|Title of Invention||
METHOD TO CONTROL A SPINNING FRAME WITH A MOTOR AND SPINNING FRAME TO CARRY OUT SAID METHOD
|Abstract||A method to control a spinning frame with a motor, a synchronous motor in particular whose rotor can be turned exactly into a defimed position, characterised in that when stopping the motor the position of its rotor is being stored, whereat positioning signals of the motor are being stored in a memory and that when restarting the motor again, based on the stored positioning signals, the start-up programme is being controlled in such a way that the movement of the rotor is being started in a selectable relation with respect to its standstill position immediately after stopping.|
|Full Text||Method to control a spinning frame with a motor and spinning frame to carry out said method.
The invention relates to a method to control a spinning frame and a spinning frame according to the preambles of the independent claims.
A general problem when driving spinning frames exists by the fact that the fibre flows have to be led under alternating conditions in such a way to keep fluctuations in quality and quantity within a very limited scope. Particularly the switching off of a frame and the following restart can cause discontinuities within the material being processed.
It is the task of "the present invention to provide a method to control a spinning frame as well as to provide a spinning frame whereat after stopping procedure and the following restart, reproducible conditions are present in the motor drive.
The spinning frame, or the method for its control allow a start of the motor drive under certain given, or selectable conditions, so that for instance drafting unit rollers will start running in a predetermined position during the start of the frame.
The invention is being described in the following according to a schematic drawing, wherein shows:
figure 1 a wiring diagram for charging the windings of the electric motor with current,
figure 2 a schematic illustration of a motor monitoring system.
Figure 1 shows a valve block 123 with current valves 1,2,3,..6 which are connected on the inlet side to a direct current source and on the outlet side to windings 14,16,18 within the stator of a motor 12, which is preferably a synchronous motor. The current valves 1,2,3,..6 of the valve block 123 are being alternatingly switched by switches 22 with control elements in an ignition distributor block 20 in such a way that the windings 14,16,18 are being put under current alternatingly or partially at the same time, depending on the requirements. Thus a given operating programmed for the motor 12 and the motor drive of the spinning frame can be realized. The motor drive of a spinning frame for instance consists of a gear block being connected to the motor 12, being composed of several not self-blocking reducing gears and one or several rollers of a drafting unit being connected to it.
In figure 2, as elements of the motor control 28 which can be a provided in the form of a frequency converter or frequency inverter, a frequency set-point adjuster 23, a valve control 24 being connected to it, as well as the mentioned valve block 123 are being connected, which co-ordinates the charging of the windings 14,16,18 of the motor 12 with current. The operating programme for the motor 12 is being stored in the frequency set-point adjuster 23. From the frequency set-point adjuster 23 the timed sequence of the variable rotor frequency of the motor is being transmitted to the valve control 24. Said valve control 24 comprises, amongst other things, the ignition distributor block 20 and a non-volatile memory 26, preferably in the form of an EPROM. Ignition wires 27 between the valve control 24 and the valve block 123 switch the current valves 1,2,3,..6 in such a way that the rotating field of the windings 14,16,18 of the motor, stop or start the rotor in a defined position. After stopping the motor by means of the current valves 1,2,3,..5,6 either direct current or any another
charging of current of a defined pulse pattern, can be applied to provide the windings 14,16,18 of the motor 12 with current, whereby the spinning frame drive can be controlled exactly in any operating phase.
The rotor of the motor can be turned into an exactly defined position, whereat during the following stopping of the motor the position of the rotor is being stored. Positioning signals of the motor 12 can be stored in the memory 26, where after during restart of the motor 12, based on the stored positioning signals, the operating programme is being controlled in such a way, that the movement of the rotor of the motor 12 starts in a selectable relation with respect to its standstill position immediately after stopping. The restart of the motor can take place exactly from the position in which it came to a standstill. However, it can also be suitable to restart the motor from a position which differs by a selectable turning angle of the rotor in relation to the previous standstill position. Particularly the rotor can be moved forwards or backwards after stopping by a selectable measure, whereat a restart of the motor will take place from the previously obtained position.
The position of the motor 12 can for instance be maintained in that the switches 22 operate bitable as switches with control elements, whereby the current valves can maintain the charging with current of defined windings 14,16,18.
By applying a pulse width modulator of the valve control, a pulse pattern can also be transmitted to the switches 22 or the current valves 1,2,3,..6 and thus to the windings 14,1,6,18, thereby turning the rotor of the motor 12 into a desired position and from which position, which is stored reproducible, it can start smoothly.
1. A method to control a spinning frame with a motor (12), a synchronous motor in particular whose rotor can be turned exactly into a defined position, characterized in that the method comprises the steps of storing the position of the rotor when the motor (12) is stopped, whereat positioning signals of the motor are being stored in a memory (26); controlling the start-up programme when restarting the motor (12) based on the stored positioning signals, the movement of the rotor is being started in a selectable relation with respect to its standstill position immediately after stopping.
2. The method as claimed in claim 1, wherein the motor (12) is restarted in exactly that position where it came to the standstill.
3. The method as claimed in claim 1, wherein the motor (12) is restarted from a position that differs by a selectable turning angle of the rotor in relation to the previous standstill position.
4. The method as claimed in claim 3, wherein after stopping the rotor it is being turned by a selectable measure forwards or backwards and that it remains in this position until the motor (12) is being restarted.
5. The method as claimed in claim 4, wherein when restarting the motor (12) it is being started from the position that it held after its forward movement.
6. The method as claimed in any one of the preceding claims, wherein when charging the stator windings (14, 16, 18) of the motor (12) with current, a pulse pattern with a predetermined interval frequency is being applied onto current valves (1,2,3, ... 6) of a valve block (123), thereby achieving a stable position of the rotor of the motor (12) between single poles.
7. A spinning frame to carry out the method according to any one of the preceding claims with a motor (12) and a motor control unit (28) which is being provided with a valve block (123) and a lined up valve control (24) whereat the valve control (24) comprises an ignition distributor block (20) and a memory (26), and with a frequency set-point adjuster (23) onto which the valve control (24) is being connected.
8. The frame as claimed in claim 7, wherein the motor (12) is a synchronous motor at whose windings (14, 16, 18) ignition wires (27) are being applied which are being connected between the current valves (1, 2, 3 ... 6).
9. The frame as claimed in claim 7 or 8 wherein the motor control (28) comprises a frequency converter or an inverter.
10. The frame as claimed in claims 7 to 9, wherein the motor (12) is being provided
for a drafting unit drive.
11. The frame as claimed in any one of claims 7 to 10, wherein within the ignition distributor block (20) the switches (22) are provided with control elements in the form of bistable switches.
|Indian Patent Application Number||2347/MAS/1998|
|PG Journal Number||13/2008|
|Date of Filing||20-Oct-1998|
|Name of Patentee||MASCHINENFABRIK RIETER AG|
|Applicant Address||KLOSTERSTRASSE 20, CH-8406 WINTERTHUR,|
|PCT International Classification Number||D01 H 13/32|
|PCT International Application Number||N/A|
|PCT International Filing date|