WO2012055489A1

WO2012055489A1 - Elastic bearing for a component and method for producing the same

Info

Publication number: WO2012055489A1
Application number: PCT/EP2011/005074
Authority: WO
Inventors: Frank Buschbeck; Günter Nagel; Eckhard Reese; Jochen Rupprecht; Hans-Rudolf Steinert
Original assignee: Daimler Ag
Priority date: 2010-10-25
Filing date: 2011-10-11
Publication date: 2012-05-03
Also published as: DE102010053732A1; DE102010053731A1

Abstract

An elastic bearing (4) for a component (1) which is produced of a fiber reinforced plastic material comprises an elastic material (6) and a metallic receiving element (5). The metallic receiving element (5) is connected to the component (2) by means of the elastic material which is a thermoplastic elastomer (6).

Description

Elastic storage for a component

and process for their preparation

The invention relates to an elastic mounting for a component according to the closer defined in the preamble of claim 1. Art also relates to a method for producing such a component.

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 process reliable and without long waiting and curing times the production of a

Thermosetting matrix systems play a subordinate role, since they typically require a rather time-consuming and lengthy processing. 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. For producing a tubular component from such a fiber composite plastic with thermoplastic Matrix material should be referenced by way of example to DE 10 2008 010 228 A1 and DE 10 2007 051 517 A1. 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.

Such components 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.

Not only in the field of vehicle construction, it is often the case that components, in particular components in the area of the chassis, should be absorbed by elastic bearings or even need. Since these elastic bearings are often bolted to the component in conventional components, this technology is not readily transferred to the field of fiber-reinforced plastic materials. These are rather critical with regard to the introduction of loads via screws or the like, so that the connection of elastic bearings in the conventional construction makes a considerable additional effort in the production and structural planning of the component made of a fiber-reinforced plastic material required. The object of the present invention is now to minimize or save this effort and provide an elastic support for a component made of a fiber-reinforced plastic material, which is correspondingly simple and efficient to implement, and which connected without significant additional effort with the component made of fiber-reinforced plastic material can be.

According to the invention this object is achieved by an elastic mounting with the features in the characterizing part of patent claim 1. A method for producing such elastic mounting is specified in claim 7. Further advantageous embodiments of the elastic bearing and the method will become apparent from the respective dependent claims.

The elastic bearing according to the invention provides a metallic receiving element, via which the bearing can be received, for example, in the area of a vehicle or of another component in a manner known per se. For this purpose, appropriate brackets, the welding of the component or the like are conceivable. The metallic receiving element is in the inventive elastic storage on the elastic material with the component of the fiber-reinforced

Plastic material connected. The elastic material is formed as a thermoplastic elastomer. This thermoplastic elastomer takes on the elastic storage on the one hand and the connection between the component and the metallic receiving element on the other hand.

In particular, in the embodiment of the fiber-reinforced component with a thermoplastic matrix material is typically melted by heating during introduction of the thermoplastic elastomer between the metallic receiving element and the component, so that a very good form and in particular cohesive bond between the thermoplastic elastomer and the component the fiber reinforced plastic material is achieved. On the other hand, the thermoplastic elastomer then adheres to the metal receiving element and so easily and efficiently forms the elastic support for the component.

In a particularly favorable and advantageous development of the elastic bearing according to the invention, it is further provided that the metallic receiving element at least in the areas where it is with the thermoplastic elastomer in

Compound having a coating with a thermoplastic material. Such a coating of the metallic receiving element with

thermoplastic plastic material additionally increases the adhesion between the thermoplastic elastomer and the coating, since this forms a material bond. As a result, the composite of the elastic bearing even better

Achieve adhesion properties between the materials involved and thus made even more stable.

In an advantageous development of the elastic mounting, it is further provided that the metallic receiving element is designed as a hollow profile which surrounds the component, wherein the space between the component and the metallic receiving element comprises the thermoplastic elastomer. This structure, in which the metallic receiving element surrounds the component as a hollow profile and the entire space is filled with the thermoplastic elastomer, allows a very good storage of the component in at least all spatial directions, in particular in all spatial directions within the sectional plane across the hollow profile of the metallic receiving element , This creates a very secure and reliable connection of the component to the metallic receiving element by the elastic bearing.

