Cutting and welding system for producing a three-dimensionally shaped exhaust pipe from a straight pipe, a cutting machine, the three-dimensionally shaped exhaust pipe and a kit

Abstract

Cutting and welding system for carrying out a process for manufacturing a three-dimensionally shaped exhaust pipe from a straight base pipe, the system comprising: - a controller configured to perform a preparation phase in which the controller prepares manufacturing instructions for the cutting and welding system using computer-aided methods: - Retrieving a desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured; - Dividing the desired pipeline route into a plurality of three-dimensionally shaped segments; - Determine, from the plurality of three-dimensionally shaped segments, a plurality of parting planes along which a separation is to be carried out by a parting stage in order to obtain from the straight base pipe the plurality of straight pipe segments which are welded together along the desired pipeline route by a welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the plurality of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate parting plane of the plurality of parting planes at respective predetermined parting angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective parting planes; and - Determining the respective orientations for the majority of straight pipe segments to generate the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between the said end sections, wherein the positive fit is defined by exactly one projection from the parting plane of one of the end sections and exactly one recess in the parting plane of the other end section, wherein the recess is shaped complementary to the projection; - the separation stage for carrying out the separation based on the manufacturing instructions, set up for: - Separating the straight base tube in such a way that the majority of tube segments, including the projections and recesses, are preserved; and - the welding stage for carrying out welding based on the manufacturing instructions, set up for: - Welding at least one of the two end sections of each of the plurality of straight pipe segments to an end section of another of the plurality of straight pipe segments, wherein the plurality of straight pipe segments are pre-assembled together along the desired pipeline route on the basis that the respective end sections of adjacent straight pipe segments to be welded together have the corresponding predetermined elliptical cross-sectional shapes and the complementary projection and complementary recess.

Description

Field of invention

[0001] The present invention relates to a cutting and welding system for carrying out a method for producing a three-dimensionally shaped exhaust pipe from a straight base pipe. The invention further relates to a cutting machine, the three-dimensionally shaped exhaust pipe, and a kit comprising straight pipe segments for forming the three-dimensionally shaped exhaust pipe. background

[0002] The manufacture of exhaust pipes is subject to various requirements and limitations. For example, the installation space for such exhaust pipes in vehicles is typically limited, and therefore exhaust pipes are typically manufactured with complex shapes, especially pipe runs. The pipe routing must fit within an allocated installation volume while meeting thermal, operational, and regulatory requirements.

[0003] It is known to manufacture three-dimensionally shaped exhaust pipes by dividing a straight base pipe into segments and reconnecting the segments along a desired path, for example, by welding. The dividing and welding can be carried out by an automated system. However, there is still a need to further improve such processes. In particular, errors can still occur during the manufacturing process, even when automated systems are used.For example, segments may be placed in the wrong order, rotated, or otherwise misaligned (such as a left-right mirror image), nearly identical segments may be confused, errors may occur in identification or label tracking, or segments may be misidentified or misplaced due to inaccuracies in the manipulation or vision system of the automated system. Such errors can be detrimental to achieving a leak-free exhaust pipe that follows the desired path and also lead to material waste. Summary of the invention

[0004] It is an objective of the present disclosure to provide a method for producing a three-dimensionally shaped exhaust pipe from a straight pipe, which at least partially alleviates the aforementioned disadvantages.

[0005] To this end, the present disclosure hereby provides a method for manufacturing a three-dimensionally shaped exhaust pipe from a straight pipe, hereinafter also referred to as a straight base pipe. The method is carried out by a cutting and welding system comprising a cutting stage configured to cut the straight base pipe into a plurality of straight pipe segments, a welding stage configured to weld the plurality of straight pipe segments together along a desired piping path to form the three-dimensionally shaped exhaust pipe, and a controller configured to control the cutting stage and the welding stage. The method includes: a preparation phase performed by the controller, wherein the controller prepares manufacturing instructions for the cutting and welding system,by performing the following steps using computer assistance: retrieving the desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured; dividing the desired pipe routing into a plurality of three-dimensionally shaped segments; determining, from the plurality of three-dimensionally shaped segments, a plurality of parting planes along which the cutting is to be carried out by the parting stage in order to obtain from the straight base pipe the plurality of straight pipe segments that are to be welded together along the desired pipe routing by the welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the plurality of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate parting plane of the plurality of parting planes, at respective predetermined parting angles relative to a longitudinal axis of the straight base pipe.and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective parting planes; and determining respective orientations for the plurality of straight pipe segments to give the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between said end sections, the positive fit being defined by exactly one projection from the parting plane of one of the end sections and exactly one recess into the parting plane of the other end section, the recess being shaped complementary to the projection; a parting phase, which is carried out by a parting stage based on the manufacturing instructions, comprising: parting the straight base pipe, such that,that the plurality of pipe segments, including the projections and recesses, is obtained; and an assembly phase, carried out by the welding stage on the basis of the manufacturing instructions, comprising: welding at least one of the two end sections of each of the plurality of straight pipe segments to an end section of another of the plurality of straight pipe segments; wherein, prior to welding, the plurality of straight pipe segments are pre-assembled along the desired pipeline path on the basis that the respective end sections of adjacent straight pipe segments to be welded together have the corresponding predetermined elliptical cross-sectional shapes and the complementary projection and recess.

