DE102018125863A1 - Process for producing a fiber composite cardan shaft tube and fiber composite cardan shaft tube - Google Patents

Abstract

The invention relates to a method for producing a fiber composite cardan shaft tube, comprising the steps of: providing a stack (10, 10-1) of a plurality of reinforcing fiber layers (20, 21, 22, 23) in accordance with a development of the cardan shaft tube to be produced, the stack (10, 10-1) on the long sides of which have corresponding, tucked edge areas (12, 14), placing the stack (10, 10-1) around a mandrel (30) in such a way that the edge areas (12, 14) come to lie on one another , wherein first and second longitudinal sides (20A, 20B) of each fiber layer are positioned adjacent to one another, fixing the stack (10, 10-1), introducing a matrix material into the stack (10, 10-1) and curing the stack soaked with the matrix material (10, 10-1) in a press tool, thereby forming the propeller shaft tube, and removing the mandrel (30) from the propeller shaft tube. A fiber composite cardan shaft tube is also specified.

Description

The invention relates to a fiber composite cardan shaft tube and a method for producing the same.

Cardan shafts are used to transmit torques and rotary movements. A propeller shaft usually contains a propeller shaft tube which is provided with a joint at at least one end.

In high-performance vehicles, for reasons of weight, the cardan shaft tubes are manufactured as fiber composite cardan tubes made of a fiber-plastic composite material. Here, carbon fiber reinforced plastic (CFRP) is used in particular.

Fiber composite cardan shaft tubes can be manufactured using the wet winding process. In the example from the DE 10 2010 047 361 A1 In known wet winding processes, the fibers are drawn off a roving spool, passed through a resin bath and wound directly onto a mandrel, hardened and the mandrel is then pulled.

The angle at which fibers are applied to the mandrel is decisive for the later component strength. The fibers are wound onto the mandrel in several layers one above the other, the angles in the individual layers being variable. However, the winding process takes a few minutes.

Against this background, the object of the invention is to provide a possibility of how a fiber composite cardan shaft tube can be produced simply and quickly.

The object is achieved by a method according to patent claim 1 and a fiber composite cardan shaft tube according to patent claim 9. Further advantageous configurations result from the subclaims and the following description.

• - Bereitstellen eines Stapels von mehreren Verstärkungsfaserlagen entsprechend einer Abwicklung des herzustellenden Gelenkwellenrohres, wobei der Stapel an seinen Längsseiten miteinander korrespondierende, geschäftete Randbereiche aufweist,
• - Legen des Faserschichten-Stapels um einen Dorn, derart, dass die Randbereiche aufeinander zu liegen kommen, wobei eine erste und zweite Längsseite jeder Faserlage benachbart zueinander positioniert werden,
• - Fixieren des Faserschichten-Stapels,
• - Einbringen eines Matrixmaterials in den Faserschichten-Stapel,
• - Aushärten des mit dem Matrixmaterial getränkten Faserschichten-Stapels in einem Presswerkzeug, wodurch das Gelenkwellenrohr ausgebildet wird, und
• - Entfernen des Dorns aus dem Gelenkwellenrohr.

A method for producing a fiber composite cardan shaft tube is specified with the steps:

• Provision of a stack of a plurality of reinforcing fiber layers in accordance with a development of the cardan shaft tube to be produced, the stack having, on its longitudinal sides, corresponding, tucked edge regions,
• Laying the stack of fiber layers around a mandrel such that the edge regions come to lie on top of one another, with first and second long sides of each fiber layer being positioned adjacent to one another,
• - fixing the stack of fiber layers,
• Introduction of a matrix material into the fiber layer stack,
• Curing the stack of fiber layers impregnated with the matrix material in a pressing tool, as a result of which the cardan shaft tube is formed, and
• - Remove the mandrel from the drive shaft tube.

According to the invention, the stack is made of reinforcing fiber layers in the manner of a tailor-made sleeve. The stack is a development of the component to be manufactured, i.e. the length of the stack is selected in accordance with the length of the cardan shaft tube and the width of the individual reinforcing fiber layers is selected in accordance with the respective circumference of the cardan shaft tube. On the long sides, the stack is busy in the edge areas, i.e. Reinforcing fiber layers are arranged in a staggered manner transversely to the longitudinal direction. The stripped edge area on one long side corresponds to the stripped edge area on the other long side in such a way that - when the stack is placed around the mandrel - the edge areas come to lie on one another and the shafts interlock. The long sides of each fiber layer are positioned adjacent to each other. In other words, the stack is made so that it can be placed around the mandrel and encloses it exactly once. The width of the individual fiber layers is chosen so that each fiber layer extends around the mandrel, but does not overlap with itself when it is placed around the mandrel. This results in a concentric arrangement of the reinforcing fiber layers around each other and around the mandrel.

Furthermore, a fiber composite cardan shaft tube is specified with a plurality of reinforcing fiber layers, which are integrated in a plastic matrix. According to the invention, the individual reinforcing fiber layers are arranged concentrically around one another, a first and a second longitudinal side of the reinforcing fiber layers being arranged adjacent to one another and the longitudinal sides of reinforcing fiber layers lying one on top of the other being offset circumferentially from one another.

