EP3141640B1 - Cross-lapper and method for controlling such a cross-lapper - Google Patents

Description

The present invention relates to a device forming a spreader-lapper intended to coat a web of fibers, in particular non-woven, in particular at the outlet of a carding device, as well as to a method for controlling a spreader-lapper of this gender.

Conventionally, a spreader-lapper arranged at the outlet of a carding device producing a web of non-woven fibers comprises a front belt bringing the web of fibers into the spreader-lapper to a mobile accumulator carriage following a movement back and forth, a rear belt bringing the accumulated web to a lapper carriage also movable following a back and forth movement and an exit apron, the accumulator carriage being arranged to return the fiber web towards the lapper trolley, and the latter being arranged to deposit the veil accumulated and returned by the accumulator trolley on the apron to obtain a tablecloth composed of layers which are at an angle, alternately in one direction and in the other, relative to the direction in length of the tablecloth.

The characteristics of the web that we wish to obtain (grammage, surface density, orientation of the folds, length of the folds, etc.) are adjusted in advance on the basis of the adjustments of the web entry speeds, speeds and strokes. moving carriages back and forth, and generally kinematic data of the constituents of the spreader spreader. The spreader-lapper devices known from the prior art have the disadvantage that defects in uniformity compared to the characteristics set in advance appearing here and there on the final tablecloth. This is especially the case when trying to increase production speed by using more powerful motors.

Of FR2791364 , EP0522893 And EP 1816243 , spreaders of this type are known and which include the characteristics of the preamble of claim 1.

Once the characteristics of the web that we wish to obtain have been adjusted, the present invention aims at a lapper spreader making it possible to obtain the most uniform web possible in relation to these characteristics set in advance, and this preferably at the speed highest possible production.

According to the invention, a spreader-lapper, in particular arranged at the outlet of a carding device producing a web of fibers, in particular non-woven, comprising a front belt bringing the web of fibers into the spreader-lapper until to a mobile accumulator carriage following a back and forth movement; a rear belt bringing the accumulated veil to a mobile lapper carriage following a back and forth movement; and an outlet apron, the accumulator carriage being arranged to return the web of fiber towards the lapper carriage, and the latter being arranged to deposit the web accumulated and returned by the accumulator carriage on the apron at an angle, alternately in one direction and in the other, relative to the length direction of the web, the front and rear belts being driven by rollers respective front and rear drive motors driven by respective front and rear main motors, is characterized by anti-slip means intended to prevent relative sliding of at least one of the front and rear belts relative to its respective roller, especially rear, preferably both front and rear mats.

The inventor of the present invention understood that the defects in uniformity with respect to the characteristics set in advance appearing on the web obtained at the outlet of the spreader-lapper are due to uncontrolled speed differentials between the front belt and the rear belt in particular in the path of the web between the accumulator carriage and the lapper carriage where the web is supported by the rear belt and capped by the front belt, as well as at speed differentials between the means bringing the card web and the front belt taking it up and speed differentials between the rear belt bringing the web into the lapper carriage and the speed of the latter depositing the web on the web being formed at the lapper outlet, each of these causes of fault is notably induced by sliding phenomena between the front belt or the rear belt and its control roller during the acceleration or deceleration phases of the belts occurring in particular at each reversal of the movement of the coating carriage. The accelerations and decelerations of the belts increase with the entry speed of the lapper, the defects induced by these sliding phenomena are accentuated with the production speed.

By providing means having the function of preventing the relative sliding of the front and/or rear belts relative to the respective drive roller, we obtain in output as a result a defect-free web compared to the web that we expect to obtain in relation to the prior settings of the spreader-lapper parameters. In addition, the slip no longer existing, we can increase the production rate of the layer of the spreader-lapper without reducing the quality of the layer obtained and/or we can provide, for the same flow rate as currently d use a less heavy and/or less powerful drive roller control motor and therefore reduce the final cost price of the non-woven web.

The anti-slip means consist of at least one auxiliary drive roller associated with an auxiliary motor, which applies a complementary actuation force to the respective drive roller of said at least one of the front and rear belts, itself driven by its respective main engine.

By thus providing an auxiliary drive roller in addition to the main drive roller, it facilitates the fine adjustment of the movement of the belt relative to the web, in particular by avoiding having to spend the effort necessary for the acceleration of any the length of the belt at a single control point and therefore increase the risk of slipping between the belt and its control roller during strong acceleration.

The or each auxiliary drive roller is driven by a torque-controlled auxiliary motor.

The or each main drive roller is driven by its speed-controlled main motor.

