EP0887126B1 - Pipe expanding device - Google Patents

Abstract

The apparatus (10) for expanding a pipe incorporates a carrier (1) for several drive rolls (20 - 25) and a unit (6) for transmitting the driving force from a drive shaft (7) to these rolls. To obtain different pipe expansion diameters, the drive rolls can be mounted on the carrier (1) at different radii relative to the axis of the drive shaft.

Description

Technical field

The present invention relates to a device for expanding a pipe according to the preamble of claim 1. In particular is such a device for expanding a cylindrical Metal pipe used for the production of a pipe connection by pushing one into the other.

State of the art

A large number of pipes are offered in the trade, in particular for sanitary material, which can be used for various purposes, for example as a rain drain pipe, Water trap, irrigation pipe, stovepipe, ventilation pipe, sewer pipe, etc., the pipes in the form of straight pipe sections, pipe bends, pipe angles, etc. offered become. Depending on the intended use, the pipes can be of different types Materials are made, whereby pipes made of metals such as copper, titanium-zinc, stainless steel, Aluminum etc. are widespread.

The common metal pipes are usually either folded or welded pipes. To push the pipes into each other by pushing them together To be able to connect, either the pipes themselves at least at their ends be conical, or there must be conical connecting pieces, so-called sliding sleeves, be used. While the folded metal pipes are often made conical and can thus be pushed into each other to a limited extent the welded metal pipes mostly have a cylindrical shape. So pushing it together possible, cylindrical metal pipes must be expanded at one end be, the inner diameter of the expanded tube, the so-called Expansion diameter to be at least twice the material thickness must be the inside diameter of the unexpanded pipe.

A device for expanding downpipes is known from the company MASC Arbeitsmittel-Vertriebs GmbH, 89160 Dornstadt, Germany. The device comprises a substantially cylindrical housing. In this case drive rollers (also called expansion rollers) are stored in side openings, which protrude with their outer sides over the periphery of the cylindrical housing. The drive rollers are usually over in devices of the type mentioned a gearbox arranged in the housing driven, which in turn by a drive shaft is driven. As a primary drive for the drive shaft can Example, a drill or a hammer drill can be used. To expand the rotating device around an axis of rotation in the axial direction in the to be expanded pipe section pushed in, the drive rollers on the Roll the inside of the tube and this on the radial distance predetermined by the axis of rotation of the device to the outside of the drive rollers Expand expansion diameter.

A disadvantage of this device is that it is only for a single, predetermined Expansion diameter can be used. It is also sensitive to dirt and therefore especially in the often harsh external conditions on construction sites susceptible to defects. In addition, the device has the disadvantage that the functional conditional shape of the housing the depth of expansion achievable with the device in particular with the straight connecting pieces of pipe bends and pipe angles the only limitation is that the straight pipe sections do not reach the end of the curve can be expanded.

In the German patent application DE-A1-37 33 990 (Fricke GmbH) there is an expanding tool described for ends of thin-walled sheet metal pipes. The expanding tool includes a base frame to which a mandrel is welded, which the Clamping the tool in a drilling machine allowed around the base frame To set the mandrel in rotation. There are several conical drive rollers on the base frame freely rotatable around axes of rotation parallel to the mandrel. The basic framework can have several individual bores arranged at different distances from the central axis have for the implementation of the axes of the drive rollers to adjust the Allow tool on different pipe diameters. Because the driving rollers are freely rotatable on the base frame and only indirectly via the one to be expanded Sheet metal tubes tend to be driven to rotate about the axes of rotation on the Sliding sheet metal pipe instead of rolling, especially when the Expanding tool. That is why this expanding tool is not for use with suitable for harsh external conditions.

Presentation of the invention

The object of the present invention is to provide a pipe expansion device, by which the disadvantages of the known devices are overcome.

The solution to the problem is the subject of claim 1.

In a preferred embodiment of the invention, each drive roller is rotatable on one axis, and the axes can be used to selectively adjust the pipe expansion diameter be firmly attached to the carrier at different locations. To attach the axles to the carrier are at the appropriate points on the carrier preferably drilled holes that have an internal thread. The axes are provided with an external thread at one end so that they fit into the holes can be screwed in. However, there are other types of connections for the axles can be attached to fixed positions on the carrier, e.g. simple plug connections, connections similar to bayonet locks, etc.

