EP3820631A1

EP3820631A1 - Expanded regulation of a jco forming press

Info

Publication number: EP3820631A1
Application number: EP19739552.8A
Authority: EP
Inventors: Mario THOME
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2018-07-09
Filing date: 2019-07-09
Publication date: 2021-05-19
Also published as: WO2020011772A1; JP2021524382A; DE102018211311B4; CN112399894B; KR20210014147A; KR102506358B1; DE102018211311A1; CN112399894A; RU2729480C1; JP7185007B2

Abstract

The invention relates to a method for producing open seam tubes from sheet panels, in particular thick sheet panels, wherein a sheet panel is fed to a tube forming press in which it is gradually formed, resting on a lower die, by a liftable and lowerable upper die, by application of a bending force, into the open seam tube that has opposite longitudinal edges for subsequent longitudinal welding with a gap, wherein an open seam tube having a non-round preform is produced by forming being carried out at least in a bending step that acts on the inner side of the sheet panel in each case on the left and the right with respect to the means predefined by the longitudinal axis of the upper die that plunges into the gradually formed sheet panel, characterized in that, for each sheet panel, the individual contour is determined, whereupon, using a geometrical model for the right-hand and left-hand side of the open seam tube, parameters are determined for support-tube positioning, in particular of the rotation angle and/or of the rotation length, and the yield strength in each side of the sheet panel is determined by an online recording and evaluation of the pressure/path profile during forming, and on the basis thereof the measure of the bending step acting on the inner side of the sheet panel in each case on the left and the right is determined.

Description

Extended regulation JCO molding press

The invention relates to a method for producing slotted tubes from metal sheets, in particular thick metal sheets, wherein a metal sheet is one

Tube form press is supplied, in which it is formed on a lower tool lying on a lifting and lowering upper tool by applying a bending force progressively to the laterally welded slot tube having a gap opposite longitudinal edges. Furthermore, the invention relates to a device for performing the method.

The pipe forming process with progressive forming or bending on pipe forming presses belongs to the process used in practice for the production of pipes from sheet metal. A tube forming or tube bending press usually has in a base frame a lower tool consisting of two supporting or bending bodies arranged next to one another at a lateral spacing, and a vertical tool that can be adjusted against the lower tool from above and is supported over the entire length by a lifting and lowering bending bar the metal sheet extending upper tool with which a bending force can be applied to the metal sheet resting on the lower tool.

For the manufacture of a pipe or large pipe according to the progressive molding process, several successive work steps are required. In a first step, the metal sheet is pre-bent on the longitudinal edges, usually in a separate edge bending press. The longitudinal edges are pre-bent so that the tube radius is evenly shaped when it is deformed into a slotted tube in the area of the subsequent seam, where the longitudinal edges of the sheet metal sheet bent over to the tube lie opposite one another for longitudinal seam welding with a gap. The sheet metal sheet pre-bent in this way is then pushed into the tube molding press and subjected to the actual bending process there. Here, by depressing the Press upper part applied a bending force to the sheet, wherein under the action of the bending sword and the upper mold tool carried by it, a deformation of the sheet is set. This process is repeated several times until the metal sheet has been formed into the slotted tube.

From DE 42 15 807 C2, a tube-bending or tube-shape press designed in frame construction has become known. The sword, which is designed as a bending tool, is guided vertically in the side stands of the frame. This upper bending tool is gimbal-mounted to a small extent on piston-cylinder units and is supported by them against the upper frame cross member. The supporting bodies of the lower bending tool are supported by a table which is also supported by piston-cylinder units which act coaxially with the upper piston-cylinder units. The opposing piston-cylinder units are designed to prevent the table from bending, even if the lower frame crossbar should bend under the workload of the press. For this purpose, more or less pressure is applied to individual piston-cylinder units.