In particular, the torque of the or each auxiliary motor is controlled as a function, in particular proportionally, of the acceleration of the lapper carriage and as a function of the layup cycles (forward acceleration, outward deceleration, return acceleration, return deceleration) so as to relieve the main motor in these acceleration and deceleration phases, thus reducing the effort to be transmitted between the main drive roller and the belt.

The present invention also relates to a method for controlling a spreader-lapper comprising a front belt, an accumulator carriage, a rear belt, a lapper carriage and an exit apron, the speeds and movements of the different elements of the spreader-lapper being adjusted in advance to obtain a web having characteristics given in advance, the front belt being driven by a front drive roller driven by a front main motor and the rear belt being driven by a rear drive roller driven by a rear main motor, the accumulator and lapper carriages being mobile in a back-and-forth movement, is characterized by the step which consists of providing anti-slip means intended to cancel the slip between at least one of the front and rear belt and its respective drive roller, comprising at least one auxiliary drive roller driven by a torque-controlled auxiliary motor, and the or each main motor being speed-controlled.

la figure 1

est une vue en perspective schématique d'un étaleur-nappeur suivant l'invention ;

la figure 2

est une vue en coupe schématique de l'étaleur-nappeur de la figure 1 dans un plan perpendiculaire au plan de la nappe déposée sur le tablier, le chariot nappeur se trouvant dans une position entre la position d'extrémité droite ou avant de dépôt lors du cycle de nappage et une position gauche ou arrière par rapport à la nappe déposée sur le tablier de l'étaleur-nappeur.

Aux figures, il est représenté un étaleur-nappeur 1 suivant un mode de réalisation de l'invention. Cet étaleur nappeur est disposé en aval d'une carde produisant un voile de non tissé qui arrive sur un tapis 2 avant sans fin. Le tapis 2 avant sans fin comporte un tronçon 21 en pente montante suivi d'un tronçon horizontal s'étendant jusqu'à un chariot 12 accumulateur. Le tapis avant sans fin comporte ensuite plusieurs tronçons en succession, notamment les tronçons 22, 23, 25, 26, 27 et 29 avant de revenir au tronçon 21. Suivant une variante représentée mais non essentielle à l'invention, il est prévu un simple rouleau 2d de détour autour duquel le tapis 2 avant effectue un demi tour, le tapis arrière 5 récupérant le voile 4 après retournement du voile afin de le transporter jusqu'au chariot nappeur 9.By way of example, we now describe a preferred embodiment of the invention with reference to the drawings in which:

Figure 1

is a schematic perspective view of a spreader-lapper according to the invention;

Figure 2

is a schematic sectional view of the spreader-lapper of the figure 1 in a plane perpendicular to the plane of the tablecloth deposited on the apron, the tablecloth carriage being in a position between the right end position or before deposition during the tablecloth cycle and a left or rear position relative to the tablecloth deposited on the spreader-lapper apron.

In the figures, a spreader-lapper 1 is shown according to one embodiment of the invention. This lapper spreader is placed downstream of a card producing a non-woven web which arrives on an endless front belt 2. The endless front belt 2 comprises a section 21 with an upward slope followed by a horizontal section extending to an accumulator carriage 12. The endless front belt then comprises several sections in succession, in particular sections 22, 23, 25, 26, 27 and 29 before returning to section 21. According to a variant shown but not essential to the invention, there is provided a simple detour roller 2d around which the front belt 2 makes a half turn, the rear belt 5 recovering the veil 4 after turning the veil in order to transport it to the lapper carriage 9.

The movements and/or displacements of the carriages 9 and 12 and the belts 5 and 2 are controlled by a central unit which controls their respective motors according to the kinematic data (positions, speeds, acceleration) desired for each, these settings define the parameters (in particular length, orientation of the bias folds and surface density) desired for the final tablecloth.

The two belts 2 and 5 are endless belts which circulate in opposite directions to each other. The front belt 2 is guided along its circulation path by rollers 2a to 2n. The rear belt 5 is guided along its path by rollers 5b to 5n. The rollers are freely rotatable, except those connected to motor means, as described in the present application.

Preferably, the two belts are driven so as to have in the zone of mutual covering of the web (between the two carriages and up to the apron, in particular in the vertical passage 17 just before the site 11 of deposit on the tablecloth located on the apron 3 (driven by rollers, including in particular the roller 3a), equal speeds corresponding to the desired speed of feeding the web 4 to the deposition site 11.

The rear belt 5 makes a 180° turn around the roller 5g after the zone 52 of mutual covering/pinching of the web by the two belts 2 and 5. To avoid compression of the web in the lapper carriage, particularly at the transition between the part 42 and the deposit zone 11, the entrance belt 2 is diverted around a detour roller 2f.

