EP0101366A1 - Cutting machine for pieces of web material - Google Patents

Abstract

Machine intended to cut transversely, along a straight or broken, oblique or orthogonal cutting line, a strip material (8) capable of being advanced parallel to its length. According to the invention, this machine comprises in combination first means (15) for unwinding said constant strip speed (8) from a reel (7) and second means (16) for, on the one hand, advancing at constant linear speed said strip (8) unwound on a fixed flat support (11) which extends at least from said second means (16) to the vicinity of the cutting system (17) and, on the other hand, allow applying an edge of said strip (8) against a lateral edge guide (31). Cutting of parts in flexible composite material.

Description

The present invention relates to a machine intended to cut transversely, along a straight or broken cutting line, a strip material capable of being advanced parallel to its length.

Already known, in particular, from patents US-A-3,207,219, US-A-3,762,259 and FR-A-1,421,910, machines of this type comprising, on the one hand, a flat horizontal surface on which can be advanced the strip material to be cut transversely and, on the other hand, an equipment transverse to said strip material, rotatably mounted about a vertical axis centered relative to the latter and carrying an animated cutting system d 'a back and forth movement.

In all of these known devices, the belt is advanced by an endless conveyor on which it rests. As a result, these devices can process sheet materials as well as web material. However, due to the relative sliding inevitably occurring between the strip and the endless conveyor on which it rests and thanks to which it is advanced, these known devices are not suitable for cutting high-precision parts from a strip coming directly of a coil, so that they can hardly be fully automated and, for example, inc. integrated in an automated manufacturing process, of the CAD type (computer-aided design).

The object of the present invention is to remedy this drawback and it relates to a fully automated cutting machine, the automation of which can be ensured by digital control and which can integrate into an automated manufacturing process, said machine directly processing a strip unwound from a roll.

To this end, according to the invention, the machine intended to cut transversely, along a straight or broken, oblique or orthogonal cutting line, a strip material capable of being advanced parallel to its length and resting on a bearing surface at least substantially planar, said machine comprising an assembly rotatably mounted about an axis orthogonal to said bearing surface and carrying a cutting system animated back and forth transversely to said strip along d 'a cutting edge, is remarkable in that it comprises, in combination, pre- _. better means for unwinding said strip from a reel at constant linear speed, second means for, on the one hand, advancing said constant strip speed at constant linear speed on a fixed flat support which extends at least from said second means to in the vicinity of the cutting system and, on the other hand, allow an edge of said strip to be applied against a lateral selvedge guide, and third means for measuring the length of strip which runs, said third means defining an orthogonal reference line to said strip and disposed at a predetermined fixed distance from said axis of rotation of said assembly, this axis of rotation passing through said cutting edge and being at constant distance from the edge of the strip in abutment against said lateral edge guide.

Thus, in the machine according to the invention, the advance of the strip in the direction of the cutting system can be precise, without sliding of the strip relative to the bearing surface, but with precise lateral guidance. In these conditions, it can be seen that the machine according to the invention lends itself particularly well to automated operation.

In an advantageous embodiment, said second means comprise a deformable pressure roller, which is applied by its generatrices to said strip and whose axis is inclined on the side of said selvedge guide. It is therefore understandable that such second pressure means impart to the strip a movement of advance having not only a longitudinal component, but also a transverse component directed towards the edge guide, and that the amplitude of this transverse component can be adjusted. , in particular as a function of the transverse rigidity of the material of the strip, by adjusting the pressure exerted by said pressure roller on said strip.

Preferably, said third means cooperate with said second means and they comprise a cylindrical roller made of a rigid material against which said deformable roller is pressed and which is associated with a counter. Thus, the length of strip which runs without sliding between the two rollers can be determined with precision from the number of revolutions made by the rigid roller and the length of the circular base of the latter.

In order to be able to take account of the reduction in the diameter of the tape reel, as it unwinds, said first means comprise a friction drive roller for the reel, mounted on an arm tilting, this roller and the deformable roller rotating at the same tangential speed.

In the case where, in known manner, the cutting tool is a rotary wheel applied against the cutting edge, while the cutting system comprises a carriage movable along a rail, it is advantageous that said wheel is mounted so as to be able to turn and slide on a shaft integral with the carriage and orthogonal to said rail, but offset with respect thereto, that said carriage can rotate at least in a limited manner around said rail, that the wheel is provided with a hub can roll on a workpiece clamp arranged along the cutting edge and that elastic means tend to separate the wheel and the carriage from one another. Thus, it is possible to press elastically not only the wheel against the cutting edge, but also the hub against the work clamp, so that dragged in rotation of the wheel can be generated by the simple rolling without sliding of said - hub on the work clamp.

