Riveting machine and corresponding method

Abstract

The invention relates to a riveting machine that is used for riveting two parts The machine comprises a motorized-drive system (2) comprising an output shaft, a set (3) of mutually articulated link rods, comprising a first link rod (31) mounted so that it rotates as one with the output shaft of the motorized-drive system (2) and a second link rod (32) articulated to the first link rod (31), a ram (4) articulated to the second link rod (32) and equipped at its opposite end from the one articulated to the second link rod with an upper rivet die (5), a guide device (6) having a through-orifice in which the ram (4) is engaged, and a lower rivet die (9), able to collaborate with the upper rivet die (5) to upset the rivet, when the rivet is placed inside an orifice pierced through the parts that are to be riveted together, between the upper and lower rivet dies. The rotation of the output shaft of the motorized-drive system (2) drives the movement of the ram (4) along the through-orifice of the guide device (6) to allow, through the movement of the link rods (31, 32) from a folded position to a deployed position, the lowering of the upper rivet die (5) so as to bring the rivet into the hole pierced through the two parts that are to be riveted together.

Description

FIELD OF THE INVENTION

[0001] The present invention relates generally to the riveting of parts, in particular the riveting of aeronautical parts, such as fuselage sheets. PREVIOUS ART

[0002] To rivet parts, such as sheets, it is known to use a riveting machine which includes an upper sheet clamp and a lower sheet clamp to allow the parts to be riveted to be clamped for drilling and then riveting.

[0003] The riveting machine comprises a lower die which is intended to cooperate with an upper die to crush a rivet disposed inside the hole drilled through the parts to be riveted.

[0004] The upper die serves as a tool for holding and placing the rivet in the drilled hole. The lower die serves as a pushing tool and is operated to exert force on the rivet in the direction of the upper die and thus crush the rivet in the drilled hole of the parts to be riveted.

[0005] To move the upper riveting die so as to bring the rivet into the drilled hole, and to hold the upper riveting die in position opposite the lower riveting die, it is known to use jack systems.

[0006] However, riveting parts, particularly in the aeronautical field, may require moving the upper riveter (down and up) over a long distance, particularly when obstacles are present near the area to be riveted.

[0007] To obtain a large travel of the upper die, using a machine of the type known in the state of the art, it is found that the jack system of the machine would have to be replaced by another jack system of larger size, which would increase the size of the machine.

[0008] Document IT UB20 152664 A1 describes a riveter comprising a frame equipped with a guide element for an insertion rod movable between a first rest position and a second insertion position, the insertion rod being actuated between its first and second position by an electric motor.

[0009] The aim of the present invention is to propose a new machine and a new riveting method making it possible to overcome all or part of the problems set out above. SUMMARY OF THE INVENTION

[0010] To this end, the invention relates to a riveting machine for riveting two parts, such as sheets, together. The machine comprises: a motorization system, for example a stepper motor associated with a reducer, comprising an output shaft; a set of connecting rods articulated together, comprising a first connecting rod mounted integral in rotation with the output shaft of the motorization system, and a second connecting rod articulated to the first connecting rod; a slide articulated to the second connecting rod and provided at its end opposite that articulated to the second connecting rod, with a rivet holding and positioning tool, called an upper rivet; a guide device configured to guide the movement of the slide along a guide axis; a thrust element, called a lower rivet, movable in a direction parallel to the guide axis of the guide device to cooperate with the upper rivet so as to crush the rivet, when said rivet is arranged inside an orifice drilled through the parts to be riveted, between said lower and upper rivets;and a drive unit configured to rotate the output shaft of the powertrain system so as to move the connecting rods of the connecting rod system from a stowed position to an extended position in which the connecting rods are aligned along an axis that intersects the axis of the output shaft of the powertrain system.;

[0011] Such an arrangement allows the alignment of the connecting rods, and the output shaft of the drive system, to withstand the thrust force applied to the rivet and which the upper die which forms a counter-support tool undergoes, reliably without the risk of untimely folding of the connecting rods, which thus makes it possible to obtain reliable crushing of the rivet by pushing the lower die in the direction of the upper die, even for a significant force.

