WO2004056553A1

WO2004056553A1 - Method for producing a shaft and a shaft produced according to this production method

Info

Publication number: WO2004056553A1
Application number: PCT/EP2003/012979
Authority: WO
Inventors: Helmut Kirmsze; Peter Meusburger
Original assignee: Thyssenkrupp Automotive Ag
Priority date: 2002-12-19
Filing date: 2003-11-20
Publication date: 2004-07-08
Also published as: DE10260115B4; DE10260115A1; AU2003283416A1

Abstract

The invention relates to a method for producing a shaft, particularly a camshaft, crankshaft or transmission shaft by producing a tubular base body (1) from a carbon fiber composite material (CFK) and by indirectly or directly placing it in work-connection with at least one functional element, particularly a cam (7) or a drive element. The invention also relates to a shaft, particularly a camshaft, crankshaft or transmission shaft, comprised of a tubular base body (1) consisting of a carbon fiber composite material and of at least one functional element, particularly a cam (7) or drive element, that is indirectly or directly connected thereto.

Description

Method for producing a shaft and shaft produced using this production method

description

The invention relates to a method for producing a shaft with torque-transmitting structural elements, in particular a camshaft, crankshaft or transmission shaft.

EP-B 0 290 758 shows a hollow shaft with torque-transmitting structural elements, such as gear wheels, curves, cams or the like, of which at least one structural element has a non-circular opening for placement on an output pipe with essentially the same wall thickness and each with at least one support body between the output tube and each construction element with a non-circular opening, the output tube being expanded for internal and non-positive connection to the construction elements by internal pressure such that the output tube with a portion of its circumference on the inner wall of the construction elements with at least another portion of its circumference the outer wall of the support body rests. The output pipe can be a metallic or non-metallic material, possibly a laminate material or a fiber-reinforced material made of different materials.

EP-B 0 303 845 shows a hollow shaft, consisting of a tube and of torque-transmitting construction elements, with a Opening for placement on the tube and support bodies, the connection between tube, construction element and support bodies being produced by reducing the space between the tube and construction element, the construction element and tube being connected to one another in a force-fitting and / or form-fitting manner and also at least in the opening of the construction element a support body is arranged and the tubular part partially abuts the support body. The tube can be formed from a metallic or non-metallic material, a laminate material or a fiber-reinforced material from various materials.

In these two publications, the choice of material is incomprehensible and even a person skilled in the art cannot readily see how he should select such materials in such a way that they spring back so little after a radial expansion of the tube that a permanent tight fit is ensured after the internal pressure has been released , This is further exacerbated by the considerable temperature fluctuations, particularly when using an internal combustion engine.

EP-B 0 826 476 shows a process for producing a plastic camshaft with a tubular metal insert, a tube made of steel being encased in plastic. The covering also includes the finished cams. However, the requirements for wear resistance and strength of the cams can hardly be met with conventional plastics. Furthermore, plastics have to be found which on the one hand can be thermoformed / injection molded and on the other hand meet the high demands on the cams over a wide temperature range.

From EP-B 0 328 009 a built shaft, in particular camshaft, crankshaft or transmission shaft, is known, formed by a pipe body and individually pushed-on drive elements, which are essentially non-positively fixed, wherein a sleeve with a larger diameter than the tubular body and guided on the tubular body, reduced diameter collar regions is pushed between two drive elements, the collar regions extending under the drive elements and between the tubular body and drive elements are clamped essentially non-positively. The tubular body and possibly also the support sleeves can be made of steel. The drive elements, in particular control cams, should be made of cast material. The intermediate sleeve can be formed from steel, aluminum, titanium or carbon fiber composite materials, in each case exclusively or in combination with one another or in combination with plastic.

The invention is based, to further reduce the weight of built shafts, in particular camshafts, crankshafts or gear shafts, to provide a manufacturing method and a shaft produced thereafter, which is simple in design and, moreover, the greatest possible freedom in the selection the connection of the functional elements with the shaft.

