WO2006045931A1

WO2006045931A1 - Consolidation machine with alternative punching movement

Info

Publication number: WO2006045931A1
Application number: PCT/FR2005/002619
Authority: WO
Inventors: Pierre Mouchard; Jean-Christophe Laune; François LOUIS
Original assignee: Asselin-Thibeau
Priority date: 2004-10-22
Filing date: 2005-10-21
Publication date: 2006-05-04
Also published as: FR2877019A1; FR2877019B1

Abstract

The invention relates to a consolidation machine (1) with an alternative punching movement, such as a needle loom, of the type that comprises: a consolidation path for a lap (2); a consolidation tool (3, 5, 7); means (4) for the alternative actuation of the tool; at least one insertion means (17) for inserting the lap (2) into the consolidation path, at least in certain operation phases; and at least one drive means (M1) for driving the insertion means (17). The invention is characterised in that the drive means (M1) can move at a periodically-variable speed and in that it is equipped with means (C, UC) for synchronising the alternative actuation means (4) and the variable speed of the drive means (M1).The inventive machine is advantageous in that the forward movement of the lap upstream of the consolidation tool is better adapted to the rhythm of the lap consolidation tool if so required by the nature of the lap and/or if the speed of the machine is high.

Description

The present invention relates to an alternative type of consolidation machine, particularly a treble machine.

A needling machine comprises needles attached to a support called a needle board which is reciprocated in a reciprocating manner such that the needles periodically penetrate through a textile web to interlace the fibers making up the web. The textile web is typically derived from a spreader-lapper, but other cases are possible. The textile web may also be derived from a previous consolidation machine, for example a previous needling machine. The web may also have been manufactured previously and enter the needling machine at the exit of an unwinder. The web may also be an overlay of at least two elementary textiles.

In the particular case of the manufacture of stationery felts, is fixed by needling successive layers of nonwoven web on an endless textile support, which is typically a scrim.

Traditional needling machines comprise introduction means upstream of the consolidation path, and extraction means downstream of the consolidation path. DE-AI 660 776 and EPO 803 000 B1 teach to give the extraction means a periodically variable speed synchronized with the punching of the needles in the consolidation path, to avoid pulling on the consolidated product while it is immobilized by the penetration of the needles. The textile being upstream of the consolidation path is generally more flexible or even totally devoid ^'mechanical strength. The prior art provides that the sheet to be consolidated is introduced at a constant or free speed and that it is the flexibility of the sheet which absorbs the difference in velocities between the part of the sheet being introduced and the part of the sheet undergoing periodically needle penetration.

This flexibility at the entry of the needling machine is one of the difficulties presented by the introduction device which, in most cases, can not effectively push the product into the needling path. Moreover, there is a constant increase in the punching rates of needling machines and introduction speeds. One of the difficulties consists in reaching such rates and speeds without the product being damaged in the zone where it is fragile, that is to say upstream of the consolidation path.

It has been found according to the invention that the adaptation explained above, between the introduction speed on the one hand and the periodic advance movement caused by the combination of the periodic work of the needles and the drive movement of the device extraction, actually produced local accelerations damaging in the product located between the introduction means and the first needles of the consolidation path (accelerations or efforts).

The object of the present invention is to propose a consolidation machine, in particular a needling machine, which eliminates or reduces the mechanical stresses, in particular the local stresses, experienced by the ply in the zone situated upstream of the needling path and by particular between the means of introduction on the one hand and the first needles on the other hand.

It offers an alternative striking consolidation machine comprising:

a consolidation path for a textile web;

- consolidation tools;

means for alternately actuating the tooling;

at least one introduction means for, at least in certain operating phases, introducing the web into the consolidation path; and

at least one driving means for the introduction means, characterized in that: the driving means is capable of a variable speed periodically; and - synchronization means are provided between the reciprocating actuating means and the variable speed of the driving means.

