EP2703532B1

EP2703532B1 - Method and device for starting a weaving machine

Info

Publication number: EP2703532B1
Application number: EP13181011.1A
Authority: EP
Inventors: Petr Jirásko; Ond ej Marek; Ale Bílkovský; Zden k Volanský
Original assignee: Vuts AS
Current assignee: Vuts AS
Priority date: 2012-08-31
Filing date: 2013-08-20
Publication date: 2015-09-30
Anticipated expiration: 2033-08-20
Also published as: EP2703532A1; CZ308027B6; CZ2012593A3

Description

Technical field

The invention relates to a method for the starting of a weaving machine, in which the beating-up mechanism of the weaving reed proceeds from standstill to operating speed, whereby before dead centre in the position of the weft insertion the kinetic energy of the moving members of the beating-up mechanism is converted to the potential energy of a flexibly deforming means and after dead centre in the position of the weft insertion the potential energy of the means which is flexibly deformed is converted to the kinetic energy of the moving members of the beating-up mechanism of the weaving reed.
The invention further relates to a device for the starting of a weaving machine, whose beating-up mechanism of the weaving reed comprises a batten arranged on means which are flexibly deformable in a direction of the working movement of the batten between its beat-up position and the position of the weft insertion, whereby the batten is coupled with electric drive by means of a connecting rod, a crank and a crank shaft.

Background art

Driving means of weaving machines drive working members which perform a cyclic movement, which is generally demanding with respect to the requirements on the input of the drive motor. The movement of the heald shafts of the shedding mechanism and particularly the rectilineal reciprocating motion of the reed account for uneven energy input in the operating mode of the machine. Its negative influence on the energetic balance of the machine manifests itself especially in the starting operation of the machine which requires substantially greater driving forces, or more precisely, torques. Although this mode is only a fragment of the working time of the machine, it is necessary to adapt to this state by the performance of the electric drive motor.
US5729114A solves the issue of starting a weaving machine by electronic controlling of asynchronous electric motor by means of a control unit upon receiving a signal from the detector of the main crank shaft revolutions of a loom. Arranged before the electric motor is a frequency converter, which controls the drive of the machine during the first moments of the start-up. This device is able to ensure that the desired technology requirements are met, nevertheless the electric motor must be dimensioned with respect to the necessity of accelerating large inertial masses during the starting operation of the machine, especially heald shafts during the start of beating-up weft.
The driving system of the weaving machine according to WO97033024A1 discloses the starting operation of the machine by electric motor coupled with capacity resistance, which has the role of intermediate storage of potential electric energy, which is consumed during the acceleration of inertial masses moving reciprocatingly.
The device according to EP1048769B1 describes a solution in which a disconnectable fly-wheel is arranged between the drive electric motor, which is during the starting operation controlled by means of a frequency converter, and the inertial masses, the fly-wheel being connected with the main shaft of the machine only after reaching the required start-up speed. In order to start the fly-wheel by means of the working electric motor, the electric motor must be appropriately dimensioned.
The device according to EP2004895B1 discloses the start-up of a machine, whose driving mechanism comprises additional rotational inertial masses running in the operating mode of the machine. The start-up of these masses and simoultaneous start-up of the working mechanisms is energy demanding, costly and unsuitable with respect to possible utilization of the fabric produced during the starting operation. The device solves mutual controlled connection of the drive motor to the main shaft of the machine and the additional rotational masses. That enables to start the machine without additional inertial rotational masses being connected and connect them only after the operating speed is achieved.
From the document CZ302391B6 there is known a weaving machine, whose reed is mounted on the stringer of the batten, which is by means of two parallel vertical leaf springs seated on the frame of the weaving machine. The stringer, which is with the aid of means connected with the drive motor alternately deflected towards the picking position and back to the beat-up position, forms in principle a parallelogram with the springs and the machine frame, and, furthermore, the springs accumulate energy when moving to dead centre position and transfer the energy to the drive mechanism when moving from dead centre position. However, the device again requires overdimensioned output power of the motor drive to maintain a stable operating mode.
Devices according to the prior art either do not solve increased dimension of the drive motor at all, or basically solve the situation by regulation means coupled with the electric motor, yet more or less with regard to disposal of losses of fabric produced during the starting mode of the machine. In addition, these are complicated solutions, wherein the need for stable operating mode of the overdimensioned drive means remains unsolved.
The goal of the invention is to remedy the drawbacks of the background art, particularly avoid utilization of an economically unfavourable overdimensioned electric motor.