[0012] The riveting machine according to the invention may also comprise one or more of the following characteristics taken in any technically admissible combination.

[0013] According to one embodiment, the machine comprises an upper sheet clamp and a lower sheet clamp for clamping the parts to be riveted against each other, the upper sheet clamp having an opening for positioning the rivet carried by the upper die in an orifice drilled through the parts to be riveted, the lower sheet clamp having an opening for the passage of the lower die and thus allowing the rivet to be crushed.

[0014] According to one embodiment, the upper sheet metal clamp, which has a section preferably of generally rectangular shape, is pivotally mounted around the axis of the slide, to allow said upper sheet metal clamp to be moved along a projecting part of the part to be riveted, on the side of which the upper sheet metal clamp is located, without interference with this projecting part.

[0015] According to one embodiment, the number of connecting rods in the connecting rod assembly is equal to two.

[0016] According to one embodiment, the first connecting rod has an end through which an orifice is provided, and the output shaft of the drive system extends through said orifice of the end of the first connecting rod.

[0017] According to one embodiment, the first connecting rod has a median longitudinal axis which intersects with the axis of the output shaft of the longitudinal drive system.

[0018] According to one embodiment, the guide device has a through orifice in which the slide is engaged, the axis of the through orifice being the guide axis of the slide.

[0019] According to one embodiment, the alignment axis of the connecting rods in the deployed state is parallel, preferably coaxial, with the axis of movement of the lower die which passes through the center of the lower die.

[0020] According to one embodiment, for the transition of the connecting rods from the folded position to the deployed position, the rotation angle of the motorization system is between 20° and 180°.

[0021] The invention also relates to a method of riveting using a machine according to any of the preceding embodiments, wherein the method comprises the following steps: positioning two parts, to be riveted together, between the lower die and the upper die; an orifice being drilled through the two parts for the introduction of a rivet held by the upper die, actuating the motorization system so as to move the connecting rods of the connecting rod system from said folded position to the deployed position in which the connecting rods are aligned along an axis coaxial with the axis of movement of the lower die, the passage of the connecting rods from the folded position to the deployed position causing the upper die to descend, and the supply of the rivet into the drilling orifice made through the two parts to be riveted; and moving the lower die towards the upper die to crush the rivet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other characteristics and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting and must be read in conjunction with the appended drawings, in which: [ Fig. 1 ] there Figure 1 is a perspective view of a riveting machine according to one embodiment of the invention; [ Fig. 2 ] there Figure 2 is a perspective view of part of the riveting machine of the Figure 1 which comprises a motorization system to which is coupled a set of connecting rods articulated to a slide which is equipped with an upper rivet and the movement of which is guided by a guide device, the set of connecting rods being in the folded position; [ Fig. 2A ] there Figure 2A is a view of part of the riveting machine of the Figure 1 , front view of the motorization system; [ Fig. 2B ] there Figure 2B is a view of part of the riveting machine of the Figure 1, in axial section of the motorization system; [ Fig. 3 ] there Figure 3 is a sectional view of part of the riveting machine of the Figure 1 , showing two parts to be riveted clamped between a lower sheet clamp and an upper sheet clamp, in the upper position of the upper riveting die which carries a rivet, and in the lower position of the lower riveting die; [ Fig. 4 ] there Figure 4 is a view of the elements of the Figure 2 during deployment of the connecting rod assembly, causing the slide to descend along the guide device; [ Fig. 5 ] there Figure 5 is a view of the elements of the Figure 4 in the deployed state of the connecting rod assembly so that the upper rivet is in the low position; [ Fig. 6 ] there Figure 6 takes up the elements of the Figure 3, in the lower position of the upper die so that the rivet is inserted into an orifice drilled through the part to be riveted, the lower die being in the lower position; [ Fig. 7 ] there Figure 7 takes up the elements of the Figure 6 , the lower die being moved to the high position to crush the rivet held by the upper die in the hole drilled through the parts to be riveted; [ Fig. 8 ] there Figure 8 is a sectional view of a part of a riveting machine according to another embodiment of the invention, for which the upper sheet metal clamp is pivotally movable around an axis parallel to the axis of up and down movement of the upper riveting die, the Figure 8 showing the upper rivet in the high position so that the rivet is not yet inserted into the hole drilled through the parts to be riveted; [ Fig. 9 ] there Figure 9 takes up the elements of the Figure 8, in the lower position of the upper rivet so that the rivet is introduced into the hole drilled through the parts to be riveted; [ Fig. 10 ] there Figure 10 is a flowchart illustrating steps of a method according to one embodiment of the invention. DETAILED DESCRIPTION

