Stabilizer

Abstract

A stabilizer (20) is disclosed, comprising a rod end formed into a stabilizer blade (22), such that the stabilizer (20) has a central section (24), the stabilizer blade (22), and a transition region (26) between the central section (24) and the stabilizer blade (22). A hole is formed in the stabilizer blade by laser cutting, or a contour of the stabilizer blade is formed by laser cutting.

Description

The invention relates to the production of stabilizers, in particular stabilizers for motor vehicles, with a rod end formed into a stabilizer blade.Conventional end processing of a stabilizer typically provides the following process flow: the rod ends are first heated inductively (one-sidedly successively or parallel on both sides), for example to a temperature range of 650-1200° C. The temperature is dependent on various geometric and customer-specific requirements, such as dimensional accuracy, hardness values, service life requirements, etc. A mechanical press processing is then carried out, wherein the heated rod end is hot-formed ("plateaued") in successive steps for forming the stabilizer blade, the formed stabilizer blade is perforated and optionally cut, and the blade surfaces are finally calibrated with regard to required / required levels of flatness and parallelism. Optionally, a bending operation of the formed stabilizer blade is possible between the hot forming and the punching / cutting.The shaping of the flattened stabilizer blade (cutting) and the introduction of a hole for receiving the chassis (punching) are currently carried out in each case by means of a mechanical cutting process. However, the tools for cutting and piercing are expensive to purchase and expensive to maintain, for example, by replacing spare and worn parts. In particular, it is necessary to regularly replace the cutting surface of the tool, since it wears and the quality of the trimming deteriorates as the useful life increases. For example, the use of tools can result in undesirable burrs on the cut surfaces. The probability increases with increasing useful life of the cut surface.Because of the burr formation and bending due to mechanical friction effects during the mechanical punching / cutting, calibration is also necessary or at least advantageous. During calibration, the screwing surfaces are pressed against one another again on the already flattened and perforated stabilizer blade. So-called calibration punches are used which ensure the necessary customer requirements with regard to flatness and parallelism on the sheet surfaces by pressing them onto one another on both sides. Thus, loosening of the screws by, for example, setting behavior or "oblique" attachment can be avoided with insufficient parallelism. Optionally, the burr formed during the piercing is also pressed against the underside of the bore again and reduced / avoided with the aid of a cone.The object of the present invention is therefore to provide an improved concept for stabilizers.The object is achieved by the subject matter of the independent claims. Further advantageous embodiments are the subject matter of the dependent claims.Exemplary embodiments show a stabilizer with a rod end formed into a stabilizer blade, so that the stabilizer has a central section, the stabilizer blade and a transition region between the central section and the stabilizer blade. The stabilizer can comprise a (spring) steel or consist predominantly of a steel, in particular a spring steel. Suitable spring steels are, for example, 26MnB5, 34MnB5, 40MnB5. In general, however, all materials which can be trimmed by means of a laser and which meet the mechanical requirements imposed on a stabilizer are suitable.A hole is made in the stabilizer blade by means of laser cutting (in contrast to mechanical punching). Additionally or alternatively, a contour of the stabilizer blade is shaped by means of laser cutting (in contrast to mechanical cutting).It is thus an idea to replace the mechanical process of punching and / or cutting by a process by means of a laser. A uniform sectional image over the entire useful life is thus guaranteed and, for example, the formation of burrs is avoided. Furthermore, the process is easier to automate by means of a laser than by means of a tool. Moreover, for the mechanical cutting, a certain amount of protrusion of the blade end is necessary in order to obtain a straight cutting edge. The waste can thus be reduced by means of the laser. Production is thus more favorable. Furthermore, when piercing or cutting with the laser, calibration of the stabilizer blade can be dispensed with.In exemplary embodiments, the stabilizer has a weld seam in the region of the transition region or of the stabilizer blade. The weld seam is advantageous in particular when using a pipe stabilizer as a stabilizer. The pipe stabilizer has a pipe section as a central section and a pipe end as a rod end.Studies have shown that the blade ends of a tube stabilizer after the hot forming process ("plateaus") are generally