|Title of Invention||
A SYSTEM FOR ON-LINE MONITORING THE QUALITY OF ROVING PRODUCED IN A ROVING FRAME MACHINE
|Abstract||(57) Abstract: This invention relates to a system for online monitoring a quality of individual roving produced in a roving frame machine. The system to has a roving machine having a number of spindle driven by a common drive such that all the center spindles are driven uniform. It ha individual sense located at a front roller to provide how to signal which is a direct measure of roving size the sensor sensing the roving sizes and provide electrical signal. A plurality of senses are connected on collector circuit module and plurality of such collector circuit module and linked to machine processing station to monitor the quality of doing in a roving machine. PRICE: THIRTY RUPEES|
The invention in general relates to a Roving Frame Machine and in particular relates to a scheme of Measuring the Quality of Roving production in a Roving Frame Machine, Extracting information related to quality of the product & system operation and displaying the same.
The end-product of a Spinning Mill is the yarn. The Mill continuously strives to maintain the quality and improve the same. Here quality is quantified in terms of different measurable parameters like
Count variation in terms of CV% for different selected lengths.
Random faults like short and long thick places, thin places etc.
The characteristics of the raw material like cotton and the quality of processing done on it at different stages in the mill together define the quality of yarn. Taking the quality of raw material as fait accompli, one has to maintain and improve the quality of processing to ensure the quality of the end product namely yarn.
The final stage in the ring spinning process is the Ring Spinning Machine which is Roving as its input. Schemes for monitoring the Ring Spinning machine are available and being used. There is a need for monitoring and ensuring the quality of Roving.
The present practice is to produce Roving in the Roving Frame Machine and check it in the laboratory for its characteristics. This procedure has its own limitations:
It is time - consuming - being done off-line. The test is carried out after production of the Roving. Hence any object detected in it, can be corrected only in subsequent batches of production. This causes production loss apart from the delay in necessary corrective measures.
There is a clear-cut need to have a scheme which will monitor the roving on-line i.e., during the production process itself. On-lien analysis of the measured data can lead to meaningful information which can be used to trace the root causes in quality deterioration.
Availability of all these information helps one to generate and provide system level information as well. This may comprise of system level monitoring, generation of data regarding machine health and also MIS data related to the roving machine.
It is the primary object of the invention to invent a system for effective on line monitoring of the quality of roving produced in a roving frame.
It is another object of the invention to device a system which is on-line, fast and accurate.
It is another object of the invention that monitoring will not result in production loss due to stoppage of the machine as the proposed system is an on-line measuring and monitoring system.
It is another object of the invention to have a system to produce data relevant to overall management information system.
A system for monitoring the quality of Roving produced in a Roving Frame Machine comprises a Roving Frame having a number of spindle driven by a common drive such that all the central spindles are driven unison, a plurality of sensor located at the front roller to provide output signal which is a direct measure of roving size, the sensors seces the roving size and provide an electrical signal in proportion to roving size. A set of eight sensors being linked to collector circuit module and further a plurality of collection circuit modules being linked and connected to machine processing station (MPS) which process information so as to monitor the quality of roving produced in a roving machine.
The invention is described subsequently with reference to the accompanying drawings wherein
- Figure 1 represents in a simplified form - Typical Roving (speed) Frame Machine.
- Figure 2 represents one Spindle/Bobbin Section of the Frame, and
- Figure 3 & 4 represents the Schematic Arrangements of the Monitoring Scheme representing the invention.
The invention claimed here, is a scheme of monitoring the quality of Roving produced on-line. It also incorporates means of analyzing such data and relate it to possible defects at different stages at Roving Machine itself as well as the previous stages of production.
The roving being a tender material, it is necessary to do non-contact measurement of the same. The invention provides such a non-contact sensor to measure the roving size. The sensor output is a direct measure of the roving size. Further the sensor assembly and positioning is transparent to the machine operation and maintenance. Each spindle of the roving frame is provided with a sensor of this type.
The signals representing the roving sizes from individual sensors are brought to a Collector Circuit Module (CCM) for further processing. Typically 1 CCM can accept inputs from 8 Nos. of sensors. The CCM is a computer based signal processing and analysis facility built in. It can analysis all the roving signals coming to it. Based on this, on-line quality checks for each of the roving are carried out. Alarm signals are generated, if any of the roving produced is outside specified limits viz. set limits.
