SK285781B6 - Dimensionally stable corrugated tube and method for producing same - Google Patents

Abstract

A dimensionally stable corrugated tube (1) made of plastic and intended in particular for the protective sheathing of electric wiring comprising a slotted opening (4) that extends along a contour line which has been provided with peaks (2) and valleys (3). The ends (5,6) of the slotted opening (4), which is creating with a diagonal cut, lie one on top of the other and the internal end (5) is then led outwards and laid over the other end (6), which was previously situated outside. The corrugated tube (1) has been made so, that has been extruded and provided with peaks (2) and valleys (3) and it has been cut along an optional contour line. The cutting is performed under a uniformly rising or falling angle, the inclination of which lies between a radius of the corrugated tube or a tangent on the corrugated tube. The cut corrugated tube (1) is compressed therein so that the ends (5,6) of the slotted opening (4) are pushed one on top of the other and then, when the corrugated tube (1) has cooled down, the internal end (5) of the slotted opening (4) is led outwards and laid over the other end (6) which was previously situated outside.

Description

Technical field

The invention relates to a shape-stable corrugated pipe and a method for producing a shape-stable corrugated pipe consisting of plastic and adapted in particular for protective wrapping of electrical conductors, with a slot opening extending along the surface line.

BACKGROUND OF THE INVENTION

Such corrugated tubes, especially made of plastic, are known and used especially in the manufacture of automobiles as protective sheathing of electric conductors. The longitudinal slot provided in such corrugated tubes, or a slot opening thereof, serves to protect the cable, usually in the form of a bundle of cables, or in the form of a bundle of branching cables, inserted into the corrugated pipe.

A variety of designs are known in the art to form the slits of the slotted openings of such corrugated tubes so that after the cable has been manually inserted, the edges can be brought into contact with each other and the closure can also be opened again with or without tools.

Depending on the formation of the edges of the slots or the corresponding closing shapes of the longitudinal slots, less or more time is needed to close such pipes, notwithstanding that the formation of the edges of the longitudinal slots can be made less or more expensive.

Thus, for example, it is known to form both edges of a slot forming an opening of a corrugated tube which forms a removable closure to one another. Such edge shaping can be made in a variety of ways, for example in the manner of a known zipper or so-called Velcro. A disadvantage here is that after insertion of the cable bundle into the corrugated pipe, care must be taken to ensure that the edges of the corrugated pipe slots persist against each other, or that they are positioned relative to one another such that the forming forms a cohesive connection. Thus, according to DE 196 41 421 A1, a removable closure can be provided as an overlapping of the two molded edges, wherein the moldings are in each case formed at the edges by radially protruding protrusions which snap into each other. In such embodiments, the opening of the longitudinal slits is difficult to recover.

In contrast to formations which are always spaced apart in the longitudinal direction of the slots, the edges of the slits of the corrugated tube can also be formed as a continuous form, as described, for example, in DE 197 47 623 A1. These continuous edges of the slots form a closing device for the slots which can be hooked into one another, wherein the closing devices are brought to one another by snapping the corrugated tube sideways and snap into one another. By pressing again, these continuous shut-off devices can be unhooked again or released from each other, thereby opening the corrugated pipe gap.

DE 197 05 761 A1 also discloses a corrugated pipe which has an overlap in the region of the slot extending in a straight line of the casing in which convex or concave waves are formed which are smaller than in the other corrugated pipe area so that opposite edges with concave and the convex waves on the longitudinal slit can be brought into overlapping engagement.

One such overlapping region is also shown in DE 197 00 916 A1, each of which overlapping in the closed state of the corrugated pipe and having different wall thicknesses is provided here always to the left or to the right of the slit of the corrugated pipe. The respective overlap regions are further characterized by a relatively complicated geometry, i.e. they require an equally complicated construction of a corrugated pipe shape in this overlap region. It can also be understood from this specification that the corrugated tube, when provided with a slit in the treated overlap region, is compressed such that the respective overlap regions are displaced over each other, thereby causing a closure.

All of these described and known edge slot designs are relatively expensive to manufacture and often create difficulties in manufacturing such corrugated plastic tubes, especially during extrusion, when different wall thicknesses and / or undercuts are provided in the partial region of the tube circumference.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the processes described above for producing corrugated tubes with a longitudinal slot so that they can be easily performed so that the corrugated tube can be closed in the simplest and hence fastest manner after opening and insertion. However, on the other hand, if necessary, it can be partially opened again in order, for example, to repair a damaged section of the cable.

