DE102010053733A1 - Load application element for applying forces in tubular component of e.g. torsion bar of motor car, has connection region by which connection to component is realized, where connection region is partially comprised of nub-like structure - Google Patents

Abstract

The element (4) has a connection region (8) by which connection to a tubular component is realized, where the connection region is partially comprised of a nub-like structure. The structure comprises nubs (9) formed by intersecting cuts (10, 11) in the connection region, where the cuts have different depths. The nubs and/or edges of the cuts are deburred, where the cuts are formed in an angle of 80 to 100 degrees to each other. The connection region is formed with a rectangular, round or oval cross-section, where the entire element is made of a metallic material. An independent claim is also included for a torsion spring or roll stabilizer comprising a tubular component made of a fiber reinforced plastic material.

Description

The invention relates to a Lasteinleitelement according to the closer defined in the preamble of claim 1. Art also relates to a torsion bar spring or a roll stabilizer with such a load introduction element.

Fiber-reinforced plastics or fiber composite plastics (FRP) are known from the general state of the art. These fiber-reinforced plastics are often used as lightweight materials, for example in the field of vehicle construction or in the aviation industry. They generally consist of fiber bundles, so-called rovings, for example of carbon, aramid, Kevlar and / or glass fibers, which are embedded in a plastic matrix of duroplastic or thermoplastic plastic material. The plastic matrix takes over the connection of the fibers with each other and ensures a stable shape of the component, while the reinforcing fibers themselves provide for the transmission of forces in the component.

As in the field of vehicle construction, a rapid series production is sought, which should allow process-reliable and without long waiting and curing times, the production of a fiber composite plastic, play here thermosetting matrix systems a minor role, as these typically make a rather complex and tedious processing necessary. The focus in the field of vehicle construction is therefore on the use of thermoplastic matrix systems. Frequently, pre-impregnated rovings, so-called prepregs, are used with the matrix material, or hybrid rovings are processed which, in addition to the reinforcing fibers, also comprise fibers of the thermoplastic matrix material. To produce a tubular component of such a fiber composite plastic with thermoplastic matrix material is intended to be exemplary of the DE 10 2008 010 228 A1 and the DE 10 2007 051 517 A1 to get expelled. From these two documents the so-called braided pultrusion is known, with which in particular bending and torsion-resistant tube profiles can be produced. In this case, a tubular fabric, in which a thermoplastic matrix material is already arranged, is pulled through a so-called pultrusion system with one or more braiding wheels or braided eyes and consolidated by heat input. At the exit from the plant, the semi-finished product is then deburred and cut to length. In this case, almost any predetermined, but for the respective tool constant profile shapes and fiber orientations can be realized.

• – Reduzierung des Bauteilgewichts
• – verbesserte Medien- und Chemikalienbeständigkeit im Vergleich zu Stahl
• – kein zusätzlicher Korrosionsschutz des Bauteils notwendig
• – verbessertes Dämpfungsverhalten des Werkstoffs
• – reduzierte Fertigungszeiten, höhere Effizienz der Fertigung
• – geringere Herstellungskosten
• – fasergerechte leichtbauende Lastweiterleitung.

Such components made of a fiber-reinforced plastic material with a thermoplastic matrix material have the following advantages:

• - Reduction of the component weight
• - improved media and chemical resistance compared to steel
• - No additional corrosion protection of the component necessary
• - Improved damping behavior of the material
• - reduced production times, higher production efficiency
• - lower production costs
• - fiber-friendly lightweight load transfer.

In particular, when used in the field of vehicle construction, this leads to significant savings in vehicle weight. This allows a significant reduction in the energy consumption of the vehicle per kilometer driven and a reduction in pollutant emissions.

Turning rods or torsion bars or roll stabilizers are also known from the general state of the art. These are torsion springs that are intended to reduce the rolling motion of a vehicle or that carry the vehicle and respond to road bumps by rebound and rebound sufficiently and record weight shifts in the longitudinal and / or transverse direction. These components are often made of high strength spring steels due to the high material requirements in terms of stiffness and strength, especially in the torsional load, and typically designed as a tube or solid material. From the priority-giving patent application for the present patent application, it is also known to produce these torsion bars or roll stabilizers made of fiber-reinforced plastic, in particular from a substantially tubular member made of a fiber-reinforced plastic material. This achieves ideal properties in terms of weight, corrosion resistance, damping properties and the forces conducted in the area of the torsion bar or roll stabilizer.

