EP0245623A2 - Tube-bending machine - Google Patents

Abstract

In a pipe bending machine with a bending table which can be pivoted about an axis and which has a bending template and a clamping jaw which is displaceable relative to the latter, and is provided with a displaceable feed carriage which has a rotatable clamping sleeve, the bending template and the clamping jaw having straight and curved sections for clamping the part to be bent Pipe adapted, each assigned clamp body with clamping surfaces, which are each spatially separated and can be brought into the working position, the one clamping body (25) has a clamping surface that has several different contours (33, 34, 35) of the pipe section to be clamped, while the during operation assigned clamping surface of the other clamping body (19) has only one clamping surface (30) corresponding to the contour of the pipe section to be clamped and thus covers the entire pipe section to be clamped on the associated adjacent side over an angular amount of 180 °.

Description

The invention relates to a pipe bending machine having a bending table pivotable about an axis, which has a bending template and a clamping jaw which is displaceable relative to the latter, and is provided with a displaceable feed carriage which has a rotatable clamping sleeve, the bending template and the clamping jaw having straight and curved sections for clamping the have adapted to each other bent pipe, each associated clamping body with clamping surfaces, which are each spatially separated and can be brought into the working position.

DE-AS 1 297 064 published in 1969 describes a fully automatic pipe bending machine for Bending pipes in which bends lying in different planes directly adjoin one another with a bending template that can be separated from its rotary drive at the end of a bend and an associated pipe clamping jaw, both of which have a pipe groove lying in the bending plane and a side branch that corresponds to the course of the curved pipe Groove are provided, wobie further a transversely acting on the unbent tube directly in front of the bending template, impression device and a return device for the separable from the drive template and a locking device for the bending template, which is effective when pushing the tube from the template , available.

Since the bending template and the clamping jaw are each provided in one piece with these in addition to the continuous tube groove lying in the bending plane with a tube groove extending therefrom, there is no comprehensive full-surface clamping of the tube at this branch. Such a junction of a straight groove and groove branched off from it is still possible in practice, provided that after the first bending, the tube is pivoted by about 90 ° in the bending plane for the subsequent bending. Unless it is by deviating sizes or smaller bending angles, the clamping surfaces of the grooves are so small that bending is not possible in practice because there is a slip that cannot be controlled and that does not permit precise bending. The clamping surfaces that are too small then in many cases lead to damage to the pipe, such as indentation in connection with a reduction in cross section and scoring in the event of slippage.

With the aid of previously known devices, the procedure is as follows: after the shaping of the first arch, the bending template is first determined in its position corresponding to the arch shape. The loose jaw is then moved back to its original position. Next, the bent end of the tube is pressed out radially to the template from the tube groove of the same under the action of force and, if possible, simultaneously pivoted into the new bending plane. If the locking device of the template is then released, it immediately returns to its starting position through the reverse rotation device. If the push-off device for the tube is then switched off, the tube either swivels automatically or under the action of the then loose clamping jaw until it rests against the template, whereby the pipe bend previously made is inserted into the branching groove template and the loose clamping jaw. So that the tube is clamped for the production of the next sheet, which is done in the usual way by rotating the template and the loose jaw.

Since the measures proposed in the aforementioned DE-AS 1 297 064 have not proven themselves in practice, various proposals have subsequently been made which have to be taken into account when bending pipes with different clamping surfaces. Reference is made to a first proposal, which emerges from the granted patent 26 26 202 of the applicant and inventor with the proviso that the clamping surfaces are spatially separated from one another and can be rotated relative to the bending table.

It can also be referred to DE-AS 27 11 340, which shows a device for cold bending of strand material, such as pipes, rods or profiles, with a bending molding which can be rotated about an axis and which has a circumferential groove for receiving the strand material, and with a with the bend molding also rotated clamping device, which has a clamping jaw arranged on the bend molding and a counter-jaw, wherein the jaws and counter-jaws each have a groove which complement each other to form a receiving channel for the strand material. Farther It can be seen that the bending fitting may have further circumferential grooves, that both the clamping jaw and the counter-clamping jaw have further different grooves associated with the same circumferential groove of the bending molding, and that the clamping jaw and the counter-clamping jaw on the one hand and the bending fitting on the other hand for changing the receiving channel in the direction of Axis of the bending molding are adjustable relative to each other.

