Fluid conduit

The invention relates to a fluid line with a tube having an envelope made of a woven fabric or braid, which in turn comprises at least one conductor.

Such a fluid line is often used for heating a fluid in motor vehicles, which is freeze-or viscous at low temperatures.

Thus, from <patcit id="pcit0001" dnum="DE19915228A1"><text>DE 199 15 228 A1</text></patcit> a heatable fluid line for a motor vehicle brake apparatus is known in which on an inner pipe made of rubber, a middle rubber layer is provided in which a sheath-forming reinforcing fabric is embedded and which is surrounded by a radially outer rubber layer. In the reinforcing fabric, an electrical heating conductor is woven or braided. The production of these multilayer fluid conduit is expensive

From the <patcit id="pcit0002" dnum="DE1775094A"><text>German patent application DE 17 75 094 A</text></patcit> is a fluid conduit according to the preamble of claim 1 is known, wherein the conductor is a low impedance electrical grounding conductor. The conductor surrounds a helically corrugated metal tube, which is surrounded with the conductor of a stainless steel wire mesh. The preparation of these fluid line is also complex.

From the <patcit id="pcit0003" dnum="EP0142624A"><text>European Patent Application EP-A-0142624</text></patcit> is a fluid line is known which comprises an inner tube of rubber and surrounding the inner tube braid layer with a rubber sheath. The braided layer includes a plurality of parallel groups of parallel Heizwiderstandsdrähten with arranged between groups textile yarn strands. The Heizwiderstandsdrahtgruppen and textile strands extending helically woven around the inner tube around and are in textile strands.

The patent <patcit id="pcit0004" dnum="US2003586A"><text>US-A-2,003,586</text></patcit> shows a case of molding helically around a bundle of fine, soft wires, preferably steel wires, wound around electrical conductors. After formation of the coil the steel wires are drawn out of the coil. The coil is then inserted in an axial passage in the wall of a rubber tube. The head serves as a power supply line of an electromagnet for actuating a valve which controls the flow through the tube. The conductor does not is a heating wire.

The invention has for its object to provide a fluid line of the aforementioned type whose structure is simpler.

According to the invention the solution in a fluid line, as defined in Claim first

In this solution eliminates a middle rubber layer in which the envelope is embedded, and embedding of the shell-forming fabric or mesh in the middle layer.

The tube need not be made of rubber, but may also consist of rubber or some other material, for example thermoplastic material or metal. The sheath, therefore, can be prepared after completion of the pipe around it in a simple manner. At the same time the conductor can be woven or braided into the sheath. Optionally, the sheath and the conductor can be retrofitted. With sufficient strength of the casing can also be to strengthen or protect the pipe serve. If one end of the conductor after the formation of the shell with an end of the sheath is flush, but protrudes the other conductor end sufficiently far from the other end of the sleeve, the conductor may be because it is loosely arranged in the shell, in a simple manner at the are detected protruding end and slightly pushed out of the sleeve to provide both ends of the conductor terminals or in two conductors from the sheath to connect outstanding or drawn-out conductor ends so that a forward and return conductors results.

Further, the casing can surround the pipe exposed to the outside. Optionally eliminates an outer rubber layer.

It may also be taken to ensure that each heating conductor is woven or braided into the sheath and through the material of the shell locally contact with the pipe. This results in a better heat transfer between pipe and heat conductor.

Furthermore, the entire shell of glass, plastic, natural, carbon, mineral or metal fibers can be made. For such fibers, the mesh or fabric can be easily produced.

Then may be arranged each conductor straight or coiled in the textile or fabric. In particular may be herumgewikkelt helically around the tube each conductor.

The tube may be smooth or corrugated, the sheath may be arranged loosely on the tube. You can then, even with a corrugated tube, easy to move on the tube to the desired position, especially when it is upgraded.

It may further be displaceable in the sleeve in the longitudinal direction of each conductor. He is then by combining dipping the shell easily accessible at its ends, to connect it to a power source. Further, the tube can be exposed by the combination of dipping sleeve at its ends temporarily for clamping the tube during insertion of a connector into the pipe end.

Alternatively, to a completely random arrangement of the casing on the tube, it may be attached to at least one location on the pipe. It is then subsequently no longer be moved.

Instead of leaving the shell outside free, it can also be surrounded by a protective sheath, comprising the thermoplastic material and disposed around the first mentioned casing around, douse or is extruded onto it. Here too, initially a part of the conductor laterally withdrawn from the first-mentioned sleeve and the first-mentioned envelope are cut to the desired length before the protective sheath is applied, so that the conductor is exposed after application of the protective cover and can be provided with connections, or two conductors whose ends can be connected to form a forward and return conductors.