[0023] The inventive concept is described more fully below with reference to the accompanying drawings, in which embodiments of the inventive concept are shown. In the drawings, the size and relative sizes of elements may be exaggerated for clarity. Like numerals refer to like elements throughout the drawings. However, this inventive concept may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Instead, these embodiments are provided so that this description is complete, and communicates the scope of the inventive concept to those skilled in the art.

[0024] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the occurrence of the phrase "in an embodiment" at various locations throughout the specification does not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0025] With reference to the figures, a riveting machine 1 is shown for riveting two parts 81, 82, such as sheets. The machine makes it possible to carry out the riveting operation with a large travel of the upper riveting die, for example 200 millimeters. The riveting machine makes it possible to apply a high thrust force to the rivet, for example of the order of 100 daN to 10,000 daN, suitable in particular for aeronautical type applications.

[0026] The thrust force is applied to the rivet by moving the lower rivet and the upper rivet serves as a counter-support. In the extension of the upper rivet 5, the assembly formed by the slide 4, the connecting rod system 3 and the motorization system 2 is arranged, as detailed below, so as to take up the thrust force reliably, without risk of the connecting rods folding and rotation of the output shaft of the motorization.

[0027] The use of a motorization system 2 on the axis of which a system of connecting rods 3 is mounted makes it possible to carry out by simple rotation, for example of the order of a quarter turn, raising and lowering of the upper rivet at a high rate, for example 0.2 seconds for a lowering and raising cycle.

[0028] Advantageously, the machine includes a drilling tool for drilling a hole through the parts to be riveted into which the rivet can then be fed by the upper riveting die. Riveting machine

[0029] The riveting machine comprises an upper assembly which includes an upper riveting die 5 connected, by a slide and a connecting rod system 3, to a motorization system 2.

[0030] The riveting machine also comprises a lower assembly which comprises a lower die 9 which can be moved, preferably vertically, towards the upper die in order to be able to exert a thrust force on a rivet positioned in an orifice drilled in the parts to be riveted, so that the rivet is crushed between the lower die and the upper die.

[0031] In the example shown in the Figure 1 , the riveting machine has in particular a C-shaped frame, the upper part of the C carrying said motorization system which makes it possible to move the upper riveter using the connecting rod system 3, and the lower part of the C carrying the lower riveter. The parts to be riveted are positioned in the opening of the C. During riveting, the parts 81, 82 to be riveted are kept pressed against each other by an upper sheet clamp 110 and a lower sheet clamp 120 as seen in the Figure 3 . Upper set

[0032] As illustrated in Figures 2A And 2B , the motorization system 2 has an output shaft 21 of axis A2. The output shaft 21 preferably extends horizontally. Advantageously, the motorization system comprises a geared motor assembly. The motor is preferably a stepper motor.

[0033] The machine also comprises a set 3 of connecting rods articulated together. A first connecting rod 31 has one end which is mounted so as to rotate securely with the output shaft 21 of the motorization system 2, and a second connecting rod 32 is articulated to the other end of the first connecting rod 31.

[0034] A slide 4 is articulated to the second connecting rod 32 and provided, at its end opposite that articulated to the second connecting rod 32, with the upper rivet 5.

[0035] According to one embodiment, the first connecting rod 31 is fixed to the output shaft 21 of the motorization system 2 by shrinking onto the output shaft 21 of the motorization system 2.