[0006] In the present disclosure, each pair of end sections to be welded together is provided with exactly one projection and exactly one recess, both of which are complementary in shape. These projections and recesses define a positive fit configured to ensure respective orientations for the plurality of straight pipe segments to produce the desired pipe routing. These projections and recesses are provided at the respective end sections of adjacent pipe segments to be welded together during the separation process. Separating the straight pipe can also be understood, for example, as subdividing a straight pipe into segments, such as by cutting the straight pipe. The positive fit behaves like a lock and key pair that is unique at the time of assembly.This complementarity ensures that, when the correct mating partner is provided, the projections can enter the recesses without elastic forcing or secondary readjustment—in other words, as a self-correcting interface. In practice, when two intended end sections are brought together, the projection of the first end section of this pair fits snugly into the recess of the second. This engagement between the complementarily shaped projection and recess creates a geometric constraint with respect to the longitudinal axes of adjacent pipe segments to be welded together. As a result, a deterministic closure between the two end sections is provided, and the degrees of freedom are reduced to a single closing orientation.Pairs of end sections that either do not have matching elliptical shapes or that have mismatched projections or recesses will simply not seat, so that the single projection and the single recess act as integrated defect avoidance. Since indexing occurs before welding, the welding stage can proceed with minimal dependence on additional post-separation inspections. In the absence of the positive fit provided as disclosed, for example, if no or multiple projections and recesses were provided, there may still be a risk that matching elliptical shapes will be joined with a rotational error of, for example, 180 degrees. The provision of the positive fit as disclosed thus advantageously eliminates ambiguous symmetrical fits.Each valid mating end section can therefore have a positive fit defined by exactly one projection in one of the mating end sections and exactly one recess in the other end section, the recess being shaped complementary to the projection. The result is a single allowable relative rotation between the adjacent straight pipe segments to be welded together; and flips about the longitudinal axis of the straight pipe are geometrically blocked. By forcing the system into the intended orientation and mating sequence, the disclosure enables the cutting and welding system to produce the three-dimensionally shaped exhaust pipes with different piping layouts or routing paths with fewer defects and is therefore able to reduce material waste.This is achieved architecturally through geometry in the straight pipe segments by providing the exact one projection and the exact one recess through the cutting stage, controlled by the controller, instead of adding sensors, labels, or complex devices. The welding stage, also controlled by the controller, can then advantageously use these projections and recesses for the correct sequencing and orientation of each segment during welding, which is a simpler way to ensure correct segment sequencing and orientation in automated systems. In other words, the process is carried out autonomously by the system, and the controller sends instructions to the cutting and welding stages. The determination step in the preparation phase can be considered a step that involves discretizing the segmented, three-dimensionally shaped exhaust pipe to be produced.These discretized subdivisions can then be mapped along its length onto the straight base tube to obtain the positions and angles at which the straight base tube is to be divided.

[0007] According to some embodiments of the disclosure, the desired piping routing includes bends in the three-dimensionally shaped exhaust pipe. These bends can typically be introduced to allow the exhaust pipe to be routed around various other components within the vehicle. The bends refer to intentional curves in the exhaust pipe formed as part of the three-dimensional shaping process by joining two elliptically shaped end sections, the elliptical shapes determining the bend angle. A single bend can also be formed by joining more than two straight pipe segments. Bends with different bend radii can be formed in this way.These bends help guide the exhaust pipe around obstacles within the vehicle structure, ensuring a proper fit and maintaining the desired exhaust flow characteristics. For example, it may be necessary to route the exhaust pipe around parts such as the engine, transmission, or structural components of the vehicle, which often occupy space that the exhaust system should avoid. By integrating bends into the piping path, the system can ensure that the exhaust pipe fits within the limited space available in a vehicle while maintaining a functional and efficient path for the exhaust flow.

[0008] According to some embodiments of the disclosure, the bends are essentially coplanar. This means that the bends can be arranged such that they lie substantially within a single plane. Essentially coplanar can also be explained as a configuration in which the bends of the exhaust pipe are aligned so that they lie predominantly within the same plane, with deviations being substantially due to manufacturing tolerances. In practical terms, this configuration simplifies the design of the exhaust system, as it allows the pipe to be routed within a more confined space, thereby reducing the complexity of its routing while still ensuring proper exhaust flow.In these embodiments, the exhaust pipe can be considered a two-dimensionally shaped tube, since all curvatures can be essentially confined to a single plane, thus providing an efficient and streamlined design that minimizes the space required inside the vehicle.

[0009] According to some embodiments of the disclosure, at least one of the bends has a directional component transverse to a plane defined by another of the bends. This can be understood as a configuration in which the direction of at least one bend deviates from the plane formed by a previous bend, resulting in a more complex three-dimensional shape for the exhaust pipe. This configuration allows for more flexible and complex routing of the exhaust pipe within the vehicle, enabling the pipe to be routed around additional components and obstacles. In contrast to simpler configurations where all bends are coplanar, the inclusion of this transverse directional component increases the overall complexity of the pipe's shape and provides greater adaptability to the spatial constraints of the vehicle.

[0010] In accordance with some embodiments of the disclosure, exactly one projection and exactly one recess are provided at the respective end sections of adjacent straight pipe segments, which are to be welded together on a major axis of the predetermined elliptical cross-sectional shape. It is recognized that a corner in the three-dimensionally shaped exhaust pipe formed by a pair of welded end sections has an angle bisector that coincides with the respective major axes of the two end sections. In these embodiments, at least one pair of end sections has exactly one projection and exactly one recess at the respective end sections on the major axis of the elliptical shape.Consequently, in these embodiments, exactly one projection of both end sections of such a pair can be adapted to the corner angle between the two end sections, for example by means of bending.

[0011] In accordance with some embodiments of the disclosure, the exactly one projection and the exactly one recess are provided at the respective end sections of adjacent straight pipe segments, which are to be welded together at a secondary axis of the predetermined elliptical cross-sectional shape. In these embodiments, the exactly one projection and the exactly one recess can be provided at the respective end sections of such a pair at their respective secondary axes, instead of at the major axes as mentioned above. Advantageously, by providing the exactly one projection and the exactly one recess at the secondary axes, the exactly one projection and the exactly one recess can be made invariant with respect to the bending radii in the entire three-dimensionally shaped exhaust pipe, and in such pairs they do not need to be adapted to the corner angles between pairs of segments.In other words, the projection and cutout on the secondary axis require no modifications based on the corner angles between adjacent segments. This provides a uniform, flawless connection across the entire exhaust pipe and reduces the complexity of the manufacturing process. As a result, the manufacturing process becomes simpler and more reliable, since the projections and cutouts can remain consistent across end sections without the need for additional adjustments to accommodate varying corner angles.

