Deep drawing and / or stretch drawing tool with device for electromagnetic cutting and processing

Abstract

Deep drawing and / or stretch forming tool (100) for the conventional forming of a sheet metal material (130), comprising at least a first (110) and a second (120) tool part which are movable relative to each other and between which the sheet metal material (130) is formed, characterized in that at least one coil (141) for electromagnetic cutting is arranged in the first (110) and / or in the second (120) tool part in order to be able to cut the sheet metal material (130) before forming, during forming or after forming along at least one defined cutting line.

Description

[0001] The invention relates to a tool for forming sheet metal material, in particular a deep-drawing and / or stretch-forming tool. The invention further relates to a method for forming sheet metal material.

[0002] According to current technology, sheet metal parts, and especially complex sheet metal parts such as vehicle body panels, are manufactured in several work steps (operations, work sequences). In this process, a flat sheet of metal is transformed into a sheet metal part using a multitude of forming and cutting tools. Since many individual forming and cutting operations are sometimes required to produce a sheet metal part, and especially a complex one, numerous tools (e.g., up to ten tools) and presses to operate these tools are needed. This results in high investment and operating costs, which is one of the disadvantages associated with the current state of the art.

[0003] One object of the invention is therefore to show ways in which the production of sheet metal parts and in particular complex sheet metal parts can be optimized, especially with regard to required investment and / or operating costs.

[0004] The problem is solved by the tool according to the invention with the features of claim 1. The problem is further solved by the method according to the invention with the features of the dependent claim. Preferred embodiments and configurations are specified in the respective dependent claims, wherein the respective embodiments and configurations relate analogously to both the tool and the method.

[0005] The tool according to the invention has at least a first and a second tool part which are movable relative to each other and between which a sheet metal material is formed, wherein at least one coil (or a functionally equivalent component such as a coil arm or the like) is arranged in the first and / or in the second tool part for electromagnetic cutting in order to be able to cut or separate the sheet metal material before, during or after the forming process along at least one defined cutting line.

[0006] For forming the sheet metal material, one of the at least two tool parts can have at least one punch and the other tool part at least one corresponding die, which effect the forming of the sheet metal material in a known manner. The tool parts can be multi-part. In particular, the tool parts are an upper tool and a lower tool. The tool according to the invention can be a first-drawing tool or a second-drawing tool.

[0007] A key idea of ​​the invention is to utilize the technology of electromagnetic forming and integrate it into a conventional tool for forming sheet metal material, in order to be able to cut the sheet metal material before or during conventional forming or after conventional forming.

[0008] A deep-drawing tool with coils integrated into the punch for the electromagnetic reshaping of details (after deep drawing of the sheet metal material) is known from US 6,047,582 A. In contrast, the invention provides that the at least one coil integrated into the tool primarily serves not for forming the sheet metal material, but for cutting or separating it, as explained in more detail below. This is not contradicted by the fact that the tool according to the invention also includes at least one coil that primarily serves for forming, and in particular for supplementary forming, of the sheet metal material. Further tools are known from US 6,751,994 B2, FR 2,913,899 A1, and DE 103 37,769 B3.

[0009] The tool according to the invention enables the execution of several work steps or operations that were previously distributed across multiple tools. This reduces the number of tools required for the production of a sheet metal part, and especially complex sheet metal parts. Furthermore, fewer presses and transfer units are needed. Compared to the prior art, this can significantly reduce investment and / or operating costs.

[0010] A further advantage of the invention is that the sheet metal material can be cut at the correct time during conventional forming. This allows, for example, the material flow to be positively influenced during the forming process, particularly by introducing parting lines, relief holes, and the like. This eliminates restrictions that previously limited the forming operation (degree of deformation) possible in a tool. In particular, performing such cutting operations makes the forming of partial areas possible in the first place.

[0011] It is also possible to perform cutting operations before forming the sheet metal material, which subsequently, for example, facilitate or even make possible the forming of the sheet metal material.

[0012] A further advantage of the invention lies in the fact that cutting the sheet metal is possible, particularly in tool areas that are inaccessible to mechanical cutting elements or only accessible through complex tool designs. In particular, the slides conventionally used in cutting tools can be eliminated.

[0013] A time-varying magnetic field, in particular a pulsed magnetic field, is generated by the coil integrated into the tool in a known manner. This field selectively induces a current in the sheet metal material to be formed or already formed, upon which the magnetic field exerts a repulsive pressure. This presses the sheet metal material against at least one cutting edge at the designated location(s) and separates it there. Preferably, at least one cutting edge corresponding to the coil is arranged opposite the coil in the other tool part. The sheet metal material is pressed against this cutting edge and cut at this edge. In particular, the cutting edge is set back from a working surface of the tool part, thus preventing the cutting edge from leaving an imprint in the sheet metal material during forming. The cutting edge can, for example, be...It can be arranged in an area that is concavely curved back with respect to the effective surface. This can also be used to create shape details on the sheet metal part and / or to facilitate the separation of the cut part and the waste part.