[0036] According to a particular aspect, the end of the connecting rod 31 has a through hole for its mounting on the output shaft 21. In the example illustrated more particularly in Figures 2 And 2B , the end of the connecting rod 31 is mounted integrally with the output shaft 21 by means of a mounting part 23, itself mounted by shrink fitting onto the output shaft 21. The connecting rod 31 is thus integral in rotation with the output shaft 21 of the motorization system.

[0037] As shown in the Figure 2A , the longitudinal median axis A31 of the first connecting rod 31 intersects with the axis A2 of the output shaft 21 of the longitudinal motorization system 2.

[0038] The articulation axis A3132 of the connecting rods is parallel to the axis A2 of the output shaft 21 of the drive system. Similarly, the articulation axis A34 of the slide 4 to the connecting rod 32 is parallel to the axis A2 of the output shaft 21 of the drive system.

[0039] The machine comprises a guide device 6 which makes it possible to guide the slide 4. In the example illustrated in the figures, the guide device 6 has a through orifice in which the slide 4 is engaged. The slide 4 is thus slidably guided by the guide device 6 in a direction perpendicular to the axis of the output shaft 21 of the motorization system 2. In the example illustrated in the figures, the slide 4 can thus slide vertically.

[0040] Advantageously, the entire motorization system, the connecting rods with slide, and the guide device, is mounted on a carriage movable along a guide rail along an axis parallel to the axis of the output shaft of the motorization system 2. According to a particular aspect, the guide rail is fixed on a support movable vertically, and possibly horizontally. Lower set

[0041] The lower rivet 9 forms a thrust element which can be moved, preferably vertically, towards the upper rivet 5 and is capable of cooperating with the upper rivet 5 to crush the rivet 7, when said rivet is arranged inside an orifice 87 drilled through the parts 81, 82 to be riveted, between said lower and upper rivets 5, 9 ( Figures 6-7 ).

[0042] As recalled above, the parts 81, 82 to be riveted are held tight against each other using a lower sheet metal clamp 120 and an upper sheet metal clamp 110.

[0043] The rotation of the motorization system 2 causes the slide 4 to move along the guide device 6, by means of the passage of the connecting rods 31, 32 from a folded position ( Figures 1-4 ) to a deployed position ( Figures 5-6 ), and vice versa.

[0044] As visible at the Figure 5 , in the deployed position, the connecting rods 31, 32 are aligned along an axis A3 coaxial with the guide axis A6 6 of the guide device, i.e. the longitudinal axis A4 of the slide 4, which also corresponds to the thrust axis A1 of the lower rivet 9. The axis A3 corresponds to the median longitudinal axis of the connecting rods in the deployed state.

[0045] The axis A2 of the output shaft 21 of the drive system 2 and the axis A3 of alignment of the connecting rods in the deployed position, which also corresponds to the thrust axis A1 of the lower rivet, are coplanar. Such an arrangement allows the alignment of the connecting rods 31, 32 and the output shaft 21 of the drive system 2 to take up the thrust force of the lower rivet 9, reliably without risk of untimely folding of the connecting rods, and thus makes it possible to obtain reliable crushing of the rivet 7 by thrust of the lower rivet 9 in the direction of the upper rivet 5, even for a significant force.

[0046] In the folded position of the connecting rods as shown in Figures 1-4, the slide is in the high position. Moving the connecting rods to the deployed position allows the slide to be moved downwards and thus the upper rivet 5 to be lowered, to bring the rivet 7 into the drilling hole 87 made through the two parts 81, 82 to be riveted.

[0047] In the example shown in the figures, the direction of feeding and pushing on the rivet is vertical.

[0048] The use of a set of connecting rods between the drive system and the upper die allows the upper die to be moved over a large stroke which is a function of the length of the connecting rods. Since connecting rods are elongated elements, such as rods, their width is limited, so that the machine can be easily designed to allow the movement of the connecting rods, while maintaining a limited machine footprint. Upper sheet metal clamp and lower sheet metal clamp

[0049] As illustrated in Figures 1 to 7, the machine comprises an upper sheet clamp 110 and a lower sheet clamp 120 for clamping the parts 81, 82 to be riveted against each other.

[0050] The upper sheet metal clamp 110 has an opening for positioning the rivet 7 carried by the upper riveting die 5 in an orifice drilled through the parts 81, 82 to be riveted.