[0012] According to some embodiments of the disclosure, the step of determining the plurality of straight tube segments to be cut from the straight tube comprises a step of mapping each of the plurality of three-dimensionally shaped segments at respective positions along a length of the straight tube, to predetermine the plurality of cutting planes that define the cutting positions, and the cutting angles associated with the cutting positions along the length of the straight tube. The cutting step is performed along the cutting planes. In certain embodiments, during the mapping process, the controller can assign each partitioned, three-dimensionally shaped segment to an axial position on the straight tube and specify the corresponding cutting angle and rotational orientation for each pair of adjacent segments.In certain advantageous implementations, this mapping can involve organizing the straight pipe into runs or sequences containing subsets of segments. Within each run, segments can then be cut back-to-back, so that pairs of pipe segments in the three-dimensionally shaped exhaust pipe can be produced by a single, shared cut operation. Within a run, scrap can thus be minimized because one cut operation yields both mating surfaces of a bend or curved section. If machine or geometric constraints do not allow the run to be extended further, the controller can insert a break in that run and define a small gap at the end of the run before initiating the next run.The mapping stage can thus produce a complete cut-off list, which includes cut-off positions along the straight pipe as well as the associated cut-off angles and rotations for each cut.

[0013] According to some embodiments of the disclosure, the straight pipe is made of materials comprising at least one of the following: stainless steel or steel alloys. Such materials provide durable solutions that are well suited to harsh thermal environments, such as those typically found in vehicle exhaust systems. Furthermore, they can advantageously provide high corrosion resistance, making them suitable for applications requiring increased durability and longevity, such as in areas of the exhaust system exposed to harsher environmental conditions.

[0014] According to some embodiments of the disclosure, the wall thickness of the straight tube is less than 2 mm, preferably less than 1.5 mm, and more preferably less than 1.2 mm. Such wall thicknesses for the straight tube can advantageously reduce process-induced stresses. For example, smaller wall thicknesses can reduce heat input during cutting and welding, thereby limiting thermal gradients and welding shrinkage forces, thus reducing residual stresses after the assembly phase. The reduced wall thickness can also decrease the bending stress required to achieve angles of projections relative to the longitudinal axis of the segment on which they are provided, thereby reducing stress concentrations at these indexing features. As a result, the dimensional accuracy of the welded joints can be improved.

[0015] According to some embodiments of the disclosure, the exactly one projection has a length between 2 mm and 12 mm, preferably between 3 mm and 9 mm, and more preferably between 4 mm and 7 mm. In these embodiments, the exactly one projection provided on the end section is dimensioned to provide a controlled engagement length sufficient to self-index and maintain the relative orientation of matching end sections during fitting and welding, but small enough to avoid excessive stresses in the weld area due to discontinuities inherent in the projections and recesses.Within these areas, the provided protrusion can provide robust rotational indexing of pipe segments during pre-welding handling, reduce the risk of protrusions snapping out of corresponding recesses under mechanical loads, and limit stress concentration and distortion during final welding and cooling. The protrusion length can be defined as the axial depth of engagement, measured from the end face defined by the end section to the furthest point of the protrusion entering the complementarily shaped recess.

[0016] According to a first aspect of the invention, a cutting and welding system for carrying out a method for manufacturing a three-dimensionally shaped exhaust pipe from a straight pipe is provided, such as the method according to the disclosure. The system comprises a controller configured to perform a preparation phase in which the controller computer-aidedly prepares manufacturing instructions for the cutting and welding system by: retrieving a desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured; partitioning the desired pipe routing into a plurality of three-dimensionally shaped segments;from the multitude of three-dimensionally shaped segments, a multitude of cutting planes are determined, along which a separation is to be carried out by a cutting stage in order to obtain from the straight base pipe the multitude of straight pipe segments which are welded together along the desired pipeline route by a welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the multitude of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate cutting plane of the multitude of cutting planes, at respective predetermined cutting angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective cutting planes;and respective orientations for the multitude of straight pipe segments are determined to achieve the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between said end sections, the positive fit being defined by exactly one projection from the cutting plane of one of the end sections and exactly one recess in the cutting plane of the other end section, the recess being shaped complementary to the projection. The system further comprises the separation stage for carrying out the separation based on the manufacturing instructions, which is arranged to: separate the straight base pipe in such a way as to obtain the multitude of pipe segments including the projections and recesses;and the welding stage for carrying out the welding based on the manufacturing instructions, which is arranged to: weld at least one of the two end sections of each of the plurality of straight pipe segments to an end section of another of the plurality of straight pipe segments, wherein the plurality of straight pipe segments are pre-assembled along the desired pipeline route on the basis that the respective end sections of adjacent straight pipe segments to be welded together have the corresponding predetermined elliptical cross-sectional shapes and the complementary projection and complementary recess.

[0017] The cutting and welding system according to the first aspect provides the respective end sections of adjacent straight pipe segments, which are to be welded together, by means of a positive fit. Preferably, the positive fit is defined by exactly one projection from the cutting plane of one of the end sections and exactly one recess in the cutting plane of the other end section, the recess being shaped complementary to the projection. The system provides these projections and recesses on the respective end sections of the segments during the cutting process. Due to the positive fit, the system is able to produce pairs of welded end sections that behave like lock-and-key pairs, uniquely sized at the moment of joining.This complementarity ensures that, when the correct counterpart is provided, the protrusions can enter the recesses without elastic forcing or secondary readjustment – ​​in other words, as a self-correcting interface.

