DE102016223323A1 - Method for producing a handlebar, and handlebar and suspension - Google Patents

Abstract

The invention relates to a method for producing a link (1), in particular a link for a wheel suspension, wherein the link (1) is produced from a support structure (6) and at least one connecting structure (8), from which the support structure (6) a continuous fiber-reinforced plastic semi-finished product (11) and the at least one connecting structure (8) is formed from a short- or long-fiber reinforced plastic semi-finished product (13). In this case, the support structure (6) was preformed as a preform and is not yet completely cured in a manufacturing process cohesively connected to the at least one connecting structure (8). In order to create a handlebar (1), which is characterized by a high load capacity with low weight, the support structure (6) and the at least one connecting structure (8) are each formed from a duroplastic plastic semi-finished product (11, 13).

Description

The invention relates to a method for producing a link, in particular a link for a suspension, wherein the link is made with a support structure and at least one connection structure, of which the support structure of a continuous fiber reinforced plastic semi-finished and the at least one connection structure of a short or long fiber reinforced plastic semi-finished product is formed, and wherein the support structure has been preformed as a preform and is not yet fully cured in a manufacturing process cohesively connected to the connection structure.

Furthermore, the invention relates to a handlebar, in particular a handlebar for a suspension, which is composed at least of a support structure and at least one connection structure, wherein the support structure of an endless fiber-plastic composite and the at least one connection structure of a short fiber or long fiber plastic Composite is formed, and wherein the support structure has been connected in a manufacturing process as a not yet completely cured preform cohesively with the at least one connecting structure. Finally, the invention has a wheel suspension for a motor vehicle with at least one aforementioned handlebar for the subject.

In wheel suspensions wheel carriers are connected via intermediate links and joints with the vehicle body, the handlebars thereby form the rigid joints of the joints. In addition to wheel guiding tasks, the handlebars are often used for the realization of structural tasks by transferring spring and damper forces. Finally, handlebars are also part of the steering and roll suspension of a motor vehicle, where they then connect to a steering gear or a stabilizer. Depending on the number of joint points to be connected, a handlebar can be realized as a 2-point link, as a 3-point link or as a 4-point link.

Typically, handlebars are made of metal in the form of cast iron, steel or even aluminum, with the steel variant in particular being characterized by high strength, rigidity and ductility. A major disadvantage of handlebars made of metal, however, is that they have a high weight, usually an additional post-processing is necessary in the context of production and also measures against corrosion are to be taken. The higher weight increases the proportion of unsprung masses, which is reflected negatively in terms of driving characteristics and also the consumption of the respective motor vehicle. Furthermore, the necessary post-processing and the additional measures in terms of corrosion protection increase the production cost. For this reason, handlebars are increasingly also in hybrid design, so a combination of a metallic material with a fiber composite material, or purely made of fiber composites, in order to achieve a particularly light, strong and well-adaptable geometry geometry.

From the DE 10 2011 003 971 A1 goes out a handlebar, which is in particular a handlebar for a suspension. The handlebar has two hinge points, which are connected to each other via a support structure made of a continuous fiber-plastic composite. The support structure is designed box-shaped and is stiffened by a connection structure, which consists of a short or long fiber-plastic composite. According to one in the DE 10 2011 003 971 A1 described possibility, the support structure and the connection structure are thereby materially connected to each other, that the support structure is inserted in a not yet completely cured state in an injection mold and then the connection structure is made in the following. In this case, both the support structure, and the connecting structure made of a thermoplastic semi-finished plastic, so that the ultimately produced handlebar consists of a thermoplastic fiber-plastic composite.

Based on the above-described prior art, it is now the object of the present invention to provide a handlebar, which is characterized by a high load capacity with low weight.

This object is achieved from the procedural point of view, starting from the preamble of claim 1 in conjunction with its characterizing features. From a device technical point of view, a solution of the problem is based on the preamble of the independent claim 10 in conjunction with its characterizing features. The respective subsequent dependent claims give each advantageous embodiments of the invention. A wheel suspension in which at least one handlebar according to the invention is used is also the subject of claim 12.

