Rivet fastening 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] The present invention relates generally to rivet fastening of members, and in particular to rivet fastening of aerospace members such as metal fuselage plates.

Background Art

[0002] For rivet fastening members such as metal plates, it is known to use a riveting machine comprising an upper plate clamp and a lower plate clamp, in order to make it possible to drill holes in the members to be riveted and then clamp these members for the purpose of riveting.

[0003] The riveting machine is provided with a lower rivet die. The lower rivet die is designed to cooperate with the upper rivet die, so that the rivet positioned inside the hole drilled through the members to be riveted can be upset.

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

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

[0006] However, rivet fastening of members, particularly in the aerospace field, requires that the upper rivet die be moved (lowered and raised) over a long distance, especially when obstacles are present in the vicinity of the area to be riveted.

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

[0008] Patent Document 1 describes a rivet fastening press having a frame with elements for guiding an insertion rod that is movable between a first position, i.e., a stationary 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 [Overview of the project] [Problems that the invention aims to solve]

[0010] The object of the present invention is to propose a novel riveting machine and a novel method of riveting that can solve some or all of the above-mentioned problems. [Means for solving the problem]

[0011] For this purpose, the object of the present invention is a riveting machine that enables riveting two members, such as metal plates, together. This riveting machine is - A motor drive system with an output shaft, for example, a stepper motor with a reduction gear, - A set of connecting rods pivotally attached to each other, comprising a first connecting rod mounted to rotate together with the output shaft of a motor drive system, and a second connecting rod pivotally attached to the first connecting rod, - A ram pivotally attached to a second connecting rod, wherein the end opposite to the end pivotally attached to the second connecting rod is provided with a tool known as an upper rivet die, which holds a rivet and inserts the rivet, - A guide device configured to guide the movement of the ram along the guide axis, - A push element known as a lower rivet die, which is movable in a direction parallel to the guide axis of a guide device in order to cooperate with an upper rivet die, for example, when a rivet is positioned inside a hole drilled through a member to be riveted, in order to set a rivet between the upper rivet die and the lower rivet die, - A control unit configured to rotate the output shaft of a motor drive system, for example, by moving the connecting rod of the connecting rod system from a folded position to an unfolded position where the connecting rod is aligned along an axis that intersects the axis of the output shaft of the motor drive system. It is equipped with.

[0012] This type of arrangement allows for alignment between the connecting rod and the output shaft of the motor drive system, thereby ensuring that the upper rivet die forming the counter support tool can withstand the thrusting force applied to the rivet without the risk of the connecting rod unintentionally folding. This, in turn, enables reliable rivet upsetting by thrusting the lower rivet die in the direction of the upper rivet die, even when significant force is applied.

[0013] The rivet fastening machine according to the present invention may include one or more of the following features, which can be optionally combined in a technically acceptable manner:

[0014] According to one embodiment, the riveting machine comprises an upper plate clamp and a lower plate clamp that enable clamping members to be riveted together, the upper plate clamp having an opening for positioning a rivet to be transported by an upper rivet die into a hole drilled through the members to be riveted, and the lower plate clamp having an opening for the lower rivet die to pass through, thereby enabling the setting of the rivet.

[0015] According to one embodiment, an upper plate clamp, preferably having a generally rectangular cross-section, is mounted to pivot about the axis of the ram, allowing the upper plate clamp to move along a projection of a member to be riveted, on the side where the upper plate clamp is located, without interfering with the projection.

[0016] According to one embodiment, the number of connecting rods in a set of connecting rods is equal to 2.

[0017] According to one embodiment, the first connecting rod has an end with a hole, and the output shaft of the motor drive system extends through the hole provided at 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 a ram engages, and the axis of the through hole is 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 extends through the center of the lower rivet die.

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

[0022] The present invention also relates to a method for riveting by the riveting machine according to any one of the above-described embodiments, the method comprising: - a step of positioning two members to be riveted to each other between a lower rivet die and an upper rivet die; - with a hole drilled through the two members for introducing the rivet held by the upper rivet die, actuating the motor drive system to advance the connecting rod of the connecting rod system from the folded position to the deployed position where the connecting rod is aligned along an axis coaxial with the movement axis of the lower rivet die, wherein the transition of the connecting rod from the folded position to the deployed position causes the upper rivet die to descend and brings the rivet into the drilled hole provided through the two members to be riveted; - a step of moving the lower rivet die toward the upper rivet die to upset the rivet The method relates to the foregoing.

