Control method of weaving machine

Abstract

The invention provides a control method of a weaving machine, which can prevent poor weaving conditions such as weft stop as much as possible under the condition that the actual value of arrival time deviates from the lower limit value of a target arrival angle range. When arrival data based on actual values of arrival timing of a plurality of weft insertion numbers deviates from a target arrival angle range, the weaving machine performs control of the main shaft control device and / or the weft insertion control device in a manner that the arrival timing returns to the target arrival angle range, setting the number of insertion of arrival data when the arrival timing is on the lower limit side smaller than the target value to a number smaller than the number of insertion of arrival data when the arrival timing is on the upper limit side and / or making the absolute value of the difference between the lower limit value and the target value of the target arrival angle range greater than the absolute value of the difference between the upper limit value and the target value of the target arrival angle range An upper limit value and a lower limit value are set for a small value.

Description

Technical Field

[0001] The present invention relates to a control method for a loom, wherein an actual value of an arrival timing of a weft is obtained based on a detection signal of a weft sensor, and a main shaft control device and / or a weft insertion control device are controlled using a target arrival angle range determined by an upper limit value on an upper limit side larger than a target value of the arrival timing and a lower limit value on a lower limit side smaller than the target value, and arrival data based on the actual values ​​of a plurality of weft insertion numbers so that when the arrival data deviates from the target arrival angle range, the arrival timing is returned to within the target arrival angle range. Background Art

[0002] It has long been known in looms that the weft insertion is controlled and the rotation speed of the loom is controlled in such a way that the arrival timing of the weft yarn after weft insertion (the timing when the front end reaches a preset position) becomes the desired timing during weaving. And, it is well known that even if the weft is inserted under the same conditions, the arrival timing of the weft yarn will have a certain degree of deviation. Therefore, in the existing above-mentioned control, with respect to the target weft arrival timing (target value), an upper limit value as an upper limit side of the allowable value greater than the target value and a lower limit value as a lower limit side of the allowable value smaller than the above-mentioned target value are determined, and on this basis, a target arrival angle range consisting of the upper limit value and the lower limit value is set, and when the actual arrival timing of the weft yarn (actual value) deviates from the target arrival angle range, the above-mentioned control is executed.

[0003] Furthermore, during weft insertion in weaving, the arrival timing of the weft yarn may change temporarily and greatly due to various reasons. However, if the above control is performed in the case where the above actual value deviates from the target arrival angle range due to such temporary changes, there is a concern that the weaving operation of the loom may become unstable. Therefore, nowadays, the above control is also performed using arrival data based on the above actual values ​​of multiple weft insertion amounts. Specifically, the above control is performed based on a comparison between the average value of the above actual values ​​of multiple weft insertion amounts and the target arrival angle range, or, as disclosed in Patent Document 1, the above control is performed in the case where the above actual value continuously deviates from the target arrival angle range over a predetermined number of weft insertions.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-069800 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the case where the conventional loom is configured to perform the control using the arrival data, the control is performed using the arrival data based on the same number of weft insertions on the upper limit side and the lower limit side. Therefore, in such a conventional loom, when the flying state of the weft yarn is such that the actual value deviates from the lower limit side, the weft insertion becomes unstable, and there is a concern that weaving defects such as weft stop may occur. The details are as follows.

[0009] First, in the case where the loom is an air jet loom, the jet period of each sub-nozzle is set as follows: the timing is determined based on the set weft yarn flight curve obtained from the set weft insertion start timing and the above-mentioned target value and the position where the sub-nozzle is set, and the period on the leading side (the leading period) and the period on the trailing side (the trailing period) are determined relative to the timing serving as the reference. Among the jet periods, the leading period is the period of leading jetting before the weft yarn reaches the position of the sub-nozzle, so it is generally set to be a period shorter than the trailing period.

[0010] In the weft insertion of such an air jet loom, when the flying state of the weft yarn is such that the actual value deviates from the lower limit value (arrival timing becomes early), in the prior art that performs the control using the arrival data, for example, when the state deviating from the lower limit value occurs continuously for a set number of weft insertions, the control is performed. In other words, until the weft insertion of the set number of weft insertions is completed, the judgment on whether to perform the control is not performed, and even in the state deviating from the lower limit value, the weft insertion is continued during the period.