In this context, reference can be made to DE-OS 34 07 499 by the applicant that on the bending template and / or clamping jaw there is a contact surface, in particular a recess for exchangeably receiving a body provided with the clamping surface, and this body is arranged on a guide and with a drive is provided which retracts or extends the body with a vertical movement into the recess and can be moved in and out into the aforementioned recess in the place of the one with a clamping surface of a different design.

In the case of the three last-mentioned documents which explain the respective development, the requirement is thus provided that the section of the tube to be clamped in each case is to be Pinching over the entire surface, ie over its entire circumference, is to be encompassed. This is necessary with the different spatial shapes that the section of a pipe to be clamped has, for example with regard to whether a widened or non-widened end of a pipe is to be clamped in or depending on the previous bend of a pipe section of many different clamping bodies with a clamping surface assigned to each clamping body. In order to accommodate these clamping bodies with the clamping surfaces assigned to them individually, the aforementioned prior art specifies various solutions. According to the first-mentioned DE-PS 26 26 202, the clamping bodies on the bending template are arranged distributed over the circumference thereof, while they are rotatable on the clamping jaw and thus also arranged locally concentrated. According to DE-AS 27 11 340, the clamping body arranged on the clamping jaw and the clamping body interacting with the bending template are a structural unit which is fastened to the clamping jaw carrier and is accordingly moved together.

The present invention is based on the object of creating a bending template with a clamping jaw fastened to this and a counter clamping jaw fastened to a clamping jaw carrier, which allow a large number of clamping surfaces of different spatial shapes with little construction effort or a few clamping jaws. To solve this The task is for a pipe bending machine with a bending table pivotable about an axis, which has a bending template and a sliding jaw that is displaceable relative to the latter, and is provided with a sliding feed carriage that has a rotatable clamping sleeve, the bending template and the clamping jaw having straight and curved sections for clamping the according to the invention proposed that one clamp body has a clamp surface that has several different contours of the pipe section to be clamped, while the clamp surface assigned during operation of the other clamping body has only one clamping surface corresponding to the contour of the pipe section to be clamped and thus covers the entire pipe section to be clamped on the assigned side over an angular amount of 180 °.

With the solution according to the invention it is thus achieved that the one clamping jaw has a clamping surface in the form of a half-shell, which is half-shell-shaped over its entire length, so that it encompasses the tube section in contact over the length of the clamping by an angular amount of 180 °, while the opposite jaw has several clamping surfaces of different spatial shapes has, which in certain areas only partially encompass the section of the pipe to be clamped by 180 °, so that in other words there is no complete clamping. It was recognized that it is sufficient when bending the pipes that the clamping only needs to be full-surface over the length of the clamping on one half of the pipe cross-section, while the opposite half only needs to be clamped in half-shell-shaped or over 180 ° zones and thus the Pinching surface has gaps that are or can be considerable.

With the solution according to the invention it is achieved that the one clamping jaw with the several different clamping surfaces is fixed in place or can be in most cases and therefore does not need a drive.

It was also recognized that it does not matter whether the half-shell-shaped complete clamping is present on the clamping jaws attached to the bending template or on the clamping jaws present on the clamping jaw carrier. Nevertheless, it is proposed in a further embodiment according to the invention that the clamping body arranged on the clamping jaw is rotatably arranged and has a plurality of clamping surfaces distributed over its circumference, each individual clamping surface being only one of the contours of the pipe section to be clamped has a corresponding clamping surface and the bending template has a clamping body with a clamping surface which has several different contours of the pipe sections to be clamped.

This proposal has the advantage that the arrangement of several clamping surfaces of different design in a jaw or, if necessary, one above the other, which is axially displaceably arranged on the bending template, due to their local concentration at one point, the unimpeded bending of a pipe by an amount up to Allow 180 °. It is particularly advantageous to arrange two more than two different clamping surfaces in a clamping jaw on a clamping jaw arranged on the bending template. The solution according to the invention makes it possible to arrange many different clamping surfaces on one clamping jaw. This then gives the further advantage that this clamping jaw arranged on the bending template can be screwed to the bending template, so that only the counter-jaw arranged on the clamping jaw carrier needs to be adjusted in terms of movement.

