CH709941B1 - Method and device for calibrating one end of a metallic pipe. - Google Patents

Abstract

The invention relates to a method and a device for calibrating the end of a metallic, in particular longitudinally welded, pipe, a first and a further outer and inner tool (18a, 18b; 17a, 17b) being provided and interacting with the outer and inner circumference of the pipe end are, directing forces can be applied against the inner tube wall by the first and further inner tool. Such a method and such a calibration device are to be created, with which in particular local roundness deviations and also ovalities at the pipe ends of the entire production spectrum, i.e. especially with smaller diameter and thick-walled pipes that require high forces in a limited installation space. For this purpose, the external and internal tools (18a, 18b; 17a, 17b) are pressed against the pipe walls together by directing forces applied in the pipe interior after being positioned against the pipe outer or pipe inner wall, the directing forces applied on the inside being passed through the pipe wall and with the The first and further external tools cooperate, which are arranged on a closed frame construction (6) which surrounds the pipe end with air and are aligned with the internal tools.

Description

Description: Method and device for calibrating one end of a metallic, in particular longitudinally welded tube, wherein a first and a further external and internal tool are provided and interacting on the outer and inner circumference of the tube end, with the first and further internal tool Directing forces can be applied against the inner pipe wall.

In the manufacture of pipes or large pipes from sheet metal, which are formed by the UOE process, the compression molding process, the 3-roll bending process or the like into a round slot tube and then welded, initially only limited roundness and straightness tolerances can be achieved become. A tube manufactured in this way, which is not sufficiently round during the shaping and is usually odd (banana shape) due to the distortion during welding processes, requires subsequent calibration and straightening to achieve the required roundness and straightness. As has been shown in large pipe production, the problem of excessive roundness and straightness deviations occurs particularly evidently with smaller diameters (below approximately 610 mm), and / or thick-walled pipes (above 25 mm) and / or high-strength pipes (above 635 MPa).

In particular, pipes for use as “line pipes” are therefore generally calibrated and straightened using an expansion process, as is known from DE 2 264 207.

The actual expander tool usually consists of a pyramidal polygon, on the lateral surface of which individual segments are arranged. By moving the polygon relative to the segments, these are moved radially, so that the diameter of the expander head increases and the tube expands. In this way, the pipes, for example up to 18 m long, are gradually expanded, calibrated and straightened.

In the manufacture of pipes with increasing wall thicknesses, e.g. Over 25 mm, and higher material strengths, as they are increasingly required, encounter the usual manufacturing processes, e.g. the expansion or reduction calibration described above and the 3/4-roll calibration bending to their limits. Depending on the system configuration, you can no longer fully meet the requirements for all products in order to guarantee an efficient, flexible (small and large batches) and thus cost-effective pipe manufacturing process. The roundness properties at the pipe ends are particularly important because local roundness deviations, e.g. the roofing or flat spots in the area of the longitudinal seam at the transition areas to the original sheet metal edges as well as ovalities, which lead to errors when welding individual pipes for the production of pipelines at the circular welds later.

To improve the roundness of the pipe ends, i.e. about the last 100 mm of the tube, a calibration device of the generic type is known from DE 20 2009 001 348 U1. The tools which act and interact on the outer and inner circumference of the pipe end are cylindrical, rotatably mounted, firmly positionable relative to one another, arranged in the pipe circumferential direction and acting only on the pipe end. The inner tool may comprise one or two rollers which cooperate with two or three rollers as the outer tool, the inner tool rollers being pressed against the outer tool rollers and the tube end being subjected to one or more three-point bending deformations by rolling rounds. The straightening force to be exerted by the inner tool is only very limited due to the bearing of the rollers and an overbending to compensate for spring-back is not possible because the rollers have to be adjusted to the spring-back ideal radius. In addition, internal and external seam increases should be removed beforehand.

To eliminate local out-of-roundness at pipe ends, a pliers-like calibration device has become known from EP 380 673 A1. This has an inner tool which is arranged on an L-shaped arm which engages in the tube and an outer tool which is arranged on a cover-like hood which overlaps the arm. In this case, the external tool, which is acted upon by a hydraulic unit to apply the straightening force, is pressed against the pipe wall and subsequently pressed against the internal tool. Because of the disadvantageous leverage and only low rigidity, this calibration device can also only apply a limited straightening force.