[0018] Accordingly, when two intended end sections obtained by separation through the separating step are brought together, the projection of the first end section of this pair can fit into the recess of the second end section. This positive fit creates a geometric constraint along the edges of the two end sections. Consequently, the system is able to provide a deterministic closure of the two end sections, reducing the degrees of freedom to a single closing orientation. Pairs of end sections that either do not have matching elliptical shapes or that have mismatched projections or recesses will simply not fit, so the precisely one projection and the precisely one complementary recess act as integrated error avoidance.Since indexing is performed before welding, the welding stage can proceed with minimal dependence on additional post-separation inspections. In the absence of the form-fit connection as described in the disclosure, for example, if no or multiple projections and recesses were provided, there may still be a risk of joining matching elliptical shapes with a rotational error of 180 degrees. Providing one of the two end sections to be welded together with only one projection at a defined position along the edge of the elliptically shaped end section and only one complementary recess at a corresponding position along the edge of the elliptically shaped end section of the other end section thus advantageously eliminates ambiguous symmetrical fits.Each valid matching end section can therefore have a positive fit defined by exactly one projection in one of the matching end sections and exactly one recess in the other end section, the recess being shaped complementary to the projection. The result is a single allowable relative rotation between the adjacent straight pipe segments to be welded together; and folds around the longitudinal axis of the straight pipe are geometrically blocked. The system thus advantageously forces itself into the intended orientation and neighborhood sequencing, enabling the cutting and welding system to produce the three-dimensionally shaped exhaust pipes with various piping layouts or routing paths with fewer errors.The system of the first aspect can therefore reduce material waste through architectural means via geometry in the pipe segments it produces, in particular by providing the positive locking through the cutting stage, controlled by the controller, instead of adding sensors, labels, or complex devices. The welding stage, also controlled by the controller, can then advantageously use these protrusions and recesses for the correct sequencing and alignment of each segment during welding. In other words, the system can autonomously produce the three-dimensionally shaped exhaust pipes. The controller sends manufacturing instructions to the cutting and welding stages.

[0019] At least certain of the advantages described above in relation to the preferred positive locking configuration - defined by exactly one projection from the cutting plane of one of the end sections and exactly one complementarily shaped recess into the cutting plane of the other end section - may also be present in a less preferred positive locking configuration.

[0020] For example, a less preferred positive fit might be defined by the fact that the respective end sections of adjacent straight pipe segments to be welded together each include exactly one projection and exactly one recess per end section, as opposed to only one of the two (as is the case with the preferred positive fit configuration), multiple projections and / or multiple recesses, or neither. However, the preferred positive fit offers an advantage over such less preferred configurations, particularly with regard to manufacturing efficiency. Each additional projection and / or recess requires additional machining during each stage of the production of the three-dimensionally formed exhaust pipe, thereby increasing manufacturing complexity and / or machining time. The preferred positive fit therefore achieves an advantageous balance between defect prevention and ease of manufacturing.

[0021] In accordance with some embodiments of the invention, the cutting stage can comprise a laser cutter and / or a saw blade arranged for cutting steel. However, the cutting stage can employ any other suitable thermal, mechanical, and / or electrochemical cutting techniques. For example, a laser cutter can provide a narrow kerf, high edge quality, and precise control of the cutting angles, resulting in the predetermined elliptical shapes of the end sections. It also offers high accuracy in providing the protrusions and recesses during cutting. Since laser cutting exerts low tool pressure, thin-walled tubes can be cut with a reduced risk of segment deformation transverse to their longitudinal axes. Alternatively, a saw blade arranged for cutting steel (e.g., a laser cutter) can be used.A cold circular saw or band saw suitable for stainless steels offers low heat input and thus reduces the risk of heat-induced deformation. Material waste can therefore be further reduced in various ways, depending on specific requirements or limitations.

[0022] In accordance with some embodiments of the invention, the welding stage comprises a laser welding cell and / or a metal inert gas (MIG) welding cell. A laser welding cell can provide high throughput and narrow heat-affected zones, thereby limiting distortion and helping to maintain the indexing provided by the single projection and recess. A MIG / MAG welding cell can provide stable performance across a wide range of stainless steels and wall thicknesses. Each welding medium can be selected according to material grades, wall thicknesses, and / or cost / throughput targets.

[0023] It is recognized that the cutting and welding system can comprise a plurality of machines configured to perform cutting in the cutting stage and / or a plurality of machines configured to perform welding in the welding stage. According to some embodiments of the invention, the control system is configured to control the cutting stage to perform cutting; and / or the control system is configured to control the welding stage to perform welding. In other words, the manufacturing sequence employed by the system can be autonomous: in these embodiments, the control system can orchestrate the entire sequence without any intermediate manual setup or intervention.The control system can convert the output from the preparation phase (desired pipe routing, partitioning, mapping, predetermined cutting positions and angles) into manufacturing instructions, such as machine instructions and command signals for the cutting and welding stages of the system. The centralized control of these systems reduces operator contact points and the risk of errors, can shorten the time between cutting and welding, and improves repeatability across different pipe routings and materials, thus providing a robust, automated workflow.

[0024] According to a second aspect, the present disclosure relates to a cutting machine for use in a method for manufacturing a three-dimensionally shaped exhaust pipe from a straight base pipe, such as the method according to the disclosure, wherein the cutting machine is arranged to cut the straight base pipe based on manufacturing instructions in order to obtain a plurality of straight pipe segments, wherein the cutting machine includes a controller configured to perform a preparation phase in which the controller computer-aidedly prepares the manufacturing instructions for the cutting machine by: retrieving a desired piping layout for the three-dimensionally shaped exhaust pipe to be manufactured; partitioning the desired piping layout into a plurality of three-dimensionally shaped segments;from the multitude of three-dimensionally shaped segments, a multitude of cutting planes are determined, along which a separation is to be carried out by a cutting stage in order to obtain from the straight base pipe the multitude of straight pipe segments which are welded together along the desired pipeline route by a welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the multitude of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate cutting plane of the multitude of cutting planes, at respective predetermined cutting angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective cutting planes;and respective orientations for the multitude of straight pipe segments are determined to achieve the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between the said end sections, wherein the positive fit is defined by exactly one projection from the cutting plane of one of the end sections and exactly one recess in the cutting plane of the other end section, wherein the recess is shaped complementary to the projection.

