KR20190005754A - Method for producing a bearing bush, bearing bush and control arm for a wheel suspension of a motor vehicle - Google Patents

Abstract

The present invention relates to a method for producing a bearing bush (7) for a control arm of a wheel suspension. A body of the bearing bush (7) is made of a fiber/plastic composite material and defines an accommodation part for a joint in a cavity. In the case, in order to produce the bearing bush (7) with load-bearing capability at low cost, the body is produced by a draw-forming process. The present invention also relates to the bearing bush (7) for the wheel suspension of a motor vehicle and the control arm.

Description

TECHNICAL FIELD The present invention relates to a bearing bush for a wheel suspension of an automobile, a bearing bush, and a control arm.

The present invention relates to a method for manufacturing a bearing bush for a control arm of a wheel suspension, wherein the body of the bearing bush is made of a fiber / plastic composite material and defines a receptacle for the joint in the cavity. The present invention also relates to a bearing bush and a control arm for a wheel suspension of an automobile.

  Control arms for wheel suspensions are typically embodied as metal parts, but this leads to an essential drawback of heavy weight, the need for additional reprocessing in the category of manufacture, and the provision of additional measures for corrosion protection. For this reason, control arms are increasingly being embodied as hybrid components, in which each control arm is partly formed of a metal material and partly of plastic. Thereby, a clear weight reduction can be achieved compared to the type in which only the metal is used, and the risk of corrosion in addition to that can be reduced.

However, the control arms of the hybrid structure also have drawbacks. That is, due to the different electronic potentials, contact corrosion occurs mainly between the metallic components and the components of the plastic material, which necessitates the use of additional adhesives or the insertion of additional boundary layers. Moreover, sufficient adhesion between the mating members made of metal and plastic can only be realized through a costly pretreatment process, or requires additional shape fittings that further complicate manufacture on the surface. Further, the mating mating members typically have different sized expansion coefficients, which can cause internal stresses in the component either during the heat load and cooling conditions during manufacture or even during subsequent operation. Finally, different stiffnesses or tensile / compressive strengths of the materials may result in sudden stiffness changes in the part. Therefore, the control arms for wheel suspensions are made partly or completely of fiber / plastic composites.

From DE 10 2015 222 297 A1 a method is disclosed for the manufacture of a bearing bush for a control arm of a wheel suspension, wherein the bearing bush is extruded or hot-compacted of a fiber preform with a fiber / plastic composite material . To this end, first of all, a fiber-matrix semi-finished product containing a duroplastic matrix is inserted into a press die and pressed to form a body, in which the body receives the receptacle for the joint of the subsequent control arm And a cavity defined therein.

It is now an object of the present invention to provide a method of manufacturing a bearing bush which enables to manufacture bearing bushes with load bearing capability under the category of a method for manufacturing bearing bushes at low cost starting from the above- .

The above problem is solved based on the premise of the claim together with the features of the feature of claim 1. The dependent claims subsequent to claim 1 reflect each of the preferred embodiments of the invention. Also, the bearing bush produced in accordance with the present invention is the subject of claims 10 and 11. Finally, in claim 12, a control arm is claimed comprising at least one bearing bush made in accordance with the present invention.

In accordance with the present invention, in the course of the method for manufacturing the bearing bushes, the body of the bearing bushes is made of a fiber / plastic composite material, which defines the receptacles for the joints in the cavity. In other words, the body, in its finished state, has one or more cavities formed therethrough, which determine the receptacles for the joints of the control arms. In this case, particularly preferably, the cavity is formed in a cylindrical shape so that a ball joint, a sleeve joint, a rubber bearing, etc. can be accommodated in the bearing bush.

The body of the bearing bush may be embodied as a solid body, except for the hollow portion. Preferably, however, the body is provided with recesses at suitable locations to save material and reduce weight. In this case, the recesses are arranged so that the bearing bush can absorb the forces and moments introduced through each joint and transmit it to the rest of each control arm.

The body of the bearing bush is composed of a fiber / plastic composite material according to the invention and correspondingly formed of reinforcing fibers and a plastic matrix.

On the other hand, the present invention includes technical teaching that the body of the bearing bush is manufactured in a draw-forming process. In other words, the process of manufacturing the body of the bearing bush with a fiber / plastic composite material is performed during the drawing and forming process.

