EP1371429A1 - Device for the manufacture of tubes - Google Patents

Abstract

The holder (1-14, 16, 17) has a longitudinal edge guide (4, 5, 6) against which both edges are brought together. The guide lies radially outside the approximate form of the tube to be produced. It is designed to deform the band material radially-inwardly, into the approximate tubular form. It acts against the elasticity of the material, which bears against the longitudinal edge guide (6). In a region of the tube circumference remote from the longitudinal edges, the holder permits the tube free to undergo elastic deformation An Independent claim is included for the corresponding method.

Description

The invention relates to a device for producing pipes Sheeting.

With web material there are flat, flexible, but at least something residual elastic materials are meant, such as thin plastic materials and especially metal sheets. If such web material has two longitudinal edges, which are generally, but not necessarily, parallel to each other, so can be made from the web material by round bending and Connect the two now opposite or abutting Longitudinal edges.

The manufacture of pipes in this way is basically known. However, there are Difficulties repeatedly occurred, the two long edges sufficient to bring them exactly into contact with each other to ensure a good connection. This applies to both point connections and continuous connections Connections between the longitudinal edges. Such are particularly pronounced Difficulties with thin-walled material. For one thing, they are caused by the small thicknesses of the in particular with thin-walled material surfaces of the longitudinal edges to be put together, secondly with individual ones Applications also certain tolerances of the pipe circumference Width of the web material, i.e. the distance between the two longitudinal edges, that lead to difficulties.

The invention is based on the technical problem, an improved device to specify for the production of pipe from web material. In particular, the In this case, the invention relates to an apparatus and a method for producing Metal pipes made of thin-walled metal sheets. Specifically, the production of Metal pipes are improved, which are caused by an axial deformation into bellows to be processed, such as for exhausts from Internal combustion engines are needed.

The invention is directed to an apparatus for making pipe from something elastic web material by connecting two longitudinal edges of the web material, which device comprises: a holding device for holding the web material in a cross-sectional shape approximating the pipe to be produced, which the Can bring longitudinal edges into contact with each other at least in places, and one Connection device for connecting the longitudinal edges at least in places with each other, characterized in that the holding device a Has longitudinal edge stop against which both longitudinal edges at least are to be brought into system in places and the radially outside of the approximate pipe cross-sectional shape, the holding device designed for this is the sheet material in the approximate tube cross-sectional shape against the elasticity of the web material through the system on the longitudinal edge stop radially inwards to deform, and the holding device the web material in one of the Longitudinal edges removed the area of the circumference of the approximate tube shape leaves elastic deformation free.

This device is preferably used for the production of Metal pipes made of thin-walled metal sheets, which have material thicknesses in the area can have from 0.05 to 1 mm.

Finally, the invention also relates to a method for producing Bellows, especially for internal combustion engine exhausts, where the for the axial deformation to the bellows serving metal pipes with the device according to the invention and the method according to the invention become. The invention is characterized by a special embodiment of the Holding the web material used holding device. This holding device has the task to put the two longitudinal edges together so that they can be connected. According to the invention there is a longitudinal edge stop provided, against which both longitudinal edges come into contact and the outside of that already approximated by the holding device Pipe cross section. In the simplest case, this is Longitudinal edge stop around a flat surface or straight edge on which the two Longitudinal edges rest so that they pass through the system to the longitudinal edge stop can be brought into contact with each other almost automatically. This is the Holding device designed so that the web material against his Self-elasticity slightly deformed inwards.

Here and in the following, we speak of "radially" inside or outside, but this does not mean any restriction to circular cross-sections of the finished tube cross-sectional shape or one approximated during the connection process. In principle, completely different cross-sectional shapes could also be produced in the manner according to the invention, in particular those which have one or more edges and / or are round, but not circular. The area with the longitudinal edges should, however, be directed a little outwards between the longitudinal edges before the manufacturer of the system. In practice, however, circular cross-sectional shapes almost exclusively play a role. The _" radial" direction generally means a direction perpendicular to the longitudinal direction of the pipe to be produced, that is to say to the longitudinal edges, and also approximately perpendicular to the web material in the local vicinity of the longitudinal edges.

