EP0561025B1 - Device for bending tubes, in particular for making serpentine-shaped tubes - Google Patents

Description

The invention relates to a device according to the preamble of claim 1.

Pipes or pipe coils produced with such devices are used in particular for convection heating surfaces of steam generators and heat exchangers. They are made from a straight tube corresponding to the length of the coil.

Devices of the generic type are so-called wall bending machines, in which the entire device is pivoted through 180 ° for alternate right and left bending. In order to make this pivoting possible, considerable manufacturing expenditure is required. For this reason, these facilities have only been able to establish themselves to a limited extent.

Furthermore, the use of so-called turning tables in connection with tube bending machines is known which can bend in only one bending direction. The bent coil is swiveled by 180 ° after each bend. This known device is also technically extremely complex and also has industrial safety problems.

A device for producing alternately bent sections on a tube, from which the preamble of claim 1 is based, is known from FR-A-2 125 193. Here, the two bending rollers can alternately about the axis of one or about the axis of other bending rollers can be pivoted. One bending roller is mounted on a side arm which projects from a rotatable sleeve through which the axis of the other bending roller passes. A complicated gearbox can either rotate the sleeve or rotate the axis passing through the sleeve. The bending roller unit is pivoted about the axis of rotation of one or the other bending roller by means of toothed racks which form the bending drive.

From FR-A-1 081 265 a pipe bending device is known which has a bending table which is rotatable about a vertical axis. A sliding block is guided in the bending table, which can be moved radially. The axes of rotation of two bending rollers are fixed on the sliding block. The sliding block can be moved so that the axis of rotation of one or the other bending roller reaches the center of the turntable. The bending roller unit is provided with a lever which can be pivoted around the bending roller unit to rotate the axis of rotation that is in the center of the turntable.

The invention has for its object to provide a device of the generic type, which is particularly simple and particularly easy to use.

This object is achieved by the features of claim 1. A thornless cold bending of the tube also takes place in the invention. By means of the measures according to the invention, it is possible in a particularly simple manner to bend alternately in opposite directions, ie alternately left and right, so that tube coils of any length can be produced in one plane according to a predetermined tube length. With the measures according to the invention, one bending roller, namely the stationary bending roller, takes over the function of a template, while the other pivotable bending roller takes over the function of a pressure roller that bends the tube around the template. This type of bending technology also makes it possible to ensure the quality of the pipe in the bent section. Due to the nature of the bend, an almost circular tube cross section is retained even in the bend section, which is only slightly reduced compared to the diameter in the straight line area due to the deformation. The invention provides a particularly simple embodiment of the bending drive which can be alternately coupled to one axis of rotation or the other axis of rotation.

Claim 2 specifies an advantageous measure by means of which an axis of rotation can optionally be fixed in place relative to the machine table and can be released again.

The advantageous embodiment according to claim 3 ensures that the two bending rollers are combined to form a stable unit, only this relatively small tool block being pivoted for pipe bending. Claims 4 to 8 indicate advantageous developments of this tool block.

The term "pipe" includes not only hollow elongated round bodies, but also elongated, solid bodies with a circular cross-section, for example normal round metal material such as wires, rods or the like, even if the device according to the invention can be used particularly advantageously for the production of pipe coils is.

Fig. 1

eine Draufsicht auf eine Einrichtung gemäß der Erfindung,

Fig. 2

einen vertikalen Längsschnitt durch die Einrichtung gemäß der Schnittlinie II-II in Fig. 1,

Fig. 3

einen vertikalen Querschnitt durch die Einrichtung entsprechend der Schnittlinie III-III in Fig. 1,

Fig. 4

einen Teilausschnitt aus Fig. 3 in vergrößertem Maßstab,

Fig. 5,6

den Bewegungsablauf der Einrichtung beim Rechtsbiegen und

Fig. 7

den Bewegungsablauf beim Linksbiegen eines Rohres.

Further advantages, features and details of the invention result from the following description of an exemplary embodiment with reference to the drawing. It shows

Fig. 1

a plan view of a device according to the invention,

Fig. 2

a vertical longitudinal section through the device according to section line II-II in Fig. 1,

Fig. 3

a vertical cross section through the device according to section line III-III in Fig. 1,

Fig. 4

3 shows a partial section from FIG. 3 on an enlarged scale,

Fig. 5.6

the movement of the device when turning right and

Fig. 7

the sequence of movements when bending a pipe to the left.

A device for pipe bending is attached to a stationary machine table 1. It has a drive pulley 2 mounted on the machine table 1, which can be pivoted about its central axis 3 by means of a drive motor 4 attached to the underside of the machine table 1. The drive motor 4 is either provided with a reversing gear or can rotate in both directions, so that the drive disk 2 can be driven in rotation in both directions about the axis 3. The drive disk 2 is provided on its upper side 5 facing away from the machine table 1 with a guide groove 6. The central longitudinal axis 7 intersects the central axis 3 of the drive pulley 2 and extends at a right angle to it. In the guide groove 6, a sliding block 8 is arranged, which is freely displaceable in the direction of the axis 7 in the guide groove 6, but is guided largely without play transversely thereto.