According to the invention, means are thus provided which allow a periodic variable speed advance of the web upstream of the consolidation tool, better adapted to the rhythm of the tooling of consolidation of the web when the nature of the web requires it and / or when the rate of the machine is high.

More precisely, the invention makes it possible, in the step of consolidating the web, when the consolidation tool is active with respect to the web, for example when the needles of a needling machine cooperate with the web, to slow down. or to stop if necessary the advance of the sheet, then resume the advance of the sheet when the needles withdraw.

According to the invention, the nature of the unconsolidated sheet is therefore no longer totally counted to absorb a differential speed of the sheet at the time of consolidation, but more reliably and reproducibly on a speed adaptation. The parameters of the adaptation (speed profile, amplitude, average speed, phase) can be determined precisely according to the consolidation parameters (no advance, typing speed, etc.) and according to the characteristics of the water table. , especially its mechanical strength. This allows a great flexibility of operation, which can be obtained thanks in addition to drive means of the electromechanical type introduction means, for example servomotor type. According to other advantageous features in this sense, it is possible to provide, as synchronization means, control and data processing means combined with a position sensor arranged on the reciprocating actuation means of the consolidation tool, making it possible to know its position and, depending on the position signal and programmed parameters, to control the phase position of the drive means of the introduction means. Advantageously, it will be preferred to create a phase shift between the drive means of the input means and the means for alternating actuation of the tooling, in particular a phase advance of the drive means, for example to anticipate the advance of the water table in the consolidation zone. At high rates, by adapting the local velocities of the web, one can for example avoid jamming problems at the first row of needles or conversely to break the needles in a non-stretchable sheet such as a textile sheet. In the particular case of the manufacture of an endless band forming a stationary felt, the invention also makes it possible to adapt the advance of the ply upstream of the consolidation means as a function of the stage of manufacture of the felt. Indeed, a felt is generally manufactured by superimposing and continuously needling successive layers of fiber web on a canvas. The mechanical strength of the felt therefore increases for each needling passage and a periodic speed curve can be provided for the drive means of the introduction means, the characteristics of which vary with each passage. The control and data processing means can be programmed for this purpose. According to other advantageous features of the invention:

- The introduction means comprises a plurality of successive individual means capable of different instantaneous speeds during operation of the machine; in this case, it is possible to provide a different amplitude of variation of the speed for each individual means and a gradual increase of the amplitude from the individual means located furthest upstream to the individual means located closest to the needling zone. ; This makes it possible to thus pass from a substantially continuous feedrate advance of the ply to the input of the introduction means to a variable speed feed periodically at the outlet of the consolidation means, the variation amplitude having been progressively adapted to match that of the consolidation cycle.

downstream of the consolidation means, it can be provided that the drive means of the extractor means is also capable of a variable speed periodically, the synchronization means of the machine being adapted to drive said drive means also according to the position signal of the reciprocating actuating means, programmed operating data, for example a greater velocity amplitude because the sheet at the outlet of the consolidation zone theoretically has a better mechanical strength and can be "pulled" by the extractor means .

the law of speed of the drive means (introductors and / or extractors) is preferably substantially sinusoidal with an elongated sequence corresponding to the slowing or stopping of the drive. Other characteristics and advantages of the invention will emerge from the following detailed description of a nonlimiting exemplary embodiment, a description given with reference to the drawings in which:

- Figure 1 shows schematically a needling machine to illustrate the various means according to the invention;

FIG. 2 illustrates periodic curves of instantaneous speeds of the means for driving the insertion means and synchronism with a needling cycle;

FIGS. 3 and 4 illustrate variants, in particular insertion means;

- Figures 5, 6 and 7 are similar to Figures 3 and 4 illustrating introduction means consisting of several individual means; and

