EP3969200A1

EP3969200A1 - Method for removing a blind rivet in a workpiece arrangement

Info

Publication number: EP3969200A1
Application number: EP20727172.7A
Authority: EP
Inventors: Jörn Skirke; Alexander SCHÄFER
Original assignee: Airbus Operations GmbH
Current assignee: Airbus Operations GmbH
Priority date: 2019-05-15
Filing date: 2020-05-12
Publication date: 2022-03-23
Also published as: WO2020229488A1; DE102019112731A1; CN113853258A; US20220134413A1; US11801549B2

Abstract

The invention relates to a method for removing a blind rivet (2) in a workpiece arrangement (4), comprising the following steps: - providing a workpiece arrangement (4) having a first surface (6) and an opposite second surface (8) and having a hole (10), which connects the first surface (6) to the second surface (8), a blind rivet (2) being fixed in the hole (10), which blind rivet has a shell (12) and a screw (14) extending through the shell (12), the shell (12) and the screw (14) arranged therein extending coaxially along a common center axis (16), the shell (12) having a shell head portion (22), a straight portion (26), a deformation portion (30) and a threaded portion (32) having an internal thread (34), the straight portion (26) being located in the hole (10) and the deformation portion (30) and the threaded portion (32) protruding out of the hole (10) on the side of the second surface (8), the screw (14) having a screw head portion (36) and a pin portion (38) having an external thread (42), the screw (14) being arranged in the shell (12) such that the internal thread (34) of the shell (12) engages in the external thread (42) of the screw (14) and the deformation portion (30) of the shell (12) is deformed so that the outside diameter of the deformed deformation portion (30) is larger than the diameter of the hole (10), - cutting the shell (12) in the region of the thread portion (32) and/or the deformation portion (30), and - removing the blind rivet (2) from the hole (10).

Description

Method for dismantling a blind rivet in a workpiece arrangement

The present invention relates to a method for dismantling a blind rivet in a workpiece arrangement. Further aspects of the invention relate to cutting tools for dismantling a blind rivet in a workpiece arrangement, in particular according to such a method.

Blind rivets are increasingly used, especially in aircraft construction, to enable increasing automation in the production process. This is mainly due to the fact that with blind rivets it is possible to attach them from only one side of the workpiece arrangement to be connected. For the e.g. Dismantling of blind rivets, which is often necessary for maintenance reasons, has hitherto been necessary to drill out the rivet, which is complex, time-consuming and usually not possible without damaging the workpiece.

It is therefore the object of the present invention to provide a simple and quick and as damage-free method as possible for dismantling a blind rivet in a workpiece arrangement.

This task is solved with a method with the following steps:

First, a workpiece arrangement is provided in which a blind rivet is located. The workpiece arrangement comprises a single workpiece or several workpieces resting against one another and to be connected, preferably structural components for pleasure vehicles such as skin elements of the fuselage or wings. The workpiece arrangement has a first surface and an opposing second surface as well as a hole, in particular a borehole or a bore, which connects the first surface to the second surface.

A blind rivet is fastened in the hole, which has a sleeve and a screw extending through the sleeve, which is also referred to as a threaded pin. Both the sleeve and the screw preferably have a circular cross-section. The screw is preferably formed from a stronger material than the sleeve. For example, the screw can be made of titanium and the sleeve of steel. The screw will too referred to as the core or core bolt. The sleeve and the screw disposed therein extend coaxially along a common central axis between a first end on the side of the first surface and a second end on the side of the second surface of the workpiece arrangement.

The sleeve, viewed along the central axis from the first to the second end, initially has a sleeve head section with a diameter which is larger than the diameter of the hole in the workpiece arrangement and in this way forms a counter-support on the side of the first end or the first surface. Subsequently, the sleeve has a straight section, the diameter of which, viewed along the central axis, is preferably constant and the outer diameter of which is smaller than or equal to the diameter of the hole. Subsequently, the sleeve has a deformation section which is formed from a deformable material and in particular deforms more easily than the thread section, so that under axial load the deformation section is initially deformed before the thread section would deform. The sleeve then has a threaded section with an internal thread. The straight section is located in the hole and preferably rests with its outer surface on the wall of the hole, possibly with some play. The deformation section and the thread section protrude from the hole on the side of the second surface.

When viewed along the central axis from the first to the second end, the screw initially has a screw head section with a diameter which is greater than the diameter of the hole. Subsequently, the screw has a pin section, the diameter of which, viewed along the central axis, is preferably constant and is smaller than or equal to the inner diameter of the sleeve, in particular the straight section of the sleeve. Viewed along the central axis, at least a part of the pin section, preferably the part that has the second end, has an external thread.

The screw is arranged in the sleeve in such a way that the internal thread of the sleeve engages in the external thread of the screw and, by a rotational movement of the screw, the threaded section is or has been moved axially along the pin section towards the first end, the deformation section of the sleeve plastically deformed, in particular outward, is or has been unfolded away from the central axis, so that the outer diameter of the deformed deformation section is greater than the diameter the hole and the deformation section in this way form a counter bearing on the side of the second end or the second surface, which is preferably in contact with the second surface. As a result, the blind rivet can be fastened in the hole simply by turning the screw at the first end, in particular at the screw head section, ie from the side of the first surface, and can hold the workpiece arrangement together. The side of the second surface of the workpiece arrangement does not have to be accessible for this.

