MIXED MULTIAXIAL PIVOTING HEAD

Abstract

The invention relates to a multiaxial pivoting head intended to be mounted at the end of moving arm (22) of a machine-tool, said pivoting head comprising, on the one hand, a yoke (30) including a support shaft (32), said yoke being able to be mounted rotatably on said arm (22), while said support shaft (32) extends substantially perpendicular to said arm (22), and on the other hand, at least two working members (38, 40) installed on said support shaft (32) in positions angularly offset relative to one another, said support shaft (32) being rotatable to be able to alternately bring each of said at least two working members (38, 40) between a position retracted inside said yoke (30) and a working position protruding from said yoke. One of said at least two working members (40) is a waterjet cutting device.

Description

The present invention relates to a multiaxial pivoting head for a machine-tool, and in particular for a so-called five-axis machining tool.

This type of machine-tool includes a moving arm situated at the end of a robot or mounted on a gantry, and a pivoting head mounted at the end of said moving arm. The pivoting head includes a fork block forming a yoke, mounted rotatably at the end of the arm, and the fork block is equipped with a support shaft which, in turn, extends substantially perpendicular to the direction defined by the arm. The support shaft is thus equipped with at least two spindles able to respectively receive a work tool. The spindles extend in planes substantially parallel to one another and perpendicular to the support shaft; they may also extend in a same plane. They are furthermore angularly offset relative to one another on the support shaft. In this way, the tools can be moved in an alternating manner, between a working position in which they extend protruding from the fork block and a retracted position in which they are brought inside the fork block, while driving the rotation of the support shaft in one direction, then in an opposite direction. Reference may in particular be made to document EP 1,405,691 A1, which describes a pivoting head allowing such an implementation.

Thus, by equipping the spindles with two different types of tool, it is easy to successively machine a part, for example crudely, then more precisely, with practically no downtime, by switching the position of the two tools through the simple rotation of the support shaft.

For certain complex parts, it is necessary to machine them, but also to perform prior cutouts or clipping. These cutouts are, under certain circumstances, done using a waterjet cutting device. Consequently, the parts are first installed on a specific machine-tool, having a moving head equipped with an injection nozzle, and a pressurizing pump to be able to inject pressurized water, usually with an abrasive. Such a machine is in particular equipped with a facility for recovering sludge resulting from spraying a mixture of water, abrasive and material.

Consequently, when the cutout must be done prior to machining, the parts should, in a first phase, be brought under the waterjet machine-tool, then next brought under the machining machine-tool. The transfer time of the part is then added to the cutting out and machining time.

One problem that arises and that the present invention seeks to resolve is to be able to reduce the treatment times for the parts, and thus to reduce the costs.

To that end, the present invention proposes a multiaxial pivoting head intended to be mounted at the end of moving arm of a machine-tool, said pivoting head comprising, on the one hand, a yoke including a support shaft, said yoke being able to be mounted rotatably on said arm, while said support shaft extends substantially perpendicular to said arm, and on the other hand, at least two working members installed on said support shaft in positions angularly offset relative to one another, said support shaft being rotatable to be able to alternately bring each of said at least two working members between a position retracted inside said yoke and a working position protruding from said yoke. One of said at least two working members is a waterjet cutting device.

Thus, one feature of the invention lies in the implementation of a waterjet cutting device of the support shaft inside the yoke, or fork block, the same way as the machining tool, so as to be able to cut out a part, then machine it without having to disassemble it and without even having any downtime. The waterjet cutting device is thus brought from a working position to a position retracted inside the yoke, by rotating the support shaft, while the other working tool is consequently brought into the working position. In this way, a single machine-tool structure is necessary, which reduces the installation cost, but furthermore, the cutting out and machining time is shortened, since no part disassembly is necessary. Additionally, the positioning precision of the cutting head and the machining head is greatly improved due to the use of a same support axis to support both. Furthermore, since it is possible to go from a cutting out phase to a machining phase without downtime, it is also conversely possible to go from a machining phase to a cutting out phase. From there, when the part has large dimensions, time is saved on the movements of the tooling head.

