|
(11) | EP 1 302 573 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||
| (54) | Method and apparatus for the production of chenille yarn |
| (57) A method for operating in parallel a plurality of machines 1, 2,... N for the production
of chenille yarn, having for each respective machine 1,2,... N a first motor M'1, M'2,... M'N that operates the cylinders shaft for feeding warp yarns, a blade and dragging rollers;
a second motor M"1, M"2,... M"N that operates a spinning head; and a third motor M"'1, M'''2,... M'''N that operates the spindles. For operating the above described motors a same first
voltage V' is supplied through a first line 101 to each first motor M'1, M'2,... M'N by a same first operating unit to an inverter A'; a same second voltage V" is supplied
through a second line 102 to each second motor M"1, M"2,... M"N by means of a same second operating unit to an inverter A"; a same third voltage
V"' is supplied through a third line 103 to each third motor M'''1, M'''2, ... M'''N by means of a same third operating unit to an inverter A"'. The voltages V', V" and
V"' and the relative currents are supplied through lines 101, 102 and 103 by inverter
circuits A', A", A"'. A same speed for each power input joint of the driven axes of
each machine is thus assured, that can be made with relevant savings in mechanical
transmissions and electronics, for having competitive costs. |
Field of the invention
[0001] The present invention relates to the field of textiles and more precisely it relates to a method for operating in parallel a plurality of machines for the production of chenille yarn. Furthermore, the invention relates to an operating unit that carries out this method.
Description of the prior art
[0002] Chenille yarn is made by a combination of a row of segments of weft yarn and a couple of continuous yarns, between which the segments are inserted transversally. A torsion follows of the continuous yarns, called warp yarns, in order to keep steadily between them the transversal segments, called pile.
[0003] To make chenille yarn plants exist that have a plurality of machines in parallel, from each of which two chenille yarns exit, wound on respective spindles. The spindles rotate continuously at a predetermined speed so that the respective chenille yarn is at the same time wound and twisted. The pile segments are made by a continuous yarn wound on a substantially triangular gauge having a vertex oriented towards below at which a blade disk is arranged. The yarn, spooled at high speed on the gauge, forms a plurality of loops that proceed towards below and are eventually cut by the blade in a plane orthogonal to the loops same, creating thus two rows of pile segments. Each row of pile segments is lowered following two separate paths, by means of counter rotating dragging rollers and are then inserted between the two warp yarns of each couple. The contemporaneous transit of a couple of warp yarns and of pile segments at the edge of one of the dragging rollers, as well as the twisting action of the rotating spindles, causes the pile segments to be captured by the warp yarns and the automatic production of chenille yarn.
[0004] The driven axes in each machine are:
- (a) A rollers shaft, or cylinders shaft, for supply the yarns coming from the cones;
- (b) an axis of rotation of the circular blade, for cutting the yarn loops on the gauge to obtain the pile segments;
- (c) the axes of rotation of the dragging rollers of the pile segments;
- (d) a rotating head that spools the yarn on the gauge;
- (e) a shaft that operates the rotation of the two spindles, the rotation of the spindles causing contemporaneously the chenille yarns to twist and to be spooled, as well as a pulling action on the upstream warp yarn portions still distinct from each other.
[0005] Machines for the production of chenille are well known that have three separate drives, of which one for axes a), b), c), one for head d) and one for the shaft of the spindles e). Alternatively, machines are known that have a single operating unit And belt transmissions with gearboxes for operating the many axes.
[0006] The solution with three separate drives is preferable for giving to the machine much more flexibility.
[0007] In particular, the characteristics of the final yarn can be modified both changing geometrical parameters, for example the length of the pile segments or the position of the blade disk, and changing the ratio between the speeds of rotation of the many axes.
[0008] As above said, moreover, many machines are provided in parallel, often tenths of machines, that carry out the same work and therefore can be operated by the same motor. Therefore, the first motor operates all the cylinder shafts, all the blades and all the dragging rollers of the various machines; the second motor operates all the heads and the third motor operates all the spindles. The transmission of the movement from each motor to the respective power input joint of the various machines is carried out by means of belts or chains.
[0009] This way, savings in the drives costs are obtained, but costs must be added for the mechanical transmission, by means of pulleys, chains and/or chains, as well as supports, bearings, as well as costs for choosing the appropriate tolerances.
[0010] Owing to thermal expansion, backlash, mechanical loss, moreover, the transmission of the movement is hardly uniform, thus causing differences of the yarn spooled on the machines closer to the motors with respect to the farthest machines.
[0011] It is also known to motorsze independently each single power input joint, with an independent axis control for each motor, but with need of a high sophistication of the controls and relevant costs of construction.
