Abstract:
A weft inserting control device for fluid jet type loom for detecting dispersion of a weft reaching angle to control the reaching angle of weft yarn is provided, including a weft insertion detecting unit for detecting dispersion of a weft reaching angle in a plurality of control cycles such as a plurality of picking numbers, for example; and a comparing unit for comparing a plurality of detection values of the weft reaching angle given by the weft insertion detecting unit with a plurality of respectively different reference value are provided. The weft inserting control device for fluid jet type loom also includes a controlling unit for controlling the weft reaching angle on the basis of a result of the comparison in every control cycle, the result being obtained by the comparing unit is also provided. The reference value is set so as to have a minus correlation with the length of the control cycle.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a weft inserting control device for fluid jet type loom for controlling weft reaching timing with relation to a rotation phase of a main shaft of the loom in weft insertion in the fluid jet type loom.  
           [0003]    2. Description of the Related Art  
           [0004]    Hitherto, in order to converge a dispersion of weft insertion completed timing for a rotation phase of a main shaft of a loom (referred to as weft reaching angle, hereinafter) at a predetermined weft reaching angle, an average deviation, which is an average of difference between an actual reaching angle and an objective reaching angle of weft yarn, has been calculated for every predetermined number of weft insertion times (referred to as picking number, hereinafter). It is arranged that, when the average deviation passes over a predetermined allowable range, fluid jet pressure of a main nozzle or an auxiliary nozzle for weft-inserting be controlled so that the reaching angle would be within the allowable range.  
           [0005]    There is also proposed a method for measuring weft inserting power for each weft insertion to accumulate a difference between the weft inserting power and a reference value, and then, controlling the pressure of fluid supplied to a weft inserting nozzle or the rotating number of the main shaft of a loom when the accumulated value passes over an allowable range, as disclosed in a bulletin of Japanese Patent Publication No.39735/1994.  
           [0006]    In the case of the former related art described above, however, it is difficult to determine a certain picking number for calculating the average deviation. Excessively large picking number leads to bad response for a rapid change of a weft reaching angle in changing supplied weft where a sort of weft is changed, which sometimes causes a unit to be out of control and stopped. On the contrary, excessively small picking number for calculating the average deviation leads to oversensitive response of a controlling system for a temporary rapid change of the weft reaching time even when the weft reaching angle is almost stable within the reference value, so that the pressure of a weft inserting nozzle would be changed and the reaching angle would not be stable in a converging direction to the contrary, which sometimes causes large dispersion of the reaching angle.  
           [0007]    In the case of the latter related art described above, the response for a rapid change of the weft reaching angle can be better in controlling than the former related art described above. It is also difficult, however, as well as the above to determine an allowable range of the accumulated value. Excessively wide allowable range leads to inferior response in controlling similarly to the above, while excessively narrow allowable range leads to oversensitive response also for insignificant deviation of the reaching angle, both of which cause a problem that the reaching angle of weft is not stable. Thus, there have been problems of response and stability in controlling, which are conflicting each other, remaining.  
         SUMMARY OF THE INVENTION  
         [0008]    In view of the above-described problems of the related art, the invention has been made and is aimed to provide a weft inserting control device for fluid jet type loom in which the response in controlling weft insertion can be better as well as the stability can be improved in a simple structure.  
           [0009]    The invention is a weft inserting control device for fluid jet type loom provided with a weft insertion detecting unit for detecting dispersion of a weft reaching angle in a plurality of control cycles such as a plurality of picking numbers, for example; comparing a unit such as a control device for comparing a plurality of detection values of the weft reaching angle given by the weft insertion detecting unit with a plurality of respectively different reference values; and a controlling unit such as a control device for controlling the weft reaching angle on the basis of a result of the comparison in every control cycle, the result being obtained by the comparing unit. The reference value is set so as to have a minus correlation with the length of the control cycle. The detection value is one or a plurality of deviation for the reference value of the weft reaching angle in the respective control cycles or is an average value of the deviation.  
