Riveting machine and corresponding method

Abstract

The present invention relates to a riveting machine used for riveting two parts, comprising a motor drive system (2) with an output shaft, a set of mutually pivoted linking rods (3) with a first linking rod (31) assembled for rotation with the output shaft of the motor drive system (2) and a second link rod (32) pivoted to the first linking rod, a ram (4) pivoted to the second link rod (3) and provided with an upper riveting die (5) at its end opposite to the end pivoted to the second link rod, a guide device (6) with a through hole in which the ram (4) engages, and a lower riveting die (9) capable of cooperating with the upper riveting die (5) to upset a rivet between the upper and lower riveting die when the rivet is located inside a hole drilled through the parts to be riveted together. Rotation of the output shaft of the motor drive system (2) causes movement of the ram (4) along the through holes of the guide device (6) to enable the lowering of the upper rivet die (5) by movement of the link rods (31, 32) from a folded position to an deployed position, thereby bringing the rivet into a hole drilled through the two members to be riveted together.

Description

[Technical field]

[0001] This invention relates generally to the riveting of components, and more particularly to the riveting of aircraft components such as metal fuselage plates. [Background technology]

[0002] For riveting components such as metal plates, it is known to use a riveting machine which has upper and lower plate clamps to enable holes to be drilled in the components to be riveted and then clamping the components for riveting purposes.

[0003] The riveting machine includes a lower riveting die that is designed to cooperate with an upper riveting die to upset a rivet that is positioned within a hole drilled through the parts to be riveted.

[0004] The upper rivet die acts as a tool for holding the rivet and inserting it into a drilled hole, and the lower rivet die acts as a thrust tool and is actuated to apply a force to the rivet in the direction of the upper rivet die, thus upsetting the rivet into the hole in the parts to be riveted.

[0005] It is known to use a system of thrusters to move the upper rivet die to present the rivet in the drilled hole and to maintain the upper rivet die in a position facing the lower rivet die.

[0006] However, riveting of components, especially in the aeronautical sector, requires the upper riveting die to be moved (lowered and raised) over long distances, especially if there are obstacles close to the area to be riveted.

[0007] It has been found that in order to achieve a long travel path of the upper rivet die using a riveting machine of the type known in the prior art, it is necessary to replace the thrust system of this riveting machine with another thrust system having a longer dimension, which increases the size of the riveting machine.

[0008] The patent document 1 describes a riveting press having a frame with elements for guiding an insertion rod movable between a first position, i.e. a rest position, and a second position, i.e. an insertion position, the insertion rod being actuated between the first and second positions by an electric motor. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] IT UB20152664A1 Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to propose a new riveting machine and a new method of riveting which make it possible to overcome some or all of the above mentioned problems. [Means for solving the problem]

[0011] For this purpose, the subject of the invention is a riveting machine, which makes it possible to rivet two parts, such as metal plates, together. This riveting machine comprises: - a motor drive system with an output shaft, for example a step motor with a corresponding reduction gear; - a set of connecting rods pivotally connected to one another, the set comprising a first connecting rod mounted to rotate together with an output shaft of the motor drive system, and a second connecting rod pivotally connected to the first connecting rod; a ram pivotally connected to the second connecting rod, the ram being provided at its end opposite the end pivotally connected to the second connecting rod with a tool for holding and inserting a rivet, known as an upper rivet die; a guide device configured to guide the movement of the ram along a guide axis; a push-in element, known as a lower rivet die, which is movable in a direction parallel to the guide axis of the guide device in order to cooperate with the upper rivet die, for example to upset the rivet between the upper and lower rivet dies when the rivet is positioned in a hole drilled through the parts to be riveted; a control unit configured to rotate an output shaft of the motor drive system, for example to advance a connecting rod of the connecting rod system from a folded position to a deployed position in which the connecting rod is aligned along an axis intersecting the axis of the output shaft of the motor drive system; It is equipped with:

[0012] This type of arrangement allows alignment of the connecting rod with the output shaft of the motor drive system, which ensures that the upper rivet die forming the counter-support tool can withstand the thrust forces applied to the rivet without the risk of the connecting rod being unintentionally folded, which therefore makes it possible to achieve reliable upsetting of the rivet by thrusting the lower rivet die in the direction of the upper rivet die, even when considerable forces are applied.