The sleeve is now cut to remove the blind rivet. In particular, the sleeve is in the area of the threaded section and / or the deformation section, i.e. on the side of the second surface of the workpiece arrangement, cut, preferably with a cutting tool which has a cutting edge which is moved in the radial direction towards the central axis against the sleeve. The blind rivet is then removed from the hole.

In this way, the blind rivet can be removed in a quick, simple and safe manner without the need for a complex and complete drilling out of the blind rivet which would damage the workpiece arrangement.

According to a preferred embodiment, the sleeve is cut with at least one cut parallel to the central axis. As a result, the sleeve bursts open along the cut, so that the diameter increases and the internal thread of the sleeve disengages from the external thread of the screw.

It is particularly preferred if the cut extends at least along the thread section, preferably along the entire thread section. In this way, the engagement of the external thread and internal thread can be released.

In a preferred embodiment, the cutting of the sleeve takes place with a cutting tool which has a blade with a straight cutting edge which is moved parallel to the central axis in a radial direction towards the central axis against the sleeve until the sleeve is cut along the cutting edge, i. is separated. In this way the sleeve can be cut with a single movement of the blade.

It is particularly preferred if the cutting tool has a support body with a contact surface for contact with the second surface of the workpiece arrangement and one of of the contact surface starting bore, which is adapted to the outer shape of the threaded section and preferably also of the deformation section, and with a guide slot extending radially outward from the bore. In the guide slot, the blade is movably guided in such a way that the cutting edge preferably runs parallel to the central axis of the bore and can be moved into the bore and preferably towards the central axis. This represents a particularly simple and effective design of the cutting tool.

To cut the sleeve, the cutting tool is arranged such that the contact surface rests against the second surface of the workpiece arrangement and the blind rivet protruding from the hole on the second surface extends into or through the bore so that the central axis of the bore is coaxial with the central axis the screw runs. The blade is then moved in the guide slot in the direction of the central axis towards the sleeve until the cutting edge cuts the sleeve, in particular the threaded section of the sleeve. In this way, the sleeve can be cut very easily and reliably.

It is also particularly preferred if on the inner wall of the bore in the circumferential direction spaced, preferably evenly spaced, one or more further cutting edges are provided from the guide slot, which extend parallel to the central axis and to which the threaded section rests when it is in the bore so that the pressure exerted on the sleeve by the cutting edge of the blade also cuts the sleeve from the other cutting edges. As a result, the sleeve is cut from several sides and the engagement of the thread can be released more easily and quickly.

In a preferred embodiment, after cutting the sleeve, the screw is removed towards the side of the first surface. This is possible because, as a result of the cutting of the sleeve, the internal thread of the sleeve is no longer or not completely in engagement with the external thread of the screw, so that the screw can be released from the sleeve.

The screw is preferably removed by striking the second end of the screw, preferably in the axial direction. This is particularly useful if there is still a slight residual engagement of the thread. In a preferred embodiment, after the screw has been removed, the sleeve head section is drilled out from the side of the first surface and then removed. The drilling is preferably carried out with a drill whose diameter corresponds to the outer diameter of the straight section of the sleeve. As a result, the undrilled outer, lateral part of the sleeve head section is separated from the straight section and can easily be removed, for example removed, toward the side of the first surface.

Preferably, after removing the sleeve head portion, the remaining parts of the sleeve, i. the straight section, the deformation section and the thread section, removed on the second surface side, for example removed. The entire blind rivet is now removed from the hole.

According to an alternative embodiment of the method according to the invention, the sleeve is made with at least one cut transversely, in particular perpendicular to the central axis, i. in the circumferential direction, cut up. In this way the severed part of the sleeve can be unscrewed from the external thread of the screw and removed.

It is particularly preferred if the sleeve is cut at the transition between the deformation section and the straight section. According to the invention, this transition between the deformation section and the straight section represents a part of the deformation section. In this way, the deformation section together with the threaded section can be released from the straight section and unscrewed from the external thread of the screw.

It is also preferred here if the sleeve is cut in an extension of the second surface. This is particularly easy since the cutting tool can be moved along the second surface.

It is also preferred if several cuts are made from different sides of the sleeve when the sleeve is cut, for example two cuts from opposite sides of the sleeve. In this way, the sleeve can be cut evenly and quickly from several sides. In a preferred embodiment, the sleeve is cut with a cutting tool that has a blade with a cutting edge that is moved perpendicular to the central axis in the radial direction towards the central axis against the sleeve until the sleeve is cut, ie separated, along the cutting edge. In this way, the sleeve can be cut very easily.

It is particularly preferred if the cutting edge is moved between the second surface and the deformation section for cutting the sleeve. In this way, the blade can be guided along the second surface and the sleeve can be cut between the deformation section and the straight section.

It is also particularly preferred if several cuts are made to cut the sleeve, the cutting tool being rotated about the central axis between the cuts so that the cuts are made at different angles, i. Cutting edge is moved towards the sleeve at a different angle for each cut. In this way, the sleeve can be cut completely from all sides.

