Press connection system for permanently connecting a fitting and fitting

Abstract

Press connection system (2) for permanently connecting a fitting (20) to a pipe (4), - with a pressing jaw (6), - with a pressing contour (16) formed on the inside of the pressing jaw (6), - wherein the pressing contour (16) has a cylindrical pressing section (16a), - with a fitting (20), - with a fitting base body (22) and a press sleeve (26) forming a press chamber (24), - wherein a sealing ring (28) is arranged at the proximal end (30) of the pressing chamber (24) relative to the fitting base body (22) and a cutting ring (32) is arranged at the distal end (34) of the pressing chamber (24) relative to the fitting base body (22), and - wherein the cutting ring (32) has a central cylindrical portion (32a), cutting elements (32b) arranged at the distal end and cutting elements (32c) arranged at the proximal end, characterized in that - that the pressing contour (16) has a distal pressing section (16b) which is conically formed at least in sections and which adjoins the cylindrical pressing section (16a) and a proximal pressing section (16c) which is conically formed at least in sections and which adjoins the cylindrical pressing section (16a), - that the distal pressing section (16b) is designed to deform the distal end of the cutting ring (32) radially inwards during a radial pressing of the pressing sleeve (26), - that the cylindrical pressing section (16a) is designed to deform the proximal end of the cutting ring (32) radially inwards during the radial pressing of the pressing sleeve (26) and - that the proximal pressing section (16c) is designed to deform the sealing ring (28) radially inwards during the radial pressing of the pressing sleeve (26).

Description

[0001] The invention relates to a press connection system for the permanent connection of a fitting to a pipe, comprising a press jaw, a press contour formed on the inside of the press jaw, wherein the press contour has a cylindrical press section, a fitting, a fitting base body, and a press sleeve forming a press chamber, wherein a sealing ring is arranged at the proximal end of the press chamber relative to the fitting base body and a cutting ring is arranged at the distal end of the press chamber relative to the fitting base body, and wherein the cutting ring has a central cylindrical section, cutting elements arranged at the distal end, and cutting elements arranged at the proximal end. The invention also relates to an aforementioned fitting in the pressed state.

[0002] The technical field relevant to the present invention is the on-site installation of piping systems, in which a piping system consisting of pipe sections and fittings is generally installed to conduct and transport a fluid, i.e., a liquid or a gas. A fitting is essentially a connecting piece for a pipeline, and a fitting is most frequently used to connect two or more pipe sections. Accordingly, the fitting preferably has two or more press sections, for example in the form of press sleeves. The most common fittings include straight connections, changes of direction in the form of pipe bends, reducers, branches such as T-pieces or intersections. However, a fitting can also be understood to mean a pipe connection of a valve or other component. For example, thermometers or pressure gauges, as fittings, only have one connection for one pipe section.Thus, the fitting of a valve has only one press section to connect a pipe section to the valve.

[0003] Press connections are used to connect pipe sections to fittings and other components. A press section of a fitting, for example in the form of a press sleeve, is radially deformed inward with the pipe section inserted using a press jaw, creating a permanent, tight, and permanent connection. A permanent connection is defined as a connection between the fitting and the pipe that can only be disassembled by at least partially destroying the connected components.

[0004] The pressing technology used for radial forming of the pressing section primarily includes radially acting pressing systems as well as pressing systems that use radial-axial pressing, whereby a part of the fitting is displaced axially during the pressing process in order to effect radial forming.

[0005] The pipeline systems described above are primarily used to transport drinking or heating water, gas for operating a heating system, or industrial gases. In principle, any fluid medium can be transported in the pipelines.

[0006] The fittings and pipes are preferably made of solid or high-strength materials, preferably of metals and alloys, in particular comprising copper, nickel and / or steel.

[0007] The pressing jaw can be designed in different shapes. On the one hand, the pressing jaw can have two lever-shaped pressing jaw inserts with or without an additional pressing element in the shape of a wedge. On the other hand, the pressing jaw can have two, preferably rounded, pressing jaw inserts with or without an additional pressing element in the shape of a wedge. Furthermore, a pressing jaw can be designed as a pressing loop or pressing chain consisting of three or more, preferably rounded, pressing jaw inserts with or without an additional pressing element in the shape of a wedge.

[0008] A pressing jaw typically comprises two lever-shaped pressing jaw inserts with or without an additional pressing element in the form of a wedge. A pressing ring, on the other hand, can consist of two, preferably round pressing jaw inserts with or without an additional pressing element (pressing jaw without / with wedge).

