DE202010006231U1 - Flexible conduit element - Google Patents

Abstract

Flexible conduit element (1), in particular for exhaust pipes of internal combustion engines in motor vehicles with a helical or ring-shaped bellows (2), at least one additional element (3) coaxially adjacent to the bellows (2), in particular a metal braided hose or a metal hose and / or inside the Bellows arranged winding tube, such as an Agraffschlauch, characterized in that between the bellows (2) and additional element (3) consisting of a metal wool damping element (4) is arranged.

Description

The The invention relates to a flexible conduit element, in particular for Exhaust pipes of internal combustion engines in motor vehicles, with a bellows, at least one additional element coaxially adjacent to the bellows, in particular a metal braided hose or a metal hose and / or a winding tube arranged inside the bellows, like an Agraff hose.

such Conduit elements are used as intermediate pieces in the exhaust pipe built-in to absorb movements and vibrations and of the Disconnect forwarding to adjacent components as they pass through Torque dependent tilting movements of the elastically mounted Motors, speed dependent vibrations, inertial Influences of vehicle parts in certain driving situations, temperature-related changes in length, etc. arise.

Of the Contact between the bellows and the additional element can occur when the vehicle is moving lead to noises. There is also the danger that due to the speed-dependent vibrations of the engine in the bellows natural vibrations are stimulated, leading to a premature Can cause fatigue damage in the bellows.

to Avoidance of these dangers will occur in the prior art known line elements different intermediate layers between provided the bellows and the additional elements.

In the EP 0 875 669 B1 the beating between bellows and metal hose is prevented by the clearance between the two parts by a gag hose play, possibly radially biased, but filled in a resilient manner. This ensures that a vibration-damping effect is permanent.

In the EP 0 657 683 B1 the damping of the bellows is accomplished from the outside by an annular, composed of compressed wire pad, which is disposed between the bellows and braid.

In the German patent DE 42 33 644 C2 the problem of bellows damping is achieved in that the damping insert surrounds the bellows radially on the outside and the connecting pieces are connected to each other via a spring seated on the outside of the damping insert. The damping insert here preferably consists of a metallic braid, woven, knitted or crocheted or pressed metal wire.

adversely in the hollow cylindrical damping hoses used in the prior art is that for every bar length and for each bellows diameter a special damping hose is needed and thus the variety of variety to accordingly high storage costs leads. Also is a flexible parameterization the damping characteristic of knitted hoses or in the case of hollow-cylindrical damping cushions made of compressed Metal wire only possible to a very limited extent.

One Another disadvantage is the lack of geometric adaptability the contact surfaces of the damping hoses towards the bellows waves. One for the friction damping Sufficient contact surface between the bellows brims and the damping hoses to achieve These are mounted with radial preload, which increases the assembly costs additionally increased. For knitted hoses It may also be necessary to achieve good damping values be rolled up in the waves and rubbed in this way as well as positively fixed to the bellows.

task The invention is therefore a conduit element of the aforementioned Art to improve so that a flexible parameterization of the damping characteristic is possible while reducing the variety of variants and with simplified installation.

According to the invention the said object by a line element of the aforementioned Kind solved, in particular for exhaust pipes of internal combustion engines in motor vehicles, with a bellows, at least one on the bellows coaxially adjoining additional element, in particular a metal braided hose or a metal knitted tube and / or one within the Balges arranged winding tube, such as a Agraffschlauch, thereby characterized in that between bellows and additional element of a metal wool existing damping element is arranged.

The Metal wool consists of fine scraped from an output wire long metal fibers. The damping principle is based on the Friction between the metal fibers, which per volume unit a variety of contact points and thus a variety of friction points exhibit. Thus, the damping parameters to be adjusted specifically via the density of the metal wool, whereby a widely variable damping characteristic is reachable.