Alternatively, it is preferred if, to cut the sleeve, the cutting edge is first moved in the radial direction towards the central axis against the sleeve and then the cutting tool is rotated around the central axis so that the cutting edge continuously cuts the sleeve in the circumferential direction. In this way, the sleeve can be cut completely from all sides without having to make several separate cuts.

In a preferred embodiment, the blade is concavely curved relative to the sleeve. In this way, a larger area of the sleeve can be cut with one cut.

It is particularly preferred if the cutting edge has a radius of curvature greater than or equal to the inner radius of the sleeve. This enables a particularly effective cut to be made.

In an alternative embodiment, however, the blade can also have a straight cutting edge. Preferably, the sleeve is then continuously in. By rotating the cutting tool relative to the sleeve about the central axis Cut in the circumferential direction. A straight cutting edge is a particularly simple and inexpensive construction.

In a further preferred embodiment, the cutting tool has two blades with opposite cutting edges, which are moved towards the sleeve from opposite, in particular opposite, sides in order to cut the sleeve. The two cutting edges preferably have the same radius of curvature.

It is particularly preferred if the cutting tool has a support body, preferably in the form of a frame, with a contact surface for contact with the second surface of the workpiece arrangement and an opening extending from the contact surface perpendicularly along a central axis into which the second surface protruding from the hole part of the blind rivet, in particular the threaded portion and the deformation portion of the sleeve, and which is adapted to the outer shape of the threaded portion of the sleeve and preferably also the pin portion of the screw. In the opening, the two blades with opposite cutting edges are arranged movably guided in such a way that the cutting edges preferably run perpendicular to the central axis and can be moved from opposite sides in the radial direction towards the central axis. This represents a particularly simple and effective design of a cutting tool.

It is also particularly preferred if the cutting tool for cutting the sleeve is arranged on the workpiece arrangement in such a way that the contact surface rests against the second surface and the blind rivet extends into or through the opening so that the central axis runs coaxially with the central axis, after which the blades are preferably moved simultaneously from opposite sides along the second surface towards the sleeve and cut it at the transition between the deformation section and the straight section. In this way, the sleeve can be cut particularly easily.

In a preferred embodiment, after the sleeve has been cut, the threaded section and the deformation section on the side of the second surface are unscrewed from the external thread of the screw and removed. With the deformation section, the counter bearing is therefore also on the side of the second surface removed so that the screw and the remaining parts of the sleeve can be removed on the opposite side of the first surface.

It is preferred here if, after removing the threaded section and the deformation section, the screw is removed towards the side of the first surface, in particular pulled out or pushed out. This is now easily possible.

It is further preferred if, after the screw is removed or at the same time as the screw is removed, the straight section of the sleeve and the sleeve head section are removed toward the side of the first surface. The blind rivet is now completely removed from the hole.

In an alternative embodiment, the cutting of the sleeve is carried out simultaneously, i. with one cut or in the same cutting process, the screw running in the sleeve is cut through, preferably in the extension of the second surface, after which the remaining part of the screw and the straight section of the sleeve and the sleeve head section are removed to the side of the first surface. This represents a particularly simple and fast embodiment, but requires that the cutting tool is able to cut the particularly strong screw, preferably made of titanium.

Another aspect of the present invention relates to a first cutting tool for dismantling a blind rivet in a workpiece arrangement. The cutting tool is preferably suitable and intended for dismantling a blind rivet in a workpiece arrangement according to an embodiment of the method described above. The workpiece arrangement and the blind rivet are designed as described above.

In particular, the workpiece arrangement has a first surface and an opposing second surface and a hole which connects the first surface to the second surface. The blind rivet, which has a sleeve and a screw extending through the sleeve, is fastened in the hole. The sleeve and the screw disposed therein extend coaxially along a common central axis between a first end on the side of the first surface and a second end on the side of the second surface of the workpiece arrangement. The sleeve has a sleeve head portion with a diameter that is larger than the diameter of the Hole in the workpiece arrangement. Subsequently, the sleeve has a straight section, the outer diameter of which is smaller than or equal to the diameter of the hole. This is followed by a deformation section and finally a threaded section with an internal thread. The straight section is located in the hole and the deformation section and the threaded section protrude from the hole on the side of the second surface. The screw has a screw head section with a diameter which is larger than the diameter of the hole, and then a pin section, the diameter of which is smaller than or equal to the inner diameter of the sleeve. Viewed along the central axis, at least a part of the pin section has an external thread. The screw is arranged in the sleeve in such a way that the internal thread of the sleeve engages in the external thread of the screw and the deformation section of the sleeve is deformed so that the external diameter of the deformed deformation section is greater than the diameter of the hole.

The cutting tool has a support body with a contact surface for contact with the second surface of the workpiece arrangement and a bore extending from the contact surface, which is preferably adapted to the outer shape of the threaded section and preferably also the deformation section, and with a bore extending radially outward from the bore Has guide slot. In the guide slot, a blade with a straight cutting edge is movably guided in such a way that the cutting edge preferably runs parallel to the central axis of the bore and can be moved into the bore and preferably towards the central axis. The features and advantages explained above in connection with the method also apply to the present cutting tool.

According to a preferred embodiment, one or more further cutting edges are provided on the inner wall of the bore in the circumferential direction, evenly spaced from the guide slot, which extend parallel to the central axis and to which the threaded section rests when it is in the bore. In this way, through the pressure exerted on the sleeve by the cutting edge of the blade, the sleeve can also be cut by the further cutting edges from another, preferably opposite, side.

