Method for joining two essentially metal sheet-type workpieces by means of friction squeeze welding using a filler material

Abstract

The invention relates to a method for joining two essentially metal sheet-type workpieces. In said method. the edge regions of the workpieces to be joined are placed at a distance from one another, at least one wire-shaped filler material is introduced into a zone between the edge regions before or during the joining process, and edge regions and the filler material are then heated to a predefined joining temperature by at least one first frictional element that moves in relation to the edge regions and the filler material, are subjected to a certain contact pressure, and are joined while being deformed.

Claims

1. A method for joining two workpieces, the method comprising: spacing at least two peripheral regions of the workpieces in relation to one another; introducing at least one filler material in the form of a wire into a region between the peripheral regions before or during a joining operation; heating the peripheral regions and the filler material to a predetermined joining temperature by means of at least a first frictional element performing a relative movement in relation to the peripheral regions and the filler material; and subjecting the first frictional element to a pressing pressure to deform the filler material and join the workpieces.

2. The method as claimed in claim 1, wherein the relative movement of the first frictional element is applied by one of rotational, turning, oscillation, and and/or longitudinal movement along the peripheral regions.

3. The method as claimed in claim 1, wherein, for the heating of the peripheral regions to the joining temperature, an additional frictional element is applied to the peripheral regions and moved in relation to the peripheral regions ahead of the first frictional element.

4. The method as claimed in claim 3, wherein an element in the form of a rod, with an end face that is beveled or provided with a radius and placed against the peripheral regions is used as the additional frictional element.

5. The method as claimed in claim 3, wherein an element in the form of a roller or roll placed against the peripheral regions is used as the additional frictional element.

6. The method as claimed in claim 1, wherein, for the heating of the peripheral regions to the joining temperature, the peripheral regions are additionally heated by means of an external heat source selected from a group consisting of resistance heating, inductive heating, a gas flame, hot gas, laser, arc, electron beam, plasma jet, and smouldering contact.

7. The method as claimed in claim 6, wherein the joined peripheral regions are smoothed in the heated state by means of a smoothing element, which performs a relative movement in relation to the peripheral regions.

8. The method as claimed in claim 7, wherein the first frictional element is moved in a rotating or oscillating relative movement in relation to the peripheral regions and in a longitudinal movement along the peripheral regions.

9. The method as claimed in claim 8, wherein the peripheral regions are formed as straight.

10. The method as claimed in claim 9, wherein the first frictional element is supported on a rear side of the workpieces by a second frictional element.

11. The method as claimed in claim 1, wherein the joined peripheral regions are smoothed in the heated state by means of a smoothing element, which performs a relative movement in relation to the peripheral regions.

12. The method as claimed in claim 11, wherein an element in the form of a rod, with an end face that is beveled or provided with a radius and placed against the peripheral regions is used as the smoothing element.

13. The method as claimed in claim 11, wherein an element in the form of a roller or roll placed against the peripheral regions is used as the smoothing element.

14. The method as claimed in claim 1, wherein an element in the form of a rod, with an end face that is beveled or provided with a radius and placed against the peripheral regions is used as the first frictional element.

15. The method as claimed in claim 1, wherein the first frictional element is moved in a rotating or oscillating relative movement in relation to the peripheral regions and in a longitudinal movement along the peripheral regions.

16. The method as claimed in claim 1, wherein the peripheral regions are formed as straight.

17. The method as claimed in claim 1, wherein the first frictional element is supported on a rear side of the workpieces by a second frictional element.

18. The method as claimed in claim 1, wherein the regions to be joined of the workpieces and of the filler material are heated to a plastifying temperature.

19. The method as claimed in claim 1, wherein an element in the form of a roller or roll placed against the peripheral regions is used as the first frictional element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described below on the basis of exemplary embodiments in conjunction with the drawing, in which:

(2) FIG. 1 shows a simplified schematic side view of a first exemplary embodiment of the method according to the invention,

(3) FIG. 2 shows a modified configurational form of the method according to FIG. 1,

(4) FIG. 3 shows a side view of the arrangement from FIG. 2,

(5) FIG. 4 shows a side view of a modified exemplary embodiment with a preceding frictional disk,

(6) FIG. 5 shows a view, analogous to FIG. 4, of a modified exemplary embodiment with a following smoothing disk,

(7) FIG. 6 shows a further exemplary embodiment, analogous to FIG. 5, using frictional and smoothing elements in rod form, and

(8) FIG. 7 shows three views of the forming of a multi-layer weld.

