WO2015024644A1

WO2015024644A1 - Shaping mould and forming device with a shaping mould and method for producing and bending hollow profiles

Info

Publication number: WO2015024644A1
Application number: PCT/EP2014/002232
Authority: WO
Inventors: Michael Hoffmann; Hans-Joachim Koriath; Alexander Pierer
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2013-08-19
Filing date: 2014-08-13
Publication date: 2015-02-26
Also published as: DE102013013762A1; DE102013013762B4

Abstract

The invention relates to a shaping mould for shaping a hollow profile, in particular a pipe, from a longitudinal profile, such as an un-shaped metal plate or sheet, by means of a pressure jacket, wherein the shaping mould has a pressure chamber, which is at least partially defined by the pressure jacket, wherein the stretching and tensioning of the pressure jacket for shaping the hollow profile can be set by setting the internal pressure in the pressure chamber by means of feeding a pressure medium into the pressure chamber and/or removing it from the pressure chamber while taking into account the deformation of the hollow profile, and also relates to forming devices for producing and bending pipes that use such a shaping mould and also to methods for producing and bending hollow profiles by using the shaping mould with the pressure jacket.

Description

Mold and forming device with mold and method for

Manufacture and bending of hollow sections

The invention relates to a molding tool, in particular a forming mandrel, with a bendable deformable pressure jacket for molding a hollow profile, and a forming device with the mold for producing and bending hollow sections, in particular longitudinally welded pipes, as well as associated methods for producing and bending hollow sections, in particular of tubes ,

Vehicle development is increasingly focusing on lightweight construction concepts for load-bearing structures and components for the transmission of forces and torques. In particular, components based on closed, longitudinally welded hollow profiles, which consist of high-strength materials and / or tailored blanks (tailored blank = sheet metal of different material grades and sheet thicknesses) have been produced, allow a significant weight savings with consistent or improved mechanical properties as hollow sections, not from such materials have been formed.

Both in the production of closed longitudinally welded longitudinal profiles in an unbent state, such as a circuit board or a sheet metal, as well as in the bending of tube-like semi-finished products, the control of dimensional and form deviations is problematic.

From the general state of the art for producing longitudinally welded hollow profiles spatially separated devices for forming the sheet and the welding are known.

A method with spatially separated forming and welding apparatus for producing longitudinally welded hollow profiles is generally known as three-roll round bending. In this method, a sheet is bent between a work roll and two back-up rolls. The bend radius can be varied by changing the relative position of the rolls. By a driven rotation of one of the rollers, the sheet can be conveyed in the direction of the profile circumference. As a result, a cross section with variable bending radii can be produced. The technically feasible field of application of this method is limited to tubes with a diameter greater than 30 mm and tube lengths of up to 2000 mm with low forming forces compared to other methods. The reason for this is that the support and work rolls bend due to the forming forces to be applied. This fact already leads to dimensional and form deviations within the mentioned technical application limits, make this manufacturing process for numerous automotive components appear to be unsuitable. Another significant disadvantage is that in this method the profile for welding must be transported in a separate welding device.

US Pat. No. 2,110,378 A describes a combined forming and welding apparatus for producing hollow profiles of round or oval cross section, commonly known as roll forming. When roll forming a sheet passes through several successively arranged profile rollers, which gradually bend the sheet to a slot profile. A disadvantage of this method is that it may come to the formation of longitudinal grooves and scratches due to the relative movement between the sheet and the profile rollers. Since the profile is guided only from the outside through the profile rollers, it comes to significant dimensional and form deviations. Downstream drawing and calibration devices remain required accordingly.

DE 966 1 11 describes a device with combined forming and welding device. The forming device has two on a common carrier mirror-symmetrically arranged mold halves for forming a sheet and for welding the sheet longitudinal edges of the bent sheet metal. The respective inner sides of the mold halves in the pressing direction have a semicircular recess which determines the outer contour of the profile to be produced. In the closed final state of the mold halves, the sheet longitudinal edges face each other and form an O-shaped slot profile. A major disadvantage of this device is that the sheet can buckle during forming. Especially with thin sheets, the risk of buckling is particularly great. Similarly, the sheet can not be pressed from the inside against the molds to calibrate the shape of the sheet against the inner contour of the mold halves.

A major disadvantage of such solutions is the low cycle time and the high technical complexity, resulting essentially from the transport of the semi-finished products to be formed between the forming and welding device. In addition, the exact alignment of the joint gap to be welded of the deformed hollow profile when inserting into the welding device is designed to be technically complex and cause for dimensional and form deviations in the finished profile and quality deviations of the weld.

Although downstream drawing or calibrating reduce the dimensional and shape deviation, however, thereby increasing the economic and technical effort considerably.

In addition, most known drawing and calibration devices provide for gripping the reshaped hollow profile at one end and passing it through a calibration matrix or via a calibration matrix To pull or press the calibration mandrel. In this case, the front side of the hollow profile is damaged, and must then be separated. The resulting waste increases the required material use and reduces the profitability of the manufacturing process.

DE 44 32 674 C1 describes a method with spatially separated forming and welding device. In the device described therein, a slot profile manufactured in another device is held in welding position by a plurality of drawstrings. The position of the gap is defined by a gap centering that can be lowered into the joint gap. The welding device for welding the profile can be moved along the joining gap. The device is only suitable for relatively thin-walled profiles with large diameter. In addition, the device is used exclusively for precise clamping and alignment of an already formed hollow profile during welding.

DE 593 622 describes a device for producing conical profiles and has two mold halves. In addition, a forming mandrel is arranged between the mold halves to support the sheet from the inside. The mandrel is designed as a rigid and massive construction. Due to the rigid design of the mandrel, the surface quality can be affected by grooves and scratches on withdrawal of the mandrel from the hollow profile.

DE 73 24 077 U describes a device for producing a hollow profile from an unshaped sheet metal, wherein the sheet is bent by means of mold halves to a rigid, expandable mandrel, so that a slot profile is formed. The joint gap of the slot profile is welded after molding. Inside the forming mandrel is a guide rod to which a plurality of axially displaceable cone rings are mounted. Between each two adjacent conical rings elastic spreading elements are arranged, which carry a longitudinally slotted jacket of the mandrel. By a displacement of the guide rod, the spreading elements are moved in the radial direction due to the wedge effect of the cone rings. Since the radial expansion is transmitted by the guide rod as a central control element, a locally gradual adjustment of the radial strain and forming force is not possible and deviations in the joint gap may result.

WO 99/67037 A1 describes a device for producing hollow profiles from sheet metal, which has devices for forming and for welding. The forming device has mold halves with a recess, which determine the outer contour of the profile. When moving together the mold halves is an intermediate sheet to reshaped a slot profile. To avoid kinking of the sheet during forming, each recess of the mold halves is associated with an inner mandrel half. The inner mandrel halves are fixedly mounted, leaving a gap to the respective associated mold, so that when the molds have moved together, a gap is provided between the respective mandrel half and the associated mold half. The problem with this device is that it comes within the gap to a relative movement between the sheet and the tool, whereby the quality of the sheet surface is significantly reduced by grooving and scratching. In addition, the removal of the welded profile designed as difficult, since technically complicated drawbars and fixtures for the mandrel are necessary. Due to the rigid executed mandrel halves targeted pressing of the sheet in the radial direction is not possible.

DE 10 2004 046 687 B3 describes an apparatus for producing hollow profiles from sheet metal, which has a device for forming and for welding. A sheet is bent by the collapse of external forming tools to a rigid mandrel, whose outer contour determines the inner contour of the profile to be generated. In this case, the collapse takes place in stepped steps, wherein a bending of the sheet during forming is initially accepted. By bending the sheet first creates a slot profile with polygonal cross-section. In the following steps, the outer forming tools move in a finely-controlled manner in position-controlled manner against the inner forming mandrel, whereby the polygonal sheet-metal profile is pressed round and calibrated against the outer contour of the forming mandrel. Due to the rigid mandrel, the surface quality can be affected by grooves and scratches when pulling out the dome from the profile.

For pipe bending numerous solutions for pipe bending machines are known. From industrial practice, it is known that the pipe material is compressed in the inner radius of the bend and thereby tends to form wrinkles and kinks. At the same time the pipe material is stretched at the outer radius, whereby the sheet is thinned out. To counteract both wrinkling and buckling and thinning, many known tube bending machines and methods use a forming mandrel which supports the tube from the inside. The mandrel reduces the risk of thinning and wrinkling. In addition, the mandrel guides and centers the tube during bending, which has a positive effect on the achievable precision of bending.

DE 10 2008 003 442 B4 describes a mandrel device for insertion into a tube, which during bending can flexibly support the inner wall of the tube. The spine device has several anchor shoes arranged about a central cam bar. By axial relative movement between the cam bar and the anchor shoes, the anchor shoes slide radially outward along the contact surface with the cam bar. The outer surface of the anchor shoes presses against the inner wall of the tube. The disadvantage is that due to the fixed mechanical translation between the axial movement of the cam rod and the radial extension of the anchor shoes no locally graded clamping force profile can be adjusted. Furthermore, the force at the contact point between mandrel and pipe is not designed metrologically accessible. The contact force can therefore be estimated at best only on the basis of the mechanical transmission ratio of the arrangement and the load of the drive unit. An exact control of the clamping force, based on actual measured values, is therefore not possible.

