DE102013021391A1 - Method for manufacturing crankshaft, involves arranging interconnected shaft portions over separating point in which positioning element is introduced, by which shaft portions are positioned relative to each other - Google Patents

Abstract

The method involves assembling two separate shaft portions (18,20) at a separating point (24). The interconnected shaft portions are arranged over the separating point in which a positioning element is introduced, into which a receptacle (28) is extended, after the separation of the shaft portions in the assembly, by which the shaft portions are positioned relative to each other. The shaft portions are assembled and are extended over the separating point across receptacle, after the positioning element is introduced.

Description

The invention relates to a method for producing a shaft, in particular a crankshaft, according to the preamble of patent claim 1.

Such a method for producing a shaft, in particular a crankshaft, is for example the DE 10 2011 115 953 A1 and the DE 10 2011 115 954 A1 to be known as known. In this method, at least two separate shaft parts of the shaft are assembled at least one separation point. For this purpose, the shaft, in particular the crankshaft, fracture-separated at least one separation point to form the shaft parts. After the fracture separation, the shaft parts are assembled. Such a shaft, which comprises at least two composite shaft parts, is usually also referred to as a built-up shaft or as a built crankshaft. Such a shaft offers the advantage that one-piece bearings can be used to support the shaft.

The fracture separation offers the advantage that breaking fractures of the shaft produce respective fracture surfaces. In other words, a first of the shaft parts has a first fracture surface and the second shaft part has a second fracture surface. These fracture surfaces are unique, so that only these two fracture surfaces fit together. However, it has been found that such a built shaft, in particular crankshaft, has high tolerances in the assembled state.

Object of the present invention is therefore to develop a method for producing a shaft of the type mentioned in such a way that these tolerances can be kept very low in a simple and cost-effective manner.

This object is achieved by a shaft having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

In order to develop a method specified in the preamble of claim 1 type such that tolerances of a built shaft, especially a built crankshaft, keep particularly low in a particularly simple and cost-effective manner, it is provided according to the invention that the interconnected shaft parts with at least one be provided over the separation point away extending recording, in which after a separation of the shaft parts at least one positioning element is introduced, by means of which the shaft parts are positioned relative to each other during assembly. In other words, the shaft parts in an interconnected state, that is, before the shaft parts are separated from each other, provided with the receptacle. During subsequent assembly, the receptacle and the positioning element serve to align the shaft parts relative to each other.

Preferably, it is provided that the shaft is fracture-separated at the separation point to form the shaft parts. The shaft parts are assembled after the fracture separation, wherein the shaft is provided temporally before the fracture separation with the over the separation point away extending recording. In the recording, the positioning element is introduced after the fracture separation, by means of which the shaft parts are positioned relative to each other during assembly. This means that the shaft, in particular before the fracture separation or before the separation of the shaft parts, is provided with a receptacle such that the receptacle extends in the axial direction of the shaft both on this side and beyond the separation point. In other words, the shaft parts to be produced, for example, by fracture cutting or to be separated from one another are provided with the receptacle in the not yet separated, in particular fracture-separated, but still connected, in particular integrally formed with each other. A first part of the receptacle extends in a first of the shaft parts, with a second part of the receptacle extending in the second shaft part. If the shaft parts are separated from each other after the shaft has been fitted with the receptacle, in particular broken-apart, the receptacle is also divided into two parts.

Following this, it is possible, for example, to arrange the positioning element in one of the parts of the receptacle. Following this, the shaft parts are assembled or assembled in such a way that the positioning element is also arranged in the other part of the receptacle. In this way, the shaft parts can be aligned particularly accurately relative to each other in a position or in a position that have taken the shaft parts before the fracture separation. In other words, an exact recovery of the fracture surfaces of the shaft parts can be realized using the positioning element and the receptacle.

The invention is based on the finding that due to a usually missing alignment, a tangential and / or radial offset of the shaft parts can occur when these are assembled or assembled. As a result of such an offset connecting surfaces, in particular in Fracture fractures resulting fracture surfaces over which the shaft parts are assembled, not interlock.

