CZ237399A3 - Half-finished products obtained by welding - Google Patents

Abstract

The welded semi-finished product forms a welding of the base parts (10,20) so that both parts lie on top of each other. Parts (10,20) are welded to each other by a laser beam (34, 36, 38) to form a uniform blank (40) which is further processed into final shape components.

Description

Welded semi-finished products

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for the welding of blanks which are used in the manufacture of shaped metal components.

BACKGROUND OF THE INVENTION

Sheet metal components of complex shape are usually manufactured from sheet blanks that are processed to a final shape by a series of forming or stamping operations. Where complex components are manufactured, it is common for these components to be manufactured from many individual elements that are molded from semi-finished products. The need to use a number of components results from the complexity of the final product, or may result from different technical properties of the material to be used in different parts of said component. For example, if the component is an automobile door frame, a larger portion of the door frame must be made of a relatively thin sheet metal, the hinge mounting points having to exhibit considerable strength. The use of many elements in the production of the final component increases the complexity of production.

In order to somewhat reduce the complexity of production, it has been proposed to produce welded blanks in which the respective shaped sheets are joined to the edges by laser welding, thereby producing a complex blanks. The blank forms a component with different material properties of the structure. This procedure allows optimum use of the material, while minimizing subsequent assembly of many elements into the final product.

The production of a welded blank requires that the base sheet metal parts be cut precisely so that laser welding can be effected efficiently and of adequate quality.

This requires precise cutting of the base components, and there are many different methods disclosed in Patent Application 9624039.5 filed November 19, 1996 and Application 9624652.5 filed November 27, 1996, and in the application entitled Overlaping.

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Joint for Laser Welding of Metals Including tubes - overlapping joints for laser welding of metals, including tubes, filed January 8, 1997, to alleviate the problems of achieving the required accuracy for base parts. In certain circumstances, it is desirable to produce components with a high-quality surface so that subsequent processing, such as paint, can be carried out after welding without major surface treatment. While laser welding requires the welded surface to be of high quality and the process disclosed in these applications facilitates the formation of a smooth outer surface, there is nevertheless a need for a welded blank that could be used directly to form the final surface.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a blank that includes a pair of sheet metal base pieces each having a pair of opposed major surfaces. The main surface of one of the components is located on the main surface of the other component, and the two components are welded to form a complex blank. The preform can be further processed into a component with different material properties.

It is preferred that the welding of the base members be performed by laser, and it is further preferred that the laser weld does not penetrate the second main surface of the second base member.

Overview of the drawings

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Fig. 1 shows a cross-section of a pair of base parts before processing; Fig. 2 shows a cross-section of components after processing; Fig. 3 shows a perspective view of the components after processing; Fig. 4 schematically illustrates a part formed from the components of Fig. 3; Fig. 6 is a cross-sectional view of an alternative embodiment of the welded blank; Fig. 8 is a cross-sectional view showing the processing of the tubular components; Fig. 9 is a perspective view of a finished component formed from the blank; Fig. 8

-3 ftft ftft ftft ftft ftft ftft ftft ftftft ftft ftftftft ftftftft ftftft ftftft ft ftftft ftftft ftftftft ft ft ftftft ftft ftft ftft ft Figure 10 shows a side view of another embodiment of a blank similar to a blank Fig. 9, Fig. 11 is a side view of another embodiment of the invention, similar to Fig. 10; Fig. 12 is a cross-sectional view of an alternative blank configuration comprising an additional component; 14 shows a section taken along line 14-14 in FIG. 13.

Fig. 15 is a cross-section similar to Fig. 14 showing the next molding step; Fig. 16 is a cross-section of the finished component; Fig. 17 is a flow chart of the sequence of steps in Figs. 13-16; Fig. 19 is a side view of the assembled blank of Fig. 18; Fig. 20 is a plan view of the blank of Fig. 19; Fig. 21 is a cross-sectional view of another embodiment of Fig. 19; 18-21.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a pair of base parts 10, 20 (each part may have different properties, in this case thickness), each of which is formed as a flat part of a weldable sheet. Each part has a pair of oppositely directed surfaces 12, 14 and 22, 24 interconnected circumferentially by the edges 16, 26.

The base portions 20, 20 are disposed adjacent one main surface 14 of the base portion 10, overlapping and contact one of the major surfaces 22 of the base portion 20. The base portion 10 having a smaller area than the base portion 20 is disposed within the periphery of the portion 20 so that after processing a greater thickness of material is available in the designated area of the finished component.