In a further particularly favorable and advantageous embodiment of the

described elastic bearing, it is further provided that the component as a torsion bar spring or part of a torsion bar or roll stabilizer for a

Motor vehicle is formed.

Turning rods or torsion bars or roll stabilizers are known from the general state of the art. These are torsion springs, which are intended to reduce the rolling motion of a vehicle or carry the vehicle and to respond to road bumps by rebound and rebound sufficiently and to accommodate weight shifts in the longitudinal and transverse directions. 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, these torsion bar springs made of fiber-reinforced plastic, in particular from a to produce substantially tubular component made of a fiber-reinforced plastic material. As a result, ideal properties in terms of weight, corrosion resistance, damping properties and in the field of

Torsion spring-directed forces achieved. In particular, such arranged in the chassis area of vehicles components, such as the torsion bar spring, are often stored on elastic bearings. For this purpose, the inventively designed elastic bearing is ideal because the torsion bar, ideally in the tubular area, on the thermoplastic elastomer safely but reliably yet with a certain elasticity in the storage with the metallic receiving element, which ideally as

Hollow profile may be formed around the tubular member of the torsion bar, is connected. The structure is simple and efficient to manufacture and ensures best storage properties with minimal weight.

Hollow profiles, in particular for a torsion bar or a roll stabilizer, sometimes require complex geometries. Therefore, it is advantageous to produce them via an hydroforming process (hydroforming).

The inventive method for producing such elastic storage provides that the metallic receiving element is arranged in its desired position relative to the component, after which the metallic receiving element and the component are connected by injection of the thermoplastic elastomer between the metallic receiving element and the component. This is particularly simple and efficient and allows a very cost-effective production of the elastic bearing.

According to the invention, therefore, we produce a composite between a rigid inorganic material, a stiff organic material and an elastic organic material in one process. This eliminates otherwise required complex

Production stages.

In a very advantageous development of the method according to the invention, it is provided that the injection of the thermoplastic elastomer takes place in an injection molding machine as a 2K injection molding process. In particular, the injection of the thermoplastic elastomer in an injection molding as 2K injection molding process is ideally suited for mass production in the production of large quantities, for example for motor vehicles, and can be in a simple without much additional effort and easily in a series production to be integrated manufacturing process, the production of the elastic bearing, for example, on the preferred component of a torsion bar spring or a roll stabilizer for a vehicle realize. The 2K injection molding process is particularly advantageously carried out in a variothermal mold with differently tempered zones: the actual injection molding process takes place in a cold zone while the elastomer is galvanized in a hot zone.

In an advantageous development of this, it is provided that the metallic receiving element in turn is at least partially coated with a thermoplastic plastic material. The coating with the thermoplastic material, typically before the further processing of the metallic receiving element, ensures the best possible bond between the thermoplastic elastomer and coated with thermoplastic material metallic receiving element on the one hand and the component of the fiber composite plastic with the preferred thermoplastic matrix on the other. The metallic receiving element can be used as an inlay and is injected in the so-called insert technique in an injection molding plant by means of the thermoplastic elastomer to a solid elastic bearing on the component of the fiber-reinforced plastic material. This results in a simple to manufacture, safe and reliable construction, the connection of the elastic bearing on the component with minimal effort in terms of the construction of the component as well as the material used. The structure is therefore correspondingly simple, inexpensive and very easy to build.

As described above, the metallic receiving element may preferably be formed as a hollow profile around the tubular member of the torsion bar. Then it is advantageous to expand the multi-component mold for the injection molding process by an IHU unit (hydroforming). Thus, not only (fully filled) solid sections can be produced, but also hollow sections (by means of inserted core). Hollow cross sections are particularly advantageous

Fiber reinforcement, eg by means of braided core. In a subsequent process can then in a similar to the in-mold coating process at the desired location of the core are reduced (open to eg about 0.1 mm) to selectively apply a primer or to activate the surface with a chemical stimulator so that the thermoplastic elastomer to be introduced adheres to the thermoplastic material. Further advantageous embodiments of the elastic bearing according to the invention will become apparent from the further dependent subclaims and will be apparent from the embodiment, which will be described below with reference to the figures.