By using the positioning element and the receptacle, however, a particularly exact alignment of the shaft parts relative to each other can be realized, so that a radial and / or tangential offset can be avoided or at least kept particularly low. As a result, the tolerances of the shaft can be kept very low.

In particular, it is possible by means of the positioning element and the corresponding receptacle to center the two shaft parts particularly precisely relative to each other and to assemble. As a result, for example, a particularly advantageous mounting of the shaft can be realized, so that upon a rotation of the shaft can be kept low on these loads acting. This leads to a high reliability of the shaft formed as a built shaft.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in:

1 a schematic and exploded perspective view of a shaft in the form of a built crankshaft having at least two fracture-separated shaft parts, which are positioned in the context of a production of the crankshaft by means of at least one positioning member and a corresponding receptacle relative to each other;

2 a detail of a schematic and perspective plan view of the recording of the crankshaft;

3 a schematic and perspective front view of one of the shaft parts, on which the positioning element is arranged; and

4 a section of a schematic and perspective side view of the shaft parts in their positioning by means of the positioning element and the recording.

1 shows a schematic and perspective side view of a shaft in the form of a built crankshaft 10 for a reciprocating internal combustion engine of a motor vehicle. The built crankshaft 10 has a plurality of shaft journals 12 on, about which the crankshaft 10 is rotatably mounted on a crankcase of the reciprocating internal combustion engine about an axis of rotation relative to the crankcase. The respective shaft journals 12 are over crank arms 14 and crankpin 16 connected with each other. At the respective crankpin 16 each connecting rod are hinged. Out 1 is also apparent that the built crankshaft 10 three shaft parts 18 . 20 and 22 includes.

As part of a production of the crankshaft 10 This is initially formed in one piece - for example, by forging. In other words, the shaft parts 18 . 20 and 22 initially formed integrally with each other. Subsequently, the crankshaft 10 under formation of the shaft parts 18 . 20 and 22 at respective interfaces 24 and 26 fracture-split. Due to the fracture separation are at the respective shaft parts 18 . 20 and 22 Fracture surfaces formed, of which in 1 one with 27 designated fracture surface of the shaft part 20 and one with 29 designated fracture surface of the shaft part 22 are recognizable. When fracture is also one with the fracture surface 27 corresponding fracture surface of the shaft part 18 educated. Furthermore, one with the fracture surface 29 corresponding fracture surface of the shaft part 20 educated. After the fracture separation, the shaft parts become 18 and 20 respectively 20 and 22 Assembled over the respective fracture surfaces, that is composed. Out 1 it can be seen that the separation points 24 and 26 at respective shaft journals 12 are provided.

Out 2 is the separation point 24 recognizable, at the initially integrally formed crankshaft 10 under formation of the shaft parts 18 and 20 is broken apart. Below is the procedure for making the crankshaft 10 the example of shaft parts 18 and 20 described. These designs can also be applied to the shaft parts 20 and 22 or their separation point 26 be transmitted.

According to 2 are the shaft parts 18 and 20 still integrally formed with each other. In other words, the crankshaft 10 in 2 shown in a state where the crankshaft 10 not yet broken. Before breaking the crankshaft 10 at the separation point 24 becomes the crankshaft 10 with one over the separation point 24 extending in the axial direction receiving in the form of a groove 28 Mistake. This means that the groove 28 in the axial direction both on this side and beyond the separation point 24 extends. In other words a part extends 30 the groove 28 in by fracture separation of the crankshaft 10 to be manufactured shaft part 20 , with a second part 32 the groove 28 in by fracture separation of the crankshaft 10 to be manufactured shaft part 18 extends.

Out 2 it can be seen that the in 2 recognizable shaft journals 12 through the fracture separation of the crankshaft 10 at the separation point 24 in two segments 34 . 36 is shared. The part 30 the groove 28 extends in the segment 36 while the part 32 the groove 28 in the segment 34 extends. Will the crankshaft 10 at the interface 24 fracture-separated, thus also the groove becomes 28 divided in two. The groove 28 For example, by mechanical processing, in particular by milling, in the shaft journal 12 be incorporated before the fracture separation.

