WO2011050897A1 - Method for producing a camshaft module, camshaft module, and assembled camshaft - Google Patents

Abstract

The invention relates to a method for producing a camshaft module (2), a camshaft module, and an assembled camshaft, in particular for use in such a camshaft module. Such a camshaft module comprises a bearing device having a plurality of axially spaced, circumferentially closed, one-piece bearing receptacles (4) for rotatably supporting a shaft body (6) of an assembled camshaft (8), and an assembled camshaft (8), wherein functional components (10) are pressed onto the camshaft body (6) using a tolerance ring (12). The method according to the invention comprises the following method steps: providing the bearing device, positioning the functional component (10) in the assembly area (MB), laterally sliding the shaft body (6) into the assembly area (MB) through one of the closed bearing receptacles (4), threading on the functional component (10) positioned in the assembly area (MB), installing and axially positioning a tolerance ring (12) on the shaft body (6), and producing a press connection between the shaft body (6), the tolerance ring (12), and the functional component (10) by means of axial relative sliding between the tolerance ring (12) and the functional component (10). The camshaft (8) according to the invention is characterized in that the tolerance ring (12) for the press connection between functional components (10) and the camshaft body (6) is arranged in a circumferential groove (14) of the camshaft body (6).

Description

 Method of manufacturing a camshaft module, camshaft module and assembled camshaft

Description:

The present invention relates to a method for producing a camshaft module, a camshaft module produced in particular according to this method, and a camshaft which is particularly suitable for use in the camshaft module according to the invention.

From DE 198 31 772 AI a cylinder head for an internal combustion engine is known, which has a camshaft housing, which has a base body, a cover and at least one mounted in bearings the gas exchange valves of an internal combustion engine controlling camshaft. The bearings are formed by aligned cylindrical holes in spaced parallel webs whose diameter is less than that of the cam elements. The (built) camshaft consists of parts which can be joined together in the cylinder head, with bearing elements being inserted into the bores and connected rotationally fixed to the camshaft elements.

Furthermore, from DE 103 31 089 AI a cylinder head cover with integrated camshaft and a known method for producing this cylinder head cover. The cylinder head cover described has at least one camshaft which protrudes through at least one bearing bridge along a bearing lane for the camshaft in the cylinder head cover. In this case, the bearing bridge on an opening or bore, which completely surrounds the camshaft in this area. The cylinder head cover described is produced according to a method in which first the camshaft is cooled to a temperature which is below the temperature of the cylinder head cover (which is for example at room temperature). In a subsequent process step, the cooled (and reduced by the cooling in their dimensions or shrunken) camshaft in the provided as a storage lane bore of the bearing bridge and fitted in the prefabricated cam. An assembly aid ensures the correct alignment of the cams, in particular for the correct distance and the predetermined rotation of the same. To simplify the installation accordingly, the temperature difference between the cylinder head cover and to be introduced camshaft be increased by the fact that the cylinder head cover is heated accordingly.

Finally, from DE 36 06 111 C2, a camshaft for actuating valve pulses in internal combustion engines is known in which individual cam elements are pressed using a tolerance ring on a camshaft body (press fit). During assembly, the tolerance rings are inserted into the bore of the cam and the thus prepared cam is then pushed in a corresponding angular position relative to the camshaft on this.

Object of the present invention is to provide a camshaft, a camshaft module and a method for producing a camshaft module, in each case a fast and cost-effective fixation of the functional elements is ensured on the camshaft. In particular, a structurally simplified shaft / hub connection is to be created, which ensures a simplified operation with regard to the assembly of a camshaft in a closed bearing frame or in a bearing frame with peripherally closed (in particular integrally executed) bearing receptacles.

According to the invention, the above object is achieved in each case by the respective entirety of the features of one of the independent patent claims. Advantageous developments of the invention are formulated in the respective subclaims.

