DE102010050221A1 - Threaded connector comprises a fiber-reinforced thermoplastic material, which is a long fiber reinforced thermoplastic material for introduction into a carrier part, and an axially extending internal thread - Google Patents

Abstract

Threaded connector (1) comprises a fiber-reinforced thermoplastic material for introduction into a carrier part (11), and an axially extending internal thread (3). The fiber reinforced plastic is a long fiber reinforced thermoplastic material (2). An independent claim is also included for an arrangement comprising the carrier part with at least one recess (12), where the long fiber reinforced thermoplastic is introduced as a reinforcement in the recess.

Description

Technical area

The invention relates to a threaded bush made of a fiber-reinforced thermoplastic plastic for introduction into a carrier part, wherein the threaded bush has an axially extending internal thread. The invention further relates to an arrangement with a carrier part with at least one recess.

Such threaded bushes or arrangements are used in a known manner as fastening elements for connecting a variety of components.

State of the art

From the WO 2009/074217 A2 an assembly of a support member and a threaded insert embedded therein has become known, both of which consist of thermoplastic material, wherein the support member has a receiving hole for the threaded insert and the threaded insert is formed as a substantially bush-shaped body with an axially extending inner hole and a plurality of helically extending ribs , and wherein the helically extending ribs have a pitch angle of more than 40 degrees. In a preferred embodiment, the threaded insert consists of a plastic with a glass fiber or carbon fiber filler.

In the automotive industry, the aim of reducing CO2 emissions is to reduce the weight of vehicles. A contribution to weight reduction is the widest possible replacement of metallic materials by plastics. Fiber-reinforced plastics generally have a lower specific weight than metals and are therefore fundamentally suitable for this purpose.

However, in automotive applications characterized by high stress, the known fiber reinforced plastics can not be used everywhere. For example, in high-stress structural parts on fiber-reinforced support parts, metal bushes must still be used to meet the requirements of strength and energy absorption. However, since a high number of threaded bushes is used, a large part of the weight savings through the metal threaded bushes is lost again.

The invention is therefore based on the object to provide a threaded bush made of fiber-reinforced plastic, which is able to cope with higher mechanical loads and thus is able to replace metallic components.

Disclosure of the invention

This object is achieved by a threaded bush of the type mentioned, which is characterized in that the fiber-reinforced plastic is a long-fiber reinforced thermoplastic plastic. Because the fiber-reinforced plastic is a long-fiber-reinforced thermoplastic resin, the threaded bushing according to the invention can be subjected to much greater load even at relatively high temperatures, in particular significantly more mechanically stressed than conventional fiber-reinforced components. This allows the use of long fiber reinforced threaded bushings in highly loaded components, especially in highly loaded motor vehicle components, whereby a weight reduction and thus a reduction in CO2 emissions can be achieved. The threaded bushing according to the invention can for this purpose in a carrier part, such as. As a motor front cover or other cover, which is typically made of plastic, are introduced. But also engine components such. As intake manifolds, cylinder head covers, oil pans, chain boxes, timing case cover, turbocharger housing, radiator housing, etc. are possible support parts. Furthermore, structural components of a motor vehicle come into question. The long-fiber reinforced threaded bushes are introduced into these support parts, that is, they are inserted into the carrier parts, screwed, pressed or the like. The threaded bush can in this case have a continuous or non-continuous internal thread. The latter is particularly advantageous when the threaded bush is inserted into an injection mold and molded with the support member, since in this case the melt of the support member can not penetrate through the end opening of the internal thread in the threaded bushing and make them useless.

Preferred is an embodiment of the threaded bush, in which the fibers of the thermoplastic resin have an average length of at least 2 mm, in particular have an average length of at least 2.5 mm. As a result, the long-fiber reinforced thermoplastics are particularly strong. "Long" fibers are in contrast to "short" fibers from a fiber length of about 1 mm. The average fiber lengths of most long fiber reinforced thermoplastics typically range between 2.5mm and 4mm. By contrast, short fibers, due to their production process (typically the so-called "compounding"), have fiber lengths of typically about 0.2 mm to 0.35 mm.