According to one particularly advantageous feature of the invention, said waterjet cutting device includes an injection nozzle and a recovery receptacle mounted across from said injection nozzle. In this way, the cutting sludge is recovered in particular incorporating water, abrasive and material debris, during the cutting out phase, owing to the recovery receptacle, which is situated across from the injection nozzle in the extension thereof. Indeed, the multiaxial pivoting head is driven, relative to the part to be cut out, so as to bring the injection nozzle on one side of the part and the reception receptacle on the other side. During the travel of the jet of water and abrasive particles, said jet crosses through the part and finishes in the receptacle. From there, the cutting out does not cause any projection of water or sludge, which makes it possible to implement the device on the support shaft, close to the other spindle, which is driven by an electric motor. Additionally, the abrasive particles and the water from the jet do not penetrate the inside of the spindle, which could damage the mechanical elements by abrasion as well as corrosion.

Preferably, said injection nozzle extends in an inclined direction relative to the tangent to said support shaft. Thus, the waterjet cutting device includes a tubing that extends along a tangent to the support shaft, and the injection nozzle extends in the extension of the tubing along a direction inclined relative to the tubing. In this way, it is easier to perform the cutout in withdrawn zones of the part, as will be explained in more detail in the continuation of the description.

According to one particularly advantageous embodiment, said waterjet cutting device comprises a discharge duct connected to said recovery receptacle. In this way, the cutting sludge is suctioned continuously as it is produced. It is then possible to operate the waterjet cutting device irrespective of the orientation of the nozzle and the receptacle, in particular when the receptacle is situated above the nozzle relative to the ground.

Furthermore, said waterjet cutting device advantageously comprises an abrasive particle intake duct connected to said injection nozzle. In this way, the pressurized water intake circuit is independent and is directly connected to the injection nozzle, while the abrasive particles are introduced into the waterjet through the intake duct at the injection nozzle.

According to one particularly advantageous alternative embodiment, said waterjet cutting device comprises a V-shaped maintaining member having two branches to keep said recovery receptacle opposite said injection nozzle. Advantageously, said V-shaped maintaining member is mounted rotatably mobile around an axis substantially perpendicular to said support shaft. Thus, said V-shaped maintaining member defines a mean plane and is connected to said support shaft such that said mean plane extends substantially perpendicular to the support shaft. The axis around which the V-shaped maintaining member is able to rotate intersects the two branches. In this way, during the cutting phase, the V-shaped maintaining member can be rotated by a predetermined amplitude, so as to be able to facilitate the movement of the pivoting head as a function of the geometry of the part.

Preferably, according to this alternative embodiment, said V-shaped maintaining member further comprises a fastening platen arranged on one of said two branches to be able to fasten said V-shaped maintaining member to said support shaft. As will be explained in more detail in the continuation of the description, the platen has controllable locking members making it possible to interchange the V-shaped maintaining member. Indeed, different types of V-shaped maintaining members are provided, so as to be able to obtain different distances between the injection nozzle and the recovery receptacle to be able to cut out parts with different thicknesses and different geometries.

Consequently, the other of said branches advantageously receives said recovery receptacle, which is open toward the other branch.

According to one particularly advantageous embodiment of the invention, said V-shaped maintaining member includes a passage pathway emerging in said receiving receptacle and in said fastening platen to form a portion of said discharge duct. Thus, the passage pathway includes, at the fastening platen, a connector intended to be connected to the inlet of another discharge duct portion, when the fastening platen is fastened on the support shaft.

Furthermore, the multiaxial pivoting head further comprises a water pressurizing device coupled to said waterjet cutting device, and said water pressurizing device is able to be housed inside said moving arm. In this way, the water pressurizing device is situated as close as possible to the injection nozzle, which makes it possible to decrease the pressure losses compared with waterjet cutting facilities according to the prior art, where they are far away from one another.

