DE102008034772B4 - Force application device - Google Patents

Abstract

A force introduction device comprising a composite material unit (10) and a force introduction unit (12) at least partially introduced in the composite material unit (10) and comprising at least one force introduction element (14) and a connection unit (16) connected to the force introduction element (14). 18, 20), characterized in that the at least two plates (18, 20) at least partially in a layered structure in the multilayer composite material unit (10) are incorporated, wherein per layer (26, 28) of the composite material unit (10) has a plate (18, 20) is introduced.

Description

The invention relates to a force introduction device according to the preamble of patent claim 1.

From the prior art, force introduction devices are known with a composite material unit, preferably designed as a fiber composite structure, and a force introduction unit, which is at least partially introduced in the composite material unit. Usually, the force introduction unit comprises a force introduction element and a connection unit connected to the force introduction element. The connection of the force introduction unit with the composite material unit is usually carried out by adhesion, such as gluing, by adhesion, such as screwing or riveting, by form-fitting, such as metallic, formed in the composite unit insert inserts connecting units, in which force introduction elements are screwed, or through combinations of the individual principles.

For bonds, however, only the first fiber layer is joined to the joining partner, the further force flow is represented by the resin matrix. As a result, delamination may occur at high loads, thus making the resin strength a dimensioning size. For connections according to the traction principle, such as glands, polymer-typical creep effects come into play. Thus, the surface pressure under a screw head leads to so-called relaxation processes, the so-called relaxing creep, in the polymer matrix, which results in a reduction of the screw prestressing and thus a deterioration of the connection quality. In conventional insert joints, a metallic component is laminated into the fiber composite structure and partially free-milled after the hardening process. At this surface is drilled and a thread cut into the insert. The disadvantage here, however, the relatively small surface area compared to the mass of the insert. So it may happen that local detachment occur and thus a loose shaking of the insert is caused.

From the utility model DE 91 15 292 U1 a generic force introduction device with a composite material unit and a force introduction unit is known. The force introduction unit comprises a connecting unit designed as a plate and a force introduction element designed as a threaded sleeve or threaded bolt. The relative to the sleeve or bolt cross-section substantially larger plate is attached to the embeddable end of the threaded sleeve or the threaded bolt via an adhesive connection, a welded joint, a solder joint, a riveted joint or a screw connection. The embedding of the end of the threaded sleeve or the threaded bolt with the plate in the composite unit is then possible by way of lamination, pouring, injection or insertion.

From the GB 499 304 A For example, a method for connecting a plurality of plate-shaped objects via bolts or screws is known.

From the DE 10 2005 039 467 B3 is a flange for screwing a crash box and a mounting bracket with a vehicle side rail known. The flange connection has in each case a flange plate on the crash box and on the vehicle longitudinal member, which have through holes for the screw connection. Between these flange plates a plate-shaped mounting lug of the mounting bracket is clamped, which has at least one passage opening for a screw passage. The mounting lug of the mounting bracket consists of a metal-plastic composite or a plastic. The screw connection consists of a screw bolt and a nut placed thereon, which act on the outer sides of the two flange plates which are remote from one another. The through hole in the flange of the crash box is incorporated into the material of the flange so that a collar is formed by forming the hole edge, which protrudes on the side facing away from the crash box side of the flange plate in the coaxial direction and in the assembled state with its annular end face on the the through hole of the flange plate rises on the side rail surrounding edge region. The length of the axial projection of the collar is slightly smaller than the thickness of the attachment lug on the mounting bracket, so that the attachment lug can be clamped frictionally between the two flange plates.

It is the object of the invention to provide a force introduction device which enables a good introduction of force into the composite material unit when the force introduction unit is safely introduced into the composite material unit.

The invention achieves this object by providing a force introduction device having the features of patent claim 1.

Advantageous embodiments and further developments of the invention are specified in the dependent claims.

According to the invention, the connection unit has at least two plates, which at least partially in a layered structure in the Composite material unit can be introduced. This layered structure advantageously leads to a good introduction of force into the composite material unit, since a plurality of, preferably all layers of the composite material unit are connected to the force introduction unit or the force introduction element. As a result, the force flow through the force introduction element takes place in all layers of the composite material unit, so that delamination of the composite material unit can be safely avoided at high loads on the force introduction device.

In an embodiment of the force introduction device according to the invention, at least one plate of the connection unit can be introduced into the composite material unit in at least one edge region. This results in a region of the force introduction unit, which is preferably suitable for the arrangement of the force introduction element. By special selection of the material of the connection unit, a secure connection of the force introduction element can be made with the connection unit.