To the elastic deformation of the web material in its cross-sectional shape allow, the holding device is further designed so that it the web material deformed radially inwards by the longitudinal edge stop and if necessary also holds in other places, but in at least one of the long edges removed area of the circumference of the approximate tube shape so far that the cross-sectional shape can change there elastically to the elastic To allow deformation by the longitudinal edge stop. Thereby of it assumed that the web material is not within its flat shape lying directions compresses, so that the elastic impression by the Longitudinal edge stop with a deformation, in particular a bulge must be linked elsewhere.

The invention relates to various conceivable techniques for connecting the two longitudinal edges, for example on gluing or soldering. However, the is preferred Use in welded joints. As already explained at the beginning, the Application of the invention to the manufacture of metal tubes from sheet metal prefers.

The already explained elastic deformation of the approximate tube cross-sectional shape by the longitudinal edge stop can preferably not only go so far that a deformation against the deformation of the approximate tube shape opposing inherent elasticity of the web material takes place, but the approximated Pipe shape through the longitudinal edge stop locally to a certain extent is pressed.

The approximate tube shape is thus in the elastic deformation by the Longitudinal edge stop locally flatter than the final pipe, so it has one larger radius of curvature than in the final pipe. This statement applies of course for a connection of longitudinal edges in one seen from the outside convex area of the tube cross-sectional shape. These relationships are with the most possible tube cross-sectional shapes, in particular with circular cross-sectional shapes.

The cross-sectional shape of the longitudinal edge stop, i.e. the contact line, is included preferably a larger radius of curvature than the radius of curvature of it touching part of the approximate tube shape. The investment line is preferred just. However, it could also be convex, but generally not bring special advantages.

Furthermore, two can be seen laterally from the longitudinal edge stop Side stops are provided, which support the approximate tube shape laterally, at an approximately circular tube shape, for example at an angular distance of about 90 ° to the long edges. This allows the peripheral portion of the Approximate tube shape between the longitudinal edges and the sections that the Side stops abut, at least a substantial part of the elastic Deformation to compensate for that caused by the longitudinal edge stop wear elastic indentation. For further illustration, reference is made to the Reference embodiment.

In principle, the invention for tube production from endless sheet material is the thus only has the two longitudinal edges, and also for the production Suitable piece material. The production of finite pipe sections is preferred Pieces of web material. Incidentally, the longitudinal edges do not necessarily have to longer than the edges of the web material corresponding to the pipe circumference. The Concept formation only follows from the later situation, which is essentially parallel to the pipe longitudinal axis is oriented.

In the case of such a discontinuous pipe production, however, it is preferred to elastically press inward the possibility, given in principle, of deforming the entire piece of web material in one piece by means of a longitudinal stop which extends over the entire longitudinal extent, and thus the longitudinal edges along their entire length into a connection such as not using welding, bringing suitable systems together. Rather, a relative movement should preferably be provided between a longitudinal edge stop that does not extend over the entire longitudinal extent, that is to say only a small part of it, and the longitudinal edges, so that the longitudinal edge stop is, as it were, displaced along the pipe or the pipe is displaced along the longitudinal edge stop. At the same time, it is preferably provided that the device necessary for the connection itself, for example a welding device, is also displaced at a short distance from the longitudinal edge stop and connects the longitudinal edges which are in contact with one another _" behind" the longitudinal edge stop (or also directly in front of it). The relative movement is preferably provided in such a way that the web material, for example the metal sheet, is moved and the longitudinal edge stop and the connecting device are fixed. For this purpose, the holding device will generally also be movable.

