Drawing tool for machining recesses of a sheet metal component, in particular of a motor vehicle

Abstract

Drawing tool (10) for machining recesses (76) of a sheet metal component (26), in particular of a motor vehicle, comprising - a supporting structure (12), - at least one support section (16) which is or can be fastened to the support structure (12) and with which the drawing tool (10) can be placed on the sheet metal component (26), - a traction means (28) connectable to the sheet metal component (26) and mounted on the supporting structure (12), and - a movement device (36) mounted on the support structure (12), with which the traction means (28) is movable relative to the sheet metal component (26), wherein - the supporting structure (12) is formed from a fiber-reinforced plastic (52), characterized in that the support section (16) is formed from the fiber-reinforced plastic (52), wherein the plastic (52) is reinforced with organic or inorganic reinforcing fibers (54), wherein the ratio of reinforcing fibers (54) to plastic (52) is between 10% and 30%, in particular between 13% and 17% (w / w).

Description

[0001] The present invention relates to a drawing tool for machining recesses of a sheet metal component, in particular of a motor vehicle.

[0002] Such drawing tools are always used when a sheet metal component, in particular the outer skins of a motor vehicle body, has been damaged as a result of unintentional contact with other objects and consequently has indentations, in particular in the form of dents.

[0003] The present invention is described with reference to motor vehicles, but application to other sheet metal components, for example of ships, trains and aircraft, is not excluded.

[0004] The drawing tool comprises a support structure on which a tension member is mounted. The tension member serves in particular to transmit tensile forces and can, for example, be designed as a tension rod. The transmission of compressive forces is not excluded. The support structure is provided with support sections with which the drawing tool can be placed on the surface of the sheet metal component. The tension member can be connected to the sheet metal component either directly or indirectly in the region of the recess. In the case of a direct connection, the tension member is spot-welded to the sheet metal component. In the case of an indirect connection, a number of tension tabs are welded or glued to the sheet metal component, wherein the tension tabs are connected to the tension member in a form-fitting manner. The drawing tool has a movement device with which the tension member can be moved essentially perpendicular to the surface of the sheet metal component.The movement of the traction device is transferred to the sheet metal component so that the recess is pulled out and the sheet metal component then has approximately the same shape as before the damage.

[0005] Such drawing tools are described, for example, in EP 0 544 191 A1, EP 0 783 926 A1, EP 1 459 814 A1, and EP 2 439 011 A1. The supporting structure of the drawing tools disclosed therein is made of metal, in particular steel or aluminum, which makes the drawing tools relatively heavy. Due to their weight, handling the drawing tools is comparatively difficult, as the user must exert a corresponding force to position the drawing tool as desired relative to the sheet metal component. This results in the user becoming fatigued relatively quickly, requiring them to take breaks at regular intervals. This increases processing times.Due to both the heavy weight and the resulting fatigue of the user, there is a risk that the drawing tool will be applied to the sheet metal component with excessive force, which can cause additional damage, particularly scratches, in addition to the damage mentioned above. Repairing the damage caused by the drawing tool involves additional time and expense.

[0006] The object of one embodiment of the present invention is to provide a drawing tool with improved handling, which, compared to known drawing tools, causes less fatigue for the user. Furthermore, the likelihood of damage to the sheet metal component being processed caused by the drawing tool is to be reduced.

[0007] This object is achieved with the features specified in claim 1. Advantageous embodiments are the subject of the subclaims.

[0008] One embodiment of the invention relates to a drawing tool for machining recesses of a sheet metal component, in particular of a motor vehicle, comprising - a supporting structure, - at least one support section which is or can be fastened to the supporting structure and with which the drawing tool can be placed on the sheet metal component, - a tension member that can be connected to the sheet metal component and mounted on the supporting structure, and - a movement device mounted on the support structure, with which the traction means can be moved relative to the sheet metal component, wherein - at least the supporting structure is made of a fiber-reinforced plastic.