The lapper carriage moves back and forth in the horizontal direction in the figure. During this movement, the belt 5 undergoes a variation in its length (substantially equal to twice the movement in one direction given from the cart 9). It is therefore appropriate to provide compensation for this variation, which is achieved by the fact that the rear belt 5 makes a 180° turn around a roller 5l carried by a compensating carriage 16 moving back and forth in synchronization with the movement of the carriage 9. Thus, regions 56 and 57 of the belt 5 shorten when regions 52, 53 and 59 of the belt 5 increase and vice versa. To achieve synchronization, a toothed belt 76 is provided fixed at one end to the lapper carriage and at the other end to the carriage 16, the belt 76 meshing with a driving pulley 77 connected to a motor with two directions of operation, controlled in speed. On the other hand, an inextensible cable 78 connects the two other sides of the carriages 9 and 16.

An identical arrangement is made to synchronize the movement of the accumulator carriage and the length of the input belt 2. The belt 2 makes a 180° turn around a roller 2l carried by a compensating carriage 14 moving back and forth in synchronization with the movement of the carriage 12. Thus, regions 26 and 27 of the belt 2 shorten when the regions 21, 22 and 23 of mat 2 increase and vice versa. To achieve synchronization, a toothed belt 71 is provided fixed at one end to the accumulation carriage 12 and at the other end to the carriage 14, the belt 71 meshing with a driving pulley 72 connected to a motor with two directions of travel , ordered in speed. On the other hand, an inextensible cable 73 connects the two other sides of the carriages 12 and 14.

Each of the belts 2, 5 passes over a respective motor roller 2i, 5i connected to a respective motor 74, 79 controlled in speed (serves motor, stepper or similar). Two return rollers, 2h, 2j and 5h, 5j are arranged on either side of the driving rollers 2i, 5i, in order to maximize the winding of the belt around its control roller and therefore its adhesion.

The drive motors 74, 79 and the pulley motors 72, 77 are controlled (by the central unit not shown) to adapt them to the desired characteristics of the final product to be obtained (length, surface density, etc.) which depend in particular on the entry speed of the web and/or the stroke of the lapper carriage and/or the accelerations of the carriages, and/or others.

A complementary motor 101 acts on the front belt 2. It operates a 2m drive roller, which is provided with an adherent coating and is preferably associated with a 2n detour roller to increase the winding of the carpet around the 2m roller. The motor roller 2i and the complementary motor roller 2m are placed relatively far from each other along the path of the belt to distribute the traction stresses as much as possible, particularly during acceleration phases.

The complementary motor 101 is controlled in torque, in particular for each point of the coating cycle of the spreader-lapper. The torque of the complementary motor is controlled to avoid relative sliding between the front belt 2 and the motor roller 2i.

A complementary motor 111 acts on the rear belt 5.

It operates a 5m drive roller, which is preferably lined with an adherent coating and associated with a 5n detour roller to increase the wrapping of the carpet around the 5m roller. The motor roller 5i and the complementary motor roller 5m are placed relatively far from each other along the path of the belt to distribute the traction stresses as much as possible, particularly during acceleration phases.

The complementary motor 111 is controlled in torque, in particular for each point of the coating cycle of the spreader-lapper.

The torque of the complementary motor is controlled to avoid relative sliding between the belt 5 and the motor roller 5i.

In particular, the complementary motors make it possible to improve the behavior of the lapper spreader by canceling on the one hand the slipping of belts on their control rollers and on the other hand by limiting the tension variations in the belts during the phases of operation. acceleration and deceleration thanks to the two-point control of each belt. We thus combat the effects induced by carpet sliding on the tablecloth. In addition, we can either use main motors that are less heavy and/or powerful than if there was only one motor per belt, or achieve higher working speeds, in particular by significantly reducing wear on the belts. by a better distribution of tensile stresses acting on the belts.

A topping cycle can be as follows:

We start from a situation where the lapper carriage is at the end of its travel on the front side.

The carriage 9 is then stopped while the carriage 12 moves at constant speed backwards to extend the regions 21 and 22 of the belt 2. The speed V74 of the main motor 74 of the belt 2 is zero because the regions 22 and 23 are immobile. The speed V12 of the carriage 12 is equal to half the entry speed of the web 4. The speed of the pinching region 52 of the belt 5 is zero because it is equal to the speed of the region 22 of the belt 2. The speed of the regions 58 and 59 is zero. Speed V111 of motor 111 is zero. The speed V79 of the motor 79 is twice the speed of the lapper carriage.

