Method for disassembling a two-piece connection in a workpiece assembly

Abstract

A method for disassembling a two-piece connector in a workpiece assembly is shown and described, the method comprising the steps of: providing a workpiece assembly (4) having a first surface (6) and an opposing second surface (8) and a hole (10) connecting the first surface to the second surface, wherein a connector (2) is fastened in the hole, the connector having a bolt (14) extending along a central axis (16) and a sleeve (12) fastened to the bolt, wherein the bolt has a head section (36) and a pin section (38) with a retaining groove (42), wherein the sleeve is fastened to the bolt on the second surface side so that an inner surface (74) of the sleeve engages the retaining groove and prevents relative movement of the bolt and sleeve parallel to the central axis, and wherein the sleeve has an outer diameter that is greater than the diameter of the hole in the workpiece assembly; cutting off the sleeve and / or the bolt; and removing the connector from the hole.

Description

Technical Field

[0001] The invention relates to a method for disassembling a two-part connection in a workpiece assembly, in particular for disassembling a mating rivet, such as a screw-fit rivet (“Hi-Lok” or “Hi-Lite”) or a closed-ring bolt (“Lockbolt”). Background Art

[0002] In aircraft construction, various improved two-part connections, such as closed-loop bolts or screw-fit rivets, are increasingly being used in order to allow for increasing automation in the manufacturing process. This is primarily due to the fact that the connection can be placed on the workpiece components to be connected in an automated manner, for example by means of a robot. However, in the past, in order to remove such connections, which often had to be done, for example for maintenance reasons, it was necessary to drill out the connection, which was complex, time-consuming and often could not be done without damaging the workpieces. Summary of the invention

[0003] It is therefore an object of the present invention to provide a method for disassembling a two-part connection in a workpiece assembly which is simple, rapid and as nondestructive as possible.

[0004] This object is achieved by a method comprising the following steps:

[0005] First, a workpiece assembly is provided, in which a two-piece connection element is located. The workpiece assembly comprises one or more workpieces that are placed against each other and to be connected, preferably aircraft structural components, such as skin elements of a fuselage or wing. The workpiece assembly has a first surface and an opposite second surface and a hole (especially a drilled hole or a borehole) that connects the first surface to the second surface.

[0006] A connector is arranged in the hole, the connector having a bolt and a sleeve coaxially fastened to the bolt. Both the sleeve and the bolt preferably have a circular cross-section. The bolt is preferably formed of a stronger material than the sleeve. For example, the bolt can be made of titanium and the sleeve can be made of steel. The bolt extends along the central axis between a first end on the first surface side of the workpiece assembly and a second end on the second surface side.

[0007] Viewed along the center axis from the first end to the second end, the bolt first has a head section, the diameter of which is greater than the diameter of the hole. Then, the bolt has a pin section, the diameter of which is preferably constant and less than or equal to the diameter of the hole, viewed along the center axis. At least the part of the pin section protruding from the workpiece component on the second surface side, preferably the part having the second end, viewed along the center axis, has a retaining groove extending at least substantially in the circumferential direction. Such a retaining groove can, for example, be an annular groove extending in the circumferential direction and spaced apart from one another in the axial direction, as in the case of a closed ring bolt, or can be an external thread, as in the case of a screw-fit rivet.

[0008] The sleeve is fastened to the bolt on the second surface side so that the inner surface of the sleeve engages with the retaining groove and prevents relative movement of the bolt and the sleeve parallel to the center axis. In addition, the sleeve has an outer diameter that is at least partially larger than the diameter of the hole in the workpiece component so that the sleeve forms a counter-bearing portion on the second surface side or on the second end side.

[0009] In order to dismantle the connecting piece, now cut off the sleeve or bolt, or cut off both sleeve and bolt.Then, the connecting piece is removed from the hole, wherein for example can take off the sleeve that is cut off.

[0010] The connecting element can thereby be removed in a quick, simple and reliable manner without having to drill out the connecting element in a complicated and damaging manner to the workpiece assembly.

[0011] According to a preferred embodiment, the sleeve is cut with at least one cut parallel to the central axis. Thus, the sleeve breaks along the cut, so that the diameter increases, and the sleeve is disengaged from the retaining groove of the bolt.

