METHOD FOR PRODUCING A MAGNETIC FLOW CONDUCTOR ELEMENT FOR A ROTATING SENSOR

Description

State of the art

[0001] The invention relates to a method for manufacturing a magnetic flux conductor element for a rotation sensor, which is designed as a sheet metal part made from a magnetically conductive sheet.

[0002] In an electromechanical power steering system of a motor vehicle, an electric steering drive couples an additional auxiliary torque and / or steering angle into the steering shaft, depending on the steering angle and the steering torque applied by the driver to the steering wheel. In a steer-by-wire steering system without a continuous mechanical connection between the steering wheel and the steered wheels, the electric drive alone generates the steering angle of the wheels.

[0003] The electric drive is controlled depending on a steering command introduced by the driver by turning the steering wheel, whereby the resulting rotation of the steering shaft and additionally or alternatively the manual steering torque introduced into the steering shaft are detected by means of an electric rotation sensor and converted into electrical control signals for the electric steering drive.

[0004] Magnetic rotation sensors are known for detecting steering commands. These sensors can be configured as torque sensors, angle sensors, or combined torque and angle sensors. One design of a magnetic torque sensor, described in the prior art, for example, in DE 10 2008 015 274 A1, has two magnetic stator elements attached to a first steering shaft section. This first steering shaft section is torsionally rotatable via a torsion bar to a second steering shaft section, which contains a magnet whose magnetic field penetrates the stator elements. This couples a magnetic field into the stator elements that depends on the relative angular orientation. This field enables the determination of the relative rotation of the two steering shaft sections due to a steering torque applied to the torsion bar, and optionally also the detection of the absolute steering angle of the steering input.

[0005] The magnetic flux coupled into the stator components is guided via magnetic flux conductors to an electronic sensor element, such as a Hall sensor, a magnetoresistive sensor (GMR sensor), or similar device. A flux conductor can be made of a highly magnetically conductive material, such as grain-oriented iron sheet (electrical steel), as a three-dimensionally shaped sheet metal component. This component is shaped three-dimensionally and adapted to the spatial conditions to ensure optimal transmission of the magnetic flux from the stator components to the sensor element.

[0006] It is known to manufacture a flux conductor as a sheet metal component, which is cut or punched from sheet metal and then three-dimensionally formed, for example by bending, pressing, or similar processes. The mechanical stresses occurring during plastic deformation locally alter the magnetic properties of the sheet metal material, which can impair its magnetic conductivity. Therefore, it is necessary to magnetically normalize the finished sheet metal component. This magnetic normalization can involve, for example, heating above a predetermined recrystallization temperature, applying an alternating magnetic field, or other external influences that homogenize the magnetic structure.

[0007] In the current state of the art, the individually supplied flux guide elements are magnetically normalized before being mounted on the stator elements. Due to the complex three-dimensional shape of the flux guide elements, processing them as bulk material is not possible, making handling and manufacturing complex.

[0008] A process of the type mentioned above is known from DE 10 2007 043502 A1. However, this process is complex, and maintaining the required tolerances for high production volumes is problematic.

[0009] In view of the problems explained above, one object of the present invention is to reduce the effort required to manufacture flow guide elements. Description of the invention

[0010] This problem is solved according to the invention by the method with the features of claim 1.

[0011] An inventive method for manufacturing a magnetic flux conductor element for a rotation sensor, which is designed as a sheet metal part made from a magnetically conductive sheet, comprises the following steps: Providing a sheet blank made of a magnetically conductive material, which has a surface area several times that of a sheet metal forming part; punching and embossing a plurality of forming part sections in the sheet blank to form a continuous semi-finished product, in which connecting webs are left standing, by means of which the forming part sections remain connected to holding sections; magnetically normalizing the semi-finished product; cutting through the connecting webs to produce separate sheet metal forming parts of the flux conductor elements from the forming part sections.

[0012] The process starts with a raw material in the form of a sheet metal blank, for example, a grain-oriented iron sheet or electrical steel sheet, which can be supplied as rolled and tempered sheet metal with defined, predetermined magnetic properties. The area of ​​the blank is a multiple of the area of ​​a sheet metal part that forms a flux conductor element. This makes it possible to cut a large number of sheet metal sections from a single blank to produce one flux conductor element each. A correspondingly large number of sheet metal sections or parts can thus be advantageously obtained from a single sheet metal blank. However, the term "multiple of the area" does not refer to an exact mathematical multiple, i.e., an exact product of the area of ​​the sheet metal part and a natural number.The term "multiple of the area of ​​the sheet metal part" refers to a larger area from which at least three sheet metal parts can be produced.

