Machine Tool

Abstract

The invention relates to a machine tool (M) comprising a kinematic structure (100) that moves an electric spindle (300) in a plane perpendicular to the axis of the electric spindle (300), notable in that said kinematic structure (100) is an articulated structure comprising two articulated arms (110, 120) articulated about axes of rotation parallel to the axis of the electric spindle (300), the second end (122) of the second arm (120) accepting the electric spindle (300), the translational movement of the workpiece (P) with respect to the tool (O) of the electric spindle (300) in a linear movement parallel to the axis of the electric spindle (300) being brought about by a workpiece (P) support module (200) or by a plate support module (130).

Claims

1. A machine tool (M) comprising a kinematic structure (100) that moves an electric spindle (300) carrying a cutting tool (0), the cutting tool (0) rotating on the axis of the electric spindle (300), the kinematic structure (100) moving the electric spindle (300) in a positioning plane perpendicular to the axis of the electric spindle (300), the machine tool (M) comprising a workpiece (P) support module (200), characterized in that said kinematic structure (100) positions the electric spindle in said positioning plane and is an articulated structure comprising two articulated arms (110, 120): a first arm (110) having two ends (111, 112), a first end (111) of the first arm (110) being mounted to pivot in relation to a plate (130) about a single axis of rotation parallel to the axis of the electric spindle (300), a first means of driving (140) in rotation comprising a rotating shaft motor ensuring the movement about this axis, a second arm (120) having two ends (121, 122), a first end (121) of the second arm (120) being mounted to pivot in relation to the second end (112) of the first arm (110) about a single axis of rotation parallel to the axis of the electric spindle (300), a second means of driving (150) in rotation comprising a rotating shaft motor ensuring the movement about this axis, the second end (122) of the second arm (120) receiving the electric spindle (300), the machining taking place by a relative translation movement of the workpiece in relation to the electric spindle positioned and held fixed by the kinematic structure in said positioning plane, the translational movement of the workpiece (P) in relation to the tool (0) of the electric spindle (300) in a linear movement parallel to the axis of the electric spindle (300) being brought about by the workpiece (P) support module (200) or by a plate (130) support module.

2. The machine tool (M) according to claim 1, characterized in that each axis of rotation of said articulated structure (100) is equipped with two encoders.

3. The machine tool (M) according to claim 1, characterized in that the axes of rotation of said articulated structure (100) each comprise two bearings.

4. The machine tool (M) according to claim 1, characterized in that the axes of rotation of said articulated structure (100) are equipped with a means for movement having a cycloidal reducer without backlash.

5. The machine tool (M) according to claim 2, characterized in that each second so-called recovery bearing supports each second encoder.

6. The machine tool (M) according to in claim 1, characterized in that it comprises a cooling circuit and/or several radiators stabilizing the structure by evacuating the heat generated by the various subassemblies of which it is composed.

7. The machine tool (M) according to in claim 1, characterized in that said workpiece (P) support module (200) comprises one or more rotary axes for orienting the workpiece (P).

8. The machine tool (M) according to in claim 1, characterized in that the positions adopted by the electric spindle (300) are divided into two zones, a machining zone proper and a maintenance zone where the electric spindle (300) may undergo a variety of operations outside of machining, the mobility provided by the articulated structure allowing the electric spindle (300) to go beyond the machining zone.

9. The machine tool (M) according to claim 1, characterized in that the plate is inclined.

10. The machine tool (M) according to in claim 1, characterized in that the plate is connected to a frame by means of a quick-change coupling interface.

11. The machine tool (M) according to claim 8, characterized in that the electric spindle carries a cleaning tool making it possible to clean not only the machining zone but also beyond this zone.

12. The machine tool (M) according to claim 2, characterized in that the encoders do not have the same functions, a first encoder being used to measure the speed, while the second encoder measures the position for each axis.