[0009] In addition to the supporting structure, the support section and the movement device can, for example, consist at least partially of or comprise a fiber-reinforced plastic.

[0010] The fact that at least the supporting structure is made of fiber-reinforced plastic ensures, on the one hand, that the forces occurring during processing of the sheet metal component are safely absorbed. On the other hand, the weight of the drawing tool is significantly reduced compared to conventional drawing tools, which significantly improves the handling of the proposed drawing tool. As a result of the lower effort required when handling the drawing tool, the user fatigues less quickly. Due to both the reduced weight and the reduced user fatigue, damage caused by the drawing tool being applied roughly to the sheet metal component to be processed is avoided or at least significantly reduced. The time and cost required to repair such damage is significantly reduced compared to conventional drawing tools.

[0011] According to the invention, the support section is made of a fiber-reinforced plastic, which can be reinforced with organic or inorganic reinforcing fibers. The drawing tool can be placed on the sheet metal component using the support section. During operation of the drawing tool, the support section is largely subjected to compressive loads. The support section is therefore subjected to lower loads than the supporting structure. However, in most cases, the sheet metal component has a more or less pronounced curvature, so that torsional loads can be introduced into the support section. These loads also manifest themselves in the support section as tensile loads, which can be well absorbed by the reinforcing fibers.

[0012] According to the invention, the ratio of reinforcing fibers to plastic is between 10% and 30%, in particular between 13% and 17% (w / w). It has been shown that within the specified weight-related ratio of reinforcing fibers to plastic, the supporting structure in particular is particularly effectively stiffened.

[0013] According to a further embodiment, the plastic is reinforced with organic or inorganic reinforcing fibers. Organic or inorganic reinforcing fibers are inexpensively available and can be integrated into the plastic matrix in such a way that the tensile strength, particularly of the supporting structure, can be increased without excessively increasing the weight of the drawing tool. Organic reinforcing fibers include, among others, aramid fibers, carbon fibers, polyester fibers, nylon fibers, polyethylene fibers, polymethyl methacrylate fibers, or natural fibers such as sisal fibers, hemp fibers, or flax fibers. Inorganic reinforcing fibers include, for example, basalt fibers, boron fibers, glass fibers, ceramic fibers, silica fibers, and / or quartz fibers.

[0014] In a further development, the plastic can be reinforced with carbon fibers. Carbon fibers can be divided into isotropic and anisotropic carbon fibers. Anisotropic carbon fibers, in particular, exhibit high strength and stiffness while simultaneously exhibiting low elongation at break in the axial direction. Carbon fibers have a comparatively high modulus of elasticity and are therefore particularly well suited for stiffening the supporting structure.

[0015] According to a further embodiment, the plastic can be a thermoplastic, in particular a polyamide. Polyamide 6.6 has proven particularly suitable for this purpose. Thermoplastics can be processed by injection molding, so that in this case the support section can be manufactured cost-effectively in large quantities. It is advisable to implement the reinforcing fibers as short fibers.

[0016] In a further embodiment, the support structure and / or the support section and / or the movement device can have a honeycomb structure, at least in sections. The honeycomb structure also contributes to increased rigidity, in particular of the support structure, the support section and / or the movement device, without significantly increasing the weight of the drawing tool.

[0017] A further developed embodiment is characterized in that the traction device comprises a threaded rod that can be screwed into a corresponding threaded bore arranged on the movement device or interacting with the movement device. The threaded rod and the threaded bore are self-locking. The threaded rod can be adjusted along its longitudinal axis by rotating it about its own longitudinal axis relative to the movement device so that the sheet metal component to be machined can be optimally connected to the drawing tool in the area of ​​the recess. The threaded rod and the threaded bore thus enable the position of the traction device to be adjusted to the existing depth of the recess of the sheet metal component to be machined.

