DE102012102309A1 - Rivet clamp for setting rivets for use with hydraulic, pneumatic or electric actuators, has connection unit, receiving port and bracket which are formed of fiber reinforced plastic composite carbon fibers - Google Patents

Abstract

The rivet clamp (1) has a connection unit (4) for connecting the rivet clamp with a rivet clamp receiver (5a). The connection unit and receiving port (3) arranged with riveting tool (8) are connected with the bracket (2). The connection unit, receiving port and bracket are formed of fiber reinforced plastic composite carbon fibers. The fiber reinforced plastic composite carbon fibers are provided with duroplastic or thermoplastic resin. The carbon fibers are formed as fabric, multi-ply fabric abd fiber bundle.

Description

The invention relates to a rivet bracket for setting rivets, comprising a connection unit for connecting the rivet bracket to a rivet bracket, a receiving connection for receiving a riveting tool and a connecting section and the receiving connection connecting bracket section.

Rivet bars are used together with hydraulic, pneumatic or electric drives. During the riveting process, a rivet is pressed between a first riveting tool and a second riveting tool arranged on the drive.

To accommodate the forces occurring during the pressing of the rivet, it is necessary to form the rivet bar particularly stable. In order to meet the stability requirements, the rivet bracket is therefore usually made of metal, preferably made of steel, but this has the disadvantage of a high weight.

In order to reduce the weight and to allow the operator easier handling of the rivet bar, it is known to adjust the rivets in their cross-sectional shape and geometry. In addition, particularly light and stable steels are used in order to be able to provide lighter rivets with the same stability.

However, because of the high specific gravity of metal, known rivets continue to be heavy and difficult to operate for a riveting person. Here are in rivets, which are set with a particularly large distance from an outer edge of the workpiece, very large sized and correspondingly heavy rivet used, which can be partially held only by several people.

The invention is therefore based on the object to provide a particularly light and easy-to-use rivet bracket.

The invention solves the problem by a rivet bracket with the features of claim 1. Advantageous developments of the invention are specified in the dependent claims.

The rivet bracket according to the invention for setting rivets has a connection unit for connecting the rivet bracket to a rivet bracket of a drive unit, a receiving connection for receiving a riveting tool and a bracket section connecting the connection unit and the reception connection, wherein the connection unit, the reception connection and / or the bracket section at least partially are formed from a fiber-reinforced plastic.

Due to the low weight of fiber-reinforced plastics compared to metals, a particularly light rivet bracket can be provided. The lightweight rivet bracket is much easier to handle and allows for very large versions, the simple operation of the rivet by a single person. As a result, the accuracy of setting the rivet is increased and greatly reduces the workload for the people.

The use of fiber-reinforced plastic also allows the rivet bracket at least partially form a hollow body, whereby the weight is further reduced.

Due to the large difference in weight between the fiber-reinforced plastic and the usually completely made of a metal rivet already causes the at least partially forming the connection unit and / or the receiving connection made of fiber-reinforced plastic a significant weight reduction of the rivet bracket over conventional rivets, resulting in a relief for the rivet hiring person.

Preferably, the connection unit and / or the receiving connection consist at least partially of a metal, while the ironing section is formed of a fiber-reinforced plastic. For example, a metal sleeve can be arranged in the connection unit, which contains an internal thread, which is designed as a pin receptacle for a pin arranged on a drive unit, which has a corresponding external thread. Also, for example, the receiving connection may be formed as a metal sleeve. This design of the rivet bracket makes it possible to connect known riveting tools to the rivet bracket and to couple the rivet bracket with known rivet bracket receptacles.

The connection unit, the receiving connection and the bracket section can be designed as separate, firmly connected components. The connection unit, the receiving connection and / or the bracket section can also be formed in one piece. The entire rivet bracket preferably has a C-shaped form.

Of particular importance for the mechanical strength of the rivet strap is, inter alia, the fiber used for the fiber-plastic composite. As fibers, for example, glass fibers, metal fibers, aramid fibers or particularly highly tear-resistant natural fibers can be used. After a Development of the invention, the fiber-reinforced plastic on carbon fibers.

Carbon fibers are characterized by their particularly high tear resistance. With carbon fibers, therefore, particularly stable rivets can be produced, wherein due to the high tear strength of the fiber-reinforced plastic must have only a small proportion of fiber. Also, blended fabrics of the aforementioned fibers, for example, which contain only partially carbon fibers can be used. Carbon fibers thus enable a particularly cost-effective production of a particularly lightweight rivet bar.