This object is achieved by a method for producing a shaft with the features of claim 1.

Advantageous developments of the method according to the invention can be found in the associated subclaims.

This object is also achieved by a shaft with the features of claim 20.

In the course of the production of the tubular base body, a metal sleeve or, if necessary, the same is inserted at predeterminable locations on the tube Functional element, such as a cam, is provided. The fixation of the functional elements when using a metal sleeve can be produced by manufacturing techniques such as pipe widening, for example by internal high-pressure forming, or rolling / knurling or pressing, welding, in particular laser beam welding, or the like.

The lamination is carried out either by pultrusion (strand drawing process) for fiber directions in the longitudinal direction or by winding techniques for fiber directions in the circumferential direction. According to a further idea of the invention, the winding techniques can be program-controlled, so that different angles and fiber densities can be set.

Different approaches to solutions can be defined with the method according to the invention:

In general, the sleeves can be attached by lamination. There are various aspects to consider when laminating:

The notch effect on the CFRP tube can be kept low by appropriately designing the metal sleeve (rounding off the peripheral edge at the base of the sleeve).

The tube is laminated gradually in the longitudinal and circumferential directions. When laminating in the circumferential direction, specific angles of the fibers to the tube axis are also optionally set. As a result, the various loads acting on the shaft from different directions can be optimally absorbed.

The following procedure for lamination is advantageous:

The tube is laminated lengthways. If required, one or two layers with a fiber direction of, for example, 45 ° to the tube axis are then laminated on.

The necessary number of metal sleeves is pushed over the pipe and positioned at the points necessary for fastening.

The second or simply a further layer is laminated in the circumferential direction, with the sleeves being quasi partially wrapped.

For this purpose, circumferential and diagonally extending depressions / grooves are provided in the sleeves.

The lamination takes place in the recesses of the sleeve in such a way that the fibers do not protrude beyond the circumference of the metal sleeve, so that the surface of the sleeve is available for joining operations, for example for receiving cams. It is particularly important to ensure that the fibers are not damaged during the entire subsequent joining process. To fix the functional components, the sleeve can then be widened by rolling or knurling. In this case, the fibers must be embedded so deeply in the recesses of the sleeve that they are not damaged by the roller rollers.

Another approach is to fix the sleeves by pressing the sleeves pushed onto the laminated tube:

The lamination is done as indicated above. The tube is laminated lengthways.

If necessary, one or two layers are then laminated on, with a fiber direction of, for example, 45 ° to the tube axis.

The outside of the tube on which the sleeves are to be attached is laminated in the circumferential direction. Otherwise the fibers could be cut, which would reduce the strength of the shaft.

Then the necessary number of metal sleeves is pushed over the pipe and positioned at the locations provided for fastening.

The pressing can take place, for example, by magnetic forming. At least one magnetic coil is pushed over the sleeve (possibly several at the same time) and activated for a predefinable period.

The pressing can alternatively be carried out directly by rolling / rolling the sleeve, for example at the edge area or even at the edge area of the cam.

Due to the possibly program-controlled winding technology, a special surface can be created in the pipe, which improves the positive locking of the subsequent joining.

In a further approach, the respective finished functional element, for example a cam, can be directly applied to the fiber composite technology provided tube pushed and attached to it, for example, by magnetic forming.

To improve the quality of the fastening, the fibers of the tube can optionally be wound in the circumferential direction in such a way that a surface profile is created in the longitudinal direction, which improves the shaping of the metal sleeve. Likewise, a contour / engraving can be worked into the inside of the metal sleeve. Possibly only on the sides protruding frets of the components are attached to the tube by the magnetic forming.

All of the above procedures can also be carried out in such a way that the metal sleeve is arranged inside the tube. As a result, end pins or end pieces on which e.g. Drive wheels are attached to the shaft using the joining techniques known for steel pipes. For example, the classic connection can be achieved by simply pressing in, which is hardly possible with plastics.