An inventively designed line element thus has an existing metal wool damping element, which is a mutual striking bellows and adjacent components, such as a winding tube or braided reliably prevented by a direct collision and thus a noise emission is avoided in particular at critical excitation frequencies, in particular at the natural frequencies of these components, or a self-adjusting forced oscillation can be limited to an acceptable level.

The as roll goods available metal wool has compared to a Knitted hose or against a pressed hollow cylindrical Wire cushions have the distinct advantage of being more flexible Consistency of the metal wool during assembly almost a form-fitting Contact between the operating brim of the bellows and the Metal wool is achieved, creating a larger Damping volume in the metal wool is activated as this with a only linear contact, z. B. at a made of wire pressed cushion, is possible.

The Installation of the metal wool available as a meter is done at a coaxially outside the bellows arranged damping element by spiraling, one or more layers wrapping the outside of the bellows with a band of metal wool whose width is at least which corresponds to two to three times the wave pitch of the bellows. In this way, you can use only one bandwidth different Ballow lengths and bellows diameter with a damping element equip. By targeted pretensioning of the metal wool tape When wrapping the bellows, the damping properties can be additionally vary. To a winding up of the so applied To prevent metal wool tape, the initial and Endpoint fixed with a wire loop or up to the bellows end reaching damping element with the later too be fixed mounting angle rings. After that it becomes coaxial arranged to the damping element additional element, for. B. a Knitted or braided hose mounted by coating and fixed by means of angle rings on the cylindrical bellows.

at an arranged inside the bellows additional element, for example a winding tube, the metal wool tape is removed before mounting the Winding hose in the bellows, on the outer diameter spiral wound up in single or multi-layered form. The resulting Outside diameter of the wrapped corrugated tube becomes smaller chosen as the clear Balginnendurchmesser. After threading of the wound with metal wool wound hose into the bellows by axial compression of the metal wool in the annular gap between the bellows and winding hose a close contact between bellows and Produce metal wool before the annulus by widening the winding tube ends is closed against the cylindrical Balgborde.

In a special embodiment of the damping element can this as a strip-shaped band of metal wool helical around the bellows-side lateral surface of the additional element in such a way be arranged that it is only part of the bellows facing Covering the surface of the additional element. This is special then makes sense, if only a small damping effect between bellows and damping element is required.

To Another design may be provided that the damping elements of several arranged on the circumference of the bellows in the longitudinal direction strip-shaped bands are made of metal wool, the expediently then to the cylindrical Balgende reach, where they simplify the assembly of the additional element, z. B. a braided hose, by means of a wire loop on the circumference be fixed.

All in all Such a flexible conduit element has been created in which a targeted damping characteristic through single or multi-layered Winding the obtainable as a roll commodity metal wool can be realized could.

Further Features and details of the invention will become apparent from the claims and from the description below, in the embodiments explained in detail with reference to the drawings are. Showing:

1 an axial section through an inventive design of a flexible conduit element in which an existing metal wool damping element between the metal bellows and Agraffschlauch is arranged.

2 an alternative design of a flexible conduit member in axial section, in which the metal wool existing damping element between the metal bellows and the coaxially adjacent metal braided hose is arranged.

This in 1 illustrated flexible conduit element 1 has a ring-corrugated bellows 2 and a surrounding knit hose 3 whose structure is shown in the uncut, rectangular section and the one with the angle rings 5 is set against the cylindrical bellows and in this way serves as a longitudinal support of the conduit member against impermissibly large axial extensions. Inside the bellows is an additional element in the form of an Agraffschlauches 3a arranged, which prevents the direct contact of the hot exhaust gases with the bellows and in addition excludes a possible vibration excitation of the bellows waves by the flowing medium. In the annulus between bellows 2 and Agraffschlauch 3a is a cushioning made of metal wool lement 4 arranged, which is wound on the outer diameter in single or multi-layer form before mounting the Agraffschlauches in the bellows. After threading the wound with metal wool Agraff hose into the bellows tight fitting contact between the inner brims of the bellows and the metal wool is achieved by axial compression of the metal wool in the annular gap between bellows and Agraffschlauch. Subsequently, the annular space is closed by expanding the Agraffschlauchenden against the cylindrical Ballows, whereby the damping element 4 is determined in his position.