The invention has for its object to provide a method and a calibration device of the generic type, with which in particular local roundness deviations and ovalities at the pipe ends of the entire product range, i.e. especially with smaller diameter and thick-walled pipes that require high forces in a limited space.

[0009] This object is achieved according to the invention with the method according to claim 1.

The simultaneous and joint action of the inner and outer tools by passing the forces through the pipe wall and their short-circuiting through the outer frame, which absorbs the deformation forces, enables a pipe end calibration with very high straightening forces, e.g. approx. 10,000 KN. The high forces required for thick-walled pipes can therefore also be realized.

An advantageous proposal of the invention provides that the tube is pre-positioned by rotating about its longitudinal axis so that a local roundness deviation to be eliminated is in the 12 o'clock position in the area of an upper outer and upper inner tool. The tube can be in a processing station, e.g. lie on a rotating device in cross transport, possibly on a roller table, so that the tools can be used in a targeted manner.

CH 709 941 B1 It goes without saying that the tube can also be rotated into any other position if this is advantageous in terms of process technology and construction.

According to a preferred proposal, the pipe end to be calibrated is supported by a means which can be brought into contact with the pipe outer wall from below. The pipe support can at the same time provide height compensation for pipes to be calibrated with different diameters.

It is advantageously proposed that the straightening forces are applied by a spreading means that can be temporarily inserted into the pipe end, in particular vertical spreading means, which, prior to the application of the straightening forces, lowers a lower internal tool until it rests on the inner wall of the pipe. Regardless of the diameter of the pipe to be straightened, at least the lower inner tool has direct contact with the inner wall of the pipe from the start.

A device for solving the problem underlying the invention is defined in claim 5.

Furthermore, an inventive device for producing longitudinally welded pipes is defined in claim 11.

[0017] Both the external tools and the internal tools can be adjusted or displaced at least partially radially to the longitudinal extension of the tube relative to the outer tube wall or the inner tube wall.

Preferably, the first outer tool is an upper, the further outer tool is a lower outer tool, the first inner tool is an upper inner tool and the further inner tool is a lower inner tool, so that the tools are extremely compact overall the present device can be integrated.

In this respect, the present spreading device can be designed in a structurally particularly simple manner as a vertical spreading device, so that the internal tools are then arranged on a vertical spreading device which can be raised and lowered at least indirectly on the side walls of the frame construction.

If necessary, the calibration device can also be designed to be mobile.

The mobility of the calibration device, e.g. arranged on a substructure that can be moved in the hallway by means of wheels or suspended in a crane, advantageously allows their integration at any point in the possibly automated production flow of longitudinally welded pipes, e.g. after expanding or reducing calibration, the pipe end calibration, which can then be followed, for example, by a water pressure test and an ultrasonic acceptance test.

The closed frame construction or the outer frame absorbs the directing or deforming forces applied by the spreading device and simultaneously redirects them to all tools by short-circuiting. To process both pipe ends, two such devices can be arranged in a line or in succession.

A raising and lowering with respect to the spreader allows on the one hand an adaptation to different pipe diameters of the pipes to be calibrated in a simple manner; on the other hand, the lowering of the spreader with the lower inner tool on the inner tube wall before the straightening forces are then applied.

According to a preferred embodiment of the invention, the spreading device has a wedge slide valve which can be acted upon by a cylinder, preferably a hydraulic cylinder, which projects into the tube interior and raises or lowers the internal tools. The wedge slide engaging the pipe interior with the upper and lower inner tool only by the calibration device, whereby the inner tools can be slidably arranged directly on the wedge slide with a smallest pipe diameter, requires only a small installation space and still brings the required, very high Forces on what can be determined by the chosen wedge angle, depending on the cylinder adjustment force. By pulling on the wedge slide by means of the cylinder, the lower and the upper inner tool for introducing the pipe forming forces or straightening forces are raised or spread accordingly. To calibrate the pipe ends of pipes with a larger diameter, an adapter can be used to adjust the length, which rests on the wedge slide and carries the upper inner tool at its other end.