[0023] Other features and advantages of the present invention will become more apparent from the following description, which is to be read in conjunction with the accompanying drawings and is merely exemplary and non-limiting. [Brief Description of the Drawings]

[0024] [Figure 1] 1 is a perspective view showing a riveting machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a part of the riveting machine shown in FIG. 1 equipped with a motor drive system, wherein a set of connecting rods pivotally attached to a ram is connected to the motor drive system, the ram is provided with an upper rivet 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]Figure 1 is a front view of the motor drive system, showing a part of the riveting machine. [Figure 2B] Figure 1 shows a cross-sectional view in the axial direction of the motor drive system, illustrating a part of the riveting machine. [Figure 3] Figure 1 is a cross-sectional view showing a part of the rivet fastening machine, showing two members to be riveted, clamped between the lower plate clamp and the upper plate clamp. The upper rivet die, which transports the rivets, is at a high position, and the lower rivet die is at a low position. [Figure 4] This figure shows the elements shown in Figure 2 during the deployment of a set of connecting rods that cause the ram to descend along the guide device. [Figure 5] This diagram shows the elements of the connecting rod set in the unfolded state, with the upper rivet die in a low position. [Figure 6] This diagram shows the elements shown in Figure 3 again, but with the upper rivet die in a lower position. The rivet is inserted into a hole drilled through the member to be riveted, and the lower rivet die is in a lower position. [Figure 7] This diagram again shows the elements shown in Figure 6, where the lower rivet die is moved to a higher position in order to set the rivet, which is held by the upper rivet die, within a hole drilled through the member to be riveted. [Figure 8] This is a cross-sectional view showing a part of a riveting machine according to another embodiment of the present invention, in which the upper plate clamp is capable of pivoting about an axis parallel to the upward and downward movement axis of the upper rivet die, and in Figure 8 the upper rivet die is shown in a high position, so that the rivet has not yet been introduced into the hole drilled through the member to be riveted. [Figure 9] This diagram again shows the elements shown in Figure 8, with the upper rivet die shown in a lower position, so that the rivet is introduced into a hole drilled through the member to be riveted. [Figure 10]This flowchart shows the steps of a method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0025] The concept of the present invention will be described more fully below with reference to the accompanying drawings. The drawings show several embodiments of the concept of the present invention. In the drawings, the size and relative size of elements may be exaggerated for clarity. In all drawings, similar reference numerals refer to similar elements. However, this concept of the present invention can be realized in a number of different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are proposed to complete this description and to convey the scope of the concept of the present invention to those skilled in the art.

[0026] Throughout this specification, any reference to “a certain embodiment” means that a function, structure, or specific feature described in relation to a certain embodiment is included in at least one embodiment of the present invention. Therefore, the appearance of the phrase “according to a certain embodiment” in various places throughout this specification does not necessarily refer to the same embodiment. Furthermore, functions, structures, or specific features can be combined in any suitable manner in one or more embodiments.

[0027] Referring to the drawing, reference numeral 1 indicates a riveting machine that enables riveting two members 81, 82, such as metal plates. This riveting machine enables riveting operations with a long travel path of the upper rivet die, for example, 200 mm. The riveting machine enables the application of high riveting forces, such as approximately 100 daN to 10,000 daN, to the rivets, making it particularly suitable for aerospace applications.

[0028] As the lower rivet die moves, a thrusting force is applied to the rivet, and the upper rivet die acts 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 withstand the thrusting force without the risk of folding of the connecting rods or rotation of the motor drive output shaft, as will be described later.

[0029] The use of the motor drive system 2, which has an axis to which the connecting rod system 3 is attached, allows the upper rivet die to be raised and lowered at a high speed, for example, in a lifting and lowering cycle of 0.2 seconds, by simple rotation, for example, of about 1 / 4 turn.

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

[0031] Rivet fastening machine The riveting machine comprises an upper assembly, which includes an upper rivet die 5 connected to a motor drive system 2 by a system 3 of rams and connecting rods.

[0032] The riveting machine also includes a lower assembly, which includes a lower rivet die 9, which is preferably movable vertically toward the upper rivet die to enable the lower rivet die 9 to exert a thrusting force on a rivet positioned in a hole drilled in the member to be riveted, thereby upsetting the rivet between the lower and upper rivet dies.

[0033] In the example shown in Figure 1, the riveting machine has a frame that is specifically "C" shaped, with the upper part of the "C" supporting a motor drive system, which allows the upper rivet die to be moved using a system 3 of connecting rods, and the lower part of the "C" supporting the lower rivet die. The members to be riveted are positioned within the opening of the "C". During riveting, as shown in Figure 3, the members to be riveted 81, 82 are held so as to be pressed against each other by the upper plate clamp 110 and the lower plate clamp 120.

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

[0035] The riveting machine also includes a set of 3 connecting rods that are pivotally attached to each other. The first connecting rod 31 has one end that is mounted to rotate together with the output shaft 21 of the motor drive system 2, and the second connecting rod 32 is pivotally attached to the other end of the first connecting rod 31.