[0012] Particularly preferably, the cut extends at least along the retaining groove. In this way, the inner surface of the sleeve is released from the engagement with the retaining groove.

[0013] In a preferred embodiment, the sleeve is cut off with a cutting tool having a blade with a straight cutting edge, which is moved relative to the sleeve in a radial direction towards the central axis with an orientation parallel to the central axis until the sleeve is cut off along the cutting edge, i.e. separated. In this way, the sleeve can be cut off by a single movement of the blade.

[0014] It is particularly preferred that the cutting tool also has a support body, which has: a contact surface for contacting the second surface of the workpiece component; a bore starting from the contact surface, which is adapted to the outer shape of the sleeve; and a guide groove extending radially outward from the bore. The blade is arranged in the guide groove so as to be guided in a movable manner, so that the cutting edge preferably extends parallel to the central axis of the bore and can be moved into the bore and preferably towards the central axis. This is a particularly simple and efficient way of constructing the cutting tool.

[0015] To cut through the sleeve, the cutting tool is arranged so that the abutment surface abuts against the second surface of the workpiece component and the connecting piece extending from the hole on the second surface extends into the drilled hole or through the drilled hole so that the central axis of the drilled hole extends coaxially with the central axis of the bolt. After this, the blade is moved in the guide groove in the direction of the central axis towards the sleeve until the cutting edge cuts through the sleeve, in particular in the area of ​​the retaining groove. In this way, the sleeve can be cut very simply and reliably.

[0016] It is also particularly preferred that one or more further cutting edges are provided on the inner wall of the drilled hole at a distance from the guide groove in the circumferential direction, preferably at a uniform distance, and that these cutting edges extend parallel to the central axis and that when the sleeve is located in the drilled hole, the sleeve bears against the cutting edges so that the sleeve can also be severed by the further cutting edges by the pressure exerted on the sleeve by the cutting edges of the blades. The sleeve is thereby severed from multiple sides and the engagement with the retaining groove can be released more simply and more quickly.

[0017] In a preferred embodiment, after cutting off the sleeve, the bolt is removed in the direction toward the first surface side. This is possible because by cutting off the sleeve, the inner surface of the sleeve no longer or no longer completely engages with the retaining groove of the bolt, so that the bolt can be loosened from the sleeve.

[0018] Preferably, the bolt is removed by striking the second end of the bolt, preferably in the axial direction. This is particularly meaningful when there is still a slight remaining engagement of the retaining groove. The bolt is then also knocked out of the sleeve.

[0019] According to an alternative embodiment of the method according to the invention, the bolt is severed with at least one cut transversely, in particular perpendicularly, to the central axis (i.e. in the circumferential direction). In this way, the bolt together with the separated part of the sleeve fastened thereto can no longer form a counter-bearing, and the remaining part of the bolt can be removed from the hole.

[0020] It is preferred here that the bolt is cut between the sleeve and the second surface in the extension of the second surface of the workpiece assembly. This is particularly easy because the cutting tool can be moved along the second surface and the sleeve is completely retained at the separated part of the bolt.

[0021] In addition preferably, when cutting off the bolt, multiple cutting is performed from the different sides of the sleeve, for example, twice cutting is performed from the opposite side of the sleeve. In this way, the bolt can be evenly and quickly cut off from multiple sides.

[0022] In a preferred embodiment, the bolt is cut off by a cutting tool having a blade having a cutting edge, which is moved relative to the bolt in a radial direction toward the central axis at a position perpendicular to the central axis until the bolt is cut off along the cutting edge, i.e., separated. In this way, the bolt can be cut off very easily.

[0023] In another preferred embodiment, the cutting tool has two blades, and these two blades have relative cutting edges, and these cutting edges move towards the bolt from opposite, especially reverse side, to cut off the bolt. Here, these two cutting edges preferably have the same radius of curvature, either straight, or concave bending.