In this case, the method of the above type for the production of bearing bushes is advantageous in that the manufacturing cost can be kept low on the basis of the manufacture in the course of the draw-forming process and, at the same time, There is also the possibility of achieving the rigidity of the body. Also, with this, more complex geometries of the body can be manufactured. As such, for example, in addition to the cavity, additional recesses can be provided without problems. At the same time, based on its implementation as a fiber / plastic composite material, the weight is kept light and the problem of corrosion is prevented.

Even in DE 10 2015 222 297 A1 the bearing bushes are made of a fiber / plastic composite material, but the production in the course of extrusion or hot pressing is correspondingly complicated.

"Drawing forming process" means that in the context of the present invention, fibers and / or semi-finished products (knitted / knitted fabric / fiber mat) are molded, impregnated and cured in the context of continuous processing, Means the well-known method. Then, the cutting to the desired length is then performed. The advantage of the process, also known as "pultrusion method" or "pultruding", is that with elongated fiber-reinforced plastic profiles that are cut to the desired length at the end of the process .

In accordance with one embodiment of the present invention, the body is made of continuous fiber reinforced fiber / plastic composite material. In this case, the use of continuous fiber reinforcement has the advantage that high rigidity can be realized in the body to be produced. Thus, through a corresponding matching of the orientation of the continuous fibers in the plastic composite against the expected load, a bearing bush with load bearing capacity similar to the metal bearing bush can be realized.

According to another possible configuration of the invention, the body is formed into one or more semi-finished products in the course of the drawing and forming process. In this case, in particular, the fabric semi-finished product is applied in the form of a knitted or knitted fabric molded into the body in the course of a drawing-forming process, or in the form of a fiber mat.

In an improvement of the above-described configurability, one or more semi-finished products are molded, impregnated, and cured into a body or a contour that forms a part of the body in the course of a draw forming process. In other words, the semi-finished product, which is present in two dimensions, is molded so that the body itself or a part of the body is constituted in the process of the drawing-forming process. Subsequently, impregnation with the matrix is carried out, followed by further curing of the formed profile. In the simplest case, a single semi-finished product is used for the manufacture of the body, that is to say the complete body is formed from the semi-finished product in the course of the drawing and forming process.

However, particularly preferably, during the drawing-forming process, a plurality of semi-finished products having different fiber orientations are used. This has the advantage that matching to different requirements with respect to the load bearing capacity of the bearing bushes through different orientations of the fibers can also be carried out. In this case, particularly preferably, two semi-finished products are used, one side semi-finished product has a fiber orientation of 0 ° and 90 °, while the other side semi-finished product has a fiber orientation of +/- 45 °. It is also conceivable in the context of the present invention that, apart from semi-finished products, fibers are also supplied in the course of a draw forming process to realize certain properties of the bearing bushes through corresponding orientations by the fibers.

 Also, in the context of the present invention, in the course of the draw-forming process, the pre-production of one or more semi-finished products is carried out in the process of the so-called pultrusion-winding method, or in the so-called pultrusion- There is also a possibility that it can be performed in the process of braiding method. Thereby, preformed members of fibers, especially of tubular shape, can be pre-manufactured, followed by additional layers of matrices and, if desired, semi-finished products.

According to another embodiment of the present invention, carbon, glass, aramid and / or basalt are used as fiber types for fiber / plastic composite materials. Further, in this case, in order to realize the different characteristics of the bearing bush, a plurality of the above-mentioned fiber types may also be combined with each other. However, the use of glass fibers or carbon fibers is particularly preferred.

As an alternative or supplement to the foregoing, thermoplastics and / or duo plastics materials are used as matrices for fiber / plastic composite materials. Again, the matrix may also be made of a mixture of the two material types. As the thermosetting material, an epoxy resin, a polyether resin, or a vinyl ester resin can be used. Conversely, in the case of thermoplastic materials, polyamide, polypropylene or polyethylene may be used.

