Welding method and welding machine

Abstract

The present invention relates to a welding method comprising the following steps: joining a first joint (1) to a second joint (2) by a pressure welding process, wherein, after joining, a weld bead (4) is formed at the edge of the joint of the first joint (1) and the second joint (2) protruding from the surfaces (3) of the joined first joint (1) and the second joint (2); then remelting the weld bead (4) by a fusion welding process, such that the bulge formed by the protruding weld bead (4) is smoothed and / or leveled. The present invention also relates to a welding machine (7) for performing such welding method.

Description

Technical Field

[0001] This invention relates to a welding method comprising the steps of joining a first joint to a second joint by a pressure welding process, wherein, after joining, a weld bead is formed at the edge of the joint portion of the first and second joints, protruding from the surfaces of the joined first and second joints. The invention also relates to a welding machine for performing this welding method. Background Technology

[0002] CN103008897A describes a combined welding method that combines laser welding and friction stir welding. In this combined welding method, a first laser beam is directed towards the rear side of the plates to be welded, and a second laser beam is directed towards the front side of the plates to be welded using a friction stir head. Specifically, just before welding with the friction stir head, the first laser beam softens the portions of the plates to be welded along the welding direction. Then, the friction stir head performs friction stir welding to join these portions. Finally, the second laser beam remelts the portions that have been welded using friction stir welding. Summary of the Invention

[0003] The purpose of this invention is to further improve the welding method so as to eliminate or at least reduce the weld beads produced by the pressure welding process, while improving the quality of the weld.

[0004] The objective of this invention is achieved through a welding method comprising the following steps: - A first joint is joined to a second joint using a pressure welding process, wherein, after joining, a weld bead is formed on the edge of the joint area of ​​the first and second joints, protruding from the surfaces of the joined first and second joints. -The weld bead is then remelted through a fusion welding process, so that the bulge formed by the raised weld bead is smoothed and / or flattened.

[0005] During pressure welding, the joints to be joined, namely the first joint and the second joint, are pressed together by force on their mating surfaces to be joined. Simultaneously and / or subsequently, the joints are heated to a welding temperature in their mating area, at which temperature the joints melt in that area. As the joints are pressed together, the molten material deforms, causing a portion of the molten material to overflow beyond the surfaces of the joined joints, thus forming a weld bead that constitutes a raised protrusion from the surfaces of the joined joints.

[0006] In many applications, such bulges, or weld beads, are undesirable. For example, when joining two rotationally symmetrical components, such as shafts, which are joined at their end faces, the weld beads produced during pressure welding may be undesirable due to the geometry. To date, such undesirable weld beads have been removed by machining. They can also be machined or ground off, for example, on a lathe. In some cases, if necessary, these undesirable weld beads can also be removed by blanking.

[0007] Depending on the specific application, turning, grinding, or punching the weld bead may be impossible, for example, due to limitations in the geometry of the component, or turning, grinding, or punching the weld bead may adversely affect the weld quality of the face weld joint produced in the pressure welding process.

[0008] By performing a pressure welding process for joining the first and second joints, and then remelting the weld bead according to the present invention using a fusion welding process, the bulges formed by the protruding weld beads are smoothed and / or leveled, which can have a positive impact on the weld quality of the surface welded joint produced in the pressure welding process compared to the prior art.

[0009] According to the present invention, it is necessary to distinguish between a pressure weld and a weld bead formed on the contact surface of the joints to be joined during the pressure welding process. Here, the pressure weld extends across the entire contact surface between the first and second joints. The weld bead, on the other hand, is formed from the molten and resolidified material of the first and / or second joints, which, in its molten state, is extruded from the joint gap across the entire contact area between the first and second joints due to the extrusion process during pressure welding, and extends beyond the surface of the first and / or second joints. Therefore, the weld bead refers to the portion of material extruded from the joint gap during the pressure welding process.

[0010] When the weld bead is remelted using the fusion welding process according to the invention to smooth and / or level the bulge formed by the raised weld bead, the actual press weld seam is not remelted; only the portion of material that forms the bulge and overflows beyond the surfaces of the first and / or second joints is remelted. By remelting, the raised weld bead can, for example, be leveled so that it protrudes less or even no longer from the surfaces of the joined joints. On the other hand, it may be sufficient to simply level the raised weld bead, making the weld bead surface uniform, without leveling it. This may be the case, for example, when unwanted solidified weld droplets on the surface of the raised weld bead are removed.

[0011] Therefore, the existing press weld will not completely melt again through remelting. Of course, the excess heat introduced during the fusion welding process may also only have a thermal effect on the press weld. In this regard, this can be a heat post-treatment, which may be related to tempering and / or annealing effects, stress reduction, and / or hardness reduction.