The base parts 10, 20 are held together by clamps 32 of a suitable configuration, for example in the form of magnetic clamps, if the individual components themselves are magnetic. The laser 34 directs the beam 36 to the main surface 12 of the base member 10 and causes the; ; from · · ί * ··· · * ··· * ·· *

The melting of the base portion 10 and the main surface 22 is controlled so that the beam 36 is partially penetrated into the portion 20, but the liquid region 38 does not expand into the lower surface 24.

The irradiated area may be protected by an inert gas in the usual manner.

The beam 36 is transmitted against the base member 10 and the surface 12 along a predetermined path such that when the beam 36 moves, the base member 10 and a portion of the base member 20 locally melt in the region indicated by the numeral 38. Further movement of the beam 36 allows the region 38 The base portions 10, 20 have hardened after the beam has passed, thereby joining the two portions 10, 20 through the weld 40.

The beam 36, shown in FIG. 3, moves transversely to other positions, thereby making further welds at specified distances, thereby joining the two parts 19, 20.

Alternatively, multiple laser beams may be used.

After welding, both parts constitute a uniform bonded blank 42 that can be subsequently converted to a component of the desired shape as shown in FIG. A pair of punches 44, 46 adjusts the facing faces 12, 24 of the blank 42 to the shape defined by said punches. The parts 20, 20 are adapted to eventually form a component with the desired complex shape.

By controlling the beam 36, it is possible for the melting to partially pass through the base member 20, whereby the main surface 24 is not adversely affected by welding, thus providing an uninterrupted smooth surface that does not require further machining before finishing. It is also appreciated that, where the condition of the final surface is not important, it is possible to fully penetrate the base 20.

In the tests performed with the blank 42 shown in Fig. 3, the following parameters were used:

Relative speed between laser beam and base: 6.2 m / min, Laser beam power: 6 kW using CO2 continuous laser, Laser beam mode: ΤΕΜθμ Laser beam diameter: 0.7 mm, Shielding gas: Helium top layer, Argon bottom layer, base part thickness 20: t ¹ = 0.86 mm base part thickness JO: t ^ = 1.88 mm base part material: galvanic (hot rolled galvanized mild steel)

The base parts may be similar to each other, that is, they may have the same thickness and composition, or they may be chosen to have different properties, such as thickness, composition, coating, and the like. By selecting the base parts JO, with the appropriate properties, the following are created: · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

A unitary blank 42 having a uniform surface but with local reinforcement to achieve different properties of the component being formed. In a particularly preferred embodiment, the base 20 is zinc coated and the base 10 is cold rolled. Thus, the surface 24 of the panel 20 is not affected by welding and provides a zinc-coated surface that can be used as an exterior dyed surface with corrosion resistance.

An alternative arrangement of the base parts and their welding is used to form the desired bonded (stitched) blank. The part 10a shown in FIG. 5 is connected to the base part 12a by intersecting weld lines 40a, so that the base part 10a is connected with its entire circumference to the base part 12a.

As shown in FIG. 6, the base member 10b may not have a rectangular shape, not even a regular shape, and the laser beam may move along a path adapted to the circumference of the base member 10b when connecting the member 10b to the irregularly shaped member 20b.

Said embodiments initiate welding of the base member at a location remote from the periphery of the base member 10a. As shown in FIG. 7, the base member 10c can be welded to the base member 12c by a loop weld 40c along the periphery of the base member 10c. If the main surface 24c is to be used as the final surface, the beam 36c is actuated to limit penetration of the base member 20c.

Said embodiments show the formation of bonded blanks from generally planar base parts. Figures 8 to 11 show the use of cylindrical base members 10d, 20d for locally strengthening the walls of the cylindrical blank. As seen in Fig. 8, the base portion 10d is cylindrical in shape and is located within the portion 20d. The laser beam impinges on the outwardly radially oriented main surface 12d, and penetrates the superposed main surfaces 14d, 22d and welds them together. The cylindrical base portion 20d can rotate about its longitudinal axis relative to the beam 36d, resulting in a circumferential weld.

Of course, the main parts 10d, 20d can be joined in longitudinally spaced locations as required for subsequent machining.

This arrangement is particularly useful where the cylindrical blank 42d is to be used for hydraulic forming in which high pressure fluid is used to push the cylindrical blank 42d into the die cavity. An example is shown in Figure 9, where the radial expansion of the cylindrical blank 42d forms an onion-shaped frame component with different wall thicknesses. Local reinforcement by the panel 20d allows to obtain different technical characteristics along the length of the final product.