DE 30 00 170 C2 describes a mandrel for a pipe to be bent. The mandrel has wedge members and spreading elements, which are lined up alternately and loosely on a steel cable. By pulling on the steel cable, the spreader slides along the wedge members to the outside and press against the pipe interior, whereby the risk of kinking and wrinkling is reduced. With this device, the clamping force can not be locally graded and metrologically detected, whereby an exact control of the clamping force is not possible. In addition, due to its flexibility of this device only useful for relatively low forming forces.

An object of the invention is to improve the precision in the manufacture of hollow sections, so that the number of drawing and calibrating devices previously required for the exact setting of the profile cross-section can be reduced or possibly completely dispensed with additional drawing and calibration devices.

Another object of the invention is to provide a molding tool, in particular a forming mandrel, and a shaping tool with the method and with which hollow profiles can be produced which are of high quality, in particular without surface damage, wherein a controllable readjustment of the mold for calibration of the high profile is possible.

Another object of the invention is to provide a molding tool, in particular a molding tool, which is applicable for use in forming devices for hollow profiles, such as bending and rolling devices, whose outer and / or inner circumference is adjustable taking into account the deformation of the tube. The above objects are achieved with a mold with the features of claim 1 according to the invention. Advantageous embodiments will be apparent from the dependent claims.

According to one aspect of the invention, there is provided a molding tool for molding a hollow profile by means of a pressure jacket, in particular a pipe, made up of a longitudinal profile such as an unshaped blank or sheet, the molding tool having a pressure chamber at least partially defined by the pressure jacket by adjusting the internal pressure in the pressure chamber, the elongation and clamping force of the pressure jacket for forming the hollow profile by supplying and / or discharge of a pressure medium in the pressure chamber is adjustable taking into account the deformation of the hollow profile. This has the advantage that the material flow in the respective bending zone can be controlled / regulated and thus an undesired material overstressing and / or deviations in shape can be avoided.

Under a hollow profile here are tubular hollow body to understand that over their entire profile length have a frontally open on both sides cavity, which is circumferentially bounded by a lateral surface. In addition to round or rounded cross-sections, polygonal cross-sectional shapes are permissible. Likewise, concave and convex cross-sectional shapes of the hollow profile are conceivable.

Under a board or a longitudinal profile here is an unshaped semi-finished, such as a sheet to understand, which is suitable for the production of a hollow profile. The material from which the board or the longitudinal profile is formed, can range from metals, metal alloys, plastics to composite materials.

According to one embodiment of the molding tool, the molding tool is formed with a forming mandrel having a substantially circular, polygonal, concave and / or convex cross section, and / or with a movable between a closed position and an open mold jaw, wherein the mandrel and / or Form jaw are at least partially surrounded by a pressure jacket. The molding tool can be designed as a molding mandrel with a bending elastic adjustable pressure jacket or as a mold half or mold block of a molding tool with an elastically adjustable inner contour. The forming mandrel is in this case a mold that can be inserted into the cavity, which is defined by outer mold halves in a closed state thereof. Both during forming of sheets into hollow profiles and during bending of pipes in tube bending machines, the forming and clamping forces can be set exactly by a controllable and controllable radial expansion of the pressure jacket of the mandrel or the mold half.

According to one embodiment of the molding tool, a molding tool is provided, wherein the pressure chamber is delimited in the longitudinal direction of the molding tool by the pressure jacket and transversely to the longitudinal direction of the molding tool by a front side wall. A pressure chamber here is to be understood as meaning a defined, sealable section in or on the molding tool in which a pressure, in particular a back pressure, can be built up by means of a gaseous and / or liquid medium supplied thereto, which counteracts the forming forces when forming a longitudinal profile Hollow profile is built.

According to one embodiment of the molding tool, a molding tool is provided, wherein on the side of the end wall facing away from the pressure chamber, a connection adapter for coupling with an actuating device for moving and / or rotating the forming mandrel, in particular in its longitudinal axis and / or about its longitudinal axis, and / or a gutter or funnel-shaped collecting device is arranged, which is connectable to a suction line. The terminal adapter is a mounting device that allows releasable coupling with an adjusting device with which the position of the molding tool can be adjusted and manipulated.

In order to remove impurities arising during welding, such as vapors, gases, metal splashes and scale from the inside of the tube and to prevent their adherence to the pipe inner surface, a trough-shaped or funnel-shaped collecting device can be attached to the front side of the forming mandrel. This collecting device is always kept below the current welding position with the described tracking of the end wall and can therefore absorb the resulting impurities during welding in an advantageous manner. In addition, the collecting device can be connected to a suction device via a supply line to suck the contaminants from the inside of the tube to the outside. When tracking the mandrel to the current welding position and the removal of the mandrel, it is advantageous to reduce the radial expansion of the pressure jacket of the mandrel. This reduces the force required to move the mandrel and, as a result, the risk of groove and scratches on the inner surface of the pipe. According to one embodiment of the molding tool, a molding tool is provided, wherein in the pressure chamber is arranged substantially centrally a mold dome at a radial distance from the pressure jacket, and / or the mandrel core extends from the end wall of the pressure chamber. The mandrel core in the mold increases the stability of the pressure chamber and may also be provided in the pressure chamber of the mold halves. Furthermore, the mandrel core can be applied with adjacent pressure jacket, without pressurizing the pressure chamber, for forming the longitudinal profile.

According to one embodiment of the molding tool, a molding tool is provided, wherein the pressure jacket has at least one intermediate wall, so that the pressure chamber at least forms a second pressure chamber, wherein the divided pressure chambers are arranged side by side and / or one above the other and / or have a honeycomb-like cross-section. The subdivision of the pressure chamber allows targeted biasing of different areas of the pressure jacket with different pressures, so that it can be better dealt with the prevailing boundary conditions during forming.

According to one embodiment of the molding tool, a molding tool is provided, wherein the pressure jacket comprises a metal material, in particular spring steel, or an elastomer or a polymer or an elastic composite material and is reinforced, in particular with fibers which comprise polymer and / or elastomer. The pressure jacket is advantageously formed of an elastic material, which allows to respond reversibly to an applied force, in particular to be able to perform the predetermined expansions and compressions of the pressure jacket without plastic deformation.

According to one embodiment of the molding tool, a molding tool is provided, wherein the pressure chamber, each pressure chamber or a predetermined number of pressure chambers is supplied by means of a pressure line and / or individually supplied. Preferably, each pressure chamber has its own pressure line for supplying the respective pressure medium, so that a targeted control and regulation of the internal pressure to adapt to the boundary conditions during forming is possible. In addition to the pressure lines, each pressure chamber can additionally have a discharge line for discharging the respective pressure medium out of the pressure chamber. The pressure lines can be arranged inside the mandrel core, in the side wall and / or in the intermediate wall of the pressure chamber.

According to one embodiment of the molding tool, a molding tool is provided, wherein the pressure chamber has or is connected to a pressure measuring device a control and control unit for transmitting the measured values is connectable and / or the pressure chamber has a Wegmessvorrichtung whose measuring direction radially to the pressure jacket for detecting the actual value of the radial deflection of the pressure jacket and / or means of strain gauges with a control and control unit for transmitting the Actual value can be connected to the same. By means of the pressure measuring device, the path measuring device and / or by means of the strain gauge, it is possible to determine indirectly or directly the bulge or expansion of the pressure jacket. As pressure measuring devices, all pressure sensors are applicable, which transform the physical quantity of pressure into an electrical output variable as a measure of the pressure, such as passive pressure sensors, relative pressure sensors, absolute pressure sensors, differential pressure sensors, etc. and work trouble-free in the conditions occurring or the sensors are protected accordingly. As Wegmeessvorrichtungen all Wegemesssensoren are applicable, which can convert a physically measured path size into an electrical signal, such as, distance measuring sensors with variable inductance or variable conductivity, etc. The elongation of the pressure jacket can also be measured by means of a Dehnmessstreifens on the side of the pressure jacket is attached, which faces the pressure chamber.

According to one embodiment of the molding tool, a molding tool is provided, wherein at least one control and control unit controls the inflow and outflow of the pressure medium in and out of the respective pressure chambers, so that the internal pressure of the pressure chamber or the deflection of the pressure jacket is adjusted to a predetermined desired value , The control and regulation unit can be integrated in the mold or separately in a corresponding control unit, such as a CPU of a computer and / or implemented by appropriate programs that calculate by receiving the signals from the pressure / displacement sensors the current stress of the pressure jacket and depending on Preset to control or regulate the internal pressure in the pressure chamber.

The above objects are achieved with a forming device according to the invention with the features of claim 1 1. Advantageous embodiments will be apparent from the dependent claims.