Across from 1 shows 2 an alternative design of a flexible conduit member in which the inventive, consisting of metal wool damping element is arranged coaxially between the outer rim of the bellows and the inside of the additional element. At the additional element 3 is in the illustrated embodiment, a braided hose whose structure in the uncut, rectangular section of the 2 is shown and the one with the angle rings 5 is set against the cylindrical bellows and in this way serves as a longitudinal support of the conduit element.

The assembly of the damping element is done in this embodiment prior to assembly of the braided hose by spiral, single or multi-layer wrapping the outside of the bellows with a strip of metal wool whose width corresponds to at least two to three times the wave pitch of the bellows. Here, the metal wool tape nestles against the contour of the Balgaußenkrempen, so that there is a nearly positive contact between the bellows and damping element after wrapping. During a swinging motion of the bellows, a large damping volume is thus activated in the contact areas between the outer bellows rim and the adjacent metal wool, which leads to a good damping of the oscillating bellows areas. In order to prevent winding of the thus applied metal wool tape, the start and end point are fixed with a wire loop on their representation in 2 has been omitted for clarity. After assembly of the braided hose, with a small axial preload by means of the angle rings 5 is fixed in the region of the cylindrical bellows, the damping element is also under a radial bias, which is the result of the associated with the elongation of the braid tube diameter reduction. By this elastic rescue of the braided hose on the metal wool obtained by the elastic effect of the metal wool in the radial direction and a soft draft stop of the flexible conduit element. Inside the bellows is as well as in 1 an additional element in the form of an Agraffschlauches 3a arranged, which serves to protect the bellows against the hot exhaust gases.

The illustrated embodiments can of course be combined with each other to particularly vibration sensitive areas of the bellows, the Agraffschlauches 3a or generally an additional element 3 targeted to dampen. For example, a design would be 2 conceivable in which the braided tube is replaced by a knitted tube to prevent lifting of the braid tube from the damping element in large axial compression movements. Another variant with a particularly high risk of resonance of the bellows would be as a modified design of the in 1 illustrated embodiment conceivable in which in addition to the illustrated Innenbedämpfung an external damping with metal wool between knitted tube and bellows outside would be provided.

1

flexible line element

2

bellows

3a

Additional element, wound metal hose, Agraff hose

3

Additional element, Knitted hose or braided hose

4

damping element made of metal wool

5

angle rings

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0875669 B1 [0005]
• EP 0657683 B1 [0006]
• - DE 4233644 C2 [0007]

Claims (6)

Flexible line element ( 1 ), in particular for exhaust pipes of internal combustion engines in motor vehicles with a helical or ring-corrugated bellows ( 2 ), at least one on the bellows ( 2 ) coaxially adjoining additional element ( 3 ), in particular a metal braided hose or a metal hose and / or a winding hose arranged inside the bellows, such as an agraff hose, characterized in that between bellows ( 2 ) and additional element ( 3 ) a metal wool existing damping element ( 4 ) is arranged. Conduit element according to claim 1, characterized in that the damping element ( 4 ) consists of a spirally wound band of metal wool. Conduit element according to Claim 1 or 2, characterized that the damping element of several superimposed wound layers of metal wool. Conduit element according to one of claims 1 to 3, characterized in that the bellows shafts facing side of the damping element ( 4 ) during assembly of the wavy outer or inner contour of the bellows ( 2 ) and thus fixed form-fitting. Conduit element according to one or more of claims 1 to 4, characterized in that the damping element ( 4 ) as a strip-shaped band of metal wool helically around the bellows-side lateral surface of the additional element ( 3 ) is arranged. Conduit element according to one or more of claims 1 to 5, characterized in that the damping element ( 4 ) consists of strip-shaped strips of metal wool, which in the longitudinal direction between bellows and additional element ( 3 ) are arranged.