virtually free of gaps (a few μm) and are therefore virtually liquid-tight. Without a material bond, however, capillary action cannot be avoided, as a result of which nevertheless (negligibly) small amounts of moisture can penetrate into the tube stabilizer. The mechanical and tool-bound subsequent process of punching / cutting promotes the pulling apart of both blade surfaces by frictional effects, whereby the gap between the two blade surfaces is enlarged and the tightness is further reduced. The consequences of a gap are, on the one hand, a possible entry of corrosive fluids, for example water, other process media such as, for example, pretreatment in the painting process, gases such as, for example, oxygen, etc., which represent later starting points for corrosion formation on the inner surface of the stabilizer. The failure of the component is thus promoted by possible corrosion-induced damage to the material. On the other hand, further deficiencies in quality occur during the painting process, since emerging fluids can have a negative influence on the coating at the blade end during powder painting and baking. Consequently, the penetration and escape of (corrosive) fluids into the unplated pipe region and out of the unplated pipe region at the blade end is to be prevented.Various methods of sealing are already known. For example, U.S. Pat. No. 6,547,894 B1 discloses the introduction of a fusion welding powder such as sodium tetraborate between the blade surfaces. By heating, the powder melts and joins together both sheet surfaces formed on top of each other, which are flattened. However, it has been found that the application of the fusion welding powder, and thus the entire method, cannot be reliably automated. Furthermore, sodium tetraborate is shown to be hazardous to health in humans due to its boron content. Alternative methods for sealing the pipe stabilizer have not been able to produce reliable tightness of the pipe stabilizer up to now.By using a weld seam in the region of the transition region or the stabilizer blade, gas and / or liquid exchange between inner pipe (i.e. the pipe section) and the environment is avoided. In particular, the weld is formed in the absence of a welding additive. Welding filler materials are usually supplied in the form of powders, rods or wires, melted and solidified in the joint between the joining partners in order to thus produce the connection. Without welding additive, the weld seam is produced exclusively by melting the materials, here the two sheet surfaces, so that the two materials fuse.This eliminates the difficult-to-automate step of applying the welding additive. Welding additives are to be distinguished from welding additives, such as inert gases, fluxes, vacuum (e.g. in electron beam welding), pastes or welding powders, which facilitate welding or even make it possible for the first time. The welding powder is used, for example, in submerged arc welding and is not to be confused with fusion welding powder as a welding additive. Examples of welding methods used without welding additives are deep welding (laser welding for short), heat conduction welding, resistance welding, laser beam-GMAW hybrid welding, laser welding in vacuum, laser transmission welding, gas fusion welding, arc hand welding, inert gas welding, submerged arc welding, electron beam welding, fire welding, cold pressure welding, friction welding, explosive welding, electromagnetic pulse welding, diffusion welding, MBP welding, arc stud welding or build-up welding. That is, the weld may be created using any of the foregoing welding methods or any combination thereof.It is of course possible to provide a plurality of welded seams instead of a single welded seam. Furthermore, the weld seam can be formed in different variants, the embodiments of which vary in a wide variety of criteria. The following criteria should be mentioned as examples at this point: arrangement or position (position of the weld seam / weld seams on the blade / arrangement of the weld seams relative to one another), shape (weld seam width, weld seam height, straight-drawn weld seam, half-round drawn weld seam, wavy drawn weld seam, arbitrarily shaped drawn weld seam, etc.), embodiment (single-layer or multi-layer weld seam).Thus, a manual, but also automatable welding process for the pipe end of the pipe stabilizer can be created. The two blade surfaces are connected to one another completely in a materially bonded and tight manner in the direction of the non-deformed tube cross section. This also results in the loss of quality due to poor paint adhesion due to fluids that may leak from the pipe stabilizer during the painting process. Furthermore, the addition of preservation media in the tube stabilizer for protecting the inner surface from corrosion is dispensed with. Furthermore, the welding process offers the advantage that the pipe stabilizer is closed in a fluid-tight manner even under reduced or excess pressure conditions. This is advantageous, for example, in the case of changing