[0012] Conversely, hardening can also be achieved by quenching, for example, with water or oil. For instance, in friction-welded drill pipes, induction heating is performed, followed by quenching under water spray to achieve the hardening process.

[0013] Especially in friction welding, it can improve toughness, particularly notched impact toughness.

[0014] Furthermore, this remelting process can produce a combined bonding connection.

[0015] After being remelted using a fusion welding process, the smoothed and / or leveled weld bead can form a final molten ring. This molten ring shrinks after the remelted material of the smoothed and / or leveled weld bead solidifies and subsequently cools, thereby creating higher tensile stresses in the material. This can increase the potential stress on the joined or bonded components. As a result, lightweight designs become possible, particularly through reductions in wall thickness.

[0016] The fusion welding process can be performed in the welding machine after the automatic pressure welding process, or it can be performed manually if necessary.

[0017] However, preferably, the fusion welding process can also be automatically executed after the pressure welding process is automatically executed in the welding machine.

[0018] Accordingly, the welding method may include the following steps: - In a welding machine, a first joint is automatically joined to a second joint using a pressure welding process. After joining, a weld bead is formed at the edge of the joint between the first and second joints, protruding from the surfaces of the joined first and second joints. -Then the weld bead is automatically remelted using a fusion welding process, so that the bulge formed by the protruding weld bead is smoothed and / or flattened.

[0019] Automatic remelting in fusion welding processes can be performed, in particular, within the same welding machine used for pressure welding. The advantage of this is that the joints formed by pressure welding do not need to be removed from the welding machine used for pressure welding before automatic remelting, nor do they need to be transferred to a separate welding machine for automatic remelting. This eliminates transportation measures and saves transportation time.

[0020] Another advantage is that automatic remelting in the fusion welding process can be achieved by performing the pressure welding process within the same welding machine: remelting in the fusion welding process is performed as long as the joint still has residual heat from the pressure welding process. This allows remelting in the fusion welding process to begin at a higher initial temperature. This can have a favorable effect on the temperature change profile during the fusion welding process, thus producing positive results after the remelted weld bead. In terms of cycle time, it is also advantageous if the joint can be held in the existing clamping device in the welding machine after pressure welding, and if remelting of the weld bead in the fusion welding process can also be performed in this original clamping device.

[0021] If necessary, the range of materials suitable for welding can be expanded by remelting the weld bead according to the invention.

[0022] Welding machines constructed and designed to perform pressure welding processes also offer the possibility of performing subsequent remelting on rotating joined components due to the rotatability of the clamping device of the joint. This has the advantage that, in particular, the welding device used to perform fusion welding processes can be stationary, i.e., non-rotating.

[0023] Here, contact with the rotating tool or chuck can be achieved through a simple sliding contact, common in welding techniques. This is necessary in most arc methods. However, contact is correspondingly not required in beam methods.

[0024] However, in a variant implementation, particularly for small weld beads, the welding apparatus used to perform the fusion welding process can also be actively guided to move around the components, namely the first and second joints that have been joined.

[0025] In another variation, remelting can be performed outside the welding machine that is constructed and designed to perform the pressure welding process, and particularly in a second welding machine that is separately constructed and designed to perform the fusion welding process.

[0026] Here, for example, cycle time can be saved on the welding machine used to perform the pressure welding process. In this regard, the welding machine used to perform the pressure welding process can, for example, perform two welding operations in the same amount of time.

[0027] Therefore, it can be specified that the first step of the basic method is performed on a first welding machine, namely, joining the first joint to the second joint by a pressure welding process, wherein after joining, a weld bead protruding from the surfaces of the joined first and second joints is formed at the edges of the joint. Such a first welding machine can be, for example, a friction welding machine, a resistance welding machine, or an MBP welding machine. The second step of the basic method can be performed on a second welding machine, different from the first welding machine, namely, remelting the weld bead by a fusion welding process, so that the bulge formed by the protruding weld bead is smoothed and / or leveled. It can be specifically specified here that the second welding machine can be positioned spatially close to the first welding machine, such that the components joined by the first welding machine, including the first and second joints, can be transported to the second welding machine with only a very short transport path. In this way, the transfer time can be kept very short, and if necessary, the components joined on the first welding machine can be further processed on the second welding machine while still hot to smooth the weld bead. If the residual heat from the joined parts is not needed or intended to be used, the second welding machine can also be positioned spatially away from the first welding machine.

[0028] Overall, in any case, it can save on very expensive chip processing machines, because the costs incurred by welding equipment, for example, are relatively much lower than those of chip processing machines.