- Figure 8 illustrates the particular case of a needling machine for textile plates. According to the example chosen and shown in FIG. 1, a single needling needle punch 1 comprises two perforated parallel plates 3, 7, designated respectively by the term table (lower plate) and stripper (upper plate), between which a fiber web 2 from another machine (not shown) located upstream of the needling machine 1, for example a spreader-lapper. This sheet of fibers 2 is driven within the needling machine 1 thanks, on the one hand, to introducing means 17 generally comprising a pair of pressing rollers 18, 19 which are situated at the top of the needling machine and, on the other hand, on the one hand, extracting means 10 also generally in the form of two pressure rollers 15 and 16. The needling machine 1 further comprises a needle board 5 which is reciprocated perpendicular to the plane of the table 3 and the stripper 7 by means of an alternative actuating device 4 located on the upper part of the needling 1 and comprising for example a crank-handle assembly. During a striking cycle, the board 5 is driven in a descending vertical movement until its needles 8 penetrate the perforations of the stripper 7, in the fibers of the sheet 2 and in the perforations of the table 8 The movement of the needles continues with a rise out of the layer of fibers 2. The web is subjected to a sequential displacement defined by a step in advance which is the distance traveled between two needling sequences.

According to the invention, the introduction rollers 18 and 19 are driven at variable instantaneous speed by means of a variable speed electromechanical device consisting of a servomotor M1. One of the rollers can be connected to the motor M1 and the other roll connected by a positive mechanical transmission to be driven in a synchronized manner. Similarly, according to the example chosen, the extraction rollers 15 and 16 are also driven to variable speed thanks to a variable speed electromechanical device consisting of an M2 servomotor. Here also one of the rollers can be controlled by the servomotor M2 and the other roll connected by a positive mechanical transmission to be driven in a synchronized manner. The servomotors Ml and M2 are independent of one another and adapted to be controlled by a central control and processing unit UC, associated with usual interface means S, such as a display monitor and a keyboard input. The CPU is also used to control the entire machine. It may include for this purpose memory means, calculation or any other suitable processing means. In order to know the position of the needle board 5 at any time, there is provided a position sensor C on the reciprocating actuator 4. The position sensor C is connected to the unit UC which uses the position signal at the output of the sensor C to synchronize the angular velocity of the servomotors Ml and M2. The operation is now described. The following operating parameters are first fixed via the central unit UC by an operator, depending on the characteristics of the needling table:

- parameters of the alternative device: frequency of striking, no advance of the tablecloth; - Parameters of the introducing means: speed curve, its shape, its amplitude and the phase with respect to the typing cycle.

- Extractor means parameters: speed curve, its shape, its amplitude and the phase with respect to the typing cycle. Referring to Figure 1, a needle ply 2 passes through the needling 1 from left to right. It is first driven between the pressure rollers 18 and 19, then imprints a first zone A defined substantially between the nip of the rollers 18 and 19 and the first row of needles 8, then a zone B in which it is needled , then a zone C downstream of the needling defined between the last row of needles and the nip of the rollers 15 and 16. It is in the zone A, upstream of the needling zone B, that the unconsolidated web may have fragility characteristics (too much flexibility or too much rigidity for example). It is at the moment of striking, that a velocity difference locally between the sheet lying in zone A and the sheet lying in zone B can cause a deterioration of the sheet, which subsequently introduces defects in the product. finished. According to the invention, the CPU UC, knowing the position of the needles at any time via the sensor C, can synchronize the driving speed of the rollers 18 and 19 by following the instantaneous speed curve previously programmed in the central unit UC. This curve corresponds to a slow advance of the sheet at a minimum instantaneous speed or zero (depending on the nature of the sheet) in zone A of the sheet while a strike sequence takes place in zone B, followed by a acceleration of the instantaneous speed of advancement of the web to a maximum during the sequence of withdrawal of the needles, corresponding to the pitch step of the web, then again a slowdown and so on periodically. A sinusoidal shape for the velocity curve reflects these periodic operating sequences. It is also possible to design another form of curve depending, for example, on the inertia of the mechanical consolidation means used, or on the desired result, for example a shape with square, rectangular, symmetrical or non-symmetrical signals. In Figure 2, there is shown by way of example at the top of the figure a periodic needling curve A, each hollow of the curve corresponding to a needling sequence and each peak to a withdrawal sequence. Just below, is represented a curve C1 of the instantaneous speed of the servomotor M1 substantially sinusoidal about an average speed Vm, the phase being synchronized with that of the curve A. On the other hand, just below it is represented a curve C2 with enlarged recesses to correspond to a longer duration at the minimum speed Vmin with respect to the peaks at the maximum speed Vmax and the case where the servomotor Ml is in advance of phase with respect to the phase of the needling cycle. This makes it possible to start the advance of the ply before the total withdrawal of the needles and to increase the amplitude of the driving speed during the withdrawal time of the needles and thus to increase the average speed of the ply in the needler.

