Pipe stabilizer

Abstract

A pipe stabilizer (20) is disclosed, comprising a pipe end formed into a stabilizer sheet (22), such that the pipe stabilizer (20) has a pipe section (24), the stabilizer sheet (22), and a transition region (26) between the pipe section (24) and the stabilizer sheet (22). Furthermore, the pipe stabilizer has a weld (28) in the region of the transition region (26) or the stabilizer sheet (22) to prevent gas and / or liquid exchange between the pipe section (24) and the environment, the weld (28) being formed in the absence of a welding filler material.

Description

[0001] The invention relates to the manufacture of tubular stabilizers, in particular tubular stabilizers for motor vehicles with a tube end formed into a stabilizer blade.

[0002] Conventional end processing of a tube stabilizer typically involves the following process flow: The tube ends are first heated inductively (either one side in succession or both sides in parallel), for example, to a temperature range of 650–1200°C. The temperature depends on various geometric and customer-specific requirements, such as dimensional accuracy, hardness values, service life requirements, etc. This is followed by mechanical press processing, in which the heated rod end is hot-formed ("flattened") in successive steps to form the stabilizer blade. The formed stabilizer blade is punched and optionally cut, and finally, the blade surfaces are calibrated for the required flatness and parallelism. Optionally, a bending operation of the formed stabilizer blade is possible between hot-forming and punching / cutting.

[0003] Investigations have shown that after the hot forming process (“flattening”) the blade ends are generally almost gap-free (a few µm) and thus almost liquid-tight. However, without a material bond, capillary action cannot be avoided, which means that (negligible) small amounts of moisture can still penetrate the pipe stabilizer. The mechanical and tool-dependent subsequent process of punching / cutting promotes the pulling apart of the two blade surfaces due to friction effects, which increases the gap between the two blade surfaces and further reduces the tightness. The consequences of a gap are, on the one hand, the possible ingress of corrosive fluids, for example water, other process media such as pretreatment in the painting process, gases such as oxygen, etc., which later represent starting points for corrosion formation on the inner surface of the stabilizer.Component failure is thus favored by any corrosion-related material damage. Furthermore, further quality defects occur during the painting process, as escaping fluids can negatively affect the coating at the blade end during powder coating and baking. Consequently, the penetration and escape of (corrosive) fluids into and from the uncoated pipe area at the blade end must be prevented.

[0004] Various sealing methods are already known. For example, US Pat. No. 6,547,894 B1 discloses the introduction of a fusion welding powder such as sodium tetraborate between the blade surfaces. Upon heating, the powder melts and bonds the two formed, flattened blade surfaces together. However, it has been found that the application of the fusion welding powder, and thus the entire process, cannot be reliably automated. Furthermore, sodium tetraborate, due to its boron content, is demonstrably hazardous to human health. Alternative methods for sealing the pipe stabilizer have so far failed to reliably ensure a tight seal.

[0005] US 9 994 083 B2 discloses a tubular element whose end portions are closed and a method for closing the end portions of the tubular element.

[0006] DE 10 2005 019 469 A1 discloses a stabilizer for motor vehicles having a hollow profile section with a flattened end.

[0007] The object of the present invention is therefore to create an improved concept for pipe stabilizers.

[0008] This problem is solved by the subject matter of the independent patent claims. Further advantageous embodiments are the subject matter of the dependent patent claims.

[0009] Exemplary embodiments show a tubular stabilizer with a tubular end formed into a stabilizer blade, such that the tubular stabilizer comprises a tubular section, the stabilizer blade, and a transition region between the tubular section and the stabilizer blade. The tubular stabilizer can comprise a (spring) steel or consist predominantly of a steel, in particular a spring steel. Suitable spring steels include, for example, 26MnB5, 34MnB5, and 40MnB5. In general, however, all weldable materials are suitable.

[0010] Furthermore, the pipe stabilizer has a weld seam in the transition area or stabilizer blade to prevent gas and / or fluid exchange between the inner pipe (i.e., the pipe section) and the environment. The weld seam is formed in the absence of a welding filler. Welding filler materials are typically supplied in the form of powders, rods, or wires, melted, and solidify in the joint between the joining partners to create the connection. Without a welding filler, the weld seam is created exclusively by melting the materials, in this case the two blade surfaces, so that the two materials fuse.