In Fig. 10, it can be seen that the base portion 20e may be located outside the tube 10e at several spaced locations. This facilitates the placement of the parts 20e as well as welding of the tubular blank 42e. The variation of wall thicknesses provided by the base parts 10e, 20e, when used, for example, in a vehicle frame, provides the final product with progressive resistance to destruction. Similarly, as shown in FIG. 11, a plurality of base members may be stacked on top of each other to create additional variations regarding wall thicknesses. Of course, a similar arrangement can also be applied to the planar components of Figures 1-7.

Lamination of the welded blanks 42 allows additional material to be included in the blanks 42. As shown in FIG. 12, the sound transmission properties may be modified by including a non-metallic layer 48, for example of plastic or paper, between the base portions 10g, 20g. The intermediate layer 48 may have a thickness of 0.10 mm, and may be located below the smaller base portion 10g where it separates the major surfaces of Mg, 22g and forms a circumferential boundary 50 in which contact between the surfaces of Mg, 22g is not limited. The base pieces may be joined by a weld around the circumferential boundary 50 to prevent moisture ingress or by an intermittent weld to maintain the layer 48. The resulting welded blank 42g may be further refined to a prescribed shape by compression, with the intermediate layer 48 remaining at its time of compression. spot.

Another example of a component formed from a welded blank is shown in Figures 13 to 16, showing the formation of an impact tower (deformation member) used in motor vehicles by the manufacturing steps of Fig. 17. The impact tower is used to support suspended vehicle components , where is itself exposed to a heavy burden? in cut. It is usually elongated to accommodate the vertical displacement of the suspended components, and therefore has a large wall area.

The blank 42h is formed from a main part 20h and a pair of first base parts 10h. The second base portion 20h is formed from a cold-rolled flat sheet with a pair of D-shaped shavings 52 located in local depressions 53 The shavings 52 and depressions 53 are obtained in the pre-forming step by molding the sheet in a conventional manner.

The first base piece 10h is cut from a piece of sheet that is thicker and stronger to serve as a mounting location while being positioned above the blanks 52. The parts 10h overlap the edges of the blanks 52 within the recesses, thereby forming a circumferential boundary of 54 stacked pieces . The depth of the depressions corresponds to the thickness of the parts 10h to the extent that the main surfaces 24h and 14h lie in one plane. This provides a flat surface that facilitates further manufacturing operations.

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The base parts 10h and 20h are welded together at the edges 54 by a continuous weld 40h.

The resulting blank 42h includes two bunker forming blanks and is thus divided along the symmetry line 56 into two blanks. Each individual blank is then processed by compression to form an impact tower (FIG. 16) having relatively thin walls but including double-thickness mounting plates provided by the base parts 10h.

The described process can also be used to obtain a blank of non-weldable components or components that are incompatible with each other for welding. For example, mild steel and aluminum are separately weldable, but welded together creates brittle intermetallic compounds.

One such arrangement is shown in Figs. 18-20 where a pair of base members 10j, 20j are joined by welds 40j and mechanically joined by another component 60. Component 60 is a plastic material with a series of rectangular depressions 62 along the boundary edges 64. A notch is formed. 66. A notch 66 is formed at the edge of the main portion 10j with the lower surface 68 separated from the main surface 24j by the thickness of the other component 60. The protrusions 70 extend from the lower surface 68 and engage in recesses 62 where they engage.

The base parts 10j, 20j are disposed on the component 60 such that the component is located therebetween. The projections 70 fit into the recesses 62 such that the component 60 is mechanically connected to the piece T0. The parts 10j, 20j are welded at 40i, thereby also securing the component 60. The resulting blank may further be formed by mechanical bonding that maintains the integrity of the parts 10j and the component 60. Preference is given to a component 60 made of a composite of plastic, glass or other a material that is not normally weldable, or it may be dissimilar to a metallic material such as aluminum.

As an alternative to the rectangular recesses 62, hemispherical recesses may be used (Fig. 21). In this embodiment, a recess or well 72 is formed in the hemispherical punch in each piece 10k, 20k and component 60k, wherein the pieces 10k, 20k are welded together to form an integral blank 40k.

The mechanical interconnection of the component 60 and the parts 10, 20 can be used in different ways (FIG. 22). The component 60 may be used as an opening cap in the panel 20 (FIG. 22a), or may provide reinforcement over a portion of the panel 20 (FIG. 22b).

The component 60 may have a circular shape (FIG. 22c) or may be formed with a peripheral rebate to form a recessed surface (FIG. 22d).