The inventive method is used to produce a camshaft module with pre-assembled camshaft, wherein the camshaft module a bearing device - for example in the form of a one-piece closed lead frame or in the form of a closed cylinder head cover - with a plurality of circumferentially closed, one-piece executed bearing mounts for rotatably supporting a shaft body of a built or Has built-in camshaft. By the method according to the invention a simplified assembly of a built camshaft within a one-piece ladder frame or a closed cylinder head cover with a correspondingly closed storage lane (wherein the bearing mounts of the storage lane have a smaller diameter than the functional elements to be mounted) to be created. This is achieved by the attachment of the functional elements / components (camshaft components such as cams, sensor or drive wheels or the like) during the assembly process for the camshaft to be installed in the bearing device by the functional elements during assembly process of the shaft body in mounting areas of the closed lead frame or the closed cylinder head cover (or held in its circumferentially closed bearing mounts) prepositioned and threaded onto the shaft body. Once the shaft body has been inserted over its entire length in the storage lane and positioned in the corresponding bearing receptacles, the final determination of the threaded functional elements takes place on the shaft body by individual circumferentially not closed tolerance rings are axially positioned on the shaft body and the individual functional elements on the them respectively assigned and axially positioned tolerance ring pushed laterally and so by means of press connection on the shaft body rotationally fixed and fixed against displacement. In this case, the tolerance rings can also be threaded onto the shaft body during the lateral insertion process of the shaft body through the closed bearing receptacle (s) of the bearing device. Alternatively, however, the tolerance rings can also be expanded and attached radially from the outside to the shaft body. In a particularly preferred embodiment of the method according to the invention, the tolerance rings are positioned axially on the shaft body by holding the Tole- ranzringe as a whole over its entire width or with a radially inwardly projecting annular extension in a corresponding recess (groove) of the shaft body (and against axial displacement secured) are.

Analogous to the method according to the invention, the invention comprises a camshaft module with a bearing device with a plurality of circumferentially closed one-piece bearing receptacles and with a built-in camshaft built into the bearing device. The camshaft is arranged rotatably mounted in the plurality of bearing mounts, wherein in a formed between two adjacent bearing mounts mounting portion of the bearing device, one or more cam element (s) (functional element (s)) by means of press connection, including each one arranged on the shaft body tolerance ring rotating - And fixed on the shaft body is / are arranged.

Furthermore, the invention comprises a correspondingly constructed camshaft for actuating gas exchange valves of an internal combustion engine, in which individual cam elements (functional components) are arranged on the shaft body by means of press-connection rotationally and non-displaceably via tolerance rings arranged in circumferential grooves of the shaft body.

The invention will be illustrated below with reference to various drawing figures for a preferred embodiment and explained in more detail. Show it: 1 shows a detail of a camshaft module according to the invention during assembly in a schematic representation in longitudinal section,

2 shows a detail of a detail in which a functional element is shown on a shaft body of a camshaft designed according to the invention,

Fig. 3a-3d a tolerance ring, as it is used according to FIGS. 1 and 2, in one possible embodiment, in different views.