In a further refinement of the force introduction device according to the invention, the plates of the connection unit have different cross sections or base surfaces in respectively directly successive layers. Ideally, a plate is inserted per layer of the connection unit, the size or the cross section of these plates preferably being varied from layer to layer. Advantageously, this results in a multi-section connection. The overlapping overlapping of the plates with the layers of the composite material unit achieves a surface enlargement which prevents the force introduction unit from shaking loose from the composite material unit.

It is proposed that the force introduction device comprises at least one region of the composite material unit constructed with composite material layers, at least one intermediate region constructed alternately with composite material layers and plates, and at least one region of the force introduction unit constructed in layers with plates. The force introduction element is preferably arranged in the at least one region of the force introduction unit constructed in layers with plates. As a result, it is possible to dispense with free-milling of the force introduction unit after a hardening process, since the force introduction unit is already accessible without free milling after introduction into the composite material unit and the hardening process. Thus, a mechanical weakening of the force introduction device is reliably avoided.

It is proposed that the force introduction element is connected via a clamping connection with the connection unit. Advantageously, this results in a simple and space-saving possibility for secure connection of the force introduction unit with the composite material unit.

The force introduction element is preferably formed by a screw and a nut cooperating with the screw. Advantageously, this results in the use of commercially available and / or normalized components.

In one embodiment of the invention, the connection unit between a screw head of the screw and the nut can be clamped. It results in an advantageous manner in a simple and inexpensive way accurate adjustability of the clamping force of the clamping connection.

Furthermore, the at least two plates of the connection unit are solid. Preferably, this results in a large surface area of the plates to be introduced into the composite material unit, as a result of which shaking loose of the force introduction unit from the composite material unit can be avoided.

In an advantageous manner, the at least two plates of the connection unit consist of at least one metallic material. The design of the plates as metallic components advantageously prevents creeping of the plates due to the clamping connection. The metallic plates endure the surface pressure generated by the clamp connection without deformation, so that, for example, a reduction of the screw bias and thus a deterioration of the connection quality between the force introduction unit and the composite unit is avoided.

It is proposed that the composite material unit consists of a fiber composite. This material allows a good incorporation of the force introduction unit in the composite material unit. The force introduction unit is comprehensively enclosed by the fibers of the composite, so that there is a secure reception of the force introduction unit in the composite material unit.

Furthermore, it is proposed that the composite material unit is at least one component of a motor vehicle.

An advantageous embodiment of the invention is shown in the single drawing and will be described below.

The single-figure FIGURE shows a longitudinal section through a force introduction device according to the invention in a schematic representation.

The force introduction device comprises a composite material unit 10 and one in the composite unit 10 at least partially introduced force introduction unit 12 , The force introduction unit 12 has at least one force introduction element 14 and one with the force introduction element 14 connected connection unit 16 on. The introduction of the force introduction unit 12 in the composite unit 10 takes place in the present embodiment by way of lamination, wherein also pouring, injecting, inserting or other, a person skilled in the seem appropriate technologies are conceivable.

In the present embodiment, it is the composite material unit 10 to a fiber composite, in particular a fiber composite plastic, which may also be other, one skilled in the appear appropriate materials or combinations of materials. A fiber composite plastic is a plastic that consists of reinforcing fibers and a plastic matrix. The plastic matrix surrounds the reinforcing fibers bonded to the plastic matrix by adhesive or cohesive forces. The fiber composite plastic can be adapted by a suitable combination of fiber and matrix material to different applications. In particular, a suitable material may result for lightweight construction applications, for example in the automotive industry. The present composite material unit 10 is executed here as a component of a motor vehicle. The mechanical and thermal properties of a fiber composite plastic can be adjusted via a variety of parameters, wherein in addition to the combination of fiber and matrix material, for example, the fiber angle or the order of the layers can be changed.

In order to provide a force introduction device, the safe introduction of the force introduction unit 12 in the composite unit 10 a good introduction of force into the composite material unit 10 allows, is proposed according to the invention that the connection unit 16 at least two plates 18 . 20 which at least partially in a layered structure in the composite material unit 10 can be introduced. Ie. every layer 26 . 28 the composite unit 10 becomes a plate 18 . 20 inserted or laminated. In the present embodiment, the plates 18 . 20 each having a circular cross-section, whereby further, to a person skilled in the appearing appropriate cross-sectional shapes, such as quadrangular or hexagonal, etc. are conceivable. Advantageously, about the cross-sectional shapes of the plates 18 . 20 Influence on a rotation lock of the force introduction unit 12 in the composite unit 10 be exercised. In particular, the respective plates 18 . 20 also have different cross-sectional shapes.