[0018] According to a further embodiment, the threaded bore is arranged in a rotatable disk which is supported on the movement device. As mentioned, the threaded rod and the threaded bore are self-locking. This results in a comparatively small thread pitch. As a result, a comparatively large number of rotations of the threaded rod around its own longitudinal axis are necessary to adjust the threaded rod along its longitudinal axis. The adjustment process can take a correspondingly long time. The disk can, for example, have a knurled surface so that it can be set into its own rotation with a corresponding movement, whereby the rotation speed can be comparatively high. The adjustment of the pulling means along its longitudinal axis can thus be noticeably accelerated, so that the adjustment process can be significantly shortened compared to known drawing tools.

[0019] A further embodiment is characterized in that the movement device comprises a lever arrangement for moving the pulling means. With this lever arrangement, the force required by the user of the drawing tool to remove the indentation from the sheet metal component being machined, also known as pulling out the indentation, can be significantly reduced, thus minimizing user fatigue.

[0020] According to a further embodiment, the support structure can comprise a cross member, wherein the support means(s) can be attached or are attached to the cross member so as to be movable along the cross member. Due to the mobility of the support means along the cross member, the support means can be optimally positioned relative to the recess of the sheet metal component to be machined. The forces acting on the sheet metal component can be optimally transmitted into the sheet metal component, taking into account the existing configuration of the recess.

[0021] According to a further developed embodiment, the plastic of the cross member is reinforced with organic or inorganic reinforcing fibers, in particular carbon fibers, with the reinforcing fibers arranged in a directional manner within the cross member. As mentioned, the support sections can be manufactured using an injection molding process, with the addition of short fibers. In this case, the short fibers are arranged randomly, so that the support sections can be loaded isotropically, i.e., regardless of direction. Compressive and tensile forces are absorbed equally.

[0022] The loads on the cross member that occur during operation of the drawing tool can be predicted relatively well, so it makes sense to align the reinforcing fibers according to the expected loads. It should be noted that the reinforcing fibers can only absorb tensile forces, not compressive forces. This allows the cross member to be manufactured with minimal material, thus saving weight.

[0023] According to a further embodiment, the plastic of the cross member is a thermoset, in particular an epoxy resin. Alternatively, vinyl ester or polyester, in particular unsaturated polyester, can also be used. In this embodiment, the cross member can be manufactured using the so-called "wet-pressing" process. Alternatively, the cross member can also be manufactured using the "prepreg" process; however, the prepreg process places greater demands on the accuracy of the amount of thermoset used than the wet-pressing process, so the wet-pressing process is more error-tolerant. Furthermore, more complex component geometries such as grooves, mounting holes, and elongated holes can be manufactured more easily using the wet-pressing process than the prepreg process.

[0024] The thermoset forms the matrix surrounding the carbon fibers. The matrix absorbs compressive forces, while the carbon fibers absorb tensile forces.

[0025] In a further developed embodiment, the support section can have a first subsection encompassing the cross member and a second subsection, wherein the second subsection is attached to the first subsection so as to be rotatable at least about a rotation axis and comprises a support surface for placement on the sheet metal component. Particularly when the sheet metal component to be machined has curved sections, this embodiment makes it possible to optimally place the support sections on the sheet metal component over a large area. Damage caused by the forces acting between the support section and the sheet metal component to be machined can be particularly effectively prevented with this embodiment.

[0026] In a further developed embodiment, the pulling means and the movement device can be fastened or attached to the cross member so as to be movable along the same. This embodiment is particularly suitable for removing large-area indentations. With such indentations, it may be necessary to pull out the indentation at several points. In this embodiment, the drawing tool can be placed in one position on the sheet metal component to be machined. After completing a pulling process, the movement device and the pulling means can be moved step by step along the cross member and the indentation can be pulled out again. Repositioning the drawing tool on the sheet metal component is therefore not necessary, which reduces the time required to remove the indentation.

