DE20215275U1 - Three-part roll bar - Google Patents

Description

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ISE Innomotive Systems Europe GmbH

Othestr. 19 51702 Bergneustadt

Three-part roll bar

Three-part roll bar

The invention relates to a three-part roll bar, consisting of two bar leg tubes which are mechanically connected to one another in a U-shape at one end via a rounded bar head.

Rollover protection systems for motor vehicles are known in a variety of designs.

Such rollover protection systems are used to protect the occupants of motor vehicles without a protective roof, typically in convertibles or sports cars.

It is known to provide a permanently installed roll bar that spans the entire width of the vehicle or to assign a permanently installed roll bar to each vehicle seat at a fixed height. In both solutions, the increased air resistance and the occurrence of driving noise are perceived as disadvantageous, apart from the impairment of the vehicle's appearance in the case of convertibles.

As a result, more and more constructive solutions are gaining importance on the market in which the roll bar is retracted in the normal state and, in the event of danger, i.e. in the event of an impending rollover, is quickly extended into a protective position in order to prevent the vehicle occupants from being crushed by the rolling vehicle.

These solutions typically have a U-shaped or a

The roll bar has a profile body which, in the normal state, is held in a lower rest position by a holding device against the pretensioning force of a drive compression spring and, in the event of a rollover, can be brought into an upper, protective position by the spring force by releasing the holding device, with a sensor-controlled locking device then coming into active engagement and preventing the roll bar from being pressed into the cassette.

The holding device typically has a holding member attached to the rollover body, which is in a detachable mechanical connection with a trigger member on a sensor-controlled trigger system, which is typically formed by a trigger magnet, the so-called crash magnet, or by a pyrotechnic trigger member. The locking device typically consists of a pivotably hinged, spring-loaded latch with tooth segments and a fixed toothed strip, a locking pin or the like, with one locking element being connected to the rollover bar and the other being fixed to the vehicle.

Such a cassette construction of a roll bar protection system is shown, for example, in DE 100 40 649 Cl.

The invention is directed to rollover protection systems that have a U-shaped roll bar. This roll bar typically consists of three components, the two leg tubes that are guided in the cassette, and the bar head, also called a cross yoke, which can also be tubular and via which the leg tubes are connected to one another in a U-shape at the head.

In the well-known U-shaped roll bars, the leg tubes and the bar head are made of steel tubes that are welded together, i.e. they are firmly connected to one another. There are also U-shaped

Roll bars are known whose components consist of aluminum tubes that are also welded together.

Because only essentially identical materials can be welded together well while meeting the high skill specifications, it is not possible to manufacture the three components of the overhead bar from different materials using state-of-the-art welding technology. Even if the components are made from the same type of material but have different material data, particularly with regard to strength, there are strict limits to the possibility of varying the material data.

In order to achieve the specified properties of the roll bar with regard to strength, elongation, deformability, in particular for energy absorption, etc., i.e. to achieve a specified path/force curve under load, it is desirable to be able to use different, adapted materials for the roll bar leg tubes and the bar head.

The invention is based on the object of designing the three-part U-shaped roll bar described at the beginning in such a way that the bar components consist of different materials and can originate from different manufacturing processes and can nevertheless be mechanically securely connected to one another.

This object is achieved with a three-part roll bar, consisting of two bar leg tubes, which are mechanically connected to one another in a U-shape at one end via a rounded bar head, according to the invention in that the connecting ends of the bar leg tubes are each positively connected to the bar head via associated connection points.

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The form-fitting connection of the bar components makes it possible to manufacture the components of the roll bar from different materials depending on the requirements for strength, deformability, etc. and to mechanically connect them firmly to one another in order to secure the survival space in the event of a rollover and to reduce load peaks in the event of a rollover. The materials can, for example, be selected in such a way that rigid, i.e. firm and not very elastic, leg tubes can be connected to one another with a defined deformable, i.e. flexible bar head.

This makes it possible to combine bracket components that were previously impossible due to their inability to weld.

The form-fitting connection of the bar components also makes new material combinations possible. For example, the bar leg tube can be made of aluminum, steel, or a fiber-reinforced plastic (GRP or CFRP) and can be form-fittingly connected to a bar head, which can alternatively be a bent steel tube or aluminum tube, or a metal die-cast or forged part, or a fiber-reinforced plastic part. So-called hybrid roll bars are therefore also possible in terms of material.