According to the invention, in one method a handlebar having a support structure and at least one connection structure is produced, of which the support structure is formed from a continuous fiber-reinforced plastic semi-finished product and the at least one connection structure is formed from a short- or long-fiber-reinforced plastic semi-finished product. there the support structure was preformed as a preform and is not yet fully cured in a manufacturing process cohesively connected to the at least one connection structure.

In the context of the method according to the invention, a link is formed which is composed of at least one support structure and at least one connecting structure. Here, the support structure of an endless fiber-plastic composite and the at least one connection structure of a short fiber or long fiber-plastic composite is formed. In addition, the support structure has been connected in a manufacturing process as a not yet fully cured preform cohesively with the at least one connection structure.

An inventive handlebar is thus made of a fiber-plastic composite, in which case a support structure of continuous fibers is combined with at least one connecting structure of short or long fibers. As a result, a handlebar can be realized, which is characterized by a low weight and a good load capacity. Because by the continuous fibers of the support structure high loads can be absorbed by appropriate alignment of the fibers, while the at least one connecting structure by their short or long fibers increases the stability by targeted stiffening of the support structure. Overall, this makes it possible to absorb both tensile and compressive forces, as well as bending loads and torsional loads by the handlebars.

The link according to the invention preferably comprises two pivot points and is accordingly realized as a 2-point link, the support structure extending between the two pivot points. Alternatively, however, it is also conceivable that the handlebar according to the invention is equipped with three or more hinge points between which the support structure extends. In this case, the link according to the invention is designed in particular for a suspension and provided here as a guide arm, support arm or as an auxiliary link. In principle, a handlebar designed according to the invention could also be used in a steering or a roll suspension of a motor vehicle as a tie rod / steering link or as a stabilizer link.

In addition, a sensor system can be integrated into the handlebar, by means of which a change in the fiber composite structure of the arm can be recognized and / or loads or overloads or overstresses can be detected. Furthermore, an elastomer material could also be integrated into the fiber composite structure to form a laminate, in order to realize an improvement in the acoustic properties in the corresponding area in the sense of acoustic damping. In addition, in the respective area by the integration of elastomers in the fiber-reinforced plastic composite also impact and splinter protection can be realized.

According to the invention, the at least one connection structure is provided in particular for stiffening the support structure and thereby integrally connected thereto by connecting the support structure and the at least one connection structure in a not yet fully cured state of the support structure. Because due to the not yet complete curing of the support structure, a material bond between the support structure and the at least one connection structure is formed, which then harden together as part of the manufacturing process. As a result, the load capacity of the handlebar according to the invention can be increased due to the improved connection of support structure and connection structure.

Furthermore, the at least one connecting structure can also be provided specifically at kinematic points of the link, for example in the region of articulation points of the link. It would also be conceivable that the at least one connecting structure produces the connection of the individual hinge point to the support structure, that is, between the support structure and the respective hinge point is provided. In this case, in the handlebar according to the invention preferably a coherent connection structure is configured, but also a plurality of separate connection structures may be present, which are provided specifically in certain areas of the support structure.

The at least one connection structure is designed in the sense of the invention, in particular rib-like, in order to realize the desired stiffening of the support structure. In this case, walls of a ribbing with respect to a longitudinal central axis of the arm can be arranged substantially diagonally diamond-shaped.

The invention now includes the technical teaching that the support structure and the at least one connecting structure are each formed from a respective duroplastic plastic semi-finished product. In this respect, the support structure and the at least one connecting structure in a link according to the invention each consist of a thermosetting fiber-plastic composite. Such a configuration has the advantage that can be realized due to the use of thermosetting materials, a resilient handlebar whose capacity is not dependent on the operating temperature. For a thermosetting material does not come after curing no longer temperature-induced changes in shape, while in thermoplastic materials in certain Temperature ranges deformations may occur. Since a handlebar is a suspension but a rigid connection and accordingly unwanted deformations are to be avoided, can be realized by manufacturing the handlebar from thermoset plastic semi-finished a suitable handlebars.

