WO2000063474A1

WO2000063474A1 - Device for feeding weft yarn lengths for use in a jet-weaving machine

Info

Publication number: WO2000063474A1
Application number: PCT/EP2000/003368
Authority: WO
Inventors: Joseph Verhulst; Jozef Peeters
Original assignee: Picanol N.V.
Priority date: 1999-04-20
Filing date: 2000-04-14
Publication date: 2000-10-26
Also published as: BE1012620A3

Abstract

The invention relates to a device for feeding a weft yarn length for use in a weaving machine. According to the invention, a holder (10) for a plurality of nozzles (9) is movably mounted on the slay (2) and is positioned and maintained in this position in relation to a guide channel (8) that is moved concurrently with the slay (2) by a drive unit (14) that functions in accordance with a defined sequence of movements.

Description

Device for inserting weft threads for a

Jet loom

The invention relates to a device for introducing weft threads for a jet weaving machine with a plurality of nozzles that can be attached to a sley, movable relative to the sley, and with a drive unit connected to the nozzles by means of coupling elements for adjusting the holder, in order to move at least one nozzle to one that moves with the sley Align the guide channel.

In air jet looms, the weft threads are transported in a guide channel mounted on the sley from the entry side to the opposite side. In the case of weaving, different weft threads are inserted one after the other, for example weft threads that differ in color. For this purpose, several nozzles are provided, each of which is intended for the insertion of one weft thread. These nozzles are held together and movably mounted on the sley in order to align the outlet of the nozzle used with the guide channel, ie to arrange it in an extension of the guide channel. While the weft thread is being inserted, the nozzle in question remains aligned with the guide channel until the inserted weft thread is inserted into a weft thread. scissors are inserted and attached to the edge of the goods. The inserted weft is then cut off using the weft scissors, after which the nozzle selected for the next weft is brought into operational readiness. In fast-running weaving machines, the time available for aligning the next nozzle to the guide channel is relatively short, so that the holder with the nozzles has to be moved with a correspondingly large acceleration relative to the guide channel and the sley. The holder with the nozzles only has to be moved relatively small distances. This movement can counteract forces that arise due to the movement of the sley.

In known constructions, the means for adjusting the nozzles are mounted on the sley. You have to apply relatively large forces to be able to move the nozzles quickly over a small distance. For this purpose, it is known (US 46 44 980, US 4 703 778, EP 0 203 256 AI) to use pneumatic drives which can deliver large forces for small movements, but only allow an adjustment between two end positions. Such drives therefore contain stops for determining the end position at which the drives or the nozzles or a holder for the nozzles stop. The striking leads to vibrations of the nozzles in the area of their exit, which is disadvantageous for the insertion of a weft thread, since the nozzle in question is not always arranged correctly in the extension of the guide channel. This is disadvantageous for the energy transmission of the fluid flowing from the nozzle to the weft thread to be introduced into the guide channel. Such vibrations are also disadvantageous for the life of such devices. If there are several nozzles and accordingly more than two positions are required, several pneumatic drive elements must be used, which are arranged side by side. Such drive elements have a mass which is moved back and forth by the sley and thus generates inertial forces which have to be absorbed by the sley. In a device of the type mentioned (JP-A 11-43 847), a drive unit is mounted on the sley as an adjusting device which contains a drive motor which is connected to the holder via a crank mechanism in order to pivot the holder and thereby the align selected nozzle to the guide channel.

The invention has for its object to provide a device of the type mentioned which increases the mass moving with the sley as little as possible and which manages with the lowest possible accelerations when aligning the nozzles to the guide channel.

This object is achieved in that the drive unit can be attached in a stationary manner and that it is assigned a control unit which adjusts the drive movement to the movement of the sley and effects an alignment of the nozzles to the guide channel.

In the device according to the invention, the control unit causes the stationary drive unit to drive the nozzles with a defined course of movement, in which a nozzle is positioned in the extension of the guide channel and is held in this position during the movement of the sley to strike a weft thread. The drive unit continuously carries out an operating movement with a predetermined movement course, so that no abrupt movements and therefore no strong accelerations occur in order to position and hold a nozzle in the extension of the guide channel. Positioning and holding the position are achieved in a flowing drive movement that is not stopped by components running against a stop. It is only necessary to change the course of movement of the drive unit in order to position another nozzle in the extension of the guide channel, without having to start a movement at all. This has the advantage that the outputs of the The nozzles vibrate very little and always remain correctly positioned in the extension of the guide channel, so that good energy transfer of the fluid flowing out of the nozzle to the weft thread is achieved, which is introduced into the guide channel. The flowing movements without abrupt accelerations or decelerations are also advantageous for the service life of the device according to the invention. Since the drive unit is arranged in a stationary manner and does not move with the sley, it also ^" does not create any inertial forces that have to be absorbed by the sley.