According to an advantageous proposal of the invention, the cylinder is flanged to a lifting block provided in relation to the pipe end behind the closed frame construction, the lifting block viewed in the direction of travel of the calibration device towards the pipe end on the left and right sides with projecting vertical columns for on the side walls of the Frame structure arranged guides is formed. All components of the spreading device, with the exception of the wedge slide with the upper and lower internal tools, are thus arranged without any spatial impairment of the pipe end, which can be passed over unhindered by the frame construction. By means of the guides or similar guide means, the lifting block and thus the spreading device can be set to a desired height dimension corresponding to the respective pipe diameter without tilting and possibly with simultaneous weight compensation.

An embodiment of the invention provides a support for the pipe end or the lower external tool, which is designed as a spindle-driven flat wedge that passes under the pipe end. By designing the wedge angle of the flat wedge to be adjusted by a spindle lifting element, a height compensation can take place and the difference between

CH 709 941 B1 a small and a large tube can be compensated, the tubes being advantageously provided on a means, preferably in the form of driven rollers, for rotating the tube.

According to a further preferred embodiment of the invention, a spindle lifting gear is provided which adjusts the upper outer tool and holds it in the bearing position on the outer tube wall. A saw threaded spindle of the lifting gear is particularly suitable, which ensures a holding force corresponding to the very high straightening forces for the upper external tool.

Further features and details of the invention emerge from the claims and the following description of exemplary embodiments of the invention illustrated in the drawings. It shows:

1 shows a schematic representation of a side view of a device for calibrating to eliminate local roundness deviations of the pipe end from metallic pipes;

2 shows the device for calibrating FIG. 1 seen from the right in a front view;

3 shows a schematic diagram of the straightening forces which are short-circuited, applied from the inside of the pipe, passed through the pipe wall and diverted to the tools via an outer, closed frame construction of the device for calibrating, here in a front view with force flow and a triangle in the variant for calibrating a roof shape;

FIG. 4 shows a basic illustration as previously in FIG. 3, in contrast in the variant for the calibration of flat spots on the pipe end;

5 shows the object of FIG. 3 or FIG. 4 in a longitudinally sectioned side view;

6 shows a schematic diagram for eliminating global ovalities of the pipe end;

7 shows, as a detail of the device for calibrating, the tool arrangement for calibrating a tube of large diameter positioned on a roller rotating device;

FIG. 8 shows a representation as in FIG. 7, on the other hand for calibrating the pipe end of a pipe having a medium diameter; and

Fig. 9 is an illustration as before in Figs. 7 and 8, in contrast to calibrating the pipe end of a small diameter pipe.

In the embodiment of FIGS. 1 and 2, a device for calibrating 1 for eliminating local out-of-roundness at the tube ends of metallic tubes 2a, 2c is shown, which at least in this embodiment with a vehicle underframe or chassis 3 and therein stored wheels 4 on the hut floor 5 movable and thus mobile.

The device for calibrating 1 or in this embodiment specifically also the vehicle underframe 3 has a structure constructed as a closed frame structure 6.

On the rear side of the frame structure 6 facing away from the pipe end, a lifting block 7 is arranged, which is provided on the left and right side with projecting vertical columns 8a, 8b (shown in broken lines in FIG. 2) with a rectangular cross section.

The lifting block 7 is raised or lowered by synchronized drives 9a, 9b and guided by means of upper and lower guides 10a, 10b running on the flat sides of the vertical columns 8a, 8b, these guides 10a, 10b in this embodiment as three -Roll guides are designed.

The guides 10a, 10b are mounted in support walls 11a, 11b, 11c, which are fastened as a cross-sectionally U-shaped unit, each with a U-profile flange as support wall 11a, to the side walls 12a, 12b of the frame construction.

On the lifting block 7, a cylinder 13 of a spreader 14 is flanged, which also has a wedge slide 15 guided through the frame window to the front, which is connected to the piston rod 16 of the cylinder 13 projecting through a through opening of the lifting block 7.