[0013] The riveting machine according to the invention may comprise one or more of the following features in any technically permissible combination:

[0014] According to one embodiment, the riveting machine comprises an upper plate clamp and a lower plate clamp which enable the parts to be riveted to be clamped together, the upper plate clamp having an opening for positioning the rivet carried by the upper riveting die in a hole drilled through the parts to be riveted, and the lower plate clamp having an opening for the passage of the lower riveting die and thus for upsetting the rivet.

[0015] According to one embodiment, the upper plate clamp, preferably having a generally rectangular shaped cross section, is mounted to pivot about the axis of the ram to enable it to be moved along, without interfering with, the protrusions of the parts to be riveted on the side on which the upper plate clamp is located.

[0016] According to one embodiment, the number of connecting rods in the set of connecting rods is equal to two.

[0017] According to one embodiment, the first connecting rod has an end with a hole therein, and the output shaft of the motor drive system extends through the hole in the end of the first connecting rod.

[0018] According to one embodiment, the first connecting rod has a central longitudinal axis that intersects the axis of the output shaft of the longitudinal motor drive system.

[0019] According to one embodiment, the guide device has a through hole into which the ram engages, the axis of the through hole being the guide axis of the ram.

[0020] According to one embodiment, the alignment axis of the connecting rod in the deployed state is parallel to, and preferably coaxial with, the axis of movement of the lower rivet die, which runs through the centre of the lower rivet die.

[0021] According to one embodiment, for the transition of the connecting rod from the folded position to the deployed position, the rotation angle of the motor drive system is between 20° and 180°.

[0022] The present invention also relates to a method for riveting with a riveting machine according to any one of the above-mentioned embodiments, the method comprising the steps of: - positioning two parts to be riveted together between a lower riveting die and an upper riveting die; - actuating the motor drive system to advance the connecting rods of the system of connecting rods from a folded position to an extended position in which the connecting rods are aligned along an axis that is coaxial with the axis of movement of the lower rivet die, with a hole being drilled through the two members for introducing the rivet held by the upper rivet die, the transition of the connecting rods from the folded position to the extended position causing a lowering of the upper rivet die and bringing the rivet into the drilled hole provided through the two members to be riveted; - moving the lower rivet die towards the upper rivet die to upset the rivet; The present invention relates to a method comprising the steps of:

[0023] Other characteristics and advantages of the invention will become more apparent from the following description, which is purely illustrative and non-limiting, and which should be read in connection with the accompanying drawings, in which: [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view of a riveting machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a portion of the riveting machine shown in FIG. 1 with a motor drive system to which a set of connecting rods pivotally mounted on a ram are connected, the ram is provided with an upper riveting die, the movement of the ram is guided by a guide device, and the set of connecting rods is in a folded position. [Figure 2A]FIG. 2 is a front view of a motor drive system showing a portion of the riveting machine shown in FIG. [Figure 2B] 2 is a cross-sectional view of a portion of the riveting machine shown in FIG. 1 taken along the axial direction of a motor drive system. [Diagram 3] FIG. 2 is a cross-sectional view of a portion of the riveting machine of FIG. 1 showing two parts to be riveted clamped between a lower plate clamp and an upper plate clamp with the upper rivet die carrying the rivet in a high position and the lower riveting die in a low position. [Figure 4] FIG. 3 shows the elements shown in FIG. 2 during deployment of a set of connecting rods, which causes the descent of the ram along the guide device. [Diagram 5] FIG. 5 shows the elements shown in FIG. 4 with the set of connecting rods deployed and the upper rivet die in a lowered position. [Figure 6] FIG. 4 shows the elements shown in FIG. 3 again with the upper rivet die in a lowered position, with the rivet inserted into a hole drilled through the parts to be riveted and the lower rivet die in a lowered position. [Figure 7] FIG. 7 shows again the elements shown in FIG. 6 with the lower rivet die moved to a higher position to upset the rivet held by the upper rivet die in a hole drilled through the parts to be riveted. [Figure 8] FIG. 8 is a cross-sectional view of a portion of a riveting machine according to another embodiment of the invention, in which the upper plate clamp is pivotable about an axis parallel to the axis of upward and downward movement of the upper riveting die, the upper riveting die being shown in an elevated position in FIG. 8 so that the rivet has not yet been introduced into the hole drilled through the parts to be riveted. [Figure 9] FIG. 9 is a view again of the elements shown in FIG. 8, showing the upper rivet die in a lowered position whereby a rivet is introduced into a hole drilled through the parts to be riveted. [Figure 10]4 is a flow chart illustrating method steps according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The inventive concepts will now be described more fully with reference to the accompanying drawings, in which several embodiments of the inventive concepts are illustrated. In the drawings, the sizes and relative sizes of elements may be exaggerated for clarity. Like numbers refer to like elements in all drawings. The inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are proposed so that this description will be thorough and will convey the scope of the inventive concepts to those skilled in the art.