DETAILED DESCRIPTION

(9) FIG. 1 shows a tool table 15, on which two workpieces 1, 2 in sheet form are arranged. These have a spacing from one another, into which a filler material 11 in the form of a wire is placed adjacent to the peripheral regions 3, 4 of the workpieces 1, 2. The filler material (wire) 11 is heated by means of a first frictional element 5 in the form of a disk and is pressed into place by means of a pressing force 6. The frictional element 5 rotates about the turning axis 14.

(10) After the heating and plastifying of the filler material 11, the peripheral regions 3 and 4 are also heated and plastified, and so this is followed by a joining weld being formed by pressing of the plastified materials.

(11) The frictional disk 5 may be produced for example from V2A material. It runs without lubrication, and consequently in a dry state, at revolutions of for example 12,000 to 18,000 rpm. The frictional element 5 does not produce any abrasion, and so there is no loss of material. Rather, the frictional element 5 serves merely for heating and plastifying and for applying the pressing force 6.

(12) FIGS. 2 and 3 show a modified exemplary embodiment, which differs from the exemplary embodiment of FIG. 1 in that, instead of the table 15, a second frictional element 5, which likewise turns about a turning axis 14, and is consequently designed for heating or plastifying and for applying a pressing force 6, is arranged on the underside of the workpieces 1, 2. Consequently, in the case of the exemplary embodiment of FIGS. 2 and 3, heating and plastifying and pressing take place on both sides.

(13) In the case of the exemplary embodiment shown in FIG. 4, a preceding frictional disk (frictional element) 8 is provided. This likewise rotates about its turning axis 14, and consequently forms an additional heat source in order to heat the workpieces 1, 2. After that, the filler material 11 in the form of a wire is introduced and, as described in conjunction with FIG. 1, is heated by means of the frictional element 5 and is squeezed by applying the pressing force (not represented), and so a joining weld is obtained. The advancing direction is represented in FIG. 4 by the arrow 7.

(14) FIG. 5 shows a configurational variant, in which a following disk 9, which rotates about a turning axis 14, is provided as a smoothing element 9, in order to form a smooth surface of the weld seam.

(15) In the case of the exemplary embodiment shown in FIG. 6, it is envisaged as a modification of the exemplary embodiment of FIG. 5 to use frictional and smoothing elements 9 in rod form that can be set in rotation about their axes of rotation 13. On the end faces, the frictional and smoothing elements are beveled and/or provided with rounded edges.

(16) It goes without saying that the variants described in FIGS. 4 to 6 can be combined with an additional heat source 8 or smoothing element 9.

(17) FIG. 7 shows a further exemplary embodiment, in which a multi-layer weld is formed. For this purpose, the peripheral regions 3, 4 of the workpieces 1, 2 are of a stepped form. In the representation on the left in FIG. 7, pressing-in of a round filler material 11 in the form of a wire first takes place, in a way analogous to the representation in FIG. 1. The representation in the middle of FIG. 7 shows the joining weld 10 formed in the first step (representation on the left in FIG. 7), onto which a further element in the form of a wire is placed as filler material 11. This has in this case a cuboidal cross section and is likewise heated and plastified by a frictional element 5 and pressed or squeezed by means of the pressing force (not represented). It goes without saying that the dimensioning of the filler material 11 and also the width of the frictional element 5 must be adapted appropriately.

(18) In the case of the representation on the right in FIG. 7, two joining welds 10 have been formed. A further rectangular filler material 11 in the form of a wire is placed on and is heated and plastified and squeezed by means of a frictional element 5. It is possible in this way to form multi-layer joining welds.

(19) Various features of the invention are set forth in the following claims.