EP0736622B1 - Driving system for shedding mechanisms on looms - Google Patents

Description

The present invention relates to mechanics for the formation of crowd on the looms, and it aims more particularly (because it is in this case that its application seems to present the most interest), but not exclusively, those of the Jacquard type.

We know that traditionally, mechanics of this type are trained from the weaving loom with which they are associated; in fact, the mechanical input shaft is connected to the main loom of the loom by a vertical drive shaft and two bevel gearboxes (couples conical). This classic arrangement implies the obligation to equip the profession of a very powerful engine associated with a clutch and a brake automatic themselves provided at high power; the drive shaft must be heavily dimensioned so that the total cost of the system is high.

In order to remedy this drawback, document FR-A-2 660 672 (STAUBLI) proposed to directly drive the input shaft of the mechanical using an independent motor, associated on the one hand with two encoders cooperating respectively with the aforementioned shaft and the main shaft of the trade, on the other hand to an electronic variator arranged for power the independent motor in synchronization with that of the trade based on information received from the above coders.

Despite the performance obtained, such an independent motor system enslaved was not entirely satisfactory. Indeed, consumption energy is high and moreover we run into serious difficulties in obtaining perfect synchronization between the trade and the mecanic. This synchronization requires the use of coders with high definition, therefore expensive and delicate. If we add to what precedes the essential oversizing of the independent motor, the cost of the whole system remains high.

Before explaining the solution proposed by the present invention for the rational training of the weaving mechanics, it will be recalled that the current Jacquard machines are most often electronically readable and thereby incorporate a pilot controller. This controller has a memory in which the desired armor is stored for the weaving and, receiving the position information from the mechanics, it controls the reading of the latter with each pick, to control the up and down movements of each of the beams of the harness.

This having been stated, it will be indicated that the present invention has set goals of reducing energy consumption, getting a perfect synchronization between mechanical and loom, to remove mandatory use of high definition coders and decrease the cost of the whole.

The training system according to the invention is defined in the claim 1

In accordance with the invention, the mechanical input shaft is actuated on the one hand by an independent motor with variable torque controlled, not enslaved to the main tree of the trade, on the other hand by a tree of synchronization linked to the aforementioned main tree.

• l'arbre de synchronisation ne transmet qu'un couple très faible, de sorte qu'il peut être établi à une section réduite ;
• la puissance est localisée au plus près de la mécanique et ne transite donc pas à travers le métier ;
• de très grandes vitesses de fonctionnement sont susceptibles d'être atteintes avec un métier à tisser et une mécanique de tissage fortement chargés ;
• le prix de revient de l'ensemble du système d'entraínement est sensiblement abaissé par rapport aux solutions antérieures.

This duality of motor sources for driving mechanics without electrical servo-control to the trade has considerable practical advantages:

• the synchronization shaft transmits only a very low torque, so that it can be established at a reduced section;
• the power is located as close as possible to the mechanics and therefore does not pass through the loom;
• very high operating speeds are likely to be achieved with a heavily loaded loom and weaving machine;
• the cost price of the entire drive system is significantly lowered compared to previous solutions.

In accordance with a particularly advantageous embodiment of the invention, the torque control of the independent motor is operated at using an electronic variator associated with a computer arranged to properly process the information received from the controller mechanical control. This calculator determines at all times the torque as a function of the elastic imbalances detected by the controller.

Fig. 1 est un schéma illustrant l'agencement général d'un système d'entraínement pour mécanique Jacquard établi conformément à la présente invention.

Fig. 2 montre de la même manière l'agencement du calculateur destiné à la commande du variateur de couple associé au moteur indépendant.

Fig. 3 et 4 illustrent les variations du couple résultant développé par la mécanique, respectivement du couple fourni par le moteur indépendant et par l'arbre de synchronisation.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:

Fig. 1 is a diagram illustrating the general arrangement of a drive system for Jacquard mechanics established in accordance with the present invention.

Fig. 2 similarly shows the arrangement of the computer intended for controlling the torque variator associated with the independent motor.

Fig. 3 and 4 illustrate the variations of the resulting torque developed by the mechanics, respectively of the torque provided by the independent motor and by the synchronization shaft.

In fig. 1, reference 1 designates the input shaft which provides the drive Jacquard mechanics shown schematically in 2. This mechanics 2 is equipped with an encoder 3 which detects the angular position of tree 1 and which sends the corresponding information 4 to the controller 5 which operates the electronic reading of the armor program introduced in said controller, in order to send the armor information 6 to the mechanics 2.