[0024] It is particularly preferred that the cutting tool has a support body (preferably in the form of a frame) with a contact surface for contacting the second surface of the workpiece component and an opening extending perpendicularly along the central axis from the contact surface, into which the part of the connecting element protruding from the hole on the second surface, in particular the pin section with the retaining groove and the sleeve, can extend, and the opening is adapted to the outer shape of the sleeve and preferably also to the outer shape of the pin section of the bolt. The two blades with opposing cutting edges are arranged in the opening so as to be guided in a movable manner, so that the cutting edges preferably extend perpendicularly to the central axis and can be moved from opposite sides in a radial direction towards the central axis. This is a particularly simple and effective way of constructing the cutting tool.

[0025] It is also particularly preferred that, in order to cut the bolt, the cutting tool is arranged on the workpiece component so that the contact surface is in contact with the second surface and the connecting element extends into or through the opening so that the center axis extends coaxially with the central axis, after which the blade is preferably moved simultaneously from the opposite side along the second surface toward the bolt and cuts the bolt in the extension of the second surface. In this way, the bolt can be cut particularly easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Preferred embodiments of the present invention are explained in detail below with the aid of the accompanying drawings. The accompanying drawings show:

[0027] Figure 1shows a cross-sectional view parallel to the central axis of an exemplary connecting element in a workpiece assembly, which connecting element can be disassembled using the method according to the invention,

[0028] Figure 2a-2d shows four sequential cross-sectional views parallel to the center axis of an exemplary second connecting member when fastened in a workpiece assembly,

[0029] Figure 3a-3c shows parallel and perpendicular to the Figure 1 , during which the sleeve is severed with an incision parallel to the central axis according to a first embodiment of the method according to the invention,

[0030] Figure 4 shows parallel and perpendicular to the Figure 1 sectional view of the central axis of the connecting element shown in FIG. 1 during the removal of the bolt from the sleeve according to a first embodiment of the method according to the invention,

[0031] Figure 5a-Figure 5b shows parallel and perpendicular to the Figure 1 Two sequential sectional views of the central axis of the connecting element shown in FIG. 1 , during which the bolt is severed with an incision perpendicular to the central axis according to a second embodiment of the method according to the invention. DETAILED DESCRIPTION

[0032] exist Figure 1 , an exemplary embodiment of a two-part connecting part 2 is shown, in the present case a screw-fit rivet, which is arranged in a workpiece component 4 and from which the connecting part 2 can be removed in a particularly simple, rapid and as non-destructive as possible manner according to the embodiment of the method according to the invention described here.

[0033] The workpiece assembly 4 has a first surface 6 and an opposite second surface 8 and a hole 10 connecting the first surface 6 with the second surface 8. A connecting member 2 is fastened in the hole 10, the connecting member having a bolt 14 and a sleeve 12 arranged coaxially around the bolt. Both the sleeve 12 and the bolt 14 have a circular cross section. The bolt 14 is made of titanium, while the sleeve 12 is made of steel. The bolt 14 extends along a central axis 16 between a first end 18 on the first surface 6 side of the workpiece assembly 4 and a second end 20 on the second surface 8 side.

[0034] Viewed along the center axis 16 from the first end to the second end 18, 20, the bolt 14 first has a head section 36, the diameter of which is greater than the diameter of the hole 10. Next, the bolt 14 has a pin section 38, the diameter of which, viewed along the center axis 16, is constant and is smaller than or equal to the diameter of the hole 10. The portion of the pin section 38, viewed along the center axis 16, which protrudes from the workpiece component on the side of the second surface 8 and has the second end 18, has a retaining groove 42 extending at least substantially in the circumferential direction.

[0035] The sleeve 12 is fastened to the bolt 14 on the second surface 8 side so that the inner surface 74 of the sleeve engages with the retaining groove 42 and prevents relative movement of the bolt 14 and the sleeve 12 parallel to the center axis 16. In addition, the sleeve 12 has an outer diameter that is greater than the diameter of the hole 10 in the workpiece component 4, so that the sleeve forms a counter-bearing portion on the second surface 8 side. Figure 1 In an embodiment in which the connection is implemented as a screw-fit rivet, the bolt is designed as a threaded rod, the retaining groove is designed as an external thread, and the sleeve is designed as a nut with an internal thread 34 engaging with the external thread. In order to fasten the screw-fit rivet in the hole 10, the screw 14 is first introduced into the hole 10, and then the sleeve 12 is screwed onto the external thread of the bolt 14 at the second end 18. The sleeve 12 is then prevented from being screwed back out by the self-fixation of the nut, in particular in the form of a crimp, and a counter-bearing portion is thus formed on the second surface 8 side.