Another aspect of the present invention relates to a second cutting tool for dismantling a blind rivet in a workpiece arrangement. Preferably that is Cutting tool suitable and intended for dismantling a blind rivet in a workpiece arrangement according to an embodiment of the method described above. The workpiece arrangement and the blind rivet are designed as described above.

In particular, the workpiece arrangement has a first surface and an opposing second surface and a hole which connects the first surface to the second surface. The blind rivet, which has a sleeve and a screw extending through the sleeve, is fastened in the hole. The sleeve and the screw disposed therein extend coaxially along a common central axis between a first end on the side of the first surface and a second end on the side of the second surface of the workpiece arrangement. The sleeve has a sleeve head portion with a diameter that is larger than the diameter of the hole in the workpiece assembly. Subsequently, the sleeve has a straight section, the outer diameter of which is smaller than or equal to the diameter of the hole. This is followed by a deformation section and finally a threaded section with an internal thread. The straight section is located in the hole and the deformation section and the threaded section protrude from the hole on the side of the second surface. The screw has a screw head section with a diameter which is larger than the diameter of the hole, and then a pin section, the diameter of which is smaller than or equal to the inner diameter of the sleeve. Viewed along the central axis, at least a part of the pin section has an external thread. The screw is arranged in the sleeve in such a way that the internal thread of the sleeve engages in the external thread of the screw and the deformation section of the sleeve is deformed so that the external diameter of the deformed deformation section is greater than the diameter of the hole.

The cutting tool has a support body, preferably in the form of a frame, with a contact surface for contact with the second surface of the workpiece arrangement and with an opening extending from the contact surface with a central axis perpendicular to the contact surface into which the hole on the second surface extends protruding part of the blind rivet, in particular the threaded portion and the deformation portion of the sleeve, and which is preferably adapted to the outer shape of the threaded portion of the sleeve and preferably also the pin portion of the screw. Two blades with opposing cutting edges are guided in this way and movable in the opening arranged that the cutting edges preferably run perpendicular to the central axis and can be moved from opposite sides in the radial direction towards the central axis. The features and advantages explained above in connection with the method also apply to the present cutting tool.

Preferred embodiments of the present invention are explained in more detail below with reference to a drawing. The drawing shows in

1 shows a cross-sectional view parallel to the central axis of an exemplary

Blind rivets in a workpiece arrangement that can be dismantled using a method according to the invention,

Fig. 2 three step-by-step cross-sectional views parallel and perpendicular to

Central axis of the blind rivet shown in Fig. 1, while the sleeve is cut according to a first embodiment of the method according to the invention with a cut parallel to the central axis,

3 shows a cross-sectional view parallel and perpendicular to the central axis of the blind rivet shown in FIG. 1, while the screw is removed from the sleeve according to the first embodiment of the method according to the invention,

FIG. 4 is a cross-sectional view parallel to the central axis of that shown in FIG

Blind rivet, while the sleeve head portion according to the first

Embodiment of the method according to the invention is drilled out,

FIG. 5 is a cross-sectional view parallel to the central axis of that shown in FIG

Blind rivets, while remnants of the drilled-out sleeve head section are removed according to the first embodiment of the method according to the invention,

6 is a cross-sectional view parallel to the central axis of that shown in FIG

Blind rivets, while the remaining parts of the sleeve are removed according to the first embodiment of the method according to the invention,

7 shows four stepwise cross-sectional views parallel and perpendicular to

Central axis of the blind rivet shown in Fig. L, while the sleeve according to a second embodiment of the method according to the invention is cut with a cut perpendicular to the central axis,

FIG. 8 is a cross-sectional view parallel to the central axis of that shown in FIG. 1

Blind rivet, while the threaded section and the deformation section of the sleeve are unscrewed from the screw according to the second embodiment of the method according to the invention,

FIG. 9 is a cross-sectional view parallel to the central axis of that shown in FIG. 1

Blind rivet while the screw is removed according to the second embodiment of the method according to the invention,

FIG. 10 is a cross-sectional view parallel to the central axis of that shown in FIG

Blind rivets, while the remaining parts of the sleeve are removed according to the second embodiment of the method according to the invention,

Figs. 11-13 cross-sectional views perpendicular to the central axis of various

Embodiments of a cutting tool for use in the method according to the invention according to the second embodiment, and

FIG. 14 is a cross-sectional view parallel to the central axis of that shown in FIG. 1

Blind rivet, which is removed according to a third embodiment of the method according to the invention.

In Fig. 1, an embodiment of a blind rivet 2 is shown, which is attached in a workpiece arrangement 4, from which the blind rivet 2 can be removed in a particularly simple, faster and largely damage-free manner according to the embodiments of the method according to the invention described below.

The workpiece arrangement 4 has a first surface 6 and an opposite second surface 8 as well as a hole 10 which connects the first surface 6 to the second surface 8. The blind rivet 2, which has a sleeve 12 and a screw 14 extending through the sleeve 12, is fastened in the hole 10. Both the sleeve 12 and the screw 14 have a circular cross section. The screw 14 is made of titanium and the sleeve 12 is made of steel. The sleeve 12 and the screw 14 arranged therein extend coaxially along a common central axis 16 between a first one End 18 on the side of the first surface 6 and a second end 20 on the side of the second surface 8 of the workpiece arrangement 4.