external temperatures during operation and also, for example, during production during an annealing process. During the tempering process, the pipe stabilizer is quenched after heating in a quenching medium, whereby large temperature and thus also pressure differences are rapidly established as a result of the enclosed air volume in the pipe stabilizer. Under these conditions, too, the tube stabilizer should be closed in a further fluid-tight manner.The weld seam is preferably formed by means of laser welding. Laser welding has the advantage that the energy is introduced into the material by means of a laser beam bundled by an optical system. By changing the optics in an automatable manner, weld seams of different widths and different depths can accordingly be realized, for example. Furthermore, the cycle times, i.e. the time until the weld seam is produced, can be adjusted in this way if the energy acts on the material in a more or less concentrated manner. The laser power is likewise adjustable and can be adjusted, for example, to different sheet thicknesses. Thus, knowing the pipe stabilizer to be welded, the weld may be automatically adjusted to, e.g., a material or wall thickness of the pipe stabilizer. The automated steps described in this disclosure may be performed by a computing unit, i.e., a computer.In conjunction with laser cutting, it is possible to use the same laser (=energization source) for laser welding. It may only be advantageous to use a different optical system for concentrating the light in order to switch between laser welding and laser cutting. The optics can be arranged in parallel on the laser, i.e. on a light source, and can be controlled by software and / or hardware switching. The optics can be connected to the light source by means of two optical waveguides. This step can likewise be automated well. However, it is also possible to use different lasers.In exemplary embodiments, the weld seam is formed on the head side, preferably over the entire width of the stabilizer blade, on the stabilizer blade. Thus, it is not necessary, for melting both sheet surfaces, to first penetrate the upper sheet surface in order to liquify material of the lower sheet surface. On the head side, both sheet surfaces are visible and can be melted simultaneously. Thus, less energy is required for welding and the welding operation is completed more quickly. However, it is then advantageous if an aperture (also referred to as a bore) through the stabilizer blade, which can serve for fastening the pipe stabilizer to the chassis, likewise has a laterally (preferably completely) encircling further weld seam which is arranged within the aperture. Or, respectively, and. Thus, the cut gap of the opening can be sealed. If all open areas of the pipe stabilizer are completely sealed at one end and no liquid can enter, at least from one side. Advantageously, both sides of the pipe stabilizer are also sealed off accordingly by means of the weld seam. For example, both ends of the pipe stabilizer are designed symmetrically or identically.Additionally or alternatively, the aperture can be sealed by the stabilizer blade with respect to the transition region or with respect to the pipe section. This can be effected, for example, by means of a weld seam which is formed laterally on the stabilizer blade or the transition region. The weld seam is arranged in this case between the pipe section and the aperture. Preferably, the weld seam extends over the entire width of the stabilizer blade or of the transition region. However, it is also possible to achieve the sealing of the blade end by means of a plurality of welds, wherein not all welds need to extend over the entire width of the stabilizer blade. For example, the hole can be sealed on the inside circumferentially by a weld seam.In order to avoid a protruding weld seam in the bore or also on any outer side of the stabilizer blade, it may be advantageous to design the bore or generally the trimming not identically continuously, but rather to provide it, for example, conically or with a shoulder around the parting plane of the blade surfaces. Such a shape can be realized more easily with a laser than with a tool. Thus, in the range of a few tenths of a millimeter, space is created for the weld seam without injuring the tolerance requirements, so that e.g. the screw connection is not impaired. Additionally or alternatively, the region of the later weld seam in the region of the parting plane or the surface of the stabilizer blade can be processed subsequently, for example with a laser, in order to remove material for the weld seam and to avoid protrusion of the weld seam. A laser which is also suitable is, for example, the laser for cutting and / or punching the stabilizer blade. Optionally, however, a different optics or a different power or a different parameter of the laser is then to be selected.In general, it is possible to introduce at least one weld seam either between the transition region and the aperture, between the blade end and the