[0026] Throughout this specification, a reference to "an embodiment" means that a feature, structure, or particular feature described in connection with an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "according to an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment. Furthermore, the features, structures, or particular features may be combined in any suitable manner in one or more embodiments.

[0027] With reference to the drawings, the reference number 1 indicates a riveting machine which makes it possible to rivet two components 81, 82, such as metal plates. This riveting machine makes it possible to carry out riveting operations with long travel paths of the upper riveting die, for example 200 mm. The riveting machine makes it possible to apply high thrust forces to the rivet, for example of the order of 100 daN to 10,000 daN, which are particularly suitable for aeronautical type applications.

[0028] The movement of the lower rivet die applies a plunge force to the rivet, the upper rivet die acting as a counter support. When the upper rivet die 5 is extended, the assembly formed by the ram 4, the connecting rod system 3 and the motor drive system 2 is designed to reliably absorb the plunge force without risk of folding of the connecting rods and rotation of the motor drive output shaft, as will be explained below.

[0029] The use of a motor drive system 2 with an axis on which the system of connecting rods 3 is attached makes it possible to perform the raising and lowering of the upper riveting die at high speed, for example with a raising and lowering cycle of 0.2 seconds, by a simple rotation, for example of about a quarter turn.

[0030] Advantageously, the riveting machine includes a drilling tool for drilling holes through the parts to be riveted, into which holes the rivets may then be brought by an upper riveting die.

[0031] Riveting machine The riveting machine comprises an upper assembly which comprises an upper riveting die 5 which is connected to a motor drive system 2 by a ram and connecting rod system 3 .

[0032] The riveting machine also comprises a lower assembly which comprises a lower riveting die 9 which is movable, preferably vertically, towards the upper riveting die to enable the lower riveting die 9 to exert a thrust force on a rivet which is positioned in a hole in the part to be riveted, so that the rivet is upset between the lower and upper riveting dies.

[0033] In the example shown in Fig. 1, the riveting machine has in particular a "C" shaped frame, the upper part of which supports a motor drive system enabling the movement of an upper riveting die by means of a system of connecting rods 3, and the lower part of which supports a lower riveting die. The parts to be riveted are positioned in the opening of the "C". During riveting, the parts to be riveted 81, 82 are held against each other by an upper plate clamp 110 and a lower plate clamp 120, as shown in Fig. 3.

[0034] Upper Assembly As shown in Figures 2A and 2B, the motor drive system 2 has an output shaft 21 having an axis A2. The output shaft 21 preferably extends horizontally. Advantageously, the motor drive system includes a geared motor assembly. The motor is preferably a stepper motor.

[0035] The riveting machine also comprises a set of connecting rods 3 which are pivotally connected to one another. A first connecting rod 31 has one end mounted for rotation with the output shaft 21 of the motor drive system 2 and a second connecting rod 32 is pivotally connected to the other end of the first connecting rod 31.

[0036] The ram 4 is pivotally mounted to a second connecting rod 32 and is provided with an upper riveting die 5 at its end opposite the end pivotally mounted to the second connecting rod 32 .

[0037] According to one embodiment, the first connecting rod 31 is fixed on the output shaft 21 of the motor drive system 2 by contracting on the output shaft 21 of the motor drive system 2 .

