Fitting to be Connected to at Least One Pipe and Method for Establishing a Connection

Abstract

The invention relates to a fitting to be connected to at least one pipe, in particular a plastic pipe or plastic-metal composite pipe, having a main body, having at least one supporting body connected to the main body for insertion into a pipe end and having at least one pressing sleeve connected to the main body for receiving the pipe end, the pressing sleeve having a cylindrical pressing section. The technical problem of improving the fitting for pressing, in particular with small motor-driven or manually driven pressing tools, is solved by the fact that the pressing sleeve is made of a metal with a microhardness of less than 65 HV 1, in particular less than 50 HV 1, preferably in the range from 40 to 50 HV 1 measured according to Vickers, and that the ratio of wall thickness of the pressing section to the outer diameter of the pressing section is less than 0.06, preferably in the range from 0.03 to 0.06. The invention also relates to a method for establishing a connection.

Claims

1. A fitting to be connected to at least one pipe, in particular plastic pipe or plastic-metal composite pipe, with a main body, with at least one to the main body connected supporting body for insertion into a pipe end, and with at least one to the main body connected pressing sleeve for receiving the pipe end, wherein the pressing sleeve has a cylindrical pressing portion, characterised in that, the pressing sleeve is made of a metal with a microhardness of less than 65 HV, in particular less than 50 HV 1, preferably in the range from 40 to 50 HV 1 as measured according to Vickers, and the ratio of wall thickness of the pressing section to the outer diameter of the pressing section is less than 0.06, preferably in the range from 0.03 to 0.06.

2. The fitting according to claim 1, characterised in that, the ratio of the length of the pressing section to the outer diameter of the pressing section is greater than 0.4 and preferably is in the range between 0.4 and 0.8.

3. The fitting according to claim 1, characterised in that, the pressing sleeve is made of copper or aluminum.

4. The fitting according to claim 1, characterised in that, the to the main body distal end of the pressing sleeve is flanged outwards, and the to the main body proximal end of the pressing sleeve has an outwardly projecting bead.

5. The fitting according to claim 1, characterised in that, the to the main body distal end of the pressing sleeve is flanged outwards, and a retaining ring connected to the main body is provided for attaching the pressing sleeve.

6. The fitting according to claim 1, characterised in that, the to the main body proximal end of the pressing sleeve has an alternately interrupted edge with holding sections and recesses and on the circumferential side the recesses release an angular section of greater than 180.

7. A method for establishing a connection between a fitting and a pipe, wherein a fitting comprises a supporting body and a pressing sleeve having a cylindrical pressing portion, where a pipe end is arranged between the supporting body and the pressing sleeve, in which a pressing tool with a cylindrical pressing contour is applied to the pressing section, and in which the pressing sleeve is radially cylindrically pressed through the pressing contour over the length of the pressing section.

8. The method according to claim 7, in which the pressing sleeve is pressed cylindrically over an axial length whose ratio to the outer diameter of the pressing section is greater than 0.4, preferably in the range between 0.4 and 0.8.

9. The method according to claim 7, in which the pressing tool is guided at least on one side of the pressing section through a limit formed by the pressing sleeve.

Description

[0036] In the following, the invention is explained using examples of embodiments with reference to the drawing. The drawings show

[0037] FIGS. 1 and 2 a first embodiment of a fitting according to the invention,

[0038] FIGS. 3 and 4 a second embodiment of a fitting according to the invention,

[0039] FIGS. 5 to 7 a third embodiment of a fitting according to the invention,

[0040] FIGS. 8 and 9 the third embodiment in detail,

[0041] FIG. 10 the main body used in the embodiments, and

[0042] FIGS. 11 to 13 the third embodiment in three phases of the establishment of a connection with a pipe end.

[0043] In the following description of the various exemplary embodiments according to the invention, components and elements with the same function and mode of operation are provided with the same reference symbols, even if the components and elements in the various exemplary embodiments may have differences in dimension or shape.

[0044] FIGS. 1 and 2 show a first exemplary embodiment of a fitting 2 to be connected to at least one pipe, in particular a plastic pipe or plastic-metal composite pipe. The fitting 2 has a main body 4, which is only shown with one end and is formed at at least one further end extending to the right in FIGS. 1 and 2 with the same fitting geometry or a different connection geometry.