[0013] In the next step, multiple sections are punched and embossed into the sheet metal blank to form a continuous semi-finished product. Connecting webs are left in place to link the sections to retaining sections. During punching, the sheet metal blank is cut along the outer contour of a section, which corresponds to the outer edge of the final sheet metal part. This punching can be done mechanically, using a punch and die, or by other methods such as laser cutting.

[0014] Punching produces a flat sheet metal section, which is then embossed into a three-dimensional shape corresponding to the sheet metal part of the flow guide element. Embossing can be achieved by pressing between a forming or embossing die and a negatively shaped die, whereby the flat sheet metal section is plastically deformed into a spatially shaped part.

[0015] Punching and embossing can advantageously be performed in a single operation, for example using combined punching and embossing tools that have spatially contoured embossing dies and cutting edges that correspond to the contour of the part section. This enables efficient production.

[0016] According to the invention, it is essential that during the stamping process, the formed part section is not completely separated from the sheet metal blank, but rather narrow connecting webs are left intact. These webs allow the formed part section to remain connected to a sheet metal section located outside of the formed part section, which forms a retaining section. According to the invention, a plurality of retaining sections remain connected to each other and / or to the formed part sections in such a way that the resulting semi-finished product remains integrally connected. In other words, the connecting webs form bridges between the circumferential contour of the formed part sections and the cut edges of the adjacent areas of the remaining sheet metal blank, which constitute the retaining sections.In this way, a continuous, sheet metal semi-finished product, or simply semi-finished product, is produced that essentially covers the entire area of ​​the original sheet metal blank. A multitude of shaped sections are connected to the holding sections by means of connecting webs. The resulting advantage is that the entire single-piece semi-finished product can be further processed, thus simplifying handling.

[0017] It is advantageous that the spatial shaping by embossing also takes place on the molded sections, which are held in a single piece with the retaining sections via the connecting webs. This allows the molded sections to already essentially have the final shape of the sheet metal part of the flow guide element. In other words, a multitude of pre-formed sheet metal parts are held together in one piece within the semi-finished product. This simplifies further handling and processing.

[0018] During die-cutting, even large residual sections, which are otherwise non-functional and lie between the shaped part sections and the holding sections, can be completely die-cut out, i.e., cut out and removed from the sheet metal blank. This offers the advantage of creating more space for tool engagement during stamping and / or when separating the blank from the semi-finished product.

[0019] According to the invention, after the formation of the molded sections, the semi-finished product is magnetically normalized. In this process, the entire multitude of molded sections held within the single-piece semi-finished product can be magnetically normalized in a single operation. This eliminates the disturbances in the magnetic structure that are unavoidably generated during punching and embossing, resulting in consistently homogeneous magnetic properties across both the molded sections and the holding sections. An advantage is that handling the semi-finished product is less complex compared to the individual flux conductor elements used in the prior art, and it can be more easily integrated into the manufacturing process.Another significant advantage is that the mounting of the molded parts during normalization is achieved solely by the connecting webs, which are made of the same material as the flux guide elements and have a precisely defined contact with the molded parts due to their dimensions. This contact cannot be affected by unavoidable tolerances during clamping or repositioning for normalization. This enables more efficient manufacturing for magnetic normalization, and furthermore, consistent magnetic properties can be achieved over high production volumes within tighter tolerances than in the prior art.

[0020] Magnetic normalization may include a thermal treatment. In this process, the semi-finished product is heated to a temperature above a normalization temperature, also known as normalizing, to create a uniform magnetic microstructure. This is followed by controlled, stress-reduced cooling. The normalization temperature and the duration of the heating and cooling cycles can be specified based on the material properties and dimensions of the sheet metal. By thermally treating the semi-finished product, manufacturing costs can be reduced and the reproducibility of the normalization can be increased.

[0021] Additionally or alternatively, further normalization measures can be implemented, such as exposing the semi-finished product to an alternating magnetic field to eliminate residual magnetization. This can also reduce manufacturing effort and improve the reproducibility of the normalization.