[0027] In a further embodiment, the traction device can have a hook-shaped connecting element at one end, with which tension tabs attached or attachable to the sheet metal component can be connected to the traction device. As mentioned above, the drawing tool can be connected either directly or indirectly to the sheet metal component to be processed. In this embodiment, the drawing tool is connected using the tension tabs and thus indirectly to the sheet metal component. The tension tabs are hooked into the hook-shaped connecting element, whereby the tensile force applied by the movement device to the traction device can be transferred to the sheet metal component, allowing the recess to be drawn out.

[0028] A further developed embodiment is characterized in that the drawing tool has an electrically operated heating device, with which a nozzle arranged at one end of the pulling means can be heated such that the nozzle can be connected to the sheet metal component, forming a welded joint. In this embodiment, the drawing tool is connected directly to the sheet metal component to be machined. This embodiment of the drawing tool is particularly suitable for smaller indentations. The use of pull tabs is therefore unnecessary, so that the effort required to remove indentations is reduced.

[0029] According to a further embodiment, the support section encloses at least one through-opening through which the pulling means can pass. As mentioned, the sheet metal component is connected to the drawing tool either directly or indirectly in the region of the recesses. In this embodiment, the support section encloses the recess either completely or at least largely. This embodiment is also particularly suitable for removing smaller recesses. Due to the fact that the recess is completely or at least largely enclosed by the support section, the force exerted on the sheet metal component when the recess is pulled out is distributed evenly across the sheet metal component, so that no permanent deformation is caused on the sheet metal component.

[0030] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings. Fig. 1 a first embodiment of a drawing tool according to the invention, Fig. 2 a second embodiment of a drawing tool according to the invention, Fig. 3 a third embodiment of a drawing tool according to the invention, each in a perspective view, Fig. 4 a basic partial representation of a drawing tool according to a fourth embodiment, and Fig. 5 a basic partial representation of a drawing tool according to a fifth embodiment.

[0031] In Fig. 1 shows a first embodiment of a drawing tool 101 according to the invention in a perspective view. The drawing tool 101 comprises a support structure 12, which in the first embodiment comprises a cross member 14. Two support sections 16 are fastened to the cross member 14, each having a first subsection 18 and a second subsection 20. The first subsection 18 forms a recess 22 through which the cross member 14 can be passed. The support section 16 can be moved along the cross member 14. The cross member 14 has two elongated holes 24, through each of which a locking screw 17 can be passed, with which the support section 16 can be fixed in the desired position relative to the cross member 14. The second subsection 20 is fastened to the first subsection 18 so as to be rotatable about a rotation axis D and serves to support the drawing tool 101 on a sheet metal component 26 (see Fig. 4 and Fig. 5), which will be discussed in more detail later. For this purpose, the second subsection 20 forms a support surface 25.

[0032] Furthermore, the drawing tool 101 comprises a pulling means 28, which in the illustrated first embodiment is designed as a threaded rod 30, which can be guided through a guide bore 32 arranged in the cross member 14 and can be moved along a longitudinal axis L in the guide bore 32. Fig. In the illustration chosen in Figure 1, a connecting element 34 is connected to the lower end of the traction means 28, which is hook-shaped in the first embodiment shown. The exact function of the connecting element 34 will be discussed in more detail later.

[0033] Furthermore, the drawing tool 101 according to the invention is equipped with a movement device 36 with which the pulling means 28 can be moved along its longitudinal axis L. The movement device 36 comprises a lever arrangement 38, in the present example with two main levers 40, which are rotatably attached on the one hand to the cross member 14 and on the other hand to a respective auxiliary lever 42. The auxiliary levers 42 are in turn rotatably connected to a force transmission element 44 belonging to the movement device, through which the threaded rod 30 passes. The force transmission element 44 interacts with a disk 46 having a threaded bore 48 into which the threaded rod 30 is screwed. By rotating the disk 46 about the longitudinal axis L of the threaded rod 30, the disk 46 can be moved along the threaded rod 30.Since the thread of the threaded rod 30 and the thread of the corresponding threaded bore 48 are self-locking, the disc 46 can be supported on the force transmission element 44 when it comes into contact with it. The disc 46 therefore acts as a type of movable stop, with which the forces emanating from the lever arrangement 36 can be transmitted to the traction means 28. The position of the traction means 28 relative to the cross member 14 can thereby be changed. Alternatively, the threaded bore 48 can also be arranged in the force transmission element 44 (not shown), into which the threaded rod 30 is screwed. In this case, the disc 46 can be omitted.