           [0010]    The controlling unit for the weft reaching angle controls supplied fluid pressure of the weft inserting nozzle, the timing of weft insertion, the rotation number of a main shaft of a loom or such in accordance with fuzzy reasoning corresponding to the above detection value. The weft reaching angle is controlled on the basis of the detection value in the shorter control cycle among the control cycles in which the detection value over the reference value is obtained, when the detection value in a plurality of control cycles is respectively over the reference value. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a schematic view of a weft inserting control device for fluid jet type loom according to the first embodiment of the invention;  
         [0012]    [0012]FIG. 2 is a flowchart showing a controlling method of the weft inserting control device according to the embodiment of the invention;  
         [0013]    [0013]FIG. 3 is a flowchart showing a method for controlling nozzle pressure and continued from the flowchart shown in FIG.  2 ;  
         [0014]    [0014]FIG. 4 is a graph showing a controlling method of the weft inserting control device according to the embodiment of the invention;  
         [0015]    [0015]FIG. 5 is another graph showing a controlling method of the weft inserting control device according to the embodiment of the invention;  
         [0016]    [0016]FIG. 6 is a flowchart showing a controlling method of the weft inserting control device according to the second embodiment of the invention;  
         [0017]    [0017]FIG. 7 is a flowchart showing a controlling method of the weft inserting control device according to the third embodiment of the invention; and  
         [0018]    [0018]FIG. 8 is a flowchart showing a controlling method of the weft inserting control device according to the fourth embodiment of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    An embodiment of the invention will be described hereinafter on the basis of the drawings. FIG. 1 is a weft inserting control device according to a first embodiment of the invention, which comprises a measuring and storing device  10  provided on a loom stand not shown in the drawings and a main nozzle  12 , which is a weft inserting nozzle for transporting weft yarn  2  by means of air jet. The main nozzle  12  is connected with a tube path  16  provided in its middle part with a valve mechanism  14 . A base end portion of the tube path  16  is connected to an air tank  18  for the main nozzle. The valve mechanism  14  is provided with an electromagnetic driving portion  20  such as a electromagnetic valve, which is connected to a control device  22  to be controlled. The air tank  18  for the main nozzle is connected to an air supplying source by a tube path  26  via an electropneumatic regulator  24 , which is connected to the control device  22  to be controlled. The loom stand is also provided with a thread feeding body  30  for feeding the weft yarn  2  so that the weft yarn  2  fed from the thread feeding body  30  would be weft-inserted through the main nozzle  12 .  
         [0020]    A plurality of auxiliary nozzles  32 , which are weft inserting nozzles, are positioned along a path for weft-inserting the weft yarn  2  in the vicinity of a weaving front of a cloth  31 , which has been weft-inserted. Each auxiliary nozzle  32  is connected with each tube path  36  provided in its middle part with a plurality of valve mechanisms  34 , similar to the main nozzle  12 . A base end portion of each tube path  36  is connected to an air tank  38  for the auxiliary nozzle. Each valve mechanism  34  is provided with an electromagnetic driving portion  40 , each of which is connected to the control device  22  to be controlled. The air tank  38  for an auxiliary nozzle is connected to an air supplying source by a tube path  46  via an electropneumatic regulator  44 , which is connected to the control device  22  to be controlled.  
         [0021]    A weft detecting device  42 , which is a weft insertion detecting unit, is provided on an anti-weft inserting side (on a side symmetrically contrary to the weft inserting nozzle with respect to the cloth) at the point preceding to the cloth  31  that the weft yarn  2  passes through. Output of the weft detecting device  42  is inputted to the control device  22 . Further, such as rotary encoder not shown in the drawings detects and inputs to the control device  22  information such as rotation number and rotation phase of a main shaft of a loom not shown. Such information is converted into digital data and inputted to the control device  22  so as to be used for a predetermined calculation.  