[0036] As an alternative to a screw-fit rivet, the connecting element 2 can also be designed as a closed-loop screw. Figure 2a-2d This embodiment of the connecting element 2 as a closed ring bolt and how to fasten the connecting element to the workpiece component 4 is shown. Thus, here, the sleeve 12 is designed as a closed ring, and the retaining grooves 42 are designed as annular grooves extending in the circumferential direction and spaced apart from each other in the axial direction. However, in other embodiments, the retaining grooves 42 can also be implemented as threads instead of annular grooves in the connecting element 2 implemented as a closed ring bolt. Figure 2a As shown in , the bolt 14 is first introduced into the hole 10, and the sleeve 12 is pushed from the second end 18 through the bolt 14 until the sleeve abuts against the second surface 8 and covers the retaining groove 42. Subsequently, the sleeve 12 is pressed into the retaining groove 42 by means of a corresponding tool 72, wherein the sleeve 12 is plastically deformed so that the inner surface 74 of the sleeve 12 engages in the retaining groove 42 and thereby fixes the sleeve 12 in the axial direction relative to the bolt 14, as shown in Figure 2b and Figure 2cFinally, the tool 72 is removed, wherein the projection 76 which supports the tool 72 and is no longer required is removed together with the tool 72 at the second end of the bolt 14, in particular removed, see Figure 2d .

[0037] In order to disassemble Figure 1 Taking the screw-fit rivet in FIG. 2 as an example, two embodiments of the method according to the present invention described below are proposed. In these embodiments, the sleeve 12 and / or the bolt 14 are first cut off with a cutting tool 46, so that the cutting edge 48 of the cutting tool 46 moves relative to the sleeve 12 or the bolt 14 in the radial direction toward the central axis 16.

[0038] According to Figure 3a-3c and Figure 4 In the first embodiment shown in FIG. 1 , the sleeve 12 is cut with at least one cut (three cuts in this embodiment) parallel to the central axis 16 and along the entire area of ​​the retaining groove. As a result, the sleeve 12 is broken along the cut, so that the diameter increases, and the internal thread 34 of the sleeve 12 is disengaged from the retaining groove 42 of the bolt 14 formed as an external thread.

[0039] According to the first embodiment of the method, the sleeve 12 is cut off at Figure 3a to Figure 3c 1 and 2, and is performed using a cutting tool 46, which has a blade 50 with a straight cutting edge 48, which is oriented parallel to the center axis 16 and moves relative to the sleeve 12 in a radial direction 52 toward the center axis 16 until the sleeve 12 is cut along the cutting edge 48. The cutting tool 46 also has a support body 54, which has: an abutment surface 56 for abutting against the second surface 8 of the workpiece component 4; and a bore 58 starting from the abutment surface 56, which is adapted to the outer shape of the sleeve 12; and a guide groove 60 extending radially outward from the bore 58. The blade 50 is arranged in the guide groove 60 so as to be guided in a movable manner, so that the cutting edge 48 extends parallel to the center axis 62 of the bore 58 and can be moved into the bore 58 toward the center axis 62.

[0040] Two additional cutting edges 66 are arranged on the inner wall 59 of the bore 58 at uniform intervals from the guide groove 60 in the circumferential direction, extending parallel to the central axis 62, and when the sleeve is located in the bore 58, the sleeve 12 is in contact with the cutting edges so that the sleeve 12 can also be cut off by the additional cutting edges 66 by the pressure applied to the sleeve 12 by the cutting edge 48 of the blade 50.