Under certain circumstances, it is not necessary to use a positive mechanical connection, but may be replaced by a friction point obtained by deflecting one or both of the main parts (Fig. 22e). ··· · * · · · · · · · · ·

22h). In this arrangement, component 60 is mechanically captured by the base parts to allow further operations to be performed.

Later, it will be shown that the preparation of the welded blank with the base pieces placed thereon allows the blank to be formed with different material properties and without the need to adjust the exact edges of said parts.

Other typical applications in which the foregoing embodiment finds application is to provide a reinforcing portion of a vehicle door to provide a door locking assembly or a mounting pad for fastening the seat belts to the vehicle floor.

Although laser welding is preferred, other alternative welding techniques, such as MASH welding, may be used to allow the assembly of the blank for further processing. A welding sample shall be selected to meet the structural requirements of the manufacturing process, including the normal properties of the preform and the components used.

The connection of the base parts to the blank prior to processing can be somewhat reduced by the need to accurately fix the seam welding part to the blank. In addition, since the desired material properties can be obtained from the blank, welding of other components after the molding process can be avoided. This is particularly important when the precise shaping of complex shapes after molding is complex and takes a lot of time. The same closed surface can also be obtained without having to rely on the integrity of the weld.

In each of the above embodiments, a continuous weld between the base parts was shown. Where the structural requirements allow, it is of course possible to carry out local welding at separate locations of the base parts so that the base parts are held together during formation, and a continuous weld is no longer necessary.

Claims (15)

A welded blank for subsequently forming a finished component, said blank comprising a pair of metal base parts, each part having a pair of opposed major surfaces with a major surface of one component disposed on a major surface of the other part, one of said base portions having a peripheral edge disposed within the main surface of the second main member, wherein said main members are welded together by a seam formed by a laser beam which is guided around said peripheral edge to provide a uniform blank. The welded blank of claim 1, wherein the other major surface of one of the major portions provides the blank to a continuous, outwardly facing surface. Weld blank according to claim 1 or 2, characterized in that the weld seam partially penetrates into the second component and ends before the second main surface of the second main part. A welded blank according to any one of claims 1 to 3, characterized in that in one of the base parts there is an opening which is covered by the other base part. 5. The welded preform for further processing into a final component comprises a pair of metal base members, each comprising oppositely oriented main surfaces, with a main surface of the base member lying on the main surface of the second main member having peripheral edges disposed therein. a main surface of said second main part, further comprising an intermediate layer positioned between the main surfaces of the main parts and lying within the peripheral edges where it forms a peripheral boundary, the base parts being joined to each other by laser welding in said peripheral boundary to maintain the intermediate layer during forming, in place. Weld blank according to claim 5, characterized in that the base parts are welded together. ! s • ·· ♦♦ · * ♦ ·. * · ·!!!!!! ; · · · · 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 ίο- »* ** ♦♦ ♦ * ·· Welded blank according to claim 5 or 6, characterized in that the intermediate layer is not a metal layer. 8. A method of forming a final component from a main body of a metal blank, said method comprising the step of forming one of the constituent parts with a peripheral edge that is located within the main surface of the other one of the constituent parts and laser beam onto said peripheral edge to melt and fuse adjacent portions of the main surface of said second portion, welding both parts together to form a welded blank with different physical properties, and then forming a welded blank of the final molded component. 9. The method of claim 8, comprising the step of forming an aperture in one of the major portions prior to placing said portions on top of each other. Method according to claim 9, characterized in that the second of the main parts is positioned so that said opening overlaps before the welding. Method according to claim 10, characterized in that a recess is formed in one main part in which the other of the main parts fits. The method of any one of claims 8 to 11, wherein the laser beam partially penetrates into the second main member and terminates before the second main surface of the second main member. 13. A method of forming a tubular component from a pair of tubular main portions comprises the steps of assembling said tubular portions by placing one portion at the end of the other portion to achieve local reinforcement by interconnecting the two portions by laser welding, placement of the joined portions and application of pressurized fluid. to achieve expansion, in order to create the final shape of the tubular component. 14. A method according to claim 13, wherein the local reinforcement is externally. -11 • 9 9 9 9 9 9 9 9 9 9 9 9 9 9 99 · · 9 * 9 999 99 99 99 99 99 9 9 999 999 9 9 99 99 A method according to claim 13, characterized in that the local reinforcement is performed internally. The method of claim 13, comprising the steps of placing a plurality of main portions between the ends of the second main portion to obtain local reinforcements.