WO2016071161A1

WO2016071161A1 - Pipe bending press

Info

Publication number: WO2016071161A1
Application number: PCT/EP2015/074881
Authority: WO
Inventors: Frank BLÖMKE
Original assignee: Siempelkamp Maschinen- Und Anlagenbau Gmbh
Priority date: 2014-11-06
Filing date: 2015-10-27
Publication date: 2016-05-12
Also published as: DE102014116192A1

Abstract

The invention relates to a pipe bending press for bending metal sheets (1) in the course of the production of pipes, having a bending blade (4) which is arranged in or on an upper press part (2) and to the lower end of which an upper tool (5) is fixed, and having two lower tools (6a, 6b) arranged in or on a lower press part (3) and spaced apart from each other (transversely with respect to the working direction). This press is for bending a metal sheet arranged between the upper press part (2) and the lower press part (3); at least one of the lower tools (6a, 6b) can be moved along the working direction (A) against the upper tool (5) and relative to the other lower tool (6b, 6a) during an operating stroke.

Description

Tube bending press Description:

The invention relates to a tube bending press for bending sheets in the course of the production of pipes, with a arranged in or on a press upper part bending rate, at the lower end of an upper tool is fixed and arranged with two in or on a press base and from each other (transverse to the direction) spaced sub-tools.

Pipe in the context of the invention esp. A longitudinally welded pipe or slot pipe. In a tube bending press of the type described above, which is also referred to as a step shape press, the sheet is bent in several temporally successive steps or bending operations. The production of a pipe and esp. Large tube is also referred to as a step-forming process or progressive molding process. The lower tools are usually designed as extending in the sheet longitudinal direction and consequently tube longitudinal direction moldings. In the course of forming, the upper tool arranged on the bending bar dips between the spaced lower tools or moldings, so that the bending force is applied to the metal sheet.

DE 18 14 066 discloses a tube bending press of the type described above, in which the two lower tools or moldings are moved against the upper tool during a working stroke together with the aid of a pressure ram.

Alternatively, from DE 102 32 098 B4 a tube bending press, in which the bending rate is lowered and depressed with the attached upper tool during a working stroke, which sets under the action of the bending load value and carried by this upper mold a deformation of the sheet. The upper tool can be articulated hinged to the lower end of the bending load. In addition, the bending bar can be articulated at the press end with its upper end. Upper part to be attached, so that a zweigelenkige design is achieved. In this way moments in the sword should be avoided during bending. The known tube bending presses have basically proven themselves in practice. However, they are subject to disadvantages and therefore capable of further development.

The invention has for its object to provide a tube bending press for bending sheets in the course of the production of pipes of the type described above, with which can be produced in a simple structure in an economical manner pipes with high quality.

To solve this problem, the invention teaches in a generic tube bending press for bending sheets in the course of the production of tubes of the type described above, that at least one of the lower tools during a working stroke along the working direction against the upper tool and for bending an arranged between press upper part and press base sheet along the working direction relative to the other lower tool is movable. In this context, moving does not mean, for example, the method transverse to the working direction in order, for. B. adjust the distance between the two sub-tools, but the method of the lower tools during a working stroke in the working direction. Working direction is the direction in which upper and lower tools are moved towards each other, d. H. usually a vertical or approximately vertical working direction.

The invention is based on the problem that raises the sheet in the known bending method of the type described above with at least one end during bending. The sheet metal is transformed step by step into several bending processes beginning on one longitudinal side. Then, the sheet rises with its not yet formed flat area in the known methods usually when the lower tools against the Upper tool are moved. This lifting or lifting affects the bending process and thus the quality of the tubes produced. Although it has already been proposed to accompany this lifting by a mechanical support in order to prevent negative influences on the forming process. However, this is associated with costly measures. Based on this problem, the invention has now recognized that the lifting of the sheet in the course of forming can be avoided in a simple manner, if not both lower tools are moved together against the upper tool, but if one of the lower tools during a working stroke against the upper tool and consequently is moved relative to the other lower tool. Assuming that the sheet is bent in several temporally successive forming operations and thereby moved step by step transversely to the sheet longitudinal direction, the invention preferably proposes that lying in this feed direction first lower tool relative to the opposite to the feed direction arranged second lower tool method. For the fact that the process of this second lower tool is dispensed with, the lifting of the sheet is prevented in the not yet bent area. Basically, it is within the scope of the invention that in the course of bending both lower tools are moved, but not simultaneously over the same stroke, but always there is a relative movement between the two sub-tools instead. Preferably, however, only one of the two lower tools is moved, while the other lower tool is fixed. In order to realize the teaching according to the invention, it is expedient if the two lower tools can be moved independently of one another against the upper tool, relative to the respective other lower tool. There is then optionally the possibility of alternately successively moving both lower tools relative to the other lower tool.