Of particular importance in this case is the connection of load-transfer elements to the component made of fiber-reinforced plastic material both in fiber-reinforced components per se and in torsion bar springs or roll stabilizers. The task of such Lasteinleitelemente is to absorb forces and to initiate in the composite of Lasteinleitelement and fiber-reinforced component, while the reinforcing fibers of the fiber-reinforced component then take over the forwarding of the forces. The load introduction elements have to do this securely and firmly connected to the component made of fiber-reinforced plastic material.

The object of the present invention is now to provide such a load-introducing element, which enables a very safe and reliable connection to the component made of fiber-reinforced plastic material simply and efficiently.

According to the invention this object is achieved by the features in the characterizing part of claim 1. Further advantageous embodiments of the invention Lasteinleitelements arise from the dependent therefrom dependent claims. In addition, a torsion bar spring or a roll stabilizer is specified in claim 8, which has such a Lasteinleitelement. Advantageous embodiments and further developments of this torsion bar spring or the roll stabilizer are specified in the dependent claims.

In the connection region through which the connection to the component made of the fiber-reinforced plastic material is realized, the load introduction element according to the invention has a knob-like structure. This knob-like structure allows the material of the component of the fiber-reinforced plastic or at least a part of this material, in particular the reinforcing fibers, a very good adhesion to the Lasteinleitelement by a positive connection between the material of the component and the knob-like structure of the connecting portion.

According to an advantageous development of the load introduction element according to the invention, it is provided that the knob-like structure has knobs which are formed by crossing first and second cuts in the connection area. The intersecting incisions can be between the individual mutually parallel first incisions each webs. As a result of the second incisions, which also extend parallel to one another, nubs are formed which are ideally suited for producing a positive-fit contact with the material of the component made of fiber-reinforced plastic. The individual pimples, which arise, harmonize ideally with a network of intersecting reinforcing fibers. They are far better suited to realize a positive fit in numerous individual areas, as would be, for example, circumferential grooves, undercuts or the like. The production of the knobs is preferably carried out by removing or reshaping, in particular by milling, cutting (eg so-called high-speed cutting = HSC), eroding or embossing. In particular, an embossing process requires very little time to provide the entire required surface with suitable nubs.

In a further very advantageous embodiment of the Lasteinleitelements invention it is also provided that the knobs and / or edges of the incisions are deburred. The deburring of the knobs and / or the edges of the incisions, in particular of all protruding elements in the connection region, is of particular advantage, since this avoids or eliminates burrs and sharp-edged regions, in particular in the case of a metallic embodiment of the load-transfer element. Such removal of burrs can advantageously be carried out by means of a removal process downstream of the generation of the nubs in the form of a liquid bath in which there is a flowing abrasive liquid or acid. It is the model of various surface cleaning processes, the surface is easily attacked and removed material. This results in a smooth surface without sharp edges, at the same time the surface is activated for a later bonding process, especially fine micropores, which arise through the removal and / or etching process in this case allow a significant improvement in adhesion by micro positive locking.

Burrs should preferably be avoided, as they could damage or even sever individual fibers upon contact with the reinforcing fibers, so that weakening of the component in the area of the positive-locking composite would thereby occur. Such is to be avoided in terms of the best possible load transfer with minimal effort in terms of the material of the reinforcing fibers. This can save costs and weight.

In an advantageous embodiment of the load-introducing element according to the invention, it is additionally provided that the connection region, preferably the entire load-transfer element, is formed from a metallic material, wherein at least parts of the connection region are coated with a bonding agent. Such a construction of metallic material is particularly simple and efficient, since it is ideal for the load transfer in the region of the load-receiving area. The components which initiate the load can be screwed here, for example, connected via bearing eyes with the Lasteinleitelement, welded to this or the like. The metallic Lasteinleitelement, or in the case that only the connection region is formed metallic, the connection region is then completely or partially coated with a bonding agent. This allows in addition to the positive connection of the material of the fiber-reinforced component with the knob-like structure of the invention Lasteinleitelements In addition, favored by the bonding agent, a material connection occurs in addition to the positive connection. The connection between the component and the Lasteinleitelement is thereby further improved.