On the wedge slide 15, a lower inner tool 17a and an upper inner tool 17b are arranged, which cooperate with an upper outer tool 18a and a lower outer tool 18b for calibrating the pipe end.

The upper outer tool 18a is employed by a spindle 19 of a screw jack 20 on the outer tube wall, while the lower outer tool 18b is supported and held by a flat wedge 21 which can be acted upon by a spindle drive 22 arranged on the vehicle underframe 3.

To calibrate a pipe end, the pipe 2a, 2b, 2c lies in a rotating device arranged by rollers 23a, 23b, as is particularly well shown in FIGS. 2 and 7-9.

CH 709 941 B1 The device for calibrating 1 is moved over the pipe end until it is in the effective area of the tools of the closed frame construction 6.

Optionally, a device for calibrating 1 can be used at each pipe end, if necessary by offset arrangements of two stations in the transverse transport for separate processing of both pipe ends.

The tube is now rotated until there is a local out-of-roundness (roofing or flat spot), for example in the 12 o'clock position and thus in the effective range of the tools. In this respect, in this exemplary embodiment, it can also be referred to as a vertical spreading device with regard to the spreading device 14, since the tools interact with the pipe aligned in the vertical direction.

The flat wedge 21 is adjusted by means of the spindle drive 22 to support the lower outer tool 18b under the tube.

The spreader 14 is lowered depending on the diameter of the pipe to be machined until the lower inner tool 17a rests against the inner wall of the pipe.

If the cylinder 13 then exerts a pull in the direction of arrow 24, the lower and the upper inner tool 17a, 17b are spread with very high force or in particular raised or lowered vertically.

The very large straightening forces generated to deform the out-of-roundness are passed through the inside of the tube wall, received by the closed frame construction 6 and diverted and returned to the action via the external tools 18a, 18b.

The upper outer tool 18a is held by the spindle 19 of the screw jack 20 and the lower outer tool 18b is held in position by the flat wedge 21 against the initiated high deformation or straightening forces.

The above-described, short-circuited flow of force by interaction with the outer, closed frame structure 6 when the form or directional forces are applied from the inside of the pipe is schematically clearly outlined in FIGS. 3 and 4.

The principle figure 3 shows the calibration of a (not shown) roof shape at the tube end of the tube 2, with a three-point directional triangle, a monosatical, upper outer tool 18a presses the roof shape against the then double-satin, upper inner tool 17b on the target radius .

To calibrate flat spots (also not shown), the flat spot is pressed out by the then single-saddle, upper inner tool 17b into the then two-piece, upper outer tool 18a, as outlined by way of example in FIG. 4.

In any case, all tools are spread by applying tension to the wedge slide 15 and supported by the force flow of the outer, closed frame structure 6 with a very large deforming force for planting inside and outside against the pipe wall or pipe walls (see FIG. 5).

The mobile device for calibrating 1 with the spreading device 14 also enables the removal of ovalities, as indicated by way of example in FIG. 6, the tube being able to be displaced several times if necessary.

The contours of all tools are optimized in such a way that there are no excessive surface impressions. The change of the first or upper outer and inner tools according to the required one or two-saddle design is preferably done manually in a simple manner.

Here, local roundness deviations (FIGS. 3 and 4) have to be corrected before the global ovalities (FIG. 6), or vice versa.

7-9 shows the pipe end calibration for pipes 2a, 2b, 2c with different diameters.

While for calibrating a tube 2c with a smallest diameter, the lower and the upper internal tool can be arranged directly on the wedge slide 15, a tube 2a with a larger diameter (cf. FIG. 8) or a tube 2a with a largest diameter (cf. FIG. 7) bridges the greater distance by a correspondingly long spacer insert 25a, 25b, the spacer inserts 25a, 25b being equipped with the upper inner tool 17b at their end remote from the wedge slide 15.