The longitudinal edge stop can have a role or essentially consist of a roll and therefore roll on the longitudinal edges. This is in Embodiment shown. This role or another Embodiment of the longitudinal edge stop is preferably perpendicular to Longitudinal direction, i.e. radial, adjustable. So that different Pipe cross-section sizes are produced or fine adjustments for optimization the operation of the device.

Furthermore, an inner counter bearing is preferably radially within the approximated one Pipe cross-sectional shape provided. This inner counter bearing should at least End of the elastic indentation of the approximate tube cross-sectional shape the longitudinal edge stop is in contact with the area of the longitudinal edges. The Longitudinal edge stop can the two longitudinal edges on this inner Press on counter bearing. This is illustrated in the exemplary embodiment.

At this point it should be noted that the inner counter bearing is not essential in the strict sense must come into contact with the longitudinal edges themselves. It is For example, preferred, a protective gas channel in the inner counter bearing To provide welding or soldering that runs directly along the longitudinal edges. However, the inner counter bearing should be the one directly adjacent to the longitudinal edges Support the area of the web material. The benchmark is the malleability given the web material. That means the inner counter bearing only so far away from the long edges that the remaining section of the The circumference of the tube shape is quasi rigid. The same could also apply to the Longitudinal edge stop apply, although here is preferred, on a groove or to do without a channel. Finally, a centering device is advantageous, which Web material centered in the holding device so that the longitudinal edges with respect a rotation in the circumferential direction are adjusted sufficiently well. This can preferably a nose or some other projection may be provided engages adjustably in the slot remaining between the longitudinal edges.

Furthermore, the holding device with a device for fixing the Web material in the position adjusted in this way, one is preferred here Clamping device, which preferably further on one of the longitudinal edges the opposite point has a clamping effect on the web material. This is part of it such a clamping device radially within the approximate tube shape provided and another part outside. In the embodiment, for example are radially driven clamping jaws on the outside and one as a counter bearing serving surface.

The preferred welding technique for sheet metal in this invention is Laser welding. Technical details on this are not clarified because it is is an established standard technology. The invention sees however, before, with the relative movement between the web material and the Welding device to use an optical detection that the slot between the longitudinal edges optically using a CCD camera or in an analogous manner detected and outputs an actuating signal with which the relative movement or Correction movement is controlled adjusting. For example, the Longitudinal movement with one of two crossed linear units, the second linear unit is used to adjust the laser impact spot on the longitudinal edges. However, it is also possible, for example, the longitudinal movement over a Generate linear unit and the laser via a servomotor driven Adjust mirror. It is essential, however, that the laser impact spot through optical tracking of the slot with sufficient accuracy on the two in the system mutually located longitudinal edges is moved.

The production of thin-walled tubes is preferred, in particular Material thicknesses of 0.05 to 1 mm are to be considered. Such pipes, in particular those made of sheet steel, can be caused by an axial deformation Bellows are processed. This axial deformation is known in principle and is not explained in detail here. However, this case represents a preferred one Application for the invention there. Because especially with bellows like this used for example for motor vehicle exhausts, represents the quality of the Weld between the longitudinal edges, i.e. their continuous tightness on the one hand and its stability when deformed into bellows, is a particular problem. The invention has made significant progress here.

An exemplary embodiment is explained in detail below, which is used for illustration and is not meant to be limiting. Individual features disclosed here can also be essential to the invention in other combinations or in each case. The the above and the following description are both related to Device features as well as in relation to corresponding process features understand.

Figur 1 eine Seitenansicht einer erfindungsgemäßen Halteeinrichtung einer Vorrichtung zur Herstellung von Rohren, die teilweise geschnitten ist;

Figur 2 eine ebenfalls teils geschnittene Seitenansicht der Vorrichtung aus Figur 1, jedoch in dazu um 90° gedrehter Perspektive;

Figur 3 eine Draufsicht auf die Vorrichtung aus den Figuren 1 und 2;

Figur 4 eine Figur 2 entsprechende Schnittansicht, jedoch nur eines Ausschnitts und in einer anderen Schnittebene.