aperture, around the aperture, or directly circumferentially at the cutting gap of the aperture or at the end trimming in various geometries and seam widths and other embodiments individually, multiplely or in any combination. This solution approach offers the advantage of a material-bonded connection of the two pressed-on blade surfaces and thus ensures a complete tightness of the stabilizer end.In further exemplary embodiments, the laser can also be used for marking, in particular engraving, the stabilizer. This enables the clear traceability of the stabilizer. As a characterizing marking, for example, a combination of numbers and / or letters can be used.Further disclosed is a method of making a cold bent stabilizer from a rod comprising the steps of: a) forging the rod or tempered stabilizer to obtain a forged rod or forged stabilizer; b) bending the rod or forged rod to obtain a stabilizer; c) tempering the bent rod to obtain a tempered stabilizer. Forging the tube comprises the following steps: a1) flattening an end of the rod such that the forged rod has a central portion, a stabilizer blade and a transition region between the central portion and the stabilizer blade; and a1a) making a hole in the stabilizer blade by means of laser cutting and / or a1b) forming a contour of the stabilizer blade by means of laser cutting. In the case of manufacturing a cold bent pipe stabilizer, a pipe is used as the rod. Otherwise, a full rod is used as the rod.In exemplary embodiments, the forging of the tube of a tube stabilizer additionally has the following further step:a2) creating a weld seam in the region of the transition region or of the stabilizer blade in order to seal the pipe section as a central section against liquid and / or gas exchange with the environment. Optionally, forging after stamping and before welding may include further process steps such as piercing and / or cutting the stabilizer blade.The production of the weld seam in step a 2) and the introduction of the hole in step a 1 a) or the shaping of the contour in step a 1 b) can be carried out using the same laser, wherein a change of the optics of the laser system can be carried out between the steps in order to use the laser either for cutting or for welding. The order of the steps of welding a 2) and cutting (a 1 aand a 1 b) is interchangeable. However, it is also possible to carry out the cutting and the welding in parallel, in particular with different lasers / light sources.By way of example, the method steps a), b) and c) can be carried out in alphabetical order, i.e. in the process order a), b) and c). Alternatively, it is possible that the method steps a), b) and c) are carried out in the process sequence b), c), a).Cold-bent tube stabilizers are currently usually piece-tempered after shaping and subsequently the stabilizer blades are forged on, i.e. in particular the ends are flattened (see also description in the introductory part). This results in lower efficiency for forging, in particular because of the complicated handling of the already bent stabilizers.By reliably sealing the pipe ends, it now becomes possible to modify the process flow in such a way that forging can be carried out with the flattening and sealing of the pipe stabilizer flattened to form the stabilizer blade, before the tempering and thus also before the bending of the pipe stabilizer (process sequence: a), b), c)). The penetration of the quenching medium during the annealing is reliably prevented by the sealed end of the tube stabilizer. By changing the sequence, considerable increases in efficiency, in particular in the forging process, are to be expected. Instead of the complicated handling of bent, tempered tubes, usually by means of an industrial robot (which is generally stationary), the straight tube can be fed in parallel to the possible, different forging stages via a linear cycle system. The closing can likewise be integrated into this process step, for example in the form of a welding process. If it turns out that there are further methods that enable reliable, automated sealing of the pipe ends, these may be just as suitable as the welding process.However, for the classic process sequence during cold bending (process sequence b), c), a) as well), the sealing of the pipe ends has advantages. It is thus possible to prevent, in the installed state in the vehicle or also in the further production process, for example, corrosive fluids, such as process media, for example, which are used in the pretreatment in the painting process, from being able to penetrate into the pipe stabilizer.Optionally, the method further comprises the step d) blasting the tempered stabilizer to obtain a blasted stabilizer. By blasting, for example shot blasting, the residual compressive stresses in the surface are adjusted. Furthermore, the surface can be roughened, so that in a further optional step e) painting the blasted stabilizer to obtain a painted stabilizer, the paint better adheres to the stabilizer.In exemplary embodiments, the stabilizer