We define as being positive the torque of the motors which makes it possible to accelerate belts 2 and 5 in the direction of the product. On the figure 2 , the torques of motors 74 and 101 are therefore defined as being positive in the counterclockwise direction while the torques of the motors 79 and 111 are defined as being positive in the clockwise direction.

In a first phase P1, the lapper carriage accelerates backwards (towards the left at the figure 2 ), starting its forward movement. The speed of sections 52, 57, 58 and 59 remain zero while sections 53 to 56 undergo an acceleration equal to twice that of the lapper carriage 9 and its compensating carriage 16. Due to the acceleration of sections 55 and 56 as well as the compensating carriage 16 on the one hand and the need to maintain zero speed in sections 52, 57, 58 and 59, the application of a positive torque in the motor 111 yet at zero speed makes it possible to oppose tension induced by the acceleration of sections 58, 59 and 52 as well as by the rotational acceleration of rollers 5j, 5k and 5l that they induce. The positive torque applied by the motor 111, although at zero speed, thus makes it possible to relieve the motor 79 while reducing the voltage induced by these accelerations in the sections 58, 59 and 52. In this phase P1, of the entire circuit of the belt before 2, only the rollers 2e, 2f and 2g undergo an acceleration induced by the acceleration of the carriage 9 which implies that a non-zero positive torque is applied by the motor 74 in order to keep the speed of the sections 22 and 23 zero. The torque applied by the motor 101 can then be zero or simply contribute to opposing the rotational friction of the roller 2l.

In a second phase P2, the carriages are at constant speed, all motor torques being low.

This phase ends beyond the middle of the travel of the lapper carriage 9 and in particular beyond the last third of its travel to enter a phase P3 of deceleration of the carriage 9 until it stops at the end of the outward travel. The speed of sections 52, 57, 58 and 59 remain zero while sections 53 to 56 undergo a deceleration equal to twice that of the lapper carriage 9 and its compensating carriage 16. Due to the deceleration of sections 53 to 56 as well that of the lapper carriage 9 on the one hand and the need to maintain zero speed in sections 52, 57, 58 and 59, the application of a negative torque in the motor 111 yet at zero speed makes it possible to oppose to the tension induced by the deceleration of sections 52 and 53 as well as by the rotational deceleration of the rollers 5g and 5h that they induce. The negative torque applied by the motor 111, although at zero speed, thus makes it possible to relieve the motor 79 while reducing the voltage induced by these accelerations in the sections 57, 56 and 55. In this phase P3, of the entire circuit of the belt before 2, only the rollers 2e, 2f and 2g undergo a deceleration induced by the deceleration of the carriage 9 which implies that by applying a non-zero negative torque in the motor 101 yet at constant speed we can relieve the motor 74 as well as reduce the voltage induced in sections 25, 26 and 27.

In phase P4, the lapper carriage 9 accelerates towards the entrance (towards the right at the figure 2 ) beginning the return phase. At the same time, the accumulator carriage which had remained at a constant speed during phases P1 to P3 begins its deceleration until it stops and then reverses.

On the circuit of the front belt 2, during this phase P4, all the rollers except 2m, 2n, 2a and 2b and all the belt sections except 27 and 21 undergo an acceleration or deceleration induced by the combination of the movements of the accumulator and lower carriages so that the optimal torque to be applied to the motor 101 can vary depending on the inertia of the different rollers. The motor 101 can in fact contribute to the deceleration of the rollers 2c and 2d induced by the deceleration of the accumulator carriage 12 but also to the acceleration of the rollers 2j to 2l induced by the need to accelerate the sail section 42 and therefore the section 22 at twice the acceleration of the lapper carriage 9 in order to maintain a speed of delivery of the veil at point 11 equal to the speed of the lapper carriage 9.

During this same phase P4, on the rear belt circuit, sections 53 to 56 and rollers 5h to 5k are at zero speed. The section of belt 52 as well as the rollers 5m, 5n and 5b undergo an acceleration equal to 2 times that of the carriage 9 in order to feed it, while the rollers 5c to 5f, as well as 5l, undergo a combination between 2 times l acceleration of the lapper carriage 9 and deceleration of the accumulator carriage 12. Thus, although stopped, the motor 79 will apply a positive torque opposing the movement of the section 53 induced by the accelerations of the rollers 5b to 5g. At the same time, a positive torque on the motor 111 will assist the motor 79 by contributing in particular to the acceleration of the roller 5l and thus to the reduction of the tensions induced in the sections 58, 59, 52 and 53.

In a fifth phase P5, the carriages are at constant speed, all motor torques being low.