[0038] According to one particular embodiment, the end of the connecting rod 31 has a through hole for attachment to the output shaft 21. In the example illustrated in more detail in Figures 2 and 2B, the end of the connecting rod 31 is integrally attached to the output shaft 21 by a mounting portion 23, which is itself mounted by shrinkage on the output shaft 21. The connecting rod 31 therefore rotates together with the output shaft 21 of the motor drive system.

[0039] As shown in FIG. 2A, the central longitudinal axis A31 of the first connecting rod 31 intersects with the axis A2 of the output shaft 21 of the longitudinal motor drive system 2.

[0040] The pivot axis A3132 of the connecting rod is parallel to the axis A2 of the output shaft 21 of the motor drive system. Similarly, the pivot axis A34 of the ram 4 to the connecting rod 32 is parallel to the axis A2 of the output shaft 21 of the motor drive system.

[0041] The riveting machine is provided with a guide device 6 that enables guiding of the ram 4. In the example shown in the drawings, the guide device 6 has a through hole with which the ram 4 engages. The ram 4 is therefore guided by the guide device 6 to slide in a direction perpendicular to the axis of the output shaft 21 of the motor drive system 2. In the example shown in the drawings, the ram 4 can therefore slide in the vertical direction.

[0042] Advantageously, the assembly of the motor drive system, the connecting rod with the ram and the guide device is mounted on a carriage that can be moved along a guide rail along an axis parallel to the axis of the output shaft of the motor drive system 2. According to one particular embodiment, the guide rail is fixed on a support that can be moved vertically and possibly horizontally.

[0043] Lower Assembly The lower rivet die 9 forms a push-in element which can be moved, preferably vertically, towards the upper rivet die 5 and can cooperate with the upper rivet die 5 to upset the rivet 7 between the upper rivet die 5 and the lower rivet die 9 when the rivet is positioned inside a hole 87 drilled through the parts 81, 82 to be riveted (Figures 6-7).

[0044] As previously mentioned, the parts 81, 82 to be riveted are held clamped together by the lower plate clamp 120 and the upper plate clamp 110.

[0045] Rotation of the motor drive system 2 causes the connecting rods 31, 32 to transition from a folded position (Figures 1 to 4) to an unfolded position (Figures 5 to 6) or from the unfolded position to the folded position, thereby moving the ram 4 along the guide device 6.

[0046] 5, in the deployed position, the connecting rods 31, 32 are aligned along an axis A3 which is coaxial with the axis A6 of the guide 6 of the guiding device, i.e. the longitudinal axis A4 of the ram 4, which also coincides with the thrust axis A1 of the lower rivet die 9. The axis A3 coincides with the central longitudinal axis of the connecting rods in the deployed state.

[0047] The axis A2 of the output shaft 21 of the motor drive system 2 and the alignment axis A3 of the connecting rods in the deployed position, which also coincides with the thrust axis A1 of the lower riveting die, are coplanar. Such an arrangement allows the alignment of the connecting rods 31, 32 and ensures that the output shaft 21 of the motor drive system 2 can withstand the thrust force of the lower riveting die 9 without the risk of the connecting rods folding up unintentionally, and therefore makes it possible to achieve a reliable upsetting of the rivet 7 by thrusting the lower riveting die 9 towards the upper riveting die 5, even when considerable forces are applied.

[0048] In the folded position of the connecting rod, as shown in Figures 1 to 4, the ram is in a high position. Transition of the connecting rod to the extended position allows the ram to move downwards and thus the upper rivet die 5 to be lowered in order to bring the rivet 7 into the drilled hole 87 provided through the two parts 81, 82 to be riveted.

[0049] In the example shown in the drawings, the direction of rivet introduction and thrust towards the rivet is vertical.

[0050] The use of a set of connecting rods between the motor drive system and the upper riveting die allows the upper riveting die to move over a long path depending on the length of the connecting rods. Because the connecting rods are elongated elements such as rods, the width of the connecting rods is limited, which allows the riveting machine to be easily designed to allow for gaps between the connecting rods while still maintaining a limited size of the riveting machine.