[0011] This eliminates the difficult-to-automate step of applying the welding consumable. Welding consumables must be distinguished from welding aids such as shielding gases, fluxes, vacuum (e.g., in electron beam welding), pastes, or welding powder, which facilitate welding or even make it possible in the first place. Welding powder is used, for example, in submerged-arc welding and should not be confused with fusion welding powder as a welding consumable. Examples of welding processes that are used without welding consumables include deep penetration welding and deep penetration welding.Laser deep penetration welding (laser welding for short), conduction welding, resistance welding, laser-MIG hybrid welding, laser welding in vacuum, laser transmission welding, gas fusion welding, manual arc welding, gas shielded arc welding, submerged arc welding, electron beam welding, forge welding, cold pressure welding, friction welding, explosive welding, electromagnetic pulse welding, diffusion welding, MBP welding, arc stud welding, or build-up welding. This means that the weld seam can be created using one of the aforementioned welding processes or any combination thereof.

[0012] Of course, it is also possible to provide multiple welds instead of a single weld. Furthermore, the weld can be designed in various variants, the designs of which vary according to a wide variety of criteria. The following criteria are examples: arrangement or position (position of the weld(s) on the sheet / arrangement of the welds relative to each other), shape (weld width, weld height, straight weld, semicircular weld, wavy weld, arbitrarily shaped weld, etc.), design type (single-layer or multi-layer weld).

[0013] The idea is therefore to create a manual but also automated welding process for the tube end of the tube stabilizer. The two blade surfaces are completely bonded together in the direction of the non-formed tube cross-section, tightly and firmly. This also eliminates quality defects due to poor paint adhesion caused by fluids that may escape from the tube stabilizer during the painting process. Furthermore, the addition of preservatives to the tube stabilizer to protect the inner surface from corrosion is no longer necessary. Furthermore, the welding process offers the advantage that the tube stabilizer is fluid-tight even under negative or positive pressure conditions. This is advantageous, for example, when external temperatures fluctuate during operation or during a tempering process during production.During the tempering process, the tube stabilizer is quenched in a quenching medium after heating, which quickly creates large temperature and thus pressure differences due to the trapped air volume in the tube stabilizer. Even under these conditions, the tube stabilizer must remain fluid-tight.

[0014] The weld seam is preferably formed by laser welding. Laser welding has the advantage that the energy is introduced into the material by means of a laser beam focused by an optics. By automatically changing the optics, weld seams of different widths and depths can be created, for example. Furthermore, the cycle times, i.e. the time taken to produce the weld seam, can be adjusted if the energy acts on the material in a more or less focused manner. The laser power is also adjustable and can be adapted, for example, to different sheet thicknesses. Thus, with knowledge of the pipe stabilizer to be welded, the weld seam can be automatically adapted, for example, to a material or a wall thickness of the pipe stabilizer. The automated steps described in this disclosure can be carried out by a processing unit, i.e. a computer.

[0015] In exemplary embodiments, the weld seam is made on the head side, preferably across the entire width of the stabilizer blade. This means that in order to melt both blade surfaces, it is not necessary to first penetrate the upper blade surface in order to liquefy material from the lower blade surface. Both blade surfaces are visible on the head side and can be melted simultaneously. This means that less energy is required for welding and the welding process is completed more quickly. However, it is advantageous if an opening (also referred to as a bore) through the stabilizer blade, which can be used to attach the tubular stabilizer to the landing gear, also has a further weld seam running laterally (preferably completely) around the entire circumference and is arranged within the opening. This means that the cutting gap of the opening can be sealed.

[0016] In order to avoid a protruding weld seam in the bore or on any outer side of the stabilizer blade, it can be advantageous not to make the bore or the cut in general identically continuous, but rather to make it conical or with a step around the parting line of the blade surfaces, for example. This creates space for the weld seam in the range of a few tenths of a millimeter without violating the tolerance requirements, so that, for example, the screw connection is not impaired. In addition or alternatively, the area of ​​the later weld seam in the area of ​​the parting line or the surface of the stabilizer blade can be subsequently machined, e.g. with a laser, in order to remove material for the weld seam and prevent the weld seam from protruding.