In one embodiment of the invention, the movement profiles of the drive unit for the nozzles, which are assigned to the individual nozzles, are entered in the control unit as programs which can be run off. In this way, the movements can be repeated very precisely, especially depending on the rotation of the main shaft of the loom.

In a further embodiment of the invention, the nozzles are assigned a sensor which detects the relative position to the guide channel and which is connected to the control unit. This sensor allows control, adjustment and compensation of tolerances. In addition, a teaching of the control unit is possible via the sensor, in which the movements of the nozzles are entered into the control unit.

In the case of a simple construction, the nozzles are held in a common holder which can be attached to the sley in a manner pivotable about an axis running transversely to the shaft of the sley. It is advantageous if it is provided in a further embodiment of the invention that the center of gravity of the holder and the elements held by it lies at least approximately in the axis of the holder. The forces required to adjust the holder are therefore relatively low. It is preferably provided that the drive unit contains a switchable reluctance motor, which is preferably connected to the nozzles via a crank mechanism and coupling elements. Such a drive motor is particularly suitable for executing a changeable, continuous movement.

In a further embodiment of the invention it is provided that the drive unit can be attached above the nozzles. In an advantageous development of the invention, it is provided that the drive shaft of the crank drive of the drive unit can be attached approximately in the bisector of a swivel angle about which the nozzles can be pivoted by means of the sley. This ensures that on the one hand the drive unit can maintain a sufficient distance from the sley, while on the other hand only relatively small adjustment paths of the drive unit are required to hold a nozzle in the position in the extension of the guide channel. The amount of movement necessary to position another nozzle in the extension of the guide channel is also limited.

Further features and advantages of the invention result from the subclaims and the following description of the exemplary embodiments illustrated in the drawings.

1 shows a schematic representation of a section of an air jet loom with a device according to the invention,

2 shows a partial section through the air jet loom with a device according to the invention and a reed shown in dashed lines,

3 is a perspective view on an enlarged scale of coupling elements of the device according to the invention, 4 shows a partial section similar to FIG. 2 with a different position of the nozzles,

5 is a view similar to FIGS. 2 and 4 of the nozzles in the position of FIG. 4 in the stop position of a sley,

6 is a partial section similar to FIG. 4 with a different position of the nozzles,

7 shows a section similar to FIG. 4 with yet another position of the nozzles,

8 shows a diagram with the movement profiles of the drive unit of a device according to the invention for a total of four different positions of nozzles and

9 and 10 diagrams similar to FIG. 8 with the movement profiles for positioning nozzles in the extension of a guide channel.

1 and 2, a weaving machine 2 is shown from a weaving machine, which contains a shaft 3 and a shop profile 4, which is connected to the shaft 3 by means of stilts 5. A reed 7, which has a guide channel 8 for a weft thread to be inserted, is attached to the shop profile 4 by means of a clamping wedge connection 6. A total of eight nozzles 9 are mounted on the shutter profile 4 of the sley 2, by means of which a weft thread can be inserted in each case. These nozzles 9 are held pivotably about an axis 11 by means of a common holder 10 in a bearing block fastened to the shop profile 4. The axis 11 extends transversely to the shaft 3 of the sley 2. The nozzles 9 of the illustrated embodiment have a holding element 24 in pairs, by means of which they are fastened to the holder 10. The nozzles 9 are also in pairs in the area of their mouths 18 by means of a support 25 held side by side on the holder 10. The orifices 18 of the nozzles 9 are located in the area of the beginning 12 of the guide channel 8.

The device 1 according to the invention also contains an adjusting device 13 in order to position a nozzle 9 with its mouth 18 in the extension of the beginning 12 of the guide channel 8. This adjusting device 13 contains a stationary mounted drive unit 14 and coupling elements 15 which connect the drive unit 14 to the nozzles 9 arranged on the drawer profile 4, i.e. with its holder 10. The drive unit 14, which is attached above the nozzles 9 to a profile 17 of the frame of the weaving machine, contains a controllable and / or adjustable drive motor, in particular a switchable reluctance motor.

The drive unit 14 is connected to the holder 10 by means of coupling elements 15. These coupling elements 15 contain a leaf spring 16, which connects a crank drive 32 or eccentric drive driven by the drive shaft 19 of the drive unit 14 with a bearing block 26 of the holder 10. The center of gravity of the holder 10 with the elements attached to it lies approximately in the axis 11, so that the drive means 13 have to absorb almost no inertial forces caused by the movement of the sley 2.

