Mandrel for the connection of two pipe ends.

p0001The invention relates to a coupling sleeve for connecting the ends of two lines for flowing media, in particular for fuel lines on internal combustion engines, with a sleeve part having at least one insertion opening for receiving a pipe end.

p0002In a variety of use cases ancillaries through pipes and / or hoses must be connected to each other with machines. This often is given also the need for a rigid pipe, for example made of metal, must be connected to a flexible hose of rubber or plastic, as is customary, for example, for fuel lines on internal combustion engines. Especially in the case of internal combustion engines, especially in the automotive mass production, it is mainly a question of that on the one hand the coupling sleeve is easy to assemble, in particular through a simple plug-in assembly, on the other hand, the sleeve connection but is so strong that it even at the strong vibrations during operation of a motor vehicle can not solve. Nevertheless, the sleeve joint must be designed so that for repair purposes both line parts can be resolved from each other, it is important that the outer surface of the pipe ends, which simultaneously serve as a sealing member, are not damaged by the connection sleeve.

p0003The invention is based on the object to provide a socket joint of the type described, which fulfills the requirements set out above.

p0004This is inventively achieved in that two transversely arranged on the sleeve part in the region of the insertion opening at least to the insertion port deflectable securing finger whose free ends are each provided with radially inwardly directed lugs, which act on the outer wall of the insertion opening forming tubular elastic sealing body, and in that an axially displaceable and latchable on the sleeve portion securing sleeve is provided, the free ends of the securing finger grips in its operating position substantially.

p0005A thus formed coupling sleeve has a number of advantages. For assembly, the free end of the cable to be connected, either a pipe or a hose can be inserted with a tube insert in the end zone in a simple plug-in assembly in the insertion opening of the socket member, which is currently on the sleeve part tubular sealing body of elastic material the narrow inserted cable end to its outer surface engages sealing. Usually, in this case has the free opening of the elastic sealing body has a somewhat smaller diameter of the outer diameter of the pipe to be inserted end so that is compressed in accordance with the inserted pipe end of the sealing body and the required sealing force is present. Since the tubular sealing body in contrast to the previously known clutches has a sufficient deformation volume, will not result in a load of the coupling sleeve by transverse forces, additional deformation of the elastic sealing body to a deterioration of the sealing force. The inserted line end comprises a sealing over a considerable length on its outer surface from the seal body, wherein in the region of the projections of the securing fingers through the pushed over retainer sleeve, a pressing force between the sealing body and end of the line becomes effective, which improves the sealing effect. Although arranged at the line end annular projection is now within the seal body, however a form locking securing the pipe end results against withdrawal by the lugs of the securing finger.

p0006can be seen according to the invention prior to the securing fingers in the region of the resting against the gasket body approaches to the outer side of projections which form, in cooperation with the locking sleeve an operating position defining locking, it can be with appropriate shaping of the projections both a backup of the operating position and the desired increase in achieve the sealing action, which does not diminish by acting on the line transverse forces.

p0007While it is basically possible to integrally manufacture the socket part with the retaining fingers, which is particularly indicated when elastic sealing bodies are used as a separate component under pre-tension in the insertion opening, the invention provides in a preferred embodiment in that the safety finger with its fixed end to a coupler part form-fitting surrounds retaining ring attached. Although the arrangement of the securing finger as a separate component requires during finishing Mupplungsmuffe an additional operation because the retaining ring and the socket part must first be put together and then the locking sleeve must be pushed. The particular advantage of this design, however, is that this makes it possible to immediately einzuvulkanisieren the elastic seal body to an open against the direction of insertion cup-like extension in the female part, since the edge of the insertion opening is exposed, so that the sleeve part and the tool are relatively moved rotationally can and the elastic material can be introduced. The particular advantage is here in the fact that the connection between sealing body and sleeve portion is completely sealed by the vulcanization of the elastic sealing body, so that should be taken only by appropriate compression between the seal body and the inserted pipe part of the seal between the sleeve portion and pipe end concern.

p0008In an advantageous embodiment of the invention is further provided that the retaining ring bearing the securing finger is divided. The retaining ring can here consist either of two separate sections or provided integrally with a thin flexible connection may be, as is possible in the manufacture of a plastic material in the form of a so-called "film hinge". The retaining ring is formed advantageously cup-shaped and engages a correspondingly shaped holding rib on sleeve part, so that the retaining ring is connected to the securing fingers positively and displaced axially fixed to the female part.

p0009In a preferred embodiment of the invention is further provided that the securing fingers are at least colored differently in the area of ​​their free ends as the locking sleeve. This has the advantage that in the assembly position described above, the mounting position is visible through the color of the securing finger, so that a visual inspection is possible, if after mounting the security sleeve is moved into the operating position. With appropriate design of the length Si cherungshülse these covers in the operating position the securing finger completely.

p0010In an embodiment of the invention provides that at least the locking sleeve made of metal and is guided on the sleeve portion at a radial distance and covering the sleeve portion including the safety finger and part of the related sleeve part flexible tube in the operating position. This allows to increase the resistance to fire even when made of plastic spigot and socket parts, as is desirable, for example for fuel lines.

p0011The invention is illustrated with reference to a schematic drawing of an embodiment.

p0012The embodiment shown comprises a rigidly connected with a sleeve part 3 the elastic sealing body 6 which is of tubular design and surrounds the inserted end of the pipe 1 on the outside of sealing over a greater length. The socket member 3 forms, together with locking fingers 16 comprises a cylindrical receiving space for the sealing tubular body 6, wherein the securing finger 16 in the assembly position loosely on the outer side of the seal body 6 rest. On the outside of the socket member 3 is comprised by an axially displaceable securing sleeve 19th

p0013The securing finger 16 are provided at their free ends, both on the inside with projections 26 and on the outside with projections 27th When pushed back locking sleeve 19, that is in the assembly position, which at its end provided with a bead 28 pipeline 1 can be pressed into the sealing member 6, since the securing fingers 16 bend accordingly due to their elasticity to the outside. Thereafter, the locking sleeve 19 is pushed into the illustrated operating position and that so far, to a on the inside befind Licher annular projection 29 which is also a ring-forming protrusions 27 of the securing finger 16 engages latching. In this way, the securing fingers 16 are pressed onto the seal body 6, so that the sealing effect between the seal body 6 and the pipe end is increased by this pressing force. At the same time, this results in a positive locking of the pipe 1 against being pulled out, as the bead 28 can not be pulled over the lugs 26, due to high deformation resistance of the material of the seal body under bias 6th Also transverse forces do not reduce the seal.

p0014If you compare the safety sleeve 19 of metal ago, with otherwise made of plastic parts, then given an additional increase in the fire resistance of the coupling sleeve, as a thermally conductive connection between these parts to a few narrow zones is limited and the gap 30 acts as an insulator. Increasing resistance to fire, for example, three minutes can save lives when used in motor vehicle accidents.

p0015In the embodiment the securing fingers 16 are integrally formed on the sleeve part 3rd In a modification, however, it is possible to form the fuse finger across an optionally axially split retaining ring as a separate component. After insertion of the seal body, the retaining ring is fitted on the socket member and then mounting the retainer sleeve.