FIXING SYSTEM ENSURING THE SECURITY OF TWO PLATES TOGETHER

Abstract

FASTENING SYSTEM FOR SECURING TWO PLATES TOGETHER The invention relates to a fastening system (100) for securing a first plate (50) to a second plate (52), each plate having a hole (50a, 52a) and a contact face (50b, 52b) against which the plates (50, 52) bear and an outer face (50c, 52c) opposite. The fastening system (100) comprises a hollow cylinder (102) having, at one end, a flange (104), where the cylinder (102) is inserted into the two holes (50a, 52a) and where the flange (104) bears against an outer face (52c) of a plate (52), and a threaded rod (110) having a head (112) and inserted into the cylinder (102) by a second end of said cylinder (102) so as to bring the head (112) against said second end. Such a fastening system allows for rapid use in process automation. Fig. 2

Description

Title of the invention: FIXING SYSTEM ENSURING THE FIXING OF TWO PLATES TOGETHER Technical field

[0001] The present invention relates to a system for fixing a first plate against a second plate, in particular in the context of a temporary fixing, as well as a method for assembling the two plates together. STATE OF THE PRIOR ART

[0002] An aircraft conventionally comprises a fuselage which is made up of several sections fixed one after the other by rivets. To ensure good positioning of two sections relative to each other before the rivets are put in place, it may be envisaged to use temporary fixings which ensure the positioning of the two sections and a non-definitive fixing.

[0003] It is then possible to put the final rivets in place before removing the temporary fixings.

[0004] Temporary fixings are not suitable for implementation in the context of automation, and it is therefore desirable to find an alternative solution. Presentation of the invention

[0005] An object of the present invention is to provide a fixing system, in particular a temporary one, for fixing two plates against each other, where the fixing system is particularly suitable for being implemented in an automation process.

[0006] To this end, a fixing system is proposed intended to ensure the fixing of a first plate with a second plate, each being pierced with a hole and having a contact face by which said plate bears against the contact face of the other plate and an external face opposite the contact face, the fixing system comprising:

[0007] - a cylinder which is hollow and has at a first end, a collar, where the cylinder is intended to be inserted into the two holes and where the collar is intended to come to bear against an external face of a plate, and

[0008] - a threaded rod having a head, where the threaded rod is inserted into the cylinder by a second end of said cylinder so as to bring the head against said second end.

[0009] Such a fixing system is therefore relatively easy to put in place from one side of the plates and by a single person, or even a robot.

[0010] Advantageously, the hardness of the threaded rod is greater than the hardness of the cylinder.

[0011] The invention also provides a method of assembling a first plate with a second plate, the assembly method comprising:

[0012] - a first supply step during which two plates are supplied, each pierced with a hole and having a contact face by which said plate bears against the contact face of the other plate and an external face opposite the contact face,

[0013] - a second supply step during which a fixing system according to one of the previous variants is provided,

[0014] - an insertion step during which the head and the second end of the fixing system thus provided are inserted into the two holes until the collar rests against the outer face of a plate, and

[0015] - a pulling step during which the end of the threaded rod is pulled from so as to crush the second end of the cylinder against the outer face of the other plate.

[0016] Advantageously, the assembly method comprises, after the pulling step, an unscrewing step during which the threaded rod is removed from the cylinder by unscrewing, and a boring step during which the holes are bored to a diameter greater than the diameters of the holes. Brief description of the drawings

[0017] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0018] [Fig-1] is a schematic and perspective representation of an assembly of two sections of aircraft fuselage,

[0019] [Fig.2] is a sectional view of a fixing system during its installation,

[0020] [Fig.3] is a sectional view of the fixing system of [Fig.2] in the position of fixation, and

[0021] [Fig.4] is a sectional view of the fastening system of [Fig.2] ready to be removed.

[0022] DETAILED DESCRIPTION OF EMBODIMENTS

[0023] [Fig.l] shows a part of a fuselage 10 of an aircraft which is made up of several sections 50 and 52, two of which have been shown. The two sections 50 and 52 are fitted into each other.