In contrast, find the handlebar of the DE 10 2011 003 971 A1 thermoplastic materials application, so that there is a risk that occur in certain temperature ranges unwanted deformations of the handlebar.

In the context of the invention, the continuous fiber-reinforced plastic semifinished product can be in particular in the form of pre-impregnated fibers (towpreg), as semi-finished textile product (prepreg), in the form of dry fibers or as semi-finished textile products (preforms) or as pre-resin transfer molding (RTM) or prepreg compression Molding (PCM) produced semi-finished product. In contrast, the plastic semifinished product of the at least one connecting structure is preferably present either as a short-fiber-reinforced plastic semi-finished product, for example in the form of bulk molding compound (BMC) or as thermoset injection molding, or is designed as a long-fiber-reinforced plastic semi-finished product, in particular in the form of sheet molding compound (SMC).

In the case of the support structure and the at least one connecting structure, different types of fiber may be used as fibers, such as carbon, glass, aramid, basalt, etc. The surrounding plastic matrix may in principle be selected from different duroplastic materials, such as epoxy, polyurethane, vinyl ester, etc In this case, the materials used may deviate between the support structure and the at least one connection structure or, in the case of several connection structures, also between the connection structures.

According to one embodiment of the invention, first at least two hinge points of the link are wrapped in preforming of the support structure, wherein the support structure is then connected in the manufacturing process cohesively with the at least one connection structure. Particularly preferably, the support structure is formed by means of wet winding process or winding process with Towpreg by the at least two hinge points are wrapped with the fibers. However, it is within the meaning of the invention also conceivable that the windings are performed on later used bearing bushes for joints of the handlebar. Furthermore, alternatively, a winding of the support structure to an already prefabricated connection structure can be completed, both of which are then completely cured in a common process step.

According to a further embodiment of the invention, an inner region is defined by the support structure, in which the at least one connection structure is provided. The support structure is accordingly provided in the produced handlebar as an outer winding, which surrounds the stiffening, at least one connection structure. According to an alternative variant, the support structure is connected to the at least one connecting structure. In this case, the support structure is realized as an inner winding, which has the advantage over an outer winding that the support structure can be better protected by the surrounding connection structure from external influences. In particular, when realizing the inner support structure, first hinge points of the link to be wrapped with the support structure.

It is a further embodiment of the invention that in addition at least one insert plate is provided, which was also prefabricated as a preform and is connected in the manufacturing process cohesively with the at least one connecting structure. The use of at least one insert plate has the advantage that in this way the load capacity of the handlebar according to the invention can be further increased.

Particularly preferably, the at least one insert plate is designed as a continuous fiber-plastic composite, by being made of a continuous fiber-reinforced plastic semi-finished product. The advantage here is that according to a selected layer structure of the insert plate and thus the orientation of the fibers can be adapted to expected load conditions can be realized. Thus, the individual layers of the layer structure can have rectified or differently oriented fibers. More preferably, an insert plate made of a continuous fiber-reinforced plastic semi-finished product is also not yet fully cured with the other components connected.

However, the at least one insert plate or even in the case of several insert plates, a single insert plate can be produced from a short- or long-fiber-reinforced plastic semifinished product or metal. In addition, if necessary, the at least one insert plate is also embedded in the connection structure without forming a material bond. Furthermore, an insert plate could also be completely eliminated in a handlebar according to the invention.

According to a further advantageous embodiment of the invention, the components to be joined in the manufacturing process by hot pressing together. For this purpose, the components are placed in a reheated tool and this closed to the pressing process to start. Due to the temperature and the pressure in the cavity, the at least one connecting structure begins to equalize and harden the tool-provided contour. In the course of the hot pressing process then harden the support structure and possibly also the at least one insert plate.