[0017] All open areas of the pipe stabilizer are completely sealed at one end, preventing any liquid from penetrating, at least from one side. Advantageously, both sides of the pipe stabilizer are sealed accordingly by the weld seam. For example, both ends of the pipe stabilizer are designed symmetrically or similarly.

[0018] Additionally or alternatively, the opening through the stabilizer blade can be sealed from the transition area or from the pipe section. This can be achieved, for example, by means of a weld seam laterally applied to the stabilizer blade or the transition area. In this case, the weld seam is located between the pipe section and the opening. The weld seam preferably extends across the entire width of the stabilizer blade or the transition area. However, it is also possible to seal the blade end using several weld seams, although not all weld seams need to extend across the entire width of the stabilizer blade. For example, the hole can be sealed all the way around the inside with a weld seam.

[0019] In general, it is possible to create at least one weld seam either between the transition area and the aperture, between the blade end and the aperture, around the aperture, or directly around the cut gap of the aperture or at the end trim in various geometries and seam widths and other designs, individually, multiple times, or in any combination. This approach offers the advantage of a materially bonded connection between the two pressed blade surfaces, thus ensuring a completely sealed stabilizer end.

[0020] Furthermore, a method for producing a cold-bent tube stabilizer is disclosed, comprising the following steps: a) forging a tube to obtain a forged tube; b) bending the forged tube to obtain a tube stabilizer; c) quenching and tempering the bent tube to obtain a quenched and tempered tube stabilizer; - wherein the forging of the tube comprises the following steps: a1) flattening one end of the tube so that the forged tube has a tube section, a stabilizer blade, and a transition region between the tube section and the stabilizer blade; and a2) creating a weld seam in the region of the transition region or the stabilizer blade to seal the tube section against liquid and / or gas exchange with the environment. Optionally, the forging can comprise further process steps after flattening and before welding, such as piercing and / or cutting the stabilizer blade and / or calibrating the stabilizer blade.

[0021] For example, process steps a), b), and c) can be performed in alphabetical order, i.e., in the process sequence a), b), and c). Alternatively, process steps a), b), and c) can be performed in the process sequence b), c), a).

[0022] Cold-bent tubular stabilizers are currently typically piece-hardened after forming, and the stabilizer blades are then forged, i.e., particularly the ends are flattened (see also the description in the introductory section). This results in lower efficiency for forging, particularly due to the complex handling of the already bent stabilizers.

[0023] By reliably sealing the tube ends, it is now possible to modify the process flow so that forging, including flattening and sealing the tube stabilizer end flattened into the stabilizer blade, can take place before quenching and tempering, and thus also before bending the tube stabilizer (process sequence: a), b), c)). The sealed end of the tube stabilizer reliably prevents the penetration of the quenching medium during quenching and tempering. Significant efficiency improvements, particularly in the forging process, are expected from this change in the process. Instead of the laborious handling of bent, quenched and tempered tubes, usually using a (usually stationary) industrial robot, the straight tube can be fed to the various forging stages in parallel via a linear transfer system. Closing can also be integrated into this process step, for example, in the form of a welding process.If it turns out that there are other processes that enable reliable, automated sealing of the pipe ends, these may be just as suitable as the welding process.

[0024] Sealing the pipe ends also has advantages for the classic cold bending process (process sequence b), c), a)). This prevents corrosive fluids, such as process media used in pretreatment during the painting process, from penetrating the pipe stabilizer when installed in the vehicle or during the subsequent manufacturing process.

[0025] Optionally, the method further comprises step d) blasting the tempered pipe stabilizer to obtain a blasted pipe stabilizer. Blasting, for example, by shot peening, adjusts the compressive residual stresses in the surface. Furthermore, the surface can be roughened so that, in a further optional step e) painting the blasted pipe stabilizer to obtain a painted pipe stabilizer, the paint adheres better to the pipe stabilizer.