13. The machine tool (M) according to claim 12, where the motors each comprise a reducer, characterized in that a first encoder is associated with the motor upstream from the reducer and provides for measuring the speed and a second encoder is associated with the recovery bearing and provides for measuring the position.

14. The machine tool (M) according to claim 13, characterized in that the second encoder for measuring the position comprises, for at least one arm, a rod sliding in a sheath and able to measure the angular position of the other end of the arm and thus to take into account the flexural deformations of the arm for which position is being measured.

15. The machine tool (M) according to claim 16, characterized in that the rod and sheath assembly further comprises one or more of the following sensors:a linear sensor measuring the deflection parallel to the axis of articulation, a linear sensor measuring the radial elongation in the longitudinal direction of the arm, an angular sensor measuring the torsion of said arm.

16. The machine tool (M) according to claim 1, characterized in that at least one articulation comprises two motors.

17. The machine tool according to claim 1, characterized in that it comprises a self-guided slide which cooperates with the articulated structure.

18. Method of machining of the machine tool according to claim 1, characterized in that it involves dividing the axes of displacement between the positioning axes implemented by the articulated structure and a working axis implemented by the translation movement and performing the machining by a relative translation movement of the workpiece with respect to the electric spindle positioned and held fixed by the kinematic structure in said positioning plane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG. 1 is a schematic drawing of a partial exterior perspective view of a first embodiment of the machine tool of the invention;

[0064] FIG. 2 is a schematic drawing of a front view of the articulate spindle support structure of FIG. 1;

[0065] FIG. 3 is a schematic drawing of a side view of the articulate spindle support structure of FIG. 1;

[0066] FIG. 4 is a schematic drawing of a cross sectional view with the two arms situated in the same cross section;

[0067] FIG. 5 is a schematic drawing of a rear view illustrating a different embodiment for the second encoder;

[0068] FIG. 6 is a schematic drawing of a perspective view of another embodiment of the machine tool with movable plate and comprising a workpiece holder module;

[0069] FIG. 6a is a schematic drawing of a perspective view of another embodiment of the machine tool with fixed plate and comprising a workpiece holder module;

[0070] FIG. 7 is a schematic drawing of a perspective view of another embodiment of the machine tool with movable plate and comprising two workpiece holder modules;

[0071] FIG. 8 is a schematic drawing of a front view of the embodiment of FIG. 7 illustrating the movement possibilities;

[0072] FIG. 9 is a schematic drawing of a front view of another embodiment of the machine tool of the invention comprising a casing for the machining zone and the movement possibilities;

[0073] FIG. 10 is a schematic drawing of a front view of another embodiment of the machine tool of the invention comprising a casing;

[0074] FIG. 11 is a schematic drawing of a top view of two machine tools according to the invention in side-by-side juxtaposition;

[0075] FIG. 12 is a schematic drawing of a top view of four machine tools according to the invention arranged in a star pattern with their machining zone at the center;

[0076] FIG. 13 is a schematic drawing of a top view of four machine tools according to the invention arranged symmetrically in two-by-two opposition as two linear cells with the machining zone at the center of the cells;

[0077] FIG. 14 is a schematic drawing of a top view of four machine tools according to the invention arranged in two-by-two opposition as two linear cells;

[0078] FIG. 15 is a schematic drawing of a top view of three machine tools according to the invention arranged in a linear cell;

[0079] FIG. 16 is a schematic drawing of the embodiment of FIG. 6 in a detachable version;

[0080] FIG. 17 is a schematic drawing of another embodiment of a machine tool according to the invention;

[0081] FIG. 18 is a schematic drawing of the embodiment of FIG. 6 equipped with a cleaning means;

[0082] FIG. 19 is a schematic drawing of a perspective view of another embodiment of a machine tool according to the invention;

[0083] FIG. 20 is a schematic drawing of a front view illustrating the movement possibilities of the articulated structure of the machine tool of FIG. 19;

[0084] FIG. 21 is a schematic drawing of a side view in cross-section with the two arms situated in the same cross-sectional plane of another embodiment, with an articulation having two motors.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0085] As illustrated in the drawings of FIGS. 1, 2, 3 and 4, the machine tool referenced overall as M comprises, arranged on a bed B, an articulated tool O holder structure 100 and a workpiece P holder module 200.