[0029] As a downstream process, it can be assumed that remelting of the weld bead will not prolong the cycle time.

[0030] In the second step of the method, the weld bead is remelted by a fusion welding process, which smooths and / or flattens the bulge formed by the protruding weld bead, reducing the geometric height of the weld bead, which is the height by which the weld bead protrudes beyond, i.e., beyond, other surfaces or walls of the joined parts. Depending on the specific circumstances, the reduction in weld bead height can even be so great as to almost completely remove the weld bead, i.e., the weld bead is remelted to the point that it is completely integrated into the surface of the joined parts.

[0031] In the case of rotationally symmetric joints, such as shafts, tubes, or cylindrical rods, a circular weld bead can be obtained. This circular weld bead is best processed in the second step of the method (i.e., by remelting the weld bead through a fusion welding process, so that the bulge formed by the protruding weld bead is smoothed and / or leveled) by the following manner: the joint joined by pressure welding in the first step of the method remains in the clamping device of the pressure welding machine, and the joint can be rotated in this clamping device such that the circular weld bead is rotatably guided through a fixed fusion welding device, thereby smoothing and / or leveling the weld bead over the entire circumference of the joined joint.

[0032] As an alternative to a fixed welding apparatus, the welding apparatus can also be movable if necessary, allowing the processing tip of the welding apparatus to move along the weld bead, particularly automatically. Whether the joined parts are rotatably mounted or fixedly arranged in the welding machine, the processing tip of the welding apparatus can be movable to allow it to move along the weld bead, particularly automatically.

[0033] Especially in pressure welding processes, such as magnetic arc welding (MBP-Schweißen) or magnetic arc welding (MagnetArc-Schweißen) and friction welding, weld beads, particularly circular ones, are formed, which can be at least smoothed and / or leveled, or even completely removed or eliminated, by the method according to the invention.

[0034] The method according to the present invention can also be applied to other pressure welding processes, such as pressure butt welding, flash butt welding, linear friction welding, or friction stir welding.

[0035] For example, in friction stir welding, this process can be used to remelt / remove frequently generated burrs. Here, burrs should be understood as a special form of weld bead. This process makes deburring during friction stir welding more repeatable and monitorable. For example, in friction stir welding, the weld bead can also be a burr-like weld bead, or burr, extending along the edges of the two parts to be joined.

[0036] In the first basic embodiment, the pressure welding process is friction welding.

[0037] In friction welding, a first and a second joint are pressed together with their opposing mating surfaces perpendicular to the mating surfaces forming the joint. Here, the two joints move relative to each other transversely to the pressure direction, i.e., within the plane of the mating surfaces. Either one or both joints can be moved. Due to this mutual movement and the extrusion force perpendicular to the mating surfaces, heat is generated on the mating surfaces due to friction, causing the material near the joint to be plasticized. Due to this plasticization, the two joints are welded together at the joint. Due to the extrusion force, material is extruded from the mating surfaces, forming a weld bead protruding from the surfaces of the two joints.

[0038] In a different first variant of the first basic implementation, the friction welding can be performed according to a welding process selected from the group including linear friction welding, friction stir welding, rotary friction welding and orbital friction welding.

[0039] Linear friction welding is a special form of friction welding in which the relative motion of the first and second joints is linear, not rotational. The two joints move towards each other in a back-and-forth motion within the joint plane, where they are pressed together perpendicular to the plane. Linear friction welding is particularly advantageous when joining non-rotationally symmetric joints. A key feature of linear friction welding is that the linear relative motion of the first joint with respect to the second, coupled with the application of a pressure load at the joint, creates a non-uniform weld bead on the circumference of the joint. Specifically, significantly more molten, plasticized material is extruded from the joint in the linear back-and-forth direction compared to the direction transverse to the linear back-and-forth motion. This results in a highly non-uniform weld bead on the circumference. By remelting the uneven weld bead using a fusion welding process after linear friction welding, the bulges formed by the protruding weld beads can be smoothed and / or leveled, thus achieving weld bead homogenization. This is particularly true by smoothing and / or leveling the higher weld bead regions formed along the linear back-and-forth direction of the linear friction welding. Here, the lower height regions transverse to the linear back-and-forth direction of the linear friction welding may either not be smoothed and / or leveled at all, or only to a very small extent. Of course, uneven bulges can also be leveled or even completely eliminated along the circumference of the uneven weld bead by remelting it using a fusion welding process.