Showing:

Fig. 1 is a torsion spring from a substantially tubular member

fiber reinforced plastic material;

Fig. 2, the torsion bar spring of Figure 1 with attached elastic bearings.

3 shows a cross section according to the line III - III in Fig. 2. and

Fig. 4, the torsion bar spring with bearing elements for connection to a vehicle.

In the illustration of Figure 1 is purely exemplary of a component made of fiber-reinforced plastic material, a torsion spring 1 for a motor vehicle to recognize. The

Torsion bar 1 consists essentially of a tubular member 2, which consists of a fiber-reinforced plastic material. The tubular component 2 may, for example, have been produced by braiding pultrusion and / or wrapping around a core remaining or lost in the component 2. 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 may, as already mentioned, remain in the tubular component 2 or be dissolved out of it, for example melted out, washed out with suitable solvents or the like.

Ideal for the invention described below, it is when the outer surface of the tubular member 2 consists of the fiber-reinforced plastic material, which is preferably formed as a thermoplastic matrix material, which with

Carbon fibers is reinforced. The carbon fibers can ideally be used in the form of preimpregnated fiber bundles or hybrid rovings and braiding and / or wrapping the tubular member to have been melted and compressed to the tubular member 2. Subsequent consolidation is possible and often useful.

At its two ends, the tubular component 2 on Lasteinleitelemente 3, which are either formed integrally with the tubular member 2 or glued thereto or connected by positive locking. In the area of this Lasteinleitelemente 3 will attack later in a conventional manner lever to initiate forces in the field of torsion spring 1. In addition to this, the torsion bar spring, as shown in Figure 1, now requires corresponding bearing for receiving the torsion spring 1 on a vehicle, not shown in its entirety. These bearings are designed as elastic bearing to compensate for vibrations and dampen and to allow slight movement of the torsion bar 1 relative to the vehicle and yet to ensure safe and reliable storage. In the

Representation of Figure 2, these elastic bearings in the field of torsion bar spring 1 can be seen and provided with the reference numeral 4. The exemplary embodiment illustrated in FIG. 2 has, as is often the case, two such elastic bearings 4. From the sectional view of Figure 3 it can be seen that these elastic bearings 4 consist of an outer receiving element 5, which is typically formed as a metallic receiving element 5 in the manner of a hollow profile or a metallic socket. This metallic receiving element 5 surrounds the tubular component 2 of the torsion spring 1 of the fiber-reinforced

Plastic material. The space between the metallic receiving element 5 and the tubular component 2 is filled by a thermoplastic elastomer 6, which forms together with the metallic receiving element 5, the elastic bearing 4 for the tubular member 2 of the fiber-reinforced plastic material. The elastic bearing 4 can thus absorb forces acting in the sectional plane shown in Figure 3, ideal. Also forces perpendicular to this cutting plane are due to the adhesion of the thermoplastic elastomer 6 to the metallic

Received element 5 on the one hand and the fiber-reinforced component 2 on the other. This creates an elastic bearing 4 in all six degrees of freedom.

In the illustration of Figure 4, the torsion spring 1 is then seen again. The elastic bearings 4 are received in bearing elements 7, which in turn are connected to the vehicle. The bearing elements 7 take the elastic bearings. 4 or their metallic receiving element 5 in a manner known per se between a storage stock 8 and a bearing cap 9, which are then connected to each other, in particular screwed together, on. About the bearing elements 7, the torsion spring 1 is then connected to the vehicle or the body of the vehicle. About the Lasteinleitelemente 3 and suitable levers, which are not shown here, can then be done in a conventional manner, the connection to the parts of the chassis whose rolling movements are to be damped or compensated by the torsion bar 1 against each other.