In some cases, it may also be advantageous to modulate the amplitude of the instantaneous speed during operation. Moreover, the striking frequency may correspond to a half-step advance so that the web is needled twice at the same place.

With regard to the extractor means, reference can be made to EP 0 803 000 B1 which describes the particular operation related to the variable-speed extraction operation of the consolidated sheet.

The variation of the speed of introduction of the sheet and the variation of the variable speed of extraction of the sheet are in fact correlated since both synchronized substantially in the same way with the strike. However, it can be provided that the amplitude of the instantaneous extraction speed is greater than the amplitude of the instantaneous speed of introduction, and / or that the shape of the speed curve is different, than the drive means are out of phase. Many combinations of operation are possible depending on the characteristics of the sheet to be consolidated. In FIG. 1, there is shown a single needle board 5 associated with an alternative actuating device 4. It goes without saying that alternative embodiments are possible, in particular the needling machine may comprise series needle boards operating from synchronized manner with or without phase shift. It may also be a so-called double-needle needling comprising an upper needle board and vis-à-vis a lower needle board, the two boards operating alternately, with a double advance frequency for the tablecloth compared to a simple needling needle. In general, synchronization means are provided for synchronizing the cycles of strike boards. In this case, a single position sensor C formed on one of the boards is sufficient for the control unit UC to synchronize the servomotor or means of introduction of the web.

In another variant, instead of a positive mechanical transmission for driving the roller 18, another perfectly synchronous motor can be provided.

FIGS. 3, 4, 5, 6 and 7 also show that the invention can be applied to other types of web introduction means than the two conventional press rollers 18 and 19 of FIG. In order to simplify these figures, the ply of fibers is not represented and the extractor means 10 are represented simply by two pressure rollers 15 and 16, the drive means of these rollers and their control being identical or different. to those of Figure 1. The other essential means of the invention present in the needling of these Figures 3, 4, 5 and 6 have the same references as in Figure 1. The alternative actuating means 4 of the board with needles are shown schematically in crank-rod with respect to FIG.

In FIG. 3, the introducer means 17 comprise rollers 18 and 19, each equipped in a groove of a guide pin, respectively 18A, 19B, which makes it possible to accompany the transfer of the roll sheet to the entry of the needling table 3 and the stripper 7. The servomotor Ml is adapted to drive under the control of the central unit UC one of the variable speed rollers, 18 in Figure 3, the other roller 19 being driven by a positive mechanical transmission at the same speed as the roller 18. Such guide fingers are known in the state of the art.

In FIG. 4, the introducer means 17 comprise means for guiding and compressing the ply formed on each side of the ply by an endless flexible belt 20, 21 formed around a roller 22, 23, and a spout 24, 25 located at the entrance of the needling machine. The beaks are inclined relative to the plane of the sheet so as to define an inlet channel for the gradually shrunken sheet for compressing the sheet. They also advantageously make it possible to approach closer to the entrance. the needling machine with great precision. Such a device is for example described in patent EP 0 334 948. In accordance with the invention, the servomotor M1 is adapted to drive the roller 22 at variable speed according to a periodic law under the control of the central unit UC. A positive mechanical transmission or a synchronous motor makes it possible to drive the roller 23 according to the same speed profile as the roller 22.

