Abstract
A method and a device may be used to assemble an adjustable camshaft that includes a shaft segment with an inner shaft that extends concentrically through a through-hole of an outer shaft. The method may involve prepositioning the inner shaft by at least partially introducing the inner shaft eccentrically into the through-hole of the outer shaft. The method may further involve introducing a positioning element in an introduction direction through a first outer shaft hole formed in a peripheral wall of the outer shaft, through an inner shaft hole that extends orthogonally to a longitudinal axis of the inner shaft, and through a second outer shaft hole formed in a peripheral wall of the outer shaft such that the positioning element projects out of the second outer shaft hole. Further, the inner shaft may be finally positioned, wherein the positioning element is moved counter to the introduction direction such that the inner shaft is orientated concentrically inside the through-hole of the outer shaft.
Claims
1.-11. (canceled)
12. A method for assembling an adjustable camshaft that includes a shaft segment with an outer shaft and an inner shaft that extends concentrically through a through-hole of the outer shaft, the method comprising: prepositioning the inner shaft such that the inner shaft is at least partially introduced eccentrically into the through-hole of the outer shaft; introducing a positioning element in an introduction direction through a first outer shaft hole formed in a peripheral wall of the outer shaft, through an inner shaft hole that extends orthogonally to a longitudinal axis of the inner shaft, and through a second outer shaft hole formed in the peripheral wall of the outer shaft, such that the positioning element projects out of the second outer shaft hole; and finally positioning the inner shaft, wherein the positioning element is moved counter to the introduction direction such that the inner shaft is oriented concentrically inside the through-hole of the outer shaft.
13. The method of claim 12 comprising pushing the positioning element out of the shaft segment at least by a magnitude of half of a maximum possible play in the introduction direction.
14. The method of claim 12 comprising moving the positioning element into the shaft segment by less than a magnitude of half of a maximum possible play counter to the introduction direction.
15. The method of claim 12 comprising moving the positioning element into the shaft segment by more than a magnitude of half of a maximum possible play counter to the introduction direction.
16. The method of claim 12 comprising moving the positioning element into the shaft segment by a magnitude of half of a maximum possible play counter to the introduction direction.
17. The method of claim 12 comprising introducing an orientation element before introducing the positioning element, wherein the orientation element is introduced in the introduction direction at least through the first outer shaft hole and the inner shaft hole at least for an orientation of the first outer shaft hole relative to the inner shaft hole.
18. The method of claim 17 comprising introducing the orientation element at least partially into the second outer shaft hole.
19. The method of claim 17 comprising moving the orientation element counter to the introduction direction out of the shaft segment.
20. The method of claim 20 comprising moving the orientation element in the introduction direction out of the shaft segment.
21. The method of claim 12 comprising introducing an orientation element before introducing the positioning element, wherein the orientation element is introduced counter to the introduction direction at least through the second outer shaft hole and the inner shaft hole at least for an orientation of the second outer shaft hole relative to the inner shaft hole.
22. The method of claim 21 comprising introducing the orientation element at least partially into the first outer shaft hole.
23. The method of claim 21 comprising moving the orientation element counter to the introduction direction out of the shaft segment.
24. The method of claim 21 comprising moving the orientation element in the introduction direction out of the shaft segment.
25. The method of claim 12 comprising positioning a fixing element on the outer shaft such that a fixing element hole that extends through a peripheral wall of the fixing element is aligned with at least one of the first outer shaft hole or the second outer shaft hole.
26. A device for assembling an adjustable camshaft having a shaft segment that comprises an outer shaft and an inner shaft that extends concentrically through a through-hole of the outer shaft, the device comprising: a first arrangement segment for prepositioning the inner shaft inside the through-hole of the outer shaft such that the inner shaft is positioned eccentrically relative to the outer shaft, wherein the first arrangement segment comprises a recess for receiving a portion of a positioning element projecting at least out of the shaft segment, wherein the positioning element is at least partially introduced through the shaft segment; and a second arrangement segment for finally positioning the inner shaft inside the through-hole of the outer shaft such that the inner shaft is positioned concentrically relative to the outer shaft, wherein the second arrangement segment comprises a contacting means for introducing the positioning element at least into the shaft segment, wherein each of the first and second arrangement segments comprises a retention means that positions the outer shaft or a fixing element that is positionable on the outer shaft.