Preferably, each of the two lower tools is equipped with at least one own press drive and movable, wherein such a press drive z. B. as a hydraulic drive, z. B. be designed as a hydraulic cylinder can. As usually sheets are formed, which have a certain length to produce tubes of a certain length, for each lower tool a (separate) series of longitudinal direction in sheet metal successively arranged drives, for. For example, cylinders may be provided.

According to a further proposal of the invention, the bending bar is rotatably or pivotally articulated in or on the press upper part and provided with at least one rotary drive. The invention is based on the recognition that the loads of the bending rate in the course of forming can be minimized by rotation of the bending rate with the upper tool arranged thereon about an axis of rotation extending along the sheet longitudinal direction. Because when forming by simply a simple method of a lower tool is basically the problem that the bending forces are asymmetrically entered into the sword. This can lead to high loads. These loads are minimized when the sword is rotated or swiveled in a suitable manner prior to the process (or possibly also during the process) of the only one lower tool, specifically to the lower tool which is raised in this case. For this purpose, it may be useful if the pipe bending press is provided with a control device, which with the sub-tools, z. B. the press drives on the one hand and with the bending rate, z. B. the rotary drive on the other hand is connected, wherein the rotational movement of the bending load value in dependence on the working movement of the lower tools or the lower tool is controllable. In general, however, it is expedient to bring the bending rate before the respective forming process in a certain position and to keep it there in this position and fix it if necessary. For example, it may be sufficient to fix the sword in a certain angular position for a specific type of sheet metal. The upper tool usually has a cross-sectionally circular working surface. It is advantageous if the circle center of this circular working surface coincides with the axis of rotation of the bending rate. The bending rate is thus around the circle center of the work surface turned. This has the advantage that, despite rotation of the bending value of the contact point of the sheet with the upper tool always remains in the same place, z. B. in the middle between the two sub-tools. The invention also relates to a method for bending sheets in the course of the production of pipes with a tube bending press of the type described. This method is characterized in that for bending the sheet during a working stroke of the lower tools against the upper tool and along the working direction relative to the other lower tool is moved.

It is within the scope of the invention that the sheet is bent in several temporally successive bending operations. The invention proposes here optionally that during a bending process only one of the sub-tools is moved, while the other lower tool is fixed. It is always expedient if the bending rate is rotated prior to the process of one of the lower tools to a rotational axis extending in the sheet longitudinal direction or pipe longitudinal axis, so that the forces are introduced symmetrically in the bending rate in the manner described. For this purpose, the bending rate can be preferably rotated in the direction of this lower tool prior to the process of one of the lower tools. Preferably, the bending rate is rotated before the working stroke of one of the lower tools in the desired working position and with the proviso that the introduced from the lower tool in the sheet resulting bending force along or substantially along the sword longitudinal direction. Overall, with the tube bending press according to the invention and with the working method according to the invention can be produced in a simple way slotted tubes with high quality. It can process a wide range of sheet types. In particular, sheets of different materials and sheets of different thickness can be processed. The press can be used variably. Thus, in particular, it is also possible to operate the press with the individually movable sub-tools in a conventional manner, ie to raise both sub-tools simultaneously. This "classic" way of working lends itself, for example, to the processing of thick sheets. Because with thick sheets lifting the sheet is less critical, so that lifting can possibly be tolerated. Then, in this variant, both lower tools can be lifted in a conventional manner. However, since within the scope of the invention, work is done with separate press cylinders for each lower tool and consequently with a total of at least two press cylinders or two rows of press cylinders, the double press force can be applied with these two press cylinders or rows. In principle, it is expedient to bend the sheets used before the described deformation in the region of the edges. This bending is usually done in a separate press brake, which is not the subject of this invention. In the following the invention will be explained with reference to a drawing showing only one embodiment. 1 shows a tube bending press according to the invention in the course of bending a sheet according to a known bending method and a tube bending press according to FIG. 1 during the forming of a sheet in the manner according to the invention;