The CCMs are connected to a Machine Processing Station (MPS) through serial links. Thus all the information generated from the cluster of sensors connected to a CCM are sent to the MPS in a structured manner through a composite serial link. A typical MPS receives such data from 15 CCM units.
One MPS is used for each machine and forms the central node of information exchange between the CCMs downstream and computer upstream. Once again all the data and allied information generated in individual CCMs are passed on to the computer in a well structured manner over a serial link.
Apart from functioning as a two way transmission hub, an MPS has the facility to accept settings and allied machine data through a keyboard. A localised display module provides the necessary acknowledgement information to facilitate proper programming. It also helps in displaying all information related to the machine and the spindles that form part of it.
All the MPS are in communication with a Central Computer (PC) dedicated to monitor the operations of a set of roving frames in a mill. The communication is once again in serial form corfirming to establish protocols. At the computer end all the information generated at the CCM levels will be collated and displated in different user friendly formats. Each format can be selected through an associated menu. Further using the information in individual machines, the PC will also generate comprehensive information related to production of individual machines and efficiency of production using pre-defined yardsticks for the same.
The Roving frame Figure 1 - comprises of a number of spindles with a common drive. The Sliver 1 is fed separately to each spindle, through the Creel 2.
The bobbins are driven separately and the position of the whole set of bobbins is decided by that of the Bobbin Carriage 3 which moves up and down in unison with the roving filling around the bobbin. The central spindles are all driven in unison. All the gearing and associated items are housed in the Spindle Drough 4.
Figure 2 shows a Spindle-Bobbin Section with associated items. Typically, a machine may have 120 such Roving Section units. Each of these converts Sliver ] (Figure 1) into roving of an appropriate size. The sliver is fed from a Can 6 (Figure 2). The Sliver coming out of the Can moves over the Creel and is fed to a set of Rollers 8 (figure 2). These rollers provide the draft necessary to the sliver. The Roving 10 (Figure 2) moving out of the front roller is taken up by the Bobbin 13 (Figure 2) on the Spindle 12 (Figure 2).
The speed of the front roller alongwith the size of the roving decides the production rate. The material coming out of the front roller is taken through Flyer and at the bottom it emerges out of the Flyer Finger. The roving is taken up by the bobbin. The Spindle alongwith all other similar spindles on the side of the machine is driven through gearing at the machine end. Apart from these, the differential gearing with an additional
Belt & Cone Arrangement Scheme drives the Whole set of flyers. The differential speed between the spindle and the flyer ensures that the roving is formed on the bobbin. Further the speed of the bobbin decides the twist of the roving which imparts some level of strength to it. This arrangement may vary in details from manufacturer to manufacturer.
The sensor 9 claimed as a part of present invention, is located close to the front roller. It provides an output signal which is a direct measure of the roving size.
Figure 3 shows the schematic arrangement of the invention. The Sensor 14 (Figure 3) referred to earlier, senses the roving size and provides an electrical signal which is a measure of the roving size. Further it will also indicate any abnormality in the operating conditions of the concerned Roving - Bobbin - Spindle - Drafting - Creel combine.
A set of 8 sensors are linked to the Collector Circuit Module (CCM) 15 (Figure 3). Further the set of CCMs extending upto 15 in number (typical) are connected to a Machine Processing Station 16 (Figure 3). Each roving frame will normally have one MPS. Further all the MPSs in a mill can be connected with a central PC 17 (Figure 3). The CCM collects signals from all the 8 sensors. It processes these signals to generate meaningful information. It takes intelligent decision to provide alarm outputs to respective sensors. Further it decides the quantitative values of various indices like U%, CV%, Hank value and other deviations from the desired values. Apart from this, it also computes the different spectral components in terms of wavelength for the roving sizes from each of the sensors sequentially. All this information is structured and arranged sequentially and transmitted on the serial link to the MPS. (Figure 4).
The MPS receives all information related to the quality of roving as described above from all the CCMs connected to it. Subsequently all this information is organized in a sequential manner by the MPS and transmitted to the PC over a serial link. Further the MPS also has a facility to accept various numerical parameter values representing quality and variation in quality. Such information is fed to the MPS through a keyboard. The MPS also has a user-friendly display. The display broadly plays 2 roles. Firstly it will indicate the parameter programmed as well as its numerical value fed from the local keyboard. The second role is one of displaying the latest value of the selected parameters. This is to facilitate quality check of any chosen section b accessing any of the selected parameters desired. Its value can be observed and related to the quality of roving produced.