According to another embodiment of the present invention, the body has grooves on the outer circumferential surface. As a result, the contact surface can be enlarged and accordingly, the connection with the adjacent portion of each control arm can be formed to have a higher load-bearing capacity, because the shape-fitting portion can thereby be realized. As such, by providing the grooves, a grooved structure can be formed on the body that also prevents the relative movement of the body with respect to the respective peripheral portion of the control arm and hence the movement of the bearing bush.

In a refinement of the above-described embodiment, a single connecting device is inserted into each individual groove, each of which includes protruding elements relative to the connecting body. Through the protruding elements, which are preferably formed in the form of a pin and provided on the support material, the connection with the peripheral part in the course of the manufacture of the control arm can be further improved. In this case, the projecting elements can be provided in one line or in multiple lines, so that in the latter case a three-dimensional connection device is achieved. Also, the individual projecting elements can be formed differently with respect to their inclination and their orientation.

The process of mounting or disposing the connecting devices in the grooves may be performed immediately before or after the draw forming process for manufacturing the body according to the present invention, while at the same time the connecting devices are each preferably bonded. Particularly preferably, the mounting is carried out immediately after curing in the course of the draw-forming process, whereby the connecting devices are also cut to the desired length together with the remainder.

The object of the invention is also a bearing bush for a control arm of a wheel suspension, the bearing bush comprising a body made of a fiber / plastic composite material and defining a receiving portion for the joint in the cavity. The joint is used for connection to adjacent components within the wheel suspension. According to the present invention, the body was manufactured in a drawing and forming process. Further, the bearing bushes can then be formed according to any of the variants described above.

The bearing bush produced in accordance with the present invention is particularly a part of a control arm for wheel suspension of an automobile. In this case, the control arm preferably includes a connecting member connecting the joints provided at the joint points to each other. In this case, one or more of the joints are made in accordance with the invention and are received in a bearing bushing which is connected to the connecting member. In this case, specifically, the control arm may be formed as a two-point, three-point or four-point control arm, wherein each of the joint points may be provided with a bearing bush made in accordance with the present invention. The connecting member is also preferably realized as a fiber / plastic composite material, and the connecting member and one or more bearing bushes are also joined together in a material-bonded manner in the course of manufacturing the control arms.

The present invention is not limited to the explicit combination of the features of the equivalents or the dependent claims. Further, possibilities of combining the individual features deduced in the claims, the following description of the preferred embodiments of the invention, or the drawings are achieved. In addition, references to the claims with respect to the drawings using the reference numerals should not limit the scope of protection of the claims.

Preferred embodiments of the present invention described below are illustrated in the drawings.

1 is a perspective view of a control arm for wheel suspension.
Figure 2 is a cross-sectional view of a bearing bush as can be applied in the control arm of Figure 1;
Figure 3 is a schematic view showing a method for manufacturing the bearing bush of Figure 2;
Figure 4 is another schematic diagram illustrating a method for manufacturing the bearing bush of Figure 2;
Figure 5 is a schematic view showing an alternative method for manufacturing the bearing bush of Figure 2;
Figure 6 is a cross-sectional view of a bearing bush, likewise applicable to the control arm of Figure 1;
Figure 7 is a view of a bearing bush as can be alternatively applied in the control arm of Figure 1;
8 is a view showing a bearing bush as can be applied as a further alternative in the control arm of Fig.
Figure 9 is a schematic view showing a portion of a method for manufacturing the bearing bush of Figure 7;
Figure 10 is a schematic view showing a portion of a method for manufacturing the bearing bush of Figure 8;
Figure 11 shows the bearing bush of Figure 8 in the process of assembling the control arm and subsequent use.

1 is a perspective view of a control arm 1 for wheel suspension of an automobile, wherein the control arm 1 is embodied as a two-point control arm. The control arm 1 thus comprises two joint points 2 and 3 at which the control arm 1 is mounted and connected to the respective adjacent components of the wheel suspension Is performed, and one joint (4 or 5) is provided for each of the joint points. In this case, the joints 4 and 5 are each embodied as a rubber bearing.

The control arm 1 is made entirely of a fiber / plastic composite material, except for the joints 4 and 5, in the case of the present embodiment. As such, the control arm 1 includes a connecting member 6 extending between the joints 4 and 5. In this case, each connection of each joint 4 or 5 to the connecting member 6 is formed through one bearing bush 7 or 8, respectively. In addition, for reinforcement of the control arm 1, a further insert member 9 is provided in the region between the joint points 2 and 3.