In addition to the selection of the type of fiber and the choice of the plastic for the stability of the rivet is crucial. The plastic as matrix material of the fiber-reinforced plastic must ensure a secure embedding of the fibers and thus a firm bond between the fiber and the plastic. The fiber-reinforced plastic therefore particularly preferably has a thermosetting or thermoplastic plastic. Thermosetting plastics or thermoplastics have proven to be particularly suitable, since these plastics on the one hand enable a particularly stable fiber composite and on the other hand also ensure lasting dimensional stability of the rivet strap.

The fibers may be unstructured in the fiber-reinforced plastic. For example. The fibers may be mixed in the plastic disordered. In order to provide a rivet bracket with a particularly high stability compared to the forces occurring during operation, however, the fibers are aligned in the rivet bracket. That is, the course of the fibers present in the attachment unit and / or in the attachment connection and / or in the strap section is predetermined and the fibers are correspondingly arranged in the fiber-reinforced plastic.

In addition, the fibers in the fiber-reinforced plastic are particularly preferably in the form of a woven fabric, fabric and / or fiber bundle. In this way, and by the optionally present directional orientation, a further reinforcement of the rivet bar against mechanical stresses during operation is possible, so that the rivet bracket can be made particularly small in size and / or the corresponding orientation of the fibers and / or particularly thin-walled, without lowering its mechanical strength.

Especially with rivets with a particularly large opening width or rivets, which are intended for setting large diameter rivets, the rivet must absorb very high forces. According to a development of the invention, the fibers therefore have a thickness of 0.01 μm to 0.1 μm in the fiber-reinforced plastic.

With the thickness of the fibers increases their tensile strength. Rivet bars with fibers in the preferred thickness range are extremely stable, so that rivets can be provided, which have a very large opening width and are easily operated by a single person.

In order to provide rivets with different mechanical properties, in particular the proportion of fibers in the fiber-reinforced plastic can vary. The higher the fiber content, the more stable the rivet bar. It is possible to arrange the fibers not only particularly close to each other, but also in several layers one above the other.

According to a development of the invention, the volume fraction of the fibers of the fiber-reinforced plastic is 50% to 70%, preferably 55% to 65%, particularly preferably 58% to 62%, preferably 60%.

Here, the volume fraction, i. the fiber density between the terminal unit, the female terminal and / or the bracket portion may be different. For example, a higher fiber density may be present in the bow section than in the attachment unit and / or in the attachment connection. The fiber density can also vary within the connection unit and / or the receiving connection and / or the bracket section.

In order to form particularly stable areas of the rivet hoop during operation, the fiber thickness, the fiber bundle thickness and / or the fiber density decreases starting from a central loading area present on the bracket section in the direction of the connection unit and / or the receiving connection.

Particularly preferably, the strap section has an inner side oriented in the direction of the connection unit and the receiving connection and an outer side opposite the inner side, the fiber thickness, fiber bundle thickness and / or fiber density being greater at least in an area of the inner side than in an area of the outer side.

As a result, the inside of the rivet strap, which is particularly stressed during the riveting process, is additionally reinforced in an additional manner without additionally reinforcing the entire rivet bar. Also, such a partially reinforced rivet bracket is very precisely adapted to the expected operating loads, making the rivet bracket is particularly easy and material-saving to produce.

In order to make the rivet bracket particularly resilient, the bracket section, the receiving connection and / or the connection unit has a metallic core with an inseparably connected sheathing, which partially consists of fiber-reinforced plastic. The core can be formed as a solid material or as a hollow chamber profile, with filler or metal composite. The metallic core in combination with the fiber-reinforced plastic makes it possible to produce a rivet hoop that is particularly stable and thus highly resilient.

Furthermore, the invention will be described in detail with reference to an embodiment. It shows:

1 a schematic cross section through an embodiment of a rivet strap. An embodiment of a rivet strap 1 is in 1 shown in a schematic cross section. The rivet strap 1 has a bracket section 2 with a C-shaped figure. At one - referring to the graphic representation - upper end 2a of the strap section 2 is one as part of the receiving connection 3 formed first metal sleeve having an internal thread with the bracket section 2 bonded.