The sleeve 12, viewed along the central axis 16 from the first to the second end 18, 20, initially has a sleeve head section 22 with a diameter which is greater than the diameter of the hole 10 in the workpiece arrangement 4 and in this way a counter-support on the side of the first End 18 or the first surface 6 forms. Subsequently, the sleeve 12 has a straight section 26, the diameter of which is constant when viewed along the central axis 16 and the outer diameter of which is smaller than or equal to the diameter of the hole 10. Subsequently, the sleeve 12 has a deformation section 30, which is formed from a deformable material and, in particular, deforms more easily than the threaded section 32, so that the deformation section 30 is initially deformed under axial load before the threaded section 32 would deform. The sleeve 12 then has a threaded section 32 with an internal thread 34. The straight section 26 is located in the hole 10 and rests with its outer surface on the hole wall. The deformation section 30 and the threaded section 32 protrude from the hole 10 on the side of the second surface 8.

The screw 14, viewed along the central axis 16 from the first to the second end 18, 20, initially has a screw head section 36 with a diameter that is greater than the diameter of the hole. Subsequently, the screw 14 has a pin section 38, the diameter of which is constant when viewed along the central axis 16 and is less than or equal to the inner diameter of the sleeve 12, in particular the straight section 26 of the sleeve 12. Viewed along the central axis 16, the part of the part of the pin section 38 which has the second end 18 has an external thread 42.

The screw 14 is arranged in the sleeve 12 in such a way that the internal thread 34 of the sleeve 12 engages in the external thread 42 of the screw 14 and the threaded section 32 is moved axially along the pin section 38 in the direction of the first end 18 by a rotational movement of the screw 14 can, wherein the deformation section 30 of the sleeve 12 is plastically deformed, in particular outward, is unfolded away from the central axis 16, so that the outer diameter of the deformed deformation section 30 is greater than the diameter of the hole 10 and the deformation section 30 in this way a counter bearing on the side of the second end 20 or the second surface 8, the on the second surface 8 rests. As a result, the blind rivet 2 is fastened in the hole 10 by turning the screw 14 on the screw head section 36, so that the workpiece arrangement 4 is held together.

To dismantle the blind rivet 2, the three embodiments of the method according to the invention described below are proposed. In all these embodiments, the sleeve 12 is first in the area of the threaded section 32 and / or the deformation section 30, i. on the side of the second surface 8 of the workpiece arrangement 4, cut with a cutting tool 46 in such a way that a cutting edge 48 of the cutting tool 46 is moved in the radial direction towards the central axis 16 against the sleeve 12.

According to the first embodiment shown in FIGS. 2 to 6, the sleeve 12 is cut with at least one cut, in the present embodiment with three cuts parallel to the central axis 16 and along the entire threaded section 32. As a result, the sleeve 12 bursts open along the cuts, so that the diameter increases and the internal thread 34 of the sleeve 12 disengages from the external thread 42 of the screw 14.

The cutting of the sleeve 12 according to the first embodiment of the method is shown in FIGS. 2a-2c shown step by step and takes place with a cutting tool 46, which has a blade 50 with a straight cutting edge 48, which is aligned parallel to the central axis 16 in the radial direction 52 to the central axis 16 against the sleeve 12 until the sleeve 12 is moved along the Cutting edge 48 is cut. The cutting tool 46 also has a support body 54 with a contact surface 56 for contact with the second surface 8 of the workpiece arrangement 4 and a bore 58 extending from the contact surface 56, which is adapted to the outer shape of the threaded section 32 and the deformation section 30, and with a from the bore 58 radially outwardly extending guide slot 60. In the guide slot 60, the blade 50 is movably guided in such a way that the cutting edge 48 runs parallel to the central axis 62 of the bore 58 and can be moved into the bore 58 towards the central axis 62.

On the inner wall 59 of the bore 58, two further cutting edges 66 are provided at a uniform distance from the guide slot 60 in the circumferential direction, which extend parallel to the central axis 62 and to which the threaded section 32 rests when it is in the bore 58 is located, so that the pressure exerted on the sleeve 12 by the cutting edge 48 of the blade 50 can also cut the sleeve 12 by the further cutting edges 66.

To cut the sleeve 12, the cutting tool 46 is arranged in such a way that the contact surface 56 rests on the second surface 8 of the workpiece arrangement 4 and the blind rivet 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 runs coaxially with the central axis 16 of the screw 14. The blade 50 is then moved in the guide slot 60 in the direction of the central axis 16 towards the sleeve 12 until the cutting edge 48 cuts the sleeve 12, in particular the threaded section 32 of the sleeve 12, as shown in FIGS. 2a-2c can be seen. At the same time, the sleeve 12 is also pressed against the two further cutting edges 66 and cut by these on the sides opposite the blade 50.

As shown in FIG. 3, after the sleeve 12 has been cut, the screw 14 is removed in the direction towards the side of the first surface 6 by striking the second end 20 of the screw 14. This is possible because the cutting of the sleeve 12 means that the internal thread 34 of the sleeve 12 is no longer or no longer fully engaged with the external thread 42 of the screw 14, so that the screw 14 can be released from the sleeve 12.