[0051] Upper and Lower Plate Clamps As shown in Figures 1 to 7, the riveting machine comprises an upper plate clamp 110 and a lower plate clamp 120 making it possible to clamp the parts 81, 82 to be riveted together.

[0052] The upper plate clamp 110 has openings for positioning the rivets 7 carried by the upper riveting die 5 in holes drilled through the parts 81, 82 to be riveted.

[0053] The lower plate clamp 120 has an opening for the passage of the lower rivet die 9, thereby enabling the rivet 7 to be upset against the upper rivet die 5 in a hole drilled through the parts 81, 82 to be riveted. The lower rivet die 9 may be moved, preferably vertically, along the axis A1 in order to push towards the rivet and thus upset the rivet, whilst the upper rivet die and the assembly formed by the ram, connecting rod and drive shaft take up the thrust force of the lower connecting rod.

[0054] According to one particular embodiment illustrated in Figures 8 and 9, the upper plate clamp 110' is mounted to pivot about an axis that is parallel, and preferably coaxial, with the axis A4 of the ram 4. The axis A4 of the ram 4 also coincides with the axis A1 of movement of the lower rivet die (or the axis of the hole in the parts to be riveted).

[0055] By pivoting itself, the upper plate clamp 110' can move along the protrusion 81A of the component 81 to be riveted on the side on which the upper plate clamp 110' is located, without interfering with this protrusion 81A.

[0056] The upper plate clamp 110' preferably has a cross-section having a generally rectangular shape and extends along an axis A1.

[0057] method The above-mentioned riveting machine 1 makes it possible to carry out a riveting method, one embodiment of which is presented below in connection with FIG.

[0058] The connecting rods 31, 32 are in a folded position such that the upper rivet die 5 is in an elevated position. The upper rivet die 5 is positioned above holes drilled through the two parts 81, 82 to be riveted.

[0059] To introduce the rivet 7 into the hole drilled through the parts 81, 82 to be riveted, the motor drive system 2 is powered, which causes the connecting rod to rotate in the direction of deployment, preferably by about 1 / 4 turn (step 1010).

[0060] Thus, rotation of the motor drive system 2 causes the ram 4 to move in the direction of descent (which is vertical) of the upper riveting die 5 along a guide area of ​​the guide device 6, which in the illustrated example is a through hole.

[0061] In step 1020, the lower rivet die 9 is pushed towards the rivet 7 and moved towards the upper rivet die 5 to upset the rivet 7, the pushing force being received by the assembly formed by the upper rivet die 5, the ram 4, the set of connecting rods 3 and the output shaft 21 of the motor drive system.

[0062] The motor drive system 2 and the movement of the different elements such as the lower riveting die 9 and, depending on the embodiment chosen, the rotation of the upper plate clamp 10' can be controlled by a control unit 100 (Figure 1).

[0063] The control unit 100 may be in the form of a processor and a data memory capable of storing computer instructions executable by the processor, or may be in the form of a microcontroller.

[0064] In other words, the described functions and steps can be implemented in the form of a computer program or via hardware components (e.g. programmable gate networks). The functions and steps executable in particular by the control unit, in particular for the instructions for the actuation of the lower rivet die, for the instructions for the motor drive system, for the motor associated with the carriage for the movement of the assembly carrying the upper rivet die and the motor drive system to which the sliding guide device is connected, and optionally for controlling the rotation of the upper plate clamp, can be executed by an instruction set or computer module implemented in a processor or controller, or by dedicated electronic components or components of the FPGA or ASIC type. It is also possible to combine computer and electronic components.

[0065] Thus, a control unit is an electronic and / or computer unit. When it is stated that said unit is configured to perform a certain operation, this means that said unit contains computer instructions and corresponding execution means enabling said unit to perform said operation and / or that said unit contains corresponding electronic components.

[0066] The invention is not limited to the embodiments shown in the drawings.

[0067] Furthermore, the term "comprising" does not exclude other elements or steps. Moreover, features or steps described in connection with one of the above-mentioned embodiments can also be used in combination with other features or steps of other of the above-mentioned embodiments.