Particularly preferred is also an embodiment of the threaded bush, in which the fibers to each other gem. the structure of a braid, in particular according to the structure of a felt braid are arranged. If the fibers according to this embodiment are arranged relative to each other, a three-dimensional, approximately isotropic distribution of the fibers in the matrix material of the threaded bushing occurs, which allows a particularly high load on the threaded bushing. Thermoplastics with a long fiber reinforcement according to the invention typically form such a three-dimensional mesh of the fibers.

In a further preferred embodiment of the invention, the fibers are selected from the group of glass fibers, carbon fibers, aramid fibers and steel fibers. Due to their material properties, such types of fibers have proven suitable for use as long fibers. It is understood that mixed forms of the above fiber types are also possible. In addition, other fibers of organic or inorganic materials can be used.

In another preferred embodiment, the fiber content in the thermoplastic resin of the threaded bush between 10 and 70 weight percent, in particular between 30 and 50 weight percent. Such a ratio between fibers and matrix material is favorable in terms of supporting the fibers in the matrix material on one side and force flow through the fibers on the other side. This thus leads to a particularly high load capacity of the threaded bush, so that they can replace a metal bushing and so a weight saving is possible.

A further preferred embodiment is characterized in that is provided as a thermoplastic plastic polypropylene, polyamide, polyphthalamide or polyphenylene sulfide. These matrix materials for fiber reinforced thermoplastics are readily available and inexpensive to buy. Polypropylene (PP), polyamide (PA 6 or PA 6.6), polyphtalamide (PPA) or polyphenylene sulfide (PPS) with long fiber reinforcement are usually in the form of rod granules with a length of 10 to 25 mm or in the direct processing method (IMC / Injection Molding Compounding).

Further, an embodiment of the invention is preferred in which the threaded bushing has as external structure teeth and / or ribs and / or a thread for positive connection with the carrier part. Then, a reliable and secure connection between the threaded bushing and the carrier part can be produced in an advantageous manner, whereby the threaded bushing according to the invention can also be used in safety-relevant components. The outer structure can be any external profile (profile in the sense of height profile or relief), external thread or a recess or indentation, indentation or the like. An external structure can also be a smooth, z. B. cylindrical outside of the threaded bushing.

Finally, another embodiment of the threaded bushing is preferred in which the threaded bushing is injection-molded together with the internal thread as a single piece. In this way, the long fibers in the matrix material remain undamaged in their entire length and can contribute in their entirety to the improved material properties of the bush according to the invention, since higher pullout forces result. This is not the case, for example, if a cutting tool is used to produce the thread after the injection molding, since this partially breaks the fibers in the area of the thread. This additionally causes damage to the surface, with which a notch effect is associated. This notch effect in the thread area is decisive for the impairment of long-term properties such as creep behavior, fatigue, etc. Therefore, it is beneficial to inject the thread directly.

In the scope of the invention, furthermore, an arrangement comprises a carrier part with at least one recess, which is characterized in that a long-fiber-reinforced thermoplastic plastic is introduced in the recess as reinforcement. Thus, the support member in the region of the recess in comparison to conventional support parts is more resilient. Thus, the support member can be easily constructed, whereby z. B. in motor vehicles CO2 emissions can be saved. As support parts include engine components such. As intake manifolds, cylinder head covers, oil pans, chain boxes, timing case cover, turbocharger housing, radiator housing and structural components of a motor vehicle in question.

In a further development of the arrangement, the reinforcement is a threaded bush according to the invention made of long-fiber-reinforced thermoplastic plastic. Then it is a gain that not only strengthens the support member in the region of the recess, but also can perform a fastening and connection function to other components.