Preferably, downstream of the cutting system, the bearing surface of the cut pieces consists of two continuous conveyors spaced from one another and a movable deflector is provided which can take an inactive position for which certain cut pieces can pass from one conveyor to another by spanning the space between said conveyors and an active position for which said deflector forces other parts to pass through the space between said conveyors.

It is thus possible, by command of the deflector, to proceed with the sorting and automatic evacuation of the cut pieces, to separate the useful pieces from the scraps.

The deflector can be mounted on tilting arms and be associated with a pressure roller mounted idly on said tilting arms and cooperating with the upstream conveyor in the active position of the deflector, in order to increase the adhesion of said parts to said upstream conveyor and therefore favor the passage of these between said carriers.

• La figure 1 est une vue d'ensemble, en perspective schématique, de la machine selon l'invention équipée de sa baie de commande.
• La figure 2 illustre, en vue de côté schématique, le dispositif de déroulement de la bobine formée pàr la matière en bande à découper.
• Les figures 3 et 4 sont des vues schématiques, respectivement en élévation et de dessus, du dispositif d'avance de la matière en bande à découper.
• La figure 5 illustre schématiquement la mesure de la longueur de la pièce à découper dans la matière en bande.
• La figure 6 illustre schématiquement en vue de côté, le dispositif de coupe de la machine selon l'invention.
• Les figures 7 et 8 montrent schématiquement, respectivement en position d'évacuation des coupes utiles et en position d'évacuation des chutes, le dispositif des pièces découpées.
• La figure 9 donne le schéma synoptique du fonctionnement automatisé de la machine selon l'invention.
• La figure 10 donne le schéma synoptique d'un processus de fabrication automatisé dans lequel peut être intégré la .machine selon l'invention.

The figures of the appended drawing will make it clear how the invention can be implemented.

• Figure 1 is an overall view, in schematic perspective, of the machine according to the invention equipped with its control bay.
• FIG. 2 illustrates, in diagrammatic side view, the device for unwinding the reel formed by the strip material to be cut.
• Figures 3 and 4 are schematic views, respectively in elevation and from above, of the device for advancing the strip material to be cut.
• FIG. 5 schematically illustrates the measurement of the length of the part to be cut from the strip material.
• FIG. 6 schematically illustrates in side view, the device for cutting the machine according to the invention.
• Figures 7 and 8 schematically show, respectively in the position of evacuation of the useful cuts and in the evacuation position of the scraps, the device of the cut pieces.
• FIG. 9 gives the block diagram of the automated operation of the machine according to the invention.
• FIG. 10 gives the block diagram of an automated manufacturing process into which the machine according to the invention can be integrated.

In these figures, identical references designate similar elements.

The machine according to the present invention, shown in FIG. 1, comprises on the one hand an electromechanical execution assembly 1 and on the other hand a control assembly 2, these two assemblies being able to be physically separated from one of the other and connected by connecting cables 3.

The control assembly 2 comprises a digital control 4 and a control bay 5.

The electromechanical assembly 1 of execution is provided with a frame 6 supporting at one of its ends a coil 7 of a strip material 8 to be cut into pieces 9, the front end of which can be delimited by lines straight or oblique, rectilinear or broken cuts and the rear end of which is delimited by straight or oblique cut lines. The coil 7 is provided with an axis 10 freely journalled on the frame 6, so as to allow the free unwinding of the strip 8.

The horizontal upper face of the frame 6 is formed by the succession (away from the roller 7 transversely to its axis 1) of a fixed plate 11, of a plate rotating 12 and two endless conveyors 13 and 14.

Furthermore, the frame 6 supports a device 15 for unwinding the strip 8 from the reel 7, a device 16 for advancing and guiding the strip 8, with which the fixed plate 11 is associated, a cutting device 17 to which belongs the turntable 12, and a device 18 for sorting and evacuating the cut pieces with which the conveyors 13 and 14 are associated.

In Figure 1, the frame 6 has been shown schematically and incomplete to allow to make visible these different elements and devices.

The unwinding device 15 (see also FIG. 2) comprises a rubberized roller 21 frictionally driving the spool 7 and rotatably mounted at the end of an arm 22 around an axis 23 parallel to the axis 10 of the spool 7. The arm 22 is itself articulated around a fixed axis 24, parallel to the axes 10 and 23, so that the rubberized roller 21 is pressed against the coil under the action of gravity, possibly reinforced by the action of elastic means not shown.