The solution according to the invention, in particular in connection with the provision described above, that the clamping jaw attached to the bending template has several different clamping surfaces, the term "attached" It is to be understood that this clamping jaw can also be axially movable on the bending template, but can also be screwed in place, in a further embodiment according to the invention enables a method for operating the pipe bending machine with clamping bodies in such a way that after the pipe has been bent by the set bending angle by rotating the bending template with the adjacent clamping jaw, the clamping jaw is released from the bending template and, when the tube feed is at a standstill, the bending template is rotated further by such an amount that the clamped section of the tube of the clamping surface is removed and the tube about its unbent longitudinal axis is unhindered by the clamping surface of the bending template is rotatable, which is the tube feed for the next and at the same time turning the bending template back to the starting position.

In previous arrangements and designs of clamping jaws and counter-clamping jaws, the tube was pushed so far after the bending process and the loosening of the counter-clamping jaw with the bending template stationary that the bent end was led out of the clamping surface of the clamping jaw of the bending template. Then the bending template was returned to the starting position.

According to the present invention, however, the bending template becomes wider by a certain amount after the bending has taken place rotated in order to achieve by this additional rotation that the clamping surface was removed from the bent pipe end. While the bent pipe end was previously removed from the bending template by the proviso that the pipe is advanced by a special input given in the existing bending template, it is now proposed to carry out the rotation of the bending template beyond the amount necessary for bending with the pipe standing so that the bent pipe end is no longer in the clamping surface and thus the bending template is moved further when the pipe is "standing". This has the advantage that the control is simplified because after the pipe has been bent, its position remains and the bending template is rotated further beyond the extent necessary for the bending itself. This "further turning" takes place in one operation and, because this "further turning" does not result in a further bending of the tube, only requires the release of the counter clamping jaw.

The end result of the proposal according to the invention is that the sequence of movements is simplified and the accuracy of the bending is increased. If, according to the previous method for detaching the bent pipe section from the clamping surface of the clamping jaw located on the bending template, the pipe is moved further by an additional movement in its axial direction, then this must be closed Additional movement to disengage from the jaw in the control program must be taken into account so that the next bend takes place at the right place after a corresponding pipe feed. The feed rate for moving the bent pipe section out of the clamping jaw must therefore be taken into account.

It was recognized that it is significantly easier for the determination and implementation of the bending program to move the bending template with the clamping jaw attached to it beyond what is necessary for the bending.

The invention is exemplified in the drawings.

• Figur 1 eine Rohrbiegemaschine in perspektivischer Darstellung,
• Figur 2 ein gebogenes Rohr in perspektivischer Darstellung,
• Figur 3 eine Biegeschablone mit Klemmbacken und Gegenklemmbacken in perspektivischer Darstellung,
• Figur 4 eine Biegeschablone mit an ihr angebrach­ter in axialer Richtung bewegbaren zwei­fachen doppelten Klemmbacke in einem ver­tikalen Schnitt,
• Figur 5 eine Biegeschablone mit Klemmbacke, die mehrere unterschiedliche Klemmflächen aufweist,
• Figur 6A - 6C eine Biegeschablone 6B und 6C mit einheit­lichem Klemmbacken, dem ein Gegenklemm­backen 6A zugeordnet ist,
• Figur 7 eine Gegenklemmbacke, die an einer Fläche mehrere unterschiedliche Klemmflächen aufweist.

Show it:

• FIG. 1 shows a pipe bending machine in perspective,
• FIG. 2 shows a bent tube in perspective,
• FIG. 3 shows a bending template with clamping jaws and counter-clamping jaws in a perspective view,
• FIG. 4 shows a bending template with a double double jaw, which is attached to it and can be moved in the axial direction, in a vertical section,
• FIG. 5 shows a bending template with a clamping jaw, which has several different clamping surfaces,
• 6A-6C a bending template 6B and 6C with a uniform clamping jaw, to which a counter-clamping jaw 6A is assigned,
• FIG. 7 shows a counter clamping jaw which has several different clamping surfaces on one surface.