In a further development of the arrangement, the recess has an internal structure for interacting with an external structure of the threaded bushing. This leads to a positive connection of carrier part and threaded bush, which is particularly strong. In such a design of the arrangement, this can also be used in safety-related components. The recess may, for. B. tapered, which is cylindrical with one on the outside formed threaded bushing results in an increasing pressure in the axial direction. Another development of the arrangement is characterized in that the threaded bushing is welded to the carrier part. This results in a material bond, which additionally secures the connection of both parts. As a welding process z. B. the ultrasonic welding can be applied.

The threaded bushing can be introduced cold or warm into the carrier part. In the latter case, (in addition to the positive connection), a cohesive connection between the respective fused surfaces of the threaded bushing and the plastic carrier part can be formed.

In a further development, the threaded bushes are introduced into the recesses by an injection molding process, in particular by 2-component injection molding. Here, the threaded bushes are locally z. B. introduced by 2-component injection molding in the space provided recesses of the support member. Alternatively, it is also possible to insert the threaded bushing (s) before the injection molding at the desired locations in an injection mold and to enclose them directly with the material of the support member.

Also preferred is a development of the arrangement in which the carrier part is formed from a preferably partially crystalline or amorphous thermoplastic plastic, in particular from polypropylene, polyamide (PA 6 or PA 6.6), polyphthalamide or polyphenylene sulfide. Finally, a development of the arrangement is also preferred, in which the carrier part is an engine component of a motor vehicle and / or a structural component of a motor vehicle.

Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures which show features essential to the invention, and from the claims. The individual features can be realized individually for themselves or for several in any combination in a variant of the invention.

Brief description of the drawings

Embodiments are illustrated in the schematic drawing and will be explained in the following description. Show it:

1 a threaded bushing according to the invention in a perspective view, wherein the threaded bushing is partially cut open,

2a a schematic section of a plate made of short fiber reinforced thermoplastic resin,

2 B a schematic section of a plate made of long fiber reinforced thermoplastic plastic;

3 a schematic representation of a motor front cover with threaded inserts according to 1 in a top view.

Embodiment (s) of the invention

In 1 is a section of a threaded bush 1 made of a long fiber reinforced thermoplastic material 2 shown. The threaded bush 1 has an axially extending, not continuous in the present example internal thread 3 and one with star-shaped grooves 4 trained outdoor structure 5 on. Due to the long fiber reinforcement of the thermoplastic resin 2 holds the threaded bushing 1 Even high loads and can therefore be used as a replacement for metallic threaded bushes. The threaded bush 1 is used for this purpose in recesses of a support member (see. 3 ).

In 2a is a schematic section of a conventional short fiber reinforced thermoplastic resin 6 shown. short fibers 7 Due to their manufacturing process, the so-called "compounding", have fiber lengths of about 0.2 mm to 0.35 mm and are usually in the thermoplastic matrix material 8th aligned along the melt stream during the mold filling process, ie the short fiber reinforced thermoplastic resin 6 has anisotropic properties (shrinkage, dimensional accuracy due to thermal expansion, mechanical properties, etc.). Depending on the flow conditions, these properties can vary greatly over the component thickness.

In 2 B is schematically a section of the long fiber reinforced thermoplastic resin 2 as shown in the threaded bushing 1 out 1 is used. The mean fiber length of the long fiber reinforced thermoplastic resin 2 is at least 2.5 mm in the present example. This forms in the thermoplastic matrix material 8th a three-dimensional structure of the long fibers 9 from a braid, z. B. a felt braid 10 , similar to that of the long fiber reinforced thermoplastic resin 2 gives substantially isotropic material properties and high mechanical strength. The fiber content in the thermoplastic matrix material 8th is typically between about 10 and 70 weight percent and in the present example is between about 30 and 50 weight percent. As long fibers 9 For example, glass fibers, carbon fibers, aramid fibers or steel fibers can be used become. As thermoplastic plastic 8th For example, polypropylene (PP), polyamide (PA 6 or PA 6.6), polyphthalamide (PPA) or polyphenylene sulfide (PPS) can be used.