[0009] A pressing sling or pressing chain consists of 3 or more round pressing jaw inserts with or without additional pressing element (pressing jaw without / with wedge)

[0010] Furthermore, a separating ring is preferably arranged between the cutting ring and the sealing ring, which creates a gap between the cutting ring and the sealing ring and prevents damage to the sealing ring by the cutting elements of the cutting ring. However, the provision of a separating ring is not necessary.

[0011] During the pressing process, the pressing jaw presses the pressing sleeve, and thus the sealing ring and cutting ring, radially inward at a uniform rate through a radially inward movement with the cylindrical pressing section. Thus, the cutting elements penetrate the pipe material to essentially the same depth.

[0012] The penetration of the cutting elements into the pipe material fixes the pipe relative to the fitting in both axial directions. In some cases, the penetration of the cutting elements also acts as an anti-rotation device. Securing the axial position is, among other things, necessary to prevent the permanent connection from bursting under excessive mechanical stress, whether due to excessive internal pressure of the medium being conveyed or due to external mechanical influences.

[0013] Tests have shown that the fittings used to date exhibit good resilience, even under severe mechanical stresses, such as axial and radial impact tests. Nevertheless, the fittings must also withstand extreme stresses in specific applications.

[0014] EP 2 394 087 B1 discloses a press fitting for permanently connecting pipes with a cutting ring inserted into a pressing chamber, with proximal and distal cutting elements. DE 10 2016 109 034 A1 also discloses a pressing tool for pressing fittings, wherein the pressing contour comprises a central cylindrical pressing section and adjacent rounded pressing sections. The pressing contour presses the fitting and the round retaining element located therein symmetrically.

[0015] WO 2017 / 043 966 A1 describes a press connection system with a pressing tool having a cylindrical pressing section used for radially pressing a fitting to be pressed. WO 2018 / 085 185 A1 shows a press connection system with an exemplary pressing tool. DE 297 21 760 U1 describes a pressing tool with a substantially cylindrical pressing contour that has a groove for locking the pressing tool. US 2019 / 0 067 922 A1 describes a press fitting.

[0016] Therefore, the present invention is based on the technical problem of further improving the pull-out protection and burst resistance of the pressed fitting.

[0017] The technical problem outlined above is solved according to the invention in a press connection system mentioned at the outset in that the press contour has a distal press section which is conically designed at least in sections and which adjoins the cylindrical press section, and a proximal press section which is conically designed at least in sections and which adjoins the cylindrical press section, in that the distal press section is designed to radially inwardly deform the distal end of the cutting ring during radial pressing of the press sleeve, in that the cylindrical press section is designed to radially inwardly deform the proximal end of the cutting ring during radial pressing of the press sleeve, and in that the proximal press section is designed to radially inwardly deform the sealing ring during radial pressing of the press sleeve.

[0018] The system described above results in a pressed fitting which is permanently connected to a pipe after actuation of the pressing jaw, wherein in the radially pressed state of the pressing sleeve the distal end of the cutting ring is, at least in sections, deformed inwards to a radius smaller than the radius of the proximal end of the cutting ring and wherein the distal cutting elements have, at least in sections, penetrated deeper into the pipe than the proximal cutting elements.

[0019] The at least partially conical design of the pressing sections means that the pressing sections assume a conical shape partially or entirely. Partial design can be achieved with sections that taper inward on the circumference. Depending on the complete or partial distribution of the conical sections of the pressing section, the pressing sleeve is then reshaped, at least in sections, to a smaller radius.

[0020] In the compressed state, the distal cutting elements have penetrated, at least in sections, deeper into the pipe material than the proximal cutting elements. The section of the cutting ring, which was cylindrical prior to compression and on which the distal cutting elements and the proximal cutting elements are arranged or formed, is formed into a conical shape tapering in the distal direction by the distal compression section, which is conical at least in sections, together with the cylindrical compression section.

[0021] The pull-out resistance of the connection between fitting and pipe is preferably also increased by aligning the distal cutting elements in the proximal direction. Since the distal cutting elements penetrate deeper into the pipe material than in conventionally pressed fittings, the pressed fitting exhibits increased resistance to pull-out forces and, in particular, to excess pressure caused by the medium conveyed in the pipe.

[0022] In the following, the invention is explained using an exemplary embodiment with reference to the drawing. Fig. 1 a section of a pressing system according to the invention before the pressing process, Fig. 2 that in Fig. 1 shown pressing system after the pressing process, Fig. 3 the pressing system according to Fig. 1 in a side view, Fig. 4 the pressing system according to Fig. 1 in cross section along the line IV-IV in Fig. 3, Fig. 5 the pressing profile of the pressing jaw Fig. 1 Fig. 6 a state-of-the-art pressing system before the pressing process in cross-section and Fig. 7 that in Fig. 6 shown pressing system after the pressing process.

