KR20190033019A - Method for starting up a warp knitting machine and warp knitting machine - Google Patents

Abstract

Disclosed is a method for starting up a warp knitting machine (1) having a new pattern. In the method, threads (4) of a warp are pulled into a guide needle (2). At least one row of stitches is formed by the interaction between the guide needle (2) and a knitting needle (3). The present invention aims to make it easier to start up the warp knitting machine. To this end, the tension of incoming threads (4) is determined and limited to a predetermined maximum value.

Description

Technical Field [0001] The present invention relates to a method of starting a warp knitting machine and a warp knitting machine,

The present invention relates to a method of starting a warp knitting machine with a new pattern wherein the threads of the warp thread are passed into a guide needle and the threads between the guide needle and the knitting needle At least one row of stitches is formed by the interaction.

The present invention also relates to a method of manufacturing an article comprising at least one main shaft, at least one guide bar, at least one knitting-needle bar, a thread equalizing device, To a warp knitting machine having a delivery drive and at least one fabric takedown.

For known items of knitwear which may also be referred to as "pattern ", the necessary data is generally available. The data includes values for the lay, the thread inlet, and the takedown, in particular. Thus, for example, when the warp knitting machine has to be started because the warp beam has been fully machined, or when the warp knitting machine has to be switched to a different pattern, the operator passes the yarn into the guide needle and generates one or more rows of knitting After each circular-forming operation, the yarn is pulled tightly by hand, and then the transfer drive is switched on to a predefined inflow value, and the warp knitting machine is capable of winding the knitted fabric with the knitted fabric take- , And then the knitted fabric take-up is switched on and production can commence.

However, if a new pattern is to be produced, all required data is not available or is not necessarily available. In general, the motion profile of the guide needle relative to the lay, i.e., the knitting needle, is predefined. However, for example, the inflow should be determined empirically. For this purpose, a certain amount of experience and corresponding sense of the operator is required. During each operation, there is a risk due to operational errors and lack of knowledge. This can create damage to the knitting element and / or also to the processing material, for example yarn. Therefore, startup is time consuming and costly.

The present invention is based on the object of making it easier to start a warp knitting machine with a new pattern.

In a method of the type mentioned at the outset, this object is achieved in that the tension of the incoming yarn is determined and limited to a predetermined maximum value.

Limiting the yarn tension prevents an excessively high yarn tension. Thus, the risk of damage to knitting tools or seal materials is considerably reduced. Also, restricting the tension of the incoming yarn allows a restriction on the freely selectable parameters, allowing the operator to work only within a limited working range. This makes starting easier because of possible variations and thus also possible errors to be kept small. The tension of the circulating threads is preferably determined here on the part which does not directly guide the yarn. This is not the tension of the individual yarn, but the tension that governs the entire yarn transferred from the beam.

Preferably, the heat of the crystallization is formed at a creep speed. Therefore, it is possible to operate the warp knitting machine at a very low speed as long as a new pattern is being started. The tension of the yarn is virtually independent of the operating speed of the warp knitting machine.

Preferably, the tension is determined when the guide needle reaches its reversal point behind the knitting needle. Here, the maximum deflection of the guide needle occurs. At this point, the spacing of the various knitting elements is greatest. Therefore, the tension of the yarn is also greatest here. This is sufficient here to determine the tension and make it the basis of further procedures.

Preferably, the tension is adjusted by controlling the transfer drive. The transfer drive actively drives the tilted beam from which the thread of the warp yarn is drawn. In subsequent manufacturing operations in which knit fabrics are continuously produced, the transfer drive is operated with a constant yarn inflow value. The inflow value is usually specified as "mm / R", ie, in millimeters per rack. One of the tasks when starting a warp knitting machine with a new pattern consists in determining the relevant yarn inflow value. This inflow value can be determined by a predefined tension, and a transfer drive that is operated in a closed control loop to ensure that the tension is achieved but not exceeded. If the transfer drive discharges too many yarn lengths per circular-forming operation, the tension is too low. If the delivery drive discharges too little yarn length per circular-forming operation, the tension is too high. Therefore, by adjusting the "transfer speed" in the transfer drive, the inflow value can be corrected with a relatively simple control. Here, it is not absolutely necessary that the transfer drive is already continuously operating at this stage of the start-up operation. It can also be operated intermittently, i. E. Supplying some yarn for a while and then stopping again. Thus, only an excessively high tension peak should be prevented. Besides, it is also entirely possible during the circular-forming operation to occasionally dominate very low tension in the yarn or even to have no tension. The transfer drive is in any case operated only in the positive drive direction, that is, the direction in which it discharges the yarn.