[0041] In order to cut through the sleeve 12, the cutting tool 46 is arranged so that the abutment surface 56 abuts against the second surface 8 of the workpiece component 4, and the connecting element 2 protruding from the hole 10 on the second surface 8 extends through the bore 58, so that the central axis 62 of the bore 58 extends coaxially with the central axis 16 of the bolt 14. After this, the blade 50 is moved in the guide groove 60 in the direction of the central axis 16 toward the sleeve 12 until the cutting edge 48 cuts through the sleeve 12, in particular the region of the sleeve 12 with the retaining groove 42, as shown. Figure 3a to Figure 3c At the same time, the sleeve 12 is also pressed against the two further cutting edges 66 and is severed by the two further cutting edges on the side opposite to the blade 50.

[0042] like Figure 4 As shown in FIG, after the sleeve 12 is cut off, the bolt 14 is removed by impacting the second end 20 of the bolt 14 in the direction toward the first surface 6 side. This is possible because by cutting off the sleeve 12, the internal thread 34 of the sleeve 12 is no longer or no longer completely engaged with the external thread of the bolt 14, that is, the retaining groove 42, so that the bolt 14 can be loosened from the sleeve 12.

[0043] According to a second embodiment of the method according to the invention for disassembling a connection element 2, Figure 5a-Figure 5b ), the bolt 14 is cut in the extension of the second surface 8 of the workpiece component 4, between the sleeve 12 and the second surface 8, with at least one cut perpendicular to the center axis 16. In this way, the separated part of the bolt 14 can be taken out of the hole 10 and removed.

[0044] As in Figure 5a and Figure 5b , the bolt 14 is cut off by a cutting tool 46 having two blades 50 with opposing cutting edges 48, which are moved from opposite sides in a radial direction toward the center axis 16 in an orientation perpendicular to the center axis 16 toward the bolt 14 in order to cut off the bolt 14 until the bolt 14 is cut off along the cutting edges 48. Here, the cutting edges 48 are moved between the second surface 8 and the sleeve 12. Here, the blades 50 have straight cutting edges 48.

[0045] The cutting tool 46 has a support body 54 in the form of a frame, which has an abutment surface 56 for abutting against the second surface 8 of the workpiece component 4, and an opening 70 extending perpendicularly along the central axis 62 from the abutment surface 56, into which a part of the connecting part 2 protruding from the hole 10 on the second surface 8, in particular the sleeve 12, can extend, and the opening is adapted to the outer shape of the sleeve 12 and the pin section 38 of the bolt 14. The two blades 50 with opposing cutting edges 48 are arranged in the opening 70 so as to be guided in a movable manner, so that the cutting edges 48 extend perpendicularly to the central axis 62 and can be moved from opposite sides in a radial direction toward the central axis 62.

[0046] In order to cut through the bolt 14, the cutting tool 46 is arranged on the workpiece component 4 so that the abutment surface 56 abuts the second surface 8 and the connecting part 2 extends through the opening 70 so that the center axis 16 extends coaxially with the central axis 62, and then the blade 50 is simultaneously moved from the opposite side along the second surface 8 toward the bolt 14 and cuts the bolt between the second surface 8 and the sleeve 12.

Claims

1. A method for disassembling a two-piece connector (2) in a workpiece assembly (4), the method comprising the following steps: - providing a workpiece assembly (4) having a first surface (6) and an opposite second surface (8) and a hole (10) connecting the first surface (6) with the second surface (8), A connecting piece (2) is arranged in the hole (10), wherein the connecting piece has a bolt (14) and a sleeve (12) fastened to the bolt (14). wherein the bolt (14) extends along a central axis (16) between a first end (18) on the first surface (6) side of the workpiece component (4) and a second end (20) on the second surface (8) side, The bolt (14) has a head section (36) whose diameter is greater than the diameter of the hole (10), and the bolt has a pin section (38) whose diameter is less than or equal to the inner diameter of the hole (10), wherein at least the portion of the pin section (38) protruding from the workpiece component (4) on the side of the second surface (8) has a retaining groove (42) extending at least substantially in the circumferential direction, as viewed along the center axis (16), wherein the sleeve (12) is fastened to the bolt (14) on the second surface (8) side so that the inner surface (74) of the sleeve engages with the retaining groove (42) and prevents the bolt (14) and the sleeve (12) from relative movement parallel to the central axis (16), and wherein the sleeve (12) has an outer diameter that is greater than the diameter of the hole (10) in the workpiece assembly (4), - cutting off the sleeve (12) and / or the bolt (14) by means of a cutting tool (46), wherein the cutting tool (46) has a support body (54), the support body (54) having an abutment surface (56) for abutting against the second surface (8) of the workpiece component (4), and a borehole (58) or an opening (70) extending perpendicularly along the central axis (62) from the abutment surface (56), the part of the connecting element (2) protruding from the hole (10) on the second surface (8) extending into the borehole (58) or the opening (70), and the borehole (58) or the opening (70) being adapted to the outer shape of the pin section (38) of the sleeve (12) and / or the bolt (14); and - Removing the connecting piece (2) from the hole (10).