[0025] According to a third aspect, the present disclosure relates to the three-dimensionally shaped exhaust pipe produced from the straight base pipe, comprising: the plurality of straight pipe segments cut from the straight base pipe and welded together along the desired pipe path to form the three-dimensionally shaped exhaust pipe. Each of the plurality of straight pipe segments comprises two end sections at respective predetermined cutting angles relative to the longitudinal axis of the straight base pipe. The respective end sections of adjacent straight pipe segments welded together have: in their respective planes of section, the corresponding predetermined elliptical cross-sectional shape; and the positive fit, wherein the positive fit is defined by exactly one projection in one of the end sections and exactly one recess in the other end section, the recess being shaped complementary to the projection.

[0026] According to a fourth aspect, the present disclosure relates to a kit comprising the plurality of straight pipe segments cut from the straight base pipe for welding together along the desired piping path to form the three-dimensionally shaped exhaust pipe, such as the three-dimensionally shaped exhaust pipe according to the third aspect. In other words, the kit comprises the plurality of straight pipe segments, which are segments cut from the straight base pipe and configured to be pre-assembled and welded together to produce the three-dimensionally shaped exhaust pipe. Each of the plurality of straight pipe segments comprises two end sections at respective predetermined cleavage angles relative to the longitudinal axis of the straight base pipe.The respective end sections of adjacent straight tube segments to be welded together have: in their respective section plane the corresponding predetermined elliptical cross-sectional shape; and the positive fit, wherein the positive fit is defined by exactly one projection in one of the end sections and exactly one recess in the other end section, wherein the recess is shaped complementary to the projection.

[0027] It is understood that features disclosed in connection with the method, the cutting and welding system, the cutting machine, the three-dimensionally shaped exhaust pipe, and / or the kit comprising the plurality of straight pipe segments may be mutually applicable unless otherwise specified. As a particular example, any embodiment described in connection with the method according to the present disclosure may be applicable to the system according to the first aspect and / or to the cutting machine according to the second aspect. As a further particular example, any embodiment described in connection with the system according to the first aspect may be applicable to the cutting machine according to the second aspect.As a further special example, any embodiment described in connection with the method according to the disclosure, including the material selection of the straight base tube, the dimensional requirements of the straight base tube and other structural or processing features relating to the manufacture of the three-dimensionally shaped exhaust pipe, can be applied equally to embodiments directed to the three-dimensionally shaped exhaust pipe according to the third aspect and / or to the kit comprising the plurality of straight tube segments according to the fourth aspect.

[0028] In general, the three-dimensionally shaped exhaust pipe according to the third aspect and the kit comprising the plurality of straight pipe segments according to the fourth aspect can be obtained by the method according to the disclosure and any embodiments disclosed in connection therewith. Brief description of the drawings

[0029] The invention is further explained by describing some specific embodiments thereof with reference to the accompanying drawings. The detailed description provides examples of possible implementations of the invention but is not to be considered a description of the only embodiments that fall within the scope of protection. The scope of protection of the invention is defined in the claims, and the description is to be considered exemplary without limiting the invention. In the drawings: The Fig. Figures 1A-1C schematically illustrate a tube at various stages during the process according to some embodiments of the present invention. Fig. Figure 2 schematically illustrates a method according to some embodiments of the present invention. Fig. Figure 3 schematically illustrates a cutting and welding system according to some embodiments of the invention. Detailed description

[0030] The Fig. Figures 1A-1C schematically illustrate an example of a three-dimensionally shaped exhaust pipe 1, such as can be produced from a straight pipe 2 in some embodiments of the present invention. Fig. Figure 1A shows a straight pipe 2 at the beginning of the process. The straight pipe 2 can, for example, be made of materials including stainless steel, steel alloys, or other suitable materials for the manufacture of exhaust pipes. Fig. 1B the straight pipe has been cut off, as further below in relation to Fig. 2 is discussed further. After cutting, a large number of straight pipe segments 201 were obtained.

[0031] As in the Fig. 1B and Fig. As shown in Figure 1C, these straight pipe segments can most preferably include exactly one projection 202 and exactly one recess 203 at the respective end sections of adjacent straight pipe segments intended to be welded together, in order to form the three-dimensionally shaped exhaust pipe 1 along a desired pipe path 105. Such a configuration, in which exactly one projection 202 can be received into exactly one complementarily shaped recess 203, defines a positive fit to ensure predetermined respective orientations between adjacent straight pipe segments 201', 201'' (in the Fig. 1B and Fig. 1C is shown as an exemplary pair of adjacent straight pipe segments to be welded together, resulting in the desired pipeline routing 105.

[0032] However, although not shown, an end section intended to be welded to an end section of an adjacent straight tube segment may alternatively, in a less preferred positive-locking configuration, comprise exactly one projection 202 and exactly one recess 203, or two or more projections and / or recesses. Nevertheless, the most preferred

[0033] A positive locking configuration is defined by exactly one projection 202 in one of the end sections of the adjacent straight tube segments 201', 201'' to be welded together, and exactly one recess in the other end section. This preferred positive locking configuration already provides error prevention against incorrect assembly of the plurality of straight tube segments. In particular, such error prevention is enhanced if the respective end sections of adjacent straight tube segments to be welded together are further defined in their respective cross-sectional plane 204', 204'' (in Fig. 1B as exemplary section planes of end sections to be welded together) have a corresponding predetermined elliptical cross-sectional shape - when the respective end sections are positioned for welding such that the section planes coincide.

[0034] As in relation to Fig. As discussed in more detail in section 2, the cutting of the straight base tube 2 is carried out based on manufacturing instructions. These manufacturing instructions are prepared by a computer-aided control system, which, in a preparation phase prior to the cutting and assembly phases, determines a multitude of cutting planes along which the cutting is to be carried out. The determined cutting planes take into account cutting angles relative to the longitudinal axis 205 of the straight base tube 2, which, in the case of a non-perpendicular cutting angle, result in the predetermined elliptical cross-sectional shape. The control system also determines the positive fit, whereby the projection 202 of one of the end sections to be welded together protrudes from the respective cutting plane, and the recess in the other end section extends into the respective cutting plane.