The torsion bar spring or the roll stabilizer according to the invention for a motor vehicle comprises a substantially tubular component made of fiber-reinforced plastic material and at least one load-introducing element. The load introduction element is designed as an inventive load introduction element according to one or more of the variants described above. This allows the construction of a torsion bar or a roll stabilizer for a motor vehicle with the substantially tubular member made of fiber-reinforced plastic material as the main component of the torsion bar spring or the roll stabilizer. This can be realized in accordance with this easily and corrosion resistant. By Lasteinleitelemente invention is known in torsion bars or roll stabilizers known connection via bearing eyes to corresponding lever elements, which initiate the rolling motion of the chassis in the torsion bar or the roll stabilizer, very easy. The forces introduced are transmitted safely and reliably via the load-transfer elements to the reinforcing fibers of the tubular component of the torsion bar spring or the roll stabilizer which are positively connected with them.

In a particularly favorable and advantageous development of the torsion bar or anti-roll bar according to the invention, it is provided that the load introduction elements is arranged in the region of one end of the tubular component, wherein the end of the tubular component is deformed into an oval shape, and thus surrounds the connection region of the load introduction element, in that at least one of the materials of the tubular component is in positive connection with the knob-like structure. This construction of the torsion bar spring or the roll stabilizer therefore makes it possible to form a very secure and simple connection by deforming the end or ends of the tubular component into an oval shape, which surrounds the connection region of the load-introduction elements. In this case, the tubular component can already be connected to the load introduction element during production, for example, in which the tubular component is produced by braiding pultrusion and the connection region of the load introduction element is braided with it. However, it is also conceivable to deform the pipe ends around the load introduction element only when the tubular component is completed. This is also the case here, in particular if a melting of the preferably thermoplastic matrix material of the component takes place at the same time, resulting in a very good form-fitting bond between the ends of the tubular component and the load introduction elements. In the event that the Lasteinleitelemente are provided with a bonding agent, in addition supportive can be achieved a substance bond.

In a particularly favorable and advantageous embodiment of the torsion bar spring or the roll stabilizer according to the invention, it is further provided that this is provided with Lasteinleitelementen having nubs, which are formed by crossing first and second cuts in the connection area. If the tubular component then comprises at least one layer of braided reinforcing fibers which extend at a braiding angle of 5 to 80 ° with respect to the central axis of the tube, wherein the first and / or the second cuts of the Lasteinleitelements extend at an angle which in an angular range of -10 ° to + 10 °, preferably -5 ° to + 5 °, is formed around the braid angle, ideal structure can be achieved. The intersecting cuts in this construction are the same or similar to the braided reinforcing fibers of the at least one braided layer of reinforcing fibers in the tubular member. In this case, the braided reinforcing fibers ideally lie around the knobs formed by the intersecting incisions, which are braided directly, for example, during the production of the fiber-reinforced plastic material. They thus ensure secure and reliable positive locking at numerous individual areas distributed over a larger contact area between the load introduction element and the component.

Further advantageous embodiments of the structure according to the invention will become apparent from the embodiment described in more detail below with reference to FIGS.

Showing:

1 a torsion spring of a substantially tubular member made of fiber-reinforced plastic material;

2 a load-introducing element according to the invention;

3 an enlarged view of a section of the Lasteinleitelements according to 2 ;

4 a composite of the load-introducing element according to the invention and the tubular component made of fiber-reinforced plastic material; and

5 a connection of the Lasteinleitelements to a lever.

In the presentation of the 1 is purely exemplary of a component made of fiber-reinforced plastic material, a torsion bar spring 1 to recognize for a motor vehicle. The torsion bar spring 1 consists essentially of a tubular component 2 , which consists of a fiber-reinforced plastic material. The tubular component 2 For example, by braiding pultrusion and / or wrapping one in the component 2 remaining or lost core. The component can either be produced as a straight tube and then bent or it can be formed by wrapping and / or braiding a already near net shape preformed core. As cores are also braided pipes of fiber-reinforced plastic material, cores made of foamed thermoplastic materials, but also cores made of sand, thin metallic hollow sections or generatively produced cores, which are produced for example by 3D printing process, laser sintering or the like conceivable. The core itself can be in the tubular component 2 remain or be removed from this, for example, melted out, washed out with suitable solvents or the like. The tubular component 2 as the main component of the torsion bar 1 is about two bearing elements 3 , which, for example, to the tubular member 2 are sprayed, connected to a receptacle, not shown, on a vehicle. This can be done in a conventional manner analogous to the usual construction of torsion springs of spring steel construction.

The two ends of the tubular component 2 each with the tubular member 2 connected load introduction elements 4 on. These are positively and optionally also cohesively with the material of the tubular member 2 connected. For this purpose, the load-transfer elements have a knob-like structure which forms a positive connection between the material of the component 2 and the load introduction element 4 allows.

