DE102017220548A1 - Composite trailer coupling for a motor vehicle and method for its production - Google Patents

Abstract

Trailer coupling for a motor vehicle, in particular a passenger car, with a connecting rod having at one end a fastening part for attachment to the motor vehicle and at the other end a fixedly connected to the connecting rod ball part, characterized in that the ball part consists of metal and the Mounting part is also made of metal and the connecting rod, however, consists of plastic, which is reinforced with a unidirectional tape, and method for its preparation.

Description

The invention relates to a trailer hitch for a motor vehicle, in particular a passenger car, with a connecting rod which has at one end a fastening part for attachment to the motor vehicle and at the other end has a fixedly connected to the connecting rod ball part, and method for its preparation.

It is well known so-called towing eyes for motor vehicles, which were usually made of steel, through the use of plastic to reduce in weight.

From the DE 44 23 633 A1 It is known to surround a towing eye for weight reduction with a plastic jacket, which is applied by encapsulation of the metal parts.

From the DE 10 2014 200 722 A1 It is known to produce a towing eye made of fiber-reinforced plastic.

From the DE 10 2007 039 482 B4 It is known to produce a towing loop made of fiber-reinforced plastic by the composite flow-pressing method.

However, there is still a need for a simple and inexpensive method of manufacturing and correspondingly manufactured trailer hitches.

This object is achieved by the reproduced in claim 1 trailer hitch or the method specified in claim 10 for the preparation.

According to the invention, it has been recognized that if the ball member is made of metal and the fixing member is also made of metal and the connecting rod is made of plastic reinforced with a unidirectional band, it is possible to inexpensively produce a lightweight tow bar with high tensile strength.

Thus, a trailer hitch is produced as a composite component, wherein the ball part (or ball head) and the fastening part usually consist of metal (for example steel) and are correspondingly easy to process and load.

On the other hand, the connecting rod (or pin) is made of plastic for weight reduction and is provided with a unidirectional band for reinforcing the tensile strength.

It is understood that under unidirectional bands also bi-axial and multi-axial bands are to fall.

Suitable plastics are: polypropylene, polyamide, polyoxymethylene (POM), polycarbonate and acrylonitrile-butadiene-styrene (ABS) and mixtures of the abovementioned. These may be filled with fillers, e.g. Glass fibers, talc, etc. Also, the plastics can be foamed.

As a reinforcing band are particularly unidirectional bands of the same or similar plastics as mentioned above. These are preferably mixed with glass fibers, carbon fibers, aramid fibers, boron fibers, basalt fibers, steel fibers, natural fibers or nylon fibers.

Inexpensive and in large numbers, the connecting rod made of plastic can be produced by the tip process.

To improve the connection between connecting rod and ball part or fastening part, it is useful if the unidirectional band passes through a recess on the fastening part and preferably also extends through a recess on a neck of the ball part or around the neck.

To stiffen and reinforce the connecting rod, this can be configured with an organic sheet or a foam block. The connecting rod need not be a solid body and can also be formed by water or gas assisted spraying as a hollow body.

It is also possible that there is a metal reinforcement within the connecting rod between the ball part and the fastening part in order to increase the tensile force and rigidity.

So that the unidirectional belt does not rupture, a rounded elevation and / or a guide groove for the unidirectional belt can be arranged on the recess on the fastening part on the side facing the ball part.

It is preferred if the unidirectional band runs on the outer surface of the connecting rod.

Alternatively or additionally, the unidirectional band can run on the inner surface of the connecting rod, that is, lining the inner circumference of the actual connecting rod.