[0040] Friction stir welding is a special form of friction welding in which, instead of two parts to be joined moving relative to each other under pressure to generate frictional heat, a different friction tool is used. This friction tool can specifically be designed as a rotating mandrel. The rotating mandrel is introduced into the joint gap between the first and second parts and rotates along the joint gap. Thus, the mandrel rubs the first joint surface of the first part on one side and the second joint surface of the second part on the other. Due to the heat generated by friction, the material of both the first and second parts in the joint gap region is plasticized. Due to the rotation of the mandrel, not only frictional heat is generated, but the plasticized material of the first and second parts also mixes with the plasticized material of the second part. Simultaneously, the mandrel advances along the joint gap between the first and second parts in the feed direction. Here, the plasticized materials of the two parts are mixed and conveyed against the feed direction into the widening joint gap, where they solidify to form a linear weld bead or linear burr. In the second step of an extended welding method, the weld bead is remelted by a fusion welding process immediately after friction stir welding so that the bulge formed by the protruding weld bead is smoothed and / or leveled. The material of the linear weld bead or linear burr located behind the mandrel along the mandrel feed direction can be remelted and thus smoothed and / or leveled.

[0041] Rotary friction welding is a special form of friction welding in which the relative movement of the first and second joints relative to each other is rotational. At least one or both joints are preferably rotationally symmetrical components, such as cylinders, tubes, or rods. Optionally, only one of the joints may be rotated, or both may be rotated. The two joints are typically joined face-to-face by rotary friction welding, i.e., the two joints are axially pressed against each other during their rotation relative to each other. This produces a weld bead that is very uniformly formed along the circumference. Immediately after rotary friction welding, the weld bead is remelted by a fusion welding process, so that the bulge formed by the raised weld bead is smoothed and / or leveled. This can be done particularly immediately after rotary friction welding, preferably in the same clamping device as rotary friction welding. It is particularly advantageous that the remelting of the weld bead by the fusion welding process is carried out using a fixed-position fusion welding device, and using a rotary clamping device from rotary friction welding, so that the circumferential weld bead is automatically guided through the processing tip of the fusion welding device by rotating the joined joints. In this regard, the fusion welding process can be performed directly in a welding machine that has previously performed rotary friction welding.

[0042] Orbit friction welding is a special form of friction welding in which the relative movement of the first and second joints is not generated by the rotational movement of the first and / or second joints. Instead, each of the first and / or second joints is held in a fixed clamping device, wherein the joints do not rotate. This makes it particularly possible to join joints that do not have rotational symmetry. The two joints move relative to each other in such a way that the clamping device of the first joint moves transversely to the joint relative to the clamping device of the second joint, and not only linearly like in linear friction welding, but also in a circular or elliptical motion within the joint plane, i.e., an orbital motion. Thus, the first joint moves in a circular motion relative to the second joint while applying extrusion force in the axial direction, i.e., perpendicular to the joint plane. In orbit friction welding, a weld bead is also formed as material melted and plasticized by frictional heat during extrusion is extruded. Due to the non-rotational symmetry design of the joints and / or due to the orbital motion of the joints, removing the weld bead by known turning operations using a cutting tool in a machine is not easily achieved. Conversely, the non-rotationally symmetric weld beads produced in track friction welding can be easily removed by the welding method according to the invention: that is, the weld beads are remelted by a fusion welding process, so that the bulges formed by the protruding weld beads are smoothed and / or flattened, or even completely eliminated, by fusion welding.

[0043] In the second basic embodiment, the pressure welding process is a resistance welding process.

[0044] In resistance welding, the first and second joints are statically pressed against each other with their opposing joint surfaces perpendicular to the joint surfaces forming the joint, i.e., without any relative movement transverse to the clamping direction. Simultaneously, electrical energy is conducted from one joint to the other through the joint. At the joint, the materials of the two mating joints are heated by Joule current heat introduced into the mating joints by electrical energy. The method according to the invention is particularly suitable when used in resistance welding, where the mating joints are also pressed against each other by clamping force, i.e., clamping pressure. Here, the material of the mating joints, plasticized by the clamping force, is also extruded from the joint gap and forms a weld bead. Here, removing this weld bead, for example, by known cutting in a machine using a lathe tool, is not easily achieved, especially in cases where the joints are not rotationally symmetrical. Instead, the welding method according to the invention can easily remove such potentially non-rotationally symmetrical weld beads generated in resistance welding by remelting the weld bead through a fusion welding process, such that the bulge formed by the protruding weld bead is smoothed and / or leveled or even completely eliminated by the fusion welding.

[0045] In different second variations of the second basic implementation, the resistance welding process can be performed according to a welding method selected from the group including resistance butt welding, pressure butt welding and flash butt welding.