[0022] Magnetic normalization can be applied to the entire semi-finished product, for example, by continuous heating. Alternatively, it is conceivable to selectively heat specific areas, such as the molded sections and, in whole or in part, the connecting webs and / or the retaining sections. It is possible to treat the semi-finished product as a whole, or to use a continuous process in which sections are normalized continuously.

[0023] Following normalization, the next step involves cutting the connecting webs to create separate sheet metal components, which can be used as flow guide elements. By cutting the connecting webs, the component sections are separated from the sheet metal blank, making them ready for assembly as flow guide elements. This cutting can be done mechanically or by other methods such as laser cutting.

[0024] By making the connecting webs relatively short compared to their circumferential length (determined by the length of the circumferential contour of the molded part section), any disturbance of the magnetic structure that occurs during cutting can be locally confined to the area of ​​the connecting web's cut edge. This ensures, with minimal effort, that the homogenization of the magnetic structure achieved during the magnetic normalization of the semi-finished product is almost completely retained in the molded part section. As a result, the magnetic conductivity of the flux conductor element, which is relevant for its function, remains virtually unaffected and can be reproduced with high accuracy.

[0025] It is possible for a molded part section to be connected to a holding section by a connecting web, which is sufficient to form a single-piece semi-finished product. An advantageous further development is to arrange two connecting webs in opposing or opposite circumferential areas of a molded part section. This has the advantage of enabling more stable fixation of the molded part section within the semi-finished product. Furthermore, it is advantageous that the cross-section of a single holding section can be smaller, thus facilitating subsequent cutting to remove the sheet metal molded part from the semi-finished product. It is also conceivable to provide more than two connecting webs, for example, to better hold a complexly shaped molded part section within the semi-finished product.

[0026] If several connecting webs are provided, these are preferably arranged in the plane of the semi-finished product in which the holding sections lie and which corresponds to the extent of the original sheet metal blank with regard to the spatial shaping of the sheet metal part.

[0027] To minimize the potential disruption of the magnetic structure when cutting the connecting webs, it is advantageous for the width of the connecting webs to be less than 5% of the length of a circumferential contour of a molded part section. It is particularly advantageous for the width of the connecting webs to be less than 1% of the length of a circumferential contour of a molded part section. The length of the circumferential contour corresponds to the circumference along which the width of the connecting webs is measured. The narrower the connecting webs, the lower the energy input required for cutting, and consequently, any potential impairment of the magnetic properties can be specifically reduced.

[0028] It is possible to achieve a defined length for a connecting web by positioning the circumferential contour of a molded part section at a defined distance from the adjacent holding section, for example, by punching out a narrow residual section between the molded part and the holding section. Due to its defined length, the connecting web can be cut more easily, and any disruption to the magnetic structure can be readily limited to the area of ​​the connecting web.

[0029] It is also possible to create a predetermined breaking point in the area of ​​a connecting web. This predetermined breaking point can be achieved by deliberately weakening the material locally, for example, by pressing in a reduced sheet thickness during embossing, creating an indentation or similar feature. This further reduces the stress required to cut through the connecting webs in this area, thus minimizing any potential disruption of the magnetic properties.

[0030] To carry out the process, it can be advantageous for the sheet metal blank to be designed as a longitudinally elongated strip into which the forming sections are inserted longitudinally, one after the other. Such a sheet metal strip can be provided as pre-fabricated strip material, forming a narrow strip of metal with a length many times greater than that of a sheet metal forming part. The sheet metal strip has the advantage of easy handling, for example, by being wound into a coil of considerable length. For the process according to the invention, the sheet metal blank can be provided as a coil from which the sheet metal strip is unwound, and forming sections are inserted at regular intervals as described above, arranged accordingly in the longitudinal direction. Production can take place as the sheet metal strip passes through a processing station, from which the semi-finished product is dispensed as a strip.It is conceivable and possible that the subsequent magnetic normalization also takes place during the passage through a normalization station, in which, for example, a section of the continuously passing semi-finished product strip is normalized at a time. The magnetically normalized semi-finished product strip is deformed as little as possible, and the finished flux conductor elements are separated out as described.

[0031] The width of the sheet metal strip or band is preferably dimensioned such that at least one longitudinally continuous retaining section is formed. This can be achieved by making the width of the sheet metal strip greater than the width of a molded part section, measured transversely to the length of the sheet metal strip. This allows the retaining section to extend along the longitudinally arranged molded part sections. Preferably, a continuous retaining section is formed on both sides of the arranged molded part sections. This ensures that the molded part sections are securely held on two sides, preferably by connecting webs directly or indirectly linked to the continuous retaining sections. A further advantage of the longitudinally continuous retaining section is that the semi-finished strip forms a kind of belt or magazine, which simplifies the handling of the molded part sections.

