DE202009003662U1 - Force distribution in a fiber-reinforced pipe - Google Patents

Abstract

Force introduction element (1) on fiber-reinforced tube (2), wherein the force introduction element (1) is positively connected to the fiber-reinforced tube (2), characterized in that the force introduction element (1) consists of fiber composite material, with an internal thread (1a) is provided and a proportion of more than 75% of the fibers (1b) located overall in the internal thread (1a) extend at an angle between 80 ° and 100 ° to the central axis of the force introduction element (1).

Description

The The present invention relates to the force introduction element in a fiber reinforced tubular component.

at The use of fiber reinforced pipes is common the fundamental problem, forces in this structure initiate. Mostly metallic threaded elements are used for this, which are embedded in the pipes. For the problematic Connection of metal elements and fiber reinforced pipes There are a lot of solutions. Such striving with tubular bodies made of fiber composite material characterized in particular by it, compared to metallic Aspiration, low weight.

Common is, the force introduction elements at the end of such struts metallic perform. In most cases, force application elements will turn off Aluminum used. These are usually cohesive by gluing to the tubular body Connected fiber composite material. The disadvantage here are the high Weight of metallic force introduction elements, the bad ones Corrosion resistance, the time-consuming quality control the adhesive bond and the associated high production costs. In rare cases, the force introduction elements exist also made of plastics whose low strength and their strongly deviating from the fiber reinforced tube coefficient of thermal expansion, adversely affect.

Just in the aircraft industry, in which such struts as struts, Connecting rods or train-pressure rods are called serve the pursuit in particular for leadership and mechanical storage or for support ("struts" or "animal deaths"), are exposed to extreme temperature fluctuations and need meet the highest quality standards. Struts of this type generally comprise one substantially tubular body, at the end of each an element (force introduction element) for mounting the strut is located.

These Aspirations come in planes in substantial quantities before, wherein a strut type in particular by varying the Length distinguishes. The variation of the length will essentially by changing the length of the in the general tubular body of the strut reached. The force introduction elements are in a brace type essentially the same, so that in particular the force introduction elements occur in large numbers.

At Such aspirations are particularly demanding on the Strength of the materials used at the same time low Weight, reproducibility and quality assurance and also put on the corrosion resistance. In addition, the Striving extremely resistant to mechanical as well environmental stresses.

The increasing demands on weight and cost savings to the limits of the potential of known construction methods for struts with tubular bodies made of fiber composite materials.

In the case of EP0841490 a threaded element is used, in which a slotted CFK sleeve is inserted between two stops. Since the slotted sleeve has to be made very accurately in order to be fitted as free of play in the threaded element, this results in an increased production costs and a problem of quality assurance.

In the case of DE 10 2006 039 565 an increased production effort is bypassed. In addition, the approach is pursued to carry out parts of the force introduction element made of fiber composite material. The disadvantage is that this embodiment is designed as an adhesive connection and thereby represents a problem of quality assurance.

at the use of metallic force introduction elements and also in the Use of force introduction elements made of plastic results in some applications, in particular those already mentioned Problem due to differences in the thermal expansion coefficient between force introduction element and the fiber-reinforced Pipe and the problem of extremely time-consuming quality assurance measures. This problem occurs in particular when using the structure in one wide temperature range.

All Previously known constructions for struts with tubular Bodies made of fiber composite materials are either too expensive and thus too expensive to manufacture and / or keep the Low weight requirements, corrosion resistance, Safety of the connection, zero backlash with temperature fluctuations and / or mechanical stresses did not stand.

Of the The invention is therefore based on the object, force introduction elements for tubular struts made of fiber composite materials in such a way that the current state of the art Disadvantages are avoided.

The object is achieved in that the force introduction element ( 1 ) consists of fiber composite material, the force introduction element with a Inner thread ( 1a ) and a large part of the fibers ( 1c ) at an angle between 80 ° and 100 ° to the central axis of the force introduction element ( 1 ). The force introduction element ( 1 ) is designed in such a way that it fits into the fiber-reinforced tube ( 2 ) is integrated.

By This construction results in the following significant advantages. Of the thermal expansion coefficient of the fiber composite material of the force introduction element can be the coefficient of thermal expansion of the fiber reinforced pipe to adjust so that the force application element When used in a wide temperature range largely free of play and stress-free integrated in the fiber reinforced tube remains. By targeting a share of over 75% the entire fibers in the thread at an angle between 80 ° and 100 ° to the central axis carries the Thread also correspondingly high loads.

The described orientation of the fibers, for example, characterized be ensured that impregnated fabric layers at a right angle to the central axis of the force introduction element one above the other be stacked. The fiber composite blank produced in this way is then mechanically processed and then form-fitting introduced into the fiber composite pipe. An additional outer Faserverbundarmierung in the region of the force introduction element can while supporting the positive connection.

When Internal threads can all known internal thread types for However, special thread forms are also used. Exemplary for Known internal thread types are round thread, trapezoidal thread, saw thread or pointed thread.

When Fiber composite material for the force introduction element can preferably, but not exclusively, continuous Glass, carbon, basalt and / or plastic fibers in conjunction with a plastic, but preferably not exclusively Epoxy, phenolic, polyester and / or vinyl ester resin or a Thermoplastics such as PP, PA, ABS, PEI, PPS or PEEK matrix use Find.

The Invention will be described below with reference to exemplary embodiments with reference to the accompanying drawings closer described.

It shows:

1 a schematic section of the fiber composite strut with the force introduction element according to the invention ( 1 ) which form fit of a fiber composite pipe ( 2 ) is surrounded. The force introduction element ( 1 ) can additionally by gluing with the fiber composite pipe ( 2 ).

The force introduction element ( 1 ) is here with an internal thread ( 1a ) Mistake. Optionally, an additional fiber reinforcement ( 3 ) be applied.

2 a schematic half section of the force introduction element ( 1 ) with an internal thread ( 1a ) which is exemplified as a round thread. The fibers ( 1c ) run in the illustration at an angle of 90 ° to the central axis of the force introduction element ( 1 ).

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0841490 [0008]
• - DE 102006039565 [0009]

Claims (5)

Force introduction element ( 1 ) on fiber-reinforced pipe ( 2 ), wherein the force introduction element ( 1 ) with the fiber-reinforced tube ( 2 ), characterized in that the force introduction element ( 1 ) consists of fiber composite material, with an internal thread ( 1a ) and a proportion of more than 75% of the total internal thread ( 1a ) ( 1b ) at an angle between 80 ° and 100 ° to the central axis of the force introduction element ( 1 ). Component according to claim 1, wherein the fiber portion of more than 45 vol .-% and at least predominantly of continuous fibers consists. Component according to claim 1 or 2, wherein glass and / or Carbon, and / or basalt and / or plastic fibers in combination with a thermoplastic and / or duromeric plastic as a fiber composite material Find use. Component according to one of claims 1 to 3, wherein the internal thread ( 1a ) is designed as a round thread and / or trapezoidal thread and / or saw thread and / or pointed thread. Component according to one of claims 1 to 4, wherein the force introduction element in addition by gluing to the fiber-reinforced tube ( 2 ) connected is.