Clinching technique and tool for its execution.

Abstract

Method for clinching a first layer (20) and a second layer (30), comprising that at least a section of an interchangeable, deformable insert (40, 40') is arranged in a clinch die cavity (52) defined in a clinch die (50), wherein the clinch die cavity (52) has an annular recess (54) adjacent to the insert (40, 40'); the first layer (20) is set up on the second layer (30); the first layer (20) and the second layer (30) are fixed between a retractable punch (60) and the clinch die (50); the stamp (60) is pressed into the first layer (20), creating a depression (22) in the first layer (20) and the second layer (30); the first layer (20) and the second layer (30) are pressed together between the punch (60) and the clinch die (50), thereby generating hydrostatic pressure in the first layer (20), the second layer (30) and the insert (40, 40'); and a section of the insert (40, 40') is subjected to extrusion and thereby fills the annular recess (54) with insert extrudate (42), while at the same time a section of the second layer (30) is extruded radially into an annular space (44) previously occupied by the insert (40, 40') and at the same time a section of the first layer (20) is extruded radially into an annular volume (34) previously occupied by the second layer (30), thereby forming an interlocking composition of the first layer (20), the second layer (30) and the insert (40, 40'); where: (i) the insert (40) has a hollow cylindrical shape (48) with an open end (49) and a closed end (43) opposite the open end (49) and wherein the insert (40) is dimensioned in such a complementary manner that it fits completely into the matrix cavity (52); or (ii) the insert (40') is a disk with a flange (41'') extending radially outwards from an outer edge (81'') of the disk, the flange (41'') being thinner in the axial direction than the disk, the flange (41'') having an outer diameter (82) that is larger than a maximum diameter (83) of the die cavity (52), and the disk being dimensioned to be complementary such that it fits into the die cavity (52); or (iii) the insert (40') is a hollow cylinder (48') having an open end (49') and a closed end (43') opposite the open end (49') and having a flange (41') extending radially outwards from an outer edge (81') of the closed end (43'), the flange (41') having an axial thickness (85) equal to an axial thickness (87) of the closed end (43') of the cylinder, the flange (41') having an outer diameter (82) larger than a maximum diameter (83) of the die cavity (52), and the open end (49') of the cylinder being dimensioned to be complementary such that it fits into the die cavity (54); or (iv) the insert (40') is a hollow cylinder (48'') having an open end (49'') and a closed end (43'') opposite the open end (49'') and having a flange (41'') extending radially outwards from an outer edge (81'') of the closed end (43''), wherein the flange (41'') has an axial thickness (85') that is thinner than an axial thickness (87') of the closed end (43'') of the cylinder (48''), wherein the flange (41'') has an outer diameter (82) that is larger than a maximum diameter (83) of the die cavity (52), and wherein the open end (49'') of the cylinder (48'') is dimensioned in a complementary manner such that it fits into the die cavity (52).

Description

TECHNICAL AREA

[0001] The present disclosure relates generally to an application-assisted clinching process and a tool for carrying it out, as is generally known from DE 10 2009 036 185 A1, which describes a method for joining two layers of material and a reinforcement layer by means of clinching. Regarding the further state of the art, reference is made at this point to the publications DE 40 09 813 C1 and DE 199 29 377 B4. BACKGROUND

[0002] Materials can be joined using numerous different methods, including temperature-controlled clinching and friction stir spot welding. Temperature-controlled clinching techniques often result in thermal expansion of the materials, while friction stir spot welding frequently leads to the formation of a brittle phase when joining dissimilar materials (e.g., aluminum and magnesium). Other clinching methods may require precise alignment of the clinching tool with specific features of the material being clinched and / or may result in gapping or cracking at the end of the clinch joint.