Other particularities and advantages of the invention will emerge from reading the following description of one particular embodiment of the invention, provided for information but non-limitingly, in reference to the appended drawings, in which:

FIG. 1 is a diagrammatic perspective view of a machine-tool including a multiaxial pivoting head according to the invention;

FIG. 2 is a partial diagrammatic perspective view of an element of the multiaxial pivoting head according to the invention according to a first embodiment;

FIG. 3 is a partial diagrammatic perspective view of the elements shown in FIG. 2 from another viewing angle;

FIG. 4 is a partial diagrammatic perspective view of the elements shown in FIG. 2 in a first working position;

FIG. 5 is a partial diagrammatic perspective view of the elements shown in FIG. 2 in a second working position;

FIG. 6 is a diagrammatic perspective view of the multiaxial pivoting head according to the invention according to a second embodiment, in the working position;

FIG. 7 is a diagrammatic view of the multiaxial pivoting head shown in FIG. 6, in an idle position; and

FIG. 8 is a detailed view of an element shown in FIGS. 6 and 7.

FIG. 1 illustrates a machine-tool 10 comprising a gantry 12 having an upper crosspiece 13 extended above a worktable 14. The latter makes it possible to immobilize a complex part 16 having a curve 18 and parallel stiffeners 20. The machine-tool 10 comprises a vertical arm 22 shown in cutaway and connected to the gantry 12 by a carriage 24 making it possible to drive the arm 22 in a direction parallel to the crosspiece 13. Furthermore, the arm 22 is translatable on its own axis, which extends vertically.

The arm 22 has an end 26 on which a multiaxial pivoting head 28 is mounted. It comprises a yoke 30 forming a fork block, and mounted rotating at the end 26 of the arm 22 around the vertical axis of the arm 22. It additionally comprises a support shaft 32 mounted rotating inside the yoke 30, along an axis substantially perpendicular to the vertical axis of the arm 22 and that will be described in more detail below in reference to FIGS. 2 to 4.

FIG. 2 shows the support shaft 32 able to be installed inside the yoke 30 or fork block to be able to be rotated around the horizontal axis B. The support shaft 32 has two opposite circular flanks 34, 36 and between the two, part of a spindle 38 extending along an axis tangential to the support shaft 32 perpendicular to the axis B and able to receive a work tool, and on the other hand a waterjet cutting device 40. The waterjet cutting device 40 extends in a position substantially diametrically opposite the spindle 38 relative to the support shaft 32.

Reference will be made to FIG. 3, providing a more detailed view of the waterjet cutting device 40. It comprises a V-shaped maintaining member 42 having two branches, a free branch 44, and a fastening branch 46 ending with a fastening platen 48. It includes an injection nozzle 50 mounted in the extension of a tubing 52. The tubing 52 extends tangentially to the support shaft 32, while the injection nozzle 50 extends in a direction inclined relative to the tubing 52, for example comprised between 150° and 170°. The fastening platen 48 has an indentation 54, and it is connected to the support shaft 32 such that the tubing extends through the indentation 54, while the injection nozzle 50 extends toward the end of the free branch 44, and more specifically toward a receiving receptacle 56 secured to the end of the free branch 44. The receiving receptacle 56 has a cylindrical shape open toward the injection nozzle 50. It is made from a high-strength material and is connected to a discharge duct 58, which extends inside the free branch 44 to next be able to extend through the pivoting head, then toward a recovery reservoir. Furthermore, the discharge conduit 58 is intended to be placed in a vacuum using a suction pump, not shown, as will be explained below.

Furthermore, the fastening platen 48 is fastened on a crown 60 shown transparently through the support shaft 32, the rotation of the crown 60 being able to be controlled using an electric actuator 62. In this way, the V-shaped maintaining device 42, as a whole, is able to be rotated. Advantageously, the tubing 54 supporting the injection nozzle 50 is rotatably secured to the crown 60 to be able to drive the receiving receptacle 56 over the course of the driving of the injection nozzle 50. In this way, the receiving receptacle 56 remains in the axis of the injection nozzle 50 irrespective of the position of the nozzle 50.

Furthermore, the injection nozzle 50 has a lateral connector 64 to be able to connect an abrasive particle intake conduit 66 that appears in FIG. 5. In this FIG. 5, the support shaft 32 is engaged between two facing flanges 68, 70 of the yoke 30 so as to be able to pivot around the horizontal axis B.