[0046] Resistance butt welding is a special form of resistance welding in which conductive mating parts are first pressed together at the joint to ensure a good electrical connection. Once a good electrical connection is established, electrical energy is directed through the joint, causing the joint area of ​​the mating parts to be heated until it melts due to Joule heating. After reaching the desired temperature, the current can be cut off, and the two mating parts can be further pressed together perpendicular to the joint surface, thus joining the two mating parts. Here, the plasticized material is extruded from the joint area due to the pressing, thereby forming a weld bead. Removing this weld bead is not easy, for example, by known turning using a lathe tool in a machine, especially in the case of a non-rotationally symmetric design of the parts. In contrast, resistance butt welding can easily remove such potentially non-rotationally symmetric weld beads: that is, by remelting the weld bead through a fusion welding process, the bulge formed by the protruding weld bead is smoothed and / or leveled, or even completely eliminated, by fusion welding.

[0047] Press-button welding is a special form of resistance welding. Similar to resistance butt welding, conductive mating parts are first pressed together at the joint to ensure a good electrical connection. Once a good electrical connection is established, electrical energy is directed through the joint, heating the mating area of ​​the mating parts until it melts due to Joule heating. After reaching the desired temperature, the current can be cut off, and the two mating parts can be further pressed together perpendicular to the joint surface, thus joining the two mating parts together. Here, the plasticized material is extruded from the joint area due to the pressing, thus forming a weld bead. Removing this weld bead is not easy, for example, by known turning using a lathe tool, especially in the case of a non-rotationally symmetric design of the parts. In contrast, press-button welding can easily remove this potentially non-rotationally symmetric weld bead: that is, by remelting the weld bead through a fusion welding process, the bulge formed by the protruding weld bead is smoothed and / or leveled, or even completely eliminated, by fusion welding.

[0048] Flash butt welding is a special form of resistance welding where, unlike resistance butt welding and pressure butt welding, the two mating parts are not pressed together under high pressure across the entire surface at the joint during current flow. Instead, they are loosely, i.e., in a small, point-like electrical contact on a single area of ​​the joint surface, allowing electrical energy to flow only through this small region. This results in a very high current density in this small area (Teilfläche), which not only liquefies the material of the mating parts in this region but also partially evaporates it or flits it away as material spatter. In this sense, the mating parts are burned off in these areas. Thus, a feed-like pressing against each other occurs during current flow. Once the joint area is sufficiently heated and enough of the mating part material has melted, the electrical energy is cut off, and the two mating parts are pressed together under high pressure to achieve a joint connection. A weld bead is thus formed. Removing this weld bead is not easily achieved, for example, by turning it with a lathe tool, especially in cases where the joint is not rotationally symmetric. Conversely, flash butt welding can easily remove this potential non-rotationally symmetric weld bead: that is, by remelting the weld bead through a fusion welding process, the bulge formed by the protruding weld bead is smoothed and / or flattened, or even completely eliminated, through fusion welding.

[0049] In the third basic implementation, MBP welding is performed as a pressure welding process.

[0050] MBP welding is also known as magnetic arc welding.

[0051] In MBP welding, two conductive mating joints come into contact at their mating surfaces, allowing electrical energy to be conducted through them. The two mating joints then move away from each other again, creating a gap between them. Due to the continued current flow, an electric arc is generated through this gap. The arc is moved by a separate magnetic field, causing it to travel along the mating surfaces and uniformly heat the materials near the mating surfaces until they melt and become plasticized. Next, the two mating joints are pressed together under pressure, simultaneously disconnecting the current and the magnetic field. This forms a weld bead. Removing this weld bead is not easily achieved, for example, by known turning operations using a lathe tool, especially in cases where the joints are not rotationally symmetric. Instead, MBP welding allows for the simple removal of such potentially non-rotationally symmetric weld beads: that is, by remelting the weld bead through a fusion welding process, the bulges formed by the protruding weld bead are smoothed and / or flattened, or even completely eliminated, through the fusion welding.

[0052] In the second process step of the basic welding method, namely, the weld bead is subsequently remelted by a fusion welding process, so that the bulge formed by the raised weld bead is smoothed and / or flattened. As an extension of the fusion welding process, laser welding can be performed.

[0053] In laser welding, heat energy is introduced into the mating joints via a laser beam to melt and plasticize the material in the mating area. To achieve remelting of the weld bead through laser welding, the laser beam is directed at the weld bead already created by pressure welding in the first step of the welding process. Since the laser beam applies its remelting energy essentially in a point-like manner to the weld bead, it must move relative to the weld bead. This can be done by actively guiding the laser beam around the weld bead while the mating joints are fixed. For example, the laser beam can be guided around the weld bead by a robot. Alternatively, the laser beam can be stationary, i.e., fixed. In this case, the mating joints must move, particularly rotate, so that the entire weld bead can be guided through the laser beam. This can be advantageously achieved by rotating the mating joints joined in the pressure welding process within a clamping device inside the pressure welding machine, and integrating the laser welding equipment as a component of the pressure welding machine.