[0014] Preferably, the cutting line, or the cutting edge defining the cutting line, has a non-planar, but rather a spatial or three-dimensional profile, and in particular a spatially curved or spatially multiply curved profile, wherein the coil is adapted at least partially to this spatial profile of the cutting line. This enables complex cutting profiles.

[0015] The cutting line along which the sheet metal is separated can have an open cutting contour. This means that the cutting line intersects the outer edge of the sheet metal at at least one point. However, the cutting line along which the sheet metal is separated can also have a closed contour, for example, to create cutouts in the sheet metal.

[0016] Preferably, the coil is integrated into an actuator designed as a modular unit, wherein the actuator is designed as an interchangeable or replaceable actuator. It is further preferred that the coil is a flat coil whose windings are not three-dimensional but essentially flat.

[0017] The method according to the invention comprises at least the following steps: - Providing a tool according to the invention; - Inserting the sheet metal material to be formed into the tool; - Relative movement of the tool parts of the tool, whereby the sheet metal material is formed; and - electromagnetic cutting of the sheet metal material prior to, concurrent with or following the forming process.

[0018] The explanations relating to the tool according to the invention apply analogously to the method according to the invention and vice versa.

[0019] Preferably, at least one relief cut, and in particular a relief hole or the like, is introduced into the sheet metal during the forming process to improve material flow and / or to prevent unwanted tears in the sheet metal. It is also preferably provided that, after forming and while the tool is still closed, the flange of a manufactured sheet metal part is at least partially cut off or separated.

[0020] It is further preferred that the electromagnetic cutting operation be combined with an electromagnetic forming operation, for example, to locally form or reshape details on the sheet metal part. In particular, such forming is only made possible by making a cut in the sheet metal material at the right time and place, e.g., directly in the forming area or in an adjacent area. In particular, the cutting of the flange can be combined with reshaping.

[0021] The invention is explained in more detail below using the figures as examples and in a non-restrictive manner. Fig. Figure 1 shows two schematic sectional views of the separation of the flange following the forming process with the tool closed. Fig. Figure 2 shows a schematic sectional view of a separation cut made during the forming process.

[0022] Fig. Figure 1a shows a forming tool designated 100, which is exemplified as a deep-drawing tool. The tool 100 comprises a first tool part or upper tool 110 with a die 111 and a second tool part or lower tool 120 with a punch 121 and a blank holder 122. Between the working surfaces of the punch 121 and the blank holder 111 is a sheet metal material 130, which has been formed by the tool 100 from an initially flat state into a three-dimensional sheet metal part. The illustration of the Fig. Figure 1a shows the final state of the forming process with tool 100 closed.

[0023] According to the invention, an actuator 140 with a coil 141 is arranged in the punch 121. The electrical connection of the actuator 140 and the coil 141 is not shown in detail. In the illustrated embodiment, the actuator 140 is arranged in the tool 100 such that it forms part of the working surface of the punch 121 in the frame area (area between the drawing part base and the flange) and thus comes into direct contact with the sheet metal material 130. The actuator 140 can also be set back from the working surface of the punch 121. Furthermore, it is conceivable to arrange the coil 141 directly (i.e., not as an actuator component) in the punch 121, provided it is appropriately insulated. Finally, it is conceivable to integrate the sheet metal material 130 to be cut into the circuit of the coil 141.

[0024] In the hold-down device 111, a recess 150 with a cutting edge 151 is arranged opposite the actuator 140. In the illustrated embodiment, the recess 150 and the cutting edge 151 are formed directly in the hold-down device 111. It is also possible to arrange a corresponding cutting insert in the hold-down device 111. Instead of a cutting edge, a cutting blade or the like can also be provided.

[0025] The actuator 140 and the corresponding cutting edge 151 serve to separate the flange area 131 from the sheet metal part when the tool 100 is closed. For this purpose, the coil 141 is electrically activated, which can be done, for example, by capacitor discharge. As a result, the sheet metal material 130 in the cutting area is pushed away from the punch 121 and separated at the cutting edge 151. The completed cutting process is shown Fig. 1b. In the cutting area, the flange to be separated (waste part) is deformed into the recess 150. This deformation occurs on the waste part and is therefore negligible. After opening the tool 100, the component (cut part) and the separated flange (waste part) can be removed.

[0026] Advantageously, the tool 100 enables both conventional forming of the sheet metal material 130 into a sheet metal part and subsequent electromagnetic cutting of the formed sheet metal part.

[0027] In the illustrated embodiment, the cutting line runs along the frame area. It is possible to arrange several coils (particularly three-dimensional coils) and corresponding cutting edges in the surrounding frame area to create a continuous cutting line. If multiple coils are provided, they can be activated simultaneously or sequentially.

[0028] To counteract the forces occurring during electromagnetic cutting, corresponding clamping forces can be applied to the tool 100, which can be achieved, for example, by the forming press. Likewise, sufficient support must be provided for the actuator 140 (or the coil 141) and the cutting edge 151 (or a cutting insert) within the tool 100.