[0011] In addition, in the case where it is not caused by an abnormality (failure) of the device, even if the flying state of the weft changes and becomes the above-mentioned state that deviates from the above-mentioned lower limit, the timing of the weft front end passing through the position of each sub-nozzle is close to the jet start timing of the sub-nozzle, but is usually within the above-mentioned advance period. However, in the weft insertion of the loom, as described above, there is a case where the arrival timing (flight state) of the weft changes temporarily and greatly. Therefore, in the flying state where the front end of the weft passes at a timing close to the jet start timing as described above, when such a large change occurs, sometimes the above-mentioned passing timing becomes earlier than the jet start timing of the sub-nozzle, that is, the weft reaches the position of the sub-nozzle before the jet of the sub-nozzle starts. Moreover, if the weft reaches the position of the sub-nozzle before the jet of the sub-nozzle starts like this, the flying state of the weft becomes unstable, resulting in weft stop and other weaving defects.

[0012] Therefore, an object of the present invention is to provide a control method for a loom, which can prevent weaving defects such as weft stoppage from occurring as much as possible in a loom that uses the above-mentioned arrival data to perform the above-mentioned control when the above-mentioned actual value deviates from the above-mentioned lower limit value.

[0013] Solutions to Solve Problems

[0014] The present invention is applied to a loom that obtains an actual value of the arrival timing of the weft based on a detection signal of a weft sensor, uses a target arrival angle range determined by an upper limit value on the upper limit side larger than the target value of the arrival timing and a lower limit value on the lower limit side smaller than the target value, and arrival data based on the actual values ​​of a plurality of weft insertion numbers, and when the arrival data deviates from the target arrival angle range, controls a main shaft control device and / or a weft insertion control device so that the arrival timing returns to the target arrival angle range. Furthermore, the control method of the loom of the present invention is characterized in that the number of weft insertions in the arrival data when the arrival timing is on the lower limit side is set to a number smaller than the number of weft insertions in the arrival data when the arrival timing is on the upper limit side and / or the upper limit and the lower limit are set so that the absolute value of the difference between the target value and the lower limit is smaller than the absolute value of the difference between the target value and the upper limit.

[0015] The effects of the invention are as follows.

[0016] According to the present invention, when the actual value deviates from the lower limit value, the control is performed at an earlier time (time when the weft insertion of a smaller number of wefts is completed) than when the actual value deviates from the upper limit value. Therefore, compared with the prior art in which the control on the lower limit side is performed using the same arrival data of the number of wefts as on the upper limit side, since the number of wefts to be continuously inserted becomes smaller when the actual value deviates from the lower limit value, the possibility of a temporary large change in the arrival timing during this period becomes lower. As a result, it is possible to prevent the occurrence of weft stop and other weaving defects as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An explanatory diagram showing an example of an air jet loom to which the present invention is applied.

[0018] Explanation of symbols

[0019] 1—loom, 11—length measuring storage device, 13—locking pin, 14—storage drum, 15—unwinding sensor, 17—main nozzle, 18—auxiliary nozzle, 19—weft feeler, 21—loom control device, 23—input setting device, 31—calculator, 33—comparator, 35—counter, 37—memory, 39—speed changer, 41—weft insertion controller, 43—spindle controller, 51—spindle, 53—spindle motor, 55—encoder, 61—supply source, 62, 64—piping, 63, 65—electromagnetic opening and closing valves, Y—weft yarn, T—warp yarn. DETAILED DESCRIPTION

[0020] The following is based on Figure 1 An embodiment of a loom control method of the present invention will be described. The example shown below is an example in which the present invention is applied to an air jet loom.