FIG. 5 shows the case where the introducing means consist of several successive individual means, here two: a first individual means consisting of a transfer belt 26 and a second individual means consisting of two pressure rollers such as the rollers 18 and 19 of Figure 1, the transfer belt being formed upstream of the rollers in the path of the unconsolidated web. The transfer belt 26 comprises two cylinders 27 and 28 around which is formed an endless belt 29 for transporting the web. According to the invention, each of the two individual means is adapted to be driven at variable speed, the rollers 18 and 19 using the servomotor Ml as in Figure 1 and the transfer belt 26 using a servomotor M3 adapted to drive the roller 28, the roller 27 being rotatably mounted and thus driven at the same speed as the roller 28. According to a preferred operation, the first individual means, located furthest upstream of the needling, here the transfer belt 26, is driven at variable speed periodically but with a smaller amplitude than the second individual means, here the two pressure rollers 18 and 19. This allows to introduce a periodic variable advance whose amplitude increases gradually for s adapting to that of the alternating actuating means 4. In FIG. 6, there is shown a variant of the introduction means of FIG. 5, according to which the transfer belt 26 used is a connected mat. u in the state of the art said accumulation with each cylinder 27, 28 can be driven at variable speed with a servomotor of its own M3, M4, respectively. The possibility of having different instantaneous speeds for the two rolls is used to accumulate if necessary the web on the belt 29. An advantageous mode of operation according to the invention may be to define here again a periodic velocity curve for three servomotors M4, M3 and Ml, respectively cylinders 27, 28 and 18, with an amplitude of variation of the instantaneous speed which is becoming stronger for a progressive adaptation to the typing cycle. The accumulation effect of the web on the belt 29 occurs when the instantaneous speeds of the cylinders 27, 28 are different. FIG. 7 shows an insertion means successively comprising a drawbench 40 and a pair of pressure rollers 18, 19 (equivalent to those described with reference to FIG. 3). The drawing bench 40 is constituted in turn by a succession of lower and upper rollers between which is guided the web to consolidate. According to the example chosen and shown, the rollers are nine in number and driven in groups of three successive rollers, each with the aid of a servomotor: the most upstream is a group G1 driven by an M7 servomotor, and then a group G2 driven by a servomotor M8, then to finish upstream of the rollers 18, and 19, a group G3 driven by a servomotor M9. Each group constitutes a stretching means and can be considered within the meaning of the invention as an individual means of introduction. According to the invention, each servomotor of the drawbench, M7, M8 and M9, is controlled by the central unit UC in response to the position signal of the sensor C formed on the alternating actuating means 4, in synchronism with the cycle needling. The periodic instantaneous velocity profiles of each group are shown in the figure. On these curves, is schematized the fact that on the one hand to obtain the desired stretching, the average speeds VmI of the drawing group 1, Vm2 of the drawing group 2 and Vm3 of the drawing group 3, are increasing, and, on the other hand, that their amplitude of variation is also increasing to progressively adapt the oscillation of the advance of the sheet. Furthermore, it is schematized that the amplitude of the last individual means of introduction, in this case the rollers 18 and 19 preferably have a greater amplitude of variation than that of the last stretching group G3. In Figure 8, there is illustrated a needling machine for textile plates that can include the means according to the invention. The particularity of this needling lies in the fact that the direction of advance of the textile plate is reversed at each passage. The introducing means are both extractors and vice versa, depending on the direction of passage of the plate. The needling machine comprises on one side a transfer belt 30 and two introducer / extractor rollers 31, 32, and, on the other side, two introducer / extractor rollers 33, 34, and a transfer belt 35. Each pair of Feeder / extractor rollers are adapted to be driven at variable speed by means of a servomotor M5, M6 driven by the central processing unit UC in synchronism with the signal at the output of the position sensor and according to the operating data in variable speed. and come programmed or detected (direction of passage, holding of the plate function of the number of passages already carried out etc.). It goes without saying that other alternative embodiments are possible without departing from the scope of the invention, in particular as regards the shape of the periodic velocity curves, the shape of the introduction means, the possible combinations of the various means of the invention. individual training of introduction and / or extraction (different or different amplitudes, phase shift in advance or not, etc.) which are a function of the particular application implemented (type of sheet, type of consolidation, etc.) .