[0035] As from the Fig. 1B and Fig. As can be seen in Figure 1C, the initial pipe ends of the straight base pipe 2 can also form the end ends of the assembled three-dimensionally shaped exhaust pipe 1. Accordingly, straight pipe segments comprising an initial pipe end can have only one end section that is separated, such that at least one of the two end sections of a straight pipe segment is defined by an intermediate section plane of the plurality of section planes between adjacent straight pipe segments to be separated.Notwithstanding the foregoing, straight pipe segments comprising an initial pipe end may alternatively have two detached end sections, for example, if an end section replacing the initial pipe end is formed at a severance angle relative to a longitudinal axis 205 of the straight base pipe 2 that deviates from substantially perpendicular, if the straight base pipe is cut to a predetermined length to form the exhaust pipe, and / or if the end section is provided with a cleanly cut finish.

[0036] Fig. Figure 2 schematically illustrates a method for manufacturing a three-dimensionally shaped exhaust pipe according to some embodiments of the invention. The method is carried out by a cutting and welding system and comprises: a preparation phase 3, which is carried out by a controller; a cutting phase 4, which is carried out by a cutting stage; and an assembly phase 5, which is carried out by a welding machine. The preparation phase 3 comprises: a step 6 of defining a desired piping path for the three-dimensionally shaped exhaust pipe 1, for example, by retrieving the desired piping path from a representation of a target exhaust pipe to be manufactured, such as a CAD model or other digital or analog geometry data. This desired piping path or routing may include bends.Such bends can be essentially coplanar and lie substantially within a single plane, or alternatively, such bends can include at least one bend that has a directional component transverse to a plane defined by another of the bends, so that the bends do not all lie substantially within a single plane. The preparation phase further includes a step 7 of partitioning the desired piping path into a plurality of three-dimensionally shaped segments. Subsequently, the controller 8 determines from the plurality of three-dimensionally shaped segments a plurality of straight pipe segments 201, which are to be cut 9 from the straight pipe 2 in order to be welded 10 to the three-dimensionally shaped exhaust pipe 1.The control system can, in particular, define a plurality of cutting planes along which a separation is to be carried out by the separation stage in order to obtain the plurality of straight pipe segments 201 from the straight base tube 2. Each of the plurality of straight pipe segments 201 obtained by step 9 of the separation process comprises two end sections at respective predetermined cutting angles relative to the longitudinal axis of the straight base tube. The respective end sections of adjacent straight pipe segments, which are to be welded together, have corresponding predetermined elliptical cross-sectional shapes in their respective cutting planes, hereinafter also referred to as elliptical shapes.Step 8, determining the plurality of straight pipe segments 201 to be cut from the straight pipe 2, can further include step 11 of mapping each of the plurality of three-dimensionally shaped segments at respective positions along a length of the straight pipe 2, in order to predetermine cutting positions and the cutting angles associated with those cutting positions along the length of the straight pipe. Step 9, the cutting process, can then be carried out at the predetermined cutting positions and along the predetermined cutting angles. The respective orientations are also determined during preparation phase 3 for the plurality of straight pipe segments to achieve the desired pipeline routing. The respective orientations between the respective end sections of adjacent straight pipe segments that are to be welded together are ensured by a positive fit between the said end sections.The positive fit is defined by exactly one projection 202 in one of the end sections and exactly one recess 203 in the other end section, the recess being shaped complementarily to the projection. Separation phase 4 comprises step 9 of separating the straight tube 2 to obtain the plurality of tube segments 201. Assembly phase 5 comprises step 10 of welding at least one of the two end sections of each of the plurality of straight tube segments 201 to an end section of another of the plurality of straight tube segments 201 with a corresponding elliptical shape. This step 10 of welding the straight tube segments 201 in the specified positions and orientations results in the three-dimensionally shaped exhaust pipe 1.During the separation 9, the separation phase 4 further comprises a step 13 of providing the respective end sections of adjacent straight pipe segments, which are intended to be welded together 10, with the positive fit defined by exactly one projection 202 in one of the end sections and by exactly one complementarily shaped recess 203 in the other end section. This exactly one projection 202 and this exactly one recess 203 are taken into account, for example, by the specific plurality of cutting planes along which the separation is to be carried out.By virtue of the corresponding predetermined elliptical cross-sectional shapes and the complementary projection 202 and the complementary recess 203, the plurality of straight pipe segments 201 can be pre-assembled relative to one another along the desired pipeline path, thereby fixing the relative orientations for the plurality of straight pipe segments before the welding of the assembly phase. In particular, such pre-assembly can be carried out before welding a circumferential weld along the joint between the respective end sections of adjacent straight pipe segments. Such a pre-assembled configuration is, for example, in . Fig. Figure 1C illustrates how the integrity of the pre-assembled straight pipe segments along the desired pipeline path can be maintained, for example, by positive locking, tack welding, and / or a fixture. The straight pipe segments are welded together to form a leak-free connection. The weld seam joining adjacent straight pipe segments can, for example, have a sufficient weld zone to provide a leak-free connection between the projection and the recess of adjacent straight pipe segments along a straight circumferential weld path, i.e., a weld path that does not follow the contour of the projection and the recess.Furthermore, the one projection 202 and the one recess 203 at the respective end sections of adjacent straight pipe segments to be welded together can be provided on a major axis of the predetermined elliptical cross-sectional shape. As described above and as known in the prior art, elliptical shapes comprise a major axis and a minor axis that define the elliptical shape. In the invention, corners formed between two segments 201 in the three-dimensionally shaped exhaust pipe 1 have an angle bisector that coincides with the major axes of connected elliptical shapes. In some embodiments, the projections 202 and recesses 203 can thus be provided on these major axes.Additionally or alternatively, the single projection 202 and the single recess 203 at the respective end sections of adjacent straight tube segments to be welded together can be provided on a secondary axis of the elliptical shape. The wall thickness of the straight tube 2 can be less than 2 mm, preferably less than 1.5 mm, and more preferably less than 1.2 mm. The single projection has a length between 2 mm and 12 mm, preferably between 3 mm and 9 mm, and more preferably between 4 mm and 7 mm.