The drive shaft 19 of the drive unit 14 runs parallel to the axis 20 of the shaft 3 of the sley 2. The crank axis of the crank mechanism 32, which is determined by a screw 34 (FIG. 3), is close to the bisector 21 of the angle, which is the movement of the limited with the sley 2 moving nozzles 9. This angle is indicated by lines 22, 23 in FIG. 2. The crank axis, as can be seen from FIG. 2, is preferably offset somewhat from the line 22, which corresponds to the stop position of the sley 2, with respect to the bisector 21. Due to this arrangement, the movement of the drive shaft 19 of the drive unit 14 is relative small to move the nozzles 9 in the manner to be explained.

As can be seen from FIGS. 1 and 3, the end of the leaf spring 16 facing the holder 10 is mounted in a bearing block 26 which is fastened to the holder 10 in the region of the mouths 18 of the nozzles 9. This end of the leaf spring 16 is provided with a clamping piece 30 which is mounted in the bearing block 26 by means of an axis 28. The axle 28 is fixed by means of ^"bolts 29 in the bearing block 26th The bearing block 26 is provided with bores 31 in order to fasten it to the holder 10 by means of screws. The other end of the leaf spring 16 is also provided with a clamping piece 35 which is mounted on the screw 34 of the crank mechanism 32 forming the crank axis. The crank part of the crank mechanism 32 is clamped onto the drive shaft 19 by means of a clamping screw 33.

The drive unit 14 is slidably attached to the profile 17 parallel to the axis of rotation 20 of the sley 3. Likewise, the holder 10, i.e. the bearing bracket receiving it, slidably attached to the shutter profile 4 in the direction of the axis of rotation 20 of the sley 2, so that the drive unit 14 and the nozzles 9 can be aligned with one another in the direction of the axis of rotation 20 such that the leaf spring 16 essentially in a vertical plane is arranged. As can be seen in particular from FIG. 3, the broad sides of the leaf spring 16 point in the direction of the axis 20 of the shaft 3 of the sley 2. This arrangement is advantageous if the drive unit 14 and the nozzles 9 are adjusted in order to carry fabrics on the weaving machine weave different widths. 2 also shows the upper and lower warp thread levels 36, which form a shed 37, as well as a fabric support 39 for the fabric 38 and a spreader 40.

The course of movement of the drive unit 14 is controlled on the one hand by means of a control unit 54 in such a way that one of the nozzles, ie a pair of nozzles 9a, 9b, 9c or 9d (FIGS. 4 to 7) is selected and positioned in front of the guide channel 8, and that this selected nozzle 9a, 9b, 9c or 9d remains in this position during the stop movement of the sley 2.

8 to 10, curves 42, 43, 44, 45 show the movement profiles of the drive unit 14, ie the angular position R (FIG. 5) of the crank mechanism 32, by means of which the nozzles 9d, 9c, 9b, 9a in the Position in extension of the guide channel 8 are held while the sley 2 is pivoted back and forth. The angular positions R of the crank mechanism 32 are shown in curves 42 to 45 for a weft insertion, ie for a rotation of 360 ° of the main shaft of the weaving machine. The angular position R of the drive unit 14 and the angular position W of the sley are detected by sensors, not shown, which are connected to the control unit 54. 4 and 5, for example, the nozzles 9b are positioned in the extension of the guide channel 8. In order to keep the nozzles 9b in this position when the sley 2 moves from the stop position 0 ° to the rearmost position (FIG. 4) and back again to the stop position 360 °, the drive unit 14 has to execute a course of movement according to curve 44 in order to to keep the nozzles 9b in the position in extension of the guide channel 8. The control unit 54 controls the drive unit 14 in such a way that it assumes the assigned angular position R corresponding to the curve 44 at every angular position W of the sley 2. The insertion of a weft thread is started when the sley 2 is in the position shown by line 46, which corresponds almost to the rearmost position. It is important that the nozzles 9b (as well as the nozzles 9a, 9c, 9d in other settings) remain positioned essentially in the extension of the guide channel 8 during the insertion of the weft thread. The nozzles 9b are preferably held in this position until the inserted weft thread has struck the fabric 38 and has been cut off from the weft thread held ready. The weft thread is cut off and struck, for example, when the sley 2 is in the position indicated by line 47. Of course, the cutting of the weft thread does not have to coincide with the striking. It can also be done shortly after striking. The curve 45 shows the course of movement in order to hold the nozzles 9 a (see FIG. 7) in position in front of the guide channel 8. Correspondingly, curve 43 belongs to the nozzle position of nozzles 9c according to FIG. 2, while curve 42 belongs to nozzles 9d according to the position according to FIG. 6.