[0086] The articulated structure 100 moves an electric tool O carrier spindle 300. The electric spindle 300 drives the tool O in rotation. The axis of the electric spindle 300 is parallel to the horizontal axis Z.

[0087] This articulated structure 100 is motorized and displaces the electric spindle 300 in a plane perpendicular to the axis of the electric spindle 300, that is, in the vertical plane perpendicular to the Z axis and defined by the X and Y axes.

[0088] According to the invention, said articulated structure 100 comprises two arms 110 and 120.

[0089] The first arm 110 has two ends 111 and 112 with a first end 111 guided in rotation relative to a plate 130 about a single axis of rotation parallel to the Z axis. A first means for driving in rotation 140 ensures the moving of said arm 110 about this axis.

[0090] The second arm 120 has two ends 121 and 122 with a first end 121 that is guided in rotation relative to the second end 112 of the first arm 110 about a single axis of rotation parallel to the Z axis. A second means of driving in rotation 150 provides for the moving of said arm 120 about this axis.

[0091] The second end 122 of the second arm 120 receives the electric spindle 300 in fixed fashion. According to the invention, the axes of rotation of the tool O, and the articulation of the arms 110 and 120, are parallel to each other and thus to the Z axis.

[0092] The translation of the workpiece P toward the tool O of the electric spindle 300 in a linear movement parallel to the Z axis for purposes of machining may be provided in various ways.

[0093] Either, for example as illustrated in the drawing of FIG. 6, the plate 130 is displaced along rails 131 and 132 and is outfitted with a moving means (not shown), the workpiece P holder module 200 being fixed in translation.

[0094] Or, according to an embodiment as illustrated, for example, in the drawing of FIG. 6a, it is the workpiece holder module 200 which is displaced along rails and outfitted with a moving means.

[0095] The articulated structure 100 provides for the displacement of the electric spindle 300 in the vertical plane defined by the X and Y axes in movements of rotation about axes parallel to Z and it is displaced in translation along the Z axis in order to bring the tool into contact with the workpiece P to accomplish the machining.

[0096] Thus, the articulated structure 100 illustrated implements only two pivot linkages and one sliding linkage along the axis of the electric spindle 300, making it possible to have a rigid structure. Such a structure in particular is able to perform with precision all the infeed machining operations by moving solely along a single axis.

[0097] In order to optimize this rigidity, each rotary axis of the articulated structure 100 is implemented with a recovery bearing which better allows for the stresses to which said rotary axes are subjected, especially during the movement of infeed translation along the Z axis. Thus, the rotary axis linking the first end 111 of the first arm 110 comprises two guide bearings 133 and 134 which are preformed in the plate 130. Likewise, the rotary axis linking the second end 112 of the arm 110 to the first end 121 of the second arm 120 comprises two guide bearings 113 and 114 which are preformed in the second end 112 of the first arm 110.

[0098] Again, for purposes of optimized rigidity, each rotary axis is placed in motion by means of a motor (140, 150) and a reducer (160, 170) of no-backlash cycloidal type, positioned directly on each axis.

[0099] In addition to this optimized rigidity, in order to allow for the deformations caused by the stresses undergone by the structure, each rotary axis is equipped with two rotary encoders 610, 620 and 630, 640. A first rotary encoder 610, 630 may be associated with the motor and reducer block (140, 160) and (150, 170) and the second one 620, 640 may be positioned as illustrated, at the end of the axis, in the area of the recovery bearing 133, 113. The distance between the two rotary encoders on each axis optimizes the precision.