Description
[0022] The method according to the invention and the device according to the invention for assembling an adjustable camshaft are explained in greater detail below with reference to drawings. In the schematic drawings:
[0023] FIG. 1 is a cross-section of an embodiment of an adjustable camshaft arranged in an embodiment of a device for assembling the adjustable camshaft in the assembly step of the prepositioning of the inner shaft inside the through-hole of the outer shaft,
[0024] FIG. 2 is a cross-section of the embodiment shown in FIG. 1 of an adjustable camshaft during the introduction of an orientation element,
[0025] FIG. 3 is a cross-section of the embodiment of an adjustable camshaft as shown in FIGS. 1 and 2 during the introduction of a positioning element,
[0026] FIG. 4 is a cross-section of the embodiment of an adjustable camshaft as shown in FIGS. 1 to 3 during the final positioning of the inner shaft relative to the outer shaft,
[0027] FIG. 5 shows the embodiment of an adjustable camshaft as shown in FIGS. 1 to 4 after the assembly has been carried out according to the method according to the invention,
[0028] FIG. 6 is a lateral section of a cutout of an additional embodiment of an adjustable camshaft with an orientation element which is introduced counter to the introduction direction,
[0029] FIG. 7 is a lateral section of a cutout of the embodiment shown in FIG. 6 of an adjustable camshaft with an orientation element which is introduced in the introduction direction,
[0030] FIG. 8 is a lateral section of a cutout of the embodiment shown in FIGS. 6 and 7 of an adjustable camshaft with a positioning element which is introduced in the introduction direction,
[0031] FIG. 9 is a lateral section of a cutout of the embodiment shown in FIGS. 6 to 8 of an adjustable camshaft with a finally positioned inner shaft,
[0032] FIG. 10 is a lateral section of a cutout of an additional embodiment of an adjustable camshaft with an orientation element which is introduced in the introduction direction,
[0033] FIG. 11 is a lateral section of a cutout of the embodiment shown in FIG. 10 of an adjustable camshaft with a positioning element which is introduced in the introduction direction, and
[0034] FIG. 12 is a lateral section of a cutout of the embodiment shown in FIGS. 10 and 11 of an adjustable camshaft with a finally positioned inner shaft.
[0035] Elements having the same function and operation are referred to in FIGS. 1 to 12 with the same reference numerals.
[0036] FIG. 1 is a cross-section of an embodiment of an adjustable camshaft 1, having an outer shaft 3 and an inner shaft 4 which extends through the through-hole 3.1 of the outer shaft 3. The inner shaft 4 is arranged eccentrically relative to the outer shaft 3, in particular inside the through-hole 3.1 thereof. The inner shaft 4 comprises an inner shaft hole 4.1. The outer shaft 3 comprises a first outer shaft hole 3.2 and a second outer shaft hole 3.3. The embodiment of the adjustable camshaft 1 shown in FIG. 1 further comprises a fixing element 5. The fixing element 5 is advantageously constructed to be annular, in particular in a sleeve-like manner. The outer shaft 3 and the inner shaft 4 extend through the fixing element 5, in particular through a through-hole of the fixing element 5. Advantageously, the fixing element 5, the outer shaft 3 and the inner shaft 4 comprise, after the final assembly has been carried out, a common longitudinal center axis, as shown in particular in FIG. 5 described below. The shaft segment 2 advantageously comprises the outer shaft 3 and the inner shaft 4. The shaft segment 2 or the camshaft 1 is arranged in a device 20 for assembling a camshaft 1 which may also be referred to below as a tool 20.