Such a cardan shaft tube can be produced in particular using the described method and, as such, achieves the same technical advantages and effects.

The necessary process time can be clearly seen by placing a stack sleeve shorten. The stack or sleeve can be manufactured in advance of the component production. The cut stack can be placed much faster than wrapping the mandrel. In the product mix of different pipe lengths, the material waste in the stack is also very low. The process is therefore easy to implement and the time for the process step is shortened.

A multiplicity of reinforcing fiber layers can be arranged in the stack. Each reinforcing fiber layer can in turn be formed from a single or a plurality of fiber layers. In order to achieve high component strengths, it is preferred if the reinforcing fiber layers are designed as a continuous fiber layer over their width, i.e. extend circumferentially around the mandrel once without interruption.

The stack of reinforcing fiber layers is cut according to the length of the tube to be produced, the fiber layers of the stack preferably extend continuously over the length of the stack.

With the method, the end faces of the propeller shaft tube can be reinforced in a simple manner. For example, in one configuration, at least one end edge region of the stack can have at least one additional reinforcement layer. This one (or more) additional reinforcement layers do not extend over the entire length of the stack, but are only arranged in a targeted manner in the areas to be reinforced. This additional reinforcement layer can e.g. be formed in the form of a narrow strip of a semi-finished fiber. It is particularly preferred if the end-face additional reinforcement layer is formed from a unidirectional scrim, the fiber orientation of which is transverse to the longitudinal axis. In this way, a mechanically heavy-duty pipe end can be produced.

The individual fiber layers can e.g. present as a fabric, braid, scrim, knitted fabric or fleece. Different reinforcing fiber layers can be combined in the stack. The individual fiber layers can advantageously be combined in accordance with the requirements for the mechanical component properties. In a preferred embodiment, reinforcing fiber layers with different fiber orientations are present in the stack, the orientation being selected according to the mechanical requirements on the component. The use of the “cuff” according to the invention is also advantageous in that the fiber orientations can be varied in the simplest manner by cutting and folding the individual layers accordingly. Here the process has a clear advantage over the winding process, since complex combinations of fiber angles, e.g. several layers with 0 degrees, 45 degrees and other angles, can be prefabricated in advance of the component production and stored temporarily.

The method is not restricted to certain reinforcing fibers, so that the known reinforcing fibers, e.g. Carbon fibers, glass fibers, aramid fibers etc. alone or in combination in question. However, it is particularly preferred if the reinforcing fibers contain or consist of carbon fibers.

The stack placed on the mandrel is fixed. For this, e.g. a fixing agent is applied to the edge regions which come to lie one on top of the other.

A matrix material is inserted into the fiber layer stack. This can e.g. already take place during the production of the fiber layer stack. In this respect, in one embodiment, the stack of reinforcing fiber layers can be used as a prepreg, i.e. preconsolidated semi-finished fiber can be provided. The prepreg stack wound around the mandrel is then pressed and cured in a known manner in a pressing tool.

However, the stack of reinforcing fiber layers can also be formed from dry reinforcing fiber layers. In this case, the matrix material is introduced into the stack around the mandrel in the pressing tool. The introduction of the matrix material and the curing can then e.g. in a known RTM process.

The matrix material is preferably a thermoset matrix material, e.g. an epoxy-based matrix material. Nevertheless, the method can in principle also be carried out with thermoplastic matrix materials. After the matrix material has hardened, the component is removed from the mold and the mandrel is removed.

Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. If the term "can" is used in this application, it is both the technical possibility and the actual technical implementation.

• 1 bis 4 unterschiedliche Verfahrensabschnitte zur Herstellung eines Gelenkwellenrohres und
• 5 einen beispielhaften Stapel von Verstärkungsfaserlagen.

Exemplary embodiments are explained below with reference to the accompanying drawings. In it show:

• 1 to 4th different process sections for the production of a cardan shaft tube and
• 5 an exemplary stack of reinforcing fiber layers.

1 shows a stack 10th of reinforcing fiber layers 20th , 21 , 22 , 23 . The stack consists of a large number of fiber layer blanks and provides an unwinding of the component to be manufactured. In the present case, the component should have a constant pipe cross section, the stack 10th consists of a large number of rectangular blanks.

In the stack 10th are a variety of reinforcing fiber layers 20th , 21 , 22 , 23 layered on top of each other. The fibers are preferably in a directional form in the reinforcing fiber layers. The individual fiber layers are aligned according to the mechanical requirements placed on the component. Different fiber layers can be arranged at different fiber angles.

At the side edges, which later run parallel to the axis of the mandrel, the stack has stripped edge areas 12th and 14 on. In the marginal areas 12th , 14 are the fiber layers 20th , 21 , 22 , 23 stepped and form corresponding shafts.