[0032] A further development can provide that at least two retaining sections are connected to each other via at least one support section arranged laterally to a molded part section. The retaining sections can, for example, be continuous in the longitudinal direction, and the support sections can be arranged transversely between them, preferably between two adjacent molded part sections. In this way, the support section and retaining sections frame the molded part section at least over a partial circumference; preferably, a molded part section can be framed by support and retaining sections around its entire circumference. This results in an advantageously increased rigidity of the semi-finished product, so that the deformation of the semi-finished product and thus of the molded part sections during handling and removal can be further reduced.

[0033] A molded part section can be connected to the adjacent holding and / or support sections via connecting webs, preferably via at least two connecting webs. For example, a connecting web can be arranged between a molded part section and one of the two longitudinally extending holding sections.

[0034] In a rotary sensor for a motor vehicle steering system, comprising two stator elements that can be attached to a first steering shaft part of a steering shaft and are magnetically coupled to an electric magnetic field sensor via at least one flux conductor element, and a magnet that can be attached to a second steering shaft part that is rotatable about a longitudinal axis relative to the first steering shaft part, wherein the magnetic field of the magnet passes through the stator elements, a flux conductor element can preferably be designed according to one of the embodiments of the inventive method described above.

[0035] A flux conductor element is designed as a sheet metal component as described above. Typically, at least two flux conductor elements are provided, each serving as a magnetically conductive connection between one of the two stator elements and the magnetic field sensor.

[0036] The stator elements form magnetic flux conductors for angle-resolved detection of the magnet's magnetic field and preferably each have a ring-shaped base body mounted coaxially on one steering shaft section. The two base bodies are magnetically coupled to the electrical magnetic field sensor, for example a Hall, GMR, or other sensor, via at least one flux conductor element according to the invention. Because the magnetic properties of the flux conductor element according to the invention can be realized within tight tolerances and provided with minimal manufacturing effort, corresponding functional and manufacturing advantages result for the rotary sensor.

[0037] By connecting the steering shaft components to each other via a torsion bar in a torsionally elastic manner, a torque sensor can be provided in a manner known per se. Flow guide elements manufactured according to the invention can also be used in rotary angle sensors.

[0038] A steering system for a motor vehicle, comprising two steering shaft parts connected to each other via a torsion bar so as to be rotatable about a longitudinal axis, between which a rotation sensor is arranged, has at least one rotation sensor with a flow guide element of the type described above. Description of the drawings

[0039] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. Specifically, they show: Figure 1 shows a motor vehicle steering system in a schematic perspective view, Figure 2 shows an enlarged detail view of the rotation sensor of the steering system according to Figure 1 in a schematically isolated view, Figure 3 shows a first partial step of the method according to the invention in a schematic representation, Figure 4 shows a Figure 3 the following sub-step, Figure 5 Figure 4 the following sub-step, Figure 6, according to the in Figures 3 to 5 semi-finished strip produced in the process steps shown, Figure 7 Figure 6 semi-finished products shown in one on Figure 5 the following sub-step during magnetic normalization, Figure 8 according to Figure 7 magnetically normalized semi-finished product in a subsequent step during the cutting of the connecting webs, Figure 9 a finished flux conductor element of a semi-finished product according to Figure 8a sheet metal part cut out in a first embodiment, Figure 10; a second embodiment of a magnetically normalized semi-finished product in the step of cutting through the connecting webs, Figures 11, 12; a finished flux conductor element of a semi-finished product according to Figure 10 a second embodiment in different perspective views of the cut-out sheet metal part. Embodiments of the invention

[0040] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0041] In Figure 1 Figure 1 schematically depicts a motor vehicle steering system 1 designed as an electromechanical power steering system. This system has a steering column 2 with a support unit 21, which can be attached to the body of a motor vehicle (not shown).

[0042] In the steering column 2, a steering shaft comprising a first, upper steering shaft section 10 is rotatably mounted about its longitudinal axis L. At the rear end, relative to the direction of travel, a steering wheel 12 is fixedly attached to the steering shaft section 10, via which a driver can apply a steering torque (hand torque) as a steering command to the steering shaft.

