EP3245436A1

EP3245436A1 - Method for fastening a connection piece to a thermally insulated pipe and rotary cutting tool for carrying out same

Info

Publication number: EP3245436A1
Application number: EP16700315.1A
Authority: EP
Inventors: Werner Schaller
Original assignee: Brugg Rohr AG Holding
Current assignee: Brugg Rohr AG Holding
Priority date: 2015-01-14
Filing date: 2016-01-05
Publication date: 2017-11-22
Also published as: CH710611A1; WO2016112472A1

Abstract

The present invention claims a method and a cutting tool with which the insulating material surrounding the inner pipe can be detached and removed from a thermally insulated pipe, such that an annular gap, in which there is no longer any insulating material and in which the now exposed inner pipe has a clean surface without residual insulating material, is produced around the inner pipe. The pipe thus prepared can subsequently be connected to another pipe section with the aid of a plastic fitting.

Description

Method of attaching a fitting to a thermally insulated pipe and rotating

Cutting tool for its implementation

Field of the invention

The invention relates to a method for fastening a piece of interference on a thermally insulated conduit according to the preamble of claim 1. Furthermore, the invention relates to a rotationally drivable

Cutting tool for carrying out the method. background

DE 10 2012 107 504 AI shows the connection of two thermally insulated pipes, wherein the use of a fitting, in particular a fitting to be avoided. The pipe end of the one pipe must be completely removed from the insulating material.

WO 2011/009598 A1 shows the connection of a connecting piece, which may be a fitting, a pipe coupling or a fitting, with a thermally insulated pipe line, which in addition to the thermal insulation has an outer jacket. The connection shown in this document makes it possible to dispense with the removal of the thermal insulation and the outer jacket.

WO 2013/110204 AI shows a connector of the same kind, which can also be fastened without removal of the thermal insulation and the outer jacket at the end of the conduit. The method or connectors described in the latter two documents ermögli ^¬ chen it to waive the complete removal of the insulating material, including outer jacket. These fittings have proven themselves. Presentation of the invention

The object of the invention is to improve the said methods, in which a sleeve-like element of the connecting piece between the inner tube and heat insulation is introduced. It should be facilitated assembly possible.

This object is achieved in that prior to the introduction of the hüisenförmigen element by means of a rotating driven cutting tool with at least two radially spaced cutting an adjacent to the inner tube annular portion of the thermal insulation material and removed from the conduit during the radially outer region of the thermal insulation and If appropriate, the outer sheath remain, and that subsequently the häusise-shaped element of the connection piece is introduced into the annular recessed area of the conduit and the further fastening steps for the connection piece take place.

By cutting an annular area of thermal insulation adjacent to the inner tube with removal of the thermal insulation material in this area, it can be avoided by inserting, inserting or knocking between the outer side of the inner ear and the thermal insulation during insertion of the sleeve-shaped element of the connection piece Compressing the thermal insulation comes, so that the force required to insert the Hüisenförmigen element is so large that the connector can not be successfully attached.

The thermal insulation can be removed over the entire length of the sleeve or only over part of its length, depending on the type of sleeve of the connecting piece and the thermal insulation material. Even in the radial direction, the thermal insulation can be removed over the entire height of the sleeve or only partially. It is particularly preferred if not only a cutting of the thermal insulation and the dissipation of heat insulation takes place, but in addition Scrape on the outside of the inner tube. In this way, residues of the heat insulation adhering to this outer side can be released and also removed, which further facilitates the introduction of the hiisenike element of the connection piece between the outside of the inner tube and the thermal insulation.

The invention further relates to a rotary drivable cutting tool for carrying out the method. This should allow the implementation of the method in a simple and cost-effective manner.

The cutting tool is designed with the features of claim 5.

The effect of the cutting tool is to annularly cut and dislodge and remove the thermal insulation material around the inner tube. The distance of the annular gap cutting causes only one annular gap is created, which is large enough to accommodate the element of the connector in the subsequent step. The thermal insulation material can be completely removed with the cutting tool. For this purpose, the thermal insulation material a) is released and b) transported away. Both are done in a single step and the generation of the annular gap can be carried out with minimal effort.

Brief description of the drawings

Further embodiments, advantages and applications of the invention will become apparent from the dependent claims and from the following description with reference to FIGS. Showing:

Figure 1 is a sectional view through the end of a conduit with an attached fitting prior to the complete screwing of the sleeve-like element on the inner tube;

FIG. 2 shows a sectional view according to FIG. 1 with a completely screwed-on element of the connection piece; Figure 3 is a perspective view of an embodiment of the cutting tool for performing the method;

FIG. 4 shows a side view of the cutting tool of FIG. 3;

Figure 5 is an axial sectional view of

Cutting tool through the central longitudinal axis of Figure 4; and

Figure 6 is a sectional view taken along the

Section line B-B of Figure 5.