The device 16 for advancing and guiding the strip 8 (see also Figures 3 and 4), comprises a drive roller 26 driven by a motor 19 associated with a transmission 20, and cooperating with a metal roller 27. The axes 28 and 29 of the rollers 26 and 27 lie in vertical planes parallel to the axis 10 of the reel 7 and these rollers press between them the strip 8, a pressure P being applied to the roll 26, using known means not shown. The roller 27 is housed in an interruption of the plate 11, for substantially flush with the upper face of the latter. In addition, an encoder or counter 30 is associated with the roller 27 to determine the number of revolutions of said roller and therefore the length of the strip 8 which runs on the plate 11.

Along a longitudinal edge of the plate 11 is provided a selvedge guide 31 for the right selvedge (relative to the direction of advance) of the strip 8.

The unwinding roller 21 of the reel 7, thanks to the transmission 20, is rotated by the same motor 19, as that which rotates the drive roller 26. The diameters of the two rollers 21 and 26, and the transmission 20 which connects them are chosen so that the peripheral speeds of these two rollers 21 and 26 are equal to each other and constant. Thus, the combination of the articulated arm 22 of the roller and 21 makes it possible to unwind the reel 7 at constant speed, whatever the diameter of this reel, this constant reel speed being equal to the speed of advance of the strip 8 on the fixed plate 11. It will be noted that this device also makes it possible, during the operation of the machine according to the invention, to keep without tension the portion of the unwound strip 8 disposed between the rollers 21 and 26.

Thus, the device 16 for advancing the strip does not have to overcome the inertia of the reel 7, but only that of the portion of strip lying between the roller 21 and the cutting device 17 and that of the roller rigid 27 associated with sensor 30.

As can be seen in schematic figure 3, the drive roller 26 is such that its axis 28, instead of being horizontal, is inclined towards the edge guide of the angle ε. Thus, the roller 26 being applied against the strip 8, the radius r ₂ with which it advances the strip 8 on the side of the edge guide 31 is smaller than the radius r ₁ with which it advances the strip 8 on the side opposite to the guide edge 31. This results in a differential feed speed, so that the edge of the strip 8 opposite the edge guide 31 is constantly applied against the latter. Indeed, as shown in Figures 3 and 4, the pressure P applied to the roller 26 generates, because of the obliquity of the axis thereof, a longidutinal component F ensuring the advance of the band 8 and a transverse component T ensuring the application of the edge of said strip 8 against the selvedge guide 31 and therefore the reference lateral positioning of the strip 8. As a result, by adjusting the pressure P, the amplitude of the component can be adjusted T, which must be sufficient to ensure the correct lateral positioning of the strip 8, while being less than the transverse rigidity of the material of the strip 8, to avoid damaging the latter and consequently distorting said positioning.

It will be noted that due to the presence of the unwinding device 15, the feed force F exerted by the feed device 16 may be low, so that the pressure P can be adjusted without inconvenience so that one obtains for the transverse component T the amplitude just sufficient for correct lateral positioning of the strip 8.

The drive roller 26 is made of a deformable material. The obliquity of its axis 28 can be obtained by giving said roller either a conical shape or a cylindrical shape, but in the latter case, it is necessary to apply pressure P in a differential manner, to communicate with the axis 28 the desired obliquity.

The cutting device 17 comprises a transverse and horizontal cylindrical rail 32 disposed above the upper surface 11, 12, 13, 14 of the frame 6 and integral with the turntable 12. This horizontal rail 32 is parallel to an edge 33 of the turntable 12 serving as a cutting edge and is used to guide a carriage 34 which can move in both directions along said rail 32, under the action of a motor or actuator not shown. The carriage 34 carries a cutting tool 35, for example a wheel, capable of following the cutting edge 33. The crew 12, 32, 33, 34, 35 can turn around a vertical axis 36, for example passing through the longitudinal axis of the strip 8 and through the cutting edge 33, under the action of an electric motor 37, associated with a sensor 38, measuring the amplitude of the rotation of said crew, that is to say the inclination of the cutting edge 33 relative to the direction of travel of the strip 8.