has a temperature at the beginning of the production of the weld seam in step a 2) which is at least 20° C., preferably at least 50° C., higher than the ambient temperature. In particular, the stabilizer has a temperature of at least 100° C., at least 175° C. or at least 250° C. It has been found that the heat of the stabilizer has a positive effect on the subsequent welding. The positive effect relates, for example, to the speed at which the weld seam can be produced and / or to the energy required for producing the weld seam and / or to the quality, i.e. the quality, of the weld seam. For example, the waste of the stabilizers during production can thus be reduced by leaking welded seams. The temperature of the stabilizer can be effected by heating in a separate process step, for example by conductive heating or in a furnace or by inductive heating. Additionally or alternatively, it is possible to utilize the residual heat of the preceding end machining of the stabilizer. In particular by utilizing the residual heat, it is also possible for the stabilizer blade to have significantly higher temperatures than 250° C., for example more than 350° C., more than 400° C. or more than 450° C. The latter is of course advantageous since no additional energy (heat) need be supplied which is not required anyway. However, rapid processing of the stabilizers must then be ensured in order to be able to use the residual heat introduced for the hot forming until welding takes place.Further optionally, after the production of the weld seam in step a 2), a step a 3) can be provided, which comprises a thermal post-treatment of at least one region around the weld seam. That is to say, after the welding process, a thermal aftertreatment of the sheet or at least of the heat influence zone can be carried out. The thermal post-treatment can counteract a possible change in structure due to welding.Optionally, a mechanical post-processing of the sheet can take place after the welding process. For example, the side, front and sheet surfaces can be adjusted in a downstream process, e.g. by cutting and / or grinding the edges.The process flow of forging can be composed of the following working steps: flattening the rod end into a stabilizer blade or pipe stabilizer blade, optionally blade bending, punching the blade and optionally trimming the blade surfaces (i.e. in particular the edges of the blade ends), (laser) welding.Further disclosed is a method of making a hot bent stabilizer comprising the steps of: a) forging a rod to obtain a forged rod, b) heating the forged rod to a temperature above the austenitizing temperature of the rod to obtain a heated rod, c) bending the heated rod to obtain a bent rod in the shape of the stabilizer; d) quenching the bent rod to obtain a hardened bent rod; e) tempering the hardened bent rod to obtain the stabilizer; wherein forging the rod comprises the steps of: a1) flattening an end of the rod such that the forged rod has a central portion, a stabilizer blade, and a transition region between the central portion and the stabilizer blade; and a1a) making a hole in the stabilizer blade by means of laser cutting and / or a1b) forming a contour of the stabilizer blade by means of laser cutting. The method can also be carried out in particular for tube stabilizers with a tube as rod.The embodiments of the method for producing a cold-bent stabilizer can be applied to the method for producing a hot-bent stabilizer.For heat-bent stabilizers, it is customary to forging these prior to shaping. The resulting sheet ends may then be cut directly by laser cutting to introduce the hole and / or shape the contour. During hot bending, the stabilizer is tempered parallel to bending. The stabilizers are bent in a heated state above the austenitizing temperature and then quenched, e.g. in an oil basin, and subsequently tempered, e.g. in an oven. The efficiency in the forging process is significantly higher in this case.Both during cold bending and during hot bending, it is advantageous if the stabilizer blades are closed in a fluid-tight manner. Thus, the quenching necessary after the tempering can in both cases take place after the forging without the quenching medium penetrating into the tube stabilizer and being able to lead to corrosion. However, even if a process flow is selected in which the annealing (in particular during cold bending) takes place before forging, corrosive fluids such as moisture, which can lead to corrosion, can subsequently penetrate into the interior of the stabilizer, inter alia also in the installed state. However, also during the pretreatment for painting as a downstream process flow, corrosive fluids are typically used, which can penetrate into the interior of the pipe stabilizer if the latter is not closed in a fluid-tight manner.It should be noted that the terms "thermoforming" and "hot bending" represent different process steps. During hot forming, the blade end or ends are produced, i.e. plateaued, among other things. The blade end is the point of