METHOD FOR ARRANGING A CAMSHAFT IN A CAMSHAFT MODULE

Abstract

A method for arranging a camshaft in a camshaft module includes arranging cam elements and a switching element on a carrier tube to so as to form a displacement element having a bearing section, outside or external to a module housing. The carrier tube is then cut in a region of a bearing section to form two parts. One of the parts is arranged into a bearing bridge in a module housing. The other part is then joined to the first part that was inserted into the bearing bridge.

Claims

1. A method for arranging a camshaft in a camshaft module for the valve drive in an internal combustion engine, wherein the camshaft module comprises a module housing in which at least one camshaft is accommodated, wherein the camshaft comprises at least one displacement element with a carrier tube, with at least two cam elements for the valve actuation and with a switching element for the axial adjustment of the displacement element in the module housing, and wherein the cam elements and the switching element are attached to the carrier tube such that an interposed bearing section for the mounting of the displacement element in a bearing bridge of the module housing is formed, the method comprising: arranging the cam elements and the switching element on the carrier tube, with the bearing section being formed, so as to provide the displacement element outside the module housing; cutting the carrier tube in the region of the bearing section into two parts so as to create a first part and a second part by way of a cutting method; arranging a connecting sleeve on either of the first or second parts; inserting either of the first or second parts into the bearing bridge in the module housing; and joining the other of the first or second parts to the first or second part that was inserted into the bearing bridge.

2. The method of claim 1, further comprising machining the displacement element that is to be provided outside the module housing into a ready-for-use state by way of at least one chip-removing machining process.

3. The method of claim 1, further comprising placing as the connecting sleeve is arranged on the outside of the bearing section of the carrier tube.

4. The method of claim 1, further comprising one of press fitting, shrink fitting, or adhesively bonding the connecting sleeve onto the outside of the bearing section of the carrier tube.

5. The method of claim 1, further comprising machining the carrier tube to have an outer diameter less or equal to the inner diameter of the carrier tube in the region of the bearing section before the carrier tube is cut into two parts.

6. The method of claim 1, further comprising machining the inner surface and/or outer circumferential surface of the connecting sleeve with one of griding or polishing process.

7. The method of claim 1, wherein said cutting step is performed by one of a sawing process, an abrasive cutting process, a thermal cutting process, or a laser-beam cutting process.

8. The method of claim 7, further comprising after said cutting step but prior to said joining step, machining the parting surfaces of the carrier tube formed from said cutting step by a chip-removing machining process.

Description

PREFERRED EXEMPLARY EMBODIMENT OF THE INVENTION

[0020] Further measures which improve the invention will be presented in more detail below in conjunction with the description of a preferred exemplary embodiment of the invention on the basis of the figures, in which:

[0021] FIG. 1 shows a schematic view of a displacement element in a ready-for-use state,

[0022] FIG. 2 shows the displacement element as per FIG. 1 with a carrier tube cut according to the invention,

[0023] FIG. 3 shows a part of the displacement element, having a carrier tube to which a connecting sleeve has been attached,

[0024] FIG. 4 shows an arrangement of the part of the displacement element with the connecting sleeve as per FIG. 3 in a bearing bridge of a module housing, and

[0025] FIG. 5 shows a schematic view of a camshaft module having a module housing in which a displacement element has been arranged, by way of the method according to the invention, in a bearing bridge.

[0026] FIG. 1 shows a displacement element 11 for arrangement in a module housing 10 of a camshaft module 100, as illustrated in FIG. 5.

[0027] The displacement element 11 comprises a carrier tube 12, and cam elements 13 and a switching element 14 are attached to the outer side of the carrier tube 12. The cam elements 13 are arranged, spaced apart from one another in pairwise fashion, on the carrier tube 12, and a first pair of, for example, two cam elements 13 is situated on a first side of a bearing section 15 of the carrier tube 12, and a further pair of, for example, two cam elements 13 is situated on the opposite side of the bearing section 15. Furthermore, the switching element 14 is seated on the carrier tube 12, which switching element adjoins one pair of cam elements 13.

[0028] The carrier tube 12 extends around a central axis 20 and, in a manner not shown in any more detail, comprises an internal toothing. A toothed shaft may be led through the carrier tube 12, such that an external toothing of the toothed shaft can be placed in engagement with the internal toothing in the carrier tube 12. In this way, when the toothed shaft rotates, the displacement element 11 can likewise be set in rotation, wherein the displacement element 11 remains longitudinally displaceable along the central axis 20. An axial displacement may be realized by way of the switching element 14 by virtue of an external actuator interacting with the switching element 14. In this way, the displacement element 11 can be placed into, for example, two different axial positions, such that, in a first position, a pick-off element interacts for example with a first cam element 13 of the cam pairs, and, in a further axial position of the displacement element 11, the same pick-off element can interact with a second cam element 13 of the respective cam pairs.