Claims

claims

A reciprocating consolidation machine (1) comprising:

- a consolidation path for a textile web (2); - consolidation tools (3,5,7);

means (4) for alternating actuation of the tooling;

- At least one introduction means (17) for, at least in certain operating phases, introducing the web (2) in the consolidation path; and - at least one drive means (M1, M3-M9) of the introduction means (17), characterized in that:

the drive means (M1, M3-M9) is capable of a variable speed periodically; and - synchronization means (C, UC) are provided between the reciprocating actuating means (4) and the variable speed of the driving means (M1, M3-M9).

2. Machine according to claim 1, characterized in that the drive means (M1, M3, M4, M5, M6) is an electromechanical means.

3. Machine according to claim 2, characterized in that the electromechanical means (M1, M3-M9) is a servomotor.

4. Machine according to one of claims 1 to 3, characterized in that the synchronization means comprise:

a position sensor (C) associated with the alternating actuating means; and

control and processing means (UC) for controlling the phase position of the driving means (M1, M3-M9) of the introduction means

(17), in response to the sensor signal (C).

5. Machine according to one of claims 1 to 4, characterized in that the synchronization means (C, UC) are adapted to create a phase shift between the reciprocating actuating means (4) and the driving means (M1, M3-M9) of the introducing means (17).

6. Machine according to claim 5, characterized in that the drive means (M1, M3-M9) is in phase advance on the reciprocating actuating means (4).

7. Machine according to any one of claims 1 to 6, characterized in that the at least one insertion means comprises a plurality of successive individual means (18,19; 26; 40) capable of different instantaneous speeds during the operation of the machine.

8. Machine according to claim 7, characterized in that the individual means (26; G1; G2; G3) located the most upstream is driven with a speed having a first amplitude of variation, and the individual means (18,19). downstream are controlled with a speed having a gradually greater amplitude of variation than the first amplitude of variation.

9. Machine according to claim 8, characterized in that the insertion means comprises a drawbench (40) comprising successive drawing means (G1, G2, G3) adapted to be driven at increasing average speeds for stretch the web of fibers and which constitute successive individual means of introduction.

10. Machine according to one of claims 1 to 9, characterized in that it comprises at least one extraction means (10) of the consolidated web driven by at least one drive means (M2, M5, M6) capable of a periodically variable speed, the synchronization means (C, UC) being adapted to synchronize the reciprocating actuating means (4) and the variable speed of the driving means (M2, M5, M6) of the extracting means ( 10).

11. Machine according to claim 10, characterized in that the drive means (M2, M5, M6) extractor means (10) is an electromechanical means.

12. Machine according to claim 11, characterized in that the electromechanical means (M2, M5, M6) is a servomotor.

13. Machine according to one of claims 10 to 12, characterized in that the control means and processing (UC) are adapted to control the phase position of the drive means (M2, M5, M6) means of extraction (10), in response to the signal from the position sensor (C), means for alternately actuating (4) the consolidation tool.

14. Machine according to one of claims 10 to 13, characterized in that the drive means (M2, M5, M6) of the extractor means (10) is controlled with a speed having a greater amplitude of variation than the amplitude of variation of the drive means (M1, M3-M9) of the introducing means (17).

15. Machine according to any one of claims 1 to 14, characterized by a shape of the law of variation of the speed of the drive means (M1-M9) substantially sinusoidal with a recess of slowing or stop elongated relative at the peak of maximum speed.