[0054] In another extended approach, the welding process can be performed using shielded gas welding. Since the shielded gas welding torch here also applies remelting energy essentially in a point-like manner to the weld bead, the torch must move relative to the weld bead. This can be achieved by the shielded gas welding torch actively moving around the weld bead while the mating joints are fixed. For example, the shielded gas welding torch can be moved around the weld bead by a robot. Alternatively, the shielded gas welding torch can be fixed in position, i.e., stationary. In this case, the mating joints must also move, particularly rotate, so that the entire weld bead can be guided through the shielded gas welding torch. This can be advantageously achieved by the mating joints joined in the pressure welding process already rotating in a clamping device inside the pressure welding machine, and the shielded gas welding torch being integrated therein as a component of the pressure welding machine.

[0055] In an alternative extension, WIG welding can be performed as a fusion welding process.

[0056] WIG welding, or tungsten inert gas welding, is similar to shielded gas welding, but the difference is that the electrodes are not burned off but remain intact. The melting temperature of the tungsten electrodes is higher than that of the two mating joints. This type of WIG welding is particularly advantageous for remelting the weld bead because no filler material is added from the electrodes. Therefore, it is particularly advantageous to smooth and / or level the bulges formed by the raised weld bead.

[0057] In another extended approach, plasma welding can also be performed as a fusion welding process when necessary.

[0058] In another further extension, electron beam welding can also be performed as a fusion welding process if necessary.

[0059] Electron beam welding is similar to laser welding, except that an electron beam is applied to the weld instead of a laser beam.

[0060] In order to remelt the weld bead via electron beam welding, the electron beam must be directed at the weld bead already created by pressure welding in the first step of the welding process. Since the electron beam applies its remelting energy to the weld bead in a essentially point-like manner, it must move relative to the weld bead. This can be done by actively moving the electron beam around the weld bead while the mating joints are fixed. For example, the electron beam can be moved around the weld bead by a robot. Alternatively, the electron beam can be stationary, i.e., fixed. Then the mating joints must be movable, particularly rotated, so that the entire weld bead can be guided through the electron beam. This can be advantageously achieved by rotating the mating joints joined in the pressure welding process within a clamping device inside the pressure welding machine, and integrating the electron beam welding equipment as a component of the pressure welding machine.

[0061] The object of the present invention is also achieved by a welding machine having: a first device designed to perform a pressure welding process inside the welding machine; a second device for performing a fusion welding process inside the welding machine; and a machine controller configured and designed to automatically operate the first and second devices and perform the welding method according to any of the embodiments described herein. Attached Figure Description

[0062] Specific embodiments of the invention will be described in detail below with reference to the accompanying drawings. Specific features of these exemplary embodiments may be considered individually or in combination as necessary to constitute the general features of the invention, regardless of where they are specifically mentioned herein.

[0063] Figure 1 A flowchart illustrating the steps of the basic method according to the present invention is shown.

[0064] Figure 2 A schematic diagram of an exemplary welding apparatus for performing a friction welding process is shown.

[0065] Figure 3 It shows according to Figure 2 A partially enlarged cross-sectional view of the welding apparatus in the joint area of ​​the first and second joints, showing the unprocessed weld bead.

[0066] Figure 4 A schematic diagram of an exemplary welding apparatus for performing a resistance welding process is shown.

[0067] Figure 5 It shows according to Figure 4 An enlarged partial cross-sectional view of the welding apparatus in the joint area of ​​the first and second joints, showing the weld beads after the fusion welding process steps.

[0068] Figure 6 A schematic diagram of an exemplary welding apparatus for performing the MBP welding process is shown.

[0069] Figure 7 It shows according to Figure 6 An enlarged partial cross-sectional view of the welding apparatus in the joint area of ​​the first and second joints, showing the weld beads after the fusion welding process steps.

[0070] Figure 8 A perspective view of an exemplary welding machine constructed as a friction welding machine type is shown. Detailed Implementation

[0071] exist Figure 1 The welding method according to the present invention is schematically illustrated in the form of a flowchart, including steps S1 and S2.

[0072] In this basic welding method, in the first step S1, the first joint 1 is joined to the second joint 2 by a pressure welding process, wherein after joining, a weld bead 4 is formed at the edge of the joint portion 5 of the first joint 1 and the second joint 2, protruding from the surfaces 3 of the joined first joint 1 and the second joint 2.