Way (s) for carrying out the invention

FIGS. 1 and 2 show, as a preferred example of a connection piece, the connection piece known from WO 2013/110204 A1. However, the connection piece can also be a connection piece designed in accordance with WO 2011/009598 A1 or another connection piece which has a sleeve-like element to be introduced onto the inner tube and between inner tube and thermal insulation.

These figures show a sectional view through the end region of a conduit, wherein the

Longitudinal axis L of the conduit located in the cutting plane. Elements extending in the direction of the longitudinal axis or the distances and distances are referred to below as axially extending elements, distances and distances; in the figures at right angles to the

Longitudinally extending elements, distances, and distances are referred to as radially extending elements, distances, and distances. To simplify these figures, only the part of the rotationally symmetrical conduit and the connection piece in the connection area substantially rotationally symmetrical connection piece is shown above the longitudinal axis L. The fitting may have any known design or function as a pipe coupling or fitting or as a fitting and outside its illustrated provided connection area with the conduit be designed accordingly. In particular, the connection piece can be configured the same at the other end as at the illustrated end. The conduit each has a thermal insulation surrounding the inner tube (not shown in full thickness) and preferably an outer sheath. In particular, therefore, no outer sheath can be provided. In particular, the thermal insulation and optionally the outer sheath are corrugated, but may also be made smooth. Such a conduit can in particular be designed or produced according to EP-A 897 788.

The conduit 1 is designed with the outer casing 4 made of plastic and the foamed heat insulation or insulation layer 3, which is preferably formed from a Pclyurethan- foam. The thermal insulation surrounds the inner tube 2 and abuts against the outer wall 6. To simplify the drawing, the conduit is not shown as a corrugated tube, but as a smooth tube. The method or fitting can be used with both types of pipes. At the end of the conduit 1, a fitting 10 is secured in the manner described below. The connecting piece 10 has a connection body 11, which is provided with a plug-in sleeve 13, which is designed for insertion into the inner tube 2 of the conduit. Thus, the outer diameter of the plug-in sleeve is adapted to the inner diameter of the inner tube 2, so that a precisely fitting plugging can take place and the plug-in sleeve achieves a fluid-tight connection with the inner wall of the inner tube. In the preferred embodiment shown, the plug-in sleeve 13 has ribs 23. The socket could additionally or alternatively be provided with other sealing means, in particular with at least one O-ring.

Subsequent to the plug-in sleeve 13, the connection body 11 has a stop 12 which, when the plug-in sleeve 13 is fully inserted, is located on the end face 5 the inner tube 2 comes to rest. On the connection body 11, a retaining ring 14 is arranged, which in particular has the apparent in the cross section of Figures 1 and 2 lying Z-shape. The retaining ring 14 forms a second stop 15 for the end face of the inner tube 2 and rests with the stop surface 16 on the end face 5, when the connection between the conduit and fitting is made. The stop 15 of the retaining ring 14 is for example designed as a continuous annular flange, but could also have interruptions. In the position of Figure 1, the stop surface 16 of the stopper 15 is not yet close to the end face 5 of the inner tube 2, but is still slightly spaced therefrom. In the position of Figure 2 then results in a concern of the surface 16 of the stopper 15 on the end face 5 of the inner tube 2. The retaining ring is attached to its other, remote from the stop 15 end 17 on the connector body 11. In the example shown, this attachment is designed in such a way that a flange 27 of the retaining ring 14 engages in a correspondingly executed groove in the connection body 11, as can be seen in FIGS. 1 and 2. This flange 27 may also be annular and continuous, but could also have interruptions. The attachment of the end 17 of the retaining ring on the connector body 10 can also be done by screws, rivets, gluing or welding. Between the stop 15 and the flange 27 or the end 17 of the retaining ring 14 extends an annular retaining ring part 18, which can be designed without interruption or with interruptions and which is not rigidly connected to the connector body 11 and thus under Can stretch train. This part does not have to rest directly on the connector body 11. The retaining ring 14 is preferably made of a plastic.

above the retaining ring 14, the sleeve-shaped element 9 is arranged on the connecting body 11, which between the outside of the inner ear and the thermal insulation is introduced. In this example of the connector, this element is referred to as a clamping sleeve 9. This has a sleeve part with an internal thread 8. This internal thread is adapted to the outer diameter of the inner tube 2, so that a screwing of the clamping sleeve can be done on the inner tube. The internal thread in this case has a configuration, in particular a rounding of the threads, which is conducive to a rolling of the threads on the outer skin of the inner tube and thereby avoiding a cutting of the outer skin of the inner tube 2 as possible. Thus, a violation of the inner tube 2 is avoided as possible. At the rear end (seen in the screwing) of the clamping sleeve 9, a substantially annular collar 19 is provided, which rests on the connecting body 11. At this end of the Spannhüise 9 an engaging means for a tool is also provided, which will be explained so that the sleeve 9 can be screwed by means of the tool on the inner tube.