Summary of the invention.
[0012] It is an object of the present invention to provide a method for operating in parallel a plurality of machines for the production of chenille yarn, that for each machine assures the same speed for the power input joint of the driven axes.
[0013] It is another object of the invention to provide an operating unit that carries out this method, that involves relevant savings in mechanical transmissions and electronics, in order to have competitive costs.
[0014] According to a first aspect of the invention, a method for actuating of a plurality of machines 1,2,... N for the production of chenille comprises the steps of:
- prearranging a first motor M'1, M'2, M'3, ... M'N that operates the cylinders shaft, the blade and the dragging rollers for each respective machine 1,2,... N; a second motor M''1, M''2, M''3, ... M''N that operates the head of each respective machine 1,2,... N; and a third motor M'''1, M'''2, M'''3, ... M'''N that operates the spindles of each respective machine 1,2,... N;
- applying a same first voltage/frequency supply V' to each first motor M'1, M'2, M'3, ... M'N by means of a same first operating unit A'; applying a same second voltage/frequency supply V" to each second motor M"1, M"2, M"3,... M"N by means of a same second operating unit A"; applying a same third voltage/frequency supply V"' to each third motor M'''1, M'''2, M'''3, ... M'''N by means of a same third operating unit A'''.
[0015] This way, after preliminarily adjusting each machine 1,2,... N for making a same reference yarn, the parameters of production of the chenille can be changed by simply adjusting the voltage/frequency of the first, and/or of the second, and/or of the third motor, according to predetermined tables of operation, and a new yarn, with different characteristics from the previous yarn can be obtained, which is homogeneous for each spindle spooled on the various machines.
[0016] Preferably, each operating unit comprises an inverter circuit that produces a control signal for adjusting its output voltage/frequency according to a predetermined value.
[0017] The use of the inverter circuits can give to each motor an open loop constant predetermined supply with minimum deviations, without any servo controls, completely acceptable for a homogeneous production of a yarn of chenille.
[0018] Each motor can be switched off singularly from the supply. Therefore, for setting up or adjusting one of the machines 1, 2,...N it is sufficient to switch off the relative motors from the respective supplies. This can be done operating respective switches, stopping at the same time all the motors of that machine from the supply.
[0019] Advantageously, to avoid abrupt variation of speed of the axes operated by the motors of a machine that has to be stopped, or that must start after a stop, respective auxiliary drives may be provided.
[0020] More precisely, for stopping the machine I, or a chosen number of machines, the motors Mi', Mi'',Mi''' of the machine, that is supplied normally by operating units A', A'', A''', are commuted on auxiliary operating units A1', A1'', A1''', at the same voltage/frequency. Then the operating units A1', A1'', A1''' are run for reducing proportionally and progressively the speed up to stopping the machine I. As the work on the machine I starts again, the operating units A1', A1'', A1''' are recycled until the motors Mi', Mi'',Mi''' are at a steady speed rate, commuting eventually on operating units A', A'', A'''. Auxiliary operating units A1', A1'', A1''' are then available for stopping a further machine or group of machines without stopping all the other machines.
[0021] According to another aspect of the invention, a plant for the production of chenille comprises a plurality of machines 1,2,... N each having:
- at least a cylinders shaft, a blade and dragging rollers that can be operated through a first power input joint; a head that can be operated through a second power input joint; a couple of spindles that can be operated through a third power input joint;
- wherein a first motor M'1, M'2, M'3, ... M'N is provided associated to said first power input joint for each respective machine 1,2,... N; a second motor M"1, M"2, M"3, ... M"N associated to said second power input joint for each respective machine 1,2,... N; and a third motor M'''1, M'''2, M'''3, ... M"'N associated to said third power input joint for each respective machine 1,2,... N;
- and wherein a same first operating unit A' is provided for applying a same first voltage/frequency supply V' to each first motor M'1, M'2, M'3, ... M'N; a same second operating unit A'' is provided for applying a same second voltage/frequency supply V" to each second motor M''1, M''2, M''3, ... M''N; a same third operating unit A''' is provided for applying a same third voltage/frequency supply V"' to each third motor M'''1, M'''2, M'''3, ... M'''N.
[0022] This way, there is a single electrical supply for each row of motors associated to the corresponding power input joints, whereas no transmission elements of the movement between the various power input joints are necessary. The cost to provide many motors, with respect to the traditional prior art, is largely compensated by structural and work savings, since no mechanical transmission elements between the power input joints of the same type are necessary. In fact, the cost of small alike motors and without single control electronics is remarkably lower than, or in any case of the same level as, the cost of special mechanical parts for the mechanical transmissions. Furthermore, the installation of many alike motors at the power input joints requires less work than adjustment and calibration of the whole mechanics to assure a homogeneous transmission, avoid sliding and reducing friction, as necessary in the known systems with a single drive for a plurality of homogeneous power input joints. Finally, if the machines must be stopped for maintenance or production reasons, it is sufficient to switch off the electrical supply without modifying the mechanical transmission.