Simultaneously, the controller 5 sends angular position information 7 and armor information 8 to a computer 9 whose arrangement functional was illustrated in fig. 2.

• le module 10 renferme en mémoire les caractéristiques de tous les ressorts de rappel associés aux lisses du harnais de la mécanique 2, de sorte que connaissant à tout moment la position angulaire (information 7), l'effort de rappel de chaque ressort en fonction de la position en hauteur de la lisse considérée, et le sens de déplacement des lisses (information d'armure 8), il est à même de calculer le couple de déséquilibre à chaque instant en fonction de la différence d'effort de rappel élastique entre les lisses qui montent et les lisses qui descendent.
• le module 11 renferme en mémoire les inerties des pièces à entraíner et il est susceptible de calculer d'une part la vitesse de ces pièces en fonction de la variation de la position angulaire 7 dans le temps t (valeur ), d'autre part l'accélération desdites pièces en fonction de la variation de la vitesse ( ), ces valeurs permettant de calculer le couple d'inertie ;
• enfin le module 12 est agencé pour prendre en compte des couples constants mémorisés, par exemple le couple de nivelage.

As shown, this computer 9 contains three modules referenced 10, 11 and 12, which all receive the angular position information 7 emitted by the controller 5:

• module 10 contains in memory the characteristics of all the return springs associated with the heddles of the harness of mechanics 2, so that knowing at all times the angular position (information 7), the return force of each spring as a function of the position in height of the heald considered, and the direction of displacement of the heald (armor information 8), it is able to calculate the unbalance torque at each instant according to the difference in elastic return force between the beams going up and beams going down.
• the module 11 contains in memory the inertias of the parts to be driven and it is capable of calculating on the one hand the speed of these parts as a function of the variation of the angular position 7 in time t (value), on the other hand l acceleration of said parts as a function of the variation in speed (), these values making it possible to calculate the torque of inertia;
• finally the module 12 is arranged to take account of the stored constant torques, for example the leveling torque.

Information 13 (imbalance torque), 14 (inertia torque) and 15 (constant pairs) respectively emitted by modules 10, 11 and 12 of the computer 9 are sent to an electronic adder 16 at level at which they are tabulated to define information 17 corresponding to the resulting torque.

This information 17 is sent to the variator 18 of an independent motor 19 (fig. 1) equipped with an automatic brake 19 ', which motor 19 drives the input shaft 1 of the mechanism 2. Between the motor 19 and the mechanism 2, the shaft 1 is provided with a conical couple 20 ensuring its connection with a vertical synchronization shaft 21, the base of which is itself connected by another conical couple 22 to the main shaft 23 which ensures loom training 24.

The input shaft 1 of the mechanics 2 is consequently driven by two separate motor sources 19 and 23, the respective values of couples exerted on said shaft 1 by these two sources varying at all moment depending on the resulting torque 17.

The latter varies considerably depending on the armor, this variation occurring in both directions (positive or motor, negative or receiver), as shown in the diagram in fig. 3 showing the estate moves (introduction of picks) from loom 24 depending on armor. We can see that if this resulting couple 17 is calculated so fairly precise, the independent motor 19 provides the majority of the power transmission applied to input shaft 1, while the synchronization shaft 21 will only serve to compensate for the errors of calculation and instantaneous variations in the speed of the loom.

Fig. 4 shows in gray the part of the torque provided by the motor 19, clearly the small part of the torque transmitted by the shaft of synchronization 21. This sharing of efforts is very favorable since it allows perfect synchronization between loom 24 and mechanical 2 using the single encoder 3, of the usual type; the economy energy is significantly reduced and the overall cost is lowered.

It is understood that the system according to the invention is capable of being applied to the mechanics of the dobby kind by incorporation an appropriate controller.

Claims (3)

1. A system for driving the mechanisms for forming the shed on looms, characterised in that it comprises, for actuating the input shaft (1) of the mechanism (2), firstly an independent motor (19) of controlled variable torque, not servo-controlled by the main shaft (23) of the loom (24), and secondly a synchronisation shaft (21) connected to the aforementioned main shaft (23).
2. A system according to Claim 1, characterised in that the torque supplied by the independent motor (19) is controlled by means of an electronic variator (18) associated with a calculator (9) arranged so as to process suitably the data (7 and 8) received from the controller (5) which effects the electronic reading of the weave program and the driving of the mechanism (2).
3. A system according to Claim 2, characterised in that the calculator (9) is arranged to calculate at any moment the torques (13, 14, 15) which are totalled by an adder (16) to define the resulting torque (17) sent to the variator (18) of the independent motor (19).

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