EP0301964A1 - Drilling and riveting machine - Google Patents

Abstract

The drilling means (14) and the riveting ferrule (69) are mounted slidably in directions which are inclined relative to the axis of the drilling/riveting head, the necessary pressure being provided by two arms (2, 3) driven by hydraulic jacks, the pieces to be assembled (A, B) being pressed against each another by sheet-clamping devices (6, 7) throughout an operating cycle. <??>Applications: automatic drilling and/or riveting in inaccessible places using known machines. <IMAGE>

Description

The present invention relates to a drilling and riveting device intended in particular, but not exclusively, for aeronautical construction.

Riveting is a method of assembling parts, generally of metal, in which, after drilling a hole passing through the two parts, a rivet can be introduced which may have a preformed head, the second head being constituted by a plastic crushing of the second end. This crushing results, most usually, from the application of strong pressure between the two ends of the rivet. Given the forces to be used and the dimensions of the parts to be riveted, the riveting installations are generally heavy installations which require, not only very large investments, but extensive premises.

An object of the present invention is a riveting device including a head whose front part is of reduced dimensions, in order to be able to work automatically in regions which are difficult to access and in particular inside a 90 ° dihedron. The traditional riveting drills do not allow under these conditions to perform the desired operations automatically. In these regions, drilling and riveting must be carried out with portable hand tools, breaking down the operations: drilling, installation of sealant, manual installation of the rivet and crushing. This breakdown results in a long and therefore costly execution time.

FR-A-2 532 205 discloses a riveter comprising, on a support console, a drilling unit, a rivet supply unit and a riveting unit, the console being able to be coupled with a robot or the like. But the riveting unit is constituted by a clamp, which does not allow permanent maintenance of the parts to be assembled during all of the operations. A power drill riveter automatic riveting is also described in US-A-4,180,195. This document relates to a conventional machine having particular methods of supplying rivets.

In view of the need to have a support piece used to form the second head of the rivet, the device according to the invention has a C-shaped configuration in which one of the branches applies pressure, and in which the second branch provides the necessary feedback.

Of course, this machine can be used as a stationary machine on a workbench, partly fixed on a bracket or suspended from a balancer, but it is particularly advantageous when it is mounted on a support whose movement can be programmed by digital control. , compared to the parts to be assembled. Thus, the part-machine reference remains constant during a work cycle, the part to be riveted can possibly also be mobile.

According to the present invention, the drilling and riveting device, of the type comprising a drill and a riveter with C-shaped configuration, is characterized in that it comprises a head provided with two arms controlled by hydraulic cylinders, respectively lower and upper , mounted sliding in slides and acting by pressure on the tools, the parts to be assembled being pressed between two sheet clamps under the control of a pneumatic cylinder, throughout an operating cycle.

Thus, the device comprises different pneumatic cylinders for positioning the members and hydraulic cylinders to ensure the force necessary for drilling and crushing the rivet. The device which is the subject of the present invention can be used as a drill alone, as a riveter alone when the holes for the passage of the rivets have been drilled beforehand or more generally in a drill and riveter. These uses are determined at the level of the digital control panel.

According to another characteristic of the invention, the drill and the riveting bolt are mounted on carriages movable in translation relative to the aforementioned arms in directions forming an angle less than 90 °. Thus, the slides of the carriages form a V on the branches of which the tools slide. This arrangement allows the riveting head to assemble in difficult positions.

• - la figure.1, une vue de côté de la tête de perçage et rivetage ;
• - la figure 2, une vue par-dessus de la même tête ;
• - la figure 3, une vue en coupe verticale de la perceuse ;
• - la figure 4, une vue du dispositif de pression sur les pièces à riveter ;
• - la figure 5, une vue par-dessus du bras d'amenée des rivets en coupe ;
• - la figure 6, une vue en élévation du dispositif de la figure 5 ;
• - la figure 7, une vue partiellement coupée de la tête de rivetage ;
• - la figure 8, une vue en coupe horizontale selon la ligne VIII-VIII de la figure 7.