3 shows the shaft part 20 after breaking the crankshaft 10 at the separation point 24 , Out 3 is also a rolling bearing 38 recognizable. By means of the rolling bearing 38 becomes the built crankshaft 10 rotatably mounted on the crankcase about the axis of rotation relative to the crankcase. The rolling bearing 38 includes a bearing inner ring 40 and a bearing outer ring corresponding thereto 42 as well as rolling elements 44 , which in the radial direction of the rolling bearing 38 between the bearing inner ring 40 and the bearing outer ring 42 are arranged. For example, the bearing inner ring 40 relative to the bearing outer ring 42 turned, so roll the rolling elements 44 on respective raceways of the bearing inner ring 40 and the bearing outer ring 42 from.

Out 3 It can also be seen that for connecting the shaft parts 18 . 20 together, a connecting element present in the form of a pin 46 is used. In the segment 36 of the shaft journal 12 For example, after the fracture separation, a first recess, for example a first bore, is introduced. In the segment 34 of the shaft journal 12 a second recess, in particular a second bore, is introduced. Out 3 is recognizable that the pin 46 Outside circumference has the shape of a straight circular cylinder.

The respective recesses have an inner contour, which with an outer contour of the pin 46 corresponds. The recesses are concentric with respective central axes of the segments 34 and 36 arranged. These central axes coincide with the axis of rotation of the crankshaft 10 together. The pencil 46 gets into the first recess of the segment 36 partially plugged in, leaving part of the pen 46 in the axial direction from the segment 36 protrudes.

When reassembling, that is when assembling or assembling the shaft parts 18 and 20 becomes the bearing inner ring 40 for positioning the shaft parts 18 . 20 used relative to each other in particular in the radial direction. For this purpose, the bearing inner ring 40 For example, the rolling bearing 38 , on the segment 36 plugged or mounted in the axial direction. Then the shaft part becomes 18 such on the shaft part 20 arranged that out of the segment 36 outstanding part of the congregation 46 in the second recess of the segment 34 is inserted. The segments 34 . 36 and thus the shaft parts 18 . 20 are doing radially over the bearing inner ring 40 aligned.

A tangential positioning is present by means of a positioning element in the form of a feather key 48 guaranteed. The feather key 48 will break into the groove after the break 28 introduced, wherein by means of the feather key 48 the shaft parts 18 . 20 be positioned relative to each other during assembly. As you can see, the groove is 28 eccentric to the axis of rotation and thus to the center axis of the shaft journal 12 arranged. In other words, the groove 28 spaced in the radial direction of the concentric with the axis of rotation or central axis recesses arranged.

For example, the feather key 48 before assembling the shaft parts 18 and 20 in the part 30 the groove 28 arranged, what made 3 is recognizable. This is only part of the key 48 in the part 30 the groove 28 arranged so that another part of the feather key 48 in the axial direction from the part 30 the groove 28 protrudes.

Then it will - like out 4 recognizable - the one from the segment 36 outstanding part of the congregation 46 in the second recess of the segment 34 inserted, whereby also from the part 30 the groove 28 in the axial direction outstanding part of the feather key 48 in the segment 34 provided part 32 the groove 28 is inserted. As a result, a particularly precise alignment of the shaft parts 18 . 20 relative to one another in a simple, time-consuming and cost-effective manner representable, so that the fracture separation surfaces of the shaft parts 18 and 20 find again and interlock exactly. This allows the tolerances of the crankshaft 10 be kept particularly low.

Alternatively or additionally, it is conceivable that a receptacle whose function of the groove 28 corresponds, in an inner diameter or inner circumference of the crankshaft 10 For example, in the respective recesses, for receiving the pen 46 is provided. In this case, it is then provided, for example, that a positioning element which performs the function of the feather key 48 has, on the connecting element (pin 46 ) is provided.