The axis 29 of the rigid roller 27 and of the sensor 30 defines a reference line, orthogonal to the strip 8, used for measuring the advance of the strip 8. This reference line 29 is arranged at a known invariable distance D from the axis of rotation 36 of the crew 12, 32, 33, 34, 35, this axis 36 being itself at a constant distance from the edge of the strip 8 bearing between the edge guide 3 (see Figure 5). It will be noted that, the sliding of the strip 8 on the roller 27 being negligible, the measurement of the strip length 8 by the counter 30 is very precise. The measurement of the advance of the strip 8 can be counted by the counter 30 as being the length of the strip 8 moving past the axis of rotation 36, the indication of the sensor 30 being zero during the first cut. To avoid any accumulation of possible length errors, each wheel pass is considered by command 2 as a new length reference.

• - les longueurs des pièces découpées sont indépendantes de l'obliquité des lignes de coupe, puisque celles-ci passent par l'axe de rotation 36.de l'équipage mobile 12, 32, 33, 34, 35 ; ..
• - la distance D de l'axe 36 de référence 29 n'intervient pas dans les mesures ;
• la distance de l'axe 36 au bord de la bande 8 en appui contre le guide-lisière 31 est une constante de la Machine, qui correspond avantageusement à la moitié de la largeur de la bande 8.

Note that in this way:

• - The lengths of the cut pieces are independent of the obliquity of the cutting lines, since these pass through the axis of rotation 36.de of the moving element 12, 32, 33, 34, 35; ..
• - The distance D from the reference axis 36 29 does not intervene in the measurements;
• the distance from the axis 36 to the edge of the strip 8 bearing against the selvedge guide 31 is a constant of the machine, which advantageously corresponds to half the width of the strip 8.

Command 2 waits for a value from counter 30 and actuates the driving roller 26 until this value is obtained. The rigid roller 27 is driven through the belt.

• - le glissement éventuel du rouleau entraîneur 26 par rapport à la bande 8 n'est pas pris en compte ;
• - le diamètre ou les variations de diamètre du rouleau entraineur 26 n'ont pas d'incidence sur la précision.

It should therefore be noted that:

• - The possible sliding of the driving roller 26 relative to the strip 8 is not taken into account;
• - The diameter or variations in diameter of the driving roller 26 do not affect the accuracy.

As shown in FIG. 6, the cutting edge 33 is constituted by a fixed knife 39 cooperating with the wheel 35.

A work clamp 40, for example in the form of an angle iron, makes it possible to apply the front edge of the strip 8 against the upper face of the knife 39. The work clamp can be clamped against the strip 8 or separated from it by means not shown.

In an advantageous embodiment, the wheel 35 is rotatably mounted on a horizontal shaft 41 overhanging with respect to the carriage 34 and it can slide along said shaft 41, a spring 42 tending to separate said wheel from said carriage. In addition, a hub 43 is integral with the wheel 35 and is capable of rolling on the work clamp 40.

It will be noted that such an arrangement is particularly advantageous. Indeed, the spring 42 allows both to apply the wheel 35 against the cutting edge 33 of the knife 39 and the cylindrical peripheral face of the hub 43 against the work clamp 40, because the reaction of the pressure of the wheel 35 against the knife 39 tends to tilt the carriage 34 around the rail 32 by moving it away from the knife 39 (arrow f), that is to say by pressing the hub 43 on the work clamp 40. Thus, thanks to this mounting of the wheel 35, it suffices to move the carriage 34 along the rail 32 to rotate said wheel, since then the hub 43 rolls without sliding on the work clamp 40. Furthermore, it will be noted that the work clamp 40 can deform slightly under the pressure of the hub 43, so that it correctly maintains the strip 8 in line with the cut.

Figures 7 and 8 schematically show the device for removing the cut pieces 9 and scrap 44 of strip material 8, said scraps 44 being made up of unusable pieces of the strip 8 comprised between two consecutive pieces 9. As can be seen in these figures, the conveyors 13 and 14 are spaced from one another and provide between them an empty space 45. A deflector 46 is mounted at the end of tilting arms 47, capable of pivoting around of transverse axes 48, under the action of a motor or an action. neur (not shown), so that said deflector 46 can occupy either a first position for which it is above the empty space 46 (FIG. 7), or a second position for which it is in said empty space 45 (Figure 8).

In the first position of the deflector 46, the cut pieces 9 can pass under the deflector and be transferred from the conveyor 13 to the conveyor 14. In the second position of the deflector 46, the latter obstructs such a transfer and the material falls 44 flexible band 8 are directed through the space 45 to a receiving tank 49. Optionally, there is provided on the arms 47 a mad pressure roller 50, pressing the scraps 44 against the conveyor 13 in the second position (Figure 8 ), so as to increase the adhesion between the conveyor 13 and the falls 44 and therefore favor the evacuation of the latter towards the tank 49.

