CN112399894B

CN112399894B - Extensionally adjusting JCO molding press

Info

Publication number: CN112399894B
Application number: CN201980046232.1A
Authority: CN
Inventors: M·托默
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2018-07-09
Filing date: 2019-07-09
Publication date: 2023-08-04
Anticipated expiration: 2039-07-09
Also published as: JP2021524382A; KR102506358B1; JP7185007B2; DE102018211311B4; CN112399894A; EP3820631A1; WO2020011772A1; DE102018211311A1; KR20210014147A; EP3820631B1; RU2729480C1

Abstract

The invention relates to a method for producing a slotted tube from a sheet material, in particular a thick sheet material, wherein the sheet material is fed to a tube moulding machine, in which the sheet material is placed on a lower die and is progressively formed into a slotted tube by applying bending forces from a liftable and lowerable upper die, which slotted tube has opposite longitudinal edges with a gap for subsequent longitudinal slot welding, wherein the slotted tube is produced from a non-circular preform, for which purpose a device predetermined at least with respect to the longitudinal axis of the upper die immersed in the progressively deformed sheet material is deformed in a bending step on the left and right side, respectively, against the inner side of the sheet material, characterized in that an individual profile is determined for each sheet material, and then parameters for supporting tube positioning, in particular the angle of rotation and/or the length of rotation, are determined for the right and left side of the slotted tube using a geometric model, and the yield limit in each side of the sheet material is determined by online registration and evaluation of the pressure-path profile at the time of deformation, and thereafter the degree of the bending step on the left and right side, respectively, against the sheet material.

Description

Extensionally adjusting JCO molding press

Technical Field

The invention relates to a method for producing a slotted tube from a sheet metal, in particular a thick sheet metal, wherein the sheet metal is fed to a tube molding press, in which the sheet metal is placed on a lower die and is progressively formed into a slotted tube by a lifting and lowering upper die by applying a bending force, the slotted tube having opposite longitudinal edges with a slot for subsequent longitudinal seam welding. The invention also relates to a device for carrying out the method.

Background

The method applied in practice for manufacturing tubes from sheet material comprises a tube forming and moulding process with progressive deformation or bending steps on a tube moulding press. Pipe forming or bending presses generally have a lower die and an upper die in a frame, the lower die being formed by two support or bending bodies arranged side by side with lateral spacing, and the upper die being vertically adjustable from above towards the lower die, being carried by a bending insert plate which can be raised and lowered, extending over the entire length of the sheet material, bending forces being applied to the sheet material placed on the lower die by the upper die.

In order to produce a tube or large tube according to a progressive forming process, a plurality of successive working steps are required. In a first step, the sheet is pre-bent at the longitudinal edges, typically in a separate edge bending press. The pre-bending of the longitudinal edges takes place in order to form the tube radius uniformly in the subsequent seam region, in which the longitudinal edges of the sheet metal bent into the tube lie opposite one another, when the slotted tube is formed, for longitudinal seam welding with a slit. This pre-bent sheet is then pushed into a tube molding press and subjected to the actual bending process. In this case, a bending force is applied to the sheet material by pressing down on the upper part of the press, wherein the shaping of the sheet material is adjusted by the insert plate and the upper die carried thereby during bending. This process is repeated several times until the sheet becomes a slotted tube.

A tube bending or tube moulding machine implemented in a frame structure is known from DE4215807C 2. The intermediate plate, which is configured as a bending die, is guided vertically in the side brackets of the frame. The upper bending die is movably fixed to the piston cylinder unit with a low degree of universal joint and is thereby supported on the upper frame cross member. The support body of the lower bending die is likewise carried by the table, which is supported by a piston cylinder unit, which acts coaxially with the upper piston cylinder unit. The interacting piston cylinder units should prevent the table from bending even if the lower frame rail is bent under the working load of the press. For this purpose, more or less pressure is applied to the individual piston-cylinder units.

The large residual gaps and stresses in slotted tubes, which are mainly influenced by the width of the insert plate, in particular remain in thick-walled tubes, for example 40mm, of openings of about 130mm to 170mm, have proven to be very problematic in progressive forming processes. The large opening width requires a high closing force to be applied in the tack welding device and there is a risk of the tack or weld tearing due to high stresses in the tack welded tube and residual stresses in the finished welded tube. A remedy is provided when an excessive opening width is identified, i.e. an experienced machine operator closes the opening as much as possible by manually repeatedly manipulating the tube molding press. This process is not only time-consuming and correspondingly reduces the throughput, but furthermore cannot be carried out with reproducible good quality.