[0021] like Figure 1 As shown, a jet loom (hereinafter simply referred to as "loom") 1 comprises: a length measuring storage device 11, which includes a storage drum 14 for storing weft yarn Y and a locking pin 13 for controlling the storage and unwinding of the weft yarn Y relative to the storage drum 14; and a main nozzle 17 arranged on the yarn supply side as a nozzle for weft insertion by ejecting compressed air, and a plurality of sub-nozzles 18 arranged in an array along the weft insertion direction (weaving width direction).

[0022] The main nozzle 17 is connected to a supply source 61 for supplying compressed air via a pipe 62. In addition, an electromagnetic on-off valve 63 for controlling the supply (injection timing) of compressed air to the main nozzle 17 is installed in the pipeline of the pipe 62 connected to the main nozzle 17. In addition, each sub-nozzle 18 is connected to the supply source 61 via a pipe 64. In addition, in the illustrated example, the sub-nozzles 18 are divided into multiple (two) groups. In addition, an electromagnetic on-off valve 65 corresponding to each group and used to control the supply (injection timing) of compressed air to the sub-nozzle 18 of the corresponding group is installed in the pipeline of the pipe 64 corresponding to each group.

[0023] The loom 1 is provided with an unwinding sensor 15 for detecting the weft yarn Y unwound from the storage drum 14, and a weft feeler 19 for detecting the weft yarn Y reaching the opposite side of the yarn supply, as weft yarn sensors for detecting the weft yarn Y. The loom 1 is provided with an encoder 55 as an angle sensor for detecting the rotation angle (crank angle) of the main shaft 51.

[0024] The loom 1 is provided with an input setting device 23 for inputting and setting various setting values ​​related to the control of various devices on the loom 1. In addition, the various setting values ​​include setting values ​​for controlling the drive of the locking pin 13, setting values ​​for controlling the drive of the electromagnetic on-off valve 63 and each electromagnetic on-off valve 65 such as the injection start timing and injection end timing of the main nozzle 17 and each sub-nozzle 18, and setting values ​​for controlling the drive of the main shaft motor 53 that rotates and drives the main shaft 51 such as the rotation speed of the main shaft 51.

[0025] Furthermore, the set values ​​include, in addition to the target value of the arrival timing of the weft yarn Y, an upper limit value as a permissible value on the upper limit side larger than the target value, and a lower limit value as a permissible value on the lower limit side smaller than the target value as a set value defining the target arrival angle range. Moreover, the upper limit value and the lower limit value are determined in advance based on weaving conditions such as the rotation speed of the loom 1 and the type of the weft yarn Y to be inserted. On this basis, in the present embodiment, the upper limit value is set to a value obtained by adding a predetermined crank angle to the target value, and the lower limit value is set to a value obtained by subtracting a crank angle equal to the predetermined crank angle from the target value. Moreover, the set values ​​input and set from the input setting device 23 are stored in the memory 37 included in the loom control device 21.

[0026] In addition to the memory 37, the loom control device 21 also includes a spindle controller 43 for controlling the drive of the spindle 51 and a weft insertion controller 41 for controlling weft insertion. The spindle controller 43 is connected to the memory 37 and the encoder 55 at its input end, and is connected to the spindle motor 53 at its output end. On this basis, the spindle controller 43 is configured to control the drive of the spindle 51 based on the set speed set (stored) in the memory 37.

[0027] The weft insertion controller 41 is connected to the encoder 55 at its input end, and is connected to the locking pin 13, the electromagnetic opening and closing valve 63, and each electromagnetic opening and closing valve 65 at its output end. On this basis, the weft insertion controller 41 is configured to control the driving of the locking pin 13, the electromagnetic opening and closing valve 63, and each electromagnetic opening and closing valve 65 based on the unwinding timing, the injection start timing of the main nozzle 17, and the injection timing of each sub-nozzle 18 set (stored) in the memory 37.

[0028] Furthermore, as a structure for bringing the arrival timing of the weft yarn Y within the target arrival angle range, the loom control device 21 includes a calculator 31 for obtaining an actual value of the arrival timing, a comparator 33 for comparing the actual value with the target arrival angle range, a counter 35 for counting the number of times the actual value continuously deviates from the target arrival angle range based on the comparison result of the comparator 33, and a speed changer 39 for changing the set speed based on the count result of the counter 35. The details of the above structure are as follows.