In this case, the bearing bushes 7 and 8 are each also made of a fiber / plastic composite material and are discussed in more detail in the following in the example of bearing bushing 7. In this case, the same reference numerals are used for the same-named parts, although the parts may differ from each other.

2 is a sectional view of a bearing bush 7 as can be applied to the control arm 1 in Fig. In this case, the bearing bush 7 is formed of a body 10 made of a fiber / plastic composite material reinforced with continuous fibers. In this case, the main body 10 defines a receiving portion in the cylindrical hollow portion 11, and the receiving portion is provided with a joint 4 corresponding to the control arm 1 in Fig. A plurality of recesses 12 are formed through the main body 10. In this case, in Fig. 2, individual fibers 13 of a fiber / plastic composite material are specified, the individual fibers extending inside the plane of the drawing. However, the fibers of the fiber / plastic composite material are arranged to extend from their orientation, so that the force and moment when using the control arm 1 will be absorbed through the bearing bush 7 in the future.

On the other hand, in Figs. 3 and 4, schematically, respectively, a method for manufacturing the bearing bush 7 of Fig. 2 is shown. In this case, the production is basically carried out in the course of a drawing-forming process known to the ordinarily skilled artisan. In this case, in the first step, the semi-finished products 14 and 15 are supplied to the pre-forming station 16 and are molded and impregnated into the contour which forms a part of the body 10, respectively, in the pre-forming station 16 . In this case, a tubular section 17 defining a cavity 11 in the body 10 is formed from the semi-finished product 15, in particular as seen in Fig. On the contrary, from the semi-finished product 14, the section 18 forming the outer peripheral surface in the following main body 10 is formed.

In this case, the shaping of the semi-finished products 14 and 15 is carried out sequentially, wherein impregnation is preferably carried out with a duo plastic matrix and / or thermoplastic matrix. The semi-finished products 14 and 15 are provided as rollers and include fiber mats. In this case, the fiber orientation of the fiber mat of the semi-finished product 14 is preferably performed at 0 ° and 90 °, while in the case of the semi-finished product 15 the fiber orientation is particularly +/- 45 °.

Following the pre-forming station 16, the shaped and impregnated semi-finished products 14 and 15 are fed to a hardening tool 19 and the hardening of the shape formed in the hardening tool is performed. Following this, cutting is performed through the saw 20, in particular as shown in Fig. 4, in accordance with the length of the bearing bushes 7. Fig. Whereby the final bearing bush 7 is formed.

As the fibers, different plastic fibers may be used, which may be bonded together if necessary. That is, the use of fibers made of carbon, glass, aramid, basalt, etc. may be considered.

5 shows, additionally, as a schematic diagram, an alternative manufacturing method for the production of the bearing bush 7. Here, the only difference from the above is that, as the tubular section 17 is made of fibers in advance by the winding or piling method, the manufacturing is finally carried out in the course of the pearl trance winding method or the pearl truss winding method It is.

Fig. 6 shows an alternative construction of the bearing bush 7 as can be applied in the control arm 1 of Fig. This configuration differs from the overall modification of Fig. 2 in that a plurality of grooves 22 are provided on the outer circumferential surface 21 of the main body 10. The grooves 22 correspondingly define the recessed structure of the bearing bush 7 so that the connection with the peripheral connecting member 6 is improved with the bearing bushes mounted in the control arm 1. [ In this case, the formation of the outer peripheral surface 21 of the main body 10 is likewise carried out in the category of the drawing forming process.

7 shows another alternative configuration of the bearing bush 7 generally corresponding to the above-described modification according to Fig. The difference is that in each of the grooves 22, one connecting device 23 is provided, each of which comprises the elements 24 protruding relative to the main body 10 of the bearing bush 7. In this case, as seen in the detail in FIG. 7, the elements are provided on the support material of the linking device 23 in a line. Also, the tilt of the elements 24 and their orientation are formed differently. In this case, through the elements 24, the shape engagement with the peripheral connecting member 6 is improved in the manufacturing process of the control arm 1.

