Method and apparatus for component manufacturing

Abstract

The invention relates to a method for manufacturing a component (100) in which at least two individual parts (110, 120) are reshaped by the action of a high-pressure working medium and subsequently joined together, and which comprises the following steps: - Inserting the individual parts (110, 120) into a forming tool (200) which has at least one window (230) permeable to a welding jet (410), - Closing the mold tool (200) so that an interior of the mold tool (200) is divided into at least two enclosed pressure areas (240, 250), - Applying a high-pressure active medium to the closed mold tool (200) such that a first internal pressure (p) is created in a first pressure area (240). i1 ) is built up, which is greater than a second internal pressure (p i2 ) in a second printing area (250), - Forming the individual parts (110, 120) until the first internal pressure (p i1 ) equal to the second internal pressure (p i2 ) is, - Joining the individual parts (110, 120) to form a component (100) by welding, wherein a welding jet (410) is directed through the at least one window (230) onto the individual parts (110, 120). The invention further relates to a device for carrying out the method.

Description

[0001] The invention relates to a method for manufacturing components according to the preamble of claim 1 and a device according to the preamble of claim 5 for carrying out the method.

[0002] It is well known that components and parts, such as vehicle structures or substructures, are assembled from many different individual parts. Each part is first manufactured in its own forming process before all parts are subsequently joined together in a separate joining process, for example by welding or bonding. This long manufacturing process chain comprises numerous individual operations and is therefore disadvantageously complex and, due to the large number of operations and the associated necessary equipment, also costly.

[0003] Current technologies include individual part forming processes such as deep drawing, conventional internal high-pressure forming, and conventional joining techniques such as welding, bonding, and mechanical joining. Disadvantages include the complex and costly manufacturing process chains. Another drawback is that some processes are solely based on bonding, which limits the number of component joints, necessitates bonding with larger flange widths, and results in lower precision.

[0004] High-pressure forming, also known as hydroforming, is a forming process used to shape pipes and sheets. A machine forms the workpiece in a closed die using a liquid medium under high pressure of up to 4000 bar. In the internal high-pressure forming variant, metallic pipes or hollow bodies are formed using internal pressure, while in the external high-pressure forming variant, sheets are typically pressurized with the medium on one side and pressed into the opposite side of the die.

[0005] DE 10 2021 005 061 A1 describes a method for producing a profile comprising at least two profile parts by means of internal high-pressure forming, in which the profile parts inserted and arranged next to each other in an internal high-pressure forming tool are subjected to a fluid under high pressure and thereby formed, wherein the profile parts inserted in the internal high-pressure forming tool are bonded together at at least one respective edge region of the profile parts before being subjected to the fluid and the bond is at least partially cured before being subjected to the fluid.

[0006] DE 195 35 870 A1 describes a method for producing shell-shaped hollow structures from doubled sheet metal blanks by means of internal high-pressure forming, which comprises the following process steps: clamping the doubled sheet metal blanks in a combined clamping / forming tool, which, with a circumferential clamping surface, seals a flange area of ​​the doubled sheet metal blanks with respect to the pressure values ​​of the forming medium occurring during internal high-pressure forming, forming the doubled sheet metal blanks by means of internal high-pressure forming by introducing a pressure medium between the clamped sheet metal blanks while allowing a controlled material flow in the clamped flange area of ​​the doubled sheet metal blanks, and welding the sheet metal blanks in the flange area.

[0007] DE 103 55 959 A1 discloses a method and a device for the medium-assisted forming of a planar, in particular multi-layered, semi-finished product with a split hydroforming tool, in which opposing medium pressures are applied to opposite side surfaces of the semi-finished product in the area to be formed.

[0008] DE 602 00 731 T2 discloses an internal high-pressure forming process for plates and a device for this purpose. The process comprises a metal sheet or metal plate internal high-pressure forming process or hydroforming process, comprising clamping two stacked metal plates or sheets between holding surfaces of a pair of upper and lower punches, each punch having cavities of the same internal contour shape as an external contour shape of a product, and introducing a fluid between matched surfaces of the two metal plates and pressurizing the fluid, causing the metal plates to bulge or warp into the punch cavities. A through-hole for introducing the fluid is formed in one of the punches, the through-hole being directed to the holding surface of one punch.A perforated hole for introducing the fluid is positioned in the through-hole formed in a punch, wherein the punched hole in one of the metal plates is formed in a region of the metal plate which region is in contact with the holding surface of the punch, and the fluid is introduced under pressure between matching surfaces of the metal plates through the punched hole from the through-hole, causing the metal plates to bulge, wherein, after the metal plates have been stretch-formed by introducing the fluid under pressure between the matching surfaces of the metal plates, regions or sections of the metal plates which regions are not required as products and which regions are in contact with the holding surfaces of the punches are cut away to obtain two formed parts at once.