[0023] An embodiment of a press connection system according to the invention is described below with reference to Fig. 1 to 5 explained.

[0024] The press connection system 2 for permanently connecting a fitting to a pipe 4 initially has a press jaw 6, which consists of two press jaw halves 6a and 6b, which are part of a pressing tool and are held by holding tabs 8 arranged on both sides, see in particular the Fig. 3 and Fig. 4. Ends The retaining tabs 8 have two bores 10a and 10b, in which two axes 12a and 12b are arranged, to which the two pressing jaw halves 6a and 6b are pivotably mounted. A further bore 14 for a fastening bolt 15 is also provided in the retaining tabs 8. The pressing jaw 6 is thus designed as a pressing loop, which can be compressed with a pressing tool at the open ends opposite the bore 14.

[0025] The drive mechanism of the pressing tool is in turn operatively connected to a pressing tool, which in particular has a double roller ram with two rollers. The double roller ram is in particular hydraulically or electrically driven, but the drive can also be implemented by a toggle lever. The double roller ram interacts with an inlet contour formed on the drive mechanism and pushes the pressing jaw halves apart, so that the pressing jaw halves are pressed together in the area of ​​the pressing contour.

[0026] The pressing jaw 6 with the pressing jaw halves 6a and 6b has a pressing contour 16 on the inside, which initially has a cylindrical pressing section 16a.

[0027] Furthermore, the press connection system 2 has a fitting 20, wherein the fitting 20 is formed with a fitting base body 22 and a press sleeve 26 having a press chamber 24. Within the press chamber 24, a sealing ring 28 is arranged at the proximal end 30 of the press chamber 24 relative to the fitting base body 22, and a cutting ring 32 is arranged at the distal end 34 of the press chamber 24 relative to the fitting base body 22. A separating ring 36 is additionally arranged between the sealing ring 28 and the cutting ring 32. Flanged sections 26a formed circumferentially at the distal end of the press sleeve 26 serve to position the elements arranged in the press chamber 24.

[0028] The cutting ring 32 has a central cylindrical portion 32a, cutting elements 32b arranged at the distal end and cutting elements 32c arranged at the proximal end.

[0029] The pressing contour 16 further comprises a conical distal pressing section 16b adjacent to the cylindrical pressing section 16a and a conical proximal pressing section 16c adjacent to the cylindrical pressing section 16a. The distal pressing section 16b is designed to radially inwardly deform the distal end of the cutting ring 32 upon radial pressing of the pressing sleeve 26 and thus of the pressing chamber 24. The cylindrical pressing section 16a is further designed to radially inwardly deform the proximal end of the cutting ring 32 upon radial pressing of the pressing sleeve 26, and the proximal pressing section 16c is designed to radially inwardly deform the sealing ring 28 upon radial pressing of the pressing sleeve 26.

[0030] As from Fig. 1, the distal outer edge 32d of the cutting ring 32 rests against the inner edge 24a of the pressing chamber 24, and the cylindrical section 32a of the cutting ring 32 rests against the cylindrical section 24b of the pressing chamber 24. The position of the inner edge 24a lies distally outside the edge shown by the dashed line between the cylindrical pressing section 16a and the conical distal pressing section 16b. Therefore, the distal outer edge 32d of the cutting ring 32 is deformed further radially inward by the conical shape of the pressing section 16b than the proximal end of the cutting ring 32 is deformed by the pressing section 16a.

[0031] Fig. 1 shows the state of the press connection system 2 before pressing and Fig. 2 shows the state of the press connection system 2 and in particular of the fitting 20 after pressing with the pipe 4.

[0032] In the radially compressed state of the compression sleeve 26, the cutting ring 32, the sealing ring 28, and the separating ring 36 are deformed radially inward, and the cutting elements 32b and 32c have partially penetrated the tube 4 in the region of the cutting edge. Due to the conical compression section 16b and the cylindrical compression section 16a, in the radially compressed state of the compression sleeve 26, the distal end of the cutting ring 32 is deformed inward to a radius smaller than the radius of the proximal end of the cutting ring 32. As a result, the distal cutting elements 32b have penetrated the tube 4 deeper than the proximal cutting elements 32c.