         [0022]    Next, an operation of the weft inserting control device for fluid jet type loom according to this embodiment will be described. First, when the loom is operated to carry out weft insertion, the weft yarn  2 , which was fed from the thread supplying body  30  and stored in the measuring and storing device  10  for a predetermined period, is jetted from the main nozzle  12  together with jet fluid such as air so as to be weft-inserted in an opening of warp yarn  4 . The weft-inserted weft yarn  2  is detected at its end by the weft detecting device  42  provided on the anti-weft insertion side, so that the weft insertion would be completed. In weft-inserting, each auxiliary nozzle  32  assists transportation of the weft yarn  2  so as to rapidly weft-insert the weft yarn  2  at a predetermined position. The air jet of the main nozzle  12  and the auxiliary nozzle  32  is carried out at timing corresponding to a predetermined rotation phase of the main shaft of a loom by opening and closing the air jet control valve not shown of the valve mechanisms  14  and  34  in accordance with a signal from the control device  22  into which information of a rotation angle of the main shaft of a loom has been inputted.  
         [0023]    The weft reaching angle in weft insertion is controlled by such as a microcomputer in the control device  22 . First, the control device  22  detects as a weft reaching angle a rotation phase of a main shaft of a loom at the time when the weft detecting device  42  detects an end of the weft yarn, as shown in FIGS. 2 and 3. Then, an average value of deviation of an actual reaching angle for an objective reaching angle is obtained in every predetermined picking number, which is a predetermined control cycle. In this embodiment, the predetermined picking number is the following three kinds: picking number  4 ,  8 , and  40 , in each control cycle of which carried out the weft inserting control.  
         [0024]    The reference value, which is an allowable value of average deviation in a control cycle for every picking number, is set to be at maximum ±10° of average deviation of the objective reaching angle in the picking cycle 4, ±5° in the picking cycle  8 , and ±1° in the picking cycle  40 . In the case that each average deviation in each control cycle is over the above reference value, when the deviation value is on the + side (on the delaying side in reaching) with respect to its objective reaching angle, the control device  22  controls electromagnetic driving portions  20  and  40  of the respective valve mechanisms  14  and  34  so that the air jet pressure of the main nozzle  12  and the auxiliary nozzle  32  would be increased by a predetermined value. On the contrary, when the deviation value is on the − side (on the accelerating side in reaching) with respect to its objective reaching angle, the control device  22  controls electromagnetic driving portions  20  and  40  of the respective valve mechanisms  14  and  34  as well as the above so that the air jet pressure of the main nozzle  12  and the auxiliary nozzle  32  would be decreased by a predetermined value.  
         [0025]    The controlling amount of the weft reaching angle in controlling weft insertion is set in accordance with fuzzy reasoning on the basis of fluctuated amount of the air jet pressure of respective nozzles  12  and  32  so as to correspond to the average detection value, which is the detection value. As for other concrete control for the weft insertion, the timing for weft-inserting or the rotation number of a main shaft of a loom may be controlled.  
         [0026]    This control is carried out by the control device  22  for every predetermined picking number, which is each control cycle. For example, as shown in FIG. 4( a ) as an example, when the average deviation is over the reference value of the allowable range in the picking cycle  4 , the control device  22  controls the air jet pressure of the main nozzle  12  and the auxiliary nozzle  32  to be decreased. Under a condition shown in FIG. 4( b ), the average deviation for the picking cycle  4  is smaller than the reference value, while the average deviation for the picking cycle  8  in which the reference value is set at 5° is over the reference value, so that the pressure of the main nozzle  12  and the auxiliary nozzle  32  is also controlled in this case. Further, as shown in FIG. 4( c ), in the case of a control cycle for the picking cycle  40  in which an even lower reference value is set, when the average deviation in the picking cycle  40  is over 1°, even if the average deviation in another control cycle is not over the predetermined reference value, weft inserting control such as adjustment of jet air pressure is carried out.  
         [0027]    Weft inserting control in each control cycle is performed separately. When the average deviation in a plurality of control cycles is over respective reference values at the same time, a controlling amount is set in accordance with fuzzy reasoning on the basis of the average deviation in the shorter control cycle among the control cycles over the reference value. When the average deviation in one of a plurality of control cycles is over a predetermined reference value, as shown in FIG. 5, a count of picking in each control cycle is reset once and re-count from the first picking is carried out in each control cycle so that the control would be performed as described above.  