[0009] DE 689 03 647 T2 discloses a device and a method for manufacturing objects by superplastic forming. The invention relates to a device and a method for forming structures from materials that are predominantly superplastic, i.e., from materials that have superplastic properties, and from materials that, although not actually superplastic according to various definitions of this term, can nevertheless be subjected to considerable stretching without breaking, e.g., composite metals such as titanium or aluminum containing silicon carbide particles, fibers, or metal wires.The mold, which can be designed as a male or female mold, is preferably made of a material that is easily shaped internally and is strong enough to withstand the differential pressures exerted on the superplastic material during the forming process. A preferred material for the mold is ceramic, which can be cast in a wooden or plastic mold and has a shape corresponding to the object to be formed. Because the mold is completely enclosed by the pressure prevailing in the container portion of the cavity, the only force exerted on the mold during superplastic forming is that resulting from the blank being pressed against it.It is subjected to considerably reduced pressures compared to known superplastic forming techniques, and this enables the use of such ceramic materials on a commercial scale.

[0010] One object of the invention is to provide a method and a device with which the forming and joining of a component comprising at least two profile parts is significantly simplified and thus made more cost-effective.

[0011] The problem is solved according to the invention by a method having the features of the characterizing part of claim 1 and a device having the features of the characterizing part of claim 5.

[0012] Advantageous embodiments of the invention are the subject of the dependent claims.

[0013] An inventive method for manufacturing a component in which at least two individual parts are reshaped by the action of a high-pressure working medium and subsequently joined together comprises the following steps: - Placing the individual parts into a mold that has at least one window permeable to a welding jet, - Closing the mold tool in such a way that the interior of the mold tool is divided into at least two enclosed pressure areas, - Applying a high-pressure working medium to the closed mold tool in such a way that a first internal pressure is built up in a first pressure area, which is greater than a second internal pressure in a second pressure area, - Reshaping the individual parts until the first internal pressure equals the second internal pressure, - Joining the individual parts to form a component by welding, whereby a welding jet is directed through at least one window onto the individual parts.

[0014] The proposed method makes it possible to join the individual parts to form the component while the pressure of the working medium is still maintained in the mold.

[0015] The working medium can then be released and the mold opened to remove the component. By dividing the mold's interior into enclosed pressure zones, a higher pressure can be built up in the first zone, initiating the forming process. This process ends when pressure equalization occurs between the zones, as the forming of the individual parts reduces the pressure in the second zone, ultimately resulting in the second internal pressure being equal to the first. Alternatively, the pressure in each of the two zones can be individually and precisely controlled.

[0016] The proposed process combines high-pressure forming of the individual parts with their assembly into a component. This simplifies manufacturing compared to known methods, resulting in significant cost savings.

[0017] In a further embodiment of the process, it may be provided that a gaseous active medium is used, for example an inert gas such as argon or nitrogen, which provides a closed protective gas atmosphere that actively and positively influences the welding result.

[0018] In a further embodiment of the process, it can be provided that the joining of the individual parts is carried out by laser beam welding or electron beam welding.

[0019] The object of the invention is also achieved by a device for manufacturing a component, comprising a forming tool for high-pressure forming and a source of active media that can be brought into a communicating connection with the forming tool for providing an active medium under high pressure, wherein the forming tool has at least one window permeable to a welding jet and the device further comprises a welding device for generating a welding jet, wherein the welding device is configured to direct the welding jet onto the window.

[0020] The proposed device allows for the combined forming and joining processes, as described above with reference to the proposed method, to be carried out quickly and easily in a single device. The radiation-transparent window of the forming tool enables welding to be performed inside the closed tool. The finished component can then be removed from the open forming tool.

[0021] In a further embodiment of the device, it can be provided that the active medium source is designed to provide a gaseous active medium, for example an inert gas such as argon or nitrogen.

[0022] In a further embodiment of the device, it can be provided that the welding device is a laser beam welding device or an electron beam welding device.

[0023] According to the invention, a gas, in particular argon or nitrogen, can be used as the pressure medium. This gas serves both to form the components and, through the resulting protective gas atmosphere in the closed tool, significantly improves the weld quality. To make advantageous use of this, transparent discs can be embedded in the tool in the joining zones for the wavelength used by the applied laser radiation. A different pressure zone is created between the discs and the components to precisely control the forming process and to define the spacing between the components for the welding process.

[0024] In this respect, the differently controllable pressure zones are an innovation in terms of plant technology, especially in combination with a high-pressure forming tool which, in the closed state, can be penetrated by the laser radiation for the welding operation.

[0025] From a process perspective, the use of shielding gases such as argon or nitrogen in the described setup allows for both component forming and an improvement of the welding process under a shielding gas atmosphere.

[0026] The invention offers the advantage of a simplified process chain for the production of a component composite or assembly such as a vehicle door, thereby achieving a reduction in cycle time.

[0027] Joining and forming are performed in a single process, resulting in cost savings by eliminating the need for additional equipment. The "two-in-one process" proposed according to the invention achieves optimal tool utilization. Component quality is also improved because the components are pressed together precisely in the fixture and joined in this state, whereas conventional methods would require repositioning them relative to each other.

[0028] The active medium also advantageously fulfills a dual function. On the one hand, the gas can apply pressure to the individual parts for forming, and on the other hand, it can provide a protective atmosphere during welding.