The thermoplastic elastomer 6 can be introduced by suitable process integration via a 2K injection molding process between the metallic receiving element 5 and the tubular component 2. In the preferred embodiment of the tubular component 2 with a matrix of a thermoplastic material, such as PA, PPA or the like, then takes place during introduction of the

thermoplastic elastomer via the 2K injection molding process in a single operation, a solid, cohesive connection between the thermoplastic elastomer 6 and the component 2. An adhesive connection also occurs between the metallic

Receiving element 5 and the thermoplastic elastomer. To such a

In addition to improve compound, it is ideally provided that the metallic receiving element 5 is cleaned in an upstream process step and preferably provided with an adhesion promoter or primer. This adhesion promoter or primer then forms the basis for a coating in a thermoplastic material. The metallic receiving element 5 is thus at least in the later facing the thermoplastic elastomer 6

Provided areas with a corresponding coating so that it also comes here to an ideal adhesion of the thermoplastic elastomer in the material connection with the coating, which in turn adheres ideally on the primer to the metallic material of the receiving element 5 comes.

In terms of process technology, this can be realized, for example, such that the metallic receiving element 5 is correspondingly cleaned and provided with adhesion promoter or primer and subsequently coated with the thermoplastic synthetic material, for example PA. The thus coated metallic receiving element 5 is then inserted as an inlay in a 2K injection molding, in which also the torsion bar 1 and the tubular member 2 of the torsion bar 1 is inserted. The two Components 2, 5 are fixed to each other at the desired distance and the gap between the metallic receiving element 5 and the component 2 is sprayed with the thermoplastic elastomer 6, preferably by means of a 2K injection molding process. In a single step, a finished elastic bearing 4 for the tubular component 2 of fiber-reinforced plastic material is produced by the injection molding process. When injecting the thermoplastic elastomer 6, this results in a cohesive connection of the thermoplastic elastomer with the matrix material of the tubular component 2. In addition, it comes to a

cohesive connection between the thermoplastic elastomer and the thermoplastic material, with which the metallic receiving element 5 is coated in the above-mentioned manner. About this insert technique can thus easily and efficiently realize an elastic bearing 4 on the torsion bar 1, which can be produced with minimal manufacturing effort, and which ensures a minimum weight of the composite of elastic bearing 4 and torsion spring 1.

Claims

claims

1. Elastic storage (4)

for a component (2) made of a fiber-reinforced plastic material,

with an elastic material (6) and a metallic receiving element (5), characterized in that

the metallic receiving element (5) over the elastic material,

which is formed as a thermoplastic elastomer (6),

is connected to the component (2).

2. Elastic bearing (4) according to claim 1,

characterized in that

the component (2) comprises a thermoplastic matrix material.

3. Elastic bearing (4) according to claim 1 or 2,

characterized in that

the metallic receiving element (5) has a coating with a thermoplastic plastic material at least in the regions in which it is in contact with the thermoplastic elastomer (6).

4. Elastic bearing (4) according to claim 1, 2 or 3,

characterized in that

the component (2) is formed with a tubular cross-section.

5. Elastic bearing (4) according to one of claims 1 to 4,

characterized in that

the metallic receiving element (5) is designed as a hollow profile, which is the Part (2) surrounds, wherein the space between the component (2) and the metallic receiving element (5) comprises the thermoplastic elastomer (6).

6. Elastic bearing (4) according to one of the preceding claims,

characterized in that

the component (2) is designed as a torsion spring (1) or as part of a torsion spring (1) for a motor vehicle.

7. Method for producing an elastic bearing (4)

according to one of the preceding claims,

characterized in that

the metallic receiving element (5) is arranged in its desired position relative to the component (2),

after which the metallic receiving element (5) and the component (2) are connected by injection of the thermoplastic elastomer (6)

between the metallic receiving element (5) and the component (2).

8. The method according to claim 7,

characterized in that

the injection of the thermoplastic elastomer (6) takes place in an injection molding machine as a 2K injection molding process.

9. The method according to claim 7 or 8,

characterized in that

the metallic receiving element (5) at least partially with a

thermoplastic plastic material is coated.

10. The method according to claim 9,

characterized in that

the metallic receiving element (5) is cleaned before coating and provided with a bonding agent.