Figure 1 shows a conventional pipe bending machine with a feed carriage 10, which is on one or more guide rails 11 on the top of the machine housing 12 can slide back and forth.

The feed carriage 10 has a hollow cylinder 13, in the interior of which there is a clamping sleeve 14, in which the end region of the pipe section or pipe 15 to be bent is clamped. The pipe section 15 is guided around a pivotably mounted bending template 16 which has a groove 16 for the pipe which corresponds to the pipe radius. On a part of the pipe piece 15 guided around the bending template 16, a clamping jaw 19 is pressed by means of a clamping device 18, which also has a groove 19 corresponding to the pipe radius as clamping surface and clamps the pipe 15 on the bending template 16. For this purpose, the bending template is provided with a releasably attached clamping jaw 25 arranged thereon. A hydraulic cylinder 20 is shown as an example, which moves the clamping device 18 of the clamping jaw 19 towards the bending template 16 for clamping the tube or removes it from this template. The bending template 16 is fixedly arranged on the bending table 21, while the clamping device 18 can be pushed back and forth in the indicated arrow direction 22 via the cylinder 20 shown as an example. If the bending template 16 is pivoted over the bending table 21 together with the clamping jaw 19 in the direction of the arrow 23, so the pipe section 15 receives a curvature which corresponds to the profile of the bending template 16. During this bending process, the end part of the pipe section 15 remains clamped in the clamping sleeve 14 of the feed carriage 10 in order to safely guide the pipe section in all positions. So that the pipe section 15 that is free between the clamping sleeve 14 and the bending template 16 cannot buckle laterally, a slide rail 24 is pressed onto this pipe section part, which also has a groove that corresponds to the pipe radius. The clamping sleeve 14 of the feed carriage 10 not only clamps the pipe section 15 firmly, but also turns it by amounts of up to 360 ° if successive pipe bends are to be curved in different directions. In order to rotate the clamping sleeve 14, a hydraulic motor rotates a worm which interacts with a worm wheel (not shown) which is connected to the clamping sleeve 14.

FIG. 2 shows an exhaust pipe which can be produced with the bending machine and in which curved sections or pipe bends S 1 and S 2 as well as S 3 and S 4 are directly connected. There are also linear intermediate lengths L 1, L 2 and L 3, which, however, do not need to be present except for the length L 1. The tube is provided with an expansion 26 at its front end.

Figure 3 shows that the jaw holder 18 is provided on both sides with cantilevers 27 and 27A, which protrude in the direction of the bending template 16 and at their front end via an axis of rotation 28 carry the counter jaw 19, which is designed as a rectangular body according to the embodiment and four clamping surfaces has, which are provided with semicircular depressions in cross section, which give the clamping surfaces 29, 30, 31 and 32. These clamping surfaces have different spatial shapes, but the common factor that they encompass the pipe section to be clamped in this in a semicircle over the entire clamping length.

According to the exemplary embodiment, the clamping jaw 25 arranged on the bending template 16 has three different circumferential grooves 31, 34 and 35, which are also shown in FIG. 4. The clamping jaw 25 is fastened to the bending template 16 by means of screws, not shown in the drawing, i.e. that this is not slidably disposed relative to the bending template. This solution is particularly advantageous because it does not require any movement mechanisms.

FIG. 3 shows that the clamping jaw 25 is arranged on the bending template 16 opposite another clamping jaw 36 which has a clamping surface with different radii of its half-shells. The part 37 with a larger radius of curvature and the part 38 with a smaller radius is ver see. This is done in order to clamp the widened end 26 in a pipe 15 according to FIG. 2 through the half-shell-shaped section 37 and the subsequent part with the radius of smaller cross section 38.

FIG. 4 shows that the clamping jaw 25 with the recesses 33, 34 and 35 arranged in it cannot grip around the tube section clamped in each case over half the circular area, but can only grip around incompletely in the areas in which the bends 34 and 35 intersect.

However, according to the knowledge of the present invention, this is harmless, provided that the counter-jaw grips the pipe by the amount of 180 °, i.e. half-shell-shaped, encompasses the entire surface over the length of the pipe section to be clamped.