[0034] In Fig. 1, the pulling tool 101 is shown in a position in which the pulling means 28 has been raised to its maximum. The two main levers 40 are in relation to the Fig. 1 selected representation in a vertical position. If the main levers 40 are each rotated by 90° so that they run approximately parallel to the cross member 14 and consequently approximately horizontally, the traction means 28 is moved relative to the Fig. 1 selected representation downwards. The most important movement in the operation of the drawing tool 101 is to move the two main levers 40 from the approximately horizontal position back to the Fig. 1 shown vertical position, whereby the traction means 28 relative to the in Fig. 1 selected display is moved up.

[0035] When in Fig. In the first exemplary embodiment shown in Figure 1, the main levers 40, the secondary levers 42, and the support sections 16 each have a honeycomb structure 50. The size of the honeycombs can vary. The first subsection 18 of the support section 16 has a honeycomb structure 50 in the area of ​​the recesses, in which the honeycombs are smaller than in the rest of the first subsection 18. The honeycombs of the honeycomb structure 50 of the secondary levers 42 are smaller than the honeycombs of the honeycomb structure 50 of the main levers 40.

[0036] In addition, Fig. 1 shows a section of the cross member 14 along the section plane AA, not enlarged to scale and shown purely in principle. The section plane AA runs perpendicular to the main load direction of the cross member 14, which runs approximately along the longitudinal axis L. From this section AA, it can be seen that the cross member 14 is made of a fiber-reinforced plastic 52. For this purpose, the plastic 52 has organic or inorganic reinforcing fibers 54, which are particularly designed as carbon fibers 56. The weight-related ratio of reinforcing fibers 54 to plastic 52 is between 10% and 30%. In this case, the plastic is a thermoset, for example a polyester, a vinyl ester, or epoxy resin. The carbon fibers 56 run in the plane AA or parallel to it.When loaded along the longitudinal axis L, the cross member 14 is subjected to bending stress, creating tensile forces in the cross member 14 that act approximately along the plane AA or parallel to it. Due to the orientation of the carbon fibers 56 in the cross member 14, these tensile forces can be well absorbed, so that the cross member 14 has high flexural rigidity.

[0037] As can also be seen from section AA, the carbon fibers 56 run crosswise at an angle α of approximately 45° relative to a cross member longitudinal axis LQ, so that the intersecting carbon fibers 56 form an angle of 90°. During operation, the drawing tool 101 is placed with the support surfaces 25 on a sheet metal component 26. In many cases, the surface of the sheet metal component 26 is curved, so that the two support sections 16 are not exactly aligned with respect to the cross member longitudinal axis LQ, but are rotated relative to one another. This introduces torsional moments into the cross member 14. As a result, tensile forces are generated in the cross member 14 that act at an angle of 45° to the cross member longitudinal axis LQ, i.e., exactly along the direction along which the carbon fibers 56 are aligned.The carbon fibers 56 can therefore absorb these forces well, achieving not only the aforementioned high flexural rigidity but also high torsional rigidity around the cross member's longitudinal axis LQ. Mats are used to align the carbon fibers 56. In this case, the carbon fibers 56 are formed as long fibers. The cross member 14 can be manufactured, for example, using the so-called "wet-pressing" or "prepreg" process.

[0038] The support sections 16 and at least parts of the movement device 36 are also made of a fiber-reinforced plastic 52. In this case, too, the weight-related ratio of reinforcing fibers 54 to plastic 52 is between 10% and 30%. The support sections 16 and the movement device 36 are made of a thermoplastic, for example, polyamide 6.6. The reinforcing fibers 54 can also be formed as carbon fibers 56, but in this case as short fibers, so that the support sections 16 and the movement device 36 can be manufactured by injection molding.