Other characteristics and advantages of the present invention will appear during the following description of a particular embodiment, given solely by way of nonlimiting example, with reference to the drawings which represent:

• - Figure.1, a side view of the drilling and riveting head;
• - Figure 2, a view over the same head;
• - Figure 3, a vertical sectional view of the drill;
• - Figure 4, a view of the pressure device on the parts to be riveted;
• - Figure 5, a view over the supply arm of the rivets in section;
• - Figure 6, an elevational view of the device of Figure 5;
• - Figure 7, a partially cut view of the riveting head;
• - Figure 8, a horizontal sectional view along the line VIII-VIII of Figure 7.

As shown in Figures 1 and 2, the working head has, as known per se, the shape of a Cé, consisting of a frame 1 carrying at its two ends an upper arm 2 and a lower arm 3, movable in translation inside slides integral with the frame 1. The translational movement of the arms 2 and 3 is obtained by action on two hydraulic cylinders 4 and 5 (FIG. 8), only the cylinder 4 of the arm upper 2 appearing in FIG. 2. The aim of these jacks is to ensure the pressure necessary for crushing the rivet, the front part of the arm 2 constituting the hammer 21 for riveting in the working axis which is symbolized in the figure. with a mixed line. The reaction piece forming an anvil is carried by the arm 3. The arms 2 and 3 slide respectively in the slide 22 and 23 (Figure 2).

However, during the riveting cycle, it is important that the sheets to be joined are pressed firmly against each other, in order to avoid in particular that, during drilling, burrs are produced which deteriorate the quality and the tightness of the contact between the two sheets.

To this end, the parts to be riveted are trapped between an upper sheet clamp 6 and a lower sheet clamp 7. The sheet clamp 6 is mounted on a plate 11 secured to the frame 1 and it has an orifice 12 allowing the passage of rivets, and that of the drill bit. The sheet clamp 7 is movable in vertical translation and is actuated by a pneumatic cylinder 8, the rod of which is secured to levers 9 articulated on the frame 1. An adjusting screw 10 makes it possible to adjust the relative position of opening between the clamp sheet 7 and the sheet clamp 6, depending on the thickness of the sheets to be riveted.

There is a distinction in FIG. 1, the drill generally designated by the reference 14, carrying a tool of the drill type 13.

As this appears better in FIG. 2, on which the upper arm has been removed, the drill 14 is integral with a sliding carriage 15, on the one hand in a first direction on a slide 16 orthogonal to the working axis, and in a direction perpendicular to the direction of the slide 16, on a slide 17, the drill 14 can thus move in two perpendicular directions, the slide 16 being, according to a characteristic of the invention, inclined with respect to the axis of symmetry of the riveting head (not shown).

Symmetrically, the support 24 for supplying the rivets and the upper bolt 69 (Fig. 1) is mounted on a carriage 25 which can move in a first direction on a slide 26, under the influence of a jack, and in a direction perpendicular to that of the slide 26, on a slide 28.

As before, the slide 26 is inclined relative to the axis of symmetry of the head, the two slides 25 and 26 forming an angle of approximately 70 °. It is the successive displacement of the carriage 15, then of the carriage 25 which will allow on the one hand the drilling of the sheets and, on the other hand, the introduction of the rivet into the hole which has just been drilled. We also distinguish, in Figure 2, a support 29 which is intended to receive the end of the tube for introducing the rivets, as will be described later. The appropriate size rivets for each operation, selected from known devices such as vibrating bowls for example, come via a tube 70 (Figure 2) on the support 29. The riveting head is also advantageously provided means 71, 72 for depositing in the milled hole or not a sealant which is pressed against the lower surface of the head of the rivet and the upper sheet by crushing the rivet.

The drill 14 is shown in section in Figure 3. In this figure, in the mandrel 31 is mounted a tool 13 for drilling the two sheets to be assembled and, optionally, for milling the upper sheet to form a rivet head housing . The axis 32 of the drill is rotated by a pinion 33, itself mechanically connected to a set of pinions 34, the pinion axis 34 furthest from the hub 33 being driven by a pneumatic motor 35, connected to a source of pressurized air through a nozzle 36.

The penetration of the drill 13 into the sheets is obtained, after the drill has been rotated, by a pressure exerted by the hammer 21 (Fig. 1) on the support plate 37, when the drill 13 is brought in the axis of work by sliding along the slide 16.