A method and a device are known from EP 2 529 849 A2, in which a slotted tube is produced from a non-round preform, in which at least in the bending step, which is effected on the left and right sides respectively with respect to the longitudinal axis of an upper die immersed in a progressively deformed sheet material, a smaller deformation is effected with respect to the other bending steps, wherein the finished slotted tube is formed by applying a pressing force on the non-round preform from the outside in the above-mentioned regions of smaller deformation on both sides respectively in a targeted manner. In terms of the apparatus, in order to deform the sheet material into a non-round preform and then into a slotted tube, a lower die configured with means reversible in its rotational direction and a die loadable from the outside toward the positioned preform are provided.

Furthermore, a method for producing a catheter for longitudinal seam welding is known from R2 543 657, in which method a main contour of a preformed tube is formed from a roughing piece, then longitudinal side edges of the formed preformed tube are joined, in a closed position the projections are welded and the side edges are welded together and the produced tube is expanded in order to obtain an outer contour, and in which method, after the formation of the outer contour of the preformed tube, reshaping of the preformed tube is carried out in at least two stages, wherein, in a first stage, the slits in the points on the circumference of the side edges of the preformed tube are rotated by an angle of 50 ° to 60 ° from an initial position and are fixed in this position, then a pressure which is uniformly distributed over the length of the preformed tube is applied in an upper region of the outer surface, which pressure causes a vertical offset of this region in the direction of the tube axis prefabricating line to be Δ0.1 to 0.4s, wherein S is the size of the slit between the side edges of the preformed tube, which after the main contour is formed, and in a second stage the slit is reduced and in the opposite direction to the maximum value in the direction of the prefabricating line, the vertical offset of this region is allowed to be uniformly distributed over the length of the preformed tube in the same direction in the first stage, and then the same amount of the vertical offset is applied in the opposite direction to the prefabricating tube in the first stage to the vertical offset of the region in the same direction, at least two further reforming stages of the preformed tube are performed as in the first two stages.

However, it has been demonstrated in practice that differences in the yield limits of the sheet material lead to slightly different slotted tubes in the closing press after moulding. The slotted tube has a partially larger or smaller radius, which is evident in different opening widths. However, the radius may also be not equally large on the left and right, which is problematic, since optimal operation of the closing press requires matched parameters between the tubes and from left to right.

Disclosure of Invention

The object of the present invention is therefore to provide a method and a device of the initially mentioned type but without the disadvantages mentioned, in particular also for thick-walled tubes of small diameter, for example of the order of 800mm, simply providing for the production of cylindrical slotted tubes with reproducible quality.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 5.

Thus, by deliberately producing a first tailored non-circular preform that has a slight deformation locally, for example a 12 ° bend, instead of a 24 ° bend, a maximally right circular slotted tube geometry with minimal openings can be formed. As a result, the pressure applied from the outside has a significantly longer lasting effect in the region of smaller deformations than in the other tube sections, and as a result a maximally circular slotted tube with a desirably more tightly closed gap is produced, as a result of this, as a result of the smaller deformed regions. Unlike reliance on the experience of the machine operator, consistent quality improves repeatability and increases productivity.

For partial non-circular preforming and final or finished forming, two bending steps or two pressing processes may be sufficient, i.e. pressing forces are applied to the left and right of the slit or opening, respectively, for the final forming.

According to the invention, the respective rotation and pressurization parameters are determined for each individual tube and for the respective two sides of the sheet to be deformed. The respective contour is determined for the slotted tube in order to determine, by means of a corresponding geometric model, for the right and left side of the slotted tube, starting from the corresponding current tube position, customized parameters for the slotted tube positioning, in particular the angle of rotation or the length of rotation. Furthermore, according to the invention, the current yield limit and thus the travel required on the left and right side of the sheet can be deduced by evaluating the pressure path profile in real time. Thus, in the positioning and pressurization of the tubes and on the left and right, different parameters are generally used for the rotation or pressurization stroke, with the exception of only the same parameters being used for the rotation or pressurization stroke over the entire sheet material and with the yield limit of the material being absolutely the same.