[0100] The two encoders for each articulation do not have the same function. More precisely, the first rotary encoder 610, 630 associated with the motor 140, 150 upstream from the reducer 160, 170 has the function of measuring the velocity, while the second encoder 620, 640 positioned in the area of the recovery bearing 133, 113 has the function of measuring the position, taking into account the deformations.

[0101] The control unit (not shown) of the machine tool M thus manages the information coming from two encoders for each rotary axis of the articulated structure. The numerical control system associated with this control unit is thus of the type adapted to machining centers and ensuring that the desired precision criteria are met.

[0102] In order to provide a moving means adapted to the mass of the different elements being moved, a configuration where the movement of the lower arm 110 on the plate 130 is provided by two motors 140 and 140 is illustrated by the drawing of FIG. 21. Each motor 140, 140 comprises a velocity encoder 610, 610 situated upstream from the reducer. As illustrated, the position encoder 620 is placed in common and situated in a central position between the two bearings.

[0103] According to one embodiment, not illustrated, each pivot linkage comprises two motor-reducers.

[0104] The quest for the most precise possible measurement of the positioning has led the patent applicant to conceive of a second encoder able to take into account for each articulation the deflection experienced by the arm with which it is associated. The embodiment illustrated by the drawing of FIG. 5 illustrates encoders 620 and 640 whose architecture takes into account the deflection of the arms.

[0105] In fact, each encoder 620 comprises a movable rotating portion whose angle of rotation is defined by the angle of rotation adopted by the distal end of the arm with respect to the encoder. To accomplish this, the rotating portion of each encoder 620 and 640 forms a sheath 621 and 641 in which a rod 622 and 642 slides, joined firmly in rotation to the distal end of the arm whose angular position is being measured. Thus, the position encoder does not simply measure the angular position of the base of the arm, but also takes into account any bending of that arm.

[0106] In order to optimize the measuring, and in accordance with the invention, the rod and sheath assembly further comprises one or more of the following sensors: [0107] a linear sensor measuring the deflection parallel to the axis of articulation situated at the level of the link between the rod and the distal end, [0108] a linear sensor measuring the radial elongation in the longitudinal direction of the arm, measuring the sliding of the rod in the sheath, [0109] an angular sensor measuring the torsion of said arm situated between the sheath and the rod.

[0110] According to the embodiment illustrated by the drawing of FIG. 1, the workpiece P holder module 200 is designed such that the workpiece P can be rotated about an axis parallel to the Y, Z plane and about a horizontal axis parallel to the X axis in the position of the drawing. To accomplish this, the workpiece P holder module comprises a movable workpiece P support bed 210. This movable bed 210 rotates with respect to a swing bed 220, which rotates about a horizontal axis with respect to a fixed portion 230 of the workpiece holder module 200. These different rotations enlarge the range of possible machining while keeping the advantages of the invention.

[0111] The embodiment illustrated by the drawing of FIG. 6 illustrates more precisely an implementing of the embodiment shown by the drawing of FIG. 1. The bed B is composed of a parallelepiped supporting the rails 131 and 132, at one end of which is arranged the workpiece holder module 200, being fixed. As illustrated, the structure is open and has easy access on all sides. Likewise, the footprint is reduced in size.

[0112] This embodiment shall serve as a basis for illustrating various technical effects provided by a machine tool according to the invention.

[0113] Thus, for example, the drawing of FIG. 7 illustrates the possibilities of such a machine working with two workpiece holder modules 201 and 202 placed alongside each other and situated at the same end of the bed B. These possibilities are due to the fact of the articulated structure formed by the two arms having the movement possibilities as illustrated by the drawing of FIG. 8.

[0114] These movement possibilities are divided into two zones: [0115] a machining zone as illustrated by the two windows Zu arranged on either side of the bed B, [0116] a maintenance zone illustrated by line Zm encompassing the two machining windows.

[0117] The machining windows correspond to the positions of the spindle making it possible to achieve the desired machining criteria, especially as regards the rigidity of the structure. The maintenance zone Zm corresponds to the positions made possible by the pivot links of the articulated structure and extends, as illustrated, far beyond the machining zones Zu.