This phase ends beyond the middle of the stroke of the lapper carriage 9 and in particular beyond the last third of its stroke to enter a phase P6 of deceleration of the carriage 9 until it stops at the end of the return stroke. The speed of sections 53, 55 and 56 remain zero while sections 52 and 57 to 59 undergo a deceleration equal to 2 times that of the lapper carriage 9 and its compensating carriage 16. Due to the deceleration of sections 52 and 57 to 59 as well as the lapper carriage 9 on the one hand and the need to maintain zero speed in sections 53, 55 and 56, the application of a negative torque in the motor 79, however, at zero speed, makes it possible to oppose the tension induced by the deceleration of sections 53, 55 and 56 as well as by the deceleration in rotation of the rollers 5b to 5g and 5l to 5n which they induce. The negative torque applied by the motor 111 thus makes it possible to relieve the motor 79 while reducing the tension induced by these accelerations in the sections 57, 56 and 55. In this phase P6, of the entire circuit of the front belt 2, all the rollers except 2m, 2n, 2a and 2b and all sections of belt except 27 and 21 undergo an acceleration or deceleration induced by the combination of movements of the accumulator and lower carriages so that the optimal torque to be applied to the motor 101 can vary depending on inertia of the different rollers. The motor 101 can in fact contribute to the acceleration of the rollers 2c and 2d induced by the acceleration of the accumulator carriage 12 but also to the deceleration of the rollers 2j to 2l induced by the need to decelerate the sail section 42 and therefore the section 22 at twice the deceleration of the lapper carriage 9 in order to maintain a speed of delivery of the web at point 11 equal to the speed of the lapper carriage 9.

Claims (5)

1. Crosslapper for forming a web (6), the crosslapper being disposed in particular at the outlet of a carding device producing a fleece of fibers, in particular of nonwoven, comprising a front belt (2) feeding the fleece (4) of fibers into the crosslapper to an accumulator carriage (12) that is movable back and forth; a rear belt (5) transporting the accumulated fleece to a laying carriage (9) that is movable back and forth; and an outlet apron (3), the accumulator carriage (12) being arranged so as to return the fleece of fibers towards the laying carriage (9), and the latter being arranged so as to lay the fleece that has been accumulated and returned by the laying carriage on the outlet apron (3) at an angle, alternately in one direction and in the other, with respect to the lengthwise direction of the web (6), the front and rear belts (2) and (5) being driven by respective front and rear drive rollers (2i, 5i) driven by respective front and rear main motors (74, 79), characterized by anti-slip means intended to prevent a relative slippage of at least one of the front and rear belts (2) and (5) with respect to its respective, in particular rear, drive roller (2i, 5i), preferably of both the front and rear belts (2, 5), the anti-slip means comprising at least one auxiliary drive roller (2m, 5m) associated with an auxiliary motor (101, 111), which applies a complementary actuating force to the respective drive roller of said at least one of the front and rear belts, itself driven by its respective main motor (74, 79), the or each auxiliary drive roller (2m, 5m) being driven by its torque-controlled auxiliary motor (101, 111) and the or each main motor (74, 79) being speed-controlled.
2. Crosslapper according to claim 1, characterized in that the anti-slip means are arranged so as to prevent a relative slippage of the front and rear belts (2, 5) with respect to their respective drive rollers (2i, 5i).
3. Crosslapper according to one of claims 1 or 2, characterized in that the torque of the or each auxiliary motor (101, 111) is controlled as a function, in particular proportionally, of the acceleration of the laying carriage and as a function of the laying cycles so as to relieve the main motor (74, 79) in the acceleration and deceleration phases, thus reducing the force to be transmitted between the respective drive roller and the belt.
4. Method for controlling a crosslapper comprising a front belt (2), an accumulator carriage (12), a rear belt (5), a laying carriage (9) and an outlet apron (3), the speeds and movements of the various elements of the crosslapper being set in advance in order to obtain a web (6) having characteristics given in advance, the front belt (2) being driven by a front drive roller (2i) driven by a front main motor (74) and the rear belt (5) being driven by a rear drive roller (5i) driven by a rear main motor (79), the accumulator and laying carriages being movable in a reciprocating or back and forth motion, characterized by the step of providing anti-slip means intended to cancel the slippage between at least one of the front (2) and rear (5) belts and its respective drive roller (2i, 5i), comprising at least one auxiliary drive roller (2m, 5m) driven by a torque-controlled auxiliary motor (101, 111) and the or each main motor (74, 79) being speed-controlled.
5. Method according to claim 4, characterized in that the anti-slip means comprise two auxiliary rollers (2m, 5m) driven by a respective torque-controlled auxiliary motor (101, 111) and each main motor being spped-controlled.

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