According to a further embodiment of the invention, a joint in the form of a rubber bearing or a ball joint is provided at a respective pivot point of the handlebar. Thus, in a 2-point link at one pivot point a ball joint and at the other hinge point may be provided a rubber bearing or also be present at both hinge points rubber bearings or ball joints.

In combination of the aforementioned embodiment with the previously described variant, according to which the components are connected to each other in a hot pressing process, it is a development of the invention that the respective joint is miteingebettet already in the course of hot pressing. As a result, the production cost can be significantly reduced, since all components are connected together in the context of a manufacturing step. In addition, in addition, a respective sensor of the handlebars are already miteingebettet. Alternatively, it is also conceivable that the corresponding joints are used only after curing of the fiber-plastic composite, in which case optionally in the course of hot pressing corresponding bearing bushes, in particular in the form of metallic bushings are provided.

An inventively designed handlebar is in particular part of a wheel suspension of a motor vehicle and is then provided here as a guide arm, as a support arm or as an auxiliary link. However, a suspension preferably comprises a plurality of handlebars designed according to the invention.

The invention is not limited to the specified combination of the features of the independent or the dependent claims. It also results in ways to combine individual features, even if they emerge from the claims, the following description of preferred embodiments of the invention or directly from the drawings. The reference of the claims to the drawings by use of reference numerals is not intended to limit the scope of the claims.

• 1 Ansichten eines Lenkers entsprechend einer ersten Ausführungsform der Erfindung;
• 2 ein schematisierter Ablauf eines Verfahrens zur Herstellung des Lenkers aus 1;
• 3 eine zerlegte Darstellung des Lenkers aus 1;
• 4 Ansichten eines Lenkers gemäß einer zweiten Ausgestaltungsmöglichkeit der Erfindung; und
• 5 Ansichten eines Lenkers entsprechend einer dritten Ausführungsform der Erfindung.

Advantageous embodiments of the invention, which are explained below, are shown in the drawings. It shows:

• 1 Views of a handlebar according to a first embodiment of the invention;
• 2 a schematic sequence of a method for producing the handlebar from 1 ;
• 3 a disassembled representation of the handlebar 1 ;
• 4 Views of a handlebar according to a second embodiment of the invention; and
• 5 Views of a handlebar according to a third embodiment of the invention.

In 1 are views of a handlebar 1 illustrated according to a first embodiment of the invention, wherein the upper view is a perspective view of the handlebar 1 and the bottom view shows a sectional view of the same. It can be seen that the handlebar 1 in the present case as a 2-point handlebar with two articulation points 2 and 3 is designed, wherein at the hinge point 2 a joint in the form of a ball joint 4 and at the hinge point 3 a - not shown in detail here - joint in the form of a rubber bearing 5 is provided.

The driver 1 consists of a fiber-plastic composite and includes a support structure 6 between the hinge points 2 and 3 runs and is composed of a thermosetting continuous fiber-plastic composite, in particular CFRP or GFRP. The support structure 6 defines an interior area 7 in which the points of articulation 2 and 3 lie. This will be the points of articulation 2 and 3 and thus also the ball joint 4 as well as the rubber bearing 5 with the support structure 6 via a connection structure 8th connected, which consists of a thermosetting short fiber-plastic composite and the interior 7 the support structure 6 largely completed. Between the hinge points 2 and 3 forms the connection structure 8th also a ribbing 9 , which - as can be seen in particular from the top view - in the longitudinal direction of the handlebar 1 Diagonal diamond-shaped is designed. Furthermore, in the connection structure 8th another insert plate 10 embedded in a thermosetting continuous fiber-plastic composite, as shown in the lower section in FIG 1 you can see. Likewise, in the handlebars 1 also still a - not shown here - be embedded with sensor technology.

