrier shaft as the first and second cam elements are seated on the carrier shaft.

29. The method of claim 24 further comprising coating the first cam element before seating the first cam element on the carrier shaft.

Description

PREFERRED EXEMPLARY EMBODIMENT OF THE INVENTION

[0025] Further measures that improve the invention will be discussed in more detail below on the basis of the figures in conjunction with the description of a preferred method procedure in the context of an exemplary embodiment of the invention. In the figures:

[0026] FIG. 1 shows a carrier shaft with a non-ground surface, such as may be provided as per method step a),

[0027] FIG. 2 shows the view of the carrier shaft with the non-ground surface and with an end component arranged on an end side of the carrier shaft, as specified in method step b),

[0028] FIG. 3 shows the assembly composed of the carrier shaft and the end component in a state in which it has been ground so as to establish readiness for use, with cam seats thus having been formed on the carrier shaft,

[0029] FIG. 4 shows the assembly of the carrier shaft with the end component, wherein, in a manner not shown in any more detail, the end component is clamped in a cam seating installation, and wherein, on the opposite side in relation to the end component, the carrier tube is held by way of a tailstock, and

[0030] FIG. 5 shows a schematic view of a carrier shaft with an end component, and cam elements are being mounted onto the carrier shaft, wherein a surface profile is being introduced into the cam seats, for which purpose a roller-burnishing tool is schematically shown.

[0031] FIG. 1 schematically shows a carrier shaft 10 with a non-ground surface 18, wherein the carrier shaft 10 is in the form of a hollow shaft and comprises a cavity 19 extending along the central axis 17. The carrier shaft 10 thus forms a weight-minimized tube which extends rotationally symmetrically about the central axis 17 and which may for example be cut to length from a bar of material.

[0032] FIG. 2 illustrates an assembly composed of the carrier shaft 10 and of an end component 11, and the end component 11 may for example be a drive wheel, a phase adjuster or a part of a phase adjuster, and in the context of the present invention, the end component 11 is part of the ready-for-use camshaft. For the fastening of the end component 11, the latter comprises a projection 20 which is, by way of example, inserted into the cavity 19 in the carrier shaft 10, wherein the end component 11 may also be fastened to the carrier shaft 10 in some other way, for example by way of a cohesive joining process or by way of connecting elements. Here, the carrier shaft 10 comprises the non-ground surface 18, wherein the end component 11 may also comprise a non-ground, in particular untreated surface. For example, the end component 11 can be joined to the carrier shaft 10 in a simple manner without regard to position and dimensional tolerances because, as will be described below, grinding machining both of the carrier shaft 10 and of the end component 11 in an assembled state is performed in a common chucking setup.

[0033] FIG. 3 shows the assembly composed of the carrier shaft 10 and of the end component 11 in a ground state. As a result of the grinding machining so as to yield a ready-for-use state of the carrier shaft 10 and of the end component 11, a sequence of cam seats 13 is shown on the outer side of the carrier shaft 10. By way of example, two bearing points 15 are also shown, and the bearing points 15 comprise a smaller diameter than the diameters of the cam seats 13. In a manner not shown in any more detail, it is also possible for the end component 11 to undergo cutting machining, and the end component 11 forms, for example, a drive wheel, a sensor disk, a part of a phase adjuster or the like.

[0034] FIG. 4 shows, in a refinement of the assembly composed of the carrier shaft 10 and of the end component 11 as per FIG. 3, the assembly in a chucking setup on a cam seating installation, wherein, in a manner not shown in any more detail, the end component 11 may be clamped and, on the opposite side in relation to the end component 11, the carrier shaft 10 is held on a tailstock 16. The tailstock 16 is for example inserted into the cavity 19 at the end side. In this chucking setup, the assembly composed of the carrier shaft 10 and the end component 11 can be set in rotation about the central axis 17.