A very problematic in the advancing molding process has been a large residual gap of the slot of about 130 to 170 mm, which is significantly influenced by the width of the blade, particularly in the case of thick-walled tubes of, for example, 40 mm, and also stresses in the slot tube. A large slot width requires high closing forces in the braze welder, and because of the high tensions in the tacked as well as residual tensions in the finished welded tube, there is a risk of a tearing tack or weld seam. If slot widths that are too large are detected, remedial measures are taken to ensure that experienced machine operators have closed the slot as far as possible by repeatedly operating the tube forming press manually. This procedure is not only time-consuming with a correspondingly reduced throughput, but also cannot be carried out with reproducible good quality. From EP 2 529 849A2, a method and a device are known in which the slotted tube is produced with a non-circular preform, in which at least one means is given on the left and right, at least in one of the means specified with respect to the upper tool, which plunges from the longitudinal axis into the progressively molded sheet metal plate on the inside of the sheet metal acting bending step, a lower molding is carried out compared to the other bending steps, whereby the finished slotted tube is formed by applying an external force to the non-circular preform in a targeted manner in the pressing force that previously formed on both sides of the center. On the device side, a lower tool designed with reversible means in its direction of rotation and a stamp which can be acted upon from outside against the positioned preform are provided for forming the sheet metal sheet into a non-circular preform and then forming it into the slotted tube.

From R 2 543 657 a manufacturing method for longitudinally welded line pipes is also known, in which the shaping of the main contour of a front pipe made of coarse rolling stock, the subsequent connection of the longitudinal side edges of the formed front pipe, the welding of tabs and the welding of these side edges in a closed position with formation a longitudinal connection seam and the expansion of the pipe produced to maintain the outer contour, and in which after the outer contour of the front pipe has been formed, its post-deformation is carried out in at least two stages, in a first stage from the starting position with the gap lying in the upper point of the circumference the side edges of the downtube are rotated by an angle of 50 to 60 ° and fixed in this position, then a pressure force is applied in the upper area of the outer surface, which is distributed evenly over the length of the downtube, which vertically displaces this area in the direction of the upstream the axis of rotation around the size D = 0.1 - 0.4 S, where S is the size of the gap between the side edges of the front tube, which arises after the main contour has been formed, the force is subsequently reduced and in the second Postforming stage a rotation of the front tube about the axis in the opposite direction by the same angle with respect to the vertical position of the gap as in the first stage, the front tube is fixed in this position, then on its upper area of the outer surface one over the entire length of the Evenly distributed compressive force is applied, which causes a vertical offset of this area in the direction of the fore-tube axis by the same size D as in the first stage, whereby if after the two post-deformation stages of the forward tube, the gap size between the side edges is larger than the maximum value permitted for this range is, further at least two post-deformation stages of the front tube, as are carried out in the first two stages.

In practice, however, it has been found that differences in the

Yield point across the metal sheet means that slightly different slotted tubes arrive in the closing press after molding. The

Slotted pipes sometimes have larger or smaller radii, which is noticeable in different slot widths. The radii can also be of different sizes on the left and right, which is problematic in that optimal operation of the closing press requires modified parameters both from tube to tube and from left to right.

The invention is therefore based on the object of creating a method and a system of the type mentioned at the outset without the disadvantages mentioned, in particular also in the case of thick-walled and small-diameter tubes, for example about 800 mm, to produce circular-cylindrical slotted tubes with reproducible quality create.

This object is achieved with a method with the features of claim 1 and with an apparatus with the features of claim 5. By deliberately creating a non-circular preform that is initially tailored with low indentation in some areas, e.g. B. is generated with a bend of 12 ° instead of a bend of 24 °, a largely circular slotted tube geometry can be formed with a minimal slit. Due to the less molded areas, the prerequisite is created that the pressure subsequently applied from outside then has a significantly more sustainable effect in these less molded areas than in the other pipe sections and results in a largely circular slotted pipe with the desired tightly closed gap. In contrast to a dependency on the experience of the machine operator, consistent quality will both improve reproducibility and increase throughput.

Two bending steps or two squeezing processes can be sufficient both for area-wise non-circular preforming and for the final or finished molding, even in the final shaping with the squeezing force applied to the left and right of the gap or slot.

According to the invention, individual turning and pressing parameters are determined for each individual tube and for the two sides of the sheet metal to be molded. For slot tubes, the individual contour should be determined in order to determine tailored parameters for slot tube positioning, in particular the angle of rotation or the turning length, based on the respective current tube position using a corresponding geometry model for the right and left side of the slot tube. In addition, according to the invention, a real-time

Evaluation of the pressure-displacement curve allows conclusions to be drawn about the current yield strength and thus the required floats for both the left and the right side of the sheet. This means that different parameters for the rotations or the press stroke are regularly used both when positioning and when pressing from tube to tube as well as left and right, only in exceptional cases and with absolutely the same yield strength of the material over the The same parameters are used for the rotations and the press stroke across the entire metal sheet.