Reference symbol list [0055]

Calibration device

2a, 2b, 2c metallic tube

Vehicle base / chassis

wheel

CH 709 941 B1

5 Hut hallway 6 closed frame construction / outer frame 7 Lifting block 8a, 8b Vertical column 9a, 9b drive 10a upper guide or upper three-roller guide 10b lower guide or lower three-roller guide 11a, 11b, 11c Support wall 12a, 12b Sidewall 13 cylinder 14 Spreader 15 Wedge gate valve 16 Piston rod 17a lower inner tool 17b upper inner tool 18a upper outer tool 18b lower outer tool 19th spindle 20th Screw jacks 21 Flat wedge 22 Spindle drive 23a, 23b Roller / rotating device 24th Pull arrow 25a, 25b Spacer insert

Claims

Claims (11)

Claims 1. A method for calibrating an end of a metallic, in particular longitudinally welded, pipe, wherein a first and a further external and internal tool are provided which act on the outer and inner circumference of the pipe end and interact, at least one tool with a directing force against the Pipe wall can be acted on, characterized in that the outer and inner tools (18a, 18b; 17a, 17b) after positioning against the pipe outer or pipe inner wall together from inside the pipe through the first and further inner tools, which are at least indirectly on the side walls of one are arranged on a frame construction guided spreading, applied straightening forces are applied against the inner tube wall, the internally applied straightening forces being passed through the tube wall and interacting with the first and further external tools, which are aligned with the closed frame construction surrounding the tube end with air are arranged end to the inner tools. 2. The method according to claim 1, characterized in that the tube (2a, 2b, 2c) is pre-positioned by rotating about its horizontal longitudinal axis so that a local roundness deviation to be eliminated is in the 12 o'clock position in the area of an upper outside and above-mentioned inner tool (18a, 17b). 3. The method according to claim 1 or 2, characterized in that the pipe end to be calibrated of the horizontally lying pipe end is supported by a means which can be brought into contact with the pipe outer wall from below. CH 709 941 B1 4. The method according to any one of claims 1 to 3, characterized in that the straightening forces are applied by a spreading means of the spreading device (14) which is temporarily retractable into the pipe end and which, before the straightening forces are applied to the horizontally lying pipe, a lower internal tool (17a ) lowered until it rests on the inside wall of the pipe. 5. Apparatus for calibrating one end of a metallic, in particular longitudinally welded, pipe for carrying out the method according to claim 1, wherein a first and a further outer and inner tool are provided, interacting and interacting with the outer and inner circumference of the pipe end, with the first and further internal tool directing forces can be applied against the inner pipe wall, characterized in that the calibration device (1) is designed with a closed frame construction (6) which surrounds the pipe end with air during operation and in which a first one can be placed at a distance from each other against the outer wall of the pipe and a further, supported external tool (18a, 18b) are provided, the first and the further external tool (18a, 18b) cooperating with one another and a first internal tool (17a, 17b) arranged in alignment with them, which bear against the inner wall of the pipe and on one at least mi Directly on the side cheeks (12a, 12b) of the frame structure (6) guided spreading device (14) are arranged. 6. The device according to claim 5, characterized in that the spreading device (14) has a wedge slide (15) which can be acted upon by a cylinder (13) and which projects into the tube interior of the tube to be calibrated and raises or lowers the internal tools (17a, 17b) . 7. The device according to claim 6, characterized in that the cylinder (13) is flanged to a lifting block (7) provided with respect to the pipe end to be calibrated behind the closed frame structure (6), the lifting block (7) being designed to be movable in the direction of travel Device for calibrating (1) towards the pipe end is formed on the left and right sides with projecting vertical columns (8a, 8b) for guides (10a, 10b) arranged on the side cheeks (12a, 12b) of the frame structure (6). 8. Device according to one of claims 5 to 7, characterized in that a support of the lower outer tool (18b) as a flat wedge (21) that can be driven under the pipe end, in particular as a spindle-driven flat wedge (21) that drives under the pipe end of the horizontally lying pipe, is trained. 9. Device according to one of claims 5 to 8, characterized by a screw jack (20) adjusting the upper outer tool (18a) and holding it in the bearing position on the outer tube wall. 10. Device according to one of claims 5 to 9, characterized in that the calibration device (1) is associated with a means for rotating the tube (5). 11. Device for producing longitudinally welded pipes, characterized in that a device for calibration according to one of claims 5 to 10 is integrated into the production flow of longitudinally welded pipes.