[0035] Finally, FIG. 5 shows the assembly composed of the carrier shaft 10 and the end component 11, and a first cam seat 13 has already been machined by way of a schematically illustrated roller-burnishing tool 21 and equipped with a cam element 12, wherein the cam seat 13 on the left-hand side adjacent to the end component 11 comprises a surface profile 14. The roller-burnishing tool 21 is shown, by way of example, with a channel structure which is reproduced on the cam seat 13 by virtue of the roller-burnishing tool 21, shown by way of example in a twofold arrangement, being pressed onto the cam seat 13 while the carrier shaft 10 is set in rotation about the central axis 17. The roller-burnishing tool 21 is shown by way of example on the second cam seat 13, which already likewise comprises a surface profile 14.

[0036] A cam element 12 is shown as having been mounted onto the first cam seat 13, and further cam elements 12 are shown by way of example over the tailstock 16 and are provided there. When the surface profile 14 has been introduced into the next cam seat 13 by way of the roller-burnishing tool 21, a further cam element 12 can be mounted onto the corresponding seat 13.

[0037] Here, the cam elements 12 may have already undergone finish machining, and for example been coated, so as to establish readiness for use.

[0038] In the sequence of FIGS. 1 to 5, the method for producing a ready-for-use camshaft 1 can be described as follows on the basis of the exemplary embodiment shown.

[0039] In the method step a), the carrier shaft 10 as per FIG. 1 is provided, and in the further method step b), the end component 11 may be joined to the carrier shaft 10 as shown in FIG. 2.

[0040] In the further method step c), grinding at least of the carrier shaft 10 so as to establish readiness for use may be performed, such that cam seats 13 as per FIG. 3 are formed. Here, during the grinding for establishing readiness for use, not only the carrier shaft 11 but also the end component 11 may undergo grinding machining. Here, the grinding for establishing readiness for use also encompasses the formation of bearing points 15 so as to establish readiness for use.

[0041] In FIG. 4, the assembly composed of the carrier shaft 10 and the end component 11 is transferred from a grinding installation (FIG. 3) to a cam seating installation (FIGS. 4 and 5). Here, FIG. 4 illustrates a tailstock 16 which serves for the chucking setup as part of the cam seating installation, and, in a manner not illustrated in any more detail, the end component 11 can be clamped so as to realize a defined chucking setup of the assembly composed of the carrier shaft 10 and end component 11.

[0042] In the further method steps d), e), f) and g), it is possible, as shown in FIG. 5, for the introduction of a surface profile 14 to firstly be performed by way of a roller-burnishing tool 21, wherein the surface profile 14 is applied to the cam seats 13 prepared by way of a grinding machining process. Subsequently, a cam element 12 with ready-for-use characteristics is provided, as shown in the region of the tailstock 16, and the cam elements 12 can be guided over the carrier shaft 10 along the arrow direction, and seating of the cam elements 12 onto the cam seats 13 provided with a surface profile 14 can be performed as per method step f).

[0043] As per method step g), the steps d) to f) may be repeated until a corresponding number of cam elements 12 has been mounted on the carrier shaft 10, and it is for example possible for the mounting to be performed a total of four times, as shown in the exemplary embodiment, because four cam seats 13 are provided.

[0044] The invention is not restricted in terms of its embodiment to the preferred exemplary embodiment specified above. Rather, a number of variants are conceivable which make use of the presented solution even in the case of fundamentally different embodiments. All of the features and/or advantages that emerge from the claims, from the description or from the drawings, including structural details and spatial arrangements, may be essential to the invention both individually and in a wide variety of combinations.

LIST OF REFERENCE DESIGNATIONS

[0045] 1 Camshaft [0046] 10 Carrier shaft [0047] 11 End component [0048] 12 Cam element [0049] 13 Cam seat [0050] 14 Surface profile [0051] 15 Bearing point [0052] 16 Tailstock [0053] 17 Central axis [0054] 18 Non-ground surface [0055] 19 Cavity [0056] 20 Projection [0057] 21 Roller-burnishing tool