[0023] Preferably, for stopping a machine operated by motors Mi', Mi'', Mi''' three auxiliary operating units A1', A1'', A1''' are provided in parallel to the ordinary electrical supply so that the electrical supply of motors Mi', Mi'', Mi''' is made independent and the machine can be set up or adjusted without stopping the other machines.
Brief description of the drawings
[0024] The invention will be made clearer with the following description of an embodiment thereof, exemplifying but not limitative, with reference to attached drawings wherein:
- figure 1 shows a diagrammatical elevational front view of a machine of known type for the production of chenille;
- figure 2 shows a diagrammatical elevational side view of the drive of the machine of figure 1;
- figure 3 shows, according to the invention, a plurality of machines in parallel and the relative system of electrical connection of the motors;
- figure 4 shows a block diagram of electrical supply of the motors of the machines of figure 3;
- figure 5 shows a block diagram of the electrical supply of the motors of the machines of figure 3, with additional inverter operating units;
- figure 6 shows in detail a possible circuitry of the motors of the heads of the block diagram of figure 5;
- figure 7 shows a different embodiment of the electrical supply of figure 6, where a motor is fed independently for the stop and start phases.
Description of the preferred embodiment
[0025] The steps of chenille spinning are not shown in detail since known to a man of the art. The sole steps concerning the operation of the moving parts are synthetically described.
[0026] With reference to figures 1 and 2, a machine for the production of chenille yarn comprises a spinning unit 10 from which two equal yarns 11 exit, wound on respective spindles 12; the latter rotate continuously at a predetermined speed for contemporaneously spooling and twisting the respective yarns 11. The rotation of the spindles 12 is operated in a known way by a motor M''', at a respective power input joint 12b. A reciprocating yarn guide 12a is provided, with separate drive.
[0027] The pile segments (non shown) are obtained from a continuous yarn 13 wound by a spinning head 14 on a gauge 15 substantially triangular with vertex towards below. The spinning head is brought into rotation by a motor M", at a respective power input joint 14a.
[0028] At the gauge 15 a blade disk 16 is arranged that forms two rows of pile segments that, by means of counter rotating dragging rollers 17, are brought into two respective zones where two warp yarns 18 and 19 of each couple are led. The two couples of warp yarns 18 and 19 are fed by cylinder shaft 20 which, with blade 16 and pile dragging rollers 17, are brought into rotation by a motor M' through a respective power input joint indicated as a transmission shaft 21.
[0029] Arranging more machines 1, 2,... N in parallel, each is equipped with motors M', M" and M"', indicated respectively as M'1, M'2, ...M'N for the first; M''1, M''2, ... M''N for the second, and M'''1, M'''2, ... M'''N for the third.
[0030] With reference to figure 3, according to the invention, for operating the above described motors, the following steps are provided:
- applying a same first voltage/frequency supply V' by means of a first line 101 to each first motor M'1, M'2, ... M'N by means of a same first operating unit to inverter A';
- applying a same second voltage/frequency supply V" by means of a second line 102 to each second motor M''1, M''2, ... M''N by means of a same second operating unit to inverter A'';
- applying a same third voltage/frequency supply V"' by means of a third line 103 to each third motor M'''1, M'''2, ... M'''N by means of a same third operating unit to inverter A'''.
[0031] In more detail, with reference also to figure 4, the voltages V', V" and V"' and the relative currents are supplied through lines 101, 102 and 103, by inverter circuits A', A", A'''. They can be inverters available on the market, for example of Mitsubishi type, of known operation and then not described in more detail. Each motor is equipped with a protection circuit C. The supply of the inverter from the network 140 is made through a start and safety circuit 141. A control unit 142 is then provided comprising a circuit 143 of signals acquisition, a control and speed circuit 144 of the inverter and a processor 145, for example a CPU, a PLC or other microprocessor based electronics. The input/output bus 146 and 147 communicate with an operating board 148 for setting the programs.
[0032] Owing to the precision of the inverter circuits and of the motors existing on the market, according to the invention the inverters A', A", A"' operate in open loop. In figure 5 a different embodiment is shown of the invention where three auxiliary operating units A1', A1'', A1''' are arranged in parallel to the main circuitry for the electrical supply of the motors Mi', Mi'',Mi''' when the machine must be set up or stopped for maintenance without stopping the other machines.