In Figure 1 it is shown that the plug-in sleeve 13 has been inserted into the inner tube 2. The clamping sleeve 9 has already been partially screwed onto the inner tube 2. Prior to the introduction of the sleeve-like element 9, according to the invention, an annular region 7 of the thermal insulation material 3 adjacent to the inner tube has been cut out of the conduit by means of a rotationally driven cutting tool with at least two radially spaced cutting edges. The radially outer region of the thermal insulation 3 and the outer shell 4, however, have not been removed. It can be seen that thus the sleeve-shaped element 9 or the clamping sleeve 9 of the connection piece is introduced into the annular recessed area 7 of the conduit. Thereafter, the further attachment steps for the connector, as will be explained below. An annular region 7 of the thermal insulation can be cut out and removed, which extends in the axial direction less far into the conduit than the maximum insertion length of the sleeve-shaped element 9 amounts. In this case, the front free end of the element 9 in the axial direction will dig a little way into the thermal insulation material and displace and compress it. This may be desirable and the front free end of the element 9 may be configured therefor. However, in another embodiment of the invention, an annular region 7 of the thermal insulation 3 can be cut out and removed, which extends in the axial direction substantially equally far into the conduit than the maximum insertion length of the sleeve-shaped element 9 is. In this case, the element 9 will not displace and compress thermal insulation material, since by cutting out the area 7, a space is created which can accommodate the whole part of the element 9 located in the thermal insulation 3. In the radial direction, the size of the region 7 can also be chosen differently. In one embodiment, a ring-shaped portion 7 of the insulation 3 is cut out and removed ^¬ which extends radially less far into the insulation, than the maximum radial extent of the sleeve-shaped element 9. This complicates the introduction of the element 9 into the thermal insulation, but exerts a pressure on the element 9, which may be desirable. In another embodiment, d wi an annular region of the thermal insulation is cut and removed, which it extends in the radial direction is substantially equal far into the insulation ^¬ than the maximum radial expansion of the sleeve-shaped element is. This facilitates Einbrin ^¬ tion of the element 9 in the thermal insulation. This variant is shown in FIG. 1 with the illustrated region 7.

The clamping sleeve 9 is further screwed from the position of Figure 1, until the collar 19 with its stop surface 29 on the stop surface 26 of the stop 15 of the retaining ring 14 comes to rest. If the clamping hoist 9 is screwed a little further onto the inner tube 2, the stopper 15 is pressed by the ^' clamping sleeve 9 against the end face 5 of the inner tube 2 and the aforementioned slight distance between the stop surface 16 and the end face 5 is closed. This can be seen in FIG. Thus, the retaining ring 14 is elastically deformed in its region 18 and on the attachment of the retaining ring 14 with its end 17 on the connector body 11 and the connector body 11 is pressed with its stop against the end face 5 of the inner tube.

It is preferred that the dimensioning of the retaining ring 14 and the collar 19 of the clamping sleeve is selected so that when completely screwed clamping sleeve of the retaining ring 14 is visible from the outside with its end 17, which - as can be seen in Figure 2 - is the case, when the collar 19 has run over the end. The retaining ring thus acts as an indicator of the correctly performed connection of the connecting piece 10 with the conduit 1. The indicator effect can be improved if the retaining ring 14 has a deviating from the terminal body 11 color.

Figures 3 to 6 show a preferred embodiment of a rotating drivable cutting tool 30 for carrying out the invention or to provide the annular region 7 or annular gap 7, which is free of thermal insulation material.

The illustrated cutting tool 30 comprises a centering part for centering the tool in the inner tube, which centering part is designed here as a centering sleeve 36. Furthermore, the tool 30 comprises an outer annular gap cutting edge 35 and an inner annular gap cutting edge 34. The centering or centering sleeve 36 is initially axially inserted into the end of the inner tube 2 of the conduit 1 or the district heating tube in order to carry out the process is introduced until the inner annular gap cutting edge 34 and the outer annular gap cutting edge 35 contact the end face of the thermal insulation foam 3. The annular gap cutting edges 34 and 35 are in this case positioned so that the annular gap cutting edge 34 comes to rest precisely on the outer surface 6 of the inner tube 2. The annular gap cutting edge 35, which is radially spaced from the annular gap cutting edge 34, thus defines the outer diameter of the annular region 7 or the annular gap to be cut. For carrying out the method in the case of conduits with different diameters of the inner tube and possibly different radial extension of the element 9, a set of cutting tools is thus provided, so that a suitable cutting tool for each inner tube diameter and possibly also different elements or clamping sleeves 9 Available . An entire set of cutting tools can in particular be provided cost-effectively if the individual cutting tool is in one piece, as can be seen in FIG. 4 and in particular also made of plastic. For this purpose, a plastic such as polyoxyethylene (POM) offers.