[0029] The invention is applicable to many semi-finished products, such as sheet metal, and to many other materials, with particular suitability for processing steels and especially light metals like aluminum. The invention enables the achievement of excellent component properties with regard to strength through coordinated joining and forming operations.

[0030] Beam welding processes, such as laser beam welding, offer high flexibility and at the same time exact precision, so that only short joining or flange areas are required.

[0031] The invention offers new possibilities for component design with regard to their complexity, allowing for free design of the weld geometry through the use of a conventional scanner optic, which can, for example, be mounted on a robot. This enables the welding optic to be moved to multiple joining areas, allowing for flexible welding of components. The invention can be implemented using conventional equipment.

[0032] An embodiment of the invention is explained in more detail below with reference to the drawings.

[0033] This shows: Fig. 1 schematically illustrates the process step of inserting, Fig. 2 schematically the beginning of the transformation, Fig. 3 schematically the end of the transformation, and Fig. 4 schematically illustrates the welding process step.

[0034] Corresponding parts are marked with the same reference symbols in the figures.

[0035] Fig. Figure 1 schematically shows a forming tool 200 comprising two tool parts, namely a first tool part 210 and a second tool part 220, which are designed to be pressure-tightly connected to one another. In the exemplary embodiment, the second tool part 220 has a radiation-transmitting window 230. Between the first tool part 210 and the second tool part 220, two individual parts, namely a first individual part 110 and a second individual part 120, are arranged, which are pressed together by the connected tool parts 210, 220, thereby forming a first pressure zone 240 below the first individual part 110, bounded by the first individual part 110 and the first tool part 210, and a second pressure zone 250 above the second individual part 120, bounded by the second individual part 120 and the second tool part 220.

[0036] The device further includes, as described in Fig. Figure 2 shows an active medium source 300, which is connected to the first tool part 210 and the second tool part 220 by means of an active medium line 310 each, and can be brought into a communicating connection by means of a valve 320 on the one hand with the first pressure area 240 arranged in the first tool part 210 and on the other hand with the second pressure area 250 arranged in the second tool part 220, in which an active medium from the active medium source 300 can be introduced into the first pressure area 240 and / or into the second pressure area 250. Initially, a first internal pressure p is established in the first pressure area 240. i1 generated, which is greater than the second internal pressure p prevailing in the second pressure range 250 i2 , causing the first single part 110 and the second single part 120 to begin to deform.

[0037] Fig. Figure 3 shows how the forming process comes to a standstill when the second pressure area 250 has shrunk so much due to the deformation of the first part 110 and the second part 120 that the second internal pressure p i2 is exactly the same as the first internal pressure p i1 . This completes the transformation of individual parts 110 and 120.

[0038] In Fig. Figure 4 shows that the device also includes a welding unit 400, which is designed and configured to generate a welding jet 410 and direct it onto the window 230 of the second tool part 220 to produce weld seams 420 by which the two individual parts 110, 120 are joined to form a component 100. This completes the combined forming and joining process. After a reduction of the internal pressures p i1 and p i2At atmospheric level, the mold 200 can be safely opened and the finished component 100 can be removed.

Claims

[1] Method for manufacturing a component (100) in which at least two individual parts (110, 120) are reshaped by the action of a high-pressure working medium and subsequently joined together, characterized by that the procedure includes the following steps: - Inserting the individual parts (110, 120) into a forming tool (200) which has at least one window (230) permeable to a welding jet (410), - Closing the mold tool (200) so that an interior of the mold tool (200) is divided into at least two enclosed pressure areas (240, 250), - Applying a high-pressure active medium to the closed mold tool (200) such that a first internal pressure (p) is created in a first pressure area (240). i1 ) is built up, which is greater than a second internal pressure (p i2 ) in a second printing area (250), - Forming the individual parts (110, 120) until the first internal pressure (p i1 ) equal to the second internal pressure (p i2 ) is, - Joining the individual parts (110, 120) to form a component (100) by welding, wherein a welding jet (410) is directed through the at least one window (230) onto the individual parts (110, 120). [2] Method according to claim 1, characterized by that a gaseous active medium is used. [3] Method according to claim 2, characterized by that the active medium is an inert gas such as argon or nitrogen. [4] Method according to any one of claims 1 to 3, characterized by , that the joining of the individual parts (110, 120) is carried out by laser beam welding or electron beam welding. [5] Device for manufacturing a component (100), comprising a forming tool (200) for high-pressure forming and a source of active medium (300) that can be brought into a communicating connection with the forming tool (200) for providing an active medium under high pressure, characterized by , that the forming tool (200) has at least one window (230) permeable to a welding jet (410) and the device further comprises a welding device (400) for generating a welding jet (410), wherein the welding device (400) is configured to direct the welding jet (410) towards the window (230). [6] Device according to claim 5, characterized by , that the active medium source (300) is designed to provide a gaseous active medium. [7] Device according to claim 5, characterized by , that the active media source (300) is designed to provide an inert gas such as argon or nitrogen. [8] Device according to claim 5, characterized by that the welding device (400) is a laser beam welding device or an electron beam welding device.

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