[0039] In Fig. 2 shows a second embodiment of the drawing tool 102 according to the invention, also in perspective. The basic structure of the drawing tool 102 according to the second embodiment largely corresponds to the structure of the drawing tool 101 according to the first embodiment, which is why the essential differences will be discussed below. Compared to the cross member 14 of the drawing tool 101 according to the first embodiment, the cross member 14 in the drawing tool 102 according to the second embodiment is significantly longer. In addition, the pulling means 28 and the movement device 36 are movable along the cross member 14, for which purpose a locking screw 58 is provided, with which the position of the pulling means 28 and the movement device 36 with respect to the cross member 14 can be fixed as soon as they have been brought into the desired position.

[0040] As in the first embodiment, the two support sections 16 are also movably mounted along the cross member 14.

[0041] The support sections 16 of the drawing tool 102 according to the second embodiment have two second subsections 201, 202, which are each mounted independently of one another on the first subsection 18 so as to be rotatable about a rotation axis D.

[0042] In the second embodiment, the support structure 12, the support sections 16, and the movement device 36 are also made of a fiber-reinforced plastic 52. In the second embodiment, the main levers 40 and the support sections 16 each have a honeycomb structure 50. Furthermore, the force transmission element 44 also has a honeycomb structure 50.

[0043] In Fig. 3 shows a third embodiment of the pulling tool 103 according to the invention. In this embodiment, the lever arrangement 38 is designed somewhat differently than in the first and second embodiments of the pulling tool 101, 102 according to the invention. The first main lever 401 of the lever arrangement 38 is fixedly attached to the cross member 14. The second main lever 402 is connected to the first main lever 401 via an intermediate lever 60. The intermediate lever 60 is rotatably connected to the first main lever 401 and rotatably connected to the second main lever 402. The second main lever 402, in turn, is rotatably connected to the pulling means 28 by means of a connecting screw 62. Consequently, the pulling means 28 follows the movement of the second main lever 402 relative to the first main lever 401. In addition, a handle element 64 is connected to the pulling means 28. A user can exert a force on the pulling means 28 via the handle element 64.

[0044] The second subsection 20 of the support section 16 forms in this case a through-opening 66, which can be penetrated by the traction means 28. At the Fig. 3 selected illustration lower end, the traction means 28 is connected to a mouthpiece 68. The mouthpiece 68 can be connected to a Fig. 3 not visible heating device 70.

[0045] The first main lever 401, the second main lever 402, the intermediate lever 60, the handle element 64 and the cross member 14 each have a honeycomb structure 50 and consist of a fiber-reinforced plastic 52 or comprise it.

[0046] In the Fig. Figure 4 shows a fourth embodiment based on a schematic partial view. The fourth embodiment of the drawing tool 104 according to the invention is largely similar to the third embodiment. Fig. 4 is intended in particular to illustrate the Fig. 3, and its mode of operation. The heating device 70 can be connected to an external voltage source 72 so that the heating device 70 can be supplied with electrical energy. Furthermore, the heating device 70 is connected to wires 74, which are passed through the traction means 28 and lead to the mouthpiece 68. The wires 74 are designed such that they essentially only heat the mouthpiece 68.

[0047] From the Fig. 4 shows the essential functioning of the drawing tool 103, 104 according to the third and fourth embodiments. The drawing tool 101 is placed with the second subsections 20 of the support section 16 onto a sheet metal component 26, which has a recess 76 that is to be machined and, in particular, removed. The sheet metal component 26 can, in particular, be a part of the outer skin of the body of a vehicle, for example, the hood or the side door. The pulling means 28 is brought into a position in which the mouthpiece 68 comes into contact with the sheet metal component 26. This position can be determined, for example, by moving the aforementioned disc 46 into a position such that it rests on the force transmission element 44 in the position shown (see, in particular, Fig. 1 and Fig. 2). The heating device 70 is then activated so that the mouthpiece 68 is heated in the area in which it comes into contact with the sheet metal component 26. The mouthpiece 68 is heated to such an extent that a weld 78 is formed between the mouthpiece 68 and the sheet metal component 26. The heating device 70 is then deactivated so that the weld 78 can cool and solidify. A force directed substantially perpendicular to the sheet metal component 26 and along the longitudinal axis L of the traction device 28 is then applied to the traction device 28, in particular using the lever arrangement 38. In the Fig. 1 and Fig. 2, the two main levers 40 are moved from a substantially horizontal position to a substantially vertical position, which in the Fig. 1 and Fig. 2 is shown.