A pipe bending tool block 9 can be coupled to the sliding block 8. This has a lower coupling 10 and an upper coupling 11, which consist of approximately triangular plates with rounded corners and have the same outline shape. Two bending rollers 12, 13 are arranged between the lower and the upper coupler, and the two coaxial couplers 10, 11 are arranged around pivot pins by means of bearing bushes 14 15,16 are rotatably mounted. These axes of rotation 15, 16 run parallel to the central axis 3 of the drive pulley 2. The bending rollers 12, 13 are of identical design; they each have an approximately semicircular groove 17 on their circumference, the radius r of which is somewhat smaller than half the diameter of a tube 18 to be bent. On both sides of the groove 17, the bending rollers 12, 13 have a cylindrical circumferential region 19, on which they abut one another, but are also arranged with little play to one another.

For the scheduled rolling of the pressure roller against the stencil roller, toothed disks 12 1/13 1 can be arranged on the tops of both rollers.

On the upper coupling 11, a tube driver 20 is attached, which has a linear drive arranged on the upper coupling 11 in the form of a hydraulically or pneumatically actuated piston-cylinder drive 21, the piston rod of which is provided with a fork-shaped gripper 22, which in the Intermediate space 23 between the upper and the lower coupling 11, 10 can be moved in or pulled out of the latter. The tube driver 20 is arranged between the two axes of rotation 15, 16, in such a way that it is arranged on the common tangent of the adjacent bending rollers 12, 13. He can intervene in an adapted depression 24 in the lower coupling 10 to increase the stability.

A machine boom 25 is attached to the machine table 1, which partially covers the tool block 9, specifically when the device is in its starting position is in which the central longitudinal axis 7 of the guide groove 6 is perpendicular to the feed direction 26 of the tube 18 and when the sliding block 8 is in a central position in the guide groove 6 and when the tool block 9 has such a position that the means -Axis 3 runs through the contact area 27 of the bending rollers 12, 13, in which the latter have the common tangent mentioned.

Couplings 28, 29 are mounted on the boom 25 at a distance a, which corresponds to the distance a between the two axes of rotation 15, 16. These each consist of a linear drive in the form of a hydraulically actuated piston-cylinder drive 30, the respective piston rod plunger 32 of which has axial contact with a spacer 31 and can be inserted into or removed from the bearing bush 14 of the respective bending roller axis in the region of the upper coupling 11 . Depending on which of the two clutches 28, 29 is actuated, the tool block 9 is thus fixed in such a way that its axis of rotation 15 or its axis of rotation 16 is held immovably relative to the machine table 1, but the tool block 9 can be pivoted about this defined axis.

On the sliding block 8, spring bolts 33, 34 are mounted at a distance a from one another, which can each slide up into the corresponding bearing bush 14 in axial contact with the spacer bolts 31 in the region of the lower coupling 10. The depressions 35 in the sliding block 8 limit the stroke of the spring bolts. In each case the spring bolt 33 or 34 is snapped into a bearing bush 14 which is assigned to the axis of rotation 15 or 16 which is not determined by the clutch 28 or 29. It is thus the case that an axis of rotation 15 is coupled to the sliding block 8 by means of a spring bolt 33, while the other axis of rotation 16 is connected in a stationary manner by means of the coupling 29 to the boom 25, and vice versa.

Seen in the feed direction 26 of the tube 18, a side guide 36 and fixed tension for the tube 18 are arranged directly in front of the tool block 9 on the machine arm 25 in order to avoid deflections of the tube 18 transversely to the feed direction 26 during bending.

The mode of operation is explained with reference to FIGS. 5 to 7. In the starting position of the drive pulley 2 and the tool block 9, the central longitudinal axis 7 of the guide groove 6 runs perpendicular to the feed direction 26 for a tube 18. A tube 18 is pushed through in the contact area 27 of the bending rollers 12, 13. Both bending rollers have a radius r of the bending roller groove in the contact or tangent region 27, which is slightly larger than half the tube diameter. This applies both to the contact area at the start of the bend and at the end of the bend of the respective 180 ° pipe bend. 5 and 6, the axis of rotation 15 is connected to the sliding block 8 by means of the spring bolt 33, while the other axis of rotation 16 is fixed in place on the bracket 25 by means of the coupling 29. The pipe 18 is gripped and fixed by the gripper 22 between the couplings 10, 11 by appropriate actuation of the pipe driver 20. Then the drive pulley 2 is turned in the direction of rotation 37 for right-hand bending, ie driven clockwise by the drive motor 4. The tool block 9 is now pivoted about the axis of rotation 16 lying eccentrically to the central axis 3 of the drive pulley 2, ie the bending roller 13 does not change its position. It has the function of a template during this bending process. In contrast, the bending roller 12, the axis of rotation 15 of which is fixed relative to the sliding block 8, is taken along by the sliding block 8 due to the rotational movement of the drive pulley 2 and in this case bends the pipe 18 around the bending roller 13 serving as a template to. An intermediate position in which the tube 18 is bent by 90 ° can be seen in FIG. 6. It should be noted that the drive pulley 2 has already been pivoted here by more than 90 °. The end of the bending process is again shown in FIG. 5, where the position of the bending roller 12, the starting position of which is shown in dashed lines, is shown in solid lines.