[0045] A supporting body 6 connected to the main body 4 and integrally formed in the present case is provided in order to be inserted into a pipe end (not shown here). For a representation with pipe end, please refer to the discussion in FIGS. 11 to 13 below. In addition, a pressing sleeve 8 connected to the main body 4 is provided for receiving the pipe end, the pressing sleeve 8 having a cylindrical pressing section 10.

[0046] In accordance with the invention, the pressing sleeve 8 is made of a metal with a microhardness of less than 65 HV 1, in particular less than 50 HV 1, preferably in the range from 40 to 50 HV 1 measured according to Vickers. As a result, the microhardness of pressing sleeve 8 is so low that, on the one hand, it can be easily and reliably formed into the required shape during production and, on the other hand, it can be formed just as easily and reliably during the production of a pipe connection.

[0047] Furthermore, the ratio of the wall thickness s of the pressing section 10 to the outside diameter d of the pressing section 10 is less than 0.06 and preferably is in the range from 0.03 to 0.06. In the exemplary embodiment shown, a value of 0.05 is present. For example, nominal diameters of 16, 20 or 25 mm can be specified as outer diameters, whereby these numbers are not to be understood as restrictive.

[0048] A further characteristic of the geometry of the pressing sleeve is the ratio of the length l of the pressing section 10 to the outside diameter d of the pressing section 10, whose value is greater than 0.4, preferably between 0.4 and 0.8. Due to this length geometry, a good deformability is achieved with a given wall thickness and diameter.

[0049] The above mentioned hardness values for the material of the pressing sleeve 8 are in a range which allows the use of copper, copper or aluminum alloys. By a suitable selection of material, geometry and manufacturing processes the pressing sleeves can be manufactured inexpensively.

[0050] As further shown in FIGS. 1 and 2, the to the main body 4 distal end 12 of the pressing sleeve 10 is flanged outwards so that a collar 14 is formed which is bent outwards up to 90 and protrudes 0.9 to 1.2 mm outwards. Similarly, the proximal to the main body 4 end 16 of the pressing sleeve 10 has a radially inwardly directed collar 18 which engages in a groove 20 formed on the main body 4. In this way, the pressing sleeve 8 is connected to the main body 4.

[0051] The collar 14 has a tapered inner contour which facilitates the insertion of a pipe end into the pressing sleeve 8. The curved outside of the collar 14 again represents a one-sided limit and a connected guide for a pressing tool, as explained below.

[0052] FIGS. 3 and 4 show a second exemplary embodiment of a fitting 2 according to the invention. The construction of fitting 2 broadly corresponds to the construction of the fitting according to FIGS. 1 and 2, so that the same reference marks designate the same elements of fitting 2. The difference in design is that the collar 18 arranged at the end 16 of the pressing sleeve 10 initially forms an outwardly projecting bead 22. Together with the collar 14, two circumferential limits for a pressing tool are formed, which axially limit the pressing section 10 on both sides. Thus an improved guidance of a pressing tool is achieved as with the first exemplary embodiment.

[0053] FIGS. 5 and 6 show a third exemplary embodiment of a fitting 2 according to the invention, whereby fitting 2 is designed as a straight fitting with two pressing sleeves 8 for connecting two pipes. The construction of the fitting 2 again broadly corresponds to the construction of the fitting according to FIGS. 1 and 2, so that again the same reference symbols designate the same elements of fitting 2.

[0054] The difference in the design is that a retaining ring 24 connected to the main body 4 is provided for fastening the pressing sleeve 8 to the main body 4. The retaining ring 24 is preferably made of plastic in order to influence the retaining properties via the material properties, in particular the degree of hardness, and the geometry, e.g. very high clamping forces or simple exchangeability. The retaining ring 24 can also be made of a metal. The retaining ring 24 is connected to the main body 4 by latching and/or clamping.

[0055] The retaining ring 24 has a circumferential groove 25 aligned with the distal end 12 of the pressing sleeve 8, in which the proximal end 16 of the pressing sleeve 8 engages and is secured by clamping and/or latching. Thus, in a similar way to the second exemplary embodiment, two circumferential limits are formed to guide a pressing tool through the collar 14 and the retaining ring 24, which axially limit the pressing section 10 on both sides.