[0029] The calculator 31 is connected to the encoder 55 and the weft feeler 19 at its input end, and is connected to the comparator 33 at its output end. Moreover, the calculator 31 is configured so that, when the detection signal from the weft feeler 19 is input, the crank angle at that moment is obtained based on the signal from the encoder 55. In addition, the obtained crank angle is the above-mentioned actual value. Moreover, the calculator 31 is configured so that a signal (angle signal) indicating the above-mentioned actual value obtained is output to the comparator 33.

[0030] The comparator 33 is connected to the memory 37, and is connected at its output end to the counter 35. Moreover, the comparator 33 is configured to compare the actual value shown by the angle signal with the target arrival angle range (specifically, the upper limit value and the lower limit value) stored in the memory 37 every time the angle signal from the calculator 31 is input.

[0031] Furthermore, as a result of the comparison, the comparator 33 is configured to output an upper limit deviation signal indicating that the actual value deviates from the target arrival angle range on the upper limit side to the counter 35 when the actual value is larger than the upper limit value, and to output a lower limit deviation signal indicating that the actual value deviates from the target arrival angle range on the lower limit side to the counter 35 when the actual value is smaller than the lower limit value. Furthermore, the comparator 33 is configured to output a non-deviation signal to the counter 35 when the actual value is greater than the lower limit value and less than the upper limit value, that is, when the actual value is within the target arrival angle range.

[0032] The counter 35 is connected to the memory 37 and is connected to the speed changer 39 at its output end. The counter 35 is provided with two counting components that input the upper limit deviation signal, the lower limit deviation signal, and the non-deviation signal from the comparator 33. One of the two counting components is an upper limit side counting component that counts the number of inputs of the upper limit deviation signal, and the other is a lower limit side counting component that counts the number of inputs of the lower limit deviation signal. The upper limit side counting component is configured to reset its count value by inputting the non-deviation signal or the lower limit deviation signal, and the lower limit side counting component is configured to reset its count value by inputting the non-deviation signal or the upper limit deviation signal.

[0033] Then, the upper limit side counting means and the lower limit side counting means respectively count the number of times the upper limit deviation signal or the lower limit deviation signal is continuously input, and the count value is equivalent to the number of weft insertions at which the actual value continuously deviates from the target arrival angle range on the upper limit side or the lower limit side.

[0034] In addition, the number of weft insertions (set number of weft insertions) is set in the memory 37, and this number of weft insertions becomes a reference for performing a correction control as a control for returning the above-mentioned actual value to the target arrival angle range when the above-mentioned actual value continuously deviates from the above-mentioned upper limit side or the above-mentioned lower limit side. In addition, the counter 35 is configured to output a decreasing instruction signal related to the rotation speed to the rotation speed changer 39 when the count value of the upper limit side counting member reaches the set number of weft insertions. In addition, the counter 35 is configured to output an increasing instruction signal to the rotation speed changer 39 when the count value of the lower limit side counting member reaches the set number of weft insertions. In addition, the counter 35 is configured to reset the count value of the upper limit side counting member with the output of the decreasing instruction signal, and reset the count value of the lower limit side counting member with the output of the increasing instruction signal.

[0035] The speed changer 39 is connected to the counter 35 as described above, and is also connected to the memory 37. In the present embodiment, the correction control is a control to increase or decrease the speed of the loom 1 by adding or subtracting the set speed (correction speed) from the current set speed of the loom 1. Therefore, the correction speed is set in the memory 37. In addition, the correction speed is obtained in advance based on the weaving conditions such as the initial set speed and the type of the weft yarn Y.

[0036] Furthermore, the speed changer 39 is configured to read the current set speed and the corrected speed from the memory 37 when the rising instruction signal or the falling instruction signal from the counter 35 is input. On this basis, the speed changer 39 is configured to add the corrected speed to the current set speed when the input signal is the rising instruction signal, and to subtract the corrected speed from the current set speed when the input signal is the falling instruction signal. Furthermore, the speed changer 39 is configured to set the set speed obtained by the addition or subtraction as a new set speed in the memory 37.