[0003] The invention is based on the objective of providing at least one implementation for solving these problems. SUMMARY

[0004] This problem is solved by a method having the features of claim 1 or by a tool having the features of claim 5. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The features and advantages of this disclosure become apparent by reference to the following detailed description and the drawings, in which the same reference numerals correspond to similar, but not necessarily identical, components. Reference numerals or features with a previously described function may, but for the sake of brevity need not, be described in conjunction with other drawings in which they appear. Fig. Figure 1 is a semi-schematic cross-sectional view of an example of a clinching tool with a first and second layer attached therein, in which an insert is shown which is dimensioned in such a complementary way that it fits into the die cavity; Fig. Figure 2 is a semi-schematic cross-sectional view of an example illustrating an insert with a flange whose outer diameter is larger than a largest diameter of the die cavity, and with a cylinder with an open end dimensioned to be complementary enough to fit into the die cavity; Fig. Figure 3 is a semi-schematic cross-sectional view of an example in which an insert is shown with a flange whose outer diameter is larger than a largest diameter of the die cavity, and with a disk that is dimensioned complementarily such that it fits into the die cavity; Fig. Figure 4 is a semi-schematic cross-sectional view of an example of a clinching tool that applies pressure into a first layer, creating a depression in the first layer and the second layer. Fig. Figure 5 is a semi-schematic cross-sectional view of the example in Fig. 4, which shows how a section of the insert essentially fills the annular recess with extrudate, while at the same time a section of the second layer is extruded radially into the annular space previously occupied by the insert and at the same time a section of the first layer is extruded radially into an annular volume previously occupied by the second layer; Fig. Figure 6 is a semi-schematic, cross-sectional top or side view of an example of an insert; Fig. Figures 7A-7D are semi-schematic, cross-sectional side views showing examples of inserts dimensioned to fit into the die cavity; and Fig. Figures 8A - 8C are semi-schematic cross-sectional side views illustrating examples of inserts with a flange whose outer diameter is larger than a largest diameter of the die cavity, and with a section dimensioned to complement the die cavity. DETAILED DESCRIPTION

[0006] Examples of the method disclosed herein advantageously enable the formation of an overlap joint between material layers. The method allows, for example, overlapping material layers to be joined by clinching. The materials to be joined can be similar or different. In one example, an aluminum alloy sheet can be joined to a magnesium alloy sheet using a disclosed, exemplary clinching method.

[0007] Further examples in the present disclosure include a clinching process in which at least one section of an interchangeable, deformable insert is arranged in a clinching die cavity defined in a clinching die. It is assumed that by creating a radial constraint force on the sheets / layers during the clinching process, cracking of the materials to be joined can be prevented. The insert remains in the assembly as part of the completed clinch joint.

[0008] In Fig. In Figure 1, to which reference is now made, in one example of the disclosed clinching process, a first layer 20 may be formed from a first material 26, and a second layer 30 may be formed from a second material 36 that differs from the first material 26. In other examples, the layers 20 and 30 may be formed from the same or substantially the same material. It is understood that materials are substantially the same if they comprise the same base alloy material. The first material 26 may be selected from aluminum, aluminum alloys, and mild steel (mild steel grades are, for example, SAE 1008 and SAE 1010 in the annealed condition). The second material 36 may be selected from magnesium, magnesium alloys, and titanium alloys. In further examples, the first material 26 and the second material 36 may each be selected from the same material.

[0009] The method further comprises arranging at least one section of an interchangeable, deformable insert 40, 40' in a clinch die cavity 52 defined in a clinch die 50. It is understood that the insert 40, 40' can be made of aluminum, aluminum alloys, or mild steel. The clinch die cavity 52 has an annular recess 54 adjacent to the insert 40. The first layer 20 is positioned on the second layer 30, and the first and second layers 20, 30 are clamped between a retractable punch 60 and the clinch die 50. The punch 60 is pressed into the first layer 20, thereby creating a (in Fig. 4 illustrated) depression 22 is formed in the first layer 20 and the second layer 30.

[0010] The process further comprises pressing the first layer 20 and the second layer 30 together between the punch 60 and the clinch die 50, thereby generating hydrostatic pressure in the first layer 20, the second layer 30, and the insert 40. A section of the insert 40 is extruded, essentially filling the annular recess 54 with insert extrudate 42, while simultaneously a section of the second layer 30 is extruded radially into an annular space 44 previously occupied by the insert 40. Simultaneously with the concurrent extrusions of the insert 40 and the second layer 30, a section of the first layer 20 is extruded radially into an annular volume 34 previously occupied by the second layer 30. These concurrent extrusions (as, for example, in Fig. (4 shown) an interlocking composition 70 of the first layer 20, the second layer 30, and the insert 40 is formed. It is understood that the term "substantially (...) fills" as used here means that at least 50 percent and up to 100 percent of the volume is filled. The process may further include removing the punch 60 from the interlocking composition 70 and removing the interlocking composition 70 from the die cavity 52.