attachment of the stabilizer to the chassis. During the hot bending, the entire shape of the stabilizer is produced, i.e. the shape of the stabilizer is adapted to the respective motor vehicle.In general, the manufacturing process of the stabilizers comprises, for example, the following process steps: forging, bending, tempering, optionally blasting, optionally painting.Preferred embodiments of the present invention will be explained below with reference to the accompanying drawings. The following are shown: FIG. 1 : shows a representation of a pipe stabilizer with a welded seam in the stabilizer blade in three different views, wherein FIG. 1 ashows a perspective representation, FIG. 1 bshows a side view and FIG. 1 cshows a scanning microscope representation of the stabilizer blade in longitudinal section; FIG. 2 : the representation from FIGS. 1 aand 1 b, wherein FIGS. 2 a, 2 b, 2 c, 2 d, 2 eand 2 fshow schematically in each case different arrangements of welded seams; FIG. 3 is a flow chart showing various process flows, FIGS. 3 aand 3 b showing different process flows for manufacturing the stabilizer, FIG. 3 c discloses a process flow of forging with welding, and FIG. 3 d discloses a process flow for hot bending; FIG. 4 : shows a schematic perspective illustration of a stabilizer.Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or identically acting elements, objects and / or structures are provided with the same reference numerals in the different figures, with the result that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.FIG. 1 shows different views of an end region of a pipe stabilizer 20 in FIGS. 1 a, 1 band 1 c. The pipe stabilizer comprises a stabilizer blade 22, a pipe section 24 and a transition region 26 which is arranged between stabilizer blade 22 and pipe section 24. In the region of the stabilizer blade 22, or additionally or alternatively also in the region of the transition region 24, a weld seam 28 is formed in order to protect the pipe section against penetrating moisture. In the stabilizer blade, an aperture 30 is also formed. The aperture, also referred to as a hole, is introduced by means of laser cutting. The process of introducing the hole is also referred to as punching for the sake of simplicity when introducing by means of the laser. Furthermore, on the end face 32 and in the aperture 30, a small gap 34 is visible between the two blade surfaces of the blade end 22.The blade end 22 of the tube stabilizer 20 can be designed differently. In addition to the illustrated curved contour (round section) and flat shape, the stabilizer blade can also have, for example, a kinked or curved shape. The contour of the blade can likewise have different shapes, for example an angular contour or a curved, for example slightly s-shaped or c-shaped end face. The contour is formed by means of laser cutting. Purely externally, the mechanical contour, in particular when using a new cutting surface of the tool, can hardly be distinguished from a laser-cut contour. Only the gap 34 between the blade surfaces is less. Furthermore, during laser cutting, burr formation is reduced, in particular macroscopically visible burr formation is predominantly avoided. Microscopically, for example under a scanning electron microscope, however, the differences between a mechanically shaped contour and a contour shaped by means of laser cutting are visible.FIG. 2 shows various options for forming the weld 28 based on the representations of FIGS. 1 aand 1 b. The welded seams 28 are shaded and are only shown schematically. FIG. 2 a discloses the weld seam 28 in the stabilizer blade 22 between the aperture 30 and the transition region 26. Figure 2b discloses two welds 28, 28'. The first weld seam 28 closes the stabilizer blade 22 on the head side. The second weld seam 28' is arranged laterally circumferentially within the aperture 30.FIG. 2 c likewise discloses, like FIG. 2 a, a weld seam 28 in the stabilizer blade 22 between the aperture 30 and the transition region 26, but the weld seam 28 is obliquely guided here. FIG. 2 ddiscloses a weld seam 28 which consists of a closed line section of here, for example, four lines. Thus, the aperture 30 is sealed from the tube portion 24 of the tube stabilizer. Furthermore, it should be ensured that at least one section of the section line seals the complete width of the stabilizer blade 22. This is solved in FIG. 2 d by the weld seam 28 between the aperture 30 and the transition region 26.FIGS. 2e and 2f each disclose a double weld 28, 28'. In FIG. 2e, the second weld 28' is disposed in the transition region 26, while the first weld 28 is disposed in the stabilizer blade 22. Furthermore, the welded seams 28, 28' are designed to be curved. FIG. 2f discloses straight parallel welds 28, 28' in the stabilizer blade 22.FIGS. 3 aand 3 b disclose the process steps forging 50, bending 52, annealing 54, blasting 56 and painting 58. However, it is expedient to carry out the blasting 56 and painting 58 successively at the end of the process in order to