Fig. 8 shows another configuration of the bearing bush 7, which can likewise be applied to the control arm 1 in Fig. In this case, grooves 22 are provided on the outer circumferential surface 21 of the body 10, similar to the modification according to Fig. 7, in which case the grooves 22 are formed in the variant example But is provided with a relatively larger extension. Also as in the variant according to FIG. 7 already, one connecting device 23 is provided, each of which includes the projecting elements 24 in each groove 22. However, contrary to the variant according to FIG. 7, the elements 24 are formed here in several rows. This also makes it possible to improve the shape engagement with the peripheral connecting member 6 in the production of the control arm 1.

9 and 10 show the timing at which the respective arrangements of the connecting devices 23 are executed in the course of the manufacturing process of each bearing bush 7. 9 and 10, the process of disposing the linking device 23 into the grooves (not shown here) is performed after curing and before the length cutting, in which the linking devices 23 are respectively inserted do.

Finally, also in Fig. 11, the bearing bush 7 of Fig. 8 is connected to the connecting member of the control arm 1 (not shown here) and in the course of the subsequent use of the control arm 1 . In this case, the connection with the connecting member is carried out through the matrix 25, at which time the protruding elements 24 form a shaped connection. When the control arm 1 is subsequently used and the load 26 shown by the arrow is applied to the control arm, the elements 24 are separated from the component 25 of the control arm 1 Thereby inhibiting the separation between them.

By means of the method according to the invention for the production of bearing bushes, the bearing bushes can be manufactured at low cost.

1: Control arm
2: joint point
3: joint point
4: Joint
5: Joint
6:
7: Bearing Bush
8: Bearing Bush
9: Insert member
10: Body
11: Cavity
12: recess
13: Fiber
14: Semifinished product
15: Semifinished product
16: pre-forming station
17: Sections
18: Sections
19: Hardening tool
20: Top
21:
22: Groove
23: Connecting device
24: Element
25: Matrix
26: Load

Claims (12)

A method for manufacturing a bearing bush (7; 8) for a control arm (1) of a wheel suspension, the body (10) of a bearing bush (7; 8) being made of a fiber / plastic composite material, And defining a receiving portion for the joint (4; 5) within the bearing bush,
Characterized in that the body (10) is manufactured in a drawing and forming process. The method of claim 1, wherein the body (10) is made of a continuous fiber reinforced fiber / plastic composite material. 3. Method according to claim 1 or 2, characterized in that the body (10) is formed into one or more semi-finished products (14, 15) in a drawing and forming process. The method according to claim 3, characterized in that at least one semi-finished product (14, 15) is molded, impregnated and cured to form a body (10) or part of the body (10) Of the bearing bush. Method according to claim 3 or 4, characterized in that a plurality of semi-finished products (14, 15) having different fiber orientations are used in the drawing forming process. 6. Method according to any one of claims 1 to 5, characterized in that carbon, glass, aramid and / or basalt are used as the fiber type for the fiber / plastic composite material. 7. A method according to any one of claims 1 to 6, characterized in that a thermoplastic material and / or a thermosetting material is used as a matrix for the fiber / plastic composite material. 8. A method according to any one of claims 1 to 7, characterized in that the body (10) has grooves (22) on the outer surface (21). A bearing bush according to claim 8, characterized in that a single connecting device (23) is inserted in the individual groove (22), each one comprising elements (24) protruding relative to the circumferential surface (21) Way. A bearing bush (7; 8) for a control arm (1) of a wheel suspension of an automobile, comprising a body (1) made of a fiber / plastic composite material and defining a receptacle for the joint (4; 5) 10. A bearing bush comprising:
The bearing bush (7; 8) according to claim 1, wherein the body (10) is manufactured in a drawing and forming process. 11. A bearing bush (7; 8) according to claim 10, characterized by a manufacture according to one or more of the claims 2 to 9 afterwards. A control arm (1) for a wheel suspension of a motor vehicle, comprising a connecting member (6) connecting the joints (4, 5) provided at joint points (2, 3)
Characterized in that at least one of the joints (4,5) comprises a control arm (1) for a wheel suspension of a motor vehicle, which is accommodated in a bearing bush (7,8) connected with a connecting member (6) .

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