The PC ha a comprehensive software with the facility to indicate all the parameters of all the spindles which have been collected downstream. Further it also provides processed data in a form which is meaningful for the operating personnel as MIS.
The system has the following characteristics:
1. On-line measurement of the roving size with the help of sensor: The signal representing the roving size will have a one to one relationship with the sensor cross sectional area and weight for unit length and hence forms a measure of the roving size.
2. Identification of an end break in the roving at the production stage itself whereby one need not wait for waste collection and detection of break as done thus far. This makes end break detection as well as corrective action faster.
3. On-line computation of U% at standard cut length. This is carried out by the CCM for all the sensors connected to it.
4. On-line detection of U% exceeding set limits and give out a corresponding alarm signal at the Sensor.
5. On-line computation of CV%. This is carried out by the CCM for user defined cut length.
6. On-line detection in the variation of CV% beyond acceptable set limits. The same if happens, is indicated by a suitable light on the sensor.
7. On-line computation of the Hank value. This is carried out by the CCM.
8. On-line detection in the variation of the Hank value outside the set limits. This is carried out by the CCM. In case the hank value exceeding a set limit, the same is indicated on the Sensor by suitable lighting of the lamp.
9. On-line and fast detection of an end break of the roving in production. Tliis is carried out b the CCM.
10. Stopping of the machine in case of a roving breakage by a suitable command generated by the MPS. This is carried out by the MPS when it receives the appropriate input from the CCM.
11. On-line computation of the spectrogram representing different wavelengths of the roving size. This is done to get a fast estimate of the quality of production.
12. On-line identification of spindle/spindles producing inferior quality roving soon after commencing of batch production.
13. On-line discrimination between an end break of roving and cleaning the separator plate / roller assembly. This is done to avoid the system misinterpreting the situation as an end break.
14. On-line discrimination between the real end back and absence of roving due to a break in sliver or exhaustion of sliver from CAN.
15. Computation of production rate for each machine at the end of the doff.
16. Computation of machine efficiency taking into account the production rate, the roving size and the number of active spindles.
17. Indication of time to do doffing.
18. Facilitation of identification of Can related problems. This is done by accumulating all the informations generated with reference to every spindle separately over a period decided by the operating personnel. This period can be the same as that taken for a full Can to be emptied at the Creel.
19. Extraction of the full spectrogram of each spindle of each machine at lest once in a day. This facilitates faster problem identification and correction. The same may be in respect of the rollers doing draft, aprons, allied items, creel drive, defects / abnormalities in the drive, gear and all other mechanical components - rotating, moving and those participating in the same. Further some of the repetitive problems related to the Combing Machine too can be identified here.
20. Identification of ratching by comparing the hank value at the beginning of production of a batch to that at the end of production, spindlewise. This is made available at the PC in an user friendly manner.
21. Facility to adjust acceptable limits of U%, CV% and hank value. This is done to enable individual mills to define their own quality level and monitor production as per the same.
22. Facility to define "Rogue Spindles" in terms of the number of end breaks exceeding a pre-defined limit or other criteria in terms of U%, CV% and hank level lying outside acceptable limits.
23. Identification of all the rogue spindles at the end of the doff using criteria for the same defined separately.
24. Facility to display the latest values of indices representing quality of roving. This can be done by way of display of U%, CV% and hank value for the selected spindle / spindles. Such display shall be available at the machine end as well as at the central computer.
25. Identification of the Creel stop as distinguished from stoppage due to any other reason in the concerned machine.
1. A system for on-line monitoring the quality of individual roving produced in a roving frame machine comprises a roving frame having a number of spindle driven by a common drive such that all the central spindles are driven unison by having individual sensors being located at front roller to provide output signal which is a direct measure of roving size the sensor sensing the roving size and providing electrical signal in proportion to roving size, a set of eight sensors being linked to Collector Circuit Module and further a plurality of Collection Circuit Module being linked and connected to machine processing station (MPS) which possess information so as to monitor the quality of roving produced in a roving machine.
|Indian Patent Application Number||1189/MAS/1996|
|PG Journal Number||30/2009|
|Date of Filing||08-Jul-1996|
|Name of Patentee||PREMIER POLYTRONICS LIMITED,|
|Applicant Address||185 ATD STREET, RACE COURSE, COIMBATORE 641 018|
|PCT International Classification Number||D01H1/32|
|PCT International Application Number||N/A|
|PCT International Filing date|