[0024] In the remainder of the description, the sections 50 and 52 are generalized in the form of a first plate 50 and a second plate 52.

[0025] Although the invention is more particularly described in the context of the fuselage 10 of an aircraft, it can be implemented in other assemblies, whether for an aircraft or not.

[0026] [Fig. 2] shows the two plates 50 and 52, and a fixing system 100 according to the invention which is put in place through the two plates 50 and 52.

[0027] The fixing systems 100 are put in place so as to fix the two plates 50 and 52 to each other, preferably temporarily, while definitive fixings, such as rivets, are put in place.

[0028] Each plate is pierced with a hole 50a, 52a. In the assembled position, the two holes 50a and 52a are coaxial and of the same diameter.

[0029] Each plate 50, 52 has a contact face 50b, 52b by which said plate 50, 52 bears against the contact face 52b, 50b of the other plate 52, 50. The two contact faces 52b and 50b are therefore opposite each other.

[0030] Opposite the contact face 52b, 50b, each plate 50, 52 has an outer face 50c, 52c. The two outer faces 50c, 52c are therefore opposite each other.

[0031] The fixing system 100 comprises a cylinder 102 which is hollow and has at a first end, a collar 104. The external diameter of the cylinder 102 is adapted to the diameter of the bores 50a and 52a so as to allow the introduction of the cylinder 102 into the bores 50a and 52a with an adapted clearance, that is to say an easy insertion without excessive movement of the cylinder 102 in the bores 50a and 52a.

[0032] When the cylinder 102 is in place in the holes 50a and 52a, the collar 104 bears against an outer face 52c of a plate 52.

[0033] The fixing system 100 also comprises a threaded rod 110 having a head 112 at one end.

[0034] The threaded rod 110 is inserted into the cylinder 102 by its end opposite the head 112. The introduction is carried out by a second end of the cylinder 102, opposite the first end and this introduction makes it possible to bring the head 112 against the second end of the cylinder 102.

[0035] The diameter of the head 112 is greater than the inside diameter of the cylinder 102 and the diameter of the threaded rod 110 is equal to the inside diameter of the cylinder 102 with a clearance to allow easy introduction of the threaded rod 110 without excessive movement.

[0036] The head 112 is here housed in a housing 108 provided at the second end of the cylinder 102.

[0037] A method of assembling the first plate 50 with the second plate 52 then consists of a first supply step during which the two plates 50 and 52 are supplied with the aligned holes 50a and 52a.

[0038] The assembly method also consists of a second supply step during which a fixing system 100 according to the invention is provided.

[0039] Afterwards, the assembly process consists of an insertion step during which the head 112 and the second end of the fastening system 100 thus provided are inserted into the two holes 50a and 52a. The fastening system 100 is introduced into the holes 50a and 52a from one side only, here for example the inside of the sections 50 and 52 and it is therefore not necessary to have a person on each side. The arrow 20 shows the direction of introduction of the fastening system 100 into the holes 50a and 52a.

[0040] When introducing the fastening system 100, the collar 104 is brought into abutment against the outer face 52c of a plate 52. The diameter of the collar 104 is therefore greater than the diameter of the holes 50a and 52a.

[0041] The assembly process then continues with a pulling step and [Fig.3] shows the pulling step and arrow 22 shows the direction of pulling of the threaded rod 110.

[0042] During the pulling step, the end of the threaded rod 110, which is opposite the head 112, is pulled so as to crush the second end of the cylinder 102 against the outer face 50c of the other plate 50. The pulling of the threaded rod 110 causes the movement of the head 112 which sinks into the cylinder 102 by spreading it and crushing it against the outer face 50c of the other plate 50 to create a bulb.

[0043] To carry out the pulling of the threaded rod 110, a device, such as a riveter, can be used. The cutting of the threaded rod 110 at the end of the pulling step is not provided, but it can be carried out.

[0044] The plates 50 and 52 are then clamped against each other between the collar 104 and the crushed part of the cylinder 102 and the pulling of the threaded rod 110 makes it possible to create a significant clamping force.