While in the preferred embodiment of the invention for cost reasons for each axis has a limited, discrete number of mounting points on the carrier and thus a number of selectable pipe expansion diameters corresponding to this number there are alternative embodiments of the invention which are continuous Allow setting of the selectable expansion diameter. For example can slide receptacles on the carrier with a screw drive be provided for the axes, or it can be displaced by means of an eccentric and fixable receptacles for the axes of the drive rollers can be provided.

In a preferred embodiment, these are elastic material selected and the roller arranged so that for all selectable settings of the expansion diameter, the elasticity of the roller is sufficient Contact between the roller and the drive rollers for the frictional Transmission of the drive force from the drive shaft to the drive rollers by means of the roller guaranteed. It can have an elastic roller for driving the drive rollers are also used for expansion devices with a fixed expansion diameter be, because the inventive use of an elastic roller for Driving the drive rollers points for different regardless of the adaptability selectable expansion diameter on other advantages, for example with regard to a low sensitivity of the device to dirt and consequently a low frequency of failure and in terms of the manufacturing cost of the pipe expansion device, because a drive by means of an elastic roller or elastic drive wheel is essential is cheaper than a gear transmission.

In a preferred embodiment of the invention, the roller is made of rubber; she can but also consist of other elastic materials.

It is preferred that the axles of the drive rollers be attached to the carrier at only one end are. As a result, the other ends of the drive roller axles and thus the Traction rollers themselves free and not surrounded by support means or carrier parts. The The end face of the expansion device is thus formed by the drive rollers, what is advantageous for achieving a maximum depth of expansion, especially when expanding of straight connecting pieces for pipe bends and pipe angles. Preferably the drive rollers to increase the contact pressure against the inside of the pipe to be expanded and thus not only the driving force causing the expansion supported by the axes of the drive rollers, but also by the roller. On the one hand, this can be achieved in that the rollers despite their elasticity sufficient rigidity to generate a considerable pressure have the drive rollers, and on the other hand the roller the drive rollers in one as possible touch a large distance from the one-sided attachment of the roller axes to the carrier, thus achieving the best possible leverage ratio to support the drive rollers becomes. As a result, greater driving forces can be achieved than with support of the driving rollers, which is caused exclusively by the axles attached to the beam on one side.

For welded sheet metal pipes, especially those containing zinc, there is the Risk of the weld seam breaking when the pipes are expanded due to the Walks caused by the expansion device. To minimize walking becomes in the preferred embodiment of the invention by the tube expansion device caused the maximum bending angle of the tube sheet as possible kept small. For a given expansion diameter and a given diameter of the drive rollers, this is achieved in that the device according to the invention preferably the one with regard to a mutual non-contact arrangement the drive rollers have the largest possible number of drive rollers on the carrier.

With a typical predetermined diameter of the drive rollers of approx. 20 mm the preferred pipe expansion device for a desired expansion diameter of about 120 mm 15 driving rollers, for one of about 100 mm 12, for one of approximately 75 to 80 mm 8 and for an expansion diameter of approximately 60 mm 6 driving rollers.

If the expansion diameter and the number of drive rollers are specified, then the drive rollers preferably selected so that they are essentially the most in view on their mutual contact-free arrangement of the largest possible diameter exhibit.

The following detailed description of an embodiment of the present In connection with the accompanying drawings, the invention serves only as an example for a better understanding of the invention. For the expert are from the following description in conjunction with the accompanying drawings and the entirety of the claims further advantageous embodiments and Feature combinations easily recognizable, but still within within the scope of the present invention as set out in the claims is defined.

Brief description of the drawings

Fig. 1

einen Längsschnitt durch eine Vorrichtung zum Ausweiten eines Rohres gemäss der vorliegenden Erfindung;

Fig. 2

eine Hinteransicht auf die Vorrichtung zum Ausweiten eines Rohres aus Fig. 1.

The drawings illustrate a preferred embodiment of the present invention.

Fig. 1

a longitudinal section through a device for expanding a tube according to the present invention;

Fig. 2

2 shows a rear view of the device for expanding a tube from FIG. 1.