The plates 18 . 20 the connection unit 16 are in at least one border area 22 . 24 in the composite unit 10 einbringbar or einlaminierbar. Ie. the plates 18 . 20 can in the composite material unit 10 be incorporated. The plates 18 . 20 the connection unit 16 have in each case directly successive layers on different cross-sections, so that in the present embodiment, a plate 18 with smaller circle diameter itself with a plate 20 alternates with larger circle diameter. This results in a layered structure, which at the edge regions of the plates 18 . 20 Free spaces between the plates 18 . 20 for introducing the material of the composite unit 10 leaves. This leads to a better anchoring of the force introduction unit 12 in the composite unit 10 , allowing a shaking of the force introduction unit 12 is avoided even at high loads.

The layered structure of the force introduction device results in at least one with composite material layers 26 . 28 built-up area 30 the composite unit 10 , at least one alternately with layers of composite material 26 and plates 20 constructed intermediate area 32 and at least one with plates 18 . 20 Layered area 34 the force introduction unit 12 ,

The force introduction element 14 is in the at least one with plates 18 . 20 Layered area 34 the force introduction unit 12 arranged. Preferably, the force introduction element 14 via a clamping connection with the connection unit 16 connected. In the present embodiment, the force introduction element 14 from a screw 36 and one with the screw 36 interacting mother 38 educated. The connection unit 16 or the plates 18 . 20 are between a screw head 44 the screw 36 and the mother 38 clamped, preferably between the screw head 44 and the top plate 18 and the mother 38 and the bottom plate 18 one washer each 40 . 42 is arranged.

Preferably, the at least two plates 18 . 20 the connection unit 16 solid executed. Preferably consisting of the plates 18 . 20 the connection unit 16 from at least one metallic material, although other materials or combinations of materials which appear appropriate to a person skilled in the art are also conceivable.

LIST OF REFERENCE NUMBERS

10

Composite unit

12

Force transmission unit

14

Force application element

16

connecting unit

18

plate

20

plate

22

border area

24

border area

26

Composite material layer

28

Composite material layer

30

Area (composite unit)

32

intermediate area

34

Range (force introduction unit)

36

screw

38

mother

40

washer

42

washer

44

screw head

Claims (12)

Force introduction device with a composite material unit ( 10 ) and one in the composite unit ( 10 ) at least partially introduced force introduction unit ( 12 ), the at least one force introduction element ( 14 ) and one with the force introduction element ( 14 ) connected connection unit ( 16 ) comprising at least two plates ( 18 . 20 ), characterized in that the at least two plates ( 18 . 20 ) at least partially in a layered structure into the multilayer composite material unit ( 10 ), wherein per layer ( 26 . 28 ) of the composite unit ( 10 ) a plate ( 18 . 20 ) is introduced. Force introduction device according to claim 1, characterized in that at least one plate ( 20 ) of the connection unit ( 16 ) in at least one edge region ( 22 . 24 ) into the composite unit ( 10 ) can be introduced. Force introduction device according to claim 1 or 2, characterized in that the plates ( 18 . 20 ) of the connection unit ( 16 ) in each immediately successive layers have different cross-sections. Force introduction device according to one of claims 1 to 3, characterized by at least one layer of composite material ( 26 . 28 ) constructed area ( 30 ) of the composite unit ( 10 ), at least one alternately with composite layers ( 26 ) and plates ( 20 ) built intermediate area ( 32 ) and at least one with plates ( 18 . 20 ) layered area ( 34 ) of the force introduction unit ( 12 ). Force introduction device according to one of claims 1 to 4, characterized in that the force introduction element ( 14 ) in the at least one with plates ( 18 . 20 ) layered area ( 34 ) of the force introduction unit ( 12 ) is arranged. Force introduction device according to one of claims 1 to 5, characterized in that the force introduction element ( 14 ) via a clamping connection with the connection unit ( 16 ) connected is. Force introduction device according to one of claims 1 to 6, characterized in that the force introduction element ( 14 ) of a screw ( 36 ) and one with the screw ( 36 ) cooperating mother ( 38 ) is formed. Force introduction device according to claim 7, characterized in that the connection unit ( 16 ) between a screw head ( 44 ) of the screw ( 36 ) and the mother ( 38 ) can be clamped. Force introduction device according to one of claims 1 to 8, characterized in that the at least two plates ( 18 . 20 ) of the connection unit ( 16 ) are made massive. Force introduction device according to one of claims 1 to 9, characterized in that the at least two plates ( 18 . 20 ) of the connection unit ( 16 ) consist of at least one metallic material. Force introduction device according to one of claims 1 to 10, characterized in that the composite material unit ( 10 ) consists of a fiber composite. Force introduction device according to one of claims 1 to 11, characterized in that it is in the composite material unit ( 10 ) is at least one component of a motor vehicle.

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