1. a) Öffnen des Spritzgusswerkzeugs;
2. b) Platzieren und Fixieren eines metallischen Befestigungsteils und eines metallischen Kugelteils in dem Spritzgusswerkzeug;
3. c) Platzieren und Fixieren eines unidirektionalen Bandes in dem Spritzgusswerkzeug;
4. d) Schließen des Spritzgusswerkzeugs;
5. e) Überspritzen des metallischen Befestigungsteils, des metallischen Kugelteils und des unidirektionalen Bandes mit Kunststoff;
6. f) Öffnen des Spritzgusswerkzeugs;
7. g) Auswerfen der fertigen Anhängerkupplung; wobei das Spritzgusswerkzeug eine Negativform mit einem ersten Bereich für das metallische Befestigungsteil, einen zweiten Bereich für das metallische Kugelteil und einen dritten Bereich zur Ausbildung der Verbindungsstange aus Kunststoff aufweist, und das unidirektionale Band an der Wandung des dritten Bereichs platziert und fixiert wird, wobei als Kunststoff derselbe Kunststoff wie derjenige des unidirektionalen Bandes eingesetzt wird.

As already stated, the trailer coupling according to the invention is suitable for being produced by injection molding. To do this, the following steps are performed:

1. a) opening the injection mold;
2. b) placing and fixing a metallic fastening part and a metallic ball part in the injection molding tool;
3. c) placing and fixing a unidirectional tape in the injection molding tool;
4. d) closing the injection molding tool;
5. e) overmolding of the metallic attachment part, the metallic ball part and the unidirectional belt with plastic;
6. f) opening the injection molding tool;
7. g) ejecting the finished trailer hitch; wherein the injection molding tool has a negative mold having a first area for the metallic fastening part, a second area for the metallic ball part and a third area for forming the connecting rod made of plastic, and the unidirectional band is placed and fixed to the wall of the third area, wherein Plastic, the same plastic as that of the unidirectional tape is used.

In other words, the unidirectional tape can be placed on the outer wall of the third and / or the inner wall of the third area.

When overmolding with plastic, a kind of welding of the parts is achieved, in particular if the matrix material of the unidirectional tape and the plastic are the same or similar (see above). Thus, an intimate connection of the connecting rod and the unidirectional belt is produced, which provides a trailer hitch with high tensile strength in a simple and cost-effective manner.

• 1 eine schematische Seitenansicht einer erfindungsgemäßen Anhängerkupplung;
• 2 eine schematische perspektivische Ansicht des Befestigungsteils aus 1 ;
• 3 eine schematische perspektivische Ansicht eines alternativen Befestigungsteils;
• 4 eine schematische Seitenansicht des Kugelteils aus 1 in zwei Varianten;
• 5 eine schematische Seitenansicht einer alternativen erfindungsgemäßen Anhängerkupplung;
• 6 eine schematische perspektivische Ansicht eines weiteren alternativen Befestigungsteils;
• 7 eine schematische perspektivische Ansicht eines weiteren alternativen Befestigungsteils und
• 8 eine schematische perspektivische Ansicht eines Kugelteils aus 4.

Further features and details of the invention will become apparent from the following description of the drawing. Show it:

• 1 a schematic side view of a trailer hitch according to the invention;
• 2 a schematic perspective view of the fastening part 1 ;
• 3 a schematic perspective view of an alternative fastening part;
• 4 a schematic side view of the ball part 1 in two variants;
• 5 a schematic side view of an alternative trailer coupling according to the invention;
• 6 a schematic perspective view of another alternative fastening part;
• 7 a schematic perspective view of another alternative fastening part and
• 8th a schematic perspective view of a ball part 4 ,

In the 1 is a designated as a whole with 1 trailer hitch. This includes a ball head 2 which has a curved substantially cylindrical shaft 3 with a fastening part 4 is provided, which is used for attachment to the motor vehicle.

While the attachment part 4 and the ball head 2 consist of steel in the usual design, consists of the shaft 3 made of plastic 5 that with a unidirectional band 6 is provided. The ribbon 6 runs on the outer surface of the shaft 3 in the longitudinal direction and beginning on one side a on the fastening part 4 where it looped through a provided elongated recess 8th passes through, and to the other side b on the ball head 2 where it is fixed.