According to another aspect, there is provided a forming apparatus for producing a hollow profile, in particular a pipe, the forming apparatus comprising at least first and second mold halves formed between a closed state in which a cavity for forming the hollow profile is formed and an open state for inserting a longitudinal profile to be formed, are movable, wherein between the Mold halves of a mold tool can be arranged, in particular a mold according to the embodiments listed above, wherein at least one of the mold halves and / or the mold a pressure jacket is arranged, which surrounds the shaping contour of the respective mold half or the mold at least partially or completely, so that a pressure chamber is formed whose internal pressure is adjustable depending on the degree of deformation of the hollow profile. The mold halves are preferably mold jaws, which form a cavity for forming the longitudinal profile in the closed state. Advantageously, the mold can be retrofitted because of its simple structure of existing forming devices in a simple manner. A longitudinal profile here means a semifinished product, in particular a metal sheet or a printed circuit board, which is in an unshaped state and should first be shaped into a slot profile and then into a hollow profile welded together at the slot location with the aid of the molding tool and the mold halves.

According to one embodiment of the forming device, a forming device is provided, wherein the first and second mold halves each have a recess which determine the outer contour of the hollow profile to be produced and, when moving together, transform the sheet into a slot profile with opposing longitudinal edges, wherein the forming tool intervenes during sheet metal forming the mold halves is arranged or can be inserted after the collapse of the molds.

According to one embodiment of the forming device, the forming device has a welding device for welding together the longitudinal edges of the slot profile. Advantageously, with the help of the welding device from the open slot profile, a closed hollow profile can be formed. The welding device used depends on the material from which the hollow profile is formed. For example, an ultrasonic welding device or an ultrasonic welding process can be provided for welding a slot profile made of plastic, while a welding process suitable for metals is provided for shaving off the joint gap of a slot profile made of sheet metal. In the formation of the slot profile of a material that tolerates only a small heat input, such as micro-alloyed steels, laser welding methods are preferably used

According to another aspect, there is provided a forming apparatus for bending a pipe into a pipe bend having a predetermined bend radius, comprising a mold insertable into a first pipe end portion of the pipe to be bent and having a pressure jacket for centering and at least partially surrounding the mold Clamping the pipe end portion of the pipe to be bent, and a pivotable bending head, which can define a second, free pipe end portion and plastically deforms the pipe during a pivoting movement; and an actuator that can move a portion of the pipe to be bent along the forming mandrel in the direction of the bending head. The mold with pressure jacket can be used for bending pipes, wherein the adjustable surface of the mold is each optimally adjustable to the respective bending and deformation state of the pipe to be bent. In particular, the adjustable pressure jacket prevents damage to the inner surface of the pipe to be bent.

According to yet another aspect, a forming device for roll profiling a long profile is provided in a roll forming device having a plurality of profile rollers arranged one behind the other, wherein a molding tool with a pressure-free adjustable jacket, in particular a mold according to the above embodiments, between the forming profile rollers is arranged. With the adjustable pressure jacket optimum adaptation of the pressure jacket to the existing forming conditions on the profile rollers is possible, and this can be carried out very gently. Under gear free in this case is an adjustment of the pressure jacket without the use of rods or small or gear components to understand to change the scope and the bulge of the pressure jacket.

According to one embodiment of the shaping device for roll forming, the molding tool has a plurality of separately controllable / controllable pressure chambers, which are at least partially defined by the pressure jacket, and are arranged in the direction of passage and / or with respect to the profile rollers. By means of the individually controllable pressure chambers, the clamping force of the pressure jacket during the forming of the molding in the hollow profile to the bending radii and the increasing forming forces in the molding of the hollow profile gradually and controlled adjustable.

According to one embodiment of the forming device, a shaping mandrel arranged between the profiling rolls has at least one pressure chamber with pressure jacket, whose expansion and clamping force can be adjusted by means of the internal pressure in the pressure chamber, taking into account the degree of deformation of the hollow profile.

The abovementioned object with regard to a method for producing and bending a hollow profile are in each case achieved according to the invention by the methods having the features according to claims 17 and 18, respectively. Advantageous embodiments of the respective methods emerge from the subclaims. According to a further aspect, a method for producing a hollow profile, in particular a longitudinally welded pipe, by means of a molding tool, in particular a molding tool according to the above-mentioned embodiments, provided, wherein the molding tool has a pressure chamber with pressure jacket whose elongation and clamping force by means of the internal pressure in the Pressure chamber is adjustable taking into account the degree of deformation of the hollow profile. By means of the pressure jacket, a contour of the hollow profile can be formed by controlling and / or regulating the internal pressure of the pressure chamber or the pressure chambers of the molding tool, taking into account the degree of deformation of the hollow profile.

According to a further aspect, a method for bending hollow sections, in particular tubes, in a tube bending apparatus is provided by means of a forming tool, wherein adjusting the radial expansion of the pressure jacket, the clamping force to the tube will change taking into account the change in cross section during bending of the tube.

According to one embodiment of the method for producing a hollow profile or for bending a tube, an adjustment of the radial expansion and clamping force of the pressure jacket of the molding tool is effected by increasing or decreasing the internal pressure in the pressure chamber, wherein the radial expansion and clamping force of the pressure jacket with the movement the shaping outer mold halves is synchronized. This has the advantage that the production of the hollow profile at any time the stress of the hollow profile to be formed is known and possibly by controlling and or regulating the internal pressure of the pressure chamber, the occurrence of damage and shape deviations can be avoided during forming on the hollow profile. The outer forming tools can be, for example, shaping jaws of a forming tool, the profiling rollers of a profiling device, or the bending head of a tube bending machine.

According to one embodiment of the method for producing a hollow profile or for bending a tube, the internal pressure in each pressure chamber of the molding tool is set individually, so that a graduated over the pressure jacket surface of the pressure shell gradient of the radial expansion and clamping force. This has the advantage that the shape formed by the pressure jacket can be adjusted in steps. The individual setting is detected by detecting the internal pressure by means of pressure sensors and / by detecting the bulging of the pressure jacket by means of distance measuring sensors and adjusted individually by means of control / regulating devices. In order to increase the precision in bending of pipes, the material flow into the bending zone must be specifically influenced in order to reduce both the wrinkling and bending at the inner bending radius and the thinning at the outer bending radius. In particular, a different clamping force for bending external and internal bending radius appears to be particularly advantageous for this purpose.

According to one embodiment of the method for producing a hollow profile or for bending a tube, the position of the molding tool is synchronized with the movement of the shaping outer mold halves by means of an adjusting device or synchronized during the welding of a joint gap of the molded hollow profile, the movement of the mold with the welding movement a lateral offset to the current welding position is maintained.

According to one embodiment of the method for producing a hollow profile or for bending a tube, the radial expansion and clamping force of the pressure jacket of the mold with the movement of the bending head and / or a feed movement of the tube is synchronized and adjusted in time.

With the devices and methods listed above, it is possible to be able to accomplish both the transformation of sheet metal to hollow profiles and the bending of pipes cost and precise.

Because of its simple and compact construction, the pressure-jacket mold, in particular the pressure-molded mandrel, is particularly suitable for retrofitting existing systems for the production of longitudinally welded hollow profiles and tube bending machines.

The invention will be explained below with reference to embodiments and accompanying drawings.

In the drawings, the pressure and flow direction of the pressure medium and the suction of the air are illustrated by small arrows. To illustrate the position and orientation of the illustrated embodiments, an X-Y-Z reference system is provided. The Z-axis of the reference system extends in the direction of the longitudinal extent of the illustrated forming tools.

In the drawings show: 1 a shows a schematic view of a partial section of a first embodiment of a molding tool, in particular a shaping mandrel, along its longitudinal direction with a pressure chamber;

1 b shows a schematic view of a section according to section line A-A according to FIG. 1 a of the molding tool from FIG. 1 a;

FIG. 2 shows a schematic view of a section along the longitudinal direction of a second embodiment of the molding tool from FIG. 1 a; FIG.

3a shows a schematic view of a partial section of a third embodiment of the molding tool along its longitudinal direction with a plurality of pressure chambers;

FIG. 3b is a schematic cross-sectional view of the mold of FIG. 3a; FIG.

4a shows a schematic view of a partial section of a fourth embodiment of the molding tool along its longitudinal direction with a plurality of pressure chambers, wherein a pressure supply of the pressure chambers takes place via the core region of the molding tool;

Fig. 4b is a schematic cross-sectional view of the mold of Fig. 4a;

5 shows a schematic view of a partial section of a fifth embodiment of the molding tool with a plurality of pressure chambers along its longitudinal direction, whereby a pressure supply of the pressure chambers takes place by means of lines in side and intermediate walls of the molding tool;

6 shows a schematic view of a partial section of a further embodiment of the molding tool with a path measuring device for detecting the deformation of a pressure jacket forming the pressure chambers;

7 shows a schematic view of a section transversely to the longitudinal direction of a sixth embodiment of the molding tool, in particular jaws, along the longitudinal direction thereof with a flexurally elastic, adjustable inner contour by means of pressure chambers;

8 is a schematic view of a section transverse to the longitudinal direction of a forming device according to the invention for producing longitudinally welded hollow profiles with two outer jaw tools in the open position with an embodiment of the molding tool; 9 shows a schematic view of a section transverse to the longitudinal direction of the device from FIG. 1 for producing longitudinally welded hollow profiles with two outer jaw tools in the closed position;

10 is a schematic view of a partial section in the longitudinal direction of a forming device for producing longitudinally welded hollow profiles with two outer jaw tool and frontal support and storage of the mold;

1 is a schematic view of a partial section in the longitudinal direction of a forming device with welding device for welding a slot profile using a molding tool, in particular a dome; with a pressure chamber;

12 is a schematic view of a partial section in the longitudinal direction of a forming device with welding device for welding a slot profile using two opposing molds;

Fig. 13 is a schematic view of a partial section of a forming apparatus for bending pipe tube bending machine using an embodiment of the pressure chamber forming tool; and

Fig. 14 is a schematic view of a partial section of a forming device for producing longitudinally welded hollow profiles by means of roll forming using one of the embodiments of the mandrel-like molding tool with pressure chamber.