[0073] In this basic welding method, in the subsequent second step S2, the weld bead 4 is remelted by a fusion welding process, so that the bulge formed by the protruding weld bead 4 is smoothed and / or flattened.

[0074] According to step S1.1, the pressure welding process can be a friction welding process. Instead of friction welding, in a modified step S1.2, a resistance welding process can be performed as the pressure welding process. Furthermore, instead of both friction welding and resistance welding, in another modified step S1.3, an MBP welding process can be performed as the pressure welding process.

[0075] According to step S2.1, the subsequent fusion welding process can be laser welding. Instead of laser welding, in a modified step S2.2, shielded gas welding can be performed as the fusion welding process. Instead of laser welding or shielded gas welding, in another modified step S2.3, WIG welding can be performed as the fusion welding process. Again, instead of laser welding, shielded gas welding, or WIG welding, in another modified step S2.4, electron beam welding can be performed.

[0076] exist Figure 2 The diagram schematically illustrates a first basic implementation of friction welding.

[0077] In different first variations of this first basic embodiment, friction welding can be performed according to a welding method selected from the group including linear friction welding, friction stir welding, rotary friction welding and track friction welding.

[0078] According to the present invention, it is necessary to distinguish between the press weld 10 and the weld bead 4 formed on the contact surfaces of the joints 1 and 2 to be joined during the press welding process. Therefore, although the press weld 10 and the weld bead 4 are formed from the same molten and plasticized material of the two joints 1 and 2 under practical conditions, in… Figure 3 , Figure 5 and Figure 7The press weld 10 and weld bead 4 are shown with different shaded lines. The press weld 10 extends across the entire contact surface between the first joint 1 and the second joint 2. Conversely, weld bead 4 is formed of the molten and resolidified material of the first joint 1 and / or the second joint 2, which, in its molten state, is extruded from the joint gap across the entire contact area between the first joint 1 and the second joint 2 due to the extrusion process (arrow P1) during press welding, specifically beyond the surface 3 of the first joint 1 and / or the second joint 2. Therefore, weld bead 4 is the portion of material extruded from the joint gap during press welding.

[0079] In the case of rotationally symmetric joints 1 and 2, such as shafts, tubes, or cylindrical rods, an annular weld bead 4 can be formed. This annular weld bead 4 is best remelted in the second step of the method, i.e., by means of a fusion welding process (the weld bead having a certain shape after pressure welding and before remelting by the fusion welding process). Figure 3 (The original shape), smooth and / or flatten the bulge formed by the raised weld bead 4, as... Figure 5 and Figure 7 As shown, in the first step S1 of the method, the joints 1 and 2, joined by pressure welding, are held in the corresponding clamping devices 5 and 6 of the pressure welding machine 7. Figure 8 ), and the couplings 1 and 2 can be used in the clamping device as Figure 2 Rotating as indicated by the middle arrow P1, the annular weld bead 4 is rotatably guided through the fixed welding device 8, thereby smoothing and / or flattening the weld bead 4 over the entire circumference of the joined parts 1 and 2.

[0080] Instead of a fixed welding device 8, the welding device 8 can also be movable if necessary, so that the processing tip 9 of the welding device 8 can move along the weld bead 4, and in particular, can move automatically along the weld bead. Whether the joined parts 1 and 2 are rotatably mounted in the welding machine 7 or fixedly arranged in the welding machine 7, the processing tip 9 of the welding device 8 can be movable so that the processing tip 9 of the welding device 8 can move along the weld bead 4, and in particular, move automatically along the weld bead.

[0081] Especially in pressure welding processes such as MBP welding, magnetic arc welding, and friction welding, a particularly annular weld bead 4 is formed, which can be at least smoothed and / or flattened, or even completely removed or eliminated, by the method according to the invention.

[0082] exist Figure 4 The diagram illustrates a second basic implementation of the resistance welding process.

[0083] In various second variations of the second basic implementation, the resistance welding process can be performed according to a welding method selected from the group including resistance welding, pressure welding and flash welding.

[0084] In resistance welding processes, such as Figure 4 As shown, the first joint 1 and the second joint 2 are statically pressed together with their mating surfaces, perpendicular to the mating surfaces forming the joint, facing each other, i.e., without any relative movement transverse to the pressing direction, as indicated by arrow P1. Simultaneously, electrical energy is conducted from one joint 1 to the other joint 2 through the joint. This is achieved through… Figure 4 The electrical contact 11 and current line 12 are shown. At the joint, the materials of the two mating joints (i.e., the first joint 1 and the second joint 2) are heated by Joule current heat introduced into the mating joints by electrical energy. Therefore, the method according to the invention is particularly advantageous in resistance welding processes where the mating joints are also pressed against each other by clamping force, i.e., clamping pressure. Here, the plasticized material of the mating joints is also extruded from the joint gap by the clamping force and forms a weld bead 4. Here, removing this weld bead 4 is not easy to achieve, for example by known turning using a lathe tool in a machine, especially in the case of a non-rotationally symmetric design of the joints. Instead, by the welding method according to the invention, the weld bead 4, which may be non-rotationally symmetric, generated during resistance welding can be easily removed by remelting the weld bead 4 by a fusion welding process, such that the bulge formed by the protruding weld bead 4 is smoothed and / or flattened, or even completely eliminated, by fusion welding, as... Figure 5 As shown.