[0056] In the subsequent discussion of further features and method steps, reference is made in each case to the third exemplary embodiment. This is not to be understood as restrictive, since the first two exemplary embodiments can also be designed and processed in the same way.

[0057] FIG. 7 shows the third embodiment of fitting 2 according to FIGS. 5 and 6, where a pipe 26 has been inserted into the pressing sleeves 8 on both sides. The pipes 26 are designed as plastic pipes. It is also possible to design pipes 26 as plastic-metal composite pipes. The pipes or pipe ends 26 are each inserted up to a limit 29 formed on the inside of the retaining ring 24. A total of three limits 29 are provided on the circumference of the retaining ring 24 for this purpose, so that in FIGS. 6 and 7 the limit 29 can only be seen above the pipe end 26 in FIGS. 6 and 7.

[0058] In the exemplary embodiments shown in FIGS. 1 to 7 and in the third exemplary embodiment again shown in detail in FIGS. 8 and 9, it is provided that the end 16 of the pressing sleeve 8 proximal to the main body 4 has an alternately interrupted edge 30 with holding sections 32 and recesses 34 and that the recesses 34 on the circumferential side release a total angular section of greater than 180. This means that the circumferential length of the recesses is greater than the circumferential length of the holding sections 32. The angle section released by the recesses can be 220 or 240, for example.

[0059] As can be seen from the figures, the holding sections 32 and the recesses 34 are evenly distributed around the circumference. This results in a stable construction. As can be seen from the perspective illustrations in FIGS. 1, 3, 5 and 8, the recesses 34 in the assembled state result in large inspection windows which allow a view into the area into which the pipe end 26 must be pushed when correctly assembled. Thus, before and especially after the pressing of the pressing sleeve 8, a clear control of the produced connection can be carried out.

[0060] FIG. 10 shows the main body 4 together with two support bodies 6 connected to it. The main body 4 has an essentially axially symmetrical shape with a central section 40 with two adjacent circumferential projections 42 and 44, which form the groove 20 mentioned above between them. Axially to the outside, axially extending webs or fins 46 are arranged, which penetrate into the material of the pipe end when the pressing sleeve is pressed and form an anti-rotation device. This is followed by several radially rotating fins 48, which also penetrate into the material of the pipe end when the pressing sleeve is pressed and form a pull-out protection. Deviating from this illustration, the axial and radial fins can also be arranged in a different order. The two distal ends 50 of the support bodies are beveled at the outer edges to facilitate insertion of supporting body 6 into a pipe end. As far as can be seen, the features described above are also marked in FIGS. 1 to 9.

[0061] FIGS. 11 to 13 show three phases of a pressing process with a fitting according to the third exemplary embodiment. In the method described above for establishing a connection between a fitting 2 and a pipe 26, said fitting 2 comprising a supporting body 4 and a pressing sleeve 8 having a cylindrical pressing portion 10.

[0062] First FIG. 11 shows the insertion of the pipe 26, so that the pipe end 26 is arranged between the supporting body 6 and the pressing sleeve 8. It should be ensured that the pipe end 26 is pushed in up to the limit 28.

[0063] Then, according to FIG. 12, a pressing tool 60 or a pressing jaw 60 of a pressing tool with a cylindrical pressing contour 62 is attached to the pressing section 10. This results in a flat contact of the cylindrical pressing contour 62 on the cylindrical pressing section 10.

[0064] As shown in FIG. 13, the pressing sleeve 8 is radially cylindrically pressed by the pressing contour 62 over the length l of the pressing section 10. This creates a flat contact of the pressing sleeve 8 at pipe end 26, which is then pressed into the contoured surface (fins 46 and 48) of supporting body 6.

[0065] As can be seen from the discussion of the exemplary embodiment fitting 2 according to the invention, the pressing sleeve 8 is pressed cylindrically over an axial length l whose ratio to the outer diameter d of the pressing section 10 is greater than 0.4, preferably in the range between 0.4 and 0.8.

[0066] It is also clear from FIGS. 12 and 13 that the pressing tool 60 is guided on both sides of the pressing section 10 by limits formed by the pressing sleeve 8 and the retaining ring 24 during setting and pressing.