Through the the hinge points 2 and 3 surrounding support structure 6 In general, tensile loads are absorbed via the continuous fibers, in combination with the stiffeners via the connecting structure 8th also pressure loads can be absorbed. The internal connection structure 8th provides additional stability with regard to bending loads along and across the grain direction of the support structure 6 and increases a moment of resistance at torsional loads. Furthermore, the additionally provided insert plate offers 10 made of endless fibers, a further reinforcement in the axial direction of the handlebar 1 and increases resistance to bending and torsion. Here is the connection structure 8th both with the support structure 6 , as well as the insert plate 10 cohesively connected.

In 2 is a method of manufacturing the handlebar 1 out 1 shown schematically. As can be seen, plastic semi-finished products are being prepared in advance 11 and 12 for the support structure 6 and the insert plate 10 , a plastic semi-finished product 13 for the connection structure 8th , the ball joint 4 and the rubber camp 5 and a sensor 14 prepared. Here are the plastic semi-finished products 11 and 12 as duroplastic endless fiber reinforced plastic semi-finished products, wherein in the case of the plastic semi-finished product 11 for the support structure 6 preimpregnated continuous filaments in the course of a wet winding process or a winding process with towpreg about two points of articulation 2 and 3 representative points are wound. In contrast, in the case of the plastic semi-finished product 12 for the insert plate 10 several pre-impregnated textile semi-finished plastic products stacked to form a layer structure, in which case an orientation of the continuous fibers per layer is adapted to the later expected load. Thus, the individual layers may have the same fiber orientation or different fiber orientations of the layers stacked on top of each other are selected.

On the other hand, the plastic semi-finished product 13 for the connection structure 8th formed by a short fiber reinforced plastic semi-finished product, wherein it is present in particular as GRP or CFRP in the form of bulk molding compound (BMC) or sheet molding compound (SMC), or as a thermoset injection molding. The plastic semi-finished products 11 to 13 then be in a tool 15 together with the ball joint 4 and the rubber camp 5 , as well as the sensors 14 positioned to each other, wherein the plastic semi-finished products 11 and 12 although as a preform but not yet fully cured. In addition, the insertion of the components in the tool should 15 timely to the prefabrication of plastic semi-finished products 11 and 12 take place to avoid contamination. With regard to the plastic semi-finished product 13 can also be a layer below and above the future insert plate 10 to be evenly distributed around the insert plate 10 to guarantee around.

In a subsequent step, the pre-heated tool 15 closed and started a hot pressing process. This starts the plastic semi-finished product 13 due to the temperature and the pressure in the cavity to match the tool-given contour and harden. Likewise, the plastic semi-finished products harden 11 and 12 to the support structure 6 and the insert plate 10 from, in which case the cohesive connections with the connection structure 8th form. In addition, as part of the curing process, the ball joint 4 , the rubber bearing 5 and also the sensors 14 embedded. Following this, then the finished handlebar 1 be removed.

In 3 are once again the items of the handlebar 1 represented, from which this is composed. It can in the support structure 6 the interior 7 be recognized, in which the connection structure 8th the insert plate 10 and also the rubber camp 5 as well as the ball joint 4 be recorded.

Furthermore, in 4 Views of a handlebar 16 illustrated according to a second embodiment of the invention. This differs from the variant described above in that a support structure 17 which are between two hinge points 18 and 19 of the handlebar 16 runs, lying inside a connection structure 20 is trained. The support structure 17 So is the connection structure 20 surrounded, the support structure 17 , as in the previous variant, consists of a thermosetting continuous fiber-plastic composite and cohesively with the connection structure 20 connected is. Likewise, there is also the connection structure 20 again from a thermoset short fiber plastic composite. In addition, the handlebars 16 an insert plate 21 made of a thermosetting continuous fiber-plastic composite. Otherwise, the variant corresponds to 4 the previous variant, so that reference is made to that described. In particular, the handlebars 16 on the to 2 described manner.