Claims

1. A riveting machine (1) making it possible to rivet together two members (81, 82), such as metal plates, comprising: - a motor drive system (2) with an output shaft (21), for example a step motor with corresponding reduction gears; - a set of connecting rods (3) pivotally connected to one another; A riveting machine (1) comprising: the set of connecting rods (3) comprises a first connecting rod (31) mounted to rotate together with the output shaft (21) of the motor drive system (2) and a second connecting rod (32) pivotally mounted to the first connecting rod (31); The rivet fastening machine (1), a ram (4) pivotally mounted on said second connecting rod (32) and comprising, at its end opposite to the end pivotally mounted on said second connecting rod (32), a tool for holding and inserting a rivet, known as an upper rivet die (5); a guide device (6) adapted to guide the movement of said ram (4) along a guide axis (A6); a push-in element known as a lower riveting die (9), which is movable in a direction parallel to the guide axis (A6) of the guide device in order to cooperate with the upper riveting die (5), for example to upset the rivet (7) between the upper and lower riveting dies when the rivet is positioned in a hole (87) drilled through the parts (81, 82) to be riveted; a control unit (100) configured to rotate the output shaft (21) of the motor drive system (2), for example to advance the connecting rods (31, 32) of the set of connecting rods (3) from a folded position to an deployed position in which the connecting rods (31, 32) are aligned along an axis (A3) that intersects the axis (A2) of the output shaft (21) of the motor drive system (2); The riveting machine (1) further comprises:

2. 2. The riveting machine according to claim 1, comprising an upper plate clamp (110, 110') and a lower plate clamp (120) enabling the components (81, 82) to be riveted to be clamped together, the upper plate clamp (110, 110') having an opening for positioning the rivet (7) carried by the upper riveting die (5) in a hole drilled through the components (81, 82) to be riveted, and the lower plate clamp (120) having an opening for the passage of the lower riveting die (9) and thus for upsetting the rivet (7).

3. 3. The riveting machine according to claim 2, wherein the upper plate clamp (110'), preferably having a cross-section of generally rectangular shape, is mounted to pivot about an axis (A4) of the ram (4) to enable the upper plate clamp (110') to be moved along a protrusion (81A) of the part (81) to be riveted on the side on which the upper plate clamp (110') is located, without interfering with said protrusion (81A).

4. 2. The riveting machine of claim 1, wherein the number of connecting rods in said set of connecting rods (3) is equal to two.

5. 2. The riveting machine of claim 1, wherein the first connecting rod (31) has an end with a hole therein, and the output shaft (21) of the motor drive system (2) extends through the hole at the end of the first connecting rod (31).

6. 2. The riveting machine of claim 1, wherein the first connecting rod (31) has a central longitudinal axis (A31) that intersects the axis (A2) of the output shaft (21) of the longitudinal motor drive system (2).

7. 2. The riveting machine according to claim 1, wherein the guide device (6) has a through hole, into which the ram (4) engages, the axis of the through hole being the guide axis (A6) of the ram.

8. 2. The riveting machine according to claim 1, wherein the alignment axis (A3) of the connecting rod in the deployed state is parallel to, and preferably coaxial with, the axis of movement (A1) of the lower riveting die (9), which extends through the centre of the lower riveting die (9).

9. 2. The riveting machine according to claim 1, wherein the rotation angle of the motor drive system for the transition of the connecting rods (31, 32) from the folded position to the deployed position is between 20° and 180°.

10. A method for riveting using a riveting machine according to any one of claims 1 to 9, comprising the steps of: - positioning two parts (81, 82) to be riveted together between said lower riveting die (9) and said upper riveting die (5); - actuating the motor drive system (2) to advance the connecting rods (31, 32) of the set of connecting rods (3) from the folded position to the deployed position in which the connecting rods are aligned along an axis (A3) that is coaxial with the movement axis (A1) of the lower riveting die (9), with holes (87) drilled through the two parts (81, 82) for introducing the rivet (7) held by the upper riveting die (5), the transition of the connecting rods from the folded position to the deployed position causing a lowering of the upper riveting die (5) and bringing the rivet (7) into the drilled hole (87) provided through the two parts (81, 82) to be riveted; - moving the lower rivet die (9) towards the upper rivet die (5) in order to upset the rivet (7); A method comprising:

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