[0026] In exemplary embodiments, the pipe stabilizer has a temperature at the beginning of the creation of the weld in step a2) that is at least 20°C, preferably at least 50°C higher than the ambient temperature. In particular, the pipe 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 pipe stabilizer has a positive effect on the subsequent welding. The positive effect relates, for example, to the speed with which the weld can be created and / or to the energy required to create the weld and / or to the grade, i.e., the quality, of the weld. For example, this can reduce the reject rate of the pipe stabilizers during production due to leaky welds. The temperature of the pipe stabilizer can be increased by heating in a separate process step, e.g.by conductive heating or in a furnace or by induction heating. In addition or alternatively, it is possible to utilize the residual heat from the previous end processing of the tube stabilizer. In particular, by utilizing the residual heat, it is also possible for the stabilizer sheet to have temperatures significantly higher than 250°C, for example more than 350°C, more than 400°C or more than 450°C. The latter is of course advantageous, as it eliminates the need to supply additional energy (heat) that is not required anyway. In this case, however, care must be taken to ensure that the tube stabilizers are processed quickly in order to be able to utilize the residual heat introduced during hot forming until welding.

[0027] Further optionally, after the creation of the weld seam in step a2), a step a3) can be provided, which includes a thermal post-treatment of at least an area around the weld seam. This means that a thermal post-treatment of the sheet or at least the heat-affected zone can be performed after the welding process. This thermal post-treatment can counteract any possible structural changes caused by welding.

[0028] Optionally, the blade can be mechanically finished after the welding process. For example, the side, end, and blade surfaces can be adjusted in a subsequent process, e.g., by cutting and / or grinding the edges.

[0029] The forging process flow can consist of the following work steps: flattening the tube end to form a stabilizer blade or tube stabilizer blade, optionally bending the blade, punching the blade and optionally trimming the blade surfaces (i.e. in particular the edges of the blade ends), calibrating the tube stabilizer, (laser) welding.

[0030] Furthermore, a method for producing a hot-bent tube stabilizer is disclosed, comprising the following steps: a) forging a tube to obtain a forged tube, b) heating the forged tube to a temperature above the austenitizing temperature of the tube to obtain a heated tube, c) bending the heated tube to obtain a bent tube in the shape of the tube stabilizer; d) quenching the bent tube to obtain a hardened, bent tube; e) tempering the hardened, bent tube to obtain the tube stabilizer; wherein the forging of the tube comprises the following steps: a1) flattening one end of the tube so that the forged tube has a tube section, a stabilizer blade, and a transition region between the tube section and the stabilizer blade;and a2) creating a weld in the area of ​​the transition region or the tube sheet to seal the tube section against liquid and / or gas exchange with the environment.;

[0031] The embodiments of the method for producing a cold-bent pipe stabilizer can be transferred to the method for producing a hot-bent pipe stabilizer.

[0032] For hot-bent stabilizers, it is common practice to forge them prior to forming. During hot bending, the tubular stabilizer is tempered and tempered simultaneously. The stabilizers are bent while heated above the austenitizing temperature, then quenched, for example, in an oil bath, and then tempered, for example, in a furnace. This significantly increases the efficiency of the forging process.

[0033] During both cold bending and hot bending, it is advantageous if the stabilizer blades are sealed in a fluid-tight manner. This means that in both cases the quenching required after tempering can take place after forging without the quenching medium penetrating the tube stabilizer and potentially causing corrosion. However, even if a process flow is selected in which tempering (particularly during cold bending) takes place before forging, corrosive fluids such as moisture can subsequently penetrate into the interior of the stabilizer, even when installed, and this can lead to corrosion. However, pre-treatment for painting, which is a downstream process flow, typically uses corrosive fluids that can penetrate into the interior of the tube stabilizer if it is not sealed in a fluid-tight manner.

[0034] It should be noted that the terms "hot forming" and "hot bending" represent different process steps. Hot forming involves producing, or flattening, the blade end(s). The blade end is the connection point between the stabilizer bar and the chassis. Hot bending creates the entire shape of the stabilizer bar, i.e., adapting the shape of the stabilizer bar to the specific vehicle.