After the screw 14 has been removed, the sleeve head section 22 is drilled out from the side of the first surface 6, as shown in FIG. 4. The drilling is carried out with a drill 68, the diameter of which corresponds to the outer diameter of the straight section 26 of the sleeve 12. As a result, the undrilled outer, lateral part of the sleeve head section 22 is separated from the straight section 26 and can easily be removed towards the side of the first surface 6, as is shown in FIG. 5.

As shown in Figure 6, after the sleeve head portion 22 is removed, the remaining parts of the sleeve 12, i. the straight section 26, the deformation section 30 and the threaded section 32, taken on the second surface 8 side. The entire blind rivet 2 has thus been removed from the hole 10.

According to the second embodiment of the method according to the invention for dismantling the blind rivet 2, which is shown in FIGS. 7 to 13 is shown, the sleeve 12 with at least a section perpendicular to the central axis 16 at the transition between the deformation section 30 and the straight section 26 and as an extension of the second surface 8. In this way, the separated part of the sleeve 12, ie the deformation section 30 and the threaded section 32, can be unscrewed from the external thread 42 of the screw 14 and removed.

As in FIGS. 7a-7d, the cutting of the sleeve 12 takes place with a cutting tool 46, which has two blades 50 with opposing cutting edges 48, which for cutting the sleeve 12 from opposite sides perpendicular to the central axis 16 aligned in the radial direction towards the central axis 16 towards the sleeve 12 to be moved until the sleeve 12 is cut along the cutting edges 48. The cutting edges 48 are moved between the second surface 8 and the deformation section 30. The blades 50 are concavely curved relative to the sleeve 12, the cutting edges 48 having the same radius of curvature which is greater than the inner radius of the sleeve 12.

The cutting tool 46 has a support body 54 in the form of a frame with a contact surface 56 for contact with the second surface 8 of the workpiece arrangement 4 and an opening 70 extending from the contact surface 56 perpendicularly along a central axis 62 into which the opening 70 on the second Surface 8 protruding from the hole 10 part of the blind rivet 2, in particular the threaded portion 32 and the deformation portion 30 of the sleeve 12, and which is adapted to the outer shape of the threaded portion 32 of the sleeve 12 and the pin portion 38 of the screw 14. In the opening 70, the two blades 50 with opposite cutting edges 48 are movably guided in such a way that the cutting edges 48 run perpendicular to the central axis 62 and can be moved from opposite sides in the radial direction towards the central axis 62.

To cut the sleeve 12, the cutting tool 46 is arranged on the workpiece arrangement 72 in such a way that the contact surface 56 rests against the second surface 8 and the blind rivet 2 extends through the opening 70, so that the central axis 16 runs coaxially with the central axis 62, after which the blades 50 are moved simultaneously from opposite sides along the second surface 8 towards the sleeve 12 and cut it at the transition between the deformation section 30 and the straight section 26. Depending on the radius of curvature of the cutting edges 48, several cuts must be made to completely cut the sleeve 12, the cutting tool 46 being rotated about the central axis 16 between the cuts, for example by 90 °, so that the cuts are made at different angles. The larger the radius of curvature, the more cuts are required. Figs. 11 and 12 show embodiments of the cutting tool 46 with further, also possible radii of curvature and FIG. 13 shows an embodiment with straight cutting edges 48. In the case of straight cutting edges 48, the sleeve 12 can then by rotating the cutting tool 46 relative to the sleeve 12 around the Central axis 16 are cut continuously in the circumferential direction.

As shown in FIG. 8, after the sleeve 12 has been cut, the threaded section 32 and the deformation section 30 on the side of the second surface 8 are unscrewed from the external thread 42 of the screw 14 and removed. With the deformation section 30, the counter bearing on the side of the second surface 8 is thus also removed, so that the screw 14 and the remaining parts of the sleeve 12 on the opposite side of the first surface 6 can be removed.

9 shows how, after the threaded section 32 and the deformation section 30 have been removed, the screw 14 is removed toward the side of the first surface 6.

After the screw 14 is removed or at the same time as the screw 14 is removed, the straight portion of the sleeve 12 and the sleeve head portion 22 are removed toward the first surface 6 side, as shown in FIG. 10. The blind rivet 2 is thus completely removed from the hole 10.

According to the third embodiment of the method according to the invention for dismantling the blind rivet 2, which is shown in FIG. 14, the sleeve 12 is similar to the second embodiment with at least one cut perpendicular to the central axis 16 at the transition between the deformation section 30 and the straight section 26 and cut as an extension of the second surface 8. According to the third embodiment, however, when the sleeve 12 is cut, the screw 14 running in the sleeve 12 is cut through at the same time. Then the remaining part of the screw 14 and the straight Section of the sleeve 12 and the sleeve head section 22 either simultaneously or one behind the other to the side of the first surface 6 removed.