[0037] The embodiment shown in FIG. 1 of a device 20 for assembling an adjustable camshaft 1 comprises a first arrangement segment 21. The first arrangement segment 21 comprises a retention means 21.1 and a recess 21.2. The retention means 21.1 is according to the embodiment shown in FIG. 1 in the form of a recess and corresponds to the geometrical shape of the camshaft 1 so that the camshaft 1 or in particular the fixing element 5 is retained by the retention means 21.1 at least over a peripheral portion. The fixing element 5 comprises a first fixing element hole 5.1 and a second fixing element hole 5.2. The fixing element holes 5.1 and 5.2 are advantageously constructed in alignment with each other. Similarly, the outer shaft holes 3.2 and 3.3 are advantageously constructed in alignment with each other. When the inner shaft 4 is prepositioned inside the through-hole 3.1 in the outer shaft 3, the inner shaft 4 is advantageously arranged in the through-hole 3.1 in such a manner that the inner shaft hole 4.1 extends from one of the outer shaft holes 3.2 or 3.3 to another of the outer shaft holes 3.3 or 3.2 of the outer shaft 3. Advantageously, the fixing element 5 is arranged on the outer shaft 3 in such a manner that one of the fixing element holes 5.1 or 5.2 is orientated congruently relative to one of the outer shaft holes 3.2 or 3.3, respectively. Advantageously, the entire camshaft 1 is inserted in the device 20 or gripped by the device 20 in such a manner that the holes, such as the fixing element holes 5.1 or 5.2, the outer shaft hole 3.2 or 3.3 and the inner shaft hole 4.1, are arranged or orientated in alignment with the recess 21.2 of the device 20 or the first arrangement segment 21 of the device 20.
[0038] It is conceivable for the holes, in particular the inner shaft hole 4.1 and/or the outer shaft hole 3.2 or 3.3 and/or the fixing element holes 5.1 or 5.2, to comprise inclined introduction members or chamfers in order to make it easier to introduce an orientation element 30 which is shown in FIG. 2 and/or a positioning element 10 which is shown in FIG. 3 into the camshaft 1 or into the shaft segment 2.
[0039] FIG. 2 is a cross-section of the embodiment shown in FIG. 1 of an adjustable camshaft 1 during the introduction of an orientation element 30. The orientation element 30 which is advantageously in the form of a pin element is introduced in an introduction direction E into the shaft segment 2, in particular into the camshaft 1. In this instance, the orientation element 30 is introduced starting from a first fixing element hole 5.1, as shown in FIG. 1, at least through a first outer shaft hole 3.2 of the outer shaft 3 into the inner shaft hole 4.1 of the inner shaft 4. It is further conceivable for the orientation element 30 to be introduced into the shaft segment 2 or the camshaft 1 to such an extent that it also at least partially extends through the second outer shaft hole 3.3 and advantageously also the second fixing element hole 5.2 of the fixing element 5.
[0040] FIG. 3 is a cross-section of the embodiment of the adjustable camshaft 1 as shown in FIGS. 1 and 2 during the assembly process of introduction of a positioning element 10. The positioning element 10 is advantageously introduced in the introduction direction E into the camshaft 1 or the shaft segment 2. For this purpose, it is necessary for the orientation element 30 shown in FIG. 2 again to be moved or pulled out of the camshaft 1 or the shaft segment 2. The withdrawal of the orientation element 30 shown in FIG. 2 is advantageously carried out counter to the introduction direction E. The positioning element 10 is advantageously introduced into the camshaft 1 or the shaft segment 2 to such an extent that it contacts the recess 21.2 of the first arrangement segment 21 of the device 20. The recess 21.2 advantageously has a depth which substantially has the magnitude of half of the maximum possible play which exists between the inner shaft and the outer shaft. Consequently, the positioning element 10 is advantageously pushed through the shaft segment 2 or the camshaft 1 to such an extent that it projects out of the shaft segment 2 or the camshaft 1 by the magnitude of half of the maximum possible play.
[0041] FIG. 4 is a cross-section of the embodiment of an adjustable camshaft 1 as shown in FIGS. 1 to 3 during the assembly step of the final positioning of the inner shaft 4. For this purpose, the camshaft 1 or the shaft segment 2 is rotated through 180 about the central rotation axis thereof so that the shaft segment 2 or the camshaft 1 can be received in a support segment 23 of the device 20 with the side which corresponds to the side in which the positioning element 10 has been introduced into the camshaft 1 or the shaft segment 2. The support segment 23 is either advantageously an independent element of the device 20 or the tool 20 for assembling an adjustable camshaft 1 or a component of the second arrangement segment 22. The second arrangement segment 22 comprises a contacting means 22.2 and a retention means 22.1. FIG. 4 shows an embodiment of the second arrangement segment 22, in which the retention means 22.1 and the contacting means 22.2 are constructed without any transition in the form of a recess. The recess advantageously comprises a geometrical shaping comparable with the outer periphery of the fixing element 5, in particular the camshaft 1 which comprises the fixing element 5 in order to at least partially contact or surround it. However, it is also conceivable for the retention means 22.1 to be constructed in the form of retention projections, retention webs or comparable retention means while the contacting means 22.2 is constructed, for example, in the form of a projection or a material hardening or surface roughening, etc. It is possible by means of the contacting means 22.2 of the second arrangement element 22 to push back the positioning element 10 counter to the introduction direction E into the shaft segment 2, in particular into the camshaft 1, advantageously by half of the maximum possible play, but in particular by the length with which it projects out of the shaft segment 2, in particular the camshaft 1. For this purpose, the second arrangement segment 22 is applied counter to the introduction direction E to the shaft segment 2, in particular the camshaft 1, in such a manner that the contacting means 22.2 contacts the end of the positioning element 10 projecting out of the shaft segment 2 or the camshaft 1. When a corresponding pressing force is applied, it is possible to push back or move the positioning element 10 counter to the introduction direction E by means of the contacting means 22.2 of the second arrangement segment 22.