Due to the now possible use of different manufacturing processes for the manufacture of the bracket head, e.g. cold forming of pipes, forging, casting, injection molding, etc., bracket heads with a special shape can be manufactured, e.g. adapted to the requirements of the limited deformability of the head.

Different color combinations of leg tube/bracket head are also possible.

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Depending on the configuration of the bracket head and the materials used for the leg tubes and bracket head, different designs of the positive connection are possible, ζ. β by embossing.

Further embodiments of the invention are characterized in further subclaims and also emerge from the description of an embodiment of the invention shown in the drawings in various views and sections.

Show it:

Figure 1 is a perspective view of a rollover protection system in

Cassette construction in which the U-shaped roll bar according to the invention, assembled from three components, is used,

Fig. 2 in a detail view from Fig. 1 the detailed structure

of the roll bar before the positive connection,

Fig. 3 is a view corresponding to Fig. 2 after installation of the

positive connection, and

Fig. 4 shows an exemplary roll bar according to the invention

achievable force-displacement curve.

Figure 1 shows a perspective view of a cassette construction of a rollover protection system for motor vehicles, each of which is assigned to a vehicle seat in which the roll bar designed according to the invention is provided. It is understood that the roll bar according to the invention can also be used in other rollover protection systems.

Figure 1 shows the retracted state of the rollover protection system, i.e. the operational state of the roll bar. In the following description

For the sake of clarity, only the essential components of the rollover protection system are discussed in Figure 1.

This rollover protection system has a U-shaped roll bar 1, which is composed of three tubes 2, 3, 4. The bar head is essentially formed by a curved tube 2, which is rigidly connected at its ends to two leg tubes 3, 4 by a positive connection 25.

In addition to cylindrical cross-sections for the bracket leg tubes, oval or square cross-sections can also be chosen for stability reasons.

The open ends of the leg tubes 3, 4 are rigidly connected to one another by means of a cross member 5. For this purpose, the cross member 5 is designed as a profile body with a predetermined height, which has holes 6 for receiving the leg tubes 3, 4, in which they are fastened.

The roll bar 1 with its two leg tubes 3, 4, which have a closed outer surface, and the connecting cross member 5, is accommodated in a cassette-like housing 7 and is held therein so that it can be extended or retracted. This housing has two side parts 8, 9, which are formed by a U-shaped profile body, which preferably consists of metal, in particular steel. These side profiles 8, 9 are connected to one another at the bottom via a floor plate part 10 and at the top via a guide block 11 fixed to the vehicle, e.g. by riveting, screwing, welding or the like.

Two spring guide bolts 12, 13 are anchored in the floor panel 10, onto which pre-tensionable compression springs (not shown) are pushed for extending the roll bar 1 in the event of danger or when it is manually released, and which guide the leg tubes.

At least one set of spread centering arms (not shown) is attached to the spring guide bolts 12, 13, preferably formed in one piece, which ensure a uniform distance between the associated compression spring and the associated leg tube 3, 4, which also has an advantageous noise-reducing effect.

It is also conceivable to surround the spring guide bolts 12, 13 with standpipes with closed jacket surfaces, which are also anchored in the base part 10 and over which the leg tubes, spanning the standpipes, are guided.

The two side profiles 8, 9 are expediently connected, at least on one front side of the cassette, to a cover plate which expediently, but not necessarily, extends over the entire height of the cassette (not shown).

The guide block 11 has two guide holes 14, 15 which laterally support the outer surface of the leg tubes 3, 4 and offer a very wide tolerance guide for the leg tubes 3, 4 moving along the guide holes 14, 15. At the upper end of the guide holes 14, 15 facing the curved tube 2, a radial countersink or annular groove is expediently created, which in a known manner accommodates an annular, radially elastic guide bush (not shown), whereby the radial play of the bracket leg tubes 3, 4 in the guide holes 14, 15 is compensated. In addition, an internal guide is provided for the leg tubes, which is ensured by the aforementioned spring guide bolts or standpipes fixed to the housing.

In order to be able to hold the roll bar 1 in its lower position, the rest position, against the force of the then pre-tensioned compression springs, a

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7 spring-loaded, pivotally mounted retaining pawl 17 with a hook-shaped bent retaining lug, which can be brought into operative engagement with a retaining bolt 18 anchored in the base part 10. When the roll bar 1 is lowered, and thus also when the cross member 5 is lowered, the retaining lug rests on the retaining bolt 18 and holds the roll bar 1 in the rest position.