[0037] In the loom 1 having the loom control device 21 having the above-mentioned structure, when the weft yarn Y after being inserted is detected by the weft feeler 19 and the detection signal thereof is input to the calculator 31, the above-mentioned actual value regarding the arrival timing is obtained in the calculator 31 and output to the comparator 33. Then, in the comparator 33, the above-mentioned actual value is compared with the above-mentioned upper limit value and the above-mentioned lower limit value, and as a result of the comparison, any one of the upper limit deviation signal, the lower limit deviation signal, or the non-deviation signal is output to the counter 35.

[0038] In the counter 35, if the upper limit deviation signal is continuously input to the upper limit side counting part or the lower limit deviation signal is continuously input to the lower limit side counting part, the number of times is counted in the upper limit side counting part and the lower limit side counting part respectively. Among them, if the non-deviation signal is input to the upper limit side counting part or the lower limit side counting part during the counting, the count value is reset. Moreover, even if the lower limit deviation signal is input to the upper limit side counting part or the upper limit deviation signal is input to the lower limit side counting part during the counting, the count value is reset. Then, if the count value of the upper limit side counting part reaches the set number of weft insertions, a descending instruction signal is output to the speed changer 39. Moreover, if the count value of the lower limit side counting part reaches the set number of weft insertions, an ascending instruction signal is output to the speed changer 39.

[0039] Then, as the counter 35 outputs a down command signal or an up command signal, the speed changer 39 changes the speed to the set speed plus or minus the correction speed, and the loom 1 is in a state of operating at the changed set speed. Then, as a result of changing the speed of the loom 1 in this way, the running speed of the loom 1 changes with respect to the flight of the weft yarn Y formed by weft insertion, and the above-mentioned actual value returns to the target arrival angle range, eliminating the state in which the above-mentioned actual value continuously deviates from the target arrival angle range.

[0040] In addition, in the present embodiment, as described above, correction control is performed based on the situation that the above-mentioned actual value continuously deviates from the target arrival angle range. Therefore, in the present embodiment, the group of the above-mentioned continuous actual values ​​is equivalent to the arrival data (the above-mentioned actual value based on the number of weft insertions) described in the present invention. And, the above-mentioned correction control (control for returning the above-mentioned actual value to the target arrival angle range) becomes a control for changing the rotation speed (operating speed) during the operation of the loom 1 by changing the set rotation speed. And, the control of the operation of the loom 1 (driving of the main shaft 51) is performed by the main shaft controller 43. Therefore, in the present embodiment, the main shaft controller 43 is equivalent to the main shaft control device that performs control to return the above-mentioned arrival timing to within the target arrival angle range.

[0041] In the loom 1 described above, in the present embodiment of the present invention, the number of weft insertions in the arrival data when the arrival timing is on the lower limit side is set to a value smaller than the number of weft insertions in the arrival data when it is on the upper limit side.

[0042] Specifically, the set number of weft insertions that serves as a reference for executing the above-mentioned correction control is input and set by the input setting device 23, and is set (stored) in the memory 37 of the loom control device 21. On this basis, the loom 1 is configured so that the input setting device 23 and the loom control device 21 (memory 37) can set the set number of weft insertions separately into the upper limit side weft insertion number related to the above-mentioned upper limit side and the lower limit side weft insertion number related to the above-mentioned lower limit side.

[0043] The counter 35 is configured to compare the count value of the upper limit side counting means with the upper limit side weft insertion number when the actual value continuously deviates from the target arrival angle range on the upper limit side. The counter 35 is configured to compare the count value of the lower limit side counting means with the lower limit side weft insertion number when the actual value continuously deviates from the target arrival angle range on the lower limit side.

[0044] The upper limit side weft insertion number and the lower limit side weft insertion number are determined based on weaving conditions such as the type of weft yarn Y. Moreover, in the present invention, the lower limit side weft insertion number is set to a value smaller than the upper limit side weft insertion number. On this basis, in this embodiment, the upper limit side weft insertion number is set to "8" and the lower limit side weft insertion number is set to "6".