SUMMARY OF THE INVENTION

This object is achieved by a shape-stable corrugated pipe consisting of plastic and adapted, in particular, for the protective sheathing of electric cables, having a slot opening extending along a surface line according to the invention, which is essentially provided with convex waves and concave waves. a surface line by oblique cut at a uniformly rising or decreasing angle, the inclination of which lies between the radius of the corrugated pipe and the tangent to the corrugated pipe, the edges of the slot opening lying on top of each other so that the oblique cut formed previously lying a pre-formed edge which has been cut by a cut.

In a further preferred embodiment, the corrugated pipe described above has a projection radially inwardly directed and parallel to the aperture on the side of the inner edge spaced from the slot opening. Such a projection parallel to the slot opening, when provided, gives the corrugated pipe a certain strength which, on the one hand, does not prevent the corrugated pipe from being laid in curves, but on the other hand limits the corrugated pipe's squeezing ability. in connection with the splitters at its connection points, it imparts a higher resistance against pulling out of the splitter.

In a further preferred embodiment, the projection is in the form of a groove or notch. Such a projection increases the desired reinforcement of the corrugated pipe and stabilizes the closed position of the overlapping edges of the corrugated pipe hose.

Preferably, the groove-shaped fold or notch also has a corrugated profile of the wall of the corrugated pipe.

According to the invention, the second, previously laid out edge abuts with its edge against the projection opposite to that edge. This achieves that the relatively sharp edge formed within the lying edge of the corrugated pipe cannot damage the electrical conductors inserted into the corrugated pipe.

The object of the present invention is to provide a shape-stable corrugated pipe consisting of plastic and especially adapted for protective coating of electrical conductors, having a slot opening extending along a surface line according to the invention, which consists in extruding the corrugated tube and equipped with convex and concave then, in a further cut section of the apparatus, is cut along any surface line, the cut being an oblique cut at a uniformly rising or decreasing angle whose inclination lies between the radius of the corrugated pipe and the tangent to the corrugated pipe and the corrugated pipe is cut is guided by a shaping device arranged downstream of the cutting device, in which it squeezes so that the edges of the slot opening are displaced relative to one another and, after cooling the corrugated tube, the inside edge of the slot opening extends outwardly and pupils, edge.

In the foregoing efforts to provide corrugated tubes with such longitudinal slit openings which, after insertion of the electrical cable, can be closed with both edges provided with special closure means so that they can also be reopened, it has been discovered that it is possible the expensive formation of the edges of the longitudinal slot opening with special closing devices when the longitudinal slot opening is not guided radially, as in all known corrugated tubes, but is, as described above, guided as an oblique cut at a certain angle lying between the radial cut on the one hand, or on the tangent to the pipe on the other. Since the corrugated tube also has a recoil force due to the shape-stable properties of the plastic also in the slit state, the longitudinal slit opening also closes again after the cable has been inserted into the corrugated tube. However, with the use of a radially extending longitudinal slit opening without a locking means formed especially at the edges of the longitudinal slit opening, there is a danger with the previously known corrugated tubes that the longitudinal slit opening when the corrugated tube with such a slit is curved or curved, the interposed cables may exit the slot opening.

However, the formation of the slit opening according to the present invention prevents such a full opening of the corrugated tube with the elongated slit opening, especially in the curved regions, so that the inserted cables cannot protrude. It is achieved by the oblique thesaus that although the slot opening of course extends when the corrugated pipe is laid in curves and curves and the edges of the corrugated pipe forming the slot opening are spaced apart, the exit of the cables is nevertheless prevented because the convex and oblique areas of convex concave wines overlap when their mutual distance is increased by laying a corrugated pipe in curves and curves. Thus, the flatter the cut is guided, the more the edges of the longitudinal slot opening can be separated without the interposed cables being able to exit the slot opening of the corrugated pipe, especially at the curve and arc location.

The compression of the corrugated tube shows that the diameter of the corrugated tube slightly decreases, but the edges of the slot opening overlap very wide. This achieves the above-mentioned advantage that the slot opening can be opened, especially in the areas of the curves, without the inserted electric cables being able to exit the corrugated pipe at the location of the slot opening.

By cooling the corrugated pipe, the plastic material from which the corrugated pipe is made gets its ultimate elasticity and flexibility, and thus now has properties that retain it constant shape stability due to the prescribed manufacturing process, i.e. the ability to regain its original shape also when forming in the longitudinal region. slot opening. By the above-described measure according to the invention, that is to say the return of the overlapping edges from their first position to the second, inverted position, the tube is provided with a uniformly strong clamping force or corresponding closing and holding capabilities, which then remain. the cable harness, for example, to repair the cable section, is reopened. Due to this great closing force, convex waves and concave waves of the overlapping edges of the longitudinal slit opening are closely interconnected, and in this slit opening region a very smooth transition region is formed on both the inner and outer side of the corrugated tube with the slit opening.