Fig. 3 shows the article of FIG. 2 in a modified, preferred

embodiment,

Fig. 4 to 8 the object of Fig. 3 in different functional positions. In the figures, a tube bending press for bending a sheet 1 during the production of a tube is shown. Such a tube bending press consists in its basic structure of a press upper part 2 and a press lower part 3. On the press upper part 2 is a bending rate 4 angeord- net, at the lower end of an upper tool 5 is attached. On the lower press part 3, two lower tools 6a, 6b are arranged, wherein these lower tools 6a, 6b are spaced apart from one another transversely to the working direction A. Working direction A is the direction along which the tools for bending are moved towards each other, ie in the embodiment the vertical direction.

In order to bend the sheet metal 1 arranged between the press upper part 2 and the press lower part 3, the lower tools 6a, 6b can be moved along the working direction A during a working stroke, namely against the upper tool 5, so that the upper tool 5 can be moved between the spaced lower tools 6a, 6b dips.

Fig. 1 shows the operation of such a tube bending press in a conventional manner, namely, when the two lower tools 6a, 6b are moved together against the upper tool 5. It can be seen that in this way the sheet can be formed in the desired manner. The problem, however, is the fact that the sheet with its left in Fig. 1 shown end, which has not yet bent in the desired manner, lifts. This is indicated by the arrow P.

In order to avoid this lifting, the two lower tools can now be moved independently of one another against the upper tool 5 and relative to the respective other lower tool 6b or 6a during a working stroke in the pipe bending press according to the invention. For this purpose, each of the two lower tools 6a, 6b is equipped with its own press drive 7a, 7b. These press drives 7a, 7b are only indicated in simplified form in the figures. In Fig. 2 it can be seen that by lifting only one of the lower tools, namely the lower tool shown in Fig. 2 lower tool 6b, the lifting of the left end of the sheet can be prevented. The tube bending press according to the invention is characterized, apart from the separately controllable press drives 7a, 7b for the two lower tools 6a, 6b in the embodiment shown in Fig. 3 to 8, also characterized in that the bending bar 4 is rotatably articulated to the press upper part 2. In this case, the bending bar value 4 is provided with a merely indicated rotary drive 8, with which the bending bar value 4 can be rotated about an axis of rotation D running along the longitudinal direction of the plate. This option is shown in FIGS. 3 to 8. As a result of this configuration, the tube bending method according to the invention can be further optimized. For it is now possible, as shown in FIGS. 3 to 8, to rotate the bending bar 4 in front of a working stroke and consequently prior to lifting one of the lower tools 6b about the axis of rotation D, in the direction of the respectively moved lower tool 6b. The rotational movement of the bending rate value 4 takes place as a function of the subsequent feed movement of the lower tool 6b, with the proviso that the resultant bending force F introduced by the lower tool 6b into the metal sheet 1 extends substantially along the longitudinal direction L. FIG. 3 shows these relationships and makes it clear that in this way an asymmetrical introduction of force into the bending load value 4 is avoided.

It is indicated in Fig. 4 that the circle center P of the circular working surface 9 of the upper tool 5 coincides with the pivot point D of the bending rate 4. The bending rate is thus rotated about the circle center P of the work surface 9. This has the advantage that the point of contact of the working surface 9 of the upper tool 5 with the sheet 1 to be formed remains despite the rotation of the bending value in the middle between the two sub-tools 6a and 6b.

The transformation of a sheet 1 in several steps can be explained by means of a comparative examination of FIGS. 3 to 8. 3 shows the arrangement before or at the beginning of the forming in the region of the right side of the sheet 1. The edges of the sheet (right and left) were already in one pre-bent and bent, not shown, in a separate bending press.

The sheet is then gradually transformed as described and thereby pushed stepwise to the right, as this is indicated in Fig. 4 and 5, so that Fig. 5 shows the end of the forming process of the right side of the sheet. Subsequently, according to FIGS. 6 to 8, the left side of the sheet can be reshaped so that FIG. 8 shows the end of the forming process in the region of the left side. It can be seen that during the forming of the right side of the sheet only the right lower tool 6b is working, whereas during the forming of the left side of the sheet only the left forming tool 6a is working. Also, the bending rate 4 is pivoted in both cases in different directions, namely each added to the working lower tool.