The invention and its developments are described below with reference to the accompanying drawings of preferred embodiments in more detail. Therein show in:<dl id="dl0001"><dt>Fig. 1</dt><dd>a side view of a first embodiment of a fluid line according to the invention,</dd><dt>FIG. 2</dt><dd>the section II-II of FIG. 1,</dd><dt>Fig. 3</dt><dd>a side view of a second embodiment of a fluid line according to the invention,</dd><dt>Fig. 4</dt><dd>the section IV-IV of FIG. 3 and</dd><dt>Fig. 5</dt><dd>a side view of a third embodiment of a fluid line according to the invention.</dd></dl>

The embodiment of the fluid conduit according to the invention according to FIGS. 1 and 2 consists of a tube 1, a pipe 1 surrounding the envelope 2 in the form of a braid and an interwoven in the mesh heating conductor 3rd

The tube 1 is made of plastic, preferably thermoplastic, such as nylon, but can also consist of rubber or metal. but it may also be a multilayer tube. In any case it is to hydrocarbons such as oil impermeable. Shown is a smooth tube. However, it may also be corrugated. Preferably it is flexible.

The casing 2 is a fiber web of plastic fibers, but they can also consist of glass, natural, mineral or metal fibers. It is loosely arranged on the pipe 2 and is located in the finished state of the fluid conduit to outside. Further, it is displaceable on the tubular second It can therefore be arranged subsequently to the tube and moved up to the desired location. The casing 2 has a high strength, so that it protects the pipe 1 at high internal pressure against excessive expansion. In addition, the sheath 2 is abrasive. It therefore protects the pipe 1 against abrasion. For repair purposes, they can be easily replaced. The tube 1 and the casing 2 are also recyclable.

The heat conductor 3 is woven into the fabric of the sheath. 2 The shell 2 can also be designed as a woven fabric, in which the heating conductor 3 is woven. It contains a heating wire 4, which surrounds an elongated insulating material helically. The insulating material is a glass fiber bundle around which the resistance wire 4 is wound helically. The heating wire 4 and the glass fiber bundle is surrounded by a transparent, flexible plastic film which is itself electrically insulating. Further, the heating conductor 3 is slidable in the sheath second

The helical shape of the heating wire 4 enables the use of a resistance wire with low resistance per unit length. By helical shape of the heat conductor 3, the heating power per unit area of ​​the tube 1 is increased compared to a linear arrangement of the heat conductor. The displaceability of the heating conductor 3 in the sleeve 2 made possible by axial compression of the braid of the sheath 2, the pushing out of end portions of the heating conductor 3 of the sheath 2 when the ends of the heating conductor 3 when cutting a sheath 2 forming portion endless of a prolonged ( " ") shell with the ends of the truncated envelope 2 are flush. The following compression of the sheath 2 outstanding at their ends portions of the heating conductor 3 can be stripped and the filament 4 are provided with a terminal, such as the connector shown schematically 5 or a terminal to connect the heating element 3 to a power source. Conversely, the heating conductor 3 when its one end to one end of the sheath 2 is flush and sufficiently protrudes the other end far from the other end of the sheath 2, are displaced so far in the shell 2, to the one end also from the case 2 protrudes to be provided with a connection to.

The embodiment according to FIGS. 3 and 4 differs from the first embodiment only in that the heating conductor 3 is not helical, but in a straight line incorporated into the sheath 2 and, instead of a heat conductor, as in the first embodiment, two diametrically opposed heating conductor 3 are provided, which can be connected in parallel either in series or such that the fluid flow is heated in the tube 1 from two sides.

The illustrated embodiments may be modified in many ways: The shell may at least one location on the pipe after it has been slid onto the pipe, may have been attached in order to prevent an unintentional displacement of the sleeve.

The casing 1 may also be surrounded by a protective sheath. These may include thermoplastic resin and arranged around the sheath 1 around, around sprayed or extruded onto it.

can almost only point-bear at those locations on the tube 1 during the circuit 3 in the embodiments of FIGS. 1 to 4, in which a few strands of the braid of the sheath 2 are side by side carried away just above him, as is schematically indicated in the drawings , the head 3 is in the embodiment of FIG. 5 large area to the tube 1, where he is carried away by a plurality of adjacent fiber bundles of the shell 2. This results in a better heat transfer between the pipe 1 and conductor. 3