Claims

1. Method for dismantling a blind rivet (2) in a workpiece arrangement (4) with the following steps:

Providing a workpiece arrangement (4) with a first surface (6) and an opposing second surface (8) and with a hole (10) which connects the first surface (6) to the second surface (8), wherein in the hole ( 10) a blind rivet (2) is attached, which has a sleeve (12) and a screw (14) extending through the sleeve (12), the sleeve (12) and the screw (14) arranged therein extending coaxially along a common central axis (16) extend between a first end (18) on the side of the first surface (6) and a second end (20) on the side of the second surface (8) of the workpiece arrangement (4),

wherein the sleeve (12) has a sleeve head section (22) with a diameter which is larger than the diameter of the hole (10) in the workpiece arrangement (4), a straight section (26), the outside diameter of which is smaller than or equal to the diameter of the Hole (10), a deformation section (30) and a threaded section (32) with an internal thread (34), wherein the straight section (26) is located in the hole (10) and the deformation section (30) and the threaded section ( 32) protrude from the hole (10) on the side of the second surface (8),

wherein the screw (14) has a screw head portion (36) with a diameter which is larger than the diameter of the hole (10) and a pin portion (38) whose diameter is smaller than or equal to the inner diameter of the sleeve (12), wherein, viewed along the central axis (16), at least part of the pin section (38) has an external thread (42),

wherein the screw (14) is arranged in the sleeve (12) in such a way that the internal thread (34) of the sleeve (12) engages in the external thread (42) of the screw (14) and the deformation section (30) of the sleeve (12) is deformed so that the outer diameter of the deformed deformation portion (30) is greater than the diameter of the hole (10),

Cutting the sleeve (12) in the area of the threaded section (32) and / or the deformation section (30), and

Remove the blind rivet (2) from the hole (10).

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

3. The method of claim 2, wherein the cut extends at least along the threaded portion (32).

4. The method according to claim 2 or 3, wherein the cutting of the sleeve (12) takes place with a cutting tool (46), the cutting tool (46) having a blade (50) with a straight cutting edge (48) which is parallel to the central axis ( 16) aligned in the radial direction to the central axis (16) is moved against the sleeve (12).

5. The method according to claim 4, wherein the cutting tool (46) has a support body (54) with a contact surface (56) and a bore (58) extending from the contact surface (56) and with one extending radially outward from the bore (58) Has guide slot (60), the blade (50) being guided movably in the guide slot (60) in such a way that the cutting edge (48) runs parallel to the central axis (62) of the bore (58) and into the bore (58) and can be moved towards the central axis (62).

6. The method according to claim 5, wherein the cutting tool (46) for cutting the sleeve (12) is arranged in such a way that the contact surface (56) rests on the second surface (8) of the workpiece arrangement (4) and that on the second surface ( 8) from the hole (10) protruding blind rivet (2) extends into the bore (58), after which the blade (50) is moved in the guide slot (60) in the direction of the central axis (16) towards the sleeve (12) until the cutting edge (48) cuts the sleeve (12).

7. The method according to claim 5 or 6, wherein on the inner wall (59) of the bore (58) in the circumferential direction spaced from the guide slot (60) one or more further cutting edges (66) are provided which extend parallel to the central axis (62) and against which the threaded portion (32) rests when it is in the bore (58).

8. The method according to any one of claims 1 to 7, wherein after cutting the sleeve (12), the screw (14) is removed in the direction of the side of the first surface (6).

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

10. The method according to claim 8 or 9, wherein after removing the screw (14), the sleeve head portion (22) is drilled out from the side of the first surface (6) and then removed.

11. The method according to claim 10, wherein after removing the sleeve head portion (22) the remaining parts of the sleeve (12) on the side of the second surface (8) are removed.

12. The method according to claim 1, wherein the sleeve (12) is cut with a cut transverse to the central axis (16).

13. The method according to claim 12, wherein the sleeve (12) is cut at the transition between the deformation section (30) and the straight section (26).

14. The method according to claim 12 or 13, wherein the sleeve (12) is cut in an extension of the second surface (8).

15. The method according to any one of claims 12 to 14, wherein when cutting the sleeve (12), several cuts are made from different sides of the sleeve (12).

16. The method according to any one of claims 12 to 15, wherein the cutting of the sleeve (12) is carried out with a cutting tool (46), the cutting tool (46) a Has a blade (50) with a cutting edge (48) which is aligned perpendicular to the central axis (16) and is moved in the radial direction to the central axis (16) towards the sleeve (12).

17. The method according to claim 16, wherein the cutting edge (48) is moved between the second surface (8) and the deformation section (30) for cutting the sleeve (12).

18. The method according to claim 16 or 17, wherein several cuts are carried out for cutting the sleeve (12), the cutting tool (46) being rotated between the cuts relative to the sleeve (12) about the central axis (16), so that the Cuts are made at different angles.

19. The method of claim 16 or 17, wherein for cutting the sleeve (12) the cutting edge (48) is first moved in the radial direction towards the central axis (16) against the sleeve (12) and then the cutting tool (46) around the Center axis (16) is rotated so that the cutting edge (48) cuts the sleeve (12) continuously in the circumferential direction.

20. The method according to any one of claims 16 to 19, wherein the blade (50) is curved concavely relative to the sleeve (12).

21. The method according to claim 20, wherein the cutting edge (48) has a radius of curvature greater than or equal to the inner radius of the sleeve (12).

22. The method according to any one of claims 16 to 21, wherein the cutting tool (46) has two blades (50) with opposite cutting edges (48) which are moved towards the sleeve (12) from opposite sides for cutting the sleeve (12) .