The fastening part 4 is a substantially U-shaped metal part resting on the corresponding end of the shaft 3 Is "attached". The fastening part 4 has lateral holes 7 on the one hand the attachment to the vehicle and on the other hand the connection with the shaft 3 serve.

How out 3 . 6 and 7 shows, there are different embodiments of the fastening part 4 , These relate essentially to the configuration of the recess 8th and the arrangement of the holes 7 , So can at the recess 8th on the fastening part 4 on the ball part facing side a rounded increase 9 (see. 3 ) and / or a guide groove 10 (see. 7 ) may be arranged for the unidirectional band. Also, the elongated recess 7 even rounded inner edges 11 (see. 6 ) respectively.

All these variants allow to make sure that the unidirectional band 6 not kinked or squashed or cut and thus possibly ruptured under load.

The holes 7 are in principle freely positionable (cf. 2 . 3 and 6 or. 10 ), especially those that "only" connect to the stem 3 serve.

How out 4 and 8th shows, the ball head 2 encapsulated in the production. For this purpose, the ball head 2 a ball part 12 and a mind about it subsequent neck part 13 on. The neck part 13 in turn, may have a reduced diameter area 14A and a thickened end area 14B respectively.

The thickened end area 14B serves for the intimate connection during injection molding, whereas the reduced diameter range 14A the attachment of the band 6 serves. In addition, in a variant, the band around the area 14A wound and glued if necessary. Alternatively, the area 14A a slot 15 through which the tape is pulled through.

How out 8th can be seen, the slot 15 also in an upper unreduced diameter range 14A1 to be ordered. Then the area reduced in diameter serves 14A2 along with the thickened end area 14B only the attachment of the shaft 6 ,

How out 5 it can be seen, between ball head 2 and fastening part 4 a metal reinforcement inside the connecting rod 16 run to increase the traction and rigidity.

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 4423633 A1 [0003]
• DE 102014200722 A1 [0004]
• DE 102007039482 B4 [0005]

Claims (10)

Trailer coupling for a motor vehicle, in particular a passenger car, with a connecting rod having at one end a fastening part for attachment to the motor vehicle and at the other end a fixedly connected to the connecting rod ball part, characterized in that the ball part consists of metal and the Mounting part is also made of metal and the connecting rod, however, consists of plastic, which is reinforced with a unidirectional band. Towbar after Claim 1 , characterized in that the connecting rod is made of plastic by the pointed method. Towbar after Claim 1 or 2 , characterized in that the unidirectional belt is connected to the ball part and to the fastening part. Towbar after Claim 3 , characterized in that the unidirectional band extends on the outer surface of the connecting rod. Towbar after Claim 3 or 4 , characterized in that the unidirectional band passes through a recess on the fastening part. Towbar after Claim 3 or 4 or 5 , characterized in that the unidirectional band passes through a recess on a neck of the ball part or around the neck. Trailer coupling according to one of the preceding claims, characterized in that the connecting rod is reinforced with an organic sheet or a foam block. Trailer coupling according to one of the preceding claims, characterized in that between the ball part and fastening part, a metal reinforcement extends within the connecting rod. Trailer coupling according to one of the preceding Claims 5 to 8th , characterized in that on the recess on the fastening part on the side facing the ball part a rounded increase and / or a guide groove for the unidirectional band is arranged. Method for producing a trailer hitch, in particular according to one of the preceding claims, by injection molding, wherein the steps are carried out: h) opening the injection mold; i) placing and fixing a metallic fastening part and a metallic ball part in the injection molding tool; j) placing and fixing a unidirectional tape in the injection molding tool; k) closing the injection molding tool; l) overmolding of the metallic attachment part, the metallic ball part and the unidirectional belt with plastic; m) opening the injection molding tool; n) ejecting the finished trailer hitch; wherein the injection molding tool has a negative mold having a first portion for the metallic fastener, a second portion for the metallic ball portion and a third portion for forming the plastic connecting rod, and the unidirectional tape is placed and fixed to the wall of the third portion, wherein Plastic, the same plastic as that of the unidirectional tape is used.

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