In Fig. 1 is a schematic, in a fragmentary longitudinal sectional view, a camshaft module according to the invention during the assembly process shown. At the same time, the method according to the invention for producing a corresponding camshaft module is illustrated according to FIG. The camshaft module 2 of FIG. 1 shows a schematic representation of a designed as a closed lead frame bearing device with a plurality of circumferentially closed integrally executed bearing receivers 4 for receiving a shaft body 6 of a built camshaft 8. Here, the shaft body 6 of the built camshaft 8 side by a first bearing receptacle 4, so that individual functional elements 10 (cam elements) can be threaded onto the shaft body 6 in the interior of the bearing frame (in a mounting region MB located between two bearing receptacles). The shaft body 6 is guided by receiving the individual aufzufadelnden functional elements 10 into an opposite bearing seat 4, wherein the shaft body 6 is arranged rotatably mounted in the bearing receivers 4 and to arrange. For rotatable mounting of the shaft body 6 in the bearing mounts 4 of the bearing device 4 bearings (not shown) may be present or subsequently introduced or be pressed laterally between the shaft body and bearing seat 4 in the bearing mounts. Alternatively, the shaft body 6 can be accommodated in corresponding plain bearing bushes of the bearing receptacles 4. In the illustrated embodiment, in each case a tolerance ring (fitting ring) 12 is threaded onto the shaft body 6 in addition to the individual functional elements 10, during the lateral insertion process of the shaft body 6, per functional element 10. As an alternative to threading on the tole- rance ringel2 these can also after completed Einschiebevorgang the shaft body 6 and threading of the functional elements 10 by corresponding expansion radially from the outside to the camshaft or the shaft body 6 are applied (eg by a so-called. Clipping - with advantage with subsequent locking the tolerance rings 12 on the shaft body 6). Are over the entire length of the shaft body 6 all functional elements 10 together with the respective tolerance rings 12 arranged on the shaft body 6, the tolerance rings 12 can be positioned axially on the shaft body 6 in a final assembly step and the respective functional elements 10 pushed onto their associated tolerance ring 12 in a corresponding rotational orientation and there according to rotation and displacement by means Press fit be positioned.

In this case, in one possible embodiment, the interference fit can be realized with a tolerance ring 12 arranged on a smooth (not profiled) shaft body 6 or in another embodiment with a tolerance ring 12 arranged in a peripheral groove 14 of the shaft body 6. The design of a press connection between the functional element 10, tolerance ring 12 and shaft body 6 with a groove 14 has the advantage that the tolerance ring 14 and thus the tolerance ring 12 associated functional element 10 is axially correctly positioned. In the embodiment according to the invention with groove 14, the individual grooves 14 at the corresponding axial functional element positions on the shaft body 6, at the finished camshaft, the functional element 10 is to be fixed, introduced.

The diameter of the passage opening (bore) of the functional element 10 is greater than or equal to the diameter of the shaft body 6, so that the functional element 10 slides on the shaft body 6 or has a slight clearance. The axial width B _{groove of} the groove 14 is dimensioned advantageously smaller than the width B of the functional element 10. This has particular advantages with regard to the centering of the functional element 10 to the shaft body 6. The diameter of the passage openings of the functional elements 10 is approximately equal to the diameter the bearing seat 4 of the bearing device (bearing frame). The alignment and positioning of the functional elements 10 in a predetermined angular and phase relationship to each other at certain axial positions of the shaft body 6 can be fully or partially automated using appropriate automated Zuführanlagen and mounting devices. In this case, the individual functional elements 10, if necessary together with their respective associated tolerance rings 12 in such a feeder, possibly even aligned in their angular position, inserted and pivoted together in the formed between two bearing receptacles 4 mounting area MB of the bearing device, so that the passage openings of the functional elements 10 and the tolerance rings 12 are aligned with the bearing receivers 4 and the shaft body 6 can be guided laterally through the bearing receivers 4 and the through openings of the functional elements 10 and tolerance rings 12. As already described above, in a final step, the functional elements 10 by lateral sliding on the Toferanzringe 12 are fixed at the corresponding axially predetermined positions via a press connection. This process can also be carried out automatically or semi-automatically via the corresponding delivery device. According to FIG. 2, a corresponding press-fit connection of a functional element 10 arranged on the shaft body 6 of the built-up camshaft 8 is shown in an enlarged view.