Preferably, after the knitted fabric take-up is switched on and the knitted fabric take-up is switched on, control of the transfer drive continues for a predetermined period of time. Switching on the knitted fabric take-up device causes a change in appearance of the knitted fabric. Without a knit winder, the individual rows of the knitting are said to be "block-wise". The loops of the individual rows of the loops are in fact placed against one another in the direction of production of the knit. As a result of switching on of the knitting machine winder, a slightly different appearance is obtained. Depending on the speed at which the knit winder is operated, it becomes a looser or more solid knit structure. The control of the transfer drive can then also be carried out in the form of a knitted fabric structure, since looser knit materials can be achieved than in the case of lower yarn lengths per circular-forming operation if the delivery drive supplies a larger yarn length per circular- Lt; / RTI > After the knit winder is switched on, the operator can then check whether the knitwear corresponds to requirements or desires. If this is not the case, the operator can change the pre-regulation of the tension.

Preferably, the inflow value of the transfer drive is displayed. The yarn tension creates an inflow value, for example mm / R, or millimeter per rack. If the knit fabric has the desired look and desired feel, then this yarn entry value can be displayed to reuse it during subsequent manufacturing operations of the same pattern. Displaying the inflow value can be performed optically here through the display. However, displaying the inflow value may also consist of printing out or storing the inflow value in another manner. It is important, however, that the inflow value is available later, i.e. during the resumed manufacture of the same pattern, and can be entered as a knitting machine.

Preferably, the predetermined maximum value is predefined as a fraction of the default value. The default values are known for each machine and can be predefined by the manufacturer. This arises, for example, from measurements on each warp machine, and variations can also be considered here. It is then possible to predefine, for example, a specific percentage of the default value as the tension. Thus, no predefining of absolute values is required.

In a warp knitting machine of the type mentioned at the beginning, this object is achieved by connecting a yarn tension measuring device to a control device which controls the delivery drive in a learning phase.

It is possible to determine the actual tensile force of the yarn of the warp yarn and to make such tension the basis of adjustment of the yarn inflow value of the delivery drive, as described above in connection with the method. Thus, firstly, overloading of the knitting element and the seal material is prevented. Secondly, the operator has a simple, possible way of changing the look and feel of the knitted fabric being produced. The operator only needs to change the set point used by the control device to control the delivery drive.

Preferably, the thread tension measuring device is arranged on the real equalizing device. Since a fluctuating yarn consumption occurs during the circular-forming operation, a real equalization arrangement is required during fabrication of the knitting machine. This actual consumption variation can be equalized through a real equalizer. Then, it is also possible to determine the thread tension by using such a room equalizing apparatus in a simple manner. "Measurement" in the sense of numerical results is often not necessary. The yarn tensioning device may also be arranged on the fixing of the yarn equalization device.

Preferably, the thread tension measuring device determines the total tension of the plurality of yarns. Thus, the result is a constant equalization across the width of the warp knitting machine. Thus, the effects of the individual chambers and their tensile forces are kept small while the total tension from the plurality of threads or even from all the threads has a significant magnitude.

Here, it is preferable that the thread tension measuring apparatus determines a tension on a thread guide. In the simplest case, the thread guide is a spring-mounted rod on which the threaded threads are guided before entering the thread guide opening of the guide needle. Then, the thread guide has its greatest deflection when the guide needle is at their turning point behind the knitting needle. At this moment, the maximum thread tension can be determined. The thread tension is preferably determined at a fixed portion here, for example, in the region between the spring arrangement having a thread guide and the frame of the warp knitting machine.

Preferably, the thread tension measuring device is synchronized with the main axis. The thread tension measuring device can then accurately determine the appropriate tension at the stated instant when the guide needle has the greatest distance therebetween from the knitting needle.

The invention will be described below with reference to exemplary embodiments, which are preferred with reference to the drawings. In the drawings,
Fig. 1 is a schematic diagram of an elevation of a portion of warp knitting machine,
Fig. 2 shows a schematic diagram of a tension profile.