[0035] In general, the manufacturing process of pipe stabilizers includes, for example, the following process steps: forging, bending, tempering, optional blasting, optional painting.

[0036] Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. They show: Fig. 1: a representation of a tubular stabilizer with weld seam in the stabilizer blade in three different views, where Fig. 1a a perspective view, Fig. 1b a side view and Fig. Figure 1c shows a scanning microscope view of the stabilizer blade in longitudinal section; Fig. 2: the representation from Fig. 1a and Fig. 1b, where Fig. 2a, Fig. 2b, Fig. 2c, Fig. 2d, Fig. 2e and Fig. 2f schematically show different arrangements of weld seams; Fig. 3: a flowchart to represent different process flows, where Fig. 3a and Fig. 3b show different process flows for the production of the pipe stabilizer, Fig. 3c reveals a process flow of forging with welding and Fig. 3d reveals a process flow for hot bending; Fig. 4: a schematic perspective view of a pipe stabilizer.

[0037] 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 equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0038] Fig. 1 shows in Fig. 1a, Fig. 1b and Fig. 1c shows different views of an end region of a tubular stabilizer 20. The tubular stabilizer comprises a stabilizer blade 22, a tubular section 24, and a transition region 26 arranged between the stabilizer blade 22 and the tubular section 24. A weld seam 28 is formed in the region of the stabilizer blade 22, or additionally or alternatively also in the region of the transition region 24, to protect the tubular section against moisture penetration. Furthermore, an opening 30 is formed in the stabilizer blade. Furthermore, a small gap 34 between the two blade surfaces of the blade end 22 is visible on the end face 32 and in the opening 30.

[0039] The blade end 22 of the tubular stabilizer 20 can be designed in various ways. In addition to the curved contour (round section) and flat shape shown, the stabilizer blade can also have a bent or curved shape, for example. The contour of the blade can also have various characteristics, for example, an angular contour or a curved, for example, slightly S-shaped or C-shaped end face.

[0040] Fig. 2 shows based on the illustrations from Fig. 1a and Fig. 1b shows various options for forming the weld seam 28. The weld seams 28 are hatched and shown only schematically. Fig. 2a discloses the weld seam 28 in the stabilizer blade 22 between the opening 30 and the transition region 26. The weld seam 28 is made laterally on the stabilizer blade. Fig. Figure 2b reveals two weld seams 28, 28'. The first weld seam 28 seals the stabilizer blade 22 at the head end. The second weld seam 28' is arranged laterally circumferentially within the opening 30.

[0041] Fig. 2c also reveals how Fig. 2a a weld seam 28 in the stabilizer blade 22 between the opening 30 and the transition area 26, but the weld seam 28 is inclined here. Fig. Figure 2d shows a weld seam 28 consisting of a closed section of, for example, four sections. Thus, the opening 30 is sealed against the tube section 24 of the tubular stabilizer. Furthermore, it is important to ensure that at least one section of the section seals the entire width of the stabilizer blade 22. This is shown in Fig. 2d by the weld seam 28 between opening 30 and transition area 26.

[0042] Fig. 2e and Fig. 2f each reveal a double weld seam 28, 28'. In Fig. 2e, the second weld seam 28' is arranged in the transition region 26, while the first weld seam 28 is arranged in the stabilizer blade 22. Furthermore, the weld seams 28, 28' are curved. Fig. 2f reveals straight, parallel weld seams 28, 28' in the stabilizer blade 22.

[0043] Fig. 3a and Fig. Figure 3b shows the process steps forging 50, bending 52, tempering 54, blasting 56, and painting 58. With the fluid-tight or at least liquid-tight sealed, especially welded, tube stabilizers, the process steps can be interchanged almost arbitrarily. However, it is advisable to perform blasting 56 and painting 58 consecutively at the end of the process to protect the paint layer. Furthermore, blasting should be performed after 56 and tempering 54. There are no further restrictions regarding the selection of the sequence of the process steps.