Out 3 is recognizable that the feather key 48 also in a corresponding recess in the form of a groove 50 of the bearing inner ring 40 engages, leaving the feather key 48 not only form-fitting with the segments 34 and 36 , but also form-fitting with the bearing inner ring 40 can interact. Out 2 it can be seen that the groove 28 in an outer peripheral side surface of the crankshaft 10 , in particular of the shaft journal 12 , is provided and in the radial direction of the crankshaft 10 is open to the outside.

In addition, it is preferably provided that the feather key 48 (Positioning element) to the bearing inner ring 40 is arranged or arranged so that the feather key 48 on the bearing inner ring 40 is held. In other words, it is preferably provided that the feather key 48 with the bearing inner ring 40 is provided as an assembly, so that the attachment of the bearing inner ring 40 on the segment 36 with the insertion of the feather key 48 in the part 30 the groove 28 at the same time. By providing the bearing inner ring 40 with the feather key 48 As assembly, a particularly simple handling can be realized.

It can be provided that the feather key 48 and the bearing inner ring 40 are integrally formed with each other. Alternatively, it is provided that the feather key 48 and the bearing inner ring 40 are formed as separately formed and interconnected components. The feather key 48 For example, with an overlap, that is by means of a press fit, on the bearing inner ring 40 fastened, especially in the groove 50 at least partially arranged. Alternatively, it is conceivable, the feather key 48 after the assembly of the bearing inner ring 40 on the segment 36 in the part 30 the groove 28 to assemble.

The basis of 1 to 4 described assembly principle of shaft parts 18 . 20 can be used not only for break-separated shafts, but also for other, two components to be assembled shaft comprehensive waves. This may be, for example, a so-called Hirth wave, in which two shaft parts are assembled via respective toothings arranged on axial end faces, in particular Hirth toothings.

LIST OF REFERENCE NUMBERS

10

crankshaft

12

shaft journal

14

crank web

16

crank pins

18

shaft part

20

shaft part

22

shaft part

24

separation point

26

separation point

27

fracture surface

28

groove

29

fracture surface

30

part

32

part

34

segment

36

segment

38

roller bearing

40

Bearing inner ring

42

Bearing outer ring

44

rolling elements

46

pen

48

Adjusting spring

50

groove

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011115953 A1 [0002]
• DE 102011115954 A1 [0002]

Claims (6)

Method for producing a shaft, in particular a crankshaft ( 10 ), wherein at least two separate shaft parts ( 18 . 20 ) of the shaft at at least one separation point ( 24 ), characterized in that the interconnected shaft parts ( 18 . 20 ) with at least one via the separation point ( 24 ) extending record ( 28 ) into which, after a separation of the shaft parts ( 18 . 20 ) at least one positioning element ( 48 ) is introduced, by means of which the shaft parts ( 18 . 20 ) are positioned relative to each other during assembly. A method according to claim 1, characterized in that the shaft at the separation point ( 24 ) with formation of the shaft parts ( 18 . 20 ), which are assembled after the fracture separation, wherein the wave before the fracture separation with the on the separation point ( 24 ) extending record ( 28 ) into which, after fracture separation, the positioning element ( 48 ) is introduced, by means of which the shaft parts ( 18 . 20 ) are positioned relative to each other during assembly. Method according to claim 1 or 2, characterized in that the receptacle ( 28 ) is provided in an outer peripheral side surface of the shaft and is open in the radial direction of the shaft to the outside. Method according to one of the preceding claims, characterized in that the positioning element ( 48 ) on a bearing inner ring ( 40 ) of a rolling bearing ( 38 ), wherein the bearing inner ring ( 40 ) on one of the shaft parts ( 18 . 20 ) is arranged. Method according to one of the preceding claims, characterized in that the positioning element ( 48 ) with a fit, in particular a press fit, in the receptacle ( 28 ) is arranged. Method according to one of the preceding claims, characterized in that the interconnected shaft parts ( 18 . 20 ) with at least one via the separation point ( 24 ) and from recording ( 28 ) spaced, second receptacle are provided, in which after the separation of the shaft parts ( 18 . 20 ) at least one second positioning element ( 46 ) is introduced, by means of which the shaft parts ( 18 . 20 ) are positioned relative to each other during assembly.

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