[0043] The upper steering shaft part 10 is connected to a second, lower steering shaft part 11 via a torsionally elastic torsion bar which is not shown here.

[0044] The steering torque is transmitted via the steering shaft sections 10 and 11, through interposed universal joints 13, to a steering pinion 14, which engages with a longitudinally displaceable rack 15. This rack converts a rotation of the steering shaft 10 during steering input into a displacement of tie rods 16, as indicated by the double arrow, which transmit the specified steering input as a steering angle to the steerable wheels 17 of the vehicle.

[0045] An electric power assist system can comprise an auxiliary power drive 3 mounted on the steering column 2 and coupled to the steering shaft 10, or an auxiliary power drive 31 coupled to the steering shaft 10 at the pinion 14, wherein the auxiliary power drives 3 and 31 can be of the same design. An auxiliary torque can be coupled into the lower steering shaft 11 and / or the steering pinion 14 by the auxiliary power drive 3 or 31 to assist the driver in steering.

[0046] An auxiliary power drive 32 may also be provided to introduce an auxiliary force supporting the steering into the rack 15.

[0047] Typically, an auxiliary power drive 3, 31, or 32 is attached at only one of the three positions shown. The auxiliary torque or force to be applied to assist the driver by means of the respective auxiliary power drive 3, 31, or 32 is determined taking into account a steering torque applied manually by the driver, as determined by a torque sensor 4.

[0048] The torque sensor 4 is mounted between the upper steering shaft section 10 and the lower steering shaft section 11, as shown in the enlarged illustration of Figure 2 It is recognizable which is a schematic perspective view of the steering column 2 from Figure 1 shows enlarged images.

[0049] A ring magnet 41 is attached coaxially to the steering shaft part 10, which is arranged inside two ring-shaped stator elements 42 that are attached coaxially to the second steering shaft part 11.

[0050] The two stator elements 42 are magnetically coupled to an electric magnetic field sensor 43 via two flux guide elements 5 manufactured according to the invention. The sensor is arranged axially between the stator elements 42. The flux guide elements 5 are designed as sheet metal parts, the manufacture of which is explained in more detail below. The terms flux guide element 5 and sheet metal part 5 are used synonymously.

[0051] The production of sheet metal components 5, which are functionally used as flow guide elements 5 in the torque sensor 4, is for a first embodiment in the Figures 3, 4, 5 , 7 and 8 explained.

[0052] In Figure 3 is a sheet metal blank, which is designed as a sheet metal strip 60 elongated in a longitudinal direction A, also referred to as sheet metal strip or strip material, shown in longitudinal section.

[0053] The sheet metal strip 60 is arranged between two tool halves 7 of a combined press-stamping tool, which have three-dimensionally shaped press punches 71 and complementary press dies 72, as well as cutting punches 73.

[0054] By moving the two tool halves 7 towards each other, as in Figure 4 As indicated by the arrows, a plastic deformation of the sheet metal blank 60 takes place.

[0055] In Figure 5 The tool halves 7 are completely closed, and through pressing and punching, the sheet metal blank 60 has been formed into a sheet metal semi-finished product 61, or simply semi-finished product 61, whereby residual sections 62 have been punched out. The semi-finished product 61 is in Figure 6 Shown in perspective after removal from the press-stamping tool.

[0056] The semi-finished product 61, which is elongated in the longitudinal direction A, has a width B transverse to it, which is identical to the width of the sheet metal blank 60.

[0057] By pressing and stamping according to Figure 5 In the semi-finished product 61, a plurality of molded sections 64 are cut out and plastically pressed into a spatial form, which provides a spatial connection of the stator elements 42 according to Figure 2 for magnetic coupling to the magnetic field sensor 43.

[0058] The molded part sections 64 are each connected via a narrow connecting web 65, which preferably has a width of less than 5%, particularly preferably less than 1% of the length of the circumferential contour of a molded part section 64, to one of two retaining sections 66, which extend on both sides of the molded part sections 64 arranged in longitudinal direction A over the entire length of the semi-finished product 61.

[0059] Optionally, the two holding sections 66 can be connected to each other in one piece via transversely continuous support sections 67, which are in Figure 6The support sections 67 are shown with dashed lines. They can also be formed during the pressing and punching processes described above. The retaining sections 66 and the support sections 67 each individually frame the molded part sections 64 within the semi-finished product 61.