In Fign. 1 a and 1 b is a partial sectional view in the longitudinal direction and in the sectional view according to section A-A in FIG. 1 a shows a first embodiment of a forming tool 1 for a forming device for producing a slot profile 2 a and hollow profile 200.

The mold 1 is shown here in the form of a mandrel 1 with an expandable pressure shell 1 1, which defines a pressure chamber 12 whose internal pressure can be controlled or regulated by means of a pressure medium which is liquid or gaseous, depending on the shaping conditions of the hollow profile to be formed , The mold 1 has, as shown in the sectional view of Figure 1 b, a substantially circular to elliptical cross-section.

Via at least one pressure line 13, the pressure chamber 12 can be hydraulically or pneumatically pressurized. The pressure jacket 1 1 is preferably designed to be flexible, so that the pressure of the inner pressure chamber 12, the bulge of Pressure jacket 11 and consequently the radial cross-sectional shape of the mandrel 1 can be adjusted.

Furthermore, the molding tool 1 has a mandrel core 14 arranged essentially centrally to the longitudinal axis L of the molding tool 1 as a supporting structure. Around the mandrel core 14 is arranged at a radial distance of the side walls 15 supported flexurally elastic pressure jacket 1 1 and a flexurally elastic membrane, so that in the space between mandrel core 14 and pressure shell 11, a pressure chamber 12 is formed. The side walls 15 each extend from the end faces of the mandrel core 14 and are preferably integrally connected thereto. For maintenance purposes, a maintenance window may be formed in one of the side walls or in both, so that the pressure chamber 12 and the side of the pressure jacket 11 facing the mandrel core 14 can be checked and serviced.

In order to ensure a good bending elastic deformation of the pressure jacket 1 1, this is suitably formed as a thin-walled membrane which is elastically deformable. Preferably, the membrane is made of highly elastic spring steel and / or fabric reinforced elastomers. Any other material that allows a flexurally elastic deformation is also suitable for the pressure jacket 1.

The outer circumference of the mandrel 1 is adapted and adjustable by means of the pressure-loaded pressure jacket 1 1 to the inner contour of the hollow profile to be produced. The outer contour of the radially to the mandrel 1 spaced pressure jacket 11 is designed in cross section, for example, circular, elliptical, oval or asymmetric rounded.

Preferably, the pressure chamber 12 is pressurized by means of a pressure line 13. As the pressure medium is preferably to use a hydraulic fluid. Alternatively, it is also possible to use air or another gas as the pressure medium. Due to the increased ability of gases to expand against liquids, additional safety measures to control the risk of explosion and bursting must occasionally be taken.

Since the pressure shell 1 1 is flexurally elastic, the bulge of the pressure jacket 1 1 and consequently the radial expansion and clamping force of the pressure jacket 11 of the mandrel 1 can be adjusted via the chamber internal pressure.

The pressure jacket 1 1 of the mandrel 1 compensates advantageously dimensional variations of the blank or sheet 2 along the circumference in the inner contour of the sheet 2 from. The regulation of the radial expansion or radial clamping force of the pressure jacket 1 1 of the mandrel 1 is determined by a control and / or regulating unit on the basis of a calculation rule, which converts the internal pressure of the pressure chamber 12 into the target variables radial expansion or radial clamping force. The internal pressure of the pressure chamber 12 is detected by a pressure measuring device which is located directly in the pressure-tight chamber 12 or connected to a corresponding hydraulic or pneumatic pressure line 13.

In addition to this, the actual value of the radial expansion can be detected directly by at least one position measuring device 101 located within the pressure chamber 12 and corrected by means of the control and regulating unit. Conveniently, the measuring direction of the distance measuring device 101 is directed to the lateral surface of the dome. In order to ensure high reliability of the path measuring device 101 and operability within any hydraulic fluid, a non-contact inductive measuring principle is preferably proposed. Alternatively, other non-contact and tactile measuring principles are possible.

The mode of action of the radially expandable pressure jacket membrane can also be transferred to outer mold halves which act on the outer circumference of the molded article or the hollow profile to be formed, wherein the direction of the radial force effect compared to a used in the cavity of the hollow profile to be molded mold or used Forming mandrel reversed. Here, the inner contour of the outer molds 300 is formed with a flexurally elastic pressure jacket, as shown for example in Fig. 7. Via supply lines 13, the pressure chambers 12 can be acted upon below the pressure jacket 1 1 with a variable pressure, which causes an expansion of the pressure jacket 11 transverse to the tool longitudinal axis L in the Y-X direction. The tool inner contour is thereby adjustable in the radial direction and is suitable for exact pressing of the sheet 2 from outside to inside.

Embodiments of the molding tool are also conceivable, wherein the contouring sides of the respective molding tool, which are involved in the shaping of the hollow profile and come into contact with the molding of the hollow profile, are each provided with a pressure jacket 11, which can be regulated via a pressure chamber 12 ,

An embodiment of the mold 1, 300 provides for precise pressure control to use for the pressure build-up and pressure reduction each separate pressure lines 13 and to control the internal pressure of the chamber 12 via separate valves or the differential pressure of a proportional or servo valve. Due to the principle, the pressure jacket 11 can bend arcuately outward, since the side walls 15 (see Fig. 1a) fix the pressure shell 1 1 at its front ends. This has the consequence that the pressure jacket 1 1 in the vicinity of the mandrel end faces 16 can make no or insufficient contact with the sheet 2 and decreases the maximum realizable forming force in this area.

To counteract this effect, the mandrel 1 is longer than the hollow profile to be produced and protrudes preferably on both sides beyond the length of the hollow profile 200, as shown for example in Figures 11 and 12. The end faces 16 of the mandrel 1 are thereby outside of the hollow profile and the uneven bending of the pressure jacket 11 in this area has no effect. In Fig. 1 1, the protrusion of an end portion of the mandrel 1 from the hollow profile to be produced 2a is exemplified.

Another not shown embodiment of the mandrel 1 provides to change the shape of the mandrel cross section along the longitudinal axis in its shape and / or its geometric dimensions to adapt, for example, the inner contour of a conical hollow section 2a with along its longitudinal axis stepped profile cross sections. As a result, a variable areally distributed profile of the radial expansion of the expansion and force of the pressure jacket 11 can be set for the profile axis and profile elements that are variable over the longitudinal axis.

About a connection adapter 17 of the mandrel 1 can be connected to an adjusting device. By means of the adjusting device of the mandrel 1 can be rotated according to a further embodiment about its longitudinal axis L and / or moved along or transversely to its longitudinal axis L, to orient the pressure chambers 12 in an advantageous manner to the enclosing hollow section 2a or tube 200.

In Fig. 2, a second embodiment of the mold 1 is shown, in which the mandrel 1 is formed without a supporting mandrel core 14, and the pressure chamber 12 is formed by the pressure shell 1 1 itself. Preferably, this embodiment of the molding tool is used because of the reduced bending stiffness of this construction of the mandrel 1 with relatively short tubes and low forming forces. In addition, the required pressure medium volume and, consequently, the required hydraulic energy consumption is increased compared to an equally large mandrel 1 with mandrel core 14.

An embodiment of the forming mandrel 1 has on the end face 16 of the mandrel 1 a gutter or funnel-shaped catching device 7. The collecting device 7 is designed such that during welding during welding of the joining sections of the Slit profiles 2a of the sheet formed around the mandrel 1, the resulting impurities such as vapors, gases, metal splashes and scale from the cavity of the closed forming device - see Fig. 9 -, or from the inner cavity of the sheet formed into a tube, can be eliminated and thus their adhesion to the pipe inner surface can be prevented.

Further advantageous embodiments of the molding tool with mandrel 1 and pressure shell 1 1 are shown in Figs. 3a, 3b, Figs. 4a, 4b and Figs. 5 each in a partial sectional view in the longitudinal direction of the mandrel 1 in the Z direction and Y direction parallel to the longitudinal axis L of the mandrel 1 and are in the sectional view in the X direction and Y direction according to section A-A of FIGS. 3a and 4b. The embodiments of the inner molding tool or molding mandrel 1 shown here have a plurality of pressure chambers 12 which are distributed over the circumference or along the longitudinal axis L of the molding mandrel 1.

The division of the pressure chambers 12 is, as shown in Fig. 3a and 3b, formed by longitudinal side walls 15a extending in the Z direction.