[0051] The lower sheet metal clamp 120 has an opening for the passage of the lower rivet 9 and thus allows the crushing of the rivet 7 against the upper rivet 5, in the orifice drilled through the parts 81, 82 to be riveted. The lower rivet 9 is movable along the axis A1, preferably vertical, to push on the rivet and thus crush it while the upper rivet, and the associated assembly formed by the slide, the connecting rods and the drive shaft take up the thrust force of the lower connecting rod.

[0052] According to a particular embodiment illustrated in Figures 8 And 9 , the upper sheet metal clamp, referenced 110', is pivotally mounted around an axis parallel, preferably coaxial, to the axis A4 of the slide 4, which also corresponds to the axis A1 of movement of the lower rivet (or the axis of the orifice drilled in the parts to be riveted).

[0053] The pivoting of the upper sheet metal clamp 110' on itself allows said upper sheet metal clamp 110' to be moved along a projecting part 81A of the part 81 to be riveted, on the side of which the upper sheet metal clamp 110' is located, without interference with this projecting part 81A.

[0054] The upper sheet metal clamp 110' has a section preferably of generally rectangular shape and elongated along the axis A1. Process

[0055] The riveting machine 1 presented above makes it possible to implement a riveting process, an example of which is proposed below in connection with the Figure 10 .

[0056] The connecting rods 31, 32 are in the folded position so that the upper riveting die 5 is in the high position. The upper riveting die 5 is positioned above an orifice drilled through the two parts 81, 82 to be riveted.

[0057] To introduce the rivet 87 into an orifice drilled through the parts 81, 82 to be riveted, the motorization system 2 is powered to rotate in the direction of deployment of the connecting rods (step 1010), preferably of the order of a quarter turn.

[0058] The rotation of the motorization system 2 thus causes the slide 4 to move along the guide zone of the guide device 6, which is a through orifice in the example illustrated in the figures, in the direction of a (vertical) descent of the upper rivet 5.

[0059] At step 1020, the lower die 9 is moved towards the upper die 5 to push on the rivet 7 and crush it, the pushing force being taken up by the assembly formed by the upper bottle 5, the slide 4, the connecting rod assembly 3 and the output shaft 21 of the motorization system.

[0060] The motorization system 2 and the movements of the various elements, such as the lower riveting die 9, and, depending on the embodiment chosen, the rotation of the upper sheet metal clamp 110', can be controlled by a control unit 100 ( Figure 1 ).

[0061] The control unit 100 may be in the form of a processor and a data memory in which computer instructions executable by said processor are stored, or in the form of a microcontroller.

[0062] In other words, the functions and steps described can be implemented in the form of a computer program or via hardware components (e.g. programmable gate arrays). In particular, the functions and steps operated by the control unit, in particular for controlling the actuation of the lower rivet, for controlling the motorization system, the motor(s) associated with the carriage(s) for moving the assembly which carries the motorization system to which the upper rivet and the sliding guide device are coupled, and for possibly controlling the rotation of the upper sheet metal clamp, can be carried out by instruction sets or computer modules implemented in a processor or controller or be carried out by dedicated electronic components or FPGA or ASIC type components. It is also possible to combine computer parts and electronic parts.

[0063] The control unit is thus an electronic and / or computer unit. When it is specified that said unit is configured to carry out a given operation, this means that the unit comprises computer instructions and the corresponding execution means which make it possible to carry out said operation and / or that the unit comprises corresponding electronic components.

[0064] The invention is not limited to the embodiments illustrated in the drawings.

[0065] Furthermore, the term "comprising" does not exclude other elements or steps. Furthermore, features or steps that have been described with reference to one of the embodiments set forth above may also be used in combination with other features or steps of other embodiments set forth above.