In 3 is schematically a so-called engine front cover 11 shown. Such engine front covers 11 are usually attached to (not shown) engine blocks and bolted to them. For this purpose, the motor front cover 11 , in particular at their edges, recesses 12 on, in the threaded bushes 1 can be introduced. In 3 are in the recesses 12 top right partially threaded bushes 1 pressed in, so that between the engine front cover 11 (the carrier part) and the threaded bushing 1 sets a positive connection. The connection between the engine front cover 11 and engine block can then be done by means not shown screws, which are anchored on the one hand in the engine block and on the other hand in the internal thread 3 the threaded bushes 1 are screwed in. In order to achieve a weight reduction, the carrier part, so the motor front cover 11 z. Example of polypropylene (PP), polyamide (PA 6 or PA 6.6), polyphthalamide (PPA) or polyphenylene sulfide (PPS) be prepared, in particular for the carrier part 11 the same plastic material as for the threaded bush 1 can be used.

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

• WO 2009/074217 A2 [0003]

Claims (15)

Threaded bushing ( 1 ) of a fiber-reinforced thermoplastic plastic for insertion into a carrier part ( 11 ), wherein the threaded bush ( 1 ) an axially extending internal thread ( 3 ), characterized in that the fiber-reinforced plastic is a long-fiber-reinforced thermoplastic ( 2 ). Threaded bushing ( 1 ) according to claim 1, characterized in that the fibers ( 9 ) of the thermoplastic resin have an average length of at least 2 mm, in particular have an average length of at least 2.5 mm. Threaded bushing ( 1 ) according to one of the preceding claims, characterized in that the fibers ( 9 ) according to the structure of a braid, in particular according to the structure of a felt braid ( 10 ) are arranged. Threaded bushing ( 1 ) according to one of the preceding claims, characterized in that the fibers ( 9 ) are selected from the group comprising: glass fibers, carbon fibers, aramid fibers and steel fibers. Threaded bushing ( 1 ) according to any one of the preceding claims, characterized in that the fiber content in the thermoplastic plastic ( 2 ) is between 10 and 70 percent by weight, in particular between 30 and 50 percent by weight. Threaded bushing ( 1 ) according to one of the preceding claims, characterized in that as thermoplastic plastic ( 9 ) Polypropylene, polyamide, polyphthalamide or polyphenylene sulfide is provided. Threaded bushing ( 1 ) according to one of the preceding claims, characterized in that an external structure ( 5 ) of the threaded bush teeth and / or ribs and / or a thread for positive connection with the carrier part ( 11 ) having. Threaded bushing ( 1 ) according to one of the preceding claims, characterized in that the threaded bush ( 1 ) together with the internal thread ( 3 ) is injection-molded as a piece. Arrangement comprising a carrier part ( 11 ) with at least one recess ( 12 ), characterized in that in the recess ( 12 ) as reinforcement a long fiber reinforced thermoplastic ( 2 ) is introduced. Arrangement according to claim 9, characterized in that the reinforcement is a threaded bush ( 1 ) according to one of claims 1 to 8. Arrangement according to claim 10, characterized in that the recess ( 12 ) an inner structure for cooperation with an outer structure ( 5 ) of the threaded bush ( 1 ) having. Arrangement according to one of claims 10 or 11, characterized in that the threaded bush ( 1 ) with the carrier part ( 11 ) is welded. Arrangement according to one of claims 10 or 11, characterized in that the threaded bush ( 1 ) by an injection molding process, in particular by 2-component injection molding, in the recess ( 12 ) is introduced. Arrangement according to one of claims 9 to 13, characterized in that the carrier part ( 11 ) made of a thermoplastic plastic ( 2 ), in particular of polypropylene, polyamide, polyphtalamide or polyphenylene sulfide is formed. Arrangement according to one of claims 9 to 14, characterized in that the carrier part ( 11 ) is an engine component of a motor vehicle and / or a structural component of a motor vehicle.

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