The subject matter of the invention is illustrated using various exemplary embodiments and is described as follows. Show it:

Figure 1 shaft with laminated metal sleeve;

Figure 2 shaft with laminated metal sleeve and applied

Rolling in preparation for a joining operation;

Figure 3 shaft with a laminated metal sleeve and joined functional element;

FIGS. 4 and 5 basic sketches for producing a CFRP base body with a laminated metal sleeve; FIG. 6 basic sketch of a CFRP base body with a slid-on

Metal shell;

FIG. 7 basic sketch of a joining process between a CFRP

Base body and a metal sleeve;

Figures 8 and 9 alternative connection method between a CFRP base body and a metal sleeve.

Figures 1, 2 and 3 show the assembly sequence for a preferred embodiment of the invention using the example of the assembly of camshafts.

FIG. 1 shows a metal sleeve 2 which is laminated in a tubular base body 1 formed from a carbon fiber composite material (CFRP). So that the carbon fiber is not damaged during the subsequent operation, the sleeve in the joining area 3 for the functional element is free of the carbon fiber. The remaining areas, at least the collar areas 4 and 5, are surrounded by laminate. When laminating, it should be noted that the metal sleeve 2 is designed in such a way that the notch effect is kept low. Sharp edges should always be avoided so that the fibers are not damaged during operation.

The curling 6 applied to the metal sleeve 2 can be seen in FIG. The curling 6 partially expands the metal sleeve 2 to such an extent that it projects beyond the inner opening of a functional element to be joined.

In the further assembly sequence, as shown in FIG. 3, a functional element, here a cam 7, is pressed over the metal sleeve 2, which was designed to be rolled in the joining area 3. The material displacement caused by the rolling process causes the metal sleeve 2 to expand. The diameter of the metal sleeve 2 expanded in the joining area 3 projects beyond the inner diameter. Knife of the opening in the cam 7. By pushing the cam 7 is pressed with the metal sleeve 2. This creates a force and - depending on the shape of the opening - a positive connection between the metal sleeve 2 and cam 7 and thus with the base body 1st

Due to the subsequent widening of the joining area 3 of the metal sleeve 2, the cams 7 can be pushed over the entire pipe length and over several metal sleeves without problems before they are pressed at the actual joining point. If several widened metal sleeves 2 were already used, the cam 7 would not be able to be pushed so easily to the intended joint.

Instead of the joining method presented in FIGS. 1 to 3, the rolling process can also be dispensed with. The cam 7 is then pushed over the metal sleeve 2 and fixed by another known joining method. For example, welding with laser welding can also be used here.

In this case, the metal sleeve 2 and the associated opening in the cam 7 must be designed accordingly.

FIG. 3 shows a possibility for increasing the connection strength between the metal sleeve 2 and the base body 1. For this purpose, the collar 4, 5 of the metal sleeve 2 can be provided on its end face 8 with tongues 9, 10 bent in opposite directions in the circumferential direction.

FIG. 4 shows a basic sketch of a basic body 1, in this example formed by carbon fibers 11 running in the longitudinal direction and formed by pulling, and in the circumferential direction running if necessary under a predetermined Narrow angle wound fibers 12, which are covered by a cover layer 1 3 if necessary.

FIG. 5 shows the base body 1 together with fibers 1 1, 1 2. Also shown is a metallic metal sleeve 2 which has circumferential and diagonally extending depressions 14, 1 5 and the fibers 1 2 the metal sleeve 2 in these areas 14, 1 5 wrap. The fibers 1 2 should not protrude beyond the peripheral surface 1 6 of the metal sleeve 2. If necessary, further layers in the form of fibers 17 can be provided. Rolling 6 for joining the functional element, for example the cam 7 (FIG. 3), is subsequently applied to the peripheral surface 16 of the metal sleeve 2.

FIG. 6 shows the CFRP base body with the metal sleeve 2 pushed on as an example for two further joining methods. In both cases, the metal sleeve 2 is pressed onto the carrier tube 1 by external force. The external force can be generated by rolling, rolling or magnetic forming. The direction of the force is indicated by the arrows.