Alternatively or in combination with the longitudinal side walls 15, which extend in the longitudinal direction L of the forming mandrel 14, the division of the pressure chamber 12 can also take place transversely to the Z-longitudinal direction in the Y and / or X direction, as shown for example in Fig. 4a. Here, the pressure chamber 12 is divided both in the longitudinal direction L and in the transverse direction into individual pressure chambers 12, which are individually controlled and regulated.

The pressure chamber 12 is divided by intermediate walls 15 a into a plurality of pressure chambers 12. Preferably, each chamber 12 can be acted upon by a separate pressure line 13 with different pressures, as shown for example in Fig. 4a.

The embodiments of the forming mandrel shown in FIGS. 3 a, 3 b and 4 a, 4 b have a plurality of pressure chambers 12 distributed over the mandrel circumference or along the mandrel longitudinal axis L, which can each be acted upon by separate pressure lines 13 with different pressures. As a result, with the pressure jacket, a variable area-distributed transverse profile along the radial mandrel strain can be adjusted with appropriate pressure jacket clamping force. This is particularly advantageous, as this can counteract occurring form deviations of the longitudinal profile or sheet 2 to be formed and when using sheets 2, which are composed of different material grades and sheet thicknesses (engl., So-called "tailored blanks"), locally the Umform- and clamping force to the metal or tube to be formed individually adjusted and thus the material flow in the respective forming zone can be selectively influenced.

For the exact process control includes an embodiment of the metrological detection of the force at the contact point between the sheet 2 and pressure jacket 12, or mold and as a subsequent step of the precise control ebendieser force.

In Fig. 6, another embodiment of the mandrel 1 is shown with pressure jacket 11, which allows direct detection and control of the radial expansion of the pressure jacket 1 1 of the mandrel 1. For this purpose, the actual value of the radial expansion is detected by at least one located within the pressure chamber 12 Wegmesssystem 100 and transmitted as an input to the described control and regulation unit. Expediently, the measuring direction 101 of the path measuring system 100 is directed onto the inside of the pressure jacket 11. In order to ensure a high system reliability of the position measuring system and operability within the pressure medium, preferably a non-contact inductive measuring principle is used. Alternatively, further non-contact and tactile measuring principles are possible.

The actual value of the radial expansion or radial clamping force of the pressure jacket 11 is determined by a control unit, not shown, based on a calculation rule. As an input to this rule, the actual value of the internal pressure of the pressure chamber 12 is measured by one or more pressure measuring device, not shown, which are located directly in the pressure-tight chamber 12 or connected to the belonging to this chamber 12 hydraulic or pneumatic pressure lines 13. Subsequently, the control unit calculates the measured internal pressure in the pressure chamber 12 in the target of radial expansion and / or radial clamping force and regulates the inflow and outflow of the pressure medium into and out of the respective pressure chambers 12 so that the radial expansion or radial Tension of the target size is adjusted. This allows precise control of these target values.

7 shows a schematic view of a section transverse to the longitudinal direction of a sixth embodiment of the molding tool 1. The molding tool 1 has a first and second mold half 300L, 300R, also referred to as jaws 300, shown here in an open state in that a semifinished product to be shaped to form a closed hollow profile 2 or a tubular slot profile 2 a can be inserted. The first and second mold halves 300L, R are between the open state shown in FIG Insertion of the semifinished product to be formed and a closed state for molding the inlaid molding into a hollow profile 200 movable.

On the first inner side 31 L of the inner contour of the first mold half 300L and the second inner side 31 R of the second mold half 300R, a pressure jacket 1 1 is arranged in each case. The pressure jacket 11 is supported and held approximately centrally by a side wall 15a, so that the pressure chamber 12 is subdivided into two pressure chambers 12 which can be regulated differently. The pressure jacket 11 is fluid-tightly connected at the end portions to the upper portion of the respective mold half 300L, 300R on the one hand, and to the lower portion of the respective mold half 300R, 300R on the other hand. The mold halves 300L, 300R can be brought into a closed state so that a blank 2 to be formed into the hollow profile can be deformed into a tubular shape. The shaping shape of the pressure jacket 12 can be controlled and / or regulated via the internal pressure in the pressure chambers 12 during the shaping process.

The internal pressure of each pressure chamber 12 can be individually controlled and / or regulated by means of its own pressure lines 13 by supplying or removing a liquid or gaseous pressure medium by means of the pressure lines 13.

In a closed state, the first and second mold halves 300L, 300R form a closed cavity, which is defined by the pressure jacket 12 in size.

The embodiment of the molding tool 1 shown in FIG. 7 provides for transmitting the operating principle of the radially expandable pressure jacket 11 to the outer, first and second mold halves or jaws 300L, 300R. Compared to the embodiment as a forming mandrel 1, only the direction of the radial force effect is reversed and maintained the basic operation. For this purpose, the inner contour of the outer molds 300 is formed by a flexurally elastic pressure jacket 11, under which there is at least one filled with pressure medium chamber 12, the internal pressure is adjusted via leads 13 and a suitable control and regulation unit. As a result, a bending elastic adjustable tool inner contour for pressing the sheet 2 from the outside to the inside is formed.

The working principles and embodiments already described for the mandrel 1 can be applied in modified form for the molds 300 with elastically adjustable tool inner contour. It is thus possible, for example, to create a plurality of pressure chambers 12, which can be adjusted independently of one another, by intermediate walls 15a underneath the membrane 11 in order to provide a locally stepped graduation over the tool inner contour To achieve expansion and deformation force distribution. Analogous to the expandable mandrel 1, the regulation of the pressure-jacket elongation is based on a measurement of the chamber internal pressure or the pressure jacket bulge. The forming of the sheet 2 can be done using a rigid mandrel 1 or a radially expandable pressure jacket 1 1 on a mandrel 1. In some cases of use can be dispensed with an inner mandrel core 14, in which case only the outer mold halves 300 with a bending elastic adjustable inner contour by means of the pressure jacket 1 1 can selectively press the sheet 2.

FIGS. 8 and 9 show a first embodiment of a forming device A1 for producing a longitudinally welded hollow profile. In Fig. 8, the forming device A1 is shown in the starting position with open mold halves 3L, 3R with already inserted to be formed board or to be formed sheet 2. In Fig. 9, the forming device A1 is shown in the end position with closed mold halves 3L, 3R with already inserted and to a hollow profile 200 shaped board 2.

The forming device A1 has at least two outer forming jaws 3L, 3R and a forming mandrel 1 with adjustable pressure shell 1 1. Furthermore, a semifinished product to be shaped into a hollow profile 200, a metal sheet 2, is shown. The outer mold jaws or molds 3L, 3R have inner contours 31 L, 31 R, which determine the outer contour of the hollow profile 2a to be produced. The molds 3L, 3R are mounted on a common base plate 5 and can be closed by an adjusting device, not shown, on the forming mandrel 1 according to the invention in the closed state, as shown in Fig. 9.

The sheet 2 and the board 2 is placed between the mandrel 1 and the base plate 5. Via pressure lines 13, the pressure in the interior of the pressure chamber 12 of the mandrel 14 can be increased. As a result, the pressure jacket 1 1 bends in the radial direction and clamps the sheet 2 against the base plate. 5

In addition, the mandrel 1 can be moved in an alternative embodiment by an adjusting device, not shown in vertical Y-direction against the base plate 5 to clamp the sheet 2 against the base plate, wherein the pressure chamber 12 via the pressure line 13 with a liquid or gaseous pressure medium is charged. The sheet 2 is fixed by the clamping between the mandrel 1 and the base plate 5 in its position and the risk of slipping during the forming is reduced. After tensioning the sheet 2 between the base plate 5 and the outer periphery of the pressurized Pressure jacket 1 1 of the mandrel 1 drive the molds 3L, 3R together until, as shown in Fig. 9, they have reached a closed position near the mandrel 1.

The molds 3L, 3R bend the sheet 2 against the outer periphery of the mandrel 1 arranged around the pressure shell 1 1 to an O-shaped slot profile 2a, the contour of the inner contour recesses 31 L, 31 R of the molds 3L, 3R approximately follows and its Longitudinal edges are parallel in the area of the joint gap 2z.

In order to set the width and position of the joint gap 2z of the slot profile 2a defined, optionally at least one stop 4 can be retracted over the entire profile length by means of an adjusting device, not shown, before the first and second mold halves 3L, 3R are closed.

In addition to the linear movements of two forming tools 3L, 3R shown in FIGS. 8 and 9, alternatively the forming tools can also be moved towards the forming mandrel 1 in a tilting or pivoting movement.

Likewise, it is provided in additional embodiments of the forming apparatus A1, with more than two outer molds on the forming mandrel with pressure jacket 1, for example, a three-piece forming apparatus A1, which has two lateral mold halves and a third lid-like mold half, which together in the closed position, the cavity to form the hollow profile.

Preferably, the movably mounted mold halves 300L, 300R, 3L, 3R are moved in a position-controlled manner by means of a hydraulic, pneumatic, mechanical and / or electrical drive.