By axial pressure on the cutting tool 30 in the foam direction and simultaneous rotation (in the example shown as a clockwise rotation) first penetrate the cutting 34 and 35 in the insulation 3 and generate the radial boundary sections of the subsequently to be removed insulation of the area 7. The rotation can be done by hand be effected with a rod which is guided through the holes 32 in the cutting sleeve body 31. Also a motor drive is possible. By further penetration of the cutting tool, the entire contiguous cutting contour, consisting of the annular gap cutting edges 34 and 35 and the intermediate connecting web 38 enters the foam in such a way that takes place by the rotational and axial movement a helical movement into the thermal insulation material inside. Limited by the section of the connecting web 38 between the annular gap cutting 34 and 35th and the circular boundary sections through the annular gap cutting 34 and 35 is a helical profile cut from the foam and subsequently removed with the aid of Spanleitstufen 37 axially to the rear of the annular gap 7 thus generated.

Preferably preloaded scraper elements 33 are provided radially against the outer side 6 of the inner tube, which ensure that the outer surface 6 of the inner tube is freed from residues of thermal insulation. Occasional retraction of the cutting tool can additionally support the removal of the foam breakage.

The depth of the annular gap produced is limited by a mechanical stop shoulder on the cutting sleeve body 31.

The present invention claims a cutting tool, with which of an insulated pipe surrounding the inner tube insulating material can be dissolved and removed, so that around the inner tube around an annular area is formed in which no more insulating material and in which the now exposed inner tube a has clean surface without insulation residues. The pipe prepared in this way can subsequently be provided with a connecting piece, in particular with the aid of a connecting piece, which is a plastic fitting, connected to another pipe section.

While preferred embodiments of the invention are described in the present application, it is to be understood that the invention is not limited thereto and may be embodied otherwise within the scope of the following claims.

Claims

claims

1. A method for attaching a connecting piece (1) on a thermally insulated conduit (2), which has an inner tube (), a thermal insulation made of a plastic material and optionally a heat-insulating outer sheath made of plastic, wherein in the attachment of the fitting to the conduit a sleeve-shaped element of the connecting piece, the outside of the inner tube contacting, is introduced into the region of thermal insulation, characterized in that prior to the introduction of the sleeve-shaped element by means of a rotating driven cutting tool with at least two radially spaced cutting an adjacent to the inner tube annular region the thermal insulation material is cut out and removed from the conduit, while the radially outer region of the thermal insulation and the optional outer sheath remain, and that subsequently the sleeve-shaped element of the Ans is introduced chlußstücks in the annular recessed area of the conduit and carried out the further attachment steps for the connector.

2. The method according to claim 1, characterized in that an annular region of the heat insulation is cut out and removed, which extends in the axial direction less far into the conduit than the maximum insertion length of the sleeve-shaped element, or that cut out an annular portion of the thermal insulation and is removed, which extends in the axial direction substantially equally far into the conduit than the maximum insertion length of the sleeve-shaped element amounts.

3. The method according to claim 1 or 2, characterized in that an annular region of the thermal insulation is cut out and removed, which is located in Radial direction extends less far into the thermal insulation than the maximum radial extent of the sleeve-shaped element, or that an annular portion of the heat insulation is cut and removed, which extends in the radial direction substantially equal to the heat insulation than the maximum radial extent of the sleeve-shaped element amounts.

4. The method according to any one of claims 1 to

3, characterized in that when cutting the insulation by the cutting tool is additionally made a separate scraping on the outside of the inner tube, which is not removed by the cutting thermal insulation residues removed from the outside and removed.

5. Rotary drivable cutting tool (30) for carrying out the method according to one of claims 1 to 3, characterized in that it has a centering part (36) intended for insertion into the inner tube and at least one axially spaced inner annular gap cutting edge (34), which is intended to abut against the outer surface (6) of the inner tube (2), and at least one outer annular gap cutting edge (35) arranged further outwards in the axial direction.

6. Cutting tool according to claim 5, characterized in that it comprises at least one clearing element (38) which is in particular a connecting the inner and the outer annular gap cutting web.

7. Cutting tool according to claim 5 or 6 for carrying out the method according to claim 4, characterized in that the cutting tool further comprises scraping elements (36).