[0045] Therefore, according to such a loom 1, when the actual value continuously deviates from the target arrival angle range, the correction control (in this embodiment, the rotation speed of the loom 1 is changed) is performed at the time when the number of weft insertions that deviated reaches the set number of weft insertions, so that the actual value returns to the target arrival angle range. On this basis, when the deviation is on the upper limit side, the upper limit side weft insertion number of the set number of weft insertions is set to 8 weft insertions, so the correction control is performed at the time when the number of weft insertions that deviated reaches 8 weft insertions.

[0046] On the other hand, when the deviation is on the lower limit side, since the number of weft insertions on the lower limit side as the set number of weft insertions is set to 6 weft insertions which is a value smaller than the number of weft insertions on the upper limit side, the correction control is executed when the number of weft insertions due to deviation reaches 6 weft insertions, that is, when the number of weft insertions is two weft insertions earlier than the upper limit side with respect to the time when the continuous deviation starts. Therefore, when the deviation is on the lower limit side, the actual value returns to the target arrival angle range side at an earlier time than when the deviation is on the upper limit side.

[0047] Furthermore, according to such a control method of the loom 1, when the deviation occurs on the lower limit side, the occurrence of weaving problems such as weft stoppage caused by the continuation of the deviation can be suppressed as much as possible.

[0048] In more detail, the reason why the above-mentioned arrival data is used to determine whether or not to perform the above-mentioned correction control is that there is a case where the arrival timing of the weft yarn Y (the above-mentioned actual value) deviates and temporarily changes greatly as described above, and the set number of weft insertions as the basis of the arrival data is set for this purpose. Moreover, regarding the set number of weft insertions, considering the influence caused by the temporary large change (temporary change) of the above-mentioned arrival timing, it is considered that it is preferable to set a larger number of weft insertions. In addition, the idea related to the change of the arrival timing is common to both the above-mentioned upper limit side and the above-mentioned lower limit side, and the trend of the change does not change much. Therefore, nowadays, there is no idea to make the set number of weft insertions different on the above-mentioned upper limit side and the above-mentioned lower limit side, and generally, the common (same) number of weft insertions is set as the set number of weft insertions on the above-mentioned upper limit side and the above-mentioned lower limit side.

[0049] On the other hand, when the above deviation is on the above lower limit side, in the setting of the jet period of the general sub-nozzle, the period from the jet start timing of each sub-nozzle to the timing when the weft tip passes through the position of the sub-nozzle in the flying state of the weft Y is set to be short, and the timing margin between the jet start timing and the above lower limit is small. Therefore, if the above temporary change occurs, the tip of the weft Y reaches the position of the sub-nozzle before the jet start timing, and sometimes a weft stop or other unfavorable situation occurs in weaving. In addition, the larger the set number of weft insertions, the higher the possibility of the above temporary change occurring in the continuous above deviation.

[0050] Therefore, in the present invention, instead of using a common set number of weft insertions on the upper limit side and the lower limit side as in the prior art, different set numbers of weft insertions can be set on the upper limit side and the lower limit side, and the set numbers of weft insertions set for each can be used. On this basis, on the upper limit side, a larger number of weft insertions is set as the set number of weft insertions, i.e., the upper limit side weft insertion number, in consideration of the change in the arrival timing, and the possibility of the occurrence of the above-mentioned bad weaving condition in this case, on the lower limit side, the set number of weft insertions is set to a smaller number of weft insertions than the upper limit side weft insertion number in consideration of such a change in the arrival timing. In addition, in the present embodiment, the upper limit side weft insertion number is set to 8, and the lower limit side weft insertion number is set to 6, in accordance with weaving conditions such as the type of weft yarn Y.

[0051] Furthermore, according to the control method of the loom 1 of the present embodiment (the present invention), when the correction control is performed based on the arrival data, the correction control is performed at an earlier time on the lower limit side than when the same set number of weft insertions is used on the upper limit side and the lower limit side, and the actual value is returned to the target arrival angle range side. Thus, in a state where the continuous deviation occurs on the lower limit side, the occurrence of the temporary change during the period and the occurrence of the above-mentioned weaving defect can be suppressed as much as possible.