In detail shows:

Figure 1 is a side view of a holding device according to the invention of a device for producing pipes, which is partially cut;

FIG. 2 shows a side view of the device from FIG. 1, also partly in section, but in a perspective rotated by 90 °;

Figure 3 is a plan view of the device of Figures 1 and 2;

Figure 4 is a sectional view corresponding to Figure 2, but only a section and in another sectional plane.

Figure 1 shows the holding device according to the invention for the device Pipe production from sheet metal in side view. On a base plate 1 is one Linear guide 2 with a linear movement via a spindle drive Sled plate 3 arranged. There is also a holding frame 4 on the base plate 1 constructed on which a cylinder 5 via a vertically oriented linear guide is movable. The cylinder 5 carries a pressure roller 6 at its lower end Longitudinal edge stop.

On the slide plate 3, a support plate 7 is attached, on which in FIG right end a mandrel 8 is mounted. The mandrel 8 stops from the right Apart from that, there is a small intermediate distance to the support plate 7, which is 9 is designated. At the left end of the mandrel 8 in FIG. 1 there is a detachable one Counter bearing 10 attached. This is shown in Figure 1, wherein it Mandrel 8 supports against the platen 7. This additional support over the counter bearing 10 is advantageous because of the length of the intermediate space 9. If that Counter bearing 10 is removed, the mandrel 8 is thus on its (according to FIG 1) right end held on the support plate 7 and the space 9 from the left accessible. The counter bearing 10 is also at its upper end drawn locking screw fixed.

FIG. 2 shows a section through the arrangement from FIG. 1, in which the mandrel 8 on the support plate 7 and the slide plate 3 is shown in section, however not the holding frame 4 with the linearly guided cylinder 5. However, the Pinch roller 6 shown in section.

It can be seen in FIG. 2 that (there on the right and left) to the side of the mandrel 8 two side stop plates 11 are vertical and at their respective are attached to the lower end of the support plate 7. Comparing Figures 1 and 2 it can also be seen that the mandrel 8 has a total of eight along its length Has clamping cylinder 12, one of which is shown in section in Figure 2. These clamping cylinders are pneumatically driven. In the rest position they are in the Mandrel 8, in such a way that its underside is flush with the space 9 facing underside of the mandrel 8 is. If pneumatic are applied, press their underside down into this space 9. The clamping cylinders 12 can also be clearly seen in the top view in FIG. 3 because insofar as this top view is kept transparent.

The cross section in FIG. 2 shows the pneumatic supply to the clamping cylinders 12 in the form of the central line 17 in the mandrel 8 and the central of this Line 17 downward junction. The central line 17 with the Branches to the clamping cylinders 12 is also in their in Figure 1 Shown longitudinal extension, with the pneumatic connection on the right in FIG is recognizable.

FIG. 4 again shows the mandrel 8 at its left end in FIG Section, the side stop plates 11, likewise recognizable in FIG. 1, not cut, but are shown in front view. You can see on the Side plates 11 and these connecting a centering plate 13, which also in Figure 1 is shown. This centering plate 13 can be along the side stop plates 11 move and also remove upwards. It has a center in Figure 4 downward centering lug 14.

The function of the device shown is as follows: If the counter bearing 10 is opened, a sheet metal 15 bent approximately to a tube, the is shown in Figures 2 and 4, between the side stop plates 11 and the mandrel 8 on the one hand and between the mandrel 8 and the support plate 7 on the other hand, that is, into the intermediate space 9. The should Longitudinal edges to be connected during pipe production in the sense of the figures above lie.

With the help of the centering plate 13 and its centering nose 14 can between Longitudinal remaining slots are centered, this centering plate 13th can be moved along the side stop plates 11 to this Ensure centering for the entire length of the sheet 15. If the tin 15 is centered, the pneumatic clamping cylinders 12 are acted upon and clamp the sheet 15 in the intermediate space 9 against the support plate 7.