conserve the paint layer. Furthermore, the blasting is to be carried out after the annealing 54 56 has been carried out. There are no further restrictions with regard to the choice of the sequence of the process steps.FIG. 3 a now discloses a process sequence which enables a fast cycle time during the production of the tube stabilizers. First, a pipe of steel is forged (step 50) to obtain a forged pipe. The process flow of forging is illustrated in FIG. 3c. Then, the forged pipe is bent (step 52) to make the pipe have the shape of the pipe stabilizer. The bending of the pipe is effected by means of cold bending, i.e. at a temperature of a maximum of 150° C., typically a maximum of 100° C., generally a maximum of 50° C. The forged pipe is tempered in step 54 in order to obtain a tempered pipe stabilizer. The tube stabilizer obtains its desired strength by the annealing. Optionally, after the annealing in step 56, the (shot) blasting of the annealed pipe stabilizer takes place. By shot peening, compressive residual stresses are adjusted in the surface. Further optionally, the tempered or blasted pipe stabilizer is painted. The paint system prevents, for example, the corrosion of the pipe stabilizer from the outside.FIG. 3 bshows a sequence of the process steps that differs from FIG. 3 a. Here, the tube is first bent (step 52) and subsequently tempered. After the tempering, the tempered tube is forged. The pipe stabilizer here obtains the end which is flattened to form a stabilizer blade by forging. Steps 56 and / or 58 are optionally also subsequently carried out here.Further process steps can be carried out in the process sequences from FIGS. 3 aand 3 b, depending on customer requirements or technical requirements. For example, it is possible to also blast the tube from the inside before forging in step 50. Thus, the compressive residual stresses are also adjusted at least in some areas on the inner surface of the tube.FIG. 3 c now discloses the process steps 50 for forging the pipe stabilizer or the steel pipe. Forging involves flattening (step 60) one end of the pipe (or both pipe ends) such that the forged pipe has a pipe section, a stabilizer blade (or two stabilizer blades), and a transition region (or two transition regions) between the pipe section and the stabilizer blade. Optionally, sheet bending is then performed in step 62. By bending the blade, the stabilizer blade can obtain a shape that deviates from the flat (exclusively plateaued) shape. In step 64, the punching (or establishment of the breakthrough) takes place. Optionally, the flattened end of the tube stabilizer is still trimmed in order to obtain the desired contour of the blade end. Trimming can be carried out in the same process step as punching or else separately.In step 68, the weld seam is produced in the region of the transition region or of the stabilizer blade in order to protect the pipe section against penetrating moisture. Steps 62 (blade bending), 64 (punching) and 68 (welding) are therefore carried out after the punching in step 60.FIG. 3 ddiscloses a process flow for hot bending the pipe stabilizer. In step 50, the forging of the (still straight) pipe first follows, for example according to the process steps described in FIG. 3 c. Steps 52 (hot bending) and 54 (tempering) are then carried out in parallel. The hot bending typically takes place above the austenitizing temperature. The annealing includes hardening in the quenching medium and subsequent tempering after heating. Steps 56 (blasting) and 58 (painting) follow, as already described with reference to FIGS. 3 aand 3 b.The method steps have been described with regard to a tube stabilizer, but can also be used for a stabilizer made of a solid rod, wherein the fluid-tight closure can be neglected here, since the solid rod does not have a cavity into which the fluid can enter.FIG. 4 shows a schematic illustration of a stabilizer 20, the stabilizer 20 having a stabilizer blade 22, 22' at each of the two ends. The stabilizer plates 22, 22' each have an aperture 30, 30', i.e. a hole. Between the two stabilizer plates 22, 22' is the central section, which in the case of a pipe stabilizer is referred to as pipe section 24. The stabilizer 20 is usually fastened to the (motor) vehicle by means of two clamps.Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device.The above-described embodiments are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented herein by way of description and explanation of the embodiments.List of reference numbers:20 Pipe stabilizer / stabilizer 22 Stabilizer blade 24 Pipe section / central section 26 Transition region 28 Weld seam 30 Aperture 32 Head side of stabilizer blade 50 ff ProzessschritteReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 6,547,894 B1

[0012]

Claims