[0118] The positioning possibilities provided by the articulated structure thus make it possible to outfit the machine tool M with a casing C to protect the machining zone Zu, such as that illustrated by the drawings of FIGS. 9 and 10. As illustrated in the drawing of FIG. 9, the electric spindle may exit from the casing C to undergo a maintenance procedure.

[0119] As illustrated in the drawing of FIG. 10, the machine tool M comprises a self-guided slide 400 which partially enters into the zone protected by the casing C. In order to do so, this slide 400 is in the form of a bracket 410 supporting a functional maintenance module 411 secured to platform on wheels 420. In order to support the bracket 410, said slide on wheels 420 has a ground surface equivalent to the projection of said bracket. In order to allow the end of the bracket 410 to enter into the zone protected by the casing C, the latter is raised with respect to the surface over which the slide is moving in order to allow the movement of said slide 400 without obstacles. As illustrated in this drawing, the functional maintenance module can reach the two articulations of the machine tool thanks to the positioning possibilities of the articulated structure.

[0120] This positioning flexibility also makes it possible to propose a machine tool M whose plate 130 moves along a plane inclined at 45 degrees, as illustrated in the drawing of FIG. 19.

[0121] FIG. 20 illustrates the movement possibilities of such a machine M, providing a great flexibility in the positioning possibilities, for example of a tool magazine.

[0122] The embodiment illustrated by the drawing of FIG. 16 illustrates another characteristic of the invention which provides an interchangeability of the moving structure of the machine tool M . Thus, the assembly formed by the plate 130, the two arms 110 and 120 and the electric spindle 300, is secured so as to facilitate its interchangeability to a bed 133 sliding on the rails 131 and 132.

[0123] As illustrated in the drawing of FIG. 17, the machine tool M can be combined with a workpiece holder module 203 of swing-tray type carrying several workpieces.

[0124] The drawing of FIG. 18 illustrates an original exploitation of the movement possibilities of the machine tool M by outfitting the electric spindle 300 with a brush O. According to the various possibilities already discussed, the brush O may provide for the cleaning of both the encased machining zone and the maintenance zone.

[0125] The accessibility of the machine tool of the invention makes possible a plurality of configurations when they need to be combined with each other.

[0126] A first example of a combination of two machine tools according to the invention is illustrated by the drawing of FIG. 11, where the machine tools M1 and M2 are placed side by side and have a symmetrical configuration.

[0127] Another example of a combination of four machine tools according to the invention is illustrated by the drawing of FIG. 12, where the four machine tools M3, M4, M5 and M6 are identical and arranged in a star pattern at 90 degrees from each other around a center where the workpiece holder modules are positioned.

[0128] Another example of a combination of four machine tools according to the invention is illustrated by the drawing of FIG. 13, where the four machine tools M7, M8, M9 and M10 are arranged symmetrically in opposition two by two in two linear cells with the machining zone situated at the center of the linear cell.

[0129] Another example of a combination of four machine tools according to the invention is illustrated by the drawing of FIG. 14, where the four machine tools M11, M12, M13, M14 according to the invention are arranged in opposition two by two in two linear cells.

[0130] The foregoing combinations have the purpose of providing the most compact configuration possible, to facilitate the maintenance and to centralize the machining zones.

[0131] The combination in a linear aligned cell of three identical machine tools M15, M16 and M17 as illustrated by the drawing of FIG. 15 provides machining zones and workpiece holder modules disposed on the same side in order to facilitate access and enable, for example, a combination with a self-guided slide.

[0132] It will be understood that the machine tool just described and represented has been done for the purpose of a disclosure, rather than a limitation. Of course, various arrangements, modifications and improvements could be made in the examples above, without exceeding the scope of the invention.

[0133] Thus, for example, a tool magazine with or without a tool changer system may complement the embodiments described above.