In this situation, the sheet 15 is fixed within the holding device and is by the side stop plates 11 laterally compressed so that the horizontal distance between these side stop plates 11 slightly smaller than the later aimed pipe diameter.

Now the pinch roller 6 can on the cylinder 5 on the holding frame 4 in so far the vertical direction that the pressure roller 6 on the Longitudinal edges sits on the upper end of the sheet 15 and both longitudinal edges and so that the upper area of the sheet 15 presses somewhat inwards. This is supposed to preferably so far that the distance between the pressure roller 6 and the platen 7 is slightly smaller than the later aimed diameter of the pipe. This leads due to the clamping by the side stop plates 11 ultimately to the fact that the upper region of the sheet 15, that is to say the two in FIG upper quadrant, is deformed. As a result, the sheet 15 is in the immediate vicinity The area around the longitudinal edges in the upper area is flatter, so it shows something larger radius of curvature than in the ultimately aimed pipe shape. something similar applies to the areas of the sheet 15 that are connected to the side stop plates 11 nudge.

Between these flatter areas, the sheet 15 is in cleared areas 18 in the compensation convex, so has a smaller radius of curvature than that final tube shape. This expresses the elastic tension of the Sheet 15, in particular the two upper quadrants (according to Figure 4), the Longitudinal edges along the section line of the cross section according to FIG Pinch roller 6 inwards and against each other. By the pressure roller 6, the Do not dodge the longitudinal edges, but hit the middle of the pressure roller 6 together. If now the holding device, ie the slide plate 3 with your Structure of support plate 7, mandrel 8, side stop plates 11, etc., through the Linear guide 2 is moved in the horizontal direction in the sense of FIG. 1, rolls the pressure roller 6 over the longitudinal edges of the sheet 15 and brings them in each case in the area of your plant together in the manner described.

The whole device makes sense, the pressure roller 6 with a Welding laser, which is not shown in the figures, is to be traced as directly as possible, to weld the longitudinal edges together there. In principle, the laser could drive ahead of the pinch roller 6, but follow-up is preferred. there pressure roller 6 and laser impact spot are basically stationary because the plate 15 with his holding device is moved. The laser spot is from the Perspective of the sheet 15 downstream of the pressure roller 6. Is upstream this, however, an optical recording of the remaining slot between the longitudinal edges of the sheet 15, with their help the laser spot in the horizontal direction perpendicular to the direction of movement Direction (horizontal in Figure 2 and orthogonal on the drawing plane in Figure 1) is adjusted. This can ensure that the laser has the longitudinal edges always hits exactly.

The centering plate 13 can be removed if it interferes.

The mandrel 8 contains in its upper area a counter bearing 16 for the Pinch roller 6, which is shown in Figure 2. This counter bearing limits the way the pressure roller 6 down and comes into contact with the environment Longitudinal edges of the sheet 15. On the one hand, the counter bearing 16 contains one directly groove lying under the longitudinal edges and running in the longitudinal direction, which as Shielding gas channel for welding. Secondly, the counter bearing 16 a thermal contact of the surroundings of the longitudinal edges of the sheet 15 to the Mandrel 8 is, which in turn is water-cooled in a manner not shown.

In addition, protective gas can also be applied from outside in the area of the laser impact spot are fed.

Overall, the device according to the invention allows simple and efficient Production of the weld seam between the longitudinal edges for the production of the pipe from the sheet 15. Tolerances of the straightness of the longitudinal edges and Tolerances of the width of the sheet 15 corresponding to the pipe circumference as a result of elastic deformation of the sheet 15 when welding easily, efficiently and be balanced automatically. The results are very reliable, resilient and flawless welds, which are particularly evident in the later manufacture of Proven bellows for exhausts by longitudinally deforming the metal pipes.

