DEVICE FOR JOINTING A PLURALITY OF ELEMENTS ON A SHAFT

Abstract

A device for jointing a plurality of elements, each comprising a cutout for a shaft, in a predetermined angular position on the shaft, may include a traversable guide carriage configured to push the shaft from above through the cutouts of the elements. The device may also include an electrical spindle drive and a pneumatic piston for displacing the traversable guide carriage.

Claims

1. A device for jointing a plurality of elements, each having a cutout for a shaft, in a predetermined angular position on the shaft, comprising: a traversable guide carriage configured to push the shaft from above through the cutouts of the elements; and an electrical spindle drive and a pneumatic piston for displacing the traversable guide carriage.

2. The device according to claim 1, wherein: the pneumatic piston is in contact with an upper side of the traversable guide carriage and is configured to apply a maximum first press-in force on the traversable guide carriage; the electrical spindle drive includes at least two spindles, which penetrate the guide carriage and which each has a spindle head at an underside of the traversable guide carriage; and the electrical spindle drive serves as an end stop for the traversable guide carriage.

3. The device according to claim 1, wherein: the pneumatic piston is in contact with an upper side of the traversable guide carriage and is configured to apply a maximum first press-in force; the electrical spindle drive includes at least two spindles, which penetrate the traversable guide carriage and which each has a spindle head at an underside of the traversable guide carriage; and the traversable guide carriage includes stop contours in regions of the spindle heads of the at least two spindles, the stop contours being disposed spaced apart from the underside of the traversable guide carriage and on which the two spindles rest with their spindle heads if a second press-in force exceeds the first press-in force.

4. The device according to claim 2, further comprising at least two guide rods for guiding the traversable guide carriage, the guide rods running parallel to the at least two spindles and parallel to the pneumatic piston.

5. The device according to claim 4, further comprising at least one cross member, wherein the guide rods are fixedly connected to the traversable guide carriage and guided vertically in a displaceable manner in the at least one cross member.

6. The device according to claim 3, wherein the stop contours are one of hook contours and pots.

7. The device according to claim 1, further comprising a detection device configured to switch off the device if at least one of a maximum first press-in force is exceeded and if the traversable guide carriage does not reach an end position.

8. A method for jointing elements, each having a cutout, on a shaft by a device for producing a control shaft, comprising: disposing the elements vertically above one another, aligned, and fixed; pushing the shaft in vertically from above though the cutouts of the elements by a traversable guide carriage of the device; displacing by a pneumatic piston of the device the traversable guide carriage and the shaft attached thereto until a maximum first press-in force is reached; and further displacing by at least two spindles of an electric spindle drive of the device the traversable guide carriage and the shaft when the maximum first press-in force is exceeded.

9. The method according to claim 8, wherein: the pneumatic piston and the at least two spindles are moved uniformly until the maximum first press-in force is reached, wherein the at least two spindles do not exert any press-in force on the traversable guide carriage; and the at least two spindles continue to rotate when the maximum first press-in force is exceeded, so that respective spindle heads of the at least two spindles disengage from an underside of the traversable guide carriage.

10. The method according to claim 9, further comprising switching off the device by a detection device if at least one of the maximum first press-in force is exceeded and if the spindle heads are raised from the underside of the traversable guide carriage.

11. The method according to claim 9, wherein: a detection device does not switch off the device if at least one of the maximum first press-in force is exceeded an the spindle heads disengage from the underside of the traversable guide carriage, so that the at least two spindles continue to rotate until the spindle heads lie against respective stop contours of the traversable guide carriage in regions of the spindle heads and the at least two spindles, with their spindle heads, continue to press the traversable guide carriage via the stop contours up to at least one of a predefined maximum second press-in force and a predefined displacement path.

12. A method for jointing elements, each comprising a cutout, on a shaft by a device, for producing a control shaft, comprising: traversing at least two spindles of an electrical spindle drive of the device into a predefined end position; disposing the elements vertically above one another, aligned, and fixed; pushing the shaft in vertically from above through the cutouts of the elements by a traversable guide carriage, of the device; and displacing by a pneumatic piston of the device a guide carriage of the device and the shaft attached thereto until a maximum first press-in force is reached.