[0052] In addition, the present invention is not limited to the above-described embodiment (the above-described embodiment), and can be implemented in the form of modified embodiments such as the following (1) to (4).

[0053] (1) Regarding the arrival data based on the actual values ​​of the arrival timings of the plurality of weft insertion numbers, in the above-mentioned embodiment, the group of the above-mentioned continuous actual values ​​corresponds to the arrival data. However, in the present invention, the arrival data is not limited to such a group of the above-mentioned continuous actual values, and may be an average value of the above-mentioned actual values.

[0054] Specifically, the loom control device is configured to obtain an average value of the actual value for each preset number of weft insertions, and compare the average value with the target arrival angle range, that is, to compare the average value with the upper limit value and the lower limit value. On this basis, the loom control device is configured to obtain two average values ​​in such a manner that the average values ​​compared with the upper limit value and the lower limit value become average values ​​obtained from different numbers of weft insertions, and compare each average value with the corresponding upper limit value or the lower limit value. In this case, the number of weft insertions used to obtain the average value compared with the lower limit value (the number of weft insertions calculated on the lower limit side) is set to a smaller number than the number of weft insertions used to obtain the average value compared with the upper limit value (the number of weft insertions calculated on the upper limit side).

[0055] Furthermore, according to such a configuration, since the number of weft insertions calculated on the lower limit side is set to a smaller number than the number of weft insertions calculated on the upper limit side, the comparison between the lower limit value and the average value is performed in a shorter period than the comparison between the upper limit value and the average value. Thus, when the arrival timing (the actual value) changes in a manner that the average value deviates from the lower limit side, the correction control is performed at a time earlier than when the actual value changes in a manner that the average value deviates from the upper limit side. Therefore, in this case, it is possible to suppress the occurrence of weaving defects associated with a temporary large change in the arrival timing as much as possible.

[0056] (2) In the example described above, the control method of the present invention (the present control method) aims to execute the correction control at an earlier timing when the arrival timing (the above-mentioned actual value) is on the above-mentioned lower limit side than when the arrival timing (the above-mentioned actual value) is on the above-mentioned upper limit side, and to achieve the above-mentioned purpose by setting the number of weft insertions of the arrival data to a number smaller than that of the above-mentioned upper limit side. However, the present control method is not limited to executing the control method by making the number of weft insertions of the arrival data different in this way, and the control method may be executed by setting the allowable range of the above-mentioned lower limit side relative to the target value of the arrival timing to be smaller than the allowable range of the above-mentioned upper limit side.

[0057] In more detail, regarding the target arrival angle range, regarding the difference (absolute value) between the target value as the allowable range on the upper limit side and the upper limit value, the upper limit value is set in the same manner as in the prior art, and on this basis, regarding the difference (absolute value) between the target value as the allowable range on the lower limit side and the lower limit value, the lower limit value is set in a manner smaller than the difference on the upper limit side. Thus, in the case where the arrival timing deviates to the upper limit side or the lower limit side with the same trend, even if the deviation amount of the lower limit value is smaller than that of the upper limit side, the arrival data deviates from the lower limit side, so in this case, it is possible to suppress as much as possible the occurrence of weaving defects associated with a temporary large change in the arrival timing.

[0058] In this example, the number of weft insertions in the arrival data may be the same on the upper limit side and the lower limit side, or the number of weft insertions in the arrival data may be set so that the lower limit side is smaller than the upper limit side as in the above embodiment and the example (1). That is, this example and the above example may be combined for implementation.

[0059] (3) Regarding the control performed to return the arrival timing to within the target arrival angle range when the arrival data deviates from the target arrival angle range (the above-mentioned correction control), in the above-mentioned embodiment, the above-mentioned correction control is performed by the spindle control device in the form of adding or subtracting a pre-set correction speed (fixed value) from the current set speed, based on taking the control object of the above-mentioned correction control as the rotational speed of the loom.