In principle, the same parts are provided with the same reference symbols in the figures.

Ways of Carrying Out the Invention

Figure 1 shows a longitudinal section through a preferred embodiment of a device 10 for expanding a pipe according to the present invention Device 10 comprises a rotating body-shaped carrier 1, which is in the form of a sleeve with a wide flange on one side (T-shaped longitudinal section in Figure 1). The Cross section of the carrier 1 is, as is given for a rotating body, circular, what can also be seen in the rear view of FIG. 2. The rotating body-shaped carrier 1 is Provide a through hole along its axis. The carrier 1 is free rotatable about its axis on a shaft 7, which through the bore in the carrier 1st is led. In the embodiment of the invention shown in the figures rotatable mounting of the carrier 1 on the shaft 7, a suitable slide bearing is provided. As an alternative, however, other bearings, in particular roller bearings, could also be used become.

The carrier 1 and the remaining parts of the pipe expansion device 10 are at one end of the shaft or drive shaft 7 (right in Figure 1), while the shaft 7 at the other shaft end 17 (left in Figure 1) by a primary drive (not shown) is driven. The drive shaft 7 is used for the transmission of Rotational energy and torque resp. Torque from a primary drive to the device 10. An electric hand drill, a rotary hammer, can be used as the primary drive or another suitable drive source can be used, the drive shaft 7 can for example be clamped in a chuck.

The carrier 1 is on the primary drive side (left in FIG. 1) by means of an adjusting ring 5 which can be fixed on the shaft 7 by means of screw 8 the while 7 backed up. A sliding bearing can be placed between the adjusting ring 5 and the carrier 1 be provided. On its other side (on the right in FIG. 1), the carrier 1 is through a roller 6 fixed to the right shaft end on the shaft 7 against displacement secured in the axial direction. In the illustrated embodiment a slide bearing is provided between the carrier 1 and the roller 6, with alternative ones Embodiments also other bearings, especially roller bearings, used can be. Thus, the arrangement 1 rotatably supported on the shaft 7, its axial position essentially by the collar 5 and the roller 6 is fixed.

So-called drive rollers 20 are essentially parallel to the shaft 7 on the carrier 1 - 25 arranged, which cause the actual expansion by taking considerable Roll the contact pressure on the inside of the pipe to be expanded and thereby the Drive pipe material apart. The drive rollers 20-25 protrude in the radial direction beyond the periphery of the carrier 1, as can be clearly seen in FIG. The The illustrated embodiment of the pipe expansion device comprises six drive rollers 20-25, with alternate numbers of Driving rollers are possible. Each of the drive rollers 20-25 is essentially on one Axle 30, 33 arranged parallel to shaft 7. Each of the axes 30, 33 has an axially provided with an external thread (left-hand side in FIG. 1), which is screwed into a bore 40b, 43b, 44b provided with a corresponding internal thread in the carrier 1. The holes 40b, 43b, 44b are in one place for the desired setting of the expansion diameter suitable distance to the shaft 7 arranged on a circular line with the shaft 7 as the center. For each of the axes 30, 33 are three different holes in the illustrated embodiment of the invention 40a, 44a, 40b, 43b, 44b, 40c, 44c provided on the carrier 1, which are concentric on three Circles with different radii are arranged. By the axes 30, 33 can be arranged on one of the three circles in the illustrated Embodiment between three different settings of the expansion diameter to be selected.

The drive rollers 20-25 are on the device 10 shown by means of plain bearings mounted on the axles and in the axial direction by means of a head-shaped axle end 50-55 at the threaded end opposite the axis end secured on the axis. Embodiments with other suitable ones are also Means for the storage and axial fixation of the drive rollers 20-25 on the Axes 30, 33 possible.

As can be seen in the figure, the end of the device 10 on the right in the figure becomes formed by the drive rollers 20-25, causing the expansion of the to be expanded Pipe to the extreme end of the device 10 allows in the direction of advance becomes. As a result, a maximum depth of expansion can be achieved with the device 10 shown.