After a weft insertion by means of one of the nozzles 9a, 9b, 9c, 9d, a weft insertion by means of another nozzle can be changed as desired. This is done in that the nozzle now selected for the weft insertion is then positioned in front of the guide channel 8 instead of the previous nozzle. This change of position takes place, as shown in FIGS. 9 and 10, while the sley moves from the stop position 0 ° to the rearmost position up to the line 46. As indicated in FIG. 9 by lines 48, 50, 51, a change between the nozzle 9d and the nozzles 9a, 9b and 9c can take place in accordance with these curves. Of course, other position changes can also be carried out, which are not shown here for reasons of clarity. In a corresponding manner, there is a change in a different direction in accordance with curves 49, 52, 53 in FIG. 10, although of course all change options are not shown here for reasons of clarity. However, it can be seen in both Fig. 9 and Fig. 10 that even when changing the nozzles, i.e. when the nozzles are repositioned in front of the inlet 12 of the guide channel 8, no abrupt movements are caused by the drive unit 14, so that no strong accelerations will occur.

The possible curves 48 to 53 (as well as further ones not shown) for the transition phases and the curves 42 to 45 are stored in the control unit 54 as callable programs in order to be available for a desired pattern for introducing weft threads. These curves are for example geometrically calculated and entered into the control unit 54 by means of an input device 55 (FIG. 1).

Of course, it is not absolutely necessary to enter the curves using the input device 55. For example, the geometric values of the entire arrangement can also be input via the input device 55, after which the control unit 54 then calculates the curves 42 to 45 and 48 to 53 (as well as all necessary further ones).

In order to exclude an influence of tolerances in the setting or with regard to the dimensions of the parts of the device 1, which influence the positioning of the mouths 18 of the nozzles 9 to the guide channel 8, means can advantageously be provided to adjust the positioning. In the embodiment according to FIG. 1, for example, a sensor 56 is provided on the bearing block for the holder 10, to which a projection 57 of the support 25 of the holder 10 is assigned. The sensor 56 is set, for example, in such a way that it delivers a maximum signal when the projection 57 is arranged exactly in front of it. The projection 57 is oriented relative to the holder 10, for example, such that it lies exactly in front of the sensor 56 when the nozzles 9c are positioned in the extension of the guide channel 8.

For adjustment, the drive unit 14 is then controlled, for example by means of the control unit 54, at each angular position W, such as the sley 2, so that the sensor 56 always delivers a maximum signal to the control unit 54. The angular position W of the sley 2 and the angular position R of the drive unit 14 are each recorded, for example, by encoder disks, not shown, which deliver signals to the control unit 54 as a function of the angular position W of the sley 2 and the angular position R of the drive unit 14. The movement course of the drive unit 14 determined in this way is stored as an adjustment curve in the control unit 54. This Adjustment curve can then be compared with curve 44, which was theoretically determined. By means of calculation, the control unit 54 then determines the tolerances on the basis of the deviations between the adjustment curve and the curve 44. Corrected curves 42 to 45 and 48 to 53 can then be calculated taking these tolerances into account. If necessary, the adjustment can be repeated several times until the adjustment curve determined by the adjustment coincides with the calculated curve 44.

Of course, there are other adjustment options that can be used to determine and eliminate the influence of tolerances. In addition, other detectors, for example optical or magnetic detectors, can also be used, with which the position of the nozzles 9 can be determined as a function of the position of the sley 2.

An adjustment curve can also be determined by attaching a stop in a defined adjustment position on the shop profile 4, against which the holder 10 or the support 25 of the holder rests. The drive unit 14 is then controlled such that the holder 10 or the support rests against this stop at any angular position W of the sley 2. The associated angular position R of the drive unit 14 can thus be determined for each angular position W of the sley 2. This adjustment course can then be converted into a movement course, a nozzle being positioned in the extension of the guide channel 8.

Of course, the different movements and the different transition phases are not limited to curves 42 to 45 and 48 to 53. Rather, they can be selected and adapted in a different way in order to ensure that a specific nozzle is positioned in front of the guide channel 8 and / or is held in front of the guide channel 8. Of course, the invention is not limited to a holder 10 with eight nozzles 9. Rather, it can also be used if more or fewer nozzles 9 are provided. In the simplest embodiment, the invention can be used if at least two nozzles are to be optionally positioned in front of a guide channel 8. The advantage of the invention is of course greater if there are more than two nozzles 9.