[0037] Fig.Figure 3 schematically illustrates a cutting and welding system 14 for carrying out a method for producing a three-dimensionally shaped exhaust pipe 1 from a straight pipe 2 according to some embodiments of the invention. The system 14 comprises a controller 15, a cutting stage 16, and a welding machine 17. The controller 15 is configured to define the desired pipe path for the three-dimensionally shaped exhaust pipe 1. The controller 15 is further configured to partition 7 the desired pipe path into a plurality of three-dimensionally shaped segments and 8 determine from the plurality of three-dimensionally shaped segments a plurality of straight pipe segments 201, which are to be cut 9 from the straight pipe 2. Each of the plurality of straight pipe segments 201 obtained in this way then comprises two end sections at respective predetermined cutting angles, which give the two end sections predetermined elliptical shapes.The controller 15 is further configured to determine 12 respective orientations for the plurality of straight pipe segments 201 to achieve the desired pipeline routing. The controller 15 can also be configured to control 151 the cutting stage 16 to perform the cutting 9. Additionally or alternatively, the controller 15 can be configured to control 152 the welding machine 17 to perform the welding 10. The cutting stage 16 is arranged to cut 9 the straight pipe 2 to obtain the plurality of pipe segments 201. For this purpose, the cutting stage 16 can include a laser cutter and / or a saw blade arranged for cutting steel. The welding machine 17 is arranged to weld 10 at least one of the two end sections of each of the plurality of straight pipe segments 201 to an end section of another of the plurality of straight pipe segments 201 with a corresponding elliptical shape.The welding machine 17 is thus arranged to perform the final operations required to obtain a tube with the desired shape. For this purpose, the welding machine 17 can comprise a laser welding cell or a metal inert gas (MIG) welding cell. Furthermore, the separating stage 16 is arranged to provide, during the separating process 9, the respective end sections of adjacent straight tube segments to be welded together with a positive fit. The positive fit is defined by exactly one projection 202 in one of the end sections and by exactly one recess 203 in the other end section, the recess being shaped complementary to the projection 202, as discussed above. The separating stage 16 thus establishes the respective orientations prior to welding.

[0038] The present invention has been described with reference to some specific embodiments thereof. It is acknowledged that the embodiments shown in the drawings and described herein are provided for illustrative purposes only and are in no way or by any means intended to limit the invention. It is assumed that the function and structure of the present invention will be evident from the foregoing description and the accompanying drawings. It will be clear to a person skilled in the art that the invention is not limited to any embodiment described herein and that modifications are possible which are to be considered to be within the scope of protection of the appended claims. Kinematic inversions are also considered to be inherently disclosed and to be within the scope of protection of the invention.Furthermore, any of the components and elements of the various disclosed embodiments can be combined or incorporated into other embodiments where this is deemed necessary, desired or preferred, without deviating from the scope of protection of the invention as defined in the claims.

[0039] Any reference numerals in the claims are not to be interpreted as limiting the claim. The terms "comprising" and "including," when used in this description or the attached claims, are not to be interpreted in an exclusive or exhaustive sense, but rather in an inclusive sense. Thus, the expression "comprising" as used herein does not preclude the presence of other elements or steps in addition to those listed in a claim. Furthermore, the words "one" and "a" are not to be interpreted as being limited to "only one," but are instead used in the sense of "at least one" and do not preclude multiple elements. Features that are not specifically or expressly described or claimed may additionally be included in the structure of the invention within its scope of protection.Any of the claimed or disclosed devices or parts thereof may be combined with one another or divided into further parts, unless expressly stated otherwise, without departing from the claimed subject matter of the invention. Expressions such as "means for..." are to be read as "component configured to..." or "part designed to..." and are to be interpreted as including equivalents for the disclosed structures. The use of expressions such as "critical," "preferred," "particularly preferred," etc., is not intended to limit the invention. Additions, deletions, and modifications within the scope of the skilled person may generally be made without departing from the spirit and scope of the invention as defined by the claims. The invention may be carried out differently than specifically described herein and is limited only by the appended claims.