[0044] Fig. Figure 3a now discloses a process flow that enables a fast cycle time in the production of tube stabilizers. First, a tube made of steel or spring steel is forged (step 50) to obtain a forged tube. The forging process flow is shown in Fig. 3c. The forged tube is then bent (step 52) to give the tube the shape of the tube stabilizer. The tube is bent by cold bending, i.e. at a temperature of maximum 150°C, typically maximum 100°C, usually maximum 50°C. The forged tube is quenched and tempered in step 54 to produce a quenched and tempered tube stabilizer. Tempering gives the tube stabilizer its desired strength. Optionally, after tempering in step 56, the quenched and tempered tube stabilizer is (shot) peened. Shot peening adjusts residual compressive stresses in the surface. Further optionally, the quenched and tempered or peened tube stabilizer is painted. The painting prevents, for example, external corrosion of the tube stabilizer.

[0045] Fig. 3b reveals a Fig. 3a shows a different sequence of process steps. Here, the tube is first bent (step 52) and then tempered. After tempering, the tempered tube is forged. Through forging, the tube stabilizer receives the flattened end into a stabilizer blade. Optionally, steps 56 and / or 58 are also performed here. The description of the process steps from Fig. 3a applies analogously here.

[0046] Further process steps can be included in the process flows from Fig. 3a and Fig. 3b can be carried out depending on customer requirements or technical specifications. For example, it is possible to blast the tube internally before forging in step 50. This also adjusts the residual compressive stresses, at least in some areas, on the inner surface of the tube.

[0047] Fig. 3c now discloses the process steps 50 for forging the tubular stabilizer or the steel tube. The forging comprises flattening (step 60) one end of the tube (or both tube ends) so that the forged tube has a tube section, a stabilizer blade (or two stabilizer blades), and a transition region (or two transition regions) between the tube section and the stabilizer blade. Optionally, the blade bending then takes place in step 62. By bending the blade, the stabilizer blade can be shaped differently from the flat (solely flattened) shape. In step 64, the piercing (or creation of the opening) takes place. Optionally, the flattened end of the tubular stabilizer is also trimmed to obtain the desired contour of the blade end. Trimming can take place in the same process step as the piercing or separately.

[0048] In step 66, the stabilizer blade is optionally calibrated. During calibration, the screwing surfaces on the already flattened and perforated stabilizer blade are pressed together again. So-called calibration punches are used, which ensure that the necessary customer requirements regarding flatness and parallelism of the blade surfaces are met by pressing them together on both sides. This prevents the screws from becoming loose due to, for example, settling behavior or a "slanted" connection if parallelism is insufficient. Optionally, the burr around the underside of the hole that occurs during drilling can be pressed back into place with the help of a cone and reduced / prevented. In step 68, the weld seam is created in the transition area or on the stabilizer blade to protect the pipe section from moisture penetration.Steps 62 (sheet bending), 64 (punching), and 68 (welding) therefore occur after flattening in step 60. Calibration occurs after punching in step 64.

[0049] Fig. Figure 3d shows a process flow for hot bending the tube stabilizer. In step 50, the (still straight) tube is first forged, for example, according to the method shown in Fig. 3c. Steps 52 (hot bending) and 54 (quenching and tempering) then take place in parallel. Hot bending typically takes place above the austenitizing temperature. Quenching and tempering involves hardening in a quenching medium and subsequent tempering after heating. Steps 56 (blasting) and 58 (painting) follow, as already described with regard to Fig. 3a and Fig. 3b.

[0050] Fig.Figure 4 shows a schematic representation of a tubular stabilizer 20. The tubular stabilizer 20 has a stabilizer blade 22, 22' at each end. The stabilizer blades 22, 22' each have an opening 30, 30', i.e., a hole. The tubular section 24 is located between the two stabilizer blades 22, 22'. The tubular stabilizer 20 is typically attached to the (motor) vehicle with two clamps.