In the presentation of the 2 is a possible Lasteinleitelement executed according to the invention 4 to recognize in a three-dimensional representation. The load introduction element 4 has an area at one end 5 for initiating a load. In this area 5 is an example of a bearing eye 6 arranged, which later in a manner described in more detail with a lever 7 for the introduction of the torsion bar spring 1 is designed to minimize rolling movements. The load introduction element 4 also has a connection area 8th on. In this connection area 8th is arranged a knob-like structure. In the particularly preferred embodiment shown here, this knob-like structure is designed so that it has a plurality of individual nubs 9 only one of which is provided with a reference numeral. The pimples 9 be there by first cuts 10 formed, which are parallel to each other across the surface of the connecting region 8th are arranged distributed. These first cuts 10 crossing are two cuts 11 arranged in a comparable manner. The angle of the incisions to each other should preferably be between 60 and 120 °, more preferably between 80 and 100 °. Overall, the incisions 10 . 11 again at an angle to the longitudinal axis of the Lasteinleitelements 4 trained, which will be discussed later. The first and second cuts 10 . 11 For example, by cutting shaping, in particular milling or the like, in the material of the Lasteinleitelements 4 , which is preferably made of a metal, in particular of a corrosion-resistant metal, to be introduced. Alternative manufacturing methods, such as erosion, are for introducing the first and second cuts 10 . 11 in the load introduction element 4 conceivable. Between the intersecting cuts 10 . 11 stay the individual pimples 9 stand in the production, as it is in particular from the enlarged view of 3 very good. In this illustration, it can also be seen that the second cuts 11 with a greater depth than the first cuts 10 are executed. This results in addition to the individual over the surface protruding nubs 9 a structure, which in the direction of the second cuts 11 grooved is executed.

The load introduction element 4 per se at least in the area where the connection area 8th is arranged, in cross-section an oval shape. This oval shape is determined in the embodiment shown here in particular by two semicircular side parts, which are connected to each other via straight lines in the area of the knob-like structure. The in the 2 and 3 recognizable knob-like structure is now also formed on the opposite side, here hidden, analog. The edges of the incisions 10 . 11 , but especially the knobs 9 , will typically have corresponding burrs after their production by milling or erosion. Such burrs could impair, in particular weaken or even destroy, the reinforcing fibers of the fiber-reinforced plastic material which is later to come into contact with the connection region. Therefore, on a very good deburring of individual pimples 9 and the edges of the incisions 10 . 11 to pay attention. Because the knob-like structure in the connection area 8th of the load introduction element 4 typically be made rather small, offers itself to the careful deburring of the pimples 9 as well as the edges of the incisions 10 . 11 Deburring via a dip. The metallic material of the load introduction element 4 will be in a suitable Liquid, such as an acid or an ablative liquid bath, as it is already used in surface cleaning processes given. The surface is easily attacked and it is a little material, especially in the area of ridges and sharp edges removed. At the same time there is a cleaning of the surface and an activation of the surface, since the removal or etching fine micropores arise. Subsequently, the Lasteinleitelement 4 then at least in the connection area 8th optionally coated with an adhesion promoter or primer. Due to the activation of the surface and the resulting micropores, this coating adheres very well in the connection area due to the surface activation during cleaning and simultaneous deburring of the knob-like structure 8th at.

The connection area 8th then comes with the material of the component 2 in contact. For this purpose, several possibilities are conceivable. In particular, the tubular component 2 over the connection area 8th of the load introduction element 4 pushed and then pressed to an oval shape. In this case, at the same time, a heating of the thermoplastic matrix material of the component 2 , For example, by preheating the pipe end and / or the Lasteinleitelements 4 , so that a firm and positive bond between the connection area 8th and the fiber reinforced material of the component 2 arises. In addition, if the thermoplastic matrix material of the component is melted, the optional adhesion promoter results in a very good material bond, so that a very good bond is achieved. The procedure described here has the advantage that it can be done independently of the production of the tubular component itself.

An alternative would be in the manufacture of the tubular component 2 , which can be made, for example, by braided pultrusion and / or winding of fiber-reinforced materials and suitable thermoplastic matrix materials, the load-introducing element 4 to contribute. The described structure of the knobs 9 and the first and second cuts 10 . 11 at a suitable angle to each other is ideal to a braided structure of the tubular member 2 customized. The braided material, which is typically braided with shelves of the order of 5 to 80 degrees from the center axis of the tube, ideally fits the angles of incisions of comparable magnitude 10 . 11 at. The material is thus very close to the pimples 8th braided and runs through the deeper second cuts 2 , This ensures a very good fit. If the thermoplastic matrix material is melted simultaneously during this process during braiding or afterward, an ideal shaping of the component takes place 2 in the area where it is with the load-introducing element 4 is in communication, so that a very good positive contact is ensured. In addition, a material bond can also be achieved here, which can be further improved by the use of the adhesion promoter or primer described above.