2. The method according to claim 1, wherein the sleeve (12) is severed with an incision parallel to the central axis (16).

3. The method according to claim 2, wherein the cutout extends at least along the retaining groove (42).

4. A method according to claim 2 or 3, wherein the cutting tool (46) has a blade (50) having a straight cutting edge (48), which moves relative to the sleeve (12) in a radial direction toward the center axis (16) in an orientation parallel to the center axis (16).

5. A method according to claim 4, wherein the support body (54) has the bore hole (58) starting from the abutment surface, and the support body (54) has a guide groove (60) extending radially outward from the bore hole (58), wherein the blade (50) is arranged in the guide groove (60) so as to be guided in a movably manner so that the cutting edge (48) extends parallel to the central axis (62) of the bore hole (58) and is capable of moving into the bore hole (58) and toward the central axis (62).

6. A method according to claim 5, wherein the cutting tool (46) for cutting off the sleeve (12) is arranged so that the abutment surface (56) abuts against the second surface (8) of the workpiece component (4), and the connecting part (2) extending from the hole (10) on the second surface (8) extends into the drilled hole (58), and then the blade (50) moves in the guide groove (60) toward the sleeve (12) in the direction of the center axis (16) until the cutting edge (48) cuts off the sleeve (12).

7. A method according to claim 5, wherein one or more additional cutting edges (66) are arranged on the inner wall (59) of the bore hole (58) in the circumferential direction and are spaced apart from the guide groove (60), the additional cutting edges extending parallel to the central axis (62), and when the sleeve is located in the bore hole (58), the sleeve (12) abuts against the additional cutting edges.

8. The method according to claim 1, wherein after the sleeve (12) is severed, the bolt (14) is removed in the direction towards the first surface (6) side.

9. The method according to claim 8, wherein the bolt (14) is removed by impacting the second end (20) of the bolt (14).

10. The method according to claim 1, wherein the bolt (14) is severed with an incision transverse to the central axis (16).

11. The method according to claim 10, wherein the bolt (14) is severed between the sleeve (12) and the second surface (8) of the workpiece component (4) in the extension of the second surface (8).

12. A method according to claim 10 or 11, wherein the cutting tool (46) has a blade (50) having a cutting edge (48), which moves relative to the bolt (14) in a radial direction toward the center axis (16) with an orientation perpendicular to the center axis (16).

13. The method according to claim 12, wherein the cutting tool (46) has two blades (50) with opposing cutting edges (48) which are moved towards the bolt (14) from opposite sides in order to sever the bolt (14).

14. A method according to claim 13, wherein the support body (54) has the opening (70) starting from the abutment surface, and the opening has a central axis (62) perpendicular to the abutment surface (56), wherein the two blades (50) having relative cutting edges (48) are arranged in the opening (70) so as to be guided in a movably manner so that the cutting edges (48) extend perpendicular to the central axis (62) and can be moved from the opposite side in a radial direction toward the central axis (62).

15. The method according to claim 14, wherein a cutting tool (46) for cutting off the bolt (14) is arranged on the workpiece assembly (4) so ​​that the abutment surface (56) abuts against the second surface (8), and the connecting member (2) extends into the opening (70), so that the center axis (16) extends coaxially with the central axis (62), and then the blade (50) moves toward the bolt (14) from the opposite side and cuts off the bolt.

16. The method of any one of claims 1 to 3, wherein the two-part connection is a closed loop bolt or a screw-fit rivet.

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