[0033] In particular, with reference to figure 7, a motor, for example the motor M2', can be switched off independently from the main circuitry for setting up the machine by the auxiliary inverter. Previously, (figure 6) all the motors M' were supplied with the same voltage/frequency V' by line 101. The commutation can be done by switch 152, excluding motor M2' from the V' supply and opening switch 152', thus commuting motor M2' to auxiliary operating unit A1'. Then operating unit A1', which is also at voltage/frequency V', is run reducing proportionally and progressively the speed of the motor M2' up to stopping the corresponding machine 2. The same step is carried out contemporaneously with the other operating units A1'' and A1''' for motors M2'' and M2'''.
[0034] In this way abrupt variation of speed is avoided of the axes operated by the motors of machine 2 that has to be stopped, or that must start after a stop.
[0035] As machine 2 starts again, operating unit A1' brings again and gradually motor M2' to steady speed rate, at voltage/frequency V'. Then, motor M2' is again commuted to operating unit A', leaving auxiliary operating unit A1' available for stopping a further machine or group of machines without stopping the other machines.
[0036] The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment.
[0037] For example, the position of the motors in the machine can be different from that indicated. Furthermore, notwithstanding the supply of the motors is done by inverter circuits, a DC or AC supply is also possible from other types of known systems, according to the type of motors used, without departing from the extent of protection of the present invention.
[0038] The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
1. A method for operating in parallel a plurality of machines 1,2,... N for the production
of chenille yarn characterised in that it comprises the steps of:
- prearranging a first motor M'1, M'2, ... M'N that operates a cylinders shaft, a blade and dragging rollers for each respective machine 1, 2, ... N; a second motor M''1, M''2, ... M''N that operates a head of the respective machines 1,2,... N; and a third motor M'''1, M'''2, ... M'''N that operates spindles of the respective machines 1, 2, ... N;
- applying a same first voltage/frequency supply V' to each first motor M'1, M'2, ... M'N by means of a same first operating unit A'; applying a same second voltage/frequency supply V" to each second motor M"1, M"2, ... M"N by means of a same second operating unit A"; applying a same third voltage/frequency supply V''' to each third motor M'''1, M'''2, ... M'''N by means of a same third operating unit A'''.
2. Method according to claim 1, wherein the supply voltages V', V", V"' are selectively
modified in a programmed way for adjusting the speed of said first, second and third
motors, contemporaneously for each machine.
3. Method according to claim 1, wherein each motor can be stopped singularly for setting
up one of the machines 1, 2,...N, switching off through the respective inverter the
relative motors from the supplies, by switching off at the same time all the motors
of a machine from the supply.
4. Method according to claim 3, wherein to avoid abrupt variation of speed of the axes
operated by the motors of a machine that has to be stopped, or that must start after
a stop, at least a row of respective auxiliary operating units A1', A1''...A1N is provided.
5. A unit for the electrical supply of a plant for the production of chenille, comprising
a plurality of machines 1,2,... N each having:
- at least a cylinders shaft, a blade and dragging rollers that can be operated through a first power input joint; a head that can be operated through a second power input joint; a couple of spindles that can be operated through a third power input joint;
- wherein a first motor M'1, M'2, ... M'N is provided associated to said first power input joint for each respective machine 1,2,... N; a second motor M''1, M''2, ... M''N is provided associated to said second power input joint for each respective machine 1,2,... N; and a third motor M'''1, M'''2, ... M'''N is provided associated to said third power input joint for each respective machine 1, 2, ... N;
- and wherein a same first operating unit A' is provided for applying a same first voltage/frequency supply V' to each first motor M'1, M'2,... M'N; a same second operating unit A'' is provided for applying a same second voltage/frequency supply V" to each second motor M"1, M"2,... M"N; a same third operating unit A''' is provided for applying a same third voltage/frequency supply V"' to each third motor M'''1, M'''2,... M'''N.
6. A unit for the electrical supply according to claim 5, wherein each operating unit
comprises an inverter circuit that produces a control signal for adjusting the output
voltage/frequency according to predetermined values chosen for each type of yarn.
7. A unit for the electrical supply according to claim 6, wherein a row of three auxiliary
operating units A1', A1'', A1''' is arranged in parallel to a main circuitry for switching off the electrical supply
of the motors Mi', Mi'',Mi''' of a machine for set up or maintenance purposes on the machine the without stopping
other machines.
8. A unit for the electrical supply according to claim 6, wherein said inverters are
supplied from a network through a circuit of signals acquisition, a driving circuit
of the inverter and a control unit having input/output bus communicating with an operating
board for programs setting.