The upper part of the picture shows how the metal sleeve 2 is fixed by rolling or rolling in the direction of force shown by the arrows. The joining operation can be carried out along the entire surface or along parts of the surface, for example on the collar regions 4 and 5 and the joining region 3, by rolling or rolling.

In the lower part of the picture it is shown how the metal sleeve 2 is fixed by magnetic forming with the magnetic coil 1 8. This process creates a shrink fit.

Figure 7 shows an arrangement of the magnetic coils 1 8, in which only the collars 4 and 5 of the metal sleeve 2 are shrunk onto the base body 1. Figure 8 shows an embodiment of the metal sleeve 2 without frets 4 and 5. Here a profile 19 is incorporated in the longitudinal body 1 to increase the connection strength. The metal sleeve 2 is then fixed on the base body 1 by magnetic shaping with the magnet coil 18.

FIG. 9 shows the state after the joining operation of the metal sleeve 2 on the base body 1. The profile 1 9 is pressed flat and thus forms an additional voltage reservoir for the non-positive connection between the base body 1 and the metal sleeve 2.

The embodiment shown in FIGS. 8 and 9 can also be carried out using rollers or roller burners as a substitute for magnetic forming.

The advantage of the solutions as shown in FIGS. 6, 7, 8, 9 is the simpler technology for producing the base body 1. The disadvantage of the technique shown in these figures is the lower durability. It must therefore be decided, depending on the requirements of the functional shaft, whether the metal sleeve 2 can be subsequently fixed on the base body 1 or whether it must be laminated directly into the fiber structure.

In a particular embodiment, the functional components, such as cams 7, can be fixed directly onto the base body 1 by means of magnetic forming without using a metal sleeve 2. The advantage here is obvious in the simple production sequence. LIST OF REFERENCE NUMBERS

1 basic body

2 metal sleeve

3 joining area

4 collar on metal sleeve

5 bundle of metal sleeve

6 rolling

7 cams

Tongue bent tongue

10 bent tongue

1 1 carbon fibers

1 2 fibers

1 3 top layer

14 deepening

1 5 deepening

1 6 circumferential surface 7 fibers

18 solenoid 9 profile

Claims

claims

1 . Method for producing a shaft with torque-transmitting structural elements by producing a tubular base body (1) from a carbon fiber composite material (CFRP) and bringing it into direct or indirect connection with at least one functional element made of another material.

2. The method according to claim 1, characterized in that the shaft is a camshaft, crankshaft or gear shaft.

3. The method according to claim 1 or claim 2, characterized in that the base body (1) via an, in particular made of a metallic material, metal sleeve (2) is brought into operative connection with the respective functional element.

4. The method according to any one of claims 1 to 3, characterized in that the base body (1) is produced by fibers (1 2, 1 7) running in the longitudinal and / or circumferential direction and / or inclined thereto.

5. The method according to any one of claims 1 to 4, characterized in that the base body (1) by pulling the carbon fibers (1 1) in the longitudinal direction and / or by winding the fibers (1 2) for fiber directions in the circumferential direction and / or by winding the fibers (1 7) for inclined fiber directions is generated.

6. The method according to any one of claims 1 to 5, characterized in that the structure of the base body (1) is carried out gradually by lamination in the longitudinal and circumferential direction or inclined thereto, in particular program-controlled.

7. The method according to any one of claims 1 to 6, characterized in that the necessary number of metal sleeves (2) is positioned at predeterminable locations of the base body (1) in the course of the production of the base body (1) or after generation of the same.

8. The method according to any one of claims 1 to 7, characterized in that the metal sleeves (2) in the course of the production of the base body (1) in the fibers (1 2, 1 7) of the carbon fiber composite material, in particular laminated, are.

9. The method according to any one of claims 1 to 8, characterized in that the metal sleeves (2) are provided on the tube side with a rounded edge.