In one embodiment, not shown, other coupling elements are provided instead of the leaf spring 16. For example, a rod can be provided which is arranged corresponding to the leaf spring 16 and which is articulated with a ball joint to the holder 10 of the nozzles 9 and with the other end to the crank mechanism 32 of the drive unit 14 by means of a ball joint. Coupling elements of this type permit spatial movements between the drive unit 14 and the nozzles 9 which can be moved relative to the sley, namely by deforming the leaf spring 16 or by twisting within the ball joints.

In one embodiment, not shown, the coupling elements contain a rope, one end of which is fastened to a winding roller arranged by the drive shaft 19 of the drive unit 14 and the other end of which is connected to the holder 10. A spring is provided between the holder 10 and the sley 2 to keep the rope taut. In a modified embodiment, the rope is attached at one end by means of a spring to the weaving machine frame and at the other end to the holder 10, this rope then being wound between the two around a winding roller driven by the drive unit 14. In this case, the holder 10 can cooperate with a tension spring or also with a compression spring in order to keep the rope taut. The invention is also not limited to the pivotable holder 10 for nozzles 9 shown. It is readily possible to provide a holder which is controlled by a drive unit and which can be moved in a guide which extends essentially perpendicular to the longitudinal axis of the sley 2. The nozzles can then be arranged, for example, as is known from US 49 62 795. The coupling elements then engage at the level of the holder guided in a guide for the orifices of the nozzles.

The guide channel 8 does not have to be part of the reed 7. Rather, a guide channel formed independently of the reed can also be used, as is known, for example, from US Pat. No. 4,644,980.

The device according to the invention is particularly suitable for easily positioning nozzles in the extension of a guide channel 8 before the insertion of weft threads and for keeping these nozzles 9 essentially in the extension of the guide channel 8 during the weft thread insertion. However, the device according to the invention can also be used to position other parts of a weaving machine as a function of a moving sley in order to bring and hold these parts in a specific position in relation to the sley.

The invention is not restricted to the illustrated embodiments. The scope of protection is rather determined only by the patent claims.

Claims

claims

1. Device for inserting weft threads for a jet weaving machine, with a plurality of nozzles (9) that can be attached to a reciprocating sley (2), movable relative to the sley, and with a drive unit (15) connected to the nozzles (9) by means of coupling elements (15) 14) for adjusting the ^' nozzles (9) in order to align at least one nozzle to a guide channel (8) which moves with the sley (2), characterized in that the drive unit (14) can be attached in a stationary manner and that the drive movement is based on the movement is assigned to the sley (2) and controls the alignment of the nozzles (9) to the guide channel (54).

2. Device according to claim 1, characterized in that the movement profiles of the drive unit (14) for the nozzles (9) are entered as drivable programs in the control unit (54).

3. Device according to claim 1 or 2, characterized in that the nozzles (9) is assigned a sensor (56, 57) which detects the relative position to the guide channel (8) and is connected to the controller (54).

4. Device according to one of claims 1 to 3, characterized in that the nozzles (9) are held in a common holder (10) which is pivotable about an axis (11) extending transversely to the shaft (3) of the sley (2) can be attached to the sley (2).

5. The device according to claim 4, characterized in that the center of gravity of the holder (10) and the elements held on it (9, 16, 26, 57) is at least approximately in the axis (11) of the holder (10).

6. Device according to one of claims 1 to 5, characterized in that the drive unit (14) contains a switchable reluctance motor.

7. Device according to one of claims 1 to 6, characterized in that the drive unit (14) drives a crank mechanism (32) and the drive shaft (19) runs parallel to the shaft (3) of the sley (2).

8. Device according to one of claims 1 to 7, characterized in that the drive unit (14) above the nozzles (9) can be attached.

9. The device according to claim 7 and 8, characterized in that the drive shaft (19) of the crank mechanism (32) of the drive unit (14) can be attached approximately in the bisector (21) of a pivot angle around which the nozzles (9) by means of the sley (2) are pivotable.

10. Device according to one of claims 1 to 9, characterized in that a leaf spring (16) is used as a coupling element between the crank mechanism (32) of the drive unit (14) and the holder (10), the broad sides of which in the direction of the shaft (3) of the sley (2) and that the leaf spring (16) is articulated to the crank mechanism (32) and the holder (10) by means of axes which run parallel to the shaft (3) of the sley (2).