For this purpose, a measuring device for determining the current geometry is required, which can be arranged preferably in the form of a measuring robot at the tube end of the closing press. According to the invention, the control provides a real-time output of the values calculated for the path and the pressure in order to achieve a stroke adjustment in relation to the yield limit.

In an advantageous embodiment according to the invention, an even number of steps are selected in the molding press, so that the closing can be effected if necessary by only a single pressing step. For this purpose, the first side is produced with a reduced immersion depth, as is known from the prior art, in order to achieve out-of-roundness, whereas the second side is preferably deformed as a conventional tube, in particular a round tube. Since the last step on the second side is not in the middle of the tube but laterally offset from it in the case of an even number of total steps, the geometric operability is achieved without the support tube being severely impacted by the insert plate in the deformation. In this case, the end gap should preferably not be selected too small in order to avoid undesired contact of the insert plate and the support tube section during deformation.

In a further preferred embodiment of the invention, it is likewise possible to produce asymmetrical preforms in the JCO molding press with an even number of steps, which has been possible to date only with an odd number of deformation steps. The final deformation step is therefore no longer in the middle of the slotted tube and a collision between the edges of the slotted tube and the insert plates during deformation can be prevented.

The advantage of the invention is that each individual tube can be influenced individually during the closing process, i.e. a customized turning and pressing stroke is performed in order to achieve as uniform a result as possible when the sheet material is deformed into a slotted tube. Better quality is thus achieved overall, since the slit pipe enters the seam welder in a uniform shape and a correspondingly more uniform pipe is produced in the tack welding process. The differences in the profile of the slotted tube, which can occur, for example, when using a constant machine parameter, are minimized to the greatest extent. As is known and necessary in the art, multiple pressurization can be avoided, thereby improving the yield of the device according to the invention. If asymmetrical preforms are produced in the molding press in an even number of steps, the closing may also be reduced to a single step if necessary.

According to an advantageous measure of the invention, it is provided that the non-round preform is positioned by rotation in the clockwise direction or in the counterclockwise direction before the application of the pressing force in the completion of the production step. Depending on the positioning, the pressing force is therefore introduced into the non-round preform to the left or right next to the opening or slit.

According to a preferred proposal of the invention, the area less deformed on the right of the middle is turned to about 3 o 'clock and the area less deformed on the left of the middle is turned to about 9 o' clock. In this pre-positioned position of the non-round preform on the support of the lower die, a maximum bending moment can be achieved for the final shaping.

The object on which the invention is based is achieved by a device which is provided with means for measuring the current geometry of the deformed sheet material, which means are connected to a device for controlling, which device can provide values for online measurement of the deformation pressure and the deformation path, so that a stroke adjustment in relation to the yield limit can thus be carried out.

Preferably, in order to deform the sheet material into a non-round preform and then into a slotted tube, a lower die configured with means reversible in its rotational direction and a die loadable from the outside towards the positioned preform are provided.

Thus, finished slotted tubes can be produced starting from a sheet material on only one tube molding machine or machine. In this case, the reversal of the direction of rotation allows precise positioning of the non-round preform, so that the pressing force acts on site, i.e. on both sides of the opening. The insert plate in the bending of the tube molding machine can also be used for applying a pressing force to the preform from the outside. Alternatively, the press may be equipped with a press die.

The preferred embodiment of the invention for increasing the throughput provides that, after at least one tube molding press for producing non-round preforms, a compression press is connected, which has a lower die which is designed with a device that can be reversed in its rotational direction and a die as an upper die which can be loaded from the outside toward the positioned non-round preform. In the production process, a compression press is therefore coupled to the tube molding press from which the non-round shaped part is pushed out, in which the transported non-round shaped part is deformed into a finished slotted tube at least in two successive steps, right and left, respectively, next to the opening or slit. Thus, non-circular preforming of the sheet material may be performed at a location unrelated to the final forming into a slotted tube.

According to the proposal of the invention, the rotatable means of the lower die are configured as two rollers which are arranged at a distance from one another and can be driven in rotation. The reversible direction of rotation of the rollers allows positioning of non-round preforms for final shaping with optimal force introduction. The time profile at the time of preforming in the tube moulding press on the one hand and the time profile at the time of finishing in the compacting press on the other hand allow the downstream compacting press to serve two tube moulding presses.

The embodiment of the invention provides that the rotatable roller is supported by a spring. The support of the non-round preform on the lower die of the compaction press can be improved by a stationary support body arranged between the rollers.