Figru 2nd shows how this stack 10th around a, for example metallic, mandrel 30th is laid and 3rd shows that completely off the stack 10th surrounding thorn 30th . The width of the individual fiber layers 20th , 21 , 22 , 23 (the width is shown B the fiber layer 20th ) are dimensioned so that each reinforcing fiber layer 20th , 21 , 22 , 23 exactly once around the thorn 30th can be laid around without an overlap of a fiber layer with itself. Rather, each fiber layer borders 20th , 21 , 22 , 23 with their long sides together. For reasons of clarity, in 2nd only the long sides 20A and 20B provided with reference numerals. The shaft is designed so that adjacent fiber layers with their long sides come to lie circumferentially offset. So it comes when laying the fiber stack 10th to an offset position of the "seams". This ensures high mechanical stability of the component, even though each fiber layer only extends around the mandrel exactly once. The stack 10th from reinforcing fiber layers 20th , 21 , 22 , 23 grips the thorn like a cuff 30th around.

Then the on the mandrel 30th applied stacks 10th in a press tool 40 processed into the cardan shaft tube, shown in 4th . The press tool 40 points between his top tool 42 and lower tool 44 a cavity in the form of the component to be manufactured, into which the mandrel 30th together with stack 10th is inserted.

If the stack is a prepreg, ie the fiber layers 20th , 21 , 22 , 23 are already impregnated with an uncured matrix material, this is done in the press tool 40 shaping by pressing and hardening of the matrix material.

The stack can also be used 10th also consist of dry reinforcing fibers. Then can be used as a pressing tool 40 an RTM tool can be used in which the fiber stack is impregnated under pressure with the matrix material (not shown) and cured.

After curing, the component can be removed from the mold and the mandrel 30th be pulled out. Further processing steps can follow.

5 shows a stack of reinforcing fiber layers, with which a reinforced shaft tube is produced on the end faces. The stack 10-1 differs from that in 1 described stack 10th through two additional reinforcing fiber layers 24-1 and 24-2 , which are arranged in the front edge areas. In the example shown, the reinforcing fiber layer has 23 a fiber alignment in the longitudinal direction to achieve a high bending stiffness of the shaft. The fiber orientation of the additional reinforcing fiber layers 24-1 and 24-2 is placed transversely to protect the ends of the tube against breaking when the joint is installed. The fiber orientations are indicated by the double arrows.

The four reinforcing fiber layers shown in the figures are purely exemplary. More or fewer layers can also be provided. Likewise, several additional reinforcing fiber layers can be provided one above the other. Other cuts than the rectangular cut shown are possible.

Reference list

10, 10-1

Stack of reinforcing fiber layers

12, 14

busy marginal areas

20, 21, 22, 23

Reinforcing fiber layer

20A, 20B

Long side

24-1, 24-2

additional reinforcing fiber layer

30th

mandrel

40

Press tool

42

Upper tool

44

Lower tool

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102010047361 A1 [0004]

Claims (10)

Method for producing a fiber composite cardan shaft tube with the steps: Provision of a stack (10, 10-1) of a plurality of reinforcing fiber layers (20, 21, 22, 23) in accordance with a development of the cardan shaft tube to be produced, the stack (10, 10-1) on its longitudinal sides corresponding to each other, used border areas (12, 14), placing the stack (10, 10-1) around a mandrel (30) in such a way that the edge regions (12, 14) come to lie on top of one another, with first and second longitudinal sides (20A, 20B) adjacent to each fiber layer be positioned to each other Fixing the stack (10, 10-1), Introducing a matrix material into the stack (10, 10-1), Hardening the stack (10, 10-1) soaked with the matrix material in a pressing tool, whereby the propeller shaft tube is formed, and removing the mandrel (30) from the propeller shaft tube. Method according to one of the preceding claims, in which the reinforcing fiber layers (20, 21, 22, 23) are designed as continuous fiber layers over their width. Method according to one of the preceding claims, in which at least one end edge region of the stack (10-1) has at least one additional reinforcing fiber layer (24-1, 24-2). Method according to one of the preceding claims, in which the reinforcing fiber layers (20, 21, 22, 23) are present as unidirectional layers. Method according to one of the preceding claims, in which different reinforcing fiber layers (20, 21, 22, 23) have different fiber orientations. Method according to one of the preceding claims, in which at least several of the reinforcing fiber layers (20, 21, 22, 23) are formed from carbon fibers. Procedure according to one of the Claims 1 to 6 , in which the stack (10, 10-1) of reinforcing fiber layers (20, 21, 22, 23) is provided as a prepreg. Procedure according to one of the Claims 1 to 6 , in which the stack (10, 10-1) is formed from dry reinforcing fiber layers and the matrix material is introduced into the pressing tool (40). Fiber composite cardan shaft with a plurality of reinforcing fiber layers (20, 21, 22, 23) which are integrated in a plastic matrix, wherein the individual reinforcing fiber layers (20, 21, 22, 23) are arranged concentrically around one another, a first and second longitudinal side (20A, 20B) of the reinforcing fiber layers (20, 21, 22, 23) being arranged adjacent to one another and the longitudinal sides of reinforcing fiber layers (20 , 21, 22, 23) are circumferentially offset from one another. Fiber composite cardan tube after Claim 9 which has at least one additional reinforcing fiber layer (24-1, 24-2) in at least one end edge region.

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