This figure also shows, on the one hand, the V-shaped maintaining member 42 equipped with the receiving receptacle 56, and the injection nozzle 50, which both extend protruding from the yoke 30, and on the other hand, the complex part 16 provided with its stiffeners 20. It will be noted that the multiaxial pivoting head is adjusted such that the injection nozzle 50 and the receiving receptacle 56 are situated on either side of the stiffener 20. The axis of the injection nozzle 50 is then substantially perpendicular to the stiffener 20.

Before describing the operation of the multiaxial pivoting head 28, we will return to FIGS. 1 and 2, showing a water pressurizing device coupled to the waterjet cutting device. More precisely, in FIG. 1, the end 26 of the arm 22 houses, inside, a pressurizing device 72 including an intensifier and an accumulator that are directly connected to the injection nozzle 50 using a high-pressure conduit 74.

Consequently, the water is brought to the pressurizing device and the intensifier using a low-pressure hose 76, while the pressurized oil is brought using two medium-pressure hoses 78. The water circuit includes a booster pump 80, and a water supply 82, while the oil circuit includes a hydraulic pump 84, a tank 86 and a distributor 88.

The hydraulic circuit makes it possible to drive, alternatingly, a piston in a chamber, and from there pressurized water, according to a well-known technique, up to pressures from 4000 to 6000 bars. Thus, owing to the proximity of the pressurizing device 72 and the injection nozzle 50, the pressurized water intake conduit is consequently shorter, and from there, the pressure losses are lower. Consequently, for a given pressure, more effective cutting is obtained.

The rigid pipe lengths with a significant curve radius that are necessary on large machines are eliminated, thereby avoiding fragile butt jointing by very high-pressure connection.

Reference will again be made to FIG. 4 illustrating the multiaxial pivoting head in the cutting position of the stiffener 20. Thus, the implementation of the pressurized water through the nozzle 50 and the concomitant injection of abrasive particles through the lateral connector 64 cause cutting of the stiffener 20. Furthermore, the discharge duct 58 connected to the receiving receptacle 56 is placed in a vacuum. In this way, the waterjet crosses through the stiffener 20, then ends up in the receiving receptacle 56 situated opposite it, driving the abrasive particles, debris from the material and lubricants with it. The sludge thus formed is suctioned continuously through the discharge duct 58. In this way, the essence of the projections due to the waterjet are suctioned through the receiving receptacle 56. Consequently, the other elements of the pivoting head, and in particular the mechanism of the support shaft 32 and the spindle 38, are not affected. Owing to this recovery arrangement for the sludge, the waterjet cutting device 40 may be arranged near the spindle 38.

The cutting of the stiffener 20 is done by translating the multiaxial pivoting head 28 parallel to the stiffener according to a predetermined speed.

After the cutting operation is complete, and when one wishes to carry out a machining step in the same zone of the complex part 16, it is then easy to command the rotation of the support shaft 32 by about 180°, for example during hidden time during the movement of the multiaxial pivoting head 28, so as to retract the waterjet cutting device 40, and to bring the spindle 38 equipped with a tool 90 to protrude from the yoke and into a working situation as illustrated in FIG. 5. This figure shows the multiaxial pivoting head 28 adjusted above the complex part 16. The waterjet cutting device 40 is then inactive and housed inside the yoke 30.

The tool 90 is precisely brought against the edge of a recess 92 arranged in the complex part 16 so as to be able to trim said edge, for example.

Conversely, when a machining phase is complete and a cutting operation is necessary in the environment near the location where the multiaxial pivoting head 28 is situated, the support shaft 32 is once again rotated by about 180° in the opposite direction, so as to again make the waterjet cutting device 40 operational.

Reference will be made to FIGS. 6 and 7 to describe the multiaxial pivoting head according to another embodiment. The elements identical to the preceding embodiment or having the same functions bear the same reference, with a prime sign:

Thus, FIG. 6 shows the multiaxial pivoting head 28′ comprising a yoke 30′ and a support shaft 32′ situated inside. The support shaft 32′ is equipped with a spindle 38′ and in a position substantially diametrically opposite a waterjet cutting device 40′. The latter has an injection nozzle 50′ and, opposite it, a receiving receptacle 56′ mounted on a V-shaped maintaining member 42′ that will be described in more detail in reference to FIG. 8.