Drawings

Further features and details of the invention result from the claims and the following description of embodiments of the invention which are shown in the figures on the basis of two separate presses. Wherein,,

figure 1 (a) schematically illustrates the manufacture of a slotted tube according to the present invention by producing a preform that is first tailored to be non-circular on a conventional tube molding press,

FIG. 1 (b) shows the production of a final slotted tube from a non-round preform in a compaction press placed downstream of the tube moulding press, and

fig. 1 (c) shows in a schematic view a finished slotted tube manufactured in accordance with the present invention in the dimensions as previously shown in fig. 1 c;

fig. 2 shows, as a detail of fig. 1, a compacting press with a non-round preform introduced therein;

fig. 3A, 3B schematically show the reshaping or deforming of a non-round preform from a tube moulding press in at least two bending steps of the press, i.e. in a first bending step by force loading the non-round preform to the right beside the opening or slit (fig. 3A) and after turning the non-round preform in a second bending step by force loading to the left beside the opening or slit (fig. 3B); and is also provided with

Fig. 4A, 4B schematically show two alternatives for producing an asymmetric preform by means of the method according to the invention, which method utilizes an even number of deforming steps.

Detailed Description

According to fig. 1a, the sheet material 3 is deformed on a tube molding machine 1 into a slotted tube 104, which has a significantly smaller opening or slot 111 (see fig. 1 c). However, this has the condition that a bending step is performed in the region of the sheet material, respectively around the longitudinal axis of the bending insert plate 7 and beside the opening or slit 11, which bending step causes a smaller bending of the sheet material than the remaining bending steps. Thus, there are defined two regions which are less deformed corresponding to the respective bending step, as illustrated in fig. 2, so that a targeted non-round preform 13 is achieved, but which is still tailored for the final deformation.

Such non-round preforms 13 produced in the first stage in the tube moulding machine 1 are fed after being output or removed from the tube moulding machine 1 to a pressing press 14 which is arranged downstream in the production process, as is shown in fig. 2 b. The pressing press 14 has a lower die 15, which is formed by two driven rollers 16a, 16b and a stationary support 17, the rollers 16a, 16b being arranged at a distance from one another and being reversible in terms of their direction of rotation, as is shown by the double arrow in fig. 2b, the support 17 bridging the distance between the rollers 16a, 16 b. The rotatable rollers 16a, 16b may be supportably supported by spring means 18 (see fig. 3). Disposed opposite the lower die 15 is an upper die 20 formed by a die 19. A pressing force is applied from the outside to the non-round preform 13 by means of the die 19 in order to produce the final slotted tube 104 which is as round as possible.

For this purpose, the non-round preform 13 is positioned by the rotatable rollers 16a, 16b in such a way that the less deformed region 12b to the right next to the opening or slit 11 is in the 3 o' clock position, as is shown by the horizontal dash-dot line in fig. 3.

In fig. 3A, the course of the first press-bending step is shown, i.e. starting from left to right with a positioned non-circular preform 13, applying a pressing force through the die 19 and lifting the die 19 after the introduction of the force.

The second press-bending step is shown in fig. 3B in the same sequence as before. In order to optimize the bending moment, the non-round preform 13, which is unchanged in the left half thereof, is positioned in such a way that the region 12a, which is less deformed to the left next to the opening or slit 11, takes up the 9 o' clock position. At this point, the pressing force F (middle picture) now applied by the die 19 on this side of the preform 13 causes the non-round preform 13 to take on the final maximally circular shape of the finished slotted tube 104, which has a significantly smaller opening or slit 111 (outer right picture) realized here.

Fig. 4A and 4B illustrate the production of an asymmetric preform with an even number of steps (fig. 4B) or an odd number of steps (fig. 4A). In fig. 4A, a so-called potato-shaped shape is introduced into the sheet 3 on side a and a semicircular shape is introduced into the sheet 3 on side B by means of a curved intermediate plate 7 acting on the sheet 3 in 21 steps, i.e. 21 deformation processes. The so-called potato shape at side a does not cause a collision of the sheet material 3 with the bent intermediate deck 7, whereas at side B (where a substantially circular shape is introduced into the sheet material 3) the sheet material 3 collides with the bent intermediate deck 7. The advantage of manufacturing an asymmetric preform in 20 steps, and thus an even number of steps, is illustrated in fig. 4B. No collision of the sheet material 3 with the deforming insert plate 7 occurs, either with the so-called potato-shaped shape being introduced into the side a of the sheet material 3 or with the deforming insert plate 7 into the side B of the substantially circular preform, since the final deforming step is carried out along the dash-dot line 21 and is thus laterally offset from the tube centre. The violent collision of the slotted tube 4 with the intermediate plate 7 is thereby avoided. The final deformation step is therefore no longer in the middle of the slotted tube 4 and a collision between the edge of the slotted tube 4 and the intermediate plate 7 can be prevented.