Claims

[1] Cutting and welding system for carrying out a method for producing a three-dimensionally shaped exhaust pipe from a straight base pipe, the system comprising: - a controller configured to perform a preparation phase in which the controller prepares manufacturing instructions for the cutting and welding system using computer-aided methods: - Retrieving a desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured; - Dividing the desired pipeline route into a plurality of three-dimensionally shaped segments; - Determine, from the plurality of three-dimensionally shaped segments, a plurality of parting planes along which a separation is to be carried out by a parting stage in order to obtain from the straight base pipe the plurality of straight pipe segments which are welded together along the desired pipeline route by a welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the plurality of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate parting plane of the plurality of parting planes at respective predetermined parting angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective parting planes; and - Determining the respective orientations for the majority of straight pipe segments to generate the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between the said end sections, wherein the positive fit is defined by exactly one projection from the parting plane of one of the end sections and exactly one recess in the parting plane of the other end section, wherein the recess is shaped complementary to the projection; - the separation stage for carrying out the separation based on the manufacturing instructions, set up for: - Separating the straight base tube in such a way that the majority of tube segments, including the projections and recesses, are preserved; and - the welding stage for carrying out welding based on the manufacturing instructions, set up for: - Welding at least one of the two end sections of each of the plurality of straight pipe segments to an end section of another of the plurality of straight pipe segments, wherein the plurality of straight pipe segments are pre-assembled together along the desired pipeline route on the basis that the respective end sections of adjacent straight pipe segments to be welded together have the corresponding predetermined elliptical cross-sectional shapes and the complementary projection and complementary recess. [2] Separation and welding system according to claim 1, wherein the separation stage for separation comprises a laser cutter and / or a cutting edge configured for cutting steel. [3] Cutting and welding system according to claim 1 or 2, wherein the welding stage comprises a laser welding cell and / or a gas metal arc welding cell. [4] Cutting and welding system according to any of the preceding claims, wherein the control is configured to control the cutting stage to perform the cutting; and / or wherein the control is configured to control the welding machine to perform the welding. [5] Separation and welding system according to any of the preceding claims, wherein the separation stage is configured to provide exactly one projection and exactly one recess at the respective end sections of adjacent straight tube segments to be welded together, on a major major axis of the predetermined elliptical cross-sectional shape. [6] Separation and welding system according to one of claims 1-4, wherein the separation stage is configured to provide exactly one projection and exactly one recess at the respective end sections of adjacent straight tube segments to be welded together on a secondary axis of the predetermined elliptical cross-sectional shape. [7] Cutting and welding system according to any of the preceding claims, wherein the straight base tube is made of materials comprising at least one of the following: stainless steel or steel alloys. [8] Cutting and welding system according to one of the preceding claims, wherein the thickness of the straight base tube is less than 2 mm, preferably less than 1.5 mm, particularly preferably less than 1.2 mm. [9] Separation and welding system according to one of the preceding claims, wherein the separation stage is configured to provide exactly one projection with a length between 2 mm and 12 mm, preferably between 3 mm and 9 mm, particularly preferably between 4 mm and 7 mm. [10] Cutting machine for use in a method for manufacturing a three-dimensionally shaped exhaust pipe from a straight base pipe, wherein the cutting machine is configured to cut the straight base pipe on the basis of manufacturing instructions, so that a plurality of straight pipe segments are obtained, wherein the cutting machine comprises a control system configured to perform a preparation phase in which the control system prepares the manufacturing instructions for the cutting machine by computer: - Retrieving a desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured; - Dividing the desired pipeline route into a plurality of three-dimensionally shaped segments; - Determine, from the plurality of three-dimensionally shaped segments, a plurality of parting planes along which a separation is to be carried out by a parting stage in order to obtain from the straight base pipe the plurality of straight pipe segments which are welded together along the desired pipeline route by a welding stage to form the three-dimensionally shaped exhaust pipe, wherein each of the plurality of straight pipe segments comprises two end sections, wherein at least one of the two end sections is defined by an intermediate parting plane of the plurality of parting planes at respective predetermined parting angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have corresponding predetermined elliptical cross-sectional shapes in their respective parting planes; and - Determining the respective orientations for the majority of straight pipe segments to generate the desired pipeline routing, wherein the respective orientations between the respective end sections of adjacent straight pipe segments to be welded together are ensured by a positive fit between the said end sections, wherein the positive fit is defined by exactly one projection from the parting plane of one of the end sections and exactly one recess in the parting plane of the other end section, wherein the recess is shaped complementary to the projection. [11] Three-dimensionally shaped exhaust pipe, made from a straight base pipe, comprising: - a plurality of straight pipe segments separated from the straight base pipe and welded together along a desired pipe path to form the three-dimensionally shaped exhaust pipe; wherein each of the plurality of straight pipe segments comprises two end sections at respective predetermined separation angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments welded together have: - a corresponding predetermined elliptical cross-sectional shape in their respective parting plane; and - a positive fit, wherein the positive fit is defined by exactly one projection in one of the end sections and exactly one recess in the other end section, wherein the recess is shaped complementarily to the projection. [12] The three-dimensionally shaped exhaust pipe according to claim 11, wherein the desired pipe routing for the three-dimensionally shaped exhaust pipe to be manufactured includes bends. [13] The three-dimensionally shaped exhaust pipe according to claim 12, wherein the curvatures are essentially coplanar. [14] The three-dimensionally shaped exhaust pipe according to claim 12, wherein at least one of the curvatures comprises a directional component transverse to a plane defined by another of the curvatures. [15] The three-dimensionally shaped exhaust pipe according to one of claims 11-14, wherein the exactly one projection and the exactly one recess are provided at the respective end sections of adjacent straight pipe segments welded together on a major major axis of the predetermined elliptical cross-sectional shape. [16] The three-dimensionally shaped exhaust pipe according to one of claims 11-14, wherein the exactly one projection and the exactly one recess are provided on the respective end sections of adjacent straight pipe segments welded together on a secondary axis of the predetermined elliptical cross-sectional shape. [17] The three-dimensionally shaped exhaust pipe according to one of claims 11-16, wherein the straight base pipe is made of materials comprising at least one of the following: stainless steel or steel alloys. [18] The three-dimensionally shaped exhaust pipe according to one of claims 11-17, wherein the thickness of the straight base pipe is less than 2 mm, preferably less than 1.5 mm, particularly preferably less than 1.2 mm. [19] The three-dimensionally shaped exhaust pipe according to one of claims 11-18, wherein the exactly one projection has a length between 2 mm and 12 mm, preferably between 3 mm and 9 mm, particularly preferably between 4 mm and 7 mm. [20] The three-dimensionally shaped exhaust pipe according to one of claims 11-19, wherein the respective end sections of adjacent straight pipe segments are welded together in such a way that a leak-free connection is formed. [21] Kit comprising a plurality of straight pipe segments separated from a straight base pipe to be welded together along a desired pipe path to form a three-dimensionally shaped exhaust pipe, wherein: Each of the plurality of straight pipe segments comprises two end sections at respective predetermined separation angles relative to a longitudinal axis of the straight base pipe, and wherein the respective end sections of adjacent straight pipe segments to be welded together have: - a corresponding predetermined elliptical cross-sectional shape in their respective parting plane; and - a positive fit, wherein the positive fit is defined by exactly one projection in one of the end sections and exactly one recess in the other end section, wherein the recess is shaped complementarily to the projection.

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