[0029] The bearing section 15, which forms a cylindrical section of the carrier tube 12, serves for the mounting of the displacement element 11 in the module housing.

[0030] The illustrated displacement element 11 is machined into a ready-for-use state, and it is for example possible for the cam contours of the cam elements 13 and the switching element 14 to be finish-machined in a chip-removing process, and the displacement element 11 shown can be supplied to a further step of the method according to the invention.

[0031] As per a further main method step, in FIG. 2, the displacement element 11 with the carrier tube 12, the cam elements 13 and the switching element 14 is shown, wherein the carrier tube 12 has been cut in accordance with the invention. After the cutting, the parting surfaces 18 may also be subjected to finish machining. As a result, as an intermediate step, two parts A and B of the displacement element 11 are obtained, wherein the cutting of the carrier tube 12 is performed in the region of the bearing section 15. For example, the parting plane is shown centrally in relation to the bearing section 15, and the parting plane may also lie eccentrically.

[0032] FIG. 3 shows a further method step, in which a connecting sleeve 17 is provided which is attached to a free section of the carrier tube 12 of a part A of the displacement element 11. The cam elements 13, the switching element 14 and the attached, for example pressed-on, connecting sleeve 17 are thus situated on the part of the carrier tube 12. In the same way, it would also be possible for the connecting sleeve 17 to be pushed onto the part B of the displacement element 11, which is shown in FIG. 2.

[0033] FIG. 4 finally shows the arrangement of the part A of the displacement element 11 with the carrier tube 12, the cam elements 13 and the switching element 14 in the bearing bridge 16, such that the connecting sleeve 17 has been led all the way through the bearing bridge 16. Here, the outer circumferential surface of the connecting sleeve 17 forms the inner sliding partner of the plain bearing formed with the bearing bridge 16, such that, as shown in FIG. 5, the further part B of the displacement element 11 can finally be joined to the first part A of the displacement element 11 again.

[0034] FIG. 5 shows the ready-for-use camshaft module 100 with a camshaft 1 which comprises, by way of example, a displacement element 11. The camshaft module 100 is schematically illustrated with a module housing 10 in which the bearing bridge 16 is incorporated. The bearing bridge 16 is in this case of non-split and closed form. The two parts A and B of the displacement element 11 have, from the respective sides of the bearing bridge 16 with the connecting sleeve 17, been pushed into the latter, such that the carrier tube 12 is, in a split state, a constituent part of the ready-for-use displacement element 11 of the camshaft 1. The first pair of cam elements 13 and the switching element 14 are seated on one part A of the displacement element 11. The part B of the displacement element 11 with the section of the carrier tube 12 is situated on the opposite side of the bearing bridge 16, and the two sections of the carrier tubes 12 are connected to one another by way of the connecting sleeve 17, which simultaneously forms the bearing section 15 by way of which the displacement element 11 is rotatably mounted in the bearing bridge 16.

[0035] For the completion of the camshaft 1, a toothed shaft 19 is inserted into the parts of the carrier tube 12 along the central axis 20. The toothed shaft 19 may for example be driven, outside the module housing 10, by way of a drive wheel, such that the displacement element 11 co-rotates with the toothed shaft 19. Here, the displacement element 11 remains axially displaceable in the direction of the central axis 20, wherein the illustrated axial position of the displacement element 11 forms an intermediate position, which may be situated for example between two switching positions of the displacement element 11.

[0036] The invention is not restricted, in terms of its embodiment, to the preferred exemplary embodiment specified above. Rather, numerous variants are conceivable which make use of the presented solution even in fundamentally different embodiments. All of the features and/or advantages which emerge from the claims, from the description or from the drawings, including design details or spatial arrangements, may be essential to the invention both individually and in a wide variety of combinations.

LIST OF REFERENCE DESIGNATIONS

[0037] 100 Camshaft module

[0038] 1 Camshaft

[0039] 10 Module housing

[0040] 11 Displacement element

[0041] 12 Carrier tube

[0042] 13 Cam element

[0043] 14 Switching element

[0044] 15 Bearing section

[0045] 16 Bearing bridge

[0046] 17 Connecting sleeve

[0047] 18 Parting surface

[0048] 19 Toothed shaft

[0049] 20 Central axis

[0050] A Part of the displacement element

[0051] B Part of the displacement element