The drive rollers 20-25 are driven by the roller 6, which in turn is due to its fixed connection to the shaft 7 is driven by the latter. The In the embodiment shown, roller 6 is made of rubber. It can however also other elastic materials, e.g. Polymer plastics, for manufacturing the roller can be used. The roller 6 touches on its outer circumference the drive rollers 20-25 with sufficient contact pressure to ensure a frictional fit To ensure transmission of the driving force from the roller 6 to the drive rollers 20-25. The elastic material of the roller 6 is selected and the roller 6 so arranged that a sufficient contact pressure for a frictional transfer the driving force not only for the arrangement of the axes 30, 33 shown in the Bores 40b, 43b, 44b but also for their arrangement in the bores 40a, 44a or 40c, 44c is guaranteed.

Furthermore, the roller 6 and the drive rollers 20-25 are arranged so that drive rollers 20 - 25 to increase the contact pressure of the drive rollers 20 - 25 against the The inside of the pipe to be expanded is pressed radially outwards by the roller 6 become. Thus, the driving force causing the expansion is not only due to the axes 30, 33 of the drive rollers 20-25, but also also by the Roll 6 generated.

In summary, it should be noted that the invention provides a device for Expanding a tube is provided, which is a selectable setting of the expansion diameter can enable the sensitivity to dirt compared to existing Devices significantly reduced and the range of achievable depth of expansion can enlarge especially with elbows and elbows.

Claims (10)

1. Device (10) for expanding a pipe, having a carrier (1) for several embossing rolls (20-25), and a drive shaft (7),
   characterised by a roller (6) of resilient material which is driven by the drive shaft (7) and which is arranged in such a manner that, for the frictionally engaged transmission of a driving force from the drive shaft (7) to the embossing rolls (20-25), it is in contact with the embossing rolls (20-25).
2. Device (10) according to claim 1, characterised in that the embossing rolls (20-25) can be fitted at different sites (40a, 44a, 40b, 43b, 44b, 40c, 44c) on the carrier (1) for selectable adjustment of the pipe expansion diameter.
3. Device (10) according to claim 2, characterised in that each embossing roll (20-25) is supported rotatably on a shaft (30, 33) which can be fitted securely to the carrier (1) at different sites (40a, 44a, 40b, 43b, 44b, 40c, 44c) for selectable adjustment of the pipe expansion diameter.
4. Device (10) according to claim 3, characterised in that the shafts (30, 33) are supported only at one end and an opposite shaft end (50, 53) is free.
5. Device (10) according to either claim 3 or claim 4, characterised in that, for selectable adjustment of the pipe expansion diameter, drilled holes (40a, 44a, 40b, 43b, 44b, 40c, 44c) equipped with an internal thread are provided at appropriate sites (40a, 44a, 40b, 43b, 44b, 40c, 44c) on the carrier (1), and the shafts (30, 33), which are provided with an external thread at one end, can be screwed into them.
6. Device (10) according to any one of claims 3 to 5, characterised in that, in order to generate a pressing force against the inside of the pipe to be expanded, and therefore to generate the driving force bringing about expansion, the embossing rolls (20-25) are supported by the shafts (30, 33) and additionally by the roller (6).
7. Device (10) according to any one of claims 1 to 6, characterised in that the roller (6) of resilient material has a resilience range and the roller (6) and the embossing rolls (20-25) are arranged in such a manner that, for all selectable adjustments of the expansion diameter, the rolls (20-25) lie within the resilience range of the roller (6), thus ensuring that there is sufficient contact between the roller (6) and the embossing rolls (20-25) for the frictionally engaged transmission of the driving force from the drive shaft (7) to the embbssing rolls (20-25) by means of the roller (6).
8. Device (10) according to any one of claims 1 to 6, characterised in that the roller (6) comprises rubber.
9. Device (10) according to any one of claims 1 to 8, characterised in that, in order to minimise the flexing of the pipe to be expanded, with given expansion diameter and diameter of the embossing rolls (20-25), a number of embossing rolls (20-25) which is as large as possible with a view to a mutual contact-free arrangement of the embossing rolls (20-25) is fitted to the carrier (1).
10. Device (10) according to any one of claims 1 to 8, characterised in that, in order to minimise the flexing of the pipe to be expanded, with a given expansion diameter and a given number of embossing rolls (20-25), the embossing rolls (20-25) have substantially the largest possible diameter with a view to a mutual contact-free arrangement.

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