The present invention, and in particular the surprising effects it has found, creates an advantage over prior art slotted-hole tubes to the extent that they can be performed on corrugated tubes which may not have shaping in the area of the sheath in which laterally radially guided longitudinal section . Thus, in the case of the pipe produced according to the inventive method, the special shaping of the edge region of the longitudinal slot opening into the closing means, or even in the present case, the additional arrangement of other closing means which is particularly cost-effective but also time-consuming.

The described object of the invention is further achieved also for a plastic consisting of a shape-stable corrugated pipe with a slot opening extending along a sheath line, designed in particular for protective wrapping of electrical conductors which has a slot opening after extrusion and after convex and concave waves. any sheath straight line at a uniformly rising or falling angle with respect to its inclination lies between the radius of the corrugated pipe or tangent to the corrugated pipe, wherein the slit corrugated pipe is compressed so that the edges or slot opening lie over each other and inside the lying edge The opening is then led outwards and is laid over the second, previously outwardly lying edge.

In a further preferred embodiment, the corrugated tube described above is located on the side of the formerly located edge at a distance from the slot opening radially inwardly directed and running parallel to the opening. Such a projection extending parallel to the slot opening, when provided, gives the corrugated pipe some rigidity which, on the one hand, does not prevent the corrugated pipe from being laid in curves, but on the other hand limits the corrugated pipe's ability to squeeze. in its connection with the manifolds at its connection points, it imparts a higher resistance against pulling out of the manifold.

In a further preferred embodiment, the projection is in the form of a groove or notch. Such a projection increases the desired reinforcement of the corrugated pipe and stabilizes the closed position of the overlapping edges of the corrugated pipe hose.

Preferably, the groove-shaped fold or notch also has a corrugated profile of the wall of the corrugated pipe.

According to the invention, the second, previously laid out edge abuts with its edge against the projection opposite to that edge. This achieves that the relatively sharp edge formed within the lying edge of the corrugated pipe cannot damage the electrical conductors inserted into the corrugated pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in more detail with reference to the preferred embodiments shown in the drawings. In the drawings, FIG. 1 shows a view of a section of convex and corrugated corrugated tube without a slot opening, with sections A-A and B-B respectively of a convex wave or a concave wave, FIG. 2 is a sectional view of a convex wave and a concave wave of a corrugated pipe having cross sections A-A or B-B with a convex wave or a concave wave, the corrugated pipe having an oblique section, FIG. 3 is a view of a section of convex wines and concave wines of corrugated pipe, with sections AA and BB of convex wave or concave wave, respectively, showing a corrugated pipe with a slot opening having an oblique cut with overlapping edges of the slot opening, behind the cutting device, FIG. 4 shows a section of convex waves and concave wines of corrugated pipe, with cross sections AA, respectively BB with convex wave or concave wave after the inner edge lying previously below the second edge has been outwardly overlapped by the second edge lying outwardly and now reversed the overlapping edges of the slot opening with its convex waves and concave waves pressed together and FIG. 5 is a view of a section of convex and corrugated corrugated tubing, with cross sections A-A, B-B, convex or concave, according to FIG. 4, in which, but in addition, on the side of the now outer edge, spaced apart from the slotted openings, is a radially inwardly directed and parallel projection extending parallel to the opening.

DETAILED DESCRIPTION OF THE INVENTION

The corrugated pipe 1 shown in the figures is made of plastic and has convex waves 2 and concave waves 3 longitudinally spaced at certain distances. The plastic material used to produce such corrugated pipes is chosen by the skilled person to give the corrugated pipe the appropriate flexibility and flexibility necessary for the corrugated pipe. shape stability so that it can be laid and held in a stable longitudinal direction on the one hand, but on the other hand it can be laid in curves and curves, the corrugated pipe having a slot opening once again opening and inserting the electric cable, the edges of the slot opening lie on top of each other again.

1 shows a corrugated tube drawn from a plastic extruder through a corrugator as shown in FIG. 2, in the cutting device downstream of the crimping device, is provided with an oblique slit 4, wherein the slit 4 extending below the angular position between the radial section and the tangent to the corrugated tube is shown as shown in a side view of FIG. As can be seen from these figures, the slope of the sloped aperture 4 can not be selected without limitation, but only up to the tangent position against the inner region of the wall formed by concave waves in the inner space of the corrugated tube.

This slit-tube is then guided by a cutting device, which is also shown in the drawings, not shown in the drawings, and the corrugated slit-tube according to FIG. 2, which has a certain diameter, decreases in diameter, while the edges 5 and 6, respectively, are displaced relative to one another, as shown in sections A-A or B-B in FIG. 3. It is evident that by this compression of the corrugated tube 1, still warm during this forming process, the edges 5 and 6 of the longitudinal slot opening 4 of the corrugated tube 1 are pushed further apart, that is to say pipe.