10. The method according to any one of claims 1 to 9, characterized in that the base body (1) is laminated in the longitudinal direction, at least one layer is laminated in the circumferential direction and / or with fiber directions of approximately 45 ° to the tube axis, the necessary number of metal sleeves (2) pushed over the base body (1) and positioned in the area of the points required for the attachment, at least one further layer in the longitudinal and / or circumferential direction and / or inclined to the base body (1) and the metal sleeve (2) is laminated on.

1 1. Method according to one of claims 1 to 1 0, characterized in that the metal sleeve (2) is provided with depressions (1 4, 1 5), in particular with grooves running in the longitudinal direction and / or circumferential direction and / or inclined thereto.

12. The method according to any one of claims 1 to 1 1, characterized in that the lamination is carried out in such a way that the fibers (1 2, 1 7) do not protrude over the peripheral surface (16) in area 3 of the metal sleeve (2).

1 3. The method according to any one of claims 1 to 7, characterized in that the base body (1) is laminated in the longitudinal direction, at least one layer is laminated in the circumferential direction and / or with fiber directions of about 45 ° to the tube axis, the necessary number Metal sleeves (2) are pushed over the base body (1) and positioned in the area of the points necessary for fastening, and the base body (1) and metal sleeves (2) are connected by pressing.

14. The method according to claim 1 3, characterized in that the pressing is carried out by magnetic shaping, in such a way that at least one magnet coil (1 8) is pushed over the metal sleeves (2) and activated for a predetermined period of time.

1 5. The method according to claim 1 3, characterized in that the pressing is carried out by rolling or rolling the sleeve, in particular at the edge regions.

1 6. The method according to any one of claims 1 to 7, characterized in that the base body (1) is laminated in the longitudinal direction, at least one layer is laminated in the circumferential direction and / or with the fiber direction of about 45 ° to the tube axis, the necessary number of functional elements are pushed over the base body (1) and positioned in the area of the points necessary for the attachment and the connection of the base body (1) and functional elements takes place by pressing.

1 7. The method according to claim 1 6, characterized in that the pressing is carried out by magnetic shaping, in such a way that at least one magnetic coil (1 8) is pushed over the functional element and activated for a predetermined period of time.

1 8. The method according to claim 1 6, characterized in that the pressing is carried out by rolling or rolling the functional elements, in particular at their edge areas.

1 9. The method according to any one of claims 1 to 1 8, characterized in that the metal sleeve (2) is brought into operative connection with the inner peripheral region of the base body (1).

20. Shaft, in particular camshaft, crankshaft or transmission shaft, consisting of a tubular base body (1) made of a carbon fiber composite material and at least one function element connected directly or indirectly, in particular cam (7) or drive element.

21. Shaft according to claim 20, characterized in that the functional element is connected to the base body (1) by a shrink connection, as is achieved, for example, by magnetic forming or rolling or rolling.

22. Shaft according to claim 20 or 21, characterized in that the functional element is connected to the base body (1) via a metallic metal sleeve (2).

23. Shaft according to one of claims 20 to 22, characterized in that the base body (1) consists of a multi-layer laminate structure, formed by fibers (1 2, 1 7) with different fiber course.

24. Shaft according to one of claims 20 to 22, characterized in that the metal sleeve (2) in the fibers (1 2, 1 7), which form the base body (1), is integrated laminated.

25. Shaft according to one of claims 20 to 24, characterized in that at least one end face (8) of the metal sleeve (2) has bent tongues (9, 1 0) offset in the radial direction.

26. Shaft according to one of claims 20 to 25, characterized in that the peripheral surface (1 6) of the metal sleeve (2) is provided with a curling (6).

27. Shaft according to one of claims 20, 22 to 26, characterized in that the functional element, such as cams (7), is connected to the peripheral surface (1 6) of the metal sleeve (2) by a non-positive and / or positive connection ,

28. Shaft according to one of claims 20 to 25, characterized in that the functional element, such as cams (7), is connected to the metal sleeve (2) by a welded connection, in particular a laser welded connection.