[0036] The ram 4 is pivotally attached to the second connecting rod 32, and at the end opposite to the end pivotally attached to the second connecting rod 32, it is equipped with an upper rivet die 5.

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

[0038] In a 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, the mounting portion 23 itself is attached to the output shaft 21 by contraction. Thus, the connecting rod 31 rotates together with the output shaft 21 of the motor drive system.

[0039] As shown in Figure 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 equipped with a guide device 6 that allows the ram 4 to be guided. In the example shown in the drawings, the guide device 6 has a through hole into which the ram 4 engages. Thus, the ram 4 is 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. Thus, in the example shown in the drawings, the ram 4 can slide vertically.

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

[0043] Lower assembly The lower rivet die 9 forms a thrust element that can preferably move vertically toward 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 members 81, 82 to be riveted (Figures 6-7).

[0044] As described above, the members 81 and 82 to be riveted together are held in place by being clamped to each other by the lower plate clamp 120 and the upper plate clamp 110.

[0045] The rotation of the motor drive system 2 causes the connecting rods 31 and 32 to move from the folded position (Figures 1 to 4) to the 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] As shown in Figure 5, in the deployed position, the connecting rods 31 and 32 are aligned along axis A3, which is coaxial with axis A6 of the guide 6 of the guide device, i.e., along the longitudinal axis A4 of the ram 4. This longitudinal axis A4 also coincides with the thrust axis A1 of the lower rivet die 9. Axis A3 coincides with the central longitudinal axis of the connecting rod 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 rod in the deployed position, which also coincides with the thrust axis A1 of the lower rivet die, are on the same plane. This configuration allows for the alignment of the connecting rods 31 and 32, and ensures that the output shaft 21 of the motor drive system 2 reliably receives the thrust force of the lower rivet die 9 without the risk of the connecting rod unintentionally folding. Therefore, even when significant force is applied, it is possible to achieve reliable upsetting of the rivets 7 by thrusting the lower rivet die 9 toward the upper rivet die 5.

[0048] As shown in Figures 1 to 4, the ram is in a high position when the connecting rod is folded. Transitioning the connecting rod to the unfolded position allows the ram to move downward, and consequently the upper rivet die 5 to descend into the holes 87 that are provided through the two members 81 and 82 to be riveted together.

[0049] In the example shown in the drawing, the direction of rivet introduction and the direction of thrust toward the rivet are vertical.

[0050] The use of a set of connecting rods between the motor-driven system and the upper rivet die allows the upper rivet die to move along a long path that depends on the length of the connecting rods. Since the connecting rods are elongated, rod-like elements, their width is limited, which makes it easier to design the rivet fastener to allow for gaps between the connecting rods while maintaining the limited size of the rivet fastener.

[0051] Upper plate clamp and lower plate clamp As shown in Figures 1 to 7, the riveting machine includes an upper plate clamp 110 and a lower plate clamp 120 that enable clamping of members 81 and 82 to be riveted together.

[0052] The upper plate clamp 110 has an opening for positioning the rivet 7, which is transported by the upper rivet die 5, into a hole drilled through the members 81 and 82 to be riveted.

[0053] The lower plate clamp 120 has an opening for the passage of the lower rivet die 9, which allows the rivet 7 to be set against the upper rivet die 5 in a hole drilled through the members 81, 82 to be riveted. The lower rivet die 9 may be moved preferably vertically along axis A1 to be pushed toward the rivet and thus set the rivet, while the upper rivet die and the assembly formed by the ram, connecting rod and drive shaft receive the pushing force of the lower connecting rod.

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

[0055] Because the upper plate clamp 110' pivots on its own, it can move along the projection 81A of the member 81 to be riveted, which is on the side where the upper plate clamp 110' is positioned, without interfering with the projection 81A.

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

[0057] method The rivet fastening machine 1 shown above enables the implementation of a rivet fastening method. One embodiment of this method is presented below with reference to Figure 10.

[0058] The connecting rods 31 and 32 are in a folded position so that the upper rivet die 5 is in a high position. The upper rivet die 5 is positioned above the holes drilled through the two members 81 and 82 to be riveted together.

[0059] Power is supplied to the motor drive system 2 to introduce the rivet 7 into the hole drilled through the members 81 and 82 to be riveted, thereby allowing it to rotate, preferably by about 1 / 4 turn, in the direction of deployment of the connecting rod (step 1010).

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

[0061] In step 1020, the lower rivet die 9 is pushed toward the rivet 7 and moved toward the upper rivet die 5 to upset the rivet 7, in which case the pushing force is absorbed by an assembly formed from 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, the movement of various elements such as the lower rivet die 9, and the rotation of the upper plate clamp 10' depending on the selected embodiment can be controlled by the 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 it 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., a programmable gate network). In particular, functions and steps that can be performed by a control unit—for instructions for the operation of the lower rivet die, for instructions for the motor drive system, for motors associated with the carriage for moving the assembly that carries the motor drive system connecting the upper rivet die and slide guide device, and for selectively controlling the rotation of the upper plate clamp—can be implemented by an instruction set or computer module implemented in a processor or controller, or by dedicated electronic components or FPGA or ASIC type components. It is also possible to combine computer components and electronic components.