As indicated above, the drill 14 is integral with a carriage 15 movable in vertical translation (in the figure) on the slide 17. After this movement of descent and drilling of the sheets, the drill is recalled upwards, as soon as the pressure on the arm 2 was released, by a spring 38 mounted between the carriage 15 and a point 39 of the slide. Thus after raising the arm 2, the spring 38 recalls the drill 14 upwards, along the slide 17. It can then carry out a translational movement on the slide 16 which releases the working axis for the introduction a rivet.

FIG. 4 is a detailed view showing the control of the lower sheet metal press 7. As indicated above, the control of the pressure on the sheets is obtained by the action of a pneumatic cylinder 8 mounted articulated around an axis 40 carried by a yoke fixed on the frame 1. The cylinder 8 is supplied by compressed air by means of a nozzle 41 which applies pressure to the piston 42 secured to the rod 43, the piston 42 being armed by a return spring 44. On the head 45 of the rod 43 of the piston is mounted a first lever 9 articulated around an axis 46 and which cooperates, by a pinion with a tooth 47, with a second lever 9 articulated at a point 48. A second lever 9 is itself articulated at 48, on the support 49 of the lower sheet metal press 7. Thus, when compressed air is introduced by the nozzle 41, the piston 42 rises inside the cylinder, which causes the first lever 9 to rotate in the dextrorsum direction, rotation which in turn causes the rotation in the direction opposite of the second lever 9 via the gear with a tooth 47, which results in an upward movement of the sheet metal clamp 7, movement which is continued until sufficient pressure is obtained on the lower plate.

Figures 5 and 6 show the device for feeding the rivets into the working axis with a view to their crushing.

Found in FIGS. 5 and 6, the elements mentioned above, namely the arm 24 for transporting the rivets, integral with the carriage 25 on the slide 28 which, itself, moves in the slide 26. The arm 24 is finished at its outer part by a clamp 50 below which extends the upper chuck 69 (not shown in Figures 5 and 6). The displacement of the carriage 25 is obtained by injection of compressed air into the cylinder 51 by the endpiece 56, the air causing the displacement of a piston 52 secured to the slides 28 on which the carriage 25 carrying the arm 24 slides. arm 24 is terminated by a clamp 50 which has the purpose of gripping the rivets arriving by the tube 70 (FIG. 2) on the tube support 29. When a rivet is present at the level of the tube 29, from the position shown in FIGS. 5 and 6, the piston 52 moves back, so as to bring the clamp 50, immediately below the entry of the tube 29, the clamp grips the rivet by its lower part, and brings it in the axis of work. Thus, the rivet is kept pinched permanently, which allows working of the riveting head in all positions. The rivet overhanging the hole formed in the sheets, the upper head 69 (fig.1) descends under the pressure of the arm 2, which releases the rivet from the clamp 50. Then the carriage moves back to grip the next rivet.

As indicated above, the introduction of the rivet into the hole provided for this purpose is carried out by a downward movement of the arm 2 which releases the rivet from the pliers 50. As in the case of the drill, the pliers holder arm 24 is recalled in the upper position, by a spring 55 fixed between the carriage 25 and a fixed point of the slide 28. The tube 29 for supplying the rivets is provided with two springs 58 making it possible to hold the rivet.

FIGS. 7 and 8 are detailed views showing the mounting of the upper 2 and lower 3 arms which are intended to apply the pressures necessary both for drilling by the arm 2 and for the actual riveting by the arms 2 and 3, this last pressure being applied to the lower 68 and upper 69 snaps. The snap 68 passes through the side clamp 7, while the snaps 69 passes through the side clamp 6.

As indicated above, the arm 2 is slidably mounted in a slide 22 of the frame, integral on the one hand with a slide 60, and on the other hand with the head 61 of the rod 62 of the piston 63, moving under the action of oil under pressure inside the cylinder 64, a spring 65 returning the upper arm upwards when the oil pressure is removed. The frame 1 also includes an opening 66 for the passage of the various cables and conduits necessary for the operation of the drilling and riveting head which is, moreover, fixed on a robot arm or the like.