Principle of the invention

The goal of the invention is achieved by a method of starting a weaving machine, whose principle consists in that the beating-up mechanism of the weaving reed from standstill in the first phase is driven at a lower speed and by a larger force, by which a flexibly deformable means is flexibly deformed before dead centre in the position of weft insertion, and subsequently, in the second phase, the beating-up mechanism of the weaving reed is driven at a higher speed, being close to the operating speed, and by a lesser force, whereby the flexibly deformable means returns to its original shape.
The principle of the device for starting a weaving machine consists in that the electric drive comprises a working drive electric motor and a starting drive electric motor, whereby the output shafts of both electric motors are coupled with a switchable drive clutch, whose outlet portion is interconnectable with the output shaft of the starting drive electric motor and/or with the output shaft of the working drive electric motor.

Description of drawings

Examples of embodiment according to the invention are schematically shown in the drawing, where Fig. 1 represents a diagram of the movement of the batten connected with leaf springs and Fig. 2 a part of the drive mechanism controlling the movement of the batten.

Specific description

Fig. 1 shows a side view of a part of a weaving machine in the area of the batten 1 which is in the position of weft insertion (continuous line), i.e. the weaving reed 3 is in a position remote from the beating up point and a shed is opening for inserting weft into the shed to be followed subsequently by beating up by the weaving reed 3 to the face of the formed fabric. In an example of embodiment the stringer 11 of the batten 1 is arranged in a well-known manner between two vertically arranged leaf springs 12 at their upper end, the lower ends of the leaf springs 12 being firmly attached to the frame 2 of the weaving machine. Mounted on the stringer 11 of the batten 1 is the weaving reed 3. The batten 1 is coupled by a connecting rod 4 with a drive mechanism 5. The beating- up position of the batten 1 is indicated by continuous line, when the leaf springs 12 are not pre-loaded and when the batten 1 beats up the weft, which has already been inserted into the shed, into the face of the formed fabric.
Fig.1 further illustrates some parts of the drive mechanism 5. The connecting rod 4 is hinge-coupled with a crank 51, pivotably mounted on the frame 2 of the machine. The rotation axis of the crank 51 is the axis of the crank shaft 52 mounted pivotably in the frame 2 of the machine, the driven pulley 53 of the toothed belt drive of the drive mechanism 5 is fixed on the crank shaft.
Fig. 2 shows a drive pulley 55 , which is mounted pivotably in the frame 2 of the machine, whereby it is connected with an unillustrated outlet member of the switchable drive clutch 56 , coupled with the electric drive 6 mounted on the frame 2 of the machine.
The electric drive 6 comprises a working drive electric motor 61 and a starting drive electric motor 62. The output shafts of the electric motors 61, 62 are mutually coaxial, the electric motors 61, 62 being arranged in position with the shafts facing each other. The shafts of the electric motors 61, 62 are connected to the hubs in the body of the switchable drive clutch 56. The switchable drive clutch 56 enables to engage the drive pulley 55 into contact with the output shaft of the starting drive electric motor 62, or with the output shaft of the working drive electric motor 61, or engage the drive pulley 55 in interposition into synchronous mutual contact with the output shafts of both electric motors 61, 62.
Control of the switchable drive clutch 56 and electric motors 61, 62 is coupled with the control unit 7 of the weaving machine.
Before the start of the weaving machine the switchable drive clutch 56 is connected with the output shaft of the starting drive electric motor 62. After its start during the first half-turn of the driven pulley 53 the batten 1 is moved by the crank 4 to the position of the weft insertion. Since the starting drive electric motor 62 is low-speed, it has a high torque, even though its performance is relatively low, and during this shifting its kinetic energy is converted into potential energy of the flexibly deformed leaf springs 12. Theoretically, as early as at this point, the control unit 7 may give an impulse to the switchable drive clutch 56 to connect the output shaft of the working drive electric motor 61 to the drive pulley 55 and to start the working drive electric motor 61.
In the following half-turn of the driven pulley 53 the potential energy of the flexibly deformed leaf springs 12 returning from the position of the weft insertion to the beat-up position is converted to kinetic energy, which together with the kinetic energy generated by the working drive electric motor 61, which was started in the meanwhile, being connected by means of the switchable drive clutch 56, acts to overcome the inertial forces caused by the weight of parts of the machine that are running up.
For a short time the output shafts of both electric motors 61, 62 can be connected to the drive pulley 55 by means of the switchable drive clutch 56, whereupon after the impulse from the control unit 7 the switchable drive clutch 56 disconnects the drive pulley 55 from the output shaft of the starting drive electric motor 61 and the starting drive electric motor 62 switches off.
In another example of embodiment the starting drive electric motor 62 assists the working drive electric motor 61 in the stretching of the leaf springs 12 into the position of the weft insertion, which is in principle the back dead centre of the movement of the batten 1, where both electric motors 61, 62 stop running. Subsequently the starting drive electric motor 62 is disconnected, the movement of the batten 1 to the beat-up position is started and in this manner the potential energy stored in the leaf springs 12 is converted, whereupon the connected working drive electric motor 61 starts up and reaches operating speed. That means that the starting drive electric motor 62 is only interconnected with the working drive electric motor 61 in the phase of "stretching" of the machine - of the batten 1.
In another example of embodiment the starting drive electric motor 62 is used for "manual" operations with the batten or positioning with the batten 1, which are performed at a low speed and during which the decreased performance of the working drive electric motor 61 would not be sufficient. In this case, i.e. for low speeds, either both electric motors 61, 62 work simultaneously, or the "manual" operations or positioning are carried out only by the starting drive electric motor 62, while the working drive electric motor 61 is connected just as a passive load.
It is apparent that the invention includes various modifications that can be made to the embodiments of the means described herein as come within the scope of the appended patent claims.
The device according to the invention relating to a weaving machine enables to employ the working drive electric motor 61 with significantly lower performance, than it would certainly have if the starting drive electric motor 62 had not been used, and so it is possible to use the working drive electric motor 61, which is considerably cheaper. This is achieved by virtue of connecting the low-speed starting drive electric motor 62, which within a short time period of the starting operation of the machine makes it possible by its high torque to overcome the initial flexible deformation of the flexible means (here the leaf springs 12 of the batten 1 ) while "stretching" the leaf springs 12 to the position of the weft insertion of the batten.