[0029] In connection with the Fig. Section 2 below explains the introduction of a parting line during the forming of the sheet metal material 130. Identical or functionally equivalent components are in Fig. 2 with the same reference symbols as in Fig. 1 named.

[0030] In contrast to the exemplary embodiment of the Fig. Actuator 140 with coil 141 is arranged in the base of the punch 121 and serves to introduce a parting line (or a relief hole) into the sheet metal 130 during the forming process, in order to selectively improve the material flow and / or prevent unwanted tearing of the sheet metal 130 in the frame area. The cutting edge 151 is arranged on a slide 112 that is movable relative to the die 111 and is pressed against the sheet metal 130 independently of the die 111 during cutting. During deep drawing, the base of the punch 121 initially comes into contact with the slide 112, which is then moved back by the punch 121 until the forming of the sheet metal 130 is complete (this state is shown). Fig. 2) Of course, other tool designs or configurations are also conceivable.

[0031] In the Fig. In the embodiment shown in Figure 2, the cutting edge 151 is arranged in a concave section 160 that is set back from the working surface in order to prevent the cutting edge 151 from leaving an imprint or mark on the sheet metal material 130 during the first deep-drawing section (before the parting cut is made). As shown, during cutting, the sheet metal material 130 is first deformed into the recessed section 160, which can be used to selectively form details.

[0032] Conversely, it is possible to first cut the sheet metal material 130 and, so to speak, provide a shaping section behind the cutting edge into which the cut sheet metal material is formed, for example, to create details. In this way, tabs and the like could be produced.

[0033] A section 160 set back from the effective surface, as in Fig. 2 shown, can also be used in the embodiment of the Fig. 1 is provided to prevent the sheet material 130 from being pulled over the cutting edge 151 during forming.

[0034] In the in the Fig. 1 and Fig. In the two illustrated embodiments, the actuators or coils are arranged in the punch and the corresponding cutting edges in the die. However, the arrangement can also be reversed. It is also possible to arrange actuators in both the die and the punch, with the corresponding cutting edges then positioned opposite each other in the other tool part. Furthermore, an arrangement of actuators and / or cutting edges in the blank holder is also conceivable.

[0035] The characteristics of the in the Fig. 1 and Fig. The two illustrated embodiments can be combined with each other. For example, a tool design is possible that allows cutting of the sheet metal material both during and after forming. Reference symbol list 100 tools (forming tools) 110 first tool part (upper tool) 111 die 112 slides 120 second tool part (lower tool) 121 stamps 122 hold-down devices 130 sheet metal 131 Flange 140 actuator 141 coil 150 Exclusion 151 Cutting edge 160 Recess (concave area)

Claims

[1] Deep drawing and / or stretch forming tool (100) for the conventional forming of a sheet metal material (130), comprising at least a first (110) and a second (120) tool part which are movable relative to each other and between which the sheet metal material (130) is formed, characterized by , that in the first (110) and / or in the second (120) tool part at least one coil (141) for electromagnetic cutting is arranged in order to be able to cut the sheet metal material (130) before forming, during forming or after forming along at least one defined cutting line. [2] Deep drawing and / or stretch drawing tool (100) according to claim 1, characterized by , that opposite the coil (141) in the other tool part at least one cutting edge (151) corresponding to the coil is arranged, against which the sheet metal material (130) is pressed and on which the sheet metal material (130) is cut. [3] Deep drawing and / or stretch drawing tool (100) according to claim 2, characterized by , that the cutting edge (151) is set back relative to an effective surface of the tool part. [4] Deep drawing and / or stretch drawing tool (100) according to any one of the preceding claims, characterized by , that the cutting line has a spatial progression, wherein the coil (141) is adapted at least section by section to this spatial progression of the cutting line. [5] Deep drawing and / or stretch drawing tool (100) according to any one of the preceding claims, characterized by that the cutting line has an open or a closed course. [6] Deep drawing and / or stretch drawing tool (100) according to any of the preceding claims, characterized by , that the coil (141) is part of an interchangeable actuator (140). [7] Deep drawing and / or stretch drawing tool (100) according to any one of the preceding claims, characterized bythat it is a first-pull tool or a second-pull tool. [8] Method for forming a sheet metal material (130) comprising the following steps: - Providing a deep drawing and / or stretch drawing tool (100) according to one of the preceding claims; - Inserting the sheet metal material to be formed (130); - Relative movement of the tool parts (110, 120), whereby the sheet metal material (130) is formed; and - preceding, simultaneous or subsequent electromagnetic cutting of the sheet metal material (130). [9] Method according to claim 8, characterized by , that during the forming process in the sheet metal material (130) at least one relief cut is defined to be made. [10] Method according to claim 8 or 9, characterized by , that after forming with the tool (100) closed, the flange (131) of a manufactured sheet metal part is cut off at least section by section.

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