List of reference numerals

1. Pipe molding press

2. Edge bending portion

3. Plate material

4, a step of; 104. slotted pipe

5a,5b support

6. Lower die

7. Bending middle plugboard

8. Mould

9. Upper die

10a, 10b mating bracket

11; 111. openings/slits

12a, 12b of lesser deformation

13. Non-circular shape

14. Compacting press

15. Lower die

16a, 16b rotatable tube

17. Support body

18. Spring device

19. Stamping die

20. Upper die

21. Dot-dash line

Claims

1. A method for producing a slotted tube (4; 104) from a sheet metal part (3), wherein the sheet metal part is fed to a tube molding press (1), in which the sheet metal part is placed on a lower mold (6) and is progressively formed into a slotted tube (4; 104) by applying a bending force from a lifting and lowering upper mold (9), which has opposite longitudinal edges with a gap (11; 111) for subsequent longitudinal seam welding,

the slotted tube is produced from a non-round preform (13), for which purpose at least the means predetermined with respect to the longitudinal axis of the upper die (9) immersed in the progressively deformed sheet material (3) are deformed in a bending step acting on the inside of the sheet material (3) on the left and right, respectively,

it is characterized in that the method comprises the steps of,

for each sheet material, a respective contour is determined, then, with the use of geometric models for the right and left sides of the slotted tube, parameters for the slotted tube positioning are determined, and the current geometry of the deformed sheet material (3) is measured, and the yield limit in each side of the sheet material is determined by online recording and evaluation of the pressure-path course at deformation, and thereafter, the extent of the bending step, which acts on the inner side of the sheet material on the left and right sides, is determined, and in the finishing phase, the non-round preform (13) is positioned by rotation in the clockwise or counterclockwise direction before the application of the pressing force (F).

2. The method according to claim 1, characterized in that the parameter is the angle of rotation and/or the length of rotation.

3. Method according to claim 1 or 2, characterized in that the final slotted tube is then formed by applying a pressing force which acts from the outside on the non-round preform in a region of less deformation on both sides of the front middle part, respectively.

4. Device for producing a slotted tube (4; 104) from a sheet material (3) for carrying out the method according to any one of claims 1 to 3, wherein the sheet material is fed to a tube moulding machine (1) in which the sheet material is placed on a lower mould (6; 15) and progressively transformed by a liftable and lowerable upper mould (9) into a slotted tube (4; 104) by applying a bending force, the slotted tube having opposite longitudinal edges with a slit (11; 111) for subsequent longitudinal seam welding, wherein,

in order to deform the sheet material (3) into a non-circular preform (13) and then into a slotted tube (104), a lower die (15) comprising means reversible in its direction of rotation and a die (19) which can be loaded from the outside towards the positioned preform (13) are provided,

the device is characterized in that means for measuring the current geometry of the deformed sheet material (3) are provided, which means are connected to a device for controlling which can provide values for online measurement of the deformation pressure and deformation path, in order to be able to implement a stroke adjustment in relation to the yield limit accordingly.

5. The device according to claim 4, characterized in that the means for controlling are designed to control each individual deformation step of the sheet material individually.

6. The device according to claim 4 or 5, characterized in that a compacting press (14) is connected after at least one tube moulding press (1) producing non-round preforms (13), which compacting press has a lower die (15) comprising means reversible in its rotational direction and a die (19) as an upper die (20) that can be loaded from the outside towards the positioned non-round preform (13).

7. Device according to claim 4 or 5, characterized in that the lower die (15) comprises two rollers (12 a, 12 b) arranged at a distance from each other and which can be driven in rotation and a support body (17) arranged between the rollers (12 a, 12 b).

8. The device according to claim 7, characterized in that the rollers (12 a, 12 b) are supported by means of springs (18).