[0042] FIG. 5 shows the final positioning of the inner shaft 4 inside the through-hole 3.1 of the outer shaft 3. In this instance, the inner shaft 4 is arranged concentrically relative to the outer shaft 3 and advantageously also concentrically relative to the fixing element 5. The positioning element 10 is advantageously arranged completely inside the camshaft 1. Consequently, the positioning element 10 advantageously does not project out of the shaft segment 2 or the camshaft 1 at any of the sides any longer.
[0043] FIG. 6 is a lateral section of a cutout of an additional embodiment of an adjustable camshaft 1. The adjustable camshaft 1 comprises, in addition to the outer shaft 3 and the inner shaft 4, a fixing element 5 in the form of a collared cam 6 or a collared cam element 6. The collared cam element 6 comprises a cam collar 6.1 and two cam paths, that is to say, a first cam path 6.2 and a second cam path 6.3. A collared cam hole 6.4 extends through the cam collar 6.1. Advantageously, the collared cam hole 6.4 is arranged in alignment with the outer shaft hole which is not illustrated here during the operation of prepositioning the inner shaft 4. In the assembly step shown in FIG. 6, an orientation element 30 is introduced counter to the introduction direction E in the movement direction B into the camshaft 1. In this case, the orientation element 30 extends through the collared cam element 6 and the shaft segment 2 of the camshaft 1 extends through the holes of the individual elements or segments which are advantageously orientated in alignment with each other.
[0044] As shown in FIG. 7, it is also conceivable for the orientation element 30 to be moved in a movement direction B which corresponds to the introduction direction E. This means that the orientation element 30 is pushed or introduced in the introduction direction E into the camshaft 1 and in particular into the shaft segment 2 of the camshaft 1 through the corresponding holes in order to allow an orientation of the fixing element 5 or the fixing element 5 in the form of a collared cam element 6 relative to the outer shaft 3 and the inner shaft 4. Advantageously, the embodiment of the cam element 1 of FIG. 7 corresponds to the embodiment of the camshaft 1 shown in FIG. 6 so that reference may be made to the description of FIG. 6 with regard to the configuration of the camshaft 1.
[0045] FIG. 8 is a lateral section of a cutout of the embodiment shown in FIGS. 6 and 7 of an adjustable camshaft 1. In FIG. 8, instead of an orientation element 30, a positioning element 10 is introduced into the holes of the camshaft 1, in particular the holes of the collared cam elements 6, the outer shaft 3 and the inner shaft 4. The positioning element 10 has advantageously been pushed through the holes of the camshaft 1 in the introduction direction E to such an extent that it extends or projects out of the camshaft 1 at least at one side thereof. The inner shaft 4 is further arranged eccentrically relative to the outer shaft 3 in this method step for assembling an adjustable camshaft 1. The positioning of the inner shaft 4 is carried out in an additional subsequent assembly step, in which the inner shaft 4 is orientated concentrically relative to the outer shaft 3. This is particularly illustrated in FIG. 9.
[0046] According to the illustration of FIG. 9, the positioning element 10 has been moved back counter to the introduction direction E by the amount by which the positioning element 10 projects out of the camshaft 1. Advantageously, this corresponds to the magnitude of half of the maximum possible play. By the positioning element 10 being moved back counter to the introduction direction E, as a result of the existing static friction force between the outer surface of the positioning element 10 which is advantageously constructed as a pin element and the surface of the inner shaft hole 4.1 (not shown) of the inner shaft 4, a joint movement of the inner shaft 4 counter to the introduction direction E is also allowed advantageously by half of the maximum possible play. After the final positioning of the inner shaft 4 has been carried out within the outer shaft 3, the positioning element 10 is advantageously also located inside the shaft segment 10 or inside the camshaft 1 in such a manner that it does not project or protrude at any of the sides.