The machine according to the invention is suitable for cutting parts from strips 8 of flexible material, whatever this material. However, it has found a particularly interesting application in the cutting of parts of composite material consisting of fibers (glass, carbon, boron, etc.) and of polymerizable resin.

Thanks to its design, the machine is particularly suitable for fully automated operation, as illustrated in Figure 9.

The digital control 4 sends orders and receives in return information from the control bay 5. The latter can control at 51 the advance of the strip 8 by controlling the devices 15 and 16, at 52 the rotation of the cutting device 17, in 53 the operation of the conveyors 13 and 14, in 54 the device 18 for sorting and evacuation of the cut pieces and offcuts and in 55 the cutting of the product by command of an internal cycle of the device 17, internal cycle which includes for example the clamping of the work clamp 40 (reference 56), the displacement of the wheel 35 by the carriage 34 (reference 57), and the loosening of the work clamp 40 (reference 58).

Under these conditions, the automated machine according to the invention fits perfectly into an automated manufacturing process of the type illustrated in FIG. 10, on which it can be seen that the machine 1, 2 can receive information from a station 59 defining CAD-type parts (computer-aided design) and interacting with a production scheduling station 60 and a management station 61 stocks of material, to supply an automated manufacturing station 62 with the cut pieces 9.

Claims (7)

1 .-. Machine intended to cut transversely, along a straight or broken, oblique or orthogonal cutting line, a strip material (8) capable of being advanced parallel to its length and resting on at least one bearing surface substantially planar, said machine comprising an assembly rotatably mounted about an axis orthogonal to said bearing surface and carrying a cutting system animated back and forth transversely to said strip along an edge of chopped off,
characterized in that it comprises, in combination with first means (15) for unwinding said constant strip (8) from a reel (7) at constant linear speed, second means (16) for, on the one hand, advancing at speed constant linear said strip (8) unwound on a fixed flat support (11) -which extends at least from said means (16) to the vicinity of the cutting system (17), and, on the other hand, allow applying an edge of said strip (8) against a lateral edge guide (31) and third means (27,30) to measure the length of strip (8) which runs, said third means determining a reference line orthogonal to said strip and arranged at a predetermined fixed distance D from said axis of rotation of said assembly, this axis of rotation passing through said cutting edge and being at constant distance from the edge of the strip bearing against said lateral edge guide. 2. Machine according to claim 1, characterized in that said second means (16) comprise a deformable pressure roller (26) which is applied by its generatrices to the strip (8) and the axis of which is inclined in the direction of said selvedge guide (31). 3.- Machine according to claim 2, characterized in that the third means comprise a rigid roller (27) against which is pressed the deformable roller (26) and which is associated with a counter (30). 4. Machine according to one of claims 1 to 3, characterized in that said first means (15) comprise a roller (21) for frictionally driving the coil (7) mounted on an oscillating arm (22), said roller (21) and the deformable pressure roller (26) rotating at the same tangential speed. - 5. Machine according to any one of claims 1 to 4, in which the cutting tool is a rotary wheel applied against the cutting edge, while the cutting system comprises a carriage movable along a rail,
characterized in that said wheel (35) is mounted so as to be able to rotate and slide on a shaft (41) integral with the carriage (34) and orthogonal to said rail (32) but eccentric with respect thereto, in that said carriage (34) can rotate around said rail (32), in that said wheel (35) is provided with a hub (43) which can roll on a work clamp (40) disposed along the cutting edge (33) , and in that elastic means (42) are provided for tending to separate the knurling wheel (35) and the carriage (34) from each other. 6.- Machine according to any one of claims 1 to 5, characterized in that, downstream of the cutting system (17-), said bearing surface consists of two continuous conveyors (13 and 14), spaced from one another and in that a deflector is provided mobile (46) which can take an inactive position for which certain cut parts (9) can pass from one conveyor to another by spanning the space (45) between said conveyors and an active position for which said deflector (46) requires other parts (44) to pass into the space (45) between said conveyors. 7.- Machine according to claim 6, characterized in that the deflector (46) is mounted on swing arms (47) and is associated with a pressure roller (50) mounted idly on said swing arms and cooperating with the upstream conveyor (13) in the active position of the deflector (46) to increase the adhesion of said parts (44) on said upstream conveyor (13) and therefore promote the passage of these between said conveyors (13 and 14).

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