In the sectional view of 4 is such a positive and cohesive bond between the tubular member 2 and the load introduction element 4 again shown in the principle sectional view.

In the 5 Finally, it is still shown how the Lasteinleitelement about its bearing eye 6 with the already mentioned lever 7 , which at torsion bars 1 is known and customary, is connected. The lever 7 is doing about a bearing element 12 and a screw 13 with the bearing eye 6 in the load introduction element 4 connected. The bearing element 12 then stands over a bearing bush 14 in rotatable connection to the lever 7 , The introduction of forces then takes place via the lever 7 and the screw with the Lasteinleitelement 4 in the region of the tubular component 2 , After this introduction of the forces on the load introduction element 4 essentially take over the reinforcing fibers in the tubular member 2 the transmission of forces. Since the reinforcing fibers allow a higher internal tension than comparable structures made of spring steel, the levers 7 be built according to shorter, which again material, and thus weight and space can be saved. The structure allows so through the load-introducing element 4 according to the embodiment shown here a very lightweight and compact torsion bar spring 1 ,

The above examples with respect to the design of a torsion bar spring are to be understood in an analogous manner for the design of a roll stabilizer.

According to the invention designed torsion bars or roll stabilizers are suitable for vehicles of all kinds, especially for passenger and trucks and rail vehicles and trailers of these vehicles.

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 102008010228 A1 [0003]
• DE 102007051517 A1 [0003]

Claims (10)

Load introduction element ( 4 ) for introducing forces into a component ( 2 ) made of fiber-reinforced plastic material, with a connection area ( 8th ), through which the connection to the component ( 2 ) and with a load-bearing area ( 5 ), characterized in that the connection area ( 8th ) has at least partially a knob-like structure. Load introduction element ( 4 ) according to claim 1, characterized in that the knob-like structure nubs ( 9 ), which by crossing first and second cuts ( 10 . 11 ) in the connection area ( 8th ) are formed. Load introduction element ( 4 ) according to claim 2, characterized in that the first cuts ( 10 ) have a different depth than the second cuts ( 11 ). Load introduction element ( 4 ) according to claim 2 or 3, characterized in that the nubs ( 9 ) and / or the edges of the cuts ( 10 . 11 ) are deburred. Load introduction element ( 4 ) according to one of claims 2, 3 or 4, characterized in that the first and second cuts ( 10 . 11 ) are formed at an angle of 60 to 120 °, preferably 80 to 100 ° to each other. Load introduction element ( 4 ) according to one of the preceding claims, characterized in that the connection region ( 8th ) has a quadrangular, round or oval cross-section, wherein the knob-like structure in at least two areas, preferably diametrically opposite areas, the lateral surface is formed perpendicular to this cross-section. Load introduction element ( 4 ) according to one of the preceding claims, characterized in that the connection region ( 8th ), preferably the entire load introduction element ( 4 ), is formed of a metallic material, wherein at least parts of the connecting region ( 8th ) are coated with a primer. Torsion bar ( 1 ) or roll stabilizer for a motor vehicle with a substantially tubular component ( 2 ) made of fiber-reinforced plastic material and at least one Lasteinleitelement ( 4 ), characterized in that the load introduction element ( 4 ) is designed according to one of claims 1 to 7. Torsion bar or roll stabilizer according to claim 8, characterized in that the Lasteinleitelement ( 4 ) in the region of one end of the tubular component ( 2 ), wherein the end of the tubular component ( 2 ) is deformed to an oval shape, and the connection area ( 8th ) of the load introduction element ( 4 ) so that at least one of the materials of the tubular component ( 2 ) is in positive connection to the knob-like structure. Torsion bar or roll stabilizer according to claim 9, having a load-introducing element according to one of claims 2 to 7, characterized in that the tubular component ( 2 ) has at least one layer of braided reinforcing fibers, which in a braid angle of 5 to 80 ° relative to the central axis of the tubular member ( 2 ), wherein the first and / or the second cuts ( 10 . 11 ) of the load introduction element ( 4 ) at an angle which is formed in an angular range of -10 ° to + 10 °, preferably -5 ° to + 5 °, around the braiding angle.

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