[0011] In Fig. Figure 1, to which reference is made again, shows an example of a clinching tool 10. The clinching tool 10 comprises a retractable punch 60 and a clinching die 50. The clinching die 50 includes a die cavity 52 defined within the clinching die 50. The die cavity 52 has an opening 56 and a counter-pressure surface 58 opposite the punch 60. The die cavity 52 further includes an annular recess 54 with an outer diameter 84, which is substantially equal to a largest diameter 83 of the die cavity 52. ​​It is understood that the term "substantially equal" used here means that the dimensions are exactly the same or that they differ from each other by less than approximately 5 percent of the larger diameter. The recess 54 surrounds the counter-pressure surface 58 and extends in the axial direction deeper than the counter-pressure surface 58 into the clinch die 50.A support surface 62 defines the opening 56 and is designed to receive the first layer 20, which overlaps the second layer 30. A replaceable, deformable insert 40 is designed such that at least one section of the insert 40 is arranged in the die cavity 52.

[0012] The clinching tool 10 can further comprise a stripper 90 with a defined opening 92, which is designed to clamp the first layer 20, which overlaps the second layer 30, against the support surface 62 while the punch 60 is advanced towards the die 50 and while the punch 60 is retracted. The die cavity 52 is designed to accommodate at least a section of the insert 40.

[0013] In Fig. Figure 1 shows an example of the interchangeable, deformable insert 40, which is shaped and dimensioned in such a way that it fits completely into the matrix cavity 52. ​​The interchangeable, deformable insert 40 is thus entirely contained within the volume defined by the matrix cavity 52 and by a plane that is in turn defined by the bearing surface 62. In contrast, in Fig. Figure 2 shows another example of the interchangeable, deformable insert 40', in which at least a section of the insert 40' is arranged in the die cavity 52, but the insert 40' is not dimensioned such that it fits completely into the die cavity 52. ​​It is understood that, according to the present disclosure, an interchangeable, deformable insert 40, in which at least a section of the insert 40 is arranged in the die cavity 52, may also have a projecting section (not shown) that protrudes from the die cavity 52 and extends beyond the plane defined by the bearing surface 62.

[0014] In Fig. 2 and Fig. 3 Other examples of the present revelation are shown, which correspond to the one in Fig. The illustrated example is similar, except that the 40' inserts shown have different shapes, as described below in relation to Fig. 8A - 8C described.

[0015] The in Fig. The clinching tool 10 shown in Figure 4 is designed such that the punch 60 is pressed into the first layer 20, forming a recess 22 in the first layer 20 and the second layer 30. The clinching tool 10 is further designed such that it compresses the first layer 20 and the second layer 30 between the punch 60 and the clinching die 50.

[0016] In Fig. As referenced in Figure 5, the compression of layers 20 and 30 in the clinching tool generates hydrostatic pressure in the first layer 20, the second layer 30, and the insert 40. This hydrostatic pressure causes a section 45 of the insert 40 to undergo extrusion, essentially filling the annular recess 54 with insert extrudate 42. Simultaneously, a section 32 of the second layer 30 is extruded into the annular space 44 previously occupied by the insert 40. At the same time, a section 24 of the first layer 20 is extruded radially into an annular volume 34 previously occupied by the second layer 30, forming an interlocking assembly 70 of the first layer 20, the second layer 30, and the insert 40.

[0017] As in Fig. As illustrated in Figures 6 and 7A-7D, examples of the insert 40 can have a ring shape 46 with an inner diameter 78 or a disc shape 47. In other examples, the insert 40 can have a hollow cylindrical shape 48 with an inner diameter 78, an open end 49, and a closed end 43 opposite the open end.