[0048] In the Fig. In the third exemplary embodiment of the drawing tool 103 shown in Figure 3, the second main lever 402 is moved toward the stationary first main lever 401. Alternatively, the handle element 64 can also be pulled. In this case, the sheet metal component 26 follows the movement of the pulling means 28 in the region of the recess 76. The pulling means 28 is moved until the mouthpiece 68, in the region in which it comes into contact with the sheet metal component 26, is approximately aligned with the rest of the sheet metal component 26. In this way, it is possible to eliminate the recess 76, so that the machined sheet metal component 26 no longer has a recess 76 or at least no visible recess 76.

[0049] The welded joint 78 can transmit comparatively high tensile forces, but it fails quickly when subjected to bending or torsion. To separate the mouthpiece 68 from the sheet metal component 26 after processing, the drawing tool 104 can be rotated or tilted, which destroys the welded joint 78.

[0050] In Fig. 5 shows a fifth embodiment of the drawing tool 105 according to the invention, also based on a schematic partial representation. The fifth embodiment essentially corresponds to the first and second embodiments of the drawing tool 101, 102. Fig. Figure 5 serves in particular to explain the function of the connecting element 34. It should be noted that the drawing tool 101, 102 according to the first and second embodiments does not have a heating device 70. Therefore, the pulling means 28 cannot be connected to the sheet metal component 26 by forming a welded connection 78. Instead, a number of pulling tabs 80 are connected to the sheet metal component 26 by forming a spot welded connection 78 in the region of the recesses 76. Depending on the size of the recess 76, it may be sufficient to connect only one pulling tab 80 in the recess 76 to the sheet metal component 26; however, the use of pulling tabs 80 is particularly suitable for larger recesses 76.

[0051] Once the pull tabs 80 are connected to the sheet metal component 26, the drawing tool 101 is positioned so that the hook-shaped connecting element 34 can engage positively in the pull tab 80. Subsequently, as already described with regard to the Fig. 4, the pulling means 28 is moved away from the sheet metal component 26 along its longitudinal axis L using the lever arrangement 38 until the welded connection 78 is approximately aligned with the remaining sheet metal component 26 outside the recess 76. Once the sheet metal component 26 has been completely machined, the engagement between the connecting element 34 and the pulling tab 80 is released and the drawing tool 105 is removed. The welded connection 78 between the pulling tab 80 and the sheet metal component 26 can be destroyed by turning and / or bending, so that the pulling tab 80 can be separated from the sheet metal component 26. List of reference symbols 10 pulling tool 101 to 105 drawing tool 12 Supporting structure 14 cross members 16 support section 17 Locking screw 18 first subsection 20 second subsection 201, 202 second subsection 22 Recess 24 slot 25 contact surface 26 Sheet metal component 28 traction devices 30 threaded rod 32 guide hole 34 connecting element 36 Movement device 38 Lever arrangement 40 main levers 401, 402 main lever 42 secondary levers 44 Power transmission element 46 disc 48 threaded hole 50 honeycomb structure 52 fiber-reinforced plastic 54 reinforcing fibers 56 carbon fiber 58 Locking screw 60 intermediate levers 62 connecting screw 64 handle element 66 passage opening 68 Mouthpiece 70 Heating device 72 Voltage source 74 wire 76 Deepening 78 Welded joint 80 pull tabs D axis of rotation L Longitudinal axis LQ cross member cross member α angle reinforcing fibers