Furthermore, a sensor-controlled trigger system is firmly attached to the base part 10 in a holder 20a, 20b, which is preferably formed by a pyrotechnic trigger element 19 that ejects a pin and can overcome the relatively high contact force of the retaining latch 17 on the retaining bolt 18 more reliably than a conventional trigger magnet. The retaining bolt 18 is also mounted in the holder 20a, 20b, which at the same time represents a shaft for a pivotable rocker 24, which has a connecting leg bent over cheeks, which lies between the front side of the pin of the trigger element and the front side of the nose of the retaining latch 17, i.e. as a movable spacer it bridges the space between the pin and the retaining bolt 18.

A locking pin 21 is attached to the guide block 11, which in the upper position can be brought into operative engagement with a locking pawl, which is also pivotably hinged in the cross member 5 about the shaft 16, in order to prevent the roll bar from being accidentally pushed in in an extended position.

Furthermore, a release lever 22 is pivoted in the cross member 5, also pivotable about the shaft 16, which has control functions since it can act on both the hook-shaped retaining pawl 17 and the locking pawl via lateral stops.

In the event of activation, the pin of the pyrotechnic trigger system 19 pushes the nose of the retaining latch 17 out of the operative engagement with the retaining bolt 18 via the cranked connecting leg of the rocker 24 and thus releases the

Roll bar 1 is released, which, together with the cross member 5, moves into its upper position, driven by the compression springs. During this raising movement, the locking pawl held in the moving cross member 5 ratchets over the teeth of the locking pin 21 attached to the guide block 11 and locks it in the upper position to prevent it from being retracted.

After an intentional release, particularly for test purposes during production and during operational inspections during driving, the roll bar must be able to be automatically reversed, here manually, into the rest position as shown in the figure, i.e. the spring-loaded retaining latch 17 must be able to automatically engage the retaining bolt 18 again. This is possible with the construction shown by means of the rocker 24.

Fig. 2 shows, in a detail from Fig. 1, the design of the three-part roll bar according to the invention with the complete bar head and only the connecting ends of the leg tubes 3, 4. In this example, the bar head is designed as a solid bent forged part and has a circumferential groove-shaped groove 2c at the connecting ends 2a, b.

Using a symbolically represented tool 26, the connecting ends of the leg tubes 3, 4 are deformed in the groove area to form a positive connection with the bracket head.

As mentioned at the beginning, the leg tubes 3, 4 can be made of aluminum or steel, but also of a fiber-reinforced plastic, or the bracket head 2 can be a bent steel or aluminum tube or a fiber-reinforced plastic part instead of a forged part. Because the bracket components and the bracket head can be made of different materials and the bracket head can be manufactured and designed using different manufacturing processes, it is possible, as

As shown in the travel/force diagram in Fig. 4, a force/travel curve must be specified for the roll bar (solid line) which lies between a maximum and minimum target curve and thus ensures safe functioning of the rollover protection system in the event of a rollover.

Figures 2 and 3 show a groove-shaped form-fitting connection. It is clear to those skilled in the art that other configurations are also possible.

Claims (8)

1. Three-part roll bar ( 1 ), consisting of two bar leg tubes ( 3 , 4 ) which are mechanically connected to one another in a U-shape at one end via a rounded bar head ( 2 ), characterized in that the connecting ends of the bar leg tubes ( 3 , 4 ) are each positively connected to the bar head ( 2 ) via associated connecting points. 2. Roll bar according to claim 1, characterized in that the connecting points ( 2 a, b) on the bar head ( 2 ) have a circumferential groove ( 2 c) into which the wall of the connecting ends is embossed to create a positive connection. 3. Roll bar according to claim 2, characterized in that the groove ( 2 c) is groove-shaped. 4. Roll bar according to one of claims 1 to 3, characterized in that the bar leg tubes ( 3 , 4 ) consist of steel or aluminum. 5. Roll bar according to one of claims 1 to 3, characterized in that the bar leg tubes consist of a fiber-reinforced plastic. 6. Roll bar according to one of claims 1 to 5, characterized in that the bar head ( 2 ) consists of a bent steel or aluminum tube. 7. Roll bar according to one of claims 1 to 5, characterized in that the bar head ( 2 ) is designed as a die-cast or forged part. 8. Roll bar according to one of claims 1 to 5, characterized in that the bar head is designed as a fiber-reinforced plastic part.