List of references

1: batten
11: stringer of batten
12: leaf spring
2: frame of weaving machine
3: reed
4: connecting rod
5: drive mechanism
51: crank
52: crank shaft
53: driven pulley
54: toothed belt
55: drive pulley
56: switchable drive clutch
6: electric drive
61: working drive electric motor
62: starting drive electric motor
7: control unit

Claims

A method for the starting of a weaving machine, in which the beating-up mechanism of the weaving reed proceeds from standstill to operating speed, whereby before dead centre, in the position of the weft insertion, the kinetic energy of the moving members of the beating-up mechanism is converted to the potential energy of a flexibly deforming means and after dead centre, in the position of the weft insertion, the potential energy of the means that is flexibly deformed is converted to the kinetic energy of the moving members of the beating-up mechanism of the weaving reed, characterized in that the beating-up mechanism of the weaving reed from standstill in the first phase is driven at a lower speed and by a larger force, by which the flexibly deformable means is flexibly deformed before dead centre in the position of weft insertion, and subsequently, in the second phase, the beating-up mechanism of the weaving reed is driven at a higher speed, being close to operating speed, and by a lesser force, whereby the flexibly deformable means returns to its original shape.
A method for the starting of a weaving machine according to Claim 1, characterized by that in the first phase the beating-up mechanism is driven mainly by a low-speed electric motor with a high torque, while in the second phase the beating-up mechanism is driven mainly by a high-speed electric motor with a low torque, whereby at the latest after reaching operating speed the low-speed electric motor is disconnected.
A device for the starting of a weaving machine, whose beating-up mechanism of the weaving reed (3) comprises a batten (1) mounted on a means which is flexibly deformable in a direction of the working movement of the batten (1) between its beat-up position and the position of the weft insertion, whereby the batten (1) is coupled by means of a connecting rod (4), a crank (51) and a crank shaft with an electrical drive, characterized in that the electric drive (6) comprises a working drive electric motor (61) and a starting drive electric motor (62), wherein the output shafts of both electric motors (61, 62) are coupled with a switchable drive clutch (56), whose outlet portion is interconnectable with the output shaft of the starting drive electric motor (62) and/or to the output shaft of the working drive electric motor (61).
A device for the starting of a weaving machine according to Claim 3, characterized in that the outlet portion of the switchable drive clutch (56) is connected with a drive pulley (55) of a toothed belt (54) drive, the driven pulley (53) being connected with the crank shaft (52).
A device for the starting of a weaving machine according to Claim 3 or 4, characterized in that the working drive electric motor (61), the starting drive electric motor (62) and the switchable drive clutch (56) are coupled with a control unit (7) of the weaving machine.