13. The device according to claim 2, wherein the traversable guide carriage includes a stop contour in a region of the two spindle heads, the stop contour being disposed spaced apart from the underside of the traversable guide carriage and on which the two spindles rest with their spindle heads if a second press-in force exceeds the first press-in force.

14. The device according to claim 13, wherein the stop contours are one of hook contours and pots.

15. The device according to claim 3, further comprising at least two guide rods for guiding the traversable guide carriage, the guide rods running parallel to the at least two spindles and parallel to the pneumatic piston.

16. The device according to claim 15, further comprising at least one cross member, wherein the guide rods are fixedly connected to the traversable guide carriage and guided vertically in a displaceable manner in the at least one cross member.

17. The device according to claim 16, wherein the stop contours are one of hook contours and pots.

18. The device according to claim 15, wherein the stop contours are one of hook contours and pots.

19. The device according to claim 2, further comprising a detection device configured to switch off the device if at least one of a maximum first press-in force is exceeded and if the traversable guide carriage does not reach an end position.

20. The device according to claim 3, further comprising a detection device configured to switch off the device if at least one of a maximum first press-in force is exceeded and if the traversable guide carriage does not reach an end position.

Description

[0018] Preferred examples of embodiment of the invention are represented in the drawings and will be explained in greater detail in the following description, wherein the same reference numbers relate to the same or similar or functionally identical components.

[0019] In the figures, in each case diagrammatically,

[0020] FIG. 1 shows a device according to the invention for jointing a plurality of functional elements, each comprising a cutout for a shaft, on the shaft in an initial position,

[0021] FIG. 2 shows a representation as in FIG. 1, but in a position in which the shaft is pushed at least partially into the functional elements and in which the guide carriage is displaced solely by means of a pneumatic piston,

[0022] FIG. 3 shows a representation as in FIG. 2, but with a jamming of the shaft on the functional elements,

[0023] FIG. 4 shows the device according to the invention in a state in which the shaft is displaced via the guide carriage solely by means of the spindle drive.

[0024] Corresponding to FIGS. 1 to 4, device 1 according to the invention for jointing a plurality of functional elements 4 each comprising a cutout 2 for a shaft 3, for example cams, balancing masses, gearwheels and/or bearings, in a predetermined angular position on shaft 3, comprises a traversable guide carriage 5 for shaft 3, by means of which shaft 3 can be pushed from above through cutouts 2 of functional elements 4 disposed vertically one above the other. According to the invention, an electrical spindle drive 6 and a pneumatic piston 7 are provided for displacing guide carriage 5 and therefore also for displacing shaft 3. Guide carriage 5 can thus be displaced optionally by means of pneumatic piston 7 or spindle drive 6.

[0025] In addition, at least two guide rods 8 are provided for guiding guide carriage 5, which run parallel to spindles 9 of spindle drive 6 and parallel to pneumatic piston 7. Guide rods 8 are fixedly connected to guide carriage 5 and are guided vertically in a displaceable manner in at least one, here two cross members 10 of device 1, said cross members being arranged one above the other, as a result of which particularly precise guidance of guide carriage 5 and therefore also particularly precise guidance of shaft 3 is enabled.

[0026] If guide carriage 5 of device 1 according to the invention is examined more closely, it can be seen that pneumatic piston 7 is in contact with an upper side 14 of guide carriage 5, wherein pneumatic piston 7 is also designed to apply a maximum first press-in force or insertion force. Electrical spindle drive 6 comprises an electric motor 11, by means of which the two spindles 9 of spindle drive 6 are driven. The two spindles 9 of spindle drive 6 penetrate guide carriage 5 and each comprise a spindle head 12 at an underside 13 of guide carriage 5. Guide carriage 5 itself comprises, in the region of the two spindle heads 12, in each case a stop contour 15, which is arranged spaced apart from underside 13 of guide carriage 5 and on which the two spindles 9 rest with their respective spindle heads 12 if a second press-in force exceeding the first press-in force is required. Stop contours 15 or the stops are constituted as hook contours or pots.