Claims

1. A riveting machine (1) which makes it possible to rivet two parts (81, 82), such as metal plates, to one another, the machine comprising: - a motorization system (2), for example a step motor which is associated with a reduction gear, comprising an output shaft (21); - a set (3) of connection rods which are articulated on one another, characterized in that said set (3) of connection rods comprises a first connection rod (31) which is fitted such as to be integral in rotation with the output shaft (21) of the motorization system (2), and a second connection rod (32) which is articulated on the first connection rod (31); and in that said machine also comprises: - a ram (4) which is articulated on the second connection rod (32), and is provided at its end opposite the one articulated on the second connection rod with a tool for retention of the rivet and putting it into place, known as the upper rivet die (5); - a guide device (6) which is configured to guide the displacement of the ram (4) along a guide axis (A6); - a thrust element, known as the lower rivet die (9), which can be displaced in a direction parallel to the guide axis (A6) of the guide device, in order to cooperate with the upper rivet die (5), such as to upset the rivet (7), when said rivet is positioned in the interior of an orifice (87) pierced through the parts (81, 82) to be riveted, between said upper and lower rivet dies; and - a control unit (100) which is configured to rotate the output shaft (21) of the motorization system (2), such as to make the connection rods (31, 32) of the system of connection rods (3) go from a folded position to a deployed position, in which the connection rods (31, 32) are aligned along an axis (A3) which intersects the axis (A2) of the output shaft (21) of the motorization system (2).

2. The machine as claimed in claim 1, wherein the machine comprises an upper plate clamp (110, 110') and a lower plate clamp (120) making it possible to clamp the parts (81, 82) to be riveted against one another, the upper plate clamp (110, 110') having an opening for the positioning of the rivet (7) carried by the upper rivet die (5) in an orifice pierced through the parts (81, 82) to be riveted, the lower plate clamp (120) having an opening for the passage of the lower rivet die (9), and thus permitting upsetting of the rivet (7).

3. The machine as claimed in claim 2, wherein the upper plate clamp (110'), which has a cross-section preferably with a generally rectangular form, is fitted such as to pivot around the axis (A4) of the ram (4), in order to allow said upper plate clamp (110') to be displaced along a projecting part (81A) of the part (81) to be riveted, on the side of which the upper plate clamp (110') is situated, without interference with this projecting part (81A).

4. The machine as claimed in any one of the preceding claims, wherein number of connection rods of the set of connection rods (3) is equal to two.

5. The machine as claimed in any one of the preceding claims, wherein the first connection rod (31) has an end through which an orifice is provided, and the output shaft (21) of the motorization system (2) extends through said orifice in the end of the first connection rod (31).

6. The machine as claimed in any one of the preceding claims, wherein the first connection rod (31) has a median longitudinal axis (A31) which intersects the axis (A2) of the output shaft (21) of the longitudinal motorization system (2).

7. The machine as claimed in any one of the preceding claims, wherein the guide device (6) has a through-orifice in which the ram (4) is engaged, the axis of the through-orifice being the axis (A6) of guiding of the ram.

8. The machine as claimed in any one of the preceding claims, wherein the axis of alignment (A3) of the connection rods in the deployed state is parallel, and preferably coaxial, with the axis (A1) of displacement of the lower rivet die (9) which passes via the center of the lower rivet die (9).

9. The machine as claimed in any one of the preceding claims, wherein for the passage of the connection rods (31, 32) from the folded position to the deployed position, the angle of rotation of the motorization system is between 20° and 180°.

10. A method for riveting by means of a machine as claimed in any one of the preceding claims, wherein the method comprises the following steps: - positioning of two parts (81, 82) to be riveted with one another, between the lower rivet die (9) and the upper rivet die (5); - with an orifice (87) being pierced through the two parts (81, 82) for the introduction of a rivet (7) held by the upper rivet die (5), actuating the motorization system (2) such as to make the connection rods (31, 32) of the system of connection rods (3) go from said folded position to the deployed position, in which the connection rods are aligned along an axis (A3) which is coaxial with the axis (A1) of displacement of the lower rivet die (9), the passage of the connection rods from the folded position to the deployed position giving rise to the descent of the upper rivet die (5), and bringing of the rivet (7) into the piercing orifice (87) provided through the two parts (81, 82) to be riveted; and - displacing the lower rivet die (9) towards the upper rivet die (5) in order to upset the rivet (87).

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