         [0028]    In the weft inserting control device for fluid jet type loom according to the embodiment, an reference value is set so that the average deviation in the three kinds of control cycles, the picking numbers  4 ,  8 , and  40 , would be a predetermined allowable range different in every control cycle and so that the reference value would be decreased for the length of a control cycle to 10°, 5°, and 1° in order, and the control cycle and the reference value are set to have a minus correlation. Accordingly, a response in controlling to a rapid change in the weft reaching angle would be good in a short control cycle, while precise control can be achieved for a gradual change, so that stable control would be possible.  
         [0029]    Next, the second embodiment of the invention will be described on the basis of FIG. 6. In this embodiment, weft inserting control is carried out in a control cycle comprising two kinds of picking number,  4  and  8 . Pressure of respective nozzles  12  and  32  is controlled as well as the above-described embodiment when deviation of the weft inserting reaching angle for any picking is 15° or more in the picking cycle  4  and when deviation of the weft inserting reaching angle of any picking is 10° or more in the picking cycle  8 . Other than the above, it is also possible to control the weft inserting timing and the rotation number of a main shaft of a loom.  
         [0030]    In this embodiment, pressure of respective nozzles  12  and  32 , for example, is controlled when the deviation of the weft reaching angle passes over even once a predetermined reference value for any picking number in each of a predetermined plurality of control cycles, so that accurate and stable control would be possible in an even simpler structure.  
         [0031]    Next, the third embodiment of the invention will be described on the basis of FIG. 7. In this embodiment, weft inserting control is carried out in a control cycle comprising two kinds of picking number,  4  and  8 . Pressure of respective nozzles  12  and  32  is controlled as well as the above-described embodiment when deviation of the weft inserting reaching angle is 15° or more for successively two picking times in the picking cycle  4  and when deviation of the weft inserting reaching angle is 10° or more for successively two picking times in the picking cycle  8 . The number of successive picking times can be set at any time properly in this case. It is also possible to control the weft inserting timing and the rotation number of a main shaft of a loom other than the above.  
         [0032]    In this embodiment, pressure of respective nozzles  12  and  32 , for example, is controlled when the deviation of the weft reaching angle passes over a predetermined reference value for successively two picking times in each of a predetermined plurality of control cycles, so that more certain control would be possible.  
         [0033]    Next, the fourth embodiment of the invention will be described on the basis of FIG. 8. In this embodiment, weft inserting control is carried out in a control cycle comprising two kinds of picking number,  4  and  8 . Pressure of respective nozzles  12  and  32  is controlled as well as the above-described embodiments when deviation of the weft inserting reaching angle is 15° or more for successively two picking times among three in the picking cycle  4  and when deviation of the weft inserting reaching angle is 10° or more for successively two picking times among three in the picking cycle  8 . The number of successive picking times in each control cycle can be set at any time properly in this case. It is also possible to control the weft inserting timing and the rotation number of a main shaft of a loom other than the above.  
         [0034]    In this embodiment, set a case that the deviation of the weft inserting reaching angle is over a reference value for a predetermined picking number during a predetermined period in each of a predetermined plurality of control cycles, so that more certain control would be possible.  
         [0035]    The weft inserting control device for fluid jet type loom according to the invention is not limited to the above embodiment. The sort and period of a plurality of control cycles are set at any time properly. The controlling amount can be also set at any time properly on the basis of the deviation value other than the fuzzy reasoning. It is also possible to properly combine controlling methods in the respective embodiments described above.  
         [0036]    The weft inserting control device for fluid jet type loom according to the invention can accurately and certainly correspond to a rapid change as well as a gradually appearing small amount of change in the weft reaching angle with a good response, so that stable control can be performed. Especially, it is arranged that the control cycle and the reference value be set to have a minus correlation, which leads to high response and accurate control available for even a slight change. Furthermore, appropriate control would be easily possible by setting the controlling amount in accordance with the fuzzy reasoning.