[0047] FIGS. 10 to 12 are lateral sections of a cutout of an additional embodiment of an adjustable camshaft 1. The adjustable camshaft 1 does not comprise, unlike the embodiment shown in FIGS. 6 to 9 of an adjustable camshaft 1, any collared cam element 6 but instead a simple cam element 7 which is consequently used inter alia as a fixing element 5. The cam element 7 comprises a first cam path 7.1 and a second cam path 7.2. A cam element hole 7.3 extends at least partially in the cam element 7. FIG. 10 shows in a first assembly step for producing an adjustable camshaft 1 the introduction of an orientation element 30 which extends through the cam element hole 7.3 and the outer shaft hole 3.2 and 3.3 (not shown here) and the inner shaft hole 4.1 (not shown here). The movement direction B of the orientation element 30 corresponds in this instance to the introduction direction E. Advantageously the orientation element 30 extends through all the holes of the camshaft 1 in order to allow the cam element 7 to be orientated relative to the outer shaft 3 and relative to the inner shaft 4 or the individual elements to be orientated relative to each other. After the orientation element 30 has been moved counter to the introduction direction E out of the cam element 1, a positioning element 10 is introduced in an introduction direction E into the holes of the cam element 7, the outer shaft 3 and the inner shaft 4 in an introduction direction E, which holes are orientated in a mutually aligned manner. This is shown in particular in FIG. 11. Advantageously, the positioning element 10 is at least partially pushed in this instance through the shaft segment 2 into the cam element hole 7.3. Advantageously, the positioning element 10 is pushed as far into the cam element hole 7.3 until a first distal end 10.1 of the positioning element 10 contacts an end wall of the cam element hole 7.3 which is in the form of a blind hole.
[0048] For the final positioning of the inner shaft 4, as shown in FIG. 12, the positioning element 10 is moved counter to the introduction direction E, advantageously by the magnitude of half of the maximum possible play, so that the inner shaft 4 is also moved counter to the introduction direction E as a result of the static friction force which exists between the outer surface of the positioning element 10 and the surface of the inner shaft hole of the inner shaft 4. As shown in FIG. 12, a second distal end 10.2 of the positioning element 10 is located outside the camshaft 1 and consequently projects out of the camshaft 1. A desired breaking location 11 is used to remove this projecting positioning element piece. By means of this desired breaking location, the removal of the projecting distal end 10.2 of the positioning element 10 is advantageously facilitated. Advantageously, the desired breaking location 11 is also used to characterize the positioning element 10 with regard to the portion or region of the positioning element 10 which is intended to be pulled out of the camshaft 1 or the shaft segment 2. This means that the desired breaking location 11 is also used as a marking.
LIST OF REFERENCE NUMERALS
[0049] 1 Camshaft [0050] 2 Shaft segment [0051] 3 Outer shaft [0052] 3.1 Through-hole of the outer shaft [0053] 3.2 (First) outer shaft hole [0054] 3.3 (Second) outer shaft hole [0055] 4 Inner shaft [0056] 4.1 Inner shaft hole [0057] 5 Fixing element [0058] 5.1 (First) fixing element hole [0059] 5.2 (Second) fixing element hole [0060] 6 Collared cam element [0061] 6.1 Cam collar [0062] 6.2 First cam path [0063] 6.3 Second cam path [0064] 6.4 Collared cam hole [0065] 7 Cam element [0066] 7.1 First cam path [0067] 7.2 Second cam path [0068] 7.3 Cam element hole [0069] 10 Positioning element [0070] 10.1 First distal end of the positioning element [0071] 10.2 Second distal end of the positioning element [0072] 20 Device/tool [0073] 21 First arrangement segment [0074] 21.1 Retention means [0075] 21.2 Recess [0076] 22 Second arrangement segment [0077] 22.1 Retention means [0078] 22.2 Contacting means [0079] 23 Support segment [0080] B Movement direction [0081] E Introduction direction