The tolerance ring 12 used here is shown in more detail in FIGS. 3a-3d. Such a tolerance ring 12, via which a frictional shaft-hub connection between the functional element 10 and shaft body 6 is to be produced, is configured in such a way that it generates an internal radial tension between the components to be connected. The positive deformations required for the generation of the radial prestressing force are absorbed by the tolerance ring 12 arranged between shaft (shaft body 6) and hub (through-opening of functional element 10). For this purpose, the tolerance ring 12 can for example be slotted or have corrugated rings made of thin spring steel which have a large number of longitudinal beads or projections which distribute uniformly over the circumference. The interference fit connection by means of tolerance ring 12 can take place via a tolerance ring 12 mounted on a smooth shaft body 6 or, in a preferred embodiment, via a tolerance ring 12 mounted in a groove 14. In Fig. 3a, the tolerance ring is shown in a radial plan view. FIG. 3b shows the tolerance ring 12 according to FIG. 3a in a side view. In FIGS. 3c and 3d, the circumferentially distributed projections of the tolerance ring 12, which is preferably made of spring steel, are shown in possible embodiments (cross-sectional representation of the tolerance ring 12).

Claims

claims: 1. A method for producing a camshaft module (2) comprising a bearing device with a plurality of axially spaced, circumferentially closed, one-piece executed bearing receptacles (4) for rotatably supporting a shaft body (6) of a built camshaft (8), and a built camshaft (8) in which a functional component (10) to be arranged on the shaft body (6) is to be mounted in a mounting region (MB) of the bearing device formed between two bearing receptacles (4), comprising the following method steps: Providing the storage facility,  Positioning the functional component (10) in the assembly area (MB),  - lateral insertion of the shaft body (6) in the mounting area (MB) by one of the closed bearing receptacles (4) and threading the in the mounting area (MB) positioned functional component (10),  - Mounting and axial positioning of a tolerance ring (12) on the shaft body (6) and producing a press connection between the shaft body (6), tolerance ring (12) and functional component (10) by axial Refatiwerschiebung between tolerance ring (12) and functional component (10). 2. The method according to claim 1, characterized in that  - The tolerance ring (12) by threading onto the shaft body (6), mounted during the lateral insertion of the shaft body (6) in the bearing mounts (4) of the bearing means and positioned by subsequent axial alignment on the shaft body (6). 3. The method according to claim 1, characterized in that  - The tolerance ring (12) by radial clipping on the inserted into the bearing receivers (4) of the bearing device shaft body (6) is mounted and positioned. 4. The method according to one or more of the preceding claims, characterized in that  - The positioning of the tolerance ring (12) in a circumferential groove (14) of the shaft body (6). Method according to one or more of the preceding claims, characterized in that  - The shaft body (6) when threading a plurality of functional components (10) by a plurality of circumferentially closed bearing receivers (4) is guided, and  - The press connection between the shaft body (6) and the functional components (10) is made only after threading all in the or each mounting area (MB) aufzufädelnden functional components (10). Camshaft module (2)  - With a bearing device having a plurality of circumferentially closed bearing receptacles (4) for receiving a built camshaft (8),  - and with a built camshaft (8),  wherein the camshaft (8) in the plurality of bearing mounts (4) is rotatably mounted, and wherein in an axial region of the camshaft (8), formed in a between two adjacent bearing mounts (4) mounting region (MB) of the bearing device, a functional component (10) by means of a press connection under inclusion of a on the WeJJenkörper (6) arranged tolerance ring (12) rotatably and non-displaceably on the shaft body (6) is arranged. Camshaft module (2) according to claim 6, characterized in that  - The tolerance ring (12) for axial positioning on the shaft body (6) in a circumferential groove (14) of the shaft body (6) is arranged. Camshaft (8) for actuating gas exchange valves of an internal combustion engine, comprising  - A shaft body (6) as well  a functional component (10) with a passage opening adapted to the cross section of the shaft body (6), which is connected to the shaft body (6) via a tolerance ring (12) by means of press-connection,  characterized in that - The shaft body (6) in the region in which the functional component (10) axially on the shaft body (6) displaceable and is rotationally positioned, a circumferential groove (14) for receiving the tolerance ring (12). 9. cam follower (8) according to claim 8, characterized in that - The width (B _groove ) of the groove (14) is dimensioned smaller than the width (B _component ) of the functional _component (10).