For this purpose, measuring devices for determining the current geometry are required, which can preferably be arranged in the form of measuring robots at the pipe end in the closing presses. According to the invention, the control is intended to provide real-time output of the values calculated for displacement and pressure in order to implement a stroke control that is dependent on the yield point. In an advantageous embodiment according to the invention, an even number of steps is selected in the molding press, so that the closing can possibly only be carried out by a single pressing step. For this purpose, as already known from the prior art, the first side should be manufactured with reduced immersion depths in order to achieve out-of-roundness, but the second side is then preferably molded in like a conventional tube, in particular a round tube. Since the last step of the second side, with an even total number of steps, does not lie in the middle of the tube, but laterally offset from it, it can be implemented geometrically without the support tube striking the forming blade too strongly. In this case, the end gap should preferably not be chosen too small in order to avoid undesired contact between the shaping sword and the support tube section.

In a further preferred embodiment of the invention, an asymmetrical preform with an even number of steps can also be produced in the JCO molding press, which previously could only be done with odd forming steps.

As a result, the last forming step is no longer in the middle of the slotted tube and a collision between the edges of the slotted tube and the shaping sword can be prevented. The advantage of the invention is that in the closing process, each individual tube can be reacted to individually, ie that tailor-made rotations and Press strokes are carried out in order to achieve the most uniform possible result when the sheet metal is formed into a slotted tube. As a result, better quality is achieved overall, since slotted tubes enter the tack welding machine with a more uniform shape and correspondingly more uniform tubes are produced in the tacking process. Differences in the slotted tube contour, which could occur when using rigid machine parameters, are minimized as far as possible. A multiple pressing, as was known and necessary from the prior art, can be avoided, so that the throughput of the device according to the invention can be increased. If the asymmetrical preform is produced in the molding press with an even number of steps, the closing can possibly also be reduced to a single step.

An advantageous measure according to the invention provides that the non-round preform is positioned in the finishing step before the application of the compressive force by rotating clockwise or counterclockwise. Depending on the positioning, the compressive force is thus introduced into the non-round preform to the left or right of the slot or gap. According to a preferred proposal of the invention, the area which is less molded to the right of the center is rotated to an approximately 3 o'clock position and the area which is molded less to the left of the center to an approximately 9 o'clock position. With such a pre-positioned position of the non-circular preform on the supporting bodies of the lower tool, a maximum bending moment can be achieved for the final shaping.

The object underlying the invention is achieved with a device in that means for measuring the current geometry of the molded-in

Sheet metal are provided, which with a device for control

connected, which is able to measure online measured values for both To provide forming pressure as well as the forming path in order to be able to carry out a stroke limit-dependent stroke control.

For forming the sheet metal sheet into an out-of-round preform and then forming it into the slotted tube, a lower tool, which is designed with reversible means in its direction of rotation, and a punch which can be acted upon from the outside against the positioned preform is preferably provided.

The finished slotted tube can thus be produced starting from the sheet metal on a single tube form press or machine. The reversal of the direction of rotation allows the non-circular preform to be positioned exactly so that the pushing force comes into effect at the location of the action, namely on both sides of the slot. The bending bar of the tubular molding press can also be used to apply the compressive force from the outside to the preform. Optionally, the press can be converted with an additional stamp.

A preferred embodiment of the invention to increase the production output provides that at least one tube forming press producing a non-round preform is followed by a squeezing press which has the lower tool designed with reversible means of rotation and, as the upper tool, the punch which can be acted upon from the outside against the positioned non-round preform , In the production flow, the tube forming press, from which the non-round shape is ejected, is followed by a squeezing press, in which the non-circular preform supplied is formed into the finished slot tube in at least two successive steps, in each case to the right and left of the slot or gap , The non-circular preforming of the metal sheet can thus be carried out at a location that is independent of the final deformation to the slotted tube. According to a proposal of the invention, the rotatable means of the lower tool are designed as two rotatably driven rollers arranged at a distance from one another. The reversal of the direction of rotation of the rollers allows the non-round preform to be positioned for the final shaping with optimized force application. The course of time on the one hand in the preforming in the tubular molding press and on the other hand in the completion in the squeezing press allows a downstream squeezing press to operate two tubular molding presses.