By adjusting the internal pressure of the pressure chamber of the mandrel 1, the forming force of the pressure jacket 12 against the sheet 2 and the board 2 are regulated and the molding or the sheet 2 targeted from the inside against the recesses 31 L, 31 R of the molds 3L, 3R be pressed.

The temporal pressure profile of the mandrel 1 is adjusted by a control and regulating device, not shown, which allows, for example, the pressure profile in the pressure chamber 12 of the mandrel 1 in response to the movement of the mold halves 3L, 3R adapt. For this purpose, pressure lines 13 are provided, by means of which a pressure medium for increasing the pressure in the pressure chamber 12 to or for lowering the pressure can be removed from the pressure chamber. Thus define the mold halves 3L, 3 by position-controlled process, the outer contour of the hollow section 2, the pressure shell 1 1 of the mandrel 1, the sheet 2 from the inside force, pressure or strain-controlled against the recesses 31 L, 31 R of the molds 3L, 3R suppressed and thereby calibrates the cross section of the hollow profile 200 against the inner contour of the molds 3L, 3R.

It may be expedient further, first without the forming mandrel 1 to transform the sheet metal 2 into a slot profile 2a only by moving the first and second mold halves 3L, 3R together, and then after forming only the forming mandrel 1 by means of a displacement device, not shown, in the Z-longitudinal direction to insert into the slot profile 2a. During insertion advantageously the radial expansion of the pressure jacket 1 1 of the mandrel 1 should be reduced by lowering the internal pressure of the pressure chambers 12 so as not to damage the inner wall of the slot profile 2a.

For displacing and displacing the forming mandrel 1 with the displacement device, a connection adapter 17 is mounted on one of the end faces, to which the displacement device can be detachably coupled to the forming mandrel 1.

Likewise, when removing the finished hollow profile 2a, it is very advantageous to reduce the radial expansion of the pressure jacket of the mandrel 1 in order to separate hollow profile 200 and forming mandrel 1 from each other with little effort, thereby avoiding scratches and grooves on the profile inner wall of the hollow profile 200.

The forces acting on the forming mandrel 1 during the forming process can generate a torque which elastically bends the forming mandrel 1 with respect to its center axis L and tilts relative to the mold halves 3L, 3R.

In Fig. 10, an embodiment is shown, which addresses this problem. For this purpose, a bearing pin 61 is provided on the terminal adapter 17 opposite end face 16 of the mandrel 1, which is laterally supported in engagement with a stationary bearing 6, the mandrel 1.

The stationary bearing 6 is designed such that when moving the forming mandrel 1 in the longitudinal direction, the connection to the stationary bearing point 6 can be made or separated. Conveniently, the mandrel 1 in the middle of the Dornstimfläche 16 for this purpose a round cross-section bearing pin 61 which can be inserted into the bearing 6 in the longitudinal direction. Any other type of embodiment of the bearing is also possible, for example, the bearing or the journal can be configured such that a coupling of the journal can be performed in a direction other than the Z-longitudinal direction.

For producing the hollow profile 200, first a slot profile 2a with the in FIG. 8 and 9, wherein a stop 4 is provided in the formation of a joining gap 2z for welding together the joining end sections of the slot profile 2a of the hollow profile 2.

After forming the sheet 2 to the slot profile 2a, the stop 4 is moved out of the joint gap 2z to release the joint gap 2z for welding. Expediently, the shaping tools 3L, 3R have a recess along the joining gap 2z in order to enlarge the working space for the welding device 8. In order to further reduce the distance between the longitudinal edges of the sheet metal for welding, it is permissible to continue the molding tools after the stop 4 has moved out.

FIG. 11 shows an embodiment of a device S1 for welding the joint gap 2z in a partial sectional view in the longitudinal direction L.

The device S1 has the forming device A1 and a welding device 8, which can be moved along the joining gap 2z by means of a displacement device, not shown. The space required for welding is created on the one hand by a recess of the molds 3L, 3R in the region of the joint gap 2z. On the other hand, a clearance is formed below the weld 82 by positioning the end wall 16, 16a with a lateral offset distance to the weld 82, i. the end wall 16, 16a is moved in parallel according to the movement of the welding device 82 at a predetermined distance from the welding point 82, as indicated by the arrows 81 in FIGS. 11 and 12.

The solid welding of the sheet on the pressure shell 1 1 of the mandrel 1 or damage to the mandrel 1 by heat and welding residues is thus prevented because the mandrel 1 is not directly below the weld 82.

During welding, the movement of the forming mandrel 1 is synchronized with the welding movement 82, so that the lateral offset distance of the mandrel 1 to the current welding position 82 is always maintained.

It can also be advantageous to lower the internal pressure of the pressure chamber 12 of the forming mandrel 1 during the descent to the frictional force between the pressure shell of the To reduce forming mandrel 1 and the inside of the hollow section 2a and thus prevent the formation of scratches and grooves.

In order to remove the impurities arising during welding, such as vapors, gases, metal splashes and scale, from the interior of the pipe and to prevent them from adhering to the pipe inner surface, an embodiment of the molding tool 1 provides, on the end face 16 of the molding mandrel 1, a channel or funnel-shaped catcher 7 to install. This collecting device 7 is always kept below the current welding position 82 with the described tracking of the mandrel and can absorb the resulting impurities during welding in an advantageous manner.

In addition, the collecting device 7 can be connected to a suction device, not shown, via a suction line 71 to suck the contaminants from the inside of the tube to the outside by applying a negative pressure.

FIG. 12 shows a further forming device S2 with improved support of the joining gap 2z. For this purpose, two opposing mandrels 1, 1 a are used. The mandrels 1, 1 a are positioned by at least one adjusting device not shown to each other so that between their end faces 16, 16 a is always maintained a substantially constant distance during the welding process. During the welding movement 82 both mandrels 1, 1 a tracked so that their end faces 16, 16a follow with lateral offset distance of the welding position 82 and leave a free space below the weld 82.

In another embodiment of the welding method described above, it is possible to dispense with the internal support of the hollow section 2 during welding and to remove the mandrel or the 1, 1 a from the hollow profile 2 before welding. In this case, instead of the forming mandrel, preferably only one collecting device 7 is arranged at the welding point and carried along by means of an adjusting device.

Another aspect relates to a method for producing longitudinally welded hollow profiles 2 with the molding tool or mandrel 1 according to the invention in combination with external molding tools, such as the first and second mold halves 3L, 3R; 300L, 300R.

In this method, initially an unshaped molding or an unshaped sheet 2 is placed between the forming mandrel 1 and a base 5, wherein the sheet longitudinal edges come to lie parallel to two opposite outer dies 3L, 3R. The sheet 2 or the molding is either flat or it was rolled or pre-bent in the direction of the subsequent indentation, so that the sheet forms a trough-shaped or U-like profile. In order to prevent slippage of the sheet 2 during the subsequent forming, the pressure jacket 1 1 of the mandrel 1 can be stretched to clamp the sheet 2 against the base plate 5.

In the next method step, at least two outer mold halves 3L, 3R; 300L, 300R, the sheet 2 from different directions against the interposed mandrel 1 to an O-shaped hollow profile 2, wherein the outer molds 3L, 3R from a mandrel 1 remote starting position, an open position - in a relative movement to each other in a position close of the mandrel circumference - are moved to a closed position.

The molds 3L, 3R thereby determine the outer contour of the hollow profile 2 to be produced. Furthermore, the outer mold halves 3L, 3R are designed such that they have a recess in the jointed position in the joining region of the longitudinal sheet metal edges. In this recess, an adjusting device extending over the entire length of the mold extending planar stop 4 is introduced. During the forming, the sheet longitudinal edges run along the predetermined by the outer molds 3L, 3R contour laterally to this stop, whereby the position of the joint gap is defined as a further rotation of the sheet beyond the stopper 4 addition is not possible.

The gap width between the forming mandrel and forming tools as well as the forming force can be selectively influenced via the radial expansion of the forming mandrel and / or by changing the relative position of the outer forming tools 3L, 3R. Preferably, the relative movement of the outer molds 3L, 3R is carried out position-controlled by an adjusting device, whereas the radial expansion of the pressure jacket 1 1 of the mandrel 1 is performed by force or pressure.

A position-controlled adjustment of the radial expansion of the pressure jacket 1 1 forming mandrel 1 can be carried out on a case by case, either the described conversion of internal pressure of the pressure chamber 12 in radial expansion or the direct detection of the radial expansion of the pressure jacket by Wegmess device or both are used. The pressure jacket 12 of the mandrel 1 thus allows a targeted pressing of the sheet 2 against the outer molds 3L, 3R, 300L, 300R, which reduces dimensional and form deviations of the profile and the shape of the hollow profile are calibrated. After forming, the stop 4 is removed from the joint gap by an adjusting device to release the joint gap 2z for the subsequent process steps. Optionally, the mold halves 3L, 3R can be moved together after the removal of the stop on to further reduce the joint gap 2z between the longitudinal edges of the sheet metal. As a result of the described forming process, an O-shaped slot profile 2a has emerged from the metal sheet 2, with the sheet longitudinal edges directly facing each other in the area of the joint gap 2z so that the sheet longitudinal edges can be welded together to form a pipe or hollow profile 200.