The warp knitting machine 1 whose parts are shown has a guide needle 2, which is arranged on a guide bar (not specifically shown). The warp knitting machine also has a knitting needle 3, which is arranged on a knitting needle bar (not specifically shown). During operation of the warp knitting machine, the guide needles 2 and the knitting needles 3 move relative to each other to form a knitted fabric. Wherein the relative movement is such that the guide needle 2 moves through a gap between the knitting needles 3 and a region in which the guide needle moves parallel to the longitudinal extent of the knitting needle bar Respectively.

During this movement, the yarn 4 drawn out of the inclined beam 5 is machined to form a circular rotation of the knit.

The thread (4) is guided to a thread guide formed as a rod (6). The rod is mounted on the spring arrangement (7). The spring arrangement 7 allows a constant mobility of the rod 6 when the tension of the thread 4 changes. This tension change occurs at least once per circular-forming cycle, as can be seen from Fig.

Fig. 2 shows a first curve 8 for reproducing the tension of the private room 4 and a second curve 9 for reproducing the corresponding tension profile of the overall tilt. The tension profile shown in curve 9 can be determined from the motion of the rod 6. For this purpose a sensor 10 is arranged on the spring arrangement 7 to determine the tension of the spring arrangement 7 and therefore the force exerted on the spring arrangement 7 by the rod 6 . Of course, it is also possible to use different sensors to determine the tension of the warp formed by the yarn 4. The sensor 10 may be formed by a strain gauge for example between a holder 19 of the spring arrangement 7 fixed to the frame 18 of the warp knob . Thus, the sensor is located on the non-moving part, which is located outside the element of the warp yarn, which does not directly guide the yarn.

The sensor (10) is connected to the control device (11). The control device 11 is connected to the transfer drive 12 of the tilted beam 5.

The warp knitting machine (1) has a main shaft (13). The spindle 13 is responsible for most of the movement of the knitting tool. This controls the movement of the guide needle 2 and the knitting needles 3 in particular. In short, the rotation of the main shaft 13 carries out a ring-forming operation in most cases, so that one row of rotations per revolution of the main shaft 13 is generated.

A rotational angle sensor 14 detects the rotational position of the main shaft 13 and also reports the rotational position to the control device 11. [

A knitted fabric winding machine in which the knitted fabric can be wound from the working area formed by the guide needle 2 and the knitting needles 3 is not specifically shown.

When the warp knitting machine is started, the yarn 4 is pulled into the guide needle 2. This is generally done by a removed guide bar, with which the guide needle 2 is more accessible. After the thread has passed, the guide bar moves to its normal working position and is mounted thereon. The operator then sets the machine to move slowly and monitors whether the guide needle 2 initially can flow through the gap between the knitting needles 3 without collision. Correction is required if necessary.

Then, the operator first performs the first circular-forming operation. Thereafter, the thread 4 is stretched by hand. Following this, one or more additional circular-forming operations are followed until at least one continuous circular array is formed over the working width of warp knitting machine 1. Between each circular-forming operation, the yarn 4 is tightened by hand.

When continuous circular formation is performed, the transfer drive 12 of the tilted beam 5 is started. Then, the oblique beam 5 feeds the yarn 4. The slices are then initially formed into blocks, that is, they are placed close to each other. Thereafter, a knitted fabric winding machine not specifically shown is started, and the production of the knitted fabric can be started.

However, it is assumed that certain parameters of the manufacture of the knit, especially the value for the so-called yarn entry (which are typically expressed in mm / R, i.e. millimeters per rack), are known. In addition to the circular density and the actual lay that can be influenced by the knife winder, yarn inflow is an important value in the manufacture of the knit.

When a new pattern is to be produced, the inflow value is not available. The inflow is adjusted by the operator's experience and sense. Here, during each stage of work, there is a risk due to operational errors and lack of knowledge of the target. This can cause damage to the knitting elements, i.e., the guide needle 2 and the knitting needles 3. In addition, the seal 4 may also be damaged.

In order to reduce the severity of this problem, the tension of the incoming yarn 4 is determined with the aid of the sensor 10, and this actual tension is transmitted onto the control device 11. The control device 11 compares the actual tension with the predefinable tension setting value and then controls the delivery drive 12 so as not to exceed this tension setting value indicating the predefinable maximum value.

When the transfer drive 12 is operated in such a way that it supplies more chambers 4, i. E., A larger yarn length per rack, the tension decreases. When the transfer drive 12 is driven in such a way that it supplies fewer threads, i. E. Shorter thread length per rack, the tension increases. With this automated procedure, it is possible for the warp knitting machine to approach the correct value of the yarn infeed itself, i. E.