The corrugated tube with the slit opening is then cooled, so that the plastic material from which the tube is made obtains its ultimate flexibility and flexibility, in particular shape stability. That is, the corrugated pipe tends to remain in the shape shown in FIG. 3, and if it is discharged from this predetermined shape, it automatically adjusts back to this predetermined shape immediately upon release.

However, such a corrugated pipe is not yet suitable for its own purpose, namely to protect the inserted electric cable against damage, since in particular the edge 5 of the longitudinal slit opening protruding into the interior of the corrugated pipe 1 could damage the electric cable. For this reason, in a further process step, for example inside another processing device, possibly also manually, for example when inserting electric conductors into such a corrugated tube, the edge 6 of the longitudinal slot opening lying in FIG. 3 von. This is achieved by the fact that the still lying edge 5 is pulled out or removed and is folded over the still lying edge 6, as shown in sections A-A and B-B in FIG.

4. In this treatment of the corrugated pipe, the diameter of the corrugated pipe is again increased through the slot opening and the corrugated pipe thus formed could again assume an earlier smaller diameter due to its shape stability. As a result of this effort, convex waves and concave waves, as shown in FIG. 4, intensely into each other, so that a relatively smooth closure of the longitudinal slot opening 4 is formed, and in particular in the interior there is no longer any danger of damaging the electrical cables lying therein.

The longitudinal slit opening shown in FIG. 4 creates an excellent closing force in the corrugated pipe 1, which in turn prevents the enclosed electrical cable from emerging from the corrugated pipe 1 when the corrugated pipe is laid in a small curve or in a very small curve and edge 5 or 6 of the longitudinal slot opening 4 should be slightly apart from each other.

Finally, a corrugated pipe according to the embodiment of FIG. 4 is shown, but which, in addition to the lateral edge of the lying edge 5, has a radial and inwardly directed protrusion 7 extending parallel to the slot 4. This protrusion 7 could be in a simple manner formed as a longitudinally extending rib, but is preferably formed as a fold 8 of the wall of the corrugated pipe 1 in the form of a notch or groove, as shown in FIG. 6. Such a longitudinally extending fold of the corrugated tube wall gives it some intrinsic rigidity, and in addition forms a stop on the sharp edges 9 of the edge 6 of the slot opening 4.

These stops prevent the corrugated tube from collapsing or compressing. This limits the shrinkage of the overlapping edges 5 or 6 of the corrugated tube aperture 4, furthermore the stability of the corrugated tube at the point of connection with the splitting pieces is increased and, in particular, a higher tearing resistance of the corrugated tube is also achieved. In particular, we can avoid pulling or dropping the ends of such corrugated pipes from the manifolds or connections by mistake.

The projection 7 and the abutment of the edge 9 of the edge 6 of the slot opening 4 also cause the sharp edge 9 not to damage the electrical cable inserted into the corrugated pipe.

Claims (6)

PATENT CLAIMS A shape-stable corrugated pipe (1) consisting of plastic and adapted, in particular, for the protective sheathing of electric cables, having a slit (4) extending along a surface line, characterized in that: That it is provided with convex waves (2) and concave waves (3), that the slot opening (4) is formed along any surface line by an oblique cut at a uniformly rising or falling angle whose inclination lies between the radius of the corrugated tube and tangent to wherein the edges (5, 6) of the slot opening (4) lie on top of one another such that the oblique cut formed previously lying edge (5) is laid over the second oblique cut formed previously lying edge (6). Shape-shaped corrugated pipe according to claim 1, characterized in that a radially inwardly directed projection (7) extending radially inwardly and parallel to the opening (4) extends radially inwardly from the slot (4) which has previously been laid inside the edge (5). . Shaped corrugated pipe according to claim 2, characterized in that the projection (7) is formed as a fold (8) of the corrugated pipe wall (1), in the form of a notch or a groove. Shape-stable corrugated pipe according to claim 3, characterized in that the groove (8) or groove (8) also has a corrugated profile of the wall of the corrugated pipe (1). Shaped corrugated pipe according to one of Claims 1 to 4, characterized in that the edge (6) which has been previously laid out abuts the projection (7) opposite the edge (6) with its edge (9). Method for producing a shape-stable corrugated pipe (1) according to claim 1, characterized in that the corrugated pipe (1) is extruded and provided with convex waves (2) and concave waves (3), then cut along any surface line, the cut is made as an oblique cut at a uniformly rising or descending angle, the inclination of which lies between the radius of the corrugated pipe and the tangent to the corrugated pipe, and the cut corrugated pipe (1) is subsequently compressed so that the edges (5, 6) 1) are displaced relative to each other and, after cooling the corrugated pipe, the inside edge (5) of the slot opening (4) is led outwards and laid over the second, previously outwardly lying edge (6).