An embodiment of the invention provides that the rotatable rollers are mounted with a suspension. The support of the non-circular preform on the lower tool of the compression press can be improved by a stationary support body provided between the rollers.

Further features and details of the invention will become apparent from the claims and the following description of an embodiment of the invention shown in the drawings on the basis of two individual presses. Show it:

Fig. 1 shows schematically the manufacture of a slotted tube according to the

Invention by producing an initially non-circular preform on a conventional tube press (a), the production of a finished slotted tube from the non-circular preform in a press press downstream of the tube press (b) and in a diagram with the dimensions as previously in Fig. 1 c shown the finished slotted tube (c) produced according to the invention;

Fig. 2 as a detail of Figure 1, the squeeze press with the non-circular preform introduced into it. 3A, 3B, the reforming or reshaping of the non-circular preform from the

Pipe shape press in at least two stages of the Press-in, in a first bending step by applying force to the non-round preform to the right of the slot or gap (FIG. 3A) and after rotating the non-round preform in a second bending step by applying force to the left of the slot or gap (FIG. 3B), represented schematically; and

4A, 4B schematically show two alternatives for producing an asymmetrical preform by means of a method according to the invention, which uses an even number of steps in the forming steps.

The shaping of a sheet metal plate 3 to form a slotted tube 104, which has a significantly smaller slit or gap 111 (cf. FIG. 1 c), is carried out on a tubular molding press 1 according to FIG. 1 a. This, however, with the proviso that in a region of the metal sheet lying on the right and left of the longitudinal axis of the bending sword 7 and thus next to the slot or gap 11, the bending step is carried out with a smaller bending of the metal sheet than in the other bending steps. There are thus defined two areas which are less molded in according to the respective bending step, as indicated in FIG. 2, so that a preform 13 which is deliberately non-circular and nevertheless tailored for the final forming is achieved.

The non-circular preform 13 thus produced in a first stage in the tube forming press 1 is, after being conveyed out or pushed out of the tube forming press 1, fed to a pressing press 14 connected in the production process, as shown in FIG. 2b. The squeeze press 14 has a lower tool 15 which consists of two rollers 16a, 16b, which are provided at a distance from one another and are reversible in their direction of rotation, as indicated by the double arrows in FIG. 2b, and a stationary roller bridging the distance between the rollers 16a, 16b Support body 17 exists. The rotatable rollers 16a, 16b can be supported by a spring means 18 (cf. FIG. 3). The lower tool 15 An upper tool 20 formed with a stamp 19 is arranged opposite. The pressing force for producing the finished, largely circular slotted tube 104 is applied to the non-circular preform 13 from the outside via the stamp 19.

For this purpose, the non-round preform 13 is positioned via the rotatable rollers 16a, 16b in such a way that the less molded area 12b to the right of the slot or gap 11 is in a 3 o'clock position, as in FIG. 3 by the dot-dash line , horizontal line indicated

The sequences of this first pressing-bending step are shown in FIG. 3A, starting from left to right with the non-circular preform 13 positioned, the application of the pressing force by the stamp 19 and the stamp 19 lifted off after the force has been applied.

The second squeeze-bend step is illustrated in Fig. 3B in the same order as before. In order to optimize the bending moment, the preform 13, which is here non-circular in its left half, has been positioned in such a way that the area 12a less molded to the left of the slot or gap 11 assumes a 9 o'clock position. The pressing force F (middle figure) now applied by the stamp 19 on this side of the preform 13 then brings the non-round preform 13 into the final, largely circular shape of the finished slotted tube 104 with the significantly smaller slit or gap 111 achieved thereby (Fig right outside).