The V-shaped maintaining member 42′ has a free branch 44′, and a fastening branch 46′ also forming the fastening platen 48. The latter has an indentation 94 and centering 96, 98 and fastening 100, 102 pins.

The end of the free branch 44′ includes a receiving receptacle 56′, and inside the free branch 44′, a discharge duct portion, concealed here, extends, which emerges in the platen 48′ at a connector 104.

Thus, the V-shaped maintaining member 42′ will be able to be installed automatically on the support shaft 32′, the injection nozzle 50′ extending through the indentation 94, whereas on the one hand, the centering spindles 96, 98 and fastening spindles 100, 102 engage in orifices provided to that end, and on the other hand, the connector 104 of the discharge duct portion is automatically and tightly connected to another portion of the discharge duct.

In this way, as illustrated diagrammatically in FIG. 7, different types of V-shaped maintaining members 42′ will be installed in a rack and the multiaxial pivoting head 28′ will be able to be brought to a given type of V-shaped maintaining member 42′ for automatic assembly. The types of V-shaped maintaining members 42′ may differ, for example, by the distance between the two branches, and consequently the distance between the receiving receptacle 56′ and the injection nozzle 50′. This is for example the distance between the first two maintaining members 106, 108 shown in FIG. 7. The third 110 is not strictly speaking operational as a tool and simply makes it possible to protect the injection nozzle 50′. The fourth 112 makes it possible to bear a measuring system and is also not operational as a tool. The last 114 is fully operational and includes a motor making it possible to rotate the fastening platen 48′.

Claims

1. A multiaxial pivoting head intended to be mounted at the end of moving arm of a machine-tool, said pivoting head comprising, on the one hand, a yoke including a support shaft, said yoke being able to be mounted rotatably on said arm, while said support shaft extends substantially perpendicular to said arm, and on the other hand, at least two working members installed on said support shaft in positions angularly offset relative to one another, said support shaft being rotatable to be able to alternately bring each of said at least two working members between a position retracted inside said yoke and a working position protruding from said yoke;

wherein one of said at least two working members is a waterjet cutting device.

2. The multiaxial pivoting head according to claim 1, wherein said waterjet cutting device includes an injection nozzle and a recovery receptacle mounted across from said injection nozzle.

3. The multiaxial pivoting head according to claim 2, wherein said injection nozzle extends in an inclined direction relative to the tangent to said support shaft.

4. The multiaxial pivoting head according to claim 2, wherein said waterjet cutting device comprises a discharge duct connected to said recovery receptacle.

5. The multiaxial pivoting head according to claim 2, wherein said waterjet cutting device advantageously comprises an abrasive particle intake duct connected to said injection nozzle.

6. The multiaxial pivoting head according to claim 2, wherein said waterjet cutting device comprises a V-shaped maintaining member having two branches to keep said recovery receptacle opposite said injection nozzle.

7. The multiaxial pivoting head according to claim 6, wherein said V-shaped maintaining member is mounted rotatably mobile around an axis substantially perpendicular to said support shaft.

8. The multiaxial pivoting head according to claim 6, wherein said V-shaped maintaining member further comprises a fastening platen arranged on one of said two branches to be able to fasten said V-shaped maintaining member to said support shaft.

9. The multiaxial pivoting head according to claim 8, wherein the other of said two branches receives said recovery receptacle.

10. The multiaxial pivoting head according to claim 4, wherein said waterjet cutting device comprises a V-shaped maintaining member having two branches to keep said recovery receptacle opposite said injection nozzle, and wherein said V-shaped maintaining member includes a passage pathway emerging in said receiving receptacle and in said fastening platen to form a portion of said discharge duct.

11. The multiaxial pivoting head according to claim 1, further comprising a water pressurizing device coupled to said waterjet cutting device, and wherein said water pressurizing device is able to be housed inside said moving arm.