[0051] 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 component of a device can also be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0052] The above-described embodiments are merely illustrative of the principles of the present invention. It is 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 in the description and explanation of the embodiments herein. List of reference symbols: 20 pipe stabilizer 22 Stabilizer blade 24 pipe sections 26 Transition area 28 Weld seam 30 Breakthrough 32 Head side of the stabilizer blade 50ff process steps

Claims

[1] Pipe stabilizer (20) with the following features: - a tube end formed into a stabilizer blade (22), so that the tube stabilizer (20) has a tube section (24), the stabilizer blade (22) and a transition region (26) between the tube section (24) and the stabilizer blade (22), characterized by a weld seam (28) in the region of the transition region (26) or the stabilizer blade (22) to prevent gas and / or liquid exchange between the pipe section (24) and the environment, wherein the weld seam (28) is formed in the absence of a welding filler material. [2] Pipe stabilizer (20) according to claim 1, wherein the weld seam (28) is formed by laser welding. [3] Pipe stabilizer (20) according to one of the preceding claims, wherein the weld seam (28) is made on the head side (32) of the stabilizer blade (22). [4] Pipe stabilizer (20) according to one of the preceding claims, wherein the stabilizer blade (22) has an opening (30), wherein the opening is sealed by means of the weld seam (28) with respect to the transition region (26) or the pipe section (24). [5] Pipe stabilizer (20) according to one of claims 1 to 3, wherein the stabilizer blade (22) has an opening (30), wherein the pipe stabilizer (30) has a further weld seam (28'), wherein the further weld seam is arranged laterally circumferentially within the opening (30). [6] Pipe stabilizer (20) according to one of claims 1, 2 or 4, wherein the weld seam (28) is made 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 opening (30). [7] A method for producing a cold-bent tube stabilizer from a tube, comprising the following steps: a) forging (50) the tube of a tempered tube stabilizer to obtain a forged tube; b) bending (52) the tube or the forged tube to obtain a tube stabilizer; c)quenching and tempering (54) the bent tube to obtain the tempered tube stabilizer; - characterized in that the forging (50) of the tube comprises the following steps: a1) flattening (60) one end of the tube so that the forged tube has a tube section (24), a stabilizer blade (22) and a transition region (26) between the tube section (24) and the stabilizer blade (22); and a2) Creating (68) a weld seam (28) in the region of the transition region (26) or the stabilizer blade (22) in order to seal the pipe section (24) against liquid and / or gas exchange with the environment. [8] Method according to claim 7, comprising the following further step: d) blasting (56) the tempered tube stabilizer after steps a) to c) to obtain a blasted tube stabilizer. [9] Method according to claim 8, comprising the following further step: e) painting (58) the blasted pipe stabilizer after step d) to obtain a painted pipe stabilizer. [10] Method according to one of claims 7 or 8, wherein the pipe stabilizer has a temperature at the beginning of the creation of the weld in step a2) which is at least 50°C higher than the ambient temperature. [11] The method according to claim 10, wherein the temperature of the tube stabilizer remains in the tube stabilizer as residual heat of the flattening in step a1). [12] Method according to one of claims 7 to 11, wherein the method, after the creation of the weld seam in step a2), provides a step a3) which comprises a thermal post-treatment of at least one region around the weld seam. [13] Method according to one of claims 7 to 12, wherein the method steps a) to c) are carried out in the said alphabetical order. [14] Method according to one of claims 7 to 12, wherein the method steps a) to c) are carried out in the following order: b), c), a). [15] A method for producing a hot-bent tube stabilizer comprising the following steps: - a) forging a tube to obtain a forged tube; - b) heating the forged tube to a temperature above the austenitizing temperature of the tube to obtain a heated tube; - c) bending the heated tube to obtain a bent tube in the shape of the tube stabilizer; - d) quenching the bent tube to obtain a hardened, bent tube; - e) tempering the hardened, bent tube to obtain the tube stabilizer; - characterized in that the forging (50) of the tube comprises the following steps: - a1) flattening (60) one end of the tube so that the forged tube has a tube section (24), a stabilizer blade (22) and a transition region (26) between the tube section (24) and the stabilizer blade (22); and - a2) creating (68) a weld seam (28) in the region of the transition region (26) or the tube sheet (22) in order to seal the tube section (24) against liquid and / or gas exchange with the environment.

Images