[0027] Generally, spindle heads 12 of spindles 9 can also serve as end stops, wherein in this case pneumatic piston 7 is in contact with an upper side 14 of guide carriage 5 and is designed to apply a maximum first press-in force onto guide carriage 5. Electrical spindle drive 6 comprises at least two spindles 9, which penetrate guide carriage 5 and each comprise a spindle head 12 at an underside 13 of guide carriage 5. Electrical spindle drive 6 can be traversed into a jointing end position and can serve as an end stop for guide carriage 5. In this case, stop contour 15 is of course not required. In this mode of operation, spindles 9 travel precisely to the subsequent end position and therefore ahead of pneumatic piston 7 and serve merely as an end stop. Guide carriage 5 does not therefore rest on spindle heads 12. Guide carriage 5 is driven forward solely by means of pneumatic piston 7 and is switched off as soon as it reaches the end stop defined by spindle heads 12 which have travelled ahead. At this time, the maximum press-in force at pneumatic piston 7 is exceeded. This is therefore a failsafe end stop which can be adjusted dynamically, e.g. if two camshafts (hood modules) lying beside one another are jointed one after the other and have different shaft end positions. The tolerance of the end position can thus also be tracked dynamically when there is a change (thermal expansions etc.) in the system.

[0028] In addition, a detection device 16 can be provided, which is constituted such that it switches off device 1 if the maximum first press-in force of pneumatic piston 7 is exceeded and/or if spindle heads 12 in spindle 9 disengage or are raised from underside 13 of guide carriage 5. This can be detected comparatively simply, for example by the opening of an electrical contact, whilst the maximum first press-in force can be monitored for example by means of a suitable sensor. Such a detection device 16 is particularly advantageous if only a thermal jointing of functional elements 4 on shaft 3 is to take place with device 1 according to the invention, for which only a comparatively small press-in force is usually required. If the maximum first press-in force required for this is exceeded, for example triggered by jamming of shaft 3 on one of function elements 4, as is represented in FIG. 3, this leads not only to the maximum first press-in force being exceeded, but also, due to the continuing rotation of the two spindles 9, to a raising of their spindle heads 12 from underside 13 of the guide carriage. The two effects can be monitored cumulatively or alternatively. Since such jamming of shaft 3 on functional elements 4 could lead to damage, detection device 16 in this case switches off device 1. Up to such jamming, a displacement of guide carriage 5 and therefore also a displacement of shaft 3 takes place solely by means of pneumatic piston 7, which is part of a pneumatic piston-cylinder unit, whilst spindles 9 of spindle drive 6 merely rotate uniformly at the same time without applying any force. In this case, therefore, spindle heads 12 of spindles 9 always lie against underside 13 of guide carriage 5, as is represented for example according to FIG. 2. The covered displacement path of spindles 9 and of pneumatic piston 7 must be identical.

[0029] In the situation represented according to FIG. 3, in which for example jamming of shaft 3 on one of functional elements 4 may be involved, detection device 16 can thus switch off device 1 in order to prevent damage. It is however also conceivable here that in this case it does not involve jamming, but that one of lower functional elements 4 is to be jointed, in addition to or as an alternative to thermal jointing, by means of a press-fit with shaft 3, for which greater forces are of course required. In this case, detection device 16 would not switch off device 1, so that spindles 9 continue to rotate until their spindle heads 12 lie against stop contours 15 (see FIG. 4) and, via said stop contours, can bring about a further introduction of force and a further displacement of shaft 3. Such a spindle drive 6 enables the application of much greater press-in forces than pneumatic piston 7. The jamming of shaft 3 or the reaching of functional element 4 to be jointed with a press-fit is denoted in FIG. 3 by a bold cross.

[0030] To guide shaft 3, use can of course also be made of a centring rod 17 with, for example, a centring tip 10, which is introduced into the usually tubular shaft 3.

[0031] With device 1 according to the invention, it is thus possible for the first time to create a hybrid device which, by means of two different drive systems, on the one hand that in pneumatic piston 7 and on the other hand in spindle drive 6, can bring about a displacement of guide carriage 5 with different press-in forces. The field of application of such a device 1 is therefore much broader than in the case of devices known hitherto from the prior art.