[0060] For magnetic normalization, the sheet metal semi-finished product 61 is placed in a normalizing station 8 as described in Figure 7The normalizing station 8 is shown schematically. It comprises heating devices by which the semi-finished product 61 is heated to a specific recrystallization temperature T, at which complete homogenization of the magnetic structure of the semi-finished product 61 occurs. This structure is formed, for example, from grain-oriented iron sheet metal, and has previously been disturbed by plastic forming. Heating can be effected by radiation, convection, contact, or other means, such as induction or resistance. Alternatively or additionally, the semi-finished product 61 can be subjected to an alternating magnetic field.

[0061] Through magnetic normalization, the semi-finished product 61 is transformed into a normalized semi-finished product 68, which is then used in Figure 8 as shown. After heating, which can also be called normalizing, the normalized semi-finished product 68 is cooled.

[0062] In Figure 9The figure shows how a cutting tool 9, which may include a mechanical cutting punch, a laser cutter, or the like, is used to cut through the connecting webs 65, thereby separating the shaped part sections 64 from the normalized semi-finished product 68, so that a single sheet metal shaped part 5 is produced, which can be used as a flux conductor element 5 as described above. This element exhibits, at most, a locally limited change in the magnetic structure at the cut points 65a, where the connecting webs 65 have been cut, but this change has no noticeable influence on the magnetic conductivity of the flux conductor element 5, which is crucial for its function.

[0063] In Figure 10 is analogous to Figure 8A second embodiment of a normalized semi-finished product 68 is shown, wherein the molded sections 64 are shaped differently and are each connected to the two retaining sections 66 via four connecting webs 65. These are also cut by means of a cutting tool 9. A flow guide element 5 obtained in this way is shown in different perspective views in Figures 11 and 12 shown, whereby as in Figure 9 The separation points 65a are recognizable.

[0064] The connecting webs 65 may have predetermined breaking points with reduced strength, for example notches or the like. Reference symbol list

[0065] 1 Steering system 10 Steering shaft section 11 Steering shaft section 12 Steering wheel 13 Universal joint 14 Pinion 15 Rack 16 Tie rod 17 Wheel 2 Steering column 21 Support unit 3, 31 Auxiliary drive 4 Torque sensor 41 Ring magnet 42 Stator element 43 Magnetic field sensor 5 Flow conductor element / Sheet metal forming part 60 Sheet metal strip 61 Semi-finished product (Sheet metal semi-finished product) 62 Remaining sections 64 Formed part section 65 Connecting web 65a Separation points 66 Holding section 67 Support section 68 Normalized semi-finished product 7 Tool halves 71 Press punch 72 Press die 73 Cutting punch 8 Normalizing station 9 Separation tool L Longitudinal axis A Longitudinal direction B Width

Claims

1. A method of manufacturing a magnetic flux conductor element (5) for a rotary sensor (4), which is formed as a sheet metal molded part (5) from a magnetically conductive sheet metal, comprising the steps of: - Providing a sheet metal blank (60) made of a magnetically conductive material, which has a surface extension of a multiple of the surface area of a sheet metal molded part (5), - punching out and embossing a plurality of shaped part sections (64) in the sheet metal blank to form a coherent semi-finished product (61), in which connecting webs (65) are left, via which the shaped part sections (64) remain connected to holding sections (66), - Magnetic normalization of the semi-finished product (61), - cutting through the connecting webs (65) to produce separated sheet metal shaped parts (5) from the shaped part sections (42).

2. Method according to claim 1, characterized in that the magnetic normalization comprises a thermal treatment.

3. Method according to one of the preceding claims, characterized in that the width of the connecting webs (65) is less than 5% of the length of a circumferential contour of a shaped part section (64).

4. Method according to one of the preceding claims, characterized in that the width of the connecting webs (65) is less than 1% of the length of a circumferential contour of a shaped part section (64).

5. Method according to one of the preceding claims, characterized in that a predetermined breaking point is produced in the region of a connecting web (65).

6. Method according to one of the preceding claims, characterized in that the sheet metal blank is formed as a sheet metal strip (60) elongated in the longitudinal direction, into which the shaped part sections (64) are introduced one behind the other in the longitudinal direction (A).

7. Method according to claim 6, characterized in that at least one holding section (66) is formed which is continuous in the longitudinal direction (A).

8. Method according to claim 6 or 7, characterized in that at least two holding sections (66) are connected to one another via at least one supporting section (67) arranged parallel to a moulded part section (64).