At one the upper end 2a opposite - based on the drawings - lower end 2 B is one as part of the connection unit 4 trained second metal sleeve with the strap section 2 bonded. The second metal sleeve also has an internal thread for connecting the rivet bracket 1 with a rivet holder 5a on a drive unit 5 on. Both metal sleeves are covered with two layers of fiber-reinforced plastic.

In the metal sleeve of the connection unit 4 is the drive unit 5 with the rivet holder 5a screwed. The drive unit 5 has a drive piston 6 with one in a head side 6a of the drive piston 6 used riveting tool 7 (Striker) on the opposite to one in the receptacle connection 3 used striker 8th is arranged.

The strap section 2 is designed as a hollow body and has an inside 9 and an outside 10 on. The strap section 10 is made entirely of fiber-reinforced plastic. The fibers in the fiber-reinforced plastic are formed by carbon fibers with a thickness of 0.05 μm. The fibers are present as tissue in the fiber-reinforced plastic, whereby warp and weft of the fabric are offset by 90 °.

The fibers are arranged in the fiber-reinforced plastic in such a way that these to a bracket section 2 continuous center axis 12 (shown here as a dotted line) are arranged at an angle of 45 ° +/- 5 °. The volume fraction of the fibers, ie the fiber density in the fiber-reinforced plastic is about 50 to 60%.

In the area of the outside 10 four fabric layers are arranged one above the other so that the wall thickness in this area is evenly approx. 5 mm +/- 0.5 mm. In the area of the inside 9 1-8 additional layers of fabric are placed on the inside 9 reinforce against occurring tensile forces during riveting. The inside 9 points in the area of a central axis 11 (shown here as a dashed line) has a thickness of about 15 mm +/- 0.5 mm. On the inside 9 and from the central axis 11 starting from the wall thickness takes the inside 9 in the direction of the connection unit 4 and the receiving connection 3 , ie the number of fiber layers - twelve in the region of the central axis 11 - Reduces evenly to four fiber layers in the area of the connection unit 4 and the receiving connection 3 ,

The plastic of the fiber-reinforced plastic is a thermosetting plastic, which is a secure bond with the metal sleeve of the connection unit 4 and the metal sleeve of the female connector 3 manufactures.

The metal sleeves in the connection unit 4 and in the receiving port 3 are covered by two layers of fiber-reinforced plastic.

Claims (9)

Rivet bar for setting rivets, with - a connection unit ( 4 ) for connecting the rivet bracket ( 1 ) with a rivet bracket ( 5a ), - a receiving connection ( 3 ) for arranging a riveting tool ( 8th ) and - one the connection unit ( 4 ) and the recording port ( 3 ) connecting strap section ( 2 ), characterized in that the connection unit ( 4 ), the female connector ( 3 ) and / or the bracket section ( 2 ) are at least partially formed of a fiber-plastic composite. Rivet bar according to claim 1, characterized in that the fiber-plastic composite comprises carbon fibers. Rivet bar according to claim 1 or claim 2, characterized in that the plastic in the fiber-plastic composite is a thermosetting or a thermoplastic plastic. Rivet bar according to one of the preceding claims, characterized in that the fibers are formed as tissue, scrim and / or fiber bundles (roving). Rivet bar according to one of the preceding claims, characterized in that the thickness of the fibers is between 0.01 μm and 0.1 μm. Rivet bar according to one of the preceding claims, characterized in that the volume fraction of the fibers in the fiber-plastic composite is between 50% and 70%, preferably between 55% and 65%, particularly preferably between 58% and 62%, preferably 60%. Riveting bar according to one of the preceding claims, characterized in that the fiber thickness, the fiber bundle thickness and / or the fiber density starting from one on the strap section ( 2 ) present central load area in the direction of the connection unit ( 4 ) and / or the receiving connection ( 3 ) decreases. Rivet bar according to one of the preceding claims, characterized in that - the bar section ( 2 ) one in the direction of the connection unit ( 4 ) and the receiving connection ( 3 ) aligned inside ( 9 ) and one of the inside ( 9 ) opposite outer side ( 10 ) and - the fiber thickness, fiber bundle thickness and / or fiber density at least in an area of the inside ( 9 ) is larger than an area of the outside ( 10 ). Rivet bar according to one of the preceding claims, characterized in that the bar section ( 2 ), the female connector ( 3 ) and / or the connection unit ( 4 ) has a metallic core with an undetachably connected at least partially sheath of a fiber-plastic composite.

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