23. The method according to claim 22, wherein the cutting tool (46) has a support body (54) with a contact surface (56) and an opening (70) extending from the contact surface (56) with a central axis (62) perpendicular to the contact surface (56) , wherein in the opening (70) the two blades (50) with opposite cutting edges (48) are arranged movably guided in such a way that the Cutting edges (48) run perpendicular to the central axis (62) and can be moved from opposite sides in the radial direction towards the central axis (62).

24. The method according to claim 23, wherein the cutting tool (46) for cutting the sleeve (12) is arranged on the workpiece arrangement (72) in such a way that the contact surface (56) rests against the second surface (8) and the blind rivet (2) extends into the opening (70) so that the central axis (16) is coaxial with the central axis (62), after which the blades (50) are moved from opposite sides towards the sleeve (12) and cut it.

25. The method according to any one of claims 12 to 24, wherein after the cutting of the sleeve (12) of the threaded portion (32) and the deformation portion (30) on the side of the second surface (8) of the external thread (42) of the screw (14 ) unscrewed and removed.

26. The method according to claim 25, wherein after removing the threaded portion (32) and deformation portion (30), the screw (14) is removed to the side of the first surface (6).

27. The method according to claim 26, wherein after the removal of the screw (14) or simultaneously with the removal of the screw (14) the straight section (26) of the sleeve (12) and the sleeve head section (22) to the side of the first surface (6 ) must be removed.

28. The method according to any one of claims 12 to 24, wherein with the cutting of the sleeve (12) at the same time the screw (14) running in the sleeve (12) is cut, after which the remaining part of the screw (14) and the straight section of the Sleeve (12) and the sleeve head portion (22) to the side of the first surface (6) is removed.

29. Cutting tool (46) for dismantling a blind rivet (2) in a workpiece arrangement (4) according to the method according to one of claims 1 to 11, wherein the workpiece arrangement (4) has a first surface (6) and an opposite second surface (8) as well as a hole (10) which connects the first surface (6) to the second surface (8),

a blind rivet (2) having a sleeve (12) and a screw (14) extending through the sleeve (12) is fastened in the hole (10),

wherein the sleeve (12) and the screw (14) arranged therein extend coaxially along a common central axis (16) between a first end (18) on the side of the first surface (6) and a second end (20) on the side of the second surface (8) of the workpiece arrangement (4) extend,

wherein the sleeve (12) has a sleeve head section (22) with a diameter which is larger than the diameter of the hole (10) in the workpiece arrangement (4), adjoining this has a straight section (26) whose outside diameter is smaller than or equal to Diameter of the hole (10), a deformation section (30) and finally a threaded section (32) with an internal thread (34), the straight section (26) being in the hole (10) and the deformation section (30) as well the threaded section (32) protrudes from the hole (10) on the side of the second surface (8),

wherein the screw (14) is arranged in the sleeve (12) in such a way that the internal thread (34) of the sleeve (12) engages in the external thread (42) of the screw (14) and the deformation section (30) of the sleeve (12) is deformed so that the outer diameter of the deformed deformation section (30) is greater than the diameter of the hole (10),

wherein the cutting tool (46) has a support body (54) with a contact surface (56) and a bore (58) extending from the contact surface (56) and with a guide slot (60) extending radially outward from the bore (58), wherein in the guide slot (60) a blade (50) with a straight cutting edge (48) is movably guided such that the cutting edge (48) runs parallel to the central axis (62) of the bore (58) and into the bore (58) and can be moved towards the central axis (62).

30. Cutting tool according to claim 29, wherein one or more further cutting edges (66) are provided on the inner wall (59) of the bore (58) spaced in the circumferential direction from the guide slot (60), which extend parallel to the central axis (62) and are attached which the threaded section (32) rests when it is in the bore (58).

31. Cutting tool (46) for dismantling a blind rivet (2) in a workpiece arrangement (4) according to the method according to one of claims 1 and 12 to 28,

wherein the workpiece arrangement (4) has a first surface (6) and an opposite second surface (8) as well as a hole (10) which connects the first surface (6) to the second surface (8),

wherein the sleeve (12) has a sleeve head section (22) with a diameter which is larger than the diameter of the hole (10) in the workpiece arrangement (4), adjoining this has a straight section (26) whose outside diameter is smaller than or equal to Diameter of the hole (10), a deformation section (30) and finally a threaded section (32) with an internal thread (34), the straight section (26) being in the hole (10) and the deformation section (30) as well the threaded section (32) of the side of the second surface (8) protrudes from the hole (10),

wherein the screw (14) is arranged in the sleeve (12) in such a way that the internal thread (34) of the sleeve (12) engages in the external thread (42) of the screw (14) and the deformation section (30) of the sleeve (12) is deformed so that the The outer diameter of the deformed deformation section (30) is greater than the diameter of the hole (10),

wherein the cutting tool (46) has a support body (54) with a contact surface (56) and an opening (70) extending from the contact surface (56) with a central axis (62) perpendicular to the contact surface (56), wherein in the opening (70 ) two blades (50) with opposite cutting edges (48) are arranged movably guided in such a way that the cutting edges (48) run perpendicular to the central axis (62) and can be moved from opposite sides in the radial direction towards the central axis (62).