In principle, it is possible to control, with the aid of a control device, on the one hand, the press drives 7a and 7b and, on the other hand, the rotary drive 8. In general, however, it will be sufficient to bring the bending bar 4 by means of the rotary drive 8 at the beginning of a forming operation in the respective desired functional position, so that then the one side of the sheet, z. B. the right side of the sheet according to FIG. 3 to 5 is processed with the same functional position of the bending load value 4. Subsequently, the other side of the sheet according to FIGS. 6 to 8 is reshaped with another but also fixed functional position of the bending load value.

Overall, with the tube bending press according to the invention and with the working method according to the invention can be produced in a simple way slotted tubes with high quality. It can handle a wide range of sheet types. In particular, sheets made of different materials and sheets of different thicknesses can be processed. The press can be used variably. Thus, in particular, the possibility exists of processing thick sheets in a conventional manner in which both lower dies 6a, 6b are simultaneously lifted. Because with thick sheets is a lifting of the Sheet less critical. When working in this variant in a conventional manner, the double pressing force can be applied by the embodiment according to the invention with two pressing cylinders.

Claims

claims:

1 . Pipe bending press for bending sheet metal (1) in the course of the production of pipes, with a bending blade (4) arranged in or on a press upper part (2), at the lower end of which an upper tool (5) is fastened and with two in or on one press lower part (3) arranged and spaced from each other transversely to the working direction A sub-tools (6a, 6b), characterized in that for bending a between press upper part (2) and press base (3) arranged sheet at least one of the lower tools (6a, 6b) during a working stroke against the Upper tool (5) and along the working direction (A) relative to the other lower tool (6b, 6a) is movable.

2. Press according to claim 1, characterized in that the two lower tools (6 a, 6 b) independently of one another against the upper tool (5) and along the working direction (A) relative to the respective other lower tool (6 b, 6 a) are movable.

3. Press according to claim 1 or 2, characterized in that each of the two lower tools (6a, 6b) with at least one press drive (7a, 7b), z. B. at least one hydraulic cylinder or a series of bleach in the longitudinal direction one behind the other arranged hydraulic cylinders is movable.

4. Press according to one of claims 1 to 3, characterized in that the bending rate (4) rotatably or pivotally articulated in or on the press upper part (2) and provided with at least one rotary drive (8).

5. Press according to one of claims 1 to 4, characterized by a control device, which with the sub-tools (6 a, 6 b) or their press drives (7 a, 7 b) on the one hand and with the bending rate (4), or its rotary drive (8). on the other hand, wherein the rotational movement of the bending rate value (4) or its position is controllable in dependence on the geometry of the tube to be produced and / or the working movement of the lower tool or the lower tooling to be performed.

6. Press according to one of claims 1 to 5, characterized in that the upper tool has a circular cross-section working surface (9) whose circle center (P) with the axis of rotation (D) of the bending rate value (4) coincides.

7. A method for bending sheets in the course of the production of pipes with a tube bending press according to one of claims 1 to 6, characterized in that for bending the sheet during a working stroke of the lower tools against the upper tool and along the working direction relative to the other lower tool is moved.

8. The method of claim 7, wherein the sheet is bent in a plurality of temporally successive bending operations, characterized in that only one of the lower tools is moved during a bending operation, while the other lower tool is fixed.

9. The method according to claim 7 or 8, characterized in that the two lower tools are moved alternately or sequentially in a plurality of successive bending operations.

10. The method according to any one of claims 7 to 9, characterized in that the bending rate before the method of one of the lower tools to a is rotated in Blechlangsrichtung or pipe longitudinal axis of rotation.

1 1. A method according to claim 10, characterized in that the bending sword before the process of one of the lower tools in the direction of this

Lower tool is turned to.

12. The method of claim 10 or 1 1, characterized in that the bending rate is brought before the working stroke of the lower tools in a position in which the introduced from the lower tool in the sheet resulting bending force along or substantially along the sword longitudinal direction.

13. The method according to any one of claims 10 to 12, characterized in that the bending rate is rotated about an axis of rotation which coincides with the circle center of the working surface of the upper tool.