[0065] Therefore, the control unit is an electronic and / or computer unit. Where it is stated that the unit is configured to perform a predetermined operation, this means that the unit includes computer instructions and corresponding execution means that enable the unit to perform the operation, and / or the unit includes corresponding electronic components.

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

[0067] Furthermore, the term “comprising” does not preclude any other element or step. Moreover, any feature or step described in relation to one of the embodiments described above may be used in combination with any other feature or step of any other embodiment described above.

Claims

1. A rivet fastening machine (1) that enables riveting two members (81, 82) such as metal plates together, - Motor drive system (2) equipped with output shaft (21), - A set of connecting rods (3) that are pivotally attached to each other and A rivet fastening machine (1) equipped with, 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 attached to the first connecting rod (31). The rivet fastening machine (1) - A ram (4) pivotally attached to the second connecting rod (32), the ram (4) having a tool for holding and inserting a rivet, known as an upper rivet die (5), at the end opposite to the end pivotally attached to the second connecting rod (32), - A guide device (6) configured to guide the movement of the ram (4) along the guide axis (A6), - A push element known as a lower rivet die (9), which, when the rivet is positioned inside a hole (87) drilled through the member (81, 82) to be riveted, cooperates with the upper rivet die (5) and is movable in a direction parallel to the guide axis (A6) of the guide device in order to set the rivet (7) between the upper rivet die and the lower rivet die, - A control unit (100) configured to rotate the output shaft (21) of the motor drive system (2), wherein the control unit (100) is configured to move the connecting rods (31, 32) of the set of connecting rods (3) from a folded position to an unfolded 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) and Furthermore, A rivet fastening machine (1) characterized in that the first connecting rod (31) has a central longitudinal axis (A31) that intersects the axis (A2) of the output shaft (21) of the motor drive system (2) in the longitudinal direction, and the first connecting rod (31) is rotatable in the circumferential direction about the axis (A2) of the output shaft (21).

2. The rivet fastening machine according to claim 1, comprising upper plate clamps (110, 110') and lower plate clamps (120) that enable clamping the members (81, 82) to be riveted together, wherein the upper plate clamps (110, 110') have openings for positioning the rivets (7) that are transported by the upper rivet die (5) into holes drilled through the members (81, 82) to be riveted together, and the lower plate clamp (120) has openings for the passage of the lower rivet die (9), and thereby for enabling the upsetting of the rivets (7).

3. The riveting machine according to claim 2, wherein the upper plate clamp (110'), which has a generally rectangular cross-section, is mounted to pivot about the axis (A4) of the ram (4) so ​​as to allow the upper plate clamp (110') to be moved along the projection (81A) of the member (81) to be riveted, on the side where the upper plate clamp (110') is located, without interfering with the projection (81A).

4. The rivet fastening machine according to claim 1, wherein the number of connecting rods in the set of connecting rods (3) is equal to 2.

5. The rivet fastening machine according to claim 1, wherein the first connecting rod (31) has an end with a hole, and the output shaft (21) of the motor drive system (2) extends through the hole provided in the end of the first connecting rod (31).

6. The rivet fastening machine according to claim 1, wherein the guide device (6) has a through hole, the ram (4) engages with the through hole, and the axis of the through hole is the guide axis (A6) of the ram.

7. The rivet fastening machine according to claim 1, wherein the alignment axis (A3) of the connecting rod in the deployed state is coaxial with the movement axis (A1) of the lower rivet die (9), which extends through the center of the lower rivet die (9).

8. The rivet fastening machine according to claim 1, wherein the rotation angle of the motor drive system is 20° to 180° for the transition of the connecting rods (31, 32) from the folded position to the unfolded position.

9. A method of riveting using a riveting machine according to any one of claims 1 to 8, - A step of positioning two members (81, 82) to be riveted together between the lower rivet die (9) and the upper rivet die (5), - With a hole (87) drilled through the two members (81, 82) to introduce the rivet (7) held by the upper rivet die (5), the motor drive system (2) is operated to move the connecting rods (31, 32) of the connecting rod set (3) from the folded position to the unfolded position, where the connecting rods are aligned along an axis (A3) that is coaxial with the moving axis (A1) of the lower rivet die (9), thereby causing the upper rivet die (5) to descend and bring the rivet (7) into the hole (87) drilled through the two members (81, 82) to be riveted, - A step of moving the lower rivet die (9) toward the upper rivet die (5) in order to set the rivet (7) Methods that include...

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