Finally, in 5 another view of a handlebar 22 shown according to a third embodiment of the invention. This, too, essentially corresponds to that in the 1 to 3 variant described, with the only difference in hinge points 23 and 24 Rubber bearing 25 and 26 are provided. Otherwise, the variant corresponds to 5 otherwise in the 1 to 3 shown embodiment, so that reference is made to that described. So will the handlebars 22 analogous to that 2 manufactured method described, in which case instead of a ball joint, a rubber bearing is provided.

By means of the inventive embodiments of a handlebar, as well as a inventive method for producing desselbigen a resilient arm made of a fiber-plastic composite can be realized.

LIST OF REFERENCE NUMBERS

1

handlebars

2

fulcrum

3

fulcrum

4

ball joint

5

Rubber bearing

6

support structure

7

interior

8th

connecting structure

9

ribbing

10

insert plate

11

Plastics semi

12

Plastics semi

13

Plastics semi

14

sensors

15

Tool

16

handlebars

17

support structure

18

fulcrum

19

fulcrum

20

connecting structure

21

insert plate

22

handlebars

23

fulcrum

24

fulcrum

25

Rubber bearing

26

Rubber bearing

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 102011003971 A1 [0005, 0017]

Claims (12)

Method for producing a link (1; 16; 22), in particular a link for a wheel suspension, wherein the link (1; 16; 22) is produced with a support structure (6; 17) and at least one connecting structure (8; 20), of which the support structure (6; 17) consists of a continuous fiber-reinforced plastic semi-finished product (11) and the at least one connecting structure (8; 20) is formed from a short- or long-fiber-reinforced plastic semi-finished product (13), and wherein the support structure (6; 17) serves as a preform was preformed and not yet completely cured in a manufacturing process materially connected to the at least one connecting structure (8; 20), characterized in that the support structure (6; 17) and the at least one connecting structure (8; 20) each consist of a thermoset Plastic semi-finished products (11, 13) are formed. Method according to Claim 1 , characterized in that first at least two hinge points (2, 3, 18, 19, 23, 24) of the link (1; 16; 22) are wrapped in preforming of the support structure (6; 17) and subsequently integrally bonded in the manufacturing process the at least one connection structure (8; 20) is connected. Method according to Claim 1 or 2 , characterized in that by the support structure (6) an inner region (7) is defined, in which the at least one connecting structure (8) is provided. Method according to Claim 1 or 2 , characterized in that the support structure (17) is connected to the surrounding at least one connecting structure (20). Method according to one of the preceding claims, characterized in that in addition at least one insert plate (10; 21) is provided, which was also prefabricated and in the manufacturing process materially connected to the at least one connecting structure (8; 20). Method according to Claim 5 , characterized in that the at least one insert plate (10, 21) made of a continuous fiber-reinforced plastic semi-finished product (12) is produced. Method according to one of the preceding claims, characterized in that the components to be joined in the manufacturing process by hot pressing are interconnected. Method according to one of the preceding claims, characterized in that at a respective hinge point (2, 3; 18, 19; 23, 24) of the link (1; 16; 22) a joint in the form of a rubber bearing (5; 25, 26) or a ball joint (4) is provided. Method according to Claim 7 and 8th , characterized in that the respective joint is already embedded in the course of the hot pressing. Handlebar (1; 16; 22), in particular handlebar for a wheel suspension, which is composed at least of a support structure (6; 17) and at least one connecting structure (8; 20), wherein the support structure (6; 17) consists of a continuous fiber plastic Composite and the at least one connecting structure (8; 20) is formed from a short-fiber or long-fiber-plastic composite, and wherein the supporting structure (6; 17) in a manufacturing process as a not yet fully cured preform cohesively with the at least one connecting structure ( 8; 20), characterized in that the support structure (6; 17) and the at least one connection structure (8; 20) each consist of a duroplastic fiber-plastic composite. Handlebar (1; 16; 22) to Claim 10 characterized in that it further comprises one or more of Claims 2 to 9 is designed. Wheel suspension for a motor vehicle, comprising at least one link after Claim 10 or 11 ,

Images