[0060] However, even when the control object is the rotational speed, the above-mentioned correction control is not limited to using such a pre-set correction rotational speed. When the arrival data is taken as the average value of the above-mentioned actual values ​​as in the example (1) above, the deviation between the average value and the above-mentioned target value can also be calculated to perform the above-mentioned correction control at a correction rotational speed corresponding to the deviation.

[0061] Furthermore, the control object of the correction control is not limited to the rotation speed of the loom, but may be weft insertion conditions such as timing and pressure related to weft insertion. Specifically, the action timing of the locking pin, the jet timing of the main nozzle and each sub-nozzle, the pressure of the compressed air supplied to the main nozzle and each sub-nozzle, etc., which are weft insertion conditions, may be controlled. When the arrival data deviates from the target arrival angle range, the weft insertion control device changes the weft insertion conditions, thereby executing the correction control (control to return the arrival timing to within the target arrival angle range).

[0062] Furthermore, in the case where the weft insertion condition is taken as the control object, the correction control may be performed by setting the correction timing and correction pressure used in changing the weft insertion condition to predetermined fixed values, and when the arrival data deviates from the target arrival angle range, the correction timing is added or subtracted from the current injection timing of the main nozzle and each sub-nozzle, or the correction pressure is added or subtracted from the current set pressure of the compressed air. Furthermore, in the case where the arrival data is taken as the average value of the actual value, the correction timing or correction pressure corresponding to the deviation between the average value and the target value is obtained, and the correction control may be performed using the correction timing and correction pressure.

[0063] Furthermore, the control object of the correction control is not limited to the rotation speed of the loom or the weft insertion condition, but may be both the rotation speed of the loom and the weft insertion condition. In this case, for example, the correction control is first performed with the weft insertion condition as the control object, and then, when the correction amount becomes larger, the correction control is switched to the rotation speed of the loom as the control object.

[0064] (4) Regarding the arrival timing used as the above-mentioned actual value, in the above-mentioned embodiment, it is obtained based on the detection signal of the weft yarn sensor (weft feeler 19) that detects the arrival of the weft yarn on the opposite side of the yarn supply. That is, in the above-mentioned embodiment, the timing of the moment when the front end of the weft yarn arrives at the predetermined position on the opposite side of the yarn supply is taken as the arrival timing. However, in the present invention, the arrival timing is not limited to the timing of the moment when the front end of the weft yarn arrives at the predetermined position on the opposite side of the yarn supply, but may also be the timing of the moment when the front end of the weft yarn passes through the predetermined position in the weft insertion direction in the warp opening. Moreover, in this case, the arrival timing is obtained based on the detection signal of the weft yarn sensor (unwinding sensor) that detects the weft yarn unwound from the storage drum of the length measuring storage device on the yarn supply side.

[0065] In addition, when the arrival timing is determined based on the detection signal of the unwinding sensor in this way, the present invention is not limited to the air jet loom of the above-mentioned embodiment, but can also be applied to a water jet loom.

[0066] Furthermore, the present invention is not limited to the above-described embodiment, and can be appropriately modified within a scope not departing from the gist of the present invention.

Claims

1. A control method for a loom, the loom obtaining an actual value of a weft arrival timing based on a detection signal of a weft sensor, using a target arrival angle range determined by an upper limit value on an upper side larger than a target value of the arrival timing and a lower limit value on a lower side smaller than the target value, and arrival data based on the actual values ​​of a plurality of weft insertion numbers, and when the arrival data deviates from the target arrival angle range, controlling a main shaft control device and / or a weft insertion control device so that the arrival timing returns to within the target arrival angle range, The control method of the loom is characterized in that: The number of weft insertions in the arrival data when the arrival timing is on the lower limit side is set to be smaller than the number of weft insertions in the arrival data when the arrival timing is on the upper limit side and / or the upper limit value and the lower limit value are set so that the absolute value of the difference between the target value and the lower limit value is smaller than the absolute value of the difference between the target value and the upper limit value.

Images