FIGS. 4A and 4B show the production of asymmetrical preforms with an even number of steps (FIG. 4B) or an odd number of steps (FIG. 4A). In FIG. 4A, with 21 steps, ie 21 forming processes, a so-called potato shape is introduced onto the metal sheet 3 by means of the bending sword 7, a so-called potato shape on the side A and a round half-shape on the side B in the metal sheet 3. While the so-called potato shape on side A does not collide with the sheet metal plate 3 and the bending bar 7 causes, the sheet metal plate 3 abuts the bending bar 7 on side B, into which a substantially round shape has been introduced into the sheet metal plate 3. FIG. 4B illustrates the advantage of having an asymmetrical preform with 20 steps, ie an even number of steps. Neither on side A, in which a so-called potato shape was introduced into sheet metal 3, nor in side B, which was formed into a substantially round preform by means of shaping sword 7, does sheet metal 3 collide with shaping sword 7, because the last forming step along the dash-dotted line 21, thus laterally offset to the center of the tube, takes place. In this way, a strong impact of the slotted tube 4 against the sword 7 can be avoided. As a result, the last forming step is no longer in the middle of the slotted tube 4 and a collision between the edges of the slotted tube 4 and the sword 7 can be prevented.

LIST OF REFERENCE NUMBERS

1 tube form press

2 edge bending

3 sheet metal

4; 104 slotted tube

5a, 5b support body

6 lower tool

7 bending sword

8 molding tool

9 upper tool

10a, b counterholders

1 1; 1 1 1 slot / gap

12a, b less molded areas

13 non-circular shape

14 squeeze press

15 lower tool

16a, b rotatable rollers

1 7 support body

18 spring means

19 stamps

20 upper tool

21 dash-dotted line

Claims

claims:

1. A method for producing slotted tubes (4; 104) from metal sheets (3), in particular thick metal sheets, wherein a metal sheet is one

Tube form press (1) is supplied, in which it rests on a lower tool (6) lying on a lifting and lowering upper tool (9) by applying a bending force progressively to the longitudinal edges opposite to a later longitudinal seam welding with a gap (11; 111) having slotted tube (4; 104) is formed, a slotted tube having an out-of-round preform (13) being produced in each case by means of at least one means predetermined in relation to the upper tool (9) immersed in the longitudinal axis of the progressively molded metal sheet (3) a molding is carried out on the left and right on the inside of the sheet metal plate (3), characterized in that

The individual contour is determined for each sheet of metal, whereupon using a geometry model for the right and left side of the slotted tube, parameters for supporting tube positioning, in particular the angle of rotation and / or the length of rotation, as well as by online recording and evaluation of the pressure During the forming process, the yield point is determined on each side of the sheet and the dimension of the bending step acting on the inside and left of the sheet is determined.

2. The method according to claim 1,

characterized,

that the finished slotted tube is subsequently formed by applying a pressing force which acts on the non-circular preform from the outside in a targeted manner in the areas previously formed on both sides of the center.

3. The method according to claim 1 or 2,

characterized in that

the non-circular preform (13) in the finishing stage before application of the pressing force (F) by turning clockwise or in

Is positioned counterclockwise.

4. Device for setting slotted tubes (4; 104) from sheet metal sheets (3), in particular thick sheet metal sheets, a sheet metal sheet being fed to a tube forming press (1) in which it is placed on a lower tool (6;

15) lying on top of a liftable and lowerable upper tool (9) by applying a bending force progressively to the slot tube (4; 104) having opposite edges for later longitudinal seam welding with a gap (11; 111), in particular for carrying out the method according to one of the claims

1-3, where

for forming the metal sheet (3) into a non-circular preform (13) and then forming it into the slotted tube (104), a lower tool (15) designed with reversible means in its direction of rotation and a punch (19) which can be acted upon from the outside against the positioned preform (13) ) is provided,

characterized in that

that means for measuring the current geometry of the molded sheet metal plate (3) are provided, which are connected to a device for control, which is able to provide values measured online for both the forming pressure and the forming path, in order to thereby carry out a stroke limit-dependent stroke control to be able to.

5. The device according to claim 4,

characterized in that the control is designed to control each individual forming step of the metal sheet separately.

6. The device according to claim 4 or 5,

characterized,

that at least one tube forming press (1) producing an out-of-round preform (13) is followed by a squeezing press (14) which presses the lower tool (15), which is designed with reversible direction of rotation, and as the upper tool (20) the non-round preform (20) 13) has actable stamp (19).

7. Plant according to one of claims 4 to 6,

characterized,

that the lower tool (15) has two rotatably driven rollers (12a, 12b) which are arranged at a distance from one another and one between the rollers

(12a, 12b) provided support body (17).

8. Plant according to claim 7,

characterized,

that the rollers (12a, 12b) are supported by a spring means (18).