Subsequently, the tube driver 20 is released by retracting the gripper 22 so that the tube 18 is no longer firmly connected to the tool block 9. Thereafter, the drive pulley 2 is pivoted back into its starting position counter to the direction of rotation 37. Subsequently, the tube 18 is pushed further in the feed direction 26, so that the already bent section 38 reaches the position shown in dashed lines in FIG. 7. The spring pin 34 is now inserted into the bearing bush 14 assigned to the axis of rotation 16 in the region of the lower coupling 10 by spring pressure, by the right coupling 29 in the axis of rotation 16 extending the piston rod immersion pin pulls out the area of the upper coupling 11. The coupling 28 is simultaneously moved into the bearing bush 14 assigned to the axis of rotation 15, so that this and thus the bending roller 12 is fixed relative to the machine table 1. The spring bolt 34 is pressed out of the bearing bush 14 by the spacer bolt 31. The tube driver 20 is actuated again, so that the gripper 22 holds the tube from the contact area 27 of the bending rollers 12, 13. Then the drive disk 2 is pivoted by means of the drive motor 4 in the direction of rotation 39 for left-turning, that is to say counterclockwise, by 180 °. Here, the sliding block 8 takes along the spring bolt 34 with the tool block 9, which is pivoted about the stationary axis of rotation 15 this time. A bent section 40 of 180 ° is again produced. The bent section 38 shown in dashed lines in FIG. 7 before the start of this second bending process is now in a position that is offset by 180.degree., Which is shown in solid lines in FIG. 7. The tube 18 is already provided with a double coil. After loosening the tube driver 20, the drive disk 2 can be pivoted back to its starting position by 180 ° against the direction of rotation 39. The next right-hand bending process can now follow, as has already been described with reference to FIGS. 5 and 6. With the device described, any number of alternately curved sections 38, 40 can be bent one after the other. The distance L of the bent sections 38, 40, that is to say the length L of a pipe coil section, can be identical over the entire pipe coil, but it must be Not. The lengths L can be selected individually from bending process to bending process.

The entire control of the device can be automated very easily via a process control, which is used to control the drive motor 4, the couplings 28, 29, the pipe driver 20 and, if appropriate, a feed device (not shown) for feeding the pipe 18.

Claims (8)

1. A device for generating curved portions (38,40) bent alternately in opposite senses in a continuously fed linear pipe (18), particularly for generating a pipe coil, comprising a machine table (1), two bending rolls (12,13) having rotational axes (15,16) extending at a fixed mutual distance (a) and parallel to each other, and having their peripheries respectively formed with grooves (17) provided for receiving the pipe (18) and adapted to the cross-section of the pipe (18), and a bending drive, one bending roll having its rotational axis fixed in position relative to the machine table (1), whereas the other bending roll is pivotable by the bending drive about said bending roll having the fixed rotational axis while bending a bent portion (38,40) of the pipe (18), wherein, in an alternate manner, a respective one of the rotational axes (15,16) can be fixed in position while the respective other rotational axis (16, 15) can be pivoted, the bending drive being rotatable alternately in opposite senses,
   characterized in
   that the bending drive comprises a rotatably driven drive disk (2) formed with a guide groove (6) having a sliding block (8) displaceably guided therein for selective coupling to one of the rotational axes (15,16), and that the coupling of the respective rotational axis (15,16) to the sliding block (8) is performed in the starting position of said device wherein the central longitudinal axis (7) of the guide groove (6) is oriented rectangularly to the feed direction of the pipe (18) and the rotational axes (15,16) of the bending rolls (12,13) are arranged symmetrically to the rotational axis (3) of the drive disk (2).
2. The device according to claim 1, characterized in that coupling means (28,29) are provided in fixed positions relative to the machine table (1) to be selectively coupled to the respective positionally fixed rotational axis (15,16).
3. The device according to claim 1 or 2, characterized in that the bending rolls (12,13) are combined to form a pipe bending tool block (9) comprising at least one coupler (10,11) carrying the bending rolls (12,13).
4. The device according to claim 3, characterized in that the tool block (9) comprises a lower coupler (10) and an upper coupler (11) for receiving and supporting the bending rolls (12,13) in an intermediate space (23) between the upper and lower couplers (10,11).
5. The device according to claim 4, characterized in that the tool block (9) can be coupled to the bending drive along one of the bending roller axes (15 or 16).
6. The device according to claim 2 and 4, characterized in that the tool block (9) can be selectively engaged with one of the coupling means (28,29).
7. The device according to claim 3, characterized in that the tool block (9) supports a pipe carrier (20).
8. The device according to claim 7, characterized in that the pipe carrier (20) comprises a gripping means (22) axially displaceable transversely to the pipe and in parallel to the rotational axes (15, 16).

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