This "learning operation" continues when the knit take-up winder is switched on, and the knitting becomes larger. Thus, for each circular turn, a greater length of the thread 4 is also consumed. Thus, the transfer drive must rotate the tilted beam 5 slightly faster to supply a greater length of the yarn 4 for each circular-forming operation. Here, the tension is also determined, and the transfer drive 12 is controlled such that it does not exceed the maximum tension.

The tension need not be input as an absolute value. Each warp knitting machine 1 typically has a default value which can be predetermined, for example, by the manufacturer, or can be determined when the warp knife is first commissioned. The operator can then predefine the percentage of this default percentage, i. E. The fraction, through the input device 15, for example, to adjust the maximum tension. The operator can then visually or sensibly monitor whether this tension value has resulted in the desired quality of the knit. If this is not the case, the percentage can be changed through the input device 15. [

As soon as the knitted fabric is made to a satisfactory quality, the inflow value can be displayed through the display device 16. [ A display device is schematically shown here. Here, it is not absolutely necessary to use a display or a printer. It is also possible to store only the inflow value, making the stored value available for subsequent manufacturing operations.

By using the yarn inflow value, subsequent knit fabrics containing the same pattern can be subsequently produced.

The outlined procedure preferably proceeds at a slower rate so that the operator can continuously monitor at a slower rate whether the knit is actually manufactured to have the desired look and desired feel.

A thread guide comprising a rod 6 and a spring device 7 forms a real equalization device during operation to equalize the volumetric yarn consumption during the circular-forming operation. It can then also be used to continuously determine the tension of the yarn.

As can be seen from the curve of FIG. 2, the tension of the yarn 4 is fairly highly volatile in the circular-forming operation. This is due to the fact that the actual consumption also varies in the circular-forming operation. The tension is greatest when the guide needle 2 is located at a turning point behind the knitting needle 3, specifically, on the hole 17 of the knitting needle 3. Here, the guide needle 2 is in the state of the largest bending with respect to the knitting needle 3. This position of the guide needle 2 is detected by the rotation angle sensor 14 which detects the rotational angle position of the main shaft 13 so that the control device 11 also detects the corresponding tension value only at this time It is possible. Thus, the control device 11 forms an instantaneous recording of the tension when the main shaft 13 is located at the predetermined rotational angular position, and only the tension at this time is compared with the predetermined or predeterminable maximum value Compare.

Claims (12)

A method of starting a warp knitting machine (1) having a new pattern, wherein threads of a warp thread (4) are drawn-in into a guide needle (2) At least one row of stitches is formed by the interaction between the knitting needles 3; Characterized in that the tension of the incoming chamber (4) is determined and limited to a predetermined maximum value. The starting method according to claim 1, wherein the heat of the crystal is formed at a creep speed. The starting method according to claim 1 or 2, wherein the tension is determined when the guide needles (2) reach their reversal points behind the knitting needles (3). The starting method according to any one of claims 1 to 3, wherein the tension is adjusted by controlling a delivery drive (12). The method according to claim 4, characterized in that the control of the transfer drive (12) continues for a predetermined period of time after the fabric takedown is switched on and the knit take- Way. A starting method according to any one of claims 1 to 5, wherein the thread inlet value of the transfer drive (12) is displayed. 7. A method as claimed in any one of claims 1 to 6, wherein said predetermined maximum value is predetermined as a fraction of a default value. A main shaft 13, at least one guide bar, a knitting-needle bar, at least one thread equalizing device 6, 7, at least one delivery A yarn tension measuring device 10 is connected to a control device 11 as a warp knitting machine 1 having a drive 12 and at least one knot winding machine and the control device 11 is connected to the transfer drive 12 Characterized in that it is controlled during a learning phase. The warp knitting machine according to claim 8, characterized in that the yarn tension measuring device (10) is arranged on a real equalizing device (6, 7). A warp knife according to claim 9, characterized in that the yarn tension measuring device (10) determines the total tension of the plurality of yarns (4). The warp knitting machine according to claim 10, wherein the thread tension measuring device (10) determines a tension on a thread guide (6). A warp knitting machine according to any one of claims 8 to 11, characterized in that the thread tension measuring device (10) is synchronized with the main spindle (13).

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