Claims

[1] Drawing tool (10) for machining recesses (76) of a sheet metal component (26), in particular of a motor vehicle, comprising - a supporting structure (12), - at least one support section (16) which is or can be fastened to the support structure (12) and with which the drawing tool (10) can be placed on the sheet metal component (26), - a traction means (28) connectable to the sheet metal component (26) and mounted on the supporting structure (12), and - a movement device (36) mounted on the support structure (12), with which the traction means (28) is movable relative to the sheet metal component (26), wherein - the supporting structure (12) is made of a fiber-reinforced plastic (52) characterized bythat the support section (16) is formed from the fiber-reinforced plastic (52), wherein the plastic (52) is reinforced with organic or inorganic reinforcing fibers (54), wherein the ratio of reinforcing fibers (54) to plastic (52) is between 10% and 30%, in particular between 13% and 17% (w / w). [2] Drawing tool (10) according to claim 1, characterized by that the plastic (52) is reinforced with organic or inorganic reinforcing fibers (54). [3] Drawing tool (10) according to claim 2, characterized by that the plastic (52) is reinforced with carbon fibers (56). [4] Drawing tool (10) according to one of the preceding claims, characterized by that the plastic is a thermoplastic, in particular a polyamide. [5] Drawing tool (10) according to one of the preceding claims, characterized bythat the support structure (12) and / or the support section (16) and / or the movement device (36) has a honeycomb structure (50) at least in sections. [6] Drawing tool (10) according to one of the preceding claims, characterized by that the traction means (28) comprises a threaded rod (30) which can be screwed into a corresponding threaded bore (48) arranged on the movement device (36) or cooperating with the movement device (36). [7] Drawing tool (10) according to claim 6, characterized by that the threaded bore (48) is arranged in a rotatable disc (46) which is supported on the movement device (36) or the support structure (12). [8] Drawing tool (10) according to one of the preceding claims, characterized by that the movement device (36) comprises a lever arrangement (38) for moving the traction means (28). [9] Drawing tool (10) according to one of the preceding claims, characterized bythat the support structure (12) comprises a cross member (14), wherein the support section(s) (16) is or are fastened to the cross member (14) so ​​as to be movable along the same. [10] Drawing tool (10) according to claim 9, characterized by that the plastic (52) of the cross member (14) is reinforced with organic or inorganic reinforcing fibers (54), in particular carbon fibers (52), wherein the reinforcing fibers are arranged in a directed manner in the cross member (14). [11] Drawing tool (10) according to one of claims 9 or 10, characterized by that the plastic (52) is a thermosetting plastic, in particular an epoxy resin. [12] Drawing tool (10) according to one of claims 9 to 11, characterized byin that the support section (16) has a first subsection (18) encompassing the cross member (14) and a second subsection (20), wherein the second subsection (20) is fastened to the first subsection (18) so as to be rotatable at least about an axis of rotation (D) and comprises a support surface (25) for placing on the sheet metal component (26). [13] Drawing tool (10) according to one of claims 9 to 12, characterized by that the traction means (28) and the movement device (36) are or can be fastened to the cross member (14) so ​​as to be movable along the same. [14] Drawing tool (10) according to one of the preceding claims, characterized by that the traction means (28) has at one end a hook-shaped connecting element (34) with which tension tabs (80) fastened or fastenable to the sheet metal component (26) can be connected to the traction means (28). [15] Drawing tool (10) according to one of claims 1 to 13, characterized bythat the drawing tool (10) has an electrically operated heating device (70) with which a mouthpiece (68) arranged at one end of the pulling means (28) can be heated in such a way that the mouthpiece (68) can be connected to the sheet metal component (26) to form a welded joint (78). [16] Drawing tool (10) according to claim 15, characterized by that the support section (16) encloses at least one through-opening (66) which can be penetrated by the traction means (28).

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