[0033] In Fig. In Figure 2, the penetration depths t1 and t2 of the cutting elements 32b and 32c are shown, and t1 is greater than t2. The asymmetric radial deformation is also evident from the angle between the cylindrical section 32a of the cutting ring 32 and the cylindrical section 24b of the pressing chamber 24.

[0034] In addition, due to the design of the cutting elements 32b and 32c, the holding force in the pull-out direction is improved, in the Fig. 1 and Fig. 2 to the right. The side of the cutting element 32b, with its steep cutting edge directed against the pull-out direction, contributes more to the holding force of the connection than the inclined cutting edge of the cutting element 32. Due to the tilting of the cutting ring 32 during pressing and the fact that the steep surface has a slight angle to the vertical, an additional small force component is created which pulls the cutting ring 32 towards the pipe 4. In addition, slipping of the cutting ring 32 has become less likely, because the inclined cutting edge of the cutting element 32c, due to the tilt angle of the cutting ring 32, is more likely to lift material from the pipe 4, similar to a plow.

[0035] Overall, this results in a reinforced, permanent connection between the fitting 20 and the pipe 4, since the cutting elements 32b act against the withdrawal direction of the pipe 4 from the fitting 20 and have penetrated deeper into the pipe 4 than in the prior art.

[0036] This is compared to the previously described embodiment of the press connection system 2 according to Fig. 1 with the pressed fitting 20 according to Fig. 2 with the one known from the state of the art and in the Fig. 6 and Fig. 7 shown press connection system 2'.

[0037] The fitting 20 with its elements is identical to the example according to the Fig. 1 to 5. However, the pressing jaw 6' has a pressing contour 16' with only one cylindrical pressing section 16a', which deforms the pressing sleeve 26 and thereby the sealing ring 28, the separating ring 36 and the cutting ring 32 radially inward in the same way. Therefore, the cutting elements 32b and the cutting elements 32c have penetrated essentially the same depth into the material of the pipe 4. This is achieved by the Fig. 7 clearly shows the penetration depths t1 and t2 of the cutting elements 32b and 32c, which are of equal size.

Claims

[1] Press connection system (2) for permanently connecting a fitting (20) to a pipe (4), - with a pressing jaw (6), - with a pressing contour (16) formed on the inside of the pressing jaw (6), - wherein the pressing contour (16) has a cylindrical pressing section (16a), - with a fitting (20), - with a fitting base body (22) and a press sleeve (26) forming a press chamber (24), - wherein a sealing ring (28) is arranged at the proximal end (30) of the pressing chamber (24) relative to the fitting base body (22) and a cutting ring (32) is arranged at the distal end (34) of the pressing chamber (24) relative to the fitting base body (22), and - wherein the cutting ring (32) has a central cylindrical portion (32a), cutting elements (32b) arranged at the distal end and cutting elements (32c) arranged at the proximal end, characterized by , - that the pressing contour (16) has a distal pressing section (16b) which is conically formed at least in sections and which adjoins the cylindrical pressing section (16a) and a proximal pressing section (16c) which is conically formed at least in sections and which adjoins the cylindrical pressing section (16a), - that the distal pressing section (16b) is designed to deform the distal end of the cutting ring (32) radially inwards during a radial pressing of the pressing sleeve (26), - that the cylindrical pressing section (16a) is designed to deform the proximal end of the cutting ring (32) radially inwards during the radial pressing of the pressing sleeve (26) and - that the proximal pressing section (16c) is designed to deform the sealing ring (28) radially inwards during the radial pressing of the pressing sleeve (26). [2] Permanent connection between a fitting (20) and a pipe (4), - with a pipe (4), - with a fitting (20) with a fitting base body (22) and a press sleeve (26) forming a press chamber (24), - wherein a sealing ring (28) is arranged at the proximal end (30) of the pressing chamber (24) relative to the fitting base body (22) and a cutting ring (32) is arranged at the distal end (34) of the pressing chamber (24) relative to the fitting base body (22), and - wherein the cutting ring (32) has a cylindrical portion (32a) and cutting elements (32b) arranged at the distal end and cutting elements (32c) arranged at the proximal end, - wherein in the radially compressed state of the compression sleeve (26), the cutting ring (32) and the sealing ring (28) are deformed radially inwards and the cutting elements (32b, 32c) have partially penetrated into the pipe (4), characterized by , - that in the radially compressed state of the compression sleeve (26), the distal end of the cutting ring (32) is formed inwards, at least in sections, to a radius smaller than the radius of the proximal end of the cutting ring (32) and - that the distal cutting elements (32b), at least in sections, have penetrated deeper into the tube (4) than the proximal cutting elements (32c).

Images