As shown in FIG. 7, the arm 3 slides under the action of a jack 5 (not shown) inside a slide 23, the arm 3 being integral with a piston rod mounted in the direction opposite to that of the piston rod 62. Thus, the application of pressure especially during riveting is constantly balanced, that is to say that the crushing pressure of the rivet results from a double action of two forces of opposite directions. The crushing action of the rivet is thus much more progressive than in the case where one of the branches of the C shape hammer, and the other anvil.

There are, at the end of the arm 3 located in the working axis, the lower chuck 68 used to crush the rivet. The arm 3 slides in the slide 23 by means of a slide 67.

In the case of a complete drilling and riveting operation, the operating cycle is as follows:

The head coming to be fixed on both sides of the two sheets to be riveted A and B (figure 1), by a pressure exerted by the jack 8, the sheets are pressed between the sheet presses 6 and 7. They will remain pressed one against the other throughout a cycle. The first operation consists in drilling a rivet passage hole. To this end, the drill 14 slides along the slide 16 to bring the tool 13 into the working axis. The pneumatic motor 35 is then set in rotation, which results in the rotation of the drill bit 13. Simultaneously, the arm 2 begins its downward movement and the head 21 comes to bear against the surface 37 of the drill 14, so that that -this descends along the slide 17 and pierces the hole, the drill 13 passing inside the opening 12. The tool 13 can perform, depending on its shape, a simple drilling or drilling-milling. The pressure on the jack 4 being removed, the spring 65 pushes the piston 62 upwards, and the arm 2 rises. Likewise, the spring 38 returns the drill 14 to the upper position, after which the drill makes a backward movement along the slide 16, so as to release the working axis. A sealant can then be injected into the hole.

A rivet present at the upper level of the tube support 29 is then gripped by the clamp 50. The support 24 makes a movement towards the working axis along the slide 26. When the rivet is brought in front of the opening 12 , the arm 2 descends again, as does the upper dowel 69 which has advanced in the working axis. When continuing the downward movement of the arm 2, the upper bolt 69 comes to bear on the rivet head, being pressed by the hammer 21. Simultaneously, the lower arm 2 rises, so that the lower bolt 68 comes to bear against the lower end of the rivet. A pressure applied simultaneously on the cylinders 4 and 5 causes the crushing of the rivet and fixing of the two sheets at the point considered. The arms 2 and 3 then resume their distant position, the head moves and a new cycle of operations begins again.

Claims (7)

1. Digitally controlled drilling and riveting device comprising a frame (1) which can be mounted on a mobile support, drilling means and means for crushing at least one end of a rivet, having a C-shaped structure, characterized in that two arms, respectively upper (2) and lower (3), controlled by hydraulic cylinders (4, 5), are slidably mounted in slides (22, 23) of the frame, the upper arm (2) bringing to its end a hammer (21), and the lower arm (3) a chuck (68), the parts to be assembled being pressed throughout a riveting drilling cycle, between an upper sheet clamp (6) and a clamp -lower plate (7) movable in the direction of the working axis. 2. Device according to claim 1, characterized in that the drilling means (14) and the upper chuck (69) are mounted by carriages (15, 25) in slides (17, 28) parallel to the axis of working, the slides (17, 28) being slidably mounted in slides (16, 26) perpendicular to the slides (17, 28), the slides (16, 26) forming an angle of less than 90 ° between them. 3. Device according to any one of claims 1 or 2, characterized in that it comprises a support (29) for receiving the tube (70) for supplying the rivets, a clamp (50), mounted on a support ( 24) being movable between the working axis and a position in which it is located below the support (29). 4. Device according to any one of the preceding claims, characterized in that the hammer (21) of the arm (2) comes to bear successively on a support plate (37) of the drill (14), then on the upper surface of the snap (69). 5. Device according to any one of the preceding claims, characterized in that the sheet metal press (7) is brought in a translational movement along the working axis by a pneumatic cylinder (8), by the intermediate levers (9) pivotally mounted on the frame 1. 6. Device according to any one of the preceding claims, characterized in that the arms (2 and 3) move in the slides (22, 23) under the action of hydraulic jacks (4, 5). 7. Device according to any one of the preceding claims, characterized in that the rivets taken from the support (29) are held in position by the clamp (50).

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