[0018] In Fig. 7C and Fig. Figure 7D shows similar inserts 40 in the different orientations in which they would be inserted into the matrix cavity 52. Fig. In 7C, the insert 40 is shown oriented such that the open end 49 is adjacent to the counter-pressure surface 58 and the closed end 43 is adjacent to the second layer 30. Fig. In 7D, the insert 40 is oriented such that the open end 49 is adjacent to the second layer 30 and the closed end 43 is adjacent to the counter-pressure surface 58. The insert 40 can be dimensioned and shaped in such a complementary manner that it (as in Fig. (shown in 1) fits entirely into the matrix cavity 52. ​​For example, an outer diameter of 80 of the in Fig. 6 and 7A - 7D illustrated insert 40 (as in Fig. (1 shown) smaller than a maximum diameter 83 of the matrix cavity 52.

[0019] As in Fig. As shown in Figure 8B, the insert 40' can be a disk 47' with a flange 41 extending radially outwards from an outer edge 81 of the disk 47'. The flange 41, 41', 41" can have an outer diameter 82 that is larger than a maximum diameter 83 of the die cavity 52. ​​As shown in Fig. As shown in Figure 8B, the flange 41 can be thinner in the axial direction than the disk 47'. The disk 47' can be dimensioned and shaped in such a complementary way that it (as shown in Figure 8B) Fig. 3 shown) fits into the matrix cavity 52.

[0020] As in Fig. As shown in Figure 8A, the insert 40' can be a cylinder 48' with an open end 49' and a closed end 43' opposite the open end 49', and with a flange 41' extending radially outward from an outer edge 81' of the closed end 43'. The flange 41' can have an axial thickness 85 that is substantially equal to the axial thickness 87 of the closed end 43' of the cylinder 48'. In this case, 'substantially equal' means that the difference between the axial thickness 85 and the axial thickness 87 is less than approximately 0.005 in (or 0.127 mm). The flange 41' can have an outer diameter 82 that is larger than a maximum diameter 83 of the die cavity 52, and the open end 49' of the cylinder 48' can be dimensioned and shaped in such a complementary manner that it (as in Fig. 2 illustrated) fits into the matrix cavity 52.

[0021] In yet another example (in Fig. (as shown in Figure 8C) the insert 40' can be a hollow cylinder 48" with an open end 49" and a closed end 43" opposite the open end 49". A flange 41" can extend radially outward from an outer edge 81" of the closed end 43". The flange 41" can have an axial thickness 85' which is substantially thinner than an axial thickness 87' of the closed end 43" of the cylinder 48". It is understood that the term "substantially thinner" as used here means that the axial thickness 85' is at least 0.127 mm (or 0.005 in) thinner than an axial thickness 87' of the closed end 43" of the cylinder 48". The flange 41" can have an outside diameter 82 which is larger than a maximum diameter 83 of the die cavity 52. The open end 49" of the cylinder 48" is dimensioned and shaped in such a complementary way that it (as in Fig.2 illustrated) fits into the matrix cavity 52.