[0085] exist Figure 4 The diagram illustrates a third basic implementation of the MBP welding method.

[0086] In MBP soldering, such as Figure 6As shown, two conductive mating joints (i.e., first joint 1 and second joint 2) are in contact at their mating surfaces, allowing electrical energy to be conducted through the mating surfaces. The two mating joints are then moved away from each other again, as indicated by double arrow P3, creating a gap between them. Due to the continued current flow, an electric arc 13 is generated through this gap. With the aid of a separately present magnetic field, the electric arc 13 is moved, causing it to travel along the mating surfaces and uniformly heat the material near the mating surfaces of the two mating joints until the material melts and plasticizes. Subsequently, the two mating joints are pressed together by pressure, simultaneously disconnecting the current and the magnetic field. Thus, a weld bead 4 is also formed here. Removing this weld bead 4 is not easily achieved, for example, by known turning operations using a lathe tool, especially in the case of a non-rotationally symmetric design of the joints. Instead, this potentially non-rotationally symmetric weld bead 4 can be easily removed using the MBP welding method by remelting the weld bead 4 through a fusion welding process, so that the bulge formed by the protruding weld bead 4 is smoothed and / or flattened, or even completely eliminated, by the fusion welding.

[0087] exist Figure 3 , Figure 5 and Figure 7 In this diagram, the processing tip 9 of the fusion welding device 8 is shown only schematically and abstractly. In a first extended embodiment, the processing tip 9 of the fusion welding device 8 can be a laser welding tip. In a second extended embodiment, the processing tip 9 of the fusion welding device 8 can be a shielded gas welding tip. In a third extended embodiment, the processing tip 9 of the fusion welding device 8 can be a WIG welding tip. In a fourth extended embodiment, the processing tip 9 of the fusion welding device 8 can be an electron beam welding tip.

[0088] exist Figure 8 The image shows a welding machine 7, which includes: a first device 14 designed to perform a pressure welding process inside the welding machine 7; a second device 15 for performing a fusion welding process inside the welding machine 7; and a machine controller 16 configured and designed to automatically operate the first device 14 and the second device 15, and thereon perform a combined welding method having steps S1 and S2 according to any of the embodiments described.

Claims

1. A welding method, comprising the following steps: - The first joint (1) is joined to the second joint (2) by pressure welding process, wherein, after joining, a weld bead (4) is formed at the edge of the joint of the first joint (1) and the second joint (2) protruding from the surface (3) of the joined first joint (1) and the second joint (2). - The weld bead (4) is then remelted by a fusion welding process, so that the bulge formed by the protruding weld bead (4) is smoothed and / or flattened.

2. The welding method according to claim 1, characterized in that, Friction welding is performed as a pressure welding process.

3. The welding method according to claim 2, characterized in that, The friction welding process is performed according to a welding method selected from the group including linear friction welding, friction stir welding, rotary friction welding and orbital friction welding.

4. The welding method according to claim 1, characterized in that, Resistance welding is performed as a pressure welding process.

5. The welding method according to claim 4, characterized in that, The resistance welding process is performed according to a welding method selected from the group including resistance butt welding, pressure butt welding and flash butt welding.

6. The welding method according to claim 1, characterized in that, The MBP welding process is performed as a pressure welding process.

7. The welding method according to any one of claims 1 to 6, characterized in that, Laser welding is performed as a fusion welding process.

8. The welding method according to any one of claims 1 to 6, characterized in that, Shielded gas welding is performed as a fusion welding process.

9. The welding method according to any one of claims 1 to 6, characterized in that, WIG welding is performed as a fusion welding process.

10. The welding method according to any one of claims 1 to 6, characterized in that, Electron beam welding is performed as a fusion welding process.

11. A welding machine, comprising: A first device (14) is designed to perform a pressure welding process inside the welding machine (7); The second device (15) is used to perform the fusion welding process inside the welding machine (7); A machine controller (16) is constructed and designed to automatically operate the first device (14) and the second device (15) and perform the welding method according to any one of claims 1 to 10.

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