In the next step, the sheet longitudinal edges are welded together supported by the outer mold halves 3L, 3R and at least one inner mandrel 1 along the joint gap 2z.

For this purpose, a welding device 8 is provided, which is arranged movably along the joining gap 2z. The lateral clearance necessary for the welding is provided by a recess of the mold halves 3L, 3R in the region of the joint gap 2z of the hollow profile 200. Below the welding position 82, a free space is formed by descending the forming mandrel 1 in the longitudinal direction, by aligning the front side wall 16 with a lateral offset relative to the current welding position 82. During welding, an adjusting device synchronizes the movement of the forming mandrel 1 with the movement of the welding device 8, so that a lateral displacement of the mandrel end face 16 to the current welding position 82 is always observed. A firm welding of the sheet 2 on the mandrel 1 or damage to the mandrel 1 during welding is prevented.

Additional embodiments in the forming device and in the welding method or in the manner of the applicable welding device 8 result from the material used to form the hollow profile 2. Thus, in addition to metallic materials, plastics, composite materials and sandwich structures are possible. The technological parameters such as forming force and forming speed of the molds 3L, 3R, 300, 1 are to be adjusted and adapted to the material selection.

In particular, the welding method used is to be adapted to the used material of the board 2 and the semi-finished product, which is to be formed into the hollow profile 200.

In the formation of the hollow profile 200 of a material that allows a larger heat input, such as metallic materials, welding methods such as induction and resistance welding can be applied. FIG. 13 shows an embodiment of a forming apparatus B1 for free-forming bending of tubes 200 in a tube bending apparatus, in which one of the above-described embodiments of the forming mandrels 1 with pressure jacket 11 is used.

A tube 200 to be bent is first placed on the mandrel 1 and centered by this in its position and biased against the pressure shell 11.

For mounting and guiding the mandrel 1 on the tube bending device B1, a pin-shaped connection adapter 17 is formed on the end face 16 of the mandrel 1, which is materially integrally connected to the end face 16 of the mandrel 1 or screwed for example by means of a screw and is detachably connected ,

The connection adapter 17 makes it possible to couple the forming mandrel 1 to an adjusting device, not shown, in order to displace it in a Z-longitudinal direction and / or to rotate it around the forming mandrel 1 about its longitudinal axis L. The force acting on the tube 200 clamping force is adjustable by means of the stretchable pressure jacket of the mandrel 1. Likewise, the pressure jacket 1 1 of the mandrel 1 by radially expanding the pressure shell 11 by increasing or decreasing the internal pressure follow changes in the tube diameter, and counteract the formation of wrinkles or thinning of the material at the bending point.

As shown in FIG. 13, the forming apparatus B1 for freely bending tubes 200 adjacent to the forming mandrel end 16 inserted into the pipe 200 to be bent has a guide means 92 which clamps the pipe 200 against locks the mold dome 1 and the projecting into a bending head 9 of the forming device B1 pipe end of the pipe to be bent 200 leads.

An adjusting device, not shown in FIG. 13, which is mountable in engagement with the connection adapter 17 of the mandrel 1, displaces the free end of the tube 200 mounted on the mandrel in the bending region of the bending head 9. The bending head 9 engages the pipe end non-positively. Pivots the bending head 9 now orthogonal to the central axis ML of the tube 200 and thereby bends the engaged tube end plastically in the direction of pivotal movement, indicated with arrow 91. After bending the frictional connection of the bending head 9 is solved with the pipe end, so that a new pipe section along the forming mandrel 1 can be pushed into the bending head 9. During bending, slippage of pipe material into the bending zone can be adjusted in a targeted manner via the clamping force of the pressure jacket 11 of the forming mandrel 1, so that wrinkling or material thinning in the bending zone can previously have occurred. A method for free-form bending of hollow sections, in particular of tubes, in the tube bending device B1 according to FIG. 13 using the forming mandrel 1 with adjustable pressure chamber 12 can be carried out as described below.

The tube to be bent 200 is inserted with one end and a predetermined length on the mandrel 1 and centered by pressurization of the pressure chamber 12 and by bulging of the pressure jacket 1 1 by means of this and stretched. The clamping force of the pressure jacket 1 1 is adjustable by adjusting the internal pressure of the pressure chamber 12.

An adjusting device, which is coupled to the connection adapter 17 of the mandrel 1, brings the free end of the tube 200 into engagement with the bending head 9, which engages around the free end of the tube non-positively. The adjusting device may in this case also be connected only to a section of the pipe.

The adjusting device does not necessarily have to be coupled to the connection adapter 17 of the forming mandrel. The task of the adjusting device is to push a new pipe section along the mandrel on the free end in the bending head.

The bending head 9 is now pivoted orthogonal to the central axis ML of the tube 200. When the bending head 9 performs the pivoting movement, as indicated by arrow 91 in Fig. 13, the engaged tube end is plastically bent in the direction of pivotal movement. In Fig. 13, the state of the tube and the position of the bending head is shown after the pivoting movement.

After bending, the frictional connection between the bending head 9 and the pipe end is released so that a new pipe section or a new pipe 200 to be bent can be introduced along the forming mandrel 1 into the opened bending head 9.

In addition, a continuous advancement of the tube 200 during bending is possible to produce radii transitions in the bent tube 200. During bending, reliable tensioning of the tube 200 on the mandrel 1 is essential to avoid unplanned slippage of the tube 200 into the bending zone and wrinkling during bending.

The mandrel 1 is particularly advantageous for this purpose, since by means of the pressure jacket 1 1, the radial clamping force for clamping the tube 200 is precisely adjustable. Thus, the mandrel 1 can specifically control the slipping of the tube during bending or optionally completely prevent it. Likewise, with an embodiment of the forming mandrel 1, which has a plurality of pressure chambers 12, a gradual pressing along the Pipe circumference possible to reduce dimensional and form deviations or, for example, to apply different clamping forces on the inner and outer bending radius.

In addition, the mandrel 1 can be used in the roll profiling as an inner support and guidance of the board or the semifinished product 2 for forming the hollow section 2, as shown in Fig. 14.

During roll forming, the blank or sheet 2 passes through profiled rolls 900 arranged one behind the other, which bend the sheet 2 in a stepwise manner and bend towards the respective opposite profiled roll 900 until the sheet longitudinal edges are directly opposite one another and a slot profile 2a is formed. Subsequently, the sheet longitudinal edges of the hollow slot profile 2a are welded together within the device, for example, with the welding device 8, so that a longitudinally welded hollow profile 2 is formed. An internally acting support of the sheet 2 and in particular a precise guidance of the sheet longitudinal edges in the region of the joint gap 2z thereby make a significant contribution to the dimensional and dimensional accuracy of the hollow profile 200 produced.

According to the method, this internally acting support and guidance of the sheet 2 is achieved in that the forming mandrel 1 is disposed between the profile rollers 900 and the sheet 2 is pressed against the profile rollers 900 from the inside by means of the adjustable pressure jacket 1 1 of the mandrel 1. In this case, the elongation and clamping force of the pressure jacket 1 1 can be adjusted by regulating or controlling the pressure in the pressure chamber 12.

In Fig. 14, an embodiment of a Walzprofilier- device T1 using the mandrel 1 with pressure jacket 1 1 and mandrel core 14 is shown.

Using the forming mandrel 1 can from a semi-finished, here a sheet 2 with the in FIG. 14 Walzprofilier- device T1 shown, according to the methods listed below, a hollow profile 200 are formed.

The unshaped sheet 2 is guided by a plurality of successively arranged profile rollers 900, which gradually bend the sheet into a slot profile 2a and weld it to a hollow profile 200 with a welding device 8, not shown. The sheet 2 can be pressed from the inside by means of the pressure jacket 1 1 of the mandrel 1 against the profile rollers 900 adjustable.

Particularly advantageous is the inner support means of the pressure jacket 1 1 in the region of the joint gap 2z, since the mandrel 1 aligns the sheet edges in the radial direction to each other and thereby favors a precise welding. As a result, dimensional and form deviations are significantly reduced.

Since the bending radius continuously with the passage 901 of the sheet 2 by the profile rollers

900 is reduced, it may be appropriate to reduce the cross section of the mandrel 1 along its longitudinal axis also. The form dome 1 follows in the direction of passage

901 becomes smaller bending radius and ensures effective support of the sheet 2 and the resulting slot profile 2a or hollow profile 200th

In an advantageous embodiment of the roll forming method and the roll forming T1 is advantageously a forming mandrel 1 with a plurality of individually adjustable, independent pressure chambers 12 applied in the direction of passage of the sheet 2, as indicated by the arrow in Fig. 14, along the Forming mandrel 1 are arranged so that the clamping force of the pressure jacket 1 1 is progressively adjustable with decreasing bending radii the increasing forming forces in the sheet 2. The pressure chambers 12 are each individually adjustable and have a pressure measuring device and / or a Wegmessvorrichtung 100 for determining the internal pressure and / or the bulge of the pressure jacket 1 1 on.