Stabilizer (20) having the following features: - a rod end formed into a stabilizer blade (22), such that the stabilizer (20) has a central section (24), the stabilizer blade (22) and a transition region (26) between the central section (24) and the stabilizer blade (22), - wherein a hole is made in the stabilizer blade by means of laser cutting or wherein a contour of the stabilizer blade is formed by means of laser cutting.Stabilizer (20) according to Claim 1, wherein the stabilizer is a pipe stabilizer, wherein the pipe stabilizer has a weld seam (28) in the region of the transition region (26) or of the stabilizer blade (22) in order to avoid gas and / or liquid exchange between the pipe section (24) as central section and the environment, in particular wherein the weld seam (28) is formed in the absence of a welding filler material.The stabilizer (20) of claim 2, wherein the weld (28) is formed by laser welding.Stabilizer (20) according to either of Claims 2 and 3, wherein the weld (28) is formed on the head side (32) on the stabilizer blade (22).Stabilizer (20) according to one of Claims 2 to 4, wherein the stabilizer blade (22) has an aperture (30), wherein the aperture is sealed off from the transition region (26) or the pipe section (24) by means of the weld seam (28).Stabilizer (20) according to one of Claims 2 to 4, wherein the stabilizer blade (22) has an aperture (30), wherein the tubular stabilizer (30) has a further weld seam (28'), wherein the further weld seam is arranged laterally circumferentially within the aperture (30).Stabilizer (20) according to one of Claims 2, 3 or 5, wherein the weld seam (28) is formed laterally on the stabilizer blade (22) or the transition region (26), wherein the weld seam (22) is arranged between the pipe section (24) and the aperture (30).A method of manufacturing a cold bent stabilizer from a rod comprising the steps of: a) forging (50) the rod or tempered stabilizer to obtain a forged rod or forged stabilizer; b) bending (52) the rod or forged rod to obtain a stabilizer; c) tempering (54) the bent rod to obtain a tempered tempered stabilizer; wherein forging (50) the tube comprises the steps of: a1) flattening (60) an end of the rod such that the forged rod has a central portion (24), a stabilizer blade (22), and a transition region (26) between the central portion (24) and the stabilizer blade (22); and a1a) making a hole in the stabilizer blade by means of laser cutting and / or a1b) forming a contour of the stabilizer blade by means of laser cutting.Method according to claim 8, wherein forging (50) the pipe of a pipe stabilizer comprises the following further step: a2) creating (68) a weld seam (28) in the region of the transition region (26) or of the stabilizer blade (22) in order to seal the pipe section (24) as a central section against a liquid and / or gas exchange with the environment.Method according to claim 9, wherein the production of the weld seam in step a2) and the introduction of the hole in step a1a) or the shaping of the contour in step a1b) takes place with the same laser, wherein a changeover of an optics of the laser system takes place between the steps in order to use the laser either for cutting or for welding.The method of any of claims 8 to 10, further comprising the step of: d) irradiating (56) the tempered stabilizer after steps a) to c) to obtain a irradiated stabilizer.The method of claim 11, further comprising the step of: e) painting (58) the blasted stabilizer after step d) to obtain a painted stabilizer.Method according to one of Claims 9 to 12, wherein the stabilizer has a temperature which is at least 20°C higher than the ambient temperature at the start of the production of the weld seam in step a2).The method according to claim 13, wherein the temperature of the stabilizer remains in the stabilizer as residual heat of the plate in step a1).Method according to one of Claims 9 to 14, wherein, after the production of the weld seam in step a2), the method provides a step a3) which comprises a thermal aftertreatment of at least one region around the weld seam.The method according to any one of claims 9 to 15, wherein the process steps a) to c) are carried out in said alphabetical order.The process according to any one of claims 9 to 15, wherein process steps a) to c) are carried out in the following order: b), c), a).A method for manufacturing a hot bent stabilizer comprising the steps of: - a) forging a rod to obtain a forged rod; - b) heating the forged rod to a temperature above the austenitizing temperature of the rod to obtain a heated rod; - c) bending the heated rod to obtain a bent rod in the shape of the stabilizer; - d) quenching the bent rod to obtain a hardened bent rod; - e) tempering the hardened bent rod to obtain the stabilizer; wherein the forging (50) of the rod comprises the following steps: - a1) flattening (60) an end of the rod, such that the forged rod has a central portion (24), a stabilizer blade (22) and a transition region (26) between the central portion (24) and the stabilizer blade (22); and - a1a) introducing a hole into the stabilizer blade by means of laser cutting and / or - a1b) forming a contour of the stabilizer blade by means of laser cutting.

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