Claims

[1] A method for clinching a first layer (20) and a second layer (30), comprising that at least a section of an interchangeable, deformable insert (40, 40') is arranged in a clinch die cavity (52) defined in a clinch die (50), wherein the clinch die cavity (52) has an annular recess (54) adjacent to the insert (40, 40'); the first layer (20) is set up on the second layer (30); the first layer (20) and the second layer (30) are fixed between a retractable punch (60) and the clinch die (50); the stamp (60) is pressed into the first layer (20), creating a depression (22) in the first layer (20) and the second layer (30); the first layer (20) and the second layer (30) are pressed together between the punch (60) and the clinch die (50), thereby generating hydrostatic pressure in the first layer (20), the second layer (30) and the insert (40, 40'); and a section of the insert (40, 40') is subjected to extrusion and thereby fills the annular recess (54) with insert extrudate (42), while at the same time a section of the second layer (30) is extruded radially into an annular space (44) previously occupied by the insert (40, 40') and at the same time a section of the first layer (20) is extruded radially into an annular volume (34) previously occupied by the second layer (30), thereby forming an interlocking composition of the first layer (20), the second layer (30) and the insert (40, 40'); where: (i) the insert (40) has a hollow cylindrical shape (48) with an open end (49) and a closed end (43) opposite the open end (49) and wherein the insert (40) is dimensioned in such a complementary manner that it fits completely into the matrix cavity (52); or (ii) the insert (40') is a disk with a flange (41'') extending radially outwards from an outer edge (81'') of the disk, the flange (41'') being thinner in the axial direction than the disk, the flange (41'') having an outer diameter (82) larger than a maximum diameter (83) of the die cavity (52), and the disk being dimensioned to be complementary to fit into the die cavity (52); or (iii) the insert (40') is a hollow cylinder (48') having an open end (49') and a closed end (43') opposite the open end (49') and having a flange (41') extending radially outwards from an outer edge (81') of the closed end (43'), the flange (41') having an axial thickness (85) equal to an axial thickness (87) of the closed end (43') of the cylinder, the flange (41') having an outer diameter (82) larger than a maximum diameter (83) of the die cavity (52), and the open end (49') of the cylinder being dimensioned to be complementary such that it fits into the die cavity (54); or (iv) the insert (40') is a hollow cylinder (48'') having an open end (49'') and a closed end (43'') opposite the open end (49'') and having a flange (41'') extending radially outwards from an outer edge (81'') of the closed end (43''), wherein the flange (41'') has an axial thickness (85') that is thinner than an axial thickness (87') of the closed end (43'') of the cylinder (48''), wherein the flange (41'') has an outer diameter (82) that is larger than a maximum diameter (83) of the die cavity (52), and wherein the open end (49'') of the cylinder (48'') is dimensioned in a complementary manner such that it fits into the die cavity (52). [2] The method of claim 1, which further comprises: the stamp (60) is removed from the interlocking assembly; and the interlocking composition is taken from the matrix cavity (52). [3] Method according to claim 1, wherein the insert (40, 40') is formed from aluminium or aluminium alloys. [4] Method according to claim 1, wherein the first layer (20) is formed from a first material and the second layer (30) is formed from a second material which differs from the first material, and wherein the first material is selected from aluminium and aluminium alloys and the second material is selected from magnesium and magnesium alloys. [5] Clinching tool (10), which includes: a retractable stamp (60); a clinch die (50), which includes: a die cavity (52) defined in the clinch die (50), wherein the die cavity (52) comprises: an opening (56), a counter-pressure surface (58) opposite the punch (60), an annular recess (54) with an outer diameter (84) equal to a maximum diameter (83) of the die cavity (52), wherein the recess (54) surrounds the counter-pressure surface (58) and extends axially deeper into the clinch die (50) than the counter-pressure surface (58); and a support surface (62) which limits the opening (56), wherein the support surface (62) is designed to accommodate a first layer (20) which overlaps a second layer (30); a replaceable, deformable insert (40, 40') which is designed such that at least one section of the insert (40, 40') is arranged in the die cavity (52); and a wiper (90) with an opening (92) defined therein, wherein the wiper (90) is designed to clamp the first layer (20), which overlaps the second layer (30), against the support surface (62) while the punch (60) is advanced towards the die (50) and while the punch (60) is withdrawn; wherein the die cavity (52) is designed to accommodate at least a section of the insert (40, 40'), and the clinching tool (10) is designed such that the punch (60) is pressed into the first layer (20), forming a depression in the first layer (20) and the second layer (30) to compress the first layer (20) and the second layer (30) between the punch (60) and the clinching die (50), thereby generating hydrostatic pressure in the first layer (20), the second layer (30), and the insert (40, 40'), wherein the hydrostatic pressure causes a section of the insert (40, 40') to be extruded, filling the annular recess (54) with insert extrudate (42), while simultaneously a section of the second layer (30) is extruded radially into a previously occupied recess by the insert.The first layer (20) is brought into an annular space (44) for extrusion, and at the same time a section of the first layer (20) is brought radially into an annular volume (34) previously occupied by the second layer for extrusion, in order to form an interlocking composition of the first layer (20), the second layer (30) and the insert (40, 40').

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