FIG. 5 shows that two clamping bodies 25 and 25a are arranged one above the other on the bending template 16, the clamping body 25 having three different clamping surfaces and the clamping body 25a having two different clamping surfaces. The clamping bodies 25 and 25a are adjustable in the vertical direction by means of a hydraulic piston-cylinder arrangement in such a way that the cylinder 36 is arranged within the bending template 16 and the piston rod 37 protrudes upward, which has a cross member 38 which is connected to the jaws 25 and 25a. The piston-cylinder arrangement can thus, as shown in FIG. 5, selectively act on the clamping jaws 25, but also by lowering the clamping jaws 25a.

It should be noted that the solution proposed in FIG. 5, shown on the bending template, can also be present on the counter-jaw holder 18, with the proviso that, in contrast to FIG. 3, the clamping surfaces are not arranged on a body rotatable about a horizontal axis, but on a body that can be moved in the vertical plane. At this point, however, it should also be noted that the clamping surfaces arranged one above the other are not as favorable as the clamping surfaces arranged in different planes, which are shown in FIG. 3 and are rotatable about the axis of rotation 28. In some cases three surfaces, but also five or six surfaces are used.

FIG. 6 shows that the bending template 16, shown in the drawings FIG. 6B and FIG. 6C, has a clamping jaw 25 which has a uniform design of its clamping surface, which can also be seen in perspective from FIG. 6A with the proviso that one has a diameter there is an enlarged half-shell 39 and a half-shell 40 with a smaller diameter, for example with the tube end 26 with a larger diameter, with the connection Send part of the tube to clamp the usual diameter. The counter clamping jaw 19 corresponding to FIG. 6A thus shows a design in which the pipe section to be clamped is completely grasped over the angular amount of 180 ° over the length of the pipe section to be clamped in, while the clamping jaw 25 arranged on the bending template 16 likewise has a full surface after the training in FIG. 6C 6 shows an entrapment extending over an angular amount of 180 °, but FIG. 6B shows this full-area entrapment only by the true pipe diameter, but not in the clamping section 39.

FIG. 7 shows the counter clamping jaws 19 with the proviso that a plurality of clamping surfaces, in the present case two clamping surfaces, are also present on a clamping surface. However, in relation to their half-shell, these are individually designed over their entire surface so that, according to the invention, they interact with a counter-clamping surface that does not cover the entire surface of the tube, i.e. with respect to the length of the counter-clamping surface. over an amount of 180 °, as can be seen, for example, from the node of the drawing in FIG. In order to bring one clamping surface 30 or the other clamping surface 31 with the different radii 40 and 39 into effect, the counter-clamping jaws 19 is displaceably mounted in the indicated double arrow direction 41.

Claims (3)

1. Pipe bending machine with a bending table pivotable about an axis, which has a bending template and a sliding jaw displaceable relative thereto, and is provided with a sliding feed carriage, which has a rotatable clamping sleeve, the bending template and the clamping jaw straight and curved sections for clamping the to be bent Pipe adapted, each assigned clamp body with clamping surfaces, which are each spatially separated and can be brought into the working position, characterized in that the one clamping body (25) has a clamping surface which has several different contours (33, 34, 35) of the pipe section to be clamped has, while the associated clamping surface of the other clamping body (19) has only one of the contours of the to (30) and thus completely covers the pipe section to be clamped on the associated adjacent side over an angular amount of 180 °. 2. Pipe bending machine according to claim 1, characterized in that the clamping body (19) arranged on the clamping jaw (18) is rotatably arranged and distributed over its circumference has a plurality of clamping surfaces (29, 30, 31, 32), each individual clamping surface merely one of the contour of the pipe section to be clamped has a corresponding clamping surface and the bending template (16) has a clamping body with a clamping surface which has several different contours (33, 34, 35) of the pipe section to be clamped. 3. A method for operating the pipe bending machine with clamping bodies according to claims 1 and 2, characterized in that after the bending of the tube by the set bending angle by rotating the bending template with the adjacent clamping jaw, the counter clamping jaw is released from the bending template and the bending template is turned around when the tube feed is at a standstill such an amount is further rotated that the clamped section of the tube is removed from the clamping surface and the tube is freely rotatable about its unbent longitudinal axis by the clamping surface of the bending template, and then the tube feed for the next bend and at the same time the turning back of the bending template into the starting position is made.

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