Both when bending sheets 2 to hollow sections 200 and when bending pipes 200, the molded dome 1 with pressure jacket 1 1 is suitable because it allows flexible adjustment of the clamping and forming forces. The basic structure of the mandrel 1 is the same for both methods and only has to be adapted in its dimensions, nominal forces and connection adapters 17 to the respective intended use. Different embodiments of the forming mandrel 1 and the pressure jacket 11 formed thereon are possible, as shown in FIGS. 1 to 6 shown and described.

The pressure shell 1 1, the mold 1, circumferentially completely or even partially surrounded, so that an inner mold or forming mandrel is formed, which acts on the inside of the molding or the sheet 2, which is particularly advantageous if the mold. 1 is used for forming the inner wall of a hollow profile as an inner mold or mandrel 1.

The pressure jacket 1 1 may also be provided on outer mold halves 3L, 3R, 300L, 300R and facing the mold cavity, so that an outer mold 300 is formed with pressure jacket 1 1 a forming device.

Claims

claims

1. molding tool (1, 1 a, 300) for forming a hollow profile (200) by means of a

Pressure jacket (1 1), in particular a tube, from a longitudinal profile, such as an unshaped board or sheet, wherein the molding tool (1, 1 a, 300) has a pressure chamber (12) which at least partially defined by the pressure jacket (1 1) is, by adjusting the internal pressure in the pressure chamber (12), the elongation and clamping force of the pressure shell (1 1) for forming the hollow profile by supplying and / or discharge of a pressure medium into the pressure chamber (12) taking into account the deformation of the hollow profile (200 ) is adjustable.

2. molding tool (1, 1 a, 300) according to claim 1, with a forming mandrel (1) having a in

Substantially circular, polygonal, concave and / or convex cross-section, and / or a movable between a closed position and an open position mold jaw (3L, 3R, 300L, 300R), wherein the forming mandrel (1) and / or the forming jaw (3L, 3R 300L, 300R) are at least partially surrounded by a pressure jacket (1 1).

3. molding tool (1, 1 a, 300) according to claim 1 or claim 2, wherein the pressure chamber

(12) in the longitudinal direction (L) of the molding tool (1, 1 a, 300) of the pressure shell (1 1) and transverse to the longitudinal direction of the molding tool (1, 1 a, 300) of a front side wall (16) is limited.

4. molding tool (1, 1 a, 300) according to claim 3, wherein on the side of

Endseitenwandung (16) facing away from the pressure chamber (12), a connection adapter (17) for coupling with an adjusting device for moving and / or rotating the mandrel (1), in particular in its longitudinal axis (L) and / or in its transverse axis and / or around its longitudinal axis and / or transverse axis, and / or a gutter or funnel-shaped collecting device (7) is arranged, which is connectable to a suction line (71).

5. molding tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 4, wherein in the pressure chamber (12) is arranged substantially centrally a mandrel core (14) at a radial distance from the pressure jacket (1 1), and / or the mandrel core (14) extends from the end wall (16) of the pressure chamber (12).

6. molding tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 5, wherein the pressure jacket (1 1) at least one intermediate wall (15 a), so the pressure chamber forms at least a second pressure chamber (12), wherein the subdivided pressure chambers (12) are arranged side by side and / or one above the other and / or have a honeycomb-like cross-section.

7. molding tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 6, wherein the pressure jacket (1 1) comprises a metallic material, in particular spring steel, or an elastomer or a polymer or an elastic composite material and / or reinforced is, in particular with fibers having polymer and / or elastomer.

8. molding tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 7, wherein the pressure chamber (12), each pressure chamber (12) or a predetermined number of pressure chambers (12) powered by at least one pressure line (13) is and / or can be supplied individually.

9. molding tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 8, wherein the pressure chamber (12) has a pressure measuring device or is connected to this and is connectable to a control and control unit for transmitting the measured values and / / or the pressure chamber (12) has at least one path measuring device (100) whose measuring direction (101) points radially to the pressure jacket (1 1) for detecting the actual value of the radial deflection of the pressure jacket (1 1) and / or by means of strain gauges with a control and control unit for transmitting the actual value can be connected to the same.

10. forming tool (1, 1 a, 300) according to at least one of the preceding claims 1 to 9, wherein at least one control and control unit controls the inflow and outflow of the pressure medium in and out of the respective pressure chambers (12), so that the internal pressure of the pressure chamber (12) or the bend of the pressure jacket (1 1) is adjusted to a predetermined desired value.

1 1. Forming device (A1, S1, S2) for producing a hollow profile, in particular one

Tube, wherein the forming device comprises at least a first and a second mold half (3L, 3R, 300L, 300R), which is formed between a closed state, in which a cavity for forming the hollow profile, and an open state for inserting a longitudinal profile to be formed, movable, wherein between the mold halves (3L, 3R, 300L, 300R) a mold (1) can be arranged, in particular a mold according to one of the preceding claims 1 to 1 1, wherein at least one of the mold halves (3L, 3R, 300L . 300R) and / or the molding tool (1) a pressure jacket (12) is arranged, which surrounds the shaping contour of the respective mold half (3L, 3R, 300L, 300R) or the mold (1, 1 a) at least partially or completely, so that a pressure chamber (12) is formed whose internal pressure is adjustable depending on the degree of deformation of the hollow profile.

12. Forming device according to claim 1 1, wherein the first and second mold halves

(3L, 3R, 300L, 300R) each have a recess (31 L, 31 R), which determine the outer contour of the hollow profile to be produced for forming a slot profile (2 a) with opposite longitudinal edges, wherein the molding tool (1, 1 a) during the sheet metal forming between the mold halves (3L, 3R, 300L, 300R) is arranged or after the collapse of the mold halves (3L, 3R, 300L, 300R) is inserted.

13. Forming device according to claim 1 1 or 12, wherein the forming device is a

Welding device (8) for Miteinader-welding the longitudinal edges of the slot profile (2a).

14. Forming device for bending a pipe (200) in a pipe bend having a predetermined bending radius, comprising in a first pipe end portion of the pipe to be bent (200) usable mold (1, 1 a), the one the mold (1, 1 a) at least partially surrounding pressure jacket (1 1) for centering and clamping the pipe end portion of the pipe to be bent (200), and a pivotable bending head (9), which can define a second, free Rohrend- section and the tube at plastically deformed a pivoting movement; and an adjusting device, which can move a portion of the pipe to be bent (200) along the forming mandrel (1, 1 a) in the direction of the bending head (9).

15. Forming device for roll forming a long profile in a roll forming device (T1) having a plurality of successively arranged profile rollers (900), wherein a molding tool (1, 1 a) with a transmission-free adjustable pressure jacket (1 1), in particular a molding tool is arranged according to one of claims 1 to 10, between the forming profile rollers (900).

16. Forming device for roll forming according to claim 15, wherein the molding tool

(1, 1 a) comprises a plurality of separately controllable / controllable pressure chambers (12) which are at least partially defined by the pressure jacket (1), and in the passage direction (901) and / or with respect to the profile rollers (900) are arranged. Forming device for roll profiling of hollow sections according to claims 15 or 16, wherein between the profiling rollers (900) arranged forming mandrel (1, 1 a) at least one pressure chamber (12) with pressure jacket (1 1) whose elongation and clamping force by means of the internal pressure in the Pressure chamber (12) is adjustable taking into account the degree of deformation of the hollow profile (200).

Method for producing a hollow profile, in particular a longitudinally welded pipe, by means of a molding tool (1, 1a, 300), in particular a molding tool (1, 1a, 300) according to one of claims 1 to 10, wherein the molding tool (1, 1a, 300) has a pressure chamber (12) with pressure jacket (1 1), the elongation and clamping force by means of the internal pressure in the pressure chamber (12) is adjustable taking into account the degree of deformation of the hollow profile.

Method for bending hollow sections, in particular tubes (200), in a tube bending device (B1) by means of a forming device, in particular a forming device according to claim 14, wherein by adjusting the radial expansion of the pressure jacket (1 1) the clamping force to the tube (200) taking into account the change in cross section when bending the tube (200) will change.

The method of claim 18 or 19, wherein an adjustment of the radial expansion and clamping force of the pressure jacket (1 1) of the molding tool (1, 1 a) by increasing or decreasing the internal pressure in the pressure chamber (12) is effected, wherein the radial expansion and Clamping force of the pressure jacket (12) with the movement of the forming outer mold halves (3L, 3R, 300L, 300R) is synchronized.

The method of at least one of claims 18 to 20, wherein the internal pressure in each pressure chamber (12) of the molding tool (1) is adjusted individually, so that sets over the pressure jacket surface of the pressure jacket (12) graduated course of the radial expansion and clamping force.

Method according to one of Claims 18 to 21 with a molding tool (1, 1a) according to at least one of Claims 1 to 10, wherein the position of the molding tool (1, 1a) is synchronized with the movement of the shaping outer mold halves (3L , 3R, 300) or during the welding of a joint gap of the shaped hollow profile, the movement of the molding tool (1, 1 a) is synchronized with the welding movement (82), wherein a lateral offset to the current welding position (82) is maintained. A method according to claim 22, wherein the radial elongation and resilience of the

Pressure jacket (1 1) of the mold (1) with the movement of the bending head (91) and / or a feed movement of the tube (200) synchronized in time and adjusted.