Claims (16)

Device for producing pipe from some elastic web material (15) by connecting two longitudinal edges of the web material (15), which device comprises: a holding device (1-14, 16, 17) for holding the web material (15) in a cross-sectional shape approximating the pipe to be produced, which can bring the longitudinal edges into contact with one another at least in places, and a connecting device for connecting the longitudinal edges to one another at least in places, characterized, that the holding device (1-14, 16, 17) has a longitudinal edge stop (4, 5, 6) against which both longitudinal edges have to be brought into contact at least in places and which is located radially outside of the approximate tube cross-sectional shape, wherein the holding device (1-14, 16, 17) is designed to radially inwardly deform the web material (15) in the approximate tubular cross-sectional shape against the elasticity of the web material (15) by the contact with the longitudinal edge stop (6), and the holding device (1-14, 16, 17) leaves the web material (15) free for elastic deformation in a region (18) of the circumference of the approximate tube shape that is distant from the longitudinal edges. Apparatus according to claim 1, which is adapted to the longitudinal edges to be welded together at least in places. Apparatus according to claim 1 or 2, wherein the sheet material is sheet metal (15) is. Device according to one of the preceding claims, in which the system the longitudinal edge stop (4, 5, 6) a cross-sectional shape of the approximate Pipe cross-sectional shape with compared to the cross-sectional shape of the finished Rohres increased radius of curvature. Device according to one of the preceding claims, wherein the Holding device (1-14, 16, 17) on both sides of the longitudinal edges of these spaced a side stop (11) for the web material (15) has, the holding device (1-14, 16, 17) being designed overall so that the elastic deformation of the web material (15) into one essential part between the longitudinal edges and at the Side stops (11) adjacent areas (18) of the circumference of the approximate pipe cross-sectional shape occurs. Device according to one of the preceding claims, which for discontinuous production of finite pipes from finite pieces of Web material (15) is designed. Apparatus according to claim 6, which is designed so that between the Longitudinal edges of the web material (15) on the one hand and the longitudinal edge stop (4, 5, 6) on the one hand and simultaneously between the longitudinal edges and a device for connecting the longitudinal edges on the other hand Relative movement takes place along the longitudinal edges. Apparatus according to claim 7, wherein the longitudinal edge stop (4, 5, 6) one Has longitudinal edge contact roller (6). Apparatus according to claim 7 or 8, wherein the longitudinal edge stop (4, 5, 6) is radially adjustable (5). Device according to one of the preceding claims, wherein the Holding device (1-14, 16, 17) a counter bearing (8) for the longitudinal edges has that at least after the elastic deformation in contact with an area adjacent to the longitudinal edges of the circumference of the approximate tube cross-sectional shape comes and radially within the approximate pipe cross-sectional shape. Apparatus according to claim 2, 3 and 10, wherein the counter bearing (8) one Has protective gas channel for supplying protective gas to an area in which the longitudinal edges are being joined together. Device according to one of the preceding claims, wherein the Holding device (1-14, 16, 17) a centering device (13, 14) for Centering the web material (15) having a projection (14) has that in a between the longitudinal edges in front of the elastic Deformation due to the slot remaining on the longitudinal edge stop (4, 5, 6) can be introduced. Device according to one of the preceding claims, wherein the Holding device (1-14, 16, 17) one radially from the inside onto one of the two Longitudinal edges approximately equally spaced portion of the circumference of the approximating tubular shape acting clamping device (9). Device according to one of the preceding claims, at least claim 2, in which the welding device has a laser and also a Detection device for optically detecting a slot between the Has longitudinal edges before welding, which is a signal for a Relative adjustment between the impact spot of the laser and the to Welding merged longitudinal edges provides, the Relative adjustment in one to the laser impact direction and to the longitudinal edges vertical direction. Method of manufacturing metal pipes from sheet metal (15) using a device according to one of the preceding claims. A method of making bellows, including a method according to Claim 15 and an axial deformation of the finished metal tubes to the bellows.

Images