[0045] At the end of the pulling step, the fixing system 100 ensures the fixing of the two plates 50 and 52 relative to each other. It is then easy to put the final rivets in place in other bores provided for this purpose.

[0046] The installation of such a fixing system 100 is relatively simple since it can be implemented by a single person, or even a robot, moving on one side of the plates 50 and 52 and with a single tool.

[0047] During the pulling step, the cylinder 102 is crushed against the threaded rod 110 and the inner face of the cylinder 102 comes to match at least in part some of the threads of the threaded rod 110. The interior of the cylinder 102 then takes the form of a thread.

[0048] This is made easier only if the hardness of the threaded rod 110 is greater than the hardness of the cylinder 102. According to a particular embodiment, the threaded rod 110 is made of steel and the cylinder 102 is made of aluminum.

[0049] When a fastening system 100 must be removed, for example, after the permanent rivets have been put in place, the assembly method continues, after the pulling step, with an unscrewing step during which the threaded rod 112 is removed from the cylinder 102 by unscrewing from the side of the head 112, that is to say from the side opposite the side from which the pulling is carried out, and therefore here from the outside of the sections 50 and 52. This unscrewing is facilitated by the deformation of the cylinder 102 which allowed the appearance of a thread.

[0050] A tool, such as a screwdriver, is used to unscrew the threaded rod 100 by acting on the head 112 which has an imprint 112a provided for this purpose.

[0051] After the removal of the threaded rod 110, a boring step during which the holes 50a and 52a of the plates 50 and 52 are bored is carried out using a drill bit 40 provided for this purpose and mounted for example on a drill.

[0052] The bore diameter is greater than the diameters of the holes 50a and 52a to allow the part of the tube 102 which is in the holes 50a and 52a to be removed. In particular, the bore diameter is equal to the diameter of the final rivets and when the fixing system 100 has been removed, a permanent rivet is put in place of the fixing system 100.

Claims

Claims

1. Fastening system (100) intended to ensure the fastening of a first plate (50) with a second plate (52), each being pierced with a bore (50a, 52a) and having a contact face (50b, 52b) by which said plate (50, 52) bears against the contact face (52b, 50b) of the other plate (52, 50) and an outer face (50c, 52c) opposite the contact face (50b, 52b), the fastening system (100) comprising: - a cylinder (102) which is hollow and has at a first end, a collar (104), where the cylinder (102) is intended to be inserted into the two bores (50a, 52a) and where the collar (104) is intended to bear against an outer face (52c) of a plate (52), and - a threaded rod (110) having a head (112), wherein the threaded rod (110) is inserted into the cylinder (102) by a second end of said cylinder (102) so as to bring the head (112) against said second end.

2. Fastening system (100) according to claim 1, characterized in that the hardness of the threaded rod (110) is greater than the hardness of the cylinder (102).

3. A method of assembling a first plate (50) with a second plate (52), the assembly method comprising: - a first supply step during which two plates (50, 52) are provided, each pierced with a bore (50a, 52a) and having a contact face (50b, 52b) by which said plate (50, 52) bears against the contact face (52b, 50b) of the other plate (52, 50) and an outer face (50c, 52c) opposite the contact face (50b, 52b), - a second supply step during which a fixing system (100) according to one of claims 1 or 2 is provided, - an insertion step during which the head (112) and the second end of the fixing system (100) thus provided are inserted into the two bores (50a, 52a) until the collar (104) is brought into contact with the outer face (52c) of a plate (52),and - a pulling step during which the end of the threaded rod (110) is pulled so as to crush the second end of the cylinder (102) against the outer face (50c) of the other plate (50).,

4. Assembly method according to claim 3, characterized in that it comprises after the pulling step, an unscrewing step during which the threaded rod (112) is removed from the cylinder (102) by unscrewing, and a boring step during which the holes (50a, 52a) are bored to a diameter greater than the diameters of the holes (50a, 52a).

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